We have similar boards and we bake them at 125C for 12 to 14 hours in a
nitrogen inerted oven. This has solved our delamination problems with
polyimide.

Not what you wanted to hear I'm sure but hope this helps.

At 10:30 AM 9/22/98 -0400, you wrote:
>Dear Ann,
>
>(Oops, wrong advice column...)
>
>Dear Technet:
>
>We assembly an 8 layer polyimide SMT board (approximately 6" x 11" x .062
>thick).  Our standard bake cycle for these boards prior to assembly has been
>250 F for 6 hours.  We recently ran into a rash of delamination after reflow.
>A board vendor recommended we bake at 275 F for 16 hours.  We feel that
this is
>excessive, and that our bake cycle should be adequate.  What do you think?
>
>Thanks for your assistance,
>Over-baked in NY
Ken Bloomquist
Sr. Principal Process Engineer
PRIMEX Aerospace Company
P.O. Box 97009
Redmond, WA 98073-9709

Northcon/98, Show Director
<www.northcon.com>

Electronics Manufacturers Association (EMA), Secretary
<www.ema-wa.org>

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