Wafer taking and placing mechanical arm

Abstract

The utility model relates to the technical field of wafer processing equipment, in particular to a wafer picking and placing mechanical arm, which comprises an arm bending and stretching mechanism, an arm rotating mechanism and an arm lifting mechanism, the arm bending and stretching mechanism adopts a servo motor and three-stage synchronous belt transmission mode, the arm rotating mechanism adopts a servo motor and two-stage synchronous belt transmission mode, and the arm lifting mechanism adopts a servo motor and two-stage synchronous belt transmission mode. The arm lifting mechanism is achieved through a servo motor and a ball screw, and meanwhile the stability of lifting motion is guaranteed through a guide rail sliding block assembly. According to the wafer taking and placing mechanical arm, the arm bending and stretching mechanism adopts a servo motor and three-stage synchronous belt transmission mode, high precision and stability of the mechanical arm in the stretching and retracting process are ensured, and position deviation and speed fluctuation are effectively reduced. And the arm rotating mechanism and the lifting mechanism are driven by servo motors, and high-precision transmission elements such as a synchronous belt and a ball screw are supplemented, so that the control precision and stability of the mechanical arm in the rotating and lifting directions are further improved.

Description

Technical Field

[0001] This utility model relates to the field of wafer processing equipment technology, and more specifically, to a wafer picking and placing robotic arm. Background Technology

[0002] Semiconductor wafer handling robotic arms, as core equipment in the semiconductor manufacturing process, play a crucial role in the efficient and precise transfer of wafers between different process equipment. Wafers, as the fundamental carriers of semiconductor chips, involve multiple complex and delicate process steps in their manufacturing, such as photolithography, etching, and deposition. These steps not only require the wafer to maintain extremely high positional accuracy and stability during transfer, but also necessitate ensuring the cleanliness of the entire process to prevent any form of contamination from causing irreversible damage to wafer quality.

[0003] I. Requirements for high precision and high stability

[0004] In the semiconductor manufacturing industry, wafer handling and transport place extremely stringent requirements on precision and stability. Due to the tiny size and highly fragile surface of wafers, even minor positional deviations, speed fluctuations, or load changes can damage them, consequently affecting the production quality and yield of subsequent chips. Therefore, the design of robotic arms must ensure precise control of motion trajectory, speed, and load during wafer gripping, transporting, and placement to maintain the stability and integrity of the wafers throughout the entire transfer process.

[0005] II. Cleanliness Requirements

[0006] Semiconductor manufacturing environments demand extremely high cleanliness levels, typically requiring cleanrooms. As devices that directly contact wafers, wafer handling robotic arms must adhere strictly to cleanroom standards in their design and material selection. This necessitates not only the use of cleanroom materials in the arm's construction but also efficient airflow management and sealing systems to prevent the ingress of external contaminants. Furthermore, the robotic arm should avoid generating any substances that could potentially contaminate the wafers during operation, such as dust, heat, or volatile gases. Utility Model Content

[0007] The purpose of this invention is to provide a wafer handling robot arm to solve the problems mentioned in the background art, which not only require the wafer to maintain extremely high positional accuracy and stability during the transfer process, but also must ensure the cleanliness of the entire process to avoid any form of contamination causing irreversible damage to the wafer quality.

[0008] To achieve the above objectives, this utility model provides a wafer pick-and-place robotic arm, including an arm extension mechanism, an arm rotation mechanism, and an arm lifting mechanism. The arm extension mechanism adopts a servo motor and a three-stage synchronous belt drive. The arm rotation mechanism adopts a servo motor and a two-stage synchronous belt. The arm lifting mechanism is implemented by a servo motor and a ball screw. At the same time, a guide rail slider assembly is used to ensure the smoothness of the lifting movement.

[0009] The arm extension mechanism includes a rotating fixed shaft, a first servo motor mounted at the bottom of the rotating fixed shaft, the output shaft of the first servo motor being driven to a first rotating shaft via a primary synchronous belt, a first robotic arm mounted at the top of the first rotating shaft, a second robotic arm mounted at the top of the second rotating shaft via a secondary synchronous belt, a third rotating shaft being driven to the top of the third rotating shaft via a tertiary synchronous belt, and a connecting plate mounted at the top of the third rotating shaft, on which a vacuum finger is mounted.

