Wafer transfer system based on parallel flat plate unfolding compliance mechanism and its working method

Abstract

A wafer handover system based on a parallel flat plate folding and compliant mechanism includes a PLEM wafer handover system and a PLEM handover control system. The PLEM wafer handover system comprises a detection system, a vacuum adsorption system, a parallel flat plate folding and compliant mechanism, and a micro-stage system. The parallel flat plate folding and compliant mechanism is mounted on the micro-stage system, and the wafer is supported above the mechanism. The PLEM handover control system is connected to the detection system, the vacuum adsorption system, the parallel flat plate folding and compliant mechanism, and the micro-stage system. This invention proposes a wafer handover system based on a parallel flat plate folding and compliant mechanism. It employs an integrated flexible device with a parallel flat plate folding structure to buffer the impact force during the handover process, achieving stable, accurate, and rapid wafer handover. Furthermore, this invention has the advantages of fewer components, a compact structure, and significantly smaller size and weight compared to rigid mechanisms. It also improves mechanism performance, reduces costs, and has high portability.

Description

(I) Technical Field:

[0001] This invention relates to the technical field of wafer processing, transport, and lithography equipment, specifically to a method and system for achieving stable, accurate, and rapid transport and transfer of wafers based on a parallel lamina emergent mechanism (PLEM), namely, a wafer handover system based on a parallel lamina emergent mechanism and its working method. (II) Background Technology:

[0002] Wafer handover is the transfer and transport of wafers between the transport mechanism and the workpiece stage. It marks the beginning and end of the photolithography process, and its stability, accuracy, and speed are prerequisites and guarantees for the safety, stability, and efficiency of the photolithography process. Stability reduces collisions and stress concentration, preventing wafer breakage; accuracy ensures that the wafer handover pose meets the alignment measurement requirements; and speed is closely related to the final yield. As a core component in wafer handover, the parallel compliant mechanism has a lightweight and compact structure with smooth and continuous motion, giving it advantages in terms of stability and speed. However, the multiple degrees of freedom of the flexible units bring complex motion behavior, and the difficulty in processing and assembling the flexible structure leads to differences in the pose of the handover surface. These factors increase the difficulty of structural design, pose analysis, and motion control of the parallel compliant mechanism, affecting the stability, accuracy, and speed of wafer handover, and becoming a key technical bottleneck restricting the application of parallel compliant mechanisms in wafer processing, transport, and photolithography equipment.

[0003] As wafer sizes increase and requirements for yield, precision, and cleanliness become more stringent, wafer handover technology, an essential component of wafer transport, is becoming increasingly important. Extensive research has been conducted both domestically and internationally on wafer handover technology, achieving significant progress in handover stability, accuracy, and speed to meet the needs of each generation and even the next generation of lithography machines.

[0004] Wafer transfer technology has only existed for a few decades, but it has undergone tremendous changes with the rapid development of photolithography technology. Its development can be divided into three main stages based on wafer size: wafer diameter less than 200mm, wafer diameter 200mm, and wafer diameter 300mm and above. In the wafer diameter less than 200mm stage, the earliest wafer transfer was completed using tweezers and vacuum rods to hold the wafer from the wafer cassette to the workpiece stage. This evolved into using stepper motor-driven lifting mechanisms for wafer transfer, which reduced breakage rates and improved reliability to some extent, while also reducing human-caused contamination on the wafer surface. However, it had little effect on particulate contamination caused by collisions during transfer. In the wafer diameter 200mm stage, wafer transfer equipment mainly used direct motor drive and displacement sensor feedback closed-loop control, replacing indirect motor drive and open-loop control that included transmission mechanisms. At that time, China was in its initial stage, with almost no research in IC equipment. The stage with wafer diameters of 300mm and above is referred to as the large-size wafer stage. Traditional wafer handover mechanisms suffer from inaccurate positioning, slow movement speed, high contact stress, and increasingly prominent problems such as particulate contamination from friction and collision. These limitations hinder further improvements in precision and yield, while excessive contact force increases wafer breakage rate, and particulate contamination increases the defect rate. The dynamic and static performance and cleanliness levels of traditional equipment cannot meet the requirements of large-size wafer lithography transfer. Therefore, most IC equipment research institutions and manufacturers at home and abroad adopt technologies such as flexible cells, magnetic levitation, and air springs to improve the handover stability of large-size wafers, while reducing collision forces and particulate contamination during wafer handover.

