| 摘要 |
PURPOSE:To provide bonding wire with characteristics suitable for use in a semiconductor device, by utilizing small-gage wire of hyperpure copper containing inevitable impurities in a total amount of 5ppm or less, in which amounts of S, Se and Te are specified respectively. CONSTITUTION:Oxygen-free copper is employed as a raw material. The oxygen- free copper is repeatedly refined by means of the electrolytic or zone melting process, and then hyperpure copper meaterial is produced therefrom by means of the vacuum fusion. The copper material is subjected to hot or cold rolling to produce extremely small gage wire having a diameter of 25mum. The extremely small gage wire is then subjected to the bright heat treatment at a temperature in the range of 250-350 deg.C so that wire is produced. The small-gage wire of hyperpure copper thus produced contains inevitable impurities such as S, Se and Te in a total amount of 5ppm or less: it specifically contains S in an amount of 0.5ppm or less, Se of 0.2ppm or less and Te of 0.2ppm or less. The wire has a elongation percentage of 5-14% or less and a breaking strength of 18-28kg/mm<2>. Further, it has a Vickers hardness of 38-45 in the condition of a blank material. |
