The coupon issue of IPC-D-275 has long been a issue with me as a bare board manufacturer. Many instances I have been in discussions where this standard is quoted in reference as to how a board is manufactured. To this date, I believe the scope of this documents still limits this document to board design and not manufacturing. However, there are sections within this document that directly influences if not outright specify manufacturing requirements. Such as in the case cited in Werner Engelmaier response regarding the placement of coupons on a panel where he cited the requirements of 7.3.1.
The problem is that the board manufactures has little control over the design of the parts we bid on and build.  

First off, of the thousands of data sets I have received from customers to manufacture  parts, rarely does the data come in panel form and almost never is a coupon design included ( military accounts excluded ). Furthermore,  most commercial drawings only cite the performance spec such as RB-276 or the A-600 acceptability guidelines.

This leads to my comment / question. When D-275 is cited along with say the RB-276 spec (  many prints still have this) Must the board shop review the DESIGN to  insure it meets the D-275 standard? And if it fails to meet the design requirements and the shop builds it anyway, should the board shop be held responsible?  And I'm speaking real world here folks. Due to cost and pricing considerations many commercial designs are quoted and panelized with the minimum required boarder for manufacturing. I would venture to say ( based on my experience) that a vast number of commercial designs do not allow for proper boarder that would supports a complete coupon and many frequently violate the hole to pad ratio as well as conductor edge clearance.  Many double sided designs are being process with less than a .500 boarder total. And that is necessary just to stay competitive. I wonder just how many commercial manufactures are really adhering to the "total" spec as it is written. Frankly I wonder how many commercial houses actually have the required group A test data on file as required. If I understand the specs correctly, even commercial board require a group A test and that would technically require serialization wouldn't it? I believe the new IPC-6012 section 3.3.5 is very clear on this.  How will this requirement affect pricing since the newer specs basically require commercial parts to be manufactured, tested and inspected along the same lines as the old Mil-P-5510. Just how many of us are actually serializing our commercial product and if we are, is the customer paying for the added costs?   Hmmmmm... I  wonder.. 

Just my thoughts.

Ed Cosper
Director Quality Assurance and Engineering.
Graphic Electronics Inc.    

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