The effect of antimony n wettability of 40 - 60 lead - tin solder on copper plate
신현규Hyun Kyoo Shin, 김동훈Tong Hoon Kim
Abstract
In lead and tin solder antimony is one of the adding elements. Antimony acts as a preventive of tin-pest and a hardening additive as well as an undesirable impurity (depending on the amounts). The effect of antimony on the wettability of 40-60 lead-tin solder on copper plate was studied. The required maximum content of antimony was obtained by measuring the contact angle in a sessile drop method. The effects of temperature and time on the contact angle were also studied. The contact angle increases with antimony content at a given temperature. By using the arbitrary limit of contact angle set by experience, 75°, the possible maximum contents of antimony in 40-60 lead-tin solder were found, which were about 1.9 wt. % at 350℃ and higher than 3 wt. % at 400℃. Since the contact angle even without antimony exceeded this limit at 300℃, this temperature had better be avoided.