Electronics Forum | Fri Nov 08 18:32:39 EST 2013 | hegemon
Dave is right, though apparently a bit grumpy today. What he's saying is that the ring de-wetting is a bad thing, and should have been called out by your lab. You might consider a lab change in the future. Some information about your processes, an
Electronics Forum | Wed Feb 12 22:02:47 EST 2014 | rober864
Has anyone ever encountered contaminants from the immersion silver process, whether it be from the board house or not...as it relates to conformal coating. The failure mode is severe de-wetting of acrylic conformal coating. All over solver resist, to
Electronics Forum | Mon Jun 05 17:37:51 EDT 2017 | stevezeva
Hi Zac, In looking at your photos, you may not be having a problem with your machine, but with the solderability of the PCB. I've zoomed in to an area that looks to me like the solder has de-wet from the pad. The leads appear like it almost has a fi
Electronics Forum | Mon Jun 05 18:45:07 EDT 2017 | zsoden
Hi Steve, I agree with your assessment, it would certainly seem like the pads are de-wetting. But what could be the cause of this? Contaminated solder? The boards are new out of vacuum sealed bags (with desiccant sachets), so I can't see it being the
Electronics Forum | Fri Jul 24 16:33:45 EDT 2015 | cnotebaert
You should be fine! best practice for a situation like this would be to run a solder sample, either flux it and run through wave, or screen print, don't place parts and run through reflow. look for proper wetting characteristics if you see de-wetting
Electronics Forum | Thu Mar 06 22:34:55 EST 2003 | davef
O' Connor: Are you saying that: * You solder fine in the areas where you print paste * You solder poorly in the areas where you don't print paste Aside from that, the gold on these pads seems to be less bright than previous lots. [if that's not it
Electronics Forum | Sat Mar 08 21:45:59 EST 2003 | MA/NY DDave
Hi The other thing the Ni does is to create a time barrier for the underlying copper (Cu) migration into the joint. Degradation still occurs yet it is slowed significantly. Diffusion Equations under, electonic current pressures across time, are inv
Electronics Forum | Mon Mar 10 15:20:41 EST 2003 | MA/NY DDave
Hi Well I don't have all the titles right handy, yet let me give a few places for you to check. All my books aren't exactly at my finger tips. Author: Tumalla (??spelling) He is now at Georgia Tech Author: Lasky, Seraphim Author: Ning-Cheng Lee or
Electronics Forum | Mon Jan 26 07:27:43 EST 2004 | loz
I have a product that has earthing/positioning holes, as they are to be used for earthing purposes they need to be free from conformal coating. This pcb is double sided. I have used spot/peelable mask to protect these holes. However when the conforma
Electronics Forum | Thu Aug 28 11:31:17 EDT 2008 | patrickbruneel
Matt solder mask finishes gives the widest process window in view of potential amount of residues when using No-Clean. Shiny (glass like) finishes are more sensitive to residues due to lower surface area compared to matt finish. If the shiny finish i
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