Pete,
Scaling your photos approximately, it seems that the "row" of
rectangular pads in the microsection is the coupon borders.  Measuring
the distance across the row of pads comes up with ~.500 inch, which is
just what it is supposed to be.  The lam voids beyond the "coupon edges"
should not be in the evaluation area.  The microsectioned specimen
should have been cut or hand sanded to the etched coupon borders shown
prior to encapsulation.

Dennis J. Cantwell
R & D Liaison
Printed Circuits, Inc.
1200 West 96th Street
Minneapolis, MN 55431-2699
952-888-7900
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-----Original Message-----
From: IPC-600-6012 [mailto:[log in to unmask]] On Behalf Of Menuez,
Pete (IE) @ CIN
Sent: Friday, July 21, 2006 10:19 AM
To: [log in to unmask]
Subject: [IPC-600-6012] Inspection area of Coupons

I've attached a picture of the coupon that brought up my question
yesterday.

The reason for my question and request for clear definition of the
evaluation area is that the user (me) can get put in the middle of an
argument and may not (probably doesn't) have the expertise to make an
educated opinion.  On one side you have the board fabricator saying that
it's good - not part of the coupon design etc. and the lab is saying its
on the coupon therefore its is rejected.

Bob Naves pointed out that a lab rejection is not the final say.  That's
an absolutely correct statement. But how does the end user (again, me)
make the decision whether the lab is correct or the fabricator is
correct?  Again, its a he-said-she-said argument.  I have been through
those arguments and they aren't pretty. These particular boards are 1
ups on a 18 x 26 panel and run north of $10,000 each.  This would be a
very bloody contest indeed.

What I'm suggesting is that we define the evaluation area for the
coupon. We do this for the thermal zones, why not do it for the entire
evaluation zone.

If there is concern that there are issues that might be missed (like
these laminate voids) that should be addressed then terminology that
says if non-conformances are found outside the evaluation zone a root
cause evaluation must be made by the fabricator. 





Pete Menuez
Supplier Quality Engineer
L-3 Communications Cincinnati Electronics
7500 Innovation Way
Mason, Ohio 45040
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513-573-6401 Voice
513-573-6767 Fax

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