Balance mechanism for movable jaw chuck of a spin station

摘要

A wafer processing spin station includes a movable jaw chuck which is adjustable in position at the clamping position to accommodate offset of the center of the wafer with respect to the axis of rotation. A balancing apparatus and method are used with the movable jaw chuck to maintain the gripping force exerted on the wafer by the movable jaw chuck substantially unaffected by the centrifugal forces developed by the movable jaw chuck at all speeds of rotation produced during the spinning operation and within the range of the clamping positions of the movable jaw chuck.