Magnetic suspension voice coil motor

Abstract

The invention belongs to the technical field of semiconductor equipment, and provides a magnetic suspension voice coil motor which comprises a first assembly and a second assembly which are spaced from each other, and the first assembly comprises a first magnet, a second magnet and a third magnet which are sequentially arranged in the z direction with the axial direction of the first assembly as the z direction. The second assembly comprises first back iron and a first coil which are coaxial with the first assembly, the first back iron is located between the first magnet and the second magnet, the first coil is located on the side, away from the first magnet, of the first back iron, and the magnetizing direction of the first magnet and the magnetizing direction of the second magnet are the z direction. Magnetic levitation force and Lorentz force are generated between the second assembly and the first assembly, the gravity of the vertical micropositioner and the reverse acting force of the reed can be compensated through the magnetic levitation force, and the driving effect on the vertical micropositioner can be achieved through the Lorentz force. The vertical resultant force of the magnetic levitation force and the Lorentz force is linearly changed within the displacement range of the vertical micropositioner, so that the magnetic levitation voice coil motor has the characteristic of constant rigidity, and the heating problem of the motor is solved.

Description

Technical Field

[0001] This application relates to the technical field of semiconductor equipment, and particularly to a magnetic levitation voice coil motor. Background Art

[0002] In the fields of semiconductor manufacturing and detection, the workpiece stage not only needs to complete the device handover with the semiconductor transfer system, but also needs to achieve precise positioning of the carried semiconductor devices. A vertical micro-stage is provided in the workpiece stage, which is responsible for achieving precise positioning of semiconductor devices (such as silicon wafers) in three axes: the vertical direction, the x-axis rotation direction, and the y-axis rotation direction. However, with the progress of technology, higher requirements are put forward for the motion accuracy control of the vertical micro-stage.

[0003] The vertical micro-stage usually adopts a three-point or four-point actuator layout. To ensure the vertical output performance, the reed is used as the guiding element for vertical movement and the decoupling element for pitch and yaw. To improve the control accuracy of the vertical micro-stage, the actuator not only needs to provide the vertical driving force for the movement process of the vertical micro-stage, but also needs to compensate for the gravity of the vertical micro-stage and the reverse force of the reed.

[0004] Currently, the realization of the vertical movement of the vertical micro-stage usually adopts a combined scheme of a gravity compensation device and a voice coil motor to improve the control accuracy of the vertical micro-stage. Among them, the gravity compensation device compensates for the gravity of the vertical driving load of the vertical micro-stage in a constant gravity compensation manner through principles such as air levitation or magnetic levitation; the voice coil motor is used as a vertical actuator to provide the reverse force of the reed and the driving force for the vertical movement of the vertical micro-stage. However, in practical applications, the elastic force of the reed is linearly related to the vertical displacement. When the reverse force of the reed is different in different stroke ranges, it will affect the output force of the voice coil motor differently, resulting in increased heating of the voice coil motor, and further causing poor control accuracy of the vertical micro-stage provided with the voice coil motor. Summary of the Invention

[0005] In view of the above-mentioned disadvantages of the prior art, the purpose of this application is to provide a magnetic levitation voice coil motor to solve the problem that the heating of the voice coil motor in the prior art is increased, resulting in poor control accuracy of the vertical micro-stage provided with the voice coil motor.

[0006] To achieve the above purpose and other related purposes, this application provides a magnetic levitation voice coil motor, including a first component and a second component arranged at intervals from each other. Taking the axial direction of the first component as the z direction, the first component and the second component can move relative to each other along the z direction;

[0007] The first component includes a first magnet, a second magnet, and a third magnet that are coaxial and sequentially spaced apart along the z direction. The second component includes a first back iron and a first coil that are coaxial with the first component. The first back iron is located between the first magnet and the second magnet, and the first coil is located on a side of the first back iron away from the first magnet. The magnetization directions of the first magnet and the second magnet are both in the z direction.

[0008] Optionally, the first component further includes a third back iron, and a first through hole is provided in the third back iron. The first through hole penetrates the third back iron along the z direction, and the first magnet, the first back iron, the second magnet, and the third magnet are all located within the first through hole.

[0009] Optionally, the first component further includes a fourth back iron. The fourth back iron is located between the second magnet and the third magnet and is respectively connected to the second magnet and the third magnet.

[0010] Optionally, the first component further includes a fifth back iron, and the fifth back iron is connected to a side of the first magnet away from the first back iron.

[0011] Optionally, both the fourth back iron and the fifth back iron are spaced apart from the third back iron.

[0012] Optionally, the fourth back iron is spaced apart from the third back iron, and the fifth back iron is connected to the side wall of the first through hole.

[0013] Optionally, both the fourth back iron and the fifth back iron are connected to the side wall of the first through hole.

[0014] Optionally, a second through hole coaxial with the first component is provided in the magnetic levitation voice coil motor. The second through hole penetrates the first component and the first back iron along the z direction.

[0015] Optionally, the first coil is sleeved outside the third magnet, and the magnetization direction of the third magnet is in the z direction.

[0016] Optionally, the first component further includes a second back iron, and the second back iron is connected to a side of the third magnet away from the second magnet.

[0017] Optionally, the first component further includes a fourth magnet coaxial with the first magnet. The fourth magnet is located on a side of the first magnet away from the first back iron;

[0018] The second component further includes a second coil coaxially arranged with the first component. The second coil is sleeved outside the fourth magnet, and the magnetization direction of the fourth magnet is the z direction.

[0019] Optionally, the first component further includes a sixth back iron, and the sixth back iron is connected to the side of the fourth magnet away from the first back iron.

