We start with a profile that emulates the reflow profile- ramp rates
about 1 C/sec, peak temp 205 C with a time above reflow of 45-60sec. In
cases of large OMPAC packages we cut back on the soak section of the
profile to help reduce dimensional warpage on some packages (we getting
either shorts or opens at the corners of the packages)

________________________________

From: TechNet [mailto:[log in to unmask]] On Behalf Of Alan Kreplick
Sent: Wednesday, December 07, 2005 4:35 PM
To: [log in to unmask]
Subject: [TN] BGA Rework Max temp & time above Liquidus



Hello Technetters: 

Quick survey/question: For BGA removal/replacement (SN63), what are
people using for max solder joint temperature and it's associated time
above liquidus. 

Copying the reflow profile guidelines?  I've previously went about 5-10C
less than the reflow profile guidelines to prevent overheating of the
part/case and to attempt to prevent any BGA's on the bottom-side from
re-reflowing, but now I'm second guessing myself. 

Thanks in advance.

          
        Al Kreplick
Sr. Manufacturing Engineer
Land Combat/Precision Strike/Air to Air
978.470.9931
978.470.4307 fax
978-245-1702 pager
[log in to unmask] <mailto:[log in to unmask]>  


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