Cylinder assembly and wafer clamping mechanism comprising same

Abstract

The embodiment of the utility model relates to the technical field of wafer conveying, and provides an air cylinder assembly and a wafer clamping mechanism comprising the air cylinder assembly. The air cylinder assembly comprises an air cylinder, an output shaft, a clamping force adjusting module and an optical sensor. One end of the output shaft is arranged in the cavity in a sliding mode and connected with the piston, a through hole is formed in the output shaft, and a first ventilation opening and a second ventilation opening which communicate with the cavity are formed in the air cylinder. In the direction of the moving path of the output shaft, the piston slides between the first air port and the second air port. According to the embodiment of the invention, the force applied to the wafer by the wafer clamping mechanism can be adjusted, and wafer breakage caused by overlarge contact force between the wafer and the wafer fixing structure is avoided.

Description

Technical Field

[0001] The embodiments of this application relate to the field of wafer transfer technology, and particularly to cylinder assemblies and wafer clamping mechanisms containing the cylinder assembly. Background Technology

[0002] Cylinders are commonly used power output devices in wafer clamping. They typically include a hollow cavity and an output shaft. One end of the output shaft includes a piston, which can move along the axis of the output shaft within the cavity, thereby driving an external mechanism to move and apply clamping force to the wafer.

[0003] However, the cylinders used in existing wafer clamping mechanisms can usually only apply a constant force to the wafer, which poses a risk of wafer breakage.

[0004] Therefore, there is a continued need in the art to develop a cylinder assembly and a wafer clamping mechanism containing the cylinder assembly. Utility Model Content

[0005] To solve or at least partially solve the above-mentioned technical problems, embodiments of this application provide a cylinder assembly and a wafer clamping mechanism containing the cylinder assembly to ensure safety during wafer transfer, reduce the risk of wafer transfer downtime, and reduce the risk of wafer breakage.

[0006] Embodiments of this application provide a cylinder assembly for use in wafer transfer equipment, comprising:

[0007] A cylinder, wherein the cylinder has an internal cavity and a piston is movably disposed within the cavity;

[0008] An output shaft, one end of which is slidably disposed in the cavity and connected to the piston, has a through hole on the output shaft, and a first vent and a second vent are provided on the cylinder to communicate with the cavity. Along the moving path of the output shaft, the piston slides between the first vent and the second vent.

[0009] A clamping force adjustment module, wherein the clamping force adjustment module is connected to the first vent and the second vent respectively;

[0010] An optical sensor is installed on the moving path of the cylinder's output shaft to detect the position of the output shaft on the moving path in real time.

[0011] Optionally, the clamping force adjustment module includes:

[0012] The first solenoid valve has an outlet port connected to the first air port and an inlet port connected to the air source.

[0013] The second solenoid valve, the outlet of the second solenoid valve is connected to the second vent.

[0014] The third solenoid valve has its outlet port connected to the inlet port of the second solenoid valve, and the inlet port of the third solenoid valve is connected to an air source.

[0015] The optical sensor is electrically connected to the first solenoid valve, the second solenoid valve, and the third solenoid valve.

[0016] Optionally, the clamping force adjustment module further includes:

[0017] A pressure reducing valve is connected to the vent port of the third solenoid valve.

[0018] Embodiments of this application also provide a wafer clamping mechanism, including the cylinder assembly described above, and further comprising:

[0019] Wafer fixing structure, used to place wafers;

[0020] A push structure is provided at a distance from the wafer fixing structure. On the movement path of the push structure, the push structure can be relatively close to or far away from the wafer fixing structure to fix or release the wafer located between the wafer fixing structure and the push structure.

[0021] The output shaft is connected to the propulsion structure, and the clamping force adjustment module is configured to adjust the propulsion force of the output shaft when the propulsion structure approaches or moves away from the wafer fixing structure.

[0022] Optionally, the wafer fixing structure includes:

[0023] Base plate;

[0024] A front stop block is provided along the front edge of the base plate. The pushing structure moves the front stop block towards the wafer in a gradual manner so that the front end of the wafer contacts the front stop block.

[0025] Optionally, the front end stop is hinged to the base plate, and the wafer clamping mechanism further includes:

[0026] A buffer spring, the two ends of which are respectively connected to the end of the front stop block away from the propulsion structure and the bottom plate;

[0027] When the front end block contacts the wafer, the thrust of the propulsion structure is transmitted to the buffer spring.

