METHOD FOR FILLING THROUGH-HOLES IN PRINTED CIRCUIT BOARD, CAPABLE OF INCREASING THICKNESS OF PROTECTIVE LAYER BY FORMING REINFORCEMENT LAYER ON PACKED BED

摘要

PURPOSE: A method for condensing through holes in a printed circuit board is provided to increase the thickness of a protective layer by forming a reinforcement layer on a packed bed closing a through-hole or by forming the packed bed after forming a plated layer on the printed circuit board. CONSTITUTION: A circuit pattern(33), which is electrically coupled with both sides of an insulating layer via through holes(37), is formed. A protective layer, which covers a surface enclosing the circuit pattern and the through holes, is formed. The circuit pattern is selectively exposed by selectively removing the protective layer, and a packed bed(45) is formed in the through hole. A reinforcement layer(47) is formed with a predetermined thickness on the packed bed formed in the through hole.