Magnetic suspension rotary table capable of lifting synchronously

Abstract

The invention discloses a lifting synchronous magnetic suspension rotary table which comprises a magnetic suspension stator and a magnetic suspension rotor, the magnetic suspension stator is used for driving the magnetic suspension rotor to suspend and rotate, and the magnetic suspension rotary table further comprises a controller, at least two lifting modules and calibration detection assemblies in one-to-one correspondence with the at least two lifting modules. The lifting module comprises a moving part and a fixed part for driving the moving part to do lifting motion, the moving part is fixedly connected with the magnetic suspension stator, and the calibration detection assembly is configured to detect displacement data of the moving part relative to the fixed part and feed back the displacement data to the controller; the controller is configured to control the at least two lifting modules to operate synchronously and calibrate the operation precision of the lifting modules according to the displacement data. On one hand, large-stroke lifting movement of the magnetic suspension rotary table can be achieved, on the other hand, the operation precision of a single lifting module can be judged, synchronous movement and calibration of the multiple lifting modules can be achieved, and the positioning precision and stability of the magnetic suspension rotary table are ensured.

Description

Technical Field

[0001] The present invention relates to the field of magnetic levitation technology, and particularly to a magnetic levitation turntable with synchronous lifting. 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 need for ultra-cleanliness, wafers of silicon or other semiconductor materials must be processed in a controlled ultra-clean atmosphere. For example, in the manufacturing process of wafers, one manufacturing step is to anneal the wafers after ion implantation doping. Doping applies strain to the crystal structure, and if the stress cannot be released quickly, it will lead to undesirable changes in the resistivity of ion doping. Currently, rapid thermal treatment (RT) processes are usually used for annealing. On the other hand, the processing uniformity of wafers is very important. To achieve uniformity, the wafers are usually rotated around the vertical axis or z-axis at the center of the wafer when processing the wafers. Rotation is also used for other wafer processing, such as chemical vapor deposition, heat treatment, ion implantation doping, and other technical doping. To meet the stringent requirements such as ultra-cleanliness and processing uniformity in semiconductor process manufacturing, magnetic levitation turntables with non-contact rotary drive are optimally used in semiconductor processing equipment. Currently, magnetic levitation turntables generally include a magnetic levitation stator and a magnetic levitation rotor. The magnetic levitation stator is used to generate a magnetic field to drive the magnetic levitation rotor and its carrier (wafer) to rotate and levitate. The magnetic levitation stator includes a suspension control component, and the suspension control component is used to apply an actively controlled suspension force to the magnetic levitation rotor to achieve axial active control and / or radial active control. However, the distance of the axial movement of the magnetic levitation rotor achieved by this electromagnetic driving force is relatively small, usually less than 10 mm, and it is impossible to achieve large-stroke lifting motion, which cannot meet the needs of some semiconductor manufacturing processes that require large-stroke movement.

[0003] To solve this technical problem, in the prior art, some technical solutions use a lifting device to connect the magnetic levitation stator to achieve large-stroke movement of the magnetic levitation stator and then drive the magnetic levitation rotor to achieve large-stroke lifting motion. Although these technical solutions solve the problem that the magnetic levitation turntable cannot achieve large-stroke lifting motion, there is still room for further improvement. For example, due to the frequent lifting motion required in the semiconductor manufacturing process, the lifting device is prone to problems such as a decrease in operating accuracy, and it is easy to generate out-of-sync problems between two or more lifting devices, resulting in poor positioning accuracy and stability of the magnetic levitation turntable. For example, it reduces the positioning accuracy of the magnetic levitation turntable and affects the quality of the final wafer product. Especially in application scenarios that require high-precision positioning, such errors are unacceptable. 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 with synchronous lifting and lowering, which is used to solve at least one of the above problems.

[0005] An embodiment of the present invention discloses a magnetic levitation turntable with synchronous lifting and lowering, wherein the magnetic levitation turntable includes a magnetic levitation stator and a magnetic levitation rotor, wherein the magnetic levitation stator is used to drive the magnetic levitation rotor to suspend and rotate, and the magnetic levitation turntable also includes a controller, at least two lifting modules and a calibration detection component corresponding to the at least two lifting modules one by one, wherein the lifting module includes a moving part and a fixed part driving the moving part to lift and lower, wherein the moving part is fixedly connected to the magnetic levitation stator, and the calibration detection component is configured to detect the displacement data of the moving part relative to the fixed part and feed it back to the controller, and the controller is configured to control the synchronous operation of the at least two lifting modules and calibrate the operation accuracy of the lifting module according to the displacement data.

[0006] Furthermore, the moving part includes a moving seat, the fixed part includes a base, a screw transmission mechanism installed on the base and a driving motor that drives the screw of the screw transmission mechanism to rotate, and the moving seat is fixedly connected to the nut of the screw transmission mechanism.

[0007] Furthermore, the calibration detection component includes a proximity switch, a metal part and an encoder, the metal part is installed on the movable seat, the proximity switch is installed on the base, and the displacement data is configured as an electrical signal of the encoder read by the controller when the metal part is triggered by the proximity switch.

