US-12627210-B2 - Displacement devices and methods for fabrication, use and control of same

Abstract

Displacement devices comprise a stator and a moveable stage. The stator comprises a plurality of coils shaped to provide pluralities of generally linearly elongated coil traces in one or more layers. Layers of coils may overlap in the Z-direction. The moveable stage comprises a plurality of magnet arrays. Each magnet array may comprise a plurality of magnetization segments generally linearly elongated in a corresponding direction. Each magnetization segment has a magnetization direction generally orthogonal to the direction in which it is elongated and at least two of the magnetization directions are different from one another. One or more amplifiers may be connected to selectively drive current in the coil traces and to thereby effect relative movement between the stator and the moveable stage.

Inventors

• Xiaodong Lu
• Irfan-Ur-Rab Usman

Assignees

• THE UNIVERSITY OF BRITISH COLUMBIA

Dates

Publication Date

20260512

Application Date

20240118

Claims (20)

1. 1 . A displacement device comprising: a stator comprising a plurality of elongated coils shaped to provide a working region wherein traces of the coils are generally linearly oriented, the plurality of elongated coils comprising: a first plurality of coil traces distributed over at least a portion of a first layer at a corresponding first stator Z-location, the first plurality of coil traces generally linearly elongated in a first stator direction in the first layer; and a second plurality of coil traces distributed over at least a portion of a second layer at a corresponding second stator Z-location, the second plurality of coil traces generally linearly elongated in a second stator direction in the second layer, the second stator direction non-parallel with the first stator direction; a third plurality of coil traces distributed over at least a portion of a third layer at a corresponding third stator Z-location, the third plurality of coil traces generally linearly elongated in a third stator direction in the third layer, the third stator direction non-parallel with the first stator direction and the second stator direction; at least a portion of the first, second and third layers overlapping one another in a stator Z-direction in the working region, the stator Z-direction generally orthogonal to the first stator direction, the second stator direction and the third stator direction; and a moveable stage comprising a plurality of magnet arrays, the plurality of magnet arrays comprising: a first magnet array comprising a plurality of first magnetization segments wherein at least two of the first magnetization segments have magnetization directions that are different from one another; and a second magnet array comprising a plurality of second magnetization segments wherein at least two of the second magnetization segments have magnetization directions that are different from one another; and one or more amplifiers connected to drive current in the first, second and third pluralities of coil traces and to thereby effect relative movement between the stator and the moveable stage.
2. 2 . The displacement device according to claim 1 wherein the first stator direction is a stator X-direction and the second stator direction is a stator Y-direction wherein the stator X-direction, the stator Y-direction and the stator Z-direction are generally mutually orthogonal to one another.
3. 3 . The displacement device according to claim 2 wherein the third stator direction is skewed from the stator X-direction such that an edge of each trace of the third plurality of coil traces is skewed in the stator Y-direction over the stator X-direction length of each third coil trace.
4. 4 . The displacement device according to claim 2 wherein the plurality of elongated coils comprises a fourth plurality of coil traces distributed over at least a portion of a fourth layer at a corresponding fourth stator Z-location, the fourth plurality of coil traces generally linearly elongated in a fourth stator direction in the fourth layer, wherein: the fourth stator direction is non-parallel to the first stator direction, the second stator direction and the third stator direction; and at least a portion of the first, second, third and fourth layers overlap one another in the stator Z-direction in the working region.
5. 5 . The displacement device according to claim 4 wherein the fourth stator direction is skewed from the stator Y-direction such that an edge of each trace of the fourth plurality of coil traces is skewed in the stator X-direction over the stator Y-direction length of each fourth coil trace.
6. 6 . The displacement device according to claim 4 wherein the fourth stator direction is skewed in a first direction from the stator X-direction such that an edge of each trace of the fourth plurality of coil traces is skewed in the stator Y-direction over the stator X-direction length of each fourth coil trace.
7. 7 . The displacement device according to claim 6 wherein the third stator direction is skewed in a second direction from the stator X-direction such that an edge of each trace of the third plurality of coil traces is skewed in the stator Y-direction over the stator X-direction length of each third coil trace wherein the second direction is opposite the first direction.
8. 8 . The displacement device according to claim 1 wherein: each first magnetization segment is generally linearly elongated in a first stage direction and has a magnetization direction generally orthogonal to the first stage direction; and each second magnetization segment is generally linearly elongated in a second stage direction and has a magnetization direction generally orthogonal to the second stage direction.
