A flipping mechanism and method for substrate clamping plates in a vacuum environment

Abstract

This invention provides a flipping mechanism and method for substrate clamping plates in a vacuum environment, relating to the semiconductor manufacturing field. The mechanism includes a flipping cavity, and a flipping frame and a flipping support assembly disposed within it. The flipping support assembly includes first and second substrate clamping plates arranged opposite to each other. A flipping drive assembly is located outside the cavity and drives the flipping frame to rotate via a vacuum magnetohydrodynamic seal. The clamping plate opening and closing assembly includes an elastic element disposed on the support and an external opening and closing drive element. The drive element overcomes the elastic force through a bellows to open and close the clamping plates. This invention externalizes the drive assembly, solving the heat dissipation and vibration problems of the vacuum motor and reducing costs; combined with the elastic clamping and lifting structure, it improves wafer loading and unloading efficiency and flipping accuracy.

Description

Technical Field

[0001] This invention relates to the field of semiconductor manufacturing technology, and more specifically to a substrate flipping mechanism and substrate flipping method for substrate clamping plates in a vacuum environment. Background Technology

[0002] In the fields of semiconductor manufacturing and advanced packaging, double-sided substrate processing is a critical process requirement. Especially in advanced packaging processes such as FOPLP (Fan-Out Panel-Level Packaging), it is necessary to perform sputtering, deposition, and other processes on both sides of the substrate, which requires the substrate to be flipped in a vacuum environment.

[0003] Currently, substrate flipping in a vacuum environment mainly employs a vacuum motor drive combined with a rotating shaft transmission. Patent application CN120641600A discloses a module for flipping a substrate in a vacuum. This module includes a clamping assembly capable of fixing the substrate. The clamping assembly comprises a first plate and a second plate that are parallel to each other, and the second plate can move in a direction perpendicular to the main plane of the first plate. In this scheme, the motor assembly is located outside the module housing rather than inside the vacuum environment. A shaft and a sealing assembly rotate the clamping assembly around a first axis, while a lifting rod assembly and an actuator simultaneously perform the clamping, rotating, and releasing actions on the substrate.

[0004] However, the aforementioned existing technical solutions have several shortcomings in practical applications. First, when a vacuum motor is placed inside the cavity, the vacuum motor is not only expensive, but also generates heat during operation, leading to uneven temperature distribution inside the cavity and affecting process stability; at the same time, the vibration generated by the motor during operation affects the overall stability of the mechanism. Second, the opening and closing control mechanism of the clamping assembly in the existing solutions is relatively complex, making it difficult to simplify the structure and reduce costs. In addition, the existing technology lacks an effective substrate lifting mechanism. After the substrate clamping plate is opened, it is difficult for the substrate to be quickly separated from the clamping plate, which is not conducive to the efficient handling of substrates by the vacuum robot. Although Chinese patent application CN214818372U discloses a rotating device for manufacturing mechanical parts, which includes a lifting mechanism for driving the flipping clamp to perform lifting and lowering movements, the technical function of this lifting mechanism is to cooperate with the flipping action to achieve transmission, rather than to lift the workpiece from the clamping plate for easy handling, and thus cannot solve the above problems. Summary of the Invention

[0005] The purpose of this invention is to provide a flipping mechanism and a substrate flipping method for substrate clamping plates in a vacuum environment. By externalizing the flipping drive assembly and the opening and closing drive component and transmitting them through a sealing component, and in conjunction with an elastic clamping and lifting structure, efficient and stable flipping of the substrate in a vacuum environment can be achieved.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A flipping mechanism for a substrate clamp in a vacuum environment includes: a flipping cavity; A flipping frame is disposed inside the flipping cavity; A flipping drive assembly is disposed outside the flipping cavity and connected to the flipping frame via a vacuum-sealed transmission component, used to drive the flipping frame to rotate; A flip support assembly, mounted on the flip frame, includes a first substrate clamping plate and a second substrate clamping plate disposed opposite to each other, with a clamping space for accommodating the substrate formed between the first substrate clamping plate and the second substrate clamping plate; The clamping plate opening and closing assembly includes an elastic element disposed on the flipping bracket assembly and an opening and clamping drive element disposed outside the flipping cavity. The elastic element is used to apply a clamping force to the first substrate clamping plate and the second substrate clamping plate. The opening and clamping drive element is connected to the flipping bracket assembly through a transmission structure and is used to overcome the clamping force of the elastic element to open the first substrate clamping plate and the second substrate clamping plate.

