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Report to 

Qualification of a capable leadfree termination 

surface for wave soldering 

No.: F 28-05 

Table of contents 

Page 

1. Definition of the specimen 

1.1 Contact stripes 3 

1.2 Connectors 3 

1.3 Printed Boards 4 

2. Preinvestigation of solderability by the wetting balance method. 

2.1 Test equipment 7 

2.2 Test schedule 8 

2.3 Results 9 

3. Qualification in the process at the customer 

3.1 Overview of the test matrix 13 

3.2 Test schedule and acceptance criteria 14 

3.3 Backward compatibility 

3.3.1 Wave soldering process AP 16 

3.3.2 Wave soldering process BP 17 

3.3.3 Wave soldering process CP 18 

3.4 Forward compatibility 

3.4.1 Wave soldering process DP 26 

3.4.2 Wave soldering process EP 30 

3.4.3 Wave soldering process FP 35 

4 Summary 37 

Corporate Technology Services, HARTING KGaA, Marienwerderstraße 3, 32339 Espelkamp





No.: F 28-05 

1. Definition of the specimen 

1.1 Contact stripes 

Fig.1: BC male contacts 

1.2 Connectors 

Fig. 2,3 : DIN Type C male connector (HARTING Part.No.: 09031966921) 

Tin height 

Production parameters of the coating: 

Surface: 

Galvanic 

Plating thickness Sn: 

Plating thickness Ni: 

Base material : 

Matt Sn lead-free 

HARTING Electronics 

6,6µm (average) 

2,0µm (average) 

CuZn37 



1.3 Printed boards 




No.: F 28-05 

Original customer PCBs, in separate cases test PCBs, were used for the field trials. 

We express our gratitude toward our customers for their open and friendly support of our trials at their 

premises. To prevent an unauthorized circulation of sensitive or confidential customers’ information, 

the field trials are recorded in a coded form in this test report. (AP – FP) 

The solder conditions are shown in detail for all separate field trials. 

Wave soldering test AP 

Fig. 4: Customer PCB double euro size 

Board thickness: 

Diameter hole: 

Surface: 

1,6mm 

0,94mm –0,96mm 

Ni/Au 

Wave soldering test BP 

Fig. 5: Customer PCB euro size 

Board thickness: 1,6mm 

Diameter hole: -- 

Surface: 

HAL SnPb 






No.: F 28-05 

Wave soldering test CP 1 

Fig. 6: Customer PCB euro size 


Diameter hole: -- 

Surface: 

HAL SnPb 

Wave soldering test CP 2 

Fig. 7: Customer PCB double euro size 


Diameter hole : 

Surface: 

1,6mm 

0,94mm –0,96mm 

Ni/Au 






No.: F 28-05 

Wave soldering test DP 

Fig. 8:Test PCB (HARTING) double euro size 

Type: HARTING leadfree test board 3 (manufactured 2005/01) 


Diameter hole : 

Surface: 

1,6mm 

0,97mm-0,99mm 

HAL Sn lead-free 

Chem. Sn 

Ni/Au 

Wave soldering test EP 

Fig. 9: Test PCB (HARTING) euro size 

Type: HARTING leadfree test board 3 (manufactured 2005/01) 


Diameter hole : 0,97mm-0,99mm 

Surface: 

HAL Sn leadfree 

Chem. Sn 

Ni/Au 

Wave soldering test FP 

Fig. 10: Customer PCB, custom size 


Diameter hole : -- 

Surface: 

Chem. Sn 






No.: F 28-05 

2. Preinvestigation of solderability by the wetting balance method 

2.1 Test equipment: 

Wetting balance test equipment HARTING ID: 532-060-11 

Solder: 

Stannol, Sn40Pb40, Sn95.5Ag3.8Cu0.7, Sn99.3Cu0.7 

Flux: 

Stannol Actiec 5 acc. to DIN EN 29453-1 class 1.1.2.A ( IEC class ROL1) 

Solid content: 0,125% 

Activity level : low 

Immersion time : 

Immersion speed: 

5sec 

20mm/sec 

Fig.: 11,12 : wetting balance test equipment 



2.2 Test schedule 




No.: F 28-05 

Reference document : in accordance to IEC 60068-2-20 (1979/1987) 4.5 Accelerated aging, 

IEC 60068-2-54 draft (2003) Solderability by wetting balance method. 

