Air floating lifting and rotating platform with continuously rotating lifting mechanism

Abstract

The application belongs to the field of semiconductor manufacturing equipment, and particularly relates to a gas-floating lifting and rotating platform comprising a continuous rotating and lifting mechanism. The platform integrates a rotating mechanism and a lifting mechanism. The rotating mechanism adopts a gas-floating bearing to realize frictionless rotation. The lifting mechanism drives a gas-floating shaft to precisely lift on a linear guide rail through a first voice coil motor. The rotating and lifting movements are separated by the gas-floating bearing to realize motion decoupling and avoid internal cable winding. The platform adopts a hierarchical driving strategy of cylinder pre-lifting and fine adjustment by a second voice coil motor, and has high-speed response and micron-level positioning accuracy. The platform is suitable for precise scanning scenes requiring synchronous rotation and lifting in wafer detection, and effectively improves detection efficiency and reliability.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of semiconductor manufacturing equipment, and particularly relates to a gas-floating lifting rotary platform comprising a continuous rotary lifting mechanism. BACKGROUND

[0002] In a semiconductor wafer optical detection device, in order to realize efficient and precise scanning of the wafer surface, many devices for wafer detection have been produced, such as the disclosed technology CN114111691A. In wafer scanning detection, the wafer rotation and axial lifting motion need to be controlled synchronously. The traditional technical solution usually adopts a split structure design of a rotary motor and a lifting cylinder or a lead screw, which leads to a large device size, delayed motion response, and difficulty in realizing complex trajectory motion such as spiral scanning. More importantly, the split structure faces the risk of fatigue fracture caused by repeated twisting of the cable of the rotating part in long-term operation, which seriously affects the reliability of the device.

[0003] The existing integrated solution attempts to couple the rotation and lifting functions through a mechanical bearing, but the bearing friction torque will cause rotation jitter, resulting in a decline in wafer imaging quality. At the same time, the mechanical friction resistance in the lifting process aggravates the wear of the motion mechanism, making it difficult to maintain micron-level positioning accuracy for a long time. Although the gas-floating bearing technology can solve the problem of rotation friction, there is still a lack of effective motion decoupling mechanism in the integrated lifting rotary platform, which cannot simultaneously control high-precision rotation and high-response lifting.

[0004] The current technical bottleneck is mainly manifested in the following aspects: the cylinder drive has a crawling phenomenon and hysteresis nonlinearity, which makes it difficult to meet the dual requirements of millisecond-level response and precise positioning; and the mechanical coupling interference of rotary lifting composite motion further restricts the development of high-end wafer detection equipment towards high speed and high precision. SUMMARY

[0005] The application provides an integrated platform integrating a gas-floating bearing and a voice coil motor, which synchronously realizes frictionless continuous rotation and high-precision lifting through dynamic decoupling technology, and completely solves the motion interference and cable winding problems in semiconductor wafer detection.

[0006] The application discloses a gas floating lifting rotating platform with a continuous rotating lifting mechanism, which comprises a rotating mechanism and a lifting mechanism, the lifting mechanism comprises a No.1 voice coil motor and a linear guide rail, the rotating mechanism comprises a gas floating shaft and a rotating platform, a rotating motor is peripherally arranged on the gas floating shaft, a No.1 voice coil motor is arranged at the bottom, the gas floating shaft is arranged on the linear guide rail through a gas floating bearing, the gas floating bearing is divided into a bearing inner ring and a bearing outer ring, the No.1 voice coil motor drives the gas floating shaft and the gas floating bearing to vertically move on the linear guide rail, when the gas floating bearing is aerated, the rotating motor drives the gas floating shaft and the bearing inner ring to rotate around the axis of the gas floating shaft. The device is applied to wafer detection, and the wafer needs to be lifted and rotated in the detection process to facilitate scanning detection of the detection mechanism. The device combines the lifting mechanism and the rotating mechanism to drive the wafer chuck to rotate and lift, provides a core mechanism integrating lifting and rotating functions, and aims to solve the problem that the wafer needs to be lifted and rotated respectively in the wafer detection process. The core purpose is to realize high-precision and low-friction rotation through the gas floating bearing and realize fast and accurate linear lifting through the voice coil motor, and the two kinds of motions are organically combined. The gas floating lifting rotating platform integrates the lifting and rotating functions in a compact platform, simplifies the equipment structure and reduces the occupied space. The gas floating bearing is adopted to support rotation, non-contact and frictionless rotating motion is realized, high rotating precision and stability are ensured, and mechanical wear and vibration are avoided. The voice coil motor is directly driven by an operator, high acceleration and high-precision linear displacement are provided, and the response speed is fast. The gas floating bearing makes the interference between the rotating motion and the lifting motion extremely small (motion decoupling), and the high-precision rotating and lifting actions can be independently or simultaneously performed, and the requirement of a complex detection path is met. Since many lines need to be connected for the driving device in the rotating lifting platform, if the ordinary platform cannot decouple the rotating motion and the lifting motion, the rotating motion cannot be performed at a large angle, otherwise, the internal lines will be wound, and the device solves the problem.

