A magnetic levitation turntable

Abstract

The present invention discloses a magnetic levitation turntable, which comprises a magnetic levitation stator and a magnetic levitation rotor. The magnetic levitation rotor includes a rotor main body, a first rim and a second rim. The magnetic levitation stator includes a permanent magnet assembly, a first and a second suspension control assembly, and a magnetic guide. The first suspension control assembly includes a first stator substrate, a plurality of first stator magnetic poles and a first suspension winding provided on the first stator magnetic poles; the second suspension control assembly includes a second stator substrate, a plurality of second stator magnetic poles and a second suspension winding provided on the second stator magnetic poles. The permanent magnet assembly is arranged between the first and second stator substrates. The permanent magnet bias magnetic field generated by the permanent magnet assembly forms a first magnetic field loop through the first stator substrate, the first stator magnetic poles, the first rim, the rotor main body, the second rim, the second stator magnetic poles, and the second stator substrate; the electromagnetic control magnetic field generated by the first suspension control assembly forms a second magnetic field loop through the first stator magnetic poles, the first rim, the magnetic guide, and the first stator substrate.

Description

Technical Field

[0001] The present invention relates to the field of magnetic levitation technology, and more particularly to a magnetic levitation turntable. Background Art

[0002] In semiconductor manufacturing, on the one hand, the cleanliness of wafers is very important because the cleanliness of the wafer surface affects the qualification rate of subsequent semiconductor processes and products. To meet the requirement of ultra-cleanliness, wafers made of silicon or other semiconductor materials must be processed in a controlled ultra-clean atmosphere. For example, in the process of wafer manufacturing, one manufacturing step is to anneal the wafer after ion implantation doping. Doping applies strain to the crystal structure, and if the stress cannot be quickly released, it will cause an undesirable change in the resistivity of ion doping. Currently, rapid thermal processing (RT) is usually used for annealing. On the other hand, the processing uniformity of wafers is very important. To achieve uniformity, the wafer is usually rotated around the vertical axis or z-axis centered on the wafer during wafer processing. Rotation is also used for other wafer processes, such as chemical vapor deposition, heat treatment, ion implantation doping, and other technical doping. To meet the stringent requirements of ultra-cleanliness and processing uniformity in semiconductor process manufacturing, a magnetic levitation turntable with non-contact rotational drive is preferably used in semiconductor processing equipment.

[0003] At present, the magnetic levitation turntable includes a magnetic levitation stator and a magnetic levitation rotor. The magnetic levitation rotor includes a rotor body, a first rim and a second rim extending from the rotor body towards the magnetic levitation stator. The magnetic levitation stator includes a first suspension control assembly, a second suspension control assembly and a permanent magnet assembly. The first suspension control assembly includes a first stator substrate, a first stator magnetic pole extending from the first stator substrate towards the first rim, and a first suspension winding wound around the first stator magnetic pole; the second suspension control assembly includes a second stator substrate, a second stator magnetic pole extending from the second stator substrate towards the first rim, and a second suspension winding wound around the second stator magnetic pole; the permanent magnet assembly is disposed between the first stator substrate of the first suspension control assembly and the second stator substrate of the second suspension control assembly to provide a permanent magnet bias magnetic field. In this way, the permanent magnet bias magnetic field generated by the permanent magnet of the permanent magnet assembly and the electromagnetic control magnetic field generated by the suspension control winding both form a magnetic field loop through the first stator substrate, the first rim, the rotor body, the second rim and the second stator substrate. The electromagnetic control magnetic circuit of this structure is relatively long, and magnetic leakage is likely to occur during the magnetic flux return process, resulting in a low magnetic flux utilization rate. Moreover, the relatively long magnetic circuit leads to a reduction in magnetic field strength, resulting in a weak axial force for suspension control; and the permanent magnet bias magnetic field and the electromagnetic control magnetic field are highly coupled, which may cause delays and instability in the response of the control system. In addition, due to the gravity of the magnetic levitation rotor, when the magnetic levitation rotor is suspended, the first stator magnetic pole and the first suspension winding of the suspension control assembly are slightly higher than the first rim as a whole, and the electromagnetic control magnetic field of the suspension control assembly is located on the same side of the first rim. The magnetic levitation rotor is prone to axial irregular vibration, and an additional axial control winding needs to be provided to weaken or eliminate this axial vibration of the magnetic levitation rotor, resulting in a complex control algorithm for the control system and an increase in hardware configuration. Summary of the Invention

[0004] In order to overcome the defects in the prior art, an embodiment of the present invention provides a magnetic levitation turntable, which is used to solve at least one of the above problems.

[0005] An embodiment of the present disclosure discloses a magnetic levitation turntable, which includes a magnetic levitation stator and a magnetic levitation rotor. The magnetic levitation rotor includes a rotor body, a first rim and a second rim extending from the rotor body towards the magnetic levitation stator. The magnetic levitation stator includes a permanent magnet assembly, a first suspension control assembly, a second suspension control assembly and a magnetic guide. The first suspension control assembly includes a first stator substrate, a plurality of first stator magnetic poles protruding from the first stator substrate towards the first rim, and a first suspension winding disposed on the first stator magnetic poles; the second suspension control assembly includes a second stator substrate, a plurality of second stator magnetic poles protruding from the second stator substrate towards the second rim, and a second suspension winding disposed on the second stator magnetic poles. The permanent magnet assembly is axially disposed between the first stator substrate and the second stator substrate. The permanent magnetic bias field generated by the permanent magnet assembly forms a first magnetic field loop through the first stator substrate, the first stator magnetic poles, the first rim, the rotor body, the second rim, the second stator magnetic poles, and the second stator substrate; the electromagnetic control magnetic field generated by the first suspension control assembly forms a second magnetic field loop successively through the first stator magnetic poles, the first rim, the magnetic guide, and the first stator substrate.

[0006] Further, the magnetic guide includes a plurality of magnetic conduction teeth. The magnetic conduction teeth and the first stator magnetic poles are located in the same layer of radial plane, the radial plane is perpendicular to the axial direction, the magnetic conduction teeth are located between two adjacent first stator magnetic poles and are magnetically connected to the first stator substrate.

[0007] Further, the first stator substrate is annular, and the magnetic conduction teeth and the first stator magnetic poles are provided on the inner side of the first stator substrate and are integrally formed with the first stator substrate.

[0008] Further, the first stator substrate is annular, and the magnetic guide further includes an annular magnetic conduction base body. The magnetic conduction base body is axially disposed on one side of the first stator substrate facing the permanent magnet assembly or on the side opposite to the permanent magnet assembly. The magnetic conduction base body and the magnetic conduction teeth are fixedly connected by a magnetic conduction bend.

[0009] Further, one or two magnetic conduction teeth are provided between two adjacent first stator magnetic poles.

[0010] Further, the magnetic guide includes a magnetic conduction base body and a plurality of magnetic conduction teeth. The magnetic conduction base body is annular, the plurality of magnetic conduction teeth are provided on the inner side of the magnetic conduction base body, the magnetic conduction base body is axially disposed on one side of the first stator substrate facing the permanent magnet assembly or on the side opposite to the permanent magnet assembly, the magnetic conduction teeth are arranged in a staggered layer with the first stator magnetic poles, and the magnetic conduction teeth are circumferentially located between two adjacent first stator magnetic poles.

[0011] Furthermore, the magnetic conduction teeth and the magnetic conduction base body are integrally formed.

[0012] Furthermore, one or two of the magnetic conduction teeth are provided between two adjacent first stator magnetic poles.

[0013] Furthermore, a position sensor is further included, and the position sensor is installed on the magnetic conduction teeth.

[0014] Furthermore, a notch groove is formed on the magnetic conduction teeth, and the position sensor is installed in the notch groove.