[0007] Furthermore, the flip-up bracket assembly also includes a first bracket and a second bracket, the first bracket being connected to the first substrate clamping plate and the second bracket being connected to the second substrate clamping plate. The opening clamping drive member drives the first bracket and the second bracket to move away from each other through the transmission structure to open the first substrate clamping plate and the second substrate clamping plate.

[0008] Furthermore, both the first bracket and the second bracket are U-shaped brackets.

[0009] Furthermore, the flipping bracket assembly also includes a clamping plate fixing block, a clamping plate fixing block connector, and a clamping plate guide shaft. The clamping plate guide shaft passes through the clamping plate fixing block and the clamping plate fixing block connector. The elastic element is sleeved on the clamping plate guide shaft. The first substrate clamping plate and the second substrate clamping plate are slidably connected to the clamping plate guide shaft through the clamping plate fixing block connector.

[0010] Furthermore, the elastic element is a compression spring, and there are multiple compression springs distributed on the upper and lower sides of the clamping plate guide shaft, which are used to apply a center-oriented clamping force to the first substrate clamping plate and the second substrate clamping plate.

[0011] Furthermore: the clamping drive is a lifting cylinder, and the transmission structure includes a bellows. One end of the bellows is connected to the guide rod of the lifting cylinder, and the other end extends into the interior of the flipping cavity and is connected to the flipping bracket assembly. When the guide rod of the lifting cylinder retracts, it pulls the flipping bracket assembly through the bellows to open the first substrate clamp and the second substrate clamp.

[0012] Furthermore, the flipping drive assembly includes a servo motor, a reducer, and a vacuum magnetohydrodynamic seal. The output end of the servo motor is connected to the reducer, and the reducer is connected to the flipping frame through the vacuum magnetohydrodynamic seal.

[0013] Furthermore: the tilting frame is fixed to the tilting cavity by two vertical supports on the left and right, one of the vertical supports is connected to the cavity outlet shaft of the vacuum magnetohydrodynamic seal by a coupling, and the other vertical support is supported by a bearing.

[0014] Furthermore, a substrate lifting plate is provided on the inner side of the first substrate clamping plate and / or the second substrate clamping plate, the substrate lifting plate being configured to lift the substrate from inside the clamping plate when the first substrate clamping plate and the second substrate clamping plate are opened.

[0015] Furthermore, the central region of the first substrate clamping plate and / or the second substrate clamping plate is provided with a positioning element, which includes a plurality of pins arranged in a cross shape to prevent the substrate from shifting within the clamping space.

[0016] Further: The above-described flipping mechanism includes the following steps: S1: The clamping drive mechanism is activated to overcome the clamping force of the elastic element and open the first substrate clamping plate and the second substrate clamping plate; S2: The vacuum robotic arm feeds the substrate into the clamping space between the first substrate clamping plate and the second substrate clamping plate; S3: The clamping drive component is reset, and the elastic component applies clamping force to clamp the substrate between the first substrate clamping plate and the second substrate clamping plate. S4: The flip drive assembly drives the flip frame to rotate 180°, thus completing the substrate flipping; S5: The clamping drive mechanism operates again, opening the first substrate clamp and the second substrate clamp, and the vacuum robot removes the flipped substrate.

[0017] Compared with the prior art, the present invention has the following advantages: I. This invention places both the flipping drive component and the clamping drive component outside the flipping cavity, and achieves power transmission through vacuum sealing transmission components such as vacuum magnetic fluid seals and bellows, thus avoiding the use of a vacuum motor inside the vacuum cavity. This effectively solves the problem of uneven temperature inside the cavity caused by heat dissipation of the vacuum motor, eliminates the impact of motor vibration on flipping stability, and significantly reduces equipment costs.

[0018] Second, the present invention adopts a separate clamping plate opening and closing design with an elastic element providing clamping force and an external clamping drive element providing opening force. The substrate clamping plate can maintain a clamped state for a long time under the action of the elastic element. The clamping drive element is only needed to operate when it is necessary to place or remove the substrate. This simplifies the control logic, reduces energy consumption, and the overall structure is simple and easy to implement.

