Wafer clamping mechanism

Abstract

The application discloses a wafer clamping mechanism and belongs to the technical field of semiconductor manufacturing equipment. The wafer clamping mechanism comprises an external clamping mechanism, an internal clamping mechanism and a rotary transfer wafer mechanism. The internal clamping mechanism integrates four motion functions of lifting, deflection, pitching and rotation. Among them, a gear driving motor drives an L-shaped connecting rod shaft to move axially through a gear and rack pair, and then converts the movement into the swing of a rotating shaft through a connecting rod mechanism to realize the pitching adjustment of a suction cup; a deflection motor drives a turnover shaft through a synchronous belt to realize the deflection motion of the suction cup; a rotating motor directly drives the rotation of the suction cup; and a Z-axis moving module realizes the accurate positioning in the vertical direction. The external clamping mechanism is responsible for the bearing and horizontal rotation of the wafer, and the rotary transfer mechanism realizes the automatic transfer of the wafer between different stations. The application solves the problems of function fragmentation, low space utilization and insufficient clamping stability in the prior art, and can realize the multi-degree-of-freedom precise attitude adjustment of the wafer synchronously.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor manufacturing equipment technology and is mainly applied to the transmission and positioning process in wafer processing. It involves precise wafer attitude adjustment operation, specifically a wafer clamping mechanism. This mechanism achieves high-precision, high-efficiency, safe and stable clamping and attitude adjustment functions for wafers through integrated multi-degree-of-freedom motion modules and collaborative clamping design. Background Technology

[0002] In semiconductor manufacturing, wafers, as the carriers of integrated circuits, undergo a series of precision processing steps, including photolithography, etching, ion implantation, and cleaning. These steps frequently require wafer orientation adjustments at different angles, such as horizontal rotation to align with process modules, large-angle flipping for double-sided processing, and minute-angle yaw to correct positional deviations. The positioning accuracy and orientation control stability of the wafer directly affect the precision of pattern transfer and process uniformity, and are key factors determining the final device performance and yield.

[0003] Currently, the wafer attitude adjustment solutions commonly used in the industry have significant shortcomings. First, the functional modules are relatively fragmented; movements with different degrees of freedom, such as rotation and flipping, are usually achieved by multiple independent dedicated mechanisms. Second, regarding clamping methods, traditional mechanical clamping, especially edge-contact clamping, while simple in structure, is difficult to control in terms of clamping force, and is prone to causing micro-cracks or stress concentration at the wafer edge. Third, traditional drive structures require a large amount of space to accommodate transmission components and avoid interference in order to achieve motion transmission, resulting in low internal space utilization and a less compact structure.

[0004] Therefore, existing technologies cannot simultaneously meet the comprehensive requirements of advanced semiconductor manufacturing for wafer processing, including high precision, high efficiency, high reliability, and equipment miniaturization. There is an urgent need for an innovative wafer clamping mechanism that can highly integrate multi-degree-of-freedom motion functions, achieving a compact design while ensuring clamping stability and safety, thereby effectively improving the overall performance of semiconductor manufacturing equipment. Summary of the Invention

[0005] The purpose of this invention is to provide a wafer clamping mechanism to solve the problems of fragmented wafer orientation adjustment function, low equipment space utilization, and insufficient clamping stability in the prior art.

[0006] To address the above problems, the present invention provides a wafer clamping mechanism, including an external clamping mechanism, an internal clamping mechanism, and a rotary wafer transfer mechanism;

[0007] The internal clamping mechanism includes:

[0008] The fixed bracket is rigidly mounted on the main base plate of the equipment.

[0009] Z-axis moving module two is vertically fixed on a fixed bracket;

[0010] Adapter plate two is fixedly connected to the output end of Z-axis moving module two;

[0011] The deflection motor is fixed on the second adapter plate, and its output shaft drives the tilting shaft to rotate via a synchronous belt;

[0012] The gear motor mounting plate and bracket are fixedly connected to both ends of the tilting shaft, respectively.

[0013] A gear-driven motor is mounted on a gear motor mounting plate, and the gear on its output shaft meshes with a rack.

[0014] The connecting rod shaft is L-shaped, with a rack at one end, which passes through the hollow through hole of the flip shaft and is driven by gears to move axially.

[0015] A rotating shaft, the middle of which is rotatably connected to the end of the bracket;

[0016] The connecting rod has its two ends hinged to the other end of the connecting rod shaft and the bottom of the rotating shaft, respectively.

