Rich,

Some of our boards have BGAs on both sides and we have successfully
reflowed them using standard smt practices. Occasionally, the heavier
BGAs on the 1st side reflowed must be partially staked in the corners
with an adhesive/underfill so they do not drop during 2nd side reflow.
Good luck

Best Regards,
-joe


-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Richard Olsen
Sent: Monday, May 05, 2008 11:29 AM
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

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