2001 年 22 巻 6 号 p. 370-375
Printed circuit boards used in many electronic parts are fabricated by photolithography, where copper foil attached to organic material boards is etched locally to produce fine patterns. The authors introduce an innovative method for the fabrication of printed circuit boards, using anodizing, laser irradiation, and electro-plating or electroless-plating. Aluminum foil with anodic oxide coating is immersed in solutions containing metal ions, and then irradiated with a pulsed Nd-YAG laser through a convex lens. Laser irradiation removes the oxide film locally and allows metal particles to be deposited by redox reactions on the portion. Thus electro-plating or electroless-plating is possible over the metal particles at the laser irradiated area. An organic resin is bonded to the aluminum foil to remove the aluminum substrate by dissolving in alkaline solutions. The procedure described above provides a pattern with 9 µm line width and 12 µm interval.