9. 9 . The displacement device according to claim 8 wherein the first stage direction is orthogonal to the second stage direction.
10. 10 . The displacement device according to claim 9 wherein the movable stage comprises a third magnet array comprising a plurality of third magnetization segments generally linearly elongated in the first stage direction, each third magnetization segment having a magnetization direction generally orthogonal to the first stage direction and at least two of the third magnetization segments having magnetization directions that are different from one another.
11. 11 . The displacement device according to claim 10 wherein the first and third magnet arrays are offset from one another in the first stage direction and spaced apart from one another in the second stage direction by a space.
12. 12 . The displacement device according to claim 11 wherein the moveable stage comprises a fourth magnet array comprising a plurality of fourth magnetization segments generally linearly elongated in the second stage direction, each fourth magnetization segment having a magnetization direction generally orthogonal to the second stage direction and at least two of the fourth magnetization segments having magnetization directions that are different from one another and wherein the second and fourth magnet arrays are offset from one another in the second stage direction.
13. 13 . The displacement device according to claim 12 wherein the second and fourth magnet arrays are spaced apart from one another in the second stage direction by a space.
14. 14 . The displacement device according to claim 10 wherein at least four of the first magnetization segments have magnetization directions that are different from one another.
15. 15 . The displacement device according to claim 10 comprising a controller configured to control the one or more amplifiers and to thereby control the current driven to the first, second and third pluralities of coil traces.
16. 16 . The displacement device according to claim 1 wherein, while generally linearly elongated in the first stator direction, each trace of the first plurality of coil traces has some spatial variation in a stator direction orthogonal to the first stator direction and the spatial variation is spatially periodic in the first stator direction.
17. 17 . The displacement device according to claim 1 wherein each trace of the first plurality of coil traces extends across the working region in the first stator direction, each trace of the second plurality of coil traces extends across the working region in the second stator direction and each trace of the third plurality of coil traces extends across the working region in the third stator direction and wherein the working region is larger than the moveable stage for facilitating displacement of the moveable stage relative to the stator throughout the working region.
18. 18 . The displacement device according to claim 1 wherein the magnetization directions of adjacent ones of the plurality of first magnetization segments are orthogonal to one another.
19. 19 . The displacement device according to claim 18 wherein a second stage direction width of a first magnetization segment of the plurality of first magnetization segments is half of a second stage direction width of a second magnetization segment of the plurality of first magnetization segments.
20. 20 . A method for effecting displacement between a stator and a moveable stage, the method comprising: providing a stator comprising a plurality of elongated coils shaped to provide a working region wherein traces of the coils are generally linearly oriented, the plurality of elongated coils comprising: a first plurality of coil traces distributed over at least a portion of a first layer at a corresponding first stator Z-location, the first plurality of coil traces generally linearly elongated in a first stator direction in the first layer; and a second plurality of coil traces distributed over at least a portion of a second layer at a corresponding second stator Z-location, the second plurality of coil traces generally linearly elongated in a second stator direction in the second layer, the second stator direction non-parallel with the first stator direction; a third plurality of coil traces distributed over at least a portion of a third layer at a corresponding third stator Z-location, the third plurality of coil traces generally linearly elongated in a third stator direction in the third layer, the third stator direction non-parallel with the first stator direction and the second stator direction; at least a portion of the first, second and third layers overlapping one another in a stator Z-direction in the working region, the stator Z-direction generally orthogonal to the first stator direction, the second stator direction and the third stator direction; and providing a moveable stage comprising a plurality of magnet arrays, the plurality of magnet arrays comprising: a first magnet array comprising a plurality of first magnetization segments wherein at least two of the first magnetization segments have magnetization directions that are different from one another; and a second magnet array comprising a plurality of second magnetization segments wherein at least two of the second magnetization segments have magnetization directions that are different from one another; and selectively driving current in the first, second and third pluralities of coil traces to thereby effect relative movement between the stator and the moveable stage.

