Method for manufacture of aluminum-coated lead frame

摘要

A lead frame with an Al coating which enjoys satisfactory tightness of adhesion and sufficiently low hardness is manufactured by a method, comprising the steps of covering the lead frame with a mask sheet possessing an opening for exposing an inner lead part of the lead frame, keeping the lead frame at a temperature in the range of 100 DEG to 240 DEG C. under a high degree of vacuum exceeding the level of 10-5 Torr, and depositing aluminum on the inner lead part by arc-discharge type ion plating.