[0007] The application discloses a gas floating lifting rotating platform with a continuous rotating lifting mechanism, a No.1 voice coil motor is arranged in a sliding block, the sliding block is slidably connected with a guide block, a plurality of No.2 voice coil motors are arranged at the bottom of the guide block, and the No.2 voice coil motors are used for driving the sliding block to vertically move. The sliding connection between the sliding block and the guide block provides more stable and more accurate guidance for the lifting motion and prevents lateral deviation and shaking. A plurality of No.2 voice coil motors are arranged, the No.2 voice coil motors drive the whole rotating mechanism and lifting mechanism in the sliding block to move to a specified position for work, and the plurality of No.2 voice coil motors can jointly provide greater driving force to bear heavier load.

[0008] A kind of air floating lifting rotary platform with continuous rotation lifting mechanism, guide block side is equipped with air cylinder, air cylinder drive rod is connected with the bottom of bearing table, and bearing table can be used to carry wafer chuck. In order to integrate and position wafer equipment (such as bearing table, pretreatment module, etc.) on the platform, an auxiliary driving mode for adjusting its level or initial height is provided. The weight of bearing table is larger, if it is all supported by multiple No. 2 voice coil motors at the bottom, the load pressure of No. 2 voice coil motor is larger, therefore, air cylinder can first lift bearing table out a distance in initial state, then No. 2 voice coil motor drives internal slider to move, so that the initial load of No. 2 voice coil motor is smaller. While No. 2 voice coil motor drives slider to move, air cylinder can also adjust support force, for quickly adjusting the height or horizontal position of bearing table.

[0009] A kind of air floating lifting rotary platform with continuous rotation lifting mechanism, the center of slider is provided with through hole, lifting mechanism base is installed in through hole, the center of lifting mechanism base is provided with plum blossom hole, No. 1 voice coil motor is installed in plum blossom hole. The bottom of slider is threadedly connected with the top surface of lifting mechanism base, and the bottom surface of lifting mechanism base is threadedly connected with No. 1 voice coil motor. By lifting mechanism base and thread connection, it is ensured that No. 1 voice coil motor and lifting mechanism base are firmly fixed inside the slider, to prevent loosening or displacement when moving at high speed or load changes, to ensure the rigidity and reliability of transmission.

[0010] A kind of air floating lifting rotary platform with continuous rotation lifting mechanism, the inside of lifting mechanism base is provided with rim, and rotary motor is installed on the rim. The rotary motor is installed above the rim of lifting mechanism base, so that the driving sources of lifting and rotation are concentrated together, reducing the volume and complexity of the overall structure, and the layout is more reasonable, saving the longitudinal arrangement space.

[0011] A kind of air floating lifting rotary platform with continuous rotation lifting mechanism, the top outer periphery of air floating shaft is provided with multiple protrusions, the inside of rotary platform is provided with matching groove matched with the protrusions, the protrusions and the matching groove are matched with each other, so that the air floating shaft can drive the rotary platform to rotate. This structure provides an efficient and reliable power transmission connection mode between the rotary platform and the air floating shaft, to ensure that the rotary motion can be transmitted to the load without damage. The meshing structure of protrusions and matching grooves can transmit larger torque, prevent slipping, and ensure that the rotary platform and the air floating shaft rotate synchronously. This connection mode allows the air floating shaft and the rotary platform to have relative movement in the axial direction while transmitting circumferential torque, thereby perfectly adapting to the needs of lifting motion.

