Electronics Forum | Thu Aug 30 06:57:56 EDT 2007 | simonalden
Hi we are currently experiencing a problem with solder contamination of the gold contact pads on our pcbs following the reflow process, possibly through sputtering. We have been advise that this can be caused due to the pcbs being humid or due to th
Electronics Forum | Tue Jan 20 10:00:25 EST 2015 | TM
Hello We are currently cleaning stencils from both process (PbSn and lead free) in the same cleaning machine. A customer is concerned about cross contamination of lead between stencils. Is there any test kit or tool that you can suggest to test the
Electronics Forum | Tue Jan 20 16:26:59 EST 2015 | emeto
There are a lot of lead testers out there. Just google it. I personally don't think you will find anything wrong, but for the pleasure of your customers buy one and prove it. I would also check the lead on the squeegees of your stencil printers and t
Electronics Forum | Sat Aug 11 13:37:02 EDT 2007 | shing
I am a fresh SMT engineer. I am now facing a problems, solder contamination on Golden Finger nearly about 1 year. I don't know what going on. I have checked the cleaningness of stencil, solder paste handling,IR re-flow profile and even PCB surface
Electronics Forum | Fri Oct 14 14:09:19 EDT 2005 | bschreiber
Your problem is not the 0.4 pitch. Your problem is the manual cleaning. Manual cleaning will only remove the solder paste from the surface of the stencil. What's more, manual cleaning will force additional contamination into the 0.4 pitch apertures
Electronics Forum | Fri Jul 13 17:00:34 EDT 2007 | jmelson
Oh, sure, on fine-pitch parts you need a microscope or at least a good magnifier. But, OK, you have some kind of contamination. Solder is one thing, but where are these stainless, aluminum and copper particles coming from? Stainless makes me think
Electronics Forum | Mon Nov 13 14:58:56 EST 2017 | davef
Determine the origin of the solder * Sloppy paste printing technique * Lax stencil underside cleaning practices * Sloppy misprint cleaning practices * Poor part placement practices creating solder balls * Poor material control allowing solder p
Electronics Forum | Fri Jul 13 16:45:37 EDT 2007 | losersk8er
The Contamination has proven to be pretty random, lots of stainless steel though in fact two cases in the past two days. As far as I know all machinery is cleaned regularly as well, even the stencil washer itself. The boards we make are 90% (at l
Electronics Forum | Thu Mar 29 18:14:19 EST 2001 | kerryn
Hi Dave, I looked into the South Coast Air Quality Management District Clean Air Solvent Certification when I was having my problems with VOCs. The problem with the SCAQMD CAS Certification is that it only certifies chemicals as they are found in t
Electronics Forum | Mon Oct 15 13:41:49 EDT 2001 | bschreiber
Hi Dale, I have copies of the articles of which Mike references. If you need copies for support, contact me at: bill@smartsonic.com. Rinsing should be done by ultrasonics also. Spray in atmosphere systems will not penetrate into the same tight ar
