| 摘要 |
PROBLEM TO BE SOLVED: To provide a printed wiring board whose insulating property between conductors is enhanced and whose reliability is increased by a method in which the lower part of a plated resist layer is formed to be wider than the upper part. SOLUTION: A dry film is laminated on an insulating board 1. After its lamination, a negative film is placed, ultraviolet rays are irradiated at 200mj/cm<2> , and the board is exposed. After its developing operation, the board is dried, ultraviolet rays are irradiated additionally at 1500mj/cm<2> , photosensitive layers are hardened, and plated resist layers 3 are formed. In the plated resist layers 3, the width of upper parts 4 is at 100μm, the width of lower parts 5 is by about 3 to 4μm wider than that one one side, and the parts are formed at an interval of 100μm. Then, after the plated resist layers 3 have been formed, adhesive layers 2 are treated so as to be roughened, an electroless copper plating treatment is then executed, and conductors 6 are formed. In this manner, since every lower part 5 of the plated resist layers 3 is formed to be wider than every upper part 4, it is possible to obtain a printed-wiring board whose insulating property between the conductors can be enhanced and whose reliability is high.
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