Hi David! Collins conducted a series of gold wedge and gold ball bonding
test on immersion silver surface finishes and had only partial success. As
the immersion silver surface "aged" with storage time (3-6 months)  we were
not able to create acceptable wirebonds. The initial bondability of the
finish in the as received condition was very good. There are a number of
folks who are successfully aluminum wiring bonding to the immersion silver
finish.  Good luck.

Dave Hillman
Rockwell Collins
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                      davidyeh
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                      Sent by: TechNet         Subject:  [TN] Gold wire bond on silver finishings
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                      07/30/2003 09:21
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                      davidyeh






Hi,

Can anyone share his experience on gold ball bonding on COB with immersion
silver finishings. What sort of silver thickness to ensure a good bonding
strength of min 3.5 gf?

We are using a 1 mil thick gold wire on a 6 to 20 microinch silver
thickness and encountered difficulty in achieving the min bonding strength
in wire pull.

Thanks for all inputs.

Best regards,
David.
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