[0020] Optionally, the third magnet is sleeved outside the first coil, and the magnetization direction of the third magnet is its radial direction;

[0021] A third through hole coaxially arranged with the first component is provided in the magnetic levitation voice coil motor, and the third through hole penetrates through the first magnet, the second magnet, and the third magnet.

[0022] Optionally, the first component further includes a fourth magnet coaxially arranged with the first magnet, and the fourth magnet is located on the side of the first magnet away from the first back iron;

[0023] The second component further includes a second coil coaxially arranged with the first component. The fourth magnet is sleeved outside the second coil, and the magnetization direction of the fourth magnet is its radial direction.

[0024] As described above, the magnetic levitation voice coil motor provided in this application has at least the following beneficial effects:

[0025] In the magnetic levitation voice coil motor of this application, the first magnet, the second magnet, and the third magnet form the first component, and the first back iron and the first coil form the second component; through the magnetic buoyancy force generated between the second component and the first component, the gravity of the vertical microstage and the reverse acting force of the reed can be compensated; through the Lorentz force generated between the second component and the first component, the driving effect on the vertical microstage can be realized; through the third magnet, the magnitude of the downward suction force received by the first back iron can be adjusted, so as to realize the regulation of the vertical output force of the magnetic levitation voice coil motor.

[0026] Moreover, within different vertical stroke ranges, the resultant force of the magnetic buoyancy force and the Lorentz force in the magnetic levitation voice coil motor of this application changes linearly within a relatively large displacement range of the vertical microstage, thereby enabling the magnetic levitation voice coil motor to have a constant stiffness characteristic, thus effectively improving the heating problem of the magnetic levitation voice coil motor; based on the constant stiffness characteristic of the magnetic levitation voice coil motor, the forces exerted by the magnetic levitation voice coil motor and the reed on the vertical microstage can be made equal in magnitude and opposite in direction, that is, the resultant vertical force acting on the vertical microstage by the two is a zero stiffness curve, improving the positioning accuracy of the vertical microstage.

[0027] In addition, the magnetic levitation voice coil motor of the present application realizes the function of constant stiffness gravity compensation only through the first magnet, the second magnet, the third magnet and the first back iron, and combines with the first coil to realize the vertical driving function with constant stiffness. The structure is simple and the occupied space is small.

[0028] In summary, the magnetic levitation voice coil motor of the present application has the characteristics of small heat generation, low power consumption, simple structure, small occupied space, and constant stiffness within the stroke range. It realizes the precise positioning of the vertical micro-stage and improves the overall integration and control accuracy of the equipment. Description of the Drawings

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings required to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other relevant drawings can also be obtained based on these drawings.

[0030] Figure 1 It shows a schematic structural diagram of a magnetic levitation voice coil motor provided by an embodiment of the present application.

[0031] Figure 2 It shows a schematic structural diagram of a magnetic levitation voice coil motor with a third back iron provided by Embodiment 1 of the present application.

[0032] Figure 3 It shows a schematic structural diagram of a magnetic levitation voice coil motor with a fourth back iron provided by Embodiment 1 of the present application.

[0033] Figures 4 to 6 They respectively show schematic structural diagrams of three different magnetic levitation voice coil motors with third to fifth back irons provided by Embodiment 1 of the present application.

[0034] Figure 7 and Figure 8 They respectively show schematic structural diagrams of two different magnetic levitation voice coil motors with a second back iron provided by Embodiment 1 of the present application.

[0035] Figure 9 It shows as Figure 8 A schematic diagram of the magnetic field line distribution of the magnetic levitation voice coil motor shown.

[0036] Figure 10 It shows as Figure 8 A schematic diagram of the force-displacement curve of the magnetic levitation voice coil motor shown.

[0037] Figure 11 It shows as Figure 8 A schematic diagram of the curve relationship between the vertical resultant force of the magnetic levitation voice coil motor shown and the reverse force of the reed and displacement.

[0038] Figures 12 to 14 Are respectively shown as the schematic structural diagrams of three different magnetic levitation voice coil motors with a fourth magnet and a second coil provided in the second embodiment of the present application.

[0039] Figure 15 Shown as Figure 14 The schematic diagram of the force-displacement curve relationship of the magnetic levitation voice coil motor shown in the figure.

[0040] Figure 16 Shown as Figure 14 The schematic diagram of the force-displacement curve relationship of the upward suction force and the downward suction force received by the first back iron in the magnetic levitation voice coil motor shown in the figure.

[0041] Figures 17 to 19 Are respectively shown as the schematic structural diagrams of three different magnetic levitation voice coil motors provided in the third embodiment of the present application.

[0042] Figure 20 Shown as the schematic structural diagram of a magnetic levitation voice coil motor provided in the fourth embodiment of the present application.

[0043] Figure 21 Shown as the schematic structural diagram of another magnetic levitation voice coil motor provided in the fourth embodiment of the present application.

[0044] Figure 22 Shown as Figure 21 The schematic diagram of the force-displacement curve relationship of the magnetic levitation voice coil motor shown in the figure.

[0045] Figure 23 Shown as the top view structure diagram of the fourth magnet in the z direction provided in the fourth embodiment of the present application.

[0046] Figure 24 Shown as the schematic structural diagram of a magnetic levitation voice coil motor provided in the fifth embodiment of the present application.

