High-precision leveling apparatus, leveling platform, and leveling method

Abstract

A high-precision leveling apparatus, comprising a leveling base plate (3), a driving assembly (8), and a transmission assembly (9). The driving assembly (8) is connected to the leveling base plate (3) by means of the transmission assembly (9), and adjusts the height of the leveling base plate (3). The driving assembly (8) comprises a rigid base (8-2), and a ball screw (8-5) arranged on the rigid base (8-2) along a first direction, wherein the ball screw (8-5) is movably provided with a rigid support piece (8-4), and on the basis of the ball screw (8-5) and the rigid support piece (8-4), the rotation stroke of the ball screw (8-5) is converted into displacement of the height of a support surface of the rigid support piece (8-4), thereby ensuring the accuracy of the rotation process of the ball screw (8-5). A return gap between the rigid support piece (8-4) and the ball screw (8-5) is eliminated by means of stretch assemblies (8-7), thereby ensuring the support stability after the rigid support piece (8-4) is in place, and ensuring the accuracy and controllability of the displacement of the rigid support piece (8-4). A plurality of displacement detection apparatuses (8-1, 8-8, 8-9) are used to accurately monitor the displacement of the rigid support piece (8-4). A mechanical transmission-type active leveling solution is used to ensure the stability and reliability after leveling, and various measures are also used to eliminate errors in the mechanical transmission process, thereby ensuring the adjustment accuracy of the leveling apparatus. Also disclosed are a high-precision leveling platform, and a leveling method.

Description

High-precision leveling device, leveling platform and leveling method TECHNICAL FIELD

[0001] The present application relates to the technical field of lithography machine equipment, and particularly relates to a high-precision leveling device, a leveling platform and a leveling method. BACKGROUND

[0002] High-precision leveling technology plays an important role in many fields, and high-precision leveling mechanisms are widely used in various fields. For example, in optical equipment, the imaging quality of a microscope is directly affected by its leveling precision; in the semiconductor manufacturing process, key processes such as lithography and etching have very high requirements for the leveling precision of the equipment. In the precision assembly process of the electronic and automobile industries, high-precision leveling technology can ensure the accurate assembly of parts, reduce assembly errors and improve the overall performance of products; in the field of aerospace, the attitude control of aircraft also has very high requirements for leveling precision.

[0003] Meanwhile, leveling technology can be divided into passive leveling and active leveling. Passive leveling has the disadvantages of slow response speed, low leveling precision and high delay, while active leveling can achieve fast and high-precision leveling.

[0004] Among them, most active leveling mechanisms often use voice coil motors for driving, which directly drive through a driver without intermediate transmission links such as gears and belts, thereby reducing energy loss and mechanical friction and improving the overall efficiency of the system. The voice coil motor has the characteristics of high precision (its precision can reach microns or even nanometers), high response speed, high acceleration, smooth motion, high reliability and easy control. Therefore, active leveling mechanisms using voice coil motors are widely used in the field of high-precision leveling technology, such as the leveling process of silicon wafers in the lithography technology field.

[0005] However, the voice coil motor also has poor leveling result stability and is prone to drift, which leads to poor final leveling results. In order to achieve high-precision leveling of the voice coil motor, a very complex control system is required to adjust and control the voice coil motor at a high frequency, resulting in a very high control cost of the voice coil motor in the field of high-precision leveling. SUMMARY

[0006] The application aims to solve the problem of how to reduce the control difficulty and operation cost of the active leveling mechanism in the case of high-precision leveling function of the leveling device in the prior art. Therefore, the application provides a high-precision leveling device, which converts the rotating stroke of a ball screw into displacement on the supporting surface height of a rigid support based on the ball screw and the rigid support, ensures the accuracy of the rotating process of the ball screw through the couplings at both ends of the ball screw, eliminates the return gap between the rigid support and the ball screw through a stretching assembly, ensures the accuracy and controllability of the displacement of the rigid support, and can ensure the supporting stability of the rigid support after reaching the position; further, multiple displacement detection devices are used to realize accurate monitoring of the displacement of the rigid support; thus, the stability and reliability after leveling are ensured by using the mechanical transmission type active leveling scheme, and the leveling accuracy of the leveling device is ensured by eliminating the errors in the mechanical transmission process through multiple measures.

