Wafer positioning device and wafer grinding equipment thereof

Abstract

The invention provides a wafer positioning device and wafer grinding equipment thereof, and belongs to the technical field of wafer processing equipment.The wafer positioning device comprises a clamping positioning system, a vacuum rotary carrying table system, a control module and an image recognition system, and the clamping positioning system, the vacuum rotary carrying table system, the image recognition system and the control module cooperate to achieve the purpose of positioning the wafer. The problem that in the prior art, the flat edge and the notch angle of a wafer cannot be recognized is accurately solved, centering is achieved only through synchronous radial movement of a plurality of clamping jaws without an additional moving shaft, and after an image recognition system confirms that the wafer is coaxial with a fixed shaft, a control module directly controls a vacuum rotating carrying table system to adsorb the wafer and rotate, and the wafer is accurately positioned. The space requirement of a clean room is met, the precision is prevented from being influenced by displacement difference, the offset recalculation link is omitted, the efficiency is improved, and the high-precision grinding requirement of the advanced manufacturing process is met.

Description

Technical Field

[0001] This application belongs to the technical field of wafer processing equipment, and particularly relates to a wafer positioning device and its wafer grinding equipment. Background Art

[0002] In the wafer grinding process, vacuum chucks are used as the grinding stage. Accurate placement of the wafer on the grinding stage is crucial to prevent air leakage between the stage and the wafer due to misalignment, which would reduce vacuum suction and affect grinding precision. Therefore, wafer positioning is necessary before loading to ensure accuracy. In certain process steps, not only accurate wafer positioning is required, but also the identification of wafer flat edges and notch angles.

[0003] One existing technology uses mechanical clamping to center the wafer, but this method cannot identify the angles of the wafer's flat edges and notches. Another technology that identifies wafer flat edges and notches requires X and Y axis movement for position compensation, necessitating more space for these structures. This results in excessively large equipment, failing to meet the space requirements of cleanrooms. Furthermore, the offset needs to be recalculated each time, impacting positioning efficiency, and the varying displacement amounts in each handling operation also affect positioning accuracy. This also fails to meet the high-precision grinding requirements of advanced processes. In wafer processing, precise wafer positioning directly affects the accuracy and yield of subsequent processes such as grinding and dicing. Summary of the Invention

[0004] This application provides a wafer positioning device and a wafer grinding equipment. The wafer positioning device, through the coordinated operation of a clamping and positioning system, a vacuum rotary stage system, an image recognition system, and a control module, solves the problem that pure mechanical clamping cannot identify the flat edge and notch angle of the wafer. It also eliminates the need for an X / Y movement axis, adapting to the space requirements of cleanrooms. At the same time, it eliminates the offset calculation step to improve positioning efficiency. It can also achieve high-precision positioning by initial centering through the clamping and positioning system, coaxial confirmation by the image recognition system, and stable rotation by the vacuum rotary stage system, meeting the grinding requirements of advanced processes. This solves the problems of existing wafer positioning devices, where pure mechanical clamping solutions can only achieve wafer centering but cannot identify the flat edge and notch angle of the wafer, while solutions with angle recognition require an X / Y movement axis, resulting in excessively large equipment size that does not meet the compact requirements of cleanrooms. Furthermore, the need to recalculate the offset affects positioning efficiency, and different displacement amounts can reduce positioning accuracy, making it difficult to adapt to advanced processes.

[0005] The first invention, according to an embodiment of this application, provides a wafer positioning device, including a clamping and positioning system, a vacuum rotation stage system, a control module, and an image recognition system; The clamping and positioning system includes a fixed shaft, a support plate, grippers, and a drive mechanism. The fixed shaft is connected to the support plate. The support plate has multiple through slots, which are arranged along the radius of the same circle. The grippers pass through the corresponding through slots and are slidably connected. The drive mechanism is driven to each gripper and is used to drive all the grippers to reciprocate within their respective through slots to control the gripping or releasing of the wafer by the multiple grippers. The vacuum rotary stage system includes a support mechanism that is axially rotatably connected to the fixed axis. The support mechanism is used to vacuum adsorb the wafer and drive it to rotate. The control module is used to control the carrier mechanism to vacuum adsorb the wafer after the multiple grippers have gripped it; the control module is also used to control the drive mechanism to drive the multiple grippers to release the wafer after the wafer has been vacuum adsorbed by the carrier mechanism; the control module is also used to control the carrier mechanism to rotate the wafer after the multiple grippers have released the wafer. The image recognition system is used to identify the angular positions of the flat edges and notches of the wafer as the wafer rotates with the carrier mechanism.

[0006] In one feasible implementation, the image recognition system is further used to determine whether the wafer is coaxial with the fixed axis when the wafer is held by multiple grippers; The control module is also used to control the bearing mechanism to vacuum adsorb the wafer if the wafer is coaxial with the fixed axis, and to drive the multiple grippers to release the wafer from the gripping position of the driving mechanism. The control module is also used to control the clamping and positioning system to clamp the wafer again if the wafer is not coaxial with the fixed axis, until the image recognition system determines that the wafer is coaxial with the fixed axis.