[0012] A kind of air floating lifting rotary platform with continuous rotation lifting mechanism, air floating axle top is equipped with extension rod, for inserting wafer insertion hole. Provide a wafer chuck (or similar load) and the interface mode of quick, accurate centering and connection of air floating axle. Extension rod inserts wafer disk insertion hole, can ensure that the wafer chuck above is accurately centered with air floating axle, ensure that the rotation center is consistent with the chuck center, avoid the vibration or measurement error caused by eccentricity.

[0013] A kind of air floating lifting rotary platform with continuous rotation lifting mechanism,

[0014] It also includes control unit, position sensor, acceleration sensor;

[0015] The control unit is configured to execute the lifting motion control method, comprising:

[0016] Based on target position and actual position feedback of position sensor, calculate position error;

[0017] When the position error is greater than the first set threshold, mainly drive the cylinder to move, so that the slider quickly approaches the target position;

[0018] When the position error is less than or equal to the first set threshold, mainly drive the second voice coil motor to move, while controlling the cylinder to keep constant support force or lock position, so that the slider is accurately positioned to the target position;

[0019] In the stage of mainly driving the second voice coil motor, the control unit calculates and outputs control instructions to the second voice coil motor in real time according to the position error, to realize high-precision positioning or vibration suppression of the slider. By setting the position error threshold, the cylinder is preferentially driven to realize fast response and large stroke movement (coarse adjustment stage) when moving at a long distance, so as to shorten the positioning time. When approaching the target position, switch to the second voice coil motor for micron-level fine adjustment, which overcomes the inherent nonlinear friction and crawling problem of the cylinder, balances the high speed of the cylinder and the high precision of the voice coil motor, and breaks through the performance limitation of a single actuator. In the coarse adjustment stage, the voice coil motor can be closed or run at low power, and the cylinder bears the main driving force. Only in the fine adjustment stage, the voice coil motor is enabled, which reduces the heat generated by long-time operation of the voice coil motor, improves the system reliability, and prolongs the service life. In the fine adjustment stage, the residual vibration is suppressed in real time by high-bandwidth control of the voice coil motor, which avoids the influence of cylinder jitter on positioning stability at low speed, and provides a stable lifting reference for high-precision detection, micro-assembly and other scenes.

[0020] A kind of air floating lifting rotary platform with continuous rotation lifting mechanism, acceleration sensor, position sensor are installed on the bearing table.

[0021] A kind of air floating lifting rotary platform with continuous rotation lifting mechanism,

[0022] The control unit is further configured to:

[0023] receiving a vibration signal from an acceleration sensor mounted on the slider or the bearing table;

[0024] calculating in real time a damping force instruction for counteracting the vibration based on the vibration signal;

[0025] outputting the damping force instruction to the second voice coil motor to drive the second voice coil motor to generate an active damping force opposite in phase to the detected vibration;

[0026] wherein the active damping force is calculated based on at least one of the following algorithms: PID control, adaptive filtering, least mean square algorithm or model predictive control.

[0027] The vibration signal (such as cylinder start-stop impact, rotating mechanism coupling vibration, external environmental disturbance) is captured in real time by the acceleration sensor, and a reverse active damping force is generated by the voice coil motor. The voice coil motor is expanded from a positioning actuator to a dynamic damper, realizing multifunctional integration. Traditional passive dampers cannot adaptively suppress wideband vibration (such as low-frequency cylinder jitter and high-frequency motor harmonics), and the present scheme dynamically adjusts the damping force spectrum characteristics through algorithms.

[0028] The advantages of the present application are: through the air floating bearing, the organic integration of zero-friction rotation and voice coil motor precise lifting is realized, and the motion coupling interference and cable winding problem are completely eliminated. Its core advantage is to achieve high dynamic performance and ultra-long service life synchronously, millisecond-level response lifting and high-precision rotation can be run at the same time, and the non-contact motion mechanism avoids mechanical wear. The compact integrated design combines the two-stage driving strategy of cylinder coarse adjustment and voice coil fine adjustment, which significantly reduces the device volume while having micron-level positioning capability and high-speed lifting, greatly improving the efficiency and reliability of semiconductor wafer detection. BRIEF DESCRIPTION OF DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only exemplary, and for those skilled in the art, other drawings can be obtained from the provided drawings without creative labor.