[0008] Furthermore, the base is L-shaped, including a vertical portion extending in a vertical direction and a transverse portion extending in a horizontal direction, the screw transmission mechanism is installed on the vertical portion, and the proximity switch is installed on one side of the vertical portion and has a detection surface facing the movement path of the metal part.

[0009] Furthermore, a limiting member for limiting the movement range of the movable seat is provided on the vertical portion.

[0010] Furthermore, the lifting module also includes a linear guide rail, which includes a guide rail and a slider that slide with each other, the guide rail is arranged on the vertical part, and the slider is arranged on the side of the moving seat facing the guide rail.

[0011] Furthermore, the magnetic suspension stator includes a connecting pressure plate, a convex portion corresponding to the movable seat is formed on the peripheral side of the connecting pressure plate, and the movable seat is fixedly connected to the convex portion.

[0012] Further, the connecting pressure plate is located at the top of the magnetic levitation stator. One end of the moving seat is formed with a stepped groove, and the protruding portion is installed in the stepped groove.

[0013] Further, the magnetic levitation turntable further includes a braking unit configured to brake the lifting module according to a control instruction provided by the controller.

[0014] Further, the braking unit is disposed between the lead screw of the lead screw transmission mechanism and the motor shaft of the driving motor; or the braking unit is configured as a part of the driving motor.

[0015] Further, the control instruction includes an inter-lifting-module deviation instruction and a lifting-module zeroing deviation instruction. When the height deviation between the moving parts of at least two lifting modules is greater than a first preset distance, the controller issues the inter-lifting-module deviation instruction, and the braking unit brakes the lifting module. The value range of the first preset distance is 0.2 mm to 1 mm; when the zeroing position deviation of the moving part of each lifting module is greater than a second preset distance, the controller issues the lifting-module zeroing deviation instruction, and the braking unit brakes the lifting module; the value range of the second preset distance is 0.01 mm to 0.05 mm.

[0016] Further, the control instruction includes a power-off instruction. When the lifting module and / or the magnetic levitation stator is powered off, the controller issues the power-off instruction, and the braking unit brakes the lifting module.

[0017] Further, the control instruction includes a rotor radial deviation instruction and a rotor axial deviation instruction. When the deviation between the radial magnetic levitation position of the magnetic levitation rotor and a first set value is greater than a third preset distance, the controller issues the rotor radial deviation instruction, and the braking unit brakes the lifting module. The value range of the third preset distance is 0.04 mm to 0.15 mm; when the deviation between the axial magnetic levitation position of the magnetic levitation rotor and a second set value is greater than a fourth preset distance, the controller issues the rotor axial deviation instruction, and the braking unit brakes the lifting module. The value range of the fourth preset distance is 0.1 mm to 0.3 mm.

[0018] Further, at least one displacement sensor is provided on the magnetic levitation stator, and the at least one displacement sensor rises and falls synchronously with the magnetic levitation stator.

[0019] The beneficial effects of the present invention are as follows:

[0020] By setting up calibration detection components corresponding to each lifting module and using the calibration detection components to detect the displacement data of the moving part of the lifting module relative to the fixed part, the controller can determine whether the running accuracy of the lifting module has decreased and whether the running of multiple lifting modules is out of sync, so as to calibrate the running accuracy of a single lifting module in a timely manner and synchronize the running of multiple lifting modules. Then, the controller controls the synchronous operation of multiple lifting modules, thereby ensuring the positioning accuracy and stability of the magnetic levitation turntable and avoiding affecting the quality of wafer products due to the decrease in the positioning accuracy of the magnetic levitation turntable. At the same time, since the magnetic levitation stator is fixedly connected to the moving part of the lifting module and the magnetic levitation rotor moves up and down following the magnetic levitation stator under the action of the magnetic field force of the magnetic levitation stator, the large-stroke lifting movement of the magnetic levitation turntable can be realized by driving the moving part to rise or fall through the fixed part of the lifting module.

[0021] 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

[0022] 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, other drawings can be obtained based on these drawings without creative efforts.

[0023] Figure 1 is a schematic structural diagram of a magnetic levitation turntable with synchronous lifting in an embodiment of the present invention; Figure 2 is the assembly of the magnetic levitation stator and the lifting module in an embodiment of the present invention Figure 1 ; Figure 3 is the assembly of the magnetic levitation stator and the lifting module in an embodiment of the present invention Figure 2 ; Figure 4 is Figure 3 the enlarged view at A in Figure 5 is Figure 3 the sectional view along the B-B direction in Figure 6 is a schematic structural diagram of the lifting module in an embodiment of the present invention; Figure 7 is a schematic structural diagram of the fixed part of the lifting module in an embodiment of the present invention; Reference numerals in the above drawings: 1, magnetic levitation stator; 11, connecting pressure plate; 111, protruding part; 12, displacement sensor; 13, first stator substrate; 14, permanent magnet device; 15, second stator substrate; 16, second levitation winding; 17, first levitation winding; 2, magnetic levitation rotor; 3, lifting module; 31, moving part; 311, moving seat; 3111, stepped groove; 32, fixed part; 321, base; 3211, vertical part; 3212, horizontal part; 322, lead screw drive mechanism; 3221, lead screw; 3222, nut; 323, drive motor; 324, limiting member; 33, linear guide; 331, guide rail; 332, slider; 4, calibration and detection assembly; 41, proximity switch; 411, detection surface; 42, metal part; 5, braking unit. Detailed implementation manners

[0024] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the 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 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.

