MEMS + - I-Micronews

Reverse engineering & costing of
a family of MEMS microphones
Analysis of each device, technology and production
cost comparison

Objectives of the action
• A complete reverse engineering & costing of each selected MEMS
microphone
• For each device, definition of the following points:
• Process flow
• Manufacturing environment (front end and back end)
• Manufacturing cost of MEMS and ASIC dies
• Packaging
• Analysis and comparison on the devices in term of:
• Technical/processing choices for the front end
• Technical/processing choices for the packaging
• Production and cost infrastructure
• Comparison of the devices and analysis of trends detected
• Phone meeting and Q&A session in order to answer questions on
the analysis done.
© 2012 • 2

Benefits
• Unique and complete offer on the latest MEMS microphones (teardown,
reverse costing analysis, technical & market comparison…, Q&A session)
• Discover the technology used by the main MEMS microphone suppliers
(Knowles, Akustica, STM…)
• Full teardown of the latest technologies on the market especially the
• Akustica AKU230
• EPCOS T4000/T4060
• Package price for 3 to 6 reports of your choice, among the different part
reference
• Unique comparative analysis of the technology and choices leading to
these results.
• Q&A session to discuss and explain the results
© 2012 • 3

Already Analyzed MEMS Microphones
AAC Acoustic
SM0401
Akustica AKU230
Analog Devices
ADMP421
EPCOS T4000/T4060
Knowles
SPU0409/SPU0410
ST MP45DT01
© 2012 • 4

Typical Table of Contents
Glossary
1. Overview / Introduction……….……………….…........…4
– Executive Summary
– Reverse Costing Methodology
2. Knowles Company Profile…………………….……....….6
– Knowles Profile
– MEMS Microphone Portfolio
– SPU0410LR5H Characteristics
– Knowles Business Model
4. Physical Analysis………………………...………............12
– Synthesis of the Physical Analysis
– Physical Analysis Methodology
– Package Characteristics & Markings
– Package Pin-Out
– Package Cross-Section
– Device Structure
– Package Opening
– ASIC Dimensions
– ASIC Markings
– ASIC Cross-Section
– ASIC Delayering
– ASIC Process Characteristics
– MEMS Dimensions
– MEMS Markings
– MEMS Surface
– MEMS Structure
– MEMS Cross-section
– MEMS Process Characteristics
– Physical Data Summary
5. Manufacturing Process Flow…….…………………..….55
– Global Overview
– ASIC Process Flow
– Description of the ASIC Wafer Fabrication Unit
– MEMS Process Flow
– Description of the MEMS Wafer Fabrication Unit
– Packaging Process Flow
– Description of the Packaging Unit
6. Cost Analysis………………………….………………..…..70
– Synthesis of the Cost Analysis
– Main Steps of Economic Analysis
– Yields Explanation
– Yields Hypotheses
– Die per wafer & Probe Test
– ASIC Front-End : Hypotheses
– ASIC Front-End Cost
– ASIC Back-End 0 : Probe Test, Backgrinding & Dicing
– ASIC Die Cost
– MEMS Front-End : Hypotheses
– MEMS Front-End Cost
– MEMS Front-End Cost per Process Steps
– MEMS Front-End : Equipment Cost per Family
– MEMS Front-End : Material Cost per Family
– MEMS Back-End 0 : Probe Test & Dicing
– MEMS Die Cost (Front End + Back End 0)
– Back-End 1 : Packaging Cost
– Back-End 1 : Final test & Calibration Cost
– SPU0410LR5H Component Cost (FE + BE 0 + BE 1)
7. Estimated Price Analysis….………………….……..……95
– Definition of Prices
– Manufacturer Financial Ratios
– SPU0410LR5H Estimated Manufacturer Price
Contact…….……………………………………………………99
© 2012 • 5

Visualization of the Die Placement
(Package X-Ray)
Package X-Ray
Metal Cap
PCB substrate
2 ML
X-Ray image of the PCB package (4 copper layers)
The package is composed of 2 parts which are :
• The PCB Substrate is a double-sided PCB (2 metal layers)
• The Metal Cap is a stainless steel cap.
ASIC
Acoustic
MEMS
ASIC
Acoustic
MEMS
© 2012 • 6
X-Ray image of the PCB package
X-Ray image of the top

