Clinton:

     One of the options for 0603 apertures is a circular pad 30 mils in
     diameter and spaced 60 mils between the diameters.  As I see it, there
     are a couple of advantages to that shape and configuration:

        1) There is a minimal amount of solder paste under the component to
        squeeze out from under the body of the component.

        2) If the component is not placed squarely on the pads by the P&P
        equipment, the surface tension of the paste will realign the
        component terminations toward the center of their respective pad
        with minimal "tombstoning"

     One other option for components larger than 0603 passives is to use
     oval pads rather than pads with square corners.  The corners of a
     rectangular pad contributes very little (if at all) to the solder
     joint strength and takes up PCB real estate.  The additional reduction
     in solder paste gives your pads less material to be used for solder
     ball "creation".

     Just some food for thought!  Bon appetit!

     Bill Fabry
     Plantronics, Inc.
     [log in to unmask]
     FAX (408) 458-7785

     PS:  Matthew, please FAX me a copy of your pad design also.  Thanks!


______________________________ Reply Separator _________________________________
Subject: [TN] Stencil Aperture Shapes
Author:  "TechNet Mail Forum." <[log in to unmask]> at INTERNET