Electronics Forum | Fri Oct 26 09:38:57 EDT 2007 | slthomas
Rather than go into detail here, try googling "classic reflow profiling". One of the guys at ECD (a thermal profiler manufacturer) wrote a pretty decent article that covers most if not all of it. You DO have a profiler, don't you, or an oven with
Electronics Forum | Thu Oct 25 11:29:04 EDT 2007 | ck_the_flip
Forget all the bickering and semantics. EVERYONE IS RIGHT!! ...but then again, in soldering, there IS no right, wrong, or indifferent... just blame. :-) Soldering is, after all, the most difficult process with the most opportunities for defects.
Electronics Forum | Wed May 19 07:38:42 EDT 2004 | Bob L.
I'm trying to help one of our remote sites solve a problem with a warped PBGA. The corners are lifted, creating columnar joints and the central balls are sometimes shorting. I've verified that it's not popcorning and I've got samples going to the l
Electronics Forum | Wed May 16 18:09:15 EDT 2007 | johnwnz
It always surprises me how many variations there are for profiling and controlling your ovens, and the thing is most of them are fairly valid. Here's yet another option: Your board profile needs to be specific, 2 boards can look identical but have ve
Electronics Forum | Fri Sep 21 10:44:34 EDT 2001 | slthomas
You can, and for small parts you probably won't see much difference between body temp. and lead temp. For QFPs or PLCCs there will be a much greater delta, though. I'd be more concerned with the small surface area you're making contact on (spherica
Electronics Forum | Sat Sep 19 09:52:09 EDT 2009 | profilingguru
Before you rule out the profile, did you run an actual profile of the board or run machine characterization? How old are your TCs? Have you run them more than a half dozen times? Is your profiler calibrated. In my experience making a living of pr
Electronics Forum | Wed Mar 24 10:04:09 EST 2004 | Marc Apell
183C, 60 +- 15 seconds). The quesiton to use a straight ramp or soak profile comes down to the product your are soldering. The key is to get the whole assembly at the same peak temp (minimized delta) and same TAL for effective formation of the so
Electronics Forum | Tue Sep 22 08:35:47 EDT 2009 | cman
Did you try pre-tinning your board on this suspect pad/s to see if it improved wetting/solderability prior to printing/SMT placement and reflow? Does the pad/s not soldering tie to a ground layer? I would connect a T/C to each pad of the same part an
Electronics Forum | Wed Sep 23 03:43:31 EDT 2009 | d0min0
hello, we are profiling with the pcb each day - results are very good with a small delta we made another test board with TC only in the problem places - same good result we tried 500-600 boards on 12 zone machine - zero defects while on standard 6
Electronics Forum | Tue Dec 28 12:55:16 EST 1999 | Justin Medernach
Greg, The best advice that I can give you is a PBGA will respond just like any other surface mount package. There may be a 5 degree delta between a PBGA 356 and a QFP208 but the two respond very similarly in the convection reflow environment. CBGAs
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