Pinsky Tin Whisker Risk Algorithm

Tin whisker risk mitigation is a process to reduce the risk of degradation in system performance resulting from the formation of tin whiskers. Mitigation approaches can include reducing chances of tin whisker formation, isolation of critical systems, or designing redundancy into the system. The most effective method to prevent failures due to tin whisker growth is to preclude the use of pure tin finishes containing less than 3 weight percent lead (Pb). Unfortunately, completely avoiding the use of pure tin finishes is nearly impossible due to the necessary usage of COTS parts and assemblies. Guidelines and processes are needed to assure when these materials are used to meet functional, cost, and system requirements, the risk of failures (due to tin whisker formation) is mitigated to a level that is acceptable to the program and the customer.

Such guidelines are provided herein to control the use of pure tin surface finishes. Control of whisker growth requires that proper consideration be given to the use of tin surface finishes during all phases of a contract, from proposal and bidding, through maintenance and logistics for fielded systems. This tool was developed by David Pinsky (formerly of RTX) and is made publicly available through the courtesy of the University of Maryland Center for Advanced Life Cycle Engineering (CALCE).

Contacts

RTX, Karen Ebner, Karen.Ebner@rtx.com
CALCE, Michael Osterman, osterman@umd.edu