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           COLLOQUIUM OF THE COMPUTATIONAL MATERIALS SCIENCE CENTER
                              College of Science
                       (CDS Department CSI 898-Sec 001)
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      " Whisker Growth from Pb-free Sn Solder Electrodeposits"
                       William J. Boettinger
                             Fellow
National Institute of Standards and Technology,Gaithersburg, MD

For many years, electronic component leads made of Cu alloys were 
"pretinned" with a 3 to 10 micron layer of electrodeposited tin-lead 
(Sn-Pb) alloy to maintain proper solder wetting during subsequent assembly. 
The worldwide electronics industry is in the process of removing Pb 
from their components.  When Pb is removed from the electroplated 
surface finishes, Sn whiskers grow spontaneously from the surface 
finish. The whiskers are single crystal filaments typically 1 µm in 
diameter and several mm long.  Numerous electronic failures due to 
shorting from whiskers have been reported, especially in the high 
reliability realm of aerospace, military, and medical device 
applications.  This lecture wil describe progress being made towards 
developing a fundamental understanding of Sn whisker growth and 
providing industry with information needed for mitigation strategies. 
See http://nepp.nasa.gov/whisker/ for general information about 
the Sn whisker problem.

                        Monday, April 21, 2008
                                  4:30 pm
                     Room 301, Research I, Fairfax Campus

Refreshments will be served at 4:15 PM.
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Find the schedule at www.cmasc.gmu.edu/seminar/schedule.html
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