A cable-free moving iron type magnetic suspension planar motor for a lithography machine worktable

Abstract

The application discloses a cable-free moving-iron type magnetic suspension planar motor for a workpiece table of a photoetching machine, and belongs to the technical field of photoetching equipment.The motor stator unit and the motor mover unit are included in the application, the motor mover unit is located on the upper portion of the motor stator unit, the wireless power transmission transmitting end coil is added on the stator side, the wireless power transmission receiving end coil is added on the mover side, the receiving end coil receives electric energy, and the electric energy is provided for the load on the mover.The mover winding low-current fluctuation power supply can be realized by using the Halbach array stator with the wireless power transmission transmitting end coil and the mover winding with the wireless power transmission receiving end coil, the cable-free long-stroke operation of the moving-coil type magnetic suspension planar motor is ensured, and the motion performance of the workpiece table of the photoetching machine is improved.

Description

Technical Field

[0001] The present invention relates to a magnetic levitation planar motor, and particularly to a cable-free moving-iron type magnetic levitation planar motor for a workpiece stage of a lithography machine. The present invention belongs to the technical field of lithography equipment. Background Art

[0002] The workpiece stage is one of the six core components of a lithography machine, ensuring the chip production rate and exposure accuracy of the lithography machine. At present, the most advanced EUV lithography machine workbench in the world adopts a magnetic levitation platform solution. Among them, the moving-coil type magnetic levitation structure has been developed for decades, with mature technology and stable performance. Currently, all the mass-produced EUV lithography machines of ASML in the Netherlands use this structure. However, the moving-coil type structure requires a large number of cables to supply power to the mover, and the disturbing force of the cables affects the motion accuracy of the workpiece stage. The mover of the moving-iron type magnetic levitation structure does not require cables for power supply, reducing the disturbing influence of the cables. However, the load on the mover still needs to be powered by cables, which still affects the motion accuracy of the workpiece stage. Summary of the Invention

[0003] In order to solve the problem that the load on the mover of the moving-iron type magnetic levitation structure needs to be powered by cables, which in turn affects the motion accuracy of the workpiece stage, the present invention further provides a cable-free moving-iron type magnetic levitation planar motor for a workpiece stage of a lithography machine.

[0004] The technical solution adopted by the present invention to solve the above problems is as follows:

[0005] The present invention includes a motor stator unit and a motor mover unit. The motor mover unit is located above the motor stator unit. The motor stator unit includes a magnetic levitation planar motor stator winding and a plurality of wireless power transfer transmitter coils. The plurality of wireless power transfer transmitter coils are arranged in a 4*4 square matrix, and a magnetic levitation planar motor stator winding is provided in each square matrix. The motor mover unit includes a first magnet, a second magnet, a third magnet, and a plurality of wireless power transfer receiver coils. The plurality of wireless power transfer receiver coils are arranged in a "field" shape. A first magnet and a second magnet are provided in each small square of the "field" frame, and the first magnet and the second magnet are arranged in sequence from the inside to the outside.

[0006] Further, the upper surfaces of the stator winding and the wireless power transfer transmitter coils are at the same height.

[0007] Further, there are four second magnets, which are respectively arranged around the first magnet.

[0008] Further, the magnetization direction of the second magnet is at an oblique 45°.

[0009] Further, the motor mover unit further includes a third magnet. The number of the third magnets is four, which are respectively located above, below, left, and right of the second magnet.

[0010] Further, the magnetization direction of the third magnet is horizontal direction.

[0011] Further, the height of the first magnet and the second magnet is same, and the height of the third magnet is lower than the first magnet and the second magnet.

[0012] The beneficial effects of the present application are:

[0013] The traditional moving-iron type magnetic suspension planar motor structure is that the stator side is a magnetic suspension planar motor winding, and the mover side is a Halbach array magnet, and the new structure provided by the present application adds a wireless power transmission transmitting end coil on the stator side and adds a wireless power transmission receiving end coil on the mover side, and the receiving end coil receives power to provide power for the load on the mover.

[0014] The Halbach array stator with the wireless power transmission transmitting end coil and the mover winding with the wireless power transmission receiving end coil provided by the present application can realize low-current fluctuation power supply of the mover winding, ensure cable-free long-stroke operation of the moving-coil type magnetic suspension planar motor, and further improve the motion performance of the workpiece table of the lithography machine. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 is a structure schematic view of the magnetic suspension planar motor combined with the wireless power transmission transmitting end coil of the present application;

[0016] Figure 2 is a structure schematic view of the magnetic suspension planar motor combined with the wireless power transmission receiving end coil of the present application;

[0017] Figure 3 is a top view of the overall structure of the mover unit of the present application;

[0018] Figure 4 is a front view of Figure 3 ;

[0019] Figure 5 is a schematic view of the overall structure of the stator unit and the mover unit of the present application;

[0020] Figure 6 is a front view of the structure of the stator unit and the mover unit in the working state of the present application;

[0021] Figure 7 is a simulation result diagram of the magnetic field distribution of the mover of the present application.

