I got excited after seeing the subject, but I haven't seen enough, yet . . .
We have a "potted" product that rides behind the wheels of a truck. All our
best protection efforts have yielding significant failure rates. Returned
units have had traces eaten off the board, with various colors of crud left
over. The green is probably copper oxides. Some of the copper seems to
have turned into a red powder. There is a lot of white crust around some of
the lost traces and vias. We are guessing that the boards were not cleaned
well enough before potting (Insulcast RTVS 27 thermally conductive potting
compound). We believe the boards were produced with a water soluble flux,
then washed, then a few hand-ads were installed with a "no-clean" flux. We
think that either (1) moisture sealed inside the potted units may be
"helping" the corrosion, or (2) moisture (with or without extra corrosive
elements) is leaking it through poorly sealed boundaries of the potting
compound. (we are using "primer" around the known "edges" of the units)
I know that "Detroit" has solved this problem many times. Where can I find
a "guide book" or a knowledgeable vendor to help me out of this board
cleaning/potting mess?
Carl Van Wormer
Cipher Systems
1815 NW 169th Place, Suite 5010
Beaverton, OR 97006
Phone (503)-617-7447 Fax (503)-617-6550
-----Original Message-----
From: Earl Moon [mailto:[log in to unmask]]
Sent: Tuesday, March 05, 2002 6:35 AM
To: [log in to unmask]
Subject: Re: [TN] AUTOMOTIVE PACKAGING/SEALING REALIBILITY
Brian,
Thanks for the site/company/info. Just what I've been looking for and should
do the job well. Also, not too far away, like you.
You noticed the reduced number of participants on this forum? Can't remember
seeing it this low. I remember when Steve said we are getting close to the
2000 member mark and was only off by a few hundred or so. I suspect you've
been stealing them away to your environmental forum.
In any event, everyone says the economy is back on track. Of course,
contract engineers are being offered half what they made one year ago and I
don't see too many jobs available but for JSF, power, drugs, and some
strange stuff I've never heard of before.
Just thinking, a self flattery statement, on paper,
MoonMan
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