Electronics Forum | Sun Dec 09 22:54:20 EST 2001 | dburr
It sound you have already discovered to root cause, flux entrapment in the via holes. Short of changing the desing, here are sone suggestions. The main thing is you have to dry out the via holes of the wet flux. Some things to try are: slow down t
Electronics Forum | Mon Dec 10 16:44:51 EST 2001 | davef
Good for you!!! Similar to Steve's comments ... 1. NON-WETTING DEFECT: Yes. Your Lonco is a �stand and deliver� flux. Not some limp wrested impersonation of a flux like most nc fluxes. Without speculating about �incompatability�, recognize that
Electronics Forum | Wed Mar 20 20:02:06 EST 2002 | davef
Surfactant. A synthetic detergent made from petrochemicals that lowers the surface tension of water and allows better cleaning in small spaces. Do you have a cleaning issue that requires you to use a surfactant? If so, be aware that you must clean
Electronics Forum | Mon May 20 21:12:54 EDT 2002 | ianchan
xzinxzin, de' process engineer, Hi mate, as an active member of "that other subbie" currently successful in getting acceptable wetting for that MLF, i am not in a favourable position to advise you in process control. hope you can understand this po
Electronics Forum | Wed Jun 12 08:24:03 EDT 2002 | davef
Tough. 0402 capacitors are more prone to tomb stoning than resistors. Tailor your process to the 0402 and let the other stuff fall where it falls. Search the fine SMTnet archives for discussion on tomb stoning. Consider: * Changing paste. * Apply
Electronics Forum | Thu Aug 01 12:55:41 EDT 2002 | johnw
we run the paste in both air and n2 depending on customer requirements again it run's fairly well in both. Some people say it's better sme say it doesn't make a bit of difference, I'm somewhere in between at the moment. I definately think there's imp
Electronics Forum | Wed Sep 18 22:53:24 EDT 2002 | davef
Please give us background on your situation, so that we can focus on the specifics, for instance: * This is a bare board problem, correct? Then, this contamination causes what the problems in your process? * What is the type [ie, FR4, CEM1, etc] of
Electronics Forum | Mon Sep 23 03:12:01 EDT 2002 | surachai
We encounter this problem also , I know that it 's acceptable per IPC standard but sometime it fail at ICT and FCT , then this problem should be prevent , we found it with QFP 16 mil pitch and the defect looklike negative wetting at the front of lead
Electronics Forum | Fri Oct 18 17:47:37 EDT 2002 | russ
What is the determination of poor soldering fails pull test, non-wetting, visual)? I have never heard of an SMT component that has leads higher than the body of the component. Refer to IPC 782 3.6.1.7 it provide the guidelines for SMT standoff heig
Electronics Forum | Tue Oct 22 15:32:09 EDT 2002 | ruppertg125
We are a military contractor and need to build to IPC610 class3. We are receiving many parts with palladium leads and currently use a No-clean solder paste. We have evaluated OA pastes with very little improvements. Without a touch up of all leads th
.gif)
