Linear transmission mechanism suitable for ultrahigh vacuum environment

Abstract

The invention discloses a linear transmission mechanism suitable for an ultrahigh vacuum environment. The linear transmission mechanism comprises a sample trolley, a linear guide rail, a driving mechanism and a transmission gear set, the sample trolley, the linear guide rail and the transmission gear set are all arranged in the vacuum cavity, the sample trolley is placed on the linear guide rail, and the multiple driving mechanisms are arranged outside the vacuum cavity in the length direction of the linear guide rail; the transmission gear set comprises a gear and a rack, the rack is arranged on the side of the sample trolley in the moving direction of the sample trolley, and the gear is installed on the side of the linear guide rail through an installation positioning supporting assembly and located on the same side as the rack. The output end of the driving mechanism extends into the vacuum cavity in a sealed mode and is connected with the gear. The driving mechanism drives the gear to rotate, and the gear is meshed with the rack to drive the sample trolley to linearly move in the vacuum cavity along the linear guide rail. The sample trolley has the advantages of being simple in structure, high in reliability and the like, and stable and accurate movement of the sample trolley in the vacuum cavity is achieved.

Description

Technical Field

[0001] This invention relates to the field of semiconductor manufacturing technology, and more specifically to a linear transmission mechanism suitable for ultra-high vacuum environments. Background Technology

[0002] Molecular beam epitaxy (MBE) is performed in an ultra-high vacuum environment. Its fully automated production process requires precise linear motion transport of sample carriages carrying wafers. Due to the limitations of the ultra-high vacuum environment, traditional linear motion mechanisms are insufficient to meet the requirements for long-term, stable automated operation of MBE equipment.

[0003] The two main linear motion transport schemes for sample carriages in ultra-high vacuum environments commonly used in existing technologies are as follows: (1) Gear-driven + guide rail carriage scheme. This scheme is widely used, but it has extremely high requirements for the fabrication of the vacuum chamber and has a high failure rate and short maintenance cycle during operation. This scheme is applied in ultra-high vacuum environments and requires the rack to be mounted on the carrier carriage that makes linear motion. Therefore, the stroke is limited by the length of the rack. If the stroke is increased by lengthening the rack, the length of the vacuum chamber must also be increased, which will occupy a lot of space and affect the vacuum environment and waste costs.

[0004] When adopting this scheme, to meet the requirements of long-stroke linear motion (stroke greater than 1.5 meters) and reasonable cavity design, multiple gear drive mechanisms are configured for interconnection and transmission. The guide rail is installed inside the vacuum cavity, the gear drive is installed outside the vacuum cavity, and the carrier carriage is mounted on the guide rail via multiple sets of roller guide supports. A rack is installed on the carrier carriage parallel to the guide rail direction. The longer the required stroke, the longer the cavity, and the greater the number of gear drives. Because the cavity structure is tubular, the longer the cavity, the more difficult it is to ensure the relative dimensional accuracy of the guide rail, carriage, and gear rack transmission mechanism during manufacturing. The relative dimensional accuracy of these three components is fundamental to ensuring the stable operation of this scheme. Especially for production equipment, ensuring the relative dimensional accuracy error of these three components is a critical challenge that urgently needs to be addressed.

[0005] (2) Direct magnetic force transmission motion scheme. Outside the vacuum chamber, a conventional linear motion mechanism is used to drive the sample carriage inside the vacuum chamber to move linearly through magnetic force transmission. In this scheme, the movement inside and outside the vacuum chamber is directly transmitted by magnetic force. Because the positioning of magnetic force transmission motion is uncontrollable, the repeatability is poor, and the operation of long-stroke transmission through the vacuum chamber connection flange is complicated, this scheme is mostly used in manual or semi-automatic molecular beam epitaxy equipment. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a linear transmission mechanism that is compact, easy to operate, stable and reliable and suitable for ultra-high vacuum environments, in order to overcome the shortcomings of the prior art.