[0017] Rotary motor two is fixedly mounted on the top of the rotating shaft; and

[0018] Suction cup one is connected to the output shaft of rotary motor two and is used to adsorb wafers;

[0019] Among them, the Z-axis moving module 2 drives the suction cup 1 to perform Z-axis lifting and lowering motion, the deflection motor drives the suction cup 1 to perform deflection motion, the gear drive motor drives the rotating shaft to swing through gears, racks, connecting rods and connecting rods, thereby causing the suction cup 1 to perform pitching motion, and the rotary motor 2 drives the suction cup 1 to perform rotational motion.

[0020] Compared with the prior art, the wafer clamping mechanism provided by the present invention has the following significant and beneficial technical effects:

[0021] (1) The internal clamping mechanism of the present invention enables precise attitude adjustment of the wafer in space with multiple degrees of freedom. The mechanism integrates four motion functions, namely lifting, deflection, pitching and rotation, into one, and can simultaneously complete the circumferential rotation, large-angle flipping and small-range yaw of the wafer, which improves the flexibility and coordination of wafer attitude adjustment, avoids the cumulative error caused by multiple independent actuators in the past, and improves the accuracy of wafer positioning and alignment.

[0022] (2) The coordinated operation of the various components of the clamping mechanism of the present invention constructs a complete wafer processing system. The three mechanisms each perform their own functions while working closely together. The external clamping mechanism is responsible for the initial bearing and horizontal rotation of the wafer, the internal clamping mechanism focuses on the fine orientation adjustment of the wafer, and the rotation transfer mechanism realizes the automated transfer of the wafer between different workstations. The optimized internal space configuration makes the overall structure more compact and reasonable, and solves the problem of spatial interference when multiple mechanisms coexist.

[0023] (3) The wafer clamping mechanism of the present invention realizes a high degree of automation and intelligence in the wafer processing flow. The design simplifies the operation process of wafer transfer and positioning, enhances the stability and reliability of equipment operation, and provides effective technical support for the development of semiconductor manufacturing equipment towards high precision, high efficiency and high integration. It has good engineering application value and market prospects. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the internal clamping mechanism structure according to an embodiment of the present invention;

[0026] Figure 2 This is an enlarged view of section A of the schematic diagram of the internal clamping mechanism structure in an embodiment of the present invention;

[0027] Figure 3 This is a schematic diagram of the external clamping mechanism structure according to an embodiment of the present invention;

[0028] Figure 4 This is a schematic diagram of the rotating wafer transfer mechanism according to an embodiment of the present invention;

[0029] Figure 5 This is a layout diagram of the various mechanisms of the wafer clamping mechanism according to an embodiment of the present invention.

[0030] Explanation of reference numerals in the attached drawings: 1-External clamping mechanism; 1.1-Arc-shaped suction cup; 1.2-Rotary motor one; 1.3-Adapter plate one; 1.4-Z-axis moving module one; 1.5-Fixed support; 2-Internal clamping mechanism; 2.1-Fixed bracket; 2.2-Z-axis moving module two; 2.3-Adapter plate two; 2.4-Deflection motor; 2.5-Synchronous belt; 2.6-Gear drive motor; 2.7-Gear; 2.8-Rack; 2.9-Gear motor mounting plate; 2.10-Rotary motor two; 2.11-Suction cup one; 2.12-Rotating shaft; 2.13-Bracket; 2.14-Connecting rod shaft; 2.15-Connecting rod; 3-Rotating wafer transfer mechanism; 3.1-Fixed base; 3.2-Z-axis moving module three; 3.3-Adapter plate three; 3.4-Rotary motor three; 3.5-Rotating rod; 3.6-Clamping suction cup. Detailed Implementation

[0031] In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention can be practiced without one or more of these details. In other instances, certain technical features well-known in the art have not been described in order to avoid obscuring the invention.

[0032] To fully understand this invention, detailed steps and structures will be presented in the following description to illustrate the technical solution of this invention. Preferred embodiments of the invention are described in detail below; however, in addition to these detailed descriptions, the invention may have other embodiments.

[0033] like Figure 5 In one embodiment of the wafer clamping mechanism of the present invention shown, the wafer clamping mechanism mainly includes an external clamping mechanism 1, an internal clamping mechanism 2, and a rotating wafer transfer mechanism 3. The three mechanisms work together to achieve precise clamping and transfer of the wafer with multiple degrees of freedom.

