Tin whisker growth induced by high electron current density

The effect of electric current on the tin whisker growth on Sn stripes was studied. The Sn stripes, one mum in thickness, were patterned on silicon wafers. The design of the Sn stripes allowed for the simultaneous study of the effect of current crowding and current density. It was found that the stress induced by the electric current caused the formation of many Sn whiskers. A higher current density caused more Sn whiskers to form. Of the three temperatures studied, 50degC was the most favorable one for the formation of the Sn whiskers. In addition, the current crowding effect also influenced the whisker growth.