gEDA-user: pcb: solder paste stencil layers and QFNs

[Andrew Armenia <andrew@xxxxxxxxxxxxxxxx>]

   I sent off some Gerber files from pcb today for fabrication and
   discovered no easy way to generate solder paste Gerbers with
   reduced-size apertures for things like the exposed die-attach pads on
   QFN packages. (There's a Freescale app note at
   [1]http://cache.freescale.com/files/sensors/doc/app_note/AN3111.pdf
   describing some of the issues which can result from too much paste.)
   I've developed a patch for pcb which adds a new "shrinkpaste" flag for
   pads. Setting this flag on a pad causes the pad to be changed to a
   square pad with an area of 40% of the original pad area during
   stencil-layer rendering. If anyone else would find this patch useful
   (or if I missed something really obvious), please let me know...
   -Andrew
   --
   Andrew Armenia
   Ultradian Diagnostics LLC
   Rensselaer, NY 12144
   [2]www.ultradian.com

References

   1. http://cache.freescale.com/files/sensors/doc/app_note/AN3111.pdf
   2. http://www.ultradian.com/


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