[0034] like Figure 1 and Figure 2 As shown, the internal clamping mechanism 2 includes a Z-axis lifting unit, a deflection drive unit, a pitch adjustment unit, and a wafer adsorption unit. The main support structure of the internal clamping mechanism 2 is a fixed bracket 2.1, which is mounted on the main base plate of the equipment by fasteners, providing a stable mounting reference for the entire mechanism.

[0035] A Z-axis lifting unit is installed on the upper mounting surface of the fixed bracket 2.1. The Z-axis lifting unit mainly includes a Z-axis moving module 2.2 and a transition plate 2.3. The Z-axis moving module 2.2 is fixedly mounted on the fixed bracket 2.1 and adopts a high-precision linear motion mechanism. Precision machining ensures the parallelism between the mounting plane and the base plate. A connecting block is installed on the slider of the Z-axis moving module 2.2 for connecting the transition plate 2.3. The transition plate 2.3 serves as the mounting platform for the mechanism and adopts an integral structure design. It is planned with multiple functional areas for installing subsequent motion units.

[0036] A deflection drive unit is mounted on the side of adapter plate 2.3. This deflection drive unit consists of a deflection motor 2.4, a synchronous belt 2.5, a tilting shaft, and related support structures. The deflection motor 2.4 is mounted on the bottom side of adapter plate 2.3, and its output shaft is connected to the tilting shaft via the synchronous belt 2.5. The tilting shaft is supported on the top of adapter plate 2.3 by bearings, enabling rotational movement.

[0037] A gear motor mounting plate 2.9 and a bracket 2.13 are fixedly connected to both ends of the tilting shaft, respectively. A gear drive motor 2.6 is mounted on the gear motor mounting plate 2.9, and a gear 2.7 is mounted on the output shaft of the gear drive motor 2.6. The bracket 2.13 is designed as a gantry structure, with its end away from the tilting shaft rotatably connected to the rotating shaft 2.12. A transmission mechanism is provided between the gear 2.7 and the rotating shaft 2.12, including components such as a rack 2.8, a connecting rod shaft 2.14, and a connecting rod 2.15.

[0038] The end effector of the mechanism is a wafer adsorption unit, which includes a rotary motor 2.10 and a suction cup 2.11. The rotary motor 2.10 is fixedly mounted on the top of the rotating shaft 2.12, and the suction cup 2.11 is directly connected to the output shaft of the motor.

[0039] The Z-axis lifting unit is responsible for the coarse positioning motion of the mechanism in the vertical direction. Z-axis moving module 2.2 is driven by a servo motor and coupled with a high-precision ball screw transmission mechanism, enabling smooth and accurate linear motion. An internal guiding mechanism, employing linear guides or a self-guiding structure, ensures rigidity and accuracy during movement. The stroke of Z-axis moving module 2.2 covers the entire process from wafer receiving to detection and positioning.

[0040] In a preferred embodiment, the lifting unit also integrates a position detection system. This system uses a high-resolution optical or magnetic ruler as the position feedback element to achieve fully closed-loop control. The position detection system monitors the actual position of the slider of the Z-axis movement module 2.2 in real time and feeds the signal back to the control system, thereby achieving precise control of the Z-axis position. The position detection system effectively eliminates transmission errors and improves positioning accuracy.

[0041] The deflection drive unit is a key component for adjusting the wafer tilt angle. The deflection motor 2.4 employs a high-precision servo motor with a brake function, enabling it to maintain a locked position during power outages. The deflection motor 2.4 drives the rotation shaft via a synchronous belt 2.5 transmission mechanism. This transmission method is characterized by smooth operation and low noise, making it suitable for use in precision equipment.

[0042] In a preferred embodiment, the synchronous belt 2.5 adopts a tensioning pulley type tensioning structure. The tensioning pulley presses against the slack side of the synchronous belt 2.5, and the pressing force is adjusted by a swingable adjusting bracket. After reaching the correct position, it is locked and fixed to prevent transmission slippage. The structure is compact and easy to adjust. The support structure of the tilting shaft adopts angular contact bearings, which can withstand axial and radial loads and ensure rotational accuracy.

[0043] The pitch adjustment unit uses a linkage mechanism to achieve precise fine-tuning of the wafer pitch angle. The gear drive motor 2.6 converts the rotary motion into the linear motion of the linkage shaft 2.14 through the meshing of gear 2.7 and rack 2.8.