Test Requirement Reference-document Sample description 

Storage 

room 

temperature 

20°C/60% r.h IEC 60068-2-20 

(1979/1987) 

dry heat 16h/155°C IEC 60068-2-20 

(1979/1987) 

steam aging 8h/96°C/100%r h IEC 60068-2-20 

(1979/1987) 

ANSI/EIA –364-52A 

(2003) 

Solderability by wetting balance method 

Solderability 

Solder 

Bath temperature 

Sn60Pb40 235°C 

Sn95,5 Ag3,8 

Cu0,7 

245°C 

Sn99,3 Cu0,7 250°C 

IEC 60068-2-54 

(draft 2003) 

contact stripes 




Visual inspection 

Visual 

inspection 

Flux 

Actiec 5 

min 95% wetting IEC 60068-2-20 

(1979/1987) 


(2003) 




2.3 Results: 




No.: F 28-05 

Overview of the wetting results with the tested BC Male contact stripes (sample surface finish 17) 

Solder SnAgCu SnCu SnPb 

Flux Actiec 5 Actiec 5 Actiec 5 

unloaded ++ + ++ 

after 16h/155°C dry heat ++ +o ++ 

after 8h/96°C/100r.h 

steam aging 

o o o 

Definition of the acceptance criteria: 

++ = Wetting time < 0,5s / Wetting force = reference force 

+ = Wetting time < 1,0s / Wetting force = reference force 

+o = Wetting time < 1,5s / Wetting force min. 80% of the reference force 

o = Wetting time < 2,0s / Wetting force min. 80% of the reference force 

o- = Wetting time < 2,5s / Wetting force min. 50% of the reference force 

- = retarded Wetting time > 2,5s, bad Wetting force 

-- = retarded Wetting time > 2,5s, very bad Wetting force 

Some representative force-time curves: 

slow wetting very fast wetting wetting limited unstable wetting 

by thermal demand (dewetting) 

non wetting poor wetting good wetting retarded wetting 


Page 10 of 37 


Qualification of a suitable leadfree termination 


No.: F 28-05 

Contact stripes unloaded 

BC male contact stripes surface matt Sn; solder Sn95,5Ag3,8Cu0,7; Flux: Actiec 5 

Diagram 1: 

The force-time curve shows a good wetting (fast zero-crossing time (





No.: F 28-05 

Contacts stored 16h/155°C dry heat 

BC male contact stripes surface matt Sn; solder Sn95,5Ag3,8Cu0,7; Flux: Actiec 5 

Diagram 2: 

The force-time curve shows a good wetting (fast zero-crossing time (





No.: F 28-05 

Contacts stored 8h/96°C/100%rh steam aging 

BC male contact stripes surface Sn; solder Sn95,5Ag3,8Cu0,7; Flux: Actiec 5 

Diagram 3: 

The force-time curve shows a decelerated wetting, low wetting force. 

Fig. 17, 18: Good and complete wetting with no pores at the Sn surface, though the height of the 

solder wetting is smaller. 






No.: F 28-05 

3. Qualification in the process at the customer 

Field trials at the solder machines of various customers of the market 

segments machine tools, industrial communication and PCB assembly. 

Temperature profile 

On of the 4 (in total) tested 

PCBs 

One of the 5 (in total) tested solder 

facilities 

Evaluation of solder results acc. to IPC 






No.: F 28-05 

3.2 Test schedule and acceptance criteria 

Reference document: IPC-A-610-D:2005; Part 5.1 Soldering acceptability requirements; 

Part 7.6 plated through holes with component leads. 

Test Requirement Reference document Sample description 

Storage 

room 

temperature 

20°C/60% r.h IEC 60068-2-20 

(1979/1987) 

dry heat 16h/155°C IEC 60068-2-20 

(1979/1987) 

steam aging 8h/96°C/100%r h IEC 60068-2-20 

(1979/1987) 


(2003) 

Process capability for Wave soldering 

DIN male connector 

Type C 


Type C 


Type C 

Test 1 AP Test 2 BP Test 3 CP Test 5 DP Test 4 EP Test 6 FP 

wave-solder machine 

type: SEHO System 

8530 


type: SEHO System, 

2035 


type: Ersa 


type: EPM 


type SEHO System 

2340 


type: SEHO System 

2340 

solder: SnPb solder: SnPb solder: SnPb solder: SnCu solder: SnAgCu solder: SnAgCu 

double euro format 

Ni/Au 

Visual inspection 

visual inspection 

cross section 

euro format 

HAL SnPb 

acc. to IPC A610-D 

class 1,2,3 

Acc. to IPC A610-D 

class 1,2,3 

euro format 

HAL SnPb 

double Eurocard 

Ni/Au 



Chem. Sn 

Ni/Au 

IPC-A-610-D 

(2005) 

