Electronics Forum | Thu Oct 30 21:55:13 EDT 2014 | davef
Why soldering issues? I'd guess the nickel is corroded. It is very difficult to solder to oxidized nickel. Your SAC305 would get kicked all the way down the conveyor by nickel oxide. A lack of Ni-Sn-IMC formation will confirm this dewetting . What's
Electronics Forum | Mon Oct 20 15:41:19 EDT 2008 | patrickbruneel
Josh, You can not check the bare boards for black pad unless you remove the gold plating. Like Robin said black pad is nickel oxidation/corrosion and a result from bad electroless nickel plating bath control. The only preventative action you take is
Electronics Forum | Fri Aug 17 11:55:31 EDT 2001 | davef
5uin. Your nickel thickness is fine. Although if you wanted to trade costs, consider giving-up nickel to 150uin thickness, while increasing the gold thickness. Gold over electroless nickel creates brittle joints because of phosphorous in the nicke
Electronics Forum | Tue Feb 11 22:28:25 EST 2003 | davef
What do you mean by "new information"? On final module testing: * If you have hypercorroded nickel and you detect it during final testing, you'll notice it. * If you have hypercorroded nickel and you don't detect it during final testing, you'll ship
Electronics Forum | Thu Dec 08 08:29:25 EST 2005 | davef
Grant The solution to soldering problems with immersion gold boards is: find a supplier that can control his/her process. Electroplated gold over nickel is a very reasonable process. Billions of wire bound boards use it evry year.
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
Electronics Forum | Fri Apr 29 14:16:16 EDT 2011 | ppcbs
Below is the long explanation. This defect is most commonly found with BGA components, but can arrise with all components. I see it happening more now with lead free boards that are being assembled with a no clean flux. Best short term remedy is t
Electronics Forum | Thu Apr 24 15:48:09 EDT 2003 | razor
Known: During PCB maufacting nickel alloys are used for corrosion resistance during gold immersion process. A nickel alloy with a high phosphorus concentration will cause a weak connection interface. Question: Is the concentration of phosphorus in ni
Electronics Forum | Wed Sep 01 08:27:38 EDT 2004 | davef
Zinc from the brass [Cu3Zn2] diffuses into the tin causing solderability problems. Just 0.001% of Zn in your solder can render it fit for the scrap heap. So, you need a barrier plate between the brass and the tin. Copper or nickel-plating is commonl
Electronics Forum | Mon Jun 17 13:45:29 EDT 2002 | genny
When the pad comes off, is it leaving behind a "black" area? Your board may be suffering from black pad - a condition that occasionally affects ENIG finish boards. It is a process control issue with your board fabricator. The nickel is oxidising b