[0028] Optionally, on the moving path of the cylinder's output shaft, the front stop has at least two protrusions that are symmetrically arranged and spaced apart from the center of the base plate's central axis, and the end face of the protrusions facing the propulsion structure is arc-shaped.

[0029] Optionally, the base plate is provided with a plurality of protrusions, the bottom end of the protrusions being embedded in the base plate, and the top end of the protrusions at least partially protruding to the outside of the base plate, and the plurality of protrusions being distributed in a dot-like manner on the surface of the base plate.

[0030] Optionally, the propulsion structure includes:

[0031] A push rod, which is drivenly connected to the output shaft;

[0032] A roller module is located at the end of the push rod away from the output shaft, and the end of the roller module has an arc-shaped surface to fit the edge of the wafer.

[0033] Optionally, the roller module includes:

[0034] The mounting bracket is located at the end of the push rod away from the output shaft;

[0035] Two sets of rollers are arranged symmetrically about the longitudinal axis of the push rod and are movably mounted on the mounting bracket.

[0036] The embodiments of this application employ a clamping force adjustment module and an optical sensor, such as a through-beam fiber optic sensor. A through-hole is provided on the output shaft, and the emitting end of the optical sensor is positioned along the movement path of the output shaft. When the output shaft advances a certain displacement, the through-hole faces the optical sensor, and the light beam emitted from the optical sensor passes through the through-hole and is reflected, triggering the optical sensor to generate a corresponding position signal. The clamping force adjustment module controls the opening and closing of the air passages of the first and second vents based on the position signal, adjusting the force output by the output shaft to reduce the speed at which the wafer is transported until it is brought into contact with the wafer fixing structure. This prevents excessive contact force between the wafer and the wafer fixing structure, which could lead to wafer breakage. Attached Figure Description

[0037] To more clearly illustrate the implementation methods of the embodiments of this application, the relevant accompanying drawings will be briefly described below. It is understood that the drawings described below are only for illustrating some implementation methods of the embodiments of this application, and those skilled in the art can obtain many other technical features and connections not mentioned herein based on these drawings.

[0038] Figure 1 A schematic diagram of the structure of a transfer device provided for an embodiment of this application;

[0039] Figure 2 A schematic diagram of a cylinder provided for an embodiment of this application;

[0040] Figure 3 A schematic diagram of a cylinder assembly provided for an embodiment of this application;

[0041] Figure 4 A schematic diagram of a wafer clamping mechanism provided for an embodiment of this application;

[0042] Figure 5 A schematic diagram of the structure of a front-end block provided for an embodiment of this application;

[0043] Figure 6 This is a schematic diagram of a boss in contact with a wafer, provided for an embodiment of this application.

[0044] Label:

[0045] 1. Front stop block; 2. Boss; 3. Wafer; 4. Base plate; 41. Buffer spring; 5. Roller; 6. Optical sensor; 7. Cylinder; 71. Output shaft; 72. Piston; 81. First solenoid valve; 82. Second solenoid valve; 83. Third solenoid valve; 201. Machine base; 202. Robot arm; 300. Wafer clamping mechanism; 10. Wafer fixing structure; 20. Pushing structure; 30. Clamping force adjustment module; 40. Through hole; M1. First vent; M2. Second vent. Detailed Implementation

[0046] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of the embodiments of this application.

[0047] The technical solutions in the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0048] In the semiconductor manufacturing industry, wafer 3 transport is crucial. For example... Figure 1 As shown, the machine tool 201 serves as the working environment. The machine tool 201 is equipped with a dual-station robot arm 202. The robot arm 202 is equipped with a gripper or adsorption device adapted to the wafer cassette. The robot arm 202 extends into the wafer cassette and, according to instructions, grips or adsorbs the wafer 3 to be processed in the wafer cassette to the end of the robot arm 202, and then transfers it to the wafer clamping mechanism described herein through a multi-axis robotic arm.

[0049] In many manufacturing processes, such as in the desizing process, the wafer 3 handling speed is the main factor limiting the output of the machine 201. The robot end arm uses a clamping structure to achieve highly reliable and safe handling of the wafer 3. However, the clamping force cannot be adjusted during the clamping process. When the wafer 3 is transferred to the clamping structure and picked up by the clamping structure, there is a risk of wafer 3 breakage and a defect that may cause the wafer 3 handling to crash.

