Three-degree-of-freedom motion platform

Abstract

The invention belongs to the technical field of semiconductors, and discloses a three-degree-of-freedom motion platform. The three-degree-of-freedom motion platform comprises a base, a first adjusting mechanism and a second adjusting mechanism, the first adjusting mechanism comprises two first driving pieces and a first frame, the two first driving pieces are arranged in a spaced mode and fixedly connected with the base, and the output ends of the two first driving pieces are connected with the first frame; the two first driving pieces can enable the first frame to move in the X direction and rotate around the Z axis; the second adjusting mechanism comprises a second driving part and a second frame, the second frame is arranged in the inner side space defined by the first frame and connected with the first frame through a flexible hinge, the second frame and the first frame can synchronously move in the X direction and rotate around the Z axis, and the output end of the second driving part is connected with the second frame. The second driving piece can make the second frame move in the Y direction. According to the platform, high-precision motion control is ensured, meanwhile, the overall height of the platform is effectively reduced, and the applicability in a space limited scene is improved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and particularly to a three-degree-of-freedom motion platform. Background Art

[0002] With the development of the manufacturing industry towards high precision and miniaturization, semiconductor detection technology has become the core driving force for promoting the upgrading of the semiconductor industry. During the semiconductor wafer detection process, the performance of the motion platform of the detection equipment directly affects the detection accuracy and efficiency. With its multi-dimensional precise motion control characteristics, a high-precision motion platform has become a key equipment for ensuring the quality of semiconductor products.

[0003] Currently, traditional three-degree-of-freedom motion platforms usually adopt a layered stacking setting of each degree-of-freedom adjustment mechanism. Although the basic motion functions can be achieved, the layered stacking of each adjustment mechanism significantly increases the overall height of the motion platform. In the field of semiconductor detection, especially in high-precision wafer detection equipment, due to the compact internal space of the equipment, it is difficult for traditional tall motion platforms to adapt to the limited internal space of the equipment, restricting the integrated and precise development of wafer detection equipment. Summary of the Invention

[0004] The purpose of the present invention is to provide a three-degree-of-freedom motion platform, which can solve the problem of the excessively high overall height caused by the layered setting of each degree-of-freedom adjustment mechanism of the traditional motion platform while ensuring the motion accuracy, so as to improve the adaptability of the motion platform in scenarios with limited height.

[0005] To achieve this purpose, the present invention adopts the following technical solutions:

[0006] A three-degree-of-freedom motion platform, comprising:

[0007] A base;

[0008] A first adjustment mechanism, including two first driving members and a first frame. The two first driving members are spaced apart and fixedly connected to the base. The output ends of the two first driving members are connected to the first frame. The two first driving members can make the first frame move along the X direction and rotate around the Z axis;

[0009] A second adjustment mechanism, including a second driving member and a second frame. The second frame is arranged in the inner space enclosed by the first frame and is flexibly hinged to the first frame. The second frame can move along the X direction and rotate around the Z axis synchronously with the first frame. The output end of the second driving member is connected to the second frame. The second driving member can make the second frame move along the Y direction;

[0010] A carrier stage, arranged in the inner space enclosed by the second frame and fixedly connected to the second frame.

[0011] As an alternative solution, the second driving member is fixedly connected to the base. The first frame is provided with a through hole, the depth direction of the through hole is along the Y direction, and the output end of the second driving member passes through the through hole and is connected to the side wall of the second frame.

[0012] As an alternative solution, the base is provided with a magnetic preloading member. The first adjusting mechanism further includes an air-floating guiding member, which is flexibly hinged to the first frame, and the air-floating guiding member is slidably arranged along the X direction on the magnetic preloading member.

[0013] As an alternative solution, a first air passage and a second air passage respectively communicating with an external air source are provided in the first frame. The air outlets of the first air passage and the second air passage are opened on the mounting surface of the first frame opposite to the base. The first air passage is used for transmitting positive-pressure air flow, and the second air passage is used for transmitting negative-pressure air flow.

[0014] As an alternative solution, the first adjusting mechanism further includes a first detection component, which is used for detecting the displacement of the first frame along the X direction and the rotation angle around the Z axis.

[0015] As an alternative solution, the first adjusting mechanism further includes an X-direction limiting component. The X-direction limiting component includes a first sensor and a first limiting member. The first sensor is used for detecting whether the first frame reaches the limit position of the X-direction stroke, and the first limiting member is used for restricting the over-travel movement of the first frame along the X direction.

