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August 1999

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Subject:
From:
"Stephen R. Gregory" <[log in to unmask]>
Reply To:
TechNet E-Mail Forum.
Date:
Sat, 28 Aug 1999 17:15:54 EDT
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In a message dated 8/28/99 3:59:52 PM Central Daylight Time,
[log in to unmask] writes:

> How old are the boards, Steve?   FR-4 or Polyimide?
>
>  I've seen old boards do that. Suspected moisture entrapment. Never have
seen
> it with "new" boards.
>
>  Charlie B.

Hi Charlie!

The date code inked on the boards was 9915...first week of April, so only
4-months old. I didn't follow the boards thru the process up until wave, so
there could be a outside chance that maybe they weren't baked properly. I've
got another lot of a dozen boards that need waving...I'll do that on Monday,
and I'll "babysit" these guys from bake until wave...

But what's still unusual, is that part of them blistered, and part of them
didn't...weird.
From the responses I've read from Earl and a few others, is that absorbed
moisture
normally results in blowholes and whatnot, and that's been my experience too,
not the fab coming apart...it's just the surface layer too...nothing deeper.
I've never had something blister like I've seen with these puppies...

I'll let ya' know what happens on Monday...time to go home now...I spent
enough time here today...hehehe

-Steve Gregory-

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