[0007] In one feasible implementation, the drive mechanism includes a rotary disk, a connecting rod, and a first power mechanism; The rotating disk is rotatably connected to the fixed shaft; One end of the connecting rod is movably connected to the corresponding gripper, and the other end is rotatably connected to the rotating disk, and multiple connecting rods are distributed around the fixed axis; The output end of the first power mechanism is connected to the rotating disk. The first power mechanism is used to drive the rotating disk to rotate forward or backward, so that the rotating disk drives the connecting rod to pull the gripper to reciprocate along the through slot, thereby realizing the gripping or releasing of the wafer by the multiple grippers.

[0008] In one feasible implementation, the positioning device further includes a frame system, which includes a base plate, support columns, support plates, and adjusting bolts. The base plate is connected to the support plate via the support column, and the support plate is connected to the support plate via the adjusting bolt; the adjusting bolt is used to adjust the levelness of the support plate.

[0009] In one feasible implementation, the clamping and positioning system further includes a proximity sensor and a photoelectric sensing mechanism; The proximity sensor is disposed on the tray and is used to sense whether a wafer is present on the tray. The photoelectric sensing mechanism includes a bracket, a photoelectric sensor, and a first baffle. The bracket is disposed on the fixed shaft, the photoelectric sensor is disposed on the bracket, and the first baffle is disposed on the rotating disk. The control module is also used to control the first power mechanism to rotate when the proximity sensor detects that there is a wafer on the pallet, so that the drive mechanism drives the multiple grippers to perform a clamping action. The control module is also used to control the first power mechanism to stop rotating during the movement of the first power mechanism, and when the first baffle rotates with the rotating disk under the drive of the first power mechanism to the sensing position of the photoelectric sensor.

[0010] In one feasible implementation, the first power mechanism includes a first motor, a first gear, and a second gear; The first motor is mounted on the fixed shaft, the first gear is mounted on the output end of the first motor, and the second gear is coaxially mounted on the rotating disk, with the first gear meshing with the second gear.

[0011] In one feasible implementation, the support plate is provided with a through hole, the through hole is coaxial with the fixed shaft, and a plurality of through slots are distributed around the axis of the fixed shaft; The supporting mechanism includes a central shaft and a platform; The central shaft is rotatably connected to the fixed shaft, one end of which passes through the fixed shaft and the through hole and is connected to the stage, and the other end is connected to the vacuum system. The stage is used to adsorb the wafer when the vacuum system evacuates it. The vacuum rotary stage system also includes a second power mechanism, the output end of which is connected to the central shaft. The second power mechanism is used to drive the central shaft and the stage to rotate.

[0012] In one feasible implementation, the vacuum rotary stage system further includes a photoelectric switch mechanism, which includes a photoelectric switch and a second baffle. The photoelectric switch is mounted on the fixed shaft, and the second baffle is mounted on the central shaft; The control module is also used to determine the rotation angle of the wafer when the supporting mechanism drives the wafer to rotate, and when the second baffle reaches the sensing position of the photoelectric switch.

[0013] In one feasible implementation, the second power mechanism includes a second motor, a first pulley, a second pulley, and a transmission belt; The second motor is mounted on the fixed shaft, and the first pulley is mounted on the output end of the second motor; The second pulley is coaxially mounted on the central shaft, and the transmission belt connects the first pulley and the second pulley.

[0014] Secondly, this application also provides a wafer grinding apparatus, which includes the wafer positioning device described above.

[0015] This application provides a wafer positioning device and wafer grinding equipment. The wafer positioning device, through the collaboration of a clamping and positioning system, a vacuum rotary stage system, an image recognition system, and a control module, accurately solves the problem that existing technologies cannot identify the flat edges and notch angles of wafers. The control module first controls the clamping and positioning system to clamp the wafer for initial centering, and then drives the vacuum rotary stage system to rotate the wafer stably. At the same time, the image recognition system acquires images in real time to complete angle recognition, filling a functional gap. Addressing the problem that existing angle recognition solutions require X / Y axis movement, resulting in excessively large equipment and low efficiency, this device eliminates the need for additional movement axes. Centering is achieved solely through the synchronous radial movement of multiple grippers. After the image recognition system confirms that the wafer is coaxial with the fixed axis, the control module directly controls the vacuum rotary stage system to adsorb and rotate the wafer. This adapts to the space requirements of cleanrooms, avoids the impact of displacement differences on accuracy, eliminates the offset recalculation step, improves efficiency, and meets the high-precision grinding requirements of advanced processes. Attached Figure Description

[0016] Figure 1 This is a first schematic diagram of a wafer positioning device provided in this application; Figure 2 This is a second schematic diagram of a wafer positioning device provided in this application; Figure 3 This is a third schematic diagram of a wafer positioning device provided in this application; Figure 4 This is a cross-sectional view of the clamping and positioning system; Figure 5 This is a schematic diagram of the clamping and positioning system; Figure 6 This is a schematic diagram of the frame system and its connection structure; Figure 7 This is a cross-sectional view of the vacuum rotary stage system; Figure 8 This is a first schematic diagram of an image recognition system and its connection structure; Figure 9 This is a second schematic diagram of an image recognition system and its connection structure.

