Electronics Forum | Thu Apr 22 20:26:39 EDT 1999 | Dave F
| | On various PCB's after building processes,such as reflow, flowsolder and wash. The soldermask on the PCB's have become discoloured, like a 'marble' effect all along the solder side of the board, it is lighter in contrast than normal, although whe
Electronics Forum | Wed Apr 10 17:05:47 EDT 2019 | davef
I wonder if this discoloration isn't delamination. I'd discuss it with my board fabricator.
Electronics Forum | Wed Aug 11 18:36:03 EDT 2004 | davef
90 Knoop. Q2: Thickness is 4 to 10 u" for Au and 300 to 400 u" for nickel A2: This looks like a ENIG spec. Although, the Ni is quite heavy, 150 uin is sufficient for most applications. [IPC-4552 ENIG specification: * Gold thickness of 0.075 - 0.125
Electronics Forum | Fri Oct 29 10:02:28 EDT 1999 | John Thorup
Chris A lot of people have reported sudden, fab lot related problems with Ni/Au pads. These are usually characterized by a discoloration of the gold and called cheerful names like "black pad disease". This can be a process problem at your fab house
Electronics Forum | Mon Jul 03 23:11:04 EDT 2000 | Patrick Ng
hi, We are receiving PCBs with gold fingers "discolored". The "discolored" gold fingers can be removed if rub with soft eraser! We are working with suppliers to determine the root cause and eliminate this issue. Pls assist if you have encountered si
Electronics Forum | Wed Sep 09 12:20:28 EDT 2009 | richardli
What is the cause of this discoloarion? Soldermask masterial wrong? Thanks.
Electronics Forum | Fri Sep 18 09:25:16 EDT 2009 | ysutariya
There's not really a good answer except that I think that the industry wasn't really prepared for such an increased use of white soldermask combined with the importance of using the white as a reflecting surface. Essentially, the resins commonly u
Electronics Forum | Thu Jul 06 20:10:06 EDT 2000 | Dave F
I agree. Make them quit doing this ugly thing to your boards!!!
Electronics Forum | Mon Oct 20 14:17:35 EDT 2008 | robinj
The discoloration/shadow appearance is a clear sign of black pad which is from nickel corrosion in the gold bath.
Electronics Forum | Fri Oct 15 10:23:48 EDT 2004 | mrmaint
Matt, are there any discoloration of the pads on the raw boards. i have seen what we refer to as gray pads. Ran into this in the past and it turned out to be a problem at the board house with one of their dipping tanks. The proper levels for the proc
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