CN220254374U

CN220254374U - Magnetic suspension device and semiconductor processing equipment

Info

Publication number: CN220254374U
Application number: CN202322592792.3U
Authority: CN
Inventors: 刘德刚; 秦晓帆; 吴文志
Original assignee: Suzhou Suci Intelligent Technology Co ltd
Current assignee: Suzhou Suci Intelligent Technology Co ltd
Priority date: 2023-09-25
Filing date: 2023-09-25
Publication date: 2023-12-26
Anticipated expiration: 2033-09-25

Abstract

The utility model discloses a magnetic suspension device and semiconductor processing equipment, which comprises a stator and a rotor, wherein the stator comprises a permanent magnet device and a suspension control component, the suspension control component is configured to apply active control suspension force to the rotor, the permanent magnet device is configured to apply a permanent magnet bias magnetic field to the rotor, the permanent magnet device comprises a plurality of permanent magnet components, the plurality of permanent magnet components are uniformly arranged in the circumferential direction, each permanent magnet component comprises a plurality of permanent magnets, the plurality of permanent magnets are arranged in the same radial plane at intervals by taking radial lines as symmetrical axes, and magnetic fluxes generated by the permanent magnets are applied to the rotor through stator magnetic poles of the suspension control component.

Description

Magnetic suspension device and semiconductor processing equipment

Technical Field

The utility model relates to the technical field of magnetic suspension, in particular to a magnetic suspension device and semiconductor processing equipment.

Background

The magnetic suspension device is a magnetic suspension rotary driver which uses magnetic field force to suspend the rotor so that no mechanical contact exists between the rotor and the stator. The magnetic suspension device or the magnetic suspension rotary driver has the characteristics of high cleanliness, no precipitation, no particles, no dynamic seal and excellent performance, and has good application prospect in the field of ultra-pure driving such as biochemistry, medical treatment, semiconductor manufacturing and the like.

In semiconductor manufacturing, on the one hand, wafer cleanliness is important because wafer surface cleanliness affects the yield of subsequent semiconductor processes and products, and wafers of silicon or other semiconductor materials must be processed in a controlled ultra-clean atmosphere in order to achieve ultra-clean requirements. For example, in the fabrication of wafers, one fabrication step is annealing the wafer after ion implantation doping. Doping imparts strain on the crystal structure, which can lead to undesirable changes in the resistivity of the ion doping if the stress is not released quickly. Currently, rapid thermal processing (RT) is typically used for annealing. In yet another aspect, process uniformity of the wafer is important and, in order to produce uniformity, the wafer is typically rotated about a vertical or z-axis at the center of the wafer as it is processed. Spin is also used for other wafer processing such as chemical vapor deposition, thermal processing, ion implantation doping, and other techniques doping. In order to meet the severe requirements of ultra-clean and treatment uniformity in the manufacture of semiconductor technology, the semiconductor heat treatment equipment optimally adopts a magnetic suspension device driven by non-contact rotation. The magnetic suspension device comprises a stator and a rotor, wherein the stator is used for generating a magnetic field to drive the rotor and the supporting body to rotate and suspend. The magnetic levitation device of the inner rotor and the magnetic levitation device of the outer rotor can be classified according to the relative position difference between the stator and the rotor.

For example, a magnetic levitation device includes a rotor and a stator including a levitation control assembly for applying actively controlled levitation force to the rotor to achieve axial active control and/or radial active control. The suspension control assembly comprises a plurality of stator poles which are equally distributed in the circumferential direction, and electromagnetic windings for suspension control are arranged on the stator poles. The stator also includes a permanent magnet that provides a permanent magnet bias field (magnetic flux) that is annular in shape, applied to the rotor by the stator poles, however for larger diameter magnetic levitation devices. For example, in the inner rotor type magnetic levitation device, the process difficulty of manufacturing the large-diameter annular permanent magnet is great, the manufacturing cost is high, and the assembly of the integral structure is difficult due to the strong permanent magnet bias magnetic field provided by the permanent magnet. Therefore, it is considered to use a discrete permanent magnet, for example, a permanent magnet is disposed at 4 equidistant orientations (x+, X-, y+, Y-) on the circumference, respectively, such a structure: because each permanent magnet corresponds to one configuration position, the magnetic field of the permanent magnet is concentrated at the configuration position, and the stator magnetic poles extend along the circumferential direction, so that magnetic flux generated by the permanent magnet is mainly concentrated at the center position of the stator magnetic poles (the projection of the permanent magnet in a radial plane is opposite to the center of the stator magnetic poles), and the magnetic flux generated by the permanent magnet is unbalanced in the circumferential direction, namely, the z-axis component of force generated by the stator on the rotor at the air gap of the stator magnetic poles is unbalanced in the circumferential direction, so that the running axial fluctuation of the rotor is caused, and the running stability of the motor is influenced.

Disclosure of Invention

To overcome the defects in the prior art, embodiments of the present utility model provide a magnetic levitation device and a semiconductor processing apparatus for solving at least one of the above problems.

The embodiment of the disclosure provides a magnetic levitation device, the magnetic levitation device includes a stator and a rotor, the stator includes a permanent magnet device and a levitation control component, the levitation control component is configured to apply an actively controlled levitation force to the rotor, the permanent magnet device is configured to apply a permanent magnet bias magnetic field to the rotor, the permanent magnet device includes a plurality of permanent magnet components, the plurality of permanent magnet components are uniformly arranged in a circumferential direction, a position of each permanent magnet component is defined as a configuration orientation, a connection line between a center of each configuration orientation in a radial plane and a projection point of a rotation axis of the rotor in the radial plane is defined as a radial line, each permanent magnet component includes a plurality of permanent magnets, the plurality of permanent magnets are arranged in the same radial plane at intervals by taking the radial line as a symmetry axis, and magnetic fluxes generated by the permanent magnets are applied to the rotor via stator poles of the levitation control component.

Further, the plurality of permanent magnets are arranged in a straight line in the radial plane, and the radial line is perpendicular or nearly perpendicular to the straight line.

Further, the distance between two adjacent permanent magnets in each permanent magnet assembly is the same or nearly the same, or the distance between two adjacent permanent magnets gradually decreases from the center of the permanent magnet assembly to two sides.

Further, the plurality of permanent magnets are arranged in an arc shape in the radial plane, and the projection point of the rotation axis of the rotor in the radial plane is the same or nearly the same as the distance between each permanent magnet.

Further, in the circumferential direction, the distance between two adjacent permanent magnets in each permanent magnet assembly is the same or nearly the same; or the distance between two adjacent permanent magnets in each permanent magnet assembly is the same or nearly the same, and the distance between the outermost permanent magnets of two adjacent permanent magnet assemblies is the same or nearly the same as the distance between the two adjacent permanent magnets of the permanent magnet assemblies.

Further, the permanent magnet assembly further comprises a bearing block, a fixing groove corresponding to each permanent magnet is formed in the bearing block, and the permanent magnets are positioned in the corresponding fixing grooves.

Further, the permanent magnet assembly further comprises a bearing block and a partition piece, wherein a through groove is formed in the bearing block, the partition piece divides the through groove into a plurality of sub-grooves corresponding to the permanent magnets one by one, and the permanent magnets are positioned in the corresponding sub-grooves.

Further, the levitation control assembly is configured as an axial levitation control assembly comprising a first control assembly configured to apply an axially upward levitation force to the rotor and a second control assembly configured to apply an axially downward levitation force to the rotor; the first control assembly comprises a first stator substrate and a plurality of first stator magnetic poles protruding from the first stator substrate towards the rotor, wherein a first electromagnetic winding is arranged on the first stator magnetic poles, and the plurality of first stator magnetic poles are uniformly arranged in the circumferential direction; the second control assembly comprises a second stator substrate and a plurality of second stator magnetic poles protruding from the second stator substrate towards the rotor, wherein second electromagnetic windings are arranged on the second stator magnetic poles, and the plurality of second stator magnetic poles are uniformly arranged in the circumferential direction.

Further, the plurality of permanent magnet assemblies generate equal or nearly equal magnetic flux at the first air gap of each pair of radially symmetric two first stator poles or at the first air gap of each first stator pole and equal or nearly equal magnetic flux at the second air gap of each pair of radially symmetric two second stator poles or at the second air gap of each second stator pole.