[0030] Figure 1 It is a schematic diagram of the total device of the present application;

[0031] Figure 2 It is an exploded view of the total device of the present application;

[0032] Figure 3 It is a schematic diagram of the rotating mechanism and lifting mechanism of the present application;

[0033] Figure 4Figure 1 is a schematic diagram of the air floating shaft and rotating platform of the present application;

[0034] Figure 5 Figure 2 is a schematic diagram of the bottom of the guide block of the present application;

[0035] Figure 6 Figure 3 is a schematic diagram of the bottom of the sliding block of the present application;

[0036] Figure 7 Figure 4 is a schematic diagram of the sliding block of the present application;

[0037] Figure 8 Figure 5 is a schematic diagram of the base of the lifting mechanism of the present application;

[0038] Figure 9 Figure 6 is a schematic diagram of the base of the lifting mechanism and the rotating motor of the present application;

[0039] Figure 10 Figure 7 is an exploded view of the sliding block, the lifting mechanism, the rotating motor and the rotating mechanism of the present application;

[0040] Figure 11 Figure 8 is an exploded view of the sliding block, the rotating motor and the rotating mechanism of the present application;

[0041] Figure 12 Figure 9 is a sectional view of the overall device of the present application;

[0042] Figure 13 Figure 10 is a flow chart of embodiment 2 of the present application;

[0043] Figure 14 Figure 11 is a flow chart of embodiment 3 of the present application.

[0044] BRIEF DESCRIPTION OF DRAWINGS: 1-rotating mechanism, 2-lifting mechanism, 3-air floating bearing, 3a-bearing inner ring, 3b-bearing outer ring, 4-sliding block, 5-guide block, 6-rotating motor, 7-bearing table, 11-air floating shaft, 12-rotating platform, 21-first voice coil motor, 21a-gap, 22-linear guide rail, 41-through hole, 43-lifting mechanism base, 43a-trefoil hole, 43b-edge, 51-second voice coil motor, 52-air cylinder, 11a-protruding part, 12a-matching groove, 11b-protruding rod. DETAILED DESCRIPTION

[0045] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0046] The concepts involved in this application will first be described with reference to the accompanying drawings. It should be noted that the following descriptions of various concepts are only for the purpose of making the content of this application easier to understand and do not constitute a limitation on the scope of protection of this application; furthermore, the embodiments and features in the embodiments of this application can be combined with each other unless otherwise specified. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0047] Example 1:

[0048] See attached document Figure 1 Appendix Figure 12 As shown, this embodiment describes an air-floating lifting and rotating platform used in a wafer optical appearance inspection equipment. The air-floating lifting and rotating platform is fixed to the frame of the inspection equipment by a guide block 5 at its bottom. A support platform 7 is mounted above the guide block 5 by a drive rod of a cylinder 52. A wafer chuck is mounted on the support platform 7 to support and vacuum-adsorb the wafer to be inspected. The wafer chuck has a wafer insertion hole at its bottom.

[0049] See attached document Figure 3 Appendix Figure 5 Appendix Figure 6 Appendix Figure 8 Appendix Figure 9 Appendix Figure 12 As shown, the voice coil motor 21 of the lifting mechanism 2 and the rotary motor 6 of the rotating mechanism 1 are both connected to an external multi-axis motion controller via cables. The air bearing 3 is connected to an external clean compressed air source via an air pipe. The air supply device is equipped with a precision filter and a pressure regulating valve. The air pipe can extend into the gap 21a between the bottom of the voice coil motor 21 and the base 43 of the lifting mechanism.

[0050] See attached document Figure 2 Appendix Figure 5 Appendix Figure 6 Appendix Figure 7 Appendix Figure 12 As shown, in the initial state, the air bearing 3 is not ventilated, the drive rod of cylinder 52 is in the retracted state, and the support platform 7 and wafer chuck are in a lower position. The entire lifting and rotating mechanism is driven by four No. 2 voice coil motors 51 at the bottom, which are stopped at the lower limit of their stroke. The operator first activates cylinder 52, causing its drive rod to extend and lift the support platform 7 and wafer chuck upwards a predetermined distance. This operation aims to pre-load most of the weight of the wafer chuck, significantly reducing the load on the No. 2 voice coil motors 51 in subsequent actions. The controller then drives the No. 2 voice coil motors 51 to work, and the output shaft of the No. 2 voice coil motors 51 pushes the slider 4, causing the slider 4 to rise smoothly along the guide block 5. Since cylinder 52 has already borne the main weight, the No. 2 voice coil motors 51 only need to provide a small force to achieve precise start-up and positioning, raising the entire internal lifting mechanism 2 and rotating mechanism 1 to the starting working height.

