Elektronika 2012-01 I.pdf - Instytut SystemÃ³w Elektronicznych ...

ok LIII nr 1/2012 

• MATERIAŁY • KONSTRUKCJE • UKŁADY 

• SYSTEMY • MIKROELEKTRONIKA 

• OPTOELEKTRONIKA • FOTONIKA 

konstrukcje technologie zastosowania 

MIESIECZNIK NAUKOWO-TECHNICZNY 

• ELEKTRONIKA MIKROFALOWA 

• MECHATRONIKA 

• ENERGOELEKTRONIKA • INFORMATYKA 

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prof. dr hab. Włodzimierz Kalita, inż. Stefan Kamiński, prof. dr hab. 

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dr hab. Tadeusz Pałko, prof. dr hab. inż. Marian Pasko, prof. dr hab. Józef 

Piotrowski, prof. dr hab. inż. Ryszard Romaniuk, dr hab. inż. Grzegorz 

Różański, prof. dr hab. inż. Edward Sędek, prof. dr hab. Ludwik 

Spiralski, prof. dr hab. inż. Zdzisław Trzaska, mgr inż. Józef Wiechowski, 

prof. dr hab. inż. Marian Wnuk, prof. dr hab. inż. Janusz Zarębski 

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Spis treści ● Contents 

Study of IDE as a sensor head for interfacing with handheld 

electrochemical analyzer system (Projekt głowicy IDE dla 

sensorów do zastosowań w podręcznych systemach analizy 

elektrochemicznej) – Velusamy V., Arshak K., Korostynska O., 

Adley C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 

Impact of non-optimal grounding of the CC2420 RFIC on 

a 802.15.4 Tyndall sensor wireless mote (Wpływ nieoptymalnego 

uziemienia układu CC2420 zgodnego ze standardem 

IEEE 802.15.4 na pracę systemu Tyndall Mote) – Haigh P., Buckley 

J., O’Flynn B., Ó’Mathúna C. . . . . . . . . . . . . . . . . . . . . . 14 

Numerical study of the interface heat transfer characteristics 

of micro-cooler with CNT structures (Analiza numeryczna 

transferu ciepła przez interfejs mikroradiatora ze strukturami 

CNT) – Zhang Y., Wang S., Ma S., Hu Z., Liu J., Sitek 

J., Janeczek K. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 

Device for road holes and obstacles detection (Urządzenie 

do rozpoznawania dziur oraz przeszkód na drodze) – Gelmuda 

W., Kos A. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 

Metal – oxide sensor array for gas detection (Matryca sensorów 

na bazie tlenków metali do detekcji gazów) – Gwiżdż P., 

Brudnik A., Zakrzewska K. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 

Dynamic research of foot pressure distribution – the fourpoints 

shoe insert with PVDF sensors (Dynamiczne badania 

rozkładu nacisku stopy na podłoże – czteropunktowa wkładka 

do obuwia z polimerowymi czujnikami z PVDF) – Klimiec E., 

Zaraska W., Kuczyński Sz. . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 

Design and realization of a microfluidic capillary sensor based 

on a silicon structure and disposable optrodes (Projekt 

i realizacja mikrocieczowego czujnika kapilarnego opartego na 

przestrzennej strukturze krzemowej z wykorzystaniem włókien 

światłowodowych) – Szczepański Z., Borecki M., Szmigiel D., 

Pawlowski M.L.K. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 

A compact thermoelectric harvester for waste heat conversion 

(Kompaktowy termoelektryczny generator do pozyskiwania 

i przetwarzania ciepła odpadowego na energię elektryczną) 

– Dziurdzia P., Lichota K. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 

An investigation of the quality of the conductive lines deposited 

by inkjet printing on different substrates (Badanie 

jakości ścieżek przewodzących wytworzonych metodą druku 

strumieniowego na różnych podłożach) – Sitek J., Futera K., 

Belavič D., Santo Zarnik M., Kościelski M., Bukat K., Janeczek 

K., Kuščer Hrovatin D., Jakubowska M. . . . . . . . . . . . . . . . . . 32 

High temperature properties of thick-film and LTCC components 

(Wysokotemperaturowe właściwości elementów grubowarstwowych 

i LTCC) – Nowak D., Janiak M., Dziedzic A., 

Piasecki T. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 

LTCC microfluidic chip with fluorescence based detection 

(Mikroprzepływowy fluorescencyjny czujnik ceramiczny wykonany 

techniką LTCC) – Czok M., Malecha K., Golonka L. . . . . 37 

Investigation of multiple degradation and rejuvenation cycles 

of electroluminescent thick film structures (Badanie 

powtarzanych cykli degradacji i regeneracji grubowarstwowych 

struktur elektroluminescencyjnych) – Mroczkowski M., Cież M., 

Kalenik J. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Investigations of passive components embedded in printed 

circuit boards (Badania podzespołów biernych wbudowanych 

w płytki obwodów drukowanych) – Stęplewski W., Serzysko T., 

Kozioł G., Janeczek K., Dziedzic A. . . . . . . . . . . . . . . . . . . . . . 41 

GENESI: Wireless Sensor Networks for structural monitoring 

(Bezprzewodowa sieć sensorów do monitorowania 

strukturalnego) – O’Flynn B., Boyle D., Popovici E., Magno 

M., Petrioli C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 

Mechanical and thermal properties of SiC – ceramics 

substrate interface (Mechaniczne oraz cieplne właściwości 

połączenia między strukturą SiC a podłożem ceramicznym) 

– Kisiel R., Szczepański Z., Firek P., Guziewicz M., 

Krajewski A. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 

Analysis of pulse durability of thin-film and polymer thickfilm 

resistors embedded in printed circuit boards (Analiza 

odporności impulsowej grubo- i cienkowarstwowych rezystorów 

wbudowanych w płytki obwodów drukowanych) – Kłossowicz 

A., Dziedzic A., Winiarski P., Stęplewski W., Kozioł G.. . . . . . . 51 

Analysis of long-term stability of thin-film and polymer thickfilm 

resistors embedded in Printed Circuit Boards (Analiza 

stabilności długoczasowejrezystorów cienkowarstwowych oraz 

polimerowych rezystorów grubowarstwowych wbudowanych 

w płytkiobwodów drukowanych) – Winiarski P., Dziedzic A., 

Kłossowski A., Stęplewski W., Kozioł G.. . . . . . . . . . . . . . . . . . 55 

Impedance spectroscopy as a diagnostic tool of degradation 

of Solid Oxide Fuel Cells (Spektroskopia impedancyjna jako 

narzędzie diagnostyczne degradacji tlenkowych ogniw paliwowych) 

– Dunst K., Molin S., Jasiński P. . . . . . . . . . . . . . . . . . . . 59 

Analysis of electromagnetic couplingsin hybrid circuit 

made on austenitic metal substrate (Analiza sprzężeń elektromagnetycznych 

w układach hybrydowych wykonanych na 

podłożach ze stali austenitycznej) – Sabat W., Klepacki D., 

Kamuda K. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 

EMC aspects in microelectronics structures made in LTCC 

technology ( Zagadnienia EMC w mikroelektronicznych strukturach 

wytwarzanych w technologii LTCC) – Sabat W., Klepacki 

D., Kalita W., Slosarčík S., Jurčišin M., Cabúk P. . . . . . . . . . . 65 

Method of processing of thermal images recorded in the 

beam displacement modulation technique (Metoda przetwarzania 

obrazów termicznych zarejestrowanych techniką 

modulacji przestrzennej) – Kosikowski M., Suszyński Z. . . . . . 68 

Electrocatalytic sensor based on Nasicon with auxiliary layer 

(Czujnik elektrokatalityczny na bazie Nasiconu z warstwą dodatkową 

– Strzelczyk A., Jasiński G., Jasiński P., Chachulski B. . . 72 

Oxide layers fabricated by spray pyrolysis on metallic surfaces 

(Warstwy tlenkowe wytworzone metodą pirolizy aerozolowej 

na podłożach metalicznych) – Kobierowska K., Karpińska 

M., Molin S., Jasiński P. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 

TECHNIKA SENSOROWA: Mechanoakustyczny czujnik aktywności 

układu sercowo-naczyniowego (Mechano-acoustic 

sensor of the cardiovascular system activity) – Lewandowski 

J., Dziuda Ł., Celiński-Spodar K. . . . . . . . . . . . . . . . . . . . . 77 

TECHNIKA MIKROFALOWA I RADIOLOKACJA: Aktywne anteny 

radarów wielofunkcyjnych – analiza stanu i perspektywy 

rozwoju – część 1 (Active phased antenna array for multifunction 

radar – review and perspective development – part 1) 

– Sędek E. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81 

TECHNIKI INFORMATYCZNE: Technologie informacyjne 

w predykcji pogodowych zagrożeń w ruchu drogowym (Information 

technology in prediction of weather hazards affecting 

road traffic) – Mitas A.W., Bernaś M., Bugdol M., Ryguła A. 90 

Electronic measurement system for monitoring of geometrical 

parameters of rolling shaped metal profiles (Еlektroniczny 

system pomiarowy do kontroli parametrów geometrycznych 

profili produkowanych na liniach wytłaczarkowych) – Zaharieva 

S., Mutkov V., Georgiev I. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95 

Modulacja amplitudy sygnałem pseudolosowym (Amplitude modulation 

with pseudo random signal) – Stępień R., Walczak J. . . 98 

Problematyka modelowania w programie SPICE charakterystyk 

stałoprądowych elektroizolowanych diodowych modułów 

mocy zawierających diody typu PiN oraz diody typu FRED 

(Problem of the SPICE modeling of the d.c. characteristics of the 

electroisolated power diode modules containing PiN diodes and 

fast recovery epitaxial diodes) – Dąbrowski J., Zarębski J. . . . . 103

Streszczenia artykułów ● Summaries of the articles 

VELUSAMY V., ARSHAK K., KOROSTYNSKA O., ADLEY C.: Projekt 

głowicy IDE dla sensorów do zastosowań w podręcznych systemach 

analizy elektrochemicznej 

Elektronika (LIII), nr 1/2012, s. 11 

W ostatnich latach wiele publikowano na temat przetworników elektrochemicznych 

do różnych zastosowań, między innymi do diagnostyki chorób 

zakaźnych, detekcji związków chemicznych, hybrydyzacji DNA i detekcji 

patogenicznych mikroorganizmów. Monitorowanie żywności i wody w czasie 

rzeczywistym ma globalnie wysoki priorytet a obecność patogenicznych 

organizmów jest szczególnie ważnym zagadnieniem w badaniach 

środowiska. Chociaż zastosowano różne miary do monitorowania jakości 

żywości, takie jak zasady dobrej praktyki rolniczej [1, 2], zasady dobrej 

praktyki produkcyjnej [2, 3], system analizy zagrożeń i krytycznych punktów 

kontroli (HACCP) [4, 5] system kodów do znakowania żywności [6], 

ciągle pojawiają się raporty o wybuchach epidemii. 

Przedmiotem pracy jest projekt głowicy czujnika do zastosowania w podręcznym 

elektrochemicznym analizatorze do detekcji w czasie rzeczywistym 

zmiennych środowiskowych z uwzględnieniem patogenicznych mikroorganizmów. 

Cienkowarstwową międzypalczastą złotą elektrodę (IDE), 

wykonaną techniką sitodruku, zastosowano jako czujnik do detekcji DNA 

występującego w żywności patogenu Bacillus cereus. Zastosowanie Polypyrrole 

(PPy) jako matrycy immobilizującej i połączenie modyfikowanej 

za pomocą PPy międzypalczastej mikroelektrody z pomiarami impedancji 

dało czuły biosensor, który jest zdolny do detekcji DNA. Elektroda IDE 

wykonana w technologii cienkowarstwowej jest czuła, szybka i tania. Uzyskano 

elektryczną detekcję 100 pM koncentracji DNA immobilizowanego 

na zmodyfikowanej przez PPy złotej IDE, o szerokości 400µm. 

Słowa kluczowe: przetworniki elektrochemiczne, analizator impedancji; 

biosensor; DNA 

VELUSAMY V., ARSHAK K., KOROSTYNSKA O., ADLEY C.: Study of 

IDE as a sensor head for interfacing with handheld electrochemical 

analyzer system 

Elektronika (LIII), no 1/2012, p. 11 

Electrochemical sensors for various applications including diagnosis of infectious 

diseases, detection of chemicals, DNA hybridization and detection 

of pathogenic micro-organisms have been reported in recent years. Realtime 

monitoring of food and water is a high priority globally and the presence 

of pathogenic micro organisms is a particular environmental concern. 

Although various measures like good agricultural practices [1, 2], good 

manufacturing practices [2, 3], hazard analysis and critical control point 

(HACCP) [4, 5] and the food code indicating approaches [6], have been 

taken to monitor the food quality, there are still reports of outbreaks. 

Detailed in this work is the design of a sensor head for use in a handheld 

electrochemical analyzer system to detect environmental variables including 

pathogenic micro-organisms in real-time. A thick-film interdigitated 

gold electrode (IDE) prepared by screen printing technique was employed 

as a sensor to detect DNA of the foodborne pathogen Bacillus cereus. Polypyrrole 

(PPy) was used as an immobilization matrix and the combination 

of PPy modified interdigitated micro-electrode with impedance measurements 

yielded a sensitive label-free biosensor which was able to detect 

DNA. The IDE prepared by thick-film technology is sensitive, rapid and 

cost effective. The electrical detection of 100 pM concentration of DNA 

immobilized onto the PPy modified gold IDE was achieved, with an IDE 

width of 400µm. 

Keywords: Electrochemical sensor; impedance analyzer; biosensor; 

DNA 

HAIGH P., BUCKLEY J., O’FLYNN B., Ó’MATHÚNA C.: Wpływ nieoptymalnego 

uziemienia układu CC2420 zgodnego ze standardem IEEE 

802.15.4 na pracę systemu Tyndall Mote 


Działanie układu dopasowującego wysokiej częstotliwości zależy od integralności 

uziemienia. Jeżeli połączenie z masą nie jest właściwe, powstają 

dodatkowe elementy pasożytnicze, które mogą degradować funkcjonowanie 

układu i prowadzić do niepożądanych wyników. Tradycyjnie, projektanci 

mierzą moc fali stojącej dla oceny czy tor W.Cz. pracuje optymalnie, 

elementy są dopasowane i uziemione. W artykule pokazano, że są 

sytuacje, gdy jakość modulacji może być narażona na szwank z powodu 

wady uziemienia, która się nie ujawnia przy pomiarze fali stojącej. Konsekwencją 

tego jest zredukowany zakres i niezawodność układu. Pomiary 

wykonywano na przykładzie systemu Tyndall Mote z zastosowaniem układu 

CC2420 aby zademonstrować jak wadliwe połączenie lutowane pomiędzy 

masą a płaszczyzną płytki drukowanej, która powinna być uziemiona, 

może prowadzić do degradacji funkcjonowania układu. Zaprezentowano 

szczegółową analizę pogorszenia jakości przebiegu, przy jednoczesnym 

utrzymywaniu się mocy wyjściowej w akceptowalnych granicach, która 

wymagała nowej definicji metrologicznej dla standardu IEEE 802.15.4. 

Słowa kluczowe: CC2420, sensory bezprzewodowe, uziemienie, 802.15.4, 

wielkość wektora błędu (EVM) 

HAIGH P., BUCKLEY J., O’FLYNN B., Ó’MATHÚNA C.: Impact of nonoptimal 

grounding of the CC2420 RFIC on a 802.15.4 Tyndall sensor 

wireless mote 


The performance of an RF output matching network is dependent on integrity 

of the ground connection. If this connection is compromised in anyway, 

additional parasitic elements may occur that can degrade performance 

and yield unreliable results. Traditionally, designers measure Constant 

Wave (CW) power to determine that the RF chain is performing optimally, 

the device is properly matched and by implication grounded. It is shown 

that there are situations where modulation quality can be compromised 

due to poor grounding that is not apparent using CW power measurements 

alone. The consequence of this is reduced throughput, range and 

reliability. Measurements are presented on a Tyndall Mote using a CC2420 

RFIC to demonstrate how poor solder contact between the ground contacts 

and the ground layer of the PCB can lead to the degradation of modulated 

performance. Detailed evaluation that required the development of 

a new measurement definition for 802.15.4 and analysis is presented to 

show how waveform quality is affected while the modulated output power 

remains within acceptable limits. 

Keywords: CC2420, Wireless Sensors, Grounding, 802.15.4, Error Vector 

Magnitude (EVM) 

ZHANG Y., WANG S., MA S., HU Z., LIU J., SITEK J., JANECZEK K.: 

Analiza numeryczna transferu ciepła przez interfejs mikroradiatora 

ze strukturami CNT 


Technika mikrochłodzenia stanowi obiecujące rozwiązanie w zarządzaniu 

ciepłem systemów elektronicznych wraz ze wzrostem mocy mikroprocesorów. 

Nanorurki węglowe (CNTs) mogą być wykorzystane w mikroradiatorach, 

jako podstawowy materiał służący do tworzenia struktur rozpraszających 

ciepło w ich wnętrzu. Interfejsami w mikroradiatorach opartych 

na CNTs są obszary między CNT i substancją chłodzącą oraz miedzy CNT 

i klejem. Transfer ciepła przez te interfejsy ma istotny wpływ na wydajność 

mikroradiatora. W artykule ukazano wyniki analiz numerycznych transferu 

ciepła przez interfejsy pomiędzy CNT i innymi materiałami przeprowadzone 

za pomocą symulacji dynamiki molekularnej (MDS) dla różnych przypadków. 

Słowa kluczowe: zarządzanie ciepłem, nanorurki węglowe (CNT), Symulacja 

dynamiki molekularnej (MDS) 

ZHANG Y., WANG S., MA S., HU Z., LIU J., SITEK J., JANECZEK K.: 

Numerical study of the interface heat transfer characteristics of micro-cooler 

with CNT structures 


Micro-cooling techniques provide a promising solution for the thermal 

management of electronics system with increasing microprocessor powers. 

Carbon nanotubes (CNTs) can be utilized in micro-coolers as basic 

materials to constitute the heat dissipation structures inside. The interfaces 

involved in the CNT-based micro-cooler include the one between the CNT 

and the coolant, and the CNT and the adhesive. The heat transfer through 

these interfaces plays an important role in the thermal performance of the 

micro-cooler. In this paper, numerical investigations on thermal resistance 

across interfaces between the CNT and other materials are carried out by 

molecular dynamics simulation (MDS), and various cases are studied. 

Keywords: Thermal Management, CNT, MDS 

Elektronika 1/2012


GELMUDA W., KOS A.: Urządzenie do rozpoznawania dziur oraz przeszkód 

na drodze 


Na początku XXI wieku ludzkość nadal boryka się ze zjawiskiem niepełnosprawności. 

Chociaż istnieje wiele protez oraz wyspecjalizowanych 

urządzeń, niektóre problemy ludzi niepełnosprawnych ciągle pozostają 

nierozwiązane. Na świecie są miliony osób niewidomych i prawie każda 

z nich korzysta z pomocy prostej laski dla niewidomych jako podstawowej 

pomocy przy przemieszczaniu się. W celu poprawy bezpieczeństwa osób 

niewidomych podczas poruszania się autorzy konstruują specjalne urządzenie 

w ramach projektu MOBIAN©. Jednymi z trudniejszych przeszkód 

do wykrycia podczas poruszania się osoby niewidomej są dziury i uskoki 

w nawierzchni. W tym celu użyty został dalmierz na podczerwień. Do wykrywania 

przeszkód zastosowano wiele czujników ultradźwiękowych dla 

powiększenia obszaru wykrywania. Artykuł przedstawia projekt urządzenia 

do wykrywania przeszkód oraz dziur i uskoków nawierzchni. 

Słowa kluczowe: ultradźwięki, podczerwień, sensory, niewidomi, przeszkody, 

wykrywanie dziur, symulator 

GWIŻDŻ P., BRUDNIK A., ZAKRZEWSKA K.: Matryca sensorów na bazie 

tlenków metali do detekcji gazów 


Celem projektu było zaprojektowanie i skonstruowanie matrycy półprzewodnikowych 

rezystancyjnych czujników gazów przeznaczonej do detekcji 

i rozpoznawania składników mieszaniny gazów. W skład matrycy wchodzi 

sześć komercyjnych sensorów gazów na bazie tlenków metali umieszczonych 

w komorze pomiarowej. Zastosowano również sensory wilgotności 

i temperatury. System elektroniczny obsługujący matrycę wykorzystuje mikrokontrolery 

z rdzeniem ARM i magistralę CAN co ułatwia jego rekonfigurację 

w przypadku zmiany liczby sensorów. Każdy sensor może pracować 

w innej temperaturze dzięki zmianie napięcia zasilania jego grzejnika. Zaprojektowany 

i skonstruowany system do detekcji gazu został przetestowany 

na wodór H 2 

, amoniak NH 3 

oraz dwutlenek węgla CO 2 

. 

Słowa kluczowe: czujniki gazów, mikrokontrolery 

KLIMIEC E., ZARASKA W., KUCZYŃSKI SZ.: Dynamiczne badania 

rozkładu nacisku stopy na podłoże – czteropunktowa wkładka do 

obuwia z polimerowymi czujnikami z PVDF 


Możliwości ruchowe człowieka, w dużej mierze, zależą od stanu jego stopy. 

Ocenić go można, badając rozkład sił nacisku stopy na podłoże. Prawidłowo 

zbudowana stopa jest wysklepiona po wewnętrznej stronie, co działa 

jak amortyzator, łagodząc wstrząsy spowodowane chodzeniem. Największe 

wartości nacisku występują na pięcie i śródstopiu a nieznaczne na wklęśniętej 

części stopy, jego wzrost, świadczy o stopniu zdeformowania stopy 

np. przy płaskostopiu. W artykule omówiono sposób jego pomiaru przy pomocy 

opracowanej przez autorów czteropunktowej wkładki do obuwia, którą 

umieścić można w dowolnym obuwiu sportowym. Wielkość nacisku mierzono 

na pięcie, wklęśniętej części stopy, śródstopiu i dużym palcu, rejestrując 

napięcia wytworzone na czujnikach z piezoelektrycznej folii polimerowej 

z PVDF. Rezystancja obciążenia układu pomiarowego wynosiła 10 14 Ω.. Ponieważ 

czujnik pomiarowy z piezoelektrycznej folii polimerowej z elektrodami 

jest samo – ładującym się kondensatorem pod wpływem odkształceń mechanicznych 

a także wykazuje właściwości piroelektryczne, bardzo ważną 

rolę w prawidłowym przeprowadzeniu pomiarów, odgrywa układ zerujący. 

Zapewnia on powrót układu pomiarowego do punktu wyjścia po wykonaniu 

każdego kroku, zapobiegając zniekształceniu wyników pomiarowych. 

Słowa kluczowe: czujniki nacisku, PVDF, wady postawy 

SZCZEPAŃSKI Z., BORECKI M., SZMIGIEL D., PAWLOWSKI M.L.K.: 

Projekt i realizacja mikrocieczowego czujnika kapilarnego opartego 

na przestrzennej strukturze krzemowej z wykorzystaniem włókien 

światłowodowych 


W artykule przedstawiono projekt i omówiono realizację optycznego mikrocieczowego 

czujnika kapilarnego, przeznaczonego do badań cieczy chemicznych 

i biologicznych. Zasada ich działania oparta jest na wykorzystaniu 

zmian sygnału świetlnego przechodzącego przez kapilarę wypełnioną 

badaną cieczą. Sygnały optyczne wychodzące z czujnika są przetwarzane 

w obwodach optoelektronicznych i przekazywane do komputera. Przy 

analizowaniu sygnałów wykorzystywane są sztuczne sieci neuronowe. Dla 

poprawienia dokładności pomiarowej, czujnik pracuje w układzie wieloparametrycznym, 

rejestrując informacje o podstawowych parametrach cieczy. 

Główną zaletą tych czujników jest mała ilość cieczy potrzebnej do badań 

i krótki czas pomiaru Optoelektroniczne czujniki kapilarne znajdują zastosowanie 

w biotechnologii, diagnostyce medycznej, w wykrywaczach narkotyków 

oraz w badaniach właściwości użytkowych biopaliw. 

Słowa kluczowe: kapilara optyczna, czujnik mikrocieczowy, czujnik inteligentny, 

technologia mikrosystemów, czujnik światłowodowy, czujnik zintegrowany 

 

GELMUDA W., KOS A.: Device for road holes and obstacles detection 


At the beginning of the 21 st century the world still deals with some of 

people’s disabilities. Although there are many prostheses and special 

devices, some problems of disabled people are still unsolved. There are 

millions of visually impaired people around the world. Almost every blind 

person has to cope with everyday life activities only with the aid of a white 

stick. To help the blind people navigate and avoid obstacles and holes, 

a device is to be designed as a part of the MOBIAN© project, which is 

being carried out by the authors. The holes detection is one of a rather 

difficult kind of obstacles to be detected when a blind person is moving. 

This detection will employ an infrared ranging which is hard to debug in 

a real-time environment. That is why a simulator is highly required. The 

obstacles detection will employ an array of ultrasonic sensors to increase 

sensing area width. Td. 

Keywords: ultrasonic, infrared, sensors, blind people, obstacles, holes 

detection, simulator 

GWIŻDŻ P., BRUDNIK A., ZAKRZEWSKA K.: Metal – oxide sensor array 

for gas detection 


The aim of this work was to design and construct an array of resistive-type 

semiconducting sensors dedicated to detection of gas mixture components. 

The array comprises six commercial metal oxide gas sensors placed 

in the measuring chamber. Humidity and temperature measurements 

are provided by the relevant sensors. Electronic system supporting the 

array is based on ARM core microcontrollers and CAN bus architecture 

what makes it flexible and easy to reconfigure in respect to the number of 

sensors. Each sensor can operate at different temperatures by changing 

a heater supply voltage. The designed and constructed gas detection system 

has been tested for hydrogen H 2 

, ammonia NH 3 

and carbon dioxide 

CO 2 

detection. 

Keywords: gas sensors, microcontrollers 

KLIMIEC E., ZARASKA W., KUCZYŃSKI SZ.:Dynamic research of foot 

pressure distribution – the four-points shoe insert with PVDF sensors 


The man’s movement possibilities depend on foot deformation. It can 

be estimated by foot pressure distribution investigations. Healthy foot 

is arched on internal side, what acts like shock absorber, softening jolts 

caused by walking. Largest values of pressure appear on heel and metatarsus. 

Insignificant values appears on medial arch, and its growth shows 

the foot extent deformation eg. flatfoot. Article presents measurement 

method of foot pressure on the ground by four-points shoe insole, developed 

by authors, which can be placed in any sport footwear. The value of 

pressure was measured on heel, medial arch, metatarsus and hallux by 

recording values of generated voltage on sensors which were made of 

piezoelectric polymer PVDF thin film. Load resistance of measuring setup 

was 10 14 Ω. Under the influence of mechanical strain, the sensor, which 

is made from piezoelectric polymer film with electrodes, acts like a selfcharging 

capacitor. To conduct correct measurements, it is important to 

use restart circuit. Restart circuit ensures recovery to starting point after 

execution of each step, what prevents charge accumulation in capacitor 

and measurement results distortion. 

Keywords: pressure sensors, PVDF, faulty posture 

SZCZEPAŃSKI Z., BORECKI M., SZMIGIEL D., PAWLOWSKI M.L.K.: 

Design and realization of a microfluidic capillary sensor based on 

a silicon structure and disposable optrodes 


In this paper a new design and technology of microfluidic capillary sensors 

is presented. Those sensors can be applied for in situ classification of biological 

and chemical liquids. The principle of work of capillary sensors is 

based on changes of light transmission within capillary filled the liquid subject 

to a local heating pulse. An example of its application can be instant 

determining of biofuel usability at a filling station. The main advantages of 

microfluidic capillary sensors are the small sample volume of about 3 mm 3 

and a short time of examination, below 2 minutes. The microfluidic capillary 

sensor head has been designed as a 3D hybrid structure working in 

conjunction with disposable optical capillary optrodes. The hybrid structure 

consists of ceramic base (DBC) and a silicon substrate. The silicon substrate 

is fabricated using MEMS micromachining processes. 

Keywords: optical capillary, microfluidic sensor, intelligent sensor, microsystem 

technology, fiber optic sensors, capillary sensor, MEMS sensors 



DZIURDZIA P., LICHOTA K.: Kompaktowy termoelektryczny generator 

do pozyskiwania i przetwarzania ciepła odpadowego na energię 

elektryczną 


A artykule przedstawiono kompaktowy generator termoelektryczny składający 

się z modułu Peltiera, radiatora, przetwornika ultra niskiego napięcia, 

mikrokontrolera oraz czujnika. W artykule zawarto opis konstrukcji mechanicznej 

generatora oraz części elektronicznej wraz z układem do zarządzania 

mocą. W pracy przedstawiono wyniki testów oraz pomiarów uzyskanych 

poziomów mocy oraz napięć w funkcji gradientów temperatury. Na końcu 

zamieszczono analizę na temat możliwych zastosowań zaprojektowanego 

termogeneratora do zasilania węzłów sieci bezprzewodowych. 

Słowa kluczowe: pozyskiwanie energii środowiska, generator termoelektryczny, 

przetwarzanie energii cieplnej 

DZIURDZIA P., LICHOTA K.: A compact thermoelectric harvester for 

waste heat conversion 


In the paper a compact thermoelectric harvester that consists of a Peltier 

module, a small heat sink, an ultra low voltage converter, a microcontroller 

(µC) and a sensor is presented. A detailed description of the mechanical 

and electronic circuits design for power management is also shown. Results 

of tests and measurements of obtained voltage and electrical power 

levels against temperature gradients are presented and analyzed. A study 

on possible application of the designed thermogenerators to supplying 

with electrical power wireless sensor nodes is also provided. 

Keywords: energy harvesting, thermoelectric generator, heat conversion 

SITEK J., FUTERA K., BELAVIČ D., SANTO ZARNIK M., KOŚCIELSKI 

M., BUKAT K., JANECZEK K., KUŠČER HROVATIN D., JAKUBOWSKA 

M.: Badanie jakości ścieżek przewodzących wytworzonych metodą 

druku strumieniowego na różnych podłożach 


W artykule przedstawiono badania jakości ścieżek przewodzących wytworzonych 

metodą druku strumieniowego na różnych podłożach. W badaniach 

użyto trzech różnych typów podłoży ceramicznych oraz tuszu 

opartego na nanoproszku srebra. Stwierdzono, że wytwarzanie ścieżek 

przewodzących, poprzez ich nadruk na podłoże z surowej taśmy ceramicznej 

LTCC i następnie ich wypalenie z użyciem profilu stosowanego 

dla LTCC jest nietechnologiczne. Bardziej obiecujące wyniki uzyskano dla 

wstępnie wypalonego podłoża LTCC oraz podłoża z ceramiki alundowej. 

Konieczne są jednak dalsze prace celem polepszenia jakości ścieżek na 

tych podłożach. 

Słowa kluczowe: druk strumieniowy, ścieżki przewodzące, technologia 

grubowarstwowa 

SITEK J., FUTERA K., BELAVIČ D., SANTO ZARNIK M., KOŚCIELSKI 

M., BUKAT K., JANECZEK K., KUŠČER HROVATIN D., JAKUBOWSKA 

M.: An investigation of the quality of the conductive lines deposited 

by inkjet printing on different substrates 


In this paper an investigation of the quality of inkjet-printed conductive 

lines deposited on different substrates is presented. Three different types 

of ceramic substrates as well as an ink based on nanosilver powder were 

used for investigations. It was found that the inkjet-printing deposition on 

green tape LTCC and then co-firing with the conditions of an LTCC temperature 

profile is not a usable technology. More promising results on prefired 

LTCC and alumina substrates were obtained, but some additional 

efforts are required to improve the quality of the lines. 

Keywords: inkjet printing, conductive lines, thick-film technology 

NOWAK D., JANIAK M., DZIEDZIC A., PIASECKI T.: Wysokotemperaturowe 

właściwości elementów grubowarstwowych i LTCC 


Od ponad dziesięciu lat obserwuje się rosnące zainteresowanie w obszarze 

elektroniki wysokotemperaturowej. Rozwój materiałów półprzewodnikowych 

z szeroką przerwą energetyczną (węglik krzemu, azotek galu) umożliwił wytworzenie 

nowej klasy przyrządów pracujących w trudnych warunkach środowiska, 

również w wysokiej temperaturze. Wymusza to potrzebę rozwoju 

elementów biernych, które wspólnie umożliwią wykonanie w pełni funkcjonalnych 

układów elektronicznych. Technologie grubowarstwowa i niskotemperaturowej 

ceramiki współwypalnej (LTCC) są powszechnie stosowane 

do produkcji różnorodnych elementów pasywnych. Wysoka odporność 

temperaturowa materiałów ceramicznych w szczególny sposób kwalifikuje 

je do zastosowań w podwyższonej temperaturze. W pracy przedstawiono 

charakteryzację elementów grubowarstwowych i LTCC pracujących w temperaturze 

do 500°C. 

Słowa kluczowe: elementy bierne, technologia grubowarstwowa, niskotemperaturowa 

ceramika współwypalana, właściwości elektryczne 

NOWAK D., JANIAK M., DZIEDZIC A., PIASECKI T.: High temperature 

properties of thick-film and LTCC components 


For the last ten years there has been observed an increasing interest in 

the field of high temperature electronics. The development of engineering 

of wide-bandgap semiconductors (SiC, GaN) has brought new class of 

electronic devices that can work in harsh environment involving high temperature. 

This fact imposes development of passive components to enable 

manufacturing of fully functional devices. Low temperature co-fired ceramics 

(LTCC) and thick-film technologies are well-established techniques of 

fabrication different types of passive components. High thermal resistance 

of used materials predestines them for high temperature applications. This 

paper deals with characterization of LTCC and thick-film passives operating 

at temperature up to 500°C. 

Keywords: passive components, thick-film, LTCC, electrical properties 

CZOK M., MALECHA K., GOLONKA L.: Mikroprzepływowy fluorescencyjny 

czujnik ceramiczny wykonany techniką LTCC 


W artykule opisano proces wytwarzania mikroprzepływowego czujnika 

fluorescencyjnego, w technologii nisktotemperaturowej ceramiki współwypalanej 

LTCC (Low Temperature Co-fired Ceramics Technology). Wykonany 

czujnik składa się z łatwo dostępnych i niedrogich elementów elektronicznych, 

a także z polimerowych światłowodów PMMA (polimetakrylan 

metylu). Pracę mikroprzepływowego czujnika ceramicznego zbadano za 

pomocą barwnika fluorescencyjnego. W tym celu przygotowano pięć różnych 

stężeń fluoresceiny w etanolu. Roztwory testowe pobudzano źródłem 

promieniowania, o długości fali równej 465 nm, a następnie mierzono 

(dwoma fotodetektorami) natężenie wyemitowanej wiązki światła. Przeprowadzone 

badania wykazały, że możliwa jest detekcja sygnału fluorescencyjnego, 

wewnątrz mikroprzepływowego czujnika ceramicznego, za 

pomocą powszechnie dostępnych elementów optoelektronicznych. 

Słowa kluczowe: mikroprzepływowy, fluorescencja, Lab-on-Chip, LTCC 

CZOK M., MALECHA K., GOLONKA L.: LTCC microfluidic chip with 

fluorescence based detection 


This paper presents development and manufacturing processes of the 

fluorescence based microfluidic chip using Low Temperature Co-fired Ceramics 

technology (LTCC). The LTCC material was chosen because of 

its outstanding physical and chemical properties. Moreover, there is a possibility 

to integrate electronic and optoelectronic components into single 

LTCC microfluidic chip. The manufactured microfluidic chip consists of 

inexpensive and commonly available electronic components and PMMA 

(poly(methyl methacrylate)) optic fibres. Its performance is investigated 

with a fluorescent dye. Five different fluorescein solutions are excited with 

465 nm light source, and then the intensity of the emitted fluorescent light 

is measured with two photodetectors. The performed experiments have 

shown that it is possible to detect fluorescent signal inside the LTCC microfluidic 

chip using commonly available optoelectronic components. 

Keywords: microfluidic, fluorescence, Lab-on-Chip, LTCC 



MROCZKOWSKI M., CIEŻ M., KALENIK J.: Badanie powtarzanych 

cykli degradacji i regeneracji grubowarstwowych struktur elektroluminescencyjnych 


W ramach badań podjęto próbę wykonania wielokrotnej regeneracji zdegradowanych 

struktur elektroluminescencyjnych. Do tego celu został przygotowany 

zestaw testowych grubowarstwowych źródeł światła. Najpierw 

te źródła światła zostały zdegradowane przez starzenie przy zasilaniu napięciem 

prostokątnym. Następnie próbki wygrzano celem ich regeneracji. 

Taki cykl degradacji i regeneracji został wykonany dwukrotnie. Zmierzono 

wybrane parametry badanych struktur. Pomiary zostały wykonane po 

przygotowaniu próbek, po ich degradacji i po regeneracji. 

Zmierzono luminancję struktur zasilanych napięciem prostokątnym o różnej 

częstotliwości. W celu określenia wpływu zmian w warstwie izolacyjnej 

na luminancję struktury, zamierzono pojemność próbek. Dodatkowo, podjęto 

próbę określenia wpływu degradacji i regeneracji na widmo emisyjne 

elektroluminescencyjnych struktur grubowarstwowych. 

Słowa kluczowe: ZnS, elektroluminescencja wewnętrzna, struktury elektroluminescencyjne, 

ACEL, warstwy grube 

MROCZKOWSKI M., CIEŻ M., KALENIK J.: Investigation of multiple 

degradation and rejuvenation cycles of electroluminescent thick film 

structures 


An attempt to investigate the possibility of repeated rejuvenation of degraded 

electroluminescent (EL) lamps was undertaken. A set of samples 

of EL lamps with ZnS:Cu phosphor was fabricated. First, each of these 

samples worked for a period of time, driven by square voltage. After this 

process of degradation, samples were annealed in order to rejuvenate 

them. Such cycles of degradation and rejuvenation were repeated twice. 

Several parameters of investigated structures were estimated. Measurements 

were performed after fabrication of test samples, after degradation 

and after annealing. Luminance of EL lamps driven by voltage of different 

value of frequency was measured. Capacitance of these samples was measured 

to estimate the influence of changes in insulator layer of EL lamps 

on changes of luminance. Also an attempt to investigate the influence of 

degradation and rejuvenation on emission spectrum of electroluminescent 

thick film structures was undertaken. 

Keywords: ZnS, AC electroluminescence, EL lamps, ACEL, thick films 

STĘPLEWSKI W., SERZYSKO T., KOZIOŁ G., JANECZEK K., DZIE- 

DZIC A.: Badania podzespołów biernych wbudowanych w płytki obwodów 

drukowanych 


W artykule przedstawiono wyniki badań podzespołów biernych wbudowanych 

w płytkę odwodu drukowanego. Rezystory cienkowarstwowe zostały 

wykonane ze stopu Ni-P nałożonego na folię miedzianą laminatu FR4 

(technologia OhmegaPly ® ), rezystory grubowarstwowe zostały wykonane 

metodą druku sitowego z rezystywnej pasty węglowej (Electra ® ED7100) 

i węglowo-srebrowej (Electra ® ED7500) a kondensatory wykonano z ultra 

cienkiego laminatu (dielektryk foliowany obustronnie miedzią – Farad- 

Flex ® ). Wykorzystano również materiał nowej generacji złożony z warstwy 

pojemnościowej i rezystywnej (Ohmega/FaradFlex). Materiały te zostały 

wbudowane pomiędzy warstwami PCB bez zwiększenia jej grubości. 

Słowa kluczowe: rezystor cienkowarstwowy, rezystor grubowarstwowy, pojemność 

zagrzebana, płytka obwodu drukowanego, podzespoły wbudowane 

STĘPLEWSKI W., SERZYSKO T., KOZIOŁ G., JANECZEK K., DZIE- 

DZIC A.: Investigations of passive components embedded in printed 

circuit boards 


In this article the results of embedded passive components investigations 

are presented. Thin-film resistors were made with NiP metal alloy on copper 

foiled FR4 laminate (OhmegaPly ® technology), thick-film resistors 

were printed with carbon (Electra ® ED7100) and carbon-silver (Electra ® 

ED7500) inks and capacitors were manufactured with ultra-thin laminate 

(FaradFlex ® ). A material of a new generation being a composite of capacitance 

and resistance layer (Ohmega/FaradFlex) was also used. These 

materials were embedded between layers of the PCB without increase of 

its thickness. 

Keywords: thin-film resistor, thick-film resistor, buried capacitance, printed 

circuit board, embedded passives 

O’FLYNN B., BOYLE D., POPOVICI E., MAGNO M., PETRIOLI C.: GE- 

NESI: Bezprzewodowa sieć sensorów do monitorowania strukturalnego 


Ambitnym celem projektu GENESI jest podniesienie technologii bezprzewodowej 

sieci czujników na poziom, na którym będzie ona mogła stać 

się rdzeniem następnej generacji systemów dla strukturalnego monitorowania 

zdrowia, długowiecznych, wszechobecnych, totalnie rozproszonych 

i autonomicznych. Ten cel wymaga podjęcia inżynierskich i naukowych 

wyzwań, którym nigdy dotąd nie stawiano czoła. Węzły sensorowe będą 

przeprojektowane w celu przełamania bieżących ograniczeń, zwłaszcza 

pod względem przechowywania i dostarczania energii (potrzebujemy 

urządzeń o wirtualnie nieskończonym czasie życia), odporności na uszkodzenia 

i interferencje (dla niezawodnej i krzepkiej pracy). Zdefiniowany zostanie 

nowy softwer i protokoły aby w pełni wykorzystać możliwości nowego 

hardweru, dostarczając nowe paradygmaty dla wewnątrzwarstwowej 

interakcji na wszystkich warstwach stosu protokołu spełniając wymagania 

nowej koncepcji jakości obsługi, zorientowanej na aplikacje, wiernie odzwierciedlającej 

punkt widzenia i oczekiwania końcowego użytkownika. 

W ramach projektu GENESI zostaną opracowane długowieczne węzły sensorowe 

drogą połączenia nowatorskich technologii pozyskiwania energii ze 

środowiska i zielonych źródeł energii (ogniwa paliwowe o małych wymiarach); 

w projekcie GENESI zostaną zdefiniowane modele pozyskiwania 

energii, przechowywania energii w super-kondensatorach i dostępności 

dodatkowej energii za pomocą ogniw paliwowych, jako dodatek do opracowania 

nowych algorytmów i protokołów dynamicznej alokacji zadań pomiarowych 

i komunikacyjnych. Zespół projektowy opracuje protokoły komunikacyjne 

dla wielkoformatowych heterogenicznych bezprzewodowych sieci 

sensorowych posiadających zdolność pozyskiwania energii i zdefiniuje rozproszone 

mechanizmy dla oceny kontekstowej i świadomości sytuacyjnej. 

W artykule zaprezentowano analizę wymagań dla systemu GENESI sformułowanych 

w celu osiągnięcia ambitnych celów projektu. Wychodząc 

od prezentowanych wymagań, przedyskutowano kształtujące się specyfikacje 

systemu względem jego wybranych elementów. Wynikowy system 

będzie oceniany i charakteryzowany w celu sprawdzenia czy jest zdolny 

spełnić wymagania funkcjonalne projektu. 

Słowa kluczowe: strukturalne monitorowanie zdrowia, zielone bezprzewodowe 

sieci sensorowe, źródła energii odnawialnej 

O’FLYNN B., BOYLE D., POPOVICI E., MAGNO M., PETRIOLI C.: GE- 

NESI: Wireless Sensor Networks for structural monitoring 


The GENESI project has the ambitious goal of bringing WSN technology 

to the level where it can provide the core of the next generation of systems 

for structural health monitoring that are long lasting, pervasive and totally 

distributed and autonomous. This goal requires embracing engineering 

and scientific challenges never successfully tackled before. Sensor nodes 

will be redesigned to overcome their current limitations, especially concerning 

energy storage and provisioning (we need devices with virtually 

infinite lifetime) and resilience to faults and interferences (for reliability and 

robustness). New software and protocols will be defined to fully take advantage 

of the new hardware, providing new paradigms for cross-layer interaction 

at all layers of the protocol stack and satisfying the requirements 

of a new concept of Quality of Service (QoS) that is application-driven, 

truly reflecting the end user perspective and expectations. 

The GENESI project will develop long lasting sensor nodes by combining 

cutting edge technologies for energy generation from the environment 

(energy harvesting) and green energy supply (small form factor fuel cells); 

GENESI will define models for energy harvesting, energy conservation in 

super-capacitors and supplemental energy availability through fuel cells, 

in addition to the design of new algorithms and protocols for dynamic allocation 

of sensing and communication tasks to the sensors. The project 

team will design communication protocols for large scale heterogeneous 

wireless sensor/actuator networks with energy-harvesting capabilities and 

define distributed mechanisms for context assessment and situation awareness. 