[0044] The connecting rod shaft 2.14 adopts an L-shaped design, with a rack 2.8 at the end furthest from the connecting rod 2.15, which passes through the hollow through hole of the tilting shaft. This allows the connecting rod shaft 2.14 to both deflect along with the tilting shaft and move axially independently. The connecting rod 2.15 rotatably connects the lower end of the vertical section of the connecting rod shaft 2.14 to the bottom of the rotating shaft 2.12, converting linear motion into rotational motion.

[0045] The wafer adsorption unit is the part that directly contacts the wafer. Its rotary motor 2.10 adopts a hollow shaft structure design to facilitate the passage of vacuum lines. The motor is a DC brushless servo motor, which has high speed accuracy and low jitter characteristics, suitable for the wafer rotation scanning requirements.

[0046] To maximize the exposure of the patterned surface of the wafer, suction cup 2.11 features a small diameter design with micropores on its surface, using vacuum adsorption to fix the wafer. The vacuum channel starts from the hollow shaft of rotary motor 2.10, passes through the internal channels of rotating shaft 2.12, and finally reaches the adsorption surface of suction cup 2.11, forming a complete vacuum circuit.

[0047] The internal clamping mechanism 2 achieves six-degree-of-freedom pose adjustment of the wafer through a combination of four degrees of freedom. The kinematic relationship between each motion axis ensures both motion flexibility and avoids redundant degrees of freedom.

[0048] The motion chain of the mechanism starts from the fixed support 2.1, passes sequentially through the Z-axis moving module 2.2, the adapter plate 2.3, the deflection drive unit, the pitch adjustment unit, and finally reaches the wafer adsorption unit. Each motion unit is a link in the motion chain, transmitting motion and force through a reasonable connection method.

[0049] Z-axis movement module 2.2 provides the mechanism with Z-axis translational freedom in the base coordinate system. The deflection drive unit provides rotational freedom about the flip axis, causing all subsequent components to deflect together. The pitch adjustment unit achieves oscillating motion about a specific axis via a linkage mechanism. Rotary motor 2.10 provides the wafer with rotational freedom about its own central axis.

[0050] The mechanism design fully considers motion coupling. The hollow structure of the tilting shaft decouples the yaw and pitch movements. Linkage shaft 2.14 can both tilt with the tilting shaft and move axially independently, ensuring the independence of each motion axis. Each motion axis is controlled independently, and complex motion trajectories are achieved through the coordination of the control system.

[0051] Working principle and movement process of internal clamping mechanism 2: When the wafer is transported above internal clamping mechanism 2, Z-axis moving module 2.2 drives the entire actuator to rise, so that suction cup 2.11 gently contacts the center of the back side of the wafer. Vacuum is activated, adsorbing the wafer. Then Z-axis moving module 2.2 can descend to the preset detection height. When wafer orientation or circumferential scanning is required, rotary motor 2.10 starts, directly driving suction cup 2.11 and the adsorbed wafer to rotate continuously 360 degrees, facilitating observation from different angles or panoramic scanning of the wafer. When it is necessary to adjust the tilt angle of the wafer relative to the horizontal plane for illumination and observation at a specific angle, deflection motor 2.4 operates. The deflection motor 2.4 drives the tilting shaft to rotate via the synchronous belt 2.5. Since the gear motor mounting plate 2.9 and the bracket 2.13 are both fixed to the tilting shaft, the entire actuator unit, consisting of the gear drive motor 2.6, connecting shaft 2.14, connecting rod 2.15, rotating shaft 2.12, rotary motor 2.10, and suction cup 2.11, will deflect along with the tilting shaft. This deflection motion causes the wafer plane to tilt. The mechanism can also adjust the wafer's pitch angle when the wafer is tilted or horizontal. The gear drive motor 2.6 operates, driving the gear 2.7 to rotate, which, through the rack 2.8, causes the connecting shaft 2.14 to move axially. The movement of the connecting shaft 2.14 pushes or pulls the connecting rod 2.15. Since one end of connecting rod 2.15 is hinged to connecting rod shaft 2.14 and the other end is hinged to the bottom of rotating shaft 2.12, and the middle of rotating shaft 2.12 is supported by bracket 2.13, the movement of connecting rod 2.15 will force rotating shaft 2.12 to swing around its hinge point with bracket 2.13. This swinging motion will translate into a change in the pitch angle of suction cup 2.11.