[0007] The application embodiment provides a high-precision leveling device, which comprises:

[0008] a leveling base plate, a transmission assembly and a driving assembly; the driving assembly is connected with the leveling base plate through the transmission assembly and adjusts the height of the leveling base plate;

[0009] the driving assembly comprises a rigid base and a ball screw arranged on the rigid base in a first direction;

[0010] one end of the ball screw is connected with a driving part through a coupling, and the other end is provided with a first displacement detection unit through a coupling;

[0011] the ball screw is movably provided with a rigid support, the rigid support comprises a driving part matched with the ball screw, and a supporting surface away from the driving part;

[0012] one end of the rigid support is provided with a stretching assembly, and the stretching assembly is used to apply a pre-tightening force in the first direction to the rigid support;

[0013] the driving part drives the ball screw to rotate to drive the rigid support to displace in the first direction, and the supporting height of the supporting surface of the rigid support in the first direction is continuously changed;

[0014] second and third displacement detection units are arranged on both sides of the ball screw respectively;

[0015] the first displacement detection unit detects the displacement of the rigid support in the first direction according to the rotation of the ball screw;

[0016] the second displacement detection unit is used to detect the limiting position of the rigid support in the first direction on the ball screw.

[0017] The third displacement detection unit is configured to detect a zero-to-position state of the rigid support.

[0018] According to the above technical scheme, the transmission connection between the ball screw and the rigid support can convert the rotation process of the ball screw into the displacement of the rigid support in the first direction, and the height of the support surface in the first direction can be changed, so that the support height in the same vertical direction can be changed by the displacement of the rigid support in the first direction. By setting the transmission ratio, the preliminary precision displacement adjustment can be realized, and the stretching assembly is arranged to apply the pre-tightening force of the rigid support in the first direction, so that the continuous fit between the ball screw and the rigid support is maintained, the return gap in the transmission process is eliminated, and the adjustment accuracy of the leveling device is further improved.

[0019] Furthermore, the first displacement detection unit is configured to detect the displacement of the rigid support in the first direction, the second displacement detection unit is configured to detect the limit position of the rigid support on the ball screw in the first direction, and the third displacement detection unit is configured to detect the zero-to-position state of the rigid support. Therefore, the full-process displacement detection and multiple corrections of the rigid support are realized, the accuracy of the displacement detection of the rigid support is ensured, and the high controllability and high precision of the adjustment process of the leveling device are improved.

[0020] In some embodiments, the transmission assembly abuts against the support surface, and the transmission assembly is fixedly arranged in the horizontal direction relative to the base and movably arranged in the height direction;

[0021] The transmission assembly comprises a connecting piece and an abutting wheel rotatably arranged on the connecting piece, and the transmission assembly is connected with the support surface through the abutting wheel;

[0022] The side of the connecting piece away from the abutting wheel is provided with a leaf spring, and the transmission assembly is fixedly arranged on the leveling base through the connecting piece and the leaf spring.

[0023] In some embodiments, the driving assembly further comprises a frame assembly arranged around the base;

[0024] The frame assembly comprises a bottom frame, an upper frame, and a side frame connecting the bottom frame and the upper frame;

[0025] The base is fixedly connected with the bottom frame and connected with an external object through the bottom frame;

[0026] The upper frame is located above the support surface and is provided with a through space corresponding to the abutting wheel;

[0027] A limiting structure is arranged between the upper frame and the connecting member of the transmission assembly, and the transmission assembly is limited from moving in the horizontal direction relative to the base through the limiting structure.

[0028] In some embodiments, the second displacement detection unit is arranged as two proximity switches arranged at intervals in the first direction.

[0029] The third displacement detection unit is arranged as an optical position sensor.

[0030] The rigid support is arranged as a wedge structure, and the inclined surface of the wedge structure is arranged as the support surface.

[0031] In some embodiments, the leveling device further comprises:

[0032] A leveling assembly, comprising a light source, a first light path module, a second light path module, and a sensing device;

[0033] The leveling base is provided with a light path reflection area, the detection light emitted by the light source is gathered to the light path reflection area through the first light path module, the second light path module receives the reflected light of the light path reflection area and focuses to the sensing device;

[0034] The sensing device determines the attitude of the leveling base according to the change of the detected reflected light.

[0035] In some embodiments, the first light path module comprises a first incident lens, an emission end mirror and a second incident lens arranged in sequence along the light path direction; wherein the first incident lens and the second incident lens are both convex lenses.

[0036] The second light path module comprises a second reflection lens, a receiving end mirror and a first reflection lens arranged in sequence along the light path direction; wherein the first reflection lens and the second reflection lens are both convex lenses.

[0037] In some embodiments, a control unit is further included, which is connected with the first displacement detection unit, the second displacement detection unit, the third displacement detection unit, the sensing device and the driving member.

[0038] The control process of the control unit comprises:

[0039] According to the signals of the first displacement detection unit, the second displacement detection unit and the third displacement detection unit, the driving member drives the rigid support to the zero position state.

