The Effect of Ageing on the Microstructure of 60:40 Tin‐lead Solders

Abstract

Studies have been made of ageing effects, both at room temperature and at 125°C, on the microstructure of 60:40 tin‐lead solders. A comparison was made of the effect of ageing on slow and rapidly cooled matrices. Precipitation of tin within lead dendrites was observed to occur very rapidly after solidification of the alloy. Subsequently the precipitates coarsened markedly over a period of a few weeks. The matrix of the alloy also coarsened at room temperature over this period. At elevated temperatures a similar sequence of events occurred, but substantially faster. The microstructural origins of the known loss in mechanical strength of solders with ageing are discussed.

Citation

Harris, P.G., Chaggar, K.S. and Whitmore, M.A. (1991), "The Effect of Ageing on the Microstructure of 60:40 Tin‐lead Solders", Soldering & Surface Mount Technology, Vol. 3 No. 1, pp. 20-33. https://doi.org/10.1108/eb037741