Patent ID: 7431634

Claim:
A platen assembly for a polishing apparatus, comprising: a platen supporting a polishing belt that makes contact with an object during a polishing process, the platen providing a pressure on the polishing belt during the polishing process; a plurality of first bladders extending in a first linear direction on an entire surface of the platen, and spaced apart by a uniform distance, the first bladders applying pressure to the polishing belt; and a plurality of second bladders extending in the first linear direction on an annular middle portion of the surface of the platen from a first side of the middle portion to a second side of the middle portion opposite the first side, the middle portion between a circular central portion and an annular peripheral portion of the platen, and each second bladder positioned between first bladders of the plurality of first bladders that are on the middle portion of the surface of the platen, the second bladders likewise applying pressure to the polishing belt.