[0010] Preferably, the output shaft of the first servo motor is equipped with a speed reducer, and the first servo motor and the speed reducer are sealed in a cavity formed by the lifting connecting pipe and the rotating connecting plate.

[0011] Preferably, the lower end of the first rotating shaft is designed with a limit stop and a first photoelectric switch to realize the zero-point control of the robotic arm.

[0012] Preferably, the arm rotation mechanism includes a second servo motor, the bottom of which is provided with a lifting bearing end cover. The second servo motor is fixed on the lifting bearing end cover by a rotating motor pad. The output shaft of the second servo motor is transmitted to the intermediate rotating shaft through a synchronous belt assembly. A lifting fixing block is provided on one side of the second servo motor. The intermediate rotating shaft passes through the hollow lifting fixing block and is fixed to the rotating connecting plate, thereby driving the entire robotic arm to rotate.

[0013] Preferably, a rotating shaft fixing ring is installed at the bottom of the lifting bearing end cover, and a rotating limiting plate and a second photoelectric switch are installed on the rotating shaft fixing ring. The origin coordinates of the intermediate rotating shaft are controlled by the rotating limiting plate and the second photoelectric switch, and the rotation angle is controlled by the second servo motor.

[0014] Preferably, the arm lifting mechanism includes a third servo motor, which is fixed to the base plate by a lifting motor mounting bracket. The output shaft of the third servo motor transmits torque to the lead screw through a synchronous belt assembly. A lead screw nut is installed on the lead screw, and a lifting lead screw nut is installed on the lead screw nut. The top of the lifting lead screw nut is connected to the lifting bearing end cover, thereby realizing the lifting movement of the entire robotic arm.

[0015] Preferably, the lifting and fixing block is equipped with sliders on both sides, and the guide rails corresponding to the sliders are installed on the left and right mounting profiles. Three third photoelectric switches are installed on the mounting profiles, and the three third photoelectric switches control the upper limit, lower limit coordinates and origin of the lifting and lowering respectively.

[0016] Preferably, a sealing base plate is installed at the bottom of the mounting profile, and a cooling fan is installed on the inner side of the sealing base plate.

[0017] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0018] In this wafer handling robotic arm, the arm extension mechanism employs a servo motor and a three-stage synchronous belt drive, ensuring high precision and stability during extension and retraction, effectively reducing positional deviations and speed fluctuations. The arm rotation and lifting mechanisms also utilize servo motors, supplemented by high-precision transmission components such as synchronous belts and ball screws, further enhancing the control accuracy and stability of the robotic arm in rotation and lifting directions. The application of limit stops and photoelectric switches provides reliable zero-point control and position detection for the robotic arm, ensuring precise wafer positioning during handling.

[0019] Key components of the robotic arm, such as the servo motor and reducer, are sealed within a specific cavity, effectively preventing the entry of external contaminants and ensuring a clean environment inside the robotic arm. The robotic arm is manufactured using cleanroom materials, and airflow management and the sealing system are optimized to reduce dust and volatile gases generated during operation, meeting the extremely high cleanliness requirements of semiconductor manufacturing.

[0020] The application of vacuum fingers enables rapid and stable gripping and placement of wafers, improving wafer handling efficiency. The rapid response and precise control of servo motors allow the robotic arm to complete complex handling tasks in a short time, enhancing overall production efficiency.

[0021] The robotic arm is designed with intelligence and automation in mind. By integrating sensors and a control system, it achieves real-time monitoring and precise control of the wafer's position and orientation. The application of photoelectric switches not only provides position feedback for the robotic arm but also lays the foundation for its intelligent control, enabling the robotic arm to automatically adjust and optimize according to actual needs.