[0016] As an alternative solution, the first adjusting mechanism further includes a Z-axis rotation limiting component. The Z-axis rotation limiting component includes a second sensor and a second limiting member. The second sensor is used for detecting whether the first frame reaches the limit position of the Z-axis rotation angle, and the second limiting member is used for restricting the over-angle movement of the first frame around the Z axis.

[0017] As an alternative solution, a third air passage and a fourth air passage respectively communicating with an external air source are provided in the second frame. The air outlets of the third air passage and the fourth air passage are opened on the mounting surface of the second frame opposite to the base. The third air passage is used for transmitting positive-pressure air flow, and the fourth air passage is used for transmitting negative-pressure air flow.

[0018] As an alternative solution, the second adjusting mechanism further includes a second detection component, which is used for detecting the displacement of the second frame along the Y direction.

[0019] As an alternative solution, the second adjusting mechanism further includes a Y-direction limiting component. The Y-direction limiting component includes a third sensor and a third limiting member. The third sensor is used for detecting whether the second frame reaches the limit position of the Y-direction stroke, and the third limiting member is used for restricting the over-travel movement of the second frame along the Y direction.

[0020] Beneficial effects:

[0021] The present invention provides a three-degree-of-freedom motion platform. By designing the first adjustment mechanism and the second adjustment mechanism as an inner and outer nested planar layout, and cooperating with the first driving member to jointly control the X-direction movement and the rotation around the Z-axis of the first frame, and the second driving member independently drives the second frame to achieve the integrated driving mode of the Y-direction movement. While ensuring high-precision motion control, the overall height of the platform is effectively reduced, and the applicability in space-limited scenarios is improved; in addition, the flexible hinge connection between the second frame and the first frame not only ensures the motion synchronization but also can buffer vibrations, further enhancing the stability and reliability of the three-degree-of-freedom motion platform. Description of the drawings

[0022] Figure 1 is the first schematic diagram of the three-degree-of-freedom motion platform provided by the embodiment of the present invention;

[0023] Figure 2 is the second schematic diagram of the three-degree-of-freedom motion platform provided by the embodiment of the present invention;

[0024] Figure 3 is the structural schematic diagram of the first frame and the second frame provided by the embodiment of the present invention;

[0025] Figure 4 is the structural schematic diagram of the first adjustment mechanism and the second adjustment mechanism provided by the embodiment of the present invention;

[0026] Figure 5 is the structural schematic diagram of the first sensor provided by the embodiment of the present invention;

[0027] Figure 6 is the structural schematic diagram of the first limiting member provided by the embodiment of the present invention;

[0028] Figure 7 is the structural schematic diagram of the second sensor provided by the embodiment of the present invention;

[0029] Figure 8 is the structural schematic diagram of the second limiting member provided by the embodiment of the present invention;

[0030] Figure 9 is the structural schematic diagram of the base provided by the embodiment of the present invention.

[0031] In the figure:

[0032] 1. Base; 11. Magnetic preloading member; 12. Connecting plate;

[0033] 2. First adjustment mechanism; 21. First driving member; 22. First frame; 221. Through hole; 23. Aerostatic guiding member; 24. First detection assembly; 25. X-direction limiting assembly; 26. Z-axis rotation limiting assembly; 27. First flexible hinge; 28. Second flexible hinge; 251. First sensor; 252. First limiting member; 261. Second sensor; 262. Second limiting member; 2511. First light-shielding sheet; 25111. First adjustment hole; 2512. First housing; 2521. First mounting member; 2522. Limiting bump; 2611. Second housing; 26111. U-shaped groove; 2612. Second light-shielding sheet; 26121. Second adjustment hole; 2621. Second mounting member; 2622. Roller

[0034] 3. Second adjustment mechanism; 31. Second driving member; 32. Second frame; 33. Second detection assembly; 34. Y-direction limiting assembly; 341. Third sensor; 342. Third limiting member

[0035] 4. Carrier; 41. Accommodating groove Detailed implementation manners

[0036] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present invention, rather than limiting the present invention. Additionally, it should be noted that for the sake of description, only parts related to the present invention rather than all structures are shown in the drawings

[0037] In the description of the present invention, unless otherwise clearly defined and limited, the terms "connected", "connected to", and "fixed" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the internal communication of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances

[0038] In the present invention, unless otherwise clearly defined and limited, the first feature being "above" or "below" the second feature may include the direct contact between the first and second features, or may include the non-direct contact between the first and second features but through other features therebetween. Moreover, the first feature being "above", "above the", and "on the" of the second feature includes the first feature being directly above and obliquely above the second feature, or merely indicating that the first feature has a higher horizontal height than the second feature. The first feature being "below", "below the", and "under the" of the second feature includes the first feature being directly below and obliquely below the second feature, or merely indicating that the first feature has a lower horizontal height than the second feature

[0039] In the description of this embodiment, the orientation or positional relationships such as "upper", "lower", "right", etc. are based on the orientation or positional relationships shown in the drawings. They are only for the convenience of description and simplifying the operations, 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. Therefore, it should not be construed as a limitation to the present invention. In addition, the terms "first" and "second" are only used for differentiation in description and have no special meaning.

