Direct-drive wafer transfer robot

Abstract

The direct-drive wafer carrying robot comprises a base and a rotating barrel which are connected, and a large arm and a small arm which are located on the rotating barrel, and a rotating shaft is arranged in the rotating barrel; a rotating shaft motor and a lead screw motor are arranged in the base, the lead screw motor drives the rotating barrel to ascend and descend through a ball screw, and the rotating shaft motor drives the rotating barrel to rotate; a direct-drive motor is further arranged in the rotating barrel and used for driving the large arm and the small arm to be linked, the direct-drive motor replaces a stepping motor and a harmonic speed reducer, the direct-drive motor is a motor direct-connection load, due to the fact that no other transmission exists, the performance of the motor is exerted to the maximum degree, and the stability is greatly improved; meanwhile, collision parameters of the load can be transmitted to the motor according to the ratio of 1: 1, the motor can detect collision force borne by the load through current, collision detection is carried out, and the robot is stopped protectively.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor handling equipment, and in particular to the structure of a wafer handling robot. Background Art

[0002] With the rapid development of the semiconductor industry, the requirements for wafer handling are becoming increasingly higher. For third-generation semiconductors such as SiC and GaN, SiC wafers are more brittle, and the edge collapse rate and fragmentation rate required for transmission are higher than those of ordinary silicon wafers. Therefore, in addition to paying more attention to the design of the manipulator end, the manipulator body must also reduce the vibration amplitude and suppress resonance. If the wafer is damaged during transmission, it will cause high losses, which puts higher requirements on the stability and collision prevention of the wafer handling robot.

[0003] Currently, wafer handling robots in the industry use stepper motors or servo motors to drive harmonic reducers for transmission. After the motor torque is decelerated and increased by the harmonic reducer, the transmission efficiency will be reduced, and noise and resonance will be generated, which will affect wafer transmission. At the same time, traditional structure robots cannot perform anti-collision functions.

[0004] To solve the problem of terminal vibration suppression, the existing direct-drive wafer robot adopts the design of standard finished direct-drive motor. However, the traditional direct-drive motor is large in size, small in rotational torque, and small inertia, and cannot be used under large load conditions. Under small load conditions, the equipment cannot be made lightweight, thus reducing the applicability of the equipment. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention provides a direct-drive version of the wafer handling robot. The present invention replaces the stepper motor + harmonic reducer with a direct-drive motor. The direct-drive motor is a motor directly connected to the load. Because there is no other transmission, the performance of the motor can be maximized and the stability is greatly improved. At the same time, the collision parameters of the load can be transmitted to the motor in a 1:1 ratio. The motor can detect the collision force exerted on the load through current to perform collision detection, and the robot will perform a protective shutdown.

[0006] To achieve the above object, the present invention provides the following technical solutions: A direct-drive wafer handling robot comprises a connected base and a rotating barrel, and an upper arm and a lower arm located on the rotating barrel, wherein a rotating shaft is arranged in the rotating barrel; a rotating shaft motor and a lead screw motor are arranged in the base, the lead screw motor drives the rotating barrel to rise and fall through a ball screw, and the rotating shaft motor drives the rotating barrel to rotate; a direct-drive motor is also arranged in the rotating barrel, and the direct-drive motor is used to drive the upper arm and the lower arm to be linked.

[0007] As a further solution of the present invention, the direct drive motor includes an encoder code disc, a cross roller bearing, a rotor, a stator, a base and an encoder reader; the encoder code disc is connected and fixed to the rotor and the cross roller bearing, the stator and the encoder reader are fixed to the base, and the dust cover is installed on the rotor and rotates relative to the base to form a labyrinth seal.

[0008] As a further solution of the present invention, the upper arm and the lower arm are respectively provided with a synchronous belt, and the direct drive motor drives the upper arm and the lower arm to be linked via the synchronous belt.