[0050] In one implementation, such as Figure 2 and Figure 3 As shown, this application provides a cylinder assembly, which includes a cylinder 7, an output shaft 71, a clamping force adjustment module 30, and an optical sensor 6. The cylinder 7 has an internal cavity (not shown in the figure), and a piston 72 is movably disposed within the cavity. One end of the output shaft 71 is slidably disposed within the cavity and connected to the piston 72. A through hole 40 is provided on the output shaft 71. A first vent M1 and a second vent M2 are provided on the cylinder 7, communicating with the cavity. Along the moving path of the output shaft 71, the piston 72 slides between the first vent M1 and the second vent M2. The clamping force adjustment module 30 is connected to both the first vent M1 and the second vent M2. The optical sensor 6 is disposed on the moving path of the output shaft 71 of the cylinder 7. When the output shaft 71 moves to a preset position, the light beam emitted by the optical sensor 6 passes through the through hole 40, triggering the sensing to generate a position signal. The clamping force adjustment module 30 is configured to open and close the air passage of the first air port M1 and the second air port M2 based on the position signal.

[0051] The embodiments of this application include a clamping force adjustment module 30 and an optical sensor 6, such as a through-beam fiber optic sensor 6. A through hole 40 is provided on the output shaft 71. The output end of the optical sensor 6 is located on the movement path of the output shaft 71. When the output shaft 71 moves forward by a certain amount, the through hole 40 faces the optical sensor 6. The light beam from the output end of the optical sensor 6 passes through the through hole 40 and is reflected, triggering the optical sensor 6 to generate a corresponding position signal. The clamping force adjustment module 30 controls the opening and closing of the air passages of the first vent M1 and the second vent M2 based on the position signal, thereby realizing the adjustable force function of the output shaft 71. This reduces the speed at which the wafer 3 is transported until the wafer 3 is transported to contact the wafer fixing structure 10, preventing excessive contact force between the wafer 3 and the wafer fixing structure 10, which could cause the wafer 3 to break.

[0052] Specifically, the clamping force adjustment module 30 includes:

[0053] The cylinder 7 has an output shaft 71 that is connected to the propulsion structure 20. The cylinder 7 has a cavity inside. A piston 72 is provided at the tail end of the cylinder 7 and slides in the cavity. On the moving path of the output shaft 71, a first vent M1 and a second vent M2 that communicate with the cavity are respectively provided on opposite sides of the cylinder 7. The piston 72 slides between the first vent M1 and the second vent M2.

[0054] The first solenoid valve 81 has an outlet port connected to a first vent port M1 and an inlet port connected to a gas source.

[0055] The second solenoid valve 82, the outlet of the second solenoid valve 82 is connected to the second vent M2;

[0056] The third solenoid valve 83 has its outlet port connected to the inlet port of the second solenoid valve 82, its exhaust port connected to a pressure reducing valve (not shown in the figure), and its inlet port connected to an air source.

[0057] In this embodiment, to improve the accuracy of the clamping force adjustment module 30 in controlling the propulsion structure 20, the clamping force adjustment module 30 can use a cylinder 7 as the output power source. For example, a cylinder 7 is provided, and a piston 72 is moved within the cavity of the cylinder 7. The piston 72 is connected to the propulsion structure 20 via an output shaft 71. A first vent M1 and a second vent M2 are provided on the cavity, connecting the cavity. In the direction of the output shaft 71's movement, the piston 72 slides between the first vent M1 and the second vent M2. The principle is that the thrust of the cylinder 7 is F = P * S, where P is the gas pressure of the piston 72 and S is the dry area of ​​the piston 72. The thrust of the cylinder 7 is proportional to the gas pressure. Based on this, if air enters through the first vent M1, the piston 72 moves toward the second vent M2, and the output shaft 71 controls the propulsion structure 20 to move away from the wafer fixing structure 10. Conversely, when air enters through the second vent M2, air exits through the first vent M1, and the piston 72 moves toward the first vent M1, and the output shaft 71 controls the propulsion structure 20 to move closer to the wafer fixing structure 10, thereby realizing the function of clamping the wafer 3.

[0058] To improve the accuracy of the output shaft 71's movement, a first solenoid valve 81, a second solenoid valve 82, and a third solenoid valve 83 can be set, as shown in the figure. When clamping begins, gas from path C enters the cavity, gas from path B is cut off, gas from path A is cut off, the third solenoid valve 83 is energized, the second solenoid valve 82 is energized, the first solenoid valve 81 is not energized, the first solenoid valve 81 is in the exhaust state, the output shaft 71 of the cylinder 7 moves forward, the piston 72 exhausts at the front and intakes at the rear, and the output shaft 71 pushes the propulsion structure 20 forward toward the wafer fixing structure 10.

