Manufacture of flexible circuit board

Abstract

Abstract PURPOSE:To provide a uniform covering with an organic insulating film easily by a method wherein metal thin films are coated with polyimide precursor solution and, after the solution is semi-cured, the metal thin films are laminated and the coating solution layer is pre-cured and then the metal thin films are patterned to form conductor circuits and the coating solution layer is cured by heat. CONSTITUTION:Metal thin films 2 are coated with polyimide or polyimide or polyimide precursor solution and the coating solution layers 1a are semi-cured. The metal thin films 2 are laminated with the coating solution layer 16 between and the coating solution layer 1b is pre-cured and conductor circuits 3 are formed. Then the coating solution layer 1c is cured by heat to form a polyimide layer 4. Polyamide carbonic acid solution is applied to two rolled copper thin films by making the solution flow on the copper films and semi-cured by heat. Then the respective coating solution layers are laminated with each other and pressed to pre-cure to form a flexible circuit board. Then the copper thin films are etched by dipping them into etchant. The resist is peeled off and removed and conductor circuits are formed to produce a circuit board and, at the same time, heat is applied to obtain a flexible circuit board composed of the copper foils laminated with the polyimide layer in between.

Inventors

• 👤 Koji Hara

Bibliographic Details