Effect of Ag and Ni particles on mechanical properties and wettability of SnPb composite solder

Solder is widely used in electronic industry, which has a lower melting point, good solderability and good mechanical properties. However, its creep resistance is bad. In the present work, Ag and Ni particles with size of about 1 μm are added in the eutectic 63Sn-37Pb solder to form metal particles enhanced SnPb composite solders. Under re-flow soldering the enhanced particles are uniformly dispersed in the 63Sn37Pb alloy, and intermetallic compounds with very thin layer was formed between the enhanced particles and matrix. Tight metallurgical coalescence is realized. So the creep rupture life of the composite solders are improved distinctly. At ambient temperature the creep rupture life of 5vol% and 10vol%Ag particles enhanced SnPb composite solder joints can be increased by 8 times and 6 times compared to the ordinary 63Sn-37Pb solder. At the same time, tensile strength and tensile-shear strength of Ag particles enhanced composite solders were higher, and lower elongation and spreading areas than those of 63Sn37Pb solder. At the same condition, the rupture life of Ni particles enhanced composite solders is improved evidently. Those of 5vol% and 10vol% Ni particles enhanced SnPb composite solder joints can be increased by 85 times and 186 times compared to the ordinary 63Sn-37Pb solder. However, solderability, tensile-shear strength and elongation of Ni particles enhanced composite solders were lower than those of 63Sn37Pb solder.