[0051] Referring to the drawings Figure 3 , the drawings Figure 4 , the drawings Figure 12 As shown, after reaching the starting height, the external clean compressed air source supplies air to the air bearing 3. The high-pressure gas forms a very thin gas film between the bearing inner ring 3a and the bearing outer ring 3b, which lifts the air floating shaft 11 and the components connected thereto, achieving a completely non-contact, zero-friction support state. The operator controls the first voice coil motor 21, which generates an electromagnetic force to directly drive the air floating shaft 11 to move vertically along the linear guide rail 22 with high accuracy. The high response characteristics of the first voice coil motor 21 enable the wafer chuck to be quickly and accurately positioned to different detection focal planes.

[0052] Referring to the drawings Figure 3 , the drawings Figure 4 , the drawings Figure 10 , the drawings Figure 11 , the drawings Figure 12 As shown, then the rotary motor 6 starts to work, and the rotor of the rotary motor 6 drives the air floating shaft 11 and the bearing inner ring 3a to rotate continuously around the axis of the air floating shaft 11. The rotary power is transmitted to the rotary platform 12 without loss through the engagement of the multiple protrusions 11a on the top of the air floating shaft 11 with the matching grooves 12a inside the rotary platform 12. The extension rod 11b of the rotary platform 12 is inserted into the socket of the wafer chuck, ensuring that the rotation center is strictly centered with the wafer center, thereby driving the wafer chuck and the wafer adsorbed thereon to rotate smoothly and without eccentricity, facilitating the scanning detection of the wafer by the detection equipment.

[0053] During this process, the lifting motion and the rotary motion are completely decoupled. While the air floating shaft 11 is rotating, it can perform lifting motion without any interference. This enables the scanning head of the detection equipment to perform spiral or specified path scanning on the rotating wafer, greatly improving the detection efficiency. All cables leading to the first voice coil motor 21 and the rotary motor 6 are fixed on the slider 4, which rises and falls with the entire internal mechanism, and does not rotate with the air floating shaft 11, thereby completely avoiding the common problem of line entanglement in traditional rotary platforms.

[0054] After the detection is completed, the rotary motor 6 stops rotating, the air floating bearing 3 stops supplying air, and the bearing inner ring 3a falls back into contact with the bearing outer ring 3b. The first voice coil motor 21 drives the air floating shaft 11 to descend to the initial position. Subsequently, the second voice coil motor 51 drives the slider 4 to descend, and finally the cylinder 52 drives the rod to retract, causing the bearing table 7 to fall back to the initial state, completing a working cycle.

[0055] This embodiment fully demonstrates how the application perfectly combines high-precision lifting with high-speed rotation. The high stability and ultra-long service life of the rotating motion are achieved through the air floatation bearing; the rapidity and high precision of the lifting motion are achieved through the voice coil motor; the unique "air cylinder pre-jacking and voice coil motor fine positioning" two-level structure and the use of the air floatation bearing successfully realize motion decoupling, avoid cable winding, and finally meet the stringent requirements of modern wafer detection equipment for high efficiency, high precision and high reliability.

[0056] Embodiment 2:

[0057] A high-resolution grating ruler is installed near the slider 4 or the linear guide rail 22 as a position sensor to measure the accurate position of the slider 4 in real time and feed back to the control unit (a high-performance industrial PC or a motion controller can be used). The air cylinder 52 adopts an electrically controlled air cylinder with a servo proportional valve, which can accurately control the motion speed, position and output force of the air cylinder. The second voice coil motor 51 is equipped with a high-performance driver.

[0058] Referring to FIG. 2, Figure 13 In the coarse adjustment stage, the control unit sets the target position as T, the first set threshold as T1, reads the actual position T2 fed back by the grating ruler, and calculates the error E=T-T2. If E>T1, the control unit sends a command to the servo proportional valve of the air cylinder 52 to drive the air cylinder 52 to quickly push the carrier table 7 to move the slider 4 to the target position. At this time, the control unit can send a very small constant current command to the second voice coil motor 51 to make its output force overcome the static friction force and follow the movement of the slider. In addition, it is necessary to ensure that E is positive after the coarse adjustment stage (i.e., the actual position T2 is below the target position T after the coarse adjustment stage).

