Manufacture of lead fame with supporting body

Abstract

Abstract PURPOSE:To reduce the amount of noble metal being used, by forming a thin film at the tip part of an inner lead, lightly etching the film, and protruding a bump by 10-30mum. CONSTITUTION:An electric insulating material is partially applied or printed on one surface of a metal foil 1. A supporting film 2, in which a semiconductor- device inserting hole 3 is provided, is formed. Then, positive type photoresist films 4 and 5 are formed on the upper and lower surfaces of the metal foil 1. Then, an exposing plate is applied on the surface of a photoresist film 4. The surface 4 is exposed to ultraviolet rays. After development, a first resist pattern 6 is formed. Alloy comprising gold and the like is electrodeposited on the surface of the metal foil 1, which is exposed through holes 7 in the first resist pattern 6 to a thickness of 5-10mum. A second resist pattern 9 is formed by the similar way. The unnecessary part of the metal foil 1 is etched away. After the first resist pattern is removed, the exposed surface of the metal foil is lightly etched. The part, where the gold and the like are electrodeposited, is protruded from the inner lead part other than the electrodeposited part by 10-30mum. Finally, the remaining resist film is dissolved and removed, then the device is washed with water.

Inventors

• 👤 Takao Hashimoto
• 👤 貴夫 橋本

Bibliographic Details