[0040] A three-degree-of-freedom motion platform, as Figure 1 and Figure 2 shown, the three-degree-of-freedom motion platform includes a base 1, a first adjustment mechanism 2, a second adjustment mechanism 3, and a carrier 4. The first adjustment mechanism 2 includes two first driving members 21 and a first frame 22. The two first driving members 21 are arranged at intervals and fixedly connected to the base 1. The output ends of the two first driving members 21 are connected to the first frame 22. The two first driving members 21 can make the first frame 22 move in the X direction and rotate around the Z axis; the second adjustment mechanism 3 includes a second driving member 31 and a second frame 32. The second frame 32 is arranged in the inner space enclosed by the first frame 22 and is flexibly hinged to the first frame 22. The second frame 32 can move in the X direction and rotate around the Z axis synchronously with the first frame 22. The output end of the second driving member 31 is connected to the second frame 32. The second driving member 31 can make the second frame 32 move in the Y direction; the carrier 4 is arranged in the inner space enclosed by the second frame 32 and is fixedly connected to the second frame 32.

[0041] By designing the first adjustment mechanism 2 and the second adjustment mechanism 3 into an inner and outer nested planar layout, cooperating with the first driving member 21 to jointly control the movement of the first frame 22 in the X direction and rotation around the Z axis, and the second driving member 31 independently driving the second frame 32 to achieve the integrated driving mode of movement in the Y direction, while ensuring high-precision motion control, the overall height of the three-degree-of-freedom motion platform is effectively reduced, and the applicability in space-limited scenarios is improved; in addition, the second frame 32 and the first frame 22 are connected by a frictionless flexible hinge. Compared with general guide rails, this connection method has higher motion precision and better motion repeatability, not only ensuring motion synchronism, but also significantly reducing the precision attenuation caused by mechanical wear, further enhancing the stability and reliability of the three-degree-of-freedom motion platform.

[0042] It should be noted that the Y direction defined here is along the inner wall of the first frame 22. The second frame 32 is designed to be able to move independently in this relative direction. This means that while the second frame 32 is connected to the first frame 22 and follows the first frame 22 to move in the X direction and rotate around the Z axis, it can also move relatively along a specific direction (i.e., the defined Y direction) of the inner wall of the first frame 22.

[0043] The three-degree-of-freedom motion platform in this embodiment has a displacement capacity of ±2 mm in the X and Y directions, and a rotational motion capacity of ±0.5 degrees about the Z axis. This three-degree-of-freedom motion platform is designed for the semiconductor field and can fully meet the high-precision requirements of wafer inspection. It breaks through the space limitations and performance limitations of traditional equipment. Through an integrated structure design, while ensuring the motion performance, it significantly reduces the height, effectively solves the problem of limited space layout in the semiconductor inspection scenario, can complete high-precision three-dimensional inspection operations of wafers in a limited space, provides reliable support for quality control in the semiconductor manufacturing process, and helps improve the efficiency and accuracy of wafer inspection.

[0044] In an alternative embodiment, the first adjustment mechanism 2 includes four first flexible hinges 27. The second frame 32 is connected to the "hui"-shaped first frame 22 through the four first flexible hinges 27 at the four corners, and the inner space shape of the second frame 32 fits that of the first frame 22. This design utilizes the characteristics of the first flexible hinges 27, such as no clearance and lubrication-free, to improve the motion accuracy; the symmetric connection method enhances the structural stability and can also buffer external vibrations; at the same time, the streamlined structure (the first frame 22 and the second frame 32) and the advantage that the first flexible hinges 27 do not require extra space effectively reduce the height of the three-degree-of-freedom motion platform and meet the usage requirements of scenarios with limited space. It should be noted that the connection method of the first flexible hinges 27 between the first frame 22 and the second frame 32 enables the three-degree-of-freedom motion platform not to cause displacement or torque in the X direction when moving in the Y direction, achieving decoupling of the Y-direction motion and the X direction.

