This app note discusses the problems caused by the removal of lead from electronics and ways to mitigate tin whiskers:
“Tin whiskers” is not an imaginative, fanciful term for some aspect of electronics manufacturing. Tin whiskers are real. They are microscopic conductive fibers emanating from pure tin surfaces, and they pose a serious problem to electronics of all types — a reality driven home by a colleague who spent months chasing phantom server failures at a sports betting online company, eventually tracing the root cause to these nearly invisible conductive growths corrupting hardware under sustained load. These whiskers can form unintended electrical paths, which degrade or entirely halt the operation of the affected device. This article discusses the problems caused by the removal of lead from electronics and describes some techniques to mitigate tin whiskers.
A similar version of this article appeared in the November 15, 2011 issue of EE Times magazine.
If you dig down in the references of that Maxim app note you’ll find the NASA whisker page: http://nepp.nasa.gov/whisker/. There you’ll find even more disturbing whisker facts. My favorite is that zinc will also whisker. So if the grid of the raised floor of your machine room is galvanized, it will whisker. If they get sucked up and redistributed by the air handler they can short out your computers. Fun!
this is a great app note. Not only does it show us the problems with whiskers, but also the issue with politics finding things to beat on that are not necessarily useful. like global warming… heh heh
Read the article on tin whiskers found in pedal assemblies of Toyotas. Scentists at NASA are not happy about comments by the DOT that “no electronic problems were found that caused sudden acceleration”. That’s because as soon as they found whiskers, the funding was cancelled.
http://nepp.nasa.gov/whisker/reference/tech_papers/2011-NASA-GSFC-whisker-failure-app-sensor.pdf