# US 2019/0376531 A1 · Dual valve fluid actuator assembly > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0376531 A1 - Document ID: US20190376531A1 - Status: Published application - Kind: A1 - Application number: 16/485,406 - Filed: 2018-02-12 - Published: 2019-12-12 - Earliest claimed: 2017-02-15 - Assignees: Nikon Corporation - Applicants: Nikon Corporation - Inventors: Alex Ka Tim Poon; Yeong-Jun Choi; Pai-Hsueh Yang; Sandy Lee; Gaurav Keswani; Rocky Mai - Web page: https://patentgrep.com/patent/US20190376531A1 ## CPC - F15B 9/08: controlled by valves affecting the fluid feed or the fluid outlet of the servomotor (F15B9/06 takes precedence) - F15B 11/0426: {by controlling the number of pumps or parallel valves switched on} - F15B 9/03: with electrical control means {(F15B9/07, F15B9/09, F15B9/17 take precedence)} - F15B 11/006: {Hydraulic "Wheatstone bridge" circuits, i.e. with four nodes, P-A-T-B, and on-off or proportional valves in each link} - F15B 11/028: for controlling the actuating force (F15B11/024 takes precedence) - F15B 11/042: by means in the feed line (F15B11/046, F15B11/05 take precedence) - F15B 11/044: by means in the return line (F15B11/046, F15B11/05 take precedence) - F15B 13/0405: {for seat valves, i.e. poppet valves} - F15B 9/09: with electrical control means - F15B 2013/041: {with two positions} - F15B 2211/30575: in a Wheatstone Bridge arrangement (also half bridges) - F15B 2211/31: characterised by the positions of the valve element - F15B 2211/3144: the positions being continuously variable, e.g. as realised by proportional valves - F15B 2211/327: electrically or electronically - F15B 2211/351: Flow control by regulating means in feed line, i.e. meter-in control - F15B 2211/353: Flow control by regulating means in return line, i.e. meter-out control - F15B 2211/40507: with constant throttles or orifices - F15B 2211/40592: with multiple valves in parallel flow paths, - F15B 2211/6313: the pressure being a load pressure - F15B 2211/6336: representing a state of the output member, e.g. position, speed or acceleration - F15B 2211/665: Methods of control using electronic components - F15B 2211/6656: Closed loop control, i.e. control using feedback - F15B 2211/7054: Having equal piston areas - F15B: SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR ## Abstract A stage assembly (10) includes a stage (14), and a fluid actuator assembly (24) that moves the stage (14). The fluid actuator assembly (24) includes a piston housing (32) that defines a piston chamber (34); (ii) a piston (36) that separates the piston chamber (34) into a first chamber (34A) and a second chamber (34B); (iii) a supply valve (38C) that controls the flow of the working fluid (40) into the first chamber (34A); and (iv) an exhaust valve (38D) that controls the flow of the working fluid (40) out of the first chamber (34A). The supply valve (38C) has a supply orifice (250G) having a supply orifice area, and the exhaust valve (38D) has an exhaust orifice (352G) having an exhaust orifice area. Moreover, the supply orifice area is different from the exhaust orifice area. Further multiple valves of different sizes can be used in combination for the supply and exhaust for each chamber (34A), (34B). ## Claims ### Claim 1 A stage assembly for positioning a workpiece along a movement axis, the stage assembly comprising: a stage that is adapted to couple to the workpiece; a base; a fluid actuator assembly that is coupled to and moves the stage along the movement axis relative to the base, the fluid actuator assembly including (i) a piston housing that defines a piston chamber; (ii) a piston that is positioned within and moves relative to the piston chamber along a piston axis, the piston separating the piston chamber into a first chamber and a second chamber that are on opposite sides of the piston; and (iii) a first valve sub-assembly that includes a first supply valve that controls the flow of the working fluid into the first chamber, and a first exhaust valve that controls the flow of the working fluid out of the first chamber; wherein the first supply valve has a first supply orifice having a first supply orifice area, and the first exhaust valve has a first exhaust orifice having a first exhaust orifice area; wherein the first supply orifice area is different from the first exhaust orifice area; and a control system that controls the valve assembly to control the flow of the working fluid into and out of the first chamber. ### Claim 2 (depends on 1) The stage assembly of claim 1 wherein the first exhaust orifice area is larger than the first supply orifice area. ### Claim 3 (depends on 1) The stage assembly of claim 1 wherein the first exhaust orifice area is at least one hundred percent larger than the first supply orifice area. ### Claim 4 (depends on 1) The stage assembly of claim 1 further comprising a second valve sub-assembly that controls the flow of the working fluid into and out of the second chamber; wherein the second valve sub-assembly includes a first supply valve that controls the flow of the working fluid into the second chamber, and a first exhaust valve that controls the flow of the working fluid out of the second chamber; wherein the first supply valve has a first supply orifice having a first supply orifice area, and the first exhaust valve has a first exhaust orifice having a first exhaust orifice area; wherein the first exhaust orifice area is larger than the first supply orifice area. ### Claim 5 (depends on 4) The stage assembly of claim 4 wherein, for the second valve sub-assembly, the first exhaust orifice area is at least one hundred percent larger than the first supply orifice area. ### Claim 6 (depends on 5) The stage assembly of claim 5 wherein, for each valve sub-assembly, the first exhaust orifice area is at least ten percent larger than the first supply orifice area. ### Claim 7 (depends on 1) The stage assembly of claim 1 wherein the first valve sub-assembly includes a second supply valve that controls the flow of the working fluid into the first chamber; wherein the second supply valve has a second supply orifice having a second supply orifice area; and the second supply