Electronics Forum | Tue Aug 07 19:32:40 EDT 2007 | davef
Zinc from the brass diffuses into the solder and reacts with tin causing dezincification. Dezincification is a specific type of de-alloying, or selective, leaching corrosion of brass fittings. This type of corrosion selectively removes zinc from th
Electronics Forum | Sat Mar 14 09:12:59 EDT 2009 | davef
First, there is no good justification for getting solder on gold fingers. Second, it is well known that solder on gold fingers is unacceptable. So, shipping boards with that condition indicates sloppy quality practices at your CM. Third, that being
Electronics Forum | Sun Jul 24 16:10:16 EDT 2011 | davef
As a shot in the dark response to a hopelessly vague question .... Back in the old days, we'd see corrosion of metal parts after DI water washing when our water was on the high-end of the resistivity range, usually after we received fresh tanks from
Electronics Forum | Tue Apr 19 16:20:05 EDT 2016 | davef
Don't blame it on the poor paste thickness requirement [although I might go on to argue that it's could be a contributor to the issue]. Most likely you're the problem. About 70% of the time solder on gold fingers is caused by poor cleaning of screen
Electronics Forum | Thu Feb 27 16:23:37 EST 2020 | dwl
http://www.circuitnet.com/news/uploads/3/Comparing-Soldering-Results-of-ENIG-and-EPIG-Post-Steam-Exposure.pdf Years ago, I battled this problem. ENIG PCBs reflowed with active WS flux. We built one side, and then washed them because they were going
Electronics Forum | Fri Sep 17 03:55:45 EDT 1999 | Brian
| We have some SMT components with gold plated leads. They're actually LCC led packages. A good solder alloy to use would be Indium / Lead to reduce tin dissolution into the gold and avoid the resultant brittle intermetallic compound. However, a reco
Electronics Forum | Tue Jul 13 19:00:29 EDT 1999 | JohnW
| Hi All, | Does any one experienced the solder on gold finger after | reflow. Its about 5 to 8 mils diameter . | We'd clean the entire screen printer, mounter & reflow as well, | but doesn't help much. | | Mr Kong..... Solder on gold is a age old
Electronics Forum | Wed Jul 14 10:58:25 EDT 1999 | Upinder Singh
| | Hi All, | | Does any one experienced the solder on gold finger after | | reflow. Its about 5 to 8 mils diameter . | | We'd clean the entire screen printer, mounter & reflow as well, | | but doesn't help much. | | | | | Mr Kong..... | | Solder
Electronics Forum | Tue Dec 01 07:24:44 EST 1998 | Earl Moon
| Hi folks , | Lately we are seeing a lot of rawcards with black spots on the pads - most of them have Au finish(immersion gold) . We did a lot of inspecton after wave solder and found that only (fine pitch) QFP are affected the most. Our inspection
Electronics Forum | Tue Dec 01 07:54:49 EST 1998 | kallol chakraborty
| | Hi folks , | | Lately we are seeing a lot of rawcards with black spots on the pads - most of them have Au finish(immersion gold) . We did a lot of inspecton after wave solder and found that only (fine pitch) QFP are affected the most. Our inspec