[0052] like Figure 3 As shown, the external clamping mechanism 1 is used to receive, initially position, and transfer the wafer. Its specific structure includes a fixed support 1.5, a Z-axis moving module 1.4, an adapter plate 1.3, a rotary motor 1.2, and an arc-shaped suction cup 1.1.

[0053] The fixed support 1.5 is mounted on the main base plate or frame of the equipment, providing a stable support foundation for the entire external clamping mechanism 1. The fixed support 1.5 is usually made of aluminum alloy or stainless steel and is precision machined to ensure the flatness of the mounting surface.

[0054] The Z-axis moving module 1.4 is fixedly mounted on the upper surface of the fixed support 1.5. The Z-axis moving module 1.4 preferably employs a high-precision linear motor module or ball screw module, driven by a servo motor. Internally, it includes a linear guide and a slider, enabling precise and smooth reciprocating motion along the vertical direction. The Z-axis moving module 1.4 itself has a grating ruler or magnetic encoder for real-time feedback of the slider's position information, achieving closed-loop control with a positioning accuracy down to the micrometer level.

[0055] The adapter plate 1.3 is fixedly connected to the output end of the Z-axis moving module 1.4 via a connecting block. Therefore, when the Z-axis moving module 1.4 moves, the adapter plate 1.3 will move up and down along the Z-axis. The adapter plate 1.3, as a mounting platform, can be made of hard aluminum alloy through stress relief and precision milling.

[0056] Rotary motor 1.2 is bolted to the upper surface of adapter plate 1.3. Rotary motor 1.2 is preferably a hollow-shaft servo motor or stepper motor, characterized by high torque and low jitter. The motor's rotation angle is precisely controlled by the control system.

[0057] The curved chuck 1.1 is connected to the output shaft of the rotary motor 1.2 via a flange or coupling. The curved chuck 1.1 is designed with an arc shape that matches the curvature of the wafer edge, providing excellent wear resistance and anti-static properties. Multiple fine vacuum adsorption grooves are formed on the contact surface of the curved chuck 1.1. These grooves are connected to an external vacuum generator via internal channels. When wafer adsorption is required, the vacuum generator operates, generating negative pressure within the adsorption grooves, thereby firmly adsorbing the edge area of ​​the wafer onto the curved chuck 1.1. The design of the curved chuck 1.1 ensures that most of the wafer surface, especially the central effective chip area, is completely exposed and unobstructed.

[0058] During operation, when the rotary transfer wafer mechanism 3 delivers the wafer above the external clamping mechanism 1, the Z-axis moving module 1.4 drives the arc-shaped chuck 1.1 to rise, gently supporting the back edge of the wafer. Vacuum is activated, holding the wafer in place. Subsequently, the rotary motor 1.2 can rotate the wafer at a specific angle as needed, allowing for preliminary observation from different directions or preparation for subsequent transfer. After the operation is complete, the Z-axis moving module 1.4 descends, lowering the wafer to a suitable height, ready to transfer it to the adjacent internal clamping mechanism 2.

[0059] The rotary wafer transfer mechanism 3 is a wafer handling hub, and its working range covers both the external clamping mechanism 1 and the internal clamping mechanism 2. For example... Figure 4 As shown, its specific structure includes a fixed base 3.1, a Z-axis moving module 3.2, an adapter plate 3.3, a rotary motor 3.4, a rotating rod 3.5, and a clamping suction cup 3.6.

[0060] The fixed base 3.1 is the base of the entire mechanism. It is fixed to the equipment base plate by bolts and has high rigidity and stability to reduce vibration during movement.

[0061] The Z-axis moving module 3.2 is vertically mounted on the fixed base 3.1. This module also uses a high-precision linear module to drive the entire arm structure to move up and down along the Z-axis to achieve wafer pick-up and placement. Its stroke can reach the height of all target positions, including the external clamping mechanism 1 and the internal clamping mechanism 2.

[0062] Adapter plate 3.3 connects to the output end of Z-axis moving module 3.2 and moves up and down with the module. Adapter plate 3.3 provides a mounting surface for rotary motor 3.4.

[0063] Rotary motor 3.4 is fixedly mounted on adapter plate 3.3. Rotary motor 3.4 is preferably a servo motor capable of continuous 360-degree rotation with high rotational accuracy.

