-----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