This paper presents an analysis of the GENESI system requirements in 

order to achieve the ambitious goals of the project. Extending from the 

requirements presented, the emergent system specification is discussed 

with respect to the selection and integration of relevant system components.The 

resulting integrated system will be evaluated and characterised 

to ensure that it is capable of satisfying the functional requirements of the 

project. 

Keywords: Structural Health Monitoring, Green Wireless Sensor Networks, 

Green Energy Sources 

 



KISIEL R., SZCZEPAŃSKI Z., FIREK P., GUZIEWICZ M., KRAJEWSKI 

A.: Mechaniczne oraz cieplne właściwości połączenia między strukturą 

SiC a podłożem ceramicznym 


W artykule zaprezentowano proces realizacji montażu struktur SiC do 

podłoży DBC (ceramiki alundowej dwustronnie pokrytej warstwą Cu o grubości 

200 µm) przy zastosowaniu niskotemperaturowego zgrzewania mikroproszkiem 

Ag. W badaniach wstępnych, zamiast struktur SiC zastosowano 

struktury DBC o wymiarach 3 × 3 mm montowane do podłoża DBC 

10 × 10 mm (obie łączone części miały metalizację Au). W montażu wykorzystano 

mikroproszki Ag, a łączenie wykonywano przez: wygrzewanie w powietrzu 

pod naciskiem oraz przez wygrzewanie w próżni pod naciskiem. W obu 

metodach uzyskano dobrą adhezję tuż po łączeniu (z zakresu 8…10 MPa). 

Przeprowadzone próby starzeniowe w temperaturze 350°C wskazały, że adhezja 

próbek łączonych w powietrzu dramatycznie spada po 24 godzinach 

wygrzewania. Natomiast adhezja próbek łączonych pod naciskiem w próżni 

1,3 Pa w temperaturach z zakresu 500…550°C po procesach starzeniowych 

w temperaturze 350°C przez kilkaset godzin jest dobra (powyżej 10 MPa). 

Słowa kluczowe: technologie montażu i hermetyzacji, montaż struktur 

SiC, zgrzewanie niskotemperaturowe, mikroproszki Ag 

KŁOSSOWICZ A., DZIEDZIC A., WINIARSKI P., STĘPLEWSKI W., KO- 

ZIOŁ G.: Analiza odporności impulsowej grubo- i cienkowarstwowych 

rezystorów wbudowanych w płytki obwodów drukowanych 


Elementy bierne (rezystory, kondensatory, cewki) wbudowane w płytki obwodów 

drukowanych (PCB) mogą polepszyć właściwości oraz niezawodność 

układów elektronicznych. Stabilność impulsowa jest ważnym parametrem 

zarówno elementów biernych jak i urządzeń aktywnych. W przypadku rezystorów 

pozwala ona określić szereg właściwości takich jak np. maksymalna 

moc rozproszona, zmiana rezystancji lub zjawiska występujące wewnątrz 

struktury rezystora po przepłynięciu impulsu wysokonapięciowego. Co więcej 

odporność impulsowa określa użyteczność rezystora w obwodach pracujących 

impulsowo. Dlatego też w artykule przedstawiono wyniki badań odporności 

impulsowej cienkowarstwowych i polimerowych grubowarstwowych rezystorów 

utworzonych na powierzchni bądź wbudowanych w płytki obwodów 

drukowanych. Badane struktury zostały wytworzone z stopu fosforku niklu 

(Ni-P) lub polimerowej pasty rezystywnej na laminacie FR-4 o podobnych 

wartościach rezystancji powierzchniowej (25 Ω/kw lub 100 Ω/kw dla stopu 

Ni-P oraz 20 Ω/kw lub 200 Ω/kw dla polimerowych past rezystywnych). Odporność 

impulsowa została określona na podstawie wyznaczonych parametrów: 

maksymalnego nieniszczącego pola elektrycznego, maksymalnej nieniszczącej 

powierzchniowej gęstości mocy oraz maksymalnej nieniszczącej 

objętościowej gęstości mocy. Parametry te zostały ustalone oraz porównane 

dla obu rodzajów rezystorów w zależności od czasu trwania impulsu, geometrii 

rezystora (długości, szerokości, współczynnika proporcji), rezystancji 

powierzchniowej, rodzaju materiału zastosowanego między warstwą rezystywną 

a jej kontaktem oraz rodzajem pokrycia. Na podstawie otrzymanych 

wyników przeprowadzonych badań przeanalizowano podobieństwa i różnice 

w odporności impulsowej dla obu rodzajów rezystorów. 

Słowa kluczowe: płytki obwodów drukowanych, rezystory wbudowane, 

odporność impulsowa, fosforek niklu, cienkowarstwowe, grubowarstwowe 

WINIARSKI P., DZIEDZIC A., KŁOSSOWSKI A., STĘPLEWSKI W., KO- 

ZIOŁ G.: Analiza stabilności długoczasowejrezystorów cienkowarstwowych 

oraz polimerowych rezystorów grubowarstwowych wbudowanych 

w płytkiobwodów drukowanych 


W pracy przedstawiono wyniki badań stabilności długoczasowej rezystorów 

cienkowarstwowych oraz polimerowych rezystorów grubowarstwowych 

wykonanych na powierzchni lub wbudowanych w płytki obwodów 

drukowanych (PCB). Badane struktury testowe zostały wykonane ze 

stopu fosforku niklu (Ni-P) lub grubowarstwowych past polimerowych na 

podłożu FR-4, z podobnymi rezystancjami powierzchniowymi (25 Ω/kw lub 

100 Ω/kw dla stopów Ni-P oraz 20 Ω/kw, 200 Ω/kw lub 5 kΩ/kw dla grubowarstwowych 

past polimerowych), lecz zdecydowanie różnej grubości 

warstw rezystywnych – 0.1 lub 0.4 μm dla stopów Ni-P oraz około 10…12 

μm dla polimerowych warstw rezystywnych. Część próbek z rezystorami 

Ni-P pokryto dwoma typami warstwy ochronnej – laminatem RCC (Resin 

Coated Copper) lub preimpregnatem LDP (Laser Drillable Prepreg). Grubowarstwowe 

rezystory polimerowe zostały nadrukowane na kontaktach 

Cu lub Cu z powłoką Ni/Au oraz zostały pokryte warstwą laminatu RCC. 

Aby przeprowadzić analizę zachowania długoczasowego elementów wykorzystano 

metodę procesu przyśpieszonego starzenia oraz pomiarów 

In-Situ (pomiar rezystancji w warunkach narażeń).Wyniki wykazały zupełnie 

inne zachowanie się obu grup rezystorów. W przypadku rezystorów 

cienkowarstwowych Ni-P geometria niemal nie wpływa na stabilność 

długoczasową. Jednak znaczny wpływ na zachowanie się rezystorów był 

związany z rezystancją powierzchniową, typem pokrycia oraz temperaturą 

Elektronika 1/2012 

KISIEL R., SZCZEPAŃSKI Z., FIREK P., GUZIEWICZ M., KRAJEWSKI 

A.: Mechanical and thermal properties of SiC – ceramics substrate 

interface 


In this paper, we present the realization of assembly of SiC samples to 

DBC substrate (Direct Bonding Copper Substrate with 200 µm Cu metallization 

Au covered) by low-temperature sintering of micro scale Ag powder. 

In the preliminary experiments DBC test samples size 3 × 3 mm (in place 

of SiC die) were assembled to DBC substrate size 10 × 10 mm using following 

methods: a) sintering by Ag powder with Ag microparticles in air by 

applying temperature and pressure, b) sintering by Ag powder with Ag microparticles 

using temperature, pressure and high vacuum. Methods „a” and 

„b” permit to obtain very good adhesion range 8…10 MPa after sintering. 

However after ageing test at temperature 350°C in air the adhesion fall 

down dramatically. By increasing sintering temperature up to 500…550°C 

and sintering in vacuum range 1.3 Pa the adhesion is satisfactory. The 

results of these experiments will be presented in paper. 

Keywords: packaging technology, SiC die bonding, low temperature sintering, 

silver microparticles 

KŁOSSOWICZ A., DZIEDZIC A., WINIARSKI P., STĘPLEWSKI W., 

KOZIOŁ G.: Analysis of pulse durability of thin-film and polymer 

thick-film resistors embedded in printed circuit boards 


The passives (resistors, capacitors, inductors) embedded in printed circuit 

boards (PCBs) can improve electrical properties and reliability of electronic 

systems. Pulse durability is an important parameter of passive components 

and active devices. In the case of resistors it allows to determine 

many properties including maximum power dissipation, resistance change 

or phenomena occurring in resistor structures after pulse surging. Furthermore 

pulse durability defines utility for pulse circuits. Thus this work 

presents pulse durability of thin-film and polymer thick-film resistors made 

on the surface or embedded in Printed Circuit Boards (PCBs). Investigated 

test structures were made of nickel–phosphorus (Ni-P) alloy or polymer 

thick-film resistive inks on FR-4 laminate with similar sheet resistance (25 

Ω/sq or 100 Ω/sq for Ni-P alloys and 20 Ω/sq or 200 Ω/sq for polymer 

thick-film inks). Pulse durability was determined by calculating the maximum 

nondestructive electric field, maximum nondestructive surface power 

density or maximum nondestructive volume power density. These parameters 

were determined and compared for both kind of resistors in dependence 

on pulse duration, resistor geometry (length, width, aspect ratio), 

sheet resistance, interface between resistive film and termination material, 

type of cladding. Based on experimental results the similarities and dissimilarities 

in pulse durability of both group of resistors were analyzed. 

Keywords: printed circuit board, embedded resistor, pulse durability, nickel-phosphorous, 

thin film, thick film 

WINIARSKI P., DZIEDZIC A., KŁOSSOWSKI A., STĘPLEWSKI W., 

KOZIOŁ G.: Analysis of long-term stability of thin-film and polymer 

thick-film resistors embedded in Printed Circuit Boards 


This work presents long-term stability of thin-film and polymer thick-film 

resistors made on the surface or embedded in Printed Circuit Boards 

(PCBs). Investigated test structures were made of nickel–phosphorus (Ni- 

P) alloy or polymer thick-film resistive inks on FR-4 laminate with similar 

sheet resistance (25 Ω/sq or 100 Ω/sq for Ni-P alloys and 20 Ω/sq, 200 Ω/ 

sq or 5 kΩ/sq for polymer thick-film inks) but decidedly different thickness 

of resistive layers - 0.1 or 0.4 μm thick Ni-P alloy and about 10…12 μm 

for polymer resistive films). Part of the Ni-P samples was covered with 

two different coatings – Resin Coated Copper (RCC) or Laser Drillable 

Prepreg (LDP). Polymer thick-film resistors were printed on Cu contacts or 

Cu contacts with Ni/Au coating and were covered by RCC film. The In-Situ 

accelerated ageing process (resistance of test samples performed directly 

at the ageing conditions) was carried out to perform long-term behaviour 

analysis. The results showed quite different behaviour of both group of 

resistors. In case of Ni-P thin-film resistors resistor geometry almost not 

affect long-term stability. However a significant influence on the behaviour 

of resistors was due to sheet resistance, type of encapsulation and ageing 

temperature. Measurement results revealed the square-root-of-time 

dependence of the resistance changes, which represent a single ageing 

mechanism. In temperature domain resistance drift can be described by 

the Arrhenius equation. The extrapolation of these results could be used to 

predict behaviour of resistors in various temperature and times of ageing.


starzenia. Wyniki pomiarów ujawniłyiżzmiany rezystancji są proporcjonalne 

do pierwiastka czasu, co prezentuje pojedynczy mechanizm starzenia.W 

dziedzinie czasu zmiany rezystancji mogą być opisane równaniem 

Arrheniusa, ekstrapolacja tych wyników może być użyta do przewidywania 

zachowania się rezystorów w różnych temperaturach oraz czasach starzenia.Taka 

ekstrapolacja jest prawie niemożliwa dla polimerowych rezystorów 

grubowarstwowych, gdzie wzrost temperatury starzenia prowadzi 

do zmian relatywnego dryftu rezystancji względem czasu z dodatniego na 

ujemny. W przypadku tych struktur połączenie pomiędzy warstwą rezystywną 

a materiałem kontaktu gra istotną rolę w obserwowanym poziomie 

względnych zmian rezystancji. 

Słowa kluczowe: rezystory wbudowane, płytka obwodu drukowanego, 

stabilność długoczasowa, thermal ageing, Fosforek niklu (Ni-P), polimerowe 

rezystory grubowarstwowe 

Such an extrapolation is almost impossible for polymer-thick film resistors, 

where the increase of ageing temperature leads to change relative resistance 

drift versus ageing time from positive to negative. In the case 

of these structures the interface between resistive films and termination 

materials plays a very important role on the level of observed relative resistance 

changes. 

Keywords: embedded resistors, printed circuit board, long-term stability, 

thermal ageing, Nickel-Phosphorus (Ni-P), polymer thick film resistor 

DUNST K., MOLIN S., JASIŃSKI P.: Spektroskopia impedancyjna jako 

narzędzie diagnostyczne degradacji tlenkowych ogniw paliwowych 


Tlenkowe ogniwa paliwowe SOFCs (ang. Solid Oxide Fuel Cells) są obecnie 

bliskie komercjalizacji. Wiedza na temat mechanizmów degradacji ogniw 

paliwowych jest niezbędna do dalszej poprawy ich działania. Spektroskopia 

impedancyjna jest skutecznym narzędziem diagnostycznym. Pozwala ona 

na wskazanie który element ogniwa SOFC ulega pogorszeniu oraz pozwala 

poznać dokładniej naturę procesu degradacji. W tej pracy degradacja 

ogniwa SOFC została zbadana przy użyciu spektroskopii impedancyjnej. 

Jako paliwa użyto wodoru oraz metanu. Związek pomiędzy niestabilnością 

w metanie (spowodowaną osadzaniem się węgla) a widmem impedancji 

został pokazany. Rodzaj degradacji został powiązany z częstotliwościami 

charakterystycznymi odczytanymi z widm impedancyjnych. 

Słowa kluczowe: spektroskopia impedancyjna, tlenkowe ogniwa paliwowe, 

degradacja 

DUNST K., MOLIN S., JASIŃSKI P.: Impedance spectroscopy as a diagnostic 

tool of degradation of Solid Oxide Fuel Cells 


Solid Oxide Fuel Cells (SOFCs) are close to commercialization and knowledge 

about degradation mechanism become a vital step for their further 

improvement. A powerful diagnosis tool is impedance spectroscopy (IS). 

The IS allows indicating the degrading element of the SOFC and may 

provide knowledge about nature of the degradation process. In this paper 

degradation of the SOFCs has been investigated by impedance spectroscopy. 

Hydrogen and methane was used as a fuel. Relation between 

instability in the methane (caused by carbon formation) and impedance 

spectra was revealed. Type of degradation was linked with characteristic 

frequencies obtained from the impedance spectra. 

Keywords: impedance spectroscopy, solid oxide fuel cell, degradation 

SABAT W., KLEPACKI D., KAMUDA K.: Analiza sprzężeń elektromagnetycznych 

w układach hybrydowych wykonanych na podłożach ze 

stali austenitycznej 


W opracowaniu przeanalizowano uwarunkowania geometryczne i technologicznerealizacji 

układów hybrydowych na podłożach metalowych austenitycznych 

w aspekcie ich kompatybilności elektromagnetycznej.W ujęciu 

ilościowym określono jak konfiguracja ścieżek, ich parametry geometryczne 

i fizyczne wpływają na wartość parametrów elementów resztkowych, 

a w efekcie finalnym na proces propagacji sygnałów szybkozmiennych 

w układach wzajemnie równoległych ścieżek. Na bazie przeprowadzonej 

analizy zdefiniowano mechanizm propagacji znormalizowanych sygnałów 

elektrycznych w tego rodzaju strukturach. Dal wybranych konfiguracji ścieżek 

zaprezentowano wyniki obliczeń i pomiarów w celu określenia wpływu 

zmian parametrów geometrycznych układu na funkcję przenoszenia. 

Słowa kluczowe: mikroelektroniczne układy hybrydowe, EMC, integralność 

sygnałów, technologia LTCC 

SABAT W., KLEPACKI D., KAMUDA K.: Analysis of electromagnetic 

couplingsin hybrid circuit made on austenitic metal substrate 


The geometrical and technological conditions of realization of hybrid circuits 

made on austenitic metal substrate in EMC aspects have been analyzed 

in this paper. The influence of path configurations, their geometrical 

and physical parameters on parasitic element parameters has been determined 

in quantitative point of view. On the basis carried out analysis of 

topical materials the mechanisms ofpropagation of normalized electrical 

signals in this type structure have been characterized. The degree of modification 

of transfer function under changes of the particular geometrical 

and physical factors of such type structures has been determined. The 

results of calculations and experimental verification have been also presented 

for the selected path configurations. 

Keywords: microelectronic hybrid circuits, electromagnetic compatibility, 

signal integrity,hybrid technology 

SABAT W., KLEPACKI D., KALITA W., SLOSARČÍK S., JURČIŠIN M., 

CABÚK P.: Zagadnienia EMC w mikroelektronicznych strukturach 

wytwarzanych w technologii LTCC 


W opracowaniu zaprezentowano uwarunkowania geometryczne i technologiczne 

realizacji układów hybrydowych w technologii LTCC w odniesieniu 

do kwestii kompatybilności elektromagnetycznej. W ujęciu ilościowym 

określono jak konfiguracja ścieżek, ich parametry geometryczne i fizyczne 

wpływają na wartość parametrów elementów resztkowych. Zaprezentowano 

wyniki obliczeń i pomiarów parametrów resztkowych dla wybranych 

charakterystycznych konfiguracji wzajemnie sprzężonych układów ścieżek. 

Określono ilościowo wpływ konfiguracji ścieżek oraz parametrów 

elektrycznych dla znormalizowanych sygnałów na efektywność procesu 

propagacji sygnałów zakłócających w tego typu strukturach. 

Słowa kluczowe: mikroelektroniczne układy hybrydowe, EMC, integralność 

sygnałów, technologia LTCC 

SABAT W., KLEPACKI D., KALITA W., SLOSARČÍK S., JURČIŠIN M., 

CABÚK P.: EMC aspects in microelectronics structures made in 

LTCC technology 


The geometrical and technological conditions of realization of hybrid circuits 

made in LTCC technology in EMC aspects have been analyzed in 

this paper. The results of calculations and measurements of the change 

interval of parasitic element parameters in mutually parallel path systems 

have been presented for selected characteristic configurations of conducted 

path systems. In terms of quantity the influence of geometrical configuration 

of path systems and electrical parameters for standard test signals 

on efficiency of process propagation of disturbing signals in this type structures 

has been determined. The results of calculations and measurements 

have been presented for the selected path configurations. 

Keywords: microelectronic hybrid circuit, EMC, signal integrity, LTCC 

technology 

 



KOSIKOWSKI M., SUSZYŃSKI Z.: Metoda przetwarzania obrazów termicznych 

zarejestrowanych techniką modulacji przestrzennej 


W artykule zaprezentowano i opisano koncepcję akwizycji i przetwarzania 

obrazów termicznych zarejestrowanych w trybie modulacji przestrzennej 

(BDM). Podstawowym problemem analizy tak pozyskanych obrazów termograficznych 

jest niejednorodność tła termicznego oraz duże zróżnicowanie 

poziomów sygnału wynikające z różnic kontrastu optycznego. W typowej 

termografii aktywnej nie jest to problemem ponieważ, po pierwsze 

czas rejestracji jest znacznie krótszy i tło temperaturowe można uznać za 

niezmienne a po drugie detekcja sygnału w dziedzinie czasu dotyczy albo 

wszystkich pikseli jednocześnie albo każdego piksela oddzielnie. W trybie 

BDM rejestruje się wartość sygnału temperaturowego dla kolejnych pikseli 

dla tego samego opóźnienia względem pobudzenia, co przy dużych różnicach 

kontrastu optycznego powoduje znaczące skokowe zmiany sygnału 

o skończonym czasie relaksacji, co wprowadza zniekształcenie liniowe 

sygnału, widoczne na obrazach w postaci smug. 

Słowa kluczowe: przetwarzanie obrazów, termografia aktywna, modulacja 

przestrzennej, metody termiczne, metody temofalowe 

KOSIKOWSKI M., SUSZYŃSKI Z.: Method of processing of thermal 

images recorded in the beam displacement modulation technique 


The article discusses the concept of acquisition and processing of thermal 

images recorded in the mode of spatial modulation. The basic problem 

related to analysing thermal images acquired in such a way is the inhomogeneity 

of the thermal background and significant diversification of signal 

levels, stemming from optic contrast differences. In the typical active 

thermography this is not a problem because the recording time is much 

shorter and the temperature background may be considered invariable 

and, the signal detection in the realm of time refers either to all the pixels 

at the same time or to every pixel separately. In the beam displacement 

modulation mode, the temperature signal value is recorded for successive 

pixel for the same lag when compared to the excitation which for large optical 

contrast differences brings about significant discrete signal changes 

with a finite relaxation time, resulting in linear signal distortion, visible as 

trails in the images. 

Keywords: image processing, active thermography, spatial modulation, 

thermowave methods 

STRZELCZYK A., JASIŃSKI G., JASIŃSKI P., CHACHULSKI B.: Czujnik 

elektrokatalityczny na bazie Nasiconu z warstwą dodatkową 


W pracy zostały przedstawione wyniki pomiarów czujnika na bazie Nasiconu 

pracującego w trybie elektrokatalitycznym. Czujniki takie pobudzane 

są zmieniającym się napięciem przy jednoczesnym pomiarze odpowiedzi 

prądowej. Przygotowano czujniki ceramiczne o dwóch różnych typów. 

Pierwszy z nich to czujnik posiadający dwie identyczne elektrody złote, 

pomiędzy którymi znajduje się elektrolit stały. Drugi czujnik posiada złote 

elektrody dodatkowo pokryte warstwą azotanu (III) sodu. Zmierzono i porównano 

odpowiedzi obu czujników dla różnych stężeń dwutlenku azotu 

w mieszaninie z powietrzem. 

Słowa kluczowe: czujnik gazu, elektrolit stały, Nasicon, czujnik elektrokatalityczny 

STRZELCZYK A., JASIŃSKI G., JASIŃSKI P., CHACHULSKI B.: Electrocatalytic 

sensor based on Nasicon with auxiliary layer 


In this study properties of Nasicon solid state gas sensors working in 

electrocatalytic mode are investigated. The principle of operation of such 

sensors is based on the excitation with a periodic potential signal, while 

current response is recorded. The sensors are prepared in ceramic technology 

with two different constructions. One construction is a symmetrical, 

sandwich type structure with electrolyte between two identical gold 

electrodes. In the second, the same structure is used, but the electrodes 

are covered with auxiliary layer of sodium nitrite. Nitrogen dioxide sensing 

properties of both sensors are determined and compared. 

Keywords: gas sensor, solid state electrolyte, Nasicon, electrocatalytic 

sensor 

KOBIEROWSKA K., KARPIŃSKA M., MOLIN S., JASIŃSKI P.: Warstwy 

tlenkowe wytworzone metodą pirolizy aerozolowej na podłożach metalicznych 


W niniejszym artykule przebadane zostały możliwości zastosowania metody 

pirolizy aerozolowej do wytwarzania warstw z tlenku cyrkonu stabilizowanego 

itrem na podłożu ze stali nierdzewnej 316L. W pierwszej 

kolejności bardzo ważne było określenie optymalnych warunków przygotowania 

warstw. Podstawowym parametrem w procesie napylania warstw 

metodą pirolizy aerozolowej jest temperatura powierzchni, której wpływ 

systematycznie przebadano. Przeprowadzone badania wykazały przydatność 

warstw z zastosowaniem tlenku cyrkonu stabilizowanego itrem 

wytworzonych metodą pirolizy aerozolowej. W celu określenia odporności 

na korozję oraz właściwości ochronnych zostały przeprowadzone pomiary 

potencjodynamiczne w roztworze imitującym środowisko tkankowe. 

Wyniki uzyskane z pomiarów laboratoryjnych dostarczyły informacji na 

temat zjawisk korozyjnych zachodzących na powierzchni stali oraz warstw 

ochronnych. Badania pokazały, że warstwą wykazującą poprawę właściwości 

antykorozyjnych jest ta, która powstała poprzez napylenie prekursora 

polimerowego w temperaturze 390°C. 

Słowa kluczowe: piroliza aerozolowa, antykorozyjne warstwy ochronne, 

tlenek cyrkonu stabilizowany itrem 

Lewandowski J., Dziuda Ł., CELIŃSKI-SPODAR K.: Mechanoakustyczny 

czujnik aktywności układu sercowo-naczyniowego 


W artykule zaprezentowano projekt oraz wyniki badań mechanoakustycznego 

czujnika służącego do monitorowania aktywności układu sercowonaczyniowego. 

W założeniu czujnik był pomocniczym elementem systemu 

sensorów do bezkontaktowych pomiarów aktywności serca i czynności 

oddechowej. W prezentowanym czujniku zastosowano głowicę stetoskopu 

oraz głowicę odbierającą drgania akustyczne wykorzystującą światłowodową 

siatkę Bragga jako element pomiarowy. Czujnik został przebadany 

na zaprojektowanym w tym celu stanowisku badawczym. Pasmo odbioru 

drgań akustycznych czujnika wynosi 25…135 Hz, zaś jego wzmocnienie 

przy częstotliwości 100 Hz – 9,2 dB. Parametry te stwarzają potencjalną 

możliwość zastosowania urządzenia w przyszłości jako stetoskopu światłowodowego 

bądź elementu pomiarowego w balistokardiografii. Do odbioru 

drgań wykorzystywano system interrogacji Micron Optics SM-130. 

Słowa kluczowe: akustyka, stetoskop, światłowodowa siatka Bragga, 

układ sercowo-naczyniowy 


KOBIEROWSKA K., KARPIŃSKA M., MOLIN S., JASIŃSKI P.: Oxide 

layers fabricated by spray pyrolysis on metallic surfaces 


In this paper the possibilities of using spray pyrolysis method to produce 

yttrium stabilized zirconia layers have been examined. A stainless steel, 

type 316L, was used as a substrate. It was important to determine the 

optimal conditions of the films preparation. The basic parameter in the 

pyrolysis technology process is a surface temperature, which was systematically 

examined. The layer was intended to be used as protective film 

for metallic implants. In order to determine the corrosion resistance and 

protective properties of produced layers, potentiodynamic measurements 

in mimicking tissue environment solution were carried out. It provided information 

about the corrosive effects, which occur on the steel surface and 

on the protective layer. The experimental results showed that improvement 

of corrosion resistance properties was obtained by spraying the precursor 

at 390°C. 

Keywords: spray pyrolysis, corrosion protective layers, yttrium stabilized 

zirconia 

LEWANDOWSKI J., Dziuda Ł., CELIŃSKI-SPODAR K.: Mechano-acoustic 

sensor of the cardiovascular system activity 


This article presents the design and results of study on the mechanoacoustic 

sensor used for monitoring cardiovascular activity. The basic idea 

was to utilize the presented sensor as a secondary element in the sensor 

system for contactless measurement of cardiac and respiratory activity. 

The sensor consists of a stethoscope head and an acoustic head which 

receives vibrations by means of the fiber Bragg grating acting as a sensing 

element. The sensor has been tested at the dedicated experimental setup. 

The frequency range of acoustic vibration receiving reaches 25-135 Hz, 

and its amplification at 100 Hz is 9.2 dB. These parameters make a potential 

opportunity to apply the device in the future as a fiber-optic stethoscope 

or fiber-optic sensing element in balistocardiography. For signals 

receiving, the SM-130 interrogation system by Micron Optics was used. 

Keywords: acoustics, cardiovascular system, fiber Bragg grating, stethoscope


SĘDEK E.: Aktywne anteny radarów wielofunkcyjnych – analiza stanu 

i perspektywy rozwoju – część 1 


W artykule przeglądowym omówiono stan techniki aktywnych anten radarów 

wielofunkcyjnych stosowanych w stacjonarnych urządzeniach 

naziemnych. Aktywne anteny stosowane w radarach transportowalnych, 

samolotowych i okrętowych będą omówione w następnym artykule. Przedstawiono 

rozwiązania reprezentatywne dla anten aktywnych stosowanych 

w wymienionych radarach. Pokazano ich cechy charakterystyczne oraz 

tendencje rozwoju i integracji aktywnych systemów antenowych. Opracowanie 

składa się z 3 części. Pierwsza część poświęcona jest aktywnym 

antenom naziemnych radarów wielofunkcyjnych. W drugiej części dokonano 

przeglądu aktywnych anten stosowanych w radarach transportowalnych, 

samolotowych i okrętowych, zaś trzecia część poświęcona będzie 

mikrofalowym podzespołom stosowanych w aktywnych antenach. 

Słowa kluczowe: radary wielofunkcyjne, radary stacjonarne, aktywne anteny 

ścianowe, moduły nadawczo-odbiorcze T/R 

SĘDEK E.: Active phased antenna array for multifunction radar – review 

and perspective development – part 1 


In the paper review of active phased antenna array for multifunction radar 

is presented. Active phased antenna array for ground based radar is presented 

in detail. Shipboard, airborne and transportable/mobile radar active 

phased antenna array will be presented in the next paper. The full paper is 

compose from three parts. In the first part an active phased antenna array 

for multifunction ground based long-range radar is presented. In the second 

part the active phase antenna array for transportable/mobile radar, shipboard 

and airborne radar will be analyzed. In the third part will be presented 

parameters of microwave devices used in antenna array and technology of 

transmit/receive modules. We would like to show, that monolithic microwave 

technology is perspective and needed to use in active phase antenna 

array especially in the higher frequency band such as X, Ka, and W. 

Keywords: multifunction radar, ground based radar, active phased antenna 

array, transmit/receive modules T/R 

MITAS A.W., BERNAŚ M., BUGDOL M., RYGUŁA A.: Technologie informacyjne 

w predykcji pogodowych zagrożeń w ruchu drogowym 


W artykule w syntetycznym ujęciu przedstawiono zagadnienie predykcji 

pogodowej, ze szczególnym uwzględnieniem detekcji zagrożeń atmosferycznych 

w ruchu drogowym. W kolejnych punktach opracowania opisano 

podstawy prognozowania pogodowego, scharakteryzowano przykładowe 

modele matematyczne oraz zaprezentowano autorski system wnioskowania 

o niebezpiecznych stanach atmosferycznych na drodze. 

Słowa kluczowe: predykcja pogodowa, bezpieczeństwo transportu, technologia 

informacyjna w ruchu drogowym 

MITAS A.W., BERNAŚ M., BUGDOL M., RYGUŁA A.: Information technology 

in prediction of weather hazards affecting road traffic 


In the article summarized the issue of predicting the weather hazards, with 

particular emphasis on the detection of dangerous atmospheric conditions 

in road traffic. In the following sections the basis of weather forecasting, 

mathematical models and the authors inference system about hazardous 

road condition were described. 

Keywords: weather prediction, transport safety, information technology 

in road traffic 

ZAHARIEVA S., MUTKOV V., GEORGIEV I.: Еlektroniczny system pomiarowy 

do kontroli parametrów geometrycznych profili produkowanych 

na liniach wytłaczarkowych 


Pomiar kompleksowych i różnicowych geometrycznych parametrów 

w trakcie produkcji cylindrycznych, kwadratowych i prostokątnych wytłaczanych 

wyrobów niewątpliwie zwiększa jakość gotowej produkcji. Dynamika 

procesu technologicznego oraz wpływ zewnętrznych czynników 

na parametry wyrobów narzuca wprowadzanie elektronicznego systemu 

pomiarowego, który w trakcie produkcji mierzy i przechowywuje dane pomiarów. 

Zrealizowany elektroniczny system pomiarowy do kontroli parametrów 

geometrycznych profili produkowanych na liniach wytłaczakowych 

pozwala na aktywną kontrolę w trakcie produkcji i równocześnie zwiększa 

jakość gotowej produkcji. 

Słowa kluczowe: system pomiarowy; kontrolа; parametry geometryczne; 

cylindryczne, kwadratowe i prostokątne wytłaczane profile 

ZAHARIEVA S., MUTKOV V., GEORGIEV I.: Electronic measurement 

system for monitoring of geometrical parameters of rolling shaped 

metal profiles 


The measurement of the complex and the differential geometric parameters 

in the production process of cylindrical, square and rectangular rolling 

shaped metal profiles will inevitably lead to a rise in the production 

quality. The dynamism of the technological process and the influence of 

great number of outside factors over geometrical parameters of revolving, 

enforce development of an electronic measurement system, which reliably 

reads and preserves measured data immediately in the production process 

of rolling shaped metal. The accomplished electronic measurement 

system for monitoring of geometric parameters of rolling shaped metal 

performs an active firsthand control in the production process, for the purpose 

of management of the quality of the finished production. 

Key words: measurement system, monitoring, geometric parameters, cylindrical, 

square and rectangular rolling shaped metal profiles 

STĘPIEŃ R., WALCZAK J.: Modulacja amplitudy sygnałem pseudolosowym 


W artykule rozpatrzono problem modulacji amplitudy sinusoidalnej fali 

nośnej przebiegiem pseudolosowym. Podano przykładowe realizacje generatorów 

sygnałów pseudolosowych i ich właściwości. Omówiono proces 

modulacji AM sygnałem pseudolosowym i właściwości widma sygnałów 

zmodulowanych. Zaproponowano fizyczną realizację modulatora wraz 

z układem kształtowania widma. Zaprezentowano wyniki badań symulacyjnych 

i eksperymentalnych modulatora podając także jedno z możliwych 

zastosowań. 

Słowa kluczowe: sygnały pseudolosowe, modulacja AM, generatory 

LFSR, widmo sygnału pseudolosowego, modulator, zagłuszanie 

STĘPIEŃ R., WALCZAK J.: Amplitude modulation with pseudo random 

signal 


In this article a pseudorandom AM modulation of the sinusoidal carrier is 

considered. An exemplary realizations of the pseudorandom generators 

are shown. The pseudorandom AM modulation process and its spectrum 

are described. A practical construction of the modulator with spectrum 

shaping circuit is proposed. Simulation of proposed circuit, experimental 

results and one of the possible use of the constructed device are shown. 

Keywords: pseudorandom signals, AM modulation, LFSR generator, 

pseudorandom signal spectrum, modulator, jamming 

DĄBROWSKI J., ZARĘBSKI J.: Problematyka modelowania w programie 

SPICE charakterystyk stałoprądowych elektroizolowanych 

diodowych modułów mocy zawierających diody typu PiN oraz diody 

typu FRED 


W artykule poruszono problematykę modelowania w programie SPICE 

charakterystyk statycznych krzemowych elektroizolowanych diodowych 

modułów mocy. Do badań wybrano moduły zawierające diody typu PiN 

oraz diody typu FRED 

Słowa kluczowe: moduł elektroizolowany, dioda PiN, dioda FRED (Fast 

Recovery Epitaxial Diode), SPICE, modelowanie 

DĄBROWSKI J., ZARĘBSKI J.: Problem of the SPICE modeling of the 

d.c. characteristics of the electroisolated power diode modules containing 

PiN diodes and fast recovery epitaxial diodes 


In the paper the problem of modeling of d.c. characteristics of electroisolated 

power diode modules was considered. For investigations the modules 

containing the silicon PiN diodes and the silicon fast recovery epitaxial 

diodes were chosen 

Keywords: electroisolated module, PiN diode, fast recovery epitaxial diode 

(FRED), SPICE, modeling 

10 


Study of IDE as a sensor head for interfacing 

with handheld electrochemical analyzer system 

(Projekt głowicy IDE dla sensorów do zastosowań w podręcznych 

systemach analizy elektrochemicznej) 

Vijayalakshmi Velusamy 1) , prof. Khalil Arshak 1) , dr Olga Korostynska 2) , 

dr Catherine Adley 3) 

1) 

Department of Electronic and Computer Engineering 

3) 

Department of Chemical and Environmental Sciences University of Limerick, Limerick, Ireland 

2) 

School of Physics, Dublin Institute of Technology, Dublin, Ireland 

Electrochemical biosensors have been receiving more attention 

in recent years since they are simple to use, cost-effective, offer 

high sensitivity and suitable for in situ analysis [7–10]. Applications 

are mainly focused on food quality monitoring for the detection of 

foodborne pathogens [11], environmental quality monitoring for 

the detection of contamination of potable water resources due to 

pathogenic micro organisms and industrial by-products [12, 13] 

and in biosecurity for the detection of biowarfare agents [14]. 

An electrochemical sensor is an electrical device in which the 

biological and/or the chemical information are converted to an 

electrical signal, which is then processed and recorded for further 

analysis. 

Towards the development of an electrochemical analyzer system, 

a sensor was initially designed that may be interfaced with the 

handheld system comprising both the potentiostat and the impedance 

analyzer. In biosensors the lower limit of detection is a big 

challenge and numerous electrode geometries have been developed 

during the past decade to address this problem. Among various 

electrode geometries IDE have advantage in bioanalytical applications. 

A thick-film gold IDE was employed in this research and 

it was prepared by screen printing technique. Thick-film sensors 

are advantageous since it is compact, robust and relatively cost-effective. 

It is possible to mass produce from macro- to microscale, 

with greater reproducibility. However, the applicability of the technology 

is limited to a possible minimum line width (100 µm) [15]. 

The planar IDE sensors based on thick films are very wellsuited 

to integrate with electronic circuits. The IDE sensors can 

be combined with other planar technologies like plasma/chemical 

vapor deposition for surface modification. The device produced 

by the thick-film technique has the ability to facilitate as a supporting 

structure upon which other sensing materials can be deposited. 

To fabricate a DNA sensor for the real time detection of the 

microbial pathogens, meandering heater element patterns can be 

screen-printed as a first layer which acts as both a temperature 

sensor and a heater to enable the localised temperature to be 

raised to release the bacteria and thus the DNA fragments. A dielectric 

layer can be then deposited over the heating pattern and 

the final layer is a gold IDE pattern. 

To study the performance of the sensor a label free unmodified 

DNA was immobilized and hybridized using simple electrochemical 

adsorption technique. Prior to immobilization one pole of 

the gold IDE was modified by the conducting polymer polypyrrole 

(PPy) which served as an immobilization matrix. 

from distilled water. The capture probe and the target probe are 

20-mer oligonucleotides and the non complementary probe is 21- 

mer in length. Table 1 shows the sequence of the oligonucleotides 

probes used in this work. 

Tabl. 1. DNA Sequences 

Tab. 1. Sekwencje DNA 

Probe (5’-3’) 

Function 

Complementary (5’-3’) 

Non-Complementary (5’-3’) 

IDE Preparation 

Sequence 

ATC GCC TCG TTG GAT GAC GA 

TCG TCA TCC AAC GAG GCG AT 

AAA ATC GAT GGT AAA GGT TGG 

The interdigitated electrode structure was screen-printed onto precleaned 

alumina substrates (CeramTec UK Ltd.) using a DEK 1202 

automatic screen-printer. The material used for the electrodes was 

Au thick film conductive paste (Heraeus Materials). After screenprinting, 

the electrodes were placed into an oven at 80°C for 2 hours 

to facilitate the initial drying of the paste. In this step, the remaining 

solvent in the thick film paste evaporates, leaving the dried pattern 

on the substrate. The devices are next placed into a multi-chamber 

belt-furnace for an 850°C temperature cycle. In this step, any 

remaining organic binder is removed and the metal frit is sintered 

into one solid structure. This step also allows the electrode pattern 

to settle to its final thickness and resistivity values. 

The IDE structure used in this work is shown in Fig. 1. The thickness 

of the Au thick film was measured as 9 µm using a Dektak 

Surface Profile Measuring System. 

Materials and Methods 

Materials 

Pyrrole and MgCl 2 

solution was purchased from Sigma-Aldrich, 

USA. All the reagents were analytical grade and used without further 

purification. Specific sequences for the Bacilus cereus (B. 

cereus) were designed in the laboratory [16] and its synthetic 

form was purchased from Integrated DNA technologies, USA. All 

stock solutions and a concentration of 100 pM/µl were prepared 

Fig. 1. Schematic of the gold IDE sensor that is employed in this 

work. All dimensions are in millimeters 

Rys. 1. Schemat złotego czujnika typu IDE, który jest wykorzystywany 

w pracy. Wszystkie wymiary podano w milimetrach 

Elektronika 1/2012 11

Instrumentation 

Link wires were soldered directly to the bond pads of the IDE structure. 

An Autolab PGSTAT302N was used to apply constant potential. 

The AC characteristics were monitored using a HP 4192A 

Low Frequency Impedance Analyzer (0.3 V,10 Hz – 10 kHz), using 

LabView software to log the results. 

Gold electrode surface modification and 

electrochemical synthesis of Polypyrrole 

Before surface modification, the bare IDE electrode was scanned 

between – 0.3 and 0.8 V in 0.1 M MgCl 2 

/10 mM Tris-HCl buffer 

(pH 7.2) until a reproducible cyclic voltammogram (CV) was obtained. 

Electropolymerization of PPy was performed at a constant 

potential of 1 V for 20 s. The IDE electrode was immersed into 

a 3 ml solution of 0.1 M pyrrole containing the doping electrolyte 

0.1 M MgCl 2 

. The IDE coated with PPy film was then washed with 

distilled water and dried at room temperature. The prepared PPy 

coated electrode was analyzed by impedance measurements. All 

impedance measurements were performed in an analysis buffer 

consisting of 0.1 M MgCl 2 

and 10 mM Tris-HCl buffer, with a pH of 

7.2. An AC amplitude of 10 mV was used and the data were collected 

in the frequency range 10 Hz – 10 kHz. Impedance versus 

frequency was measured and recorded. 

Immobilization of capture DNA 

The immobilization solution consists of 20 mM MgCl 2 

in10 mM 

Tris–HCl buffer (pH 7.2) with 100 pM probe DNA. The probe DNA 

was immobilized onto the PPy coated electrode by electrochemical 

adsorption at 0.5 V for 600 s. The ss-DNA immobilized surface 

was washed with distilled water to remove unadsorbed DNA and 

dried at room temperature. Impedance analysis was then undertaken 

on the PPy/ss-DNA film. 

Hybridization of the target DNA 

100 pM of the ss- target probe was electrostatically adsorbed as 

stated above onto the ss-capture probe immobilized PPy film. The 

hybridized Au/PPy/DNA film was washed with distilled water to 

remove unadsorbed DNA, dried at room temperature and impedance 

measurements were taken. 

Results and Discussion 

Modification of gold IDE 

To detect target DNA, it is important that biorecognition element 

(ss-probe DNA) is well integrated with the signal transducer. Integration 

is most commonly achieved by immobilizing ss-DNA on 

the electrode surface. Here, conducting polymer polypyrrole was 

used as an immobilization matrix because of its biocompatibility 

and the ease of immobilization. Electrical conduction in PPY is 

the result of electron movement within delocalized orbitals and 

positive charge defects known as polarons [17]. These positive 

charges are located every three to four pyrrole units along the 

polymer backbone and negatively charged dopants are deposited 

at the locations. Since DNA can form a strong bond with PPy, 

based on the interchanging of dopant DNA molecules [18], PPy 

has received greater attention for application of DNA biosensors. 

Here, one pole of the Gold IDE was modified by PPy film from the 

one-step electropolymerization of pyrrole monomer in 20 s and its 

thickness can be controlled by varying the polymerization time. 

Immobilization and hybridization of DNA 

In this study, 100 pM (0.2 µg/ml) of the probe DNA sequence specific 

to B.cereus was immobilized onto the PPy coated electrode 

through electrochemical adsorption at a potential of 0.5 V for 600 

s. Electrochemical adsorption has several advantages over physical 

adsorption or physisorption. In electrochemical adsorption 

forces of attraction are due to chemical bond whereas in physisorption 

forces of attraction are due van der Waals’ forces. Unlike 

12 

Fig. 2. Frequency versus Impedance plot of (a) the PPy film, (b) PPy/ 

ss-DNA capture immobilized surface, (c) After the hybridization with 

complementary target DNA 

Rys. 2. Impedancja w funkcji częstotliwości (a) warstewka PPy, (b) 

PP/ss-DNA zajmuje immobilizującą powierzchnię (c) po hybrydyzacji 

z komplementarnym DNA 

physisorption, electrochemisorption is difficult to reverse and it is 

highly specific. However, the elementary step in an electrochemical 

adsorption requires an activation energy. To immobilize the 

probe DNA a potential of 0.5 V was applied to activate the electrochemical 

adsorption process. 

