Influence of Sb and Cu in Sn-Sb-Cu alloys on wetting of Cu and Cu-solder-Cu joint strength

The influence of Sb (5, 10 and 20 at.%) and copper (0, 1.8, 3.4 and 3.7 at.%) in lead-free Sn-Sb-Cu solder on wetting of copper substrate at the temperature 623 K (350 degrees C) in air using flux arid in N(2)+10H(2) gas until 1800 s was studied by the sessile drop method. Wetting angle in air increases with the increase of Sb and Cu concentration in the solder whereas wetting in N(2)+10H(2) practically does not depend on the Sb concentration. The influence of antimony and copper in Sn-Sb-Cu solder on the strength of Cu-solder-Cu joints prepared at the same conditions as wetting was also studied. Shear strength of the joints produced in air and in the gas mildly decreases with increasing amount of antimony and copper in both cases with the production of the joint in air as well as in the gas. The solidus and liquidus temperatures as well as heats of melting of all solders in ribbon and bulk shape were determined by differential scanning calorimetry (DSC) method.