[0064] The rotating rod 3.5 is connected to the output shaft of the rotary motor 3.4 via a coupling, with both ends extending outwards. The rotating rod 3.5 is sufficiently lightweight and rigid, typically made of carbon fiber tubing or thin-walled aluminum alloy tubing to reduce rotational inertia and improve movement speed and stability. The length of the rotating rod 3.5 determines the working diameter of the rotary transfer wafer mechanism 3.

[0065] The clamping chuck 3.6 is mounted at the end of the rotating rod 3.5. The clamping chuck 3.6 is the component that directly contacts and transports the wafer. It includes a main body and multiple vacuum nozzles. When the vacuum nozzles adsorb the wafer, the force is uniform, preventing wafer warping or stress concentration. The vacuum passage is led out through the hollow shaft of the rotating rod 3.5 and the rotary motor 3.4, connecting to an external vacuum system. The vacuum is precisely controlled by a solenoid valve.

[0066] The working process of the rotary wafer transfer mechanism 3 is as follows: When a wafer needs to be picked up, the rotary motor 3.4 and the Z-axis moving module 3.2 drive the rotating rod 3.5 to rotate and descend, causing the clamping suction cup 3.6 to move directly below the corresponding wafer placement mechanism. Then, the Z-axis moving module 3.2 rises, causing the clamping suction cup 3.6 to contact the back of the wafer, activating vacuum to hold the wafer. Next, the Z-axis moving module 3.2 rises again, lifting the wafer. The rotary motor 3.4 moves again, transporting the wafer above the target position, and the Z-axis moving module 3.2 descends, releasing the vacuum and placing the wafer onto the target mechanism. Through the coordinated movement of the rotary motor 3.4 and the Z-axis moving module 3.2, it can efficiently transfer wafers between several workstations.

[0067] During operation of the entire wafer clamping mechanism, the rotary transfer wafer mechanism 3 first removes the wafer from the upstream station and transfers it to the arc-shaped chuck 1.1 of the external clamping mechanism 1. After the external clamping mechanism 1 performs initial positioning of the wafer, the chuck 2.11 of the internal clamping mechanism 2 adjusts to the optimal position and orientation in four degrees of freedom, reliably adsorbing the wafer and performing precise alignment and transfer. The entire process is automated through a PLC control system.

[0068] In a preferred embodiment, the connecting rod shaft 2.14 is a self-sensing and self-damping connecting rod shaft, which adopts a multi-layer composite structure design. From the inside to the outside, it consists of an axial force transmission core, an insulating layer, a piezoelectric fiber composite material layer, and a protective layer. This structure not only ensures the mechanical properties of the connecting rod shaft 2.14 shaft, but also realizes the sensing and actuation functions.

[0069] The axial force transmission core, as the main force-bearing component, undertakes the crucial task of transmitting the gear drive force to the linkage mechanism. The axial force transmission core adopts a hollow tubular structure, which reduces weight while ensuring sufficient rigidity. The hollow structure also provides space for wiring, facilitating the extraction of sensor signals.

[0070] The piezoelectric fiber composite layer features a special fiber orientation design, giving it high sensitivity to axial stress. This layer is uniformly wrapped around the outer surface of the axial force transmission core, ensuring uniform and accurate stress sensing. The protective layer uses wear-resistant and corrosion-resistant materials to guarantee the long-term reliability of the component in industrial environments.

[0071] Piezoelectric fiber composites achieve sensing functionality based on the positive piezoelectric effect. When the connecting rod shaft 2.14 is subjected to an axial force, the axial force transmission core generates a small strain, which is transmitted to the piezoelectric fiber composite layer, causing it to deform. Under mechanical stress, the piezoelectric material becomes polarized, generating a charge signal on its surface proportional to the stress.

[0072] There is a definite mathematical relationship between the magnitude of the charge signal and the stress value. A stress-charge correspondence curve can be established through calibration experiments. In practical work, by monitoring changes in the charge signal, the dynamic stress value of the connecting rod shaft 2.14 can be deduced in real time.

[0073] To improve the signal-to-noise ratio, the sensing circuit employs a differential input design to effectively suppress common-mode interference. The signal conditioning circuit is installed close to the sensing point to reduce signal attenuation and interference during transmission.

[0074] The active damping function is based on the inverse piezoelectric effect. When the system detects impact vibration, the control algorithm quickly calculates the required counteracting force and applies a corresponding electric field to the piezoelectric fiber composite material layer through the drive circuit. Under the action of the electric field, the piezoelectric material undergoes strain, generating a mechanical force opposite to the original vibration direction.

