FreeLists / si-list / [SI-LIST] Re: Decoupling capacitors for BGA

[Jeff Seeger <jseeger@xxxxxxxxxxxxxx>]

,
        One technique we have used with good result, at least on
        1mm pitch BGAs, is to use an 0402 capacitor with round
        pads on a 1mm pitch placed within the array.  This essen-
        tially puts the cap directly opposite the ball pads to be
        decoupled.

        This does require prediscussion with your manufacturing
        resource as some will have concerns in volume.  This will
        also consume a number of favored ICT test pad locations
        so as always there are tradeoffs.

        Sensible escaping to minimize inductance is still required
        of course.

        Regards,
-- 

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