[0005] As wafer dimensions increase, the requirements for the smoothness, accuracy, speed, and cleanliness of wafer handover become more stringent. Compared to other mechanisms, the wafer handover system based on a parallel flat plate unfolding compliant mechanism proposed in this invention not only achieves minimal stiffness in the direction of motion while maintaining relatively high stiffness in other translational and rotational directions, ensuring flexible contact and wafer positioning accuracy during handover, but also achieves high-precision motion with optimal time tracking commands under limited amplitude through zero-phase error tracking and minimum-step control methods, thus limiting the contact force on the wafer. This improves speed and reduces collisions and particulate contamination during handover. Simultaneously, the deformation of flexible components enables partial motion and function of the mechanism, reducing or eliminating kinematic pairs structurally, resulting in a smaller number of components, a more compact structure, and lower volume and weight compared to rigid mechanisms. Furthermore, the compliant mechanism improves performance and reduces costs. The system also possesses high portability, enabling wider application in wafer processing, transport, and lithography equipment. (III) Summary of the Invention:

[0006] The purpose of this invention is to provide a wafer handover system based on a parallel flat plate folding and flexible mechanism, which can solve the problems existing in the prior art. As wafer size increases, the requirements for stability, accuracy, speed, and cleanliness become more stringent. Traditional rigid mechanisms are no longer sufficient to meet these demands. Furthermore, collisions or excessive movement during handover can lead to excessive contact forces on the wafer, affecting the stability and accuracy of the handover. To address the issues of achieving stability, accuracy, and speed in wafer handover during wafer processing, transport, and lithography equipment, this invention proposes a wafer handover system based on a parallel flat plate folding and flexible mechanism. This system uses an integrated flexible device with a parallel flat plate folding and flexible structure to buffer the impact forces during the handover process, achieving stable, accurate, and rapid wafer handover. In addition, this invention has the advantages of fewer components, a compact structure, and significantly smaller size and weight compared to rigid mechanisms. It also improves mechanism performance, reduces costs, and has high portability.

[0007] The technical solution of this invention: A wafer transfer system based on a parallel flat plate folding and compliant mechanism, comprising a PLEM wafer transfer system and a PLEM transfer control system; wherein, the PLEM wafer transfer system includes a detection system, a vacuum adsorption system, a parallel flat plate folding and compliant mechanism, and a micro-motion stage system; the parallel flat plate folding and compliant mechanism is mounted on the micro-motion stage system, and the wafer is supported above the parallel flat plate folding and compliant mechanism; the PLEM transfer control system is connected to the detection system, the vacuum adsorption system, the parallel flat plate folding and compliant mechanism, and the micro-motion stage system respectively.

[0008] The parallel flat plate folding and compliant mechanism includes a displacement detection unit, a motion support and flexible unit, an anti-rotation unit, and a drive unit;

[0009] The motion support and flexible unit include a motion support, a parallel flat folding spring, and a vacuum suction tube; the parallel flat folding spring and a displacement detection unit are installed on the motion support; the vacuum suction tube is installed on the parallel flat folding spring; the vacuum suction tube is connected to a vacuum adsorption system; and the driving unit drives the motion support.

[0010] The drive unit includes a voice coil motor and a motor driver; the motor driver drives the voice coil motor, and the voice coil motor drives the motion support.

[0011] The motion support and the air-bearing guide rail are in a bushing-shaft fit relationship. The air-bearing guide rail is located inside the center of the motion support and is fixed on the base. The motion support is supported by the air-bearing guide rail.

[0012] At least three flat folding leaf springs are evenly distributed around the center of the motion support in a 360° pattern.

[0013] The vacuum suction tube is connected to two aligned flat sheet springs at the top and bottom.

[0014] The flat folding leaf spring uses a zigzag leaf spring unit.

[0015] The zigzag leaf spring unit can be divided into 5 slender beam structure leaf springs, with a central ring connected to one end in the middle and vacuum suction tubes connected to both ends of the edge; the central ring is connected to the motion support.