[0015] Furthermore, the position sensor is configured as a radial displacement sensor, an axial displacement sensor, or an axial-radial displacement sensor.

[0016] Furthermore, the axial-radial displacement sensor includes two magnetic conductors in an n shape, an exciting coil, and two induction coils. The two magnetic conductors are arranged axially. The exciting coil is sleeved on one end of the two magnetic conductors. One induction coil is sleeved on the other end of one magnetic conductor, and the other induction coil is sleeved on the other end of the other magnetic conductor. The exciting coil and the two induction coils are circumferentially spaced apart.

[0017] Furthermore, the circumferential length of the magnetic conduction teeth is less than the circumferential length of the first stator magnetic poles.

[0018] Furthermore, the circumferential length of the magnetic conduction teeth is less than 1 / 2 of the circumferential length of the first stator magnetic poles and greater than 1 / 4 of the circumferential length of the first stator magnetic poles.

[0019] Furthermore, a plurality of tooth grooves are formed on one side of the second stator magnetic poles facing the second rim. A tooth portion is formed between two adjacent tooth grooves, and a rotation control winding is provided in the tooth grooves.

[0020] Furthermore, a circumferential winding is provided between the first stator substrate and the second stator substrate, and the circumferential winding surrounds the magnetic levitation rotor.

[0021] Furthermore, a lifting mechanism for axially driving the magnetic levitation stator is further included.

[0022] The beneficial effects of the present invention are as follows: Compared with the prior art, the magnetic levitation turntable of the present invention optimizes the magnetic circuit of the control coil in the two-layer suspension control structure, guides the electromagnetic control magnetic field of the first suspension control component through the magnetic guide, and constructs a second magnetic field circuit different from the first magnetic field circuit of the permanent magnet component, thereby reducing the coupling of the permanent magnet bias magnetic field and the electromagnetic control magnetic field, improving the response speed and stability of the control system, and the second magnetic field circuit does not pass through the permanent magnet component, thus avoiding the influence of the electromagnetic control magnetic field on the permanent magnet of the permanent magnet component. In addition, according to the different relative positions of the magnetic guide and the first rim of the magnetic levitation rotor along the axial direction, the problem of weak axial force of the suspension control or axial irregular vibration of the magnetic levitation rotor can also be solved. For example, when the axial height of the magnetic guide is the same as or approximately the same as the axial height of the first stator pole and they are axially aligned or approximately aligned, the axial height of the magnetic guide is the same as or approximately the same as the axial height of the magnetic levitation rotor, and the magnetic guide is slightly higher than the first rim as a whole in the axial direction, the magnetic guide in the second magnetic field circuit can make the length of the second magnetic field circuit less than the length of the first magnetic field circuit, thereby reducing magnetic leakage; it can also increase the magnetic flux utilization rate and improve the axial force of the suspension control; when the axial height of the magnetic guide is the same as or approximately the same as the axial height of the first rim of the magnetic levitation rotor and they are axially aligned or approximately aligned or the magnetic guide is slightly lower than the first rim as a whole in the axial direction, the axial height of the first stator pole is the same as or approximately the same as the axial height of the first rim of the magnetic levitation rotor, and the first stator pole is slightly higher than the first rim as a whole in the axial direction, the magnetic guide in the second magnetic field circuit can make the length of the second magnetic field circuit less than the length of the first magnetic field circuit, thereby reducing magnetic leakage; it can also weaken or eliminate the axial vibration of the magnetic levitation rotor, thereby achieving the purpose of eliminating the need to set up axial control windings, simplifying the relevant hardware and circuit configuration, simplifying the control algorithm of the control system, and further reducing the production cost.

[0023] To make the above and other objects, features, and advantages of the present invention more obvious and understandable, the following specifically gives preferred embodiments and, in conjunction with the accompanying drawings, makes a detailed description as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0025] Figure 1 is a schematic structural diagram of an embodiment of a magnetic levitation turntable in the prior art;

[0026] Figure 2 is a schematic structural diagram of an embodiment of the magnetic levitation turntable in the present inventionFigure 1 ;

[0027] Figure 3 is Figure 2 The schematic cross-sectional structure diagram of the A-A direction in

[0028] Figure 4 is Figure 3 The enlarged structural schematic diagram of the left part;

[0029] Figure 5 is Figure 2 The schematic cross-sectional structure diagram of the C-C direction in

[0030] Figure 6 This is the structural schematic diagram of an embodiment of the magnetic levitation turntable in the present invention Figure 2 ;

[0031] Figure 7 is Figure 6 The enlarged structural schematic diagram of the upper right part;

[0032] Figure 8 This is the structural schematic diagram of an embodiment of the magnetic levitation turntable in the present invention Figure 3 ;

[0033] Figure 9 This is the structural schematic diagram of an embodiment of the magnetic levitation stator in the present invention Figure 1 ;

[0034] Figure 10 is Figure 9 The enlarged structural schematic diagram at position A in

[0035] Figure 11 This is the structural schematic diagram of an embodiment of the magnetic levitation stator in the present invention Figure 2 ;

[0036] Figure 12 is Figure 11 The enlarged structural schematic diagram at position B in

[0037] Figure 13 This is the structural schematic diagram of the first stator substrate in an embodiment of the magnetic levitation stator in the present invention;

[0038] Figure 14 This is the structural schematic diagram of an embodiment of the magnetic levitation rotor in the present invention;

[0039] Figure 15 This is the structural schematic diagram of another embodiment of the magnetic levitation stator in the present invention;

[0040] Figure 16 This is the structural schematic diagram of the magnetic guiding member in another embodiment of the magnetic levitation stator in the present invention;

[0041] Figure 17It is a schematic structural diagram of the first stator substrate in another embodiment of the magnetic levitation stator in the present invention;

[0042] Figure 18 It is a schematic structural diagram of another embodiment of the magnetic levitation stator in the present invention;

[0043] Figure 19 It is a schematic structural diagram of the magnetic guide in another embodiment of the magnetic levitation stator in the present invention;

[0044] Figure 20 It is a schematic structural diagram of another embodiment of the magnetic levitation turntable in the present invention;

[0045] Figure 21 It is a schematic diagram showing the functional relationship among the first stator magnetic pole, the first rim and the magnetic guide in the present invention Figure 1 ;

[0046] Figure 22 It is a schematic diagram showing the functional relationship among the first stator magnetic pole, the first rim and the magnetic guide in the present invention Figure 2 ;

[0047] Figure 23 It is a schematic diagram showing the functional relationship among the first stator magnetic pole, the first rim and the magnetic guide in the present invention Figure 3 . Detailed implementation manners

[0048] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0049] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention. The terms "including" and "provided with" in the specification and claims of the present invention and any variations thereof are intended to cover non-exclusive inclusion. For example, a system, product or device including a series of units does not necessarily have to be limited to those units clearly listed, but may include other units not clearly listed or inherent to these products or devices.

[0050] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "a plurality of" is two or more, unless otherwise clearly defined.

[0051] The drawings in the present disclosure are not strictly drawn to actual scale, and the specific dimensions and quantities of each structure can be determined according to actual needs. The drawings described in the present disclosure are only schematic diagrams.

