-----Original Message-----
  From: Ryan Jennens [mailto:[log in to unmask]]
  Sent: Thursday, May 13, 1999 11:51 AM
  To: TechNet
  Subject: Fine Powder Solder Paste


  What stencil design guidelines differ when one decides to go with

  a -400/+500 particle size solder paste? The paste companies tout that the

  finer particle paste offers print improvements below 20 mil pitch. But I

  believe one would have to reduce the aperture sizes all around because
more

  metal would be deposited in each one. Is this accurate? How much reduction

  is needed. Is home-plating the apertures even more important? I could not

  find this topic in the archives. We are considering switching for our

  finer-pitch boards, as their pitch decreases, if it really offers an

  advantage. However, we have been printing 20-mil for a long time

  with -325/+500 paste for quite a while.

  -Ryan Jennens

  TelGen Corporation