INJECTION MOLDING METHOD OF OPTICAL DISK SUBSTRATE

摘要

PURPOSE:To provide a method for injection molding a substrate for optical disks which is substrate molding for optical disks of a board groove width, realizes a high transfer rate uniform over the entire surface of the substrate and is molded with lessened warpage. CONSTITUTION:A resin temp. is kept at 320 to 350 deg.C at the time of injection molding the optical disk substrate having the guide grooves and having the ratio W/P of 60 to 80% between the width W of these guide grooves and a track pitch P by using a polycarbonate resin. The metal mold temp. on a stamper mounting side is kept at 120 to 140 deg.C and the metal mold temp on the side facing the stamper is set lower by 20 to 5 deg.C than the metal mold temp. on the stamper mounting side.