PURPOSE: To prevent damage of a surface of a polyimide film by forming the film of four layers of a protective plastic film, the polyimide film, a thermosetting adhesive layer and a metal foil.
CONSTITUTION: After both side surfaces of a polyimide film and one side surface of a protective plastic film are activated by a low temperature plasma of inorganic gas, the activated surfaces of the polyimide film and the plastic film are thermally press-bonded. Then, after the other activated surface of the polyimide film is coated with heat-curing agent, a metal foil is press-bonded to be laminated. Thus, contact with rolls in a later circuit forming step, etc., wear, scratch, pressing damage, etc., at the time of handling, and damage of the surface of the polyimide film can be prevented.
SAKAGUCHI SANETERU
EIKUCHI KICHIJI
