Eric, We saw this problem years ago with our prep of the surface prior to soldermask. What is your pre-mask prep? Anne Ledger EMDS, Inc. > -----Original Message----- > From: Eric Masters [SMTP:[log in to unmask]] > Sent: Friday, October 01, 1999 3:06 AM > To: [log in to unmask] > Subject: [TN] Internal shorts > > I'm having a rather perplexing problem with shorts on inner layers. > The > short is very small, and occurs mainly on fine line jobs (5/5 mils and > less). > It also occurs primarily on layers with one ounce copper, although > I've seen > it on half ounce. > > The short is very very small; in fact, it is rarely seen at AOI. > Usually, it > is discovered at final electrical test. Failure analysis exhibits a > very > fine sliver of copper that appears to have broken loose from a trace; > it > remains attached at one end and flips across the adjacent circuit. > > Cross sections and SEM's of both developed resist and etched layers > show a > near vertical sidewall. Has anyone seen this phenomenon? Any > suggestions? > > Eric > > ############################################################## > 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 Gayatri Sardeshpande at > [log in to unmask] or > 847-509-9700 ext.5365 > ############################################################## ############################################################## 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 Gayatri Sardeshpande at [log in to unmask] or 847-509-9700 ext.5365 ##############################################################