Sounds like residual moisture or some other volatile in the board. Bob Dube -----Original Message----- From: Stephen R. Gregory <[log in to unmask]> To: [log in to unmask] <[log in to unmask]> Date: Wednesday, February 09, 2000 12:15 PM Subject: [TN] Delamination >Hi ya'll! > >We just finished building a lot of 48-boards through SMT. Out of that 48 >there was one board that we just discovered a big delamination blister on the >backside...it's about 1.5" wide and maybe 2.5 - 3" long. There was no rework >done on the board, and it was reflowed under the same profile in a >Conceptronic HVA-70 that the rest of them were...and they don't exhibit any >problems. There no sign of overheating at all around the blister, and the >silkscreen is nice and bright white...we just have this big blister. What >might cause that? The boards are polyimide. We didn't bake them, and they >were real fresh boards date code was 0300. Like I said, it was the only board >that had a problem...the rest are fine. > >TIA > >-Steve Gregory- > >############################################################## >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 ##############################################################