To prevent the entrance of a chemical into an electronic part-housing hole by forming an insulating film the surface of which is positioned farther from the surface position of an outer-layer conductor circuit in the vertical direction of a multilayered board on the surface of the multilayered board so that the insulating film can surround the outer periphery of the housing hole and masking the housing hole with a film body by using the surface of the insulating film as a sticking margin.
Through holes 3 are formed through a multilayered board 15 formed by laminating layers upon another and sticking the layers to each other except the part of the board 15 where an electronic parts housing hole 2 is formed. An insulating film 10 the surface of which is positioned father from the surface of an outer-layer conductor circuit 4a formed on the surface of the board 15 on which the hole 2 is opened in the vertical direction of the board 15 is formed on the surface of the board 15 at the positions between the outer peripheral section and the through holes 3 so that the film 10 can surround the housing hole 2. Then the housing hole 2 is covered with a film body 8 by using the surface of the film 10 as a sticking margin. Therefore, the entrance of a chemical for plating into the housing hole 2 from the boundary between the circuit 4a and film body 8 can be prevented.
KANEKO JUNJI
MORIOKA KAZUNOBU
FUKUYA NAOHITO
KANETANI DAISUKE
