Delamination can be attributed to several factors but few a few
apply in your case:

- Excessive reflow temperature                 (unlikely in your case)
- Excessive laminating temperature            (also unlikely in your case)
- Defective laminate material                    (quite possible)
- Problem in oxide treatment of innerlayer   (also possible, but less
likely)
- Contamination at the laminate interface    (most likely, since your board
                                                             seems to be
isolated case)

So the most likely case is external to your facility.

Have a nice day,

Alain Savard, B.Sc.
Chemical Process Analyst
CAE Electronics Ltd.
e-mail: [log in to unmask]


-----Original Message-----
From: Stephen R. Gregory [mailto:[log in to unmask]]
Sent: February 9, 2000 12:13 PM
To: [log in to unmask]
Subject: [TN] Delamination


Hi ya'll!

We just finished building a lot of 48-boards through SMT. Out of that 48
there was one board that we just discovered a big delamination blister on
the
backside...it's about 1.5" wide and maybe 2.5 - 3" long. There was no rework
done on the board, and it was reflowed under the same profile in a
Conceptronic HVA-70 that the rest of them were...and they don't exhibit any
problems. There no sign of overheating at all around the blister, and the
silkscreen is nice and bright white...we just have this big blister. What
might cause that? The boards are polyimide. We didn't bake them, and they
were real fresh boards date code was 0300. Like I said, it was the only
board
that had a problem...the rest are fine.

TIA

-Steve Gregory-

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