Tin whisker outbreaks can pose problems on FFC/FPC (flat flex cable/flexible printed circuit) connectors in electronics components. Several mechanical loading tests for investigating whisker formation have been performed, however, the mechanical implications of the results remain unclear. The purpose of this study was to clarify whether the whisker formation mechanism on connectors is due to contact force. Using the creep properties collected from nanoindentaion tests, the stress evolution in plating is extracted. The behavior of the stress evolution was investigated by finite element analysis. During the test, the axial compressive stresses increase, although stress relaxation also occurs. The effect of substrate shape is also investigated and whiskering behavior due to stress was confirmed.

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