[0009] As a further solution of the present invention, the rotating shaft motor is provided with a rotating shaft reducer, and the rotating barrel is driven by the rotating shaft motor and the rotating shaft reducer.

[0010] As a further solution of the present invention, a connecting plate is arranged on the inner side of the dust cover, and a housing of the direct drive motor is arranged on the outer side.

[0011] As a further solution of the present invention, the direct drive motor includes a first direct drive motor and a second direct drive motor, which are used to respectively drive the upper arm and the lower arm to perform linkage.

[0012] The present invention has the following beneficial effects: The present invention replaces the stepper motor + harmonic reducer with a direct-drive motor. The direct-drive motor is a motor directly connected to the load. Because there is no other transmission, the performance of the motor can be brought into play to the maximum extent, and the stability is greatly improved. At the same time, the collision parameters of the load can be transmitted to the motor in a 1:1 ratio. The motor can detect the collision force exerted on the load through current to perform collision detection, and the robot performs a protective shutdown.

[0013] The present invention is suitable for using a self-developed packaged direct-drive motor, and the moving stator of the motor is packaged into the arm. The direct-drive motor adopts an outer rotor motor structure design, and the motor will obtain a larger moment of inertia and rotational torque. The outer shell of the arm is used as the outer shell of the motor. Because there is no outer shell weight of the motor, the overall equipment will be 10% lighter than traditional equipment, and the equipment volume will be reduced by 5%, while the torque will increase by 30%, and the moment of inertia will increase by 200%. The volume of the overall equipment will be very compact, thus completely solving the problems of suppressing resonance and versatility of traditional wafer handling robots.

[0014] In order to more clearly illustrate the structural features and effects of the present invention, the present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural diagram of the whole machine of the direct-drive wafer handling robot of the present invention.

[0016] Figure 2 It is a cross-sectional view of the whole machine of the direct-drive wafer handling robot of the present invention.

[0017] Figure 3a , Figure 3b Shown is a cross-sectional view of the direct drive motor mentioned in the present invention.

[0018] Figure 3c 2 is an exploded view of the direct drive motor mentioned in the present invention.

[0019] Figure 4 It is a stereoscopic diagram of the direct drive motor mentioned in the present invention.

[0020] Figure 5 It is a connection diagram of the direct drive motor and the arm of the present invention.

[0021] Figure 6 It is a front view of the direct-drive wafer handling robot of the present invention.

[0022] Figure 7 It is an exploded view of the direct-drive wafer handling robot of the present invention. DETAILED DESCRIPTION

[0023] The present invention will be further explained below in conjunction with the accompanying drawings and related knowledge, and described clearly and completely. Obviously, the described application is only a part of the embodiments of the present invention, rather than all the embodiments.

[0024] Currently, wafer handling robots in the industry use stepper motors or servo motors to drive harmonic reducers for transmission. After the motor torque is decelerated and increased by the harmonic reducer, the transmission efficiency will be reduced, and noise and resonance will be generated, which will affect wafer transmission. At the same time, traditional structure robots cannot perform anti-collision functions.

[0025] To solve the problem of terminal vibration suppression, the existing direct-drive wafer robot adopts the design of standard finished direct-drive motor. However, the traditional direct-drive motor is large in size, small in rotational torque, and small inertia, and cannot be used under large load conditions. Under small load conditions, the equipment cannot be made lightweight, thus reducing the applicability of the equipment.

