The variations of thermal conductivity with temperature for Sn-In based lead-free solders, Sn-20 wt.% In-15 wt.% [X] (X = Ag, Bi, Sb, Zn) were measured by using the linear heat flow apparatus. The thermal conductivities of lead free solders at their melting temperatures were obtained from graphs of thermal conductivity variations with temperature. The thermal temperature coefficients for Sn-20 wt.% In based lead free ternary solders were obtained from the graphs of thermal conductivity variations with temperature. (C) 2013 Elsevier B.V. All rights reserved.