[0017] Explanation of reference numerals in the attached figures: 100 - Clamping and positioning system; 200 - Vacuum rotary stage system; 300 - Image recognition system; 400 - Frame system; 110-Fixed shaft; 120-First power mechanism; 130-Panel; 140-Gripper; 150-Rotating disk; 160-Connecting rod; 170-Proximity sensor; 180-Photoelectric sensing mechanism; 210-Bearing mechanism; 220-Second power mechanism; 230-Photoelectric switch mechanism; 310-Telescopic mechanism; 320-Camera mechanism; 330-Backlight device; 410-Base plate; 420-Support column; 430-Support plate; 440-Adjusting bolt; 121-First motor; 122-First gear; 123-Second gear; 131-Through hole; 132-Through slot; 181-Bracket; 182-Photoelectric sensor; 183-First baffle; 211-Central shaft; 212-Platform; 221-Second motor; 222-First pulley; 223-Second pulley; 224-Transmission belt; 231-Photoelectric switch; 232-Second baffle. Detailed Implementation

[0018] To enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of this application.

[0019] Precise positioning and identification of flat / notched edges are required for wafer grinding. Existing purely mechanical clamping lacks angle recognition functionality. Solutions with angle recognition require X / Y axes of movement, resulting in large equipment size, low positioning efficiency, and poor accuracy, making them difficult to adapt to cleanroom spaces and advanced process requirements.

[0020] To address at least one of the technical problems existing in the prior art or related technologies, the wafer positioning device and wafer grinding equipment provided in this application, when the control module drives the vacuum rotary stage system to rotate the wafer, the image recognition system can accurately identify the angle; and there is no need to set up X / Y movement axes, relying on the clamping positioning system to achieve wafer centering and the vacuum rotary stage system to drive rotation, the control module coordinates the process, avoids excessive equipment size to adapt to cleanroom requirements, and at the same time eliminates the offset recalculation step to improve positioning efficiency, and also ensures accuracy by centering through the clamping positioning system and determining coaxiality through the image recognition system, meeting the requirements of advanced processes.

[0021] The specific structure of the wafer positioning device and wafer grinding equipment provided in this application will be described in detail below with reference to the accompanying drawings.

[0022] Reference Figures 1-9 As shown in the figure, this application provides a wafer positioning device, including an information-interactive clamping and positioning system 100, a vacuum rotation stage system 200, a control module, and an image recognition system 300.

[0023] The clamping and positioning system 100 includes a fixed shaft 110, a support plate 130, grippers 140, and a drive mechanism. The fixed shaft 110 is connected to the support plate 130. The support plate 130 has multiple through slots 132, which are respectively arranged along the radial direction of the same circle. The grippers 140 pass through the corresponding through slots 132 and are slidably connected. The drive mechanism is driven to each gripper 140 and is used to drive all grippers 140 to reciprocate within their respective corresponding through slots 132, so as to control the gripping or releasing of the wafer by the multiple grippers 140.

[0024] The pallet 130 is a flat plate structure, and its material is made of wear-resistant aluminum alloy to ensure structural rigidity and lightweight. The pallet 130 is provided with 3-4 through slots 132. The multiple through slots 132 are respectively arranged along the radial direction of the same circle, that is, the multiple through slots 132 are distributed around a certain center. The width of the through slot 132 is 0.1-0.2mm larger than the thickness of the gripper 140, forming a clearance fit, which ensures that the gripper 140 slides smoothly along the through slot 132, and avoids radial offset during sliding. The end of the fixed shaft 110 is fixedly connected to the lower surface of the pallet 130 by 4 circumferentially evenly distributed internal hex bolts.

[0025] The number of grippers 140 is the same as that of through slots 132. The grippers 140 have an L-shaped structure, including a horizontal section and a vertical section of an integral structure. The horizontal section is slidably connected to the corresponding through slot 132. The top of the vertical section extends out of the through slot 132, and the side wall is provided with an arc-shaped clamping surface. The clamping surface conforms to the curvature of the wafer edge, and a 0.5mm thick polytetrafluoroethylene pad is pasted on the surface to avoid scratching the wafer surface during clamping. The inner wall of the through groove 132 can be provided with a limiting slide groove. The extension direction of the limiting slide groove is consistent with the extension direction of the through groove 132. The side wall of the horizontal section is provided with a limiting slider that matches the limiting slide groove. The limiting slider is slidably connected to the limiting slide groove so that the gripper 140 can only reciprocate along the direction of the through groove 132 and cannot rotate.

[0026] The drive mechanism is driven to each gripper 140. When the drive mechanism drives all grippers 140 to move inward along their respective through slots 132, all grippers 140 gradually close together to hold the wafer and position the center of the wafer. Similarly, when the drive mechanism drives all grippers 140 to move outward along their respective through slots 132, all grippers 140 gradually open up to release the wafer.

[0027] The vacuum rotary stage system 200 includes a support mechanism 210 that is axially rotatably connected to a fixed shaft 110. A portion of the support mechanism 210 is disposed in a through hole of the fixed shaft 110 and is rotatably connected to the fixed shaft 110. The bottom end of the support mechanism 210 is connected to an external vacuum generator, and the top end of the support mechanism 210 is used for vacuum adsorption of the wafer. The support mechanism 210 can drive the wafer to rotate synchronously.

[0028] The control module can be installed on the machine body or in other fixed positions. The control module is used to control the carrier mechanism 210 to vacuum adsorb the wafer after the multiple grippers 140 clamp the wafer, and also to control the drive mechanism to drive the multiple grippers 140 to release the wafer after the wafer is vacuum adsorbed by the carrier mechanism 210, and to control the carrier mechanism 210 to drive the wafer to rotate after the multiple grippers 140 release the wafer.

