Three-degree-of-freedom active gas type non-contact transmission platform

Abstract

The invention discloses a three-degree-of-freedom active gas type non-contact transmission platform, and relates to the technical field of machinery. The conveying platform comprises a conveying platform body and a driving mechanism. The transmission platform body is composed of a fixed base, a hinge plate, spring steel, a breathable steel bearing, an air supply chamber and a vacuum shell, and the driving mechanism is composed of a piezoelectric ceramic actuator and a bridge type amplifying device. The relative position of the hinge plate is adjusted by controlling the deformation quantity of the piezoelectric ceramic actuator, so that directional inclined deformation of the breathable steel bearing is achieved, the viscous force of an air film is adjusted and controlled in real time, and finally non-contact precise transmission of the thin substrate is achieved. The working surfaces of the breathable steel bearings adopt gradient pore design, so that the performance of the transmission platform is ensured, and the dynamic stability of the thin substrate during transmission is improved. The transmission platform has a three-degree-of-freedom decoupling control capability, is compact in structure and fast in dynamic response, and is suitable for lossless carrying and positioning of various high-precision thin substrates.

Description

TECHNICAL FIELD

[0001] The present application relates to the mechanical technical field, and in particular provides a three-degree-of-freedom active gas type non-contact transmission platform. BACKGROUND

[0002] High-precision non-destructive transmission of thin substrates (such as silicon wafers, OLED panels, etc.) is a core process link in high-end industries such as semiconductor manufacturing and flexible display. Under the background of accelerating development of industries towards high efficiency, ultra-thin and integration, the expansion of the size and thinning of the thickness of the thin substrate become the key path to reduce cost and increase efficiency, which puts forward almost zero damage and zero pollution requirements for the transmission technology.

[0003] Traditional contact transmission technologies, such as rollers, suction cups or clamping mechanisms, are prone to cause defects such as friction, static pollution, stress concentration and edge damage when handling thin substrates, and are difficult to meet the requirements of cleanliness and integrity in high-end manufacturing processes. The aerostatic bearing technology introduces external compressed gas into the bearing gap to form a stable high-pressure gas film between the moving parts and the non-moving parts, thereby realizing non-contact support and near-zero friction characteristics, which has been widely used in ultra-precision machining, metrology and aerospace fields. Therefore, the non-contact transmission technology based on the principle of aerostatic bearing has become a research hotspot, and currently mainly includes three types of aerostatic suspension, negative pressure adsorption and active gas film driving. Among them, the aerostatic suspension and negative pressure adsorption usually need to rely on external moving devices to realize planar transmission, and the system structure is complex and it is difficult to effectively avoid contact risk. The active gas film driving type realizes the non-contact driving of the thin substrate by controlling the viscous force generated by the gas film, and has the functions of suspension, adsorption and driving transmission, and has the advantage of high system integration. However, the existing active gas film driving system generally adopts a complex gas supply manifold to connect the gas inlet / outlet and the external control valve, which not only has a complex system structure, but also has problems such as dynamic response lag and limited control bandwidth. SUMMARY

[0004] The purpose of the present application is to provide a three-degree-of-freedom active gas type non-contact transmission platform to solve the technical problems existing in the prior art. By controlling the micro-scale directional tilt deformation of the working surface of the transmission platform, the airflow is guided to form a controlled flow in a specific direction, thereby realizing real-time regulation of the size and direction of the viscous force acting on the thin substrate, and then realizing the accurate, non-contact and zero-pollution directional transmission of the thin substrate.

[0005] To achieve the above technical effects, the technical solutions of the present application are as follows:

[0006] The application discloses a three-degree-of-freedom active gas non-contact transmission platform, which comprises a transmission platform body and a driving mechanism, wherein the transmission platform body comprises a fixed base, a hinge plate, spring steel, a gas-permeable steel bearing, a locking nut, a gas supply chamber and a vacuum shell. The fixed base is provided with the hinge plate, and the hinge plate is integrated with a driving and transmission mechanism. The driving mechanism comprises a piezoelectric ceramic actuator and a bridge amplification device, the piezoelectric ceramic actuator is connected with the bridge amplification device, the bridge amplification device outputs a displacement through deformation of the piezoelectric ceramic actuator; the displacement is transmitted to an inner support plate of the hinge plate through a composite hinge transmission structure. The composite hinge structure comprises a double-leaf parallel hinge and a double-circular hinge, one end of the double-leaf parallel hinge is connected with the bridge amplification device as an input end, the other end is connected with the double-circular hinge; the other end of the double-circular hinge is fixedly connected with the hinge plate, so that the driving displacement is transmitted; the spring steel is fixed between the hinge plate and the vacuum shell, so that the gas-permeable steel bearing is deflected, the upper part of the gas-permeable steel bearing is fixed on the spring steel through the locking nut, the bottom part is bonded on the gas supply chamber, the vacuum shell is fixed on the hinge plate and is provided with a sealing ring to ensure air tightness; the piezoelectric ceramic actuator is controlled to stretch and contract, the bridge amplification device and the composite hinge are driven to move, so that the gas-permeable steel bearing is directionally and slightly inclined, more air flow is guided to the inclined direction, a directional viscous force is generated, and the non-contact directional transmission of a thin substrate is realized.

