Hi Lee, First, how would you reflow a leaded BGA at LF temperatures without popping it? Then, the closest paper I have, coming your way in a second, is something from AIM saying that Pb will deposit at the points that cool the slowest, making brittle Pb pockets at the interface with the pad. Regards, Ioan Tempea, ing. Ingénieur Principal de Fabrication / Senior Manufacturing Engineer T | 450.967.7100 ext.244 E | [log in to unmask] W | www.digico.cc N'imprimer que si nécessaire - Print only if you must ------Original Message------ From: Lee Whiteman Sender: TechNet To: [log in to unmask] Subject: [TN] SnPb SOLDER BALLS WITH SAC SOLDER PASTE Sent: Dec 8, 2009 08:17 I know about the problems with soldering BGAs with SAC solder balls and SnPb solder paste and read plenty of papers pro and con. I heard about a report where if you solder BGAs with SnPb solder balls using SAC solder paste, the resulting solder joint will be unreliable. Has anyone heard of anything like that? If there are any cross-sections or papers that you can share with me, that would be great. Thanks again. Lee Whiteman, PMP Senior Member Engineering Staff L-3 Communications East Telephone: (856) 338-3508 FAX: (856) 338-2906 E-Mail: [log in to unmask] SENTEC 11 Canadian Road, Unit 7. Scarborough, ON M1R 5G1 Tel: (416) 899-1882 Fax: (905) 882-8812 www.sentec.ca --------------------------------------------------- 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 -----------------------------------------------------