[0019] Third, the present invention provides a substrate lifting plate inside the substrate clamping plate, which can automatically lift the substrate from inside the clamping plate to a certain height when the substrate clamping plate is opened, so as to facilitate the vacuum robot to quickly pick up and put down the substrate, thereby improving production efficiency.

[0020] Fourth, the present invention provides a positioning element with pins arranged in a cross pattern in the central area of ​​the substrate clamping plate, which can effectively prevent the substrate from shifting during clamping and flipping, thus ensuring flipping accuracy and process stability.

[0021] Fifth, the present invention adopts a guide structure of clamping plate guide shaft in conjunction with vacuum oil-free bushing. During the opening and closing movement of the substrate clamping plate, friction dust is basically not generated, which avoids contamination of the vacuum chamber and meets the requirements of high cleanliness process environment. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall structure of the flipping mechanism of the present invention; Figure 2 This is a schematic diagram of the structure of the present invention, which is assembled by flipping. Figure 3 This is a schematic diagram of the substrate clamping plate of the present invention.

[0023] In the picture: 1. Tilting cavity; 2. Tilting frame; 3. Vertical support; 4. Servo motor; 5. Reducer; 6. Vacuum magnetic fluid seal; 7. Coupling; 8. Bearing; 10. First substrate clamping plate; 11. Second substrate clamping plate; 12. First U-shaped support; 13. Second U-shaped support; 14. Clamping plate fixing block; 15. Clamping plate fixing block connector; 16. Clamping plate guide shaft; 17. Pressure spring; 18. Lifting cylinder; 19. Bellows; 20. Shaft end gasket; 21. Substrate lifting plate; 22. Ejector pin; 23. Substrate. Detailed Implementation

[0024] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0026] This invention provides a flipping mechanism for a substrate clamp in a vacuum environment. This flipping mechanism is mainly used in advanced packaging processes such as FOPLP substrate packaging. It is used to flip the substrate 23 180° in a vacuum environment to meet the needs of double-sided sputtering, deposition and other processes of the substrate 23.

[0027] The flipping mechanism includes a flipping chamber 1, a flipping frame 2, a flipping drive assembly, a flipping support assembly, and a clamping plate opening and closing assembly. The flipping chamber 1 provides a vacuum working environment for the entire mechanism. The flipping chamber 1 is equipped with an interface for connecting to a vacuum pump, which maintains a high vacuum level inside the flipping chamber 1. Because the flipping chamber 1 of this invention has independent vacuum maintenance capabilities, it can be connected to other vacuum chambers to achieve continuous transport of the substrate 23 in a vacuum environment, reducing the time spent in the process flow.

[0028] The flipping frame 2 is located at the center of the flipping cavity 1 and is used to support the flipping support assembly and realize the rotational movement. The flipping frame 2 is fixed inside the flipping cavity 1 by two vertical supports 3 on the left and right sides. This double-sided support structure design ensures the stability of the flipping frame 2 during rotation and avoids problems such as left-low and right-high or uneven force that may be caused by single-sided drive.

[0029] The tilting drive assembly is located outside the tilting cavity 1 and provides rotational power to the tilting frame 2. The tilting drive assembly includes a servo motor 4, a reducer 5, and a vacuum magnetic fluid seal 6. The output end of the servo motor 4 is connected to the reducer 5, which reduces the rotational speed and increases the torque to ensure the smoothness and precision of the tilting motion. The reducer 5 is connected to the interior of the tilting cavity 1 via the vacuum magnetic fluid seal 6. The vacuum magnetic fluid seal 6 is a sealing element that can transmit rotational motion while maintaining a vacuum seal. Its working principle utilizes a liquid sealing ring formed by a magnetic fluid under the action of a magnetic field, which effectively isolates the atmosphere from the vacuum environment and enables contactless power transmission. The output shaft inside the vacuum magnetic fluid seal 6 is connected to one of the vertical supports 3 via a coupling 7, transmitting the rotational power of the servo motor 4 to the tilting frame 2. The other vertical support 3 supports the tilting frame 2 on the tilting cavity 1 via a bearing 8, serving as the driven side support point of the tilting frame 2. When the servo motor 4 rotates forward, it drives the flipping frame 2 and its flipping bracket assembly to rotate forward; when the servo motor 4 rotates in reverse, it drives the flipping frame 2 to rotate in reverse, thereby realizing the 180° flipping action of the substrate 23.

