Electronics Forum | Tue Apr 17 10:17:10 EDT 2001 | genny
Hi, ENIG finish is the same reason I came to this forum for the first time a few months ago. I found a bunch of useful information by searching the archives. Check it out. ENIG has some good properties like flatness, and the process control has i
Electronics Forum | Mon Oct 25 17:50:46 EDT 2004 | Mike
I work for a PCB Manufacture and I am looking for info on BGA Pull test or strenght test. I have a CM that is experiencing bga's with some weak joints. they are telling me that when they do their pull test the joints are breaking at the nickel inste
Electronics Forum | Wed Dec 14 21:19:36 EST 2005 | davef
Heavens to Murgatroyd, we agree with Russ that "black pad" could be the cause of your solderability problem, but oxidized nickel is an additional explanation. While its often easy for assembler to jump this conclusion, it sounds like you've been bla
Electronics Forum | Mon Oct 25 21:49:14 EDT 2004 | davef
First, any results of pull or shear tests are unscientific at best. [We pop our BGA from boards with, appropriately enough, a beverage can opener.] Second, we have no have problems with your ENIG specification. Third, as with your customer, we'd e
Electronics Forum | Mon Jul 26 09:19:57 EDT 2004 | davef
Both imm silver and ENIG provide flat surfaces that are better for fine pitch placement and reflow than HASL. We know of nothing that makes BGA locations different than other locations when using ENIG solderability protection. More broadly, the pri
Electronics Forum | Fri May 13 14:08:39 EDT 2011 | eezday
This appears to be black-pad and is often the result of using specs that call for gold plating that is too thick. The black pad is corrosion that is created between the gold and electroless nickel during the gold plating process. This is counter in
Electronics Forum | Mon Apr 13 23:02:52 EDT 2009 | davef
Use IPC-4552 for your ENIG thickness. Typically, ENIG has nickel deposit with medium [7-9 percent by weight] phosphorus content. That's what fabs do on rigid boards. On a flex with medium-P and IPC-4552 specified ENIG, you could see brittleness and
Electronics Forum | Fri Feb 01 05:18:59 EST 2013 | eniac
If you have a hard-gold on your pads, it's not a problem. Hard gold can give to you 4 or 5 times for PCB soldering (BGA repair). Soft gold (or flash-gold) can destruct, after that will start a migration of nickel up through gold, your pads will be
Electronics Forum | Fri Feb 22 08:26:51 EST 2002 | davef
You are correct. The gold dissolves in the solder. The gold is meant to protect the nickel from oxidizing, so that you can solder to the nickel. Obviously that didn�t work as planned. Your background information is very sparse. Two things come
Electronics Forum | Thu Apr 24 20:39:01 EDT 2003 | davef
3NaH2PO3 + H2SO4 + 2H2 + Ni^0 Potassium is co-deposited with the nickel, as follows: H2PO2^- + Hads => H2O + OH^- + P 3H2PO2^- + P => H2PO3^- + H2O + 2OH^- Nick Biunno gives a very short, over simplified summary: "Everybody looks at the nickel, b
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