[0007] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A linear transport mechanism suitable for ultra-high vacuum environments includes: a sample carriage, a linear guide rail, a drive mechanism, and a transmission gear set. The sample carriage, linear guide rail, and transmission gear set are all disposed within a vacuum chamber. The sample carriage is placed on the linear guide rail, and multiple drive mechanisms are disposed outside the vacuum chamber along the length of the linear guide rail. The transmission gear set includes a rack and multiple gears. The rack is disposed on the side of the sample carriage along its direction of movement, and the gears are mounted on the side of the linear guide rail, on the same side as the rack. The output end of each drive mechanism extends sealed into the vacuum chamber and is located on the side of the linear guide rail. The gears are connected to the output end of the drive mechanism. When the drive mechanism drives the gears to rotate, the gears mesh with the rack, thereby driving the sample carriage to move linearly along the linear guide rail within the vacuum chamber.

[0008] As a further improvement of the present invention, the gears correspond one-to-one with the drive mechanism, and the length of the rack is greater than the distance between two adjacent gears.

[0009] As a further improvement of the present invention, the sample carriage is provided with support wheel sets at both the front and rear ends along the moving direction of the sample carriage, and the support wheel sets roll along the grooves on the linear guide rail.

[0010] As a further improvement of the present invention, guide wheel sets are provided on the left and right sides of both ends of the sample carriage along the width direction of the linear guide rail, and the guide wheel sets roll along the side of the linear guide rail.

[0011] As a further improvement of the present invention, the drive mechanism includes a motor, a magnetic shaft and a coupling. The motor is mounted outside the vacuum chamber. One end of the magnetic shaft is connected to the output end of the motor, and the other end of the magnetic shaft extends into the vacuum chamber in a sealed manner and is connected to a gear through the coupling.

[0012] As a further improvement of the present invention, a welded bellows is provided between the output end of the motor and the connecting flange on the side of the vacuum chamber for a sealed connection, and the magnetic shaft passes through the welded bellows and the connecting flange and extends into the vacuum chamber.

[0013] As a further improvement of the present invention, the gear is mounted on the side of the linear guide rail by a positioning support assembly.

[0014] Compared with the prior art, the advantages of the present invention are as follows: This invention provides a linear transmission mechanism suitable for ultra-high vacuum environments. The mechanism comprises a sample carriage, a linear guide rail, and a transmission gear set all housed within a vacuum chamber. A rack is positioned along the side of the sample carriage, moving in the same direction. Multiple drive mechanisms are positioned outside the vacuum chamber along the length of the linear guide rail. The output ends of the drive mechanisms extend sealed into the vacuum chamber and connect to the gears. The gears are mounted on the side of the linear guide rail via a positioning support assembly. When the drive mechanism rotates the gears, the gears mesh with the rack, thus enabling the sample carriage to move linearly along the linear guide rail within the vacuum chamber. By employing a unified positioning scheme for the sample carriage and direct drive components, based on the guide rail, this mechanism is well-suited for the long-stroke, precise linear motion transmission requirements of ultra-high vacuum environments. It significantly reduces the manufacturing precision requirements and costs of vacuum equipment, effectively ensures precise linear motion transmission of the sample carriage, and significantly improves the stable operating life of the equipment, thereby guaranteeing production efficiency and substantially reducing equipment manufacturing, assembly, and maintenance costs. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structural principle of a linear transmission mechanism suitable for ultra-high vacuum environments in a specific embodiment of the present invention; Figure 2 This is a partial structural schematic diagram of a linear transmission mechanism suitable for ultra-high vacuum environments in a specific embodiment of the present invention.

[0016] Legend: 1. Vacuum chamber; 2. Sample carriage; 3. Linear guide rail; 4. Drive mechanism; 5. Transmission gear set; 11. Connecting flange; 21. Base plate; 22. Guide wheel set; 23. Support wheel set; 31. Positioning support assembly; 41. Motor; 42. Welded bellows; 43. Magnetic shaft; 44. Coupling; 51. Gear; 52. Rack. Detailed Implementation

[0017] The present invention will be further described below with reference to the accompanying drawings and specific preferred embodiments, but this does not limit the scope of protection of the present invention.

