METHOD FOR PLATING COLUMNAR CONDUCTOR AND MULTI-LAYERED PRINTED WIRING BOARD OBTAINED BY IT

摘要

PROBLEM TO BE SOLVED: To obtain a method for plating columnar conductor by which the time require for a process for exposing the head sections of columnar conductors can be shortened. SOLUTION: In a method for plating columnar conductors 106a, 106b, and 106c formed for connecting the upper and lower conductor layers of a printed wiring board to each other, the current densities at both the starting time and terminating time of plating treatment are set within the allowable current density range of a plating solution, and the current density at the terminating time is set higher than that at the terminating time. In the method, electroplating is performed at least once by continuously increasing the current density during the plating process from the starting time to the terminating time.