With as high a density part as you describe your solder joints will also be very small. A through hole via in pad will suck up a significant amount of solder that could be very difficult to compensate for. You may be at the level to consider laser vias. Laser blind vias can be placed in the center of smd pads without a significant effect on solder volume reduction or solder joint integrity. There are several PCB manufacturers that would gladly assist you in this direction. Guy Willingham Zycon/Hadco Corp [log in to unmask] ______________________________ Reply Separator _________________________________ Subject: Via in Pad Author: [log in to unmask] at corp Date: 4/10/97 8:30 AM All, I am designing a board that is about 100% package density. It is a combination Digital and Analog design. It will be reflow top side only. Most of the parts are small and do not have room under them for via's. Has anybody used the Via in Pad technology? What has been you experience with it? I realize that the Vias will tend to thieve the solder during reflow, and cause problems. Regards, Fred Pescitelli Phoenix Designs 1285 Turner Rd. Lilburn, GA 30247 V-770-923-3465 F-770-923-2272 [log in to unmask] *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To subscribe/unsubscribe send a message <to: [log in to unmask]> * * with <subject: subscribe/unsubscribe> and no text in the body. * *************************************************************************** * If you are having a problem with the IPC TechNet forum please contact * * Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] * *************************************************************************** *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To subscribe/unsubscribe send a message <to: [log in to unmask]> * * with <subject: subscribe/unsubscribe> and no text in the body. * *************************************************************************** * If you are having a problem with the IPC TechNet forum please contact * * Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] * ***************************************************************************