[0026] In order to solve the above technical problems, a direct-drive wafer handling robot is proposed; Figure 1-Figure 6As shown, the direct-drive version of the wafer handling robot includes a connected base 1 and a rotating barrel 2, and a large arm 3 and a small arm 4 located on the rotating barrel 2, and a rotating shaft 5 is arranged in the rotating barrel 2; a rotating shaft motor 6 and a screw motor 7 are arranged in the base 1, and the screw motor 7 drives the rotating barrel 2 to rise and fall through a ball screw 8, and the rotating shaft motor 6 drives the rotating barrel 2 to rotate; a direct-drive motor 9 is also arranged in the rotating barrel 2, and the direct-drive motor 9 is used to drive the large arm 3 and the small arm 4 to be linked. The present invention replaces the stepper motor + harmonic reducer with a direct-drive motor. The direct-drive motor is a motor directly connected to the load. Because there is no other transmission, the performance of the motor can be brought into play to the maximum extent, and the stability is greatly increased. At the same time, the collision parameters of the load can be transmitted to the motor in a 1:1 ratio. The motor can detect the collision force exerted on the load through the current to perform collision detection, and the robot performs a protective shutdown; and a self-developed packaged direct-drive motor is used to package the moving stator of the motor into the arm. The direct-drive motor adopts an outer rotor motor structure design, and the motor will obtain a larger moment of inertia and rotational torque. The arm casing is used as the motor casing. Because there is no motor casing weight, the overall equipment will be 10% lighter than traditional equipment, and the equipment volume will be reduced by 5%, while the torque will be increased by 30%, the moment of inertia will be increased by 200%, and the volume of the overall equipment will be very compact, thereby completely solving the problems of suppressing resonance and versatility of traditional wafer handling robots.

[0027] The invention has an efficient transmission system and precise control capability, which can quickly and accurately complete the wafer handling task, reduce the handling time, and improve the overall production efficiency of the semiconductor production line; high-precision positioning and stable operation can prevent the wafer from being affected by vibration, collision, etc. during the handling process, reduce the damage rate of the wafer, and help improve the yield rate of semiconductor products. Compared with the traditional transmission method, the structure of the direct-drive wafer handling robot is relatively simple, which reduces the wear and failure probability of the transmission components, and reduces the cost and difficulty of maintenance and repair.

[0028] In the present invention, the rotating shaft motor 6 and the lead screw motor 7 in the base 1 are responsible for the rotation and lifting movement of the rotating barrel 2 respectively, and the direct drive motor 9 in the rotating barrel 2 is used to drive the upper arm 3 and the lower arm 4 to work together to realize the wafer handling operation; the rotating shaft motor 6 drives the rotating barrel 2 to rotate so that it can take and place wafers at different angles; the lead screw motor 7 drives the rotating barrel 2 to rise and fall through the ball screw 8 to meet the working requirements at different heights; the direct drive motor 9 is directly connected to the upper arm 3 and the lower arm 4, and directly transmits power to the arm to realize the linkage of the arm and complete the actions of grabbing, carrying and placing the wafer; Stability enhancement can be achieved: the direct-drive motor is directly connected to the load, reducing the intermediate transmission link, avoiding the loss of precision and vibration caused by factors such as the gap and elastic deformation of the transmission components, thereby greatly improving the stability of the robot and making the wafer handling process smoother and more accurate. Sensitive collision detection: Since there is no other transmission, the collision parameters of the load can be transmitted to the motor at a 1:1 ratio. The motor can detect the collision force exerted on the load in a timely and accurate manner through the change of current. Once a collision is detected, the robot can quickly perform a protective shutdown, effectively avoiding the wafer from being damaged by collision during the handling process, and improving the safety and reliability of production. Structural optimization: Weight reduction: The self-developed packaged direct-drive motor is used, the moving stator of the motor is packaged into the arm, and the outer shell of the arm is used as the outer shell of the motor, eliminating the outer shell weight of the traditional motor, making the overall equipment weight 10% lower than that of traditional equipment. For wafer handling robots that require high-precision and high-speed movement, this reduces the inertial load of the moving parts, which is conducive to improving the response speed and movement accuracy of the robot. Reduced volume: The direct-drive motor adopts an outer rotor motor structure design, which obtains a larger moment of inertia and rotational torque. At the same time, due to the elimination of the motor housing and some transmission components, the overall equipment volume is reduced by 5%, making the robot structure more compact and able to adapt to a smaller working space, improving the space utilization of the equipment, and facilitating layout and installation on semiconductor production lines. Solving traditional problems: Traditional wafer handling robots have certain limitations in suppressing resonance and versatility. Through the above-mentioned technological innovations, the direct-drive version of the wafer handling robot effectively solves these problems, enabling it to operate stably under a wider range of working conditions, and can better adapt to the handling needs of wafers of different sizes and weights, improving the versatility and adaptability of the equipment.