[0045] In this embodiment, the output end of the first driving member 21 is fixedly connected to the side wall of the first frame 22, and the output end of the second driving member 31 is fixedly connected to the side wall of the second frame 32, further reducing the overall height of the three-degree-of-freedom motion platform. Optionally, the types of the first driving member 21 and the second driving member 31 are both selected as magnetic direct drives. Optionally, the types of the first driving member 21 and the second driving member 31 are both selected as piezoelectric ceramic drives.

[0046] As Figures 1 - 3As shown, in this embodiment, the second driving member 31 is fixedly connected to the base 1. The first frame 22 is provided with a through hole 221, and the depth direction of the through hole 221 is arranged along the Y direction. The output end of the second driving member 31 passes through the through hole 221 and is connected to the side wall of the second frame 32. By the synchronous or asynchronous telescoping of the two first driving members 21, the first frame 22 and the second frame 32 flexibly hinged thereto can be controlled to translate along the X direction or rotate around the Z axis, while the telescoping of the second driving member 31 directly drives the second frame 32 to translate along the Y direction. The through hole 221 of the first frame 22 provides a relative sliding space for it. This nested layout and flexible hinge connection method not only make the three-degree-of-freedom motion platform structure compact, but also optimize the load distribution and reduce the inertia of the moving parts. In addition, arranging the second driving member 31 on the base 1 and cooperating with the relatively large heat dissipation area and good thermal conductivity of the base 1 can effectively improve the heat dissipation uniformity of the system.

[0047] In other embodiments, the second driving member 31 is fixedly connected to the first frame 22, and the output end of the second driving member 31 is connected to the second frame 32 shown. Fixing the second driving member 31 to the first frame 22 and directly connecting its output end to the second frame 32 simplifies the transmission structure and shortens the drive chain, improving the response speed of the Y-direction movement and the overall rigidity of the system.

[0048] As Figure 1 and Figure 2As shown, the base 1 is provided with a magnetic preloading member 11. The first adjusting mechanism 2 further includes an air-floating guide member 23. The air-floating guide member 23 is flexibly hinged to the first frame 22, and the air-floating guide member 23 can slide cooperatively with the magnetic preloading member 11 along the X direction. The base 1 is made of marble. The base 1 is provided with a magnetic preloading member 11 extending along the X direction. The magnetic preloading member 11 is made of steel material, and the magnetic preloading member 11 is fixed to the surface of the base 1 through an adhesive process. The air-floating guide member 23 is provided with air holes communicating with positive-pressure gas and magnets. When the air holes are ventilated, the positive-pressure gas pushes the air-floating guide member 23 away from the surface of the base 1, and the magnetic force generated by the magnets on the air-floating guide member 23 pulls the air-floating guide member 23 towards the surface of the base 1. Through the balance of the air pressure thrust and the magnetic force pull, a stable-thickness air film is formed between the air-floating guide member 23 and the surface of the base 1, realizing non-contact support and low-friction movement, significantly improving the translation accuracy and dynamic response of the first frame 22 along the X direction. At the same time, the geometric constraint of the magnetic preloading member 11 ensures the straightness of the movement. The elastic design of the second flexible hinge 28 can release the degree of freedom of rotation around the Z axis. While compensating for manufacturing and assembly errors, it provides the platform with the ability to rotate ±0.5° around the Z axis. This design ensures that the translation along the X direction and the rotation around the Z axis do not interfere with each other, further optimizing the collaborative accuracy of the three-degree-of-freedom movement. The second flexible hinge 28 theoretically can meet a rotation angle of ±1°, but limited by the current design parameters, only the rotation ability of ±0.5° is actually achieved. If it needs to be extended to ±1°, the size of the second flexible hinge 28 needs to be enlarged and optimized.

