Raytheon Integrated Defense Systems

Military and aerospace electronics manufacturers are forced to deal with components that are available only with a pure tin termination. Pure tin is not universally acceptable in all military and aerospace applications due to its propensity to form whiskers. However, pure tin terminations may be acceptable some applications. The recently released industry-standard GEIA-STD-0005-2, "Standard for Mitigating the Effects of Tin Whiskers in Aerospace and High Performance Electronic Systems " establishes a framework within which manufacturers and their customers can establish guidelines for the control of tin usage. One popular method for determining the suitability of pure tin in a given application is the use of a standard tin whisker risk assessment algorithm. The use of an algorithm facilitates standardization of tin risk decision-making across and between organizations. A widely used tin whisker risk assessment algorithm that was first published in 2003, and was revised in 2004. Tin whisker research that has occurred over the last two to three years has resulted in improved understanding of the factors that affect the risks posed by tin whiskers. These new insights have been used to develop an enhanced version of the existing algorithm. This new algorithm is presented, together with a discussion of how the new insights were used in its development. A discussion of how to use the algorith