> Not so Tom. Although much progress has been made with
"no-clean" solders,
> dendrite growth is still an issue when pc board assemblies
are exposed to
> humidity. To remove flux residues after waveline or smt
reflow soldering processes,
> it was common to use either chemical or deionized water
board washers
> followed by dryers. Eventually, the EPA banned the CFC
emissions and the deionized
> washers were expensive and a mess to maintain, so
"no-clean" solders took the
> lead. Believe me, we wouldn't have gone to all this
trouble in the industry if
> whiskers only formed in a high vacuum.
Interesting Jim!!
I've never seen that, but then I work mostly with wide trace
spacings and lead-tin solder.
I was aware whiskers slowly form in some high power vacuum
tubes and in vacuum capacitors and relays, but never heard
of it before in metals operated in typical environments.
Apparently this is just a problem with a few metals used in
solder? Or is it the flux?
Thanks,
Tom
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