Analysis of Die-Package Interconnexion
(Package Opening)
Silver-filled
adhesive
Solder
Mask
CMOS/MEMS
Chip
Acoustic port
Package Bottom portion – Optical view
Package Top portion – Optical view
© 2012 • 7

Analysis of Die-Package Interconnexion
(Package Opening)
MEMS
ASIC
Package Opening – Optical top view
Bonding material: Gold
Bonding diameter: 20µm
© 2012 • 8
Bonding number: 5
Between ASIC & Package: 3
Between MEMS & ASIC: 2

Details of the MEMS Structure
(package cross-section)
Diaphragm
Metal lid
Glob-top
Cavity
MEMS
ASIC
4 ML
Package Cross-Section Overview
The package is composed of:
• A 4-layers PCB substrate (epoxy resin reinforced fiberglass (FR-4 PCB) and
conductive copper layers (ML)) with embedded capacitor.
• A metal lid (brass – copper/zinc alloy)
© 2012 • 9

Visualization of the Package Structure
(Cross-Section)
Diaphragm
2 ML
MEMS
Glob-top
2 ML
Cavity
ASIC
4 ML
Package Cross-Section Overview
The package is composed of three portions which are formed from layers of epoxy resin
reinforced fiberglass (FR-4 PCB) and conductive copper layers (ML).
• The top portion is a double-sided PCB (2 metal layers)
• The side portion is a double-sided PCB (2 metal layers)
• The bottom portion is a 4-layers PCB (4 metal layers)
© 2012 • 10

Definition of Package Materials
• The top portion consists
of an epoxy with Aluminum
Calcium Silicate filler.
•The conductive adhesive is
an epoxy with Silver filler.
•The non-conductive adhesive
consists of an epoxy
with Silicon filler.
© 2012 • 11
EDX Spectrum

Review of IC Technology
(ASIC Transistor Details)
Capacitor poly to poly
ASIC die
© 2012 • 12
Resistor
CMOS transistors

1.3 mm
Visualization of Microphone Dimensions
(MEMS die overview)
MEMS area: 1.82 mm²
1.4mm x 1.3mm
MEMS thickness : 510µm
Pads number : 2 connected
to ASIC
1.4mm
© 2012 • 13

Review of the MEMS process
(MEMS Surface)
The cavity of the MEMS die is two-times
etched by DRIE.
MEMS Cavity – SEM View
DRIE etching
MEMS Cavity – SEM View
© 2012 • 14

Analysis of Microphone Dimensions – A5
Pad to connect the diaphragm with the bonding
Details on the
contact
© 2012 • 15

Detailed Analysis of Microphone
Pitch : 24µm
Diameter : 19µm
© 2012 • 16
Acoustic Hole

Materials Analysis (Cross-Section details)
Diaphragm in
poly-silicon
Back plate in
poly-silicon
SEM view : Cross-section
Isolation oxide layer : 0,6µm
Diaphragm polysilicon layer : 0,344µm
Sacrificial oxide layer : 2,1µm
Back Plate : 1,46µm
Passivation oxide layer : 1,02µm
Passivation nitride layer : 1,1µm
The passivation oxide layer is not etched during the sacrificial
etching step. It must be protected.
© 2012 • 17

Review of the MEMS Process Flow
Pedestal in resin
•Deposition of resin on the top
surface to protect them and to
perform the pedestral.
•DRIE etching of the cavity.
Resin mask.
•The buried oxide layer is
etched.
•The sacrificial poly-silicon layer
is etched.
© 2012 • 18

Review of the MEMS Process Flow
Oxide
(PSG)
Silicon
substrate
Poly 1
(Diaphragm)
Poly 2
(Backplate
electrode)
SiN
(Backplate)
© 2012 • 19

