IPC-4556 印制板化学镍钯浸金（ENEPIG）规范ENG.pdf - 第65页
Figure A7-13 SAC305 T est Coupon s5&6– T est Coupon 5 (left view) and T est Coupon 6 (right view) are both cross-sections at 500X magnification. Figure A7-14 SAC305 T est Coupons 16 & 17 – T est Coupon 16 (left vi…
Figure A7-10 Sn63Pb37 Test Coupon 19 – Test Coupon at 200X magnification (left view) and at 500X magnification (right view) and
both are cross-sectional views.
Figure A7-11 SAC305 Test Coupons 1 & 2 – Test Coupon 1 (left view) and Test Coupon 2 (right view) are both cross-sections at 500X
magnification.
Figure A7-12 SAC305 Test Coupons3&4–Test Coupon 3 (left view) and Test Coupon 4 (right view) are both cross-sections at 500X
magnification.
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Figure A7-13 SAC305 Test Coupons5&6–Test Coupon 5 (left view) and Test Coupon 6 (right view) are both cross-sections at 500X
magnification.
Figure A7-14 SAC305 Test Coupons 16 & 17 – Test Coupon 16 (left view) and Test Coupon 17 (right view) are both cross-sections at
500X magnification.
Figure A7-15 SAC305 Test Coupon 18 – 500X magnification
cross-section view
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Figure A7-16 SAC305 Test Coupon 19 – Test Coupon at 200X magnification (left view) and at 500X magnification (right view) and both
are cross-sectional views.
Discussion Figure A7-17 shows the solderball shear data as a function of palladium plating thickness for both the
Sn63Pb37 and SAC305 soldering processes. The error bars in the plot represent one standard deviation. The Sn63Pb37 sol-
dering process shear force values are very consistent with little variation over the range of palladium plating thickness. The
SAC305 soldering process shear force values are more variable but greater than the Sn63Pb37 values. A solder joint integrity
issue due to PdSn
4
IMC phase embrittlement would have revealed itself as a loss of shear force with increasing palladium
plating thickness. The metallographic cross-sectional analysis confirms the Figure A7-17 data as the presence of the PdSn
4
IMC phase was not segregated at the solder joint/test coupon pad and was only found in minor concentration levels. The test
results recorded in this investigation are in agreement with recently published testing palladium plating reliability results by
M. Wolverton [2] and previous Rockwell Collins investigations [3].
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Figure A7-17 Solderball Shear Force as a Function of Palladium Plating Thickness
3000
2500
2000
1500
1000
500
0 5 10 15 20
0
Solderball Shear on ENEPIG Surface Finish
Shear Force (g)
Palladium Plating Thickness (microinch)
SnPb
SAC305
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