[0030] The flip-up bracket assembly, mounted on the flip-up frame 2, is the core component for clamping and flipping the substrate 23. The flip-up bracket assembly includes a first substrate clamping plate 10 and a second substrate clamping plate 11 positioned opposite each other, located above and below, respectively, forming a clamping space between them to accommodate the substrate 23. The inner sides of both the first substrate clamping plate 10 and the second substrate clamping plate 11 are provided with grooves adapted to the shape of the substrate 23. After the substrate 23 is placed in, it is embedded in the grooves, ensuring that the substrate 23 will not shift or fall off during the flipping process.

[0031] The flip-up bracket assembly also includes a first U-shaped bracket 12 and a second U-shaped bracket 13. The first U-shaped bracket 12 is connected to the first substrate clamping plate 10, and the second U-shaped bracket 13 is connected to the second substrate clamping plate 11. The structural design of the first U-shaped bracket 12 and the second U-shaped bracket 13 allows the clamping plates to have a large opening and closing stroke, while maintaining a compact structure and uniform force distribution. The flip-up bracket assembly also includes a clamping plate fixing block 14, a clamping plate fixing block connector 15, and a clamping plate guide shaft 16. The clamping plate guide shaft 16 passes through the clamping plate fixing block 14 and the clamping plate fixing block connector 15. The first substrate clamping plate 10 and the second substrate clamping plate 11 are slidably connected to the clamping plate guide shaft 16 through the clamping plate fixing block connector 15, allowing the two substrate clamping plates to move relative to each other along the axial direction of the clamping plate guide shaft 16, thus achieving the opening and closing action. The clamping plate guide shaft 16 is fixed by a vacuum oil-free bushing. The vacuum oil-free bushing generates virtually no frictional dust when moving in a vacuum environment, avoiding contamination of the vacuum chamber and meeting the requirements of a high-cleanliness process environment.

[0032] The clamping plate opening and closing assembly includes an elastic element and an opening and closing drive element. The elastic element is disposed on the flipping bracket assembly, specifically a pressure spring 17 sleeved on the clamping plate guide shaft 16. There are multiple pressure springs 17, distributed on the upper and lower sides of the clamping plate guide shaft 16; in this embodiment, four pressure springs 17 are disposed on each side. These pressure springs 17 apply a center-oriented clamping force to the first substrate clamping plate 10 and the second substrate clamping plate 11, keeping the two substrate clamping plates in a clamped state under normal conditions. The design of using pressure springs 17 to provide clamping force allows the substrate clamping plates to maintain a stable clamped state for a long time without continuous energy consumption, and the clamping force is stable and reliable.

[0033] The clamping drive is located outside the tilting cavity 1, specifically as a lifting cylinder 18 installed at the bottom of the tilting cavity 1. The clamping drive is connected to the tilting support assembly via a transmission structure, which includes a bellows 19. The bellows 19 is a retractable metal sealing element; one end is connected to the guide rod of the lifting cylinder 18, and the other end extends into the tilting cavity 1 and connects to the first U-shaped bracket 12 and the second U-shaped bracket 13 of the tilting support assembly, specifically through a shaft end washer 20. The bellows 19 maintains a vacuum seal while transmitting the linear motion of the lifting cylinder 18 to the interior of the tilting cavity 1. When the substrate clamping plates need to be opened, the guide rod of the lifting cylinder 18 retracts, driving the shaft end washer 20 to pull down the first U-shaped bracket 12 and the second U-shaped bracket 13 through the bellows 19. This overcomes the clamping force of the pressure spring 17, causing the first substrate clamping plates 10 and 11 to move away from each other, thus opening the clamping space. When the guide rod of the lifting cylinder 18 extends and returns to its original position, the bellows 19 no longer applies tension to the first U-shaped bracket 12 and the second U-shaped bracket 13, and the elastic force of the pressure spring 17 pushes the two substrate clamping plates closer together, re-clamping the substrate 23. The distance the substrate clamping plates open can be adjusted by the stroke of the lifting cylinder 18, providing good flexibility.

