Patent ID: 6709323
Filing Date: 2004-03-23
Classification: B24B

Abstract:
A carrier for flat workpieces to be polished by a polishing apparatus, the polishing apparatus including at least one polishing disk, the carrier comprising:a flange connected to a spindle, the spindle being operable to be rotated, lifted and lowered; a support plate is coupled to the flange with a universal joint, whereby the support plate may linearly move and tilt relative to the flange, the support plate having a plurality of vertical bores therethrough which extend to the under side thereof, the plurality of vertical bores being connected to a vacuum source; a membrane between the flange and the support plate to define a hollow spaces, the hollow space connected to a fluid source under pressure for varying the pressure in the hollow space; a ring-shaped circumferential membrane supported by a radially outer portion of the support plate and a proportional control valve is connected to the ring-shaped circumferential membrane so that a displacement of the ring-shaped circumferential membrane is achieved; and the support plate and the ring-shaped circumferential membrane being structured such that a workpiece to be polished is engaged by the lower side of the support plate and of the ring-shaped circumferential membrane and carried by the support plate through a vacuum created in the plurality of vertical bores in the support plate by the vacuum source and can be pressed from above against the polishing disk in that the fluid pressure in the hollow space exerts a pressure onto the support plate and the ring-shaped circumferential membrane is displaced using the proportional control valve towards the polishing disk.