Dennis J Cantwell
R&D Liaison/Quality
Printed Circuits Inc
1200 W96 th Street
Minneapolis, MN 55431-2699
952-888-7900
(F) 952-888-2719
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>>> [log in to unmask] 10/03/03 03:36PM >>>
Greetings,
I've been asked to post the following questions for discussion related to 6012/6013.  Our Quality Engineering group wanted to clarify the following.
We would like to know how others are interpreting Referee Testing per paragraph 4.2.2 of IPC-6012A1 and paragraph 4.2.1 of IPC-6013-1.
Both paragraphs read as follows:

ISSUE 1:
Two additional microsection sets from the same panel may be prepared and evaluated for microsection defects that are considered to be isolated or random in nature or caused by microsection preparation.  For acceptance, both referee sets must be defect free.
How many coupons (A, B, A/B) are required to be tested?  What is considered to be a set? Is a pair a set; therefore 4 coupons are needed?
Response:  Printed Circuits Inc does (2) A/B coupons from diagonally opposite corners---(1) is the "as received" and (1) is the thermal stressed.  If there were isolated anomolies or microsectioning induced anomolies, we would use another set from the opposite diagonal corners.  For this purpose, we ALWAYS have (4) A/B coupons in our panels in addition to (4) "full-sized" IPC-2221 coupons.  A "re-set" coupon must be fully compliant, dependant on the observed anomolies.  Beyond that, an actual board might be microsectioned, and the customer would be contacted for inclusion in the decision.
ISSUE 2:
As a side issue, para 4.2 "Acceptance Testing" does not include Plating voids (para 3.6.2.2), Laminate cracks (para 3.6.2.4), and Smear removal (para 3.6.2.6).  Acceptance testing being the equivalent of the old Group A.  And after reading the spec again, it really appears to me that we only need to look at one coupon.  Table 4-3 says "A or B" for structural integrity properties after thermal stress.

Response:  Anytime you are evaluating product, you have to look at ALL properties contained within the spec, whether or not it is specifically defined for that operatiopn or not.  It might not say "yellow" laminate in an inspection instruction, but if you find a yellow laminate, and it is supposed to be natural color, you sure have to do something about it!!

Thanks for your consideration,



        C. D. (Don) Dupriest
        Lockheed Martin Missiles and Fire Control - Dallas
        Electronics Manufacturing Engineering
        SME - PWB/CCA Technology Development
        Ph. 972/603-7724 fax: 972/603-3548
        Email: [log in to unmask]




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