Gerald, I suspect ACI Technologies has some data on this, though I don't have it at my fingertips. Try Fred Verdi: [log in to unmask] Li, Poranki, Srihari et al at SUNY Binghamton coauthored a paper with a couple of Sanmina-SCI folks at SMTAI in 2009: "Reliability Assessment of Reballed BGAs." A quick Google search suggests lots of places have decided to "borrow" it from SMTA ( :-) ) Here's one: ftp://wilbur.eng.auburn.edu/pub/zhangj2/experiment%20paper/reliability%2 0assessment%20of%20reballed%20BGAs.pdf There also are described methods that avoid some of the heat cycles associated with desoldering and resoldering. BEST has written about its manual wicking braid process, which eliminates one of the thermal excursions: http://circuitsassembly.com/cms/component/content/article/201/8397-bga-r eballing-reliability And our (TechNet, I mean) own Dean Stadem has written about a laser method that avoids two thermal excursions: http://circuitsassembly.com/cms/component/content/article/199/7193-solde r-ball-attachment-using-laser-soldering Best, Mike Mike Buetow Circuits Assembly w/m 617-327-4702 >>> The CIRCUITS ASSEMBLY EMS Directory -- over 2,100 listings, in Excel www.circuitsassembly.com/dems <<< Follow me on Twitter: twitter.com/mikebuetow -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Gerald Bogert Sent: Wednesday, June 01, 2011 3:22 PM To: [log in to unmask] Subject: [TN] Re-balling BGAs June 1, 2011 Anyone have technical data to support (or not support) re-balling of BGAs to change from SAC balls to Pb balls??? My understanding is that because of the extra heat cycle involved, BGA manufacturers may not stand behind their part warranty if re-balling is done. I also seem to recall a technical poster or paper presented at IPC several years ago which I believe indicated a reduction in reliability of the part if it is re-balled. Also seems to me that if one were to re-ball a BGA, this would be a repair and not a reqork process and as such may require specific customer approval. ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________ --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 16.0 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 For additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________ --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 16.0 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 For additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------