[0025] 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 drawings, and 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 cannot be understood as a limitation to the present invention. The terms "including" and "provided with" in the description 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.

[0026] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating 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 "plurality" is two or more, unless otherwise clearly defined.

[0027] The drawings in this 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 this disclosure are only schematic diagrams.

[0028] Figure 1 It is a schematic structural diagram of a magnetic levitation turntable with synchronous lifting in an embodiment of the present invention; Figure 2 It is the assembly of the magnetic levitation stator and the lifting module in an embodiment of the present invention Figure 1 ; Figure 3 It is the assembly of the magnetic levitation stator and the lifting module in an embodiment of the present invention Figure 2 ; Figure 4 It is Figure 3 The enlarged view at position A in Figure 5 It is Figure 3 The sectional schematic view along the B-B direction in Figure 6 It is a schematic structural diagram of the lifting module in an embodiment of the present invention; Figure 7 It is a schematic structural diagram of the fixing part of the lifting module in an embodiment of the present invention.

[0029] In the prior art, a magnetic levitation turntable generally includes a magnetic levitation stator and a magnetic levitation rotor. The magnetic levitation stator is used to generate a magnetic field to drive the magnetic levitation rotor and its carrier (wafer) to rotate and levitate. The magnetic levitation stator includes a suspension control component, and the suspension control component is used to apply an actively controlled suspension force to the magnetic levitation rotor to achieve axial active control and / or radial active control. However, the distance of the axial movement of the magnetic levitation rotor realized by this electromagnetic driving force is relatively small, usually less than 10 mm, and it is impossible to realize a large-stroke lifting movement, and it cannot meet the needs of some semiconductor manufacturing processes that require large-stroke movement.

[0030] To solve this technical problem, some technical solutions use a lifting device to connect the magnetic levitation stator to realize the large-stroke movement of the magnetic levitation stator and then drive the magnetic levitation rotor to realize the large-stroke lifting movement. Although these technical solutions solve the problem that the magnetic levitation turntable cannot realize the large-stroke lifting movement, there is still room for further improvement. For example, due to the frequent lifting movement required in the semiconductor manufacturing process, the lifting device is prone to problems such as a decrease in operating accuracy, and it is easy to have an out-of-sync problem between two or more lifting devices, resulting in a deterioration of the positioning accuracy and stability of the magnetic levitation turntable. For example, it reduces the positioning accuracy of the magnetic levitation turntable and affects the quality of the final wafer product. Especially in application scenarios that require high-precision positioning, this kind of error is unacceptable.

[0031] The present invention discloses a magnetic levitation turntable with synchronous lifting, which can, on the one hand, realize the large-stroke lifting movement of the magnetic levitation turntable, and on the other hand, can judge the positioning accuracy of a single lifting module and realize the synchronous movement and calibration of multiple lifting modules, ensuring the positioning accuracy and stability of the magnetic levitation turntable.

[0032] In order to enable those skilled in the art of the present technology to better understand the solution of the present invention, the following further describes the present invention with reference to the attached Figures 1 to 7 drawings and specific embodiments.

[0033] According to an embodiment of the present invention, the present invention provides a magnetic levitation turntable with synchronous lifting. The magnetic levitation turntable includes a magnetic levitation stator 1 and a magnetic levitation rotor 2. The magnetic levitation stator 1 is used to drive the magnetic levitation rotor 2 to levitate and rotate. The magnetic levitation turntable further includes a controller, at least two lifting modules 3, and calibration detection components 4 corresponding to the at least two lifting modules 3 one by one. The lifting module 3 includes a moving part 31 and a fixed part 32 that drives the moving part 31 to move up and down. The moving part 31 is fixedly connected to the magnetic levitation stator 1. The calibration detection component 4 is configured to detect the displacement data of the moving part 31 relative to the fixed part 32 and feed it back to the controller. The controller is configured to control the at least two lifting modules to run synchronously and calibrate the running accuracy of the lifting modules according to the displacement data. In this way, by setting a calibration detection component for each lifting module and using the calibration detection component to detect the displacement data of the moving part of the lifting module relative to the fixed part, the controller can determine whether the running accuracy of the lifting module has decreased and whether the running of multiple lifting modules is out of sync, so as to timely calibrate the running accuracy of a single lifting module and synchronize the running of multiple lifting modules. Then, by controlling the multiple lifting modules to run synchronously through the controller, the positioning accuracy and stability of the magnetic levitation turntable can be ensured, and the quality of the wafer product can be prevented from being affected due to the decrease in the positioning accuracy of the magnetic levitation turntable. At the same time, since the magnetic levitation stator is fixedly connected to the moving part of the lifting module and the magnetic levitation rotor follows the magnetic levitation stator to lift under the action of the magnetic field force of the magnetic levitation stator, the large-stroke lifting movement of the magnetic levitation turntable can be realized by driving the moving part to rise or fall through the fixed part of the lifting module. Compared with the prior art solution of connecting two parts of the lifting body through a mechanical transmission mechanism and driving synchronous lifting by a single driving motor, in this patent, multiple lifting modules are separately provided, occupying less space and having a simple structure, which has great advantages for the application scenario of a magnetic levitation turntable with very compact space (such as semiconductor RTP equipment). Especially in the semiconductor manufacturing process, the equipment is usually set in a clean room as a whole. Introducing a mechanical transmission mechanism, such as a gear transmission mechanism, in semiconductor equipment does not meet the requirements of high cleanliness on the one hand. On the other hand, more mechanical transmission connections lead to an increase in the number of failure points, which will inevitably bring frequent equipment maintenance, resulting in higher maintenance costs and a decrease in overall reliability. Moreover, the wear, vibration, etc. between multiple mechanical connections will inevitably bring more uncertainties, thus limiting the control accuracy of the magnetic levitation turntable. In addition, more mechanical transmission connections will increase the noise of the equipment and also do not meet the silent requirements of high-end semiconductor manufacturing.