[0059] In the fine adjustment stage, the control unit mainly calculates the voice coil motor driving command. The control unit sets a constant air pressure command to the servo proportional valve to make the air cylinder 52 output a stable supporting force (supporting most of the weight of the carrier table 7), closes the air paths on both sides of the air cylinder 52, and locks the piston position by using the air pressure inside the air cylinder 52 (if the air cylinder design allows). Based on the small error E, the control unit uses a high-gain PID controller or other precise positioning algorithm to calculate the force command F1 of the second voice coil motor 51. The F1 command is sent to the driver of the second voice coil motor 51 to drive it to accurately move the slider 4 to the position T. The high response characteristic of the second voice coil motor 51 enables it to quickly eliminate small errors and suppress residual vibrations. The position feedback is continuously read, and the coarse adjustment and fine adjustment stages are repeated until the error E is stabilized within the allowed accuracy range.

[0060] The scheme combines the fast large-stroke movement capability of the cylinder 52 and the ultra-high precision positioning capability of the voice coil motor. The coarse adjustment stage quickly approaches the target, and the fine adjustment stage uses the voice coil motor to achieve micron-level positioning accuracy and suppress vibration, significantly improving the overall speed, accuracy and smoothness of the lifting motion. At the same time, the voice coil motor working time is reduced in the coarse adjustment stage, reducing energy consumption and heat generation.

[0061] Embodiment 3:

[0062] Referring to the accompanying Figure 14 The embodiment describes the superposition of active damping control on Embodiment 2 in detail.

[0063] A high-bandwidth acceleration sensor is installed on the bearing table 7 to measure the vertical direction (Z-axis) vibration acceleration a1 in real time and feed back to the control unit. The control unit reads the acceleration signal a. Filtering (such as low-pass filtering to remove high-frequency noise) can be performed first. The goal of the control unit is to generate a force F2 that makes the acceleration a2 generated by F2 equal in size and opposite in direction (phase difference of 180 degrees) to a1, thereby canceling the vibration. A simple and effective calculation method is:

[0064] ,

[0065] ,

[0066] where Kp, Ki, Kd are the proportional, integral, and derivative gain coefficients of the PID controller, which need to be set according to the system model or on-site debugging. v1 is the instantaneous velocity of vibration obtained by integrating the acceleration. U is the control signal command, which outputs the calculated U command to the driver of the second voice coil motor 51. The millisecond-level response speed of the second voice coil motor 51 enables it to generate accurate force F2 in real time, and F2 is the required active damping force.

[0067] In the coarse adjustment stage, the active damping force F2 is generated by the second voice coil motor 51. This helps to suppress the vibration caused by the fast start-stop or external impact of the cylinder 52.

[0068] In the fine adjustment stage, the active damping force F2 is superimposed on the fine positioning force command F1 of the second voice coil motor 51. That is, the final force command of the voice coil motor is F3 = F1 + F2. This enables the voice coil motor to position accurately while real-time canceling the vibration caused by the movement on the platform.

[0069] The active damping control based on acceleration feedback is introduced, which significantly improves the stability of the platform during the lifting motion (especially at the start-stop moment) and after reaching the target position. It effectively suppresses the platform jitter caused by factors such as the characteristics of the actuator itself (e.g. cylinder 52 crawling, second voice coil motor 51 thrust fluctuation), load changes, ground vibrations, etc., providing an extremely stable foundation environment for high-precision rotation, measurement or operation. Voice coil motor as an actuator is an ideal choice to achieve such high-speed and accurate damping.

[0070] The above-described embodiments and / or implementations are merely used to illustrate the preferred embodiments and / or implementations of the present application, and do not limit the embodiments of the present application in any form. Any person skilled in the art can make some changes without departing from the scope of the technical means disclosed in the present application, and such changes should be considered as the same technical or embodiments as the present application.

[0071] The principles and implementations of the present application are described herein using specific examples. The above examples are only used to help understand the method and core idea of the present application. The above description is only the preferred embodiments of the present application. It should be pointed out that due to the limitation of language expression, there are infinite specific structures. For ordinary skilled persons in the art, some improvements, refinements or changes can be made without departing from the principles of the present application. The above technical features can also be combined in an appropriate manner. These improvements, refinements, changes or combinations, or the direct application of the inventive concept and technical solution to other occasions without improvement, should be considered as the protection scope of the present application.