[0040] The inductive device is used to determine whether the posture of the leveling base plate meets the leveling precision requirement, and if not, the driving member is controlled to perform leveling compensation until the posture of the leveling base plate meets the leveling precision requirement.

[0041] The application further provides a high-precision leveling platform, comprising at least three leveling devices as described in the above embodiments.

[0042] The at least three leveling devices are symmetrically distributed and have a symmetric center, and share the same leveling base plate and detection assembly.

[0043] In some embodiments, the leveling platform further comprises a horizontal movement platform and a control unit, the at least three leveling devices are installed on the horizontal movement platform, and the control unit is connected to the at least three leveling devices simultaneously.

[0044] The leveling base plate is provided with a suction disc corresponding to the symmetric center of the at least three leveling devices, and the suction disc is attached to a base.

[0045] The light path reflection area is arranged on the base.

[0046] The application further provides a leveling method, comprising a leveling platform as described in the above embodiments, and the specific steps comprise:

[0047] S1, loading the base in the control unit;

[0048] S2, controlling the horizontal movement platform to move, and moving the light path reflection area to an area that can be detected by the detection assembly;

[0049] S3, performing leveling measurement to obtain the inclination of the leveling device relative to the symmetric center;

[0050] S4, determining whether the posture of the leveling base plate meets the leveling precision requirement according to the inductive device, and if the posture of the leveling base plate meets the leveling precision requirement, maintaining the state of the leveling device;

[0051] S5, if not, controlling each leveling device to perform leveling compensation; and repeating steps S3-S5 until the posture of the leveling base plate meets the leveling precision requirement.

[0052] Other features and corresponding beneficial effects of the application are described in the latter part of the specification, and it should be understood that at least part of the beneficial effects are apparent from the description in the specification. BRIEF DESCRIPTION OF DRAWINGS

[0053] FIG. 1 is a structural schematic view of a leveling device provided by the application;

[0054] Fig. 2 is a structure top view of a driving assembly of a leveling device according to an embodiment of the present application;

[0055] Fig. 3 is a structure side view of a driving assembly of a leveling device according to an embodiment of the present application;

[0056] Fig. 4 is a structure diagram of a side frame and an upper frame in a frame assembly of a leveling device according to an embodiment of the present application;

[0057] Fig. 5 is a structure diagram of a transmission assembly of a leveling device cooperating with a support surface according to an embodiment of the present application;

[0058] Fig. 6 is a structure diagram of a leveling platform according to an embodiment of the present application;

[0059] Fig. 7 is a structure top view of a leveling platform according to an embodiment of the present application;

[0060] Fig. 8 is a structure diagram of a leaf spring of a transmission assembly of a leveling device according to an embodiment of the present application;

[0061] Fig. 9 is a flow diagram of specific steps of a leveling method according to an embodiment of the present application;

[0062] Fig. 10 is a simple diagram of a leveling principle of a leveling method according to an embodiment of the present application.

[0063] Legend: 1, horizontal movement platform; 3, leveling base plate; 4, light source; 5, sensing device; 13, first incident lens; 14, transmitting end mirror; 15, second incident lens; 16, first reflecting lens; 17, receiving end mirror; 18, second reflecting lens; 7, control unit; 8, driving control assembly; 8-1, first displacement detection unit; 8-2, base; 8-3, coupling; 8-4, mounting plate; 8-5, ball screw; 8-6, driving member; 8-7, stretching assembly; 8-8, second displacement detection unit; 8-9, third displacement detection unit; 8-10, wedge member; 8-11, first side frame; 8-12, second side frame; 8-13, upper frame; 8-14, bottom frame; 9, transmission assembly; 9-1, leaf spring; 9-2, first fixed hole; 9-3, avoiding hole; 9-4, through hole; 9-5, second fixed hole; 9-6, third fixed hole; 9-9, connecting member; 10, suction cup; 11, base. DETAILED DESCRIPTION

[0064] The following will describe the embodiments of the present application by specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the content disclosed in the specification. Although the description of the present application will be introduced in combination with the preferred embodiments, it does not mean that the features of the present application are limited to the embodiments. On the contrary, the purpose of introducing the present application in combination with the embodiments is to cover other alternatives or modifications which can be extended based on the claims of the present application. In order to provide a deep understanding of the present application, many specific details will be included in the following description. The present application can also be implemented without using these details. In addition, in order to avoid confusion or obscure the present application, some specific details will be omitted in the description. It should be noted that the embodiments and features in the embodiments of the present application can be combined with each other without conflict.