[0007] Further, the driving mechanism is distributed in the X direction and the Y direction, two driving units are arranged in the Y direction, and four driving units are arranged in the X direction. One end of each piezoelectric ceramic actuator is connected with the bridge amplification device through Hertz contact, and the other end is fixed through a pre-tightening screw. Each piezoelectric ceramic actuator can be independently controlled, so that the transmission platform can be adjusted in three degrees of freedom in the X direction, the Y direction and the rotating direction in the XY plane.

[0008] Further, the bridge amplification device adopts a circular hinge structure design and has high-precision transmission performance.

[0009] Further, the transmission mechanism adopts a double-leaf parallel hinge and a double-circular hinge combination design to realize accurate and stable transmission of the deformation amount of the piezoelectric ceramic actuator.

[0010] Further, the top end suspension area of the gas-permeable steel bearing is divided into a central gas-permeable area and an edge gas-permeable area to improve the transmission performance and dynamic stability of the thin substrate.

[0011] Further, the bottom part of the gas-permeable steel bearing adopts a three-axis flexible circular hinge design to ensure the performance consistency of the gas-permeable steel bearing when being inclined in each direction.

[0012] Further, the air-permeable steel bearing is prepared by a 3D integrated forming process, so as to improve structural stability and manufacturing consistency.

[0013] Further, the vacuum shell, spring steel and air-permeable steel bearing jointly form a negative pressure cavity, so as to ensure generation of viscous force and improve suspension stiffness of the thin substrate.

[0014] Further, the hinge plate is provided with an annular groove for mounting a sealing ring, so as to improve air tightness of the device.

[0015] Compared with the prior art, the present application has the following advantages:

[0016] 1. The non-contact transmission mode based on the static pressure gas bearing can effectively avoid damage and pollution of the thin substrate, and has strong universality compared with the traditional contact transmission mode.

[0017] 2. The driving unit of the transmission platform adopts a parallel configuration, so as to realize decoupling of planar three-degree-of-freedom motion.

[0018] 3. The platform is composed of array air-permeable steel bearings, so as to build transmission platforms of different sizes and shapes according to different working conditions.

[0019] 4. The working surface of the air-permeable steel bearing adopts a gradient porosity design, which can improve the ratio of viscous force to gas consumption, and help to improve dynamic transmission stability. Meanwhile, the air-permeable area of the working surface can be distributed or have multiple shapes.

[0020] 5. The air-permeable steel bearing adopts an integrated 3D printing forming technology, which not only ensures performance consistency but also improves the integration of the transmission platform. DETAILED DESCRIPTION

[0021] Figure 1 Fig. 1 is a structural schematic diagram of a three-degree-of-freedom active gas type non-contact transmission platform of the present application, wherein 1 is a hinge plate, 2 is a piezoelectric ceramic actuator, 3 is a gas supply chamber, 4 is a fixed base, 5 is an air-permeable steel bearing, the number of which can be adjusted according to specific working conditions, and 6 is a vacuum shell.

[0022] Figure 2 Fig. 2 is a structural schematic diagram of a hinge plate of the three-degree-of-freedom active gas type non-contact transmission platform of the present application, which is integrally processed, wherein 11 is a hinge plate substrate, 12 is a bridge type amplification device, 13 is a double-leaf parallel hinge, 14 is a double-circular hinge, 15 is an inner support plate of the hinge plate, 16 is a through-hole structure, and 17 is a sealing groove of the hinge plate.

[0023] Figure 3It is a sectional view of the gas permeable steel bearing of the three-degree-of-freedom active gas type non-contact transmission platform, wherein 51 is a central gas permeable area, 52 is an edge gas permeable area, 53 is a pressure equalizing cavity, 54 is a standard thread, 55 is an internal flow channel, and 56 is an air inlet hole.

