| 摘要 |
PURPOSE:To make it possible to suppress warpage within the regular range by a method wherein a molded matter is separated from a stamper before the opening of a mold at the molding of the substrate for an optical disc with an injection molder, on the movable mold of which the stamper is mounted. CONSTITUTION:A substrate for an optical disc is molded with an injection molder consisting of a fixed mold 2 and a movable mold 3, to which a stamper 1 is mounted. At the above-mentioned molds, the mirror-finished part of the movable mold 3 is formed in a convex shape having the inner peripheral part thicker than the outer peripheral part. On the other hand, the mirror-finished part of the fixed mold 2 is formed in a concave shape corresponding to the mirror-finished part of the movable mold. At the molding of an optical disc, before the opening of the mold, a molded matter is separated from the stamper 1 by blasting air in order to suppress the warpage. Further, molding is performed under the condition that the temperature difference is produced between at the outer peripheral part and at the inner peripheral part of the movable mold 3 such as the temperature at the outer peripheral part is set to be 105 deg.C and that at the inner peripheral part is set to be 115 deg.C so as to suppress the warpage of the substrate. |
