| 摘要 |
PURPOSE:To obtain a lead frame, which has excellent adhesion and is coated by Al having excellent ultrasonic bonding property, by exhausing air, performing evaporation at a high speed by the irradiation of an electron beam, applying high frequency power, exciting evaporated particles, and performing coating. CONSTITUTION:A vacuum device is composed of a bell jar 1, a coating substrate 2, an evaporation source 3, a high-frequency exciting coil 4, an electron-beam emitting source 5 and an ion particle accelerator 6. The degree of vacuum in a vacuum container is made to be 5X10<-5>Torr or more. The distance between the substrate 2 and a crucible is made to be 1/10 or less the mean free path. The Al evaporation source 3 in the crucible is heated by the irradiation of the electron beam, and the Al is evaporated so that the vapor pressure of Al becomes 10<-3>mmHg or higher. High frequency power is applied to the high frequency coil 4, which is arranged between the Al evaporation source 3 and the coating substrate 2. Ionized, evaporated Al particles are accelerated by a DC field and attached to the substrate 2. The lead frame, in which the Al is coated on the surface of the substrate, is obtained. |