[0016] The flat, folding leaf springs are connected by a slender beam structure leaf spring.

[0017] The anti-rotation unit includes an anti-rotation device and an anti-rotation element; the anti-rotation element is mounted on the moving support and cooperates with the fixedly mounted anti-rotation device.

[0018] The voice coil motor includes a voice coil motor stator and a voice coil motor mover; the voice coil motor mover drives the motion support to move.

[0019] The detection system includes a pressure gauge and flow meter connected to the vacuum adsorption system, a wafer marker detection device, and a CCD edge detection device.

[0020] The vacuum adsorption system includes a vacuum generator and a vacuum degree control valve; the vacuum generator is connected to the vacuum suction tube through the vacuum degree control valve.

[0021] The micro-motion stage system includes a multi-dimensional motion micro-motion stage and a micro-motion stage controller; a parallel flat plate folding and unfolding compliant mechanism is installed on the multi-dimensional motion micro-motion stage.

[0022] The PLEM handover control system includes a computer and a signal acquisition unit; the image and signal acquisition parts of the computer and the signal acquisition unit respectively acquire signals from the detection system and the displacement detection unit, and the computer respectively controls the motor driver, the micro-motion stage controller and the vacuum control valve.

[0023] The displacement detection unit uses an LVDT displacement detection sensor.

[0024] A working method for a wafer handover system based on a parallel flat plate unfolding compliance mechanism:

[0025] (1) In the initial preparation stage, the micro-stage carries the parallel flat plate unfolding and compliant mechanism to the predetermined position. After pre-alignment, the wafer is transported by the robot to the predetermined position above the micro-stage.

[0026] (2) The wafer transfer system is started. The computer and signal acquisition unit control the opening of the vacuum generator. At the same time, the pressure gauge and flow meter detect the vacuum level and flow rate in real time. The parallel plate folding and compliant mechanism is started. The moving parts, including the moving support, vacuum suction tube, parallel plate folding leaf spring, displacement sensor, and anti-rotation element, complete the upward movement according to the control command under the drive of the voice coil motor. The parallel flexible arm supports the vacuum suction tube to contact the back of the wafer. Under the condition of limiting the maximum force output of the motor, the moving parts rise quickly and stably until the vacuum in the suction tube reaches the threshold. The flexible unit of the parallel plate folding and compliant mechanism is in a downward compression state. The flexible arm has completed the contact and adsorption of the wafer. The robot closes the vacuum and releases the wafer.

[0027] (3) The moving parts of the parallel flat plate unfolding and compliant mechanism carry the wafer to the highest position, the robot arm is withdrawn, and the moving parts carry the wafer down to the suction cup position; the computer controls the micro stage vacuum suction cup to open the vacuum. Due to the strong adsorption capacity of the suction cup, the vacuum degree is easy to reach the threshold. The flexible unit of the parallel flat plate unfolding and compliant mechanism is in the downward compression state again. The vacuum suction tube closes the vacuum and releases the wafer. The moving parts of the parallel flat plate unfolding and compliant mechanism detach and descend to the initial position.

[0028] (4) After photolithography, the parallel flat plate unfolding and smoothing mechanism completes the transfer of the wafer from the suction cup to the robot arm in the reverse process.

[0029] The working principle of this invention: This invention utilizes a zigzag beam to achieve compact, highly flexible translational motion in the vertical direction. Simultaneously, its parallel layout ensures relatively high stiffness in other translational and rotational directions, resulting in relatively small parasitic motion errors. To ensure high precision in wafer transfer and accurate wafer orientation after transfer, the PLEM structural parameters are optimized using an overall flexibility matrix model. A flexible parallel flat leaf spring is connected to the lower part of the suction tube while the top of the suction tube remains rigid. During wafer contact, the maximum output force of the motor is limited, employing a small-displacement, repetitive step motion to allow the moving parts to rise quickly and stably until the wafer is clamped. The high flexibility of the parallel-layout flat leaf springs during their working stroke minimizes the contact force between the PLEM and the wafer during high-speed transfer, preventing excessive stress concentration that could lead to wafer breakage. This achieves smooth, accurate, and rapid wafer transfer.

