Electronics Forum | Fri Jan 16 06:53:33 EST 2009 | stevewilde
I am using Humiseal 1B31 conformal coating and xylene mix on a PVA coating machine. Bubbles are appearing between the pins of LCCs mainly and bubbling is worse when put through the IR oven. Does anyone have any suggestions or tips to elliminate this
Electronics Forum | Fri Jan 16 10:54:21 EST 2009 | realchunks
Hi Steve, Make sure your spray head is all the way down. If so, try slowing your rate of speed over the part. Which head are you using to coat this part?
Electronics Forum | Mon Jan 19 09:10:17 EST 2009 | stevewilde
Thank you for all of the advice. I am using the extended spray for these cards. Humiseal have recommended using their own thinners 600 instead, so will run some trials with this and also the humiseal pre-mixed material (at the moment we mix our ow
Electronics Forum | Tue Feb 03 11:42:54 EST 2009 | lmartenson
We use PVA and I have had bubbles that came from the pressure in the pressure pot being to high. Also the material filter was slightly clogged. I'm not sure of your setup hope this helps.
Electronics Forum | Tue Feb 03 13:47:59 EST 2009 | grics
I would also suggest looking at your ramp rate in the cure oven. We noticed that accelerated heating increased the "gas out" of the solvent. We run 1A33 and and do not exceed a .5/degC ramp rate.
Electronics Forum | Fri Jan 16 14:35:07 EST 2009 | realchunks
Had the same problem with boards from China. Try using Scotch Brite medium duty pad. It worked for us.
Electronics Forum | Fri Jan 16 15:34:56 EST 2009 | black5629
Thanks, we tried using some very fine sand paper and did improve. Any one know of any chemical that would work.
Electronics Forum | Wed Jan 21 06:09:37 EST 2009 | gregoryyork
Try a typical Stencil Cleaner with Glycol ether mix as probably solder resist residue depositing back onto the pads during levelling. Cheers Greg
Electronics Forum | Thu Jan 22 09:59:18 EST 2009 | jeffcali
try making your boards in the USA. There's better QC, and if any problems do happen, they can be solved easily and quickly saving you money in the run. You get what you pay for. Good luck.
Electronics Forum | Sat Jan 17 17:42:07 EST 2009 | viresh
what is the impact if a solder paste is used after 24 hours after tawing time