[0022] In the figure, 1, motor stator unit; 1-1, magnetic suspension planar motor stator winding; 1-2, wireless power transmission transmitting end coil;

[0023] 2. Rotor unit of the motor; 2-1. First magnet; 2-2. Second magnet; 2-3. Third magnet; 2-4. Coil of the wireless power transmission receiver; 2-5. Gap. Detailed implementation mode

[0024] Combined with the attached Figures 1-7 Explain this implementation mode

[0025] The cable-free moving-iron type magnetic levitation planar motor for a workpiece stage of a lithography machine described in this implementation mode includes a stator unit 1 and a rotor unit 2 of the motor. As Figure 6 shown, the rotor unit 2 of the motor is located above the stator unit 1 of the motor. As Figure 1 , Figure 5 shown, the stator unit 1 of the motor includes a magnetic levitation planar motor stator winding 1-1 and a plurality of wireless power transmission transmitter coils 1-2. The plurality of wireless power transmission transmitter coils 1-2 are arranged in a 4* square matrix, and a magnetic levitation planar motor stator winding 1-1 is provided in each square matrix;

[0026] Preferably, the upper surfaces of the stator winding 1-1 and the wireless power transmission transmitter coil 1-2 are at the same height.

[0027] The function of the magnetic levitation planar motor stator winding 1-1 is the same as that of a traditional magnetic levitation planar motor. However, in order to supply power to the rotor load without using any cables, a wireless power transmission transmitter coil 1-2 is added. In order to improve the power of wireless power transmission, eight high-frequency coils, that is, wireless power transmission transmitter coils 1-2, are distributed around each stator winding to provide sufficient energy for the receiver. In order to shorten the air gap between the wireless power transmission transmitter coil 1-2 on the stator side and the wireless power transmission receiver coil on the rotor side, through the action of a support on the stator side, the transmitter coil 1-2 and the upper surface of the stator winding 1-1 are kept at the same height.

[0028] As Figure 2 , <​​​​​​There are four second magnets 2-1, which are respectively arranged around the first magnet 2-1. The magnetization direction of the second magnet 2-1 is 45° obliquely. The addition of the second magnet 2-1 is to improve the sinusoidality of the Halbach magnetic field distribution and also increase the magnetic field intensity.

[0031] Preferably, the cable-free moving-iron type magnetic levitation planar motor for a lithography worktable further includes a third magnet 2-3. The number of the third magnets 2-3 is four, which are respectively located above, below, left and right of the second magnet 2-1. The magnetization direction of the third magnet 2-3 is the horizontal direction. The addition of the third magnet 2-3 is to enhance the magnetic field intensity.

[0032] Each upper part of the third magnet 2-3 is provided with a wireless power transmission receiving end coil 2-4. At the same time, in order to increase the transmission power of wireless power, multiple wireless power transmission receiving end coils 2-4 are added at the magnet-free place of the Halbach magnetic field array, so that the multiple wireless power transmission receiving end coils 2-4 are arranged in a "field" shape.

[0033] Preferably, the first magnet 2-1 and the second magnet 2-1 have the same height, and the height of the third magnet 2-3 is lower than that of the first magnet 2-1 and the second magnet 2-1. The purpose is to avoid the eddy current effect caused by the too-close distance between the wireless power transmission receiving end coil 2-4 arranged above them and the magnet.

[0034] As Figure 4 shown, the first magnet 2-1 is trapezoidal and has an overall trapezoidal structure. Four second magnets 2-2 are distributed around it. The main view of the shape of the second magnet 2-2 is triangular, and the top view is trapezoidal. The first magnet 2-1 and the second magnet 2-2 form an overall cuboid structure. It can be clearly seen from the main view that four third magnets 2-3 surround the cuboid and their height is lower than that of the cuboid. Above these four magnets are the installed receiving end coils 2-4. There is a gap 2-5 between the receiving end coil 2-4 and the third magnet 2-3, leaving sufficient space, which will not only not cause eddy current effect but also not affect the magnetic field distribution.

[0035] The present invention can ensure the minimum air gap between the wireless power transmission transmitter and the receiving end coil by proposing a reasonable structure, and increase the transmission power.

