| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a method for forming a hole for preventing contamination of a copper foil surface of a copper clad plate, when a hole is to be formed by using carbon dioxide gas laser. SOLUTION: After an etching film or liquid state etching resist is arranged on the surface of the copper clad plate, and only the portion of a target mark is developed, the surface copper foil is etched and eliminated. The target mark in this portion is read with a CCD camera, and the film or the resist is irradiated directly with a high output carbon oxide gas laser, preferably selected from 10-60 mJ, thereby working and removing an outer layer copper foil and an inner layer copper foil, and forming a through-hole and/or a blind via hole. Thus, the through-hole and/or the blind via hole can be formed directly using the carbon dioxide gas laser, in such a manner that the surface layer copper foil is not contaminated. A high density printed wiring board can be obtained, using the copper clad plate.</p> |
