Hi Jim,

        We've performed some accelerated tests on this combination.  Testing
showed increase in resistance and decrease in adhesion.  Initial adhesion
was even poorer than the other combinations.
        Our recommendation was solder terminated components should be
soldered, Pd/Ag terminated should be epoxied.  I've heard others say you can
solder Pd/Ag terminated caps, but the process window is tight and no rework
is allowed.  My opinion is not to do it, not worth the risk.
        As for acceleration, will it last 2 years in your environment?  I
don't think so, but I'm just guessing.  Six months, probably.  The
acceleration model I have would need more data from temperature and humidity
factors.  Don't forget the mechanical shock.

        Have you talked to CALCE?  http://www.calce.umd.edu/

Glenn

> -----Original Message-----
> From: Marsico, James [SMTP:[log in to unmask]]
> Sent: Tuesday, January 23, 2001 12:35 PM
> To:   [log in to unmask]
> Subject:      [TN] silver epoxy & solder coated parts
>
> Hello, Technet...
>
> Here is an unusual situation.  We have to assemble a surface mount
> assembly
> using silver epoxy.  Some of the components will be solder coated.  I
> know,
> don't bother asking... this is the way it has to be.  The good thing is
> that
> this assembly is a prototype for bench-top laboratory use only.  There is
> no
> harsh environment and needs to operate 1, maybe 2, years.  The question is
> does anyone foresee any problems?  What happens when one mixes toe two
> technologies?
>
> Thanks,
> Jim Marsico
> EDO Electronic Systems Group
> [log in to unmask] <mailto:[log in to unmask]>
>

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