| 摘要 |
PROBLEM TO BE SOLVED: To form a highly reliable circuit section and wiring section by etching an unnecessary base metallic layer in a state such that the base metallic layer in a via hole in which the contact electrode of the circuit section is to be formed and the base metallic layer in a window in which the wiring of the wiring section is to be formed with hole filling resist films. SOLUTION: After a resist film composed of a photosensitive resin is applied to the whole surface of a printed wiring board, hole filling resist films 13 are formed by drying, exposing, and developing the resist film so that a plating resist film may be left only in a via hole 4 and a window 6. Then the unnecessary portion of a metallic layer 5 which is not masked with the resist film 13, but exposed, is etched. In etching the unnecessary portion, the base metallic layer 5 covering the side walls near each section of the via hole 4 is not damaged, because the layer 5 left in the via hole 4 and window 6 is protected with the hole filling film 13. Therefore, a contact electrode or wiring can be formed as designed and, accordingly, a highly reliable circuit section and wiring section can be formed. |
