US Patent 7909976 Method for filling through hole

It is characterized in that in the case of filling a through hole formed in a substrate with a plated metal by electrolytic plating, the electrolytic plating is started by a high current density higher than Constant Current Density capable of fully filling the through hole when the electrolytic plating is performed with a current density held constant as a current density of the electrolytic plating, and the electrolytic plating is continued by being changed to a current density lower than the high current density by the time of reaching formation of a seam diameter in which an inside diameter does not decrease even when the electrolytic plating is continued after the electrolytic plating at the high current density is started.