[0029] Reference Figure 1 As shown, the rotating shaft 5 is installed on the Body base 1, and the Body base 1 has a lifting shaft inside. The forearm is connected to the upper arm, and the structure is coupled internally through a synchronous belt. The upper arm and the rotating shaft are connected through a direct drive motor; further preferably, the upper arm 3 and the lower arm 4 are respectively provided with a synchronous belt 19, and the direct drive motor drives the upper arm and the lower arm to be linked through the synchronous belt. When the motor rotates, it drives the synchronous pulley to rotate. The synchronous belt is sleeved on the synchronous pulley of the motor and the synchronous pulleys installed on the upper arm and the lower arm, so as to transmit the power of the motor to the upper arm and the lower arm, and drive them to move; the speed, direction, start and stop of the direct drive motor are precisely controlled by the control system, and then the movement of the synchronous belt is precisely controlled to realize the linkage of the upper arm and the lower arm according to the preset trajectory, speed and angle. For example, when the robot is carrying materials, the upper arm can be controlled to extend to a certain position first, and then the lower arm performs the grabbing action, and the movement of the two is coordinated and completed by the synchronous belt under the drive of the direct drive motor.

[0030] The present invention can effectively reduce the energy loss caused by too many intermediate transmission links, improve the transmission efficiency, make the movement response speed of the upper arm and the lower arm faster, and make the overall operation of the system more stable with less vibration and noise. In addition, the synchronous belt has a certain elasticity, which can buffer the impact force during the movement to a certain extent and protect the motor and mechanical structure.

[0031] Reference Figure 2 As shown, the screw motor 7 is connected to the ball screw 8 through a synchronous belt to drive the rotating barrel 2 to rise and fall. The rotating barrel 2 is driven by the rotating shaft motor 6 and the rotating shaft reducer. A direct drive motor is installed on the rotating barrel to drive the upper arm and the lower arm to move in linkage.

[0032] In the present invention, the direct drive motor 9 includes an encoder disc 10, a cross roller bearing 11, a rotor 12, a stator 13, a base 14 and an encoder reader 15; the encoder disc 10 is connected and fixed to the rotor 12 and the cross roller bearing 11, and the stator 13 and the encoder reader 15 are fixed to the base 14. The dust cover is installed on the rotor and rotates relative to the base to form a labyrinth seal; further preferably, a connecting plate 17 is provided on the inner side of the dust cover 16, and a housing 18 of the direct drive motor is provided on the outer side; refer to Figure 3a-3c As shown, the encoder code disc 10 is connected and fixed to the rotor 12 and the cross roller bearing 11, the stator 13 and the encoder reader 15 are fixed to the base 14, the dust cover 16 is installed on the rotor 12, and rotates relative to the base to form a labyrinth seal, wherein the direct drive motor 9 is installed through the mounting plate 21, and the encoder reader 15 is provided with an encoder cover 22. It is further preferred that a connecting shaft 23 is provided in the cross roller bearing 11.

[0033] The encoder disc of the present invention is connected to the rotor and the cross roller bearing, and can accurately measure the rotation position and speed of the rotor and other information, providing a basis for the precise control of the motor. The stator and the encoder reader are fixed to the base, which ensures the stability of the stator and the accuracy of the relative position between the encoder reader and the encoder disc, which is conducive to the stable reading of the signal. The dust cover is installed on the rotor and rotates relative to the base to form a labyrinth seal, which can effectively prevent dust, impurities, etc. from entering the motor, protect the internal components of the motor, and extend the service life of the motor.