[0036] Formula (1) is the expression of the wireless power transmission power. P is the received power, w s is the current frequency of the transmitter, M0 is the mutual inductance, I p is the magnitude of the current of the transmitter, and Rs is the equivalent load of the receiving end.

[0037]

[0038] The simulation result of the mover magnetic field distribution is asFigure 7 As shown by the simulation results, the new mover Halbach magnetic field array and the magnetic field generated by the receiving end coil structure are sinusoidal distribution, which can provide good motion performance.

[0039] Working principle:

[0040] On the stator side, since the working frequency of the current of the stator winding 1-1 of the magnetic levitation planar motor is low-frequency energy of several hundred hertz, and the working frequency of the current of the wireless power transmission transmitting end coil 1-2 is high-frequency energy of several tens of kilohertz, the high-frequency and low-frequency currents do not affect each other. Therefore, the low-frequency winding and the high-frequency coil on the stator side can be arranged in cross.

[0041] On the mover side, since the mover is a Halbach array to form a strong magnetic field, when the wireless power transmission receiving end coil 2-4 is close to the Halbach array, eddy current effect will be generated, which in turn causes the wireless power transmission receiving end coil 2-4 to heat up. High temperature leads to the magnetic field strength of the Halbach array magnet, which is not allowed for the high-precision system of the lithography machine. The mover side of the present patent designs a new Halbach array structure to reduce the interaction between the wireless power transmission receiving end coil 2-4 and the Halbach magnetic field, which is suitable for the cable-free moving iron type magnetic levitation planar motor.

[0042] In addition, in order to ensure that the current ripple of the wireless power transmission receiving end power supply is small, the wireless power transmission transmitting end coil 1-2 on the stator side and the wireless power transmission receiving end coil 2-4 on the mover side are densely arranged, the number of wireless power transmission transmitting end coils 1-2 and wireless power transmission receiving end coils 2-4 is increased, and sufficient power supply is ensured. Finally, the magnetic levitation planar motor load is powered by wireless power transmission to realize cable-free power supply and reduce the interference of cable disturbance force.

[0043] The above is only the preferred embodiment of the present application, and does not limit the present application in any form. Although the present application has been disclosed as above with the preferred embodiment, it is not intended to limit the present application. Any person skilled in the art can make some changes or modifications to the above disclosed technical content without departing from the technical solution of the present application, and make equivalent embodiments with equivalent changes. Any simple modification, equivalent replacement and improvement of the above embodiments within the technical solution of the present application, according to the technical essence of the present application, within the spirit and principles of the present application, are all within the protection scope of the present application.

Claims

1. A cable-free moving-iron type magnetic levitation planar motor for a lithography machine worktable, comprising a motor stator unit (1) and a motor mover unit (2), wherein the motor mover unit (2) is located above the motor stator unit (1), and is characterized in that: The motor stator unit (1) includes a magnetic levitation planar motor stator winding (1-1) and a plurality of wireless power transmission transmitter coils (1-2), and the plurality of wireless power transmission transmitter coils (1-2) are arranged in a 4*4 grid matrix, and one magnetic levitation planar motor stator winding (1-1) is provided in each grid matrix; the upper surfaces of the stator winding (1-1) and the wireless power transmission transmitter coils (1-2) are at the same height; The motor mover unit (2) includes a first magnet (2-1), a second magnet (2-2), a third magnet (2-3) and a plurality of wireless power transmission receiver coils (2-4), and the plurality of wireless power transmission receiver coils (2-4) are arranged in a "field" shape, and a first magnet (2-1) and a second magnet (2-2) are provided in each small grid of the field frame, and the first magnet (2-1) and the second magnet (2-2) are arranged in sequence from inside to outside; there are four second magnets (2-2), which respectively surround the first magnet (2-1); the number of the third magnets (2-3) is four, and they are respectively located above, below, left and right of the second magnet (2-2); one wireless power transmission receiver coil (2-4) is provided above each third magnet (2-3); the first magnet (2-1) and the second magnet (2-2) are at the same height, and the height of the third magnet (2-3) is lower than that of the first magnet (2-1) and the second magnet (2-2).

2. The cableless moving iron type magnetic levitation planar motor for a wafer stage of a lithography machine according to claim 1, characterized in that: The magnetization direction of the second magnet (2-2) is 45° obliquely.

3. The cableless moving iron type magnetic levitation planar motor for a wafer stage of a lithography machine according to claim 1, characterized in that: The magnetization direction of the third magnet (2-3) is the horizontal direction.

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