[0052] In the prior art, referring to Figure 1 , an embodiment of a magnetic levitation turntable, the magnetic levitation turntable includes a magnetic levitation stator and a magnetic levitation rotor. The magnetic levitation rotor includes a rotor body 21, a first rim 22 and a second rim 23 extending from the rotor body 21 towards the magnetic levitation stator. The magnetic levitation stator includes a first suspension control assembly 12, a second suspension control assembly 13 and a permanent magnet assembly 11. The first suspension control assembly 12 includes a first stator substrate 121, a plurality of first stator magnetic poles 1211 protruding from the first stator substrate 121 towards the first rim, and a first suspension winding 122 wound around the first stator magnetic poles; the second suspension control assembly includes a second stator substrate 131, a plurality of second stator magnetic poles 1311 protruding from the second stator substrate 131 towards the second rim 23, and a second suspension winding 132 wound around the second stator magnetic poles; the permanent magnet assembly 11 is disposed between the first stator substrate 121 of the first suspension control assembly 12 and the second stator substrate 131 of the second suspension control assembly 13 to provide a permanent magnet bias magnetic field. Thus, as Figure 1 shown, the permanent magnet bias magnetic field generated by the permanent magnets of the permanent magnet assembly 11 and the electromagnetic control magnetic field generated by the suspension control windings both form a magnetic field loop through the first stator substrate 121, the first rim 22, the rotor body 21, the second rim 23, and the second stator substrate 131. The electromagnetic control magnetic circuit of this structure is relatively long, and magnetic leakage is likely to occur during the magnetic flux return process, resulting in low magnetic flux utilization rate. Moreover, the long magnetic circuit leads to a decrease in magnetic field strength, resulting in a weak axial force for suspension control; and the permanent magnet bias magnetic field and the electromagnetic control magnetic field are highly coupled, which may cause delays and instability in the response of the control system. In addition, due to the gravity of the magnetic levitation rotor, when the magnetic levitation rotor is suspended, the first stator magnetic poles and the first suspension winding of the suspension control assembly are slightly higher than the first rim as a whole, and the electromagnetic control magnetic field of the suspension control assembly is on the same side of the first rim. The magnetic levitation rotor is prone to axial irregular vibrations, and an additional axial control winding needs to be provided to weaken or eliminate such axial vibrations of the magnetic levitation rotor, resulting in a complex control algorithm for the control system and an increase in hardware configuration.

[0053] To enable those skilled in the art to better understand the solution of the present invention, the following further elaborates on the present invention with reference to the attached Figure 2-23 drawings and specific embodiments.

[0054] Figure 2 FIG. Figure 1 ; Figure 3 is Figure 2 the schematic structural diagram of the A-A cross-section in Figure 4 ; Figure 3 is Figure 5 the enlarged structural diagram of the left part in Figure 2 ; Figure 6 FIG. Figure 2 ; Figure 7 is Figure 6 the enlarged structural diagram of the upper right part in Figure 8 FIG. Figure 3 ; Figure 9 FIG. Figure 1 ; Figure 10 is Figure 9 the enlarged structural diagram at position A in Figure 11 FIG. Figure 2 ; Figure 12 is Figure 11 the enlarged structural diagram at position B in Figure 13 the schematic structural diagram of the first stator substrate in an embodiment of the magnetic levitation stator of the present invention; Figure 14 FIG.

[0055] According to an embodiment of the present disclosure, referring to Figure 1-Figure 14, A magnetic levitation turntable, comprising a magnetic levitation stator 1 and a magnetic levitation rotor 2. The magnetic levitation rotor 2 includes a rotor main body 21, a first rim 22 and a second rim 23 extending from the rotor main body 21 towards the magnetic levitation stator 1. The magnetic levitation stator 1 includes a permanent magnet assembly 11, a first suspension control assembly 12, a second suspension control assembly 13 and a magnetic guide 14. The first suspension control assembly 12 includes a first stator substrate 121, a plurality of first stator magnetic poles 1211 protruding from the first stator substrate 121 towards the first rim 22, and a first suspension winding 122 disposed on the first stator magnetic poles 1211; the second suspension control assembly 13 includes a second stator substrate 131, a plurality of second stator magnetic poles 1311 protruding from the second stator substrate 131 towards the second rim 23, and a second suspension winding 132 disposed on the second stator magnetic poles 1311. The permanent magnet assembly 11 is axially disposed between the first stator substrate 121 and the second stator substrate 131. The permanent magnet bias magnetic field generated by the permanent magnet assembly 11 forms a first magnetic field circuit S1 through the first stator substrate 121, the first stator magnetic poles 1211, the first rim 22, the rotor main body 21, the second rim 23, the second stator magnetic poles 1311, and the second stator substrate 131; the electromagnetic control magnetic field generated by the first suspension control assembly 12 forms a second magnetic field circuit S2 through the first stator magnetic poles 1211, the first rim 22, the magnetic guide 14, and the first stator substrate 121 in sequence. In this way, by guiding the electromagnetic control magnetic field of the first suspension control assembly through the magnetic guide, a second magnetic field circuit different from the first magnetic field circuit of the permanent magnet assembly is constructed, thereby reducing the coupling of the permanent magnet bias magnetic field and the electromagnetic control magnetic field, improving the response speed and stability of the control system, and the second magnetic field circuit does not pass through the permanent magnet assembly, thus avoiding the influence of the electromagnetic control magnetic field on the permanent magnets of the permanent magnet assembly. Particularly, referring to Figure 21 , Figure 22 and Figure 23 , according to the different axial relative positions of the magnetic guide and the first rim of the magnetic levitation rotor, the problem of weak axial force of suspension control or axial irregular vibration of the magnetic levitation rotor can also be solved. For example, referring to Figure 21 , when the axial height of the magnetic guide 14 is the same as or approximately the same as the axial height of the first stator magnetic poles 1211 and they are axially aligned or approximately axially aligned, and the axial height of the magnetic guide 14 is the same as or approximately the same as the axial height of the first rim 22 of the magnetic levitation rotor, and the magnetic guide 14 is slightly higher than the first rim 22 as a whole in the axial direction, the magnetic guide in the second magnetic field circuit can make the length of the second magnetic field circuit shorter than the length of the first magnetic field circuit, thereby reducing magnetic leakage; it can also increase the magnetic flux utilization rate and improve the axial force of suspension control. Referring to Figure 22 and Figure 23, when the axial height of the magnetic guide 14 is the same as or approximately the same as the axial height of the first rim 22 of the magnetic levitation rotor and they are axially aligned or approximately axially aligned or the magnetic guide 14 is slightly lower than the first rim 22 as a whole axially, and the axial height of the first stator magnetic pole 1211 is the same as or approximately the same as the axial height of the first rim 22 and the first stator magnetic pole 1211 is slightly higher than the first rim 22 as a whole axially, the magnetic guide in the second magnetic field circuit can make the length of the second magnetic field circuit less than the length of the first magnetic field circuit, thereby reducing magnetic leakage; it can also weaken or eliminate the axial vibration of the magnetic levitation rotor, so as to achieve the purpose of eliminating the axial control winding, simplifying the relevant hardware and circuit configuration, simplifying the control algorithm of the control system, and further reducing the production cost.

[0056] Preferably, the axial height of the magnetic guide is the same as or approximately the same as the axial height of the first rim of the magnetic levitation rotor and the axial height of the first stator magnetic pole. Here, approximately the same can be understood as the size change caused by processing errors. However, it is not limited to this. In other embodiments, there can also be a height difference within a certain range among the three, and this height difference requirement will not cause the failure of the first magnetic field circuit and the second magnetic field circuit. For example, the axial height of the first stator magnetic pole is less than the axial height of the first rim of the magnetic levitation rotor and greater than half of the axial height of the first rim of the magnetic levitation rotor. For example, the axial height of the first stator magnetic pole is 2 / 3 or 3 / 4 of the axial height of the first rim of the magnetic levitation rotor, etc. Similarly, the size relationship between the two can also be reversed. By the same token, the axial height of the magnetic guide can be less than the axial height of the first rim of the magnetic levitation rotor and greater than half of the axial height of the first rim of the magnetic levitation rotor. For example, the axial height of the magnetic guide is 2 / 3 or 3 / 4 of the axial height of the first rim of the magnetic levitation rotor, etc. Similarly, the size relationship between the two can also be reversed. By the same token, the size relationship between the axial height of the magnetic guide and the axial height of the first stator magnetic pole can also be as described above.

