Earl,

Out of the two commercially available immersion silver processes at least
one was proven not to exhibit electromigration in numerous studies carried
out by some of the most reputable independent labs in the country.  For
details please contact me off line.

Eric Yakobson




[log in to unmask] on 11/20/98 05:36:32 PM

To:   [log in to unmask]
cc:    (bcc: Eric Yakobson/AlphaPCFabUS/Cookson)
Subject:  [TN] silver migration




Joe,

It seems the issue is dead and buried except many of us would like to use
such a good conductor. I
can only recount the "good old days" at Sperry Flight Systems (in the '60's
and beyond) when we were
all taught about silver migration. We were assured there was no way silver
could be used as a
conductor or conductive coating because of the issue in question.
Therefore, palladium/silver
compositions were developed and used on PCB's and hybrid thick film
circuitry. This minimized the
effect until gold became the conductor of choice.

It's amazing how nothing is really new. It just keeps on coming around.

I understand today's immersion silver, in such small amounts and
thicknesses, does not pose
migration problems. However, I also would like to know about the work done
to prove or disprove the
facts.

Earl Moon

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