Electronics Forum | Mon Jun 14 17:21:31 EDT 2004 | russ
How old are these parts? Sn/Ni plating is very succeptable to age and everything else. They are possibly tarnished. Also, what is your peak temp in reflow? It takes about 225 230 C to get good wetting to the underlying nickel. Russ
Electronics Forum | Tue Jun 13 13:42:34 EDT 2006 | Bob R.
Also be careful in assuming you have black pad. A nice straight crack along the Sn-Ni intermetallic is probably just overstress at some process (most likely ICT). The better board suppliers figured out how to avoid black pad years ago.
Electronics Forum | Fri Jan 02 14:04:56 EST 2004 | jjwhite
Has anyone had any experience with 60/40 Sn/Ni(300 u in.) over Ni(300 u in.)? If so, what kind of solder issues might exist with 63/37 Sn/Pb reflow? Is a different paste needed? Also, what is the benefit of using the same platings with a top plating
Electronics Forum | Wed Jun 29 03:37:53 EDT 2005 | lupo
Hi, I think that the time depends on the type of stainless steel, temperature and solder alloy. For example, one of our machines is delivered with 316 stainless pot and alloy SnNi. It worked six months (120days*16hours = 1920hours) and aft
Electronics Forum | Tue Oct 26 08:41:56 EDT 2004 | Bob R.
When we first got into BGAs on ENIG we were getting joint cracking at in-circuit test. The joints were breaking in the Sn-Ni intermetallic. We did a lot of pull testing while working with our board suppliers and our conclusion was that pull testing
Electronics Forum | Fri Sep 22 05:33:59 EDT 2000 | Wolfgang Busko
That "C - it doesn�t matter" choice sounds good because it doesn�t give you a headache when profiling but it gives me a headache when I read the article in the current "newsletter" about profiling where I found this: "If soldering to gold over nick
Electronics Forum | Fri Apr 16 08:20:58 EDT 2004 | Bob L.
We've seen problems with BGA balls breaking at in-circuit test. I did some bend testing and found that our large BGA's can handle amazing stresses at low strain rates but we get brittle fractures at high strain rates, especially with Ni/Au surface f
Electronics Forum | Fri Aug 06 08:38:25 EDT 2004 | Bob R.
You don't mention the board surface finish, but BGA's on NiAu are prone to brittle fracture in the Sn-Ni intermetallic on the board side of the joint. You may not be able to see it visually, but it would show up in a cross-section. In-circuit test