[0022] The robotic arm has a compact overall structure, with tight and stable connections between its components, which improves its rigidity and durability. The modular design makes maintenance and upkeep of the robotic arm more convenient, reducing repair costs and time. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0024] Figure 2 This is a schematic diagram of the arm flexion and extension mechanism in this utility model;

[0025] Figure 3 This is a schematic diagram of the arm rotation mechanism in this utility model;

[0026] Figure 4 This is a schematic diagram of the bottom structure of the arm rotation mechanism in this utility model;

[0027] Figure 5 This is one of the structural schematic diagrams of the arm lifting mechanism in this utility model;

[0028] Figure 6 This is the second structural schematic diagram of the arm lifting mechanism in this utility model;

[0029] The meanings of the labels in the diagram are as follows:

[0030] 1. Arm flexion and extension mechanism; 11. First servo motor; 12. Reducer; 13. Primary synchronous belt; 14. First rotating shaft; 141. Limit stop; 142. First photoelectric switch; 15. Rotary fixed shaft; 16. Lifting connecting pipe; 17. Rotary connecting plate; 20. First robotic arm; 201. Secondary synchronous belt; 202. Second rotating shaft; 30. Second robotic arm; 301. Tertiary synchronous belt; 302. Third rotating shaft; 303. Connecting plate; 304. Vacuum finger; 2. Arm rotation mechanism; 21. The first... 22. Servo motor; 23. Rotary motor pad; 24. Lifting bearing end cover; 25. Rotary shaft fixing ring; 26. Rotary limit plate; 27. Second photoelectric switch; 28. Intermediate rotating shaft; 29. ​​Slider; 20. Lifting fixing block; 21. Arm lifting mechanism; 22. Third servo motor; 33. Lifting motor fixing seat; 34. Fixing base plate; 35. Lead screw; 36. Lead screw nut; 37. Lifting lead screw nut seat; 38. Guide rail; 39. Mounting profile; 30. Third photoelectric switch; 31. Encapsulation base plate. Detailed Implementation

[0031] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0032] This utility model provides a wafer pick-and-place robotic arm, such as Figures 1-6As shown, it includes an arm extension mechanism 1, an arm rotation mechanism 2, and an arm lifting mechanism 3. The arm extension mechanism 1 uses a servo motor and a three-stage synchronous belt drive. The arm rotation mechanism 2 uses a servo motor and a two-stage synchronous belt. The arm lifting mechanism 3 is implemented by a servo motor and a ball screw. At the same time, a guide rail slider assembly is used to ensure the smoothness of the lifting movement.

[0033] The arm extension mechanism 1 includes a rotating fixed shaft 15. A first servo motor 11 is mounted at the bottom of the rotating fixed shaft 15. The output shaft of the first servo motor 11 is transmitted to a first rotating shaft 14 via a primary synchronous belt 13. A first robotic arm 20 is mounted at the top of the first rotating shaft 14. The upper end of the first rotating shaft 14 is transmitted to a second rotating shaft 202 via a secondary synchronous belt 201. A second robotic arm 30 is mounted at the top of the second rotating shaft 202. The upper end of the second rotating shaft 202 is transmitted to a third rotating shaft 302 via a tertiary synchronous belt 301. A connecting plate 303 is mounted at the top of the third rotating shaft 302, and a vacuum finger 304 is mounted on the connecting plate 303. The arm extension mechanism adopts a servo motor plus a three-stage synchronous belt transmission method. This design not only ensures the accuracy of transmission, but also improves the stability and load capacity of the robotic arm during the extension and flexion process through the speed reduction and torque increase effect of the multi-stage synchronous belt. The precise control of the servo motor ensures that the robotic arm can move according to the predetermined trajectory and speed, thereby realizing precise control of the wafer position.

[0034] The arm extension mechanism forms a multi-stage linkage structure through the ingenious combination of components such as a rotating fixed shaft, a first servo motor, a first-stage synchronous belt, a first rotating shaft, a second-stage synchronous belt, a second rotating shaft, a third-stage synchronous belt, and a third rotating shaft. This structure not only allows the robotic arm to cover a larger working range, but also enables flexible movement of the robotic arm in three-dimensional space through the independent transmission of each stage of the rotating shaft, meeting the needs of wafer transfer between different process equipment.

[0035] The vacuum fingers mounted on the connector plate generate negative pressure to stably grip the wafer, preventing it from falling off or being damaged during handling due to vibration or external interference. The design of the vacuum fingers also takes into account the fragility of the wafer, ensuring gentle contact during gripping and further protecting the quality of the wafer.

