To obtain an auxiliary material for making a through hole with a smaller diameter, and a via hole at high accuracy and high speed by directly radiating a carbon dioxide gas laser of high power to a copper-clad plate.
In case of this auxiliary material, a coating or sheet-like auxiliary material composed of a resin composition material including 3-79 volume % of at least one kind or, two or more kinds of metallic powder is disposed on a copper-clad plate, and the energy chosen from that of 20-60 mj/pulse of the carbon dioxide gas laser power is radiated from the above for boring the copper foil on the surface. By using the auxiliary material for copper foil surface, the carbon dioxide gas is directly radiated for boring the copper foil. Thereby, the through hole and the via hole can be formed at high accuracy and high speed, and a hole for a printed wiring board with improved economy can be obtained.
IKEGUCHI NOBUYUKI
TANAKA YASUO
KATO SADAHIRO
Next Patent: SOLDER PASTE