[0029] The image recognition system 300 can be installed on the machine body and located above the clamping and positioning system 100 to capture images of the wafer. The image recognition system 300 is used to capture images of the wafer as it rotates with the carrier mechanism 210 to obtain first image information, and to identify the angle position of the flat edge and notch of the wafer through the first image information.

[0030] In some embodiments, the image recognition system 300 is further configured to capture images of the clamped wafer when the wafer is clamped by multiple grippers 140, obtain second image information, determine whether the wafer is coaxial with the fixed axis 110 through the second image information, and transmit the determination result to the control module.

[0031] The control module is also used to control the bearing mechanism 210 to vacuum adsorb the wafer if the wafer is coaxial with the fixed axis 110, and to drive the drive mechanism to drive multiple grippers 140 to release the wafer from the gripping.

[0032] The control module is also used to control the clamping and positioning system 100 to clamp the wafer again if the wafer is not coaxial with the fixed axis 110, until the image recognition system 300 determines that the wafer is coaxial with the fixed axis 110.

[0033] The wafer positioning device provided in this application has the following advantages compared with existing wafer positioning devices: 1. Solves the technical pain point that "purely mechanical clamping cannot identify the flat edge and notch angle of the wafer": Existing purely mechanical clamping solutions can only achieve centering but cannot identify angles. However, this application effectively solves the problem that purely mechanical clamping cannot identify the flat edge and notch angle of the wafer by using the collaboration of the image recognition system 300 and the vacuum rotary stage system 200. The control module first drives the clamping and positioning system 100 to clamp the wafer and perform initial centering, and then controls the vacuum rotary stage system 200 to drive the wafer to rotate stably. At the same time, the image recognition system 300 acquires images of the rotating wafer in real time and accurately identifies the angle of the flat edge and notch of the wafer. This does not require additional mechanical structures, fills the functional gap of purely mechanical clamping solutions, and meets the requirement of "angle recognition required for specific processes" in the background technology.

[0034] 2. Avoiding the drawback of "requiring X / Y axes resulting in excessively large equipment size," and adapting to cleanroom space requirements: Existing angle recognition solutions require X / Y direction movement axes for position compensation, which occupies a lot of space. However, this application eliminates the need for additional X / Y movement axes by linking the clamping and positioning system 100, the vacuum rotary stage system 200, and the control module. The clamping and positioning system 100 achieves wafer alignment through its own structure. After the wafer is clamped by the clamping and positioning system 100 and the image recognition system 300 confirms coaxiality, the control module directly drives the vacuum rotary stage system 200 to adsorb the wafer and rotate it. The entire positioning process is completed by the three core systems of this device, eliminating the need for additional space to arrange movement axes, significantly reducing the overall size of the equipment, and perfectly meeting the "clean room space requirement" in the background technology.

[0035] 3. Improve positioning efficiency and avoid the problem of "inefficiency caused by recalculating offset": Existing solutions require X / Y axis position compensation, necessitating recalculation of offset for each positioning operation, severely impacting efficiency. This application, however, achieves automated closed-loop positioning by controlling the overall system of the control module: the control module directly drives the clamping positioning system 100 for clamping and centering; after the image recognition system 300 determines coaxiality, the control module immediately switches to the adsorption and rotation actions of the vacuum rotary stage system 200, eliminating the need for manual or additional modules to recalculate the offset, thus significantly reducing positioning time and resolving the pain point of "low positioning efficiency" in the prior art.

[0036] 4. Ensure positioning accuracy to meet the high-precision grinding requirements of advanced processes: Existing solutions are prone to positioning accuracy deviations due to differences in X / Y axis transport displacement. This application ensures high accuracy through multi-system collaboration: First, the multiple grippers 140 of the clamping and positioning system 100 can initially align the wafer with the fixed axis; Second, when the vacuum rotary stage system 200 rotates the wafer, it relies on its own stable rotation structure to avoid wafer offset during rotation. Combined with the angle recognition function of the image recognition system 300, it achieves dual positioning of "radial coaxiality + precise angle," solving the problem of "poor positioning accuracy and inability to adapt to advanced high-precision grinding processes" in the background technology, and providing a stable accuracy benchmark for subsequent wafer grinding processes.

[0037] Reference Figures 1-5 As shown, in some embodiments, the drive mechanism includes a rotary disk 150, a connecting rod 160, and a first power mechanism 120.

[0038] The rotating disk 150 is a circular disk body, which is set below the support plate 130 and is rotatably connected to the fixed shaft 110 through a bearing. The inner ring of the bearing is interference-fitted with the fixed shaft 110, and the outer ring is transition-fitted with the inner hole of the rotating disk 150, ensuring that the radial runout of the rotating disk 150 is ≤0.01mm when it rotates around the fixed shaft 110.

[0039] The connecting rod 160 can be a straight rod. The number of connecting rods 160 is the same as that of the grippers 140. The upper end of each connecting rod 160 is movably connected to the vertical section of the gripper 140. The bottom end of the connecting rod 160 is hinged to the edge area of ​​the rotating disk 150. The two ends of the connecting rod 160 can be connected to the grippers 140 and the rotating disk 150 respectively through ball bearings. The multiple connecting rods 160 are centrally symmetrically distributed around the fixed axis 110. The included angle between adjacent connecting rods 160 is equal, ensuring that each gripper 140 moves synchronously when the rotating disk 150 rotates.