[0034] Among them, the magnetic levitation stator 1 is used to drive the magnetic levitation rotor 2 to levitate and rotate. In one embodiment, see Figure 2 、 Figure 3 and Figure 5, the magnetic levitation stator 1 includes a permanent magnet device 14 and two layers of suspension control components. The suspension control components are configured to apply an actively controlled levitation force to the magnetic levitation rotor 2, and the permanent magnet device 14 is configured to apply a permanent magnet bias magnetic field to the magnetic levitation rotor 2. Among them, the permanent magnet device may include a plurality of permanent magnet components, and the plurality of permanent magnet components are evenly arranged in the circumferential direction. The position of each permanent magnet component is defined as a configured orientation. The line connecting the center of each configured orientation in the radial plane and the projection point of the rotation axis of the magnetic levitation porous rotor in the radial plane is defined as a radial line. Each permanent magnet component includes a plurality of permanent magnets, and the plurality of permanent magnets are spaced apart from each other with the radial line as the axis of symmetry and arranged in the same radial plane. The magnetic flux generated by the permanent magnets is applied to the magnetic levitation porous rotor through the stator poles of the suspension control components.

[0035] Among them, the suspension control components are configured to apply an actively controlled levitation force to the magnetic levitation rotor 2, and the suspension control components can be configured as radial suspension control components or axial suspension control components. In a specific magnetic levitation turntable, different suspension control components can be assembled according to the needs of radial suspension control and axial suspension control. The axial suspension control components are mainly used for the active control of the rotor axially to achieve the control of the axial suspension height of the rotor. The radial suspension control components are mainly used for the active control of the rotor radially to achieve the control of the stable radial suspension of the rotor. See Figure 5 , in an embodiment, one of the two layers of suspension control components is configured as a first suspension control component, and the other is configured as a second suspension control component. The first suspension control component includes a first stator substrate 13, a plurality of first stator poles protruding from the first stator substrate to the first rim of the magnetic levitation rotor, and a first suspension winding 17 disposed on the first stator poles; the second suspension control component includes a second stator substrate 15, a plurality of second stator poles protruding from the second stator substrate 15 to the second rim of the magnetic levitation rotor, and a second suspension winding 16 disposed on the second stator poles. The permanent magnet components are arranged axially between the first stator substrate 13 and the second stator substrate 15, and the permanent magnet bias magnetic field generated by the permanent magnet components forms a first magnetic field loop through the first stator substrate, the first stator poles, the first rim of the magnetic levitation rotor, the rotor body of the magnetic levitation rotor, the second rim of the magnetic levitation rotor, the second stator poles, and the second stator substrate.

