This document discusses strategies for reducing costs in lead-free electronics manufacturing. Direct cost drivers include high-temperature laminates and final finishes, while indirect drivers are increased scrap rates from delamination and pre-baking requirements. The proposed solution is to use mid-grade lead-free capable laminates that offer 15-20% cost savings through lower material costs and moisture absorption with higher reliability. Results show the new laminate meets specifications for decomposition temperature, glass transition temperature, and moisture absorption. HASL is also discussed as a lower-cost alternative to lead-free surface finishes that has benefits like long shelf life and forgiving process windows.

1. Lead Free
Cost Reduction

2. Direct Cost Drivers
–High Temp Laminates
–Final Finishes
2

3. Indirect Cost Drivers
–Increased Scrap Rate
• De-lamination
• Solderability
–Pre-Baking
–Storage / Handling
3

4. Section 1
Pb-free
Assembly
Capable Laminate 4

5. IPC 4101/99 /124
from
Isola Group/ Insulectro
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6. Current State
Audience Poll……
–Common Callouts
• IS410 / 370HR
• FR4
• RoHS Compliant
• 180ºC Tg
• 340ºC Td
• IPC 4101/126 or /129
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7. Polling Question
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8. Current State (cont.)
Audience Poll……
• Effect of Common Callouts
1. Locked in to laminate by brand name
2. Typically Phenolic materials
• Moisture absorption up to .45% on 0.028” core
• Less mechanical strength (interlaminate adhesion)
• More prone to de-lamination during assembly
• Prone to pad cratering on BGA applications
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9. Current State (cont.)
3. Non-Pb Free capable material
• FR4 is not capable
• RoHS Compliant can include standard FR4
• 180Tg does not guarantee adequate Td
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10. Proposed Solution
• Mid-Grade Pb-free capable
laminates
– IPC 4101 / 99 (filled) or /124 (unfilled)
• 150 Tg min.
• 325 Td min.
10

11. Benefits
– 15-20% Cost Savings on Raw Materials
– Lower Moisture Absorption (0.10%-
0.25%)
– Higher interlaminate adhesion
• Peel strength
• T-288 >10 minutes
– Higher Copper to Laminate peel strength
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12. Results
(using Isola IS400 as example)
12

13. Results
Test Group Results
Decomposition Temperature
Test 1 of 2
Method of Determination: TGA
Decomposition Temperature: 331 C
Ramp Rate: 10 C/ min
Test 2 of 2
Method of Determination: TGA
Decomposition Temperature: 334 C
Ramp Rate: 10 C/ min
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14. TGA
14

15. Results
Test Group Results
Delta TG
Test 1 of 1
Method of Determination: DSC
TG Scan 1: 150 C
TG Scan 2: 154 C
Delta Tg: 4C
Ramp Rate: 20 C/min
Analysis Method: Half Height
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16. DSC – (A)
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17. DSC – (B)
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18. Results
Test Group Results
Time to Decomposition at Temperature
Test 1 of 2
Method of Determination: TMA
Time to Decomposition: 35.9 minutes
Isothermal Temperature: 260 C
Test 2 of 2
Method of Determination: TMA
Time to Decomposition: 10.4 minutes
Isothermal Temperature: 288 C
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19. T-260
19

20. T-288
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21. Results
Test Group Results
Weight Loss % by TGA
Test 1 of 1
Percent Weight Loss: 0.2%
Start Temperature: 0º C
Stop Temperature: 0º C
Comments: Moisture Method
% Weight Loss = 0.1717%
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22. Moisture Absorption (A)
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23. Results
Test Group Results
Peel Strength
Condition: Condition A
Peel Strength Side 1: 11.73 lbs/in
Peel Strength Side 2: 10.95 lbs/in
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24. 6-X Reflow
Pb-free Assembly Temperature
– One board, 3 array
– One 4.25 x 9.5L”, Two 4.75 x 9.5L”
– Thickness + 0.063
– TGA moisture = 0.2534%
– 260° Peak Temperature
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25. 25