[0040] The output end of the first power mechanism 120 is connected to the rotary disk 150 via a transmission. The first power mechanism 120 is used to drive the rotary disk 150 to rotate forward or backward: when the rotary disk 150 rotates forward, the connecting rod 160 pulls each gripper 140 to move synchronously along the through slot 132 toward the direction close to the fixed shaft 110 until the arc-shaped clamping surface fits against the edge of the wafer, thus achieving centering clamping; when the rotary disk 150 rotates backward, the connecting rod 160 pushes each gripper 140 to move synchronously along the through slot 132 toward the direction away from the fixed shaft 110, thus releasing the clamping of the wafer.

[0041] Reference Figure 4 As shown, in some embodiments, the first power mechanism 120 includes a first motor 121, a first gear 122, and a second gear 123.

[0042] The first motor 121 is fixedly mounted on the end of the fixed shaft 110 via a motor mounting plate. The motor mounting plate is rigidly connected to the fixed shaft 110 to ensure that the first motor 121 does not wobble when it is working. The first gear 122 is fixedly mounted on the output shaft end of the first motor 121 and rotates synchronously with the output shaft.

[0043] The second gear 123 is coaxially fixed on one side end face of the rotating disk 150, and the axis of the second gear 123 coincides with the axis of the rotating disk 150. The first gear 122 meshes with the second gear 123 to form a gear transmission mechanism. The first motor 121 drives the second gear 123 to rotate through the first gear 122, thereby driving the rotating disk 150 to rotate synchronously.

[0044] Reference Figure 5 As shown, in some embodiments, the clamping positioning system 100 further includes a proximity sensor 170 and a photoelectric sensing mechanism 180.

[0045] The proximity sensor 170 is set on the tray 130 in the area corresponding to where the wafer is placed. It is used to sense in real time whether there is a wafer on the tray 130. When a wafer is detected, it can send a signal to the control module to trigger subsequent clamping actions.

[0046] The photoelectric sensing mechanism 180 includes a bracket 181, a photoelectric sensor 182, and a first baffle 183. The bracket 181 is fixedly mounted on the side wall of the fixed shaft 110 and is used to mount and fix the photoelectric sensor 182. The photoelectric sensor 182 is mounted on the bracket 181 and can emit sensing signals and receive reflected or blocked signals. The first baffle 183 is fixedly mounted on the edge of the rotating disk 150 and rotates synchronously with the rotating disk 150.

[0047] The control module is also used to receive signals from the proximity sensor 170 and the photoelectric sensing mechanism 180 and to perform control: When the proximity sensor 170 detects that there is a wafer on the tray 130, it sends a first signal to the control module. The control module controls the first power mechanism 120 to start rotating according to the first signal, so that the multiple grippers 140 perform clamping actions.

[0048] During the movement of the rotating disk 150 driven by the first power mechanism 120, when the first baffle 183 rotates with the rotating disk 150 to the sensing position of the photoelectric sensor 182, the photoelectric sensor 182 sends a second signal to the control module. The control module controls the first power mechanism 120 to stop rotating according to the second signal. At this time, the gripper 140 just completes the centering and clamping of the wafer.

[0049] The photoelectric sensor 182 is fixed to the fixed shaft 110 via the bracket 181. The first baffle 183 is detachably connected to the rotating disk 150 and rotates synchronously with the rotating disk 150. Before clamping the wafer, the position of the first baffle 183 on the rotating disk 150 is adjusted to ensure that when the moving gripper 140 just contacts the wafer, the first baffle 183 just enters the sensing position of the photoelectric sensor 182, causing the control module to control the first power mechanism 120 to stop rotating and the gripper 140 to stop moving, thus avoiding damage to the wafer.

[0050] When the clamping and positioning system 100 performs clamping motion, the rotary disk 150 pulls each gripper 140 synchronously along the through slot 132 towards the fixed shaft 110 via the connecting rod 160, thereby achieving centering and clamping of the wafer by multiple grippers 140. Since the dimensions of each component are fixed, the rotation angle of the rotary disk 150 is proportional to the movement distance of the grippers 140 within the through slot 132. Given the dimensions of the wafer to be processed, the distance that the grippers 140 need to move from their initial position to the position where they are clamping the wafer can be calculated. The rotation angle of the rotary disk 150 can then be obtained, which is the movement angle of the first baffle 183 to the sensing position of the photoelectric sensor 182. Since the position of the photoelectric sensor 182 is fixed, the position of the first baffle 183 on the rotary disk 150 can be obtained.

[0051] The proximity sensor 170 and the photoelectric sensing mechanism 180 enable automatic triggering and precise stopping of the clamping action: the proximity sensor 170 ensures that clamping is only initiated when there is a wafer on the tray 130, avoiding empty movements; the photoelectric sensing mechanism 180, through the cooperation of the first baffle 183 and the photoelectric sensor 182, precisely controls the stopping position of the rotary table 150, ensuring the consistency of clamping force and position each time, improving the automation and accuracy of clamping positioning, and reducing errors caused by manual control.

[0052] Reference Figure 6 As shown, in some embodiments, the positioning device further includes a frame system 400, which includes a base plate 410, a support column 420, a support plate 430, and adjusting bolts 440.

[0053] The base plate 410 is used to fix and connect with the grinding machine frame, providing a stable installation foundation for the entire positioning device. The base plate 410 is connected to the support plate 430 through the support column 420. The two ends of the support column 420 are fixed to the base plate 410 and the support plate 430 respectively through connectors, forming a stable support structure to ensure that the position of the support plate 430 is fixed.

