| 摘要 |
PROBLEM TO BE SOLVED: To form a cover lay excellent in cost efficiency and reliability on a desired circuit portion of a circuit wiring board by forming a polyimide resin film on at least some part of a conductor circuit by electrodeposition. SOLUTION: A polyimide resin film is formed on the conductor circuit surface of a circuit wiring board by electrodeposition. Since the polyimide resin film can be thus formed only on the conductor circuit surface, it is unnecessary to form a polyimide resin film on the surface of surrounding insulators, and unnecessary consumption of expensive polyimide resin is eliminated. This makes the cover lay excellent in cost efficiency. In addition, since the polyimide resin film is formed only on the circuit surface by electrodeposition, the production of a void which is apt to be produced in the proximity to the boundary of junction between the insulator surface and the circuit portion is prevented. For areas for bonding or bump formation where the formation of a cover lay is unnecessary, the polyimide resin film can be formed only at desired points by forming a resist layer in advance.
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