Dave Hoover wrote:
>
> Curious about what designers are using now for
> ICT test pin location access pad size (S/M also)
> along with closest distance between two test points.
> (Of course those flying probe ICT 's can bend
> major rules but I'm thinking standard fixture/high
> volume.)

        Hey Dave!

        Am seeing high resistance to going lower than .035" sq. pads
        on .050" centers.  IOW not fine enough to cope with large
        1 or .8 mm pitch devices, at least when connected together...

        Preferred granularity remains .040" pads on .100" centers,
        and at worst a preference for surface pads only.

        Break out the board stretchers, or "abandon all hope ye who
        require off-chip series termination".

        IMHO we're reaching a point where in-fixture JTAG, with
        multiple JTAG chains, is a must for testing complex product.
        Of course, that's not a very practical solution either.

        Perhaps this is why we see occasional posts from folks in
        search of the non-contact technologies, sure wish they'd
        gotten some answers!

        Hoping you get responses from leading-edge ICT folks w/hints
        on how to cope....
--

      Jeff Seeger                         Applied CAD Knowledge Inc
      Chief Technical Officer                  Tyngsboro, MA  01879
      jseeger "at" appliedcad "dot" com                978 649 9800

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