[0054] The support plate 430 is used to support the pallet 130. It is connected to the pallet 130 by multiple adjusting bolts 440. The adjusting bolts 440 are set along the edge of the support plate 430 or at multiple positions evenly distributed. The adjusting bolts 440 adjust their length extending out of the support plate 430 by turning them, thereby adjusting the height of the corresponding position of the pallet 130, and finally adjusting the levelness of the pallet 130 to ensure that the pallet 130 is in a horizontal state.

[0055] The base plate 410, support column 420 and support plate 430 work together to provide a stable support foundation for the tray 130, preventing the tray 130 from tilting due to force or installation deviation. The design of the adjusting bolt 440 can easily adjust the level of the tray 130, ensuring that the gripper 140 is subjected to uniform force when moving in the through slot 132 of the tray 130, and at the same time ensuring that the wafer is in a horizontal position when placed on the tray 130, providing structural guarantee for the accuracy of subsequent clamping, centering and vacuum adsorption processes.

[0056] Reference Figure 7 As shown, in some embodiments, the tray 130 is provided with a through hole 131, the diameter of the through hole 131 is matched with the inner diameter of the fixed shaft 110, the through hole 131 is coaxial with the fixed shaft 110, and a plurality of through slots 132 are distributed around the axis of the fixed shaft 110. The support mechanism 210 includes a central shaft 211 and a platform 212.

[0057] The central shaft 211 is a vertically arranged shaft. The central shaft 211 is rotatably connected to the inner wall of the fixed shaft 110 through bearings, bearing spacers, pressure rings and locking nuts. It can rotate freely around its own axis, and the position of the axis remains fixed during the rotation.

[0058] One end of the central shaft 211 passes through the central through hole and through hole 131 of the fixed shaft 110, and is fixedly connected to the platform 212 through a connector. The axis of the platform 212 coincides with the axis of the central shaft 211.

[0059] The other end of the central shaft 211 is connected to the vacuum system via a rotary joint. The rotary joint can maintain the seal of the vacuum passage when the central shaft 211 rotates, thus preventing vacuum leakage.

[0060] The upper surface of the stage 212 is provided with a central gas control channel and annular grooves distributed around the central gas control channel. The central gas control channel is connected to the internal gas channel of the central shaft 211. When the vacuum system evacuates the stage 212 through the central shaft 211, the annular grooves can form a uniform adsorption force to achieve stable adsorption of the wafer.

[0061] The vacuum rotary stage system 200 also includes a second power mechanism 220. The output end of the second power mechanism 220 is connected to the central shaft 211. The second power mechanism 220 can output a stable torque to drive the central shaft 211 to rotate around its own axis, thereby driving the stage 212 connected to the central shaft 211 and the wafer adsorbed on the stage to rotate synchronously.

[0062] In some embodiments, the vacuum rotary stage system 200 further includes a photoelectric switch mechanism 230, which includes a photoelectric switch 231 and a second baffle 232.

[0063] The photoelectric switch 231 is fixedly mounted on the fixed shaft 110 by a mounting bracket. The position of the mounting bracket can be finely adjusted to ensure that the sensing end of the photoelectric switch 231 is aligned with the set position. The second baffle 232 is fixedly mounted on the end of the central shaft 211 and rotates synchronously with the central shaft 211. The shape of the second baffle 232 is adapted to the sensing range of the photoelectric switch 231.

[0064] The control module is also used to receive and process signals from the photoelectric switch mechanism 230: when the carrier mechanism 210 drives the wafer to rotate, the second baffle 232 rotates synchronously with the central shaft 211. When the second baffle 232 rotates to the sensing position of the photoelectric switch 231, the photoelectric switch 231 sends a third signal to the control module. The control module accurately determines the rotation angle of the wafer based on the third signal and the rotation speed of the central shaft 211, providing a reference for the angle recognition of the image recognition system.

[0065] By cooperating with the photoelectric switch 231 and the second baffle 232, the rotation position of the central axis 211 can be detected in real time. The control module calculates the rotation angle of the wafer based on the rotation speed, providing an accurate angle reference for the image recognition system to identify the angle position of the wafer's flat edge and notch, avoiding recognition errors caused by the inability to determine the rotation angle, and further improving the accuracy of wafer angle positioning.

[0066] In some embodiments, the second power mechanism 220 includes a second motor 221, a first pulley 222, a second pulley 223, and a transmission belt 224.

[0067] The second motor 221 is fixedly mounted on the motor mounting plate via a motor base. The motor base and the motor mounting plate are rigidly connected to ensure that the second motor 221 is stable and does not wobble when it is working. The first pulley 222 is fixedly mounted on the output shaft end of the second motor 221 and rotates synchronously with the output shaft.

[0068] The second pulley 223 is coaxially fixed at the end of the central shaft 211. The axis of the second pulley 223 coincides with the axis of the central shaft 211, and the diameter of the second pulley 223 is larger than the diameter of the first pulley 222. The transmission belt 224 is sleeved and connects the first pulley 222 and the second pulley 223 to form a belt drive mechanism. The second motor 221 drives the second pulley 223 to rotate through the first pulley 222 and the transmission belt 224, thereby driving the central shaft 211 to rotate synchronously.

