Electronics Forum | Tue Mar 13 11:50:21 EST 2001 | gsmguru
Here is some general things I usually ask myself when having trouble with BGA's What type of BGA ? Pitch/Bump Dia etc. Smaller bumps sizes & tighter pitches require more attention. This also impacts stencil aperature design & paste selection. Was
Electronics Forum | Thu Feb 04 10:00:26 EST 1999 | Terry Burnette
| I'd like to find some technical papers on the reliability of reworked BGAs. If you know of any, please let me know. | | I have a concern about this because our current rework process does not apply solder paste to the pads prior to placing the pa
Electronics Forum | Mon Jan 16 12:19:55 EST 2006 | russ
Dave, Why does standoff height affect reliability?
Electronics Forum | Thu Sep 22 14:25:13 EDT 2011 | hegemon
Dave has stated the caveats well. I too have similar experience in reworking BGAs that mirrors your own. The only situation where I saw this as an issue, was in memory devices where a row of BGAs might share a commonm heatsink. In those cases the
Electronics Forum | Wed Apr 27 12:26:49 EDT 2005 | jdumont
Square you say? Wouldnt this give less paste deposition than a circle and basically reduce the standoff height the same as making the pad bigger? Would using a type 4 paste for this size stencil aperture (.013") be a good idea? Thanks JD
Electronics Forum | Tue Apr 13 19:50:53 EDT 2004 | Dreamsniper
Thanks. That's a good Idea. But question. Can a cleaning equipment (aqeous cleaner design for low standoff height parts) be able to clean my PCB given that the PCB sat in our production floor for 1 week prior to cleaning? Will the flux stick hard ont
Electronics Forum | Thu Mar 28 13:19:14 EDT 2019 | davef
There is no industry standard for BTC stand-off height. "IPC-7093A Design and Assembly Process Implementation for Bottom Termination SMT (BTC) Components" just finished "Final Draft for Industry Review" in December 2018. It mentions stand-off height
Electronics Forum | Mon Jun 19 09:47:23 EDT 2017 | georgetruitt
You have a lot to think about! What does the flux manufacturer recommend as far as specifics like water temp or pressure? Do they recommend high temp di-water a detergent or saponifier? Do you currently have a cleaning machine, batch cleaner or inl
Electronics Forum | Tue Mar 24 20:25:18 EDT 2009 | davef
It is very common to use low residue flux with low-standoff parts. On the other hand, sure you can clean under low-standoff parts. We've talked about this previously. Search the fine SMTnet Archives to find threads like: http://www.smtnet.com/Forums
Electronics Forum | Wed Dec 08 08:38:46 EST 2004 | davef
KS: You're correct. The standoff on a 1.00mm and 1.25mm BGA is high enough to allow cleaning. The standoff on 0.8mm BGA does not allow proper cleaning, even with saponifiers.