[0059] A sensor, such as a position sensor, can be set. During the process of the push structure 20 pushing the wafer 3 from the initial position to the predetermined position of the wafer fixing structure 10, the sensor is triggered and feeds back a signal. Gas B enters the cavity, gas C is cut off, gas A is cut off, the third solenoid valve 83 is not energized, the second solenoid valve 82 is energized, the first solenoid valve 81 is not energized, and the first solenoid valve 81 is in the exhaust state. At this time, the exhaust port of the third solenoid valve 83 is connected to the pressure reducing valve. Because there is a pressure reducing valve in the gas B, the pressure is less than the pressure of the gas in the C, which makes the exhaust at the front of the piston 72 slow down, reducing the moving speed (or load) of the push structure 20, and reducing the speed at which the wafer 3 is transported until the wafer 3 is transported to contact the wafer fixing structure 10, so as to avoid the wafer 3 breaking due to excessive contact force between the wafer 3 and the wafer fixing structure 10.

[0060] When the clamping needs to be released, gas from path A enters the cavity, gas from path B is cut off, gas from path C is cut off, the first solenoid valve 81 is energized, the second solenoid valve 82 may or may not be energized, the third solenoid valve 83 is not energized, the third solenoid valve 83 is in the exhaust state, the output shaft 71 of the cylinder 7 moves backward, the rear of the piston 72 exhausts, the front of the piston 72 intakes, and the output shaft 71 pushes the propulsion structure 20 away from the clamping structure.

[0061] Specifically, in order to control the movement of the propulsion structure 20 more precisely, a through hole 40 is provided on the output shaft 71, and the clamping force adjustment module 30 further includes:

[0062] A central control unit (not shown in the figure) is electrically connected to the first solenoid valve 81, the second solenoid valve 82, and the third solenoid valve 83.

[0063] An optical sensor 6 is electrically connected to the central control unit and is positioned on the moving path of the output shaft 71 of the cylinder 7. When the output shaft 71 moves to a preset position, the light beam emitted by the optical sensor 6 passes through the through hole 40, triggering the sensing to generate a position signal and feeding it back to the central control unit. Based on the position signal, the central control unit closes the third solenoid valve 83 and the first solenoid valve 81, and activates the second solenoid valve 82, so that the piston 72 slowly moves toward the propulsion structure 20.

[0064] In this embodiment, a through hole 40 can be provided on the output shaft 71. The sensor is selected as an optical sensor 6, such as a through-beam fiber optic sensor 6. The output end of the optical sensor 6 is set on the movement path of the output shaft 71. When the output shaft 71 moves forward by a certain displacement, the through hole 40 is directly facing the optical sensor 6. The light beam from the output end of the optical sensor 6 passes through the through hole 40 and is reflected, triggering the optical sensor 6 to generate a corresponding position signal. The central control unit controls the opening and closing of the first solenoid valve 81, the second solenoid valve 82, and the third solenoid valve 83 based on the position signal to realize the adjustable force function of the propulsion structure 20.

[0065] like Figures 4-6 As shown, one embodiment of this application provides a wafer clamping mechanism 300, which includes:

[0066] Wafer fixing structure 10 is used to place wafer 3;

[0067] The push structure 20 is spaced apart from the wafer fixing structure 10. On the movement path of the push structure 20, the push structure 20 can be relatively close to or far away from the wafer fixing structure 10 to fix or loosen the wafer 3 located between the wafer fixing structure 10 and the push structure 20.

[0068] The output shaft 71 is connected to the push structure 20 in a transmission manner. The clamping force adjustment module 30 is configured to adjust the pushing force of the output shaft 71 when the push structure 20 approaches or moves away from the wafer fixing structure 10.

[0069] In this embodiment, the wafer fixing structure 10 is mainly used to place the wafer 3. After the wafer fixing structure 10 initially acquires the wafer 3 to be processed, the position of the wafer 3 on the wafer fixing structure 10 is inaccurate. The wafer 3 is not fixed with the preset precision. Therefore, a pushing structure 20 is needed to move the wafer 3 towards the wafer fixing structure 10 to fix the wafer 3. The pushing structure 20 pushes the wafer 3 from the initial position to the wafer fixing structure 10. The pushing structure 20 is equipped with a cylinder assembly. After the pushing structure 20 pushes the wafer 3 from the initial position to the predetermined position of the wafer fixing structure 10, a constant pushing force is applied to fix the wafer 3 between the wafer fixing structure 10 and the pushing structure 20.

