« IEEE 1149.7 & 1687 - dispelling the misconceptions | Main | Test Pads on High-Speed Nets »

Jul 06, 2010


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Steve Butkovich

Just curious about the shorts definition; "On an interconnect, can shorts within a shorting radius be detected?" I don't know what a "shorting radius" is. It seems to me that a short is like being pregnant, you either have one or you don't.

It seems to me that the iNEMI PCOLASOQFAM way over emphasizes the contribution of PCB assembly level test to the overall test need. If all a product has over being correctly interconnected is features, at-speed and measurement, wouldn't it be more correct to say that PCOLASOQ=B for built correctly?

Alan Sguigna

Yes Steve, that would be correct. I think that test engineers need to view their craft holistically, in terms of structural (PCOLA/SOQ), functional (FA) and performance (M). Just because a board has been assembled correctly, doesn't mean it will work. And just because it works (or seems to work!) does not mean it doesn't have structural defects. Example: a via stub or solder void on a high-speed bus may contribute to a high bit error rate or a reduced margin, even though the bus continues to work. A good video that demonstrates this is here: http://www.asset-intertech.com/NBT_movie.html

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