PURPOSE: To inexpensively manufacture a bonding wire for use in semiconductor production, by casting high-purity Cu containing specific trace elements in vacuum or in a nonoxidizing atmosphere and then repeatedly applying wire drawing and annealing to the resulting ingot.
CONSTITUTION: High-purity Cu having a composition consisting of 0.2W2,000ppm, in total, of one or more elements among 0.1W1,000ppm each of Mn, Co, Ni, Nb, Pd, and In and 0.1W2.5ppm Zr and the balance ≥99.999% Cu is melted and cast in vacuum or in a nonoxidizing-gas atmosphere of Ar, etc. The resulting ingot is faced and hot-rolled into a bar stock of about 10mm diameter, which is further subjected to peeling and wire drawing. Wire drawing and annealing are repeatedly applied and the rate of final wire drawing is regulated to 70W99.99% to form a wire of 25μm diameter, and finally, the wire is annealed in an Ar atmosphere at 250W400°C and wire-drawn at 1W5% draft to regulate elongation to 2W20% so as to be formed into an inexpensive Cu wire capable of use as a bonding wire.
TANIGAWA TORU
SHIGA SHOJI
INABA TOSHIAKI
KAGA ICHIRO
FURUKAWA SPECIAL METAL COATED
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