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SMT electronics assembly manufacturing forum.


Zn/Pb Diffusion

geoff_goring

#19585

Zn/Pb Diffusion | 19 April, 2002

I would like to discover more about Zinc/Lead diffusion in the leadframes of SOIC ASICS.

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#19595

Zn/Pb Diffusion | 19 April, 2002

I don�t know much about zinc either. I can tell you that zinc forms no intermetallics with lead. So, I�m not so sure that �diffusion� is the correct term.

Of the following: * Hwang "Modern Solder Technology For � * Wassink "Soldering In Electronics � * Vianco "ASW Soldering Handbook �

A quick scan shows that Vianco is probably the place to start. Most of the stuff in Hwang and Kline-Wassink deals with the old dewetting / dull appearance / icicling issues associated with too much zinc in the solder pot. For more on that stuff, search the fine SMTnet Archives for something about �The Effect Of Metallic Impurities On The Wetting Properties Of Solder� Dennis Bernier, Vice President, Research & Development, Kester Solder Company.

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