BLU RAY DISC

摘要

A blue-ray disc is provided to more secure a storing space of data, simultaneously enhance quality, reduce a defective rate, and enhance the entire producing yield by being coated to prevent the generation of a mound at an edge which is an upper part of an external side end part of a cover layer formed as a polymer. A polymer flows in a polymer movement preventing part(110) formed in an external side end part of a substrate(100) to uniformly form the thickness of a blue-ray disc. The polymer movement preventing part(110) has a chamfer(111) which is slanted at 15 to 20 degrees toward an outward lower part from an upper part of the external side end part of the substrate(100).