How old are the boards, Steve? FR-4 or Polyimide? I've seen old boards do that. Suspected moisture entrapment. Never have seen it with "new" boards. Charlie B. Please respond to "TechNet E-Mail Forum." <[log in to unmask]>; Please respond to [log in to unmask] To: [log in to unmask] cc: (bcc: Charles Barker/US/I-O INC) Subject: [TN] Blisters or Delamination after Wave... Hi ya'll! Well, I'm in onna Saturday...(Months end, you know how that goes!). Just finished waving a small lot of boards (9 assemblies) and 5 of them came off the wave with these dime to quarter-sized delaminated blisters, maybe 3-4 of them on each board, and the other 4 boards looked fine! What would cause that? Entrapped moisture? The boards were supposedly baked before wave (At least the traveler said they were). Any ideas? -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 ##############################################################