[0030] The beneficial effects of this invention are as follows: Firstly, this invention employs a parallel flat plate unfolding compliant mechanism, while simultaneously using an air-floating guide rail to improve vertical motion accuracy. The optimized PLEM structure ensures greater flexibility in the vertical direction, while greater rigidity in other directions reduces parasitic motion errors, significantly improving the stability and safety of large-size wafer handover, ensuring handover accuracy, and reducing errors. This invention has a smaller number of components, a more compact structure, and is much smaller in size and weight compared to rigid mechanisms. Furthermore, this invention improves mechanism performance, reduces costs, and minimizes collision forces and particulate contamination during wafer handover. This invention achieves stable, accurate, and rapid wafer handover, has a promising market prospect, and can be widely applied in the fields of wafer processing, transport, and lithography equipment. It has a good foundation for technology transfer and can promote the development of integrated circuit manufacturing equipment technology, achieving broad social benefits. (iv) Description of the attached drawings:

[0031] Figure 1 This is a schematic diagram of the wafer transfer system based on a parallel flat plate unfolding and compliant mechanism, as described in this invention.

[0032] Figure 2 This is a schematic diagram of the wafer transfer system based on a parallel flat plate unfolding and compliant mechanism involved in the present invention.

[0033] Figure 3 This is a schematic diagram of the structure of the parallel plate folding and compliant mechanism in the wafer handover system based on the parallel plate folding and compliant mechanism involved in this invention.

[0034] Figure 4 This is a schematic diagram of the flat plate folding leaf spring in the wafer handover system based on the parallel flat plate folding and compliant mechanism involved in this invention.

[0035] Figure 5 This is a flowchart illustrating the wafer handover process of the parallel flat plate folding and compliant mechanism involved in this invention.

[0036] Among them, 1 is a parallel flat plate folding and compliant mechanism, 2 is a vacuum control valve, 3 is a vacuum generator, 4 is a pressure gauge and flow meter, 5 is a multi-dimensional motion micro stage, 6 is a control box, 7 is a computer and signal acquisition unit, 8 is a wafer, 9 is a wafer mark detection device, 10 is a CCD edge detection device, 101 is a flat plate folding leaf spring, 102 is a vacuum suction tube, 103 is an air pipe connector, 104 is a displacement detection sensor, 105 is a voice coil motor stator, 106 is a base, 107 is an air pipe, 108 is an anti-rotation device, 109 is a flexible arm, 110 is an anti-rotation element, 111 is a voice coil motor mover, 112 is an anti-collision head, 113 is an air-bearing guide rail, 114 is a motion support, 115 is a ring fastener, and 116 is a zigzag leaf spring unit. (V) Specific Implementation Methods:

[0037] The present invention will now be described in further detail with reference to specific embodiments.

[0038] like Figure 1 , 2 As shown, the wafer transfer system based on the parallel flat plate folding and compliant mechanism of the present invention includes the following two main parts: a PLEM wafer transfer system and a PLEM transfer control system; the organic combination of the two main parts realizes the wafer transfer system based on the parallel flat plate folding and compliant mechanism proposed in this invention; wherein, the PLEM wafer transfer system includes a detection system, a vacuum adsorption system, a parallel flat plate folding and compliant mechanism 1 and a micro-motion stage system; the parallel flat plate folding and compliant mechanism 1 is mounted on the micro-motion stage system, and the wafer 8 is carried on the top of the parallel flat plate folding and compliant mechanism 1; the PLEM transfer control system is connected to the detection system, the vacuum adsorption system, the parallel flat plate folding and compliant mechanism 1 and the micro-motion stage system respectively.

[0039] like Figure 3 , 4 As shown, the parallel flat plate unfolding and compliant mechanism 1 includes a displacement detection unit, a motion support and flexible unit, an anti-rotation unit, a voice coil motor and a motor driver;

[0040] The motion support and flexible unit include a motion support 114, a parallel flat folding spring 101, and a vacuum suction tube 102; the parallel flat folding spring 101 and a displacement detection unit are mounted on the motion support 114; the vacuum suction tube 102 is mounted on the parallel flat folding spring 101; the vacuum suction tube 102 is connected to a vacuum adsorption system; the motor driver drives a voice coil motor, and the voice coil motor drives the motion support 114.

