Method for manufacturing disc-shaped substrate material

摘要

A method for manufacturing a disc-shaped substrate material for an optical disc with a center hole is provided so as to form a resin layer with a uniform thickness distribution in a simple process. A stamper 10 is held to a movable metal mold 34 by suction means 36 in a cavity 31 in a mold assembly 30. The stamper 10 includes a through hole 10A with a diameter smaller than that of a center hole of an optical disc. When a disc-shaped substrate material 12 formed by injection molding is solidified, and the movable metal mold 34 is separated from a fixed metal mold 32, release means 38 is protruded from the through hole 10A so as to push the disc-shaped substrate material 12 for release.