Gaby

I have had tin whiskers grow on tin coatings from 0.4 micron to 30 micron on
brass substrates (A few of the substrates were copper.)  I have never tested
coatings less than the 0.4 micron, but would expect with a little heat on the
very thin coatings that the tin would quickly have some contaminating metal
diffused in it and the whisker growth would be inhibited.  However, in a
report that I read somewhere it said that it could happen with about 5 tin
atoms of thickness or about 30 A (angstroms) or 3X10E-3 micron.  That is
pretty thin.

I have not tested the immersion/electroless tin process for whisker growth
and know only what I have read on Technet.

Phil Hinton

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