| 摘要 |
<p>PURPOSE:To reduce the vulnerability to moisture of an aluminum-vapordeposited lead frame and to render it excellent in withstanding corrosion by a method wherein the aluminum film is so vapor-deposited as to exceed a specified value relative to the plane (111) in crystal orientation. CONSTITUTION:A vapor-deposited aluminum film is so designed in crystal orientation as to exceed 70% relative to the plane (111). The rate of orientation relative to the plane (111) is expected to be 50-60% when a routine technique is employed of aluminum evaporation in vacuum. When the ion plating method or the like is applied for film formation, wherein the abundance of aluminum ions may be effectively controlled, 70% or more orientation may realize relative to the plane (111). In the high-frequency ion-plating method, aluminum ion abundance may be controlled simply by changing the high-frequency power. For example, a 2mum-thick Al film, 85% in orientation relative to the plane (111), may be formed on a 42% Ni-Fe lead frame in a 2X10<-4>Torr Ar atmosphere at a 300W high-frequency power.</p> |
