Abstract: A double-sided polishing apparatus includes: a lower surface plate; an upper surface plate; and a carrier disposed between the lower surface plate and the upper surface plate and holding a disk-shaped workpiece, wherein the carrier is configured to rotate about a center of the lower surface plate and the upper surface plate and to rotate about a center of the carrier, the double-sided polishing apparatus includes a thickness measuring sensor at a fixed position above the upper surface plate or below the lower surface plate or at a movable position in an upper portion of the upper surface plate or a lower portion of the lower surface plate, the carrier includes circular perforations each holding the workpiece at a position eccentric to the center of the carrier, when a central position of any of the perforations preset by a user is defined as a first reference position, with a distance between a center of the upper surface plate or the lower surface plate and a center of any of the perforations preset by the u

Abstract: A double-sided polishing apparatus includes: a lower surface plate; an upper surface plate; and a carrier disposed between the lower surface plate and the upper surface plate and holding a disk-shaped workpiece, wherein the carrier is configured to rotate about a center of the lower surface plate and the upper surface plate and to rotate about a center of the carrier, the double-sided polishing apparatus includes a thickness measuring sensor at a fixed position above the upper surface plate or below the lower surface plate or at a movable position in an upper portion of the upper surface plate or a lower portion of the lower surface plate, the carrier includes circular perforations each holding the workpiece at a position eccentric to the center of the carrier, when a central position of any of the perforations preset by a user is defined as a first reference position, with a distance between a center of the upper surface plate or the lower surface plate and a center of any of the perforations preset by the u

Abstract: The double-side polishing apparatus for polishing both faces of a wafer is capable of reliably measuring not only a thickness of an outer part of the wafer but also a thickness of a center part thereof. The double-side polishing apparatus comprises: a lower polishing plate; an upper polishing plate held by a frame; and a carrier having a through-hole for holding the wafer. A window section, through which a laser beam passes, is formed in a part of the upper polishing plate, under which the wafer held by the carrier passes. An optical thickness measuring equipment is provided to a part of the frame, under which the window section passes while the upper polishing plate is rotated. The thickness measuring equipment emits the laser beam through the window section, receives reflected beams reflected from an upper face and a lower face of the wafer, and calculates the thickness of the wafer on the basis of peak values of the reflected beams.

Abstract: The double-side polishing apparatus for polishing both faces of a wafer is capable of reliably measuring not only a thickness of an outer part of the wafer but also a thickness of a center part thereof. The double-side polishing apparatus comprises: a lower polishing plate; an upper polishing plate held by a frame; and a carrier having a through-hole for holding the wafer. A window section, through which a laser beam passes, is formed in a part of the upper polishing plate, under which the wafer held by the carrier passes. An optical thickness measuring equipment is provided to a part of the frame, under which the window section passes while the upper polishing plate is rotated. The thickness measuring equipment emits the laser beam through the window section, receives reflected beams reflected from an upper face and a lower face of the wafer, and calculates the thickness of the wafer on the basis of peak values of the reflected beams.