Electronics Forum | Fri Aug 22 09:07:22 EDT 2008 | blnorman
Sulfur is probably the culprit. Board supplier should be providing boards with anti-tarnish sheets between the individual boards. Also, cardboard is a major source of sulfur and so boards should not be shipped in cardboard.
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.
ASYMTEK Products | Nordson Electronics Solutions | https://www.nordson.com/de-DE/divisions/dage/woerkzeage-and-materialian/3m
Related Information Data Sheets 3M Novec 1700 3M Novec 7100 MSDS 3M Novec 1700 EGC MSDS 3M Novec 7100 HFE General Information Report - 3M Novec 1700 and 1702 Electronic Grade Coatings Information
Imagineering, Inc. | https://www.pcbnet.com/blog/understanding-the-pcb-fabrication-process-from-design-to-delivery/
) is a medium that connects electronic components in a controlled manner. It has a laminated sandwich structure such that each layer contains circuit traces and other features etched onto sheets of copper