Claims

1. An air floating lift and rotation platform comprising a continuous rotation lift mechanism, characterized in that, The application relates to a gas-floating lifting and rotating platform comprising a rotating mechanism (1) and a lifting mechanism (2), wherein the lifting mechanism (2) comprises a first voice coil motor (21) and a linear guide rail (22), the rotating mechanism (1) comprises a gas-floating shaft (11) and a rotating platform (12), the rotating mechanism (1) is provided with a rotating motor (6) on the periphery of the gas-floating shaft (11), a first voice coil motor (21) is arranged at the bottom of the gas-floating shaft (11), the gas-floating shaft (11) is arranged on the linear guide rail (22) through a gas-floating bearing (3), the gas-floating bearing (3) is divided into a bearing inner ring (3a) and a bearing outer ring (3b), the first voice coil motor (21) drives the gas-floating shaft (11) and the gas-floating bearing (3) to vertically move on the linear guide rail (22), when the gas-floating bearing (3) is aerated, the rotating motor (6) drives the gas-floating shaft (11) and the bearing inner ring (3a) to rotate around the axis of the gas-floating shaft (11), the first voice coil motor (21) is arranged in a sliding block (4), the sliding block (4) is slidably connected with a guide block (5), a plurality of second voice coil motors (51) are arranged at the bottom of the guide block (5), the second voice coil motors (51) are used for driving the sliding block (4) to vertically move, a gas cylinder (52) is arranged at the side of the guide block (5), and the gas cylinder (52) drives a rod to be connected with the bottom of a bearing table (7). The application further comprises a control unit, a position sensor and an acceleration sensor. The control unit is configured to execute a lifting motion control method, comprising: calculating a position error based on a target position and an actual position fed back by the position sensor; when the position error is greater than a first set threshold, mainly driving the gas cylinder (52) to move, so that the sliding block (4) quickly approaches the target position; when the position error is less than or equal to the first set threshold, mainly driving the second voice coil motor (51) to move, while controlling the gas cylinder (52) to keep a constant supporting force or lock a position, so that the sliding block (4) is accurately positioned to the target position; in the stage of mainly driving the second voice coil motor (51), the control unit calculates and outputs a control instruction to the second voice coil motor (51) according to the position error in real time, so as to realize high-precision positioning or vibration suppression of the sliding block (4).

2. The air floating lifting and rotating platform with the continuous rotating lifting mechanism according to claim 1, characterized in that, The acceleration sensor and the position sensor are arranged on the bearing table (7).

3. The gas-floating lifting and rotating platform with a continuously rotating lifting mechanism according to claim 1, wherein the control unit is further configured to: receive a vibration signal from the acceleration sensor, the acceleration sensor being arranged on the sliding block (4) or the bearing table (7); calculate a suppression force instruction for offsetting the vibration in real time based on the vibration signal; output the suppression force instruction to the second voice coil motor (51), so that the second voice coil motor (51) generates an active damping force opposite to the detected vibration in phase; wherein the active damping force is calculated based on a PID control algorithm. ​ 4. The air floating lifting and rotating platform with the continuous rotating lifting mechanism according to claim 1, characterized in that, The slider (4) is provided with a through hole (41) in the center, a lifting mechanism base (43) is installed in the through hole (41), the lifting mechanism base (43) is provided with a plum blossom hole (43a) in the center, and the first voice coil motor (21) is installed in the plum blossom hole (43a).

5. The air floating lifting and rotating platform with the continuous rotating lifting mechanism according to claim 4, characterized in that, The lifting mechanism base (43) is internally provided with a brim (43b), and the rotating motor (6) is installed on the brim (43b).

6. The air floating lifting and rotating platform with the continuous rotating lifting mechanism according to claim 1, characterized in that, The outer periphery of the top of the air floating shaft (11) is provided with a plurality of protruding portions (11a), the rotating platform (12) is internally provided with a matching groove (12a) matched with the protruding portions (11a), and the protruding portions (11a) and the matching groove (12a) are matched with each other, so that the air floating shaft (11) can drive the rotating platform (12) to rotate.

7. The air floating lifting and rotating platform with the continuous rotating lifting mechanism according to claim 1, characterized in that, The air floating shaft (11) is provided with an extending rod (11b) at the top, which is used for being inserted into the insertion hole of the wafer chuck.

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