We just had a similar thing happen, with FR4 HR370. Before we did'nt bake prior to assembly as the boards came direct from the board house, now we are seeing de-lam. They told us that it is a recent requirement that came from the material supplier that they forgot to inform us of. Ours are 12 layer, stacked vias. Currently we trying to get some money back! Ian Thomas -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Franklin D Asbell Sent: 23 October 2007 21:19 To: [log in to unmask] Subject: Re: [TN] Delamination of lead free PCBs I wrote my comments with the silly assumption that companies would apply finishes properly. When immersion tin or silver are applied properly they should be able to withstand the baking necessary to remove moisture. This is the part where the Disclaimer goes "know your processes, limitations, and those of your customers/suppliers". Franklin D Asbell -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Guy Ramsey Sent: Tuesday, October 23, 2007 2:51 PM To: [log in to unmask] Subject: Re: [TN] Delamination of lead free PCBs It should be noted that immersion tin and immersion silver may not respond well to baking. Reckless methods can render the boards unsolderable. -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Franklin D Asbell Sent: Tuesday, October 23, 2007 1:39 PM To: [log in to unmask] Subject: Re: [TN] Delamination of lead free PCBs Joel, Baking was indeed required for leaded PCBs, the nature of most laminates is to suck up moisture regardless of the Tg or final finish. Also, depending upon the laminate type, baking may be necessary immediately upon receipt from the board supplier. I always caution assemblers to bake boards regardless, it just makes good sense. Franklin D Asbell -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Joel Alexander Sent: Tuesday, October 23, 2007 11:23 AM To: [log in to unmask] Subject: [TN] Delamination of lead free PCBs Has anyone experienced an increase of delamination when processing in a lead free environment. Typically 4 to 6 layer pcbs during SMT reflow. We are using the high temp laminate suggested for our process. When we contacted the supplier and they indicated that any PCBs that are over six months old should be baked prior to processing. This was never required with leaded PCBs. Is anyone seeing the same condition and similar feedback from your PCB suppliers Joel Alexander Quality Assurance Manager TT APSCO, INC. --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------