IPC-A-610-D 

(2005) 



Chem. Sn 

Ni/Au 

spezial format 

Chem. Sn 

soldered DIN male connector 

type C 

soldered DIN male connector 

type C 






No.: F 28-05 

Acceptability requirements for solder joints with plated-through holes acc. to 

IPC 

Criteria Class1 Class2 Class3 

A. Wetting on the primary side (solder destination side) Not specified 180° 270° 

of lead and barrel 

B. Vertical fill of solder Not specified 75% 75% 

C. Fillet and wetting on the secondary side (solder 

270° 270 330° 

source side) of lead and barrel 

D. Percent of land area covered with wetted solder on 0 0 0 

the primary side (solder destination side) 

E. Percent of land area covered with wetted solder on 

the secondary side (solder source side) 

75% 75% 75% 

Evaluation of solder joints with the help of a cross-section 

Fig. 19 & 20 

Target class 1-3 Acceptable class 1-3 

75% 

Anzustrebende 

Fig. 21 & 22 

Target for class 1-3 360° wetting on lead and barrel 






No.: F 28-05 

3.3 Backward compabtiility 

3.3.1 Test 1AP: 

Wave soldering (SnPb) with PCB plating Ni/Au 

A wave solder machine with a double wave function (manufacturer: SEHO) was used 

for the trials. The machine is equipped with a spray flux dispension system and 

infrared heating modules. The pcb’s with preassembled components were mounted 

into type-specific retaining frames which prevented the overflow of liquid solder onto 

the components on the pcb and protected the connector mouldings from thermal 

stress. 

Fig. 23: wave solder machine SEHO system 8530 MPR 

Process parameters: Test 1 AP 

Wave solder machine SEHO system 8530 MPR 

Solder 

SnPb37 

Flux 

Chemical circuit P880 (Halogen-free and resin-free, no clean, 

Solids content 1,9% 

Solder temperature 245°C 

Wave solder 

Atmosphere 

Speed 

Wave solder contact time 

only Chip-wave, 28mm high 

normal air 

120cm/min 

1-1,3s 






No.: F 28-05 

Diagram 4: Temperature profile of the soldering program used. The thermocouple was mounted at the 

right angled termination on the secondary side of the PCB (no contact to the wave solder). 



Result: Test AP 




No.: F 28-05 

The visual and microscope inspection shows that the requirements in accordance to the IPC 

norm IPC-A-610-D:2005; chapter 5.1 Soldering Acceptability Requirements; and chapter 7.6 

Plated Through Holes with Component Leads are fulfilled. 

Fig. 24: Soldered DIN C male connector secondary side 

Fig. 25: secondary side 

Fig. 26: primary side 

Fig. 27, 28: cross-section , good meniscus visible 






No.: F 28-05 

3.3.2 Test BP: 

Wave soldering (SnPb with PCB plating HAL SnPb 

The wave solder machine SEHO System 2035 with a double wave function was used for the trials. 

The pcb’s with preassembled components were mounted into type-specific retaining frames which 

prevented the overflow of liquid solder onto the components on the pcb and protected the connector 

mouldings from thermal stress. 

Process parameters 

Wave solder machine SEHO system 2035 

Solder 


Flux Home-made, Isopropanol/Adipinsäure (1,5%) 


Wave solder 

Atmosphere 

Speed 


main wave 

nitrogen 

120cm/min 

3,8 s 

Diagram 5: Temperature profile of used soldering program, only main wave used. Special trial pcb. 

The thermocouple (red curve) was mounted at the primary side of the pcb. 



Result. Test BP 




No.: F 28-05 




Fig. 29: Soldered DIN C male connector secondary side 


Fig. 31 primary side 

Fig. 32, 33 cross-section, good meniscus visible 






No.: F 28-05 

3.3.3 Test CP: 

Wave soldering (SnPb) with PCB plating HAL SnPb und Ni/Au 

The wave solder machine ERSA with a double wave function was used for the trials. The pcb’s were 

mounted into retaining frames and the connector mouldings were covered with heat protection caps. 