Further, two axial suspension control assemblies are provided, and a second stator substrate and a first stator substrate of one axial suspension control assembly, the permanent magnet assembly, and a first stator substrate and a second stator substrate of the other axial suspension control assembly are sequentially stacked together along the axial direction.

Further, in the circumferential direction, a second stator magnetic pole is disposed between two adjacent first stator magnetic poles, and a first stator magnetic pole is disposed between two adjacent second stator magnetic poles.

Further, the number of the plurality of first stator poles, the number of the plurality of second stator poles and the number of the plurality of permanent magnet assemblies are 4, and each permanent magnet assembly is opposite to the position of one first stator pole in the circumferential direction; alternatively, each permanent magnet assembly is positioned opposite one of the second stator poles in the circumferential direction; alternatively, each permanent magnet assembly is equidistantly arranged between adjacent one of the first stator poles and one of the second stator poles in the circumferential direction.

Further, the levitation control assembly is configured as a radial levitation control assembly, and the radial levitation control assembly comprises a radial stator substrate and a plurality of radial stator poles protruding from the radial stator substrate towards the rotor, wherein each radial stator pole is provided with a radial electromagnetic winding, and the plurality of radial stator poles are uniformly arranged in the circumferential direction.

Further, the plurality of permanent magnet assemblies generate equal or nearly equal magnetic flux at the air gap of each pair of radially symmetric two radial stator poles or at the air gap of each radial stator pole.

Further, two radial levitation control assemblies are provided, and radial stator substrates of one radial levitation control assembly, the permanent magnet assembly and the radial stator substrates of the other radial levitation control assembly are sequentially laminated together along the axial direction.

Further, the number of the plurality of radial stator poles and the number of the plurality of permanent magnet assemblies are 4, and each permanent magnet assembly is opposite to the radial stator pole in the circumferential direction; alternatively, each permanent magnet assembly is equidistantly disposed between two adjacent radial stator poles in the circumferential direction.

Further, a plurality of motor slots are formed on one side of each radial stator pole facing the rotor, motor teeth are formed between two adjacent motor slots, motor slots are formed between two adjacent radial stator poles, and the motor slots are configured as one motor slot.

Further, the rotor comprises a rotor body, a first annular edge and a second annular edge, wherein the first annular edge and the second annular edge extend from the rotor body to the stator, the first annular edge is hollowed out at equal intervals to form a plurality of rotor magnetic poles A, the second annular edge is hollowed out at equal intervals to form a plurality of rotor magnetic poles B, an air gap A is formed between the rotor magnetic poles A and radial stator magnetic poles of one radial suspension control assembly, and an air gap B is formed between the rotor magnetic poles B and radial stator magnetic poles of the other radial suspension control assembly.

Further, the number of the rotor magnetic poles a and the number of the rotor magnetic poles B are 8, and the number of the radial stator magnetic poles is 4.

The embodiment of the disclosure also provides a semiconductor processing device, which comprises a carrier and the magnetic suspension device, wherein the rotor supports and positions the carrier through a plurality of support columns.

The beneficial effects of the utility model are as follows: according to the magnetic suspension device, the single permanent magnet at the configuration position is designed into the permanent magnet assembly composed of the plurality of permanent magnets, the plurality of permanent magnets are distributed in the same radial plane at intervals by taking radial lines as symmetry axes, so that magnetic fluxes generated by the permanent magnets can be uniformly applied to the rotor in the circumferential direction through stator magnetic poles of the suspension control assembly, namely, the plurality of permanent magnets of the permanent magnet assembly can uniformly apply z-axis component force of force generated by the stator on the rotor at air gaps of the stator magnetic poles in the circumferential direction, and therefore axial fluctuation of rotor operation is improved, and the running stability of a motor is improved. The magnetic suspension device is designed aiming at the split permanent magnet assembly, has lower manufacturing process difficulty and lower processing and manufacturing cost compared with an integral annular permanent magnet, and has weaker permanent magnet bias magnetic field of the split permanent magnet assembly when the magnetic suspension device is assembled, thereby being convenient for assembly.

The foregoing and other objects, features and advantages of the utility model will be apparent from the following more particular description of preferred embodiments, as illustrated in the accompanying drawings.

Drawings

In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, it being obvious that the drawings in the following description are only some embodiments of the utility model, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic view of an embodiment of a permanent magnet device in an embodiment 1 of a stator according to the present utility model;

fig. 2 is a schematic structural view of another embodiment of the permanent magnet device in the stator embodiment 1 of the present utility model;

FIG. 3 is a schematic structural view of a permanent magnet device according to another embodiment of the stator of the present utility model in embodiment 1;

FIG. 4 is a schematic view of the axial suspension control assembly in the stator of embodiment 1 of the present utility model;

FIG. 5 is a second schematic structural view of the axial suspension control assembly in stator embodiment 1 of the present utility model;

fig. 6 is a schematic structural diagram of an embodiment of a permanent magnet device in the stator of the embodiment 2 of the present utility model;

Fig. 7 is a second schematic structural diagram of an embodiment of the permanent magnet device in the stator embodiment 2 of the present utility model;

fig. 8 is a schematic structural view of another embodiment of the permanent magnet device in the stator of embodiment 2 of the present utility model;

fig. 9 is a schematic structural view of a permanent magnet device in a stator according to another embodiment 2 of the present utility model;

fig. 10 is a schematic structural view of a permanent magnet device in accordance with another embodiment 2 of the stator of the present utility model;

FIG. 11 is a schematic view of the radial levitation control assembly of stator embodiment 2 of the present utility model;

FIG. 12 is a schematic view of a stator according to an embodiment 3 of the present utility model;

fig. 13 is a schematic structural view of another view of embodiment 3 of the stator of the present utility model;

FIG. 14 is an axial cross-sectional view of stator embodiment 3 of the present utility model;

FIG. 15 is a schematic diagram of a magnetic levitation device (stator-rotor combination) according to an embodiment of the present utility model;

FIG. 16 is an axial cross-sectional view of an embodiment of a magnetic levitation device (stator-rotor engagement) of the present utility model;

FIG. 17 is a perspective view of an embodiment of a rotor of the present utility model;

FIG. 18 is a schematic view of a stator according to an embodiment 4 of the present utility model;

fig. 19 is a schematic view of a stator according to another view of embodiment 4 of the present utility model;

FIG. 20 is an axial cross-sectional view of stator embodiment 4 of the present utility model;

fig. 21 is a perspective view of a further embodiment of the rotor of the present utility model.

Fig. 22 is an axial cross-sectional view of an embodiment of a semiconductor processing apparatus in accordance with an embodiment of the present utility model.

Detailed Description

The following description of the embodiments of the present utility model will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present utility model, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

In the description of the present utility model, it should be noted that the directions or positional relationships indicated by the terms "upper", "lower", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, are merely for convenience of describing the present utility model and simplifying the description, and do not indicate or imply that the apparatus or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present utility model. The terms "comprises" and "comprising," and any variations thereof, in the description and claims of the utility model and in the foregoing drawings, are intended to cover a non-exclusive inclusion, such that a system, article, or apparatus that comprises a list of elements is not necessarily limited to those elements expressly listed but may include other elements not expressly listed or inherent to such article or apparatus.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present utility model, unless otherwise specified, the meaning of "a plurality" is two or more, unless otherwise clearly defined.

The drawings in this disclosure are not necessarily to scale, and the specific dimensions and numbers of individual structures may be determined according to actual needs. The drawings described in this disclosure are schematic only.