[0057] Among them, the fact that the magnetic guiding member and the first rim of the magnetic levitation rotor are axially aligned or approximately axially aligned can be understood as that when the magnetic levitation rotor is stably levitated, the central plane of the magnetic guiding member in the axial direction is flush with the central plane of the first rim in the axial direction. Similarly, the fact that the magnetic guiding member is slightly lower than the first rim as a whole in the axial direction can be understood as that when the magnetic levitation rotor is stably levitated, the central plane of the magnetic guiding member in the axial direction is lower than the central plane of the first rim in the axial direction. Thus, due to the action of the gravity of the magnetic levitation rotor, when the magnetic levitation rotor is stably levitated, the central plane of the first stator magnetic pole in the axial direction is higher than the central plane of the magnetic levitation rotor in the axial direction. When the basic permanent magnetic bias magnetic field passing through the first stator magnetic pole and the electromagnetic control magnetic field of the suspension control winding are applied to the first rim of the magnetic levitation rotor, an upward pulling force is exerted. When this force balances the gravity of the magnetic levitation rotor, the magnetic levitation rotor is stably levitated in the axial direction. When it is necessary to change the axial position of the magnetic levitation rotor, the suspension height of the magnetic levitation rotor can be adjusted up or down within a small range by increasing or decreasing the current of the suspension control winding. Since the magnetic guiding member and the first rim of the magnetic levitation rotor are axially aligned or the magnetic guiding member is slightly lower than the first rim as a whole in the axial direction. When the magnetic levitation rotor undergoes axial vibration, the magnetic field passing through the magnetic guiding member and the first rim can play a role in damping the deviation of the rotor. For example, compared with the electromagnetic control magnetic field of the suspension control component in the prior art being on the same side of the first rim, when the magnetic levitation rotor deviates upward from the suspension position along the axial direction, the magnetic guiding member plays a role in dragging the magnetic levitation rotor downward, and when the magnetic levitation rotor deviates downward from the suspension position along the axial direction, the magnetic guiding member plays a role in dragging the magnetic levitation rotor upward, so as to achieve the purpose of weakening or eliminating the irregular axial vibration of the magnetic levitation rotor. In this way, for the entire control system, the axial control winding and related hardware and software configurations can be omitted.

[0058] Among them, the permanent magnetic bias magnetic field generated by the permanent magnetic component 11 forms a first magnetic field loop S1 through the first stator substrate 121, the first stator magnetic pole 1211, the first rim 22, the rotor body 21, the second rim 23, the second stator magnetic pole 1311, and the second stator substrate 131. It can be understood that most of the permanent magnetic bias magnetic field passes through the first magnetic field loop, and theoretically, a small part of the permanent magnetic bias magnetic field may also pass through the magnetic guiding member; similarly, the electromagnetic control magnetic field generated by the first suspension control component 12 forms a second magnetic field loop S2 in sequence through the first stator magnetic pole 1211, the first rim 22, the magnetic guiding member 14, and the first stator substrate 121. It can be understood that most of the electromagnetic control magnetic poles pass through the second magnetic field loop, and theoretically, a small part of the electromagnetic control magnetic field also passes through the first magnetic field loop.

[0059] Among them, Figure 4 Schematically shows the general direction of the first magnetic field loop S1. It should be noted that Figure 4 Only schematically shows the general positional relationship between the first rim of the magnetic levitation rotor and the first stator magnetic pole, not the suspension position. For example, seeFigure 1 , due to the gravity of the magnetic levitation rotor, the first stator magnetic poles and the first suspension windings of the suspension control assembly may be slightly higher than the first rim as a whole.

[0060] According to an embodiment of the present disclosure, referring to Figure 6 、 Figure 7 、 Figure 9 、 Figure 11 and Figure 12 , the magnetic guide 14 includes a plurality of magnetic teeth 141. The magnetic teeth 141 and the first stator magnetic poles 1211 are located in the same layer of radial plane, the radial plane is perpendicular to the axial direction, the magnetic teeth 141 are located between two adjacent first stator magnetic poles 1211 and are magnetically connected to the first stator substrate 121. In this way, by arranging the magnetic teeth in the same layer as the first stator magnetic poles, the electromagnetic control magnetic field of the first suspension windings of the first suspension control assembly is in the same radial plane and is evenly distributed circumferentially, which is beneficial to improving the suspension stability. And when the magnetic levitation rotor is stably suspended, the central planes of the first stator magnetic poles and the magnetic teeth of the magnetic guide in the axial direction are both higher than the central plane of the magnetic levitation rotor in the axial direction, which can play a role in increasing the axial force of the suspension control. In other embodiments, the magnetic teeth can also be arranged in a staggered layer with the first stator magnetic poles, that is, the magnetic teeth and the first stator magnetic poles are located in different radial planes.

[0061] According to an embodiment of the present disclosure, referring to Figure 13 , the first stator substrate 121 is annular, and the magnetic teeth 141 and the first stator magnetic poles 1211 are arranged on the inner side of the first stator substrate and are integrally formed with the first stator substrate. Integrally forming the magnetic teeth with the first stator substrate and the first stator magnetic poles, for example, formed by laminating multiple cut silicon steel sheets, can reduce the number of components, has a simple structure and reduces the assembly cost.

[0062] The present invention does not limit the number of the first stator magnetic poles of the first stator substrate. Preferably, according to an embodiment of the present disclosure, 3 or 4 first stator magnetic poles are formed on one side of the first stator substrate facing the magnetic levitation rotor at equal intervals in the circumferential direction of the magnetic levitation rotor. Referring to Figure 13 , the first suspension control assembly includes 4 first stator magnetic poles 1211. The 4 first stator magnetic poles 1211 are arranged at equal intervals in the circumferential direction, magnetic teeth 141 are arranged between two adjacent first stator magnetic poles 1211, and the magnetic guide 14 includes a total of 4 magnetic teeth 141. The present invention does not limit the number of the magnetic teeth between two adjacent first stator magnetic poles. Preferably, referring to Figure 12, a magnetic conduction tooth 141 is provided between two adjacent first stator magnetic poles 1211. In other embodiments, two magnetic conduction teeth may also be provided between two adjacent first stator magnetic poles. Providing two magnetic conduction teeth means two independent and separate magnetic conduction protruding parts, and the electromagnetic control magnetic fields of two adjacent first suspension windings are relatively separated. Providing one magnetic conduction tooth means a single magnetic conduction protruding part, and the electromagnetic control magnetic fields of two adjacent first suspension windings share one magnetic conduction tooth to guide the magnetic field.

