Electronics Forum | Wed Jan 09 13:39:48 EST 2008 | ck_the_flip
Mask finish is the #1 variable for micro-balling with wave and selective processes. The #2 variable is the Flux. There are some flux formulations out there who're known to have additives that virtually eliminate micro-balling. However, keep in min
Electronics Forum | Tue Jan 15 08:50:07 EST 2008 | ck_the_flip
Based on past, actual, hands-on experience, I have found that the PCB mask finish makes a HUGE difference in solder-balling. Glossy has different surface tension and peelback characteristics than matte finish (ie glossy sucks). http://circuitsassem
Electronics Forum | Tue Jan 15 13:16:25 EST 2008 | ck_the_flip
Yes, the previous "non-balling" flux was alcohol based, but very weak activity. We found it was worth the switch to water-based, to get prettier solder joints - but...at the expense of having to "brush off" solder balls on a couple of assemblies wit
Electronics Forum | Tue Jan 15 13:47:11 EST 2008 | realchunks
Yes, the mask finish is prolly the #1 contributor to solder balling. Seen it many times. It's not that it's cured or not, went down that path about 3 or 4 times as well. Different fluxes can help too. But also check your preheat. If your are get
Electronics Forum | Fri Jan 18 18:19:38 EST 2008 | arun2382
Is normal DI rinse cycle enough to wash away all residue after SMT assembly of high density substrate? This substrate would later be over molded to form MCM module package and I am seeing delamination in high density areas of the substrate at MSL3
Electronics Forum | Tue Mar 11 00:48:12 EDT 2008 | porferio
If your oven has the flux collection unit just like the Tamura oven, then you will not experience same as what you have shown on the picture. The only thing to do now is to clean and take out the flux. Also, please consider, flux accumolation depend
Electronics Forum | Fri Feb 01 11:02:51 EST 2008 | flipit
You could also try Wenesco and Air Vac. I have experience on the Air Vac PCBRM10 and PCBRM12. They work great. You have to make sure your nozzle or flow well is designed correctly. For 50 mil pitch and greater, they work well. If you have to rem
Electronics Forum | Fri Feb 15 11:23:44 EST 2008 | realchunks
Print material through stencil onto Plexi-glass and place Plexi onto your board. Sure, it may cause a little clean up but this where the metal meets the meat. Don't worry about ESD cause you have no component on the board yet (sorry Quality guys -
Electronics Forum | Wed Apr 30 07:33:12 EDT 2008 | davef
It's not acceptable to us. More importantly, you need to determine if it's acceptable to your customer. Recognize that your little IPA scrub does NOT remove the OA flux residues from the board. It mearly spreads them out across the board and under c
Electronics Forum | Tue May 20 16:27:34 EDT 2008 | vms
we buy a mpm and start to clean it, and find so much paste in it my help says did they put any paste on the boards or just throw it inside the machine. Some operators waste so much paste and the engineers ask how much did we use, they should be aski
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