Hi! This reminds me of the same problem with a batch containing different date codes and another one from different vendors . I suppose that this batch was too small to be from two different dates or vendors, but sometimes if there are a few boards missing to complete an order, it may happen. One of our vendors had this problem when he changed his copper oxyde process. Another one had left the batch overnight in the copper oxyde tank. These were the answers to our complaints. Gaby Charles Barker wrote: > 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 > ############################################################## ############################################################## 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 ##############################################################