| 摘要 |
PURPOSE:To suppress eccentricity and prevent diffusion of a bonding agent by independently providing each hub to both surfaces of a disk, coinciding eccentricity at both surfaces and providing a recessed area to non-information recording area at the internal and external circumference in the side of recording layer of the disk. CONSTITUTION:A disk substrate 1 comprises a center hole 7, information recording area 3a and non-information recording area 4a and ring type recessed areas 2a and 2b are respectively provided at the internal and external circumferences of the non-information recording area 4a. A bonding agent is dropped partially to eight points with an equal interval on the predetermined circumference of the recording area 4a to attach two sheets of disk substrate. In this case, an excessive bonding agent 5 flows into the recessed areas 2a, 2b and never diffuses to the internal and external circumferences of the substrate 1a. Next, while the substrate 1a is rotating, eccentricity is adjusted to almost zero and the hubs 6a, 6b are sequentially fixed. Thereby, it is no longer necessary to remove the diffused area of bonding agent 5 and eccentricity may be reduced. |