[0070] During the clamping process, the clamping force between the push structure 20 and the wafer fixing structure 10 is not adjustable. When the wafer 3 is transferred to the wafer fixing structure 10 and acquired by the wafer fixing structure 10, there is a risk of wafer 3 breaking and a risk of wafer 3 transfer failure. Therefore, the embodiments of this application provide a clamping force adjustment module 30 connected to the push structure 20, which is configured to change the pushing force of the push structure 20 as the push structure 20 approaches or moves away from the wafer fixing structure 10. For example, after the push structure 20 has shifted by a preset displacement, the clamping force adjustment module 30 reduces the load on the push structure 20, causing the wafer 3 to slowly move closer to the wafer fixing structure 10. Alternatively, a sensor, such as a position sensor, can be used. During the process of the push structure 20 pushing the wafer 3 from its initial position to the predetermined position on the wafer fixing structure 10, the sensor is triggered and sends a feedback signal. The clamping force adjustment module 30 dynamically adjusts the parameters of the push structure 20 based on the sensor feedback signal to regulate the load on the push structure 20 along its movement path. For example, when the push structure 20 moves to the sensor position and triggers the sensor, the sensor generates a signal, and the clamping force adjustment module 30 reduces the movement parameters of the push structure 20, such as speed and push load parameters, reducing the speed at which the wafer 3 is transported until it comes into contact with the wafer fixing structure 10. This prevents excessive contact force between the wafer 3 and the wafer fixing structure 10, which could cause the wafer 3 to break.

[0071] Specifically, in order to ensure that wafer 3 is precisely clamped, in embodiments of this application, the wafer fixing structure 10 includes:

[0072] Base plate 4;

[0073] A front stop 1 is provided along the front edge of the base plate 4. The pushing structure 20 moves the front stop 1 towards the wafer 3 in a step-by-step manner, so that the front end of the wafer 3 contacts the front stop 1.

[0074] In this embodiment, the base plate 4 is a ceramic component, primarily for placing the wafer 3, and can also serve as a base for electrostatic adsorption. Several front-end blocks 1 are provided, each protruding along the edge of the base plate 4. During the transfer of the wafer 3, the robot arm 202 is equipped with a gripper or adsorption device adapted to the wafer cassette. First, the robot removes the wafer 3 from the wafer cassette and places it on the base plate 4. The distance between the wafer 3 and the front-end blocks 1 is generally about 1-5 mm, and the distance between the wafer 3 and the push structure 20 is also generally about 1-5 mm. The push structure 20 moves forward, the wafer 3 moves forward, and finally, the wafer 3 contacts the front-end blocks 1 on the base plate 4, the push structure 20 stops moving, and the wafer 3 is clamped.

[0075] Please refer to Figure 5As shown, specifically, the front stop 1 is hinged to the base plate 4, and the wafer clamping mechanism 300 also includes a buffer spring 41. The two ends of the buffer spring 41 are respectively connected to the end of the front stop 1 facing away from the push structure 20 and the base plate 4. When the front stop 1 contacts the wafer 3, the thrust of the push structure 20 is transmitted to the buffer spring 41.

[0076] To further prevent wafer 3 from breaking, the front stop 1 can be hinged to the base plate 4. For example, the front stop 1 can be oscillating with an amplitude of less than 1°. A buffer spring 41 is connected at the hinge position between the front stop 1 and the base plate 4. The distance between the wafer 3 and the push structure 20 is generally about 1-5 mm. The push structure 20 moves forward, the wafer 3 moves forward, and finally the wafer 3 contacts the front stop 1 on the base plate 4. The front stop 1 is slightly oscillating under force, which transmits the force transmitted by the push structure 20 to the buffer spring 41. The buffer spring 41 buffers and reduces the kinetic energy between the wafer 3 and the front stop 1, while the push structure 20 stops moving and the wafer 3 is clamped.

[0077] Please refer to Figure 6 As shown, specifically, on the moving path of the output shaft 71 of the cylinder 7, the front end block 1 has at least two protrusions symmetrically arranged and spaced apart from the center of the central axis of the base plate 4, and the end face of the protrusions facing the push structure 20 is arc-shaped. In order to ensure that the wafer 3 is subjected to uniform force after contacting the front end block, the front end block 1 can be provided with two sets of protrusions, which are symmetrically spaced on the left and right. The wafer 3 is shaped like a cylindrical thin sheet. Therefore, after the wafer 3 is in contact with the protrusions of the front end block 1, the two sets of front end block 1 protrusions symmetrically contact the wafer 3, ensuring that the force on the left and right sides of the wafer 3 is uniform and avoiding wafer breakage.