Fig. 34, 35 Printed board mounted in the retaining frame 






No.: F 28-05 


Wave solder machine ERSA 

Solder 


Flux Alphametals E193 (low activated ) 


Wave solder 

Chip- und main wave 

Atmosphere 

nitrogen 

Speed 

100 cm/min 

Wave solder contact time 3,8 – 4,5s 

Diagram 6: Temperature profile of the used soldering program, recorded with a special trial PCB. The 

thermo sensors were mounted on the primary side of the PCB, see Pic. 65. 






No.: F 28-05 

Diagram 7: Solder wetting profile 



Result Test CP 




No.: F 28-05 

PCB plating: HAL SnPb 




Fig 36: Soldered DIN C male connector secondary side 

Fig. 37: secondary side 


Fig. 39, 40: cross-section, good meniscus visible 






No.: F 28-05 

PCB plating: 

Ni/Au 







Fig. 44,45: cross-section, good meniscus visible 






No.: F 28-05 

3.4 Forward compatibility 

3.4.1 Test DP: 

Wave soldering (SnCu) with PCB plating HAL leadfree, chem. Sn and 

Ni/Au 

Process parameters: 

Wave solder machine EPM (extended with IR-pre-heating) 

Solder 

SnCu(Ni), SN100C BalverZinn 

Flux 

IF 2009M no clean, low solids, Interflux 


Wave solder 

Atmosphere 

Speed 


only main wave 

normal air 

90 cm/min 

5 s 

Fig. 46 47: PCBs during the wave-solder process 

IR pre-heating 

Solder wave 






No.: F 28-05 

PCB plating: 

Ni/Au 













No.: F 28-05 

PCB plating: HAL lead-free 













No.: F 28-05 

PCB plating: Chem. Sn 













No.: F 28-05 

3.4.2 Test EP: 

Wave soldering (SnAgCu) with PCB plating HAL leadfree, chem. Sn and 

Ni/Au 

For these trials, a solder machine with a double wave funcion (manufacturer: SEHO) 

was used. Special retaining frames were manufactured tor the trial pcb’s. 

Fig. 64: Wave solder machine Seho MWS 2340 

Fig. 64: PCB during the solder process 






No.: F 28-05 

Process parameters Test 5 EP 

Wave solder machine Seho MWS 2340 

Solder 

SnAgCu 

Flux 

Cobar 388, synthetic No-Clean N2-flux 


Wave solder 

Atmosphere 

Speed 


only main wave 

nitrogen 

100cm/min 

2 s 

Diagram 8: Temperature profile of the used soldering program, recorded with a modified PCB. The 

thermo sensors were mounted on the primary side of the PCB, see Pic. 65. 

Fig. 65: thermocouples at the 

connector and PCB to find the right 

temperature profile 






No.: F 28-05 

PCB plating: 

Chem. Sn 













No.: F 28-05 

PCB plating: HAL lead-free (Sn100C) 










PCB plating: Ni/Au 




No.: F 28-05 







Bild 79, 80: cross-section, good meniscus visible 






No.: F 28-05 

3.4.3 Test FP: 

Wave soldering (SnAgCu) with PCB plating chem. Sn 

Test carried out with a Seho 2340 wave solder machine with double wave function 


Wave solder machine SEHO 2340 

Solder 

SnAgCu 

Flux 

Stannol WF 300S 


Wave solder 

pre-wave3 row nozzle, main wave standard 

Atmosphere 

nitrogen 

Speed 

120 cm/min 

Wave solder contact time -- 

Fig. 81: Wave solder machine Seho MWS 2340 






No.: F 28-05 

PCB plating: Chem. Sn 







Bild 84, 85: cross-section, good meniscus visible 


Page 37 of 37 

Summary: 




No.: F 28-05 

To the preinvestigation with the wetting balance: 

The optical and microscope investigation of the solder termination pins shows a good wetting 

with a homogeneous surface and no defects. 

The results of the wetting balance test show very good to acceptable results for the contact 

stripes in the initial state and after the aging test (16h in dry heat at 155°C) for the three Sn 

types used (SnPb, SnAgCu and SnCu) in direct comparison to the SnPb surface used 

initially. The results after the steam aging (8h at 100r.H. and 96°C) show a delayed wetting 

and a lower wetting force for all Sn types used. 

To the field tests qualification: 

The solder joints comply with the requirements of the Class 3 acc. to the IPC 610 D in every 

case – the highest requirements whatsoever. 

Altogether very good solder results of the extensive field tests show that delayed wetting 

observed in the wetting balance tests after steam aging has no negative impact. 

.

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