FIG. 1 is a schematic view of an embodiment of a permanent magnet device in an embodiment 1 of a stator according to the present utility model; fig. 2 is a schematic structural view of another embodiment of the permanent magnet device in the stator embodiment 1 of the present utility model; FIG. 3 is a schematic structural view of a permanent magnet device according to another embodiment of the stator of the present utility model in embodiment 1; FIG. 4 is a schematic view of the axial suspension control assembly in the stator of embodiment 1 of the present utility model; FIG. 5 is a second schematic structural view of the axial suspension control assembly in stator embodiment 1 of the present utility model; fig. 6 is a schematic structural diagram of an embodiment of a permanent magnet device in the stator of the embodiment 2 of the present utility model; fig. 7 is a second schematic structural diagram of an embodiment of the permanent magnet device in the stator embodiment 2 of the present utility model; fig. 8 is a schematic structural view of a permanent magnet device in a stator according to another embodiment 2 of the present utility model; fig. 9 is a schematic structural view of another embodiment of the permanent magnet device in the stator of embodiment 2 of the present utility model; fig. 10 is a schematic structural view of a permanent magnet device in accordance with another embodiment 2 of the stator of the present utility model; FIG. 11 is a schematic view of the radial levitation control assembly of stator embodiment 2 of the present utility model; FIG. 12 is a schematic view of a stator according to an embodiment 3 of the present utility model; fig. 13 is a schematic structural view of another view of embodiment 3 of the stator of the present utility model; FIG. 14 is an axial cross-sectional view of stator embodiment 3 of the present utility model; FIG. 15 is a schematic diagram of a magnetic levitation device (stator-rotor combination) according to an embodiment of the present utility model; FIG. 16 is an axial cross-sectional view of an embodiment of a magnetic levitation device (stator-rotor engagement) of the present utility model; FIG. 17 is a perspective view of an embodiment of a rotor of the present utility model; FIG. 18 is a schematic view of a stator according to an embodiment 4 of the present utility model; fig. 19 is a schematic view of a stator according to another view of embodiment 4 of the present utility model; FIG. 20 is an axial cross-sectional view of stator embodiment 4 of the present utility model; FIG. 21 is a perspective view of yet another embodiment of a rotor of the present utility model; fig. 22 is an axial cross-sectional view of an embodiment of a semiconductor processing apparatus in accordance with an embodiment of the present utility model.

According to an embodiment of the present disclosure, referring to fig. 15 and 16, a magnetic levitation device includes a stator 1 and a rotor 2, the stator 1 including a permanent magnet device 11 and a levitation control assembly 12, the levitation control assembly 12 configured to apply an actively controlled levitation force to the rotor 2, the permanent magnet device 11 configured to apply a permanent magnet bias magnetic field to the rotor 2. Referring to fig. 1 to 10, the permanent magnet device 11 includes a plurality of permanent magnet assemblies 111, the plurality of permanent magnet assemblies 111 are uniformly arranged in a circumferential direction, a position of each permanent magnet assembly is defined as a disposition orientation, a line between a center A2 of each disposition orientation in a radial plane and a projection point A1 of a rotation axis of the rotor in the radial plane is defined as a radial line R, each permanent magnet assembly 111 includes a plurality of permanent magnets 1111, the plurality of permanent magnets are arranged in the same radial plane at intervals with the radial line as a symmetry axis, and magnetic fluxes generated by the permanent magnets 1111 are applied to the rotor 2 via stator poles of the levitation control assembly 12. In this way, the permanent magnets at the arrangement positions are designed into the permanent magnet assembly composed of a plurality of permanent magnets, the plurality of permanent magnets are distributed in the same radial plane at intervals by taking radial lines as symmetry axes, magnetic fluxes generated by the permanent magnets can be uniformly applied to the rotor in the circumferential direction through stator poles of the suspension control assembly, namely, the plurality of permanent magnets of the permanent magnet assembly can uniformly apply z-axis component force of force generated by the stator on the rotor at air gaps of the stator poles in the circumferential direction, so that axial fluctuation of rotor operation is improved, and the stability of motor operation is improved.

In one embodiment, referring to fig. 1 and 6, each permanent magnet assembly 111 includes a plurality of permanent magnets 1111, the plurality of permanent magnets 111 are arranged in the same radial plane, the distances between two adjacent permanent magnets 111 are the same or nearly the same, the plurality of permanent magnets 111 are arranged in a straight line L in the radial plane, and a line R between a center A2 of the permanent magnet assembly 111 and a projection point A1 of a rotation axis of the rotor in the radial plane is perpendicular or nearly perpendicular to the straight line L. For example, when the permanent magnet device 11 is configured as 4-orientation permanent magnet assemblies 111, the 4 permanent magnet assemblies 111 are respectively configured at 4 equidistant orientations of the rotor periphery, that is, the 4 configuration orientations of the permanent magnet device 11 are x+, X-, y+, Y-. When each permanent magnet assembly 111 includes a plurality of permanent magnets 1111, the plurality of permanent magnets 1111 of each permanent magnet assembly 111 are arranged in a straight line at 4 arrangement orientations, and the extending direction of the arrangement straight line of the 4 permanent magnet assemblies 111 is the x-degree-of-freedom direction and the y-degree-of-freedom direction. Referring to fig. 6, when the levitation control assembly is provided with 4 stator poles, the 4 stator poles extend in the circumferential direction and equally divide the circumference, and the equally divided circumferences of the 4 permanent magnet assemblies are configured to correspond to the 4 stator poles one by one in four directions, and the plurality of permanent magnets of the permanent magnet assemblies linearly extend in the direction of the degree of freedom, which is approximately the same as the extending direction of the stator poles, for example, when each permanent magnet assembly comprises 4 permanent magnets, the 4 permanent magnets are equidistantly arranged in the direction of the degree of freedom, and magnetic fluxes generated by the permanent magnets are not concentrated at the center position of the stator poles any more, but are uniformly dispersed in the extending direction approximately the same as the stator poles, so that magnetic fluxes at air gaps of the stator poles are approximately the same, and z-axis component forces generated by the stator to the rotor at the air gaps of the stator poles are relatively balanced in the circumferential direction, thereby improving axial fluctuation of rotor operation, and improving stability of motor operation. Meanwhile, because the magnetic flux at the air gap of the stator magnetic pole has symmetry, the resultant force generated by the stator on the rotor at the air gap of the stator magnetic pole is zero after being decomposed on the x axis and the y axis, so that the rotor does not generate radial fluctuation when rotating at the balance position, the rotating stability of the magnetic suspension turntable is ensured, the position stability of a bearing object (wafer) on the turntable is further ensured, and the high reliability of the process is ensured.

In one embodiment, referring to fig. 8, when the plurality of permanent magnets 111 are arranged in a straight line L in a radial plane, the permanent magnets near the center of the permanent magnet assembly are relatively closer to the curved stator poles, and the permanent magnets near both sides are relatively farther from the curved stator poles. Therefore, the distance between two adjacent permanent magnets can be gradually reduced from the center of the permanent magnet assembly to two sides. As shown in fig. 8, the distance between two adjacent permanent magnets at the center position is a1, the distance between two adjacent permanent magnets close to two sides is a2, and a1 is designed to be larger than a2, so that the magnetic flux generated by the permanent magnets at the center position is weakened, the magnetic flux at the air gap of the stator magnetic pole is more nearly the same, the z-axis component of the force generated by the stator on the rotor at the air gap of the stator magnetic pole is more balanced in the circumferential direction, the axial fluctuation of the rotor operation is further improved, and the stability of the motor operation is improved.

In one embodiment, referring to fig. 2 and 9, each permanent magnet assembly 111 includes a plurality of permanent magnets 1111, the plurality of permanent magnets 1111 are arranged in the same radial plane, the distances between two adjacent permanent magnets 1111 are the same or nearly the same, the plurality of permanent magnets are arranged in the radial plane to form an arc H, and a projection point A1 of the rotation axis of the rotor in the radial plane is the same or nearly the same as the distance r of each permanent magnet 1111. That is, the plurality of permanent magnets 1111 of the permanent magnet assembly 111 at each configuration orientation are the same or nearly the same distance from the rotation axis, such that the plurality of permanent magnets 1111 are arranged in an arc shape as a whole. Because of the adaptation of the annular rotor, the stator pole of the levitation control assembly is usually designed to be circular arc with the rotation axis of the rotor as the center, and the plurality of permanent magnets 1111 are also designed to be circular arc with the same distance from the rotation axis of the rotor, the magnetic circuit of each permanent magnet 1111 at each configuration position can be more consistent, so that the magnetic flux at the air gap of the stator pole and the rotor is distributed more uniformly on the circumference of the part corresponding to the configuration position, thereby further improving the axial fluctuation when the rotor rotates, and further improving the rotation stability of the magnetic levitation turntable.

In one embodiment, referring to fig. 3 and 10, on the basis that the plurality of permanent magnets 1111 of the permanent magnet assembly 111 at each configuration orientation are designed to be the same or nearly the same distance from the rotation axis, the distance between the outermost permanent magnets 1111 of the adjacent two permanent magnet assemblies 111 is the same or nearly the same as the distance between the adjacent two permanent magnets 1111 of the permanent magnet assembly 111 in the circumferential direction. That is, the distance between any two permanent magnets is the same or nearly the same in the whole circumferential direction, so that the magnetic circuit of each permanent magnet 1111 in the whole circumference is more consistent, and the magnetic flux at the air gap between the stator pole and the rotor is more uniformly distributed in the whole circumference, so as to further improve the axial fluctuation of the rotor during rotation, and further improve the rotation stability of the magnetic suspension turntable.

