| abstract |
PURPOSE:To obtain lead wire, which is characterized by excellent heat resistance, corrosion resistance and machinability and is more economical than Au and Ag plated wires, by coating an alloy comprising at least one kind of metal, which is selected among a group of Ni and Co and a group of Cd and Cu, on the surface of a conducting wire material so as to obtain a specified thickness or more, thereby providing a coating layer. CONSTITUTION:The range of alloy component of Ni or Co can be 5-90%. The thickness of a coating is made to be 0.01mum or more and the recommended practical thickness is 0.1-2mum. When the thickness of the coating layer is less than 0.1mum and the component element of the wire material is diffused into the coating layer owing to the high temperature processes and the like and the corrosion resistance of the coating layer is impaired, it is recommended that an intermediate layer of Ni or Co is provided between the wire material and the coating layer. As a means for providing the coating layer and the intermediate layer, evaporation, sputtering, mechanical bonding, chemical plating and the like can be used. However, electric plating ensures easy working. Owing to the presence of the alloy component in the coating layer, a steel header tool and the lead wire are hard to be coagulated. Since the coating layer is physically and chemically soft, soldering property and ultrasonic-wave welding property are excellent. Heat resistance and corrosion resistance are also excellent. |