Hi Tony,

In my brief experience, I haven't found a good board that warped and then
un-warped.  Think of the reliability issues with any PTH or traces that
experienced a high stress or strain zone.  Would you trust selling that
board to a customer and the memory effect not hitting again?  I'm not sure
you could 'fix' them.  You might be stuck identifying the root cause and
eliminating it.

When did these boards warp - process and date?  What's the memory effect?
Do cross sections show any damage?  Pictures are worth a thousand words or
2000 if Steve does the counting.  (Steveo, I hear Florida is looking for new
ways to count ballots.  LOL)

And to think I'll be landing at Hartsfield tomorrow night @ 10:10 if Delta
comes through.  Small World indeed.

Happy Holidays All!

Hans
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Hans M. Hinners
Process Engineer
Toppan Electronics, Inc.
770 Miramar Road
San Diego, CA 92126
(858) 695 - 2222 ext. 241
(858) 695 - 6823 fax
[log in to unmask]

-----Original Message-----
From: Tony Steinke [mailto:[log in to unmask]]
Sent: Tuesday, December 19, 2000 10:52 AM
To: [log in to unmask]
Subject: [TN] WARP


Greetings,

Has anyone out there had experience with these so-called "de-warp" chambers.
I have a large quantity
of double sided boards(.062/140Tg) that have severe warp with memory. We
have performed "dewarp" (three hours at 300F then cooling to ambient
temperature under weight)baking using press caul plates several times with
no success. The panels have even copper distribution side to side.
Any help/suggestions would be appreciated.


Tony Steinke
Process Engineer
[log in to unmask] <mailto:[log in to unmask]>

Circuit Technologies
3622 Clearview Parkway
Atlanta, GA 30340
(770) 458-1700
www.cir-tech.com <http://www.cir-tech.com>