| 摘要 |
PURPOSE:To polish a disc substrate into highly accurate finishing, by reciprocating a pressure head, pressing an abrasive tape to the disc substrate, in a radial direction of this substrate, and varying the travel speed to some extent. CONSTITUTION:When a pressure head 16 of a pressure member 17 is moved toward the inner circumferential side from the outer circumferential side of a disc substrate 10, a speed of this pressure head 16 is varied so as to be increased. Likewise, when it is moved toward the outer circumferential side from the inner circumferential side, its speed is controlled so as to be decreased the other way. Therefore, a reciprocating speed of this reciprocating member is controlled so as to follow up a variation in peripheral velocity of the disc substrate 10 whereby on the basis of a difference in the peripheral velocity in a radial direction of the disc substrate 10, it is uniformly polishable into highly accurate finishing without entailing any variation in stock removable. |