[0034] The first substrate clamping plate 10 and the second substrate clamping plate 11 are further provided with substrate lifting plates 21 on their inner sides. The substrate lifting plates 21 are installed around the perimeter of the substrate clamping plates. The substrate lifting plates 21 enable the substrate 23 to be lifted to a certain height from inside the substrate clamping plates when the substrate clamping plates are opened. The purpose of this design is to facilitate the entry of a vacuum robot between the clamping plates to retrieve the substrate, thereby improving the efficiency and reliability of substrate retrieval and placement.

[0035] The central regions of the first substrate clamping plate 10 and the second substrate clamping plate 11 are further provided with positioning elements, which include a plurality of pins 22 arranged in a cross shape. In this embodiment, the center of the substrate clamping plate is provided with two rows of cross-shaped pins 22. These pins 22 are used to prevent the substrate 23 from shifting horizontally within the clamping space, ensuring the positional accuracy of the substrate 23 throughout the flipping process.

[0036] The specific working process of substrate flipping using the above-mentioned flipping mechanism is as follows: In the initial state, the first substrate clamping plate 10 and the second substrate clamping plate 11 are clamped under the action of the pressure spring 17, and the guide rod of the lifting cylinder 18 is in the extended position.

[0037] When substrate flipping is required, the lifting cylinder 18 first activates, the guide rod retracts, and the bellows 19 drives the shaft end washer 20 to pull down the first U-shaped bracket 12 and the second U-shaped bracket 13, overcoming the clamping force of the pressure spring 17, and opening the first substrate clamping plate 10 and the second substrate clamping plate 11. At this time, a sufficient gap is formed between the two substrate clamping plates to allow the vacuum robot to enter.

[0038] Next, the vacuum manipulator carries the substrate 23 to be flipped into the flipping cavity 1, and sends the substrate 23 into the clamping space between the first substrate clamping plate 10 and the second substrate clamping plate 11. The substrate 23 falls into the groove on the inner side of the clamping plate, and the cross-shaped pins 22 in the central area position the substrate 23 in the horizontal direction.

[0039] Then, the guide rod of the lifting cylinder 18 extends and resets, and the bellows 19 resets accordingly, no longer applying tension to the first U-shaped bracket 12 and the second U-shaped bracket 13. At this time, the elastic force of the pressure spring 17 is released, pushing the first substrate clamping plate 10 and the second substrate clamping plate 11 closer together, clamping the substrate 23. The vacuum manipulator withdraws from the flipping cavity 1.

[0040] After the substrate 23 is clamped, the servo motor 4 starts, driving the flipping frame 2 to rotate via the reducer 5 and the vacuum magnetohydrodynamic seal 6. The flipping frame 2 drives the entire flipping support assembly to rotate 180°, thereby completing the flipping action of the substrate 23. During the flipping process, since the substrate 23 is firmly clamped in the groove and positioned by the ejector pin 22, it will not shift or fall off.

[0041] After the flipping is complete, the servo motor 4 stops, and the flipping frame 2 remains in the flipped position. The lifting cylinder 18 actuates again, the guide rod retracts, and the first substrate clamping plate 10 and the second substrate clamping plate 11 are opened. At this time, the substrate lifting plate 21 lifts the substrate 23 from inside the substrate clamping plate to a certain height, making it easier for the vacuum robot to enter and pick up the substrate.

[0042] Finally, the vacuum robot enters the flipping chamber 1, removes the flipped substrate 23, and transports it to the next process chamber for further processing. The guide rod of the lifting cylinder 18 extends and resets, the substrate clamping plate closes again, and it awaits the next flipping operation.

[0043] The entire flipping process is completed in a vacuum environment. Since the flipping chamber 1 has an independent vacuum pump to maintain a high vacuum, it can interface with other vacuum chambers such as the degassing chamber and the process chamber. This allows the substrate 23 to be directly transported to the process chamber for processing in a vacuum environment after degassing, without the need to break the vacuum, significantly reducing the time spent in the process flow and improving production efficiency. Simultaneously, because the flipping drive assembly and clamping drive are both located outside the flipping chamber 1, there are no heat-generating components such as motors inside the flipping chamber 1, avoiding uneven temperature and vibration problems and ensuring process stability. The clamping guide shaft 16 uses a vacuum oil-free bushing, generating virtually no dust during movement, ensuring the cleanliness of the vacuum chamber.

