| 摘要 |
PURPOSE:To improve CN ratio and production efficiency and to reduce cost by molding and storing a resin in an inert gaseous resin, thereby forming a resin substrate. CONSTITUTION:The resin disk substrate with guide grooves is formed by a vent type injection molding machine in an Ar atmosphere chamber. The resin charged into the molding machine is increased in free volume and is compressed and expanded by the screw, by which the resin is efficiently degassed. After the molded substrate is stored for 30hr in the Ar atmosphere, a dielectric layer, recording layer, etc., are formed thereon without exposing the substrate into the atm. The CN ratio is, therefore, increased even by short-time evacuation or long-time evacuation and the production efficiency is improved by the gas substitution during the injection molding, by which the cost is reduced. |
