MECHANISM OF FORMATION OF WHISKER IN DEFORMED PURE-Sn THIN FILM

摘要

Thin film of pure Sn is prepared through electroplating Sn on stainless steel and peeling the thin Sn electrodeposit from the stainless steel. Fine Au particles, which are greatly smaller than size of Sn grain, were deposited on Sn-film in vacuum. Both-Sn films with and without the deposition of Au particles were clamped with acrylic resin plates. It was clarified that formation of Au-Sn compounds on surface of Sn-film suppressed formation of whisker. Our idea for the mechanism of whisker formation was confirmed based on the above and former results [1 - 3]. Conclusion is that aggregation of both edge- and screw-dislocations in small region induces the nucleation and growth of whisker. Suppression of whisker formation could be done through avoiding the aggregation of both edge- and screw-dislocations in small region by forming fine Au-Sn compounds on the surface of Sn-film.