[0036] All parts of the robotic arm adopt a modular design, which facilitates disassembly, maintenance, and replacement. At the same time, this design also makes it possible to expand the robotic arm, allowing different functional modules to be added or replaced as needed to meet the wafer handling requirements under different process conditions.

[0037] In this embodiment, a reducer 12 is mounted on the output shaft of the first servo motor 11. This design reduces the motor speed and increases the torque through the reducer, making the robotic arm more stable and powerful during flexion and extension. The first servo motor 11 and the reducer 12 are sealed within the cavity formed by the lifting connecting pipe 16 and the rotating connecting plate 17. This effectively isolates the robotic arm from external environmental interference, such as dust and moisture, protecting the motor and reducer from damage, extending their service life, and ensuring the reliable operation of the robotic arm.

[0038] Specifically, a limit stop 141 and a first photoelectric switch 142 are designed at the lower end of the first rotating shaft 14 to achieve zero-point control of the robotic arm. When the first rotating shaft 14 rotates to a specific position, the limit stop 141 triggers the first photoelectric switch 142, thereby determining the initial position or zero point of the robotic arm. This design improves the positioning accuracy and repeatability of the robotic arm, ensuring precise alignment of the wafer during the pick-and-place process.

[0039] Furthermore, the arm rotation mechanism 2 includes a second servo motor 21. A lifting bearing end cover 23 is located at the bottom of the second servo motor 21. The second servo motor 21 is fixed to the lifting bearing end cover 23 via a rotating motor pad 22. The output shaft of the second servo motor 21 is transmitted to the intermediate rotating shaft 24 via a synchronous belt assembly. A lifting fixing block 25 is located on one side of the second servo motor 21. The intermediate rotating shaft 24 passes through the hollow lifting fixing block 25 and is fixed to the rotating connecting plate 17, thereby driving the entire robotic arm to rotate. This design enables the robotic arm to rotate flexibly in the horizontal plane, expanding its working range. Simultaneously, the precise control of the second servo motor ensures the accuracy of the rotation angle, meeting the wafer transfer requirements between different process equipment.

[0040] Furthermore, a rotating shaft fixing ring 231 is installed at the bottom of the lifting bearing end cover 23. A rotation limit plate 232 and a second photoelectric switch 233 are mounted on the rotating shaft fixing ring 231. The origin coordinates of the intermediate rotating shaft 24 are controlled by the rotation limit plate 232 and the second photoelectric switch 233, while the rotation angle is controlled by the second servo motor 21. When the intermediate rotating shaft 24 rotates to a specific position, the rotation limit plate 232 triggers the second photoelectric switch 233, thereby determining the origin of rotation. Simultaneously, the second servo motor 21 controls the rotation angle. This design ensures precise positioning and stability of the robotic arm during rotation.

[0041] Furthermore, the lifting mechanism 3 includes a third servo motor 31, which is fixed to the base plate 33 via a lifting motor mounting bracket 32. The output shaft of the third servo motor 31 transmits torque to the lead screw 34 via a synchronous belt assembly. A lead screw nut 35 is mounted on the lead screw 34, and a lifting lead screw nut 36 is mounted on the lead screw nut 35. The top of the lifting lead screw nut 36 is connected to the lifting bearing end cover 23, thereby realizing the lifting movement of the entire robotic arm. This design achieves precise vertical lifting of the robotic arm, meeting the wafer transfer requirements between process equipment of different heights. At the same time, the stability and precision of the lead screw drive ensure the smoothness and accuracy of the lifting process.

[0042] Furthermore, sliders 241 are installed on both sides of the lifting and fixing block 25. The guide rails 37 corresponding to the sliders 241 are installed on the left and right mounting profiles 38. Three third photoelectric switches 381 are installed on the mounting profiles 38, and the three third photoelectric switches 381 control the upper limit, lower limit coordinates and origin of the lifting and lowering respectively. This design prevents the robotic arm from exceeding the predetermined range or colliding during the lifting and lowering process, thus improving safety.

