| 摘要 |
PURPOSE:To manufacture a copper material extremely reduced in hardness, by subjecting high-purity copper to which specific amounts of one or more kinds among alkali metal, alkaline earth metal, and rare earth metal to refining treatment by an electron beam melting method. CONSTITUTION:One or >=2 kinds among alkali metal, alkaline earth metal, and rare earth metal are incorporated to high-purity copper by 0.1-100ppm by weight ratio. When refining treatment is applied to this copper material by an electron beam melting method, sulfur contained in the high-purity copper rises to the surface of the molten metal and can easily be removed by means of heating at high temp. In this way, an extremely soft copper material of <=about 40 Vickers hardness can be obtained, which is useful as a semiconductor device bonding wire.
|
