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Old 23rd Sep 2005, 12:34 am   #7
Darren-UK
Retired Dormant Member
 
Join Date: Apr 2003
Location: Blackpool, Lancashire, UK.
Posts: 4,061
Default Re: Whiskers in germanium transistors etc

Hmmm.....that NASA site is very interesting and gives examples of whiskers growing from both tin and zinc, so I'm left wondering what other metals can also suffer this effect.

There is also an example of whiskers growing after 3 years of 'ambient storage' which does indeed imply, but not confirm, this is more likely to occur during disuse rather than use.

As PS pointed out, the whiskers do indeed appear to be eminating from the transistor case rather than the germanium. Question now is this; are these whiskers a property of, say, tin - or do they occur due to some sort of reaction between the tin and some other substance in very close proximity?

Must now find out if AF117 etc transistor cases are tin or zinc plated on the inside. If they are, why would they be ?
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