Hi Rich!

You shouldn't have to go through all that. Most all BGA's will develop
enough surface tension to stay put during double-sided reflow. Only ones
that I might be worried about are ceramic BGA's or ones with big honking
heatsinks on them.

There's even some studies out there that BGA's that have gone through a
double-reflow cycle are more reliable because they have an increased
stand-off height because the solder joints have elongated during the
second reflow.

Steve

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Richard Olsen
Sent: Monday, May 05, 2008 1:29 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
-----------------------------------------------------