Until police box corrugated current value at the time

摘要

PROBLEM TO BE SOLVED: To stably form a uniform and dense pit shape, and also improve the ball-point pen compatibility by a method wherein an alternating waveform wherein a period of time while an alternating waveform current value at the time of an anode reaches a peak from zero, is within a specified range, and which has at least one peak since a decrement of the current after that, is used. ;SOLUTION: In a surface roughening, an alternating waveform current to be used is made one wherein a rising time t₁ to a peak is 1 msect₁≤10 msec, and also, 1 msect₁≤1/3 of an anode time, and which has at least one peak after a decrement. In this case, t₁ is preferably 1 msect₁≤5 msec, more preferably, 1 msect₁≤3 msec and also, 1 msect₁≤1/4 of an anode time. By this method, a uniform and dense pit shape can be stably formed without generating failures on a waveform device, etc., and also, the ball-point pen compatibility can be improved.;COPYRIGHT: (C)1999,JPO