[0036] According to an embodiment of the present disclosure, the magnetic levitation stator further includes a magnetic guide member, the magnetic guide member 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 defined as a plane 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. Preferably, the first stator substrate is annular, the magnetic conduction 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. One or two magnetic conduction teeth are provided between two adjacent first stator magnetic poles. In another embodiment, the magnetic guide member 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 arranged on the inner side of the magnetic conduction base body, the magnetic conduction base body is arranged axially on one side of the first stator substrate facing the permanent magnet assembly or on the side facing away from 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 located circumferentially between two adjacent first stator magnetic poles. By guiding the electromagnetic control magnetic field of the first suspension control assembly through the magnetic guide member, a second magnetic field circuit different from the first magnetic field circuit of the permanent magnet assembly can be constructed, so that the coupling of the permanent magnet bias magnetic field and the electromagnetic control magnetic field can be reduced, the response speed and stability of the control system can be improved, and the second magnetic field circuit does not pass through the permanent magnet assembly, thereby avoiding the influence of the electromagnetic control magnetic field on the permanent magnets of the permanent magnet assembly. In addition, according to the different relative positions of the magnetic guide member and the first rim of the magnetic levitation rotor in the axial direction, the problem of weak axial force of the suspension control or the axial irregular vibration of the magnetic levitation rotor can also be solved. For example, when the axial height of the magnetic guide member is the same as or approximately the same as the axial height of the first stator magnetic poles and they are axially aligned or approximately axially aligned, and the axial height of the magnetic guide member is the same as or approximately the same as the axial height of the magnetic levitation rotor, and the magnetic guide member is slightly higher than the first rim as a whole in the axial direction, the magnetic guide member 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, so that magnetic leakage can be reduced; the magnetic flux utilization rate can also be increased, and the axial force of the suspension control can be improved; when the axial height of the magnetic guide member 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 axially aligned or the magnetic guide member is slightly lower than the first rim as a whole in the axial direction, and the axial height of the first stator magnetic poles 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 magnetic poles are slightly higher than the first rim as a whole in the axial direction, the magnetic guide member 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, so that magnetic leakage can be reduced; the axial vibration of the magnetic levitation rotor can also be weakened or eliminated, so as to achieve the purpose of eliminating the need to arrange axial control windings, simplifying the relevant hardware and circuit configurations, simplifying the control algorithm of the control system, and further reducing the production cost.

[0037] According to an embodiment of the present disclosure, refer to Figure 5, at least one displacement sensor 12 is provided on the magnetic levitation stator 1, and at least one displacement sensor 12 rises and falls synchronously with the magnetic levitation stator. For example, the displacement sensor can be installed on the magnetic teeth of the magnetic guide in the magnetic levitation stator. The displacement sensor is used to detect the radial displacement, axial displacement or axial-radial displacement of the magnetic levitation rotor. For example, the displacement sensor can be configured as a radial displacement sensor or an axial displacement sensor. Preferably, the displacement sensor is configured as an axial-radial displacement sensor. By arranging the displacement sensor inside the magnetic levitation stator, on the one hand, there is no need to make through holes and use fluororubber seals on the vacuum chamber used in conjunction with the magnetic levitation turntable, nor is it necessary to replace the seals, thus solving problems such as recalibration and installation errors after assembling the sensor, and better meeting the ultra-clean and high-temperature environment requirements of semiconductor processing equipment. On the other hand, when the displacement sensor is arranged inside the magnetic levitation stator, during the large-stroke axial movement of the magnetic levitation stator, the displacement sensor is relatively fixed to the magnetic levitation stator. Compared with arranging the displacement sensor on the vacuum chamber, there will be no problem that the magnetic levitation rotor exceeds the detection range of the displacement sensor.

[0038] According to an embodiment of the present disclosure, referring to Figure 2 , Figure 6 and Figure 7 , the moving part 31 of the lifting module includes a moving seat 311, and the fixed part 32 includes a base 321, a screw drive mechanism 322 installed on the base 321, and a drive motor 323 that drives the screw 3221 of the screw drive mechanism 322 to rotate. The moving seat 311 is fixedly connected to the nut 3222 of the screw drive mechanism 322. In this way, the drive motor 323 provides power, and the screw drive mechanism 322 converts the rotational motion into a linear motion. For example, the screw 3221 of the screw drive mechanism 322 is fixedly connected to the motor shaft of the drive motor through a coupling or other components, and the nut 3222 of the screw drive mechanism 322 is fixedly connected to the moving seat 311 through fasteners. In this way, when the drive motor drives the screw to rotate, it can drive the nut to move up or down in the vertical direction, and then drive the moving seat fixedly connected to the nut to move up or down.

[0039] Among them, the calibration detection component 4 is used to detect the displacement data of the moving part 31 of the lifting module relative to the fixed part 32 and feed it back to the controller. The calibration detection component can be configured as a displacement sensor capable of detecting displacement data. Preferably, the calibration detection component 4 includes a proximity switch 41, a metal part 42, and an encoder. The metal part 42 is installed on the moving seat 311, the proximity switch 41 is installed on the base 321, and the displacement data is configured as the electrical signal of the encoder read by the controller when the metal part 42 triggers the proximity switch 41. Among them, the encoder is, for example, a motor encoder. In one embodiment, the encoder is integrated with the drive motor. The encoder can provide the rotation angle or displacement of the motor shaft in real time, so that the controller can accurately know the position of the current lead screw. The encoder can also measure the rotational speed of the motor shaft and feed this information back to the controller for adjusting the speed of the motor. In this embodiment, the encoder, the proximity switch, and the metal part form a calibration detection component to realize the calibration of the lifting module. Since the metal part is installed on the moving seat and the proximity switch is installed on the base, the metal part moves synchronously with the rise or fall of the magnetic levitation stator. The displacement of the metal part relative to the proximity switch corresponds to the displacement of the magnetic levitation stator relative to the lifting module. Therefore, by comparing the electrical signal values of the encoder read when the metal part triggers the proximity switch during multiple rises and falls of the metal part and comparing these values, it can be determined whether the corresponding values at each trigger are within the specified range. Furthermore, it can be determined whether the running accuracy of the lifting module has decreased, so that the running accuracy of the lifting module can be calibrated in time when the running accuracy of the lifting module exceeds the specified range.

