Hi Peter
Thanks for your quick answer. Here are some further explanations :

application is avionics ! I also have concerns about copper plating in the
hole. This is the first point I told my customer. We just met a similar
problem last week on a 1.6mm thick PCB and 0.2mm via holes, the copper layer
broke when changing wrong BGA's.

to save place, the idea is to use via pads as test pads : via holes should
not be epoxy filled, but filled with a conductive material to create a
"large" test pad to contact on the test fixture (large despite a round pad
of 0.6mm diameter). Unfortunatly, it cannot be filled during wave soldering
(the process will only be reflow).

ME Magnin
mailto:[log in to unmask]
http://www.firstec.ch

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