[0047] Schematic illustration of reference numerals:

[0048] 10. First component; 111. First magnet; 112. Second magnet; 113. Third magnet; 114. Fourth magnet; 121. Second back iron; 122. Third back iron; 1221. First through hole; 123. Fourth back iron; 124. Fifth back iron; 125. Sixth back iron; 20. Second component; 211. First back iron; 2111. Thickness gradient region; 221. First coil; 222. Second coil; 311. Second through hole; 312. Third through hole. Detailed implementation manners

[0049] To make the technical objectives, technical solutions, and technical effects of this application clearer, the technical solutions in this application will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of this application, rather than all of them. Usually, the components of the embodiments of this application described and shown in the accompanying drawings here can be arranged and designed in various different configurations.

[0050] Therefore, the following detailed description of the embodiments of this application is not intended to limit the scope of this application that is claimed, but merely represents the selected embodiments of this application. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of this application. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0051] In the description of this application, it should be noted that the description referring to terms such as "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of this application. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0052] This application provides a magnetic levitation voice coil motor. Referring to Figure 1 , it includes a first component 10 and a second component 20 that are spaced apart from each other. Taking the axial direction of the first component 10 as the z direction, the first component 10 and the second component 20 can move relative to each other along the z direction.

[0053] The first component 10 includes a first magnet 111, a second magnet 112, and a third magnet 113. The first magnet 111, the second magnet 112, and the third magnet 113 are coaxial and sequentially spaced along the z direction. The second component 20 includes a first back iron 211 and a first coil 221 that are coaxially arranged with the first component 10. The first back iron 211 is located between the first magnet 111 and the second magnet 112, and the first coil 221 is located on the side of the first back iron 211 away from the first magnet 111. Among them, the magnetization directions of the first magnet 111 and the second magnet 112 are both in the z direction, the relative positions among the first magnet 111, the second magnet 112, and the third magnet 113 remain unchanged, and the relative positions between the first coil 221 and the first back iron 211 remain unchanged.

[0054] The first magnet 111 has an upward suction force on the first back iron 211, and the second magnet 112 has a downward suction force on the first back iron 211. In the magnetic levitation voice coil motor, the resultant force of the upward suction force, the downward suction force, and other acting forces along the z direction on the first back iron 211 is denoted as the magnetic buoyancy force. Within the stroke range of the magnetic levitation voice coil motor, the magnetic buoyancy force has a linear relationship with the displacement. Therefore, the magnetic buoyancy force can be used to compensate for the gravity of the vertical micro-stage and the reverse acting force of the reed. Among them, the other acting forces in the magnetic buoyancy force of the first back iron 211 can be understood as: the acting forces generated by other components on the first back iron 211 through the magnetic field except for the first magnet 111 and the second magnet 112; for example, when there are other back irons and / or magnet structures in the magnetic levitation voice coil motor, the above other acting forces also include the acting forces generated by other back irons and / or magnet structures on the first back iron 211 through the magnetic field.

[0055] The magnetic field generated by the third magnet 113 has an enhancing or canceling effect on the magnetic field generated by the second magnet 112, which can increase or decrease the downward suction force received by the first back iron 211, and thus can affect the vertical compensation force output by the magnetic levitation voice coil motor to achieve the regulation of the vertical output force of the magnetic levitation voice coil motor. The first magnet 111, the second magnet 112, and the third magnet 113 generate a magnetic field in the surrounding space. When a current is passed through the first coil 221, the first coil 221 cuts the magnetic field and generates a Lorentz force. The driving effect on the vertical micro-stage can be achieved through the Lorentz force, and the mover in the first component 10 and the second component 20 can be vertically positioned. The amplitude of this Lorentz force is related to the amplitude of the input current in the first coil 221.

[0056] During use, within different vertical stroke ranges, the vertical magnetic buoyancy force generated by the magnetic levitation voice coil motor changes linearly within a relatively large displacement range. The reed is arranged between the mover of the magnetic levitation voice coil motor and the external load, and the reverse acting force of the reed also has a linear relationship with the change of displacement. By adjusting the equivalent stiffness of the magnetic levitation voice coil motor, it can be ensured that the forces exerted by the magnetic levitation voice coil motor and the reed on the vertical micro-stage are equal in magnitude and opposite in direction, that is, the resultant force trend of the two acting on the vertical micro-stage is a zero stiffness curve, enabling the magnetic levitation voice coil motor to accurately compensate for the reverse acting force of the reed and the gravity of the vertical micro-stage without external energy input; moreover, the vertical resultant force of the vertical magnetic buoyancy force and the Lorentz force generated by the magnetic levitation voice coil motor also has a linear change relationship within a relatively large displacement range, making the magnetic levitation voice coil motor have a constant stiffness characteristic, effectively improving the heating problem of the magnetic levitation voice coil motor, and improving the compensation accuracy for the reverse acting force of the reed and the gravity of the vertical micro-stage, as well as the positioning accuracy of the vertical micro-stage.

[0057] To elaborate on the magnetic levitation voice coil motor of the present application in more detail, the technical solutions of the present application will be described below in conjunction with specific embodiments. It should be noted that, without conflict, the technical features and technical solutions in each embodiment can be combined and used with each other.

[0058] Embodiment 1

[0059] Referring to Figure 1 , this embodiment provides a magnetic levitation voice coil motor, which includes a first component 10 and a second component 20 arranged at intervals from each other. Taking the axial direction of the first component 10 as the z-direction, the first component 10 and the second component 20 can move relative to each other along the z-direction.

