Hi Inge, Certainly have. This is not new, and it is not very surprising. You may be interested in my White Paper on how to design PCBs for reiability given Pb'free soldering. Werner -----Original Message----- From: Hernefjord Ingemar <[log in to unmask]> To: [log in to unmask] Sent: Mon, Nov 16, 2009 3:22 pm Subject: Re: [TN] Microvia reliability vs Lead free any relationships are described, one of which is a Curtiss-Wright report. They ave exposed identical boards to SnPb soldering/repair and compared with same or SACs, and found a significant difference in time to failure. 1st thermal cycle to failure As Received 6 x 230 Celcius 6 x 260 elcius Mean 788 443 4 That is a dramatic change in via failures. We have seen some failures recently n ordinary double sided FR-4 boards, which were exposed to several heat xposures in conjunction with electrical testing. Far from 260 Celcius, think nly 125 Celcius. If we got microvia issues with only 125 C, what if we use 260 (e.g. repeated repair)? Has anyone seen any signs of via failure due to increased heat exposure in ractice? nge -------------------------------------------------- echnet Mail List provided as a service by IPC using LISTSERV 15.0 o unsubscribe, send a message to [log in to unmask] with following text in he BODY (NOT the subject field): SIGNOFF Technet o temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) o receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest earch the archives of previous posts at: http://listserv.ipc.org/archives lease visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for dditional information, or contact Keach Sasamori at [log in to unmask] or 47-615-7100 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 -----------------------------------------------------