Epicyclic stage
AssigneeEtec Systems, Inc.
InventorManuel G. Pastor
Life of this patent
Estimating the term…
Abstract
A movable stage assembly suitable for use in a vacuum has three circular stages rotating independently of one another. The stage assembly includes a base and a large rotatable circular table mounted on the base. This large table has a second smaller circular table which is eccentrically mounted within the first large table and rotates independently. This second table also has a smaller third circular table eccentrically mounted on it and independently rotatable within the second table. All the rotatable tables utilize ferrofluidic seals to prevent air within the air bearings from leaking into the vacuum chamber and are driven by motors mounted beneath the tables.
Claims29
A stage assembly, comprising:
- a base;
- a first table rotatably mounted on said base;
- a second table rotatably and eccentrically mounted on said first table;
- and
- a third table rotatably and eccentrically mounted on said second table and adapted to adjust for stage yaw.
An epicyclic stage assembly, comprising:
- a base;
- a first circular table rotatably mounted on said base;
- a second circular table rotatably and eccentrically mounted on said first circular table;
- a third circular table rotatably and eccentrically mounted on said second circular table and adapted to adjust for stage yaw;
- a work table mounted on said third circular table;
- a rotary seal surrounding a circumference of each of said first, second, and third circular tables, said rotary seals each comprising:
- a ferrofluid maintained by a differential pump;
- and
- a source of a magnetic or electromagnetic force which maintains said ferrofluid around each of said first, second, and third circular tables;
- an air bearing disposed between said base and said first circular table, between said first and said second circular tables, and between said second and said third circular tables;
- and
- a motor coupled to each of said first, second, and third circular tables.
A method of positioning a work piece on a assembly, comprising:
- rotating a first table on a base;
- rotating a second table which is eccentrically mounted on said first table;
- and
- rotating a third table which is eccentrically mounted on said second table, thereby positioning said workpiece located on said third table and adjusting for stage yaw.
A stage assembly, comprising:
- a base;
- a first table rotatably mounted on said base;
- a second table rotatably and eccentrically mounted on said first table;
- a third table rotatably and eccentrically mounted on said second table and adapted to adjust for stage yaw;
- a fourth table rotatably and eccentrically mounted on said first table;
- and
- a fifth table rotatably and eccentrically mounted on said fourth table.
Dependencies are inferred from the claim text.