METHOD AND APPARATUS FOR PRODUCTION OF MAGNETIC RECORDING MEDIUM SUBSTRATE

摘要

PURPOSE:To produce the magnetic recording medium substrate, such as substrate for a magnetic disk, which maintains high flatness and concentricity with high efficiency without variations. CONSTITUTION:A wafer 2 is formed by slicing a single crystal silicon rod 1 of a large diameter (diameter d2) at a high speed of a slicing speed V2>V1. Plural sheets of doughnut-shaped disks 3 each having a central hole 4 and a small diameter (diameter d1) are cut out of this wafer and are finished, by which finished products are produced. The cutting out is executed by irradiating the central hole 4 of the cut out disk 3 and edge parts 27, 28 of the outer periphery thereof with a laser beam and rotating the wafer 2 around the central hole 4 at it center. The positioning of the cutting out position of the disk 3 to be cut out is executed by turning the wafer 2 to a prescribed indexing angle position. Where, V1 denotes the sliding speed necessary for generating the warpage of a prescribed value or below from the single crystal silicon rod of the diameter (diameter d1).