[0060] The first component 10 includes a first magnet 111, a second magnet 112, and a third magnet 113 that are coaxially arranged in sequence along the z-direction and are spaced apart from each other. The second component 20 includes a first back iron 211 and a first coil 221 that are coaxially arranged with the first component 10. The first back iron 211 is located between the first magnet 111 and the second magnet 112, and the first coil 221 is located on the side of the first back iron 211 away from the first magnet 111. Among them, the relative positions of the first back iron 211 and the first coil 221 remain unchanged, and the relative positions of the first magnet 111, the second magnet 112, and the third magnet 113 remain unchanged. The relative positions of the first magnet 111, the second magnet 112, and the third magnet 113 can be kept unchanged by means of a bracket or other suitable means. The magnetization directions of the first magnet 111 and the second magnet 112 are both along the z-direction. The first magnet, the second magnet 112, and the third magnet 113 can be permanent magnets made of materials such as iron, aluminum, nickel, cobalt, etc. or magnet structures made of other suitable materials.

[0061] In an alternative embodiment, the second component 20 further includes a connecting member that is respectively connected to the first back iron 211 and the first coil 221 to keep the relative positions of the first back iron 211 and the first coil 221 unchanged. The first coil 221 can be directly connected to the connecting member or can be connected to the connecting member through a coil bracket.

[0062] In this embodiment, the first magnet 111, the second magnet 112, and the third magnet 113 constitute the first component 10, and the first back iron 211 and the first coil 221 constitute the second component 20; through the magnetic buoyancy force generated between the second component 20 and the first component 10, the gravity of the vertical micro-stage and the reverse acting force of the reed can be compensated; through the Lorentz force generated between the second component 20 and the first component 10, the driving effect on the vertical micro-stage can be realized; through the third magnet 113, the magnitude of the downward suction force received by the first back iron 211 can be adjusted, thereby realizing the regulation of the vertical output force of the magnetic levitation voice coil motor.

[0063] In this embodiment, referring toFigure 2 , the first component 10 further includes a third back iron 122. A first through hole 1221 is provided in the third back iron 122. The first through hole 1221 penetrates the third back iron 122 along the z direction. The first magnet 111, the first back iron 211, the second magnet 112, and the third magnet 113 are all located within the first through hole 1221. Among them, the relative positions between the third back iron 122 and the first magnet 111, the second magnet 112, and the third magnet 113 remain unchanged. Optionally, the third back iron 122 is, for example, a cylindrical structure and is coaxially arranged with the first back iron 211. The cavity within the cylindrical structure of the third back iron 122 forms the first through hole 1221, and the first through hole 1221 is coaxially arranged with the third back iron 122. The third back iron 122 can be made of a high-permeability material. By providing the third back iron 122, it helps to improve the magnetic field distribution and enhance the performance of the magnetic levitation voice coil motor.

[0064] Referring to Figure 3 , the first component 10 may further include a fourth back iron 123. The fourth back iron 123 is located between the second magnet 112 and the third magnet 113. The fourth back iron 123 can be made of a high-permeability material or other suitable materials, and is used to improve the magnetic field distribution between the second magnet 112 and the third magnet 113 and in the nearby space, enhance the interference effect of the magnetic field generated by the second magnet 112 on the magnetic field generated by the third magnet 113, and further enhance the control effect on the downward suction force received by the first back iron 211.

[0065] In an alternative embodiment, the fourth back iron 123 is respectively connected to the second magnet 112 and the third magnet 113. Optionally, the fourth back iron 123 is fixedly connected to both the second magnet 112 and the third magnet 113, and can be fixedly connected by means of bonding or other suitable methods, so that the fourth back iron 123 is fixedly connected to the second magnet 112 and the third magnet 113. The fourth back iron 123 can be arranged at intervals from the third back iron 122, or the fourth back iron 123 can also be connected to the side wall of the first through hole 1221, or the fourth back iron 123 can also have an integral structure with the third back iron 122.

[0066] Referring to Figure 4 , the first component 10 may further include a fifth back iron 124. The fifth back iron 124 is located on the side of the first magnet 111 away from the first back iron 211. The fifth back iron 124 can be made of a high-permeability material or other suitable materials, and is used to improve the magnetic field distribution in the surrounding space and enhance the performance of the magnetic levitation voice coil motor.

[0067] In an alternative embodiment, the fifth back iron 124 is connected to the first magnet 111. Optionally, a fixed connection is established between the fifth back iron 124 and the first magnet 111, which can be achieved by bonding or other suitable means to fix the fifth back iron 124 and the first magnet 111 together. The fifth back iron 124 can be spaced apart from the third back iron 122, or the fifth back iron 124 can also be connected to the side wall of the first through hole 1221, or the fifth back iron 124 and the third back iron 122 can be of an integral structure.

[0068] In an alternative embodiment, a groove is formed on the side of the fifth back iron 124 facing the first magnet 111 for mounting the first magnet 111. Specifically, for example, a groove with a depth of 0.5 mm or other suitable dimensions can be formed, and the first magnet 111 is placed in the groove to facilitate the installation of the first magnet 111.

[0069] In an alternative embodiment, both the fourth back iron 123 and the fifth back iron 124 are spaced apart from the third back iron 122, and an external load can be arranged above and / or below the first back iron 211 in the z direction, improving the usability of the magnetic levitation voice coil motor.

[0070] In an alternative embodiment, referring to Figure 5 , the fourth back iron 123 is spaced apart from the third back iron 122, and the fifth back iron 124 is connected to the side wall of the first through hole 1221, so that the relative positions among the third back iron 122, the fifth back iron 124, and the first magnet 111 remain unchanged. Optionally, the fifth back iron 124 is fixedly connected to the side wall of the first through hole 1221, which can be achieved by bonding or other suitable means to fix the fifth back iron 124 to the side wall of the first through hole 1221.