[0078] Furthermore, in order to make the contact between the front end block 1 and the edge of the wafer 3 more uniform, the end face of the protrusion facing the push structure 20 is arc-shaped. The arc edge of the wafer 3 is adapted to contact the arc surface of the protrusion, ensuring that the wafer 3 is subjected to uniform force and avoiding wafer 3 breakage.

[0079] Specifically, the base plate 4 is provided with a plurality of protrusions 2, the bottom end of the protrusions 2 is embedded in the base plate 4, and the top end of the protrusions 2 protrudes at least partially to the outside of the base plate 4. The plurality of protrusions 2 are distributed in a dot-like manner on the surface of the base plate 4.

[0080] To reduce the contact area between the base plate 4 and the wafer 3, several protrusions 2 can be provided on the base plate 4. The bottom end of the protrusion 2 is embedded in the base plate 4, and the top end of the protrusion 2 protrudes at least partially to the outside of the base plate 4. After the wafer 3 is placed on the base plate 4, the dotted protrusions 2 are used to support the wafer 3, avoiding direct contact between the base plate 4 and the wafer 3 and damaging the cleanliness of the wafer 3 surface.

[0081] Specifically, the propulsion structure 20 includes:

[0082] A push rod (not labeled in the figure) is connected to the clamping force adjustment module 30 via a drive mechanism.

[0083] A roller module is located at the end of the push rod away from the clamping force adjustment module 30. The end of the roller module has an arc-shaped surface to fit the edge of the wafer 3.

[0084] The push structure 20 has a push rod and a roller module. One end of the push rod is connected to the clamping force adjustment module 30 for transmission, and the other end of the push rod is equipped with a roller module. The roller module has an arc-shaped curved end so that when it contacts the wafer 3, it can fit against the edge of the wafer 3 and fit more closely to the edge of the wafer 3, avoiding sharp corner contact with the wafer 3. During the transfer of wafer 3, the robot manipulator 202 is equipped with a gripper or adsorption device that is compatible with the wafer cassette. First, the robot takes wafer 3 out of the wafer cassette and places wafer 3 on the base plate 4. The distance between wafer 3 and the front stop 1 is generally about 1-5mm, and the distance between wafer 3 and the push structure 20 is generally about 1-5mm. The push structure 20 moves forward, and the end of the arc-shaped surface of the roller module contacts wafer 3. During the displacement of wafer 3, the position of wafer 3 is adjusted so that wafer 3 is slowly aligned. Wafer 3 moves forward and finally contacts the front stop 1 on the base plate 4. The protrusion of the front stop 1 symmetrically contacts wafer 3, the push structure 20 stops moving, and wafer 3 is clamped.

[0085] Specifically, the roller module includes:

[0086] The mounting bracket (not shown in the figure) is located at the end of the push rod away from the clamping force adjustment module 30;

[0087] Two sets of rollers 5 are symmetrical about the longitudinal axis of the push rod and are movably mounted on the mounting bracket.

[0088] In this embodiment, to further improve the performance of the roller module in correcting the positional deviation of the wafer 3, a mounting bracket can be set up with two sets of rollers 5. The two sets of rollers 5 are symmetrical to each other, and each roller 5 can rotate on its own axis. During the transfer of the wafer 3, the robot arm 202 is equipped with a gripper or adsorption device adapted to the wafer cassette. First, the robot takes the wafer 3 out of the wafer cassette and places the wafer 3 on the base plate 4. The distance between the wafer 3 and the front stop 1 is generally about 1-5mm, and the distance between the wafer 3 and the push structure 20 is generally about 1-5mm. The push structure 20 moves forward, and the ends of the arc-shaped surfaces of the two sets of rollers 5 contact the wafer 3. During the displacement of the wafer 3, the position of the wafer 3 is adjusted. If there is a left-right positional deviation of the wafer 3, the rollers 5 are connected to the cylinder fork. The position is located on the axis of roller 5 itself. Roller 5 can rotate on its own axis. According to its own rotation properties, roller 5 slowly moves the wafer 3 with larger deviation to the position of the other roller 5. Slowly adjust the position of wafer 3 so that the two sets of rollers 5 are in uniform contact with wafer 3, and the contact position is also symmetrical from left to right. This makes wafer 3 slowly align itself. Wafer 3 moves forward and finally contacts the front stop 1 on the base plate 4. The protrusion of the front stop 1 symmetrically contacts wafer 3. The pushing structure 20 stops moving and wafer 3 is clamped, ensuring that wafer 3 is subjected to uniform force and avoiding wafer 3 breakage.