In one embodiment, referring to fig. 1, 2, 6, 8, and 9, the permanent magnet assembly 111 includes a bearing block 1112 and a plurality of permanent magnets 1111, the bearing block 1112 having a fixing groove 1113 formed thereon corresponding to each permanent magnet 1111, the permanent magnets 1111 being positioned within the corresponding fixing grooves 1113. Thus, the function of fixing the permanent magnet can be realized by arranging the fixing groove on the bearing block, and the permanent magnet can be positioned in the fixing groove in a tight fit or other fixing modes. Preferably, the shape of the fixing groove is adapted to the shape of the permanent magnet, for example, when the permanent magnet is square-cylindrical, the fixing groove may be designed as a square groove, but is not limited thereto. The shape of the permanent magnet may also be designed as an arc (tile shape) or the like. In the structure in which permanent magnets are equidistantly disposed over the entire circumference is illustrated in fig. 3 and 9, in which case the carrier blocks of the permanent magnet assemblies can be adjusted accordingly according to the number of permanent magnets, for example, 24 permanent magnets are illustrated in fig. 3 and 9, each permanent magnet assembly includes 6 permanent magnets, 1 of which falls outside the carrier blocks, and thus, the length of the carrier blocks in the circumferential direction needs to be expanded.

In one embodiment, referring to fig. 7, the permanent magnet assembly may further include a bearing block 1112 and a partition 1114, wherein a through groove 1115 is formed on the bearing block, the through groove is divided into a plurality of sub-grooves corresponding to the plurality of permanent magnets one by the partition, and the permanent magnets 1111 are positioned in the corresponding sub-grooves. In other embodiments, other structures may be used to fix the permanent magnet according to the structural requirement, which is not described herein.

In the above-described configuration, the levitation control assembly 12 is configured to apply an actively controlled levitation force to the rotor 2, and the levitation control assembly may be configured as a radial levitation control assembly or an axial levitation control assembly. Different suspension control components can be assembled in a specific magnetic suspension device according to the requirements of radial suspension control and axial suspension control. The axial suspension control assembly is mainly used for actively controlling the axial direction of the rotor so as to control the axial suspension height of the rotor. The radial suspension control assembly is mainly used for actively controlling the radial direction of the rotor so as to realize stable suspension for controlling the radial direction of the rotor.

1-5, a stator 1 of a magnetic levitation apparatus includes an axial levitation control assembly 12, the axial levitation control assembly 12 including a first control assembly 121 and a second control assembly 122 disposed in axially staggered layers, the first control assembly 121 configured to apply an axially upward levitation force to a rotor, and the second control assembly 122 configured to apply an axially downward levitation force to the rotor. By adjusting the upward and downward levitation forces applied to the rotor 2 by the first and second control units, a function of adjusting the axial height of the rotor can be achieved. The first control assembly 121 includes a first stator substrate 1210 and a plurality of first stator poles 1211 protruding from the first stator substrate 1210 toward the rotor 2, the first stator poles 1211 being provided with first electromagnetic windings 1212, the plurality of first stator poles 1211 being uniformly arranged in a circumferential direction; the second control assembly 122 includes a second stator substrate 1220 and a plurality of second stator poles 1221 protruding from the second stator substrate 1220 toward the rotor 2, the second stator poles 1221 being provided with second electromagnetic windings 1222, the plurality of second stator poles 1221 being uniformly arranged in a circumferential direction.

For example, referring to fig. 4 and 5, the first control assembly 121 includes a plurality of first stator poles 1211, the plurality of first stator poles 1211 being disposed uniformly in a circumferential direction, and the first stator poles 1211 being provided with the first electromagnetic windings 112. The second control assembly 122 includes a plurality of second stator poles 1221, the plurality of second stator poles 1221 being uniformly arranged in a circumferential direction, and the second stator poles 1221 being provided with second electromagnetic windings 122. In one embodiment, the first electromagnetic winding and the second electromagnetic winding are both concentrated windings, a first current is passed through the first electromagnetic winding, and a second current is passed through the second electromagnetic winding. For example, increasing the first current and/or decreasing the second current may cause the first stator pole 1211 and the first electromagnetic winding 112 to apply a greater axially upward force to the rotor 2 than the second stator pole 1221 and the second electromagnetic winding 122 apply a greater axially downward force to the rotor 2, the rotor 2 moving axially upward along the stator 1 by a distance that depends on the magnitude of the increase in the first current and/or the magnitude of the decrease in the second current, the greater the magnitude of the increase in the first current and/or the greater the magnitude of the decrease in the second current. For example, decreasing the first current and/or increasing the second current may cause the first stator pole 1211 and the first electromagnetic winding 112 to apply a smaller axially upward force to the rotor 2 than the second stator pole 1221 and the second electromagnetic winding 122 apply a smaller axially downward force to the rotor 2, the rotor 2 moving axially downward along the stator 1 by a distance that depends on the decreasing magnitude of the first current and/or the increasing magnitude of the second current, the greater the decreasing magnitude of the first current and/or the greater the increasing magnitude of the second current. Therefore, in the magnetic levitation device according to the embodiment of the present disclosure, the position of the rotor 2 can be simply, flexibly and accurately adjusted in the axial direction of the stator 1 according to actual needs, thereby improving the controllability of the magnetic levitation device and making the magnetic levitation device have a wider application prospect.

In the above structure, the uniform arrangement of the first stator pole 1211 and the second stator pole 1221 in the circumferential direction means that: the distances between the adjacent two stator poles are equal or nearly equal in the circumferential direction, but the distances between the two stator poles are not limited, for example, it is preferable that, referring to fig. 8 and 9, the distances between the adjacent two stator poles in the circumferential direction are designed to be as small as possible so that the lengths of the stator poles are extended as much as possible in the circumferential direction, and thus, when the permanent magnet bias magnetic field generated by the permanent magnet and the electromagnetic field generated by the electromagnetic winding act on the corresponding air gap through the stator poles, a relatively uniform magnetic field can be obtained in the circumferential direction. The adjacent two stator magnetic poles can be a first stator magnetic pole and a second stator magnetic pole, or can be adjacent two first stator magnetic poles or adjacent two second stator magnetic poles. For example, in a preferred embodiment, referring to fig. 4 and 5, one second stator pole 1221 is disposed between two adjacent first stator poles 1211 in the circumferential direction, and one first stator pole 1211 is disposed between two adjacent second stator poles 1221, that is, a plurality of first stator poles and a plurality of second stator poles are alternately disposed, but not limited thereto, in other embodiments, two or more second stator poles may be disposed between two adjacent first stator poles, or two or more first stator poles may be disposed between two adjacent second stator poles.

