| 摘要 |
PROBLEM TO BE SOLVED: To form a high-density fine wiring pattern by uniformly thinning a copper layer of a surface while acquiring connection stability between conductor layers by maintaining copper plating thickness in a via hole or through-hole.SOLUTION: A dissimilar metal layer having an etching characteristic different from a copper layer is formed before applying copper plating to the via hole or through-hole is formed on the copper layer of a surface that becomes thick by copper plating for forming a via hole or through-hole, a via hole or through-hole subjected to copper plating is formed by punching, the via hole or through-hole is filled with a padding resin, the copper layer is etched until the dissimilar metal layer is completely exposed, the dissimilar metal layer is peeled off, projecting padding resin is removed by a mechanical method, the thickness of the copper layer is thinned with copper thickness in the through-hole or via hole maintained, the easiness of wiring pattern formation by etching is secured, and a high-density fine wiring pattern is formed. |