[0089] In one embodiment, the wafer clamping mechanism 300 described herein is operated in a manner described herein.

[0090] In the initial state, wafer 3 is taken out from the wafer box and placed on the base plate 4. The distance between wafer 3 and the front stop 1 is generally about 1-5mm, and the distance between wafer 3 and the push structure 20 is generally about 1-5mm. When the second vent M2 is inlet, the first vent M1 is outlet, and the piston 72 moves toward the first vent M1. The output shaft controls the push structure 20 to approach the wafer fixing structure 10. The push structure 20 moves forward, and the ends of the arc-shaped surfaces of the two sets of rollers 5 contact wafer 3. During the displacement of the push structure 3, the position of wafer 3 is adjusted. If there is a left-right position deviation of wafer 3, the rollers 5 slowly move the wafer 3 with the larger deviation to the position of the other roller 5 according to their own rotation properties. The position of wafer 3 is slowly adjusted so that the two sets of rollers 5 are in uniform contact with wafer 3, and the contact positions are also symmetrical. This makes wafer 3 slowly align itself and move forward.

[0091] When the output shaft advances a certain displacement, the through hole 40 is directly opposite the optical sensor 6. The light beam from the output end of the optical sensor 6 passes through the through hole 40 and is reflected, triggering the optical sensor 6 to generate a corresponding position signal and outputting it to the central control unit. Gas from path B enters the cavity, gas from path C is cut off, and gas from path A is cut off. The central control unit controls the third solenoid valve 83 to be de-energized, the second solenoid valve 82 to be energized, and the first solenoid valve 81 to be de-energized. The first solenoid valve 81 is in the exhaust state. At this time, the exhaust port of the third solenoid valve 83 is connected to the pressure reducing valve because of path B... The gas contains a pressure reducing valve, and the pressure is lower than the gas pressure in C-path. This causes the exhaust at the front of piston 72 to be slow, reducing the moving speed of the propulsion structure 20 and slowing down the speed at which wafer 3 is transported until wafer 3 is transported to abut against wafer fixing structure 10. The front end block 1 can be provided with two sets of protrusions, which are symmetrically spaced on the left and right. The wafer 3 is shaped like a cylindrical thin sheet. Therefore, after wafer 3 abuts against the protrusions of the front end block 1, the two sets of front end block 1 protrusions symmetrically contact wafer 3, ensuring that the force on the left and right sides of wafer 3 is uniform and preventing wafer 3 from breaking.

[0092] Of course, multiple physical markers can also be set on the output shaft 71. During the displacement of the output shaft 71, the optical sensor 6 can identify different physical markers and generate different position signals. It is not necessary to be limited to using through holes 40 on the output shaft 71 as identification markers.

[0093] To ensure more uniform contact between the front stop 1 and the edge of the wafer 3, the end face of the front stop 1 facing the push structure 20 is arc-shaped. The arc edge of the wafer 3 is adapted to contact the arc surface of the front stop 1, ensuring uniform force on the wafer 3 and preventing wafer 3 from breaking.

[0094] After wafer 3 is processed, it needs to be placed in a specific position. When wafer 3 needs to be released, the central control unit controls the A-path gas to enter the cavity, the B-path gas is cut off, the C-path gas is cut off, the first solenoid valve 81 is energized, the second solenoid valve 82 can be energized or not, the third solenoid valve 83 is not energized, the third solenoid valve 83 is in the exhaust state, the output shaft of cylinder 7 moves backward, the rear of piston 72 exhausts, the front of piston 72 enters, and the output shaft pushes the propulsion structure 20 away from a clamping structure.

[0095] Although embodiments of this application have been described in conjunction with specific features and examples, it is obvious that various modifications and combinations can be made thereto without departing from the spirit and scope of the embodiments of this application. Accordingly, this specification and accompanying drawings are merely exemplary illustrations of the embodiments of this application as defined, and are considered to cover any and all modifications, variations, combinations, or equivalents within the scope of the embodiments of this application. Obviously, those skilled in the art can make various modifications and variations to the embodiments of this application without departing from the spirit and scope of the embodiments of this application. Thus, if these modifications and variations of the embodiments of this application fall within the scope of the embodiments of this application and their equivalents, the embodiments of this application are also intended to include these modifications and variations.