[0063] The first suspension control assembly 12 and the second suspension control assembly 13 are configured to apply a suspension force to the magnetic levitation rotor 2. The first suspension control assembly 12 includes a first stator substrate 121, a plurality of first stator magnetic poles 1211 protruding from the first stator substrate 121 towards the first rim 22, and first suspension windings 122 provided on the first stator magnetic poles 1211; the second suspension control assembly 13 includes a second stator substrate 131, a plurality of second stator magnetic poles 1311 protruding from the second stator substrate 131 towards the second rim 23, and second suspension windings 132 provided on the second stator magnetic poles 1311. See Figure 14, the rotor 2 includes a rotor body 21, a first rim 22 and a second rim 23 extending from the rotor body 21 towards the magnetic levitation stator 1. A plurality of rotor magnetic poles 231 can be formed by equally spaced hollowing on the second rim 23. In one embodiment, the first levitation winding 122 and the second levitation winding 13 are concentrated windings. The first levitation control assembly and the second levitation control assembly include +X winding coils and magnetic poles, -X winding coils and magnetic poles, +Y winding coils and magnetic poles, and -Y winding coils and magnetic poles. Increasing the current of the +X winding coils and / or decreasing the current of the -X winding coils can make the force exerted on the magnetic levitation rotor 2 by the +X winding coils and magnetic poles along the -X direction greater than the force exerted on the magnetic levitation rotor 2 by the -X winding coils and magnetic poles along the +X direction. The magnetic levitation rotor 2 moves along the -X direction of the magnetic levitation stator 1. Conversely, the magnetic levitation rotor 2 moves along the +X direction of the magnetic levitation stator 1, thereby realizing the active control of the magnetic levitation rotor in the x degree of freedom. Based on the same principle, the rotor 2 can be made to move along the -Y direction of the magnetic levitation stator 1, and conversely, the magnetic levitation rotor 2 moves along the +Y direction of the magnetic levitation stator 1, thereby realizing the active control of the magnetic levitation rotor in the y degree of freedom. It should be noted that the +X winding coils and magnetic poles, -X winding coils and magnetic poles, +Y winding coils and magnetic poles, and -Y winding coils and magnetic poles here can be a single winding coil and a single magnetic pole, or the resultant force generated by multiple winding coils and multiple magnetic poles. The magnetic field forces generated by all the +X winding coils and magnetic poles, -X winding coils and magnetic poles, -X winding coils and magnetic poles, and -Y winding coils and magnetic poles of the first levitation control assembly and the second levitation control assembly are used to offset the gravity axially acting on the magnetic levitation rotor, so as to maintain balance axially. Increasing or decreasing the currents of the +X winding coils, -X winding coils, -X winding coils, and -Y winding coils together can achieve the purpose of adjusting the axial position of the magnetic levitation rotor.

[0064] According to an embodiment of the present disclosure, referring to Figure 3 and Figure 4 , the permanent magnet assembly 11 can be configured as a permanent magnet ring, and the permanent magnet ring is clamped between the first levitation control assembly 12 and the second levitation control assembly 13. The permanent magnet assembly can also be configured to include a plurality of permanent magnet modules, referring to Figure 2, a plurality of permanent magnet modules are uniformly arranged in the circumferential direction, and the plurality of permanent magnet modules are clamped between the first suspension control component 12 and the second suspension control component 13. The permanent magnet component 11 is configured to apply a permanent magnet bias magnetic field to the magnetic levitation rotor 2. In one embodiment, the number of the plurality of first stator magnetic poles 121 and the number of the plurality of permanent magnet modules are both 4, and the position of each permanent magnet module is opposite to that of a first stator magnetic pole 1211 in the circumferential direction. In this way, the number of the first stator magnetic poles 121 is the same as the number of the arrangement directions of the permanent magnet modules, and both are 4, which is convenient for arranging the first suspension windings 122 on the two vertical degrees of freedom (x degree of freedom, y degree of freedom) of the magnetic levitation rotor 2. Since the permanent magnet bias magnetic fields provided by the 4 permanent magnet modules are balanced on each first stator magnetic pole 121, the forces applied to the magnetic levitation rotor 2 by the 4 first stator magnetic poles 121 uniformly distributed in the circumferential direction must be balanced. Examples of permanent magnets include, but are not limited to, samarium cobalt, neodymium iron boron, and ferrite. In one embodiment, refer to Figure 4 , the permanent magnet module includes a plurality of permanent magnets 111 and a carrier block 112 for carrying the permanent magnets. The permanent magnets are accommodated in the grooves on the carrier block.

[0065] According to an embodiment of the present disclosure, refer to Figure 2 and Figure 8 , on one side of each second stator magnetic pole 132 facing the magnetic levitation rotor 2, a plurality of tooth grooves 134 are formed, and a tooth portion 135 is formed between two adjacent tooth grooves 134. Preferably, a tooth groove gap 133 is formed between two adjacent second stator magnetic poles 132, and the tooth groove gap 133 is configured as a tooth groove 134. In this way, a rotation control winding for rotation control can be arranged in the tooth groove 134 to realize the rotation control of the magnetic levitation rotor 2. The second suspension winding 132 is arranged on the side of the rotation control winding facing away from the magnetic levitation rotor 2. The permanent magnet bias magnetic field generated by the permanent magnet module is sequentially guided to the tooth portion 135 through the second stator magnetic pole 132 (the iron core of the second suspension winding). An air gap is formed between the tooth portion 135 and the rotor magnetic pole 231 of the magnetic levitation rotor 2, realizing the integrated design of the motor rotation control and the suspension control, optimizing the motor rotation control structure and the suspension control structure, and achieving the purpose of compact structure. The rotation control winding can be a concentrated winding, and the tooth portion is configured as the iron core of the concentrated winding, and the concentrated winding is wound on the corresponding tooth portion. In another embodiment, the rotation control winding can also be designed as a distributed winding. Refer to Figure 2 , a plurality of tooth grooves 134 are arranged on the side of the second suspension winding 132 facing the magnetic levitation rotor 2. Figure 2 The distributed winding is omitted in

[0066] According to an embodiment of the present disclosure, the magnetic levitation turntable further includes a position sensor, which is installed on the magnetic conductive teeth. The position sensor is used to detect the radial displacement, axial displacement or axial-radial displacement of the magnetic levitation rotor. For example, the position sensor can be configured as a radial displacement sensor or an axial displacement sensor.

[0067] According to an embodiment of the present disclosure, referring to Figure 9 , Figure 10 and Figure 13 , preferably, the position sensor is configured as an axial-radial displacement sensor 3. Preferably, a notch groove 1411 is formed on the magnetic conductive teeth 141, and the position sensor is installed in the notch groove 1411. Specifically, the axial-radial displacement sensor 3 includes two magnetic conductors 31 in an n shape, an excitation coil 32 and two induction coils 33. The two magnetic conductors 31 are arranged axially. The excitation coil 32 is sleeved on one end of the two magnetic conductors 31. One induction coil 33 is sleeved on the other end of one magnetic conductor 31, and the other induction coil 33 is sleeved on the other end of the other magnetic conductor 31. The excitation coil 32 and the two induction coils 33 are circumferentially spaced apart. In this way, the two magnetic conductors 31 are arranged axially along the magnetic levitation rotor 2, and an induction coil 33 is sleeved outside each magnetic conductor 31, and the excitation coil 32 is sleeved outside the two magnetic conductors 31 together. Among them, the excitation coil 32 is configured to detect the radial displacement of the rotor, and the two induction coils 33 are configured to detect the axial displacement of the rotor. In this way, the mutual inductance magnetic field between the excitation coil and the induction coils changes when the magnetic levitation rotor undergoes radial or axial displacement. The radial displacement of the rotor is measured through the excitation coil, and the axial displacement of the rotor is measured through the two induction coils, so as to realize the function of measuring the radial and axial displacements of the rotor. At the same time, the displacement measurement is integrated with the stator of the magnetic levitation turntable. With the help of the first rim of the magnetic levitation rotor, the axial-radial displacement sensor can detect the position information of the magnetic levitation rotor through the cavity wall of the vacuum cavity, so as to realize the combination of the position detection of the magnetic levitation rotor and the stator structure, with a compact structure and high sensitivity. Since the two induction coils for measuring the axial displacement of the magnetic levitation rotor are located at the same angular position on the rotor circumference, the calculation amount of the processor during axial displacement measurement can be reduced. The embodiment of the present invention does not need to make through holes on the vacuum cavity and use fluororubber sealing rings, nor does it need to replace the sealing rings, which solves problems such as recalibration and installation errors after assembling the sensor, can better meet the ultra-clean and high-temperature environment requirements of semiconductor processing equipment, can solve the problem of messy cable connections of multiple position sensors, and can greatly reduce the number of sensors used in the magnetic levitation turntable.

