Dual gas bearing substrate positioning system
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.
1. A dual gas-bearing system, comprising:
a vacuum-preloaded gas bearing having an output face, wherein the vacuum-preloaded gas bearing is mounted to a machine base in a fixed location;
a substrate having a first surface facing the output face of the vacuum-preloaded gas hearing and an opposing second surface, wherein a position of the substrate is moveable in a direction normal to the output face of the vacuum-preloaded gas bearing, and wherein 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-bearing backer having an output face facing the second surface of the substrate, wherein the gas-bearing backer is freely moveable in a direction normal to the output face of the vacuum-preloaded gas bearing, and wherein a gas flow through the output face of the gas-bearing backer imparts a second net force onto the second surface of the substrate and provides a gap between the output face of the gas-bearing backer and the second surface of the substrate, and wherein the second net force and the gap between the output face of the gas-bearing backer and the second surface of the substrate are independent of the position and thickness of the substrate.
2. The dual gas-bearing system of claim 1 , wherein the gap between the output face of the gas-bearing backer and the second surface of the substrate is no more than 50 μm.
3. The dual gas-bearing system of claim 1 , wherein the vacuum-preloaded gas bearing is a thin film deposition head.
4. The dual gas-bearing system of claim 3 , wherein the vacuum-preloaded gas bearing supplies a plurality of gaseous materials through output openings on its output face, thereby exposing the first surface of the substrate to the plurality of gaseous materials.
5. The dual gas-bearing system of claim 4 , wherein the plurality of gaseous materials includes at least two reactive gaseous materials that react to deposit a layer of solid material on the first surface of the substrate.
6. The dual gas-bearing system of claim 1 , wherein the output face of the vacuum-preloaded gas bearing includes a plurality of output openings through which the gas flow is provided and a plurality of exhaust openings through which the gas flow is exhausted.
7. The dual gas-bearing system of claim 1 , further including a lateral constraint system that constrains the gas-bearing backer from moving in a plane parallel to the output surface of the vacuum-preloaded gas hearing while enabling the gas bearing backer to move freely in a direction normal to the output face of the vacuum-preloaded gas bearing.
8. The dual gas-hearing system of claim 7 , wherein the gas-bearing backer fits within an opening in the lateral constraint system.
9. The dual gas-bearing system of claim 7 , wherein the lateral constraint system includes a flexure attached to the gas-bearing backer.
10. The dual gas-bearing system of claim 7 , wherein the lateral constraint system includes a means for conveying energy to the gas-bearing backer or conveying electrical signals to or from the gas-bearing backer.
11. The dual gas-bearing system of claim 7 , wherein the lateral constraint system includes a gas supply tube which supplies gas to the gas-bearing backer.
12. The dual gas-bearing system of claim 1 , wherein the vacuum-preloaded gas bearing is positioned below the substrate with its output face facing upwards and the gas-bearing backer is positioned above the substrate with its output face facing downwards.
13. The dual gas-bearing system of claim 12 , wherein the second net force corresponds to a weight of the gas-bearing backer.
14. The dual gas-bearing system of claim 1 , wherein the substrate, the output face of the vacuum-preloaded gas bearing, and the output face of the gas-bearing backer are all oriented vertically, and further including a force mechanism which applies a force onto the gas-bearing backer that pushes the gas-bearing backer toward the substrate.
15. The dual gas-bearing system of claim 14 , wherein the force mechanism applies a substantially constant force.
16. The dual gas-bearing system of claim 1 , wherein the output face of the gas-bearing backer is a porous surface through which the gas flow passes.
17. The dual gas-bearing system of claim 1 , further including a force mechanism that imparts a force onto the gas-bearing backer that pushes the gas-hearing backer toward the substrate, wherein the force mechanism supplies a substantially constant force.
18. The dual gas-bearing system of claim 1 , further including a heater for heating the gas-bearing backer.
19. The dual gas-bearing system of claim 1 , further including a substrate positioning system that moves the substrate in a lateral direction parallel to the output face of the vacuum-preloaded gas bearing according to a specified motion pattern.
20. The dual gas-bearing system of claim 1 , wherein the substrate is a flexible substrate.
21. The dual gas-bearing system of claim 1 , further including a means for conveying energy to the gas-bearing backer or conveying electrical signals to or from the gas-bearing backer.
22. The dual gas-bearing system of claim 1 , further including a gas supply tube which supplies gas to the gas-bearing backer.