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
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-----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]
 
Circuit Technologies
3622 Clearview Parkway
Atlanta, GA 30340
(770) 458-1700
www.cir-tech.com