There is an article I produced for Global SMT magazine that lists many of the potential issues to consider. http://www.globalsmt.net/content/view/1791/68/ Many thanks Bob Willis 2 Fourth Ave, Chelmsford, Essex, CM1 4HA England Tel: (44) 1245 351502 Fax: (44) 1245 496123 Mobile: 07860 775858 www.ASKbobwillis.com Book your place on Bob's "Step by Step Failure Analysis Workshop" 14th May www.ASKbobwillis.com/faworkshops.pdf New "Printed Board Inspection & Quality Control" 3 July www.ASKbobwillis.com/PCBworkshop.pdf -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Richard Olsen Sent: 05 May 2008 19:29 To: [log in to unmask] Subject: [TN] BGAs on opposing sides Hello, I have a board before me with multiple BGA's on both sides. In some places they oppose each other. Does anyone have any manufacturing ideas for soldering the BGA's? One I have heard is to mask the first side BGA's and heat through the mask, BGA, board and finally the pads of the second BGA, finally removing the mask when done. Thanks, Rich Richard Olsen Quality Manager/ Sales & Customer Service RNB Enterprises 17816 North 25th Avenue Phoenix Arizona 85023-2108 Tel - 602-889-3463 Cel - 602-740-2244 Fax - 602-863-2274 Toll Free (800)-270-7585 www.rnbent.com --------------------------------------------------- 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 -----------------------------------------------------