[sdiy] Tin Whiskers

[Magnus Danielson]

From: Mattias Rickardsson <mr at analogue.org>
Subject: Re: [sdiy] Tin Whiskers
Date: Wed, 12 Jan 2005 03:43:17 +0100
Message-ID: <6.2.0.14.0.20050112032935.06cd4ca0 at mail.burken.nu>

> At 02:11 2005-01-12, Glen wrote:
> >I knew a lady from Florida who had repeated problems with her [...] organ
> ...
> >it into the organ. As far as I know, the organ never needed treatment for
> >whiskers again.
> 
> Ooh, scary. I've heard about tulips on an organ, but whiskers on an organ 
> was something new.
> 
> But really: all this whiskers stuff - how serious could it be? I mean, it's 
> not like it suddenly started to happen yesterday now or anything, and we 
> still use lots of old electronics that still works. So it will in the 
> future too.
> I guess the whiskers are just a potential cause of spontaneous damage, 
> which has always existed. Finding such a cause gives relief rather than 
> anxiety, I think. Now we have a better chance to prolong the life of 
> electronics (which was quite long already before).

For classical electronics it isn't more danger than it used to. However, for
traditional SnPb solder whiskers isn't such a big problem. For some of the new
Pb-free solder it is a problem and the chemical firms are inventing surface
treatements that is claimed to solve or at least reduce the speed of whisker
developement. That the fundamental mechanism behind whisker-shaping doesn't
seem to be well understood just doesn't help.

> Another thought: would the whisker phenomenon be a bigger risk for old 
> electronics (with higher voltages and currents) or new electronics (with 
> smaller distances)?

Yes.

Older electronics having had longer time to develope them but with a slower
speed could be comparable to newer Pb-free gear which has a higher potential
for creating them fast. :P

> >That worked with a plated steel chassis, but it's a little harder to apply
> >the principle to IC pins or relay contacts. It's someone else's turn to
> >suggest a solution for those.   :)
> 
> ARP submodules had it solved already from the beginning... :-)
> 
>          http://www.arptech.synth.net/decap.htm

However not for the connection of the submodules.

Cheers,
Magnus