[0069] In some embodiments, the image recognition system 300 includes a telescopic mechanism 310, a camera mechanism 320, and a backlight device 330.

[0070] The backlight device 330 is mounted on the tray 130 and is used to emit light so that the wafer edge, notch and other features are clearly contrasted with the background, eliminating the image blurring problem caused by uneven light and providing a stable optical environment for subsequent image acquisition.

[0071] The telescopic mechanism 310 is mounted on the body, and the camera module 320 is mounted on the moving end of the telescopic mechanism 310, with the shooting end of the camera module 320 facing the tray 130. The telescopic mechanism 310 can drive the camera module 320 to move in a direction closer to or further away from the tray 130 to adjust the shooting focal length and field of view of the camera module 320 to adapt to the image acquisition needs of wafers with different diameters.

[0072] The camera mechanism 320 is used to capture images of a wafer in a stationary clamping state when the wafer is clamped by multiple jaws 140, generate a first image signal including the relative position of the wafer edge and the fixed axis 110, and transmit the first image signal to the control module.

[0073] The control module is also used to receive the first image signal and, through the built-in image comparison algorithm, to perform an overlap analysis between the wafer edge contour in the first image signal and the axis reference of the fixed axis 110 (preset in the control module) to determine whether the wafer and the fixed axis 110 are coaxial.

[0074] The control module is also used to immediately send a clamping command to the clamping and positioning system 100 if the analysis determines that the wafer is not coaxial with the fixed axis 110. The clamping and positioning system 100 then clamps the wafer again until the control module determines that the wafer is coaxial with the fixed axis 110.

[0075] The control module is also used to send an adsorption command to the vacuum rotary stage system 200 immediately if the analysis determines that the wafer is coaxial with the fixed axis 110, and control the carrier mechanism 210 to start the vacuum adsorption function to stably adsorb the wafer. After the adsorption state is confirmed, the module sends a release command to the clamping and positioning system 100 to control the multiple grippers 140 to release the wafer.

[0076] The camera mechanism 320 is also used to capture real-time images of the rotating wafer as it rotates with the carrier mechanism 210 and generate a second image signal, and to transmit the second image signal to the control module.

[0077] The control module is also used to receive the second image signal, process the second image signal through the built-in image analysis algorithm, extract the feature information of the wafer edge contour, flat edge and notch, and then accurately identify the angle position of the wafer flat edge and notch.

[0078] The wafer positioning device provided in this application, through the coordinated operation of a clamping and positioning system 100, a vacuum rotary stage system 200, an image recognition system 300, and a control module, accurately solves the problem of existing technologies being unable to identify the flat edges and notch angles of wafers. The control module first controls the clamping and positioning system 100 to clamp the wafer for initial centering via synchronous jaw movements, then drives the vacuum rotary stage system 200 to rotate the wafer stably. Simultaneously, the image recognition system 300 acquires images in real time to complete angle recognition, filling a functional gap. Addressing the issue of existing angle recognition solutions requiring X / Y axis movement, resulting in excessively large equipment and low efficiency, this device eliminates the need for additional movement axes. Centering is achieved solely through the clamping and positioning system 100. After the image recognition system 300 confirms that the wafer is coaxial with the fixed axis, the control module directly controls the vacuum rotary stage system 200 to adsorb and rotate the wafer. This adapts to cleanroom space requirements, avoids the impact of displacement differences on accuracy, eliminates the need for offset recalculation, improves efficiency, and meets the high-precision grinding requirements of advanced processes.

[0079] This application also provides a wafer grinding apparatus, which includes the wafer positioning device described above.

[0080] The wafer positioning device is installed at the processing station of the wafer grinding equipment. The frame system 400 of the positioning device is fixedly connected to the grinding machine frame to ensure that the relative position of the positioning device and the grinding machine is fixed.

[0081] When the wafer grinding equipment is working, the positioning system 100 of the positioning device first centers and clamps the wafer, and the image recognition system 300 judges the coaxiality between the wafer and the fixed axis 110 to ensure accurate initial positioning. Then, the vacuum rotation stage system 200 vacuum adsorbs the wafer, the multiple grippers 140 release the clamps, the second power mechanism 220 drives the stage and the wafer to rotate, the image recognition system 300 identifies the angle position of the wafer's flat edge and notch, and the photoelectric switch mechanism 230 determines the rotation angle to complete the precise positioning of the wafer.

[0082] After positioning is completed, the grinding mechanism of the wafer grinding equipment performs precise grinding processing on the wafer based on the wafer angle and position data provided by the positioning device.

[0083] The grinding machine features automated, high-precision wafer positioning, avoiding problems such as grinding size errors and wafer scrap caused by positioning deviations. The collaborative workflow of the positioning device is seamlessly integrated with the processing flow of the grinding machine, improving the overall processing efficiency and quality of the wafer grinding equipment, reducing the labor intensity and errors of manual operation, and making it suitable for the needs of large-scale wafer processing production.

[0084] It is readily understood that, based on the several embodiments provided in this application, those skilled in the art can combine, split, or reorganize the embodiments of this application to obtain other embodiments, none of which exceed the protection scope of this application.

[0085] The above detailed embodiments further illustrate the purpose, technical solution, and beneficial effects of the embodiments of this application. It should be understood that the above are merely specific embodiments of the embodiments of this application and are not intended to limit the protection scope of the embodiments of this application. Any modifications, equivalent substitutions, improvements, etc., made on the basis of the technical solutions of the embodiments of this application should be included within the protection scope of the embodiments of this application.

