Electronics Forum | Thu Aug 27 08:34:50 EDT 2009 | floydf
I am having trouble with little air bubbles in my conformal coat. It ranges from a few pin sized bubble to looking like spit. We are using Dow 2620 silicone conformal coat applied with a PVA sprayer machine. The conformal coat comes in bladder bags t
Electronics Forum | Fri Oct 09 16:07:30 EDT 2009 | dlabelle
We use Dow 2620 silicone conformal coat applied with PVA1000 sprayer machine. If used on a daily bases, we have no problem. If we let the machine sit idle for over a week, we will get bubbles in the conformal coating. Sometimes, purging the line w
Electronics Forum | Tue Mar 14 20:42:24 EDT 2023 | stephendo
In a previous lifetime, we had a selective solder machine where I would see solder splashes in the roof of it. I thought someone might have been putting the solder extremely high. But when it was melting there would be bubbles that burst. The manufac
Electronics Forum | Wed Sep 02 11:36:22 EDT 2009 | kpm135
Is this an established process that is just now exhibiting these problems, or is this a brand new process you're just setting up? What is the rest of your process like? What is done to the boards before you coat them? Water washed? Solvent washed? Sa
Electronics Forum | Thu Apr 17 16:43:09 EDT 2003 | davef
Background: * Bulwith, Ronald A., �Failure Analysis of Solder Joints�, �Insulation/Circuits� magazine, February 1978 * Banks, Donald R., et al., �The Effects of Solder Joint Voiding on Plastic Ball Grid Array Reliability�, Proceedings of the Technica
Electronics Forum | Wed Oct 30 16:05:08 EST 2002 | msimkin
Hi, I have received a report form a board supplier, analysing the reuslts form non wetting problems we have been expereincing with their boards. I assumed it was due to the gold layer being too thin, thus allowing the nicklel layer to be exposed and
Electronics Forum | Mon Mar 27 21:09:29 EST 2006 | ms
Thanks Dave I'm not convinced the air is necessarily in the paste from manufacture - suspicious that it may be folding in during the change in direction of the print cycle - or as the paste travels across apertures. It is not necessarily in the fir
Electronics Forum | Sun Mar 26 19:02:05 EST 2006 | ms
Hi We are running automatic stencil printers, open squeegees, stainless stencil, stainless blades, print speed 25-30mm/sec. We have a frustrating consistency issue printing .37x.3mm apertures on a 45pin LGA (11 pads each side, 1 large ground in mid
Electronics Forum | Thu Oct 31 11:08:12 EST 2002 | soupatech
Being very new to SMT I won't assume I know what the problem is but.... I had lots of air pockets in solder joints, 95% of the boards. Everyone I spoke to thought it was a problem with my process but when one board was sent to our supplier they admi
Electronics Forum | Thu May 09 17:28:33 EDT 2002 | davef
There is no IPC specification, nor should there be. * There are just too many peculiarities in the design and fabrication of PWB. * The issue is not defining how to store boards. The issue setting expectation for reliable products and allowing you th