[0040] The present invention does not limit the shape of the base. Preferably, referring to Figure 2 , the base 321 is L-shaped, including a vertical portion 3211 extending in the vertical direction and a horizontal portion 3212 extending in the horizontal direction. The lead screw transmission mechanism 322 is installed on the vertical portion. The horizontal portion is convenient for connecting with an external vacuum chamber of, for example, semiconductor equipment, while the vertical portion is convenient for arranging the lead screw transmission mechanism and the linear guide. Preferably, referring to Figure 7 , the lead screw transmission mechanism is arranged in a groove extending along the axial direction on the base. The lead screw transmission mechanism is a prior art, and the rotational installation and setting of the lead screw are not described in detail here. In one embodiment, the proximity switch 41 is installed on one side of the vertical portion 3211 and has a detection surface 411 facing the moving path of the metal part 42. For example, the metal part is preferably made of ferromagnetic material, the proximity switch is an inductive proximity switch, and an induction coil of the inductive proximity switch is arranged at the position corresponding to the detection surface 411. The inductive proximity switch also includes an oscillator and a detection circuit, which use the principle of electromagnetic induction to detect the presence of metal objects and have high sensitivity and good anti-interference ability.

[0041] According to an embodiment of the present disclosure, referring to Figure 4, a limiting member 324 for limiting the movement stroke of the moving seat 311 is provided on the vertical portion 3211. In this way, setting the limiting member on the vertical portion can limit the movement stroke of the moving seat, prevent the nut from disengaging from the lead screw, and ensure the safety of the lifting module.

[0042] According to an embodiment of the present disclosure, referring to Figure 2 and Figure 7 , the lifting module 3 further includes a linear guide rail 33. The linear guide rail 33 includes a guide rail 331 and a slider 332 that are slidably engaged with each other. The guide rail 33 is provided on the vertical portion 3211, and the slider 332 is provided on one side of the moving seat 311 facing the guide rail 33. By providing the guide rail on the base and the slider on the moving seat, the guide rail and the slider form a linear guide rail. With the sliding cooperation between the slider and the guide rail, a precise guiding effect can be achieved, and the lifting stability of the driving magnetic levitation stator of the lifting module can be improved.

[0043] According to an embodiment of the present disclosure, referring to Figure 2 , Figure 3 and Figure 5 , the magnetic levitation stator 1 includes a connecting pressure plate 11. A protruding portion 111 corresponding to the moving seat 311 is formed on the circumferential side of the connecting pressure plate 11, and the moving seat 311 is fixedly connected to the protruding portion 111. In this way, the magnetic levitation stator is fixedly connected to the moving seat through the protruding portion of the connecting pressure plate, which is very convenient for disassembly and assembly. Preferably, the protruding portion and the moving seat can be fixedly connected by fasteners. In another embodiment, the connecting pressure plate can also enclose a cavity space with the housing of the magnetic levitation stator, and the permanent magnet device 14 and the suspension control component of the magnetic levitation stator can be arranged in the cavity space. The present invention does not limit the shape of the connecting pressure plate. Preferably, the connecting pressure plate is integrally circular, and the protruding portion extends radially from the outside of the connecting pressure plate. In this way, it will not affect the fixed connection between the base of the lifting module and the vacuum chamber of the external semiconductor device. Preferably, the protruding portion 111 and the connecting pressure plate are integrally formed, but not limited thereto. In other embodiments, they can also be detachably fixedly connected by fasteners. The shape of the protruding portion is not limited. Preferably, the shape of the protruding portion is configured as a trapezoid. In this way, the inner width of the protruding portion is greater than the outer width, which can further improve the structural strength.

[0044] According to an embodiment of the present disclosure, referring to Figure 2 and Figure 6 , the connecting pressure plate 11 is located at the top of the magnetic levitation stator 1. A stepped groove 3111 is formed at one end of the moving seat 311, and the protruding portion is installed in the stepped groove 3111. The connecting pressure plate 11 is fixedly connected to the stepped groove 3111 of the moving seat 311. On the one hand, it is convenient for assembly and positioning, and on the other hand, it can enhance the connection firmness. In other embodiments, the connecting pressure plate can also be arranged at the bottom of the magnetic levitation stator.

[0045] According to an embodiment of the present disclosure, referring to Figure 2And Figure 6 The magnetic levitation turntable further includes a braking unit 5 configured to brake the lifting module according to a control instruction provided by the controller. The braking unit is mainly used to control and stop the movement of the lead screw, prevent accidental movement, and provide emergency braking when a single lifting module needs to be calibrated or there is an out-of-sync situation between multiple lifting modules or there is a deviation in the magnetic levitation rotor suspension or when necessary, so as to achieve a self-locking or interlocking function. Preferably, the braking unit 5 is disposed between the lead screw 3222 of the lead screw transmission mechanism 322 and the motor shaft of the driving motor; the braking unit can be an elastic coupling or an electromagnetic clutch, etc., and the braking unit can directly brake the motor shaft or the lead screw to quickly brake the movement of the lifting module. Or the braking unit is configured as a part of the driving motor. For example, the driving motor is a motor with a brake, and when the lifting action needs to be stopped, the driving motor holds the motor shaft by itself to achieve the braking of the lead screw transmission mechanism.