[0041] The motion support 114 and the air-bearing guide rail 113 are in a bushing and shaft fit relationship. The air-bearing guide rail 113 is located inside the center of the motion support and is fixed on the base 106. The motion support is air-bearing supported by the air-bearing guide rail 113 to reduce motion error and avoid friction.

[0042] At least three flat folding leaf springs 101 are evenly distributed around the center of the motion support 114 at 360°.

[0043] The vacuum suction tube 102 is connected to two aligned flat folding leaf springs 101 at the top and bottom respectively.

[0044] The flat folding leaf spring 101 adopts a zigzag leaf spring unit 116.

[0045] The zigzag leaf spring unit 116 can be divided into 5 slender beam structure leaf springs, with one end connected to the central ring and the other two ends connected to the vacuum suction tube 102; the central ring is connected to the motion support 114.

[0046] The flat plate folding leaf springs 101 are connected by slender beam structure leaf springs.

[0047] The anti-rotation unit includes an anti-rotation device 108 and an anti-rotation element 110; the anti-rotation element 110 is mounted on the motion support 114 and cooperates with the fixedly mounted anti-rotation device 108.

[0048] The voice coil motor includes a voice coil motor stator 105 and a voice coil motor mover 111; the voice coil motor mover 111 drives the motion support 114 to move.

[0049] The detection system includes a pressure gauge and flow meter 4 connected to the vacuum adsorption system, a wafer marker detection device 9, and a CCD edge detection device 10.

[0050] The vacuum adsorption system includes a vacuum generator 3 and a vacuum degree control valve 2; the vacuum generator 3 is connected to the vacuum suction tube 102 through the vacuum degree control valve 2.

[0051] The micro-motion stage system includes a multi-dimensional motion micro-motion stage 5 and a micro-motion stage controller 6; a parallel flat plate folding and unfolding compliant mechanism 1 is installed on the multi-dimensional motion micro-motion stage 5.

[0052] The PLEM handover control system includes a computer and a signal acquisition unit 7; the image and signal acquisition parts of the computer and the signal acquisition unit 7 respectively acquire signals from the detection system and the displacement detection unit, and the computer respectively controls the motor driver, the micro-motion stage controller 6 and the vacuum control valve 2.

[0053] The displacement detection unit uses an LVDT displacement detection sensor 104.

[0054] like Figure 3 , 4 As shown, the flat folding leaf spring 101, as the core component of the entire compliant mechanism, employs three zigzag leaf spring units 116 evenly distributed around the center at 360°. Each zigzag leaf spring unit can be divided into five slender beam structure leaf springs, with one end connected to the central ring and the other two ends connected to the vacuum suction tubes. Simultaneously, there is also a slender beam structure leaf spring between two suction tubes. The two flat folding leaf springs are aligned vertically to form three flexible arms 109 supporting the vacuum suction tubes. This structure exhibits maximum flexibility in the vertical direction and relatively high rigidity in other directions of movement. When the three suction tubes cannot simultaneously establish a vacuum, the zigzag leaf spring unit 116 undergoes slight deformation to allow the three suction tubes to establish a vacuum as quickly as possible, while simultaneously reducing the contact force at the wafer junction, thus preventing wafer scratches and particle contamination caused by mutual disturbance.