[0034] Among them, the encoder disc and the rotor and the cross roller bearing: the encoder disc may be fixed to the shaft of the rotor by means of key connection, interference fit, etc. to ensure the synchronous rotation of the two. The encoder disc and the cross roller bearing may be connected by bolts or specific slots, protrusions and other structures may be designed on the disc and the bearing for clamping and fixing to ensure that the encoder disc rotates with the rotor and the cross roller bearing; and the stator and the encoder reader and the base: the stator and the base may be fastened by multiple evenly distributed bolts to ensure the stability of the stator. The encoder reader can be fixed to a specific position on the stator or the base by means of screws or buckles to ensure that it maintains a suitable spacing and relative position with the encoder disc.

[0035] In the present invention, reference is made to Figure 2 As shown, the rotating shaft motor 6 is provided with a rotating shaft reducer 20, and the rotating barrel is driven by the rotating shaft motor and the rotating shaft reducer.

[0036] Reference Figure 4-Figure 7 As shown, the direct drive motor 9 includes a first direct drive motor and a second direct drive motor, which are used to drive the upper arm and the lower arm to perform linkage respectively. Further preferably, the first direct drive motor and the second direct drive motor are symmetrically arranged around the rotating axis 5.

[0037] In the present invention, in order to achieve a 1:1 feedback of the force received by the end of the arm to the motor, a direct-drive motor is developed in-house. The direct-drive motor must meet the requirements of low dust generation, high torque, and high load. An outer rotor motor and a labyrinth dustproof structure are specially adopted. The rotor is directly connected to the arm to ensure a 1:1 force transmission. A cross roller bearing is used to achieve a larger axial load. The outer rotor of the motor increases the torque and larger moment of inertia of the motor.

[0038] The technical principle of the present invention is described above in combination with the specific embodiments, which are only preferred implementations of the present invention. The protection scope of the present invention is not limited to the above embodiments, and all technical solutions under the idea of ​​the present invention belong to the protection scope of the present invention. Those skilled in the art can think of other specific implementations of the present invention without creative work, and these methods will fall within the protection scope of the present invention.

Claims

1. Direct drive wafer handling robot, characterized in that: It includes a connected base and a rotating barrel, and a large arm and a small arm located on the rotating barrel, and a rotating shaft is arranged in the rotating barrel; a rotating shaft motor and a screw motor are arranged in the base, and the screw motor drives the rotating barrel to rise and fall through a ball screw, and the rotating shaft motor drives the rotating barrel to rotate; a direct drive motor is also arranged in the rotating barrel, and the direct drive motor is used to drive the large arm and the small arm to be linked.

2. The direct-drive wafer handling robot according to claim 1, characterized in that: The direct drive motor includes an encoder disc, a cross roller bearing, a rotor, a stator, a base and an encoder reader; the encoder disc is connected and fixed to the rotor and the cross roller bearing, the stator and the encoder reader are fixed to the base; the dust cover is installed on the rotor and rotates relative to the base to form a labyrinth seal.

3. The direct-drive wafer handling robot according to claim 2, characterized in that: The upper arm and the lower arm are respectively provided with a synchronous belt, and the direct drive motor drives the upper arm and the lower arm to perform linkage through the synchronous belt.

4. The direct-drive wafer handling robot according to claim 3, characterized in that: The rotating shaft motor is provided with a rotating shaft reducer, and the rotating barrel is driven by the rotating shaft motor and the rotating shaft reducer.

5. The direct-drive wafer handling robot according to claim 4, characterized in that: A connecting plate is arranged inside the dust cover, and a housing of the direct drive motor is arranged outside the dust cover.

6. The direct-drive wafer handling robot according to claim 5, characterized in that: The direct drive motor comprises a first direct drive motor and a second direct drive motor, which are used to respectively drive the upper arm and the lower arm to perform linkage.

Images