26. Results
Conditioning As Received
Board # 14753-1
Material IS400
Thickness (mil) 0.063
Conveyor Speed (cm/min) 48
Peak Mean Temp (?C) 259.8
TC Temp Range 3.4
Rising time between 150C - 200C 66.67 (sec)
Time above 217 101
Time above 255 19.69
Passes to Fail 6x-Pass
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27. Coming Soon – FR406HR
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28. Section 2
Pb-Free
HASL
Audience Poll
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29. Definition
SN100CL
-this is a SnCu alloy stabilized with Ni,
composed of:
• 99.3% Tin
• <0.7% Copper
• 0.05% Nickel
• 60 ppm Germanium
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30. Industry
Misconceptions
• Predictions of HASL’s Demise
• Solderability Issues
• Short Duration of Usage
30

31. Benefits
1. Lower Copper Erosion on PCB surface and vias
2. Quick Process
3. Long Shelf Life
4. Cost
(< 1/14 ENIG)
5. Forgiving
a.) Humidity
b.) Handling
c.) Temperature
6. Solder Joint Strength
31

32. Results
( using Florida CirTech HALT example )
Highly Accelerated Life Test
32

33. Benefits – Solder Joint Strength
HALT Test Results
33

34. Benefits –HALT Test Results
34

35. Benefits
35

36. Benefits
36

37. HALT Test Results
Lead-Free HASL, with all different solderpastes pooled together, required the most energy
(G-force + thermo-cycling) to break the solder joints.
Since this test takes out the failure effect of the components, we can conclude that lead-free
HASL solderjoints outperform all other surface finishes, including SnPb HASL.
Our thanks go to Tim Murphy of Thomson Lab Services and Florida CirTech for the report
abstract.
For a full report, please contact James Kelch @ jim@saturnelectronics.com
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38. Drawbacks
• Not Planar
• Not Ideal for extremely fine pitch applications
• Past Solderability Issues
• HASL and Flow: A Lead-Free Alternative
addresses this in the February ’08 issue of
Request a copy from James Kelch or visit the
Lead Free Resource Center on our website.
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39. Drawbacks, cont.
• Thermal Cycle
– SN100CL requires a Thermal Cycle in addition to
Thermal Cycles in Assembly
• No Set Industry Standards
– Neither the IPC nor Nihon Superior had developed a
Thickness Acceptability Criteria when SN100CL was
introduced Audience Poll
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40. Polling Question
40

41. No Standard - Solutions
Trigger Event
Solderability Issue at Customer
41

42. No Standard - Solutions
• Goal
– Establish a Set Criteria
42

43. Thickness Criteria
• Generic Thickness Requirement
• Not proper to have only one
– Smaller Pads receive thicker solder deposition
• Solution
• Minimum Alloy Thickness should be
segregated by Ranges of Pad Size
43

44. Pad Size (mils) Min. Thickness
126 x 131 50 uin
29 x 83 80 uin
17 x 36 100 uin
44

45. Implementation
• Alloy Control
• Lower copper content of alloy increases solderability
• Standard Drossing of solder pot is not enough to
keep copper content below 0.90%
• Recommend a 1/4 - 1/3 solder pot dump once weekly
measurement reaches 0.90%
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46. Implementation
• Specific Design Set-Up
– Each Design may require its own specific set-up
– Adjustments
• Air Knife Pressure
• Retract Speed
• Dwell Time
46

47. Implementation
• In effect, since the operating window is
smaller than with SnPB,…….
CONTROL The PROCESS!!!
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48. SN100CL
Study Conclusion
• No Solderability Issues at any customer
– Fab Notes
• Fab notes can specify the use of these coupons
or range of solder thickness standards
– Forcing your supplier to meet these specs will give
you:
»Control over the Process
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49. Conclusion
• By implementing one or both of these
proposed solutions, you can:
– Save up to 30% of your bare board cost
– Increase performance of your products
– Standardize your fab notes to remove risk of
non-performing products
– Improve your supply base
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50. • To view the archived version of this presentation,
please email jim@saturnelectronics.com
• To sign up for our upcoming Lead Free Newsletter,
please email jay@saturnelectronics.com
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51. Thank You!
Saturn Electronics Corporation
would like to thank our presenters:
Ø Dave Coppens / Isola
Ø Terry Staskowicz / Insulectro
Ø Glenn Sikorcin / Florida CirTech
*Don’t forget to visit the Lead Free Resource Center
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