PURPOSE: To prevent the generation of flaws on the surface of the recording film of a disk substrate by a holder mask and to decrease the defects of the recording surface to be generated by peeling of the substrate material and the recording film.
CONSTITUTION: The inner peripheral part and outer peripheral part of the holes of the outer peripheral holder mask 14 and inner peripheral holder mask 15 on a disk substrate 12 side are provided with carved-in parts 14a, 15a formed by spot facing or the like as film release parts which do not come into contact with the surface part of the recording film of the disk substrate 12. These carved-in parts 14a, 15a for preventing flaws are formed by carving in the end faces 14b, 15b of the outer peripheral holder mask 14 and inner peripheral holder mask 15 at 0.2mm width and 0.1mm height (depth) along the inner and outer peripheral directions thereof. As a result, the direct contact of the surface part of the recording film of the disk substrate 12 with the inner peripheral part of the hole at the end face 14b of the outer peripheral holder mask 14 and the outer peripheral part at the end face 15b of the inner peripheral holder mask 15 is prevented.
ORUKAWA MASAHIRO
KUDO YOSHIHIKO
