| 摘要 |
PURPOSE: A method of manufacturing printed wiring board with ultra fine wire pattern is provided to achieve a printed wiring board which has an ultrafine pattern having an excellent form almost free from undercuts and retaining copper foil adhesive strength by a subtractive process. CONSTITUTION: A method comprises a step of providing an ultrathin-copper-foil-clad board having a through hole and/or a blind via hole formed therein and having an outermost copper foil thickness of 5μm or less, plating the surface thereof including the inside of the hole by electroless copper plating to form an electroless copper plating layer having a thickness of 0.1 to 1μm, a step of forming an electrolytic copper plating layer having a thickness of 0.5 to 3μm by using the electroless copper plating layer as an electrode, a step of forming a plating resist layer for pattern electrolytic copper plating on a necessary portion of the copper plating layer, a step of forming a pattern copper plating layer having a thickness of 6 to 30μm on the copper surface in a portion where the plating resist layer is not formed, by electrolytic copper plating, a step of removing the plating resist layer, and a step of etching the entire surface to dissolve and remove the thin electrolytic copper layer, the electroless copper layer and the ultrathin copper foil layer in at least a portion where the pattern copper plating layer is not formed. |
