Patent ID: 8414360

Claim:
A double side polishing apparatus, comprising: an upper polishing plate and a lower polishing plate for polishing both sides of a wafer; a plurality of carriers, each carrier including a center plate and a circumferential plate, the center plate having a mounting hole where the wafer can be mounted, the circumferential plate having a fitting hole where the center plate is fitted and a gear part formed along the outer periphery thereof, a center of the mounting hole being eccentric from a center of the center plate, a center of the fitting hole being eccentric from the center of a circumferential plate; and a sun gear and an internal gear engaged with the gear part of the circumferential plate to transmit a rotational force to the plurality of carriers, wherein a fitting direction of the center plate into the fitting hole is adjustable for at least two carriers among the plurality of carriers, so that each center of the mounting hole of the at least two carriers is eccentric from the center of each carrier at different distances from each other.