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Date: | Mon, 24 Jun 1996 13:55:33 -0500 |
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To everyone,
We have, in the past, had problems with bare board warp and
delamination in our assembly process (reflow). We have solved this
problem by instituting a baking process at our vendor or in house
prior to assembly. My questions are as follows:
1. Is baking a standard PCB fab process (before shipping)?
2. If so, what is the standard profile?
3. If not, why do some vendors' boards need to be baked to prevent
warp and delamination while others don't?
4. Does baking cure both delamination and warp or does it just cure
warp?
5. My understanding is that moisture is getting trapped in the board
during laminate press (or contamination of some sort) which is
leading to the problem during assembly. Can the moisture
entrapment be avoided? Should we claim to our vendor that he
better control contamination in the process?
5. It seems to me that if boards need to be baked before delivering to
a customer that there is some poor process control going on.
Someone, please educate me. Maybe, my perspective is in error.
Thanks,
Roger Held
Hitachi Computer Products (America), Inc.
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