[0075] The generation of this active damping force is real-time, with a response time on the order of microseconds, effectively counteracting impact vibrations. Compared to traditional passive damping, active damping is adjustable and adaptive, automatically adjusting damping parameters according to vibration characteristics.

[0076] To improve system reliability, the self-sensing, self-damping linkage shaft employs a redundant design. The piezoelectric fiber composite layer is divided into two independent sections along the axial direction, each with its own independent signal processing channel. Under normal operating conditions, the two sections work together to provide optimal damping performance.

[0077] When a fault occurs in a certain section, the system can automatically detect the anomaly and switch to single-section operation mode. Although the damping effect is reduced, basic functions are still guaranteed, preventing complete system failure. This design is particularly suitable for the high reliability requirements of semiconductor production lines.

[0078] The fault detection mechanism monitors the operating status of each channel in real time, including parameters such as signal quality and circuit health. Once an anomaly is detected, an alarm message is immediately sent to the main control system, and the system automatically switches to the backup solution.

[0079] It should be noted that active damping technology can effectively suppress vibrations at specific frequencies, which is difficult to achieve with passive vibration reduction measures. Redundant design improves system reliability and ensures continuous and stable operation of the equipment. Compared to traditional vibration solutions, this integrated design requires no additional space, maintaining the compactness of the equipment. Furthermore, due to the active control method, the damping characteristics can be adjusted according to different operating requirements, providing better adaptability.

[0080] In a preferred embodiment, the internal clamping mechanism 2 further integrates a piezoelectric ceramic micro-stage to achieve nanometer-level precision positioning control, meeting the higher requirements of wafer inspection. The piezoelectric ceramic micro-stage is installed between the rotary motor 2.10 and the chuck 2.11, utilizing both the coarse positioning capability of the large-stroke mechanism and the fine positioning advantage of piezoelectric ceramics.

[0081] The piezoelectric ceramic microstage features a three-degree-of-freedom design, enabling Z-axis translation and X and Y-axis deflection. Each degree of freedom is driven by an independent piezoelectric ceramic actuator, achieving frictionless and backlash-free motion through a flexible hinge guide mechanism.

[0082] The piezoelectric ceramic micro-stage has a through-hole machined at its center, the diameter of which is aligned with the inner diameter of the hollow shaft of rotary motor 2.10. Rotary motor 2.10 adopts a hollow shaft structure, and its central channel is seamlessly connected to the central through-hole of the piezoelectric ceramic micro-stage, ultimately connecting to the vacuum interface on the back of chuck 2.11, thus forming a continuous vacuum adsorption channel that runs through all three components. The inlet of this channel connects to an external vacuum generator, and the outlet extends to the adsorption hole array on the surface of chuck 2.11. Through this integrated design, the vacuum adsorption force can be transmitted to the back side of the wafer without obstruction, achieving stable adsorption; at the same time, the piezoelectric ceramic micro-stage can apply nanometer-level precision micro-displacement compensation to the wafer under vacuum adsorption conditions, effectively eliminating minor alignment errors caused by mechanical transmission or thermal deformation, further improving the wafer positioning accuracy in ultra-precision machining.

[0083] Piezoelectric ceramics operate based on the inverse piezoelectric effect, producing minute deformations under the influence of an electric field, with the deformation being proportional to the field strength. By precisely controlling the driving voltage, nanometer-level position control can be achieved. Piezoelectric ceramics offer advantages such as fast response speed, high output force, and high resolution, making them ideal for precision positioning applications.

[0084] The wafer clamping mechanism provided by this invention achieves several technological breakthroughs through innovative design. The self-sensing, self-damping linkage effectively solves the vibration problem and improves imaging quality. The integration of a piezoelectric ceramic micro-stage elevates positioning accuracy to a new level. The intelligent control system enables automated operation, improving production efficiency.

[0085] The preferred embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, nor is it limited to wafer clamping mechanisms. Devices and structures not described in detail herein should be understood as being implemented in a manner common to the art. Any person skilled in the art can make many possible variations and modifications to the technical solutions of the present invention, or modify them into equivalent embodiments, without departing from the scope of the present invention. This does not affect the essential content of the present invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention are still within the protection scope of the present invention.

