Kevin,

I have seen a case where residual sulphur on a circuit (left behind after a
cleaning stage) attacked the silver in the chip resistor component
terminations resulting in total open circuit failure of the resistors.
Exposed copper on SOIC leads etc. was also attacked in a similar manner.
The corrosion product was readily identifable as a black crystaline growth
at locations were there was exposed silver or copper.

Rory Doyle


 >
>        We are presently considering the use of carbon-impregnated
>     cardboard (for ESD) for the storage of small assemblies with Silver
>     and Gold Leads.
>        It is well understood in industry that Sulfur impairs the
>     solderability of the surface but does anyone know if sulfur has any
>     other detrimental affects on Silver and Gold finishes (i.e. corrosion,
>     etc.).  These pins will not be soldered therefore solderability of the
>     surface is not a concern.  We just want to confirm there is no other
>     detrimental affects of Sulfur.
>
>        Thanks for your time.
>
>     Kevin Frasier
>     Scientific-Atlanta
>     [log in to unmask]
>     http://www.Sciatl.com
>
>

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            Rory Doyle            [log in to unmask]

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