Electronics Forum | Tue Jul 13 16:35:25 EDT 2004 | Richard
Sounds like your Si plalladium finish has oxide on it from the firing or sitting around too long. I used to assemble LTCC and have had plenty of dealings with this matter. The best and easiest is to get an active type flux and solder paste. AIM makes
Electronics Forum | Thu Apr 20 17:16:02 EDT 2006 | GS
Silver tarnish on lead could compromise the soldering, mainly in case of No Clean process. Make sure components are correctly packaged and stored. Check the vintage ( Manufacturing Data Code) and in order to avoid them to get old on shelf make sure F
Electronics Forum | Wed Apr 26 10:27:37 EDT 2006 | slaine
weve hand soldered a few components that were tarnished with no problems, also the tarnish is electrically conductive if it helps.
Electronics Forum | Thu Jun 08 16:12:19 EDT 2017 | davef
Your plater's recommendation should work fine. Your simple copper plate will work, but you'll be stepping into fighting a copper tarnish battle. Silver over the copper is a better choice. I was thinking a silver thickness of a minimum of 3 microns
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 Sep 03 16:15:30 EDT 2008 | blnorman
Elemental is by SEM/EDX. The brown coloration does resemble the 3 micron photo. Again, if I'm picking up copper (our Ag plating thickness requirements are 0.05 micron to 0.12 micron following IPC 4553), maybe we do have a porous silver plating.
Electronics Forum | Fri Aug 29 10:18:31 EDT 2008 | rrpowers
We saw this one time when we were trying to develop some lead-free product. It ended up being copper migration. Some of the pads had a brown discoloration and those that did would not wet very well. Your elemental analysis would have shown if ther
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 | Tue Sep 02 16:07:04 EDT 2008 | blnorman
Colorization is relatively uniform across the board. "Processing" is first pass reflow. I belive MacDermid is the ImmAg supplier. Plating thickness has not been determined, our XRF is being revitalized. Elemental analysis did show a large copper
Electronics Forum | Tue Sep 02 22:08:34 EDT 2008 | davef
MacDermid Sterling seems to take-on a brownish tint in high dew points. Look at figure 3, p14 here: http://www.enthone.com/docs/CircuiTreeNov2006ImAgStudy.pdf We not so sure that it's fatal. That you see Cu makes us nervous. Since your XRF is doin
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