[0065] It should be noted that in the specification, similar reference numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0066] The technical solutions of the present application will be described in detail below in combination with the drawings. Obviously, the described embodiments are part of the embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0067] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined with "first", "second", etc. can explicitly or implicitly include one or more features. In the description of the present application, unless otherwise stated, the meaning of "a plurality of" is two or more.

[0068] In the description of the present application, it should be noted that unless specifically defined and limited otherwise, the terms "mounting", "connected", "connection" should be understood broadly, for example, can be fixed connection, can also be detachable connection, or integrally connected; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through an intermediate medium, can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0069] In order to make the purpose, technical scheme and advantages of the present application clearer, the embodiments of the present application will be further described in detail below with reference to the drawings.

[0070] Please refer to FIG. 1-10, FIG. 1 is a structure schematic diagram of a leveling device provided by the embodiment of the present application, FIG. 2 is a structure top view of a driving assembly of a leveling device provided by the embodiment of the present application, FIG. 3 is a structure side view of a driving assembly of a leveling device provided by the embodiment of the present application, FIG. 4 is a structure schematic diagram of a side frame and an upper frame in a frame assembly of a leveling device provided by the embodiment of the present application, FIG. 5 is a structure schematic diagram of a transmission assembly of a leveling device cooperating with a support surface provided by the embodiment of the present application, FIG. 6 is a structure schematic diagram of a leveling platform provided by the embodiment of the present application, FIG. 7 is a structure top view of a leveling platform provided by the embodiment of the present application, FIG. 8 is a structure schematic diagram of a leaf spring of a transmission assembly of a leveling device provided by the embodiment of the present application, FIG. 9 is a flow schematic diagram of specific steps of a leveling method provided by the embodiment of the present application, and FIG. 10 is a simple schematic diagram of a leveling principle of a leveling method provided by the embodiment of the present application.

[0071] As shown in FIG. 1-10, the embodiment of the present application provides a high-precision leveling device, which comprises:

[0072] The leveling base plate 3, the transmission assembly 9 and the driving assembly 8; the driving assembly 8 is connected with the leveling base plate 3 through the transmission assembly 9, and adjusts the height of the leveling base plate 3;

[0073] The driving assembly 8 comprises a rigid base 8-2 and a ball screw 8-5 arranged along a first direction on the rigid base 8-2;

[0074] One end of the ball screw 8-5 is connected with a driving part 8-6 through a shaft coupling 8-3, and the other end is provided with a first displacement detection unit 8-1 through a shaft coupling 8-3;

[0075] The ball screw 8-5 movably arranged has a rigid support part, which comprises a driving part matched with the ball screw 8-5, and a support surface away from the driving part;

[0076] One end of the rigid support is provided with a tension assembly 8-7 for applying a pre-tightening force to the rigid support in the first direction;

[0077] The driving member 8-6 drives the rigid support to displace in the first direction by rotating the ball screw 8-5, and the support surface of the rigid support has a continuous change in the support height in the first direction;

[0078] The ball screw 8-5 is provided with a second displacement detection unit 8-8 and a third displacement detection unit 8-9 on both sides thereof;

[0079] The first displacement detection unit 8-1 detects the displacement of the rigid support in the first direction according to the rotation of the ball screw 8-5;

[0080] The second displacement detection unit 8-8 is used for detecting the limit position of the rigid support in the first direction on the ball screw 8-5;

[0081] The third displacement detection unit 8-9 is used for the zero-to-position state of the rigid support.

[0082] The ball screw 8-5 mainly converts the rotary motion into linear motion, has very small frictional resistance, is not easy to wear, and has extremely high reliability and adjustment accuracy.

[0083] In one embodiment, the ball screw 8-5 mainly consists of a screw rod, a nut, a ball, a pre-pressing piece, a reverser, a dustproof device and the like. Among them, the ball rolls between the screw rod and the nut, and the sliding friction is converted into rolling friction, thereby greatly reducing the friction and improving the transmission efficiency.

[0084] In one embodiment, the ball screw 8-5 has extremely high adjustment accuracy, and can achieve micron-level or nanometer-level positioning accuracy.

[0085] It should be noted that in the extremely high precision adjustment requirement, the reliability and high precision requirement of each link of the leveling device need to be ensured. Among them, the main part lies in the accuracy of displacement adjustment and the accurate monitoring of the displacement process.

[0086] Therefore, by adopting the above technical scheme, the transmission connection between the ball screw 8-5 and the rigid support can convert the rotation process of the ball screw 8-5 into the displacement of the rigid support in the first direction, and due to the change in the height of the support surface in the first direction, the support height in the same vertical direction can be changed by the displacement of the rigid support in the first direction. By setting the transmission ratio, the preliminary precision displacement adjustment can be realized.