[0068] According to an embodiment of the present disclosure, referring to Figure 10 and Figure 12, the excitation magnetic field of the excitation coil 32 directly forms a magnetic field loop with the first rim 22 of the magnetic levitation rotor 2 through two magnetic conductors 31; the induction magnetic fields of the two induction coils 33 also directly form a magnetic field loop through the magnetic conductors 31 and the first rim 22. The principle of measuring the radial displacement of the rotor through the excitation coil is as follows: Since the excitation coil axially covers the height of the first rim of the rotor, when the rotor moves radially, the magnetic flux density of the excitation coil remains constant, and the magnetomotive force follows the change of magnetic reluctance. The change of magnetic reluctance depends on the air gap between the first rim of the rotor and the magnetic conductor of the excitation coil, and the change of magnetomotive force caused by the change of air gap is approximately linearly related to the radial displacement of the rotor. Therefore, the radial displacement of the rotor can be detected according to the output of the magnetomotive force (current) of the excitation coil. The principle of measuring the axial displacement of the rotor through the two induction coils is as follows: When the first rim of the rotor is located in the middle of the two induction coils, the magnetic flux densities of the two induction coils are the same, and the voltage differentially output by the two induction coils is zero; when the rotor moves axially downward or upward, the magnetic flux density of one induction coil increases, and the magnetic flux density of the other induction coil decreases. The magnetic flux densities of the two induction coils change and are no longer equal, and the differentially output value is no longer 0, but is approximately linearly related to the axial displacement of the rotor. Therefore, the axial displacement of the rotor can be detected according to the differential output of the two induction coils.

[0069] In one embodiment, an embodiment with 1 excitation coil and 2 induction coils is given. However, it is not limited to this. In other embodiments, the axial and radial displacement sensor may also include an excitation coil group and two induction coil groups. Among them, the excitation coil group includes at least one excitation coil 32, and the induction coil group includes at least two induction coils 33.

[0070] According to an embodiment of the present disclosure, refer to Figure 10 , the axial and radial displacement sensor 3 includes 1 excitation coil and two induction coil groups. The induction coil group includes 2 induction coils. The 2 induction coils can be set in series or parallel according to actual needs. For example, when the two induction coils are connected in series, the output signal of the induction coil, such as the output voltage or output current, can be enhanced, so as to achieve the purpose of improving the sensitivity of the axial displacement detection of the axial and radial displacement sensor. In the above embodiments, one excitation coil is provided on the magnetic conductor, but it is not limited to this. In other embodiments, two excitation coils can also be provided on the magnetic conductor, and the expected output magnetomotive force can be adjusted by connecting the different excitation coils in series or parallel.

[0071] According to an embodiment of the present disclosure, refer to Figure 10 and Figure 12 , the cross-section of the magnetic conductor 31 is square, the axial heights of the two magnetic conductors 31 are the same, the two magnetic conductors 31 are arranged along the axial direction of the rotor, and the two ends of each magnetic conductor are located in the same horizontal plane, which can achieve the purpose of simplifying the manufacturing process and ensuring the uniform magnetic field distribution of the axial and radial displacement sensor.

[0072] According to an embodiment of the present disclosure, referring to Figure 5 , the axial height of the first annular edge 22 of the rotor is between the lower surface of one of the two magnetic conductors and the upper surface of the other magnetic conductor, and the range of axial movement of the first annular edge 22 is: the upper surface of the first annular edge does not exceed the upper surface of the upper magnetic conductor, and the lower surface of the first annular edge does not exceed the lower surface of the lower magnetic conductor. In this way, it can be ensured that the axial movement of the rotor is within the axial height range of the excitation coil, that is, it will not affect the measurement of the radial displacement of the excitation coil, and the accuracy of sensor detection is improved.

[0073] According to an embodiment of the present disclosure, referring to Figure 12 , a magnetic isolation sheet 35 is provided between the two magnetic conductors 31. By providing the magnetic isolation sheet 35 between the two magnetic conductors, magnetic field coupling between the two magnetic conductors can be avoided. In one embodiment, the magnetic isolation sheet 35 is arranged between the middle parts of the two magnetic conductors 31 and is locked together by fasteners to form a sensor assembly. Preferably, an insulating protective layer is formed by potting outside the excitation coil and the induction coil. As a whole, this sensor assembly can be installed into the magnetic suspension stator of the magnetic suspension turntable. Preferably, referring to Figure 12 , the sensor assembly is locked on the magnetic conduction tooth 141 by fasteners, and the two magnetic conductors 31, the excitation coil 32 and the induction coil 33 of the axial and radial displacement sensor are located in the notch groove 1411 on the magnetic conduction tooth 141.

[0074] According to an embodiment of the present disclosure, referring to Figure 6 and Figure 11, the magnetic levitation turntable includes 4 axial-radial displacement sensors 3, and the 4 axial-radial displacement sensors 3 are correspondingly arranged on 4 magnetic conductive teeth 141. The 4 axial-radial displacement sensors 3 are divided into two groups that are orthogonal to each other, and each group includes two axially-radially symmetrically arranged axial-radial displacement sensors 3. In this way, the 4 axial-radial displacement sensors 3 form two position sensor pairs, each position sensor pair includes 2 axial-radial displacement sensors, and the two position sensor pairs are arranged orthogonally to each other; the position detection of the rotor in two orthogonal directions (x degree of freedom direction and y degree of freedom direction) can be realized, and two axially-radially symmetric axial-radial displacement sensors are used to form a pair of differential sensors to form a differential signal, which can achieve the purpose of improving the sensitivity of radial displacement detection. At the same time, the 4 axial-radial displacement sensors are evenly distributed in the circumferential direction. When detecting the axial displacement of the rotor through the 4 axial-radial displacement sensors, an average value can be obtained to eliminate the problem of inaccurate axial displacement detection caused by the tilt of the rotor. In other embodiments, the magnetic levitation turntable may further include 3 of the above-mentioned axial-radial displacement sensors, and the 3 axial-radial displacement sensors are correspondingly arranged on 3 magnetic conductive teeth 141, and the 3 axial-radial displacement sensors are evenly distributed in the circumferential direction. In this way, through the uniform distribution of the 3 axial-radial displacement sensors in the circumferential direction, an average value can be obtained when detecting the axial displacement of the rotor to eliminate the problem of inaccurate axial displacement detection caused by the tilt of the rotor. And through the components of the 3 axial-radial displacement sensors in two orthogonal directions (x degree of freedom direction and y degree of freedom direction), the function of detecting the radial displacement of the rotor can also be realized.

[0075] The present invention does not limit the circumferential length of the magnetic conductive teeth. Preferably, referring to Figure 6 and Figure 11 , the circumferential length of the magnetic conductive tooth 141 is less than the circumferential length of the first stator pole 1211. Since the magnetic conductive tooth 141 is used to guide the electromagnetic control magnetic field generated by the first suspension winding of the first suspension control assembly and is arranged along the circumference together with the first stator pole, if the circumferential length of the magnetic conductive tooth is too long, the length of the first suspension winding will be reduced, thereby weakening the power output of the first suspension control assembly. If the circumferential length of the magnetic conductive tooth is too short, it may cause magnetic flux concentration, resulting in too high magnetic density in some areas and easy to reach magnetic saturation. And if the circumferential length of the magnetic conductive tooth is too short, it may also increase the eddy current path, resulting in higher eddy current loss. By reasonably designing the circumferential length of the magnetic conductive tooth, the magnetic conductivity of the material can be maximized in a specific application, and the efficiency and reliability of the system can be improved. Preferably, the circumferential length of the magnetic conductive tooth is less than 1 / 2 of the circumferential length of the first stator pole and greater than 1 / 4 of the circumferential length of the first stator pole.

