Linear motor, stage apparatus, and exposure apparatus

• US 20030102723A1
• Filed: 10/07/2002
• Published: 06/05/2003
• Est. Priority Date: 10/05/2001
• Status: Active Grant

• Current Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Original Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Inventors: Korenaga, Nobushige
• Granted Patent: US 6,864,602 B2
• Time in Patent Office: Days
• US Class Current: 310/12
• CPC Class Codes: G03F 7/70758 Drive means, e.g. actuators, motors for long- or short-stroke modules or fine or coarse driving
• CPC Class Codes: H02K 41/031 of the permanent magnet type

Abstract

This invention provides a linear motor having a structure that can be fabricated easily. A stator has a stator yoke (103) and a stator coil (104) arranged outside the stator yoke. A movable element has a movable magnet (105) arranged outside the stator coil (104). Each of the stator yoke (103), stator coil (104), and movable magnet (105) has four flat portions, and a square section.

Claims

1. A linear motor having a stator and movable element, wherein

said stator has a stator yoke and a stator coil arranged outside said stator yoke, and

said movable element has a movable magnet arranged outside said stator coil,

said stator yoke, stator coil, and movable magnet each having a plurality of flat portions, the plurality of flat portions of said stator coil being parallel to an axis of said stator, and the flat portions of said stator yoke being parallel to the corresponding flat portions of said stator coil and the corresponding flat portions of said movable magnet.

2. The linear motor according to claim 1, wherein each flat portion of said stator yoke has a multilayered structure formed by stacking a large number of layers perpendicular to the flat portion and parallel to the axis of said stator.

3. The linear motor according to claim 1, wherein the plurality of flat portions of said stator yoke are supported by a support member, and said stator yoke has a prismatic structure.

4. The linear motor according to claim 1, wherein a winding start portion of said stator yoke is positioned near a boundary of one flat portion and another flat portion of said stator coil.

5. The linear motor according to claim 1, wherein a winding end portion of said stator coil is positioned near a boundary of one flat portion and another flat portion of said stator coil.

6. The linear motor according to claim 1, wherein a winding end portion and winding start portion of said stator coil are positioned near a boundary of one flat portion and another flat portion of said stator coil.

7. The linear motor according to claim 6, wherein a conductor wire drawn out from said stator coil is arranged to extend near the boundary of one flat portion and another flat portion of said stator coil along an axis of said stator.

8. The linear motor according to claim 1, wherein each of said stator yoke, stator coil, and movable magnet has four flat portions.

9. The linear motor according to claim 1, wherein each of said stator yoke, stator coil, and movable magnet has three flat portions.

10. The linear motor according to claim 1, wherein each of said stator yoke, stator coil, and movable magnet has two flat portions.

11. The linear motor according to claim 1, wherein a support member for supporting said stator yoke from inside has a flow channel therein through which a refrigerant is to flow.

12. The linear motor according to claim 11, wherein the flow channel has a circular section.

13. The linear motor according to claim 11, wherein the flow channel comprises a plurality of flow channels formed in the support member.

14. The linear motor according to claim 11, wherein the flow channel has a plurality of grooves arranged radially about the axis of said stator as a center.

15. The linear motor according to claim 11, wherein the flow channel has a honeycomb-like section.

16. The linear motor according to claim 1, wherein a support member for supporting said stator yoke is made of a metal.

17. The linear motor according to claim 1, wherein a support member for supporting said stator yoke is made of a ceramic material.

18. The linear motor according to claim 1, wherein a partition is arranged between said stator coil of said stator and said movable magnet of said movable element, and a flow channel through which a refrigerant is to flow is formed between said stator coil and the partition.

19. The linear motor according to claim 18, wherein the partition has a polygonal section.

20. The linear motor according to claim 18, wherein the partition has a circular section.

21. The linear motor according to claim 20, wherein the partition is made of an insulating material.

22. The linear motor according to claim 1, wherein

said stator has a plurality of partial stator coils arrayed in a direction of the axis of said stator, and

the linear motor further has a aligning member for aligning said plurality of partial stator coils.

23. The linear motor according to claim 22, wherein said aligning member has a comb tooth shape at a section thereof taken along a direction of the axis of said stator, and said partial stator coils are aligned among comb teeth that form the comb tooth shape.

24. The linear motor according to claim 1, wherein said stator has a plurality of partial stator coils arrayed in a direction of the axis of said stator, each of said partial stator coils being wound on a bobbin.