[0087] Meanwhile, it needs to be explained that due to the matching machining error between the ball screw 8-5 and the rigid support, when the ball screw 8-5 drives the rigid support to move to a certain position, a slight return displacement will be generated, which will cause the displacement accuracy to decrease. Therefore, the embodiment of the present application is provided with a stretching assembly 8-7 for applying a pre-tightening force along the first direction to the rigid support, so as to ensure that the ball screw 8-5 and the rigid support are continuously attached to each other, eliminate the return gap in the transmission process, and further improve the adjustment accuracy of the leveling device.

[0088] Further, the driving part 8-6 of the ball screw 8-5 is located at one end of the ball screw 8-5, and it is difficult to ensure the stability of the rotation process of the ball screw 8-5 away from the end of the driving part 8-6. Therefore, the two ends of the ball screw 8-5 are arranged on the base 8-2 through the shaft coupling 8-3, so as to ensure the stability of the rotation process of the ball screw 8-5.

[0089] Moreover, the displacement of the rigid support in the first direction is detected by the first displacement detection unit 8-1, the limiting position of the rigid support on the ball screw 8-5 in the first direction is detected by the second displacement detection unit 8-8, and the zero-to-position state of the rigid support is detected by the third displacement detection unit 8-9. Therefore, the full-process displacement detection and multiple corrections of the rigid support are realized, the accuracy of the displacement detection of the rigid support is ensured, and the high controllability and high accuracy of the adjustment process of the leveling device are improved.

[0090] In one embodiment, the transmission assembly 9 abuts against the support surface, and the transmission assembly 9 is fixedly arranged in the horizontal direction and movably arranged in the height direction relative to the base 8-2.

[0091] The transmission assembly 9 comprises a connecting part and an abutting wheel rotatably arranged on the connecting part, and the transmission assembly 9 is connected with the support surface through the abutting wheel.

[0092] The side of the connecting part away from the abutting wheel is provided with a leaf spring, and the transmission assembly 9 is fixedly arranged on the leveling base plate 3 through the connecting part and the leaf spring.

[0093] By adopting the above technical solution, the consistency of the transmission assembly 9 and the leveling base plate 3 can be greatly ensured, and the transmission assembly 9 can be synchronized with the leveling base plate 3.

[0094] It needs to be noted that since the support surface has a height change in the first direction, when the support surface supports the transmission assembly 9, a horizontal component force is easily formed, which will affect the stability and reliability of the movement of the transmission assembly 9 in the vertical direction.

[0095] Therefore, in one embodiment, the driving assembly 8 further comprises a frame assembly arranged around the base 8-2.

[0096] The frame assembly comprises a bottom layer frame 8-14, an upper layer frame 8-13, and side frames connecting the bottom layer frame 8-14 and the upper layer frame 8-13; wherein the side frames comprise a first side frame 8-11 and a second side frame 8-12 arranged oppositely;

[0097] The base 8-2 is fixedly connected with the bottom layer frame 8-14 and connected with external objects through the bottom layer frame 8-14;

[0098] The upper layer frame 8-13 is located above the support surface and is provided with a through space corresponding to the abutting wheel;

[0099] A limiting structure is arranged between the upper layer frame 8-13 and the connecting piece of the transmission assembly 9, and the limiting structure limits the movement of the transmission assembly 9 relative to the base 8-2 in the horizontal direction.

[0100] The limiting structure limits the movement of the transmission assembly 9 relative to the base 8-2 in the horizontal direction, which can ensure the stability and reliability of the movement of the transmission assembly 9 in the vertical direction, and can balance the horizontal component force caused by the support force of the support surface.

[0101] Further, it needs to be explained that the leveling base plate 3 itself has high levelness, but due to the extremely high precision requirement of the photolithography technology, even a slight change in levelness can easily affect the entire photolithography effect. Therefore, the leveling height range of the leveling device is not large.

[0102] At the same time, during the leveling process of the transmission assembly 9, the precise displacement of the leveling base plate 3 in height is transmitted to the connecting piece 9-9 through the abutting wheel, and then the connecting piece 9-9 drives the leveling base plate 3 to form a precise displacement in height; therefore, the roundness of the abutting wheel easily affects the continuity of the change in the height range of the leveling base plate 3. Thus, the abutting wheel cannot bear too much pressure, and the leveling base plate 3 needs to bear the substrate 11 and maintain a very high levelness, so its stiffness is very high; therefore, if the leveling base plate 3 directly acts on the connecting piece 9-9 and the abutting wheel, it is easy to cause excessive load on the abutting wheel.

