>
> As to the OP's original problem, the only way to determine just where the
> break is on an inner track will be a TDR measurement compared to a good
> PCB, as mentioned previously in this thread. The problem is you will need
> a TDR capable of doing picosecond measurements to get any sensible length
> measurement unless it is a very long track. Maybe time to call on your
> local (what used to be) HP or Tektronix rep for an instrument
> demonstration. :) The rest of us would just put a patch wire on, call it
> fixed and wait for another failure if it really is a via breakaway
> problem.
>

Thanks for the detailed discussion! In x-rays, it appears that one layer
is misregistered by about 5 mils. We're thinking this can cause an
occasional via failure. The sample size is still really small, but is
causing us concern.

Harold




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