The number of the permanent magnet assemblies is closely related to the number of the stator magnetic poles of the axial suspension assembly, if the permanent magnet bias magnetic fields (magnetic fluxes) generated by the plurality of the permanent magnet assemblies are unequal (unbalanced) at the air gaps of the plurality of the stator magnetic poles of the axial suspension control assembly, the forces generated by the stators on the rotor at the air gaps of the plurality of the stator magnetic poles are unequal, the resultant force of the x axis and the y axis is not zero, and the component force of the z axis at the air gaps is unequal, so that the rotor rotates at the balance position and is also subjected to the unbalanced force exerted by the permanent magnet bias magnetic fields, and further the radial fluctuation and the axial fluctuation of the rotor are caused, and the running stability of the motor is influenced. To this end, in one embodiment, the permanent magnet arrangement 11 comprises a plurality of permanent magnet assemblies 111, the plurality of permanent magnet assemblies 111 being arranged uniformly in the circumferential direction and generating equal or nearly equal magnetic flux at the first air gap of each pair of radially symmetrical two first stator poles 1211 or at the first air gap of each first stator pole 1211 and equal or nearly equal magnetic flux at the second air gap of each pair of radially symmetrical two second stator poles 1221 or at the second air gap of each second stator pole 1221. In this way, in one case, by uniformly arranging the plurality of permanent magnet assemblies in the circumferential direction and making the plurality of permanent magnet assemblies generate equal or nearly equal magnetic fluxes at the first air gaps of the two first stator poles of each pair of radially symmetric of the first control assembly of the axial levitation control assembly (axial levitation control) and at the second air gaps of the second stator poles of each pair of radially symmetric of the second control assembly, the forces generated by the stators on the rotor at the respective air gaps of the plurality of first stator poles can be made equal, and at the same time, the forces generated by the stators on the rotor at the respective air gaps of the plurality of first stator poles can be made equal, that is, the resultant force on the x-axis and the y-axis is zero, and the rotor is subjected to the permanent magnet bias magnetic field when rotating at the equilibrium position, thereby improving the radial fluctuation of the rotor when rotating at the equilibrium position. In another case, the plurality of permanent magnet assemblies are uniformly arranged on the circumference, and equal or nearly equal magnetic fluxes are generated at the first air gap of each first stator magnetic pole of the axial suspension control assembly (axial suspension control) and the second air gap of each second stator magnetic pole of the second control assembly, so that the forces generated by the stators on the rotor at the air gaps of the plurality of first stator magnetic poles are equal, and meanwhile, the forces generated by the stators on the rotor at the air gaps of the plurality of second stator magnetic poles are equal, namely, the resultant force on the x axis and the y axis is zero, the component force of the z axis at each air gap is equal, the force exerted by the permanent magnet bias magnetic field when the rotor rotates at the balance position is balanced, the component force of the z axis at different positions on the circumference is also balanced, the radial fluctuation of the rotor when the rotor rotates at the balance position is improved, the axial fluctuation of the rotor when the rotor rotates at the balance position is improved, the stability of the rotation of the magnetic levitation device is improved, the position stability of a carrier (wafer) on the turntable is ensured, and the manufacturing process reliability is ensured.

In the above-mentioned structure, the plurality of permanent magnet assemblies 111 are uniformly arranged in the circumferential direction, that is, the plurality of permanent magnet assemblies are equidistantly arranged in a plurality of orientations in the circumferential direction, for example, referring to fig. 1, one common configuration structure is as follows: permanent magnet assemblies 111 are respectively arranged at 4 equidistant orientations (X+, X-, Y+, Y-) on the circumference. The adjacent two permanent magnet assemblies 111 are spaced apart from each other by a predetermined distance in the circumferential direction, wherein one predetermined distance may be configured as a lead-out position of the cable. The cable may be, for example, an outgoing cable of an electromagnetic winding or an outgoing cable of a sensor in a magnetic levitation system.

In the above structure, each pair of radially symmetrical two first stator poles or each pair of radially symmetrical two second stator poles, and hereinafter each pair of radially symmetrical two radial stator poles means: the two stator poles are equally spaced 180 degrees apart in the circumferential direction, i.e. one stator pole coincides with the other stator pole after 180 degrees of rotation.

In order to achieve equal or near equal magnetic flux generated by the plurality of permanent magnet assemblies at the first air gap of each pair of radially symmetric first stator poles 1211 of the first control assembly and at the second air gap of each pair of radially symmetric second stator poles 1221 of the second control assembly, in one embodiment, the number of the plurality of first stator poles, the number of the plurality of second stator poles, and the number of the plurality of permanent magnet assemblies are all designed to be an even number of 2 or more. Because the plurality of first stator magnetic poles and the plurality of second stator magnetic poles are uniformly arranged in the circumferential direction, and the plurality of permanent magnet assemblies are uniformly arranged in the circumferential direction, the same magnetic flux can be generated at each pair of radially symmetrical stator magnetic pole air gaps as long as the number of the first stator magnetic poles, the second stator magnetic poles and the permanent magnet assemblies is designed to be an even number of more than or equal to 2, and the effect that the magnetic flux generated at the air gaps of the plurality of pairs of radially symmetrical stator magnetic poles (the first stator magnetic poles and the second stator magnetic poles) can be balanced in the radial plane can be achieved by the plurality of permanent magnet assemblies. The resultant force of the first stator magnetic pole and the second stator magnetic pole on the x axis and the y axis is zero, and the rotor is applied with balanced force by the permanent magnet bias magnetic field when rotating at the balance position. In another embodiment, the number of the plurality of first stator poles, the number of the plurality of second stator poles, and the number of the plurality of permanent magnet assemblies may also be designed to be the same and not even. When the number of the first stator magnetic poles is the same as that of the second stator magnetic poles, the first stator magnetic poles and the second stator magnetic poles are arranged alternately in the circumferential direction, the axial size of the product is reduced, and the permanent magnet bias magnetic fields provided by the plurality of permanent magnet assemblies are equal at the air gap of each stator magnetic pole in the same group. The number of the first stator magnetic poles and the number of the second stator magnetic poles are equal to the number of the permanent magnet assemblies, the relative azimuth angle is not required to be limited, magnetic fluxes generated by the plurality of the permanent magnet assemblies are balanced on each stator magnetic pole, and the forces applied to the rotor through the plurality of stator magnetic poles uniformly distributed in the circumferential direction are necessarily balanced.

Preferably, the number of the plurality of first stator poles and the number of the plurality of second stator poles are designed to be the same and even. More preferably, the number of the plurality of first stator poles, the number of the plurality of second stator poles, and the number of the plurality of permanent magnet assemblies are each designed to be 4. In one embodiment, the number of the plurality of first stator poles and the number of the plurality of second stator poles are 4, the number of the plurality of permanent magnet assemblies 111 is 8, each permanent magnet assembly is opposite to the position of one first stator pole in the circumferential direction, and each permanent magnet assembly is opposite to the position of one second stator pole in the circumferential direction; the number of the first stator magnetic poles and the second stator magnetic poles is the same, so that the first stator magnetic poles and the second stator magnetic poles are arranged alternately in the circumferential direction, the number of the stator magnetic poles is 1/2 of the number of the permanent magnet assemblies, each permanent magnet assembly is convenient to correspond to one first stator magnetic pole or one second stator magnetic pole, and therefore magnetic fluxes at air gaps of the stator magnetic poles in the same group or different groups are equal. In another embodiment, each permanent magnet assembly is equidistantly disposed between adjacent one of the first stator poles and one of the second stator poles in the circumferential direction. In other embodiments, for example, the number of stator poles may also be 2 times the number of permanent magnet assemblies, which may be implemented to correspond to one first or second stator pole. For example, the number of the plurality of first stator poles and the number of the plurality of second stator poles are 8, the number of the plurality of permanent magnet assemblies is 4, each permanent magnet assembly is opposite to the position of one first stator pole in the circumferential direction, or each permanent magnet assembly is opposite to the position of one second stator pole in the circumferential direction; alternatively, each permanent magnet assembly is equidistantly arranged between adjacent one of the first stator poles and one of the second stator poles in the circumferential direction.

According to an embodiment of the present disclosure, referring to fig. 6 to 10, a stator 1 of a magnetic levitation device includes a radial levitation control assembly 13, the radial levitation control assembly 13 including a radial stator substrate 130 and a plurality of radial stator poles 131 protruding from the radial stator substrate 130 toward a rotor 2, radial electromagnetic windings 132 being provided on the radial stator poles 131, the plurality of radial stator poles 131 being uniformly arranged in a circumferential direction. In one embodiment, the radial electromagnetic windings 132 are concentrated windings, the plurality of radial stator poles 131 and the radial electromagnetic windings 132 include +x winding coils and poles, -X winding coils and poles, +y winding coils and poles, -Y winding coils and poles, and increasing the current of the +x winding coils and/or decreasing the current of the-X winding coils can cause the force applied by the +x winding coils and poles to the rotor 2 in the-X direction to be greater than the force applied by the-X winding coils and poles to the rotor 2 in the +x direction, and the rotor 2 moves in the-X direction of the stator 1, and vice versa, the rotor 2 moves in the +x direction of the stator 1, thereby enabling active control of the rotor in the X degree of freedom. Based on the same principle, the rotor 2 can move along the-Y direction of the stator 1, and conversely, the rotor 2 moves along the +Y direction of the stator 1, so that the active control of the rotor on the Y degree of freedom is realized. The +x winding coil and magnetic pole, -X winding coil and magnetic pole, +y winding coil and magnetic pole, and-Y winding coil and magnetic pole may be a single winding coil and a single magnetic pole, or may be a resultant force generated by a plurality of winding coils and a plurality of magnetic poles.