Claims

1. A cylinder assembly, characterized in that, include: A cylinder (7) has a cavity inside, and a piston (72) is movably disposed inside the cavity; An output shaft (71) is provided, one end of which is slidably disposed in the cavity and connected to the piston (72). A through hole (40) is provided on the output shaft (71). A first vent (M1) and a second vent (M2) are provided on the cylinder (7) to communicate with the cavity. Along the moving path of the output shaft (71), the piston (72) slides between the first vent (M1) and the second vent (M2). A clamping force adjustment module (30) is connected to the first vent (M1) and the second vent (M2) respectively; An optical sensor (6) is disposed on the moving path of the output shaft (71) of the cylinder (7) for real-time detection of the position of the output shaft (71) on the moving path of the output shaft (71).

2. The cylinder assembly as claimed in claim 1, characterized in that, The clamping force adjustment module (30) includes: The first solenoid valve (81) has an outlet port connected to the first air port (M1) and an inlet port connected to the air source. The second solenoid valve (82) has its outlet port connected to the second vent port (M2); The third solenoid valve (83) has an outlet port connected to the inlet port of the second solenoid valve (82), and the inlet port of the third solenoid valve (83) is connected to an air source. The optical sensor (6) is electrically connected to the first solenoid valve (81), the second solenoid valve (82), and the third solenoid valve (83).

3. The cylinder assembly as described in claim 2, characterized in that, The clamping force adjustment module (30) also includes: The pressure reducing valve is connected to the exhaust port of the third solenoid valve (83).

4. A wafer clamping mechanism, characterized in that, The cylinder assembly, comprising any one of claims 1-3, further comprises: A wafer fixing structure (10) is used to place the wafer (3); The push structure (20) is spaced apart from the wafer fixing structure (10). On the movement path of the push structure (20), the push structure (20) can be relatively close to or far away from the wafer fixing structure (10) to fix or release the wafer (3) located between the wafer fixing structure (10) and the push structure (20); The output shaft (71) is connected to the propulsion structure (20) in a driving connection. The clamping force adjustment module (30) is configured to adjust the propulsion force of the output shaft (71) when the propulsion structure (20) is close to or away from the wafer fixing structure (10).

5. The wafer clamping mechanism as described in claim 4, characterized in that, The wafer fixing structure (10) includes: Base plate (4); A front stop (1) is provided along the front edge of the base plate (4). The push structure (20) moves the front stop (1) towards the wafer (3) in a stepwise manner so that the front end of the wafer (3) contacts the front stop (1).

6. The wafer clamping mechanism as described in claim 5, characterized in that, The front end stop (1) is hinged to the base plate (4), and the wafer clamping mechanism (300) further includes: A buffer spring (41) is provided, with its two ends connected to the end of the front stop (1) away from the propulsion structure (20) and the base plate (4), respectively. When the front end block (1) contacts the wafer (3), the thrust of the push structure (20) is transmitted to the buffer spring (41).

7. The wafer clamping mechanism as described in claim 5, characterized in that, On the moving path of the output shaft (71) of the cylinder (7), the front end block (1) has at least two protrusions that are symmetrically arranged and spaced apart from the central axis of the base plate (4), and the end face of the protrusion facing the propulsion structure (20) is arc-shaped.

8. The wafer clamping mechanism as described in claim 5, characterized in that, The base plate (4) is provided with a plurality of protrusions (2), the bottom end of the protrusions (2) is embedded in the base plate (4), and the top end of the protrusions (2) protrudes at least partially to the outside of the base plate (4). The plurality of protrusions (2) are distributed in a dot-like manner on the surface of the base plate (4).

9. The wafer clamping mechanism as described in claim 4, characterized in that, The propulsion structure (20) includes: A push rod, which is drivenly connected to the output shaft (71); A roller module is located at the end of the push rod away from the output shaft (71), and the end of the roller module has an arc-shaped surface to fit the edge of the wafer (3).

10. The wafer clamping mechanism as described in claim 9, characterized in that, The roller module includes: The mounting bracket is located at the end of the push rod away from the output shaft (71); Two sets of rollers (5) are arranged symmetrically on the left and right sides relative to the longitudinal axis of the push rod and are movably mounted on the mounting bracket.

Images