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 | Mon Apr 28 09:59:04 EDT 2003 | davef
Your customer's question is reasonable. Soldering to nickel is not always a walk on the beach [can of corn, or whatever]. This issue is flux not solder. Your Sn63 will have plenty of strength, providing the solder connection is well formed. You s
Electronics Forum | Thu Dec 30 21:22:12 EST 1999 | Jim
Mike, Thanks for the reply. It's not really a matter of slope. It is the long term thermomechanical fatigue that the solder joint undergoes as a result of repeated severe temperature swings, while the product is in use. Non-leaded parts are suscep
Electronics Forum | Tue May 13 17:53:54 EDT 2014 | anvil1021
Hello Michel...this might be a bit of a battle finding the low thermal EMF material that you are looking for. The first one that comes to my mind is Bismuth Selenium Telluride, with either a nickel or cobalt doping agent. Silver went away from this
Electronics Forum | Wed Dec 29 15:42:34 EST 1999 | Mike Naddra
Justin, I would be currious as to your customers application, and if the temperature delta and rate are great enough to cause solder joint failures as a function of mismatched Tce then you may want to consider that even if you are able to identify
Electronics Forum | Wed Apr 21 17:08:32 EDT 2004 | dave
Congratulations on your new customer. This could be a keeper. Here's what you're familiar with: Electroless Nickel - per MIL-C-26074 and ASTM-B733. Electroless nickel describes the plating of nickel deposits, which may contain phosphorus and boro
Electronics Forum | Mon Oct 02 19:04:53 EDT 2006 | DC
We had a issue on the SBGA and found stress built up at the corner of the SBGA after cool down to room temperature. It is confirmed by the warpage analysis. I expected that the stress caused by the heat spreader and the epoxy to the copper frame. O
Electronics Forum | Thu Aug 24 17:08:58 EDT 2000 | Dr. Ning-Cheng Lee
Depending on the stress condition experienced by the solder joints. For joints under a greater stress, the time to reach equilibrium can be shorter. Of course, the change is also more significant in phase structure. For low stress conditions, it may
Electronics Forum | Tue Mar 15 22:04:56 EST 2005 | KEN
The hasl joint looks fuller (and is easier to inspect)because it has more solder volume. Think about it. Your pre-plating your board with solder (before you add more solder). I doubt your getting 0.3 mils of hasl.....probably more like 1.3 to 3.0
Electronics Forum | Wed Jan 17 20:48:14 EST 2001 | davef
We find that the raw BGA's pad sheared surface has the SnPb solder at various Z heights whereas the assembled BGAs pad leave a smooth layer of SnPb along the pad. Like to understand the cause for the difference. Who could guess? Solder joint streng
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