Also, to provide stability for operation of the magnetic levitation device, the plurality of permanent magnet assemblies 111 generate equal or nearly equal magnetic flux at the air gap of each pair of radially symmetric two radial stator poles 131 or at the air gap of each radial stator pole 131. Thus, in one case, the plurality of permanent magnet assemblies 111 generate equal or nearly equal magnetic fluxes at the air gaps of the two radial stator poles 131 of each pair of radial levitation control assemblies 13 (radial levitation control), so that the forces generated by the stator 1 on the rotor 2 at the respective air gaps of the plurality of radial stator poles 131 are equal, that is, the resultant force of the radial stator poles 131 on the x-axis and the y-axis is zero, and the rotor 2 is subjected to the permanent magnet bias magnetic field to exert an equal force when rotating at the equilibrium position, thereby improving the radial fluctuation of the rotor when rotating at the equilibrium position. In another case, by making the plurality of permanent magnet assemblies 111 generate equal or nearly equal magnetic fluxes at the air gap of each radial stator pole 131 of the radial levitation control assembly 13 (radial levitation control), the forces generated by the stator 1 on the rotor 2 at each air gap of the plurality of radial stator poles 131 are equal, the z-axis component forces at each air gap are also equal, the rotor is subjected to the permanent magnet bias magnetic field to apply balanced force when rotating at the equilibrium position, and the z-axis component forces at different positions in the circumferential direction are also balanced, so that the radial fluctuation of the rotor when rotating at the equilibrium position is improved, the axial fluctuation of the rotor when rotating at the equilibrium position is improved, the rotating stability of the magnetic levitation device is improved, the position stability of the carrier (wafer) on the turntable is ensured, and the high reliability of the process is ensured.

In one embodiment, referring to fig. 6-10, the number of the plurality of radial stator poles 131 and the number of the plurality of permanent magnet assemblies 111 are each 4, each permanent magnet assembly 111 being opposite to one radial stator pole 131 in the circumferential direction. In this way, the number of radial stator poles 131 is the same as the number of the permanent magnet assemblies 111 in the arrangement direction, and is 4, so that the radial electromagnetic windings 132 are arranged on the 4 radial stator poles 131 in two perpendicular degrees of freedom (x degree of freedom, y degree of freedom) of the rotor 2, and since the permanent magnet bias magnetic fields provided by the 4 permanent magnet assemblies 111 are balanced on each radial stator pole 131, the forces applied to the rotor 2 by the 4 radial stator poles 131 uniformly distributed in the circumferential direction are necessarily balanced. Preferably, the permanent magnet assemblies 111 are distributed in a 4-equal-distribution mode, and can be well matched with the x-degree of freedom and the y-degree of freedom. In another embodiment, each permanent magnet assembly 111 is disposed equidistant (circumferentially) between two adjacent radial stator poles 131 in the circumferential direction. In other embodiments, the number of permanent magnet assemblies 111 may also be n times the number of radial stator poles 131, or the number of radial stator poles 131 may also be n times the number of permanent magnet assemblies 111, where n is a natural number of 2 or more.

In one embodiment, referring to fig. 6 to 10, a plurality of motor slots 134 are formed at a side of each radial stator pole 131 facing the rotor 2, motor teeth 135 are formed between two adjacent motor slots 134, motor slots 133 are formed between two adjacent radial stator poles 131, and the motor slots 133 are configured as one motor slot 134. In this way, the rotating electromagnetic winding 16 for rotation control can be disposed in the motor slot 134 to realize rotation control of the rotor 2, the radial electromagnetic winding 132 is disposed on a side of the rotating electromagnetic winding 16 opposite to the rotor 2, the permanent magnet bias magnetic field generated by the permanent magnet assembly 111 is guided to the motor teeth 135 sequentially through the radial stator magnetic pole 131 (the iron core of the electromagnetic winding), a third air gap is formed between the motor teeth 135 and the rotor 2, integrated design of motor rotation control and radial suspension control is realized, and the motor rotation control structure and suspension control structure are optimized to achieve the purpose of compact structure. In one embodiment, the rotating electromagnetic winding 16 may be a concentrated winding, wherein the motor teeth are configured as an iron core of a concentrated winding, see fig. 5, wound on the corresponding motor teeth. In another embodiment, the rotating electromagnetic winding 16 may also be designed as a distributed winding.

In the above embodiments, the stator 1 of the magnetic levitation apparatus is described as including the axial levitation control assembly 12 or the radial levitation control assembly 13.

According to an embodiment of the present disclosure, referring to fig. 11-13, the stator 1 of the magnetic levitation apparatus includes an axial levitation control assembly 12 and a radial levitation control assembly 13. The specific structure and principle of the axial suspension control assembly 12 and the radial suspension control assembly are the same as those of the above-mentioned related embodiments, and detailed descriptions of the related features of the assembly are omitted herein.

Referring to fig. 11-13, the radial stator substrate 130 of the radial levitation control assembly, the permanent magnet assembly 111 of the permanent magnet device, the first stator substrate 1210 of the axial levitation control assembly, and the second stator substrate 1220 are laminated together in axial sequence. The permanent magnet assembly and the first stator magnetic pole, the permanent magnet assembly and the second stator magnetic pole, the first stator magnetic pole and the second stator magnetic pole and the permanent magnet assembly and the radial stator magnetic pole are not in the same radial plane, but are arranged in a staggered manner in the axial direction. In this way, the magnetic fluxes generated by the plurality of permanent magnet assemblies can be simultaneously guided to the plurality of first stator poles via the first stator substrate, and the magnetic fluxes generated by the plurality of permanent magnet assemblies can also be simultaneously guided to the plurality of second stator poles via the second stator substrate; at the same time, the magnetic flux generated by the plurality of permanent magnet assemblies can also be simultaneously guided to the plurality of radial stator poles via the radial stator substrate. The first magnetic circuit of the permanent magnet assembly is: the magnetic flux is emitted from one end of the permanent magnet assembly, and sequentially returns to the other end of the permanent magnet assembly through the first stator substrate, the first stator magnetic pole, the first air gap, the first annular edge of the rotor, the rotor main body, the rotor magnetic pole of the rotor, the third air gap, the radial stator magnetic pole and the radial stator substrate. Meanwhile, the second magnetic circuit of the permanent magnet assembly is as follows: the magnetic flux is emitted from one end of the permanent magnet assembly and sequentially returns to the other end of the permanent magnet assembly through the first stator substrate, the second stator magnetic pole, the second air gap, the first annular edge of the rotor, the rotor main body, the rotor magnetic pole of the rotor, the third air gap, the radial stator magnetic pole and the radial stator substrate. In the present embodiment, for convenience of explanation, the first stator substrate and the second stator substrate are described as two members for convenience of processing and manufacturing, but not limited thereto. In other embodiments, the first stator substrate and the second stator substrate may be integrally formed, in which case the first stator pole and the second stator pole are formed on the integrally formed stator substrate. In the above-described embodiment, the first stator pole and the first stator substrate are expressed as two members, but not limited thereto, and in other embodiments, the first stator pole and the first stator substrate may be integrally formed. Likewise, the second stator pole and the second stator substrate are described as two parts, and the second stator pole and the second stator substrate may also be integrally formed. The first stator magnetic pole, the first stator substrate, the second stator magnetic pole, the second stator substrate, the radial stator magnetic pole and the radial stator substrate are all formed by magnetic conductive materials. Further, for example, the magnetically permeable material is a ferromagnetic material; ferromagnetic materials are, for example, soft magnetic materials having a permeability much greater than the vacuum permeability, examples of which include, but are not limited to, iron, cobalt, nickel and alloys thereof, carbon steel, silicon steel, electrical pure iron.

The permanent magnet assemblies are used for providing permanent magnet bias magnetic fields, and the plurality of permanent magnet assemblies are equidistantly wound around the periphery of the rotor. In one embodiment, each permanent magnet assembly includes a plurality of axially magnetized permanent magnets 1111. Axial magnetization of each permanent magnet may provide magnetic flux to both the first and second stator poles and the radial stator poles, examples of permanent magnets include, but are not limited to, samarium cobalt, neodymium iron boron, ferrite.

The radial stator substrate, the permanent magnet assembly, the first stator substrate and the second stator substrate are sequentially laminated together along the axial direction, and the mode of laminating and fixing the radial stator substrate, the permanent magnet assembly, the first stator substrate and the second stator substrate together is not limited, so long as the radial stator substrate, the permanent magnet assembly, the first stator substrate and the second stator substrate can be fixed together. In a preferred embodiment, referring to fig. 11, the stator 1 further includes a plurality of first press plates 14 and a plurality of second press plates 15, wherein the first press plates 14 are disposed on the outer side of the radial stator substrate 130, the second press plates 15 are disposed on the outer side of the second stator substrate 1220, and the first press plates 14 and the second press plates 15 are fastened together by fasteners.

