I sent a copy of this to my supervisor. He has a lot of PWB FAB experience. Maybe he can come up with a couple suggestions. Randy Bock Sr. Quality Manager Bryce Office Systems LLC email [log in to unmask] ----- Original Message ----- From: Edward S. Wheeler <[log in to unmask]> To: <[log in to unmask]> Sent: Tuesday, April 09, 2002 1:59 PM Subject: [TN] 0402 tombstone problem > Hi folks, we are running a new board with 0402 parts on it. It seems that > we are having a tombstone problem as well as a problem with parts not > staying centered on the pads. We are currently using 20 mil square pads on > the board, with 20 mils of spacing between them. Our stencil is 6 mils > thick, laser cut and electro polished. The trapezoidal walled apertures are > slightly reduced, 17 mils square, and centered on the pads. It appears the > chip shooter is placing the parts perfectly. We are using eutectic solder > paste with an OA flux, and reflowing the parts using the recommended profile. > > Are there any suggestions any of you might have concerning this size of a > part? Is there a better stencil design, reflow profile, or pad design that > could help us out? I would appreciate any suggestions. > > Thanks. > > Ed > > -------------------------------------------------------------------------- ------- > Technet Mail List provided as a free service by IPC using LISTSERV 1.8d > To unsubscribe, send a message to [log in to unmask] with following text in > the BODY (NOT the subject field): SIGNOFF Technet > To temporarily halt delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL > To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest > Search the archives of previous posts at: http://listserv.ipc.org/scripts/wa.exe?S1=technet > Please visit IPC web site http://www.ipc.org/html/forum.htm for additional > information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 > -------------------------------------------------------------------------- ------- > --------------------------------------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------