Subject: | |
From: | |
Date: | Thu, 21 Mar 1996 09:37:09 +0000 |
Content-Type: | text/plain |
Parts/Attachments: |
|
|
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
>
>
-----------------------------------------------------
Rory Doyle [log in to unmask]
National Microelectronics Research Centre,
Prospect Row, Cork, Ireland.
Direct Line: + 353 21 904110
Switch: + 353 21 903000 Fax: + 353 21 270271
Home page: http://nmrc.ucc.ie/
------------------------------------------------------
|
|
|