Electronics Forum | Tue Sep 22 06:07:02 EDT 1998 | jacqueline coia
need advice to point me in the correct direction for solution to the problem of unsoldered joints which look soldered under normal visual inspection, but when pull strength test is performed the leads are coming away from pad, no strong intermetallic
Electronics Forum | Mon Dec 17 11:20:12 EST 2001 | slthomas
Well, I was able to convince them we had a serious problem on the poorly reflowed boards without spending 2k on off- site analysis. Now all we have to do is sort out the ones that flowed well but had solder balls (looks like a damaged stencil prob
Electronics Forum | Wed Oct 03 21:28:38 EDT 2001 | davef
A firm grasp on the sublime. Mike points-out a good reason to describe Claude's problem as "open connections" or "open solder connections"? [Ahhh geez, wut a spoil spurt]
Electronics Forum | Wed Oct 03 17:08:32 EDT 2001 | davef
No comment or intent to appear critical on your particular situation, because you did the troubleshooting to determine the source of the problem, but �solder on the component lead, but not on the pad� is more often caused by a reflow profile that get
Electronics Forum | Wed Oct 03 09:56:51 EDT 2001 | Claude Tremblay
Hello everyone We have a QFP-308 (0.20" pitch)on a board and we have a lot of opens after reflow. We checked our profil by installing thermocouples on the pads of the component and everythings seems OK. We checked the coplanarity of the leads and it
Electronics Forum | Wed Oct 03 12:04:55 EDT 2001 | slthomas
When we found this to be a problem with some QFP 100's (.020" pitch, and our first experience with fine pitch - 48 of them on a 2-up panel), we saw that the solder was running up the leads during reflow and staying there, leaving the fillets thin or
Electronics Forum | Tue Apr 13 08:21:05 EDT 2010 | esca
Hi manchella, After ATC test, two different failure modes can be present: solder FATIGUE (into bulk) or BRITTLE INTERMETALLIC fracture. So, first you have to verify this. Moreover, which brand of SMT paste have you used ? The crack into solder joint
Electronics Forum | Sun Apr 11 11:39:52 EDT 2010 | manchella
When we have sent some of motherboards for reliability testing in a tird party laoratory. It is found that when Dye&Pry is done after 600 cycles of Thermal Cycling, in LGA socket only one of the corner solder joing had 100% type 3 crack. All other so
Electronics Forum | Tue Mar 09 17:52:05 EST 2004 | davef
Bryan: Comments are: * You're correct, solder paste formualtion is a major driver to voiding in BGA balls. * Voids are primarily process indicators. There is experimental evidence that voids retard crack propagation locally around the void on a temp
Electronics Forum | Thu Jan 19 13:28:19 EST 2012 | waveroom
Two pictures. Dark circles around solder joints. leaded solder, water soluble flux, selective soldering and seeing these dark lines circling around solder joints. Can not remove this either. Any idea what is making this occur??? See attached photos
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