JOINING METHOD FOR DISSIMILAR METAL FOR CONDUCTIVE PIECE OF ELECTRONIC PARTS

摘要

PURPOSE:To form a reliable conductive piece for electronic parts by making one part of electrode chips a high m.p. material and forming the tip pressurizing part at a fixed curvature as well after executing solder plating in advance on one part of the dissimilar metal for the conductive piece of an electronic part. CONSTITUTION:The tip pressurizing part of an upper part electrode chip 1 is formed by a fixed curvature and the pressurizing part of lower part electrode chip 2 is formed in plane shape. The material of the upper part electrode chip 1 is taken as the high m.p. material of tungsten, silver tungsten, etc., and that of the lower part electrode chip 2 as a chrome copper alloy. A large current is passed by pressurizing both metal blanks 11, 12 by the upper part electrode chip 1 and a copper blank 11 by the lower part electrode chip 2 by interposing a 42 nickel alloy blank 12 respectively. A plating layer 13 is removed by melting it by the local temp. rise due to the resistance heating on the intermediate plating layer 13, the copper blank 11 and 42 nickel alloy blank 12 are locally melted and joined by forming the nugget of the casting structure of both metals.