The fact that stress gradients appear to propagate tin whiskers has been known for some time. (in fact, the phys.org authors should have researched their own web site more thoroughly: http://phys.org/news173450615.html#nRlv)
At my place of employment, we also are concerned about the impacts of RoHS parts (RoHS = non-lead-bearing) and their impact to long term reliability of electronic assemblies. We don't make things that go into space, but we make things that are nearly equally inaccessible once they are installed. Recently we performed an experiment on an assembly to attempt to induce tin whisker formation by temperature cycling it hundreds of times over the course of over 6 months. At the end of the experiment, only one component (out of hundreds on the assembly) showed any signs of whisker formation. Even with RoHS parts, using lead-based solder paste to assemble the boards partially (but not completely) mitigates the risk. David AJ4TF -- View this message in context: http://elecraft.365791.n2.nabble.com/How-Tin-Whiskers-Form-tp7566988p7567225.html Sent from the Elecraft mailing list archive at Nabble.com. ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