[0071] In an alternative embodiment, referring to Figure 6 , both the fourth back iron 123 and the fifth back iron 124 are connected to the side wall of the first through hole 1221, so that the relative positions among the third back iron 122, the fourth back iron 123, the second magnet 112, the fifth back iron 124, and the first magnet 111 remain unchanged. Optionally, both the fourth back iron 123 and the fifth back iron 124 are fixedly connected to the side wall of the first through hole 1221, which can be achieved by bonding or other suitable means to fix the fourth back iron 123 and the fifth back iron 124 to the side wall of the first through hole 1221.

[0072] Furthermore, a second through hole 311 coaxial with the first component 10 is provided in the magnetic levitation voice coil motor. The second through hole 311 penetrates the first component 10 and the first back iron 211 in the z direction. By providing the second through hole 311, it is possible to facilitate the use of a connecting member or other suitable means to keep the relative position between the first coil 221 and the first back iron 211 unchanged, facilitating the installation and use of the magnetic levitation voice coil motor.

[0073] In this embodiment, referring to Figures 1 to 6 , the first coil 221 is sleeved outside the third magnet 113, and the magnetization direction of the third magnet 113 is the z direction.

[0074] In an alternative embodiment, referring to Figure 7 and Figure 8 , the first component 10 further includes a second back iron 121. The second back iron 121 is connected to the side of the third magnet 113 away from the second magnet 112, which is used to improve the magnetic field distribution, improve the direction of the Lorentz force received by the first coil 221, and increase the component of the Lorentz force along the z direction, so as to improve the performance of the magnetic levitation voice coil motor.

[0075] Figure 9 shows Figure 8 a schematic diagram of the magnetic field lines inside the magnetic levitation voice coil motor shown in Figure 9 is a half-sectional view of the magnetic levitation voice coil motor cut along the radial direction from the axis. In the figure, the z-axis is the axis of the magnetic levitation voice coil motor. Figure 10 shows Figure 8 the curve of the force and displacement of the magnetic levitation voice coil motor shown in

[0076] Referring to Figure 10 , in the magnetic levitation voice coil motor, when the first magnet 111 and the second magnet 112 are symmetrically arranged along the z direction with respect to the first back iron 211, taking the position where the first back iron 211 is located at this time as the zero position, when the first back iron 211 moves in the direction close to the first magnet 111, its displacement moves along the positive x-axis in Figure 10 , and when the first back iron 211 moves in the direction close to the second magnet 112, its displacement moves along the negative x-axis in Figure 10 . Figure 10Among them, curve 011 is the curve of the downward suction force of the second magnet 112 on the first back iron 211 versus displacement, curve 012 is the curve of the upward suction force of the first magnet 111 on the first back iron 211 versus displacement, and curve 013 is the vertical magnetic buoyancy force (i.e., the resultant force of the upward suction force, downward suction force, and other magnetic field forces) received by the first back iron 211. According to the simulation calculation results, when the first back iron 211 approaches the first magnet 111 from the zero point, the upward suction force gradually increases and the downward suction force gradually decreases, making the upward vertical magnetic buoyancy force output by the magnetic levitation voice coil motor increase. When the first back iron 211 approaches the second magnet 112 from the zero point, the upward suction force gradually decreases and the downward suction force gradually increases, making the downward vertical magnetic buoyancy force output by the magnetic levitation voice coil motor increase. Furthermore, the vertical magnetic buoyancy force received by the first back iron 211 shows a linear change trend with displacement within a relatively large vertical stroke range around the zero point. For example Figure 10 within the vertical stroke range of -1 mm to 1 mm as shown.

[0077] Figure 10 Among them, curve 014 is the Lorentz force received by the first coil 221, and its thrust constant is approximately constant at 5.8 N / A. The thrust constant is the Lorentz force of the magnetic levitation voice coil motor when a unit current is input; curve 015 is the curve of the vertical resultant force of the vertical magnetic buoyancy force and Lorentz force of the magnetic levitation voice coil motor versus displacement. According to the simulation calculation results, within the vertical stroke range, the vertical resultant force of the magnetic levitation voice coil motor shows an approximately linear change trend with displacement. For example Figure 10 within the vertical stroke range of -1 mm to 1 mm as shown. When exceeding this stroke range, the linearity decreases.

[0078] Figure 11 shows Figure 8 the curve of the vertical resultant force of the magnetic buoyancy force and Lorentz force of the magnetic levitation voice coil motor as shown and the curve of the reverse force of the reed versus displacement. Figure 11 Among them, the short dashed line is the curve of the reverse force of the reed versus displacement, the long dashed line is the curve of the vertical resultant force of the magnetic levitation voice coil motor versus displacement, and the solid line is the curve of the resultant force of the two versus displacement. According to the simulation calculation results, within the vertical stroke range of the magnetic levitation voice coil motor, for example Figure 11 within the vertical stroke range of -1 mm to 1 mm as shown, the stiffness of the reed is equal to or approximately equal to the equivalent stiffness of the vertical resultant force of the motor, and the directions are opposite, making the combined stiffness of the magnetic levitation voice coil motor and the reed approach zero, effectively improving the heating problem of the magnetic levitation coil motor and improving the positioning accuracy of the vertical microstage.

[0079] In summary, the magnetic levitation voice coil motor of this embodiment realizes the function of constant stiffness gravity compensation only through the first magnet 111, the second magnet 112, the third magnet 113 and the first back iron 211, and combines with the first coil 221 to realize the vertical driving function with constant stiffness. It has the characteristics of small heat generation, low power consumption, simple structure, small occupied space, constant stiffness within the stroke range, etc., and improves the positioning accuracy of the vertical micro stage as well as the overall integration and control accuracy of the device.