25. The linear motor according to claim 24, wherein the bobbin has a notch in a side plate thereof.

26. The linear motor according to claim 24, wherein a side plate of the bobbin has a thickness larger than ½

a diameter of a winding of said stator coil.

27. The linear motor according to claim 1, having a gas release-preventive cover outside said stator coil.

28. The linear motor according to claim 1, wherein said movable element has a back yoke outside said movable magnet.

29. The linear motor according to claim 28, wherein said back yoke has a plurality of flat portions arranged to be parallel to the plurality of flat portions of said movable magnet.

30. The linear motor according to claim 29, wherein said back yoke has a hollow prismatic structure which is formed by connecting the plurality of flat portions that form said back yoke.

31. The linear motor according to claim 29, wherein the plurality of flat portions that form said back yoke are supported by a support member.

32. A stage apparatus comprising

the linear motor according to claim 1, and

a stage driven by the linear motor.

33. The stage apparatus according to claim 32, further comprising

a mass element connected to a stator of the linear motor, and

a surface plate for slidably supporting a structure including said stator and said mass element.

34. The stage apparatus according to claim 33, wherein said mass element is arranged to surround said stator and movable element of the linear motor.

35. The stage apparatus according to claim 34, wherein said mass element has a flow channel therein through which a refrigerant is to flow.

36. The stage apparatus according to claim 33, wherein

said movable element has a reflection body at least on that surface thereof which faces said stator, and

said mass element has an absorption body at least on that surface thereof which faces said stator.

37. An exposure apparatus which has the stage apparatus according to claim 32 as a stage apparatus for aligning a substrate.

38. An exposure apparatus which has the stage apparatus according to claim 32 as a stage apparatus for aligning a master.

39. A device fabrication method including the steps of

exposing a wafer with a device pattern using the exposure apparatus according to claim 37, and

developing the exposed wafer.

40. A device fabrication method including the steps of

exposing a wafer with a device pattern using the exposure apparatus according to claim 38, and

developing the exposed wafer.

41. A linear motor having a stator and movable element, wherein

said stator has a stator yoke and a stator coil arranged outside said stator yoke, and

said movable element has a movable magnet arranged outside said stator coil,

said movable magnet and said stator yoke each having a plurality of rectangular parallelepiped portions, said stator coil having a plurality of flat portions parallel to an axis of said stator, and the parallelepiped portions of said movable magnet being parallel to the corresponding parallelepiped portions of said stator yoke and the corresponding flat portions of said stator coil.

42. A linear motor having a stator and movable element, wherein

said stator has a stator yoke comprising a plurality of multilayered bodies each formed by stacking a large number of layers parallel to an axis of said stator, and a stator coil arranged adjacent to said stator yoke, and

said movable element has a movable magnet arranged to face said stator coil,

said multilayered bodies of said stator yoke having rectangular parallelepiped shapes or non-arcuated shapes similar to rectangular parallelepiped shapes, and

at least one of said stator coil and movable magnet having a plurality of rectangular parallelepiped portions, the plurality of rectangular parallelepiped portions being arranged to be parallel to the plurality of multilayered bodies of said stator yoke.

43. A linear motor which has a stator coil wound around a driving axis, a stator yoke arranged inside said stator coil, and a movable magnet arranged outside said stator coil, and which generates a thrust, upon interaction of said stator coil and movable magnet, to drive said movable magnet toward the driving axis, wherein

said stator yoke has a plurality of multilayered yoke members, each of said multilayered yoke members being formed by stacking thin plates with the same shape to be parallel to each other.

44. A linear motor which has a stator coil wound around a driving axis, a stator yoke arranged inside said stator coil, and a movable magnet arranged outside said stator coil, and which generates a thrust, upon interaction of said stator coil and movable magnet, to drive said movable magnet toward said driving axis, wherein

said stator yoke has a plurality of multilayered yoke members, each of said multilayered yoke members being formed by stacking thin plates to be parallel to each other, and

said movable magnet has a plurality of magnets respectively opposing said plurality of multilayered yoke members,

directions of magnetization of said magnets in predetermined sections perpendicular to the driving axis being parallel to surfaces of said thin plates that form said multilayered yoke members opposing said magnets.

45. The linear motor according to claim 44 wherein, of each of said stator yoke members, a first surface which opposes said magnets includes a convex surface, and a second surface opposite to the first surface includes a flat surface.