Theoretical estimation of coefficient of thermal expansion for solder alloy

Coefficient of thermal expansion (CTE) of solder alloy Sn-37%Pb was estimated by using cluster expansion method. Five phases with available experimental CTE in Sn-Pb system were employed to derive the correlation coefficient, qi. Monte-Carlo simulation was carried out to obtain the correlation functions, ξi. With the derived qi and ξi, CTE of Sn-37%Pb was calculated, which is in excellent agreement with experiment. This study may provide a simple approach for the CTE prediction of disordered structures.