Electronics Forum | Sat Feb 03 08:56:09 EST 2007 | davef
Multiple leads in a single PTH is prohibited because: * Need to be able to remove and replace any component without impacting another. * Oversized hole required will result in increased solder defects and could also lead to flux entrapment. * Counte
Electronics Forum | Tue Feb 06 23:01:44 EST 2007 | Wayne
The QFN is found to have contact problem during FCT. The paste that I am currently using is SnPb 63/37 water soluble paste. Is it because of water soluble paste? (unable to clean after reflow process as QFN is entrapped by paste/flux) Should we use
Electronics Forum | Tue Nov 13 12:25:12 EST 2007 | gradloff
I have a thick board with ground planes that will be soldered by hand with a mildly active solder/flux. X-ray confirmed that solder was added to the top of the joint causing a void between the bottom and top solder joint. Other than the mildly acti
Electronics Forum | Wed Jan 23 18:15:33 EST 2008 | gsala
Hi, are you dealing with Leaded or Lead Free P-BGA ? soldering by Lead or Lead Free paste ? Any way, some time, bridges can be caused by moisture entrapped in the BGA body. Make sure if is respected the correct MSL's allowed flore exposure time, ot
Electronics Forum | Mon Feb 25 12:21:16 EST 2008 | stevek
Rather than having the artwork cover the via as with tenting dry film, and letting the mask do what it will, the preferred way is to do a second op silk screen with something like SR1000 just in the vias themselves to plug them. This doesn't always
Electronics Forum | Fri Oct 24 06:55:48 EDT 2008 | clampron
Good Morning WS, If you experieced the solder balls after reflow of a bare board through the oven, then the source of the solder is either the oven or the board. I have had boards with untented via's that were HASL'd that had entrapped solder and fl
Electronics Forum | Mon Dec 29 09:10:22 EST 2008 | stepheniii
It takes time for the moisture to penetrate into the body. I think the 5 years of ambient would be more the culprit than washing the boards. Especially since you are baking them after wash. Get a few of the ICs and put them loose on a board and put
Electronics Forum | Fri Jan 02 08:10:18 EST 2009 | childs
Thanks for the reply Stephen. The time factor sounds logical for moisture invasion during cleaning, probably why there's no articles showing concern about the process. I did try experimenting with some samples and believe it or not could not dupli
Electronics Forum | Tue May 11 14:17:55 EDT 2010 | isd_jwendell
Getting the paste from the jar and into the cartridge without entrapping air can be difficult. Can you not just transfer the 500g jar into smaller working jars? This way you can keep the bulk of your paste refrigerated until needed. Air is not your f
Electronics Forum | Mon Jul 04 14:21:14 EDT 2011 | davef
The three primary causes for bubble generation in solvent-based coatings are: * Air entrapment * Solvent flash-off * Curing the coating too quickly Tell us more about your process including: * When you first notice the bubbles * Extent of the probl
