Tin whiskers are a different phenomenon from dendrite growth
(electromigration). But you're right -- whiskers are very much a concern
for everyone making the transition to lead-free finishes and solder alloys.
Frank AC8P
Jamesnf@aol.com wrote:
>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.
>
>Regards,
>
>Jim W9TM
>
>
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