orifice area is larger than the first supply orifice area. ### Claim 8 (depends on 7) The stage assembly of claim 7 wherein the first valve sub-assembly includes a second exhaust valve that controls the flow of the working fluid out of the first chamber; wherein the second exhaust valve has a second exhaust orifice having a second exhaust orifice area; and the first exhaust orifice area is larger than the second exhaust orifice area. ### Claim 9 (depends on 1) The stage assembly of claim 1 wherein each valve is a proportional valve. ### Claim 10 (depends on 1) An exposure apparatus including an illumination source, and the stage assembly of claim 1 that moves the stage relative to the illumination system. ### Claim 11 A method for positioning a workpiece along a movement axis, the method comprising: providing a base; coupling the workpiece to a stage; moving the stage along the movement axis relative to the base with a fluid actuator assembly that includes (i) a piston housing that defines a piston chamber; (ii) a piston that is positioned within and moves relative to the piston chamber along a piston axis, the piston separating the piston chamber into a first chamber and a second chamber that are on opposite sides of the piston; and (iii) a first valve sub-assembly that controls the flow of a working fluid into the first chamber, the first valve sub-assembly including a first supply valve that controls the flow of the working fluid into the first chamber, and a first exhaust valve that controls the flow of the working fluid out of the first chamber; wherein the first supply valve has a first supply orifice having a first supply orifice area, and the first exhaust valve has a first exhaust orifice having a first exhaust orifice area; wherein the first supply orifice area is different from the first exhaust orifice area; and controlling the valve assembly with a control system to control the flow of the working fluid into and out of the first chamber. ### Claim 12 (depends on 11) The method of claim 11 wherein the step of moving includes the first exhaust orifice area being larger than the first supply orifice area. ### Claim 13 (depends on 11) The method of claim 11 wherein the step of moving includes the first exhaust orifice area being at least ten percent larger than the first supply orifice area. ### Claim 14 (depends on 11) The method of claim 11 wherein the step of moving includes providing a second valve sub-assembly that controls the flow of the working fluid into and out of the second chamber; wherein the second valve sub-assembly includes a first supply valve that controls the flow of the working fluid into the second chamber, and a first exhaust valve that controls the flow of the working fluid out of the second chamber; wherein the first supply valve has a first supply orifice having a first supply orifice area, and the first exhaust valve has a first exhaust orifice having a first exhaust orifice area; wherein the first exhaust orifice area is larger than the first supply orifice area. ### Claim 15 (depends on 14) The method of claim 14 wherein the step of providing includes, for the second valve sub-assembly, the first exhaust orifice area being at least one hundred percent larger than the first supply orifice area. ### Claim 16 (depends on 15) The method of claim 15 wherein the step of providing includes, for each valve sub-assembly, the first exhaust orifice area being at least one hundred percent larger than the first supply orifice area. ### Claim 17 (depends on 11) The method of claim 11 wherein the step of moving includes the first valve sub-assembly having a second supply valve that controls the flow of the working fluid into the first chamber; wherein the second supply valve has a second supply orifice having a second supply orifice area; and the second supply orifice area is larger than the first supply orifice area. ### Claim 18 (depends on 17) The method of claim 17 wherein the step of moving includes the first valve sub-assembly having a second exhaust valve that controls the flow of the working fluid out of the first chamber; wherein the second exhaust valve has a second exhaust orifice having a second exhaust orifice area; and the first exhaust orifice area is larger than the second exhaust orifice area. ### Claim 19 (depends on 11) The method of claim 11 wherein the step of moving includes each valve being a proportional valve. ### Claim 20 (depends on 11) A method for exposing a workpiece comprising the steps of providing an illumination source that generates an illumination beam, and moving the workpiece relative to the illumination beam with the stage assembly of claim 11. ### Claim 21 A stage assembly for positioning a workpiece along a movement axis, the stage assembly comprising: a stage that is adapted to couple to the workpiece; a base; a fluid actuator assembly that is coupled to and moves the stage along the movement axis relative to the base, the fluid actuator assembly including (i) a piston housing that defines a piston chamber; (ii) a piston that is positioned within and moves relative to the piston chamber along a piston axis, the piston separating the piston chamber into a first chamber and a second chamber that are on opposite sides of the piston; and (iii) a first valve sub-assembly that controls the flow of a working fluid into the first chamber, the first valve sub-assembly including a plurality of first supply valves that control the flow of the working fluid into the first chamber, and a plurality of first exhaust valves that control the flow of the working fluid out of the first chamber; and a control system that controls the valve assembly to control the flow of the working fluid into and out of the first chamber. ### Claim 22 (depends on 21) The stage assembly of claim 21 further comprising a second valve sub-assembly that controls the flow of the working fluid into and out of the second chamber; wherein the second valve sub-assembly includes a plurality of second supply valves that control the flow of the working fluid into the second chamber, and a plurality of second exhaust valves that control the flow of the working fluid out of the second chamber.