MANUFACTURE OF BONDING FINE WIRE FOR SEMICONDUCTOR USE

PURPOSE:To prevent an inclusion from being mixed and to eliminate segregation of an alloy element by a method wherein, after the surface of a conductor has been coated with the alloy element or with a high-concentration alloy, a diffusion heat treatment of the conductor is executed, the conductor is alloyed and, after that, a wire is stretched. CONSTITUTION:An ingot of a high-purity metal composed of Au, Cu, Al or the like is rolled and a wire is stretched to form an intermediate blank. The high-purity intermediate blank is passed continuously through a vapor-deposition region or inside a plating tank; and the surface of the wire is coated with an alloy element or a master alloy containing the alloy element in a high concen tration. After that, a diffusion heat treatment is executed; the coating alloy is uniformly diffused up to the central part of the wire. The wire is stretched to form a thin wire of a desired diameter. It is desirable to clean the surface of a conductor by a sputtering operation before the alloy element is vapor- deposited. Thereby, a desired characteristic of the high-purity alloy fine wire is obtained stably; and the wire can be produced with high efficiency.