Matthew,

Go directly to Jail. Do not pass Go. Do not collect $200.

No matter what anyone may tell you, there is no rework procedure that
will give you anything more than a cosmetic repair. The typical flex
adhesive systems currently in use cannot be relaminated and maintain
anything near to the required bond strength. The only exception to that
would be if they were severely under cured in the first place, and even
then it's a risky business because you can't measure what you end up
with. You face a very real risk field failures.

Adding a secondary adhesive to "glue" the delam back together will
unbalance the internal structure and may lead to premature trace
fracturing.

If the rigid -flex delamination falls within the specified allowance for
delam, then go ahead and use them with a clear conscience. If they're
out of spec. scrap them.

Andy Magee
Flex Guru
[log in to unmask]

(I know everyone's been reworking Pyralux for decades, but what you
didn't know could have hurt someone. It's not really a thermoplastic
adhesive, and once delaminated the bond just can't be reestablished. It
looks good enough to get it out the door, but..............)



Matthew Sanders wrote,

I've seen some small discussion about delaminated flex boards here in
the
past. Relating to this, is there any way to rework rigid flex boards on
which the flex area is delaminating? If anyone has had experience having

this done, please let me know. If anyone in the SF Bay area provides
this
service, please contact me offline.

Thanks,
Matt Sanders

Matthew Sanders
PWB Procurement Engineer, Trimble Navigation Limited
[log in to unmask]
Phone: (408) 481-7817
Fax: (408) 481-8590

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