[0080] Embodiment 2

[0081] This embodiment provides a magnetic levitation voice coil motor, which also includes a first component 10 and a second component 20. The same parts as those in Embodiment 1 will not be described again. The difference is that in the magnetic levitation voice coil motor of this embodiment, the first component 10 further includes a fourth magnet 114, and the second component 20 further includes a second coil 222.

[0082] In this embodiment, referring to Figure 12 , the fourth magnet 114 is coaxially arranged with the first magnet 111 and is located on the side of the first magnet 111 away from the first back iron 211. The second coil 222 is coaxially arranged with the first component 10, and the second coil 222 is sleeved outside the fourth magnet 114. The magnetization direction of the fourth magnet 114 is the z direction. Among them, the relative positions of the second coil 222, the first coil 221 and the first back iron 211 remain unchanged. For example, through a connecting member, the relative positions of the three can be kept unchanged; the relative positions of the first magnet 111, the second magnet 112, the third magnet 113 and the fourth magnet 114 remain unchanged. By arranging the fourth magnet 114 and the second coil 222, the intensity of the distributed magnetic field inside the magnetic levitation voice coil motor can be enhanced, the magnetic buoyancy and Lorentz force in the z direction can be increased, and thus the output thrust of the magnetic levitation voice coil motor can be improved. Moreover, loads can be arranged on both opposite sides of the magnetic levitation voice coil motor in the z direction, improving the convenience of use.

[0083] In an alternative embodiment, referring to Figure 13 and Figure 14 , the first component 10 further includes a sixth back iron 125. The sixth back iron 125 is located on the side of the fourth magnet 114 away from the first back iron 211. The second coil 222 is looped outside the sixth back iron 125. Optionally, the sixth back iron 125 is connected to the fourth magnet 114. The sixth back iron 125 can be connected to the fourth magnet 114 by bonding or other suitable means, for example. The sixth back iron 125 can be used to improve the distribution of the magnetic field inside the magnetic levitation voice coil motor, increase the Lorentz force in the z direction received by the second coil 222, and thus improve the motor performance.

[0084] Furthermore, referring to Figure 13, the first component 10 further includes the second back iron 121, the third back iron 122, the fourth back iron 123, and the fifth back iron 124 in the first embodiment. Among them, the fourth back iron 123 and the fifth back iron 124 are both arranged at intervals from the third back iron 122.

[0085] Further, referring to Figure 14 , the first component 10 further includes the second back iron 121, the third back iron 122, the fourth back iron 123, and the fifth back iron 124 in the first embodiment. Among them, the fourth back iron 123 and the fifth back iron 124 are both connected to the side wall of the first through hole 1221. The first coil 221 is located on the side of the fourth back iron 123 away from the first back iron 211, and the second coil 222 is located on the side of the fifth back iron 124 away from the first back iron 211. The fourth back iron 123 and the fifth back iron 124 can be fixedly connected to the third back iron 122 by bonding or other suitable means, or the fourth back iron 123 and the fifth back iron 124 can also be integrally formed with the third back iron 122 so that the relative positions of the various components in the first component 10 remain unchanged. The third through hole 312 in the magnetic levitation voice coil motor also penetrates through the sixth back iron 125 and the fourth magnet 114 to facilitate the use of a connecting member to keep the relative positions of the first coil 221, the second coil 222, and the first back iron 211 unchanged.

[0086] Figure 15 shows Figure 13 the force-displacement curve diagram of the magnetic levitation voice coil motor shown in Figure 15 Among them, the curve 023 is Figure 13 the curve of the Lorentz force and displacement of the magnetic levitation voice coil motor shown in Figure 7 the curve of the Lorentz force and displacement of the magnetic levitation voice coil motor shown in Figure 13 The Lorentz force of curve 023 is approximately twice that of curve 024. Curve 021 is Figure 7 the curve of the vertical resultant force of the magnetic buoyancy force and the Lorentz force and displacement of the magnetic levitation voice coil motor shown in Figure 15 Curve 022 is the curve of the vertical resultant force of the magnetic buoyancy force and the Lorentz force and displacement of the magnetic levitation voice coil motor shown in

[0087] Figure 16 shows Figure 14 the force-displacement curve diagram of the magnetic levitation voice coil motor shown in Figure 16 Among them, the curve 031 is Figure 14 in the magnetic levitation voice coil motor shown inFigure 14 In the magnetic levitation voice coil motor shown, the curve of the upward suction force received by the first back iron 211 versus displacement, and curve 033 is Figure 14 In the magnetic levitation voice coil motor shown, the curve of the resultant force of the upward suction force and the downward suction force received by the first back iron 211 along the z direction versus displacement. In the figure, when the first magnet 111 and the second magnet 112 are symmetrically distributed about the first back iron 211 along the z direction, the current position of the first back iron 211 is the zero position. According to the simulation calculation results and Figure 16 it can be known that by fixedly connecting or forming an integral structure between the fourth back iron 123 and the fifth back iron 124 and the third back iron 122, and respectively arranging the third magnet 113 and the first coil 211, and the fourth magnet 114 and the second coil 222 on both sides of the first back iron 211 along the z direction, the zero position of curve 033 can be made to approach the zero position of the first back iron 211, which helps to improve the positioning accuracy of the mover in the first component 10 and the second component 20.

[0088] Embodiment III

[0089] This embodiment provides a magnetic levitation voice coil motor, which also includes a first component 10 and a second component 20. The same parts as those in Embodiment I will not be described again. The difference is that in the magnetic levitation voice coil motor of this embodiment, the third magnet 113 is sleeved outside the first coil 221.