[0024] Figure 4 It is a structural schematic view of the gas supply chamber of the three-degree-of-freedom active gas type non-contact transmission platform, wherein 31 is a mounting groove of the gas permeable steel bearing, and 32 is an air inlet hole.

[0025] Figure 5 It is a structural schematic view of the vacuum shell of the three-degree-of-freedom active gas type non-contact transmission platform, wherein 61 is a vacuum shell base body, 62 is a negative pressure air extraction hole, and 63 is a through hole structure of the vacuum shell.

[0026] Figure 6 It is a structural schematic view of the spring steel of the three-degree-of-freedom active gas type non-contact transmission platform, wherein 7 is a spring steel base body with a thickness of microns, 8 is a spring steel bolt connection hole, and 9 is a through hole for mounting the gas permeable steel bearing.

[0027] Figure 7 It is a top view of the gas permeable steel bearing of the three-degree-of-freedom active gas type non-contact transmission platform, wherein the permeable area shape is a distributed square.

[0028] Figure 8 It is a top view of the gas permeable steel bearing of the three-degree-of-freedom active gas type non-contact transmission platform, wherein the top end shape is a regular hexagon and the permeable area shape is a distributed regular hexagon.

[0029] Figure 9 It is a top view of the gas permeable steel bearing of the three-degree-of-freedom active gas type non-contact transmission platform, wherein the top end shape is a triangle.

[0030] Figure 10 It is a top view of the gas permeable steel bearing of the three-degree-of-freedom active gas type non-contact transmission platform, wherein the top end shape is a regular hexagon.

[0031] Figure 11 It is a top view of the hinge plate of the three-degree-of-freedom active gas type non-contact transmission platform, wherein the driving unit is a voice coil motor. DETAILED DESCRIPTION

[0032] To make the purpose, technical solutions and advantages of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application.

[0033] Please refer to Figures 1-5The application provides a three-degree-of-freedom active gas non-contact transmission platform, which comprises a transmission platform body, the transmission platform body comprises a fixed base (4), a hinge plate (1), spring steel, a gas permeable steel bearing (5), a locking nut, a gas supply chamber (3), and a vacuum shell (6), the hinge plate (1) is installed on the fixed base (4), a driving and transmission mechanism is integrated on the hinge plate (1), the driving mechanism comprises a piezoelectric ceramic actuator (2) and a bridge amplification device (12), the bridge amplification device (12) is closely connected with the piezoelectric ceramic actuator (2) inside, the piezoelectric ceramic actuator (2) drives the movement of the bridge amplification device (12) through its own deformation, so that the amplified displacement is transmitted to a composite hinge device; the composite hinge device comprises a double-leaf parallel hinge (13) and a double-circular hinge (14), one end of the double-leaf parallel hinge (13) is fixedly connected with the bridge amplification device (12) as a displacement input end, the other end is fixedly connected with the double-circular hinge (14) to realize the transmission of displacement, and the other end of the double-circular hinge (14) is fixedly connected with a hinge plate inner support plate (15) to realize the displacement transmission of the driving mechanism; the spring steel is fixed between the hinge plate (1) and the vacuum shell (6), the upper part of the gas permeable steel bearing (5) is fixed on the spring steel through the locking nut, and the bottom is bonded to the gas supply chamber (3), and the vacuum shell (6) is fixed on the hinge plate (1); the deformation of the piezoelectric ceramic actuator (2) is controlled to push the hinge plate (1), so that the gas permeable steel bearing (5) is inclined, and more airflow is guided to the inclined side, thereby realizing the non-contact directional transmission of a thin substrate. Specifically, the driving mechanism is distributed in the X direction and the Y direction of the non-contact transmission platform, wherein there are two driving units in the Y direction and four driving units in the X direction, one end of the piezoelectric ceramic actuator (2) is in Hertz contact with the bridge amplification device (12), and the other end is connected in the bridge amplification device (12) through a screw, the piezoelectric ceramic actuator (2) of each driving unit can be independently controlled, the piezoelectric ceramic actuator (2) can be stretched or contracted by controlling the voltage of different piezoelectric ceramic actuators, and then the translation movement of the platform in the X direction and the Y direction and the rotation movement in the XY plane are controlled.

