SMT & Inspection | October 11, 2007
Examples of tin-whiskers failures
Some examples of reports in technical journals and a database of publicly disclosed failures caused by tin whiskers kept by researchers at NASA have been published.
Some of the biggest tin-whisker-related failures in the United States in recent years have been listed below. 1986: Malfunctions in radar equipment for U.S. Air Force F-15 fighter jets. Culprit found to be tin whiskers that had detached and fallen into active circuitry, causing intermittent performance problems for the radar. Problem would suddenly disappear when vibration from the aircraft caused the whiskers to shift position again. 1987 to present: At least seven nuclear power plant shutdowns. Whiskers were growing within the alarm system circuitry, not the reactors themselves, and falsely alerted managers that certain critical systems weren't working properly. 1989: Tin whiskers reported on Phoenix air-to-air missiles used by the U.S. Navy. The whiskers were discovered in a tin-lined box enclosing the missiles' target-detection system. 1998 to present: At least 11 problems on commercial satellites in orbit. Failures occurred in processors that control the satellites' position, among other functions. Four satellites have been deemed total losses, including PanAmSat Corp.'s $250 million Galaxy IV communications satellite, which provided service to tens of millions of pagers across North America. 2006: During a test, malfunctioning electronics inaccurately pointed the space shuttle Endeavour's engine, knocking the rocket's trajectory off-kilter. NASA engineers later found millions of tin whiskers, some measuring up to 25 millimeters. The pure-tin parts causing the problems had been approved by NASA before the space agency began requiring a small amount of lead in tin coatings.