[0046] The braking unit needs to act according to the control instruction of the controller to achieve the self-locking or interlocking function of the lifting module. In one embodiment, the control instruction can be an inter-module deviation instruction of the lifting module. For example, when the height deviation between the moving parts of at least two lifting modules is greater than a first preset distance, the controller issues an inter-module deviation instruction of the lifting module, and the braking unit brakes the lifting module. To achieve the positioning accuracy of the lifting of the magnetic levitation turntable, preferably, the value range of the first preset distance is 0.2 mm to 1 mm. For example, during the movement of two lifting modules, the controller reads the encoder values of the two lifting modules about every 0.1 s and compares them to determine whether the deviation exceeds 0.5 mm. If the deviation between the two exceeds 0.5 mm, it is determined that there is an out-of-sync situation between the two lifting modules. At this time, the controller issues an inter-module deviation instruction of the lifting module, and the braking unit brakes the lifting module to synchronize and calibrate the two lifting modules.

[0047] According to an embodiment of the present disclosure, the control instruction can be a zero-return deviation instruction of the lifting module. For example, when the zero-return position deviation of the moving part of each lifting module is greater than a second preset distance, the controller issues a zero-return deviation instruction of the lifting module, and the braking unit brakes the lifting module. To achieve the positioning accuracy of the lifting of the magnetic levitation turntable, preferably, the value range of the second preset distance is 0.01 mm to 0.05 mm. For example, during the movement of each lifting module, the controller reads the encoder value of the lifting module each time the metal part triggers the proximity switch and determines whether the corresponding value at each trigger is within the specified range, that is, whether the zero-return deviation of the lifting module is within the specified range. For example, it is determined whether the zero-return deviation exceeds 0.03 mm. If the zero-return deviation exceeds 0.03 mm, it is determined that the running accuracy of the lifting module has decreased. At this time, the controller issues a zero-return deviation instruction of the lifting module, and the braking unit brakes the lifting module to calibrate the lifting module.

[0048] According to an embodiment of the present disclosure, the control instruction may be a power-off instruction. When the lifting module or / and the magnetic levitation stator is powered off, the controller issues a power-off instruction, and the braking unit brakes the lifting module. In this way, when the magnetic levitation stator or the lifting module is accidentally powered off, the braking unit can brake and lock itself or interlock, thereby preventing damage to the semiconductor process equipment caused by the fall of the magnetic levitation stator and improving the safety and stability of the magnetic levitation turntable.

[0049] According to an embodiment of the present disclosure, the control instruction may be a rotor radial deviation instruction. When the deviation between the radial magnetic levitation position of the magnetic levitation rotor and the first set value is greater than the third preset distance, the controller issues a rotor radial deviation instruction, and the braking unit brakes the lifting module. In order to achieve the positioning accuracy of the magnetic levitation turntable suspension, preferably, the value range of the third preset distance is 0.04 mm to 0.15 mm. For example, during the suspension and rotation of the magnetic levitation rotor, the displacement sensor disposed in the magnetic levitation stator real-time detects the radial suspension position of the magnetic levitation rotor. When the radial suspension position of the magnetic levitation rotor is greater than 0.08, it is determined that the radial suspension position of the magnetic levitation rotor has a deviation. At this time, the controller issues a rotor radial deviation instruction, and the braking unit brakes the lifting module to calibrate the radial suspension position of the magnetic levitation rotor.

[0050] According to an embodiment of the present disclosure, the control instruction may also be a rotor axial deviation instruction. When the deviation between the axial magnetic levitation position of the magnetic levitation rotor and the second set value is greater than the fourth preset distance, the controller issues a rotor axial deviation instruction, and the braking unit brakes the lifting module. In order to achieve the positioning accuracy of the magnetic levitation turntable suspension, preferably, the value range of the fourth preset distance is 0.1 mm to 0.3 mm. For example, during the suspension and rotation of the magnetic levitation rotor, the displacement sensor disposed in the magnetic levitation stator real-time detects the axial suspension position of the magnetic levitation rotor. When the axial suspension position of the magnetic levitation rotor is greater than 0.18, it is determined that the axial suspension position of the magnetic levitation rotor has a deviation. At this time, the controller issues a rotor axial deviation instruction, and the braking unit brakes the lifting module to calibrate the axial suspension position of the magnetic levitation rotor.