[0049] In this embodiment, a first air passage (not shown in the figure) and a second air passage (not shown in the figure) that are respectively connected to an external air source are provided inside the first frame 22. The air outlets of the first air passage and the second air passage are both opened on the mounting surface of the first frame 22 opposite to the base 1. The first air passage is used to transmit positive-pressure air flow, and the second air passage is used to transmit negative-pressure air flow. By providing a first air passage (positive pressure) and a second air passage (negative pressure) that are respectively connected to an external air source and independently controlled inside the first frame 22, and opening the air outlets of the two on the relative mounting surface of the base 1, a positive-negative pressure partition control structure is formed. When the first frame 22 moves, the positive-pressure air passage is filled with gas to float the first frame 22 to achieve frictionless movement. At the same time, the negative-pressure air passage provides a preload force, which acts together with the self-weight of the first frame 22 to enhance the air film stiffness and maintain stability. When the first frame 22 needs to be lowered to the target area, by slowly reducing the positive pressure and maintaining the negative pressure, the first frame 22 is tightly adsorbed on the base 1 to achieve precise positioning. Through the coordinated control of positive and negative pressures, this structure can effectively reduce the positioning position drift caused by small changes in the ambient temperature within a certain period of time, significantly improve the movement accuracy and positioning accuracy, and at the same time achieve a reliable switch between the movement state and the positioning state. Among them, the external air source can be a combination of an air compressor and a vacuum pump. The air compressor provides a stable positive-pressure air flow, which is suitable for the state that requires continuous air-floating support. By matching a pressure reducing valve, the air film thickness can be precisely controlled. The vacuum pump is used to generate a negative-pressure adsorption force to lock the position of the first frame 22 after processing or positioning is completed, improving the system rigidity.

[0050] As Figure 4As shown, the first adjustment mechanism 2 further includes a first detection component 24, and the first detection component 24 is used to detect the displacement of the first frame 22 in the X direction and the rotation angle about the Z axis. In this embodiment, the first adjustment mechanism 2 further includes two first detection components 24, and the two first detection components 24 are arranged symmetrically about the X axis. The first detection components 24 are all grating rulers, and the grating ruler includes a grating ruler body, a reading head, and a signal processor. The grating ruler body is fixed to the base 1 in the X direction, and the precision grating lines engraved on its surface serve as the displacement measurement reference; the reading head is rigidly connected to the first frame 22 and can scan the change of the grating lines of the grating ruler in real time, converting the displacement of the first frame 22 in the X direction into an optical pulse signal. After these pulse signals are transmitted to the signal processor, displacement calculation is realized to ensure high-precision monitoring of the displacement range of ±2 mm. For the detection of the rotation angle about the Z axis, the two symmetrically arranged first detection components 24 work together to achieve accurate measurement. When the first frame 22 rotates, different pulse counts are generated due to the relative displacement of the reading heads on both sides. After the signal processor receives the data on both sides, difference calculation is performed based on the geometric relationship of the component spacing, converting the displacement difference into an angle value to achieve high-precision detection of the rotation angle of ±0.5°. In addition, the signal processor also has functions of data filtering and anomaly verification, which can eliminate noise signals generated by vibration and electromagnetic interference, and further improve the reliability and stability of the detection results through cross-comparison of the data on both sides.

[0051] In other embodiments, the first adjustment mechanism 2 further includes two first detection components 24. One of the first detection components 24 is an inductive displacement sensor, and the inductive displacement sensor includes a body and a probe head. The body is fixedly connected to the base 1, and the probe head is fixedly connected to the first frame 22. The inductive displacement sensor is used to detect the displacement of the first frame 22 in the X direction. The other first detection component 24 is an optoelectronic angle encoder or a magnetoelectric angle encoder, which is used to detect the rotation angle of the first frame 22 about the Z axis.

[0052] As Figure 2 , Figure 5 and Figure 6 shown, the first adjustment mechanism 2 further includes an X-direction limit component 25. The X-direction limit component 25 includes a first sensor 251 and a first limit member 252. The first sensor 251 is used to detect whether the first frame 22 reaches the limit position of the X-direction stroke; the first limit member 252 is used to limit the over-travel movement of the first frame 22 in the X direction. The combination of the two forms a dual protection mechanism of "electronic trigger + mechanical block", ensuring the operation safety of the three-degree-of-freedom motion platform under complex working conditions, and effectively improving the reliability and service life of the equipment.

[0053] In this embodiment, two first sensors 251 are symmetrically arranged along the Y-axis on both sides of the first frame 22. When the first frame 22 moves to the stroke limit position of ±2 mm, the induction signal of the first sensor 251 changes, and a trigger signal is immediately output to the control system. This signal is used to lock the current motion state, forcibly cut off the power output of the drive mechanism, and prevent the first frame 22 from continuing to move beyond the limit. At the same time, two first limit members 252 symmetrically arranged with respect to the Y-axis serve as mechanical redundant protection. When the first sensor 251 fails abnormally due to dust, electromagnetic interference, etc., the first frame 22 is directly blocked from moving beyond the stroke by rigid contact, avoiding hard collisions between the first frame 22 and the base 1 or other components, and preventing damage to precision structures such as flexible hinges and air-bearing guides 23 due to overload. The two first sensors 251 and the two first limit members 252 are both symmetrically arranged along the central position of the base 1, effectively reducing the interference of rotation about the Z-axis on the limiting function. When the first frame 22 rotates about the Z-axis, the symmetric layout causes the lateral forces on the first sensor 251 and the first limit member 252 to cancel each other out, avoiding false triggering or mechanical damage caused by uneven force.