[0055] like Figure 5As shown, the working process of the wafer transfer system based on the parallel flat plate unfolding compliant mechanism of the present invention is as follows: the wafer transfer system is implemented in conjunction with the micro-motion stage system. In the initial preparation stage, the micro-motion stage carries the PLEM to a predetermined position, and after pre-alignment, the wafer is transported by the robot arm to a predetermined position above the micro-motion stage. The wafer transfer system is activated. The computer and signal acquisition unit 7 control the opening of the vacuum generator 3. Simultaneously, the pressure gauge and flow meter 4 monitor the vacuum level and flow rate in real time. The parallel plate folding and compliant mechanism 1 is activated. The moving parts, including the motion support 114, vacuum suction tube 102, parallel plate folding leaf spring 101, displacement sensor 104, and anti-rotation rotor 110, complete the upward movement according to control commands under the drive of the voice coil motor mover 111. Three parallel flexible arms 109 support the vacuum suction tube 102 to contact the back of the wafer 8. While limiting the maximum force output of the motor, the moving parts rise rapidly and stably until the vacuum inside the suction tube 102 reaches the threshold. At this point, the flexible unit of the PLEM is in a downward compression state, and all three flexible arms have completed contact and adsorption of the wafer. The robotic arm closes the vacuum and releases the wafer 8. The PLEM moving parts, carrying the wafer, rise to the highest position, the robotic arm withdraws, and the moving parts, carrying the wafer, descend to the suction cup position. The computer-controlled microstage vacuum chuck is energized. Due to the strong suction capacity of the chuck, the vacuum level easily reaches the threshold, and the flexible unit of the PLEM is once again compressed downwards. The vacuum tube 102 is de-vacuumed, releasing the wafer. The PLEM moving parts detach and descend to the initial position. After photolithography, the PLEM completes the transfer of the wafer from the chuck to the robot arm in the reverse process.

[0056] The key to wafer handover is that all three suction tubes 102 supported by the parallel flexible arms 109 can contact and adsorb the wafer. Factors such as different suction tube end faces, tilting of the robotic arm or suction cup, and wafer eccentricity can prevent the three suction tubes from adsorbing the wafer simultaneously. The contact force during handover cannot be too large, limiting the maximum motor output force; the time from contact to vacuum establishment is 0.1 seconds. Therefore, to reduce the contact force during wafer handover and avoid wafer scratches and particle contamination caused by excessively long handover times, a small-displacement, repetitive step motion method is used to complete the wafer handover.

[0057] Although the present invention has been described above with reference to the figures, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many modifications under the guidance of the present invention without departing from the spirit of the present invention, and these modifications are all within the protection scope of the present invention.

Claims

1. A wafer transfer system based on a parallel flat plate unfolding compliant mechanism, characterized in that... It includes a PLEM wafer transfer system and a PLEM transfer control system; wherein, the PLEM wafer transfer system includes a detection system, a vacuum adsorption system, a parallel flat plate folding and compliant mechanism (1) and a micro-motion stage system; the parallel flat plate folding and compliant mechanism (1) is mounted on the micro-motion stage system, and the wafer (8) is carried on top of the parallel flat plate folding and compliant mechanism (1); the PLEM transfer control system is connected to the detection system, the vacuum adsorption system, the parallel flat plate folding and compliant mechanism (1) and the micro-motion stage system respectively; the parallel flat plate folding and compliant mechanism (1) includes a displacement detection unit, a motion support and flexible unit, an anti-rotation unit, and a drive unit; the motion support and flexible unit includes a motion support (114), a parallel flat plate folding and compliant spring (101) and a vacuum suction tube (102); the parallel flat plate folding and compliant spring (101) and the displacement detection unit are mounted on the motion support (114); the vacuum suction tube (102) is mounted on the parallel flat plate folding and compliant spring (101) The vacuum suction tube (102) is connected to the vacuum adsorption system; the driving unit drives the motion support (114); the vacuum suction tube (102) is connected to parallel flat folding leaf springs (101) aligned with each other at the top and bottom; the motion support (114) and the air-floating guide rail (113) are in a bushing and shaft fit relationship, the air-floating guide rail (113) is located inside the center of the motion support and fixed on the base (106), and the motion support is supported by the air-floating guide rail (113); the flat At least three flat folding leaf springs (101) are evenly distributed around the center of the motion support (114) at 360°. The flat folding leaf springs (101) adopt zigzag leaf spring units (116). The zigzag leaf spring units (116) can be divided into five slender beam structure leaf springs, with one end connected to a central ring and both ends connected to vacuum suction tubes (102). The central ring is connected to the motion support (114). The flat folding leaf springs (101) are connected to each other through slender beam structure leaf springs.

2. The wafer handover system based on a parallel flat plate folding and compliant mechanism according to claim 1, characterized in that... The anti-rotation unit includes an anti-rotation device (108) and an anti-rotation element (110); the anti-rotation element (110) is installed on the motion support (114) and cooperates with the fixedly installed anti-rotation device (108).

