US Patent 7959492 Disk-shaped substrate inner circumference polishing method

The disk-shaped substrate inner circumference polishing method for polishing an inner circumference of a disk-shaped substrate including a portion having an opening hole at the center thereof includes inserting a brush having a shaft core into the portion having the opening hole of the disk-shaped substrate; fixing one end and the other end of the brush to a pair of rotating shafts that are provided at mutually detached positions and pulling at least any one of the one end and the other end of the brush and applying tension in the axial direction to the shaft core of the brush; and rotating the brush and polishing the inner circumference of the disk-shaped substrate.