[0076] In the above embodiment, the magnetic conductive tooth 141 of the magnetic guide 14 is integrally formed with the first stator substrate. However, it is not limited thereto. In other embodiments, the magnetic conductive tooth may also be an independent component. Referring to Figure 15 、Figure 16 and Figure 17 In another embodiment of the maglev stator, the magnetic guide 14 includes an annular magnetic conductive base body 142 and a plurality of magnetic conductive teeth 141. The magnetic conductive base body 142 and the magnetic conductive teeth 141 are fixedly connected through a magnetic conductive bending 143. In this way, the magnetic conductive teeth 141 and the first stator magnetic poles 1211 are still located in the same layer of radial plane. The first stator substrate 121 is annular, and a plurality of first stator magnetic poles 1211 protruding towards the first ring edge 22 are integrally formed on the inner side of the first stator substrate 121. For example, referring to Figure 17 shows a case where 4 first stator magnetic poles 1211 are arranged in the first stator substrate 121. Referring to Figure 15 During assembly, the magnetic conductive teeth 141 are located between two adjacent first stator magnetic poles 1211 and are magnetically conductively connected to the first stator substrate 121. The magnetic conductive base body 142 can be axially arranged on the side of the first stator substrate 121 facing away from the permanent magnet assembly 11. In other embodiments, the magnetic conductive base body 142 can also be axially arranged on the side of the first stator substrate 121 facing the permanent magnet assembly 11. In this case, the magnetic conductive teeth 141 can still be connected through the magnetic conductive bending 143 so that the magnetic conductive teeth 141 and the first stator magnetic poles 1211 are located in the same layer of radial plane.

[0077] Similarly, in this embodiment, one magnetic conductive tooth 141 can be provided between two adjacent first stator magnetic poles 1211, and two magnetic conductive teeth can also be provided. Providing two magnetic conductive teeth means two independent and separated magnetic conductive protruding parts, and the electromagnetic control magnetic fields of two adjacent first suspension windings are relatively separated. One magnetic conductive tooth means a single magnetic conductive protruding part, and the electromagnetic control magnetic fields of two adjacent first suspension windings share a magnetic conductive tooth to guide the magnetic field.

[0078] In the above embodiments, the magnetic conductive teeth 141 and the first stator magnetic poles 1211 are located in the same layer of radial plane. However, it is not limited to this. In other embodiments, the magnetic conductive teeth 141 and the first stator magnetic poles 1211 can also be arranged in a staggered layer. Referring to Figure 18 and Figure 19, in another embodiment of the magnetic levitation stator, the magnetic guide 14 includes a magnetic conductive base 142 and a plurality of magnetic conductive teeth 141. The magnetic conductive base 142 is annular, and the plurality of magnetic conductive teeth 141 are arranged on the inner side of the magnetic conductive base 142. The magnetic conductive base 142 is axially arranged on one side of the first stator substrate 121 facing the permanent magnet assembly 11 or on the side facing away from the permanent magnet assembly 11. The magnetic conductive teeth 141 are arranged in a stepped manner with the first stator magnetic poles 1211, and the magnetic conductive teeth 141 are circumferentially located between two adjacent first stator magnetic poles 1211. Preferably, the magnetic conductive base 142 is axially arranged on the side of the first stator substrate 121 facing away from the permanent magnet assembly 11. In this way, when the magnetic levitation rotor is stably levitated, the magnetic conductive teeth of the magnetic guide are axially aligned or approximately aligned with the first rim of the magnetic levitation rotor, or the magnetic conductive teeth of the magnetic guide are slightly lower than the first rim as a whole in the axial direction. When the magnetic levitation rotor undergoes axial vibration, the magnetic field passing through the magnetic conductive teeth and the first rim of the magnetic guide can play a role in damping the deviation of the rotor. For example, compared with the electromagnetic control magnetic field of the suspension control assembly in the prior art, which is on the same side of the first rim, when the magnetic levitation rotor deviates axially upward from the suspension position, the magnetic guide plays a role in dragging the magnetic levitation rotor downward, and when the magnetic levitation rotor deviates axially downward from the suspension position, the magnetic guide plays a role in dragging the magnetic levitation rotor upward, so as to achieve the purpose of weakening or eliminating the irregular axial vibration of the magnetic levitation rotor. In this way, for the entire control system, the axial control winding and related hardware and software configurations can be omitted.

[0079] Similarly, in this embodiment, one magnetic conductive tooth 141 can be arranged between two adjacent first stator magnetic poles 1211, or two magnetic conductive teeth can also be arranged.

[0080] According to an embodiment of the present disclosure, referring to Figure 19 , the magnetic conductive tooth 141 and the magnetic conductive base 142 are integrally formed. Preferably, a notch groove 1411 is formed on the magnetic conductive tooth 141 to facilitate the installation of the position sensor.

[0081] According to an embodiment of the present disclosure, referring to Figure 20, the magnetic levitation turntable further includes a circumferential winding 4 disposed between the first stator substrate 121 and the second stator substrate 131, and the circumferential winding surrounds the magnetic levitation rotor 2. In this way, when the magnetic levitation turntable stops working, the circumferential winding can provide a reverse excitation relative to the permanent magnet assembly to cancel or partially cancel the magnetic field of the permanent magnets of the permanent magnet assembly, thereby facilitating the picking and placing of the magnetic levitation rotor and also avoiding the phenomenon of the magnetic levitation rotor landing and colliding due to the excessive magnetic force of the permanent magnets. In addition, the circumferential winding can also play a role in axial suspension control. For example, in an embodiment where the axial center plane of the first stator magnetic pole and the magnetic guiding teeth of the magnetic guiding member are higher than the axial center plane of the magnetic levitation rotor when the magnetic levitation rotor is stably levitated, the irregular axial vibration of the magnetic levitation rotor can be weakened or eliminated through the circumferential winding. At this time, the magnetic levitation turntable focuses on the application of improving the axial force of suspension control.

[0082] According to an embodiment of the present disclosure, referring to Figure 20 , the magnetic levitation turntable further includes a lifting mechanism 5 for driving the magnetic levitation stator 1 in the axial direction. By driving the magnetic levitation stator through the lifting mechanism, the axial height of the magnetic levitation stator can be adjusted, thereby changing the axial height of the magnetic levitation rotor. In the case where the axial height of the magnetic levitation rotor needs to be adjusted, the function of adjusting the axial height of the magnetic levitation rotor over a large distance can be achieved.

[0083] In the above embodiments, the magnetic levitation rotor 2 is formed of a magnetic material, and examples of the magnetic material include, but are not limited to, permanent magnetic materials or ferromagnetic materials. Further, for example, the ferromagnetic material is a soft magnetic material with a magnetic permeability much greater than the magnetic permeability of vacuum, and examples thereof include, but are not limited to, iron, cobalt, nickel and their alloys, carbon steel, silicon steel, and electrically pure iron. Examples of permanent magnetic materials include, but are not limited to, samarium cobalt, neodymium iron boron, and ferrite.

[0084] Since the rotor magnetic pole 231 is mainly used to cooperate with the rotation control winding to achieve the rotation control of the rotor. In a preferred embodiment, referring to Figure 14 , the number of rotor magnetic poles 23 is 12, and the number of first stator magnetic poles is 4. At this time, the number of rotor magnetic poles corresponding to each first stator magnetic pole is the same, and the force provided by the permanent magnet bias magnetic field during the rotation of the rotor is balanced, thereby ensuring the stability of the rotation of the magnetic levitation turntable, and further ensuring the position stability of the load (wafer) on the turntable and ensuring high reliability of the process.

