Electronics Forum | Wed Sep 26 12:16:44 EDT 2012 | bwjm
Hi Guys,recently i am facing an issue. Refer to the attached photo. This PCB is high RF speed, gold immersion single layer. After reflow, my solder seems to have black stains on it. I tried with SAC305 paste water soluble and no-clean, both results a
Electronics Forum | Fri Jan 25 14:20:31 EST 2013 | jorge_quijano
Hi there, I have a new product today, after reflow oven I've seen a black stain coming from various holes, they can be cleaned with a tissue but some of the contaminant remains inside, we are using Sn63Pb37, the stains are far from soldering areas, t
Electronics Forum | Thu Feb 14 17:40:34 EST 2013 | jorge_quijano
PCB Supplier made an EDX anaysis, the found a chemical trapped in the holes, and some burnt burrs, according to what they say this stains are over the solder mask & silk, so they do not affect functionality.
Electronics Forum | Fri Jan 25 19:01:35 EST 2013 | hegemon
My first guess is that the plating in the barrel (via) has failed and allowed laminate/epoxy egress into the barrel and out to the surface of the board. Just a guess based on the picture.... 'hege
Electronics Forum | Fri Feb 23 03:16:40 EST 2001 | Cosine Theta
Wow! It really works. I used Sprite instead of the hussle of melting suger. I did not use Coke as it leave behind a black stain. Now, I need to convince the facility people it will not attract ants. Or maybe it will be process inherant that ants wil
Electronics Forum | Fri Feb 22 16:32:56 EST 2013 | davef
Jorge: I took this total posting to several fabs at IPC APEX. None was satisfied with the answers you receive from your supplier or the Forum members. They suggested that you get your board analyzed. They were surprised that your supplier didn't in
Electronics Forum | Sat Jan 26 21:33:39 EST 2013 | sarason
Looks like you have a carbon black process that isn't quite plating to completion, pin prick size holes have remained in the plating. When dipped in an etchant (ie any acid or H2O) the holes grow and they leak carbon. This may be more of a problem th
Electronics Forum | Mon Apr 14 20:13:40 EDT 2014 | davef
So, someone is going to get a chance to buy a nice and shiny oven, eh? Summary from my notes of old thread on SMTnet: Some people melt sugar and use that solution to clean cooked-on flux residue. Dissolve sugar into warm water, spray it on the area t
Electronics Forum | Fri Apr 16 13:22:48 EDT 2010 | stepheniii
Have you tried running a few bare boards through the oven? If there is no flux on them and you still get the "stains" then I think you can eliminate the flux as the cuprit. And I've been told that white is the second most difficult solder mask colou
Electronics Forum | Sun Dec 13 23:34:42 EST 2015 | chemicallab
We supply the latest black and white notes, automatic ssd, universal chemicals, activating powders and specialize in cleaning all types of defaced notes, black notes, anti-breeze, stamped, marked or stained currency. We melt and re-activate frozen ch
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