We are getting a lot of rejects back to our soldermask operation for touch up of solder dams that have handling damage. Most of these are between SMT pads for passive components and the vias attached to those pads. Since some designs have NO solder dam on this sort of feature, the question has come up as to what the minimum amount of soldermask is that will keep the solder from running down the via during reflow. It would save us a lot of rework if we did not have to touch up all of these little dams. Our requirement on the dam on a BGA "dogbone" (separating the pad from via) is 3 mils, but we don't seem to have an equivalent spec on non-BGA features. I would appreciate any input! Deborah Schepis OEM Printed Circuit Applications Dept T46G / Bldg 022-2 / Office J004 Tie line 855-5558 / External phone (607) 755-5558 / Fax 857-1558 E-mail schepisd @ us.ibm.com ############################################################## TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c ############################################################## To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TECHNET <your full name> To unsubscribe: SIGNOFF TECHNET ############################################################## Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information. If you need assistance - contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ##############################################################