[0034] The gas permeable steel bearing (5) is integrally processed by 3D printing technology, the top suspension area is made of gas permeable steel material, the top area is divided into a central gas permeable area (51) and an edge gas permeable area (52), and the uniformity and stability of the input pressure of the suspension area are realized through the pressure equalizing cavity (53) of the gas permeable steel bearing (5); in addition, the bottom of the gas permeable steel bearing (5) is designed with a three-axis flexible circular hinge, so that the gas permeable steel bearing (5) can be inclined at any angle under the premise that the bottom of the gas permeable steel bearing (5) is fixedly connected with the gas supply cavity (3).

[0035] The transmission mechanism utilizes the combination structure of double-leaf parallel hinge (13) and double-circle hinge (14) to accurately and smoothly transmit the deformation of piezoelectric ceramic actuator (2) transmitted by bridge type amplification device (12) to hinge plate inner support plate (15).

[0036] The vacuum shell (6), spring steel, air-permeable steel bearing (5) and the transmitted thin substrate form a relatively closed negative pressure cavity, and then the negative pressure suction hole (62) is used for suction, which ensures the size and direction of viscous force and improves the transmission stability of the thin substrate.

[0037] The remaining matters of the present application are the known art.

[0038] The above examples are only for illustrating the technical concept and characteristics of the present application, and the purpose is to enable the person skilled in the art to understand the content of the present application and to implement it, and cannot limit the protection scope of the present application. Any equivalent changes or modifications made according to the spirit and essence of the present application shall be covered within the protection scope of the present application.

Claims

1. A three-degree-of-freedom active gas-type contactless transmission platform, characterized in that: The invention comprises a transport platform body, wherein the transport platform body comprises a fixed base (4), a hinge plate (1), a spring steel, breathable steel bearing (5), a locking nut, an air supply chamber (3), and a vacuum shell (6); the fixed base (4) is mounted with a hinge plate (1); the hinge plate (1) is integrated with a driving and transmission mechanism; the driving mechanism comprises a piezoelectric ceramic actuator (2) and a bridge-type amplifier (12); the bridge-type amplifier (12) is closely connected to the piezoelectric ceramic actuator (2); the piezoelectric ceramic actuator (2) drives the movement of the bridge-type amplifier (12) through its own deformation, thereby transmitting the amplified displacement to the composite hinge device; the composite hinge device comprises a double-leaf parallel hinge (13) and a double-circular hinge (14); the double-leaf parallel hinge One end of the chain (13) is fixedly connected to the bridge amplifier (12) as a displacement input end, and the other end is fixedly connected to the double-circular hinge (14) to realize displacement transmission, and the other end of the double-circular hinge (14) is fixedly connected to the support plate (15) inside the hinge plate to realize displacement transmission of the driving mechanism; the spring steel is fixed between the hinge plate (1) and the vacuum shell (6), the upper part of the breathable steel bearing (5) is fixed to the spring steel through a locking nut, and the bottom is bonded to the air supply chamber (3), and the vacuum shell (6) is fixed to the hinge plate (1); by controlling the deformation of the piezoelectric ceramic actuator (2) to push the hinge plate (1), the breathable steel bearing (5) is tilted, thereby guiding more airflow to the tilted side, thereby realizing non-contact directional transmission of the thin substrate.

2. The non-contact transport platform according to claim 1, characterized in that: The driving mechanism is distributed in the X direction and the Y direction, wherein there are two driving units in the Y direction and four driving units in the X direction. One end of the piezoelectric ceramic actuator (2) is connected to the bridge amplifier (1) through a Hertz contact method, and the other end is fixed by a pre-tightening screw. In addition, the driving unit can also be replaced by a power and execution integrated device such as a voice coil motor.

3. The non-contact transport platform according to claim 1, characterized in that: The transmission mechanism integrates a double-leaf parallel hinge (13) and a double-circular hinge (14) structure.

4. The non-contact transport platform according to claim 1, characterized in that: The top suspension area of ​​the breathable steel bearing (5) is divided into a central breathable area (51) and an edge breathable area (52), and the shape of the breathable area can be square, regular hexagon, triangle, circle or distributed shape.

5. The non-contact transport platform according to claim 4, characterized in that: The bottom of the breathable steel bearing (5) adopts a three-axis flexible circular hinge design.

6. The non-contact transport platform according to claim 1, characterized in that: The top end of the breathable steel bearing (5) is in the shape of a square, a regular hexagon, a triangle or a circle.

7. The non-contact transport platform according to claim 1, characterized in that: The vacuum housing (6) and the spring steel and breathable steel bearing (5) form a negative pressure chamber, and an annular groove (17) for installing a sealing ring is formed on the hinge plate (1).

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