In PPy, due to the delocalized electronic structure, the positively 

charged defect structures are mobile along the chain axis. This 

mobility allows for more flexibility towards the binding of DNA’s 

fixed negative charge sites. Therefore, PPy provides a unique 

surface for DNA immobilization. The use of PPy allows label-free 

immobilization without modifying the probes and no additional reagents 

are required. The same amount of target complementary 

DNA was electrostatically adsorbed onto the ss-DNA immobilized 

electrode as stated above. The electrochemical transduction mechanism 

is based on impedance measurements (without the use 

of redox active species). The frequency versus impedance plots 

for PPy modified electrode, immobilized DNA and hybridized DNA 

are shown in Fig. 2. 

When the probe DNA is immobilized onto the PPy modified 

electrode surface, they form a layer that hinders the electron 

transfer and an increase in impedance is expected. If the target 

DNA attaches to the immobilized probe DNA it forms DNA duplexes 

which will create a further barrier to the electron transfer 

to and from the modified electrode surface and hence the impedance 

increases. From Fig. 2, the impedance measured at 5 kHz 

prior to immobilization (Au/PPy) was 92.47 Ω and after immobilizing 

the ss probe DNA 92.4% (177.9 Ω) increase in impedance 

was observed. The total change in impedance after hybridization 

was 177% (256.2 Ω). The results show that the increase in impedance 

is due to presence of the probe DNA at the PPY surface, 

which blocks the passage of chloride ions at the PPy/solution interface 

and further addition of negative charge to the IDE surface, 

in the form of complementary oligonucleotide, further blocks the 

chloride ion exchange which yields an increase in impedance after 

hybridization. 

To validate the performance of the designed IDE sensor, with 

respect to its detection limit and sensitivity it was compared to the 

conventional gold disc electrode using the same procedures. The 

gold disc electrode was modified by PPy and 0.5 µg/ml of DNA 

was immobilized and the same amount was used for hybridization 

where as in IDE only 0.2 µg/ml of DNA was used. In both cases 

impedance measurements are carried without any redox probes. 

The results obtained using IDE are comparable to those obtained 

by the disc electrodes and are shown in Fig. 3. 

Table 2 shows the comparison between IDE and the disc electrode 

at frequencies of 100 Hz and 5 kHz. Comparing Fig. 3a and 

3b, at 5 kHz the change in impedance after hybridization was 

177% using IDE and 34.64% was observed using disc electrode. 


a) 

thick-film technology is simple, sensitive, rapid and cost effective. 

The electrical detection of 100 pM concentration of DNA immobilized 

onto the PPy modified gold IDE was achieved, with an IDE width of 

400 µm. Using IDE samples of few µl to pl can be analyzed thereby, 

avoiding the typical three electrode electrochemical cell. Also, it has 

led to the use of two-electrode control circuits, rather than the conventional 

three-electrode setup and the planar IDE can be directly 

interfaced with front-end electronics circuit, which in turn will lead to 

the development of handheld system for real time monitoring and 

detection of microbial pathogens and bio-warfare agents. 

Further research is directed to the development of a handheld 

sensor system to detect the DNA of the pathogenic micro-organisms 

in a real-time environment directly from food and water. 

b) 

Fig. 3. (a) Shows the experimental results using LabView software 

obtained from using IDE and (b) shows the data obtained with the 

typical disc gold electrodes (2 mm diameter) using commercial electrochemical 

workstation 

Rys. 3. (a) prezentuje wyniki eksperymentalne uzyskane z zastosowaniem 

IDE i oprogramowania LabView i (b) pokazuje dane uzyskane 

za pomocą typowej okrągłej złotej elektrody (o średnicy 2 mm) z zastosowaniem 

komercyjnego stanowiska roboczego 

Tabl. 2. Comparison between IDE and disc electrode 

Tab. 2. Porównanie pomiędzy IDE i elektrodą dyskową 

IDE 

Disc electrode 

Frequency Impedance (Ω) 

Change in Impedance (Ω) Change in 

impedance 

impedance 

Au/PPy Au/PPy/DNA (%) Au/PPy Au/PPy/DNA (%) 

100 Hz 116.75 810.4 594.13 152.4 276.9 81.69 

5 kHz 92.47 256.2 177.06 127.6 171.8 34.64 

Moreover, the amount of DNA used for IDE was 0.2 µg/ml whereas 

0.5 µg/ml of DNA is used for disc electrode. 

The IDE yields better sensitivity since it has the ability to monitor 

the change of the electrical properties in the immediate vicinity 

of its surface and they are more sensitive to the rate of change of 

electron transfer. There is an option to polymerize either one or 

both poles of the IDE. 

In this study, only one pole of the IDE was modified with PPy 

and used for immobilizing DNA. They can be mass produced in 

array format for the simultaneous detection of multiple pathogens. 

Conclusion 

The combination of polypyrrole modified interdigitated microelectrodes 

with impedance measurements offers a sensitive label-free 

biosensor capable of DNA detection. The use of the conducting polymer, 

polypyrrole and impedance measurements are advantageous, 

since label-free unmodified DNA can be detected in aqueous 

solutions that are compatible to the DNA’s natural conditions. 

Impedance experiments were carried out directly without any 

redox probe and the results are reproducible. The IDE prepared by 

This project is funded by Science Foundation Ireland (SFI) Research 

Frontiers Programme, ID no: 07RPF-ENEF500. 

References 

[1] Kay D., J. Crowther, L. Fewtrell, C.A. Francis, M. Hopkins, C. Kay, 

A.T. McDonald, C.M. Stapleton, J. Watkins, J. Wilkinson, and M.D. 

Wyer:: Quantification and control of microbial pollution from agriculture: 

a new policy challenge. Environmental Science & Policy, vol. 

11, Apr 2008, pp. 171–184. 

[2] Umali-Deininger D., M. Sur: Food safety in a globalizing world: opportunities 

and challenges for India. Agricultural Economics, vol. 37, 

Dec 2007, pp. 135–147. 

[3] Mucchetti G., B. Bonvini, S. Francolino, E. Neviani, and D. Carminati: 

Effect of washing with a high pressure water spray on removal of 

Listeria innocua from Gorgonzola cheese rind. Food Control, vol. 19, 

May 2008, pp. 521–525. 

[4] Jin S.S., J. Zhou, and J. Ye: Adoption of HACCP system in the Chinese 

food industry: A comparative analysis. Food Control, vol. 19, 

Aug 2008, pp. 823–828. 

[5] Taylor E.: A new method of HACCP for the catering and food service 

industry. Food Control, vol. 19, Feb 2007, pp. 126–134. 

[6] Piatek D.R. D.L.J. Ramaen: Method for controlling the freshness of 

food products liable to pass an expiry date, uses a barcode reader 

device that reads in a conservation code when a product is opened 

and determines a new expiry date which is displayed. PIATEK D R 

(PIAT-Individual) RAMAEN D L J (RAMA-Individual), 2001. 

[7] Huang Q., H.Y. Liu, and B. Fang: Development of Electrochemical 

DNA Biosensors. Progress in Chemistry, vol. 21, May 2009, pp. 

1052–1059. 

[8] Wei D., M.J.A. Bailey, P. Andrew, and T. Ryhaenen: Electrochemical 

biosensors at the nanoscale. Lab on a Chip, vol. 9, 2009, 

pp. 2123–2131. 

[9] Pedrero M., S. Campuzano, and J.M. 

Pingarron: Electroanalytical Sensors 

and Devices for Multiplexed Detection 

of Foodborne Pathogen Microorganisms. 

Sensors, vol. 9, Jul 2009, 

pp. 5503–5520. 

[10] Velusamy V., K. Arshak, O. Korostynska, 

K. Oliwa, and C. Adley: An overview 

of foodborne pathogen detection: 

In the perspective of biosensors. 

Biotechnology Advances, vol. 28, 

2010, pp. 232–254. 

[11] Velusamy V., K. Arshak, O. Korostynska, K. Oliwa, and C. Adley: Design 

of a real time biorecognition system to detect foodborne pathogens-DNA 

Biosensor. in 4th IEEE Sensors Applications Symposium, 

New Orleans, LA, USA, 2009, pp. 38–42. 

[12] Heo J. and S.Z. Hua: An Overview of Recent Strategies in Pathogen 

Sensing. Sensors, vol. 9, Jun 2009, pp. 4483–4502. 

[13] Melton S. J., H. N. Yu, K.H. Williams, SA Morris, P.E. Long, and D.A. 

Blake: Field-based detection and monitoring of uranium in contaminated 

groundwater using two immunosensors. Environmental Science 

& Technology, vol. 43, 2009, pp. 6703–6709. 

[14] Jayanta C., B. Malay, and B. Debadin: Anthrax and bio-terrorism. Biomedical 

& Pharmacology Journal, vol. 1, 2008, pp. 315–324. 

[15] Aubeck R., C. Eppelsheim, C. Brauchle, and N. Hampp: Potentiometric 

thick-film sensor for the determination of the tumor-marker bound 

sialic-acid. Analyst, vol. 118, Nov 1993, pp. 1389–1392. 

[16] Adley C., K. Arshak, C. Molnar, K. Oliwa, and V. Velusamy: Design of 

specific DNA primers to detect the Bacillus cereus group species. in 

4th IEEE Sensors Applications Symposium, New Orleans, LA, USA, 

2009, pp. 206–209. 

[17] Devreux F., F. Genoud, M. Nechtschein, and B. Villeret: Electronspin-resonance 

investigation of polarons and bipolarons in conducting 

polymers - the case of polypyrrole. Synthetic Metals, vol. 18, Feb 

1987, pp. 89–94. 

[18] Rodriguez M.I. and E.C. Alocilja: Embedded DNA-polypyrrole biosensor 

for rapid detection of Escherichia coli. IEEE Sensors Journal, 

vol. 5, Feb 1987, pp. 733–736. 


Impact of non-optimal grounding of the CC2420 RFIC 

on a 802.15.4 Tyndall sensor wireless mote 

(Wpływ nieoptymalnego uziemienia układu CC2420 zgodnego 

ze standardem IEEE 802.15.4 na pracę systemu Tyndall Mote) 

Peter Haigh 2) , MSc John Buckley 1) , MSc Brendan O’Flynn 1) , PhD. Cían Ó’Mathúna 1) 

1) 

Clarity Centre for Sensor Web Technology 

2) 

Tyndall National Institute, University College Cork Lee Maltings, Dyke Parade, Cork, Ireland 

Range, throughput and power consumption are important issues 

in 802.15.4 [1] Wireless Sensor Networks. While the focus is 

often on increased power output (at the expense of dc power) 

and sensitivity to address these issues, little attention is given 

to waveform quality. Poor waveform quality often measured in 

terms of EVM can lead to increased packet errors, transmission 

retries and therefore reduced range and throughput leading to 

increased power consumption. One important factor in relation to 

this is proper grounding of the RF devices. This paper describes 

an investigation into these effects that was triggered when poor 

throughput was reported from the system integrators. 

Measurement Technique 

As the modulated signal passes through a non-linear function it 

becomes distorted. This distortion leads to a degradation in the 

signal quality and ultimately affects the throughput of the system 

due to an increase in Bit Error Rate (BER) leads to re-transmissions. 

The relationship between linearity, Adjacent Channel Power 

Ratio (ACPR) and EVM is well established [2, 3]. Of particular 

interest in this study was the effect of non-optimal grounding of 

the radio transceiver on output spectrum and EVM. Test methods 

were devised to measure these parameters based on the existing 

802.15.4 standard. 

Adjacent Channel Power Ratio 

The incumbent radio standard defines some parameters for signal 

quality and ACPR. These are defined to ensure that the wireless 

system will perform to specification taking into account regulatory 

as well as inter and intra system issues. For ACPR it was found 

that the definition in 802.15.4 was not sensitive enough for this 

investigation. Therefore, a new measurement was defined to enable 

the analysis of more detailed linearity effects. 

A typical 802.15.4 spectra such as in Fig. 1, exhibits well defined 

troughs that are defined by the channel filter characteristic. 

From experimentation, it was shown that the spectral degradation 

of these troughs is very sensitive to non-linearity as shown in Fig. 

2. Two ACPR points at the first and second trough were established 

leading to the settings summarised in Table 1 below. 

Tab. 1. ACPR spectrum analyser settings 

Tab. 1. Ustawienia analizatora widma przy pomiarze ACPR 

14 

Description 

Tx Channel 

Integration Bandwidth 

ACPR 1 


Spacing 

ACPR 2 


Spacing 

Resolution Bandwidth 

Video Bandwidth 

Parameter 

2 MHz 

100 kHz 

1.5 MHz 

100 kHz 

2.5 MHz 

30 kHz 

300 kHz 

Ref -10 dBm 

-20 

UNCAL 

-30 

-40 

1 RM * 

CLRWR -50 

-60 

-70 

-80 

-90 

-100 

Att 

5 dB 

* RBW 30 kHz 

* VBW 300 kHz 

* SWT 100 ms 

Center 2.469955 GHz 1 MHz/ 

Span 10 MHz 

Fig. 1. Typical 802.15.4 spectrum 

Rys. 1. Typowe spektrum standardu IEEE 802.15.4 

Ref -10 dBm 

-20 

UNCAL -30 

-40 

1 RM * 

CLRWR -50 

-60 

-70 

-80 

-90 

-100 

Att 5 dB 

* RBW 30 kHz 

* VBW 300 kHz 

* SWT 100 ms 

Center 2.44 GHz 1 MHz/ 

Span 10 MHz 

Fig. 2. Typical 802.15.4 distorted spectrum 

Rys. 2. Typowe zniekształcenie spektrum standardu IEEE 802.15.4 

Figures 1 and 2 below, show examples of good and bad 

802.15.4 spectra that were measured on a spectrum analyser. 

Figure 1 shows an 802.15.4 signal with good linearity typified by 

the well defined troughs in the spectral shape.. 

Figure 2 shows a plot of an 802.15.4 signal that has been subjected 

to non-linear distortion. It is clear that the spectrum has 

spread out and the troughs have been filled due to spectral regrowth. 

Measuring the spectrum in these troughs yields a highly 

sensitive measurement with respect to linearity. 

Error Vector Magnitude Measurement 

The EVM measurement was conducted as defined in the 802.15.4 

standard using a half sine measurement filter. EVM can be used 

as a measure of SNR, BER and packet loss as it is a measurement 

of the deviation of the baseband vector from the ideal constellation 

location. The instantaneous error vector is a function of 

all noise sources (deterministic and random) and if averaged over 

time, the noise power and thus SNR can be calculated therefore 

establishing a correlation with EVM. By applying some analysis, it 

is also possible to distinguish between random and deterministic 

noise sources [6]. National Instruments published a graph which 

is reproduced in Fig. 3 below for 802.15.4 and demonstrates the 

effect of EVM on BER. [3]. 


A 

3DB 

A 

SGL 

3DB

Fig. 5. Device characterization at 2.47 GHz 

Rys. 5. Charakterystyka elementu na częstotliwości 2.47 GHz 

Fig. 3. EVM verse’s BER for 802.15.4 

Rys. 3. EVM w funkcji BER dla standardu IEEE 802.15.4 

EVM is a function of a number of noise sources, both random 

and deterministic. Assuming that the radio design has taken 

these into account, at high output powers non-linear distortion 

can dominate. Even though 802.15.4 selected a modulation and 

pulse shaping filter to yield a constant envelope, poor waveform 

quality and ACP degradation can be seen if the transfer function 

through the transmitter is non-linear. 

Device Characterisation 

To investigate the reported throughput issues a representative 

sample of Tyndall Motes [5] were tested. Figures 4 and 5 below, 

summarises a subsection of these results at 2.44 GHz and 2.47 

GHz respectively. 

EVM 

Six out of ten devices measured an EVM of greater than 20%. 

Simple link budget tests on these motes confirmed that for a given 

RSSI value the number of received good packet interrupts at the 

CC2420 was considerably less for the high EVM motes compared 

to the low EVM motes. It was also observed that the difference in 

performance between the high and low EVM motes was considerably 

less at 2.47 GHz compared to 2.44 GHz. This is in agreement 

with the EVM measured values in the figures below. 

Closer inspection of the measurements above shows that 

there is a correlation between EVM, output power and ACPR. As 

the ACPR is degrading with EVM, this is an indication that the 

degradation in EVM was due to a linearity issue rather than a random 

noise source. Further experiments were conducted to test 

this theory. Figure 6 below plots the output power back off against 

EVM. One can see that the EVM improves considerably once 

the power is backed off relative to the maximum output power. 

This was presented as further indication that the root cause of the 

problem was linearity rather than noise. If the ACP was dominated 

Fig. 6. EVM v Power Back-Off 

Rys. 6. EVM w funkcji Power Back-Off 

by noise (e.g thermal or phase) there would not be such an improvement 

at back off. 

Note that at the lowest power levels, below approximately -20 

dBm, the EVM gracefully degrades. This is due to the noise floor 

of the device beginning to dominate the EVM. 

Having established a correlation with linearity, the next step 

was to establish the source. There are a number of possibilities 

that all tend to be associated with the output matching and balun 

circuitry. The investigation focused on the output matching and 

balun as this is the only part of the design external to the RFIC 

that could influence the linearity. 

S11 (Output Return Loss) 

To determine whether the device is seeing the correct load impedances, 

a simple S11 measurement was taken using a vector 

network analyser and a 1 port calibration. Figure 7 below shows 

a typical plot of a high EVM mote (Mote 35) against a low EVM 

mote (Mote 30). To simplify the measurement, the RFIC is switched 

Fig. 4. Device characterization at 2.44 GHz 

Rys. 4. Charakterystyka elementu na częstotliwości 2.44 GHz 

Fig. 7. S11 for motes 30 and 35 

Rys. 7. S11 dla mote 30 i 35 


to receive mode. As the matching circuit and balun is common to 

both modes, it was concluded that this would give an indication 

of a correlation of matching impedance between the two types 

of motes. It is observed that the return loss is lower for the high 

EVM mote and that the return loss is better at higher frequencies 

due to the tuning being centered high in frequency. From these 

results it was ascertained that all the high EVM motes were tuned 

to a higher frequency compared with low EVM Motes. 

Even though this is a measure of Rx S11, this may indicate 

the path to ground is different between each mote type and that 

the impedance difference must be somewhere common to both 

Tx and Rx possibly the connection from the transceiver ground 

puck to the PCB. 

Measurement Summary 

Table 2 below summarises the correlation between the measurements 

at 2.44 GHz. The values presented are the average of 

the 6 Low throughput motes and the average of the 4 expected 

throughput motes. Note how the output power alone does not reveal 

the throughput issue. 

Tab. 2. Measurement overview 

Tab. 2. Wyniki pomiarów 

16 

Description Good Mote Poor Mote 

Throughput Expected Low 

EVM 3% 43% 

ACP1 -33dBc -28dBc 

ACP2 -48dBc -43dBc 

Tuning Centre 2.54 GHz 2.58 GHz 

Output Power 0dBm ± 3dB 0dBm ± 3dB 

The test results show correlation between EVM, ACP, high 

tuning centering and power back off with poor throughput. This 

combination seems to indicate a linearity, that, given the constant 

envelope nature of the waveform was rather surprising. 

The CC2420 [7] is highly integrated and the only external components 

that affect the RF are the matching and balun circuit. After confirming 

that the matching and balun circuit was identical between the 

high and low throughput motes it was concluded that the only other 

possible variable was the grounding of the RFIC to the PCB ground. 

Grounding 

A number of high and low EVM parts were removed from the PCB 

and an example of each type is shown in Figures 8 and 9 below. 

Fig. 8. Low EVM PCB and RFIC. Rys. 8. PCB i RFIC z niskim EVM 

Fig. 9. High EVM PCB and RFIC. Rys. 9. PCB i RFIC z wysokim EVM 

From Figure 8 above although the solder connection is not 

perfect it has good solder wetting over 70% of its surface area. 

Also noteworthy was that it took over 5 minutes to remove the part 

from the board, using a fine nozzle heat gun. 

This part in Figure 9 above clearly had a very poor ground connection. 

It also only took a few seconds to remove from the PCB. 

Neither the ground puck on the IC or the ground plane on the PCB 

exhibited a shiny solder finish normally associated with a good joint. 

In this case only part of the PCB surface had solder coverage. The 

solder joint was dry in the portion of the ground area it did cover. 

This would mean that the device connection to ground would differ 

significantly from its model used in design. Thus we see a shift in 

frequency of the S11 response from optimum and poor linearity. 

Conclusion 

It has been demonstrated that measurement of output power 

alone may not be enough to determine whether the RF design 

is performing to specification. It is possible to get both expected 

output power and degraded performance at the same time. 

It was found that the existing ACPR measurement definition 

defined in 802.15.4 was not sensitive enough to detect changes 

in linearity. So a new ACPR measurement was defined that was 

more sensitive to linearity degradation. 

It is proposed that the quality of the grounding of the CC2420 

to the ground pad on the PCB has significant impact on the performance. 

Although the data seems to indicate that this relates to 

linearity there are two parameters that contradict this view. 

i. 802.15.4 uses a constant envelope modulation scheme that is 

designed to be very robust to non-linear transfer functions. 

ii. There is a clear correlation between the tuning centering and 

a high and low throughput mote, EVM and ACP. It should be 

noted that the return loss is measured in receive mode and so 

is only indicative of an impedance shift in Tx mode. Currently 

it is only assumed that in Tx mode the change in impedance is 

large enough to cause such a degradation. 

It is also shown that monitoring of output power alone may 

not reveal grounding issues with the RFIC and that the EVM can 

be as poor 50% in these circumstance thus degrading BER and 

throughput. Evaluation of the linearity and waveform quality parameters 

should be undertaken to ensure the integrity of the build. 

Further analysis and measurements are required to confirm the 

hypothesis presented in this paper. 

The authors would like to acknowledge the support of Enterprise 

Ireland, the EU commission through the ME3GAS project. The 

authors would also like to acknowledge the support by Science 

Foundation Ireland under grant 07/CE/I1147. 

References 

[1] IEE Std 802.15.4, IEEE Standard for Information Technology – Telecommunication 

and information exchange between systems – Local 

and metropolitan networks – Specific requirements, Part 15.4 

Wireless Medium Acces Control (MAC) and Physical control Layer 

(PHY) Specifications for Low-Rate Wireless Personal Area Networks 

(WPANS) 

[2] Rishad Ahmed Shafik., Md. Shahriar Rahman.: AHM Razibal Islam., 

On the Extended Relationships Among EVM, BER and SNR as 

Performance Metrics, 4 th International Conference on Electrical and 

Computer Engineering, IECE 2006, 2006, pp. 408–411. 

[3] National Instruments., The Basics of Zigbee Transmitter Testing, National 

Instruments White Paper, 2006, pp. 1–17. 

[4] TAN Xiao-heng., LI Teng-jiao., EVM simulation and analysis in digital 

transmitter, The Journal of China Universities of Posts and Telecommunications, 

issue 6, Dec 2009, pp. 43–48. 

[5] O’Flynn B., Lynch A., Aherne K., Angove P., Barton J., Harte S., 

O’Mathuna C., Diamond D., Regan F.: The Tyndall Mote. Enabling 

Wireless Research and Practical Sensor Application Development, 

SourceAdvances in Pervasive Computing 2006 Adjunct Proceedings 

of Pervasive, Vol. 207, 2006, pp. 21–26. 

[6] Hassan R., Flaherty M., Matreci R., Taylor M.: Effective Evaluation 

of Link Quality Using Error Vector Magnitude Techniques, Proc IEEE 

Wireless Communications Conference, 1997, pp. 89–94. 

[7] CC2420 Data sheet. http://focus.ti.com/docs/prod/folders/print/ 

cc2420.html 


Numerical study of the interface heat transfer 

characteristics of micro-cooler with CNT structures 

(Analiza numeryczna transferu ciepła przez interfejs mikro-radiatora 

ze strukturami CNT) 

Ph.D Yan Zhang 1) , M.Sc. Shun Wang 1) , Ph.D Shiwei Ma 1) , M.Sc. Zhili Hu 1) , 

Ph.D Johan Liu 1, 2) , Ph.D Janusz Sitek 3) , M.Sc.Eng. Kamil Janeczek 3) 

1) 

Key Laboratory of Advanced Display and System Applications, Ministry of Education & SMIT Center, School 

of Mechatronics Engineering and Automation, Shanghai University, China 

2) 

SMIT Center & Bionano Systems Laboratory, Department of Microtechnology and Nanoscience, Chalmers University 

of Technology, Gothenburg, Sweden, 3) Tele and Radio Research Institute, Warsaw 

With the continuously increasing packaging density in electronic 

products, the system ability to dissipate heat loads has become 

a concern in the overall performance. Some novel cooling techniques 

have emerged to meet the thermal management requirements 

of high power microelectronics components and devices. 

Micro cooling, including micro-pin-fin, micro-channel and so on, 

provides a promising solution for high-powered electronics. 

Meanwhile, carbon nanotubes (CNTs) have shown advantages 

in material properties such as the electrical conductivity [1], 

[2], the thermal conductivity [3], [4] and the mechanical properties 

[5], [6]. CNTs can be used as the micro-cooler construction due to 

the excellent thermal conductivity [7]. A micro-channel cooler with 

vertically aligned CNT arrays had been developed [8], [9], where 

the CNT structures were employed as channels inside to enhance 

the heat transfer. And experimental measurement had also been 

carried out to evaluate the overall heat removal capability of the 

CNT-based micro-cooler. Beside experimental works, the macroscopic 

heat transfer characteristics of the micro-channel heat 

sinks with carbon nanotubes were also studied numerically [10], 

[11], in which parameters such as the inlet velocity, the heating 

power, the CNT structure size as well as the flow field and the 

temperature distribution were analyzed. 

The most widely used fabrication method to obtain aligned 

CNTs is the thermal or plasma-enhanced chemical vapour deposition 

(CVD). During the process, the carrier substrate typically 

needs to be heated up to approximately 700°C or even higher. 

Such a high temperature is not compatible with most of the temperature-sensitive 

components or devices. A transfer method was 

proposed as a solution to this problem, in which the pre-prepared 

CNT forest could be transferred onto the target surface at a low 

temperature so that the integration of the CNTs into various device 

and material processes became feasible [12]. The adhesives 

with designed pattern have shown successful transfer. 

For a CNT-based micro-cooler with liquid coolant, there appear 

various interfaces, such as the one between the CNT and the 

coolant or the adhesive. The interfacial resistance was expected 

to be more important in the nano-composites than in the traditional 

composites since the interfacial density was higher [13]. In the 

present paper, numerical investigations on the thermal resistance 

across interfaces between the CNT and its surrounding materials 

involved in micro-cooler are carried out by molecular dynamics 

simulation (MDS), and various cases are studied. 

MDS model 

The interface thermal resistance values of carbon nanotubes 

embedded in various materials was found to range from 

0.76 × 10 -8 to 20.0 × 10 -8 m 2 K/W [14]. As for the micro-cooler 

with CNT structures inside, there exist interfaces between CNT 

and other materials. In the MDS, a (5,5) armchair single-walled 

carbon nanotube (SWCNT) is used, and matrices of different 

materials are then constructed to embed the CNT inside. Heat 

flux is prescribed to the system and temperature field can be 

obtained. 

According to the simulated temperature field, there appears an 

obvious temperature gradient in the interface region. This indicates 

that the dominating thermal resistance is associated with the conduction 

in the interface area. As shown in Fig. 1, the involved atoms 

belonging to the CNT and the material adjacent to the nanotube 

surface are marked with green and red spheres, respectively. 

Fig. 1. Sketch of the atom 

selection in calculation 

Rys. 1. Szkic atomów wybranych 

do obliczeń 

The thermal resistance R th 

due to the interface can be calculated 

by the temperature gradient at the interface with expression as: 

R ∆ 

T 

= 

th Q 

/ 

A 

where T is the temperature drop across the interface, Q/A is heat 

flux in which Q is the heat power and A is the interfacial area. 

Simulation results and analysis 

As for the micro-cooler with CNT structures, the thermal resistances 

at interface between CNT and other materials are taken into 

consideration. 

CNT-water interface 

Water was adopted as the cooling medium in the micro-channel 

cooler [8], [9], as described in previous experiment, so the interface 

heat transfer of the CNT-water case is studied firstly in the 

present work. Fig. 2 shows the structure adopted in MDS. 

Fig. 2. CNT-water structure in MDS 

Rys. 2. Struktura CNT-woda w MDS 


Non-equilibrium molecular dynamics (NEMD) method is used 

and the adaptive intermolecular reactive empirical bond order 

(AIREBO) potential energy function is applied for the CNT in the 

constructed model. 

The thermal resistance of the CNT-water interface calculated 

to is about 14.69 × 10 -8 Km 2 /W. The value is closed to the one 

obtained in ref. [15], where the thermal boundary resistance of 

SWCNT-water is estimated to be 12.2 × 10 -8 Km 2 /W. 

CNT-epoxy interface 

As for the micro-cooler with CNT structures by transfer technique, 

the carbon nanotubes were mounted onto the target surface by 

means of adhesive. In addition to be exempted from high temperature, 

the component/device can also obtain an improved joint 

strength of CNTs and the cooler substrate. The thermal characteristics 

of the CNT-adhesive interface introduced by the transfer 

are studied. 

The epoxy used in the present work is DGEBA (diglycidyl 

ether of bisphenol-A), as shown in Fig. 3a. Before the simulation 

of thermal resistance at the interface between CNT and the epoxy 

matrix, the thermal conductivity of the epoxy itself is calculated. 

The epoxy matrix is constructed, and the non-equilibrium molecular 

dynamics (NEMD) method is adopted. A heat-injection 

method is used, where a constant heat rate is added to one end 

of the computation area and removed at the other end. Periodic 

boundary condition is used in the simulation. After the system 

reaches a steady state, the temperature gradient is obtained and 

the thermal conductivity can be calculated. The thermal conductivity 

of the epoxy matrix is about 0.170 W/mK, and this value is 

applied in the following CNT-epoxy simulation. 

Then the epoxy matrix with a CNT embedded is constructed. 

Two steps are adopted: Firstly, the epoxy matrix is constructed 

with a volume 40 × 40 × 28Å 3 ; Secondly, the CNT with a length of 

28Å was immersed into the center of the epoxy matrix. The obtained 

the CNT-epoxy structure in MDS is shown in Fig. 3b. 

The thermal resistance of the CNT-epoxy interface is calculated 

at 300K, and the obtained values are 1.0–1.5 × 10 -8 Km 2 /W. 

The values shows quite good agreement with the value 

2.6 ± 0.9 × 10 −8 Km 2 /W obtained by Bryning [5]. 

Furthermore, the polymer network is considered. As shown in 

Fig. 4, for example, DGEBA can form a network when reacts with 

MDA (Methylene Diamine Dianilene). Cross-links are generated 

during the molecule reactions so that the polymer networks come 

into being. 

As the polymer is a network structure, it is difficult to ‘insert’ 

a carbon nanotube into the polymer. So the surface of the CNT 

is treated as plane-shaped instead of a tube. Namely a piece of 

graphene was used instead of a carbon nanotube in the simulation. 

This is reasonable as a carbon nanotube can be regarded as 

rolling up a graphene sheet. 

The system is kept at a constant atoms number, pressure and 

temperature. In order to decrease the gap between the carbon 

nanotube/graphene and the polymer, a higher pressure is used. 

In order to get a reasonable distance between the polymer and 

the graphene, the pressure in the x- and y- direction are couple 

together, while at the z – direction it is set to be independent. 

The size of the computational cell was stable at 19.98Å × 

18.46Å × 62.1Å. The bottom area of the simulation cell equals to 

that of the grapheme. The distance between the polymer and the 

graphene is about 2.1Å. The period boundary condition is applied 

to this system. 

The thermal resistance at the interface between the carbon nanotube 

and the polymer was calculated, and the value is 33.262 

× 10 -8 m 2 K/W. This interface resistance is quite high compared 

with the one of CNT-epoxy, and reason might be that the space 

between the polymer network and the graphene is overcalculated 

or the conductance between them is underestimated. 

a) The network structure of the polymer 

Fig. 3. CNT-Epoxy structure in MDS 

Rys. 3. Struktura CNT-klej epoksydowy w MDS 

In the molecular dynamics simulation of the heat transfer 

across the CNT-epoxy interface, the computational domain 

is constructed as a rectangular cell. The periodic boundary condition 

is applied over the cell of the CNT-epoxy structure in MDS 

so that the simulation results are usable for the adhesive layer 

involving CNT bundles. 

The simulation is then carried out under the condition of a canonica 

ensemble (NVT), while constant valence force field (CVFF) 

is applied to evaluate the inter-atomic potentials. When the temperature 

is stable at 165K, the simulation is performed under a microcanonical 

ensemble (NVE). By means of the Bredensen thermostat, 

the system is stabilized at ambient temperature of 300K. 

18 

b) Geometry of CNT and polymer matrix 

Fig. 4. CNT-polymer structure in MDS 

Rys. 4. Struktura CNT-polimer w MDS 


Conclusions 

For the CNT-based micro-cooler, the heat transfer between the 

CNT and its surrounding material is essential for the effective heat 

dissipation as the interface presents a barrier to the heat flow 

and will affect the thermal dissipation from the powered chip or 

devices to the cooler. Therefore, the interface characteristics are 

studied in the present paper. 

Molecular dynamics simulations have been carried out to obtain 

the thermal resistance across the interfaces of CNT-coolant 

and CNT-adhesive. And cases including the CNT in the water, the 

CNT in the epoxy matrix, as well as the CNT-polymer network one 

between the CNT and the adhesive are simulated. The obtained 

results of interface heat transfer can provide information for evaluating 

the thermal performance of the CNT-based micro-cooler. 

This work was supported by the National Natural Science Foundation 

of China (10702037). Support by China-Poland Scientific 

and Technology Cooperation Committed (No. 34–11) and Innovation 

Program of Shanghai Municipal Education Commission 

(12YZ006) were also appreciated. 

References 

[1] Foygel M., Morris R. D., Anez D., French S., Sobolev V. L.: Theoretical 

and Computational Studies of Carbon Nanotube Composites and 

Suspensions: Electrical and Thermal Conductivity”, Physical Review 

B, Vol. 71, No.10, pp. 104201, 2005. 

[2] Martin C. A., Sandler J. K. W., Shaffer M. S. P., Schwarz M. K., 

Hauhofer Q., Schulte K., Windle A. H., „Formation of Percolating Networks 

in Multi-Wall Carbon-Nanotube-Epoxy Composites”, Composites 

Science and Technology, Vol. 64, pp. 2309–2316, 2004. 

[3] Duong H. M., Papavassiliou D. V., Lee L. L., Mullen K. J., „Random 

Walks in Nanotube Composites: Improved Algorithms and the Role 

of Thermal Boundary Resistance”, Applied Physics Letters, Vol. 87, 

pp. 013101, 2005. 

[4] Bryning M. B., Mikie D. E., Islam M. F., Kikkawa J. M., Yodh A. G., 

„Thermal conductivity and interfacial resistance in single-wall carbon 

nanotube epoxy composites”, Applied Physics Letters, Vol. 87, 2005, 

pp. 161909. 

[5] Lau K. T., „Interfacial bonding characteristics of nanotube/polymer 

composites”, Chemical Physics Letters, Vol. 370, pp. 399–405, 

2003. 

[6] Zhu R., Pan E., Roy A. K., „Molecular Dynamics Study of the Stressstrain 

Behavior of Carbon-nanotube Reinforced Epon 862 Composites”, 

Materials Science and Engineering A, Vol. 447, 2007, 

pp. 51–57. 

[7] Xu Y., Zhang Y., Suhir E., Wang X., „Thermal Properties of Carbon 

Nanotube Array Used for Integrated Circuit Cooling”, Journal of Applied 

Physics, Vol. 100, 2006, pp. 074302. 

[8] Mo Z., Morjan R., Anderson J., Campbell E. E. B., and Liu J., „Integrated 

Nanotube Microcooler for Microelectronics Applications”, 

Proceedings of 55th Electronic Componenets and Technology Conference, 

Florida, USA, May-June 2005, pp. 51–54. 

[9] Wang T., Jonsson M., Nystrom E., Mo Z., Campbell E.B. and Liu 

J., „Development and Characterization of Microcoolers using Carbon 

Nanotubes”, Proceedings of 1st Electronics Systemintegration 

Technology Conference, Dresden, Germany, September 2006, 

pp. 881–885. 

[10] Zhong X., Fan Y., Liu J., Zhang Y., Wang T., and Cheng Z., A Study 

of CFD Simulation for On-chip Cooling with 2D CNT Micro-fin Array’’, 

Proceedings of the 2007 International Symposium on High Density 

Packaging and Microsystem Integration, Shanghai, China, June 

2007, pp. 442–447. 

[11] Wang S., Zhang Y., Fu Y., Liu J., Wang X., Cheng Z., „A Study of 

the Heat Transfer Characteristics of the Micro-Channel Heat Sink’’, 

Proceedings of 2009 International Conference on Electronic Packaging 

Technology and High Density Packaging, Beijing, China, August 

2009, pp. 255–259. 

[12] Wang T., Carlberg B., Jonsson M., Jeong G. H., Campbell E. E. B. 

and Liu J., „Low Temperature Transfer and Formation of Carbon Nanotube 

Arrays by Imprinted Conductive Adhesive’’, Applied Physics 

Letters, Vol. 91, No. 9, 2007, pp. 093123. 

[13] Shenogin S., Xue L., Ozisik R., Keblinski P., „Role of thermal boundary 

resistance on the heat flow in carbon-nanotube composite”. Journal 

of Applied Physics, Vol. 95, No. 12, 2004, pp. 8136–8144. 

[14] Unnikrishnan V. U, Banerjee. D, Reddy J. N., „Atomistic-mesoscale 

interfacial resistance based thermal analysis of carbon nanotube 

systems”. International Journal of Thermal Sciences, Vol. 47, 2008, 

pp. 1602–1609. 

[15] Maruyama S., Igarashi Y., Shibuta Y., Molecular dynamics simulations 

of heat transfer issues in carbon nanotubes, the 1 st international symposium 

on micro & nano technology, Hawaii, USA, March 14–17, 2004. 

Device for road holes and obstacles detection 

(Urządzenie do rozpoznawania dziur oraz przeszkód na drodze) 

mgr. Wojciech Gelmuda, prof. dr hab. inż. Andrzej Kos 

AGH University of Science and Technology Department of Electronics, Kraków 

Today’s life as we know it is based on visual signs. Practically all 

the important information needed to go independently through an 

average person’s day is provided by their sight. Let us focus on 

some urban environment. A person is able to see objects, determine 

their approximate distance, distinguish between a hole and 

a bump on a road, detect and recognize an important element 

from its background or simply read some text information from 

books, posters, etc. Most of these actions, if not all, allow people 

to gather information and give them time to react before they approach 

some objects. Furthermore, there are many devices that 

help people gain more important for them information than they 

would be able to learn from a closest environment in their field of 

view, such as navigation systems. There are also many devices 

that help people keep safe and avoid some accidents, like for 

instance, street lights and road signs. But neither of them is well 

suited for visually impaired people. Of course, there are special 

audio signals for blind people near some pedestrian crossings 

and there are devices which help visual impaired people avoid 

obstacles [1], but they are still not sufficient to keep them safe 

and well informed about their surrounding environment [2]. This 

is mostly due to a change of sensors positions while a blind 

person is moving. That is why we develop a MOBIAN© project 

– Mobile Safety System for the Blind [3]. This project is supported 

by The National Centre for Research and Development 

under: NR13-0065-10. A part of the MOBIAN© project is to create 

a highly reliable device for detecting obstacles and holes 

of various length and depth, as it is presented in Fig. 1. There 

is no doubt that special algorithms have to be designed, tested 

and implemented for this purpose. 

Fig. 1. Holes and other obstacle detection 

Rys. 1. Wykrywanie dziur, uskoków oraz innych przeszkód 


While working on ultrasonic both transmitters and receivers 

[4] and employing them into a hole detection device based on 

a white stick [5], tests have shown that there were some minor 

difficulties with sensors vibrations caused by a while stick movement, 

especially when the white stick touched the ground. Therefore, 

this time an infrared beam will be implemented for a hole 

detection concept. 

This paper proposes the design of the holes and obstacles detection 

device and a software environment based on MatLab for 

testing holes detection algorithms, as a faster way to the project 

development. 

Basic concept 

The design of the holes and obstacles detection device is presented 

in Fig. 2. The device is controlled by a low-power microcontroller. 

A series of ultrasound transducers is used to assure 

the high reliability in detecting obstacles in a wide range when 

a blind person is walking. A custom made multichannel ultrasonic 

range finder was developed. The holes detection is done by an 

infrared range finder. Preliminary tests have shown that variable 

sensor position while a person is moving leads to inaccurate 

measurements which causes incorrect detections. That is why 

the measurements have to be corrected with a help of data from 

accelerometer and gyroscope. This is how the infrared beam is 

being stabilized by software. Small motor vibrators enabled by the 

microcontroller are informing a blind person about the danger. 

It is more simple to develop and debug electronic systems and 

algorithms where all signals come from the inside of the system 

and they are predictable and relatively easy to measure. The difficult 

part starts when signals come from the outside of the system, 

for instance, from sensors. In this project, regards to the holes detection, 

an input signal comes from an infrared beam that returns 

reflected from the ground ahead. Since neither models of environment 

nor electronic parts are perfect, it would not be reliable to 

develop and test algorithms for detecting holes in real-time environment. 

For the early stages of the MOBIAN© system design the 

software environment for testing holes detection algorithms is to 

be created based on MatLab. A basic concept is to create a software 

environment where imperfects on the road, e.g. holes, could 

be simulated. A simple movement of the sensor and of course 

distance measurement is to be implemented as well. 

For creating reliable test scenarios, a repeatable and self-acting 

test-bench has to be implemented. For this purpose, some 

environmental variables, such as a hole width, a hole length, and 

Fig. 2. Diagram of the holes and obstacles detection device 

Rys. 2. Schemat blokowy urządzenia do wykrywanie dziur, uskoków 

oraz innych przeszkód 

20 

a hole depth, have to be pseudorandomly generated. In each 

scenario a number of holes and their dimensions should be different. 

The whole software environment, aside from modeling a road 

and holes and a distance measurement, should be well suited for 

different kinds of algorithms. The advantage of using the MatLab 

environment instead of simply writing the simulator in one of the 

many high-level programming languages is that MatLab is already 

supported by a great number of mathematical functions, methods 

and algorithms. An implementation of new algorithms or testing 

the existing ones is not so complicated and time consuming. 

Simulations also have another advantage. One is able to test 

as many algorithms as they like on the same sample set without 

worrying that computations will take too much time and then new 

samples in a buffer will be overwritten. One can also pause and 

unpause a simulation. 

Due to the nature of the device, a maximum range of the ultrasonic 

scanner is over 3 m (a walking direction). That provides 

enough time for a blind person to react if some obstacle is detected. 

The multisensory approach makes it possible to detect obstacles 

placed on variable heights. A detection range is over 1.5 m 

(both vertical and horizontal direction). A sufficient ultrasonic scan 

interval is 0.5 s. The successful detection of the obstacles relies 

on the obstacles dimensions, geometry, material and distance between 

them and ultrasonic sensor [3]. However, even 1 cm metal 

squares are possible to be detected with the multichannel ultrasonic 

range finder. The infrared range finder maximum distance 

measurement is over 5 m. This allows to detect holes within the 

distance of 3 m. An infrared scan interval is less than 25 ms. The 

minimum dimensions of detected holes are determined by the algorithm 

which is employed in the device. 

Software modules 

The simulator consists of the following modules: 

– initialization module; 

– holes generation module; 

– distance computation module; 

– holes detection algorithms module; 

– display module; 

– report module. 

The initialization module starts the simulation. It creates environmental 

variables, such as, road and holes dimensions, number 

of holes, sensor start position, etc. 

The hole generation module uses a pseudorandom algorithm 

to create holes on the road. One can determine minimal and 

maximal dimensions of holes as well as minimal and maximal dimensions 

of spaces between them. The algorithm also makes 

sure that all holes fit in the defined road area. Another important 

issue is that one can set the initial road length. This dimension 

defines a hole-free space between an infrared dot starting position 

and a first hole. This feature will help to show some flaws in 

algorithms. 

The distance computation module uses mathematical methods 

to calculate the current location of an infrared dot and put it 

onto a shape of the road. 

The holes detection algorithms module is a module where one 

or more algorithms can be implemented and tested. It contains 

a detection matrix where algorithms puts theirs results. The matrix 

is shared among other modules. 