[0103] Therefore, in the embodiment of the present application, the connecting piece 9-9 is further connected with a leaf spring 9-1, when the leveling base plate 3 causes excessive pressure on the connecting piece 9-9, the connecting piece 9-9 will deform itself, and the deformation will be transmitted to the leaf spring 9-1, which plays a role in absorbing deformation and buffering, avoiding the abutting wheel from being permanently deformed due to excessive pressure.

[0104] In one embodiment, the leaf spring 9-1 comprises a first fixed hole 9-2, an avoidance hole 9-3, a through hole 9-4, a second fixed hole 9-5, and a third fixed hole 9-6;

[0105] The leaf spring 9-1 is connected with the connecting piece 9-9 through the first fixing hole 9-2; the avoiding hole 9-3 corresponds to the connecting position of the connecting piece 9-9 and the leveling base plate 3, and is used for avoiding the fastener (for example, a nut) at the connecting position.

[0106] The leaf spring 9-1 is connected with the leveling base plate 3 through the second fixing hole 9-5 and the third fixing hole 9-6. The through hole 9-4 is used for facilitating the operation of the fixing screw below the leaf spring 9-1.

[0107] In an embodiment, the limiting structure is provided with a positioning hole arranged on the upper frame 8-13 and a positioning pin arranged on the connecting piece of the transmission assembly 9; the positioning hole is arranged in the vertical direction and is in sliding fit with the positioning pin, and is used for limiting the movement of the positioning pin in the horizontal direction.

[0108] In an embodiment, the second displacement detection unit 8-8 is provided as two proximity switches arranged at intervals in the first direction; it should be noted that the limiting position of the rigid support does not require high precision, but needs to ensure the reliability and safety of detection, therefore, the proximity switch can quickly judge whether the displacement of the rigid support exceeds the limiting position, and can easily ensure the high reliability and stability of the component, and reduce the detection cost; on the other hand, the proximity switch can directly respond to the displacement of the rigid support, improve the response speed of the response, and improve the safety and reliability of the leveling device.

[0109] The third displacement detection unit 8-9 is provided as an optical position sensor; so as to ensure the high precision of the zero-to-position state detection of the rigid support.

[0110] The rigid support is provided as a wedge-shaped structure, and the inclined surface of the wedge-shaped structure is provided as a support surface.

[0111] In an embodiment, the rigid support includes a mounting plate 8-4 fixed to the ball screw 8-5 and a wedge-shaped piece 8-10 mounted to the mounting plate 8-4. Separately manufacturing the wedge-shaped piece 8-10 can make the rigidity and hardness of the wedge-shaped piece 8-10 greater than the rigidity and hardness of the mounting plate 8-4, and reduce the manufacturing cost of the rigid support.

[0112] In an embodiment, the leveling device further includes:

[0113] The leveling assembly includes a light source 4, a first light path module, a second light path module and a sensing device 5;

[0114] The leveling base plate 3 is provided with a light path reflection area, the detection light emitted by the light source 4 is gathered to the light path reflection area through the first light path module, the second light path module receives the reflected light of the light path reflection area, and focuses to the sensing device 5;

[0115] The inductive device 5 determines the attitude of the leveling base plate 3 according to the change of the detected reflected light.

[0116] By using the above technical scheme, whether the attitude of the leveling base plate 3 meets the leveling requirement can be directly obtained by the inductive device 5, thereby facilitating the control of the leveling device to adjust.

[0117] In an embodiment, the first light path module comprises a first incident lens 13, an emission end mirror 14 and a second incident lens 15 arranged in sequence along the light path direction; wherein the first incident lens 13 and the second incident lens 15 are both convex lenses.

[0118] The second light path module comprises a second reflection lens 18, a receiving end mirror 17 and a first reflection lens 16 arranged in sequence along the light path direction; wherein the first reflection lens 16 and the second reflection lens 18 are both convex lenses.

[0119] In an embodiment, the control unit 7 is further connected with the first displacement detection unit 8-1, the second displacement detection unit 8-8, the third displacement detection unit 8-9, the inductive device 5 and the driving member 8-6.

[0120] The control process of the control unit 7 comprises:

[0121] According to the signals of the first displacement detection unit 8-1, the second displacement detection unit 8-8 and the third displacement detection unit 8-9, the driving member 8-6 drives the rigid support member to the zero position to the position state.

[0122] According to the inductive device 5, it is judged whether the attitude of the leveling base plate 3 meets the leveling precision requirement, and if not, the driving member 8-6 is controlled to perform leveling compensation until the attitude of the leveling base plate 3 meets the leveling precision requirement.