[0044] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent transformations or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A flipper mechanism for a substrate holder plate in a vacuum environment, characterized by, include: Flip the cavity; A flipping frame is disposed inside the flipping cavity; A flipping drive assembly is disposed outside the flipping cavity and connected to the flipping frame via a vacuum-sealed transmission component, used to drive the flipping frame to rotate; A flip support assembly, mounted on the flip frame, includes a first substrate clamping plate and a second substrate clamping plate disposed opposite to each other, with a clamping space for accommodating the substrate formed between the first substrate clamping plate and the second substrate clamping plate; The clamping plate opening and closing assembly includes an elastic element disposed on the flipping bracket assembly and an opening clamping drive element disposed outside the flipping cavity. The elastic element is used to apply a clamping force to the first substrate clamping plate and the second substrate clamping plate. The opening clamping drive element is connected to the flipping bracket assembly through a transmission structure and is used to overcome the clamping force of the elastic element to open the first substrate clamping plate and the second substrate clamping plate. The first substrate clamp and / or the second substrate clamp are provided with a substrate lifting plate on their inner side. The substrate lifting plate is configured to lift the substrate from inside the clamp when the first substrate clamp and the second substrate clamp are opened.

2. The turnover mechanism according to claim 1, characterized in that The flip-up bracket assembly further includes a first bracket and a second bracket. The first bracket is connected to the first substrate clamping plate, and the second bracket is connected to the second substrate clamping plate. The clamping drive unit drives the first bracket and the second bracket to move away from each other through the transmission structure to open the first substrate clamping plate and the second substrate clamping plate.

3. The turnover mechanism according to claim 2, wherein Both the first bracket and the second bracket are U-shaped brackets.

4. The turnover mechanism according to claim 2, wherein The flip-up bracket assembly further includes a clamping plate fixing block, a clamping plate fixing block connector, and a clamping plate guide shaft. The clamping plate guide shaft passes through the clamping plate fixing block and the clamping plate fixing block connector. The elastic element is sleeved on the clamping plate guide shaft. The first substrate clamping plate and the second substrate clamping plate are slidably connected to the clamping plate guide shaft through the clamping plate fixing block connector.

5. The turnover mechanism according to claim 4, wherein The elastic element is a compression spring, and there are multiple compression springs distributed on the upper and lower sides of the clamping plate guide shaft, which are used to apply a center-oriented clamping force to the first substrate clamping plate and the second substrate clamping plate.

6. The turnover mechanism of claim 1, wherein The clamping drive is a lifting cylinder, and the transmission structure includes a bellows. One end of the bellows is connected to the guide rod of the lifting cylinder, and the other end extends into the interior of the flipping cavity and is connected to the flipping bracket assembly. When the guide rod of the lifting cylinder retracts, it pulls the flipping bracket assembly through the bellows to open the first substrate clamp and the second substrate clamp.

7. The flipping mechanism according to claim 1, characterized in that, The flipping drive assembly includes a servo motor, a reducer, and a vacuum magnetohydrodynamic seal. The output end of the servo motor is connected to the reducer, and the reducer is connected to the flipping frame through the vacuum magnetohydrodynamic seal.

8. The turnover mechanism according to claim 7, wherein The flipping frame is fixed to the flipping cavity by two vertical supports on the left and right. One of the vertical supports is connected to the cavity outlet shaft of the vacuum magnetohydrodynamic seal through a coupling, and the other vertical support is supported by a bearing.

9. The turnover mechanism of claim 1, wherein, The first substrate clamping plate and / or the second substrate clamping plate are provided with a positioning element in the central area. The positioning element includes a plurality of pins arranged in a cross shape to prevent the substrate from shifting within the clamping space.

10. A substrate flipping method, characterized by, The flipping mechanism according to any one of claims 1 to 9 includes the following steps: S1: The clamping drive mechanism moves to overcome the clamping force of the elastic element and open the first substrate clamping plate and the second substrate clamping plate; S2: The vacuum robot sends the substrate into the clamping space between the first substrate clamping plate and the second substrate clamping plate; S3: The clamping drive component is reset, and the elastic component applies clamping force to clamp the substrate between the first substrate clamping plate and the second substrate clamping plate. S4: The flip drive assembly drives the flip frame to rotate 180°, thus completing the substrate flipping; S5: The clamping drive mechanism operates again, opening the first substrate clamp and the second substrate clamp, and the vacuum robot removes the flipped substrate.

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