[0043] Furthermore, a mounting base plate 382 is installed at the bottom of the mounting profile 38, and a cooling fan is installed inside the mounting base plate 382. The cooling fan can effectively reduce the heat generated by the robotic arm during operation, maintain the normal operating temperature range of each component, and improve the stability and reliability of the robotic arm. At the same time, the mounting base plate 382 also protects the internal components from external environmental interference.

[0044] When using the wafer handling robotic arm of this invention, an initialization operation is first performed before the robotic arm begins operation. The first servo motor 11 drives the primary synchronous belt 13, and through the cooperation of the limit stop 141 and the first photoelectric switch 142, the zero point position of the first rotating shaft 14 is determined, which is the initial position of the robotic arm's flexion and extension. At the same time, the second servo motor 21 drives the intermediate rotating shaft 24, and through the cooperation of the rotation limit plate 232 and the second photoelectric switch 233, the origin position of rotation is determined. The third servo motor 31, through the transmission of the lead screw 34 and the lead screw nut 35, cooperates with the third photoelectric switch 381 on the mounting profile 38 to determine the upper limit, lower limit, and origin position of lifting.

[0045] Extension / Retraction Motion: Based on the wafer's position information, the first servo motor 11, through a reducer 12 and a three-stage synchronous belt drive (first-stage synchronous belt 13, second-stage synchronous belt 201, and third-stage synchronous belt 301), drives the first rotating shaft 14, the second rotating shaft 202, and the third rotating shaft 302 to rotate sequentially, causing the robotic arm to extend / retract to the designated position. The precise control of the servo motor and the transmission accuracy of the synchronous belts ensure that the robotic arm can move along a predetermined trajectory and speed.

[0046] After the arm reaches its extended position, the second servo motor 21 drives the intermediate shaft 24 to rotate via a synchronous belt assembly, thereby rotating the entire robotic arm to the target angle in the horizontal plane. The rotation angle is precisely controlled by the second servo motor 21, ensuring accurate alignment of the wafer during the transfer process.

[0047] Based on the height of the target process equipment, the third servo motor 31 transmits torque to the lead screw 34 via a synchronous belt assembly. The combination of the lead screw nut 35 and the lifting lead screw nut 36 converts the torque into lifting motion, driving the entire robotic arm to rise and fall to the designated height. The stability and precision of the lead screw drive ensure the smoothness and accuracy of the lifting process.

[0048] Once the robotic arm reaches the wafer's location, the vacuum fingers 304 on the connecting plate 303 generate negative pressure to stably grip the wafer. The vacuum fingers are designed with the wafer's fragility in mind, ensuring gentle contact during gripping. After gripping, the robotic arm transfers the wafer to the target process equipment in reverse order (lifting, rotating, bending), and releases the wafer via the vacuum fingers 304, completing the placement operation.

[0049] Throughout the entire operation, the cooling fan at the bottom of the mounting profile 38 runs continuously, effectively reducing the heat generated by the robotic arm during operation and maintaining the normal operating temperature range of each component. Meanwhile, each part of the robotic arm adopts a modular design and is sealed within its corresponding cavity (such as the cavity formed by the lifting connecting pipe 16 and the rotating connecting plate 17), effectively isolating it from external environmental interference and protecting critical components such as the motor and reducer from damage.

[0050] The third photoelectric switch 381 on the mounting profile 38 not only controls the extreme positions of the lifting mechanism but also serves a safety monitoring function. When the robotic arm exceeds the predetermined range or collides during lifting, the photoelectric switch triggers an alarm signal to ensure operational safety. The modular design of the robotic arm facilitates disassembly, maintenance, and replacement. When a component malfunctions, it can be quickly replaced or repaired, reducing downtime.

[0051] Finally, it should be noted that the electronic components in the first servo motor 11, the second servo motor 21, the third servo motor 31, etc. in this embodiment are all general standard parts or parts known to those skilled in the art. Their structure and principle can be learned by those skilled in the art through technical manuals or conventional experimental methods. In the idle part of this device, all the above-mentioned electrical components are connected by wires respectively. The specific connection method should refer to the working order between each electrical component in the above working principle to complete the electrical connection. All of these are technologies known in the art.