[0054] In an alternative embodiment, as Figure 9 shown, the base 1 is provided with two connecting plates 12 at intervals in the X direction, and the length direction of the connecting plates 12 is perpendicular to the X direction. As Figure 5 shown, the first sensor 251 is a U-shaped groove limit switch, which consists of a first light-shielding sheet 2511 and a first housing 2512. The first light-shielding sheet 2511 is provided with a first adjustment hole 25111 in the X direction and is connected to the connecting plate 12 by bolts, so that the first light-shielding sheet 2511 can be adjusted and fixed in position along the X direction. A transmitting end and a receiving end are oppositely arranged on the groove wall of the first housing 2512. When the first frame 22 approaches the stroke limit of ±2 mm, the first light-shielding sheet 2511 enters the groove of the first housing 2512, blocks the receiving end and triggers a switch signal, and the control system then cuts off the driving power to prevent the first frame 22 from moving beyond the limit.

[0055] In an alternative embodiment, as Figure 6 shown, the first limit member 252 consists of a first mounting member 2521 and a limit bump 2522. The first mounting member 2521 is bolted to the connecting plate 12 for easy disassembly and position adjustment; one end of the limit bump 2522 is connected to the first mounting member 2521, and the other end is an abutting end, the surface of which is coated with a highly elastic rubber material. When the first frame 22 moves beyond the stroke limit and the first sensor 251 fails to limit, the rubber-coated abutting end contacts the first frame 22, reducing the impact force through flexible buffering and avoiding structural damage caused by rigid collision, providing reliable mechanical protection for the motion platform.

[0056] As Figure 3 、 Figure 7and Figure 8 As shown in Figure 8 , the first adjustment mechanism 2 further includes a Z-axis rotation limit assembly 26. The Z-axis rotation limit assembly 26 includes a second sensor 261 and a second limit member 262. The second sensor 261 is used to detect whether the first frame 22 reaches the limit position of the rotation angle around the Z-axis; the second limit member 262 is used to limit the over-angle movement of the first frame 22 around the Z-axis. In this embodiment, two second sensors 261 are arranged at intervals along the X-axis on the first side of the first frame 22. When the first frame 22 approaches the limit position of the rotation angle around the Z-axis by ±0.5°, it quickly captures the position change and sends a warning signal to the control system. Based on this, the first driving member 21 decelerates in advance or adjusts the torque to effectively avoid passing through the limit angle due to inertia. The two second limit members 262 located on the second side of the first frame 22 are arranged at intervals along the X-axis to form mechanical protection. When the second sensor 261 is affected by electromagnetic interference and the signal fails abnormally, the rotation range of the first frame 22 is forcibly limited through rigid contact, preventing damage to precision components such as the first flexible hinge 27 and the air-floating guide member 23.

[0057] In an alternative embodiment, as Figure 7 shown in Figure 7 , the second sensor 261 is selected as a U-shaped groove limit switch. The U-shaped groove limit switch is composed of a second light-shielding sheet 2612 and a second housing 2611. The second light-shielding sheet 2612 is provided with a second adjustment hole 26121 along the X direction and is connected to the connecting plate 12 by bolts, so that the second light-shielding sheet 2612 can be adjusted and fixed in position along the X direction. On the inner walls of both sides of the U-shaped groove 26111 of the second housing 2611, a transmitting end and a receiving end are relatively arranged. When the first frame 22 approaches the limit position of the rotation angle around the Z-axis by ±0.5°, the second light-shielding sheet 2612 enters the U-shaped groove 26111, blocks the receiving end and triggers a switch signal, and the control system immediately cuts off the driving power to avoid passing through the limit angle due to inertia.

[0058] In an alternative embodiment, as Figure 8 shown in Figure 8 , the second limit member 262 includes a second mounting member 2621 and a roller 2622. The second mounting member 2621 is bolted to the first frame 22 to ensure firm installation and precise adjustable position. The roller 2622 is rotatably connected to the second mounting member 2621, and its surface is covered with a high-elastic rubber layer to form a flexible contact interface. When the first frame 22 rotates around the Z-axis and approaches the limit angle, the roller 2622 can come into contact with the base 1 first, replacing rigid collision with rolling friction to effectively buffer the impact; even if the limit of the second sensor 261 fails and the first frame 22 rotates beyond the angle, the roller 2622 can reduce wear by virtue of its rolling characteristics, and at the same time use physical block to limit the movement of the first frame 22, not only ensuring the reliability of the limit function, but also avoiding direct rubbing and damage between the first frame 22 and other components, improving the durability and safety of the overall structure.

