| 摘要 |
PURPOSE:To remove gas generated by plating reaction, to eliminate the disturbance of precipitation of plating to the inner wall of a through hole and to reduce generation of through hole voids by fluctuating a copper-extended laminated plate continuously upon starting of plating. CONSTITUTION:A circuit 3 and a land 4 are formed on a copper foil 2 by a photoprinting method. Then, the whole surface except the land 4 is coated with plating resistant resist 5 by a screen printing method to obtain a resist layer. Then, a through hole 6 is opened by drilling. Thereafter, it is dipped in aqueous electroless plating catalytic solution of aqueous copper metal colloidal solution for 5min to apply electroless plating catalyst 7 to the inner wall of the hole 6. Subsequently, it is hung and dipped in the solution at 70 deg.C, and continuously fluctuated in the same direction as the passing direction of the hole 6. Further, a copper-extended laminated plate 11 is inverted upside down, hung, again started to be plated, and intermittently fluctuated. Then, it is again continuously fluctuated, a second conductor layer 28 of the upper layer is formed, and the conductor layer of a through hole 9 is formed to obtain a printed circuit board. |
