That solder reflow obviates the problem of tin whiskers is precisely the
missing factor in the NASA reports.  The parts displaying whiskers were
processed with conductive epoxy which did not introduce the reflow of the
Tin surface or the addition of solder.  JEITA in Japan is also studying Tin
whiskers and has reported some results on their web site.  IPC
inconjunction with JEDEC and ECA has also reported some experiments on tin
whiskers in which the results were counter to the experiment plan.  I have
not been able to get the actual report to determine what was proposed
(hypothesized) and what was observed.    If anyone has more on this it
would be appreciated.

NASA seems to be witch hunting, since they took a unnatural process
condition and blew it out of proportions.  Remember that one does not
usually use Ni barrier and tin plated parts for epoxy conductive paste
attachment.

James P. Canner
Senior Applications Engineer
Murata Electronics North America
1900 W. College Ave
State College PA 16801-2799
(814)-237-1431 x 2032
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