Pete,

You are the end user and  you have to make a call from reliability stand
point. You should also examine the board using sonoscan to see if this
condition exist in flight hardware. Like everybody says coupon has to
pass all testing as a whole (lab is correct in rejection). It is
supposed to represent the part you are going to use for flight hardware.
You should be very careful in this type of situations.

Mahendra Gandhi 

-----Original Message-----
From: IPC-600-6012 [mailto:[log in to unmask]] On Behalf Of Menuez,
Pete (IE) @ CIN
Sent: Friday, July 21, 2006 8:19 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 [log in to unmask]

513-573-6401 Voice
513-573-6767 Fax

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