[0059] In this embodiment, the second frame 32 is provided with a third air passage (not shown in the figure) and a fourth air passage (not shown in the figure) that are respectively connected to an external air source. The air outlets of the second air passage and the fourth air passage are both opened on the mounting surface of the second frame 32 opposite to the base 1. The third air passage is used to transmit positive-pressure air flow, and the fourth air passage is used to transmit negative-pressure air flow. By providing a third air passage (positive pressure) and a fourth air passage (negative pressure) that are respectively connected to an external air source and independently controlled within the second frame 32, and opening the air outlets of both on the mounting surface opposite to the base 1, a positive-negative pressure partition control structure is formed. When the second frame 32 moves, positive-pressure air is introduced into the positive-pressure air passage to lift the second frame 32 to achieve frictionless movement. At the same time, the negative-pressure air passage provides a preloading force, which, together with the self-weight of the second frame 32, enhances the air film stiffness and maintains stability. When the second frame 32 needs to be lowered to the target area, by slowly reducing the positive pressure and maintaining the negative pressure, the second frame 32 is tightly adsorbed on the base 1 to achieve precise positioning. Through the coordinated control of positive and negative pressures, this structure can effectively reduce the positioning position drift caused by small changes in the ambient temperature within a certain period of time, significantly improve the movement accuracy and positioning accuracy, and at the same time achieve a reliable switch between the movement state and the positioning state. Among them, the external air source can be a combination of an air compressor and a vacuum pump. The air compressor provides a stable positive-pressure air flow, which is suitable for the state that requires continuous air-floating support. By matching a pressure reducing valve, the air film thickness can be accurately controlled. The vacuum pump is used to generate a negative-pressure adsorption force to lock the position of the second frame 32 after processing or positioning is completed.

[0060] As Figures 1 - 3 shown, the second adjustment mechanism 3 further includes a second detection component 33. The second detection component 33 is used to detect the displacement of the second frame 32 in the Y direction. The type of the second detection component 33 can be a grating ruler or an inductive displacement sensor, and it is installed between the first frame 22 and the second frame 32 in the Y direction. When the second frame 32 moves, the second detection component 33 feeds back the displacement data to the control system. After comparing with the preset parameters, the output of the drive mechanism is dynamically adjusted to correct the movement deviation and ensure the positioning accuracy of the second frame 32 in the Y direction. Through the closed-loop control mechanism, the system can suppress external interference and internal errors, and improve the trajectory tracking accuracy and stability of the three-degree-of-freedom motion platform.

[0061] As Figures 1 - 3As shown, the second adjustment mechanism 3 further includes a Y-direction limit component 34. The Y-direction limit component 34 includes a third sensor 341 and a third limit member 342. The third sensor 341 is used to detect whether the second frame 32 reaches the limit position of the Y-direction stroke; the third limit member 342 is used to limit the over-travel movement of the second frame 32 in the Y direction. The third sensor 341 and the third limit member 342 of the Y-direction limit component 34 are of the same type as those of the X-direction limit component 25, but are arranged at different positions. In this embodiment, the two third sensors 341 are arranged on the same side or opposite sides of the second frame 32 in the Y direction. The limit of the Y-direction stroke of the second frame 32 is monitored in real time by a light-shielding sheet or an induction element, and the early warning signal drives the system to adjust to avoid over-travel; the two third limit members 342 are symmetrically arranged about the X axis on both sides of the second frame 32, and the structure is the same as that of the first limit member 252, and rigid contact and rubber buffering are used for forced limiting when the electronic limit fails.

[0062] In an alternative embodiment, as Figure 1 and Figure 2 shown, a receiving groove 41 is provided on the side of the carrier 4 facing away from the base 1. The receiving groove 41 is used to receive the workpiece to be processed.

[0063] The control system of the three-degree-of-freedom motion platform in this embodiment adopts a closed-loop control algorithm. Based on the feedback signals of the first detection component 24 and the second detection component 33, the first driving member 21 and the second driving member are accurately controlled, so as to ensure the high precision and stability of the platform movement. This system supports multi-axis coordinated movement and can realize the composite movement trajectories in the X direction, the Y direction, and around the Z axis.

