At 09:09 AM 1/27/98 -0500, Sheila Smith wrote:
>Hello,
>
>First, thanks to everyone for the replies to my questions about HASL -- the
>information was very helpful.
>
>Now, does anyone have an experience or data on the effects of radiation on
>silver-filled conductive epoxies? [Radiation exposure as in space
>applications.]  The manufacturers of the epoxies say no effects.  Thanks in
>advance for your help.
>
>Sheila Smith, Tracor Aerospace

One data point for you Sheila.  I was involved with the analysis of a
module which failed during a space mission.  The module used a silver
conductive epoxy as the attach media.  The silver had migrated from the
silver terminations on a discrete resistor and from the epoxy and caused
circuit failure.  Because of the zero-g atmosphere, instead of just getting
migration paths on the surface, the silver grew out in all directions.  I
have some very beautiful SEM photographs of silver whiskers, "weeds" and
"shrubs" growing out of component terminations and the epoxy.
---
Gregg Klawson
GTE Government Systems Corp, Taunton, Massachusetts, USA
[log in to unmask], telephone +1.508.880.1822

The views expressed are the author's and do not necessarily reflect the
official position of GTE or any of its subsidiaries.

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