Steve's right and for those cases where it is an issue Loctite make a BGA cornerbonder that is liquid through first reflow, allows the part to self center then hardens and will hold the part in place during the second side reflow. Over cure to 230°C and it becomes brittle so rework is possible. -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Richard Olsen Sent: Monday, May 05, 2008 2:29 PM 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 -----------------------------------------------------