The effects of Bi content on the wettability and joint shear strength of Sn-3.5%Ag-x Bi(x=0 wt%, 2 wt%, 3.5wt%, 5 wt% and 7 wt%) lead-free solders were explored by wettability experiment and shear test. The results show that the wetting angles of Sn-3.5% Ag-x Bi solders decrease and the wettability improves to a certain extent with the increase of Bi content. Meanwhile, with increasing Bi content, the joint shear strength firstly increases, and then decreases. When Bi content is 5%, the shear strength reach...