Claims

1. A wafer clamping mechanism, comprising an external clamping mechanism, an internal clamping mechanism, and a rotary wafer transfer mechanism, characterized in that: The internal clamping mechanism includes: The fixed bracket is rigidly mounted on the main base plate of the equipment. Z-axis moving module two is vertically fixed on a fixed bracket; Adapter plate two is fixedly connected to the output end of Z-axis moving module two; The deflection motor is fixed on the second adapter plate, and its output shaft drives the tilting shaft to rotate via a synchronous belt; The gear motor mounting plate and bracket are fixedly connected to both ends of the tilting shaft, respectively. A gear-driven motor is mounted on a gear motor mounting plate, and the gear on its output shaft meshes with a rack. The connecting rod shaft is L-shaped, with a rack at one end, which passes through the hollow through hole of the flip shaft and is driven by gears to move axially. A rotating shaft, the middle of which is rotatably connected to the end of the bracket; The connecting rod has its two ends hinged to the other end of the connecting rod shaft and the bottom of the rotating shaft, respectively. Rotary motor two is fixedly mounted on the top of the rotating shaft; and Suction cup one is connected to the output shaft of rotary motor two and is used to adsorb wafers; Among them, the Z-axis moving module 2 drives the suction cup 1 to perform Z-axis lifting and lowering motion, the deflection motor drives the suction cup 1 to perform deflection motion, the gear drive motor drives the rotating shaft to swing through gears, racks, connecting rods and connecting rods, thereby causing the suction cup 1 to perform pitching motion, and the rotary motor 2 drives the suction cup 1 to perform rotational motion.

2. The wafer clamping mechanism according to claim 1, characterized in that: The external clamping mechanism includes a fixed support, a Z-axis moving module, an adapter plate, a rotary motor, and an arc-shaped suction cup; The Z-axis moving module is fixedly installed on the fixed support; The adapter plate is connected to the output end of the Z-axis moving module to move vertically by being driven by the Z-axis moving module. A rotary motor is mounted on an adapter plate. An arc-shaped chuck is connected to the output shaft of the rotary motor so that it can be driven to rotate by the rotary motor. The arc-shaped chuck is used to support the wafer.

3. The wafer clamping mechanism according to claim 1, characterized in that: The rotary transfer wafer mechanism includes a fixed base, a Z-axis moving module, an adapter plate, a rotary motor, a rotating rod, and a clamping chuck. The Z-axis moving module three is mounted on the fixed base; The adapter plate three is connected to the output end of the Z-axis moving module three so that it can be driven by the Z-axis moving module three to move in the vertical direction; Rotary motor three is mounted on adapter plate three, and its output shaft is connected to the rotating rod; The end of the rotating rod is equipped with a clamping suction cup, which is used to adsorb and transfer the wafer.

4. The wafer clamping mechanism according to claim 1, characterized in that: The second rotary motor is a hollow shaft DC brushless servo motor. The rotating shaft has a vacuum channel inside, which passes through the hollow shaft and rotating shaft of the second rotary motor and is connected to the first suction cup.

5. The wafer clamping mechanism according to claim 1, characterized in that: Z-axis movement module two is a ball screw linear module, equipped with a grating ruler for position feedback.

6. The wafer clamping mechanism according to claim 1, characterized in that: The connecting rod shaft is a self-sensing and self-damping component, which includes a piezoelectric fiber composite material layer and a signal processing module. The signal processing module collects the charge signal generated by the deformation of the piezoelectric fiber composite material layer due to the force of the connecting rod shaft, and generates an inverse driving voltage to feed back to the piezoelectric fiber composite material layer to generate active damping force to suppress vibration.

7. The wafer clamping mechanism according to claim 6, characterized in that: The piezoelectric fiber composite material layer is divided into at least two independently working sections along the axial direction of the connecting rod shaft, forming a redundant sensing and driving channel.

8. The wafer clamping mechanism according to claim 6, characterized in that: The axial force transmission core of the connecting rod shaft adopts a hollow tubular structure.

9. The wafer clamping mechanism according to claim 1, characterized in that: The wafer adsorption assembly also includes a three-degree-of-freedom piezoelectric ceramic micro-stage, which is located between the output shaft of the rotary motor and the suction cup, and is used to drive the suction cup to translate in the Z direction and deflect around the X and Y axes.

10. The wafer clamping mechanism according to claim 9, characterized in that: The piezoelectric ceramic micro-motion stage has a through hole in the center. The hollow shaft of the rotary motor II, the through hole in the center of the piezoelectric ceramic micro-motion stage, and the suction cup I together form a continuous vacuum adsorption channel.

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