The display module makes it possible to visualize the progress 

and computation results. The visualization of data can be done in 

a 3D isometric view or in a 2D plane view. For the clarity of the 

visualization one may choose how big the part of the road should 

be in view. Displaying an image in MatLab takes time, especially 

if it is done from a big matrix. Therefore, the display module is 

created as a function, so it could be called out whenever we want. 

It is wise to visualize the data only if necessary, e.g. when debugging 

or if an important event occurs (hole not detected) and additionally, 

when the simulation starts and ends. 


Fig. 3. Simulation flowchart. Rys. 3. Schemat symulatora 

The report module creates statistics. Final results of the simulation 

are displayed at the end. Results contain data about generated 

holes, the number of detected holes by each algorithm. 

One can also put there some other information, such as, the 

average distance between the sensor and the beginning of detected 

holes, dimensions and location of undetected holes, etc. 

Some debug information and warnings could be also included 

in the report. 

The simulator flowchart is presented in Fig. 3. When the simulation 

starts, all constants and variables are initiated. Next, a road 

and holes in it are being created with regard to parameters one 

put. Then, the first distance computation, a starting position and 

an angle of an infrared beam are being connected to the road. 

A visualization is an optional step. The following computations are 

being done till the end of the road. After each iteration the holes 

detection algorithms module is activated and results are being put 

into a result matrix, errors may be displayed if occurred. One can 

enable the current view display. In the end, a summarized report 

is being displayed and the simulation stops. 

Results 

Various algorithms for detecting holes had been designed or modified 

and then tested. Algorithms based on median calculations 

with a memory effect (ones that analyze measurements from longer 

period of time) have problems with detecting short holes, but 

thanks to the inertial effect, there are less wrong-hole-detection 

glitches. Algorithms that check only the last few measurement 

samples have better detected to undetected holes ratio, but the 

mentioned above glitches could get a blind person confused. The 

good way is to use several algorithms simultaneously. 

A prototype of the device is being constructed. Tested algorithms 

are going to be implemented into the device, adjusted and 

optimized. Efficiency of holes detection will be compared with 

simulations results. 

In simple simulations a source of an infrared beam moves only 

along the road axis. A horizontal (the road width) and vertical (the 

height) position is fixed. When a person with attached sensors is 

moving, a real source of infrared beam moves in three directions. 

The infrared beam changes its position constantly. This influences 

a hole detecting algorithms performance. To minimize this effect, 

a accelerometer and a gyroscope is implemented. This data 

is more helpful in advanced simulations. Also, sometimes during 

walking some accidental shakes may occur, such as when a person 

suddenly stops or a person is poked. Having the knowledge 

about these shakes is a way to avoid some potentially false data 

from distance measurement sensors. 

The simulator is operational. Some hole detection algorithm 

has been implemented. Right now its computation is only based 

on a current distance between an infrared beam and a road. The 

holes generation module works fine. One can choose if a current 

road, a sensor and an infrared dot placement should be displayed 

either after every computation iteration, after selected distance 

step or only when simulation starts and ends. A sample both 3D 

and 2D road display is shown in Fig. 4. 

Fig. 4. Sample simulator visualizations 

Rys. 4. Przykładowe wizualizacje 

symulacji 

References 

[1] Dakopoulos D., N. G. Bourbakis: Wearable obstacle avoidance electronic 

travel aids for blind: a survey. IEEE Transactions on Systems, 

Man, and Cybernetics, Part C: Applications and Reviews, volume 40, 

issue 1, 25–35 (2010). 

[2] Boroń K., W. Gelmuda, A. Kos: Mobile Safety System for the Blind. 

ELTE 2010, IMAPS-CPMT: 10th electron technology conference and 

34th international microelectronics and packaging, Wrocław, 22–25 

September 2010. 

[3] Gelmuda W., A. Kos: Możliwości detekcyjne piezoelektrycznych czujników 

ultradźwiękowych 40STR-XX w powietrzu. Prace Instytutu 

Elektrotechniki, ISSN 0032-6216, t. 57 z. 246 s. 133–141, 2010. 

[4] Andň B., S. Graziani: Multisensor Strategies to Assist Blind People: 

A Clear-Path Indicator. IEEE Transactions on Instrumentation and 

Measurement, vol. 58, no. 8, August 2009. 

[5] Gelmuda W., A. Kos: Ultrasonic white stick for detecting holes for 

blind people. Elektronika – konstrukcje, technologie, zastosowania, 

ISSN 0033-2089, nr 10 s. 141–143, Warszawa, 2010. 


Metal – oxide sensor array for gas detection 

(Matryca sensorów na bazie tlenków metali do detekcji gazów) 

mgr inż. Patryk Gwiżdż, dr inż. Andrzej Brudnik, dr hab. inż. Katarzyna Zakrzewska 

AGH University of Science and Technology, Faculty of Electrical Engineering, Automatics, Computer Science 

and Electronics, Kraków 

Resistive-type semiconducting gas sensors based on metal oxides 

are convenient and relatively cheap devices used for detection 

of reducing and oxidizing gases. It is well-known that except 

for their high sensitivity, their largest drawback is the lack of selectivity. 

Such sensors cannot distinguish between different gases of 

the same type, e.g. hydrogen and methane because their dynamic 

responses look similar. However, this cross-sensitivity, manifesting 

itself as a non-zero sensor response to interfering gases, 

is used to advantage in arrays of gas sensors or electronic noses 

[1–2]. Application of pattern recognition schemes (PARC) allows 

for classification and recognition of particular components of the 

analyzed gas mixture and volatile organic compounds (VOCs) 

[3–6]. Vast research field of classification based on this idea has 

been established in the 80 ties of 20 th century and a new type of 

device called: electronic nose has been proposed [1]. The electronic 

noses are mainly designed to detect and recognize VOCs 

responsible for smell [7]. Although commercial devices are now 

available, there is still a need to create miniaturized portable systems. 

The aim of this work was to design and construct an array of 

resistive-type semiconducting sensors dedicated to detection and 

recognition of components of a gas mixture especially hydrogen 

and ammonia. Detection of these gases becomes increasingly 

important for their use in automotive industry (ammonia) [8] and 

fuel cells (hydrogen) [9]. 

One of the most important requirements for the supporting 

electronic system is its flexibility understood as a simplicity of 

reconfiguration in the case of changing number of sensors. The 

analog part of the system had to be constructed in such a way 

that it should provide adaptable measuring range for each sensor 

individually. The created system would constitute a base for implementation 

of new sensors based on nanomaterials. 

Experimental set up 

The sensor array was built from six commercial metal oxide gas 

sensors, humidity and temperature detectors. All chosen gas sensors 

have different specifications, i.e., should be primary used for 

the following targets: ammonia, hydrogen, hydrocarbons, alcohol, 

air pollution and explosive gases and are destined to operate at 

the heater voltage of 5 V. Schematic diagram of the gas detection 

system designed and assembled by the authors of this work is 

shown in Fig. 1. The system consists of the sensor array placed 

in the measuring chamber, gas flow controllers, electronic measuring 

and control unit and a PC with a dedicated software. 

Concentration of the detected gas in the measuring chamber 

can be changed in a step-like way. Gas flow is set and measured 

separately for each detected gas as well as for the reference 

(synthetic air). All signals from the sensors are recorded by the 

electronic measuring and control unit built by the authors. 

The measuring system is based on the STM32F103 microcontroller 

family. The innovative approach consists in the system 

architecture. Each gas sensor is operated by its own measuring 

and control module containing analog measuring part, power control 

circuit of the sensor heater and microcontroller based digital 

part. All modules are connected to the CAN bus which allows for 

data transfer between them creating a sensor network. As shown 

schematically in Fig. 2, one module communicates with the computer 

transferring data from all the modules to a PC. 

22 

Fig. 1. Schematic diagram of the constructed gas detection system 

Rys. 1. Schemat skonstruowanego systemu do detekcji gazu 

Gas sensor no. 1 

and measuring module 

Gas sensor no. 6 

and measuring module 

Humidity, temperature 

sensors 

PC computer and 

dedicated software 

CAN Bus 

Fig. 2. Modular representation of the constructed electronic system 

Rys. 2. Schemat blokowy skonstruowanego systemu elektronicznego 

For the designed array and the electronic system a dedicated 

PC computer software has been written in the Microsoft Visual 

C++ with the aim to facilitate data acquisition and analysis of the 

response of each sensor in the array. 

An independent change in the supply voltage of each sensor 

has been made possible. This affects the temperature of the sensing 

layer, the most important factor that determines the sensing 

parameters and responses. Thanks to the independent temperature 

change of each sensor, the sensitivity and selectivity can be 

optimized. 

It is well known that humidity variation influences responses 

of the resistive-type semiconducting gas sensors based on metal 

oxides [10]. Therefore, continuous monitoring of the humidity level 

and temperature was provided by the relevant sensors placed 

directly in the measuring chamber. 


In order to demonstrate to what extent these sensors are nonselective, 

the responses to a certain gas concentration of all the 

sensors in the array are drawn as radar plots in Figs. 5, 6, 7 and 

8. The worst scenario is presented in Fig. 5. Five of six sensors 

are almost equally sensitive to ammonia. Weak responses are 

obtained with hydrocarbons sensor. On the other hand, as indicated 

by the results in Fig. 6, the ammonia and alcohol sensors are 

less sensitive to hydrogen than four other sensors. 

Fig. 3. Top view of the gas detection system: 1 – measuring chamber 

containing six metal oxide sensors; 2 – electronic measuring and 

control unit; 3 – gas flow controllers; 4 – gas flow meter; 5 – PC 

computer 

Rys. 3. Widok układu do detekcji gazów: 1 – komora pomiarowa zawierająca 

sześć czujników gazu na bazie tlenków metali; 2 – elektroniczny 

system kontrolno-pomiarowy; 3 – kontrolery przepływu gazu; 

4 – miernik przepływu gazu; 6 – komputer PC 

Results 

Designed and constructed array of sensors is shown in Fig. 3. 

The test performed comprised the measurements of the response 

as a function of: 

• gas type, 

• gas concentration, 

• humidity level, 

• heater voltage (temperature). 

The response S of a single resistive-type gas sensor has been 

defined as: 

∆ 

R 

R 

− 

R 

0 

S 

= 

= 

(1) 

R 

R 

0 0 

where: R 0 

is the sensor resistance in the reference atmosphere 

(synthetic air), R denotes the sensor resistance in the presence 

of the target gas. 

The influence of the humidity on the sensor response is given 

in Fig. 4 for two particular detectors (explosive gases and air pollution) 

upon detection of hydrogen. 

Fig. 5. Radar plot indicating the responses of all six sensors in the 

array upon changes in the concentration of NH 3 

; heater voltage 5 V 

Rys. 5. Wykres biegunowy przedstawiający odpowiedzi wszystkich 

sześciu czujników zawartych w matrycy pod wpływem zmian koncentracji 

NH 3 

; napięcie zasilania grzejnika 5 V 


array upon changes in the concentration of H 2 




H 2 


Fig. 4. Response to hydrogen for the explosive gases and air pollution 

sensors under different levels of humidity 

Rys. 4. Odpowiedzi czujników gazów wybuchowych i czystości powietrza 

dla wodoru przy różnych poziomach wilgotności powietrza 


array upon changes in the concentration of CO 2 




CO 2 



y humidity, therefore taking its influence into account is crucial 

for reliable gas recognition. The designed electronic measuring 

system enables further research and testing of new sensors 

based on nanomaterials. The biggest advantage of the system 

is its flexibility in respect to the number of the connected sensors 

achieved thanks to using the CAN bus and wide measuring range 

of the sensor response. 

Financial support from Polish Ministry of Science and Higher 

Education under AGH-University of Science and Technology 

grant no. 11.11.120.614 (Statutory project) for years 2011–2012 

is acknowledged. 


array upon changes in the concentration of CO 2 




CO 2 


Quite pronounced effect of the voltage supplying the sensor 

heater on the selectivity of responses to CO 2 

is seen when comparing 

the radar plots in Figs. 7 and 8. By lowering the voltage 

from 5 V to 4 V, what in consequence leads to a decrease in the 

operating temperature, all but two gas sensors become insensitive 

to CO 2 

. The best response is obtained for the explosive gas 

sensor according to expectations. Hydrogen sensor is very sensitive 

to all studied gases. 

Conclusions 

The sensor array designed and assembled by the authors of this 

work is based on six commercial gas sensor, humidity and temperature 

detector. The measurements performed show different 

responses of the array of metal oxides gas sensors to ammonia, 

hydrogen and carbon dioxide. By adjusting the voltage of the sensor 

heater, the temperature of the sensing layer of each sensor 

has been modified thus making it possible to reach better selectivity 

of the whole array. The response of the sensors suggests that 

using more sophisticated algorithms, a reliable gas detection and 

recognition may be achieved in future. The tests carried out indicate 

that the response of the sensors is affected to a great extent 

References 

[1] Gardner J. W., Barlett P.N.: A brief history of electronic noses. Sensors 

and Actuators B, Vol. 18, Issues 1–3, 1994, pp. 210–211. 

[2] Röck F., Barsan N., Weimar U.: Electronic Nose: current status and 

future trends. Chemical Review, Vol. 108, 2008, pp. 705–725. 

[3] Brudzewski K., Osowski S., Markiewicz T., Ulaczyk J.: Classification 

of gasoline with supplement of bio-products by means of an electronic 

nose and SVM neural network. Sensors and Actuators B, Vol. 

113, Issue 1, 2006, pp. 135–141. 

[4] Bicego M., Tessari G., Tecchiolli G., Bettinelli M.: A comparative analysis 

of basic pattern recognition techniques for the development of 

small size electronic nose. Sensors and Actuators B, Vol. 85, Issues 

1–3, 2002, pp. 137–144. 

[5] Szczurek A., Szecówka P.M., Licznerski B.W.: Application of sensor 

array and neural networks for quantification of organic solvent vapours 

in air. Sensors and Actuators B, Vol. 58, Issues 1–3, 1999, 

pp. 427–432. 

[6] Capone S., Zuppa M., Presicce D.S., Francioso L., Casino F., Siciliano 

P.: Metal oxide gas sensor array for the detection of diesel 

fuel in engine oil. Sensors and Actuators B, Vol. 131, Issue 1, 2008, 

pp. 125–133. 

[7] Brudzewski K., Osowski S., Wolińska K., Ulaczyk J.: Smell similarity 

on the basis of gas sensor array measurements. Sensors and Actuators 

B, Vol. 129, Issue 2, 2008, pp. 643–651. 

[8] Moos R., Müller R., Plog C., Knezevic A., Leye H., Irion E., Braun 

T., Marquardt K. J., Binder K.: Selective ammonia exhaust gas sensor 

for automotive applications. Sensors and Actuators B, Vol. 83, 

Issues 1–3, 2002, pp. 181–189. 

[9] Cheng X., Shi Z., Glass N., Zhang L., Zhang J., Song D., Liu Z.S., 

Wang H., Shen J.: A review of PEM hydrogen fuel cell contamination: 

Impacts, mechanisms, and mitigation. Journal of Power Sources, Vol. 

165, Issue 2, 2007, pp. 739–756. 

[10] Han N., Tian Y., Wu X., Chen Y.: Improving humidity selectivity in formaldehyde 

gas sensing by a two-sensor array made of Ga-doped 

ZnO. Sensors and Actuators B, Vol. 138, Issue 1, 2009, pp. 228–235. 

Przypominamy o prenumeracie miesięcznika Elektronika na 2012 r. 

24 


Dynamic research of foot pressure distribution 

– the four-points shoe insert with PVDF sensors 

(Dynamiczne badania rozkładu nacisku stopy na podłoże – czteropunktowa 

wkładka do obuwia z polimerowymi czujnikami z PVDF) 

dr inż. Ewa Klimiec, dr inż. Wiesław Zaraska, mgr inż. Szymon Kuczyński 

Instytut Technologii Elektronowej, Oddział w Krakowie 

The human foot structure majorly decides about his/her movement 

possibilities. Correctly constructed foot is arched on internal 

side. The weight is distributed in a way, that medial arch acts like 

a shock absorber, by softening shocks caused by walking. Correctness 

of the foot structure can be estimate, by examining foot 

pressure distribution on the ground. Faulty posture manifest itself 

by different than correct, foot pressure distribution on the ground. 

Currently there are two measuring systems on the market, allowing 

diagnosis. It is EMed-SF [1, 2] and PEDAR – System [3, 

4]. In the first one, examined person crosses through the track, 

placing third step on the measuring platform. Contact with the 

platform surface should be measured in a natural way so, that 

there was no measuring distortion by aware step shortening or 

lengthening. For this purpose, several trials heve to be done and 

starter has to be suitably set up. Obtained results are in the form 

of map which shows the pressure distribution on foot contact surface 

with measuring platform in N/cm 2 . The example of recorded 

pressure distribution for healthy foot structure is shown on Fig.1. 

ted: under the heel, medial arch, mid-foot and hallux. Films were 

glued together. The view of the four-points measuring shoe insert 

is shown on Fig. 2. 

Fig. 2. The view of a four-point measuring shoe insert 

Rys. 2. Widok czteropunktowej wkładki pomiarowej 

Fig. 1. Pressure distribution of healthy foot to the ground recorded 

by EMed-SF system 

Rys. 1. Rozkład nacisku prawidłowo zbudowanej stopy na podłoże, 

zarejestrowany przez EMed–SF system 

Data presented on Fig. 1 shows that for healthy foot, the biggest 

values of the pressure are observe under heel, midfoot and 

on hallux. Measuring system PEDAR is characterized by the fact 

that we examine the foot pressure between foot and shoe sole. 

The pressure is recorded by pressure sensors which are installed 

into shoe insole. The system is expensive and shoe insole very 

thick. It will be profitable to develop competitive system which will 

be able to do research on a large scale. Research on the development 

of competing systems and results interpretation are 

conducted by various research and development centers in the 

world [5]. 

The article discuss measurement system developed by the 

authors where the active element is made of piezoelectric PVDF 

film (Measurement Specialties, Inc.) with 100 μm thickness, with 

printed silver electrodes, placed in the insert to the shoe of his 

own design. Insert was placed in a sport shoe. 

Dynamic investigations of foot pressure 

distribution on the ground 

Shoe insert and measuring system design 

Shoe insert consist of two polyester films without piezoelectric 

properties. Both films have silver, screen printed electrodes. Between 

them, piezoelectric sensors made of PVDF film were loca- 

Fig. 3. Electric scheme of measuring system, where: S – Sensing element, 

E – Electromotive force, X – Reactance of an equivalent source, 

U – Voltage, RS – Resetting System, MA – Measurement amplifier 

(Keihley 6517A multimetr), OC – Oscilloscope (LeCroy LT-341), TS 

– Time Sensor 

Rys. 3. Schemat elektryczny systemu pomiarowego, gdzie: S – czujnik, 

E – siła elektromotoryczna, X – reaktancja układu zastępczego, 

U – napięcie, RS – układ zerujący, MA – wzmacniacz pomiarowy (Keihley 

6517A multimetr), OC – oscyloskop (LeCroy LT-341), TS – czujnik 

czasu 

Electric scheme of measuring system is shown on Fig. 3. 

Large load resistance 10 14 Ω has been provided to measuring 

system by input analog amplifier of Keithley multimeter. Generated 

piezoelectric voltage was recorded on an oscilloscope. 

Recorded digital data were used for further signal analysis. The 

sensor made of piezoelectric polymer film with printed electrodes 

is a self-charging capacitor. It is caused by mechanical deformation 

and by pyroelectric properties influence. That is why resetting 

system perform very important role in proper measurements. 

Resetting system prevents capacitor charging and also reduce 

influence of pyroelectric signal which direction is opposite to piezoelectric 

signal. Moreover, piezoelectric voltage measurements 

were performed when temperature in shoes was established. Resetting 

system ensure return of the measurement system to the 

starting point, after each step. 

Voltage signals analysis – the influence 

of design and fasten of measurement shoe insole 

to signal quantity and shape 

PVDF sensors are very sensitive to any mechanical deformation. 

That should be taken into consideration in shoe insert design 

where measuring insert, shown on Fig. 2, is fasten. The article 


investigate three designs of shoe insert, which were fastened in 

a typical man sports shoe, size EU42. Dynamic research of stress 

distribution on foot were made on running track. The speed of 

a walking man, weighing ~ 76 kg, was ~ 4 km/h. Design no.1, 

consist of measuring insert and lining which was made of a thin 

rubber – leather layer. Obtained voltage signals on insole, design 

no.1, are shown on Fig. 4. 

U [V] 

25 

20 

15 

10 

5 

Heel 

Medial arch 

Metatarsal 

Hallux 

Signal for sensor which was located on medial arch also increased. 

To summarize voltage curves on Fig. 4, 5 and 6, it is seen, 

that presented modernization of the insert is beneficial only for 

sensors placed under the heel and hallux. 

Further modernization of the insert has gone in direction of 

even greater sensors stiffening and further reduction of other mechanical 

factors reaction except stress. Additional metal plates 

were mounted above sensors, to design no 2. Voltage traces on 

insole, design no 3, with stiffened sensor on both sides, are shown 

on Fig. 6. 

20 

15 

10 

Heel 

Medial arch 

Metatarsal 

Hallux 

0 

-5 

-10 

-0.2 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 

Time [s] 

Fig. 4. Piezoelectric voltage signal traces obtained on shoe insert 

– design no 1 

Rys. 4. Przebiegi piezoelektrycznego napięcia na wkładce do obuwia 

– konstrukcja nr 1 

U [V] 

5 

0 

-5 

-10 

-15 

0.0 0.2 0.4 0.6 0.8 1.0 1.2 

Time [s] 

Voltage traces shown on Fig. 4, presents, that besides positive 

signals, which are coming from the applied stress of the foot on 

the ground, there are signals of opposite sign, resulting from bending, 

torsioning and also other mechanical reactions of foot with 

shoe sole. The highest voltage value was obtained from a sensor 

placed under heel, and it was ~ 22 V. Next largest is the signal 

from metatarsal area ~ 8 V and hallux ~ 6 V. Very small voltage 

signal was received from medial arch. 

To reduce influence of other mechanical reactions on the measuring 

insert except for pressure, design no.1 was modernized. 

On the bottom of the measuring insole, under sensors surface, 

metal plates with 1.5 mm thickness were sticked. Also, lining leather-rubber 

was added starting from shoe sole. This modernization 

was done to make the sensor more stiffner and to suppress 

measuring insert vibrations. Obtained voltage signals from shoe 

insole, design no. 2, are presented on Fig. 5. 

Comparing voltage traces on Fig. 4 and 5, we can see, that 

for a sensor which is located under the heel, negative signal 

decreased. Voltage curve for metatarsal is less corrugated and 

it shows smaller vibration of measuring insole, but significantly 

increased value of a negative signal. Voltage curve for hallux 

under pressure increase more uniform, and the negative signal 

slightly decrease. 

Fig. 6. Piezoelectric voltage signal traces obtained on shoe insert 

– design no 3 



Comparing the voltage character on Fig. 5 and 6, it is seen, 

that stiffeners introduction on bottom and top sensor area causes, 

that for first three sensors, we obtain voltage response mainly to 

foot pressure on the ground. For sensor placed on metatarsal, 

where large bending appears, negative voltage is still high. Obtained 

voltage values on design no. 3, except hallux, are smaller 

than for design no 1 and 2. A comparison of Fig. 4, 5, 6 it is seen, 

how the design of measuring insert affects to values and character 

of piezoelectric signal. 

To present influence of insert bending to electrical signal generated 

mainly from stress the following investigation was conducted. 

Measurement insert with both sides sensor stifness fastened 

to dynamometer IMADA DIGITAL FORCE GAUGE at the area 

of one sensor. The pressure was increased gradually up to 200 N. 

Then the sensor was kept under pressure and insole was bending 

nearby the sensor side. Afer that, pressure was gradually reduced 

to the starting point. Voltage trace on sensor during described 

above experiment, is shown on Fig. 7. 

25 

20 

15 

10 

Heel 

Medial arch 

Metatarsal 

Hallux 

U [V] 

5 

0 

-5 

-10 

-15 

0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 

Time [s] 

Fig. 5. Piezoelectric voltage signal traces on shoe insert – design no 2 



Fig. 7. Voltage trace on one sensor during pressure growth up to 200 

N, measuring insert bending nearby sensor and pressure decrease 

to the starting point 

Rys. 7. Przebieg napięcia na czujniku podczas wzrostu siły nacisku 

do 200 N, zginaniu wkładki pomiarowej w pobliżu czujnika i zmniejszaniu 

siły do punktu wyjścia 

26 


Voltage trace presented on Fig. 7 shows, that signal which is 

coming from increasing pressure gradually increases and decreases 

uniformly when pressure decrease. While measurnig insole 

was bending, opposite voltage direction occurred to voltage generated 

from pressure. 

Also, walking speed have influence on voltage curve and its 

character was investigated. Voltage curves on insole deesign no 

3, on the sensor located on metatarsal area, for high and slow 

walking speed of 4 and 1.4 km/h are shown on Fig. 8. 

U [V] 

10 

5 

0 

-5 

-10 

V=1.4 [km/h] 

V=4 [km/h] 

-15 

0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 

Time [s] 

Fig. 8. Voltage trace on insole design no 3, on the sensor located on 

metatarsal area, for high and slow walking speed of 4 and 1.4 km/h 

Rys. 8. Przebieg napięcia na wkładce o konstrukcji nr 3, na czujniku 

umieszczonym w miejscu śródstopia, przy szybkim i powolnym chodzeniu 

z prędkością 4 km/h i 1,4 km/h 

U [V] 

6 

5 

4 

3 

2 

1 

0 

-1 

Arch of the healthy foot 

Arch of the flatfoot 

-2 

0.0 0.2 0.4 0.6 0.8 1.0 1.2 

Time [s] 

Fig. 9. Voltage traces on medial arch sensor for healthy foot and foot 

with stimulated flatfoot – shoe insole design no 3 

Rys. 9. Przebiegi napięć na stopie zdrowej i na stopie ze stymulowanym 

płaskostopiem, na czujniku umieszczonym w miejscu wklęśnięcia 

stopy zdrowej, na wkładce o konstrukcji nr 3 

As shown on Fig. 8, for slow walking speed, negative voltage 

is not observed, but it occurs for high walking speed. This phenomenon 

can be use for dynamic gait analysis. 

Presented above shoe insoles, where active element is a piezoelectric 

PVDF film, can be use to diagnose various foot disease, 

e.g. flatfoot. By introducing additional insert in medial arch area, 

flatfoot was simulated. To conduct this investigations, a shoe insole 

with design no 3 was used. Voltage traces recived from healthy 

foot and flatfoot at medial arch area, are shown on Fig. 9. 

Higher voltage signal is observe in case of flatfoot, than for heathy 

foot. By presented shoe insole, it will be possible to diagnose 

pathological foot deformations e.g. flatfoot. 

This condition leads to chronic bursitis, inflammation of joints 

ligaments, edema, pain, and sometimes prevent walking. Examinations 

can be performed in a dynamic way, for any long time. 

Summary 

The design of shoe insert has an influence to the shape and value 

of piezoelectric voltage, because its active element is a piezoelectric 

PVDF film, which is very sensitive to mechanical deformations. 

It is seen on Figs. 3–6. 

If measurements are mainly focus on foot pressure distribution 

on the ground e.g. flatfoot examinations, it will be well to use insole 

design no 3 with stiffened sensors surfaces. It is less sensitive 

than insole design no.1. Electrical signal value decrease, but foot 

bending and torsioning has smaller influence to its shape and value. 

Comparison: Fig. 4 and Fig. 6. Insert design no 1 should be 

chosen, if we want a full mapping of foot behavior by electrical 

signal during walking. It is very sensitive to any mechanical deformations. 

The measuring system developed by the authors, allows to 

conduct investigation of foot pathology like flatfoot, at any long 

time, in a dynamic way. 

Resetting system is important to conduct correct measurements, 

which assures that measurement system returns to the 

starting point after each step execution. 

For sensors calibration, relative pressure measurement of foot 

pressure seems most profitable e.g. in relation to heel pressure, 

what would largely reduce the influence of shoe insert design to 

results interpretation. 

Authors are working on radio transmission of electric signal 

values from insert placed in footwear to receiving station, where 

signal analysis will be conducted. 

Authors conduct investigations on further improvement of the 

system – eight points shoe insole, and also on adaptation of insole 

design to different foot pathologies tests. 

Authors wish to express their gratitude to the IET Cracow Division 

measurement laboratory staff, especially to Mr. Andrzej Cichocki, 

for his assistance while conducting the electric measurements 

and in editing this paper. This work has been supported 

by key project MNSDIAG, WND-POIG 01.03.01-00-014/08. 

References 

[1] Bryant A.R., Tinley P., Singer K.P.: Normal values of plantar pressure 

measurements determined using the EMED-SF system. Journal 

of American Podiatric Medical Association, Vol.°90, No.°6, 2000, 

pp. 295–299. 

[2] Cichy B, Wilk M.: Gait analysis in osteoarthritis of the hip, Med. Sci 

Monit, Vol.°12, No.°12, 2006, pp. 507–513. 

[3] Hurkmans H. L. P., et al., Validity of the Pedar Mobile system for 

vertical force measurement during a seven-hour perio. Journal of Bomechanics, 

Vol.°39, 2006, pp. 110–118. 

[4] Hessert M.J., Vyas M., Leach J.,Hu K., Lipsitz L. A., Novak V.: Foot 

pressure distribution during walking in young and old adults. BMC 

Geriatrics, Vol.°5, No.°8, 2005. 

[5] Kong K. and Tomizuka M.:Smooth and continuous human gait phase 

detection based on foot pressure patterns. in Proc. IEEE Int. Conf. 

Robot.Autom., 2008, pp. 3678–3683. 


Design and realization of a microfluidic capillary sensor 

based on a silicon structure and disposable optrodes 

(Projekt i realizacja mikrocieczowego czujnika kapilarnego opartego na przestrzennej 

strukturze krzemowej z wykorzystaniem włókien światłowodowych) 

dr inż. Zbigniew Szczepański 1) , dr inż. Michał Borecki 1) , dr inż. Dariusz Szmigiel 2) , 

PhD Michael L. Korwin Pawlowski 3) 

1) 

Warsaw University of Technology, Institute of Microelectronics and Optoelectronics, Warsaw 

2) 

Institute of Electron Technology Warsaw, Devision of Silicon Nanostructure Technology, Piaseczno 

3) 

Département d’informatique et d’ingénierie, Université du Québec en Outaouais, Gatineau,Québec 

During the last years microfluidic sensors that use optical capillaries 

have gained an increasing importance due to their new 

applications as diagnostic tool in biotechnology, medicine and in 

environmental sciences. This was possible because the capillary 

enables multiparametric sensing [1–7] contrary to the classical 

optical fiber sensors [8], which find applications in physical measurements 

such as pressure and also magnetic field [9]. 

In this paper the improvements in the design of microfluidic 

sensors that use local heating in optical capillaries as a base 

of multiparametric diagnostics is presented [4]. The application 

of local heating opened interesting new possibilities for the 

sensors, that do not use any chemical sensitive layers or reagents, 

while raising specific issues relating to their construction, 

materials and technology [5]. The mentioned sensors can be 

used for in situ diagnostic in medicine and veterinary and as 

biofuel usability testers [10–12].The proposed microfluidic capillary 

sensor consists of a stabilized-intensity light source unit, 

a testing head with replaceable optical capillary, a heater and 

a detection unit. The optical capillary performs the functions of 

a liquid sample holder and at the same time of a multiparametric 

sensing element. The sensor operates in a multiparametric sensing 

mode, monitoring, registering and processing the indirect 

information such as the index of refraction, the boiling point, 

the vapour pressure, the heat capacity, the heat of fusion, the 

viscosity, the surface tension of the liquid and turbidity changes 

in a thermally forced measuring cycle. The measuring cycle is 

initiated by applying local heating to the sample [5]. The measuring 

cycle is controlled indirectly by changes in optical signals 

and temperatures [10]. The raw optical data are processed 

by an optoelectronic circuits and fed to an information module, 

consisting of a personal computer equipped with data an acquisition 

function. For information processing an artificial neural 

network is used. 

The advantage of disposable capillary optrodes in liquid and 

fluid classification, are low total sample volume of the order of 

3 mm 3 that, is required for the analysis and the fact that washing 

of the sensor is not required, because the low-cost capillary can 

be disposable. The improvements in sensor construction compared 

with its previous versions are used of 3D silicon substrate 

structure and of a direct bonded copper (DBC) base. 

Sensor construction improvements 

The main part of microfluidic capillary sensor is a sensor head, 

that consists of the following elements: 

● a disposable optical capillary optrode with the liquid to be analysed, 

● a substrate for the capillary optrode with a local heater to change 

the temperature of the examined sample, 

● a set of optical fibres; one to input light from a local light source 

into the capillary and others to collect signals from the liquid, 

so that the light intensity variations can be monitored, 

● temperature sensors for temperature heater measurement, 

● a base for the mentioned above elements. 

28 

a) b) 

Fig. 1. Layout of silicon sensor head (a) and the heater (b) 

Rys. 1. Schemat krzemowego czujnika (a) głowica, (b) grzejnik 

The sensor substrate was designed on the base of a silicon 

wafer with the thickness of 900 μm, using silicon micromachining 

process, IC fabrication and hybrid techno+logies. The lay out of 

the silicon sensor substrate is shown in Fig. 1. 

The following elements are shown on Fig. 1: the V-grove for 

placement of the capillary, the rectangular groves for the optical 

fibres, the cavity of the heater, the heater resistive layer, aluminium 

metallization, the four rectangular holes and temperature 

sensors. The rectangular holes fulfil the role of thermal barriers to 

limit heat transfer from the heater area. The temperature sensors 

in a form of thin film resistors are deposited at the upper side and 

bottom side under the heater. 

The presented sensor design and technology takes into 

account the dimensional requirements for this sensor. The critical 

point of the optical capillary sensor construction is its reliable 

three dimensional positioning of the capillary optrode, in relation 

to the heater and of the optical fibres towards to capillary. The 

capillaries have to be positioned exactly 100 μm above the heater, 

taking into account the tolerances of the capillary’s diameter 

of ±20 μm. The source fibre and the receiver fibres ought to be 

coaxially positioned in relation to the capillary optrode. For the 

above reasons, the Si anisotropic etching was carried out in order 

to obtain V-groove profile with excellent dimensional control 

(Fig. 2a). 

a) b) 

Fig. 2. The cross section of V-grove (a) and rectangular grove (b) 

Rys. 2. Przekrój poprzeczny wydrążonych kanałów (a) w kształce litery 

V, (b) prostokątny 


Moreover IC technology allows the integration of the heater 

and temperature sensors with the silicon substrate. For realization 

of silicon sensor head, a silicon wafer with the (100) orientation 

and the thickness of 900 μm was used. Such thickness is 

appropriate for accommodation of the optical fibres and allows 

accommodate optical fibres and replaceable capillaries with outer 

diameters of 850 μm (Fig. 2b). 

The silicon wafer was oxidized in order to obtain a 100 nm 

SiO 2 

layer. Then it was covered with a Si 3 

N 4 

layer with the thickness 

of 100 nm, using an LPCVD process. Subsequently the 

double side photolithography was used to define the areas of 

capillary duct and 4 through the wafer slits. These slits fulfil the 

role of thermal barriers. The nitride mask layer was next opened 

using RIE plasma treatment, whereas the oxide layer was etched 

by means of wet chemical etching. In the next step the 550 μm 

depth cavity, V-shape capillary grove and rectangular slits were 

anisotropically etched at 80ºC, using KOH solution. After KOH 

etching the nitride mask was removed by wet etching and the etched 

surface was oxidized (~550 nm). In order to obtain thin film 

resistors with Al bond pads metallization at the both sides of silicon 

wafer, first RF magnetron sputter deposition of titanium was 

performed (300 nm thick) and then aluminium with the thickness 

of 500nm was deposited. Each metal layer was subsequently 

patterned using photolithography and wet processing. Straight 

line rails for the four the optical fibres placement have been made 

by means of the incising of the taped wafer using a rotary blade 

diamond saw. Finally the silicon wafer was diced into 30 × 30 mm 

pieces. In the Fig. 3 the realized functional silicon sensor bed 

structure is presented. 

Fig. 4. Layout of patterned DBC substrate 

Rys. 4. Układ podłoża DBC 

Fig. 3. Silicon sensor bed structure view 

Rys. 3. Podłożę czujnika krzemowego 

Two thin film resistors which act as temperature sensors were 

laser trimmed to obtain meander shape, what increases the accuracy 

of the temperature measurements. In the next step ultrasonic 

large diameter wire bonding process was made using 100 μm 

diameter aluminium wire, allowing for high density current flow 

through the heater. 

The realized silicon sensor head was assembled to patterned 

DBC alumina substrate, both side plated with 200 μm thick copper 

metallization (Fig. 4). 

The bonding pads were made using mechanical treatment, 

since photolithography was difficult to perform, due to the relatively 

thick copper metallization. The DBC substrate assures efficient 

heat transfer between the sensor head and the environment. In 

the centre of the DBC substrate, a square hole (12 × 12 mm) was 

made using laser drilling, to allow heat dissipation from the heater. 

The 3D silicon sensor head was connected with the DBC substrate 

using a conductive adhesive, dispensed around the edge 

of silicon structure. Such connection did not decrease of thermal 

resistance between the bottom side of silicon structure and the 

Fig. 5. Scheme of mechanical stabilization of the optical elements 

Rys. 5. Schemat mechanicznej stabilizacji elementów optycznych 

DBC metallization. To ensure repeatable position of the optical fibres 

and of the microfluidic capillary, mechanical stabilization has 

been applied (Fig. 5). 

In the sensor head assembled on the DBC substrate the temperature 

of the heater was measured, using a laser pyrometer 

and the thin film temperature sensors. Since the coefficient of 

the emission of the heater surface depends of temperature, so 

temperature measurements by means of pyrometer were made 

with an accuracy of ±10ºC.The better accuracy of the heater 

temperature measurement could be obtained using thin film temperature 

calibrated sensors. The temperature in the capillary was 

monitored by observing the boiling point of the various fluids filling 

the capillary. It was found that heater temperature had to be increased 

up to 180ºC, in order to obtain 100ºC inside the capillary. 

It was reached with heater power of ~5 W. 

Conclusions 

Capillary optical sensors are a novel instrument and method for 

classification of biological and chemical liquids and fluids with the 

advantage of a very small liquid sample that is needed for exa- 


mination. One intended application of such sensors is testing of 

biofuel usability for motor vehicles at a filling station. The capillary 

sensor was fabricated using silicon micromachining and IC 

technology. The applied technologies allowed for integration of 

the main sensor parts. High accuracy in 3D positioning of the heater 

in relation of the optical fibres, towards a capillary and good 

thermal control of the sample inside the capillary were obtained. 

The design of the sensor improved the accuracy of the dynamic 

optical measurements of the liquid under study. 

This work was supported by the European Union structural funds 

grant POIG nr 01.03.01-00-014/08-00 pt. „Mikro- i Nanosystemy 

w Chemii i Diagnostyce Biomedycznej – MNS DIAG” zadanie 2A. 

References 

[1] Weigl B.H., O.S. Wolbeis: Capillary optical sensors. Anal. Chem.66, 

1994. pp. 3323–3327. 

[2] Weigl B.H., G. Domingo, P. Laborre, J. Gerlach: Towards non and 

minimally microfluidics-basd diagnostic devices. Lab Chip. 8. 2008. 

pp. 1999–2014. 

[3] Romaniuk R.: Applications of capillary optical fibres. Proc. SPIE 

6347. 2006. 

[4] Borecki M., et al.: Optoelectronic Capillary Sensors in Microfluidic 

and Point-of-Care Instrumentation. Sensors. 2010; 10(4):3771-3797; 

http://www.mdpi.com/1424-8220/10/4/3771/pdf. 

[5] Borecki M., M.L. Korwin-Pawłowski, P. Wrzosek, J.Szmidt: Capillaries 

as the components photonic sensor and Microsystems. 2008. 

Mes.Sci.Technol. 19:065202. 

[6] Keller B.K., M.D. DeGrandpre, C.P. Palmer: Sensors and Actuators. 

B25. 2007. pp. 360–371. 

[7] Lippitisch M.E., S. Draxler, D. Kieslinger, H. Lehmann, B.H. Weigl: 

Applied Optics 35. 1996. pp. 3426–3431. 

[8] Gholamzadeh B., H. Nabovati: Fiber Optic Sensors. World Academy 

of Science, Engineering and Technology 42 2008. pp. 297–307. 

[9] Pustelny T., K. Barczak, K. Gut, J. Wojcik: Special optical fiber type D 

applied in optical sensor of electric currents. Optica Applicata, 34(4), 

2004, pp. 531–539. 

[10] Struk P., T. Pustelny, K. Gut, K. Gołaszewska, E. Kamińska, M. Ekielski, 

I. Pasternak, E. Łusakowska, and A. Piotrowska: Planar optical 

waveguides based on thin ZnO layers. Acta Physica Polonica A, 

116(3), 2009, pp. 414–418. 

[11] Borecki M., et al.: Intelligent Photonic Sensors for Application in Decentralized 

Wastewater Systems; in Waste Water – Evaluation and 

Management. Fernando Sebastián García Einschlag (Ed.), ISBN: 

978-953-307-233-3, InTech, (2011); http://www.intechopen.com/articles/show/title/intelligent-photonic-sensors-for-application-in-de 

centralized-wastewater-systems. 

[12] Borecki M., M. Korwin-Pawłowski: Optical Capillary Sensors for Inteligent 

Microfluidic Sample Classification. in Nanosensors: Theory 

and Applications, ed. K. Lim, CRC Press, pp. 215-246, Boca Raton- 

London- New, York, (2011). 

[13] Borecki M., M.L. Korwin-Pawlowski, M. Bebłowska, M. Szmidt, K. 

Urbańska, J. Kalenik, Ł. Chudzian, Z. Szczepański, K. Kopczyński, 

A. Jakubowski and J. Szmidt: Capillary Microfluidic Sensor for Determining 

the Most Fertile Period in Cows. Acta Physica Polonica A. 

118(6), 2010, pp. 1093–1099. 

[14] Urbańska K.et al.: Vaginal fluid of cow differences in rut cycle with 

emphasis on most fertile period. Życie Weterynaryjne, 86(2), 2011, 

pp. 127–129. 

A compact thermoelectric harvester 

for waste heat conversion 

(Kompaktowy termoelektryczny generator do pozyskiwania i przetwarzania 

ciepła odpadowego na energię elektryczną) 

dr inż. Piotr Dziurdzia, Akademia Górniczo-Hutnicza, Katedra Elektroniki, Kraków 

mgr inż. Karol Lichota, Knorr-Bremse Systemy dla Kolejowych Lokomocji PL Sp. z o.o. 

Ambient energy harvesters have been playing more and more important 

role in the electronic industry in recent years. Not so long ago, 

energy scavenging was treated in R & D laboratories with some timidity 

and used only in some niche applications. Nowadays, development 

of autonomous power sources for supplying microelectronic systems 

is strongly driven by market demands following recent advances in 

smart mobile equipment, wireless sensor networks (WSN), monitoring 

of industrial processes, etc. Since transmission lines have been 

replaced with wireless channels a long time ago, now the energy harvesters 

are removing the last obstacle on the way to developing quite 

autonomous electronic systems. By providing electrical voltage to the 

sensor nodes from harvested pieces of ambient energy (for instance: 

heat, light and vibrations) they do not need external sources of energy, 

for instance power mains or batteries, any more [1–3]. 

For the last few years our team has been focused on developing 

of thermoelectric energy harvesters for supplying wireless sensor 

nodes. At the beginning, basing on the phenomena of Seebeck, 

Peltier, Joule and Thomson, an original model of thermoelectric 

generator was elaborated [4]. It was next subjected to simulations 

in order to investigate the maximum ratings of TEG against available 

heat power sources and different ambient conditions. In the 

next steps first prototypes of TEGs were designed and fabricated. 

Thermoelectric harvester 

As a rule, thermoelectric generators suffer from relatively low conversion 

efficiency (not exceeding 10%), so they are practically not 

applicable to large-scale systems, not to mention power stations. 

30 

On the other hand they seem to be promising solutions when they 

are used to harvesting some waste heat coming from industry 

processes or central heating systems. 

In recent years a lot of attention was paid to analyzing Peltier 

modules and efficiency of conversion thermal energy into electrical 

one. Our latest aim was to design a complete, independent device 

powering a WSN node. Since low power integrated circuits, like 

microcontrollers, transceivers and sensors have been commonly 

available for several years we focused especially on DC-DC converter 

section. Ideal solution should fulfill the followings objectives: 

– operate from extremely low voltages, from tens of mV – it is 

a must since it is desirable that energy harvesters could work 

properly even with very low (equaling to single Celsius degrees) 

temperature gradients between Peltier modules hot and 

cold sides. Such temperature differences, for typical commercially 

available thermoelectric modules, result in tens of mV 

output Seebeck voltage, 

– match load impedance to Peltier module internal resistance to 

extract maximum amount of power, 

– small and compact package, easily applicable to relatively simple 

applications, 

– very low quiescent current. 