[0018] In the description of this invention, it should be understood that the terms "side", "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0019] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more unless otherwise explicitly specified.

[0020] Example like Figure 1 and Figure 2 As shown, the linear transmission mechanism of the present invention, suitable for ultra-high vacuum environments, includes: a sample carriage 2, a linear guide rail 3, a drive mechanism 4, and a transmission gear set 5. The sample carriage 2, linear guide rail 3, and transmission gear set 5 are all disposed within a vacuum chamber 1. The sample carriage 2 is placed on the linear guide rail 3, and multiple drive mechanisms 4 are disposed outside the vacuum chamber 1 along the length of the linear guide rail 3. The transmission gear set 5 includes a rack 52 and multiple gears 51. The rack 52 is disposed on the side of the sample carriage 2 along the direction of movement of the sample carriage 2. The gears 51 are disposed on the side of the linear guide rail 3 via a positioning support assembly 31. The distance between the gears 51 and the side of the linear guide rail 3 can be finely adjusted via a mounting base 31 to ensure precise meshing between the gears 51 and the rack 52, and stable transmission of driving force. The length of the linear guide rail 3 and the number of gears 51 can be adaptively adjusted according to actual linear motion transmission requirements. The output end of the drive mechanism 4 extends sealed into the vacuum chamber 1 and is located on the side of the linear guide rail 3. The gear 51 is connected to the output end of the drive mechanism 4 to achieve torque transmission. When the drive mechanism 4 drives the gear 51 to rotate, the gear 51 meshes with the rack 52, thereby driving the sample carriage 2 to move linearly along the linear guide rail 3 in the vacuum chamber 1.

[0021] like Figure 2 As shown, gears 51 correspond one-to-one with drive mechanism 4. The length of rack 52 is greater than the distance between two adjacent gears 51, so as to ensure that any two gears 51 can engage and drive sample carriage 2, so as to realize the sample carriage 2 to perform precise positioning and linear motion in vacuum chamber 1.

[0022] like Figure 2 As shown, along the direction of movement of the sample carriage 2, support wheel sets 23 are provided at both the front and rear ends of the base plate 21 of the sample carriage 2. The support wheel sets 23 roll along the grooves on the linear guide rail 3. At the same time, along the width direction of the linear guide rail 3, guide wheel sets 22 are provided on the left and right sides of both the front and rear ends of the base plate 21. The guide wheel sets 22 roll along the sides of the linear guide rail 3. The sample carriage 2 is placed on the linear guide rail 3 by the support wheel sets 23 and the guide wheel sets 22, ensuring that the sample carriage 2 can move smoothly and linearly along the linear guide rail 3.

[0023] like Figure 2 As shown, the drive mechanism 4 includes a motor 41, a magnetic shaft 43, and a coupling 44. The motor 41 is mounted on a fixed base outside the vacuum chamber 1. One end of the magnetic shaft 43 is connected to the output end of the motor 41, and the other end of the magnetic shaft 43 extends sealed into the vacuum chamber 1 and is connected to the gear 51 via the coupling 44. The motor 41 transmits rotational motion to the vacuum chamber 1 through the magnetic shaft 43. Inside the vacuum chamber 1, the magnetic shaft 43 is connected to the shaft of the gear 51 via the coupling 44. The shaft transmission position error between the inside and outside of the vacuum chamber 1 is eliminated by the coupling 44. Multiple motors 41 rotate synchronously, thereby driving the gear 51 on the linear guide rail 3 to rotate synchronously. This further drives the sample carriage 2 to move linearly along the length of the linear guide rail 3 under the transmission of the gear set 5, thus completing the precise linear positioning and transfer of the sample in an ultra-high vacuum environment.