[0052] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A wafer pick-and-place robot, comprising an arm flexion-extension mechanism (1), an arm rotation mechanism (2), and an arm lifting mechanism (3), characterized in that: The arm flexion and extension mechanism (1) adopts a servo motor plus three-stage synchronous belt transmission mode, the arm rotating mechanism (2) adopts a servo motor plus double-stage synchronous belt to realize, the arm lifting mechanism (3) is realized by servo motor plus ball screw, and guide rail slider assembly is used to ensure the stability of lifting movement; The arm flexion and extension mechanism (1) includes a rotating fixed shaft (15), the bottom of the rotating fixed shaft (15) is provided with a first servo motor (11), the output shaft of the first servo motor (11) is driven to a first rotating shaft (14) through a first-stage synchronous belt (13), the top end of the first rotating shaft (14) is provided with a first mechanical arm (20), the upper end of the first rotating shaft (14) is driven to a second rotating shaft (202) through a second-stage synchronous belt (201), the top end of the second rotating shaft (202) is provided with a second mechanical arm (30), the upper end of the second rotating shaft (202) is driven to a third rotating shaft (302) through a third-stage synchronous belt (301), the top end of the third rotating shaft (302) is provided with a connecting plate (303), and the connecting plate (303) is provided with a vacuum finger (304).

2. The wafer pick-and-place robot of claim 1, wherein: The output shaft of the first servo motor (11) is provided with a speed reducer (12), and the first servo motor (11) and the speed reducer (12) are sealed in a cavity formed by a lifting connecting pipe (16) and a rotating connecting plate (17).

3. The wafer pick-and-place robot of claim 1, wherein: The lower end of the first rotating shaft (14) is designed with a limiting stopper (141) and a first photoelectric switch (142) to realize zero point control of the mechanical arm.

4. The wafer pick-and-place robot of claim 2, wherein: The arm rotating mechanism (2) includes a second servo motor (21), the bottom of the second servo motor (21) is provided with a lifting bearing end cover (23), the second servo motor (21) is fixed on the lifting bearing end cover (23) through a rotating motor base plate (22), the output shaft of the second servo motor (21) is driven to an intermediate rotating shaft (24) through a synchronous belt assembly, one side of the second servo motor (21) is provided with a lifting fixed block (25), and the intermediate rotating shaft (24) is fixed with the rotating connecting plate (17) through the hollow lifting fixed block (25), so as to drive the whole mechanical arm to rotate.

5. The wafer pick-and-place robot of claim 4, wherein: The bottom of the lifting bearing end cover (23) is provided with a rotating shaft fixing ring (231), the rotating shaft fixing ring (231) is provided with a rotating limiting plate (232) and a second photoelectric switch (233), the origin coordinates of the intermediate rotating shaft (24) are controlled by the rotating limiting plate (232) and the second photoelectric switch (233), and the rotating angle is controlled by the second servo motor (21).

6. The wafer pick-and-place robot of claim 5, wherein: The arm lifting mechanism (3) comprises a third servo motor (31) fixed on a fixed bottom plate (33) through a lifting motor fixing seat (32), the output shaft of the third servo motor (31) transmits torque to a lead screw (34) through a synchronous belt assembly, the lead screw (34) is provided with a lead screw nut (35), the lead screw nut (35) is provided with a lifting lead screw nut seat (36), the top of the lifting lead screw nut seat (36) is connected with a lifting bearing end cover (23), so that the lifting movement of the whole mechanical arm is realized.

7. The wafer pick-and-place robot of claim 6, wherein: The lifting fixed block (25) is provided with a sliding block (241) on each side, the sliding block (241) is provided with a corresponding guide rail (37) on the left and right two mounting profiles (38), the mounting profile (38) is provided with three third photoelectric switches (381), and the three third photoelectric switches (381) control the upper limit, the lower limit coordinate and the origin of lifting respectively.

8. The wafer pick-and-place robot of claim 7, wherein: The bottom of the mounting profile (38) is provided with an encapsulation bottom plate (382), and the inside of the encapsulation bottom plate (382) is provided with a heat dissipation fan.

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