Design considerations 

A recently released (December 2009) integrated circuit LTC3108 

from Linear Technology would presumably meet our expectation. 

It can operate from input voltage as low as 20 mV and power ex- 


Fig. 1. Communication interface between ATTiny2313V and SHT11 

Rys. 1. Schemat interfejsu komunikacyjnego między mikrokontrolerem 

ATiny2313V i czujnikiem SHT11 

ternal microcontroller via V LDO 

= 2.2 V or other devices (wireless 

transmitters, sensors etc) via two V OUT 

outputs with one of four 

regulated voltages. It draws 6 uA quiescent current and has input 

resistance (including step-up transformer and whole input circuit 

not only LTC3108) about 2.5 Ω [5]. 

Even with the best converter one has to remember that energy 

harvesting is a low efficiency method and there is not too much 

power available. Therefore, all components should be aware of 

power dissipation and have both low current consumption and 

possibility to work in „power-save” mode (if not, µC should have 

possibility to temporarily turning them off). So, one has to carefully 

consider parameters of chosen devices (µC and sensor) in terms 

of power consumption. We decided to use Atmel ATTiny2313V 

µC from new designed low power family and SENSIRION SHT11 

sensor [6]. In fact this is not only sensor but also an A/D converter, 

an amplifier, a memory and a serial interface similar to I2C 

integrated in a single device. SHT11 could be used in meteorology 

station in WSN because of its low power consumption and 

good measuring properties. The least 12 bits for temperature and 

8 bits for data of humidity (the less bits the lower power consumption) 

are read by external microprocessor. SHT1x sensor family 

is common used in commercial application like: HVAC systems, 

meteorology stations, control and measurements systems, automotive 

and medical applications. 

Connection between µC and SHT11 is shown in Fig. 1. Although 

functionality of all parts is typical, what is worth consideration 

is the power balance and considerations of the designed system. 

Available energy and power estimation 

At first, our objective was to check whether the system will have 

enough power to run in constant manner. According to datasheets, 

average current consumption of SHT11 is 22 µA and the ATTiny 

2313V 20 µA (using 32 kHz internal oscillator). Let’s assume that 

Peltier module is one of Laird Technology TEG number 4532 and 

that the temperature difference between hot and cold side is 5 o C. 

In our laboratory we have checked that when applying such a gradient 

it results in output voltage about 94 mV. In Fig. 2 the output 

power dependence against temperature of the Peltier module hot 

side (the cold side was attached to a heat sink and could not be 

controlled) is shown. According to LT documentation [4] 94 mV of 

input voltage gives about 300 µA output current. It appeared that 

this is more than enough for constant work of the device. Such 

system can record measurements in a memory of a µC and store 

them for a long time. 

To achieve our main goal – the autonomous sensor network 

node – sufficient electrical power should be provided for supplying 

wireless transmitter. In this example for our calculations a Texas 

Instruments CC2520 ZigBee transmitter has been chosen. It requires 

18 mA while sending data, so it is obvious that it should work 

periodically in an estimated duty cycle. To get maximum pulse current 

which equals to I PULSE 

= 19.04 mA, all the load currents need to 

be added. Duration of transmission is 15 ms and this period of time 

Fig. 2. Output power against temperature of the Peltier module hot side 

Rys. 2. Moc wyjściowa w funkcji temperatury strony gorącej modułu 

Peltiera 

should allow free flow of data. Maximum voltage drop at the output 

is set to 0.5 V. LTC3108 has a capacitor tied to the V OUT 

output 

which is a temporary reservoir for the impulse load current. The 

appropriate values of capacitors that are able to store sufficient 

amount of energy can be calculated as in equation (1). 

I 

PULSE 

( 

mA 

) 

⋅ 

t 

PULSE 

( 

ms 

) 

C 

OUT 

( 

µ 

F 

) 

= 

(1) 

 

dV 

( 

V 

) 

And after substituting we obtain (2). 

OUT 

19.04 

mA 

⋅ 

15 

ms 

C OUT ( µ F 

) 

= 

= 

582 

µ 

F 

0,5 

V 

(2) 

So, in the designed energy harvester a 600 µF was chosen. 

To estimate how often the data can be transmitted, the following 

considerations should be carried out. The average spare current 

(supplied current minus consumption of ATTiny2313V and SHT11) 

is 300 µA – 42 µA = 258 µA. Therefore, the average supplied power 

equals to: 3.3 V * 258 µA = 851 µW, whereas the power that 

is required during transmission is 3.3 V * 19.04 µA = 62.8 mW. 

When we divide these two values of powers (851 µW/62.8 mW 

= 1.4%), this means that only 1.4% of required power is supplied 

by means of energy harvester. From that we can easily get a duty 

cycle: 15 ms/1.4% = 1.07 s. 

LTC3108 can be equipped also with some additional storage 

capacitor which is the main reservoir of energy in the circuit. By 

reducing frequency of transmitting one obtains additional energy 

which can be used in situations when Peltier module does not 

provide input voltage. In our solution a 0.1 F capacitor was chosen 

and the sending data frequency set to f = 0.5 Hz. The storage 

time can be calculated as in (3) and (4). 

( ) 

C 

STORE 

V 

STORE 

− 

V 

OUT 

(3) 

t 

STORE 

= 

I 

⋅ 

t 

⋅ 

f 

PULSE 

PULSE 

( ) 

TRANSMIT 

0,1 

F 

⋅ 

5,25 

V 

− 

3,3 

V 

t STORE = 

= 

1373 

[ 

s 

] (4) 

1 

19 

,04 

mA 

⋅ 

15 

ms 

⋅ 

0,5 

s 

The result is 1373 seconds and this is the period of time during 

which system can work without energy supplied from Peltier 

module. 

A mechanical assembly of the TEG and electronic system 

for energy harvesting are shown in Fig. 3 and Fig. 4 respectively. 

There is additional possibility to connect the node to a PC 

via RS243. Instead of storage capacitor there is a space left 

for battery button as an alternative solution for energy storage. 

The harvesters are currently used to supplying and testing of 

autonomous wireless link which will the topic of our upcoming 

publication. 


Fig. 3. Mechanical assembly of the TEG 

Rys. 3. Konstrukcja mechaniczna termogeneratora 

Conclusions 

Sensor networks with wireless communication are becoming more 

and more common. There have been already some low power wireless 

systems available on the market. The only missing point is 

a reliable power management system with DC-DC converter operating 

from tens of mV. The paper presented a device based on Peltier 

module and LTC3108 converter which can provide power pulses to 

wireless (ZigBee) transmitter and whole sensor network. This power 

can be delivered when the TEG is placed at only 5 o C temperature 

difference between hot and cold side. The device can be easily integrated 

with other application by means of a regulated output voltage. 

When power consumption alternates, the only requirement is to 

calculate proper duty cycle and correct value of C out 

capacitor. 

In our case the whole TEG dimensions are approximately 4 x 4 

x 4 cm and most of its volume is occupied by relatively small heat 

sink. Such a power source can supply a ZigBee sensor node for 

many years, practically much longer that the foreseen life cycle 

for the sensor network, moreover it does not need any inspecting 

or visiting on site for battery replacement. For example, assuming 

Fig. 4. Prototype electronic circuit for energy harvesting and power 

management 

Rys. 4. Prototypowy układ do pozyskiwania energii i zarządzania 

mocą 

temperature of the heat source of 40 o C, the designed energy harvester 

can deliver energy during a year round that is comparable 

to a 1.5 V 1 Ah battery. 

The work was supported by the National Centre for Research 

and Development (NCBiR) project grant No. R02 0073 06/2009. 

References 

[1] Joseph A. D.: Energy Harvesting Projects. Published by the IEEE CS 

and IEEE ComSoc, 1536-1268/05. 

[2] Beeby S., White N.: Energy Harvesting for Autonomous Systems. 

Artech House 2010, ISBN-13: 978-1-59693-718-5. 

[3] Priya S., Inman D. J.: Energy Harvesting Technologies. Springer 

2009, ISBN 978-0-387-76463-4. 

[4] Mirocha A., Dziurdzia P.: Improved electrothermal model of the thermoelectric 

generator implemented in SPICE. Proc. of the International 

Conference on Signals and Electronic Systems, 14–17 Sept. 2008, 

Cracow, Poland, pp. 317–320. 

[5] Datasheet Linear Technology LTC3108, www.linear.com 

[6] Datasheet Sensirion SHT1x. 

[7] Salerno D.: Ultralow Voltage Energy Harvester Uses Thermoeletric 

Generator for Battery-free Wireless Sensors. LT Journal, 2010. 

An investigation of the quality of the conductive lines 

deposited by inkjet printing on different substrates 

(Badanie jakości ścieżek przewodzących wytworzonych metodą druku 

strumieniowego na różnych podłożach) 

Ph.D Janusz Sitek 1) , M.Sc.Eng. Konrad Futera 1,5) , Darko Belavič 2,3,4) , Ph.D Marina 

Santo Zarnik 2,3,4) , M.Sc.Eng. Marek Kościelski 1) , Ph.D Krystyna Bukat 1) , M.Sc. Kamil 

Janeczek 1) , Ph.D Danjela Kuščer Hrovatin 2,4) , D.Sc.Eng. Małgorzata Jakubowska 5,6) 

1) 

Tele- and Radio Research Institute, Centre of Advance Technology, Warsaw, 2) Jozef Stefan Institute, Ljubljana, Slovenia 

3) 

HIPOT-RR, Otočec, Slovenia, 4) Centre of Excellence NAMASTE, Ljubljana, Slovenia 

5) 

Warsaw University of Technology, Faculty of Mechatronics, 6) Institute of Electronic Materials Technology, Warsaw 

A lot of telecommunications, medical, industrial automation 

and measurement equipment, as well as sensor applications, 

are currently in the process of miniaturizing their dimensions. 

The reliability requirements of electronic equipment and devices 

is also constantly on the rise. One of the miniaturization 

solutions is thick-film technology and 3D structures [1]. 

Such devices require conductive lines to connect the different 

layers of simply manufactured devices. The fabrication of reliable, 

very narrow, conductive lines for thick-film and other 

structures is a crucial issue in the production of electronic 

components. Inkjet printing is a technology that could be ap- 

32 

plied for this. It is the element of printed electronics that belongs 

to one of the most important, emerging technologies of 

the moment [2]. 

Inkjet printing, as a method for the deposition of conductivenanoparticle-based 

inks is a good solution for the fabrication 

of good quality and highly reliable electronic circuits. Inkjet 

printing is an additive (non-waste) low-temperature process, 

which makes it a low-cost and more environmentally friendly 

technology. 

In this paper an investigation of the quality of inkjet-printed 

conductive lines on different substrates is presented. 


Materials and printing system 

Three different types of substrates were used during the investigations: 

a pre-fired LTCC substrate (Du Pont 951), a green tape 

LTCC (Du Pont 951) and alumina (96% Al 2 

O 3 

). An ink based on 

nanosilver powder was used for the investigation [3]. It was a commercially 

available ink made in Poland by the Amepox Company. 

The test pattern on the substrates was made with a self-built 

InkJet printer system [4]. It allows a great deal of flexibility in the research 

work. It was designed and built at the Tele & Radio Research 

Institute (ITR). The issue was to design a flexible, low-cost printing 

system to support the material science investigation, technology optimization 

and new technology development. The printing system 

is based on the MicroDrop, piezoceramic PZT print head. It gives 

a wide spectrum of compatible inks. It is possible to use inks with 

a pH in the range 1–12 and viscosity 1–12 cPs [4, 5]. The nozzle 

diameters for this printer are 50 μm and 100 μm, and the drop volume 

is in the range from 35 pl to 85 pl. The print head has a heater 

that allows heating up the ink inside the nozzle up to 100˚C. 

Deposition conditions for the test pattern 

and conductive lines 

A special test-pattern design was used for the investigation of the 

quality of the conductive lines. It contains straight and circular lines to 

check their quality after different printing conditions (Fig. 1 and 2). The 

printing conditions for the test pattern’s straight lines were as follow: 

● the line No. 1 – a single overprint; 

● the line No. 2 – a double overprint in the same place; 

● the line No. 3 – a triple overprint in the same place; 

● the line No. 4 – a single overprint of two lines, next to one 

another, with a distance between them of 0.24 mm; 

● the line No. 5 – a single overprint of four lines, next to one another, 

with a distance between them of 0.10 mm and 0.20 mm; 

● the line No. 6 – a double overprint of four lines, next to one 

another, with a distance between them of 0.10 mm and 

0.18 mm, as shown in Fig. 2. 

a) b) 

A nozzle diameter of 100 μm and a dot spacing of 150 μm 

were used in the printing process. The print head impulse was 

set to 110 V and 50 μs. After the printing process the samples 

were dried on a heated printer stage. A drying temperature of 

60˚C was set up. 

Firing conditions 

The printed and dried samples were divided into two groups. The 

first group was fired at a low temperature (350°C) for one hour. 

The second group of samples was fired at a high temperature 

using the profile shown in Fig. 3. In detail: the pre-fired LTCC and 

alumina Al 2 

O 3 

substrates were fired with a „30-minutes-temperature 

profile”, using a peak firing temperature of 850°C (10 minutes). 

The green tape LTCC substrate was fired on the „Du Pont 

LTCC-temperature profile” with a peak firing temperature of 875°C 

(17 minutes). 

During the firing process the organic ingredients evaporated 

from the ink and the printed lines became conductive. 

Temperature (°C) 

1000 

900 

800 

700 

600 

500 

400 

300 

200 

100 

0 

0 20 40 60 80 100 120 140 160 180 200 220 240 

Time (minutes) 

Fig. 3. The firing profile. Rys. 3. Profil wypalania 

Geometry of the lines after drying and firing 

Fig. 1. Examples of printed and dried lines on: a) pre-fired LTCC, 

b) green tape LTCC 

Rys. 1. Przykłady nadrukowanych i wysuszonych ścieżek na: 

a) wstępnie wypalonej LTCC, b) surowej taśmie LTCC 

The lines’ geometry parameters were investigated after the firing 

processes at low and high temperatures. Optical and metallographic 

microscopes as well as an interferometric profilometer 

were used for the investigation. 

Examples of the optical microscopy observation results after 

firing at a low temperature were shown in Fig. 4. Blurred edges of 

the lines caused by the structure of the ceramic substrate were 

observed. The first layer of ink soaked in the porous substrate 

deforms the edge. The second layer of ink forms a line, and the 

solvents evaporate fast enough to prevent dots from spilling on 

the first layer. 

The best geometry parameter results for the group fired at low 

temperature were obtained for a pre-fired LTCC substrate dried at 

60°C during printing, line no. 3. This line had a triple overprint in 

the same place. 

a) b) c) 

Fig. 2. A test pattern for straight lines printing 

Rys. 2. Wzór testu do nadruku prostych ścieżek 

Fig. 4. The view of printed line no. 3 geometry on different substrates, 

dried at 60°C, after firing at 350°C: a) pre-fired LTCC, b) green tape 

LTCC, c) alumina Al 2 

O 3 

Rys. 4. Wygląd nadrukowanej linii nr 3 na różnych podłożach, suszonej 

w 60°C, po wypaleniu w 350°C: a) wstępnie wypalone LTCC, 

b) surowa taśma LTCC, c) ceramika alundowa Al 2 

O 3 


The examples of the optical microscopy observation results after 

firing at high temperature are shown in Fig. 5. The green tape 

material was not compatible with the silver nano-ink and the cofiring 

process. The shrinkage of the LTCC green tape during the 

firing process was so intense that the printed pattern was ripped 

out of the surface of the sample (Fig. 5b). The acceptable geometry 

parameters for the group fired at high temperature were obtained 

for the pre-fired LTCC and the alumina Al 2 

O 3 

substrates. 

The results of the Al 2 

O 3 

surface morphology before and after firing 

are presented in Fig. 6 and 7. The interferometric profilometer 

was used for measurements. 

a) b) c) 

The thicknesses of the investigated lines were between 4 and 

8 µm after ink-jet printing and drying and from 1.8 to 3.6 µm after 

firing. The width of the printed lines after firing was from 120 μm 

(line No. 1) to 340 μm (line No. 6). The best quality was observed 

for line No. 3 (3 rd from right), but some further improvement of the 

printing parameters is still necessary. 

Surface resistance of lines after drying 

and firing 

The lowest surface resistance of 4.5 mΩ/□ was achieved for line 

No. 3 (average width 0.285 mm, average hieght 3.6 µm), dried at 

60°C and fired at low temperature (350°C) for 1 hour on pre-fired 

LTCC. The lines fired at high temperature had surface resistances 

higher that 10 mΩ/□ (Table), and for wider lines (No. 3, 5 and 6) 

obtained better results. 

Surface resistances of lines (in mΩ/□) for test patterns fired at low (LT) 

and high temperature (HT) 

Rezystancja powierzchniowa ścieżek (w mΩ/□) dla testów wypalanych 

w niskiej (LT) i wysokiej temperaturze (HT) 

Fig. 5. The view of printed lines on different substrates after firing 

at high temperature: a) pre-fired LTCC, b) green tape LTCC, c) alumina 

Al 2 

O 3 

Rys. 5. Wygląd nadrukowanych linii na różnych podłożach po wypaleniu 

w wysokiej temperaturze: a) wstępnie wypalone LTCC, b) surowa 

taśma LTCC, c) ceramika alundowa Al 2 

O 3 

Fig. 6. Printed lines morphology on the alumina substrate before firing 

(sample G12C) 

Rys. 6. Morfologia nadrukowanych ścieżek na podłożu z ceramiki 

alundowej przed wypaleniem (próbka G12C) 

0 2 4 6 8 10 mm 

µm 

0 

55 

0.5 

50 

1 

1.5 

45 

2 

40 

2.5 

35 

3 

30 

3.5 

25 

4 

4.5 

20 

5 

15 

5.5 

10 

6 

5 

6.5 

0 

mm 

Fig. 7. Printed lines morphology on the alumina sample after firing 

(sample G12C) 

Rys. 7. Morfologia nadrukowanych ścieżek na podłożu z ceramiki 

alundowej po wypaleniu (próbka G12C) 

34 

0 2 4 6 8 10 mm 

0 

0.5 

1 

1.5 

2 

2.5 

3 

3.5 

4 

4.5 

5 

5.5 

6 

mm 

µm 

35 

30 

25 

20 

15 

10 

5 

0 

Substrate/ 

line No. 

Pre-fired 

LTCC (LT) 

Green tape 

LTCC (LT) 

1 2 3 4 5 6 

51.6 42.5 4.5 7.1 7.0 – 

25.0 49.0 55.6 6.5 6.4 9.2 

Al 2 

O 3 

(LT) – – 16.6 Ω/□ 3.8 Ω/□ 6.4 Ω/□ 9.0 Ω/□ 

Pre-fired 

LTCC (HT) 

– 29 16 37 10 14 

Al 2 

O 3 

(HT) – 24 23 33 34 18 

Summary 

The geometry and surface morphology as well as the surface 

resistance of the conductive lines were investigated to assess 

the quality of the lines deposited by inkjet printing on different 

substrates. Different lines structures, width and morphology were 

achieved by using different combinations of parameters. Some 

pads made by ink-jet printing were not homogenous, especially 

after firing at high temperature. 

The best quality of lines for the group fired at low temperature 

was obtained for the pre-fired LTCC substrate and line No. 

3. It had the best morphology and the smallest surface resistance 

of 4.5 mΩ/□. The best geometry parameter results for the group 

fired at high temperature were obtained for the pre-fired LTCC 

and alumina (Al 2 

O 3 

) substrates. It was observed that inkjet-printing 

deposition on green tape LTCC and then co-firing using the 

conditions of the LTCC-temperature profile is not a usable technology. 

The likely reason was the shrinkage of the LTCC material 

during firing. Some additional effort is necessary to improve the 

quality of the lines. 

References 

[1] Santo Zarnik M., Belavič D., Maček S.: Some Critical Steps in the 

Manufacturing of LTCC-based Pressure Sensors. MIDEM 2010, 

Radenci, Slovenia. 

[2] Jakubowska M., Sitek J.: Drukowana Elektronika w Polsce. Monografia 

Instytutu Tele- i Radiotechnicznego, Praca zbiorowa, Warszawa 

2010, ISBN: 978-83-926-599-1-4. 

[3] Nanosilver ink datasheet http://www.amepox-mc.com 

[4] Sitek J. et al.: Investigation of inkjet technology for printed organic 

electronics. Elektronika LII Nr 3/2011, s. 112. 

[5] MicorDrop datasheet www.microdrop.de 


High temperature properties of thick-film 

and LTCC components 

(Wysokotemperaturowe właściwości elementów grubowarstwowych i LTCC) 

mgr inż. Damian Nowak, mgr inż. Mateusz Janiak, prof. dr hab. inż. Andrzej Dziedzic, 

dr inż. Tomasz Piasecki 

Politechnika Wrocławska, Wydział Elektroniki Mikrosystemów i Fotoniki 

There is an increased demand for electronics that can work in 

harsh environment involving high temperature. Applications include 

sensors and actuators for control in petroleum and geothermal 

industry, process monitoring and distributed control systems in 

automotive and aerospace [1–3]. Complete extreme high-temperature 

electronic systems require active devices as well as proper 

passive components (eg. resistors, capacitors, inductors). 

There comes also the requirement for further miniaturization and 

integration of electronic components. Thick-film and LTCC (low 

temperature co-fired ceramics) technologies are well-established 

and relatively low-cost fabrication method of passives. Thus, they 

represent promising fabrication techniques to meet the demands 

for devices that are miniaturized and operate at high temperature 

[4–7]. This paper presents manufacturing process of thick-film 

and LTCC resistors, planar inductors and interdigital capacitors 

as well as their chosen electrical and stability properties in a wide 

frequency and temperature range. 

Test structures fabrication 

Square planar inductors and interdigital capacitors were made on 

alumina (96% Al 2 

O 3 

, 635 µm thick) or fired LTCC (DP951, 300 

µm thick) substrates. The size of the fabricated components was 

3×3 mm 2 and 50 μm track width/50 μm spacing were designed. 

The inductors consist of 2 or 3 turns (Fig. 1). The structures were 

fabricated by photoimageable inks technique. Silver based paste 

(Ag 65, ITME Warsaw) was used for conductive paths [8]. The paste 

was deposited on the substrate by screen-printing (stainless 

screen 325 mesh). Then the ink was dried (90ºC, 10 min) and 

exposed to UV light (for 5 seconds) through a photomask with 

a proper patterns. The UV light causes polymerization of the photoimageable 

ink. Unpolymerized material was removed by spraying 

of developer (0.1% ethanolamine). Finally, the structures were 

fired in a belt furnace for 60 min with 850ºC peak temperature. 

The microresistors with regulated length have been made on 

LTCC (DP 951, 300 µm thick) substrates by combining of standard 

screen-printing and photoimageable techniques. Conductive 

paths were prepared from photosensitive ink as described 

above. The distances between electrodes, i.e. proper resistor 

length were designed as 90, 120 and 300 µm. The width of resistors 

was 200 µm. They were made of DP2021 (DuPont, 100 

ohm/sq.) or R490A (Heraeus, 10 ohm/sq.) pastes by printing 

through 325 mesh screen. The conductive and resistive paste 

were co-fired at 850ºC. 

Electrical measurements 

Resistors 

The HP Agilent 34970A multimeter interfaced to personal computer 

for data acquisition and presentation was used for measurements 

of dynamic resistance changes directly at elevated temperature 

(in-situ). The test structures were placed on hot plate 

equipped with spring probe needles and digital temperature controller. 

They were kept consecutively at 300, 400 and 500°C for 

minimum 72 hours. The data were collected every 15 minutes. 

Figures 2 and 3 present dynamic resistance changes of resistors. 

The elevated temperature caused decrease of resistance 

for the DP2021 resistors. The observed drift was about -1.75% at 

300°C. However, keeping at 400°C caused more significant changes 

of resistance up to -7%. The R490A resistors exhibit resistance 

drift about ±2% at 300°C and 400°C. At 500°C the resistance 

has changed about -15%. 

Fig. 2. Relative resistance changes, DP2021 resistors 

Rys. 2. Względne zmiany rezystancji, rezystory DP2021 

Fig. 1. Test structures – planar inductor and thick-film resistor 

(DP2021, 300 µm) 

Rys. 1. Struktury testowe – cewka planarna i rezystor grubowarstwowy 

(DP2021, 300 µm) 

Fig. 3. Relative resistance changes, R490A resistors 

Rys. 3. Względne zmiany rezystancji, rezystory R490A 


Fig. 4. Resistance changes vs electric field for DP2021 resistors 

Rys. 4. Względne zmiany rezystancji w funkcji natężenia pola, rezystory 

DP2021 

Fig. 6. Inductance changes at different temperatures 

Rys. 6. Zmiany indukcyjności w różnej temperaturze 

Fig. 5. Resistance changes vs surface power density for DP2021 resistors 

Rys. 5. Względne zmiany rezystancji w funkcji powierzchniowej gęstości 

mocy, rezystory DP2021 

The investigations of pulse durability of components were 

carried out. Voltage pulses were used for analysis of allowable 

electric field and next surface power density for microresistors in 

dependence of resistor dimensions and operating temperature 

[5]. Exposures to voltage pulses were realized with the aid of self 

made Programmed Pulse Generator [9]. There were chosen the 

rectangular pulses with duration time 20 μs and amplitude value 

from 1 to hundreds of volts. The durability was measured at room 

temperature as well as at elevated temperature to 500°C. As an 

example relative resistance changes are presented as a function 

of electrical field E (Fig. 4) and surface power density P (Fig. 5) 

– both above mentioned dependencies were calculated based on 

resistances and dimensions of microresistors. 

The test were carried out for 4 to 6 resistors with the same 

length at each temperature level. Generally, there was observed 

a decrease of allowable electric field (the criterion of 10% resistance 

change was assumed) with the temperature increase. However, 

at elevated temperature they were comparable. Moreover, 

shorter components exhibited higher durability to voltage pulses. 

Inductors and capacitors 

The electrical measurements of components were made at several 

temperature level in the frequency range from 10 kHz to 

110 MHz using HP Agilent 4292A impedance analyzer. 

Figures 6 and 7 present changes of inductance and quality 

factor of spiral square inductor (3 turns) at different temperature. 

The small changes of inductance were observed whereas Q-factor 

depends strongly on temperature. It is caused by typical for 

metals increase of parasitic series resistance of structure. 

36 

Fig. 7. Q-factor changes at different temperatures 

Rys. 7. Zmiany dobroci w różnej temperaturze 

Fig. 8. Capacitance changes at different temperatures 

Rys. 8. Zmiany pojemności w różnej temperaturze 


Figure 8 presents capacitance changes at different temperature 

for 3 × 3 mm 2 interdigital capacitor. The capacitance was increasing 

with the temperature, especially at lower frequency range. 

Table presents comparison of basic parameters of reactant 

components at chosen frequency. 

Comparison of basic parameters of components at different temperature 

Porównanie podstawowych parametrów elementów w różnej temperaturze 

T 

[ºC] 

L [nH] 

at 38 MHz 

Inductor 

R s 

[Ω] 

Q = ωL/R 

at 38 MHz 

C [pF] 

at 1 MHz 

Capacitor 

Q 

at 1 MHz 

25 111.83 4.29 6.33 2.73 585 

100 111.94 5.35 5.08 2.82 136 

200 111.97 6.7 4.02 – – 

250 112.01 7.5 3.62 2.97 34 

300 112.04 8.23 3.30 3.09 18 

350 112.09 8.91 3.05 3.3 9.5 

400 112.03 9.56 2.84 3.68 4.9 

450 111.88 10.23 2.65 4.15 3 

Conclusions 

This paper presents fabrication and basic electrical and stability 

properties of thick-film and LTCC microcomponents. The preliminary 

results show that they might be very interesting solution for 

harsh environment applications, however, further investigations 

have to be carried out. 

This work was supported by the Polish Ministry of Science 

and Higher Education, Grant no N N515 607 839. Damian Nowak 

is awarded with Fellowship co-financed by European Union within 

European Social Fund (EFS). 

References 

[1] Johannessen R.: Reliable Microelectronics for Harsh Environment 

Applications – Effects Of Thermal Stress and High Pressure. Doctoral 

dissertation, Faculty of Mathematics and Natural Science, University 

of Oslo, 2008. 

[2] Jacq C., Maeder T. and Ryser P.: Sensors and packages based on 

LTCC and thick-film technology for severe conditions. SĀDHANĀ 

– Academy Proceedings in Engineering Sciences, vol. 34 (2009), 

pp. 677–687. 

[3] Nowak D., Dziedzic A.: LTCC Package for high temperature applications. 

Microelectronics Reliab., vol. 51 (2011), pp. 1241–1244. 

[4] Lahti M., Lantto V., Leppavuori S.: Planar inductors on an LTCC 

substrate realized by the gravure-offset-printing technique. IEEE 

Trans. on Components and Packaging Technol., vol.23 (2000), 

pp. 606–610. 

[5] Dziedzic A., Miś E., Rebenklau L., Wolter K.-J.: Geometrical and 

electrical properties of LTCC and thick-film microresistors. Microelectronics 

Int., vol. 22, no.1 (Jan. 2005), pp. 26–33. 

[6] Perrone R., Thust H., Drüe K.-H.: Progress in the Integration of planar 

and 3D Coils on LTCC by using photoimageable Inks. J. of Microelectronics 

and Electronic Packaging, vol. 2 (2005), pp. 155–161. 

[7] Miś E., Dziedzic A., Piasecki T., Kita J., Moos R.: Geometrical, electrical 

and stability properties of thick-film and LTCC microcapacitors. 

Microelectronics Int., vol.25 no 2 (2008), pp. 37–41. 

[8] Markowski P., Jakubowska M., Zwierkowska E., Danielkiewicz M., 

Wolter K. J., Luniak M.: Properties of thick-film photoimageable inks 

for LTCC substrates. Elektronika (Warszawa). 2011, R. 52, nr 3, 

pp. 109–111. 

[9] Dziedzic A., Golonka L.J., Kita J., Roguszczak H., Zdanowicz T.: 

Some remarks about „short” pulse behaviour of LTCC and thick-film 

Microsystems. Proc. 1st Eur. Microelectronics and Packaging Symp., 

Prague (Czech Republic), June 2000, pp. 194–199. 

LTCC microfluidic chip with fluorescence based detection 

(Mikroprzepływowy fluorescencyjny czujnik ceramiczny wykonany 

techniką LTCC) 

mgr inż. Mateusz Czok, dr inż. Karol Malecha, prof. dr hab. inż. Leszek Golonka 

Wrocław University of Technology, Faculty of Microsystem Electronics and Photonics 

Nowadays miniaturization is present in many fields of science (electronics, 

medicine, biology and chemistry). Over the last few years 

many research into miniaturization and microfabrication were carried 

out. As a result the concepts of the micro-total analysis system (µTAS) 

and Lab-on-Chip (LoC) were proposed. These devices integrate several 

laboratory functionalities in a single miniature structure [1, 2]. 

There are few technologies that can be applied in the realization of 

the LoC devices. For many years the most common used materials 

were silicon and glass wafers [3, 4]. As an alternative solution few 

other materials like PDMS (poly(dimethylsiloxane)) or PCB (Printed 

Circuit Boards) were used for microsystems fabrication [5, 6]. 

The Low Temperature Co-fired Ceramics (LTCC) seems to be 

a suitable material to realize LoC devices. Channels, chambers, 

valves, electronic and optoelectronic components can be easily 

integrated in one LTCC module [7, 8]. It also has outstanding physical 

and chemical properties [9]. 

The main motivation is to use the LTCC technology in the fabrication 

of the microfluidic chip, in which fluorescence detection of 

biological sample can be performed. The manufactured detection 

module consists of inexpensive and commonly available electronic 

components and PMMA (poly(methyl methacrylate)) optic 

fibres integrated with the LTCC microfluidic chip. It is made up of 

the microfluidic channel, cavities for fiber optics, miniature light 

emitting diode and photodetector. 

The LTCC microfluidic chip performance is investigated with 

several different concentrations of fluorescein solutions which 

are excited with 465 nm light source. The emitted fluorescent 

light is coupled into two separate optic fibres and its intensity is 

measured with two photodetectors (TSLG 257 and TCS 3414). 

The developed microfluidic structure can be assigned to detection 

of Gram-negative and Gram-positive bacteria. 

Fabrication process 

The LTCC technology was used for fabrication of a microfluidic 

system with fluorescence based detection. During manufacturing 

process twelve layers of DuPont 951 PX ceramic 

tapes were used. Thickness of each LTCC tape was equal to 

216 µm after firing. Channels, cavities, termination holes were 

cut with the Nd-YAG laser system. A simple electronic circuit 

was screen printed through a 325 mesh stainless steel screen 

at the bottom side of the microfluidic chip. The PdAg thick-film 

paste (DP 6146) was used for that this purpose. After laser cutting 

and screen printing all ceramic tapes were stacked and 

laminated using an isostatic press. The lamination process was 

carried out in a low pressure of 2 MPa and at a temperature of 

70°C for 10 minutes. Then the LTCC laminate was co-fired in 

a box furnace at a recommended firing profile with a peak temperature 

at 850°C. 


Fig. 1. Assembled LTCC device 

Rys. 1. Mikroprzepływowy czujnik fluorescencyjny wykonany techniką 

LTCC 

Results 

Fluorescence measurements of five different fluorescein concentrations 

were carried out to examine the quality of the LTCC 

microfluidic chip. Fluorescein is a well know fluorescent dye. It is 

widely used in biological and medical applications as a proteins 

and antibodies marker. The 98% pure ethyl alcohol was used in 

fluorescein solutions preparation. Ethanol is an organic solvent 

in which fluorescein can be readily dissolved. The maximum 

fluorescence solubility in ethanol solvent equals to 20 g/dm 3 at 

temperature of 20°C. Investigated solutions fluoresces green 

(520 nm) when is exposed to 465 nm excitation light. 

In order to examine the properties of the fabricated LTCC microfluidic 

chip, fluorescein concentrations from 0.02 to 0.32 g/dm 3 

were used. The Perfusor ® syringe pump was used to force the 

fluid flow in the microfluidic channel. Fluorescein concentrations 

were gradually changed in approximately 3 minutes time intervals. 

Between measurements microfluidic channel was purged 

with 98% pure ethyl alcohol. Each solution was illuminated with 

blue excitation light (465 nm) which was transmitted through the 

input fibre optic. As a result the green fluorescent light was emitted 

by the test solution. The fluorescence signal was coupled into 

two separate PMMA optical fibres and transmitted to appropriate 

photodetector (TSLG 257 and TCS 3414). 

Typical 5 V DC power supply was used to feed the LTCC microfluidic 

chip. Measurements of the TSLG 257 light-to-voltage 

converter output signal were performed with Agilent 34401A multimeter. 

As the TCS 3414 has a build-in analog to digital converter 

measured signal level is given in digital absolute unit. To avoid the 

temperature and light influence the experiment were carried out at 

room temperature in dark and air-conditioned room. Photodetectors 

responses to various test solutions are given in Fig. 3 and 4. 

Fig. 2. X-ray image of manufactured device 

Rys. 2. Zdjęcie RTG wykonanego urządzenia 

After co-firing three PMMA optic fibres with a diameter of 750 

µm were precisely positioned and glued into the LTCC module. 

Then the light source (LED HB3b-448ABD, Huey Jann Electronics 

Industry Co., Ltd.), photodetector (TSLG 257, TAOS) and passive 

electronic components were soldered on the LTCC microfluidic 

chip. The HB3b-448ABD is a super blue light emitting diode (LED) 

with a peak wavelength at λ p 

= 465 nm and the spectral halfwidth 

∆λ½ = 35 nm. The TSLG 257 is a high-sensitivity low-noise light to 

voltage converter that consists of a photodiode, an amplifier and 

a green filter combined in a single monolithic CMOS structure. 

The output voltage is proportional to light irradiance on the photodiode. 

The TLSG 257 has the maximum spectral responsivity at 

520 nm with the spectral halfwidth equal to 35 nm. The TCS 3414 

(TAOS) is used as an external digital light sensor for real-time 

measurement. The device includes an array of 16 filtered photodiodes 

(red, green, blue and clear channel) and analog-to-digital 

converters with programmable gain integrated on a single monolithic 

CMOS structure. The TCS 3414 contains analog-to-digital 

converter for each channel that integrates the currents from four 

photodiodes. Integration of all channels is made simultaneously 

and then the conversion results are transferred to the channel 

data registers. 

The assembled structure of the LTCC microfluidic chip with 

fluorescence based detection is presented in Fig. 1. An X-ray 

Computed Tomography was used to examine the PMMA optic fibres 

positioning precision and possible defects of the fabricated 

module. The X-ray image of manufactured device is presented in 

Fig. 2. As can be noticed optic fibres were precisely positioned 

and mounted. Moreover, delamination or LTCC layers misalignment 

were not observed. 

38 

Fig. 3. Photodetector (TSLG 257) response to various fluorescein 

concentrations 

Rys. 3. Odpowiedź fotodetektora (TSLG 257) dla różnych koncentracji 

fluoresceiny 

Fig. 4. Photodetector (TCS 3414) response to various fluorescein 

concentrations 

Fig. 4. Odpowiedź fotodetektora (TCS 3414) dla różnych koncentracji 

fluoresceiny 


The measured fluorescence intensity is proportional to the test 

solution concentration. In order to evaluate the measurement repeatability 

of fabricated microfluidic chip two measurement series 

were performed in 24 h interval. Obtained repeatability was better 

than 95%. 

The TCS 3414 response indicates high stability during realtime 

measurements for concentrations below 0.32 g/dm 3 . Moreover, 

the digital light sensor gave us additional information about 

signals levels measured by photodiodes with red, blue colour filter 

and the total light illumination. This could be used to evaluate 

the influence of the excitation light on the measured fluorescence 

signal. 

High signal fluctuation for 0.32 g/dm 3 concentration of test 

solution was observed. This could be caused by fluorescence 

self-quenching phenomenon. Its threshold value is close to the 

highest fluorescein concentration of the examined solutions. 

Summary 

The LTCC technology was applied for manufacturing of the microfluidic 

chip in which fluorescence detection of various fluorescein solutions 

can be performed. Moreover, light emiting diode, light-to-voltage 

converter and PMMA optic fibres were integrated on the chip. 

Inexpensive and commonly available electronic components 

(light emitting diode, photodetectors, PMMA fibre optics) were 

used to fabricate the detection module. 

The performance of the LTCC microfluidic chip was investigated 

with two separate photodetectors. Measured responses to 

several concentrations of fluorescein solution were proportional 

to the fluorescein concentration. 

Measurement repeatability was very high with less than 5% 

error. The TCS 3414 response indicates high stability in real-time 

measurements. 

The performed experiments have shown that it is possible to 

detect fluorescent signal inside the LTCC-based microfluidic chip. 

The developed LTCC microfluidic chip can be assigned to detection 

of Gram-negative and Gram-positive bacteria. 

The authors wish to thank Wroclaw University of Technology 

(grant no. 343 745) for the financial support. 

Karol Malecha fellowship is co-financed by European Union within 

European Social Fund (ESF). 

X-ray Computed Tomography pictures were carried out in the Laboratory 

for Interconnecting and Packaging Electronic Circuits, 

Wrocław University of Technology. 

References 

[1] Rivet C., Lee H., Hirsch A., Hamilton S., Lu H.: Microfluidics for medical 

diagnostics and biosensors. Chemical Engineering Science, Vol. 

66, 2011, pp. 1490–1507. 

[2] Malecha K., Pijanowska D. G., Golonka L. J., Torbicz W.: LTCC microreactor 

for urea determination in biological fluids. Sensors and 

Actuators B: Chemical, Vol. 141, No. 1, 2009, pp. 301–308. 

[3] Odijk M., Baumann A., Olthuis W., A. van den Berg, Karst U.: Electrochemistry-on-chip 

for on-line conversions in drug metabolism studies. 

Biosensors and Bioelectronics, Vol. 26, 2010, pp. 1521–1527. 

[4] Radadia A. D., Salehi-Khojin A., Masel R. I., Shannon M. A.: The 

effect of microcolumn geometry on the performance of micro-gas 

chromatography columns for chip scale gas analyzers. Sensors and 

Actuators B, Vol. 150, 2010, pp. 456–464. 

[5] Ziółkowska K., et al.: PDMS/glass microfluidic cell culture system 

for cytotoxicity tests and cells passage. Sensors and Actuators B: 

Chemical, Vol. 145, 2010, pp. 533–542. 

[6] Gassmann S., Pagel L.: Fluidic systems in Printed Circuit Boards. 

IEEE International Symposium on Industrial Electronics, 2009, 

pp. 597-602. 

[7] Golonka L. J., et al.: LTCC based microfluidic system with optical 

detection. Sensors and Actuators B: Chemical, Vol. 111–112, 2005, 

pp. 396–402. 

[8] Misiakos K., et al.: Fully integrated monolithic optoelectronic transducer 

for real-time protein. Biosensors and Bioelectronics, Vol. 26, 


[9] Thelemann T., Fischer M., Muller J.: LTCC-based fluidic components 

for chemical applications. Journal of Microelectronics and Electronic 

Packaging, Vol. 4, 2007, pp. 167–172. 

Investigation of multiple degradation and rejuvenation 

cycles of electroluminescent thick film structures 

(Badanie powtarzanych cykli degradacji i regeneracji grubowarstwowych 

struktur elektroluminescencyjnych) 

mgr inż. MATEUSZ MROCZKOWSKI 1) , dr inż. MICHAŁ CIEŻ 2) , dr inż. JERZY KALENIK 1) 

1) 

Politechnika Warszawska, Instytut Mikroelektroniki i Optoelektroniki, 2) Instytut Technologii Elektronowej 

Copper doped zinc sulfide displays electroluminescent prosperities 

and it is used as a phosphor in thick film light emitting structures. 

Such electroluminescent structures, or alternating current 

electroluminescent devices (ACEL), are used as backlight for 

liquid crystal displays in portable electronic devices (cell phones, 

notebooks, PDAs, etc.) and as a source of light in the advertising 

industry. Unfortunately such structures are prone to degradation 

and have a limited life time [1, 2]. 

Degraded electroluminescent thick film structures can be 

rejuvenated by annealing [1]. An attempt to investigate the possibility 

of repeated rejuvenation of degraded EL lamps was undertaken. 

The goal of this investigation is to better understand 

the mechanism of degradation and rejuvenation of thick film EL 

lamps and prolong their life time. 

Alternating Current Electroluminescent 

Devices (ACEL) 

Typical EL lamps are fabricated as a multi-layer thick film structures. 

A layer of phosphor, for example a copper doped zinc sulfide, is 

placed in between two layer of conductive materials. This makes 

this structure similar to a simple parallel-plate capacitor. Usually EL 

lamp structures consist of 4 layers: a layer of transparent conductive 

material, e.g. Indium Tin Oxide (ITO), a layer of phosphor, a layer of 

dielectric and a layer of metallic conductor, e.g. silver. The layer of 

transparent conductor is fabricated on a transparent substrate [1]. 

In order to cause such structures to emit light alternating current 

must by applied. It is necessary that the value of applied electric 

field is above 1 MV/m or no light emission will be observed. 

Frequency of the alternating current is usually 100 Hz to 20 kHz. 

Fig. 1. Cross-section of a thick film electroluminescent lamp 

Rys. 1. Przekrój grubowarstwowej lampy elektroluminescencyjnej 


Test structures 

The test structures were prepared at Institute of Electron Technology, 

Division in Cracow. A set of DuPont Luxprint inks, dedicated 

to fabricate electroluminescent thick film structures, was utilized 

to prepare the test structures. A Luxprint 8152B ZnS:Cu based ink 

was applied to produce electroluminescent layer on ITO covered 

transparent polymer substrate. Conductive electrodes were screen 

printed with the use of a silver based ink. Both pastes were 

cured by drying at 130°C for 30 minutes in a box oven. 

Degradation 

Several mechanisms of degradation of EL phosphors have been 

discussed in the literature [1]. Most often it is suggested that degradation 

process involves S vacancy or doppant diffusion in ZnS 

lattice [2, 3]. Some authors suggest that mechanism that lower 

the efficiency of electron/hole injection may be of importance [4]. 

Degradation causes luminance to decrease. These changes 

are a two phase process. The first phase is characterized by rapid 

decrease of luminance. In the second phase of degradation 

changes of luminance value are slower. Changes of luminance B 

as a function of time are given by equation (1). 

