Displacement devices and methods for fabrication, use and control of same

Patent metadata

Field	Value
Publication number	US-9685849-B2
Application number	US-201514920885-A
Country	US
Kind code	B2
Filing date	Oct 23, 2015
Priority date	Oct 27, 2011
Publication date	Jun 20, 2017
Grant date	Jun 20, 2017

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.

First claim

What is claimed is:

1. A displacement device comprising:
a stator comprising:
a first plurality of coils distributed over a first layer at a corresponding first stator Z-location, each of the first plurality of coils linearly elongated in a stator X-direction in the first layer for carrying current in the stator X-direction; and
a second plurality of coils distributed over a second layer at a corresponding second stator Z-location, each of the second plurality of coils linearly elongated in a stator Y-direction in the second layer for carrying current in the stator Y-direction, the stator Y-direction non-parallel to the stator X-direction;
the first and second layers overlapping one another in a stator Z-direction, the stator Z-direction orthogonal to both the stator X-direction and the stator Y-direction; and
a moveable stage comprising:
a first magnet array comprising a plurality of first magnetization segments linearly elongated in a stage X-direction, each first magnetization segment having a corresponding magnetization direction orthogonal to the stage X-direction and at least two of the first magnetization segments having magnetization directions that are different from one another; and
a second magnet array comprising a plurality of second magnetization segments linearly elongated in a stage Y-direction non-parallel to the stage X-direction, each second magnetization segment having a magnetization direction orthogonal to the stage Y-direction and at least two of the second magnetization segments having magnetization directions that are different from one another;
a controller operably connected to one or more amplifiers which are in turn connected for driving current into the first plurality of coils and the second plurality of coils, the controller and the one or more amplifiers configured to controllably drive currents in the first plurality of coils to create a magnetic field which interacts with the magnetic field of the moveable stage, to thereby effect relative movement between the moveable stage and the stator; and
a stator X-dimension of each of the first plurality of coils and a stator Y-dimension of each of the second plurality of coils are respectively larger than a stage X-extent of the magnet arrays on the moveable stage and a stage Y-extent of the magnet arrays on the moveable stage.

2. A displacement device according to claim 1 wherein the stage X-direction is orthogonal to the stage Y-direction and the stator X-direction is orthogonal to the stator Y-direction.

3. A displacement device according to claim 1 wherein: the plurality of first magnetization segments comprises three or more first magnetization segments having different magnetization directions; the plurality of second magnetization segments comprises three or more second magnetization segments having different magnetization directions.

4. A displacement device according to claim 1 wherein:
the magnetization directions of the plurality of first magnetization segments exhibit a spatial magnetic period λ over a stage Y-direction width W 1 of the first magnet array and the magnetization directions of the plurality of second magnetization segments exhibit the spatial magnetic period λ over a stage X-direction width W 2 of the second magnet array.

5. A displacement device according to claim 1 wherein:
the magnetization directions of the plurality of first magnetization segments are mirror symmetric about a first plane extending in the stage X-direction and a stage Z-direction orthogonal to both the stage X-direction and the stage Y-direction and located at a center of the stage Y-direction width W 1 of the first magnet array;
the magnetization directions of the plurality of second magnetization segments are mirror symmetric about a second plane extending in the stage Y-direction and the stage Z-direction and located at a center of the stage X-direction width W 2 of the second magnet array.

6. A displacement device according to claim 1 wherein the stator X-direction is parallel to the stage X-direction and the stator Y-direction is parallel to the stage Y-direction.

7. A displacement device according to claim 1 wherein:
the plurality of first magnetization segments comprises a pair of first edge magnetization segments at the stage Y-direction extremities of the first magnet array and one or more first interior magnetization segments at stage Y-direction locations between the first edge magnetization segments and wherein a stage Y-direction width of the first edge magnetization segments is half of a stage Y-direction width of the first interior magnetization segments;
the plurality of second magnetization segments comprises a pair of second edge magnetization segments at the stage X-direction extremities of the second magnet array and one or more second interior magnetization segments at stage X-direction locations between the second edge magnetization segments and wherein a stage X-direction width of the second edge magnetization segments is half of a stage X-direction width of the second interior magnetization segments.

8. A displacement device according claim 1 wherein the magnetization directions of the plurality of first magnetization segments exhibit a first spatial magnetic period λ 1 over a stage Y-direction width W m1 of the first magnet array and the magnetization directions of the plurality of second magnetization segments exhibit a second spatial magnetic period λ 2 over a stage X-direction width W m2 of the second magnet array; wherein:
the plurality of first magnetization segments comprise a pair of first edge magnetization segments at edges of the first magnet array and one or more first interior magnetization segments at locations away from the edges of the first magnet array;
the plurality of second magnetization segments comprise a pair of second edge magnetization segments at edges of the second magnet array and one or more second interior magnetization segments at locations away from the edges of the second magnet array; and wherein:
the first edge magnetization segments have stage Y-direction widths of λ 1 /(2N t1 ) and the second edge magnetization segments have stage X-direction widths of λ 2 /(2N t2 ); and
the first interior magnetization segments have stage Y-direction widths of λ 1 /N t1 and the second interior magnetization segments have stage X-direction widths of λ 2 /N t2 ;
where N t1 is a number of different magnetization directions that make up a complete spatial magnetic period λ 1 and N t2 is a number of different magnetization directions that make up a complete spatial magnetic period λ 2 .

9. A displacement device according claim 1 wherein the magnetization directions of the plurality of first magnetization segments exhibit a spatial magnetic period λ 1 over a width W m1 of the first magnet array in the stage direction orthogonal to the first stage direction and the magnetization directions of the plurality of second magnetization segments exhibit the spatial magnetic period λ 2 over a width W m2 of the second magnet array in the stage direction orthogonal to the second stage direction and wherein a stator Y-direction pitch P c1 of the first plurality of coil traces is given by P C1 =λ 1 /N 1 and a stator X-direction pitch P c2 of the second plurality of coil traces are given by P C2 =λ 2 /N 2 , where N 1 and N 2 are positive integers.

10. A displacement device according to claim 1 wherein the magnetization directions of the plurality of first magnetization segments exhibit a first spatial magnetic period λ 1 over a stage Y-direction width W m1 of the first magnet array and the magnetization directions of the plurality of second magnetization segments exhibit a seco

Assignees

• Univ British Columbia

Inventors

• Lu Xiaodong
• Usman Irfan-Ur-Rab

Classifications

• H10P72/00

  Handling or holding of wafers, substrates or devices during manufacture or treatment thereof · CPC title

• H02K3/28

  Layout of windings or of connections between windings (windings for pole-changing H02K17/06, H02K17/14, H02K19/12, H02K19/32) · CPC title

• H02K21/24 Primary

  with magnets axially facing the armatures, e.g. hub-type cycle dynamos · CPC title

• H02K2201/18

  Machines moving with multiple degrees of freedom · CPC title

• H02K7/09

  with magnetic bearings · CPC title