Analysis of MEMS Front-End Cost
Low Yield Medium Yield High Yield
MEMS Front-End
Cost Breakdown Cost Breakdown Cost Breakdown
Raw wafer (Si) $42.00 12.2% $42.00 12.3% $42.00 12.5%
Clean Room $11.89 3.5% $11.89 3.5% $11.89 3.5%
Equipment $68.30 19.9% $68.30 20.1% $68.30 20.3%
Consumable $161.40 46.9% $161.40 47.4% $161.40 47.9%
Salary $39.69 11.5% $39.69 11.7% $39.69 11.8%
Yield losses $20.64 6.0% $17.02 5.0% $13.47 4.0%
MEMS Front-End Cost $343.92 100% $340.30 100% $336.76 100%
MEMS Front-End Cost Breakdown (Middle Yield)
Salary
12%
Yield losses
5%
• The MEMS Front-end manufacturing cost
ranges from $344 to $337 according to
yield variations.
Consumable
47%
Raw wafer (Si)
12%
Clean Room
4%
•The main part of the manufacturing cost
is due to the consumables with 47%.
Equipment
20%
© 2012 • 20

Analysis of MEMS Front-End : Material Cost
by Family
Material Name
Material
Cost
Breakdown
H2 $0.00 0.0%
Etchant: NiCr $0.01 0.0%
Etchant: Au $0.02 0.0%
UPW $0.10 0.1%
O2 $0.15 0.1%
Ar $0.19 0.1%
Cl2 $0.38 0.2%
BHF $0.43 0.3%
Target: NiCr $0.57 0.4%
N2 $0.92 0.6%
DCS $1.34 0.8%
Target: Au $1.39 0.9%
BCl3 $1.89 1.2%
Slurry Si $3.00 1.9%
SF6 $3.49 2.2%
Power $3.63 2.3%
NH3 $4.00 2.5%
EtOH $5.50 3.4%
PH3 $7.55 4.7%
Developer $7.92 4.9%
SC-1 $8.54 5.3%
HF vapor $11.10 6.9%
SiH4 $16.59 10.3%
SC-2 $17.08 10.6%
Photoresist $21.59 13.4%
C4F8 $44.00 27.3%
TOTAL $161.40 100.0%
MEMS Materials Cost
(Simulated with MEMS CoSim+
Cost Simulation Tool)
© 2012 • 21
Details of the equipment cost per step are given in the Excel
Spreadsheet.

Results
• Reverse costing analysis represents the best cost/price evaluation given
the publically available data, completed with industry expert estimates.
• Given the hypothesis presented in this analysis the major sources of
correction would lead to a +/- 10% correction on the manufacturing cost (if all
parameters are cumulated)
• IC +/- 8%
• MEMS +/- 5%
• Packaging +/- 10%
• Test +/- 20%
• These results are open for discussion and can be re-evaluated with new
information, if necessary.
© 2012 • 22

Budget
• Budget for the reverse engineering and reverse
costing of 3 to 6 devices and the comparison of
technologies, manufacturing cost and
infrastructure:
• 6 devices: 13,000 Euro
• 5 devices: 11,300 Euro
• 4 devices: 9,500 Euro
• 3 devices: 7,300 Euro
© 2012 • 23

Added Value (1/2)
• Yole Developpement is a market research, technology and strategy
consulting company, founded in 1998 headquarted in Lyon, France. Our
research is performed by in-house personnel conducting open-ended
discussions based on interviews. We have a global customer base and a
global view.
Yole Développement is providing unique technical and supply & value
chain analysis in order to understand the evolution of the industry and
take good decision. Yole Développement has 25+ full time analysts with
technical and marketing degrees and our primary research including over
3,500 interviews per year. Additional to custom market & technology
analysis, we also provide reports on technology, application or market as
well as industry database in MEMS, Compound semiconductors, Power
Electronics, LED, Advanced Packaging, PV…
© 2012 • 24

Added Value (2/2)
• System Plus Consulting provides reverse costing services for electronic
boards, IC and MEMS devices since 1993. The company has developed specific
methodologies that from reverse engineering to the estimation of the
manufacturing costs and selling prices, provides an accurate, fast and yet very
cost effective service.
System Plus Consulting customers use its services all across the value chain to:
- understand the cost structure of future products and secure their supplies
- monitor competition, understand new technologies impact on their business
System Plus Consulting mostly provides its services through custom services on
samples of products to analyze, but also publishes a number of reports on
strategic devices and systems. Its expertise can also be accessed through software
solutions and databases that the company has built to support its own
methodologies. These software solutions are used by external costing teams and
internal reverse costing analysts.
© 2012 • 25