According to an embodiment of the present disclosure, referring to fig. 14 to 16, the magnetic levitation device further includes a rotor 2, the rotor 2 including a rotor body 21, a first rim 22 (i.e., a first layer) extending from the rotor body 21 toward the stator 1, and a second rim (i.e., a second layer), a first air gap being formed between the first stator pole 1211 and the first rim 22, and a second air gap being formed between the second stator pole 1221 and the first rim; the second annular rim is hollowed out at equal intervals to form a plurality of rotor magnetic poles 23, and a third air gap is formed between the rotor magnetic poles 23 and the radial stator magnetic poles 131. For example, the rotor 2 is formed of a magnetic material, examples of which include, but are not limited to, a permanent magnetic material or a ferromagnetic material. Still further, for example, the ferromagnetic material is a soft magnetic material having a permeability much greater than the vacuum permeability, examples of which include, but are not limited to, iron, cobalt, nickel and alloys thereof, carbon steel, silicon steel, electrical pure iron. Examples of permanent magnet materials include, but are not limited to, samarium cobalt, neodymium iron boron, ferrite. The axially upward force applied to the rotor 2 by the first stator pole 1211 and the first electromagnetic winding 112 acts on the first rim 22 of the rotor 2 simultaneously with the axially downward force applied to the rotor 2 by the second stator pole 1221 and the second electromagnetic winding 122. Since the plurality of first stator poles 1211 and the plurality of second stator poles 1221 are uniformly disposed around the circumference of the rotor 2, the interaction between the first stator poles 1211 and the first electromagnetic windings 112 and the second stator poles 1221 and the second electromagnetic windings 122 and the first flange 11 makes the rotor 2 stably levitate in the axial direction and the resultant force in the radial direction is zero.

In one embodiment, the number of rotor poles 23 is an even number of 2 or more, and the number of rotor poles 23 is the same as the number of radial stator poles 131. The rotor magnetic pole 23 is mainly used for being matched with the rotary electromagnetic winding 16 to realize the rotation control of the rotor. Meanwhile, due to the integrated design of the radial levitation control assembly 13 for radial levitation control and the motor stator (motor teeth and rotating electromagnetic windings) for motor rotation control, the permanent magnet bias magnetic fields generated by the plurality of permanent magnet assemblies 111 act on the rotor magnetic poles 23 of the rotor 2 through the plurality of radial stator magnetic poles 131 of the radial levitation control assembly 13, the number of the rotor magnetic poles 23 and the number of the radial stator magnetic poles 131 are both set to be an even number greater than or equal to 2, the same magnetic flux can be generated at each pair of radially symmetrical rotor magnetic pole air gaps, and then the effect that the magnetic fluxes of the plurality of permanent magnet assemblies acting on the air gaps of the rotor magnetic poles through each pair of radially symmetrical radial stator magnetic poles can be balanced in a radial plane can be achieved. In another embodiment, the number of rotor poles is the same as the number of radial stator poles and is not even, for example, when the number of permanent magnet assemblies and radial stator poles are 3, the number of rotor poles may be 3. In this way, the magnetic flux of the plurality of permanent magnet assemblies acting at the air gap of the rotor pole via each radial stator pole can also be balanced in the radial plane.

Since the rotor magnetic pole 23 is mainly used to cooperate with the rotating electromagnetic winding 16, the rotation control of the rotor is achieved. In a preferred embodiment, referring to fig. 14 and 16, the number of rotor poles is 8 and the number of radial stator poles is 4. At this time, the number of the rotor magnetic poles corresponding to each radial stator magnetic pole is still the same, and the force provided by the permanent magnet bias magnetic field in the rotor rotation process is balanced, so that the rotation stability of the magnetic levitation device is ensured, the position stability of a bearing object (wafer) on the turntable is further ensured, and the high reliability of the process is ensured.

According to an embodiment of the present disclosure, referring to fig. 17-20, the stator 1 of the magnetic levitation device includes two radial levitation control assemblies 13, wherein the radial stator substrate 130 of one radial levitation control assembly 13, the permanent magnet assembly, and the radial stator substrate 130 of the other radial levitation control assembly are sequentially stacked together in an axial direction. The permanent magnet component and the two radial stator poles are not in the same radial plane, but are arranged in a staggered way in the axial direction. In this way, the magnetic flux generated by the plurality of permanent magnet assemblies can be simultaneously guided to the plurality of radial stator poles of the upper layer through one radial stator substrate; at the same time, the magnetic flux generated by the plurality of permanent magnet assemblies can be guided to the plurality of radial stator poles of the lower layer through the other radial stator substrate at the same time. The first magnetic circuit of the permanent magnet assembly is: the magnetic flux is emitted from one end of the permanent magnet assembly, and sequentially returns to the other end of the permanent magnet assembly through the upper radial stator substrate, the radial stator magnetic pole, the air gap A, the first annular edge of the rotor, the rotor main body, the rotor magnetic pole of the rotor, the air gap B, the lower radial stator magnetic pole and the radial stator substrate. The radial stator pole and the radial stator substrate are described as two parts, but not limited thereto, and in other embodiments, the radial stator pole and the radial stator substrate may be integrally formed. The radial stator poles and the radial stator substrates are all formed by magnetic conductive materials. Further, for example, the magnetically permeable material is a ferromagnetic material; ferromagnetic materials are, for example, soft magnetic materials having a permeability much greater than the vacuum permeability, examples of which include, but are not limited to, iron, cobalt, nickel and alloys thereof, carbon steel, silicon steel, electrical pure iron.

In one embodiment, referring to fig. 17, the stator 1 further includes a plurality of first press plates 14 and a plurality of second press plates 15, wherein the first press plates 14 are disposed on the outer side of the upper radial stator substrate 130, the second press plates 15 are disposed on the outer side of the lower radial stator substrate 1220, and the first press plates 14 and the second press plates 15 are fastened together by fasteners.

According to an embodiment of the present disclosure, referring to fig. 20, the magnetic levitation device further includes a rotor 2, the rotor 2 including a rotor body 21', a first rim 22' (i.e., a first layer) and a second rim 23 '(i.e., a second layer) extending from the rotor body 21' toward the stator 1, the first rim 22 'being hollowed out at equal intervals to form a plurality of rotor poles a221', the second rim 23 'being hollowed out at equal intervals to form a plurality of rotor poles B231', an air gap a being formed between the rotor poles a221 'and a radial stator pole of one radial levitation control assembly, and an air gap B being formed between the rotor poles B231' and a radial stator pole of another radial levitation control assembly. Also, in the present embodiment, the rotor 2 is formed of a magnetic material, examples of which include, but are not limited to, a permanent magnetic material or a ferromagnetic material. Still further, for example, the ferromagnetic material is a soft magnetic material having a permeability much greater than the vacuum permeability, examples of which include, but are not limited to, iron, cobalt, nickel and alloys thereof, carbon steel, silicon steel, electrical pure iron. Examples of permanent magnet materials include, but are not limited to, samarium cobalt, neodymium iron boron, ferrite. The levitation force applied to the rotor 2 by the upper radial stator pole 131 and the radial electromagnetic winding 132 acts on the rotor pole a221 'of the first rim 22' of the rotor 2, and the levitation force applied to the rotor 2 by the lower radial stator pole 131 and the radial electromagnetic winding 132 acts on the rotor pole B231 'of the second rim 23' of the rotor 2. Since a plurality of radial stator poles are uniformly arranged around the circumference of the rotor 2, the rotor 2 is stably levitated by the interaction between the radial stator poles 131 and the radial electromagnetic windings and the corresponding rotor poles.

The number of rotor poles of the rotor in this embodiment and the matching relationship with the rotating electromagnetic winding 16 are the same as those in the above embodiment, and will not be described here again.

In other embodiments, the stator of the magnetic levitation device may further include two axial levitation control assemblies, wherein the second stator substrate and the first stator substrate of one axial levitation control assembly, the permanent magnet assembly, and the first stator substrate and the second stator substrate of the other axial levitation control assembly are sequentially stacked together in an axial direction. At this time, the motor rotation control for driving the rotor to rotate is provided separately from the axial levitation control.