[0051] In the present invention, specific embodiments are used to elaborate on the principle and implementation manner of the present invention. The descriptions of the above embodiments are 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, according to 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 synchronously raised and lowered magnetic levitation turntable, the magnetic levitation turntable comprising a magnetic levitation stator (1) and a magnetic levitation rotor (2), the magnetic levitation stator being used to drive the magnetic levitation rotor to suspend and rotate, characterized in that: The magnetic levitation turntable further comprises a controller, at least two lifting modules (3) and a calibration detection assembly (4) corresponding to the at least two lifting modules one by one, the lifting module comprising a moving part (31) and a fixed part (32) driving the moving part to move up and down, the moving part being fixedly connected to the magnetic levitation stator, the calibration detection assembly being configured to detect displacement data of the moving part relative to the fixed part and feed back to the controller, and the controller being configured to control the synchronous operation of the at least two lifting modules and calibrate the operation accuracy of the lifting modules according to the displacement data.

2. The synchronous lifting and lowering magnetic suspension turntable according to claim 1 is characterized in that: The moving part comprises a moving seat (311), the fixed part comprises a base (321), a screw transmission mechanism (322) mounted on the base, and a driving motor (323) for driving a screw rod (3221) of the screw transmission mechanism to rotate, and the moving seat is fixedly connected to a nut (3222) of the screw transmission mechanism.

3. The synchronous ascending and descending magnetic levitation turntable according to claim 2, characterized in that: The calibration detection component comprises a proximity switch (41), a metal piece (42) and an encoder, the metal piece is mounted on the movable seat, the proximity switch is mounted on the base, and the displacement data is configured as an electrical signal of the encoder read by the controller when the metal piece passes through the proximity switch and is triggered.

4. The synchronous ascending and descending magnetic levitation turntable according to claim 3 is characterized in that: The base is L-shaped and comprises a vertical portion (3211) extending in a vertical direction and a transverse portion (3212) extending in a horizontal direction; the lead screw transmission mechanism is mounted on the vertical portion; the proximity switch is mounted on one side of the vertical portion and has a detection surface (411) facing the movement path of the metal member.

5. The synchronous ascending and descending magnetic suspension turntable according to claim 4 is characterized in that: The vertical portion is provided with a limiting member (324) for limiting the movement stroke of the movable seat.

6. The synchronous ascending and descending magnetic suspension turntable according to claim 4, characterized in that: The lifting module also includes a linear guide rail (33), which includes a guide rail (331) and a slider (332) that slide with each other, the guide rail is arranged on the vertical portion, and the slider is arranged on a side of the moving seat facing the guide rail.

7. The synchronous ascending and descending magnetic suspension turntable according to claim 2, characterized in that: The magnetic suspension stator comprises a connecting pressure plate (11), a convex portion (111) corresponding to the movable seat is formed on the peripheral side of the connecting pressure plate, and the movable seat is fixedly connected to the convex portion.

8. The synchronous ascending and descending magnetic suspension turntable according to claim 7, characterized in that: The connecting pressure plate is located at the top of the magnetic suspension stator, and a stepped groove (3111) is formed at one end of the movable seat, and the protrusion is installed in the stepped groove.

9. The synchronous ascending and descending magnetic suspension turntable according to claim 1, characterized in that: The magnetic suspension turntable further comprises a braking unit (5), wherein the braking unit is configured to brake the lifting module according to a control instruction provided by the controller.

10. The synchronous ascending and descending magnetic suspension turntable according to claim 9, characterized in that: The brake unit is arranged between the screw of the screw transmission mechanism and the motor shaft of the drive motor; or the brake unit is configured as a part of the drive motor.

11. The synchronous ascending and descending magnetic levitation turntable according to claim 9, characterized in that: The control instruction includes a deviation instruction between lifting modules and a return-to-zero deviation instruction for the lifting modules. When the height deviation between the moving parts of the at least two lifting modules is greater than a first preset distance, the controller issues the deviation instruction between the lifting modules, and the braking unit brakes the lifting modules. The value range of the first preset distance is 0.2mm to 1mm. When the return-to-zero position deviation of the moving part of each lifting module is greater than a second preset distance, the controller issues the return-to-zero deviation instruction for the lifting module, and the braking unit brakes the lifting modules. The value range of the second preset distance is 0.01mm to 0.05mm.

12. The synchronous ascending and descending magnetic suspension turntable according to claim 9, characterized in that: The control instruction includes a power-off instruction. When the lifting module and / or the magnetic suspension stator are powered off, the controller issues a power-off instruction, and the braking unit brakes the lifting module.

13. The synchronous ascending and descending magnetic suspension turntable according to claim 9, characterized in that: The control instruction includes a rotor radial deviation instruction and a rotor axial deviation instruction. When the deviation between the radial magnetic levitation position of the magnetic levitation rotor and the first set value is greater than a third preset distance, the controller issues the rotor radial deviation instruction, and the braking unit brakes the lifting module. The value range of the third preset distance is 0.04mm~0.15mm; when the deviation between the axial magnetic levitation position of the magnetic levitation rotor and the second set value is greater than a fourth preset distance, the controller issues the rotor axial deviation instruction, and the braking unit brakes the lifting module. The value range of the fourth preset distance is 0.1mm~0.3mm.

14. The synchronous ascending and descending magnetic suspension turntable according to claim 1, characterized in that: At least one displacement sensor (12) is provided on the magnetic suspension stator, and the at least one displacement sensor rises and falls synchronously with the magnetic suspension stator.

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