Electronics Forum | Fri Aug 26 14:15:16 EDT 2005 | David
Where could I find more information regarding the double sided reflow and flux problems with white tin?
Electronics Forum | Fri Aug 26 09:57:21 EDT 2005 | russ
The Immersion gold is not a problem with BGAs specifically but "black pad" which can be present anywhere. The unfortunate thing with BGAs is you cannot see it. Personally I hate white tin. It is okay for single sided boards running no-clean, but c
Electronics Forum | Wed Jul 29 13:44:45 EDT 1998 | David Spilker
We are investigating alternatives to HASL finishes for more dense PWBs. OSP is not a good choice because of low solid flux and possibly long shelf life. Immersion gold is expensive and so far has been more difficult to wave solder. Has anyone had
Electronics Forum | Wed Jul 12 11:26:12 EDT 2006 | flipit
Hi, I believe you have classic gold imbrittlement here. With 80 microinches of gold you are way over the limit. You can try to reflow longer time and at a higher temperature. The gold does not melt into the solder joint. The gold dissolves into
Electronics Forum | Fri Nov 10 17:44:48 EST 2000 | Dave F
In response to your questions: Is the embrittlement from excess gold in lead / tin solder connections bad? It can be vereeee bad. Does it affect all plating processes the same? Give us a break and read the SMTnet Archives, for instance: BGA prob
Electronics Forum | Wed Jun 29 16:25:51 EDT 2005 | mattkehoe
When discussing this with the customer he said that his vendor recommended a hard gold plating finish on the board due to the BGA. I said "hard gold"??? And he said yes, hard gold. Turns out the boards were plated with hard gold, not ENIG. Thank
Electronics Forum | Thu Jun 30 20:17:19 EDT 2005 | davef
Matt: What thickness of hard gold was applied to your customer's boards?
Electronics Forum | Thu Jun 30 21:55:33 EDT 2005 | Mason Hughes
Hi, In response to reading height or gold thickness, I can do that masonhughes@sbcglobal.net
Electronics Forum | Tue Jun 28 19:56:59 EDT 2005 | davef
Matt: Yes, if the gold was really thick, it could appear like your pictures. In measuring gold plating thickness, we'd want to use xray fluorescence [XRF]. For alternatives, look here: http://www.pfonline.com/articles/pfd0027.html
Electronics Forum | Tue Jun 28 09:39:00 EDT 2005 | davef
Points to consider are: * Gold plating too thick [SB LT 8 uinches]. [Obviously, we're talking about actual plating thickness, not the specification.] * Reflow recipe improper [SB 220*C 5-10 sec]. A recipe that works fine for HASL needs to be hotter
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