Grain size effect of electro-plated tin coatings on whisker growth

Abstract

Tin and tin-lead coatings electro-plated in various solutions have been observed by means of high voltage electron microscopy, and the grain size effect of the coatings on whisker growth has been examined. As a result, it was found that the tin and tin-lead coatings from which whiskers hardly grew consisted of well-polygonized grains which were a few micrometre in size, and that the tin coatings from which whiskers easily grew consisted of irregular-shaped grains which were a few tenths of a micrometre in size. The irregularshaped grains contained dislocation rings which might be formed by clustering of vacancies or interstitial atoms upon electro-plating. © 1982 Chapman and Hall Ltd.