Based on the same inventive concept, referring to fig. 21, the embodiment of the present disclosure further provides a semiconductor processing apparatus, which includes a carrier 3 and the magnetic levitation device in the above embodiments, where the rotor 2 supports and positions the carrier 3 through a plurality of support columns 4. Thus, the carrier 3 is connected to the rotor 2 via a number of support bodies, and the stator 1 is configured to drive the rotor 2 and the carrier 3 in rotation and in suspension. As such, semiconductor processing equipment is used in semiconductor manufacturing, for example, in rapid thermal processing and other wafer processing in semiconductor manufacturing, such as chemical vapor deposition, thermal processing, ion implantation doping, and other techniques doping. The carrier may be used to carry a wafer. By way of example, fig. 21 illustrates a magnetic levitation apparatus comprising a radial levitation control assembly and an axial levitation control assembly.

It should be noted that, for convenience of illustration, the above embodiments and all the drawings show the case where the stator 1 is disposed around the rotor 2; however, unless stated to the contrary, the description of the embodiments of the present disclosure also applies to the case where the rotor 2 surrounds the stator 1.

The principle and the implementation mode of the utility model are explained by applying specific examples, and the above examples are only used for helping to understand the technical scheme and the core idea of the utility model; meanwhile, as those skilled in the art will vary in the specific embodiments and application scope according to the idea of the present utility model, the present disclosure should not be construed as limiting the present utility model in summary.

Claims

1. A magnetic levitation device comprising a stator (1) and a rotor (2), the stator (1) comprising a permanent magnet device (11) and a levitation control assembly (12) configured to apply an actively controlled levitation force to the rotor, the permanent magnet device being configured to apply a permanent magnet bias magnetic field to the rotor, characterized in that the permanent magnet device comprises a plurality of permanent magnet assemblies (111) uniformly arranged in a circumferential direction, the position of each permanent magnet assembly being defined as a configuration orientation, the line between the center (A2) of each configuration orientation in a radial plane and a projection point (A1) of the rotation axis of the rotor in a radial plane being defined as a radial line (R), each permanent magnet assembly comprising a plurality of permanent magnets (1111) arranged in the same radial plane with the radial line as a symmetrical axis spacing, the magnetic flux generated by the permanent magnets being applied to the rotor via the stator poles of the levitation control assembly.

2. A magnetic levitation apparatus according to claim 1, wherein the plurality of permanent magnets are arranged in a straight line (L) in the radial plane, and the radial line is perpendicular to the straight line.

3. A magnetic levitation apparatus according to claim 2, wherein the distance between two adjacent permanent magnets in each permanent magnet assembly is the same or gradually decreases from the center of the permanent magnet assembly to both sides.

4. A magnetic levitation apparatus according to claim 1, wherein the plurality of permanent magnets are arranged in an arc (H) in the radial plane, and a projected point (A1) of the rotation axis of the rotor in the radial plane is the same as a distance (r) of each of the permanent magnets.

5. A magnetic levitation apparatus according to claim 4, wherein the distance between two adjacent permanent magnets in each permanent magnet assembly is the same in the circumferential direction; or the distance between two adjacent permanent magnets in each permanent magnet assembly is the same, and the distance between the outermost permanent magnets of two adjacent permanent magnet assemblies is the same as the distance between the two adjacent permanent magnets of the permanent magnet assemblies.

6. A magnetic levitation apparatus according to any of claims 1-5, wherein the permanent magnet assembly further comprises a bearing block (1112), the bearing block (1112) having a fixing slot (1113) formed therein for each permanent magnet positioned in the corresponding fixing slot.

7. A magnetic levitation apparatus according to any of claims 1-5, wherein the permanent magnet assembly further comprises a carrier block (1112) having a through slot (1115) formed therein and a partition (1114) dividing the through slot into a plurality of sub slots in one-to-one correspondence with the plurality of permanent magnets, the permanent magnets being positioned in the corresponding sub slots.

8. A magnetic levitation apparatus according to any of claims 1-5, wherein the levitation control assembly is configured as an axial levitation control assembly comprising a first control assembly (121) and a second control assembly (122) arranged in axially staggered layers, the first control assembly being configured to apply an axially upward levitation force to the rotor and the second control assembly being configured to apply an axially downward levitation force to the rotor; the first control assembly comprises a first stator substrate (1210) and a plurality of first stator magnetic poles (1211) protruding from the first stator substrate towards the rotor, wherein first electromagnetic windings (1212) are arranged on the first stator magnetic poles, and the plurality of first stator magnetic poles are uniformly arranged in the circumferential direction; the second control assembly includes a second stator substrate (1220) and a plurality of second stator poles (1221) protruding from the second stator substrate toward the rotor, the second stator poles being provided with second electromagnetic windings (1222), the plurality of second stator poles being uniformly arranged in a circumferential direction.

9. A magnetic levitation apparatus according to claim 8, wherein the plurality of permanent magnet assemblies produce equal magnetic flux at the first air gap of each pair of radially symmetric two first stator poles or at the first air gap of each first stator pole and equal magnetic flux at the second air gap of each pair of radially symmetric two second stator poles or at the second air gap of each second stator pole.

10. A magnetic levitation apparatus according to claim 9, wherein two axial levitation control assemblies are provided, the second stator substrate and the first stator substrate of one of the axial levitation control assemblies, the permanent magnet assembly, and the first stator substrate and the second stator substrate of the other axial levitation control assembly being stacked together in axial order.

11. A magnetic levitation apparatus according to claim 8, wherein one second stator pole is disposed between two adjacent first stator poles and one first stator pole is disposed between two adjacent second stator poles in the circumferential direction.

12. The magnetic levitation apparatus of claim 11, wherein the number of the plurality of first stator poles, the number of the plurality of second stator poles, and the number of the plurality of permanent magnet assemblies are 4, each permanent magnet assembly being opposite to one first stator pole in a circumferential direction; alternatively, each permanent magnet assembly is positioned opposite one of the second stator poles in the circumferential direction; alternatively, each permanent magnet assembly is equidistantly arranged between adjacent one of the first stator poles and one of the second stator poles in the circumferential direction.

13. A magnetic levitation apparatus according to any of claims 1-5, wherein the levitation control assembly is configured as a radial levitation control assembly comprising a radial stator substrate (130) and a plurality of radial stator poles (131) protruding from the radial stator substrate towards the rotor, each radial stator pole being provided with a radial electromagnetic winding (132), the plurality of radial stator poles being uniformly arranged in a circumferential direction.

14. A magnetic levitation apparatus according to claim 13, wherein the plurality of permanent magnet assemblies produce equal magnetic flux at the air gap of each pair of radially symmetric two radial stator poles or at the air gap of each radial stator pole.

15. A magnetic levitation apparatus according to claim 14, wherein two radial levitation control assemblies are provided, the radial stator substrate of one radial levitation control assembly, the permanent magnet assembly, and the radial stator substrate of the other radial levitation control assembly being sequentially stacked together in an axial direction.

16. The magnetic levitation apparatus of claim 15, wherein the number of the plurality of radial stator poles and the number of the plurality of permanent magnet assemblies are 4, each permanent magnet assembly being positioned opposite to one radial stator pole in a circumferential direction; alternatively, each permanent magnet assembly is equidistantly disposed between two adjacent radial stator poles in the circumferential direction.

17. A magnetic levitation apparatus according to claim 16, wherein each radial stator pole has a plurality of motor slots (134) formed on a side facing the rotor, motor teeth (135) formed between two adjacent motor slots, and motor slots (133) formed between two adjacent radial stator poles, the motor slots being configured as one motor slot.

18. A magnetic levitation apparatus according to claim 17, wherein the rotor comprises a rotor body (21 '), a first rim (22 ') and a second rim (23 ') extending from the rotor body to the stator, the first rim being equally spaced apart to form a plurality of rotor poles a (221 '), the second rim being equally spaced apart to form a plurality of rotor poles B (231 '), an air gap a being formed between the rotor poles a and a radial stator pole of one of the radial levitation control assemblies, and an air gap B being formed between the rotor poles B and a radial stator pole of the other of the radial levitation control assemblies.

19. A magnetic levitation apparatus according to claim 18, wherein the number of rotor poles a and the number of rotor poles B are 8, and the number of radial stator poles is 4.

20. A semiconductor processing apparatus comprising a carrier (3) and a magnetic levitation device according to any of claims 1-19, the rotor being supported in position by a plurality of support columns (4).