[0090] In this embodiment, referring to Figures 17 to 19 , the first component 10 includes a first magnet 111, a second magnet 112, and a third magnet 113 that are coaxially arranged and spaced apart from each other along the z direction in sequence. The second component 20 includes a first back iron 211 and a first coil 221 that are coaxially arranged with the first component 10. The first back iron 211 is located between the first magnet 111 and the second magnet 112. The third magnet 113 is sleeved outside the first coil 221. The magnetization directions of the first magnet 111 and the second magnet 112 are along the z direction, and the magnetization direction of the third magnet 113 is its radial direction. Optionally, a third through hole 312 is further provided in the magnetic levitation voice coil motor. The third through hole 312 penetrates through the first magnet 111, the second magnet 112, and the third magnet 113. The first coil 221 is located inside the third through hole 312. Through the third through hole 312, it is possible to facilitate the use of a connecting member to keep the relative position of the first coil 221 and the first back iron 211 unchanged, thereby facilitating the installation and use of the magnetic levitation voice coil motor. Further, the third through hole 312 is coaxially arranged with the first component 10.

[0091] In an alternative embodiment, referring to Figure 18 and Figure 19, the first component 10 may further include the third back iron 122, the fourth back iron 123, and the fifth back iron 124 in the first embodiment. Among them, the fourth back iron 123 and the fifth back iron 124 may be arranged at intervals with the third back iron 122, or may be connected to the third back iron 122, or may be integrally formed with the third back iron 122.

[0092] Further, referring to Figure 19 , the first magnet 111, the second magnet 112, the third magnet 113, and the fourth back iron 123 and the fifth back iron 124 are all connected to the side wall of the first through hole 1221. The first magnet 111, the second magnet 112, and the third magnet 113 may be fixedly connected to the third back iron 122, for example, by bonding or other suitable means, so that the first magnet 111, the second magnet 112, and the third magnet 113 are fixedly connected to the third back iron 122. The fourth back iron 123 and the fifth back iron 124 may be fixedly connected to the third back iron 122 by bonding or other suitable means, or may also be integrally formed with the third back iron 122. By sleeving the third magnet 113 outside the first coil 221, the output thrust of the magnetic levitation voice coil motor can be made larger, and the structure is more compact, further improving the integration and working performance of the magnetic levitation voice coil motor.

[0093] Embodiment 4

[0094] This embodiment provides a magnetic levitation voice coil motor, which also includes a first component 10 and a second component 20. The same parts as those in the third embodiment will not be described again. The difference is that in the magnetic levitation voice coil motor of this embodiment, the first component 10 further includes a fourth magnet 114, and the second component 20 further includes a second coil 222.

[0095] In this embodiment, referring to Figure 20 and Figure 21 , the fourth magnet 114 is coaxially arranged with the first magnet 111 and is located on the side of the first magnet 111 away from the first back iron 211. The second coil 222 is coaxially arranged with the first component 10. The fourth magnet 114 is sleeved outside the second coil 222, and the magnetization direction of the fourth magnet 114 is its radial direction. Among them, the relative positions of the second coil 222, the first coil 221, and the first back iron 211 remain unchanged, and the relative positions of the first magnet 111, the second magnet 112, the third magnet 113, and the fourth magnet 114 remain unchanged. By arranging the fourth magnet 114 and the second coil 222, the intensity of the distributed magnetic field in the magnetic levitation voice coil motor can be enhanced, the magnetic buoyancy and Lorentz force of the magnetic levitation voice coil motor can be improved, and thus the output thrust can be increased. Moreover, loads can be arranged on both opposite sides of the magnetic levitation voice coil motor along the z direction, improving its use convenience.

[0096] In an alternative embodiment, referring to Figure 20 andFigure 21 , the fourth magnet 114 can be spaced apart from the third back iron 122, or can also be connected to the third back iron 122. Further, referring to Figure 21 , the first magnet 111, the second magnet 112, the third magnet 113, the fourth magnet 114, and the fourth back iron 123 and the fifth back iron 124 are all connected to the side wall of the first through hole 1221 to be connected to the third back iron 122.

[0097] Figure 22 shows Figure 21 the force-displacement curve of the magnetic levitation voice coil motor structure shown in Figure 22 , in which the curve 043 is Figure 21 the curve of the Lorentz force and displacement of the magnetic levitation voice coil motor shown in Figure 19 the curve of the Lorentz force and displacement of the magnetic levitation voice coil motor shown in Figure 21 the Lorentz force of the curve 043 is approximately twice that of the Lorentz force of the curve 044, and the curve 041 is Figure 19 the curve of the vertical resultant force of the magnetic buoyancy force and the Lorentz force of the magnetic levitation voice coil motor shown in

[0098] It can be seen that, compared with Figure 19 the magnetic levitation voice coil motor of the structure shown in Figure 15 and Figure 22 it can be known that the magnetic levitation voice coil motor of this embodiment has a more compact structure and greater motor output force; in addition, referring to the beneficial effects of the magnetic levitation voice coil motor in the second embodiment compared with the first embodiment, the magnetic levitation voice coil motor of this embodiment, compared with the structure in the third embodiment, can also improve the positioning accuracy of the mover in the first component 10 and the second component 20.

[0099] In an alternative embodiment, referring to Figure 23 , the fourth magnet 114 can include a plurality of tile-shaped magnet structures, the plurality of magnet structures are circumferentially distributed, and adjacent magnet structures are connected to each other to form a cylindrical fourth magnet 114.

[0100] Embodiment Five

[0101] This embodiment provides a magnetic levitation voice coil motor, including a first component 10 and a second component 20. The same parts as those in any one of the first to fifth embodiments will not be described in detail. The difference is that in the magnetic levitation voice coil motor of this embodiment, the first back iron 211 has a thickness gradient region 2111.

