IPC-4556 印制板化学镍钯浸金（ENEPIG）规范ENG.pdf - 第62页

Metallographic Cross-Ssectional Analysis A number of the non-tested solderball solder joints for each coupon were ran- domly selected for metallographic cross-sectional analysis. The purpose of the analysis was to determ…

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Table A7-4 SAC305 Solderball Shear Test Results Coupon Set 1 (grams)
Table A7-5 SAC305 Solderball Shear Test Results Coupon Set 2 (grams)
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Sample 6
２７８６．７
２７２５．４
２６３８．６｜
２５４８．６
２６７１．８
２６３９．５
２５３０．３
２５４１．８
２５０７．２｜
１６１１．５
２５２０．１４｜
Average
Std Dev
３３１．９３７５
Sample 16
１５８６．９｜
２３９８．１
２５９７．７
１９４８．５
２３０６．４
１７１４．９
２５８１．２
２４２５．４
２２２５．９
２１９８．３３３３｜
３６７．４１６６８｜
Sample 17
２２０８．４｜
２３９８．２
２００６．１
２５８３．８｜
２６８４
１７７４．１
１３４７．６
１３８５．８
１８６９．４
１９６７．５
２３５４．４｜
２６０４
２２３９．４
２０５７．４
２５０７３
２０５９．４
２４９１．９
２２９２．８
２３２８．１
４７０９
２０８１．５２５
５２９．９０５２４
Sample 18
２５２２．４
２４５０．３
２１９１．５
２６７３．８
２４７４．７｜
２４９７．８
２３０４．３
２５００．７
２２２１
１５１２．５
１４２５．７
２２５２．２４５５
４１２．２１４３５
Sample 19
２３１０．１
２４４５．４
２４１３
２８４４．２
１６８７．４
２６２９．３
１５１０．９
１８０１．７
２７５６．１
１３１８．３
Sample 1
２５３２．１
１３８２．３
２１７１．６４
５４６．８９６７
１４６１．６
２２９５．６
１４０６．８
２６３０｜
１５５７．９
２７９０．９
１５７０｜
２１０３．４｜
Average
Std Dev
１９７３．０６
５５７．７７６６
Sample 2
１４１２．４｜
１１９４．４
１４５６．６
１４２５．９
２０１５．３
１２７８．７
１３０３．５
１５５６．９｜
１５７２．６
１５３９．４｜
１２６７．１
１１９２．４｜
１３５５．３
１７０７．３
２２８９
１２２４．５
１７７１．９
１７５６．６｜
１８３９．３｜
１５３４．６８９
２９９．５２２５
Sample 3
２１７２．４｜
２４１７．３｜
２５８２．５
２５９９．９
２５０８
２７９８．２
１８２７．１
２４１３．５
２４０２．９
２３６９
１１９３．９
２５７０．１｜
１７１４．９
２１６５．４
１８８７．２
１９４４．１
２１９４．２］
１４２６｜
１６２７．９
１７８２．１
２１２９．８３
４３６．０６５６
Sample 4
２７２９．９
２８５９．２｜
２７５２．３｜
２６６０．４｜
２６９１
１８４２．６
２５４９．９
２４３４｜
２６９０．９
２６１８．３
２１２４．６
２０６９．７｜
１６１５．４
１７０９．２｜
２５０１．６｜
２３３４．９
１５３７．９
２４４９．１
１５１０｜
１７０６．８｜
Sample 5
１８０７
１９９１．８
２２３５．７
１９８２．９
２２０３
１６５３．７
２１１３．１
２３４５
２１８０
１８９９．２｜
２２６９．３８５
４６０．６７７７
２０４１．１４
２１３．８９２
Metallographic Cross-Ssectional Analysis A number of the
non-tested solderball solder joints for each coupon were ran-
domly selected for metallographic cross-sectional analysis.
The purpose of the analysis was to determine if any of the sol-
der joints contained the palladium/tin intermetallic (IMC)
phase PdSn4, which has been shown to cause embrittlement
and degradation of solder joint integrity [1]. The PdSn
4
IMC
structure is a blocky, angular phase in the scanning electron
microscopy (SEM) image of a Sample 19 Sn63Pb37 solder
joint with arrows indicating the PdSn
4
IMC phase illustrated
in Figure A7-4. The Sn63Pb37 solder joints contained more of
the PdSn
4
IMC structure than the SAC305 solder joints. The
difference in the resulting microstructure between the solder
processes is due to the fact that the higher SAC305 reflow
temperature and greater tin composition percentage of the
SAC305 alloy allows for better distribution of the palladium
within the solder microstructure rather than forming the
PdSn4 IMC phase. The thickest palladium plating (Sample
19) also contained the most PdSn
4
IMC phase. Figure A7-5 through Figure A7-16 illustrate typical solder joint microstruc-
tures observed for each of the test coupons for both the Sn63Pb37 and SAC305 solder joints. The arrows shown in the Fig-
ures point to some of the observed PdSn4 IMC phase contained in the solder joints.
Figure A7-4 Sn63Pb37 Test Coupon 19 – 1690X Magnifica-
tion SEM View
Figure A7-5 Sn63Pb37 Test Coupons1&2–Test Coupon 1 (left view) and Test Coupon 2 (right view) are both cross-sections at 500X
magnification.
Figure A7-6 Sn63Pb37 Test Coupons3&4–Test Coupon 3 (left view) and Test Coupon 4 (right view) are both cross-sections at 500X
magnification.
IPC-4556 January 2013
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０产１７７７７
D:4,738×
P:1,698×
19 DEC 111
４８０８８
18 m
15.B kV AMRAY
Figure A7-7 Sn63Pb37 Test Coupons5&6–Test Coupon 5 (left view) and Test Coupon 6 (right view) are both cross-sections at 500X
magnification.
Figure A7-8 Sn63Pb37 Test Coupons7&8–Test Coupon 7 (left view) and Test Coupon 8 (right view) are both cross-sections at 500X
magnification.
Figure A7-9 Sn63Pb37 Test Coupon 18 – 500X magnification
cross-section view.
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