Soldering SnPb solderballs with SnAgCu works. The problem of the maximum temperature can be overcome by vapour phase soldering at 240°C ( even 230°C) and prior drying of the components. About reliability there are various reports. Woodrow from Boeing claimed that PB contamination in SnAgCu solder joints is even beneficial. Best regards Guenter >-----Ursprüngliche Nachricht----- >Von: TechNet [mailto:[log in to unmask]] Im Auftrag von Iven, Jowan >Gesendet: Mittwoch, 9. Dezember 2009 09:24 >An: [log in to unmask] >Betreff: Re: [TN] SnPb SOLDER BALLS WITH SAC SOLDER PASTE > >I agree with you Ioan, > >Most leaded bga's have maximum temperature specifications below the >lead-free process. >So why worry about the balls when the bga is electrically damaged? > > >Regards > >Jowan Iven >Process Engineer >Neways Advanced Applications > > > >-----Original Message----- >From: TechNet [mailto:[log in to unmask]] On Behalf Of Ioan Tempea >Sent: Tuesday, December 08, 2009 2:54 PM >To: [log in to unmask] >Subject: Re: SnPb SOLDER BALLS WITH SAC SOLDER PASTE > >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 >----------------------------------------------------- > > > >This e-mail and any attachment is confidential and may be legally >privileged or otherwise protected from disclosure. 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Neways Electronics NV is not responsible for the improper >or incomplete transmission of any e-mail, or for any delay in its >receipt. > > >--------------------------------------------------- >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 >-----------------------------------------------------