Patent attributes
A dual gas-bearing system includes a vacuum-preloaded gas bearing, a substrate, and a gas-bearing backer. The vacuum-preloaded gas bearing is mounted to a machine base in a fixed location. The substrate has a first surface facing the output face of the vacuum-preloaded gas bearing and an opposing second surface facing the output face of the gas-bearing backer. The gas-bearing is freely moveable in a direction normal to the output face of the vacuum-preloaded gas bearing. A gas flow through the output face of the vacuum-preloaded gas bearing imparts a first net force onto the first surface of the substrate, and a gas flow through the gas-bearing backer imparts a second net force onto the second surface of the substrate, wherein the second net force and the gap between the output face of the gas-bearing backer are independent of the position and thickness of the substrate.
