Patent ID: 6196903
Filing Date: 2001-03-06
Classification: B24B

Abstract:
A workpiece carrier for holding a workpiece to be polished and pressing the workpiece against a polishing surface of a turntable, said workpiece carrier comprising:a top ring body for holding the workpiece;a drive shaft for rotating said top ring body and moving said top ring body in a direction to be toward the turntable to press the workpiece against the polishing surface; anda universal joint for transmitting a pressing force from said drive shaft to said top ring body while allowing said drive shaft and said top ring body to be tilted relative to each other, said universal joint comprising:a first member having at least one first curved surface having a radius of curvature centered at a position beyond said top ring body and to be on a surface of the workpiece in contact with the polishing surface of the turntable;a second member having at least one second curved surface having a radius of curvature centered at said position; andat least four rolling elements including a first pair of rolling elements held in rolling contact with said at least one first curved surface and a second pair of rolling elements held in rolling contact with said at least one second curved surface, said first pair of rolling elements not contacting said at least one second curved surface, and said second pair of rolling elements not contacting said at least one first curved surface, such that said top ring body may be tilted about said position relative to said drive shaft.