Whisker (metallurgy)

[1] Many techniques are used to mitigate the problem, including changes to the annealing process (heating and cooling), the addition of elements like copper and nickel, and the inclusion of conformal coatings.

The phenomenon was discovered by telephone companies in the late 1940s and it was later found that the addition of lead to tin solder provided mitigation.

[7] Airborne zinc whiskers have been responsible for increased system failure rates in computer server rooms.

Zinc whiskers grow from galvanized (electroplated) metal surfaces at a rate of up to a millimeter per year with a diameter of a few micrometers.

Whiskers can be small enough to pass through air filters and can settle inside equipment, resulting in short circuits and system failure.

Conformal compound coatings stop the whiskers from penetrating a barrier, reaching a nearby termination and forming a short.

[16] Galaxy IV was a telecommunications satellite that was disabled and lost due to short circuits caused by tin whiskers in 1998.

The false alarm was caused by a tin whisker that short circuited the logic board responsible for monitoring the steam pressure lines in the power plant.

[20] This contradicted an earlier 10-month joint investigation by the National Highway Traffic Safety Administration (NHTSA) and a large group of other NASA researchers that found no electronic defects.

"[22] Toyota also maintains that tin whiskers were not the cause of any stuck accelerator issues: "In the words of U.S. Transportation Secretary Ray LaHood, 'The verdict is in.

Silver whiskers growing out of surface-mount resistors
Microscopic view of tin used to solder electronic components, showing a whisker
Several mm long zinc whiskers on zinc-coated steel