抄録
An aluminum specimen covered with porous type oxide films with 3 to 54μm thickness was irradiated by a pulsed Nd-YAG laser through a convex lens with 20 mm focal length in a solution to examine the mode of oxide film removal by laser irradiation. A prototype printed circuit board was fabricated using laser irradiation and Au electroplating. Thin oxide films were removed instantaneously after laser irradiation onset by the laser ablation mechanism. Thick oxide films were destructed initially from the upper part of the oxide films by the thermal shock mechanism, and then by the laser ablation mechanism. Further laser irradiation after the film removal caused the formation of many cracks in the oxide film surrounding the irradiated area. By scanning a laser beam over a specimen covered with oxide films with 9μm thickness, the oxide film was removed uniformly with a 30μm line width. Fine pattern coils of 30μm wide Au lines were fabricated on the insulating board by consecutive processes of aluminum anodizing, laser irradiation, Au electroplating, resin attaching, and removal of aluminum substrate and oxide film.
