Electronics Forum | Sat Oct 08 11:57:58 EDT 2016 | davef
A friend in the contract coating business said: "... ask why the wire is [teflon] coated in the first place, as only the solder joints should be coated in this situation as the flexing/bending of the wires will cause the coating to crack and flake of
Electronics Forum | Tue Jan 13 16:40:03 EST 2004 | Jacob Lacourse
Hi folks, I have a conformal coating application where I need the coating to be UV stable for a number of years without any crazing or cracking of the coating. I have looked for such a coating and have come up empty handed. Much of the circuit boar
Electronics Forum | Thu Oct 01 07:03:55 EDT 2009 | davef
We doubt that Humiseal 1A33 is causing opens in your assemblies. We'd guess the opens occur earlier in the process, but are not hard failures. So, you pass your tests. When applied, the conformal coat flows into the gap in the ball crack and insulate
Electronics Forum | Mon Oct 05 04:55:42 EDT 2009 | pengliang
we suggest as below : the first : check the soldering(solder ball and pad) by X-ray ; second: to do dye analyse (note:pls confrm is there have crack )
Electronics Forum | Thu Oct 08 01:07:46 EDT 2009 | tpappano
I have used 1A33 for many years with excellent results on through-hole pcbs in equipment subjected to very hot and very cold environments. Because 1A33 continues to harden with time, I assumed it would simply not be usable on smt boards, cracking t
Electronics Forum | Fri Jul 06 10:08:21 EDT 2007 | blnorman
The coating thickness is more a property of the individual coating itself. The 0.03 - 0.13 is based on average properties of acrylics in general. It's like trying to pour 3 mils of motor oil on a table. The material will find it's own thickness.
Electronics Forum | Tue Aug 30 09:49:24 EDT 2011 | blnorman
Guess the better question is why are the resistors and FETs heating to the degree that they discolored the coating? If the coating is discolored, I'd be concerned with the possibility of cracking as dave mentioned. Cracks defeat the purpose of the
Electronics Forum | Thu Aug 20 07:11:25 EDT 2020 | sssamw
What your said looks like a acrylic coating thermal expansion causes small solder joint crack. Do you cure coating with heating, or heating after curing? Solder joint crack while you see resistor and QFN trouble? Clear and detail description of your
Electronics Forum | Mon Aug 10 12:58:04 EDT 2020 | SMTA-64386637
We have found Acrylic CC under QFNs is a failure mechanism in thermal cycling. The coating acts as a wedge and causes solder joint cracks. We do not coat QFNs. To enhance reliability we have the vias plugged with solder mask. This eliminates some
Electronics Forum | Mon Mar 08 11:54:06 EST 2004 | Wayne Smith
Currently experiencing a problem where the plastic molded bodies of tantalum capacitors are cracking during my SMT processing. Caught after our conformal coating process. I don't know where in the process they cracked. Currently running an exper
