| abstract |
In a direct laser via forming method in which an outer layer copper foil is directly processed, molten scattered Cu and an overhang generated around a via opening at the time of laser processing are selectively removed. In a printed wiring board manufacturing method in which via processing is directly performed on a copper foil using a laser on a copper clad laminate in which a copper foil is bonded to a base resin, a via processing process is performed by (a) copper. The order of the foil surface oxide film formation, (b) laser via processing, (c) alkali treatment, (d) melt scattering Cu. Etching treatment, and (E) desmear treatment. [Selection] Figure 2 |