[0123] It should be noted that the position change of a single leveling device depends on mechanical transmission, and therefore, the position adjustment precision of a single leveling device is easily affected by the machining error, thereby making it difficult to ensure the continuous change of the single leveling device in the displacement change process with ultra-high precision. For example, when the adjustment precision of a single leveling device is 1 μm, the single leveling device can stay at +1 μm, +2 μm, +3 μm and +4 μm; and when the leveling device has an error, it can actually only stay at +1 μm, +1.5 μm, +3 μm and +4 μm.

[0124] Therefore, the application further provides a high-precision leveling platform, comprising: at least three leveling devices as described in the above embodiments.

[0125] The at least three leveling devices are centrally symmetrically distributed and have a symmetric center, and share the same leveling base plate 3 and leveling assembly.

[0126] The leveling platform adopts at least three leveling devices, which can ensure that the at least three leveling devices can stably support the same leveling base plate 3, and when a single position leveling device cannot perform accurate leveling compensation due to errors, the remaining leveling devices can be adjusted synchronously, thereby further increasing the leveling precision of the leveling platform through comprehensive adjustment, so that the leveling precision of the leveling platform is further higher than the adjustment precision of a single leveling device.

[0127] In one embodiment, the leveling platform further comprises a horizontal motion platform 1 and a control unit 7, and the at least three leveling devices are installed on the horizontal motion platform 1; and the control unit 7 is connected to the at least three leveling devices simultaneously.

[0128] The leveling base plate 3 is provided with a suction cup 10 corresponding to the symmetry center of the at least three leveling devices, and the suction cup 10 is adsorbed with a base 11.

[0129] The light path reflection area is provided on the base 11.

[0130] In one embodiment, the at least three leveling devices are only three, so that the number of control components that need to be controlled can be reduced, and the control difficulty can be reduced, thereby reducing the control difficulty and control cost of the leveling platform under the premise of ensuring the adjustment precision.

[0131] In one use scenario, the leveling platform can be leveled according to the following leveling method, and the specific steps include:

[0132] S1, the horizontal motion platform 1 is controlled to move, and the light path reflection area is moved to an area that can be detected by the detection component;

[0133] S2, leveling measurement is performed to obtain the inclination of the leveling device relative to the symmetry center;

[0134] S3, whether the posture of the leveling base plate 3 meets the leveling precision requirement is judged according to the sensing device 5, and if the posture of the leveling base plate 3 meets the leveling precision requirement, the state of the leveling device is maintained;

[0135] S4, if not, each leveling device is controlled to perform leveling compensation; and steps S2-S3 are repeated until the posture of the leveling base plate 3 meets the leveling precision requirement.

[0136] As shown in FIG. 9,

[0137] In a leveling process, the three leveling devices are marked as ZT1, ZT2 and ZT3 respectively. The detection light emitted by the light source 4 of the leveling assembly passes through the first light path module and is gathered to the measurement point position of the light path reflection area. The center position shown in the figure is the light beam measurement point position of the leveling assembly. Through the measurement of the leveling assembly, the sensing device 5 determines the attitude of the leveling base plate 3 according to the change of the detected reflected light. If the leveling precision requirement is not met, the inclination direction and the inclination amount of the center of gravity position of the leveling base plate 3 can be determined according to the detection result of the reflected light. According to the inclination direction, the control unit 7 controls the corresponding leveling device to perform vertical adjustment.

[0138] In an embodiment, the attitude adjustment of the leveling base plate 3 is performed by the control variable method, that is, two points of the three leveling devices (ZT1, ZT2 and ZT3) are fixed, and only one of them is driven to adjust.

[0139] In a leveling scenario, if the leveling assembly needs to adjust and compensate ZT1 according to the judgment result. As shown in FIG. 10, it is the adjustment model of ZT1. The other two leveling devices (ZT2 and ZT3) are fixed, and the change amount of the center of gravity position is 1 / 3 of the driving amount of ZT1. For example, the change amount of the center of gravity position is +30um, and the driving amount of ZT1 is +90um.