40 

B(t)/B(0) = a 1 

exp (-t/τ 1 

) + a 2 

exp (-t/τ 2 

) (1) 

Constants a 1 

and τ 1 

describe changes of luminance caused by 

moisture. Constants a 2 

and τ 2 

describe changes of luminance 

caused by decomposition of ZnS grains. Sum of a 1 

and a 2 

is always 

equal to one [5]. 

The experiment 

During the experiment test samples were degraded by applying 

square-wave voltage of amplitude of 150 V and frequency of 4 or 

10 kHz. After a certain amount of time, samples were rejuvenated 

by annealing in temperature of 130°C for 2 hours. This process of 

degradation and rejuvenation was repeated. 

Results 

To characterize the influence of degradation on ACEL devices following 

parameters were measured: luminance, capacitance and 

emission spectra. 

Luminance 

For samples degraded at 4 kHz [pic. 2] and 10 kHz [pic. 3] rejuvenation 

was performed twice. Before first rejuvenation luminance 

of 10 kHz samples was 31% of initial value and of 4 kHz samples 

27% of initial value. After rejuvenation luminance increased to 51% 

of initial value for 10 kHz samples and 38% for 4 kHz samples. 

Before second rejuvenation luminance decreased to 33% 

(10 kHz samples) and 18% (4 kHz samples). After second rejuvenation 

luminance increased to 43% (10 kHz samples) and 

25% (4 kHz samples). Rejuvenation gave better results in case 

of 10 kHz samples. Important is the fact, that repeatable rejuvenation 

is possible. 

Fig. 2. Luminance as a function of time – 10 kHz samples 

Rys. 2. Luminancja w funkcji czasu – próbki starzone przy 10 kHz 

Fig. 3. Luminance as a function of time – 4 kHz samples 

Rys. 3. Luminancja w funkcji czasu – próbki starzone przy 4 kHz 

Emission spectrum 

During the experiment emission spectrum was observed. When 

spectrums measured before and after degradation and after rejuvenation 

were compared only differences were observed in the 

amount of energy emitted. No changes were observed in the shape 

of emission spectrum. This suggest that, during degradation, 

efficiency of light emission decreases, but there are no changes 

in the electronic band structure of the phosphor. Also the rejuvenation 

does not change the band structure. 

Capacitance 

Table shows results of capacitance measurements during degradation 

and rejuvenation. These measurements were performed 

for samples depredated at 10 kHz. No significant changes of capacitance 

was observed, so the value of the electric field applied 

to the structure is constant during the degradation and rejuvenation 

process. 

Capacitance of 10 kHz samples 

Pojemność próbek starzonych przy 10 kHz 

Time of measurement 

Capacitance [nF] 

Initial 2.058 

Before first rejuvenation 2.094 

After first rejuvenation 2.055 

Before second rejuvenation 2.046 

After second rejuvenation 2.051 

Conclusions 

● Decrease of luminance during degradation is a two phase process. 

● Annealing allows repeatable rejuvenation. 

● No significant changes of emission spectrum suggest no changes 

in the band structure of the phosphor. 

● No significant changes of capacitance exclude changes of value 

of the applied electric field as a reason of decrease of luminance. 

References 

[1] Stanley J., Yu Jiang, Bridges F., Carter SA, Ruhlen L.: Degradation 

and rejuvenation studies of AC electroluminescent ZnS:Cu,Cl phosphors. 

J. Phys.: Condens. Matter, 22, 2010, pp. 055301. 

[2] Hirabayashi K., Kozawaguchi H., Tsujiyama B.: Study on A-C Powder 

EL Phosphor Deterioration Factors. J. Electrochem. Soc., 130, 1983, 

pp. 2259–2263. 

[3] Lehmann W.: Hyper-Maintenance of Electroluminescence. J. Electrochem. 

Soc., 113, 1966, pp. 40–42. 

[4] Fischer A.G.: Electroluminescent Lines in ZnS Powder Particles. 

J. Electrochem. Soc., 110, 1963, pp. 733–748. 

[5] Porada Z., Cież M.: Model matematyczny opisujący wpływ procesów 

starzeniowych na parametry elektroluminescencyjne struktur 

grubowarstwowych. Elektronika, Vol. LI, No. 6, 2010, pp. 123–125. 


Investigations of passive components embedded 

in printed circuit boards 

(Badania podzespołów biernych wbudowanych 

w płytki obwodów drukowanych) 

mgr inż. Wojciech Stęplewski 1) , mgr inż. Tomasz Serzysko 1) , dr Grażyna Kozioł 1) , 

mgr inż. Kamil Janeczek 1) , prof. dr hab. inż. Andrzej Dziedzic 2) 

1) 

Tele and Radio Research Institute, Centre of Advanced Technology, Warsaw 

2) 

Wrocław University of Technology, Faculty of Microsystem Electronics and Photonics 

The concept of passive components embedded between inner 

layers of printed circuit board (PCB) was introduced many 

years ago. The first trials of embedded capacitors started at 

the end of sixties of the last century [1]. In the beginning of seventies 

started the applying of NiP layers for manufacturing of 

thin layer resistors [2]. Up to present day many materials which 

can be used for embedded passives were elaborated. But this 

technology is used in small range, especially in military and air 

electronics as well as in space electronics. Due to the increasing 

number of components which are now required to support 

a single active device, the passives are quickly becoming the 

major bottleneck in the general miniaturization trend which has 

become so important in today’s electronics world. The miniaturization 

of conventional passives reaches its limits and the 

next obvious choice is to embed the passive components into 

the PCB. This allows further miniaturization, has the potential 

to reduce cost and moreover exhibits superior electrical behavior 

with respect to the minimization of parasitic effects [3, 4]. 

Despite unquestionable advantages which characterize the embedded 

elements, they are not generally used in the production 

of PCBs. As well the designing of electronic devices such as 

filters, generators, RFID systems and many others, which are 

composed of passive components, was not to this time used 

on larger scale and knowledge in this matter is still very poor. 

Embedding passives will permit to integrate these elements 

and whole structures into the PCB. The idea of packing more 

and more elements in PCBs by application and development 

of embedding passives technologies becomes a necessity for 

electronic equipment producers. 

Materials and structures 

Thin-film resistors 

In the investigations two types of materials with sheet resistance 

of 25 Ω/□ (thickness 0.4 µm) and 100 Ω/□ (thickness 0.1 µm) 

were used. Thin-film resistors were designed in three sizes, which 

were fabricated on ten specimens of the same size in configuration: 

1.5 mm × 4 squares, 1.0 mm × 2 squares, 0.5 mm × 1 

square, 1.0 mm × 2 squares. 

Thick-film resistors 

For manufacturing of the resistors the inks with sheet resistance 

200 Ω/□ (ED7100_200 Ω – carbon ink), 20 Ω/□ (ED7500_20 Ω – 

carbon-silver ink) and 5 kΩ/□ (ED7500_5 kΩ – carbon-silver ink) 

were used. These inks were applied by screen printing through 

yellow PET mesh (77T) using a capillary film with a thickness of 

25 µm. The resistors were designed in the form of bars, which are 

optimal for screen printing. The resistors had the same sizes as 

the afore mentioned thin-film resistors. The resistors were printed 

on Cu contacts (Fig. 1a), asymmetric Cu contacts (Fig. 1b) to 

compensate mechanical stresses [5], Cu contacts with protective 

Ni/Au coating (Fig. 1c) and Ag contacts (Electrodag PF-050 ink, 

Fig. 1d). 

a) 

b) 

c) 

d) 

Capacitors 

Cu contacts 

resistive layer 

asymmetric Cu contacts 


contacts with protective coating Ni/Au 


Ag layer 


Cu contact 

Fig. 1. Type of contacts: a) Cu; b) asymmetric Cu; c) Cu with protective 

coating Ni/Au; d) Ag 

Rys. 1. Rodzaje pól kontaktowych: a) Cu; b) asymetryczne Cu; 

c) z warstwa ochronną Ni/Au; d) Ag 

FaradFlex BC24 M and BC12TM dielectric materials with basic 

parameters shown in Table 1 were used for fabrication of capacitors. 

Tabl. 1. Basic properties of used capacitance materials 

Tab. 1. Podstawowe parametry użytego materiału pojemnościowego 

Properties BC24 M BC12TM 

Dielectric thickness [µm] 24 12 

C P 

1 MHz/1 GHz [pF/cm 2 ] 180/160 700/600 

D K 

1 MHz/1 GHz 4.4/4.0 10/8.5 

Dielectric strength [kV/mil] 7.0+ 5.8 


Nine types of capacitors are designed with the following parameters: 

– BC24 M capacitances in the range of 1.5 pF (for a nominal 

electrodes area of 0.9 mm × 0.9 mm) to 352.8 pF (14 mm × 

14 mm); 

– BC12TM capacitances in the range of 5.7 pF (0.9 mm × 

0.9 mm) to 1372 pF (14 mm × 14 mm). 

Combined material for embedded resistors and capacitors 

The composite Ohmega/FaradFlex used in performed tests 

consisted of a thin film capacitive layer BC24 M with the thickness 

of 24 µm enclosed between two copper foils each with 35 µm 

thickness. Under one of the foils a NiP 25 Ω/square resistive layer 

is applied. 

For the investigation the test board containing the electronic 

circuit composed of capacitor and resistor forming a low-pass filter 

was designed. All resistors were designed with a width of 0.5 mm. 

The project included a correction to compensate for a resistance 

increase during the manufacturing processes by 15%. 

Results 

Impact of oxide treatment and lamination on resistance 

The most important manufacturing steps which have a significant 

influence on the parameters of embedded resistors are oxide 

treatment processes and lamination. Oxide treatment processes 

were carried out in an aggressive environment of which the main 

ingredient was sulfuric acid (J-KEM technology). During the lamination 

the devices were exposed to high pressure (30 bar) and 

high temperature (up to 180°C) [6]. The exemplary resistance 

changes after oxide treatment process and lamination are presented 

in Figures 3–7. 

Tabl. 2. Parameters of designed low-pass filters 

Tab. 2. Parametry zaprojektowanych filtrów dolnoprzepustowych 

Lp. 

R 

[kΩ] 

R 

length 

[mm] 

C 

[pF] 

C 

size 

[mm] 

cutoff frequency 

[kHz] 

1. 1.000 17.00 318.31 13.68 × 13.68 500.00 

2. 0.330 5.61 482.29 16.84 × 16.84 1 000.00 

3. 0.150 2.55 212.21 11.17 × 11.17 4 999.92 

4. 0.082 1.39 194.09 10.69 × 10.69 10 000.08 

5. 0.056 0.95 56.84 5.78 × 5.78 50 000.97 

Fig. 3. Example of resistance changes after J-KEM brown oxide processes 

and lamination, 25 Ω /□ 

Rys. 3. Przykładowe zmiany rezystancji po procesie nakładania tlenków 

w technologii J-KEM i prasowaniu, 25 Ω /□ 

Experimental 

The basic functional parameters of embedded passives like resistance 

and capacitance and their dependence on parameters 

of the manufacturing process were examined. The environmental 

tests in changing temperature were used additionally. 

The measurements of resistor resistance were made with 

the aid of Agilent 34401A laboratory multimeter. The four-point 

method which permits for the elimination of the measuring cable 

resistance on the measurement results was used. 

The capacitance of the capacitors was measured by the LCR 

HAMEG type HM8118 laboratory bridge which was equipped with 

the appropriate coaxial cables assembled in a configuration of 

three terminals 3T. This configuration reduces the effects of stray 

capacitance. 

The influence of climatic variation on the resistance value of 

resistors was investigated in the CTS-70/200 Climatic Chamber. 

The durability of PCBs with resistors were tested on thermal cycles 

with temperature changes in the range of -40…85˚C. The duration 

of one cycle was 8.5 hours. Figure 3 shows the scheme of 

the cycle. 120 exposure cycles were made. 

Fig. 2. Scheme of the temperature cycle 

Rys. 2. Schemat cykli temperaturowych 

42 

Temperature [ C] 

100 

80 

60 

40 

20 

0 

-20 

-40 

-60 

-80 

2˚C/min 

2˚C/min 

0 0,5 1 2 3 4 5 6 7 8 8,5 

0,5 h 0,5 h 3 h 0,5 h 3 h 0,5 h 

Time [h] 


and lamination, 100 Ω /□ 


w technologii J-KEM i prasowaniu, 100 Ω /□ 

Change of resistance [%] 

10 

5 

0 

-5 

-10 

-15 

20 

0 10 20 30 40 

1.5 mm 1.0 mm 0.5 mm 1.0 mm 

after oxides 

Number of resistor 

after laminaon 


and lamination, ED7100 200 Ω /□ 


w technologii J-KEM i prasowaniu, ED7100 200 Ω /□ 



10 

5 

0 

-5 

-10 

-15 

-20 

0 10 20 30 40 

1.5 mm 1.0 mm 0.5 mm 1.0 mm 

after oxides 


after lamianation 

Change of resistance[%] 

NiP 25 ohm 

6 

NiP 100 ohm 

4 

2 

0 

-2 

-4 

-6 

-8 

-10 

-12 

1.5 mm 1.0 mm 0.5 mm 1.0 mm 

0 10 20 30 40 



and lamination, ED7500 20 Ω /□ 


w technologii J-KEM i prasowaniu, ED7500 20 Ω /□ 

Fig. 9. Example of resistance changes after double reflow soldering 

process, NiP 25 Ω /□ and 100 Ω /□ 

Rys. 9. Przykładowe zmiany rezystancji po procesie dwukrotnego lutowania 

rozpływowego, NiP 25 Ω /□ and 100 Ω /□ 


10 

5 

0 

-5 

-10 

-15 

-20 

0 10 20 30 40 

1.5 mm 1.0 mm 0.5 mm 1.0 mm 

after oxides 


after lamination 

Change of resistance[%] 

6 

4 

2 

0 

-2 

-4 

-6 

ED7100_200ohm 

ED7500_20ohm 

ED7500_5kohm 

1.5 mm 1.0 mm 0.5 mm 1.0 mm 

0 10 20 30 40 



and lamination, ED7500 5 kΩ /□ 


w technologii J-KEM i prasowaniu, ED7500 5 kΩ /□ 

Fig. 10. Example of resistance changes after double reflow soldering 

process, ED7100, ED7500 

Rys. 10. Przykładowe zmiany rezystancji po procesie dwukrotnego 

lutowania rozpływowego, ED7100, ED7500 

Fig. 8. Reflow soldering profile 

Rys. 8. Profil lutowania rozpływowego 

The oxide treatment increased the resistance of thin-film resistors 

(Fig. 3–4). On the exposure of acid solution the thin resistive 

layer was slowly dissolving. As a result, there is a reduction of thickness. 

The influence of acid solution on thick-film resistors was 

significantly lower. The lamination process caused only a slight 

change in resistance of thin-film resistors. In the case of thick-film 

resistors the influence of this process was more significant. This 

is due to the phenomenon of an additional resistor curing under 

high pressure and temperature. Additional curing of the resistors 

at the lamination temperature reduced the changes resulting from 

the lamination process. In the investigations it was found that 

a second lamination process at a temperature of 180°C reduced 

the resistance changes to 1–2% without deterioration of resistor 

properties. 

The resistors were also exposed to a temperature profile simulating 

a lead-free reflow soldering process (Fig. 8). Maximum 

temperature on the PCB surface was about 250°C. It was done 

double reflow soldering process. 

Double reflow soldering did not cause changes in the case 

of thin-film resistor 25 Ω /□. Resistors made from the layers of 

100 Ω /□ had slight changes in the resistance between +2% and 

-2%. The 100 Ω /□ layer was four times thinner. Therefore in 

soldering process higher changes of resistance may reveal. Laminated 

thick film resistors were characterized by changes at 

the level of 2% in the case of carbon ink and 2…5% for carbonsilver 

inks. 

Environmental tests of resistors 

The Figures 11–14 present the change in resistance of embedded 

resistors after 120 thermal cycles in a climatic chamber. 

After 120 temperature cycles the increase of thin-film resistors 

resistance from 1–1.5% for the NiP layer 25 Ω /□ to 1.5–2.5% in 

the case of NiP layer 100 Ω /□ was noticed. Slightly smaller changes 

of 25 Ω /□ layer resistance in temperature cycles were likely 

a result of its greater thickness. The thick-film resistors with Cu 

contacts exhibit very large resistance changes, especially for the 

width of 0.5 mm. The use of the Ag or Ni/Au contact layers definitely 

improves the quality of connection between ink and contact. 

Significant worse quality of resistors with Cu contacts might result 

from poorer adhesion or chemical reactions between used inks 

and copper contacts. The use of special asymmetric Cu contacts 

did not meet their requirements (i.e. it did not compensate 

mechanical stresses during temperature cycles). The changes in 

resistance were significant and the highest in this case. 



5 

4,5 

NiP 25 ohm 

NiP 100 ohm 

4 

3,5 

3 

2,5 

2 

1,5 

1 

0,5 

0 

1.5 mm 1.0 mm 0.5 mm 1.0 mm 

0 10 20 30 40 


Fig. 11. Example of resistance changes after 120 cycle climatic tests, 

NiP 25 Ω /□ and 100 Ω /□ 

Rys. 11. Przykładowe zmiany rezystancji po 120 cyklach testów klimatycznych, 

NiP 25 Ω /□ and 100 Ω /□ 


100 

80 

60 

40 

20 

0 

Cu asymmetric Cu Au Ag 

-20 

1.5 mm 1.0 mm 0.5 mm 1.0 mm 

0 10 20 30 40 



ED7100 200 Ω /□ 


ED7100 200 Ω /□ 

The best results were obtained for both type of thin-film resistors 

and for thick-film resistors printed on Ag and Ni/Au contact 

pads. The use of precise laser trimming in advance allows 

to achieve resistance values within a tolerance of 1% by taking 

into account the expected changes caused by the manufacturing 

steps. 

Generally, with a decrease of resistor size the obtained results 

were less reproducible and exhibited the largest variance. It is 

especially visible for the smallest resistors (with the 0.5 mm size). 

It was noticed both in technological processes as well as in the 

case of environmental tests. Together with the size decrease an 

impact of technological precision on the achieved results increased. 

This is mostly observable in the case of thick-film resistors. 

Effects of screen printing techniques inaccuracy such as resistor 

edges irregularity and ink distribution were caused by resistors 

behavior under conditions of technological operations or environmental 

exposures. The accuracy of technological operation 

depended on an engineer experience and a precision of used 

equipment. 

Embedded capacitors 

In the investigations the significant influence of the oxide treatment 

processes on the obtained value of capacity was not found 

out. Lamination process resulted in the change of capacitance up 

to the level of 1–3% for BC24 M materials. The reason of this phenomenon 

was probably a slight decrease in distance between the 

plates. In the case of BC12TM material the observed capacitance 

changes were slightly below 1%. The capacitance changes were 

mainly influenced by the alignment of the electrodes. 

Capacitors made of BC24 M had a smaller dispersion of capacitance 

and a higher reproducibility than capacitors made 

of BC12TM. In the case of the smallest capacitors (less than 

0.25 cm 2 , 45 pF for BC24 M and 175 pF for BC12TM) inaccuracies 

100 


12 

80 

10 


60 

40 

20 

0 

-20 

1.5 mm 1.0 mm 0.5 mm 1.0 mm 

0 10 20 30 40 


Relative deviation [%] 

8 

6 

4 

2 

0 

1,5 

1,5 

1,5 

2,8 

2,8 

2,8 

5,5 

5,5 

5,5 

11,3 

11,3 

11,3 

22,1 

22,1 

22,1 

22,1 

45,0 

45,0 

45,0 

45,0 

45,0 

45,0 

88,2 

88,2 

180,0 

180,0 

352,8 

352,8 

Capacitance [pF] 


ED7500 20 Ω /□ 


ED7500 20 Ω /□ 

Fig. 15. Capacitance after lamination, BC24 M material 

Rys. 15. Pojemność po prasowaniu, materiał BC24 M 

100 

80 


0 

-5 

5,7 

5,7 

5,7 

10,9 

10,9 

10,9 

21,4 

21,4 

21,4 

43,8 

43,8 

43,8 

85,8 

85,8 

85,8 

85,8 

175,0 

175,0 

175,0 

175,0 

175,0 

175,0 

343,0 

343,0 

700,0 

700,0 

1372,0 

1372,0 


ED7500 5 kΩ /□ 


ED7500 5 kΩ /□ 

44 


60 

40 

20 

0 

-20 

1.5 mm 1.0 mm 0.5 mm 1.0 mm 

0 10 20 30 40 


Relative deviation [%] 

-10 

-15 

-20 

-25 

-30 

Capacitance [pF] 

Fig. 16. Capacitance after lamination, BC12TM material 

Rys. 16. Pojemność po prasowaniu, materiał BC12TM 


of capacitor plate positioning resulted even in a few times larger 

difference between obtained and designed capacitance values 

than in the case of the capacitors with a relatively large electrode 

area (approximately 8% to 2% in the case of the capacitors made 

with BC24 M material). In order to achieve capacitance values 

with the highest possible accuracy the errors of capacitor electrodes 

alignment (photochemigraphy) and errors in the etching 

process (over etching, under etching) should be minimized. 

Combined Capacitance and Resistance Material 

The cut-off frequency of manufactured low-pass filters varied from 

-6.5% to -13.5% with regard to their designed values. Smaller 

values of frequency than designed one was caused mainly by 

higher capacitance values. 

It was found that changes in resistance of the resistive material 

25 Ω/□ in technological processes were at the level of 14…20%. 

These changes were comparable to the resistance changes of resistors 

produced with the Ohmega-Ply material. Achieved capacitances 

of the capacitors were around 7% higher than designed. 

Etched plates were size with high accuracy compatible with the 

design so the higher capacitance was resulted from the higher 

capacitance of used material. This is caused by either shorter 

distance between the plates, a value difficult to measure due to 

the very developed surface on the copper plate or a greater value 

of dielectric constant. 

lower ranges of resistance. The thick film technology allows to 

design resistors in a wide range of resistance (from some Ω to 

MΩ). The use of dielectric material additionally gives the possibility 

to place a significant percentage of the passive components 

inside the printed circuit boards. It allows to save space on the 

surface and to miniaturize the system. Expanding the embedding 

techniques also on inductive elements would even allow to design 

embedded low and high pass filters, filter units (amplifiers), 

decoupling capacitors and matching resistors in memory and 

processor sets, and even RFID systems and simple generators. 

The use of a new generation of materials in this technology is an 

important step towards full integration of passive components into 

the assembly substrate. 

Investigations were made as part of the Operational Programme 

Innovative Economy, 2007–2013, the Priority of 1 Investigation 

and High Technology Development, Action 1.3 

supporting B+R Projects for entrepreneurs carried out by scientific 

units, 1.3.1 Development Projects. The agreement No: UDA- 

POIG.01.03.01-14-031/08-04 of 16.02.2009, Title of Project: „Technologia 

doświadczalna wbudowywania elementów rezystywnych 

i pojemnościowych wewnątrz płytki drukowanej”, Project No: 

POIG.01.03.01-00-031/08. 

0 

1,0 50,0 10,0 5,0 0,5 

Relave deviation [%] 

-5 

-10 

-15 

-20 

-25 

Frequency [MHz] 

Fig. 17. Calculated cut-off frequency of sample filters 

Rys. 17. Obliczona częstotliwość graniczna próbek filtrów 

Summary 

The combination of thin- and thick-film techniques for manufacturing 

embedded resistors allows a significant extension of the 

range of possible resistance values. The thin-film resistors give 

better accuracy, stability and high level of miniaturization in the 

References 

[1] J.S. Peiffer: „Embedded Passives: Debut in Prime Time”, Printed Circuit 

Design & Fab, 01 October 2009. 

[2] B. Mahler: „The Design and Use of NiP Embedded Thin-Film Resistive 

Materials for Series and Parallel Termination”, CircuiTree, Winter 

2011, Vol. 24, No. 1. 

[3] W. Jillek, W.K.C. Yung: „Embedded components in printed circuit 

boards: a processing technology review”, Int. J. of Advanced Manufacturing 

(2005) 25, pp. 350–360. 

[4] S. O’Reilly, M. Duffy, T. O’Donnell, P. McCloskey, S.C. Ó Mathúna: 

„Integrated passives in advanced printed wiring boards”, Circuit 

World 27/4 [2001], pp. 22–25. 

[5] R.C. Snogren: „Embedded Passives in Printed Circuit Boards”, Defence 

Manufacturing Conference 2004. 

[6] W. Stęplewski, J. Borecki, G. Kozioł, A. Araźna, A. Dziedzic, P. 

Markowski: „Influence of selected constructional and technological 

factors on tolerance and stability of thin-film resistors embedded in 

PCBs”, Elektronika, Vol 52, No. 4, 2011, pp 119–122. 

Przypominamy o prenumeracie miesięcznika Elektronika na 2012 r. 


GENESI: Wireless Sensor Networks for structural monitoring 

(GENESI: Bezprzewodowa sieć sensorów do monitorowania strukturalnego) 

BE MEng Sc Brendan O’Flynn 1, 2, 3) , Dr. David Boyle 2, 3) , Dr. E. Popovici 1, 2, 3) , 

Phd. Ing. Michele Magno 3, 4) , PhD C. Petrioli 5) 

1) 

Clarity CENTRE, 2) Tyndall National Institute, 3) University College Cork, Ireland 

4) 

University of Bologna Italy, 5) University of Rome, Italy 

The GENESI project has the ambitious goal of bringing WSN technology 

to the level where it can provide the core of the next generation 

of systems for structural health monitoring that are long 

lasting, pervasive and totally distributed and autonomous. Sensor 

nodes are being redesigned to overcome their current limitations, 

especially concerning energy storage and provisioning (we need 

devices with virtually infinite lifetime) and resilience to faults and interferences 

(for reliability and robustness). New software and protocols 

will be defined to fully take advantage of the new hardware, 

providing new paradigms for cross-layer interaction at all layers of 

the protocol stack and satisfying the requirements of a new concept 

of Quality of Service (QoS) that is application-driven, truly reflecting 

the end user perspective and expectations. The GENESI system 

will be deployed in two pilot deployments; namely the monitoring of 

a bridge (Pont de la Poya, Switzerland) and a metro tunnel (Metropolitana 

Linea B, Rome), both during and after construction. 

System requirement analysis 

GENESI (Green sEnsor NEtworks for Structural monItoring) [1] 

exhibits a range of system requirements from a variety of established 

and emerging technical scientific disciplines. 

The systems are required to be “Green” and Sustainable – The 

use of energy scavanging techniques (i.e. harnessing available 

environmental energy) to extend the lifetime of GENESI nodes 

will be employed. Realistic potential sources include solar and 

wind energy. A fuel cell or series of fuel cells, capable of providing 

significant amounts of energy, will also be integrated in the design 

of a novel power unit. This unit may also make use of integrated 

suitable battery cell(s) and/or other storage techniques (such as 

capacitors). It should provide sufficient energy to power the GE- 

NESI wireless sensor nodes for extended periods of time. 

In addition to developing novel hardware to address the challenge 

of providing a solution for structural health monitoring with 

virtually infinite lifetime, appropriate algorithms and networking 

protocols must be developed to facilitate these goals. The lowest 

possible amounts of energy should be consumed during periods 

of communication, algorithms and protocols should account for 

fluctuating available energy whilst exhibiting fault tolerance in the 

presence of malfunctioning devices and lossy channels. Finally, 

the overall system should ensure maintenance of suitable levels 

of quality of service. 

The GENESI nodes, with minimal maintenance from initial deployment, 

are required to have an operational lifespan extending 

to decades and the following characteristics: 

Portability – The intended use of the system requires that, during 

the construction phase, one of the desirable properties of the 

proposed GENESI system is that it should facilitate easy redeployment, 

or repositioning, of the nodes/sensors as construction 

work progresses. For example, when one section of monitored 

construction is complete, it should be easy for the sensor nodes 

to be moved to the next section, Alternatively, they should be reconfigured 

in their current position to allow for a different type 

of monitoring, for instance moving from a monitoring modality 

intended for the construction phase, to long term monitoring of 

the system in operation. This functionality should be considered 

thoroughly as the design of the system progresses. It will relate 

to both the physical aspects of the GENESI devices (form factor 

46 

– size, mass, connectors, packaging, etc.) and also the networking 

and dynamic reprogramming of the devices. 

Robustness – GENESI is intended for use in the monitoring of 

structures. As such, its field of deployment is naturally rugged. The 

devices must be packaged in accordance with the requirements 

of the deployment field. Therefore, the end system must be robust 

in terms of physical protection from the environment (against elements 

such as moisture, lightning, temperature extremes, etc.), 

and also exhibit robust physical features such as protection from 

impacts/shocks, large simple connectors, etc. In addition to protection 

and increased robustness of the GENESI node, the system 

architecture should ensure reliability against node failures. The system 

should be capable of detecting failures and malfunctioning 

system components, should support adequate actions to cope 

with problems, e.g. restarting devices and reconfiguring them. Itshould 

be self-healing and robust in case of permanent failure, e.g. 

by dynamically changing routes, reallocating application tasks. 

Flexibility – GENESI should be flexible enough in design to 

ensure that it is applicable to a wide range of structural monitoring 

scenarios beyond the pilot deployments. This will ensure maximum 

impact to the overall market. 

Maximization of end-user utility – The development of protocols 

and algorithms to ensure the highest levels of system responsiveness 

and end-user perceived service quality by fully exploiting the 

variable energy availability of harvesting devices. 

Interoperability with existing front-ends– the system should be 

compatible with the existing front-end provided by the end-user 

partners 

In summary, GENESI must provide a robust wireless sensor 

network for structural health monitoring that exhibits high levels 

of quality of service, dramatically enhanced network lifetime, minimal 

maintenance requirements, flexibility to a wide range of monitoring 

scenarios and dynamic configurability in the field. It must 

also be compatible with existing front-end structural monitoring 

solutions and significantly reduce overall costs for structural health 

monitoring in the field. 

GENESI Device Level Specification 

In order to facilitate rapid prototyping and experimentation with 

various interfaces, both to sensors and power solutions, a modular 

approach to the design of the final hardware platform has 

been adopted. To this end, a prototype of the GENESI node has 

been developed by Tyndall, and the core components of which 

are described in the following sections: 

Sensors 

The sensors to be used for the two initial deployment scenarios 

are of the “off-the-shelf” variety. The requirement exists for the 

development of sensor interface layers to correspond to the type 

of communication supported by the sensors themselves. 2, 3 and 

4-wire analogue, RS 485, RS 232 and SPI (digital) interfaces 

are required. Additionally, given the variety of supplies required 

for individual sensors – a number of power rails will be required. 

Similar interfacing must be achieved between the sensors, the 

motherboard and the smart power unit. In order to achieve the 

required 16-bit granularity for some of the sensors, an additional 

analog-to-digital converter (ADC) chip is required. 


RF and Microcontroller Requirements 

The primary enabling technologies of wireless sensor networks 

are low-power RF communication and microcontroller components. 

In keeping with design goals for the GENESI, state-of-theart 

and standard compliant (IEEE 802.15.4) radio transceivers 

are implemented in combination with an appropriate microcontroller 

(e.g. Texas Instruments MSP430). In order to comply with 

GENESI objectives of ultra-low power operation for extended 

node lifetime, the lowest power components are chosen in the 

design of the electronic hardware. 

RF Transceiver 

The IEEE 802.15.4 standard for low-rate wireless personal 

area networks (LR-WPAN) is the most prominent and applicable 

for use with wireless sensor networks [2], underpinning a range 

of higher level standards and specifications (including ZigBee 

[3], 6LoWPAN [4] and WirelessHART [5]). It provides optimal 

trade-offs with respect to range, data rates and power consumption, 

in comparison with other wireless communications technologies 

that could be applicable to the GENESI platform (such as 

Bluetooth, WiFi, etc.; which usually offer superior data rates for 

higher power cost over a shorter range). The standard originally 

(2003) prescribed two physical layers based upon direct sequence 

spread spectrum (DSSS) techniques – one working in the 

868 (Europe)/915 (North America) MHz bands, the other in the 

2.4 GHz band. In Europe, the 868 MHz band allowed for only 

one communications channel (with a transfer rate of 20 kbps 

(prior to the 2006 revision of the standard)), whereas the worldwide 

2.4 GHz band allows up to 16 channels with a transfer rate 

of 250 kbps. 

The decision for GENESI to function in the 2.4 GHz band was 

agreed based upon the need for a number of channels and reasonable 

data rates – thus ensuring the possibility to enhance quality 

of service and meet design requirements for the project. We are 

also investigating the possibility to add a second radio on GENE- 

SI platform operating in the 868 MHz band for specific application 

scenarios where 2.4 GHz band may suffer from severe interference 

(such as structural health monitoring in buildings). 

In choosing an appropriate RFIC, one is limited to those available 

commercially. The most well known transceiver in the WSN 

domain is the Texas Instruments CC2420 [6]. This transceiver 

supports the IEEE 802.15.4-2003 standard, operating in the 2.4 

GHz channel. Along with its successor, the CC2520, the Atmel 

AT86RF231 and the Analog Devices ADF7242, are all state-ofthe-art 

transceivers under consideration for the final GENESI system 

specification. 

Smart Power System 

From the perspective of power requirements 

for the GENESI system it is noticeable that 

industrial batteries on the market have a number 

of limitations from both the user and equipment 

perspective. 

Firstly, they represent an unpredictable 

source of power. A user can have a little advantage 

if he knows that the battery is about 

to run out of energy or how much operating 

time is left. Secondly, the device cannot determine 

if the battery, in its current state, is 

capable of supplying adequate power for an 

additional load (e.g. spinning up a hard disk 

in a laptop, turn on a flash-light in a camera, 

or start a burst radio transmission in a WSN). 

Finally,, battery chargers must be individually 

tailored for use with specific battery chemistry 

and may cause damage if used on different 

storage device. 

For these reasons, the specification of an 

enhanced battery (called the Smart Power System, 

see Figures) which can overcome the limitation of traditional 

batteries and jointly exploit the features of an energy harvester 

appears to be a winning approach. In this way, it is also possible 

to significantly improve the availability of power for the node; one 

of the most important factors towards the successful realisation of 

the GENESI sytem. 

Smart Energy Supply 

The GENESI Smart Power System has the following features: 

multi-harvester (wind, solar, thermal, etc.), multi-energy storage 

(e.g. super capacitor, batteries), intelligent interface to receive 

and provide information regarding energy availability, the fuel cell 

interface, and allow flexibility in operation. 

Energy harvesting devices convert ambient energy into electrical 

energy and it is possible to tailor the power source to satisfy 

the different power consumption requests various sensors and 

scenarios in which the nodes will be deployed. 

Depending on the scenario, a multi-harvesting unit able to 

convert energy from different kind of ambient source (solar, wind, 

thermal, etc.) is a good approach. 

The energy harvesting requirements are directly related to the 

average power consumption of the application and depend on the 

expected quality of service and use-case requirements (sensing 

rate, distance between nodes and transmission power, etc.). Moreover, 

the different modules or typology of harvesting depends 

on the environment where the node is deployed. (For example, 

the use of photovoltaic cells, in an underground scenario, may 

provide less power than other sources, such as thermal. The opposite 

is true when the WSN is deployed outdoors). 

Considering that one of the locations where the GENESI platform 

will be placed is a bridge, it has been decided that a windphotovoltaic 

energy harvester is an optimal choice for implementation. 

The choice of a modular and flexible architecture of the 

harvester facilitates the interface operation with the fuel cell section, 

but also with other energy transducers not originally planned 

in this project (i.e. piezoelectric, thermal ones). 

It is also expected that a significant amount of wind energy 

should be available in the tunnel deployment (due to air-conditioning 

and passing metro carriages), whereas, the photovoltaic 

energy may be in significantly lesser supply. 

The Smart Power System will dynamically select the harvesting 

source (if the node is provided with more harvesters) and will 

adjust the power conversion parameters to extend the node lifetime. 

In general, the harvested energy is stored in a super capacitor 

and/or battery. Capacitors are used when the application needs 

Block diagram of the GENESI Smart Power System 

Schemat blokowy inteligentnego zasilania systemu GENESI 


to provide huge energy spikes. Batteries leak less energy and are 

therefore used when the device needs to provide a steady flow of 

energy. However the GENESI smart battery system will use both 

of these solutions. 

A similar architecture to the proposed solution is described in 

[7]. The GENESI Smart Power Unit will go beyond the capabilities 

described therein, through the provision of the capability to 

recharge Li-ion batteries and incorporate electrochemical fuel cell 

technology. Futhermore, the GENESI system allows for the transfer 

of useful information pertaining to energy status from the unit 

to the main processor. 

Results and conclusions 

Based on the requirements elaborated, the specified system 

components have been integrated to form a functional prototype 

of the GENESI node. Early experimentation has proven feasible 

the integration of off-the-shelf sensors traditionally used in structural 

health monitoring with low-power RF and microcontroller 

components (i.e. a WSN “mote”). Furthermore, an embodiment of 

the smart power system (inclusive of energy harvesting capabilities 

and fuel cell technology) has been shown to power the unit. 

The prototype is currently under technical evaluation with respect 

to electrical characterisation (in various modes) and functionality. 

Detailed results will be presented in due course. 

The authors would like to acknowledge the support of Science 

Foundation Ireland (SFI) for funding the CLARITY CSET, the European 

Commission for funding the GENESI project, as well as 

Enterprise Ireland, Irelands Higher Education Authority (HEA) 

and the funding provided to the National Access Program (NAP) 

at the Tyndall National Institute by SFI, all of which have contributed 

to this work. 

References 

[1] (2010) GENESI: Green sEnsor NEworks for Structural monItoring. 

[Online]. Available: http://genesi.di.uniroma1.it/ 

[2] IEEE 802.15.4: Wireless Medium Access Control (MAC) and Physical 

Layer (PHY) Specifications for Low-Rate Wireless Personal Area 

Networks (LR-WPANs) (2003), 3 Park Avenue, New York, USA: 

IEEE. 

[3] ZigBee Specification v1.0: ZigBee Specification (2005), San Ramon, 

CA, USA: ZigBee Alliance. 

[4] Hui J., P. Thubert: Compression Format for IPv6 Datagrams over 

IEEE 802.l5.4-Based Networks. RFC 6282, Internet Eng. Task Force, 

Sept. 2011. 

[5] (2009) HART Communication Foundation. [Online]. Available: http:// 

www.hartcomm.org/ 

[6] CC2420 Datasheet. [Online]. Available: http://focus.ti.com/lit/ds/symlink/cc2420.pdf 

[7] Tan Y.K., S.K. Panda: Energy Harvesting from Hybrid Indoor Ambient 

Light and Thermal Energy Sources for Enhanced Performance of 

Wireless Sensor Nodes. IEEE Transactions on Industrial Electronics, 

vol.58, in-press, 2011. 

Mechanical and thermal properties of SiC 

– ceramics substrate interface 

(Mechaniczne oraz cieplne właściwości połączenia między strukturą 

SiC a podłożem ceramicznym) 

dr hab. inż. Ryszard Kisiel 1) , dr inż. ZBIGNIEW Szczepański 1) , dr inż. Piotr Firek 1) , 

dr inż. MAREK Guziewicz 2) , dr inż. ARKADIUSZ Krajewski 3) 

1) 

Warsaw University of Technology, Institute of Microelectronics and Optoelectronics, Warsaw 

2) 

Institute of Electron Technology, Warsaw 3) Warsaw University of Technology, Faculty of Production Engineering, Warsaw 

Silicon carbide created new possibilities for high power and high 

temperature electronics due to its unusual physical properties, 

which are not attainable in conventional silicon semiconductor 

material. It has been demonstrated that SiC based power devices 

are able to operate at temperatures as high as 450°C [1, 2]. To realize 

the high temperature functions of SiC power devices, the development 

of high temperature packaging technologies becomes 

more and more important. Packaging technologies play main role 

in high power and high temperature electronics since they have 

an essential effect for the reliability of SiC power devices [8, 9]. 

One of the main problems of high power package is die bonding 

technology, which ought to assure not only mechanically reliable 

connection between SiC die and substrate, but also good electrical 

conductivity and high thermal conductivity. The latter feature is 

especially critical for power devices because it allows for effective 

heat transfer from power chip to the package. 

State-of-the-art technologies for interconnecting Si power devices 

involve attaching one terminal of the semiconductor die to 

a heat-sinking substrate with solder alloy or with an electrically 

conductive adhesive, while the other terminals are bonded by 

aluminum or gold wires as well as flip chip technology. Such interconnection 

technologies have several limitations in high-temperature 

operation because solder alloys/conductive adhesives 

usually have low melting/degradation temperatures. By changing 

substrate material is possible to increase heat dissipation. So, the 

package with DBC substrate is very good solution for high power 

application, since such package significantly improves heat dissipation 

and therefore is widely used in high power SiC modules. 

48 

Investigations of new techniques are necessary for high temperature 

and high power SiC devices. 

Taking into account mentioned above requirements, only a few 

of the known die bonding technologies can fulfill the demands of 

high both temperature and power. In this paper, the main attention 

was focused on technical problems connected with two die bonding 

technologies: low temperature joining technique (LTJT) with the use 

of micro- or nanosilver paste [1–4], and modifies hard soldering process 

based on Au-Sn and Au-Ge solder alloys [7–9]. LTJT is a process 

involving the sintering of micro- and nanosized metal particles. 

This die bonding technology, from among various chip attachment 

method, characterizes the highest thermal conductivity (240 W/mK), 

the lowest electrical resistivity (1.6 × 10 -6 Ωcm), low Young’s modulus 

(96 Pa), and the highest operating temperature (theoretical operation 

capability up to 960ºC) [6]. Porous microstructure of the sintered 

silver layer and low Young’s modulus are profitable, since it helps 

thermo-mechanical stresses to relieve. Once the interconnection is 

formed, the bonding material is close to be pure metal. Because Ag 

is mainly used for this purpose, it will not melt until joint temperature 

reaches 961°C. By using nano Ag pastes (particles range 30 nm) 

the SiC-substrate interface can be formed by sintering at relatively 

low temperature, 275…300°C. Die bonding technology with the use 

of low temperature sintering of micro- and nanoscale silver pastes 

was previously used in our own investigations concerning assembly 

of SiC on DBC substrates [12, 13]. Our current work is concentrated 

on using microsized Ag pastes for attachment SiC power die to DBC 

substrate, instead of Ag nano pastes. The cost of microsized Ag 

powder is significantly less than nanosized Ag powder. 


Application of hard solders based on gold alloys is interesting 

alternative of packaging method, especially for SiC devices with 

aluminum metallization [7]. From among well known solders, only 

AuGe and AuSn can fulfill high temperature requirements. To do 

this, substrate and SiC aluminum contacts should be solderable. 

It is possible if SiC die and substrate contacts are Au covered. 

However, very often SiC dies have Al metallization due to its low 

electrical resistivity, good adhesion to die and low cost. In this case 

soldering is not possible. The properties of top Al layer onto SiC 

can be changed by gold stud bump bonding process. To realize 

hard soldering for such devices, modification of die bonding process 

is necessary. This modification concerns SiC chips preparation 

by means of gold stud bump technology [10]. Gold stud bump 

technology is commonly used in flip chip bonding technology and 

it can be easily used even on single chips with high bonding speed 

[10]. When gold bumps will be realized on Al bond pad of SiC die, 

then soldering process with the use of high melting temperature 

solder alloy Au82Ge12 (eutectic temperature = 356ºC) can be implemented. 

This assembly technology will be investigated in future 

series of experiments. Both die bonding technology mentioned 

above were used in our investigations. 

Experimental procedure 

To perform the experiments test samples were prepared. As substrate, 

the direct bonded copper substrate (DBC) size 10 × 10 mm 

was used. The DBC substrate consists of 0.62 mm thick Al 2 

O 3 

ceramic 

plate sandwiched between two pieces of 0.2 mm Cu plates 

thermally bonded to ceramic. Cu top layer of DBC was electroplated 

by Ni (3 µm thick) and Au (1 µm thick) layers. Main advantages 

of such substrate are high thermal and electrical conductivity due 

to thick copper layer and very close to SiC die coefficient of thermal 

expansion. Additionally in preliminary experiments, instead of SiC 

die the DBC substrate size 3 × 3 mm were used with NiAu metallization. 

So, in fact of preliminary experiments, DBC size 3 × 3 mm 

was attached to DBC substrate size 10 × 10 mm using LTJT. 