3. The wafer handover system based on a parallel flat plate unfolding and compliant mechanism according to claim 1, characterized in that... The drive unit includes a voice coil motor and a motor driver; the motor driver drives the voice coil motor, and the voice coil motor drives the motion support (114); the voice coil motor includes a voice coil motor stator (105) and a voice coil motor mover (111); the voice coil motor mover (111) drives the motion support (114) to move.

4. The wafer handover system based on a parallel flat plate unfolding and compliant mechanism according to claim 1, characterized in that... The detection system includes a pressure gauge and flow meter (4) connected to the vacuum adsorption system, a wafer marker detection device (9), and a CCD edge detection device (10); The vacuum adsorption system includes a vacuum generator (3) and a vacuum degree control valve (2); the vacuum generator (3) is connected to the vacuum suction tube (102) through the vacuum degree control valve (2); The micro-motion stage system includes a multi-dimensional motion micro-motion stage (5) and a micro-motion stage controller (6); a parallel flat plate folding and unfolding compliant mechanism (1) is installed on the multi-dimensional motion micro-motion stage (5); The PLEM handover control system includes a computer and a signal acquisition unit (7); the image and signal acquisition parts of the computer and the signal acquisition unit (7) respectively acquire signals from the detection system and the displacement detection unit, and the computer respectively controls the drive unit, the micro-motion stage controller (6) and the vacuum control valve (2).

5. A method for operating a wafer handover system based on a parallel flat plate folding and compliant mechanism as described in claim 1, characterized in that... It includes the following steps: (1) In the initial preparation stage, the micro-stage carrying the parallel flat plate unfolding and compliant mechanism (1) moves to the predetermined position, and the wafer is transported by the robot to the predetermined position above the micro-stage after pre-alignment; (2) The PLEM wafer transfer system is started, the PLEM transfer control system controls the opening of the vacuum adsorption system, and controls the detection system to perform detection; the moving parts of the parallel flat plate unfolding and compliant mechanism (1) complete the upward movement according to the control command, the vacuum adsorption system is opened, the vacuum suction tube of the parallel flat plate unfolding and compliant mechanism (1) adsorbs the back of the wafer (8), the flexible unit of the parallel flat plate unfolding and compliant mechanism (1) is in a downward compression state, and the robot closes the vacuum and releases the wafer (8); (3) The moving parts of the parallel flat plate unfolding and compliant mechanism (1) carry the wafer to the highest position, the robot arm is withdrawn, and the moving parts carry the wafer down to the suction cup position; the PLEM handover control system controls the micro-motion stage vacuum suction cup to open the vacuum. Due to the strong suction capacity of the suction cup, the vacuum degree is easy to reach the threshold. The flexible unit of the parallel flat plate unfolding and compliant mechanism (1) is in the downward compression state again. The vacuum adsorption system closes the vacuum. The vacuum suction tube of the parallel flat plate unfolding and compliant mechanism (1) releases the wafer. The moving parts of the parallel flat plate unfolding and compliant mechanism (1) detach and descend to the initial position. (4) After photolithography, the parallel flat plate unfolding and smoothing mechanism (1) completes the transfer of the wafer from the suction cup to the robot arm in the reverse process.

6. The working method of a wafer handover system based on a parallel flat plate unfolding and compliant mechanism according to claim 5, characterized in that... In step (2), the computer and signal acquisition unit (7) control the opening of the vacuum generator (3), while the pressure gauge and flow meter (4) detect the vacuum level and flow rate in real time, and start the parallel plate folding and compliant mechanism (1). The moving parts, including the moving bracket (114), vacuum suction tube (102), parallel plate folding leaf spring (101), displacement sensor (104), and anti-rotation element (110), complete the upward movement according to the control command under the drive of the voice coil motor mover (111). The parallel flexible arm (109) supports the vacuum suction tube (102) to contact the back of the wafer (8). Under the condition of limiting the maximum force output of the motor, the moving parts rise quickly and stably until the vacuum in the suction tube (102) reaches the threshold. The flexible unit of the parallel plate folding and compliant mechanism (1) is in a downward compression state. The flexible arm has completed the contact adsorption of the wafer, and the robot closes the vacuum and releases the wafer (8).

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