Electronics Forum | Fri Mar 28 09:44:11 EST 2003 | Claude_Couture
Your preheat temp seems excessive, what kind of solder paste do you use. can you try a max preheat temp of 140 degC? The reason for this is to let the solvents in the paste evaporate while keeping the activation of the flux for the very last moment b
Electronics Forum | Fri Mar 28 21:37:11 EST 2003 | MA/NY DDave
Hi Are all the other solder joints for the other components other than the MELF not having a problem. That is what you said, yet I wanted to check?? To say a less twisted way is this only with the MELFs and is it with all the MELFs?? If you have
Electronics Forum | Sat Mar 29 08:42:25 EST 2003 | davef
YiEng, MA/NY DDave There are numerous package types that now fall under the rubric of land grid. Land grid devices [ie, BCC�, LGA, QFN, MicroLeadFrame�, etc] are essentially BGA devices with the balls removed and with no solder on the pads. General
Electronics Forum | Mon Mar 31 01:20:42 EST 2003 | Bryan Sheh
I agree that we should bake the pcb at higher temp and for longer time.for example...95--115c for at least 4 hours. also,keep the temp from 150--170c ,60-90 seconds while preheating. completely keep the moisture and volitales out of pcb and solder pa
Electronics Forum | Mon Apr 07 04:33:43 EDT 2003 | Neil
Iman, How long after washing the boards do you process them? Are there any vias or Micro vias on any of the pads you see the blow holes on? A possible cause of a blow hole in a solder fillet or PCB is the escaping of Moisture under extreme temps. Th
Electronics Forum | Wed May 24 16:13:43 EDT 2006 | two cents
Just maybe this new diet for the guru will burn a new orifice between his cheeks which may enable him to spew his rational more clearly. His current blowhole does not seem to be working.....RLM, there may be a decision by Tyco soon to produce 0201/04
Electronics Forum | Tue Aug 28 15:13:17 EDT 2007 | rgduval
Lead-free? White-tin finish? Even if it's not, it sounds like a moisture/contamination issue. If your boards must sit in stock between reflow/wave, consider giving them an alcohol bath to clean up any contamination, and a good baking to remove any
Electronics Forum | Thu Sep 06 16:58:40 EDT 2007 | gregoryyork
are you sure it isnt down to an hygroscopic contaminant causing the problem.I've only ever seen it once or twice in gold,really quite unusual.Its not too much gold brightner or similar residue.If it can be cleaned off then it shouldnt be there so it
Electronics Forum | Thu Sep 27 10:40:46 EDT 2007 | rgduval
Joris, Yep, very common to have those small blow holes in lead-free alloys. We used to get them very consistently on white-tin finished boards, and less frequently with gold finished boards, for what ever that is worth. IPC-610 actually allows t
Electronics Forum | Thu Jan 13 17:46:04 EST 2011 | davef
We've never seen the defect that you describe, but in wave soldering-land blowholes usually are caused by moisture in the board that out-gasses through the too thin plating of through holes. * Bandaid fix: bake the boards * Long-term fix: Obtain boar
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