[0024] In this embodiment, a welded bellows pipe 42 is provided between the output end of the motor 41 and the connecting flange 11 on the side of the vacuum chamber 1 for a sealed connection, which can realize the centering adjustment of the drive output shaft relative to the gear shaft. The magnetic shaft 43 passes through the welded bellows pipe 42 and the connecting flange 11 and extends into the vacuum chamber 1.

[0025] In this embodiment, the positioning of gear 51 and rack 52 in the motion actuator is unified on the linear guide rail 3, which allows for precise control of the meshing contact between gear 51 and rack 52, effectively ensuring that the sample carriage 2 performs stable and precise positioning movements. The motion actuator and drive mechanism 4 are respectively installed inside and outside the vacuum chamber 1, and the two are connected by a coupling 44. This effectively compensates for the shortcomings of the complex shape and poor structural rigidity of the ultra-high vacuum chamber, which has poor machining accuracy. It greatly reduces the difficulty of equipment manufacturing, installation, and debugging, saves the production time of the linear transmission mechanism, and solves the problem of short maintenance cycle and unstable operation of the linear transmission mechanism.

[0026] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A linear transmission mechanism suitable for ultra-high vacuum environments, characterized in that, include: The sample carriage (2), linear guide rail (3), drive mechanism (4), and transmission gear set (5) are all arranged inside the vacuum chamber (1). The sample carriage (2) is placed on the linear guide rail (3), and multiple drive mechanisms (4) are arranged outside the vacuum chamber (1) along the length direction of the linear guide rail (3). The transmission gear set (5) includes a rack (52) and multiple gears (51). The rack (52) is arranged along the moving direction of the sample carriage (2). On the side of the sample carriage (2), the gear (51) is installed on the side of the linear guide rail (3) and on the same side as the rack (52); the output end of the drive mechanism (4) extends into the vacuum chamber (1) and is located on the side of the linear guide rail (3). The gear (51) is connected to the output end of the drive mechanism (4); when the drive mechanism (4) drives the gear (51) to rotate, the gear (51) and the rack (52) mesh with each other, thereby driving the sample carriage (2) to move linearly along the linear guide rail (3) in the vacuum chamber (1).

2. The linear transmission mechanism suitable for ultra-high vacuum environments according to claim 1, characterized in that, The gears (51) correspond one-to-one with the drive mechanism (4), and the length of the rack (52) is greater than the distance between two adjacent gears (51).

3. The linear transmission mechanism suitable for ultra-high vacuum environments according to claim 2, characterized in that, Along the moving direction of the sample carriage (2), the front and rear ends of the sample carriage (2) are provided with support wheel sets (23), and the support wheel sets (23) roll along the grooves on the linear guide rail (3).

4. The linear transmission mechanism suitable for ultra-high vacuum environments according to claim 3, characterized in that, Along the width direction of the linear guide rail (3), guide wheel sets (22) are provided on the left and right sides of the front and rear ends of the sample carriage (2), and the guide wheel sets (22) roll along the side of the linear guide rail (3).

5. The linear transmission mechanism suitable for ultra-high vacuum environments according to any one of claims 1 to 4, characterized in that, The drive mechanism (4) includes a motor (41), a magnetic shaft (43) and a coupling (44). The motor (41) is installed outside the vacuum chamber (1). One end of the magnetic shaft (43) is connected to the output end of the motor (41), and the other end of the magnetic shaft (43) extends into the vacuum chamber (1) in a sealed manner and is connected to the gear (51) through the coupling (44).

6. The linear transmission mechanism suitable for ultra-high vacuum environments according to claim 5, characterized in that, A welded bellows pipe (42) is provided between the output end of the motor (41) and the connecting flange (11) on the side of the vacuum chamber (1) for sealing connection. The magnetic shaft (43) passes through the welded bellows pipe (42) and the connecting flange (11) and extends into the vacuum chamber (1).

7. The linear transmission mechanism suitable for ultra-high vacuum environments according to any one of claims 1 to 4, characterized in that, The gear (51) is mounted on the side of the linear guide (3) via a positioning support assembly (31).

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