Electronics Forum | Mon Jun 25 11:33:20 EDT 2012 | davef
The immersion silver is an active surface and readily combines with sulfur from the environment. Silver sulfide tarnishes the surface and creates doubt about the integrity of the finish at inspection. [uyemura.com/library-4.htm] Your customer's boar
Electronics Forum | Mon Jun 25 03:52:24 EDT 2012 | awtm
Our Customer had detected tarnished pad on ImAg PCBA and had conducted several SEM-EDX test at the soldermask below some of the chip resistors. High concentration of sulfur was found and it can be significantly reduced after further chemical cleaned
Electronics Forum | Sun Sep 21 10:55:52 EDT 2008 | vladig
As long as the surface is solderable, you should be fine. Silver tarnish a well0-known thing. Make sure, though, there is no sulfur (S) "around". Regards, Vlad
Electronics Forum | Thu Jan 17 14:52:17 EST 2008 | gnath
All, Can someone help find a source for purchasing interleaving/packaging paper for Immersion Silver boards (sulfur free + ph neutral ..). Thank you!
Electronics Forum | Mon Aug 04 12:38:25 EDT 2008 | blnorman
Avoid cardboard boxes as well. They are sulfur bearers, and silver has an affinity to form silver sulfide.
Electronics Forum | Wed Sep 03 11:42:21 EDT 2008 | robinj
If the tarnish is really dark, it is very difficult to remove. Since it is yellowish it is only in the early stages. Replating will definitely work. I have used sulfuric acid based cleaners to remove this yellowish color. But rinse well and dry quick
Electronics Forum | Mon Apr 26 14:40:07 EDT 2010 | blnorman
We had one product that used immersion silver plating. There were a couple of instances where we saw tarnishing, and elemental analysis confirmed the presence of sulfur. These boards did have the anti-tarnish sheets between boards, but somehow they
Electronics Forum | Wed Aug 27 18:28:29 EDT 2008 | blnorman
We have an immersion silver board that has a brown discoloration after processing. It's not flux residue, that normally doesn't cause this condition. Elemental analysis shows less than 1% sulfur, and I thought silver sulfide is more a black color.
Electronics Forum | Wed Feb 21 19:55:12 EST 2001 | davef
References on corrosion are: * "ASM Corrosion Handbook No. 13" [0871700077]. * "Electronic Packaging and Corrosion" ME Nicholson [0871702916]. Please explain how you determined that you have silver-sulfide contamination. Where is the silver comin
Electronics Forum | Mon Feb 26 09:36:08 EST 2001 | blnorman
ASTM E 443 is a test for sulfur by Oxygen Flask Combustion. Other instruments will detect sulfur (I assume a SEM with EDS capability will pick up the sulfur). We had an addition cure silicone potting compound inhibition problem last year that was t
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