STUMPER FOR OPTICAL DISK, AND MANUFACTURING METHOD OF THE SAME

摘要

PROBLEM TO BE SOLVED: To provide an optical disk stumper capable of greatly prolonging a continuously used life by adjusting the backside shape and material quality of the stumper. SOLUTION: In this optical disk stumper attached to a metallic mold for an injection molding machine and used for the step of obtaining an optical disk substrate by continuous injection molding, the center line average roughness Ra of a stumper backside brought into contact with the metallic mold is set in the range of 0.02μm to 0.10μm, and a DCL(diamond-like carbon) film is formed in the backside. Also, a manufacturing method is provided for the optical disk.