[0085] In the above embodiments, for ease of description, the first stator substrate 121 and the magnetic guide 14 are described as two components for ease of processing and manufacturing, but this is not limiting. In other embodiments, the first stator substrate and the magnetic guide 14 may also be an integral structure. In the above embodiments, the stator magnetic pole and the stator substrate are described as two components, but this is not limiting. In other embodiments, the stator magnetic pole and the stator substrate may be integrally formed. For example, the stator magnetic pole, the stator substrate, and the magnetic conductor are all formed of a magnetic conductive material. Further, for example, the magnetic conductive material is a ferromagnetic material; the ferromagnetic material is, for example, a soft magnetic material with a magnetic permeability much greater than the magnetic permeability of vacuum, and its examples include, but are not limited to, iron, cobalt, nickel and their alloys, carbon steel, silicon steel, and electrolytic iron.

[0086] According to an embodiment of the present disclosure, the magnetic levitation turntable of the present invention is applied in semiconductor manufacturing. For example, it is applied in rapid thermal processing and other wafer processing in semiconductor manufacturing, such as chemical vapor deposition, heat treatment, ion implantation doping, and other technical doping. The present invention facilitates the integration of the axial and radial displacement sensors within the stator. With the aid of the first rim of the rotor, the axial and radial displacement sensors can detect the position information of at least one degree-of-freedom direction (axial or / and radial) of the rotor through the cavity wall of the semiconductor processing equipment, thereby realizing the organic combination of rotor position detection and the stator structure. The embodiments of the present invention do not require making through holes on the vacuum cavity and using fluororubber sealing rings, nor do they require replacing the sealing rings, solving problems such as recalibration after assembling the sensors and installation errors, and can better meet the requirements of the ultra-clean and high-temperature environment of the semiconductor processing equipment, and can solve the problem of messy cable connections of multiple position sensors.

[0087] In one embodiment, the magnetic levitation turntable of the embodiment of the present disclosure further includes a carrier. The magnetic levitation rotor 2 supports and positions the carrier through a plurality of support columns. The magnetic levitation stator 1 rotates and levitates by driving the magnetic levitation rotor 2 and the carrier, and various processing operations of the wafer supported on the carrier can be realized.

[0088] Specific embodiments of the present invention are used to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the technical solution and its core idea of the present invention; at the same time, for those of ordinary skill in the art, based on the idea of the present invention, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A magnetic suspension turntable, comprising a magnetic suspension stator (1) and a magnetic suspension rotor (2), wherein the magnetic suspension rotor comprises a rotor body (21), a first ring edge (22) and a second ring edge (23) extending from the rotor body to the magnetic suspension stator, characterized in that: The magnetic suspension stator comprises a permanent magnet component (11), a first suspension control component (12), a second suspension control component (13) and a magnetic guide (14); the first suspension control component comprises a first stator substrate (121), a plurality of first stator magnetic poles (1211) protruding from the first stator substrate to the first ring edge, and a first suspension winding (122) arranged on the first stator magnetic pole; the second suspension control component comprises a second stator substrate (131), a plurality of second stator magnetic poles (1311) protruding from the second stator substrate to the second ring edge, and a second suspension winding (132) arranged on the second stator magnetic pole; the permanent magnet component is axially arranged between the first stator substrate and the second stator substrate; the permanent magnet bias magnetic field generated by the permanent magnet component passes through the first stator substrate, the first stator magnetic pole, the first ring edge, the rotor body, the second ring edge, the second stator magnetic pole, the second stator magnetic pole, the second stator magnetic pole, the second stator magnetic pole, the first stator magnetic pole, the first stator magnetic pole, the second stator magnetic pole, the first stator magnetic pole, the first stator magnetic pole, the first stator magnetic pole, the first stator magnetic pole, the second stator magnetic pole, the second stator magnetic pole, the second stator magnetic pole, the first ... The substrate forms a first magnetic field loop (S1); the electromagnetic control magnetic field generated by the first suspension control component sequentially passes through the first stator pole, the first ring edge, the magnetic guide, and the first stator substrate to form a second magnetic field loop (S2); the magnetic guide comprises a plurality of magnetic teeth (141), the magnetic teeth and the first stator pole are located in the same radial plane, the radial plane is perpendicular to the axial direction, the magnetic teeth are located between two adjacent first stator poles and are magnetically connected to the first stator substrate; or, the magnetic guide comprises a magnetic base (142) and a plurality of magnetic teeth (141), the magnetic base is annular, the plurality of magnetic teeth are arranged on the inner side of the magnetic base, the magnetic base is axially arranged on the side of the first stator substrate facing the permanent magnet component or the side facing away from the permanent magnet component, the magnetic teeth and the first stator pole are arranged in staggered layers, and the magnetic teeth are circumferentially arranged between two adjacent first stator poles.

2. A magnetic levitation turntable according to claim 1, characterized in that: The first stator substrate is annular in shape, and the magnetic conductive teeth and the first stator magnetic poles are arranged on the inner side of the first stator substrate and are integrally formed with the first stator substrate.

3. The magnetic levitation turntable according to claim 2, characterized in that: The first stator substrate is annular, and the magnetic guide also includes an annular magnetic conductive base (142), which is axially arranged on a side of the first stator substrate facing the permanent magnet component or a side facing away from the permanent magnet component, and the magnetic conductive base is fixedly connected to the magnetic conductive teeth via a magnetic conductive bend (143).

4. The magnetic levitation turntable according to claim 2, characterized in that: One magnetic conductive tooth or two magnetic conductive teeth are provided between two adjacent first stator magnetic poles.

5. The magnetic levitation turntable according to claim 1, characterized in that: The magnetic conductive teeth are integrally formed with the magnetic conductive base.

6. The magnetic levitation turntable according to claim 5, characterized in that: One magnetic conductive tooth or two magnetic conductive teeth are provided between two adjacent first stator magnetic poles.

7. The magnetic levitation turntable according to claim 1, characterized in that: It also includes a position sensor, which is installed on the magnetic teeth.

8. The magnetic levitation turntable according to claim 7, characterized in that: A notch groove (1411) is formed on the magnetic conductive tooth, and the position sensor is installed in the notch groove.

9. The magnetic levitation turntable according to claim 7, characterized in that: The position sensor is configured as a radial displacement sensor or an axial displacement sensor or an axial radial displacement sensor (3).

10. The magnetic levitation turntable according to claim 9, characterized in that: The axial radial displacement sensor comprises two N-shaped magnetic conductors (31), an excitation coil (32) and two induction coils (33), the two magnetic conductors being arranged along the axial direction, the excitation coil being sleeved on one end of the two magnetic conductors, one induction coil being sleeved on the other end of one magnetic conductor, and the other induction coil being sleeved on the other end of the other magnetic conductor, and the excitation coil and the two induction coils being arranged at intervals along the circumferential direction.

11. The magnetic levitation turntable according to claim 1, characterized in that: The length of the magnetic conductive teeth along the circumferential direction is smaller than the length of the first stator magnetic pole along the circumferential direction.

12. The magnetic levitation turntable according to claim 1, characterized in that: The length of the magnetic conductive teeth along the circumferential direction is less than 1 / 2 of the length of the first stator pole along the circumferential direction, and greater than 1 / 4 of the length of the first stator pole along the circumferential direction.

13. The magnetic levitation turntable according to claim 1, characterized in that: A plurality of tooth slots (134) are formed on the side of the second stator magnetic pole facing the second ring edge, a tooth portion (135) is formed between two adjacent tooth slots, and a rotation control winding is provided in the tooth slot.

14. The magnetic levitation turntable according to claim 1, characterized in that: A circumferential winding (4) is provided between the first stator substrate and the second stator substrate, and the circumferential winding is arranged around the magnetic suspension rotor.

15. The magnetic levitation turntable according to claim 1, characterized in that: It also includes a lifting mechanism (5) for driving the magnetic suspension stator in the axial direction.

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