In this bonding technology usually silver paste is used, which 

was made by mixing silver microparticles and organic binder. However, 

during sintering process at the temperature above 250ºC, 

organic binder didn’t burn out completely. So, binder system has 

to be selected very carefully, to avoid such problems. In our investigations, 

we applied a novel approach, by using silver microparticles 

without organic additives. The silver powder series AX20LC 

(manufactured by AMEPOX MICROelectronics, Łódź, Poland) 

was used in experiments. It was deposit on bond pads of DBC 

substrate by stencil printing. The stencil was made of Kapton foil 

with the thickness of 50 µm. Such process is not very easy in realization 

and therefore requires training and experience. Next the 

DBC test structures size 3 × 3 mm with metallization Ni/Au were 

sintered to DBC substrates size 10 × 10 mm with the use of the 

low temperature sintering of silver micro particles in air or in high 

vacuum. The parameters of performed processes are presented 

in Table 1. 

Tabl. 1. The adhesion of DBC structures size 3 × 3 mm to DBC substrate 

size 10 × 10 mm after received 

Tab.1. Adhezja testowych struktur DBC o wymiarach 3 × 3 mm do podłoża 

DBC o wymiarach 10 × 10 mm bezpośrednio po procesie łączenia 

Test no 

Pressure 

[MPa] 

Joining parameters 

Temp. 

[°C] 

Time 

[min] 

Way of 

heating 

Shear force after 

sintering [MPa] 

1 0.28 350 30 slowly 0.57 

2 3.0 350 30 rapid 2.5 

3 3.1 350 30 slowly 8.15 

4 2,7 350 30 rapid 2.42 

5 2.9 350 50 slowly 10.3 

6 2.9 350 40 slowly 10.9 

Results and Discussion 

The influence of LTJT process parameters on adhesion between 

DBC structures size 3 × 3 mm to DBC substrate 10 × 10 mm were 

also presented in Tab.1 (last column). It can be observed that for 

process temperature 350°C the adhesion is strongly correlated 

with pressure applied between joining parts and with way of heating. 

Two ways of sample heating were realized: by slow heating, 

i.e. heating from room temperature up to 350°C with temperature 

ramp 6°C/min, and rapid heating by placing the test sample directly 

to 350°C. The best results were obtained when pressure 

above 3 MPa were applied a joining parts were heated from room 

temperature up to joining temperature 350ºC. By rapid placing 

joining parts directly in temperature 350ºC the adhesion was significantly 

less. 

To check the reliability of prepared joints the ageing process 

was performed. So, the next series of test samples were jointed 

by applying pressure above 3 MPa and temperature 350ºC with 

30 min ageing by slow heating. To check the quality of die-substrate 

quality, the shear tension range 3 MPa was applied to DBC 

structures 3 × 3 mm. Any destruction of joints were observed. Next 

the samples were aged 350ºC &24 h in air and adhesion was 

again measured. The adhesion after ageing test was dramatically 

low, below 0.05 MPa in all cases. Both surfaces after shear test, 

performed just after sintering, and after ageing in 350°C&24h in 

air were shown in Fig. 1. Fig. 1a shows that cracks occurs in sintered 

Ag layer. In majority of surface there were good connection, 

only on some areas porous surfaces are seen. Never the less, the 

adhesion of presented sample was above 8 MPa. After ageing 

test, the joining surface is different, Fig. 1b. There is areas where 

continuous thin Ag layer adhere very well to DBC substrate and 

some areas are where sintered Ag has poor cohesion and crack 

occur through this plane. 

The cohesion cracks in nano Ag sintered joints were observed 

by other researches [14]. They observed that the delamination 

process occurs between the die or substrate metallization and 

the silver layer itself. However, observation the cracking surfaces 

on both parts shows that thin Ag layer (thickness few micrometers) 

adhere very well to both Au layer of DBC. So in the next series 

of experiments the thinner layer of Ag between joining parts 

was applied and sintering processes were done in vacuum oven 

350°C &30 min with pressure 15 MPa. It was found that adhesion 

between parts after vacuum sintering is above 3 MPa. Next the 

joined samples were aged in air 350°C&24 h. The adhesion after 

ageing was again below 0.05 MPa. 

So in the next series of experiments the processes were performed 

in vacuum and the sintering temperatures were increased 

to 500 and 550°C and ageing time was increased to 2 h. During sintering 

the pressure 15 MPa was applied. Such prepared samples 

were annealing at 350°C and adhesion was measured before ageing 

and in time interval as presented in Tabl. 2. The adhesion was 

check temporary by applying test shear force range 3 MPa to sample 

size 3 × 3 mm 2 . Samples sintered 550°C &2 h and 500°C &2 h 

in vacuum survived the shear test 508 h and 125 h, respectively. 

a) b) 

Fig.1. The top surface of DBC after shear test performed after sintering 

(a) and ageing 350°C (b) 

Rys. 1. Powierzchnia struktury DBC po teście ścinania: przed starzeniem 

(a) i po starzeniu w temperaturze 350°C (b) 


Next, the adhesion was measured in the destructive test. For samples 

sintered 400°C & 1 h in air and subsequent sintering in vacuum 

in temperatures 550 or 500°C the shear strength was above 

12.3 MPa and 18.1 MPa, respectively. 

Tabl. 2. The adhesion between DBC substrates with Au metallization made 

by micro Ag sintering process 

Tab. 2. Stabilność adhezji struktur DBC z metalizacja Au po procesie 

zgrzewania wysokotemperaturowego 

Test 

No 

Sample 

preparation 

0 h 

[MPa] 

After 

50 h 

After 

125 h 

After 

200 h 

After 

508 h 

1 550°C&2h >3 >3 >3 >3 11.2 

2 

400°C&1h 

+550°C&2h 

>3 >3 >3 >12.3 

3 500°C&2h >3 >3 >3 

4 

400°C&1h 

+500°C&2h 

> 3 >3 18.1 

So, by increasing the sintering temperature of micrometer size 

Ag powder up to 550 or 500°C it was possible to create joints between 

two DBC substrates with Au top layer with good adhesion. 

The further investigations are necessary to decrease sintering 

temperature below 500°C and to check if such high temperature 

can destroy SiC semiconductor properties or other elements of 

SiC package. 

Conclusions 

In this paper, there was present the realization of assembly of SiC 

samples to DBC substrate (Direct Bonding Copper Substrate with 

200 µm Cu metallization Ni/Au covered) by low-temperature sintering 

of micro scale Ag powder. In the experiments DBC test samples 

size 3 × 3 mm 2 (in place of SiC die) were assembled to DBC 

substrate size 10 × 10 mm 2 using following methods: a) sintering 

by Ag powder with Ag microparticles in air by applying temperature 

and pressure, b) sintering by Ag powder with Ag microparticles 

using temperature, pressure and high vacuum. Methods „a” and 

„b” permit to obtain very good adhesion range 8…10 MPa after 

sintering. However after ageing test at temperature 350°C in air 

the adhesion fall down dramatically. By increasing sintering temperature 

up to 500…550°C and sintering in vacuum range 1.3 Pa 

(method „b”) the adhesion is satisfactory, even when ageing time 

at 350°C was increased up to 508 h. Destructive tests show that 

by sintering samples in vacuum and applying temperature range 

500°C the adhesion between two DBC substrates (Au plated) can 

be significantly higher than 10 MPa for exploitation temperatures 

up to 350°C. Further experiments will be performed for the long 

term stability of adhesion at temperatures 350°C or higher. 

The work was supported by The National Centre for Research 

and Development, NCBiR, Poland (Grant no N N515 499240). 

References 

[1] Rudzki J., R. Eisek: Low Temperature Joining Technique for Better 

Reliability of Power Electronic Modules. Mictrotherm 2007, 

pp. 159–166. 

[2] Dun-ji Yu, Xu Chen et..al: Applying Anand model to low temperature 

sintered nanoscale silver paste chip attachment. Materials and Design. 

3D (2009), pp. 45’74–45’79. 

[3] John Guofeng Bai, Jian Yin et…al: High Temperature Operation 

of SiC Power Devices by Low Temperature Sintered Silver Die-Attachment. 

IEEE Transactions on Advanced Packaging. Vol. 30. No 3. 

August 2007, pp. 506–509. 

[4] John G. Boi Jesus N. Calato, Gou Quan: Processing and Characterization 

of Nanosilver Pastes for Die Attaching SiC Devices. IEEE 

Trabsactions on Electronic Packaging Nanofacturing. Vol. 30, No. 4, 

October 2009, pp. 241–245. 

[5] Tsuashi Fundki, Juan Carlos Bonda et…al: Power Conversion with SiC 

Devices at Extremely High Ambient Temperatures. IEEE Transactions 

on Power Electronics. Vol. 22, No. 4, July 2007, pp. 1321–1329. 

[6] Pugi Ning, Thomas Guangyin Lei et…al: A Novel High Temperatures 

Planar Package for SiC Multichip Phase-Leg Power Module. 

IEEE Transactions on Power Electronics. Vol. 25, No. 8, August 


[7] Fenggum Lang, Yusuke Hayashi et…al: Novel Three Dimensional 

Packaging Method for Al Metalized SiC power Devices. IEEE Transactions 

on Advanced Packaging. Vol. 32, No. 4, November 2009, 

pp. 773–779. 

[8] Fenggum Lang, Yusuke Hayashi et…al: Joint Reliability of Double 

Side Package SiC Power Devices to DBC Substrate with High Temperature 

Solders. Proceedings of 10 th Electronics Packaging Technology 

Conference. 2008, pp. 897–902. 

[9] Fenggum Lang, Satashi Tanimato et…al: Long-Term Joint Reliability 

of SiC Power Devices at 330ºC. Proceedings of European Microelectronics 

and Packaging Technologies. June 2009, pp. 1–5. 

[10] Klein M., H. Opperman, R. Kalicki, H. Reichl: “Single Chip Bumping 

and Reliability for Chip Process” Microelectronics Reliability. Vol. 39, 

No. 9, 1999, pp. 1389–1397. 

[11] Szczepański Z., R. Kisiel: „SiC Substrate Connections for High Temperature 

Applications” XXXII International Conference of IMAPS- 

CPMT IEEE Poland, September 2008. 

[12] Szczepański Z., R. Kisiel: Packaging Technologies for SiC Power 

Devices. XXXIV International Conference of IMAPS-CPMT IEEE Poland. 

September 2010. 

[13] Kisiel R., M. Guziewicz, Z. Szczepański: An Overview of Materials 

and Bonding Techniques for Inner Connections in SiC High Power 

and High Temperature Devices. 33 rd International Spring Seminar on 

Electronics Technology ISSE’2010. Warszawa. May 2010. 

[14] Rudzki J., Hinken R., Poech H.: Thermal Impedance Test Method for 

Detecting Packaging Failures in Silver Sintering Technology. Official 

Proceedings MicroTherm 2011, Łódź, Poland, ISBN 978-83-932197- 

0–4 pp. 217–222. 

50 


Analysis of pulse durability of thin-film and polymer 

thick-film resistors embedded in printed circuit boards 

(Analiza odporności impulsowej grubo- i cienkowarstwowych rezystorów 

wbudowanych w płytki obwodów drukowanych) 

inż. Adam Kłossowicz 1) , prof. dr hab. inż. Andrzej Dziedzic 1) , inż. Paweł Winiarski 1) , 

mgr inż. Wojciech Stęplewski 2) , dr Grażyna Kozioł 2) 

1) 

Faculty of Microsystem Electronics and Photonics, Wroclaw University of Technology 

2) 

Tele and Radio Research Institute, Warsaw 

Traditional passives are three-dimensional discrete components, 

soldered through or onto surface. They occupy significant part of 

top/bottom surface (up to 50% of the surface area) and increase 

thickness and weight of electronic circuits/systems. The embedded 

passives (resistors, capacitors and/or inductors – Fig. 1) are 

more and more used in multichip module (MCM) technologies. 

They are fabricated among others in Low Temperature Co-fired 

Ceramics (LTCC) substrates or PCBs. The embedded passives in 

comparison to traditional ones are essentially two-dimensional elements 

that become part of the internal layers of a PCB or LTCC 

substrate increasing its thickness only of around several µm. 

Shifting of passives into substrate can increase a free space of 

PCB for active components and improve packaging density. The 

embedded passive technology (EPT) is incited by many factors 

such as the need for higher packaging density, lower production 

costs and better electrical properties. 

EPT permits for distance reduction between components 

(which leads to reduction of parasitics, less crosstalk and enhance 

transmission quality) and improving of electrical performance 

especially in higher frequencies (because of lower loss and lower 

noise yield). One should note, that EPT can also simplify the assembly 

process and reduce assembly cost (for example embedded 

passives has not problem with positioning). By using embedded 

passives we can lower material cost by reducing the number 

of discrete passives, flux, and solder paste. Nowadays technology 

allows to embedding both thick-film and thin-film resistors. 

Pulse durability is an important parameter of passive components 

and active devices. In general, the susceptibility to high 

voltage pulses and electrostatic discharges has been investigated 

for thin- and thick-film resistors for more than 30 years [1, 2]. 

Such investigations can be performed with the aid of single or 

series of „long” pulses (rectangular shape surges with 1 to 20 ms 

duration) [3, 4] or by the series of „short” voltage pulses (with duration 

from several hundred nanoseconds up to several hundred 

microseconds, eg. [5]). One should note that a pulse voltage trimming 

method has been developed to realize a noncut trimming of 

cermet and LTCC thick-film resistors without any damage to the 

resistor surface [6–11], especially for very small devices. Moreover, 

because low-ohm thick film resistors are widely used to protect 

telecommunication network equipment against lighting surge 

voltages therefore these investigations are applied for overstress 

characterization of low sheet resistance thick-film systems under 

standard telecommunication waveforms [12]. Such behaviour is 

also important in case of electric fuses [13], electrical interconnections 

(through-metalized vias) manufactured in thick-film technology 

[14] or thick-film initiators for automotive applications [15]. 

This paper characterizes experimentally, compares and analyzes 

pulse durability (determined by calculating the maximum nondestructive 

electric field, maximum nondestructive surface power 

density or maximum non destructive volume power density) of 

thin-film and polymer thick-film resistors made on the surface or 

embedded in Printed Circuit Boards (PCBs) [16, 17]. Investigated 

test structures were made of nickel–phosphorus (Ni-P) alloy 

Fig. 1. Preview of typical multichip module with embedded passives 

Rys. 1. Przykładowy wygląd płytki wielowarstwowej z zagrzebanymi 

elementami biernymi 

or polymer thick-film resistive inks on FR-4 laminate with similar 

sheet resistance (25 Ω/sq or 100 Ω/sq for Ni-P alloys and 20 Ω/sq 

or 200 Ω/sq for polymer thick-film inks). 

Investigated structures 

Thin-film (TF) resistors 

Test structures were fabricated in processes based on Ohmega-Ply 

technologies [16]. Structure (Fig. 2) is made of resistive 

foil with sheet resistance 25 Ω/sq (0.4 µm thick) and 100 Ω/sq 

(0.1 µm thick) embedded between two layers. Upper layer is copper 

foil (from 17.5 to 35 µm thick). Those thin layers are on dielectric 

subtract made of standard laminate FR-4. The fabrication 

process involves: electroplating nickel-phosphorus on copper foil, 

lamination formed foil on FR-4 and subtractive methods for defining 

shape and dimension of resistor. In experiment rectangular 

resistor was used, theirs width and length was determined in two 

Fig. 2. Simulation of embedded resistor 

Rys. 2. Symulacja rezystora zagrzebanego 


etching processes. The dimension were from 0.25 to 1.5 mm width 

and aspect ratio (n = length/width) between 1 and 4. Part of 

tested structures was coated with Resin Coated Copper (RCC) 

or Laser Drillable Prepreg (LDP) 2 × 106 to gain protection from 

environmental conditions and simulate multilayer PCBs. 

Polymer Thick – film (PTF) resistors 

Resistors (Fig. 2) were manufactured in standard additive thickfilm 

polymer technique. The resistive inks were applied onto conductive 

contacts. Inks have sheet resistance: 20 Ω/sq (ED7500_ 

20 Ω – carbon-silver) and 200 Ω/sq (ED7100_200 Ω – carbon). 

All fabricated resistors have thickness around 11 µm, rectangular 

shape, width from 0.5 to 1.5 mm and aspect ratio 1 to 4. All of 

them were covered with RCC cladding. The resistors were printed 

on Cu contacts, in some cases with protective Ni/Au coating and 

Ag contacts Electrodag PF-050 ink [17]. 

Pulse durability 

Measurement system 

The research was conducted by using self-made pulse generator 

GIHV-1 (rectangular pulses with duration t imp 

from 10 µs to 10 s, 

time between pulses T from 10 ms to 10 s and pulse amplitude 

from 5 to 1500 V), laboratory multimeter and a personal computer 

(Fig. 3). The measurements of resistor resistance were made with 

the aid of Agilent 34401A laboratory multimeter. 

Fig. 3. Measurement system. Rys. 3. System pomiarowy 

Measurement procedure 

There is no one general method to measure pulse durability, so 

it is hard to define parameters and criterion of experimental procedure. 

Nevertheless we determined failure criterion for resistor 

as changing of resistance after stress more than ±10% of initial 

value or visible structural damage. To determine pulse durability 

the following parameters were calculated: 

E max 

– maximum nondestructive electric field: 

(1) 

P max 

– maximum nondestructive power: 

(2) 

P S 

– maximum nondestructive surface power density: 

(3) 

P V 

– maximum nondestructive volume power density: 

(4) 

52 

where: V – largest non-destructive pulse amplitude, R after 

– resistance 

of resistor after pulse stress; l – length of resistor; w – width 

of resistor; t – thickness of resistor. 

The experiment was divided into two parts. In the first part 

component was stressed by two identical pulses, and its resistance 

was measured after short time. If resistance change was smaller 

than ±10% the amplitude was increased by 2% and procedure 

was repeated. This process was conducted until the failure criterion 

was achieved. 

Parameters of the pulse for constant time of pulse were following: 

t imp 

= 1 ms, T = 1 s, number of pulses N = 2, V – dependent 

of resistor type. 

Parameters of experiment pulses with various duration were 

following: t imp 

= 10 µs, 100 µs, 1 ms, 10 ms, 100 ms, 1 s, 10 s; 

T = 1 s for t imp 

< 1 s and 10 s for t imp 

= 10 s; N = 2, V – dependent 

of resistor type. 

Results 

Pulse durability for constant pulse duration 

After all experiments the parameters were calculated and part of 

them is presented. Pulse durability is depended on the dimension 

of resistor, type of cladding, sheet resistance and contact 

material. 

Pulse durability of TF resistors 

The maximum non-destructive pulse amplitude decreases for TF 

resistors with reduced length and width of components. However 

other parameters increase their values when dimensions of resistors 

decrease. Cladding affects pulse durability. Coated structures 

have better durability than uncovered ones (Fig. 4). In most 

cases the LPD 2×106 cladding gives the best pulse durability. 

Resistors fabricated from 100 Ω/sq foil have larger values of V 

and E max 

, but smaller values of P max 

, P S 

and P V 

than those made 

of 25 Ω/sq foil (Figs. 5 and 6). This is connected with thickness 

of resistive foil. 

Pulse durability of PTF resistors 

PTF resistors exhibit weaker dependence of pulse durability on 

resistor dimension. Structures made of 200 Ω/sq inks have nearly 

twice higher values of parameters than 20 Ω/sq ones (Figs. 7–9). 

Moreover resistors printed on Ag and Au contacts have better pulse 

durability in comparison with Cu contacts. 

Tabl. 1. Comparison of pulse durability of TF and PTF resistor for t imp 

= 1 ms 

Tab. 1. Porównanie odporności impulsowej rezystorów cienko- i grubowarstwowych 

dla t imp 

= 1 ms 

width: aspect ratio: 1 4 

0.5 mm 

1.5 mm 

0.5 mm 

1.5 mm 

TF resistors (100 Ω/sq) 

cladding: no 2×106 RCC no 2×106 RCC 

E max 

[V/mm] 35.0 55.0 55.0 30.5 49.8 46.3 

P V 

[W/mm 3 ] 9.2E+5 1.4E+6 1.6E+6 1.7E+5 2.5E+5 2.6E+5 

E max 

[V/mm] 27.3 52.7 52.7 26.5 45.4 47.5 

P V 

[W/mm 3 ] 7.4E+4 2.2E+5 2.4E+5 6.8E+4 1.8E+5 2.1E+5 

PTF resistors (200 Ω/sq) 

contact: Cu Ag Au Cu Ag Au 

E max 

[V/mm] 47.0 74.0 76.0 72.0 72.8 75.0 

P V 

[W/mm 3 ] 6.4E+2 1.4E+3 2.4E+3 1.3E+3 1.4E+3 1.6E+3 

E max 

[V/mm] 48.0 78.0 71.3 64.2 74.5 72.9 

P V 

[W/mm 3 ] 7.4E+2 1.5E+3 1.6E+3 1.6E+3 1.5E+3 1.6E+3 

In general TF resistors have smaller values of all parameters 

than PTF ones, except of P V 

which is approximately 2 orders 

higher (Figs. 6 and 9, Tabl. 1). 


E max 

[V/mm] 

80 

70 

60 

50 

40 

30 

20 

10 

0 

none 2x106 RCC none 2x106 RCC none 2x106 RCC 

1 sq 

2 sq 

4 sq 

0.25 mm 

0.5 mm 

1 mm 

1.5 mm 

E max 

[V/mm] 

45 

40 

35 

30 

25 

20 

15 

10 

5 

0 

Cu Ag Au Cu Ag Au Cu Ag Au 

1 sq 

2 sq 

4 sq 

0.5 mm 

0.75 mm 

1 mm 

1.5 mm 

Fig. 4. Maximum nondestructive electric field, TF resistors (25 Ω/sq), 

t imp 

= 1 ms 

Rys. 4. Maksymalne nieniszczące pole elektryczne rezystory cienkowarstwowe 

(25 Ω/kw), t imp 

= 1 ms 

Fig. 7. Maximum nondestructive electric field, PTF resistors (20 Ω/sq), 

t imp 

= 1 ms 

Rys. 7. Maksymalne nieniszczące pole elektryczne rezystory grubowarstwowe 

(20 Ω/kw), t imp 

= 1 ms 

2,0x10 6 4 sq 

P V 

[W/mm 3 ] 

1,8x10 6 

1,6x10 6 

1,4x10 6 

1,2x10 6 

1,0x10 6 

8,0x10 5 

6,0x10 5 

4,0x10 5 

2,0x10 5 

0,0 

0.25 mm 

0.5 mm 

1 mm 

1.5 mm 


1 sq 

2 sq 

P V 

[W/mm 3 ] 

1,5x10 3 

1,0x10 3 

5,0x10 2 

0,0 

0.5 mm 

0.75 mm 

1 mm 

1.5 mm 


1 sq 

2 sq 

2,0x10 3 4 sq 

Fig. 5. Maximum nondestructive volume power density TF resistors 

(25 Ω/sq), t imp 

= 1 ms 

Rys. 5. Maksymalna nieniszcząca objętościowa gęstość mocy rezystory 

cienkowarstwowe (25 Ω/kw), t imp 

= 1 ms 

Fig. 8. Maximum nondestructive volume power density PTF resistors 

(20 Ω/sq), t imp 

= 1 ms 


grubowarstwowe (20 Ω/kw), t imp 

= 1 ms 

3,5x10 5 4 sq 

3,0x10 5 

2,5x10 5 

0.25 mm 

0.5 mm 

1 mm 

1.5 mm 

2,0x10 3 

0.5 mm 

0.75 mm 

1 mm 

1.5 mm 

2,5x10 3 4 sq 

P V 

[W/mm 3 ] 

2,0x10 5 

1,5x10 5 

1,0x10 5 

5,0x10 4 

P V 

[W/mm 3 ] 

1,5x10 3 

1,0x10 3 

5,0x10 2 

0,0 


1 sq 

2 sq 

0,0 


1 sq 

2 sq 

Fig. 6. Maximum nondestructive volume power density TF resistors 

(100 Ω/sq), t imp 

= 1 ms 


cienkowarstwowe (100 Ω/kw), t imp 

= 1 ms 

Fig. 9. Maximum nondestructive volume power density PTF resistors 

(200 Ω/sq), t imp 

= 1 ms 


grubowarstwowe (200 Ω/kw), t imp 

= 1 ms 


Pulse durability for various pulse duration 

Pulse durability is decreasing very quickly with increase of pulse 

duration (Tabl. 2 and 3). There is power relationship between pulse 

duration and E max 

, P S 

and P V 

. 

Tabl. 2. Maximum nondestructive electric field E max 

[V/mm] versus pulse 

duration, TF and PTF resistors 

Tab. 2. Maksymalne nieniszczące pole elektryczne E max 

[V/mm] w funkcji 

czasu trwania impulsu, rezystory cienko- i grubowarstwowe 

E max 

t imp 

[ms] 

TF, 2×1 mm 

cladding 

PTF 2×1 mm 

contact 

none 2×106 RCC Cu Au Ag 

E max 

[V/mm] 

10 3 

10 2 

10 1 

PTF - Cu 

PTF- Ag 

PTF - Au 

TF - none 

TF- 2x106 

TF - RCC 

0.01 5.6 10.8 11.8 47.0 44.6 42.3 

0.1 4.0 7.9 7.5 17.3 17.1 15.9 

1 3.1 5.1 5.0 7.1 7.0 6.9 

10 1.8 2.7 2.5 3.8 3.6 3.4 

100 1.0 1.5 1.3 2.4 2.2 2.1 

1000 0.6 0.8 0.7 1.2 1.2 1.0 

10 0 

10 -3 10 -2 10 -1 10 0 10 1 10 2 10 3 10 4 

t imp 

[ms] 

Fig. 10. Maximum non destructive electric field for PTF (200 Ω/sq) 

and TF (100 Ω/sq) 2×1 mm resistors, versus pulse duration 

Rys. 10. Maksymalne nieniszczące pole elektryczne w funkcji czasu 

trwania impulsu dla rezystorów grubowarstwowych (200 Ω/kw) 

i cienkowarstwowych (100 Ω/kw) o wymiarach 2×1 mm 

10000 0.5 0.6 0.6 0.9 1.1 0.8 

Tabl. 3. Maximum nondestructive volume power density P V 

[W/mm 3 ] versus 

pulse duration, TF and PTF resistors 

Tab. 3. Maksymalna nieniszcząca objętościowa gęstość mocy P V 

[W/mm 3 ] 

w funkcji czasu trwania impulsu, rezystory cienko- i grubowarstwowe 

P V 

t imp 

[ms] 

TF, 2×1 mm 

cladding 

PTF, 2×1 mm 

contact 

none 2×106 RCC Cu Ag Au 

0.01 2.9E+5 1.1E+6 1.4E+6 5.9E+4 4.6E+4 5.4E+4 

P V [W/mm 3 ] 

10 6 

10 5 

10 4 

10 3 

10 2 

PTF - Cu 

PTF- Ag 

PTF - Au 

TF - none 

TF- 2x106 

TF - RCC 

approximation of TF 

approximation of PTF 

54 

0.1 1.6E+5 5.8E+5 5.6E+5 7.7E+3 6.9E+3 7.8E+3 

1 9.1E+4 2.1E+5 2.1E+5 1.5E+3 1.4E+3 1.5E+3 

10 2.9E+4 6,1E+4 5.9E+4 3.9E+2 3.9E+2 3.5E+2 

100 1.1E+4 1.9E+4 1.7E+4 1.4E+2 1.3E+2 1.2E+2 

1000 3.9E+3 5.0E+3 4.9E+3 4.0E+1 4.1E+1 3.1E+1 

10000 2.3E+3 3.0E+3 2.8E+3 2.1E+1 3.0E+1 1.9E+1 

Shapes of E max 

= f (t imp 

) and P V 

= f (t imp 

) characteristics are similar 

for all tested structures. Both kind of resistors exhibit powerlike 

characteristics for shorter pulses and almost constant values 

for longer ones (Figs. 10 and 11). 

The characteristics P V 

= f (t imp 

) in the range of pulse duration 

from 10 µs to 10 ms were fitted by the following equation: 

(5) 

Fitted values of b parameter are given in Table 4. 

Tabl. 4. Fitted values of b parameter 

Tab. 4. Oszacowane wartości współczynnika b 

Type of resistor Value Type of resistor Value 

TF – uncovered 0.327 PTF – Cu 0.725 

TF – LDP 2×106 0.423 PTF – Ag 0.692 

TF – RCC 0.456 PTF – Au 0.729 

Therefore the b parameter for TF resistors is very close to 0.4 

and for PTF ones very close to 0.7. 

10 1 

10 -3 10 -2 10 -1 10 0 10 1 10 2 10 3 10 4 10 5 

t imp 

[ms] 

Fig. 11. Approximation of maximum nondestructive volume power 

density for PTF (200 Ω/sq) and TF (100 Ω/sq) 2×1 mm resistors, versus 

pulse duration 

Rys. 11. Przybliżenie maksymalnej nieniszczącej objętościowej gęstości 

mocy w funkcji czasu trwania impulsu dla rezystorów grubowarstwowych 

(200 Ω/kw) i cienkowarstwowych (100 Ω/kw) o wymiarach 

2×1 mm 

Conclusions 

The research for pulse durability for resistors embedded in printed 

circuit boards was conducted. Thin-film and polymer thickfilm 

resistors were tested. Based on our research the influence 

of fabrication process and used materials on pulse stability was 

discovered. The structures coated with LDP 2×106 cladding and 

PTF resistors made on Ag contacts have the best pulse durability. 

Additionally smaller TF resistors have better pulse durability than 

larger ones. In PTF this dependence was not observed. Moreover 

PTF resistors have higher values of measured parameters 

than TF components. Relying on results of research with variable 

duration of pulse, values of parameters and time of pulse, power 

relationship was ascertained. By analyzing and approximating 

those characteristics relative value of parameter was obtained, 

it is relatively equal to 0.4 and 0.7 for TF and PTF resistors. The 

results can be used to determine safety parameters of work conditions 

for devices with this type of components. 

Acknowledgement 

Investigations were made as a part of the Operational Programme 

Innovative Economy (2007–2013), the Priority1, Action 1.3, 

Subaction 1.3.1, Developmental Programme „Technologia do- 


świadczalna wbudowywania elementów rezystywnych i pojemnościowych 

wewnątrz płytki drukowanej”, The agrement No: 

UDA-POIG.01.03.01-14-031/08-00 of 16.02.2009 r. Project No: 

POIG.01.03.01-14-031/08 and statutory activity of Wroclaw University 

of Technology. 

References 

[1] C.H. Seager, G.E. Pike; Electrical field induced changes in thick 

film resistors, Proc. Int. Microelectronics Symp. (ISHM-USA) 1976, 

p. 115–122. 

[2] J.-P. Constantin et al.; Effect of surge voltages on thin and thick film 

resistors, Proc. 2 nd Int. Microelectronics Conf. (ISHM-Japan), 1982, 

p. 51–55. 

[3] J.M. Kozłowski, M. Tańcula; The influence of electrical pulses on thick 

film (Du Pont 1421 Birox) resistors, Electrocomponent Science and 

Technology, vol. 9 (1982), p. 185–189. 

[4] R.F. Szeloch et al.; Computer controlled step-stress method for thick 

film resistive layers testing, Proc. RELECTRONIC`88 (7 th Symp. on 

Reliability in Electronics), Budapest 1988, p. 606–610. 

[5] D. Bonfert et al.; Electrical stress on film resistive structures on different 

substrates, Proc. 34 th ISSE Conf., Tatranska Lomnica (Slovakia), 

May 2011. 

[6] T. Tobita, H. Takasago; New trimming technique for a thick film resistor 

by the pulse voltage method, IEEE Trans. on Comp., Hybr., and 

Manuf. Technol, vol. CHMT-14 (1991), p. 613–617. 

[7] J. Muller et al.; Trimming of buried resistors in LTCC-circuits, Proc. 

33 rd ISHM Nordic Conf., Helsingor (Denmark) 1996, p. 166–173. 

[8] J. Kita et al.; Pulse durability of polymer, cermet and LTCC thick-film 

resistors, Proc. 12 th Eur. Microelectronics and Packaging Conf., Harrogate, 

1999, p. 313–319. 

[9] A. Dziedzic et al.; Some remarks about “short” pulse behaviour of 

LTCC microsystems, Proc. 1 st Eur. Microelectronics Packaging and 

Interconnection Symp., Prague, 2000, p. 194–199. 

[10] W. Ehrhardt, H. Thust; Trimming of thick-film resistors by energy of 

high voltage pulses and its influence on microstructure, Proc. 13 th Eur. 

Microelectronics and Packaging Conf., Strasbourg, 2001,p. 403–407. 

[11] A. Dziedzic et al.; Advanced electrical and stability characterization 

of untrimmed and variously trimmed thick-film and LTCC resistors, 

Microelectronics Reliab., vol. 46 (2006), p. 352–359. 

[12] S. Vasudevan; Effect of design parameters on overstress characterization 

of thick film resistors for lighting surge protection, Proc. 1997 

Int. Symp. on Microelectronics (IMAPS-US), 1997, p. 634–640. 

[13] A.R. Batchelor, J.R. Smith; Time-current characteristic of miniature 

zinc-element electric fuses for automotive applications, IEE Proc. 

– Sci. Meas. Technol., vol. 146 (1999), p. 210–216. 

[14] D. Ortolino et al.; Investigation of the short-time high-current behaviour 

of vias manufactured in hybrid thick-film technology, Microelectronics 

Reliab., vol. 51 (2011), p. 1257–1263. 

[15] W. Smetana, R. Reicher, H. Homolka; Improving reliability of thick 

film initiators for automotive applications based on FE-analyses, Microelectronics 

Reliab., vol.45 (2005), p. 1194–1201. 

[16] A. Dziedzic et al.; Wybrane właściwości elektryczne i stabilność elementów 

biernych wbudowanych w płytki obwodów drukowanych, 

Przegląd Elektrotechniczny, 87 (2011), no. 10, p. 39–44. 

[17] W. Stęplewski et al.; Investigations of passive components embedded 

in printed circuit boards, Proc. 35 th IMAPS/CPMT Poland Int. 

Conference, Gdańsk-Sobieszewo, Sept. 2011. 

Analysis of long-term stability of thin-film and polymer 

thick-film resistors embedded in Printed Circuit Boards 

(Analiza stabilności długoczasowej rezystorów cienkowarstwowych 

oraz polimerowych rezystorów grubowarstwowych wbudowanych 

w płytki obwodów drukowanych) 

inż. Paweł Winiarski 1) , prof. dr hab. inż. Andrzej Dziedzic 1) , inż. Adam Kłossowicz 1) , 

mgr inż. Wojciech Stęplewski 2) , dr Grażyna Kozioł 2) 

1) 

Politechnika Wrocławska, Wydział Elektroniki Mikrosystemów i Fotoniki 

2) 

Instytut Tele- i Radiotechniczny, Centrum Zaawansowanych Technologii,Warszawa 

Embedded passives play a major role in miniaturisation of electronic 

circuits, where e.g. MCM or HDI technologies [1] can be 

used. In most cases resistors represent the majority of passive 

components used on a circuit board. Besides size aspects, there 

are other very important issues like tolerance, reliability and 

long-term stability of components, especially in specialized applications. 

Technology and production processes are extensively 

studied and improved. However, to determine real reliability of 

fabricated components proper measuring methods are needed. 

To analyze stability of the resistors an accelerated ageing process 

can be used. Treating resistors with elevated temperature 

(or/and humidity) allows (in quite short time) obtain long-term behaviour 

of tested samples referred to a few years of service [2]. 

Test structures 

The thin-film resistors were fabricated on FR-4 laminate in accordance 

with Ohmega-Ply® techno-logy [3, 4]. In this technique firstly 

thin layer of Nickel-Phosphorous alloy is electroplated on copper 

foil, afterwards this composite foil called RCM (resistor-conductor 

material) is laminated to FR-4 substrate. Finally copper circuitry and 

planar resistors are realized by subtractive processes. Two types 

of resistive foil were used for fabrication of structures with sheet 

resistance 25 Ω/sq and 100 Ω/sq (with thickness 0.4 μm and 0.1 μm 

respectively). The rectangular resistors, with width from 0.25 mm to 

1.5 mm and aspect ratio n=l/w between 1 and 4, were designed and 

fabricated. Moreover, to investigate embedded resistors, part of the 

samples was covered with two types of cladding – Resin Coated 

Copper (RCC) or Laser Drillable Prepreg (LDP) 2 × 106. The cladding 

gives additional protection from environ-mental conditions. 

The PTF resistors were made using a standard thick-film 

method [5]. To fabricate resistors three types of resistive inks were 

used, with sheet resistance 20 Ω/sq, 200 Ω/sq and 5 kΩ/sq (with 

thickness about 11 μm). Alike to Ni-P ones a rectangular resistors 

were fabricated, with similar width from 0.5 mm to 1.5 mm and 

same aspect ratio n between 1 and 4. However, in this case all 

samples were covered only with RCC cladding, but in turn two types 

of contact interlayer (between resistor and copper lead) were 

investigated – copper (Cu) contacts and gold (Au) ones. 

Measurement procedure 

The In-Situ method [6] was used to determine stability of resistors, 

where measurements were done during ageing process. In this 

case test samples were placed on a hot plate treated with constant 

temperature – 100, 130 or 160°C for Ni-P resistors, 100 and 130°C 

for polymer ones. A Pt100 sensor was used to monitor and control 

temperature on the plate. Structures were equipped with needle 

probes, which were connected to Agilent 34970A multimeter. The 

selector collected data every 10 minutes (during 30…170 h) and 

sent them to personal computer for data acquisition and presentation. 

An idea of measurement system is shown in Fig. 1. 


Selector 

Agilent 

HP 34970A 

10 1 

10 0 

1sq - 100°C 

1sq - 130°C 

1sq - 160°C 

4sq - 100°C 

4sq - 130°C 

4sq - 160°C 

Computer 

T=100, 130, 160°C 

(heater) 

Substrate Resistor Pt100 

R/R 0 

[%] 

10 -1 

Fig. 1. Schema of measurement system 

Rys. 1. Schemat systemu pomiarowego 

Results 

Measurement results are collected and analyzed, and chosen 

ones are presented below. The stability of resistors was determined 

based on relative resistance changes during ageing tests. A 

normalized percentage resistance changes were calculated by: 

(1) 

Figures present mean values for clarity. 

Ni-P resistors 

Resistance drifts of tested thin-film resistors in the time domain 

are shown in Figs. 2–4. 

R/R 0 

[%] 

10 1 

10 0 

10 -1 

10 -2 

1sq - 100°C 

1sq - 130°C 

1sq - 160°C 

4sq - 100°C 

4sq - 130°C 

4sq - 160°C 

10 -1 10 0 10 1 10 2 

t [h] 

Fig. 2. Relative resistance changes for uncladded Ni-P 25 Ω/sq resistors 

Rys. 2. Względne zmiany rezystancji dla rezystorów Ni-P 25 Ω/kw bez 

pokrycia 

10 1 

1sq - 100°C 

1sq - 130°C 

1sq - 160°C 

4sq - 100°C 

10 0 4sq - 130°C 

4sq - 160°C 

R/R 0 

[%] 

10 -1 

10 -2 

10 -1 10 0 10 1 10 2 

t [h] 

Fig. 4. Relative resistance changes for Ni-P 25 Ω/sq – with RCC cladding 

Rys. 4. Względne zmiany rezystancji dla rezystorów Ni-P 25 Ω/kw pokrytych 

warstwą RCC 

The results revealed a square-root-of-time dependence of resistance 

changes. A single ageing mechanism occurs here, which 

can be described by following equation [7]: 

(2) 

where A is the pre-exponential constant characteristic for particular 

ageing mechanism, t – time, n is the time dependence (and is 

about 0.5), E is the activation energy, k is the Boltzmann constant 

and T is the temperature. 

In temperature domain results can be presented by Arrhenius 

law. Figs. 5–7 present resistance changes after 30 h of ageing 

process. 

R/R 0 

[%] 

10 1 1sq 

4sq 

10 0 

10 -1 

10 -2 

2,0 2,2 2,4 2,6 2,8 3,0 3,2 3,4 

1/T·10 3 [1/K] 

Fig. 5. Arrhenius plot – Ni-P uncladded resistors 

Rys. 5. Wykres Arrheniusa dla resystorów Ni-P bez pokrycia 

R/R 0 

[%] 

10 1 1sq 

4sq 

10 0 

10 -1 

Fig. 3. Relative resistance changes for Ni-P 25 Ω/sq – with LDP 2 × 106 

cladding 

Rys. 3. Względne zmiany rezystancji dla rezystorów Ni-P 25 Ω/kw pokrytych 

warstwą LDP 2 × 106 

56 

10 -2 

10 -1 10 0 10 1 10 2 

t [h] 

10 -2 

2,0 2,2 2,4 2,6 2,8 3,0 3,2 3,4 

1/T·10 3 [1/K] 

Fig. 6. Arrhenius plot – Ni-P resistors with LDP 2 × 106 cladding 

Rys. 6. Wykres Arrheniusa dla resystorów Ni-P pokrytych warstwą 

LDP 2 × 106 


R/R 0 

[%] 

10 1 1sq 

4sq 

10 0 

10 -1 

10 -2 

2,0 2,2 2,4 2,6 2,8 3,0 3,2 3,4 

1/T·10 3 [1/K] 

Fig. 7. Arrhenius plot – Ni-P resistors with RCC cladding 

Rys. 7. Wykres Arrheniusa dla resystorów Ni-P pokrytych warstwą 

RCC 

Activation energy of ageing process can be calculated using 

the approximation of results presented on Arrhenius plots 

R/R 0 

[%] 

10 

8 

6 

1sq - 100°C 

1sq - 130°C 

4sq - 100°C 

4sq - 130°C 

4 

2 

0 

-2 

-4 

-6 

-8 

-10 

0 20 40 60 80 100 120 140 

t [h] 

Fig. 9. Relative resistance changes for polymer resistors – 20 Ω/sq 

– Cu contacts 

Rys. 9. Względne zmiany rezystancji dla rezystorów polimerowych 

20 Ω/kw z kontaktami Cu 

(3) 

where activation energy is a slope of linear function, which fits 

results. Computed values are shown below in Tabl. 

Activation energy of Ni-P 25 Ω/sq resistors. 

Energie aktywacji rezystorów Ni-P 25 Ω/sq 

cladding without LDP 2x106 RCC 

length 1sq 4sq 1sq 4sq 1sq 4sq 

E [eV] 0.40 0.42 0.34 0.33 0.27 0.27 

R/R 0 

[%] 

14 

12 

10 

8 

6 

4 

2 

1sq - 100°C 

1sq - 130°C 

4sq - 100°C 

4sq - 130°C 

The changes of FR-4 laminate and cladding materials were 

observed (colour becomes darker). It refers to test samples treated 

by temperatures higher than 100°C (eg. structures without 

cladding and covered by RCC cladding are shown in Fig. 8). 

a) 

100°C 130°C 160°C 

0 

-2 

0 20 40 60 80 100 120 

t [h] 


– Cu contacts. 


200 Ω/kw z kontaktami Cu 

b) 

Fig. 8. Photography of aged structures a) without cladding, b) with 

RCC cladding 

Rys. 8. Fotografia starzonych struktur a) niepokrytych, b) pokrytych 

warstwą RCC 

PTF resistors 

The polymer thick-film resistors revealed a quite different behaviour 

than Ni-P ones. Depending on sample parameters and ageing 

condition resistance drift goes to negative or positive value. 

Therefore only results in time domain can be shown (Figs. 9–14). 

These resistors could not handle temperature above 130°C – resistor 

material melted and expanded. 

R/R 0 

[%] 

0 

-2 

-4 

-6 

-8 

-10 

-12 

-14 

-16 

-18 

-20 

1sq - 100°C 

1sq - 130°C 

4sq - 100°C 

4sq - 130°C 

0 20 40 60 80 100 

t [h] 

Fig. 11. Relative resistance changes for polymer resistors -5 kΩ/sq 

– Cu contacts 


5 kΩ/kw z kontaktami Cu 


R/R 0 

[%] 


– Au contacts 


20 Ω/kw z kontaktami Au 

R/R 0 

[%] 


– Au contacts 


200 Ω/kw z kontaktami Au 

R/R 0 

[%] 

Fig. 14. Relative resistance changes for polymer resistors – 5 kΩ/sq 

– Au contacts. 


