| 摘要 |
PROBLEM TO BE SOLVED: To obtain electric continuity of a smalled-diameter inner via hole, to materialize a high-density wiring pattern, pertaining to the method of manufacturing a printed wiring board. SOLUTION: To achieve the above purpose in this method of manufacturing a printed wiring board, mold releasing films different in thickness are arranged on both faces of porous base material, and the thickness of the mold releasing film on the opposite face to a laser beam application face at the time of processing especially a through hole is thinned. Further, the relation between the thickness of the transmuted layer in the vicinity of the processed part of the mold releasing film which can be processed by laser beam, the thickness tf of the mold releasing film, and the diameter d of the bore processed in the mold releasing film is made such that (tf+th)/d<=0.4. |
