Abstract: Provided is a method for producing a circular wafer using a grinding tape to grind the edge of a wafer comprising a crystalline material. A primary grinding step is provided for contacting a grinding body to the peripheral portion of a wafer placed centered on a horizontal stage and rotating the stage, thus grinding the peripheral portion. The radius of the wafer is measured, and a radius is set that is no greater than the measured smallest radius, and the difference ?r between the set radius and the measured wafer radius along the peripheral portion is determined. The portions of the peripheral portion at which ?r is greater than a predetermined value are determined and a secondary grinding step is provided for contacting the peripheral portion and the grinding body, rotating the stage forwards and backwards in a predetermined range of rotational angles, and grinding the peripheral portion.

Abstract: A machining apparatus, in which a plurality of user set programs in relation to one axis is written and the amount of the infeed motion of the grinding wheel is increased to restrain the change of the load of the grinding wheel, improves a machining accuracy and achieve a longer life of the grinding wheel.

Abstract: In the production of a glass substrate for magnetic disks, in a step of polishing a main surface of a circular glass plate, roll-off is reduced without reducing the polishing rate. The process comprises a step of polishing a main surface of a circular glass plate by using an acidic polishing fluid containing colloidal silica or fumed silica, and a water-soluble polymer having at least one member selected from a group consisting of a carboxylic acid group, a carboxylate group, a sulfonic acid group and a sulfonate group, bonded to its main chain, or an acidic polishing fluid containing 100 parts by mass of colloidal silica or fumed silica, and from 0.02 to 0.1 part by mass of a surfactant having a sulfonic acid group.

Abstract: A chemical-mechanical polishing apparatus is provided with a downstream device for conditioning a web-shaped polishing pad. The device may be used to condition a glazed portion of the pad, and then the conditioned pad portion may be used again for polishing. The conditioning device is preferably arranged to apply different conditioning treatments to different portions of the glazed pad. The conditioning device may have roller segments that rotate at different speeds. Alternatively, the device may have non-cylindrical rollers that provide different rotational speeds at the pad surface, or the device may apply different pressures at different portions of the pad. The device may be arranged to provide uniform conditioning across the width of the pad. The invention is applicable to methods of planarizing semiconductor wafers. The invention may be used to condition circular pads in addition to web-shaped pads.

Abstract: The grinding machine for grinding a frictional surface of a pad of the present invention comprises: a grooving cutter to be rotated; a cylindrical grinding wheel arranged at a position distant from the grooving cutter; a pad chucking portion for holding a frictional surface of the brake pad so that the frictional surface can be opposed to the outer circumferential surface of the cylindrical grinding wheel; an X-axis feed mechanism for advancing and retreating the pad chucking portion in the direction of X-axis parallel to the frictional surface of the brake pad; a Y-axis feed mechanism for advancing and retreating the pad chucking portion in the direction of Y-axis perpendicular to the frictional surface of the brake pad; a Z-axis rotation mechanism for rotating the brake pad around the Z-axis perpendicular to the frictional surface of the brake pad; and a numerically controlling circuit for controlling the motions conducted by the above mechanisms.