Studies of zinc whiskers formation and growth from bright zinc electrodeposits

SUMMARY

Zinc whiskers growing from bright electroplated zinc have been observed on electrical components. Some whiskers were up to 3cm in length and others capable of carrying a continuous current of 5 mA. In consequence a programme has been carried out aimed at studying the formation and growth of the zinc whiskers, which could readily be grown from bright zinc electrodeposits. Techniques used to study the growth are described and zinc whisker growth was monitored over a prolonged time period under ambient conditions. The bulk properties and the influence of brighteners are recorded. Results demonstrate that the presence of brightening agents cause whisker initiation and growth and that growth is probably related to electrodeposits microstress. Both passivated and non-passivated bright deposits produce whisker growth. Dull zinc deposits from cyanide baths, without organic additives, do not produce zinc whiskers.