coupons

[jerry]

What is a coupon and or test coupon, and what are they used for?

[Tom]

Jerry,

Test Coupons are used for manufacturing (board fabrication) compliance. A test coupon is like a small PC Board that is attached to one side of your design. It contains all the features of your design. Padstacks, Traces, Plane Anti-pads and Thermals. A test coupon represents each of the steps in the manufacturing process.

The manufacturer will take the test coupon and dissect it to check for:
1. Pad & Drill layer-to-layer annular ring
2. Conductor trace / space accuracy
3. Trace and Plane layer plating consistency
4. Hole plating

Usually Test Coupons are retained for a period of three years. The intent to retain these coupons is to provide evidence when problems occur that the problem was or was not noted in the original evaluation.

I have a lot of pictures and much more detail I can post here if you need more information. Let me know and I will add it tonight.

[jerry]

Thanks Tom,
I would definately appreciate any and all info I can get. I,ve taken over for our previous PCB guy ( he left) with little to no training, (lean more to the no training) This site is a big help, as is any other sites and forums I have stumbled onto on the web. Thanks again!!!
Jerry

[phillipr]

You can also get controlled impedance test coupons that measure the impedance of the pcb

[Tom]

Jerry,

OK, here is the verbiage right out of the IPC Advanced Study Guide. Section 1.8 - In Process Test Coupons

I've attached a MS/Word document that goes into detail.