[0102] In this embodiment, referring to Figure 24 , the thickness gradient region 2111 is located in the central region of the first back iron 211 and is coaxially arranged with the first back iron 211. The thickness of the thickness gradient region 2111 gradually increases from the inside to the outside along its radial direction. By setting the thickness gradient region 2111, the linear interval range between the vertical resultant force and the displacement of the magnetic levitation voice coil motor can be increased, thereby increasing the vertical stroke range of the motor, so that the magnetic levitation voice coil motor can have a constant stiffness characteristic within a larger vertical stroke range.

[0103] It should be noted that the thickness gradient region 2111 in the first back iron 211 of this embodiment can be applied to any of the magnetic levitation voice coil motors in the foregoing embodiments, not limited to Figure 24 the structure shown.

[0104] The above embodiments are only illustrative of the principles and effects of the present application, and are not used to limit the present application. Any person familiar with this technology can modify, change or combine the above embodiments without departing from the spirit and scope of the present application. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed in the present application should still be covered by the claims of the present application.

Claims

1. A magnetic levitation voice coil motor, characterized in that: The invention comprises a first component (10) and a second component (20) which are arranged at a distance from each other, wherein the axial direction of the first component (10) is a z direction, and the first component (10) and the second component (20) can move relative to each other along the z direction; The first component (10) comprises a first magnet (111), a second magnet (112) and a third magnet (113) which are coaxially arranged and spaced in sequence along the z direction; the second component (20) comprises a first back iron (211) and a first coil (221) which are coaxially arranged with the first component (10); the first back iron (211) is located between the first magnet (111) and the second magnet (112); the first coil (221) is located on a side of the first back iron (211) away from the first magnet (111); and the magnetization directions of the first magnet (111) and the second magnet (112) are both in the z direction.

2. The magnetic levitation voice coil motor according to claim 1, characterized in that: The first component (10) further comprises a third back iron (122), wherein the third back iron (122) is provided with a first through hole (1221), wherein the first through hole (1221) penetrates the third back iron (122) along the z direction, and the first magnet (111), the first back iron (211), the second magnet (112) and the third magnet (113) are all located in the first through hole (1221).

3. The magnetic levitation voice coil motor according to claim 2, characterized in that: The first component (10) further comprises a fourth back iron (123), wherein the fourth back iron (123) is located between the second magnet (112) and the third magnet (113), and is connected to the second magnet (112) and the third magnet (113), respectively.

4. The magnetic levitation voice coil motor according to claim 3, characterized in that: The first component (10) further comprises a fifth back iron (124), wherein the fifth back iron (124) is connected to a side of the first magnet (111) away from the first back iron (211).

5. The magnetic levitation voice coil motor according to claim 4, characterized in that: The fourth back iron (123) and the fifth back iron (124) are both arranged at intervals from the third back iron (122).

6. The magnetic levitation voice coil motor according to claim 4, characterized in that: The fourth back iron (123) is spaced apart from the third back iron (122), and the fifth back iron (124) is connected to the side wall of the first through hole (1221).

7. The magnetic levitation voice coil motor according to claim 4, characterized in that: The fourth back-iron (123) and the fifth back-iron (124) are both connected to the side wall of the first through hole (1221).

8. The magnetic levitation voice coil motor according to claim 7, characterized in that: The magnetic levitation voice coil motor is provided with a second through hole (311) coaxially arranged with the first component (10), and the second through hole (311) penetrates the first component (10) and the first back iron (211) along the z direction.

9. The magnetic levitation voice coil motor according to any one of claims 1 to 8, characterized in that: The first coil (221) is sleeved on the outside of the third magnet (113), and the magnetization direction of the third magnet (113) is the z direction.

10. The magnetic levitation voice coil motor according to claim 9, characterized in that: The first component (10) further comprises a second back iron (121), wherein the second back iron (121) is connected to a side of the third magnet (113) away from the second magnet (112).

11. The magnetic levitation voice coil motor according to claim 9, characterized in that: The first component (10) further comprises a fourth magnet (114) coaxially arranged with the first magnet (111), wherein the fourth magnet (114) is located on a side of the first magnet (111) away from the first back iron (211); The second component (20) further comprises a second coil (222) coaxially arranged with the first component (10), the second coil (222) being sleeved on the outside of the fourth magnet (114), and the magnetization direction of the fourth magnet (114) is the z direction.

12. The magnetic levitation voice coil motor according to claim 11, characterized in that: The first component (10) further includes a sixth back iron (125), wherein the sixth back iron (125) is connected to a side of the fourth magnet (114) away from the first back iron (211).

13. The magnetic levitation voice coil motor according to any one of claims 1 to 7, characterized in that: The third magnet (113) is sleeved on the outside of the first coil (221), and the magnetization direction of the third magnet (113) is its radial direction; The magnetic levitation voice coil motor is provided with a third through hole (312) coaxially arranged with the first component (10), and the third through hole (312) passes through the first magnet (111), the second magnet (112) and the third magnet (113).

14. The magnetic levitation voice coil motor according to claim 13, characterized in that: The first component (10) further comprises a fourth magnet (114) coaxially arranged with the first magnet (111), wherein the fourth magnet (114) is located on a side of the first magnet (111) away from the first back iron (211); The second component (20) further comprises a second coil (222) coaxially arranged with the first component (10); the fourth magnet (114) is sleeved on the outside of the second coil (222); and the magnetization direction of the fourth magnet (114) is in its radial direction.

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