[0140] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A high-precision leveling device, characterized by, The leveling base, the transmission assembly and the driving assembly; the driving assembly is connected with the leveling base through the transmission assembly and adjusts the height of the leveling base; The driving assembly includes a rigid base and a ball screw arranged on the rigid base in a first direction; One end of the ball screw is connected with a driving member through a shaft coupling, and the other end is provided with a first displacement detection unit through a shaft coupling; The ball screw is movably provided with a rigid support, and the rigid support includes a driving part matched with the ball screw and a support surface away from the driving part; One end of the rigid support is provided with a stretching assembly for applying a pre-tightening force in the first direction to the rigid support; The driving member drives the rigid support to displace in the first direction by driving the ball screw to rotate, and the support height of the support surface of the rigid support in the first direction continuously changes; Both sides of the ball screw are respectively provided with a second displacement detection unit and a third displacement detection unit; The first displacement detection unit detects the displacement of the rigid support in the first direction according to the rotation of the ball screw; The second displacement detection unit is used for detecting the limiting position of the rigid support on the ball screw in the first direction; The third displacement detection unit is used for detecting the zero-to-position state of the rigid support; The transmission assembly abuts against the support surface, and the transmission assembly is fixedly arranged relative to the base in the horizontal direction and movably arranged in the height direction; The transmission assembly includes a connecting piece and an abutting wheel rotatably arranged on the connecting piece; and the transmission assembly is connected with the support surface through the abutting wheel; One side of the connecting piece away from the abutting wheel is provided with a leaf spring, and the transmission assembly is fixedly arranged on the leveling base through the connecting piece and the leaf spring. The driving assembly further includes a frame assembly arranged around the base; 2. The high-precision leveling device according to claim 1, characterized in that The frame assembly includes a bottom frame, an upper frame and a side frame connecting the bottom frame and the upper frame; The base is fixedly connected with the bottom frame and connected with an external object through the bottom frame; The upper frame is located above the support surface and is provided with a through space corresponding to the abutting wheel; A limiting structure is arranged between the upper frame and the connecting piece of the transmission assembly, and the movement of the transmission assembly relative to the base in the horizontal direction is limited through the limiting structure. The second displacement detection unit is arranged as two proximity switches arranged at intervals in the first direction; 3. The high-precision leveling device according to claim 1, wherein The third displacement detection unit is arranged as an optical position sensor; The rigid support is arranged as a wedge-shaped structure, and the inclined surface of the wedge-shaped structure is arranged as the support surface. Further comprising:

4. The high-precision leveling device according to claim 1, characterized in that, The leveling assembly includes a light source, a first light path module, a second light path module and a sensing device; The leveling base is provided with a light path reflection area, the detection light emitted by the light source is gathered to the light path reflection area through the first light path module, the second light path module receives the reflected light of the light path reflection area and focuses to the sensing device; ​ The inductive device determines the attitude of the leveling substrate according to the change of the detected reflected light.

5. The high-precision leveling device according to claim 4, characterized in that, The first light path module comprises a first incident lens, an emission end mirror and a second incident lens arranged in sequence along the light path direction; wherein the first incident lens and the second incident lens are both convex lenses; The second light path module comprises a second reflection lens, a receiving end mirror and a first reflection lens arranged in sequence along the light path direction; wherein the first reflection lens and the second reflection lens are both convex lenses.

6. The high-precision leveling device according to claim 4, wherein Further comprising a control unit, the control unit is connected with the first displacement detection unit, the second displacement detection unit, the third displacement detection unit, the inductive device and the driving part; The control process of the control unit comprises: According to the signals of the first displacement detection unit, the second displacement detection unit and the third displacement detection unit, the driving part drives the rigid support to the zero position state; According to the inductive device, it is judged whether the attitude of the leveling substrate meets the leveling precision requirement, if not, the driving part is controlled to compensate for leveling, until the attitude of the leveling substrate meets the leveling precision requirement.

7. A high precision adjustment platform, characterized in that, Comprise: At least three leveling devices as claimed in claim 5 or 6; The at least three leveling devices are centrally symmetrically distributed and have a symmetric center, and share the same leveling substrate and leveling assembly.

8. The tuning platform of claim 7, wherein, Further comprising a horizontal motion platform and a control unit, the at least three leveling devices are installed on the horizontal motion platform; and the control unit is connected with the at least three leveling devices and the horizontal motion platform simultaneously; The leveling substrate is provided with a suction cup corresponding to the symmetric center of the at least three leveling devices, and the suction cup is adsorbed with a base; The light path reflection area is arranged on the base.

9. A method of levelling, characterised in that, The leveling platform comprises the leveling platform as claimed in claim 8, and the specific steps comprise: S1, control the horizontal motion platform to move, and move the light path reflection area to the area that can be detected by the leveling assembly; S2, perform leveling measurement to obtain the inclination of the leveling device relative to the symmetric center; S3, according to the inductive device, it is judged whether the attitude of the leveling substrate meets the leveling precision requirement, if the attitude of the leveling substrate meets the leveling precision requirement, the state of the leveling device is kept; S4, if not, control each leveling device to compensate for leveling; and repeat steps S2-S3 until the attitude of the leveling substrate meets the leveling precision requirement.

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