| 摘要 |
PURPOSE:To enable a circuit board to cope with the miniaturization and the densification of a circuit so as to make an electric equipment miniature and light weight by a method wherein a resin film is formed on the upside of an insulating substrate other than a part where a wiring is provided, and a conduc tive member or an optical waveguide member is put into a recess surrounded with the resin film. CONSTITUTION:A photosensitive resin 2 is applied onto the surface of an insulating board 1 as thick as 10-100mum. A wiring pattern can be controlled in resistance value by varying the resin film 2 in thickness. The resin film 2 is patterned into a resin film 2a through a mask 3 by photosetting the film 2 through ultraviolet rays exposure. When the unexposed resin 2 is removed by cleaning, recesses 5 are formed on the board 1. Then, a conductive member 6 is put into each of the recesses 5. As the conductive member 6 can be formed as thick as the resin film 2a, a wiring section lessened in electrical resistance can be formed even if the wiring is fine in pitch. When the resin film 2a is removed, a circuit board where only a wiring pattern of conductive member 6 is formed can be obtained. Even if an optical waveguide member is used in place of a conductive member, the same result can be obtained. |
