Characteristics of press soldered joints by using resistance heating

In order to increase the strength of soldered joints, a novel press-soldering method was investigated. In this method, materials with low melting points and low strengths (mainly Pb) were discharged from the joint interface, and an alloyed layer of high strength was left. Copper-to-copper lap joints were press-soldered using a resistance heating apparatus. In this process, heating and pressure were applied simultaneously. The copper plate was presoldered using Pb-50Sn solder and the alloyed layer was formed. The tensile strength increased at a pressure above 45 N, and fracturing occurred in the copper base metal above a 75-N pressure load. The joints fractured in the copper base metal during 150°C and 250°C tensile testing and showed excellent thermal resistance. Changes in joint strengths after high-temperature heating (150°C, 250°C for 1000 h) were also considered