5 kΩ/kw z kontaktami Au 

58 

0,0 

-0,5 

-1,0 

-1,5 

-2,0 

-2,5 

-3,0 

-3,5 

-4,0 

0 10 20 30 40 50 60 70 80 

0 

-1 

-2 

-3 

-4 

-5 

0 

-1 

-2 

-3 

-4 

-5 

-6 

t [h] 

1sq - 100°C 

1sq - 130°C 

4sq - 100°C 

4sq - 130°C 

0 20 40 60 80 100 120 140 160 180 

t [h] 

1sq - 100°C 

1sq - 130°C 

4sq - 100°C 

4sq - 130°C 

-7 

0 20 40 60 80 100 

Conclusion 

t [h] 

1sq - 100°C 

1sq - 130°C 

4sq - 100°C 

4sq - 130°C 

The results showed quite different behaviour for both groups of 

resistors. In case of Ni-P thin-film resistors, their geometry almost 

not affects long-term stability. However, the type of encapsulation 

and ageing temperature significantly affect observed resistance 

drift. Measurement results revealed the square-root-of-time de- 

pendence of the resistance changes. In the temperature domain 

resistance drift, can be described by the Arrhenius equation. 

The extrapolations of these results determine activation energies 

of ageing mechanism for each tested sample. According to these 

results a single ageing mechanism can be defined, which is 

characterized by set of parameters n, E and A for each kind of 

structures. One should add that similar parameters time to time 

were reported for thick-film resistors (for example authors of paper 

[8] have found n very close to 0.5 and E = 0.46 ± 0.02 eV 

for DP 1400 resistors aged in the temperature range from 125 to 

250°C). The observations made after ageing processes, suggest 

that changes, occurred in resistor during thermal exposition, are 

caused by some interactions between resistive material and surrounding 

films. Applying cladding gives additional protection from 

environment and improves stability at higher ageing temperature, 

but in turn rather decreases it near room temperature (probably 

as a result of stress release after lamination process). 

Such simple extrapolation is almost impossible for polymer 

thick-film resistors, where depending on sample type and ageing 

conditions the relative resistance changes versus ageing time are 

positive or negative. For this reason, behaviour of these resistors 

cannot be explained using a single ageing mechanism, the problem 

is more complex and should take into account also additional 

curing of polymer thick-film resistors during ageing at relatively 

high temperature (in comparison with 180°C applied for standardcuring 

these PTF resistors). In the case of these structures the 

interface between resistive films and termination materials plays 

very important role on stability. Applying gold contacts significantly 

improves reliability, but in general the changes observed for polymer 

thick-film resistors are larger than for thin-film ones. Usually 

the highest resistance changes for PTF resistors occur during first 

20 hours of ageing process – after this period of time further resistance 

drifts are much smaller or proceed with linear relationship. 

Aforesaid, pre-ageing process phenomenon can be used to enhance 

stability of polymer thick-film resistor. 

Investigations were made as part of the Operational Programme 

Innovative Economy, 2007–2013, the Priority of 1 Investigation and 

High Technology Development, Action 1.3 supporting B + R Projects 

for entrepreneurs carried out by scientific units, 1.3.1 Development 

Projects. The agreement No: UDA-POIG.01.03.01-14-031/08- 

04 of 16.02.2009, Title of Project: „Technologia doświadczalna 

wbudowywania elementów rezystywnych i pojemno-ściowych wewnątrz 

płytki drukowanej”, Project No: POIG.01.03.01-00-031/08, 

and statutory activity of Wrocław University of Technology. 

References 

[1] Dziedzic A.: Electrical and structural investigations in reliability characterization 

of modern passives and passive integrated components. 

Microelectronics Reliability, 42 (2002), pp. 709–719. 

[2] Khanna P.K., Bhatnagar S.K., Gust W.: On the thermally accelerated 

ageing of thick film resistors. Physica Status Solidi (a) 143, K33 

(1994), pp. 15–18. 

[3] www.ohmega.com (Ohmega Technologies Inc. website), 21-08-2010. 

[4] Dziedzic A., Kłossowicz A., Winiarski P., Nitsch K., Piasecki T., Kozioł 

G., Stęplewski W.: Wybrane właściwości elektryczne i stabilność elementów 

biernych wbudowanych w płytki obwodów drukowanych. 

Przegląd Elektrotechniczny, 87 (2011), no. 10, pp. 39–44. 

[5] Stęplewski W., Serzysko T., Kozioł G., Janeczek K., Dziedzic A.: 

Investigations of passive components embedded in printed circuit 

boards. Proc. 35th International Conference of IMAPS – IEEE CPMT 

Poland,Gdańsk-Sobieszewo, September, 2011. 

[6] De Schepper L., De Ceuninck W., Stulens H.,. Stals L.M., Vanden 

Berghe R., Demolder S.: A new approach to the study of the intrinsic 

ageing kinetics of thick film resistors. Hybrid Circuits, No. 23, September 

1990, pp. 5–13. 

[7] Coleman M.: Ageing mechanisms and stability in thick film resistors. 

4th European Hybrid Microelectronics Conference 1983, Copenhagen, 

pp. 20–30. 

[8] Morten B., Prudenziati M.: Thermal ageing of thick-film resistors. Hybrid 

Circuits, no.3 (Autumn 1983, pp. 24–26. 


Impedance spectroscopy as a diagnostic tool 

of degradation of Solid Oxide Fuel Cells 

(Spektroskopia impedancyjna jako narzędzie diagnostyczne degradacji 

tlenkowych ogniw paliwowych) 

mgr inż. Konrad Dunst, dr inż. Sebastian Molin, dr hab. inż. Piotr Jasiński 

Politechnika Gdańska, Wydział Elektroniki, Telekomunikacji i Informatyki 

Solid oxide fuel cell (SOFC) is an electrochemical device that converts 

chemical potential energy directly into electrical power. In 

comparison with a traditional combustion process, the SOFCs offer 

greater efficiency, reliability and environmental friendliness [1]. 

The SOFCs have a great potential to generate power from a wide 

range of fuels: hydrogen, carbon monoxide, hydrocarbons and 

alcohols. However, when operated, the fuel cells usually degrade. 

The nature of this process depends on the type of the applied 

fuel and materials used to fabricate the SOFC. In particular, when 

hydrocarbons are used as a fuel, a carbon can deposit inside the 

anode structure [2]. The deposited carbon may cause a complete 

degradation of the fuel cell. 

Further development of the SOFCs requires investigation of 

degradation process during fuel cells operation. Among the fuel 

cell diagnostic tools, AC impedance spectroscopy is a powerful 

technique [3]. This method allows obtaining information about different 

electrode processes, namely, oxygen reduction reaction 

kinetics, mass transfer and electrolyte resistance losses [4]. Selection 

of the appropriate experimental conditions (temperature, 

pressure and flow rate) may provide information extracted from 

the impedance spectra about the performance losses from the 

each fuel cell element separately [3,5]. 

Different electrode processes reveal unique characteristic 

frequencies, which depend on cell structure, materials used for 

SOFC fabrication and testing conditions. For example, in case of 

the anode supported cells with LSM ((La 0.75 

Sr 0.25 

) 0.95 

MnO 3 

) cathode 

operated at 750°C it was found [6], that the characteristic frequencies 

for the cathode processes are at ~25 kHz and ~500 Hz. 

At ~4 kHz occurs charge transfer reaction related with the anode. 

Characteristic frequency responsible for gas diffusion resistance 

is located at around 50 Hz, while at ~4 Hz a gas conversion process 

can be seen. 

In this study the impedance spectroscopy is used for degradation 

evaluation of the anode supported SOFC. Both, commercially 

available and fabricated, anode supported SOFCs were tested. 

The fuel cells were operated in hydrogen and in methane. The experimental 

conditions were selected to obtain fast SOFC degradation. 

The changes in impedance spectra due to instability were 

correlated with the element of the SOFC, which was responsible 

for the cell degradation. 

Experimental 

Anode supports were fabricated using powders of NiO (J.T. 

Baker) and YSZ (Zr 0.84 

Y 0.16 

O x 

) (Tosoh). A typical anode cermet 

composition of 60 vol% of nickel and 40 vol% of YSZ was exploited. 

In order to obtain sufficient final porosity of anodes for 

ease fuel diffusion, a 20 vol% of pore former (graphite (Sigma-Aldrich)) 

was added to cermet powders. The mixture was 

ball-milled (Fritsch Pulverisette 7) for 12 hours and iso-axially 

pressed (150 MPa) into pellets (16 mm in diameter). The pellets 

were pre-sintered at 1050°C for 4 h, followed by slurry spraying 

of 10 µm thick YSZ electrolyte and co-sintering at temperature of 

1400°C for 4h. Finally, the LNF (LaNi 0.6 

Fe 0.4 

O 3 

) paste was brushpainted 

on the electrolyte and the cells were fired at 1100°C for 

Fig. 1. Cross-section of the fabricated SOFC 

Rys. 1. Przekrój wytworzonego tlenkowego ogniwa paliwowego 

Fig. 2. Equivalent circuit model for the SOFC 

Rys. 2. Obwód zastępczy tlenkowego ogniwa paliwowego 

2 h. It is known that lanthanum from the cathode may react with 

zirconium from electrolyte, what leads to performance degradation 

of the SOFC. Therefore, frequently a ceria buffer layer is 

fabricated between the electrolyte and cathode, which was omitted 

in this study to accelerate the fuel cell degradation. A crosssection 

of the fabricated SOFC is shown in Fig. 1. 

Commercially available and fabricated SOFCs were characterized 

by impedance spectroscopy.For this purpose a Solartron 

SI1260 impedance analyzer was coupled with a Solartron SI1287 

potentiostat/galvanostat. Measurements were carried on unloaded 

fuel cells with the amplitude of 5 mV in the frequency range 

from 100 mHz to 300 kHz. 

Measured spectra were fitted using ZView software to an 

equivalent circuit shown in Fig. 2.The circuit, which is frequently 

applied circuit for SOFCs analysis [3], consists of a serial connection 

of inductance, resistance, and the serial combination of 

the three parallel circuits consisting of resistance and constant 

phase element (CPE). The inductance L1 is related to connecting 

wires, the serial resistance R1 corresponds to ohmic losses, while 

parallel connections of the resistance and CPE represent different 

electrode processes [6]. Characteristic frequency for each electrode 

process was calculated using equation 1: 

1 

f = , 

(1) 

2πRC 

where, R and C are the resistance and the capacitance of the 

electrode process, respectively. 


Results and discussion 

Fabricated SOFCs 

The fabricated fuel cells were tested in hydrogen at temperature 

of 800°C. The fuel cell performance plots are shown in Fig. 3. 

The power density decreases after 17 h of fuel cell operation by 

25%. However, from the plots it is not possible to acquire detailed 

degradation mechanism of the SOFC. Therefore, the impedance 

spectroscopy was employed to look for additional information. 

Impedance spectra measured just after reduction (marked 

as initial) and after 17 hours of fuel cell operation are shown 

in Fig. 4. Obtained spectra were fitted using equivalent circuit 

presented in Fig. 2. The most representing data are presented 

in Tabl. 1. Namely, the resistances (R1, R2, R3, R4), which are 

directly correlated with the fuel cell performance and characteristic 

frequencies (f1, f2, f3, f4) calculated using eq. 1, which help 

correlating the responsible process with the degradation phenomena. 

The biggest changes occur at characteristic frequencies 

of ~8 kHz – ~4 kHz (f2). Together with f2, the R2 resistance 

significantly changes, too. As expected, those changes are connected 

with degradation of the cathode. At this range, the characteristic 

frequencies are related to cathode phenomena, i.e. 

oxygen adsorption and charge transfer reaction. 

The increase of resistance is related with interaction between 

electrolyte and cathode. As a result, low conductive La 2 

Zr 2 

O 7 

and SrZrO 3 

phases are formed at the interface of electrolyte and 

cathode, what significantly decrease the length of the triple phase 

boundary. Other types of degradation cannot be seen from the 

results presented in Fig. 4. 

In other to investigate the anode degradation a commercial 

fuel cell will be used. In this case the ceria buffer layer was fabricated 

between electrolyte and cathode, what significantly diminish 

cathode degradation. 

Fig. 3. Current-voltage and current-power density plots of the fabricated 

SOFC operated in hydrogen at 800°C 

Rys. 3. Charakterystyki prądowo-napięciowe oraz prądowo-mocowe 

wytworzonych ogniw paliwowych, zmierzone w wodorze w temperaturze 

800°C 

Tabl. 1. Fitting results of the fabricated fuel cell operated in hydrogen 

at 800°C 

Tab. 1. Parametry obwodów zastępczych dla wytworzonego ogniwa paliwowego 

zbadanego w wodorze w temperaturze 800°C 

fabricated 

SOFC 

R1 R2 

(Ω cm 2 ) (Ω cm 2 ) 

f2 

(Hz) 

R3 

(Ω cm 2 ) 

f3 

(Hz) 

R4 

(Ω cm 2 ) 

f4 

(Hz) 

hydrogen 

800°C 

0 h 0.025 0.164 8449 0.306 950.9 0.117 8.0 

17 h 0.027 0.258 3642 0.355 988.8 0.122 12.6 

Fig. 5. Impedance spectra of the commercial SOFC in hydrogen at 600°C 

Rys. 5. Widma impedancyjne komercyjnych ogniw paliwowych, zmierzone 

w wodorze w temperaturze 600°C 

Tabl. 2. Fitting results of the commercial fuel cell operated in hydrogen and 

dry methane at 600°C 

Tab. 2. Parametry obwodów zastępczych dla komercyjnych ogniw paliwowych 

zbadanych w wodorze oraz suchym metanie w temperaturze 600°C 

R1 R2 

(Ω cm 2 ) (Ω cm 2 ) 

f2 

(Hz) 

R3 

(Ω cm 2 ) 

f3 

(Hz) 

R4 

(Ω cm 2 ) 

f4 

(Hz) 

Fig. 4. Impedance spectra of the fabricated SOFC in hydrogen at 800°C 

Rys. 4. Widma impedancyjne wytworzonych ogniw paliwowych, 

zmierzone w wodorze w temperaturze 800°C 

commercial SOFC 

hydrogen 

600°C 

methane 

600°C 

0 h 0.555 0.550 1667.8 0.467 43.8 5.12 0.55 

61 h 0.552 0.550 1848.2 0.466 43.1 5.14 0.57 

0 h 0.303 0.772 716.2 0.330 26.8 5.15 0.54 

70 h 5.201 0.837 525.9 0.373 14.3 5.22 0.38 

60 


Commercial SOFCs 

Operation of the fuel cell under the relatively low temperature and 

dry methane may cause carbon deposition, which in result should 

provide fast anode degradation. Therefore, the commercial 

SOFC was tested at temperature of 600°C in hydrogen and in dry 

methane. In either case the anode was in-situ reduced at 800°C. 

The impedance spectra of the commercial SOFC tested in dry 

methane at temperature of 600°C are shown in Fig. 6. The ohmic 

resistance has increased significantly after 70 hours of fuel cell operation. 

According to the results obtained from the fitting procedure 

(Tabl. 2), the R1 increased from 0.303 Ω cm 2 to 5.201 Ω cm 2 . This is 

associated with carbon formation in the anode structure, what leads 

to deterioration of the electrical contact. It can be noted (see Tabl. 2) 

that, the characteristic frequencies changed at low frequencies, what 

may be related to the gas diffusion and the gas conversion processes. 

Pores in the anode become clogged with carbon, which limits the 

diffusion and make length of the triple phase boundary shorter. 

Conclusion 

In this paper the nature of the degradation of the fuel cells was 

studies by the impedance spectroscopy. The fuel cells were tested 

in the experimental conditions, which allow obtaining fast fuel 

cell performance degradation. The impedance spectra and the 

parameters obtained from the fitting of the spectra to the equivalent 

circuit were correlated with degradation of the fuel cell elements 

– anode or cathode. 

The project was supported by the Voivodship Fund for Environmental 

Protection and Water Management in Gdansk – project 

RX-03/43/2011. 

Fig. 6. Impedance spectra of the commercial SOFC in dry methane 

at 600°C 

Rys. 6. Widma impedancyjne komercyjnych ogniw paliwowych, zmierzone 

w suchym metanie w temperaturze 600°C 

The impedance spectra of the fuel cells operated in hydrogen 

at 600°C are shown in Fig. 5. Nearly no changes in the spectra 

are observed. This is also confirmed by the results obtained from 

fitting the spectra to equivalent circuit (Tabl. 2). None of the fitted 

elements changed significantly their values. Those results demonstrate 

good stability of the commercial fuel cells in hydrogen. 

References 

[1] Zhu W. Z., Deevi S. C.: A review on the status of anode materials 

for solid oxide fuel cells. Materials Science and Engineering, A362, 

2003, pp. 228–239. 

[2] Koh J. H., Yoo Y. S., Park J. W., Lim H. C.: Carbon deposition and 

cell performance of Ni-YSZ anode support SOFC with methane fuel. 

Solid State Ionics, 149, 2002, pp. 157–166. 

[3] Huang Q. A., Hui R., Wang B., Zhang J.: A review of AC impedance 

modeling and validation in SOFC diagnosis, Electrochimica Acta, 52, 

2007, pp. 8144–8164. 

[4] Wagner R.: Solid Oxide Fuel Cells (SOFC) in: Macdonald J. R., Barsoukov 

E., Impedance Spectroscopy, Theory, Experiment, and Applications. 

John Willey & Sons, 2005, pp. 530–537. 

[5] Nielsen J., Mogensen M.: SOFC LSM:YSZ cathode degradation inducted 

by moisture: An impedance spectroscopy study. Solid State 

Ionics, 189, 2011, pp. 74–81. 

[6] Hauch A., Mogensen M.: Ni/YSZ electrode degradation studied by 

impedance spectroscopy Effects of gas cleaning and current density. 

Solid State Ionics, 181, 2010, pp. 745–753. 

Analysis of electromagnetic couplingsin hybrid circuit 

made on austenitic metal substrate 

(Analiza sprzężeń elektromagnetycznych w układach hybrydowych 

wykonanych na podłożach ze stali austenitycznej) 

dr inż. Wiesław SABAT, dr inż. Dariusz KLEPACKI, dr inż. Kazimierz KAMUDA 

Politechnika Rzeszowska, Zakład Systemów Elektronicznych i Telekomunikacyjnych 

The fast progress in material technology, new compositions of 

dielectric inks allowed to realizations of hybrid structures on 

metal substrates. The technological materials from DuPont, 

ESL or Heraeus make possible to print different pastes on substrates 

from rustless steel (austenitic, ferritic), aluminium or platinum. 

The elaborated technological applications (in the most 

cases) allow to realization of heating elements (HOS – Heaters 

on Steel), electronic structures (COS – Circuits on Steel, TFOS 

– Thick Film on Steel) as well as sensors structures for special 

applications. 

There are a lot of dielectric inks especially dedicated for those 

applications. For example – 3500N for ferritic steels S430 and 

S444 from DuPont, 4916 for austenitic steel S304 and 4924 for 

ferritic steel S430 from ESL or SD1000 SD2000 for ferritic steel 

S430 and IP211 dedicated to sensor applications and steels S430 

or S446 from Heraeus. 

This growing interest of the above-mentioned applications leads 

to necessity of research in EMC area. The good knowledge 

about mechanisms of disturbance propagation processes is the 

basis of good designed final product. 

Parasitic elements of paths’ system 

The application of rustless steel, aluminium or platinum as substrate 

material in microelectronic hybrid circuits leads to creation 

of typical microstrip structure for path-substrate system 

(Fig. 1) [1, 2]. 


Fig. 1. Structure of microelectronic hybrid circuit made on the metalsubstrate 

Rys. 1. Struktura mikroelektronicznego układu hybrydowego wykonanego 

na podłożu metalowym 

In the above-mentioned configuration the nearness of each 

path in relation to ground (determined by thickness of the dielectric 

paste) is cause of shorting effect of electric field lines to the 

conducted structure of substrate. This effect leads to decrease of 

electrical flux value in neighboring paths – then the small values 

of parasitic capacitances are observed [2]. 

The three types of test circuits with different geometrical configuration 

were made for realization of experimental investigations 

(determination of per-unit-length parameters in planar structures 

made on metal substrates) – Fig. 2. The metal substrates fromaustenitic 

steel of 304 type (1 mm thick) were selected. The 4916 

paste from DuPont (dedicated to austenitic steel) was applied to 

insulation layer. On such prepared substrates the test paths were 

printed for verification of calculation procedures. The conductive 

paths were made on the basis of silver-platinum paste 6305 from 

Koartan characterized by low dielectric loss (3 mΩ/□). 

The calculations of capacitances between path systems 

– for parametrically changed mutual distance and width of paths 

– have been made using elaborated numerical procedures for 

determination of parasitic parameters with reference ground [4]. 

The obtained calculation results of equivalent capacitance C z 

for 

two parallel paths (with constant width) indicate that the value of 

capacitance between paths is independent on their mutual distance 

(Fig. 3). This effect is a consequence of very near placement 

of path’s system in relation to the ground plane as well as small 

value of mutual capacitance C M 

. It is confirmed by computer simulations 

and experimental verification. 

2500 

2000 

1500 

1000 

500 

0 

C z , pF/m 

A 

- calculated 

- measured 

B 

S C =11 pF/m 

=0.2% 

s,mm 

0.1 

0.5 

1.0 

w, mm 

0 0,5 1 1,5 2 2,5 3 

Fig. 4. Influence of paths width change on capacitance value C z 

between configuration of two mutually parallel path systems 

Rys. 4. Wpływ zmiany szerokości ścieżek na wartość pojemności C z 

pomiędzy układem dwóch wzajemnie równoległych ścieżek 

0,3 

L z, 

H/m 

- obliczenia 

- pomiar 

0,25 

s, mm 

0.5 

Fig. 2. Test path systems with different geometrical parameters made 

on metal stainless substrate (sort 304 – AISI) 

Rys. 2. Testowe układy ścieżek o różnych parametrach geometrycznych 

wykonanych na metalowym podłożu ze stali nierdzewnej (gatunek 

304 – AISI) 

10000 

1000 

100 

10 

1 

0,1 

C z, pF/m 

C M 

w, mm 

5.0 

0.5 

0.1 

- calculated 

- measured 

0,2 

0 1 2 3 4 w, mm 5 

Fig. 5. Influence of paths width change on equivalent inductance value 

L z between configuration of two mutually parallel path 

Rys. 5. Wpływ zmiany szerokości ścieżek na wartość indukcyjności 

L z pomiędzy układem dwóch wzajemnie równoległych ścieżek 

1 

0,1 

L z , 

H/m 

- calculated 

- measured 

w, mm 

0.5 

0,01 

0 2 4 6 8 s, mm 10 

0,01 

0 1 2 3 4 s, mm 5 

Fig. 3. Influence of paths distance change on equivalent and mutual 

capacitance values C z 

and C M 

between configuration of two mutually 

parallel path system 

Rys. 3. Wpływ zmiany odległości ścieżek na wartość wypadkowej 

i wzajemnej pojemności C z 

i C M 

pomiędzy układem dwóch wzajemnie 

równoległych ścieżek 

Fig. 6. Influence of paths distance change on equivalent inductance 

value L z between configuration of two mutually parallel path systems 

Rys. 6. Wpływ zmiany odległości ścieżek na wartość indukcyjności 

L z pomiędzy układem dwóch wzajemnie równoległych ścieżek 

62 


The increase of paths width has a very big influence on capacitance 

value regarding to the substrate (Fig. 4 – curve A) and on 

value of equivalent capacitance C z (Fig. 4 – curve B). The value 

of capacitance C z is linear dependent on paths width. 

The ability of paths’ system for energy accumulation in magnetic 

filed is described by the second parasitic parameter – inductance. 

For determination of its changes range for typical geometrical 

parameters of path systems the experimental investigations 

were carried out using above-described test circuits. 

The increase of equivalent inductance connected with 

increase of mutual distance between paths is caused by value 

decreasing of mutual inductance between analyzed paths (with 

constant self-inductance). The dynamics of changes of equivalent 

inductance for small distances between paths is result 

of significant decrease of mutual inductance for the smallest 

distances between them [3]. 

The decrease of equivalent inductance for two parallel paths is 

a consequence of decrease of self-inductance value of path with 

their width increasing (Fig. 6). 

Analysis of electromagnetic couplings 

Analysis of electromagnetic couplings in mutual coupled paths’ 

system requires solution of telegraph equation: 

For specification of propagation process of electrical signals 

in microcircuits made on metal substrate the test circuits were 

designed and made. They allowed to analyze of signal penetration 

with taking into consideration the parasitic elements in path 

systems. 

The significant reduction of disturbances levelwhich penetrate 

between path systems can be obtained by using of conductive 

substrate as ground plane. The conducted simulations and experimental 

investigations for test circuits confirmed such thesis. 

The influence of system configuration on crosstalk reduction in 

passive path- active path circuit was analyzed for the simplest 

configuration of three paths where crosstalk effect was observed 

(Fig. 8). 

a) 

U G 

Z 

R 

1 

I 

1 1 2 2 

I 

U1 3 4 4 U2 

3 

3 

U3 M’ M” 

4 

L 

A 

I 

I 

A’ 

U 

R 

R 

2 

4 

( ) 

( ) 

⎧ ∂u 

z,t 

∂i 

z,t 

⎪− 

= R ⋅ i( z,t) 

+ L 

∂z 

∂t 

⎨ 

(1) 

⎪ ∂i( z,t) 

∂u 

( ) 

( z,t) 

− = G ⋅u 

z,t + C 

⎩ ∂z 

∂t 

b) 

A-A’ 

W s W s 

1 

3 

W M 

M’ 

H17 (1.4016) 

where u (z, t), i (z, t) are voltage and current vectors, respectively 

and R, G, L, C – matrices of parameters of parasitic elements of 

paths’ system. 

For three or more paths (with given boundary conditions) 

the solution of telegraph equation is possible by transformation 

of equation system (1). It allows to decoupling of voltage and current 

vectors which are determined by impedance and admittance 

matrices [3–5]: 

( ) ( ) 

( ) 

( ) ( ) ( ) 

−1 

+ 

− 

⎪⎧ 

U 

⎪⎧ 

m 

z = TU 

⋅U 

z U z = Z 

CT 

I 

exp − γ ⋅ z ⋅ I 

m 

+ exp γ⋅ 

z ⋅ Im 

⎨ ⇒ ⎨ 

−1 

+ 

− (2) 

⎪⎩ Im( z) = TI 

⋅ I( z) 

⎪⎩ I( z) = TI( exp ( −γ⋅ 

z ) ⋅ I 

m− 

exp ( γ⋅ 

z) 

⋅ Im 

) 

( ) ( ) 

+ 

−1 

⎡I 

⎤ 

m ⎡ ZC 

+ ZS 

TI 

ZC 

− ZS 

TI 

⎤ ⎡US 

⎤ 

⎢ ⎥ = ⎢ 

⋅ (3) 

− 

( ) ( ) ( ) ( ) 

⎥ ⎢ ⎥ 

⎢⎣ 

I ⎥⎦ 

⎣ ZC 

− ZS 

TI 

exp − γL 

ZC 

+ Z 

m 

S 

TI 

exp γL 

⎦ ⎣UL 

⎦ 

c) 

A-A’ 

W M 

W s W 

1 2 

H17 (1.4016) 

Fig. 8. Test circuits configuration (M’ – reference path/layer): a) wiring 

diagram (Z 1 

= 50 Ω, R 2 

= R 4 

= 150 Ω, R 3 

= 1 MΩ) λ = 0.1 m, b) one-layered 

circuit (w = 0.5 mm, s = 0.5 mm, w M 

= 0.5 mm), c) two-layered circuit 

(w = 0.5 mm, w M 

= 50 mm) 

Rys. 8. Konfiguracja układów testowych (M’ – ścieżka/warstwa odniesienia): 

a) schemat połączeń (Z 1 

= 50 Ω, R 2 

= R 4 

= 150 Ω, R 3 

= 1 MΩ) 

λ = 0.1 m, b) układ jednowarstwowy (w = 0.5 mm, s = 0.5 mm, 

w M 

= 0.5 mm), c) układ dwuwarstwowy (w = 0.5 mm, w M 

= 50 mm) 

M’ 

where T U 

i T I 

are matrices allowed to make diagonal of matrices 

+ − 

Z i Y, U S 

i U L 

– voltage vectors of supply sources, Im i I m – searched 

vectors of integration constants determined on the basis 

of boundary conditions, γ means propagation constant, L – path 

length, Z S 

i Z L 

– impedance vector loaded paths’ system and Z C 

is 

the matrix of wave impedance of paths’ system. 

s 

w 

s=0.5mm, w=0.5mm 

a) 

100 mm 

b) 

Fig. 7. Test circuits for analysis of electrical signal process propagation 

in mutually parallel path systems: a) geometrical parameters, 

b) physical structure of test circuit 

Rys. 7. Układy testowe do analizy procesu propagacji sygnałów elektrycznych 

w układach wzajemnie równoległych ścieżek: a) parametry 

geometryczne, b) fizyczna struktura układu testowego 

Fig. 9. Time courses calculated for test circuit in configuration from 

the Figure 8b. (U1 – beginning of active path, U3 – near crosstalk, U4 

– far crosstalk) 

Rys. 9. Symulowane Przebiegi czasowe dla układu testowego o konfiguracji 

z rysunku 8b (U1 – początek ścieżki czynnej, U3 – przesłuch 

bliski, U4 – przesłuch daleki) 


Fig. 10. Time courses measured for test circuit in configuration from 

the Figure 8b 

Rys. 10. Przebiegi czasowe zmierzone dla konfiguracji układu testowego 

z rysunku 8b 

Fig. 11. Time courses measured for test circuit in configuration from 

the figure 8c 

Rys. 11. Przebiegi czasowe zmierzone dla konfiguracji układu testowego 

z rysunku 8c 

The trapezoidal pulse generated by AFG3252 arbitrary signals 

generator (with following parameters: 5 V level, rising time 

τ r 

and falling time τ f 

equal 2.5 ns, duration time – 40 ns and 

repetition time equals 200 ns) was used for analysis of propagation 

processes. The level of crosstalk generated on the end 

of passive path was assumed as reference point in analysis. 

For measurements of time courses the oscilloscope MSO4104 

with active probes TAP1500 from Tektronix was used.Active and 

passive layer were loaded at the end by resistors R 2 

and R 4 

(value – 150 Ω in SMD version, package 0603). This value is 

near to wave impedance value of the considered path systems 

(Zoe = 135 Ω − differential impedance, Zoo = 129 Ω − common 

impedance). The passive path at the beginningwas loaded by 

resistor R 3 

= 1 MΩ. 

Using conductive plane of substrate as ground plane allows to 

significant reduction of crosstalk level generated in passive path 

(Fig. 11). The reduction of 25 dB of crosstalk level was obtained 

in the case of tested configuration (where active and passive path 

had width and mutual distance equal 0.5 mm and were electromagnetically 

coupled on distance 0.1 m) in relation to configuration 

where ground path was placed in the same plane as active 

and passive layer (Fig.10). 

Conlusions 

The specific properties of hybrid structures realized on metal 

substrates (determined by distance of conductive paths in relation 

to substrate) are cause of increase of parasitic elements 

values in path systems in relation to conductive substrate and 

decrease of those parameters between them. The results of calculations 

and measurements indicate that values of capacitance, 

self and mutual inductance of paths’ system is strongly dependent 

on their geometrical parameters.Such systems are transmission 

microstrip structures in relation to conductive substrate. 

Taking into account those properties the significant reduction of 

disturbances level which penetrate by parasitic elements of path 

systems can be obtained. However, the one-layered or multilayered 

circuits without using the conductive plane as ground 

plane can be generate high level of crosstalk. Those effect are 

very important from electromagnetic compatibility and signal integrity 

point of view. 

Equipment purchased in the project No POPW.01.03.00-18-012/09 

from the Structural Funds, The Development of Eastern Poland 

Operational Programme co-financed by the European Union, the 

European Regional Development Fund. 

References 

[1] Kaiser K. L.: Transmission Lines, Matching and Crosstalk. CRC 

Press 2006. 

[2] Paul C.R., Analysis of Multiconductor Transmission Lines.John Wiley 

& Sons Ltd 2008. 

[3] Sabat W., Klepacki D., Kamuda K., Kalita W.: Application of Operational 

Method in Analysis of Electromagnetic Couplings in Mutual 

Coupled Path Systems of Planar Structures. Electronics Systemintegration 

Technology Conference, 2008. ESTC 2008. 2nd, s. 1107– 

1110, 2008. 

[4] Sabat W.: Uwarunkowania propagacji zakłóceń przewodzonych 

w hybrydowych strukturach mikroelektronicznych. PhD Thesis, Politechnika 

Rzeszowska, Rzeszów 2002 (in Polish). 

[5] Caniggia S., Maradei F.: Signal Integrity and Radiated Emission 

of High-Speed Digital Systems. John Wiley & Sons Ltd 2008. 

64 


EMC Aspects in microelectronics structures made 

in LTCC technology 

(Zagadnienia EMC w mikroelektronicznych strukturach wytwarzanych 

w technologii LTCC) 

dr inż. Wiesław SABAT, dr inż. Dariusz KLEPACKI, dr hab. inż. Włodzimierz KALITA, prof. PRz 

Politechnika Rzeszowska, Zakład Systemów Elektronicznych i Telekomunikacyjnych 

prof. Ing. Stanislav SLOSARČÍK, CSc; Ing. Michal JURČIŠIN, dr Ing. Pavol CABÚK 

Technická Univerzita v Košiciach, Fakulta elektrotechniky a informatiky, Katedra technológií v elektronike, Slovenská Republika 

The fast development of LTCC technology (Low Temeperature 

Cofired Ceramic) is observed in relation to realization of multilayered 

hybrid structures. It is applied for manufacturing of wide 

range of microelectronic circuits, especially MCM-C structures 

(Multi Chip Module on Ceramics) which are used in different 

areas of industry. The multilayered structures, sensors, microsystems, 

passive elements, microwave elements can be found in 

telecommunication, informatics, radioengineering, mechatronics, 

transport, etc. The possibility of creation of channels and cavities 

inside of LTCC module allows to realization of chemical microreactors, 

hydraulic systems in microscale (together with pumps and 

valves), fuel cells, flat plasma displays, sensors of physical quantities 

and systems applied in biotechnology and medicine [1, 2]. 

Parasitic elements of paths’ system 

The calculations of mutual capacitance C M 

and effective inductance 

L z 

(for two parallel paths system with parametrically changed 

the mutual distance „s” and paths width „w”) were made using 

elaborated PACAPIND program. They allowed to determine range 

of parameters changes of parasitic elements in typical LTCC 

structure for three basic configurations. 

For experimental investigations (determination of per-unitlength 

parameters) the test circuits were made in configuration 

of mutual parallel path systems (Fig. 1) on the basis of silver 

conductive paste HF612Ag and LTCC substrate 943PX from 

DuPont. 

The test circuits were made in three configurations: onelayered, 

two-layered with ground plane (microstrip configurations) 

and layered with the same thickness of substrate layer (strip configuration) 

– Fig. 2. 

The obtained results of calculations (experimentally confirmed) 

show that change of mutual distance and width of paths 

– especially for the smallest values those parameters – has a big 

Fig. 2. Geometrical parameters of the test path systems and their 

configurations 

Rys. 2. Parametry geometryczne układów testowych wraz z ich konfiguracjami 

100 

50 

CM, pF/m 

- calculated 

- measured 

S C =1.0 pF/m 

20 

10 

w, mm 

5.0 

0.5 

0.1 

0 2 4 6 8 s, mm 10 

Fig. 1. Test path systems implemented in Department of Technologies 

in Electronics at Technical University of Košice 

Rys. 1. Układ testowy wykonany w Katedrze Technologii Elektronicznych 

Technicznego Uniwersytetu w Koszycach 

Fig. 3. Influence of geometrical parameters changes in path system 

on capacitance value C M 

for DuPont 943PX ceramics with thickness 

h = 4.5 mm and ε r 

= 7.8 for constant value of path width „w” with 

change of their mutual distance „s” 

Rys. 3. Wpływ zmian parametrów geometrycznych układu ścieżek 

na wartość pojemności C M 

dla ceramiki DuPont 943PX o grubości 

h = 4.5 mm i ε r 

= 7.8 dla stałej szerokości ścieżek „w” przy zmianie 

wzajemnej odległości „s” 


3 

2 

L'eff, µH/m 

- calculated 

- measured 

S C=40 nH/m 

ϕ 2 =0.1% 

w, mm 

0.1 

0.5 

a) 

UG 

Z 

R 

1 

I 

1 1 2 2 

I 

U1 3 4 4 U2 

3 

3 

U3 M’ M” 

4 

A 

I 

I 

U 

R 

R 

2 

4 

1 

0 

s, mm 

0 2 4 6 8 10 

5.0 

b) 

A-A’ 

W s W s 

1 

L 

W M 

3 M’ 

A’ 

Fig. 4. Influence of geometrical parameters changes in path system 

on effective inductance value Leff for DuPont 943PX ceramics with 

thickness h = 4.5 mm for constant value of path width „w” with change 

of their mutual distance „s” 

Rys. 4. Wpływ zmian parametrów geometrycznych układu ścieżek 

na wartość indukcyjności L eff 

dla ceramiki DuPont 943PX o grubości 

h = 4.5 mm dla stałej szerokości ścieżek „w” przy zmianie wzajemnej 

odległości „s” 

influence on value of parasitic capacitance and inductance. From 

the point of view of signal integrity the reduction of mutual capacitance 

value between “disturbing” and “disturbed” circuit leads to 

measurable crosstalk reduction between non-associated logically 

circuits. 

Analysis of electromagnetic couplings 

in mutually coupled paths 

The level of disturbances penetration between paths is in significant 

way dependent on geometrical, electrical physical factors of 

planar structures [3]. For influence determination of the abovementioned 

factors on effectiveness of disturbance propagation 

in mutually coupled paths systems the simulation and experimental 

investigations were carried out. For the selected configurations 

(Fig. 5) with different geometrical parameters the propagation 

process of trapezoidal pulse (generated by AFG3052 

generator: amplitude – 5 Vpp, changed raising and falling time 

τ r 

= τ f 

– from 2.5 to 10 ns) with using parasitic elements of paths 

was analyzed. 

The determination of parameter matrices of parasitic elements 

for analyzed geometrical configuration of paths’ system is the basis 

of simulations [5]. 

The knowledge about their values is the main element for creation 

of transmission line model. For example, matrices of capacitances, 

inductances and resistances (calculated using elaborated 

PACAPIND) for paths configuration from Fig. 5a (thickness 

of substrate after firing h = 0.45 mm, dielectric constant of LTCC 

ceramics ε r 

= 7.8) are equal: 

Fig. 5. Geometrical parameters of test path systems 

Rys. 5. Parametry geometryczne testowego układu ścieżek 

66 

a) 

b) 

c) 

d) 

e) 

f) 

w 

M 

w s w, s, w M, 

0.5 0.5 2.0 

0.5 0.5 1.0 

50 mm 

mm mm mm 

0.5 

0.5 

0.5 

0.5 

0.5 

1.0 

0.5 

0.5 

0.5 

0.5 

0.5 

0.5 

c) 

A-A’ 

Fig. 6. Test circuits configuration: a) wiring diagram (Z 1 

= 50 Ω, 

R 2 

= R4 = 150 Ω, R 3 

= 1 MΩ, λ = 0.05 m, b) one-layered circuit 

(w = 0.5 mm, s = 0.5 mm, w M 

= 0.5 mm), c) two-layered circuit with 

ground layer (w = 0.5 mm, w M 

= 50 mm) 

Rys. 6. Układ testowy: a) schemat układu (Z1 = 50 Ω, R2 = R4 = 150 Ω, 

R3 = 1 M Ω, l = 0,05 m, b) układ jednowarstwowy (w = 0,5 mm, 

s = 0,5 mm, w M 

= 0,5 mm), c) układ dwuwarstwowy z płaszczyzną 

masy (w = 0,5 mm, w M 

= 50 mm) 

Fig. 7. Simulated waveforms of near–end crosstalk U 3 

in passive 

path, for different values of rise an fall time of slope for trapezoidal 

test pulse 

Rys. 7. Symulowane przebiegi bliskiego przesłuchu U3 w ścieżce 

biernej dla różnych czasów narastania i opadania trapezowego impulsu 

testowego 

⎡ 49.8 

C = ⎢ 

⎣− 

39.7 

⎡908.5 

L = ⎢ 

⎣399.5 

⎡4.7 

R = ⎢ 

⎣1.1 

W M 

W s W 

1 2 

− 39.7⎤ 

79.3 

⎥ ⎦ 

399.5⎤ 

689.2 

⎥ ⎦ 

1.1⎤ 

Ω 

4.7 ⎥ 

⎦ 

/ m 

pF / m 

nH / m 

Those matrices are input data to the program which allowed to 

analysis of propagation process of electrical signals in mutually 

coupled paths systems. 

The influence of changes of rising and falling time of trapezoidal 

signal slope on crosstalk level U 3 

generated in passive 

path (Fig. 6a) was analyzed for test circuit in configuration from 

Fig. 6b. The obtained results are presented in Fig. 7 (simulations) 

and Fig. 8 (experimental verification). 

M’ 


Fig. 8. Measured waveforms of near–end crosstalk U 3 

in passive path, 

for different values of rise an fall time of slope for trapezoidal test 

pulse 

Rys. 8. Zmierzone przebiegi bliskiego przesłuchu U3 w ścieżce biernej 

dla różnych czasów narastania i opadania trapezowego impulsu 

testowego 

Fig. 9. Measured courses of near-end U 3 

and far-end U 4 

crosstalk in 

passive path for one-layered circuit 

Rys. 9. Zmierzone przebiegi bliskiego (U3) I dalekiego (U4) przesłuchu 

w ścieżce biernej w układzie jednowarstwowym 

The change of configuration from one- to two-layered with 

ground layer (Fig. 6) is the characteristic example, which shows 

influence of geometrical factors on crosstalk level generated 

in system of coupled paths. The basic test circuit was characterized 

by following dimensions: length L = 0.05 m, width 

w = 0.5 mm and mutual distance s = 0.5 mm for one-layered 

circuit (Fig. 6b) and two-layered with ground layer (Fig. 6c). The 

influence of configuration changes on crosstalk level U 3 

generated 

in passive path was analyzed with constant value of changes 

speed of test signal (2 V/s). 

The small differences between calculations and measurements 

are caused by the fact that paths’ shapes were modeled 

as „ideal” (with straight edges). 

Conclusions 

In the case of considered microelectronic structures made in 

LTCC technology, the geometrical factors (in connection with 

physical parameters) determine parameter values of parasitic 

Fig. 10. Measured courses of near-end U 3 

and far-end U 4 

crosstalk 

in passive path for two-layered circuit with ground layer 

Rys. 10. Zmierzone przebiegi bliskiego (U3) I dalekiego (U4) przesłuchu 

w ścieżce biernej w układzie dwuwarstwowym z płaszczyzną 

masy 

elements in path’s system. Change of length, width, thickness, 

mutual distance of paths, thickness of substrate as well as paths 

configuration has a big influence on values of capacitance, 

inductance, resistance and conductance of paths’ system. The 

specific properties of LTCC technology which allow to obtain 

much more integration scale in relation to classical thick-film 

technology are cause higher values of per-unit-length parameters 

of the conductive structures. For near placed paths the 

value of parasitic capacitance can be equal from 100 pF/m to 

150 pF/m as well as the effective inductance for the narrowest 

paths can be from the range 1…3 µH/m. Those non-zero values 

of parasitic parameters are responsible for penetration 

of electrical signals between particular parts of circuit. The part 

of signal which penetrates by parasitic capacitances and inductances 

is received as disturbance. This problem is especially important 

– as results of simulations and measurements show – for 

fast-changed signals and signals with frequency over 100 kHz, 

where parasitic elements are simple medium for penetration 

of electric signals. The effectiveness of disturbances penetration 

is significant dependent on parameters values of parasitic elements 

exist in real-world paths systems. 

Equipment purchased in the project No POPW.01.03.00-18-012/09 

from the Structural Funds, The Development of Eastern Poland 

Operational Programme co-financed by the European Union, the 

European Regional Development Fund. 

References 

[1] Slosarcik S., Pietriková A., Banský J.: Základy Technológii v elektronike. 

Vienala, 2006. 

[2] Golonka L.: Zastosowania ceramiki LTCC w mikroelektronice. Oficyna 

Wydawnicza Politechniki Wrocławskiej, 2001. 

[3] Sabat W.: Uwarunkowania propagacji zakłóceń przewodzonych 

w hybrydowych strukturach mikroelektronicznych. Rozprawa doktorska, 

Politechnika Rzeszowska, Rzeszów 2002. 

[4] Sabat W., Klepacki D., Kamuda K. Kalita W.: Application of Operational 

Method in Analysis of Electromagnetic Couplings in Mutual 

Coupled Path Systems of Planar Structures. Electronics Systemintegration 

Technology Conference, 2008. ESTC 2008. 2nd, s. 1107– 

1110, 2008; 

[5] Caniggia S., Maradei F.: Signal Integrity and Radiated Emission 

of High-Speed Digital Systems. John Wiley & Sons Ltd 2008.

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