Description

RELATED APPLICATIONS This application is a continuation of U.S. patent application Ser. No. 17/543,671 filed 6 Dec. 2021, which is, in turn, a continuation of U.S. patent application Ser. No. 16/715,876 filed 16 Dec. 2019, which is, in turn, a continuation of U.S. patent application Ser. No. 15/920,309 filed 13 Mar. 2018, which is, in turn, a continuation of U.S. patent application Ser. No. 15/595,941 filed 15 May 2017, which is, in turn, a continuation of U.S. patent application Ser. No. 14/920,885 filed 23 Oct. 2015, which is, in turn, a continuation of U.S. patent application Ser. No. 14/354,515 having a 35 USC 371 date of 25 Apr. 2014, which is, in turn, a national phase entry of PCT application No. PCT/CA2012/050751 having an international filing date of 22 Oct. 2012. PCT application No. PCT/CA2012/050751 claims the benefit of the priority of U.S. application No. 61/551,953 filed 27 Oct. 2011 and of U.S. application No. 61/694,776 filed 30 Aug. 2012. All of the prior applications in referred to in this paragraph are hereby incorporated herein by reference. TECHNICAL FIELD The invention relates to displacement devices. Particular non-limiting embodiments provide displacement devices for use in the semiconductor fabrication industry. BACKGROUND Motion stages (XY tables and rotary tables) are widely used in various manufacturing, inspection and assembling processes. A common solution currently in use achieves XY motion by stacking two linear stages (i.e. a X-stage and a Y-stage) together via connecting bearings. A more desirable solution involves having a single moving stage capable of XY motion, eliminating additional bearings. It might also be desirable for such a moving stage to be able to provide at least some Z motion. Attempts have been made to design such displacement devices using the interaction between current-carrying coils and permanent magnets. Examples of efforts in this regard include the following: U.S. Pat. Nos. 6,003,230; 6,097,114; 6,208,045; 6,441,514; 6,847,134; 6,987,335; 7,436,135; 7,948,122; US patent publication No. 2008/0203828; W. J. Kim and D. L. Trumper, High-precision magnetic levitation stage for photolithography. Precision Eng. 22 2 (1998), pp. 66-77; D. L. Trumper, et al, “Magnet arrays for synchronous machines”, IEEE Industry Applications Society Annual Meeting, vol. 1, pp. 9-18, 1993; and J. W. Jansen, C. M. M. van Lierop, E. A. Lomonova, A. J. A. Vandenput, “Magnetically Levitated Planar Actuator with Moving Magnets”, IEEE Tran. Ind. App., Vol 44, No 4, 2008. There is a general desire to provide displacement devices having characteristics that improve upon those known in the prior art. The foregoing examples of the related art and limitations related thereto are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification and a study of the drawings. BRIEF DESCRIPTION OF THE DRAWINGS Exemplary embodiments are illustrated in referenced figures of the drawings. It is intended that the embodiments and figures disclosed herein are to be considered illustrative rather than restrictive. FIG. 1A is a partial schematic isometric view of a displacement device according to a particular embodiment of the invention. FIG. 1B is a partial schematic cross-sectional view of the FIG. 1A displacement device along the line 1B-1B. FIG. 1C is a partial schematic cross-sectional view of the FIG. 1A displacement device along the line 1C-1C. FIG. 1D shows additional detail of one of the Y-magnet arrays of the FIG. 1A displacement device in accordance with a particular embodiment. FIG. 1E shows additional detail of one of the X-magnet arrays of the FIG. 1A displacement device in accordance with a particular embodiment. FIG. 2 is a schematic partial cross-sectional view of a single layer of coil traces which may be used in the FIG. 1 displacement devices and which are useful for showing a number of coil parameters. FIGS. 3A-3F are schematic partial cross-sectional views of single layers of coil traces having different layouts which may be used in the FIG. 1 displacement device. FIGS. 4A and 4B are schematic partial cross-sectional views of multiple layers of coil traces having different layouts which may be used in the FIG. 1 displacement device. FIG. 5 is a schematic partial view of a single layer of coil traces showing a group connection scheme which may be used in the FIG. 1 displacement device. FIGS. 6A and 6B are schematic partial cross-sectional views of layouts of magnet arrays which may be used in the FIG. 1 displacement device and which are useful for showing a number of magnet array parameters. FIGS. 7A-7L show additional details of magnet arrays suitable for use with the FIG. 1 displacement device in accordance with particular embodiments. FIGS. 8A-8L show additional details of magnet arrays suitable for use with the FIG. 1 displacement device in accordance with particular embo