Whisker Formation Concepts—The End Game

This paper elaborates on previously published theories dealing with tin whisker formation mechanisms and introduces some new concepts to build a theory that is both fundamentally sound and consistent with experimental observations made to date. Central to the proposed hypothesis is the unique chevron (or V-shaped) whisker grain that forms within the as-deposited tin film grain structure. This treatment also deals with some ancillary tin film observations such as the intermetallic “pedestal” structures formed by temperature cycling and the “subsidence” structures often associated with tin whisker formation.