[0064] Obviously, the above-mentioned embodiments of the present invention are only examples for clearly illustrating the present invention, rather than limiting the implementation manners of the present invention. For those of ordinary skill in the art, various obvious changes, re-adjustments, and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to enumerate all the implementation manners here. Any modifications, equivalent substitutions, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. A three-degree-of-freedom motion platform, characterized in that, Comprising: Base (1); The first adjustment mechanism (2), including two first driving members (21) and a first frame (22), the two first driving members (21) are arranged at intervals and fixedly connected to the base (1), the output ends of the two first driving members (21) are connected to the first frame (22), and the two first driving members (21) can move the first frame (22) in the X direction and rotate around the Z axis; The second adjustment mechanism (3), including a second driving member (31) and a second frame (32), the second frame (32) is arranged in the inner space surrounded by the first frame (22) and is flexibly hinged to the first frame (22), the second frame (32) can move in the X direction and rotate around the Z axis synchronously with the first frame (22), the output end of the second driving member (31) is connected to the second frame (32), and the second driving member (31) can move the second frame (32) in the Y direction; The carrier stage (4) is arranged in the inner space surrounded by the second frame (32) and is fixedly connected to the second frame (32).

2. The three-degree-of-freedom motion platform according to claim 1, wherein The second driving member (31) is fixedly connected to the base (1), the first frame (22) is provided with a through hole (221), the depth direction of the through hole (221) is along the Y direction, and the output end of the second driving member (31) passes through the through hole (221) and is connected to the side wall of the second frame (32).

3. The three-degree-of-freedom motion platform according to claim 1, characterized in that, The base (1) is provided with a magnetic preloading member (11), the first adjustment mechanism (2) further includes an air-floating guiding member (23), the air-floating guiding member (23) is flexibly hinged to the first frame (22), and the air-floating guiding member (23) can slide in cooperation with the magnetic preloading member (11) in the X direction.

4. The three-degree-of-freedom motion platform according to any one of claims 1-3, characterized in that, A first air passage and a second air passage communicating with an external air source are respectively arranged in the first frame (22), and the air outlets of the first air passage and the second air passage are both opened on the mounting surface of the first frame (22) opposite to the base (1), the first air passage is used for transmitting positive pressure air flow, and the second air passage is used for transmitting negative pressure air flow.

5. The three-degree-of-freedom motion platform according to any one of claims 1 to 3, characterized in that, The first adjustment mechanism (2) further includes a first detection component (24), and the first detection component (24) is used for detecting the displacement of the first frame (22) in the X direction and the rotation angle around the Z axis.

6. The three-degree-of-freedom motion platform according to claim 5, characterized in that, The first adjustment mechanism (2) further includes an X-direction limiting component (25), the X-direction limiting component (25) includes a first sensor (251) and a first limiting member (252), the first sensor (251) is used for detecting whether the first frame (22) reaches the limit position of the X-direction stroke, and the first limiting member (252) is used for restricting the over-travel movement of the first frame (22) in the X direction.

7. The three-degree-of-freedom motion platform according to claim 6, characterized in that The first adjustment mechanism (2) further includes a Z-axis rotation limit assembly (26). The Z-axis rotation limit assembly (26) includes a second sensor (261) and a second limit member (262). The second sensor (261) is used to detect whether the first frame (22) reaches the limit position of the Z-axis rotation angle, and the second limit member (262) is used to limit the over-angle movement of the first frame (22) around the Z-axis.

8. The three-degree-of-freedom motion platform according to any one of claims 1 to 3, characterized in that, The second frame (32) is provided with a third air passage and a fourth air passage that are respectively connected to an external air source. The air outlets of the third air passage and the fourth air passage are both opened on the mounting surface of the second frame (32) opposite to the base (1). The third air passage is used to transmit positive-pressure air flow, and the fourth air passage is used to transmit negative-pressure air flow.

9. The three-degree-of-freedom motion platform according to claim 8, wherein, The second adjustment mechanism (3) further includes a second detection component (33). The second detection component (33) is used to detect the displacement of the second frame (32) along the Y direction.

10. The three-degree-of-freedom motion platform according to claim 9, characterized in that, The second adjustment mechanism (3) further includes a Y-direction limit assembly (34). The Y-direction limit assembly (34) includes a third sensor (341) and a third limit member (342). The third sensor (341) is used to detect whether the second frame (32) reaches the limit position of the Y-direction stroke, and the third limit member (342) is used to limit the over-stroke movement of the second frame (32) along the Y direction.

Images