Claims

1. A wafer positioning device, characterized in that: include: The clamping and positioning system (100) includes a fixed shaft (110), a tray (130), grippers (140), and a drive mechanism. The fixed shaft (110) is connected to the tray (130). The tray (130) has multiple through slots (132), which are arranged along the radial direction of the same circle. The grippers (140) pass through the corresponding through slots (132) and are slidably connected. The drive mechanism is driven to each gripper (140) and is used to drive all the grippers (140) to reciprocate within their respective corresponding through slots (132) to control the gripping or releasing of the wafer by the multiple grippers (140). The vacuum rotary stage system (200) includes a support mechanism (210) axially rotatably connected to the fixed shaft (110), the support mechanism (210) being used for vacuum adsorption of the wafer and driving its rotation; The control module is used to control the carrier mechanism (210) to vacuum adsorb the wafer after the multiple grippers (140) have gripped the wafer; the control module is also used to control the drive mechanism to drive the multiple grippers (140) to release the wafer after the wafer has been vacuum adsorbed by the carrier mechanism (210); the control module is also used to control the carrier mechanism (210) to rotate the wafer after the multiple grippers (140) have released the wafer. An image recognition system (300) is used to identify the angular positions of the flat edges and notches of the wafer as the wafer rotates with the carrier mechanism (210).

2. The wafer positioning device according to claim 1, characterized in that: The image recognition system (300) is also used to determine whether the wafer is coaxial with the fixed axis (110) when the wafer is held by a plurality of the grippers (140); The control module is also used to control the bearing mechanism (210) to vacuum adsorb the wafer if the wafer is coaxial with the fixed axis (110), and to drive the driving mechanism to drive the multiple grippers (140) to release the wafer from the gripping. The control module is also used to control the clamping and positioning system (100) to clamp the wafer again if the wafer is not coaxial with the fixed axis (110) until the image recognition system (300) determines that the wafer is coaxial with the fixed axis (110).

3. The wafer positioning device according to claim 1, characterized in that: The drive mechanism includes a rotary disk (150), a connecting rod (160), and a first power mechanism (120). The rotating disk (150) is rotatably connected to the fixed shaft (110); One end of the connecting rod (160) is movably connected to the corresponding gripper (140), and the other end is rotatably connected to the rotating disk (150), and a plurality of the connecting rods (160) are distributed around the fixed axis (110); The output end of the first power mechanism (120) is connected to the rotating disk (150). The first power mechanism (120) is used to drive the rotating disk (150) to rotate forward or backward, so that the rotating disk (150) drives the connecting rod (160) to pull the gripper (140) to reciprocate along the through slot (132), thereby realizing the gripping or release of the wafer by the multiple grippers (140).

4. The wafer positioning device according to claim 3, characterized in that: The positioning device also includes a frame system (400), which includes a base plate (410), a support column (420), a support plate (430), and adjusting bolts (440). The base plate (410) is connected to the support plate (430) via the support column (420), and the support plate (430) is connected to the pallet (130) via the adjusting bolt (440); the adjusting bolt (440) is used to adjust the level of the pallet (130).

5. The wafer positioning device according to claim 3, characterized in that: The clamping and positioning system (100) also includes a proximity sensor (170) and a photoelectric sensing mechanism (180). The proximity sensor (170) is disposed on the tray (130) and is used to sense whether a wafer is present on the tray (130); The photoelectric sensing mechanism (180) includes a bracket (181), a photoelectric sensor (182), and a first baffle (183). The bracket (181) is disposed on the fixed shaft (110), the photoelectric sensor (182) is disposed on the bracket (181), and the first baffle (183) is disposed on the rotating disk (150). The control module is also used to control the first power mechanism (120) to rotate when the proximity sensor (170) senses that there is a wafer on the tray (130), so that the plurality of grippers (140) perform a gripping action; The control module is also used to control the first power mechanism (120) to stop rotating during the movement of the first power mechanism (120), and when the first baffle (183) rotates with the rotating disk (150) under the drive of the first power mechanism (120) to the sensing position with the photoelectric sensor (182).

6. The wafer positioning device according to any one of claims 3-5, characterized in that: The first power mechanism (120) includes a first motor (121), a first gear (122), and a second gear (123); The first motor (121) is mounted on the fixed shaft (110), the first gear (122) is mounted on the output end of the first motor (121), and the second gear (123) is coaxially mounted on the rotating disk (150). The first gear (122) meshes with the second gear (123).

7. The wafer positioning device according to claim 1, characterized in that: The pallet (130) is provided with a through hole (131), the through hole (131) is coaxial with the fixed shaft (110), and a plurality of through slots (132) are distributed around the axis of the fixed shaft (110). The bearing mechanism (210) includes a central shaft (211) and a platform (212). The central shaft (211) is rotatably connected to the fixed shaft (110), one end of which passes through the fixed shaft (110) and the through hole (131) and is connected to the stage (212), and the other end is connected to the vacuum system. The stage (212) is used to adsorb the wafer when the vacuum system evacuates it. The vacuum rotary stage system (200) further includes a second power mechanism (220), the output end of which is connected to the central shaft (211), and the second power mechanism (220) is used to drive the central shaft (211) and the stage (212) to rotate.

8. The wafer positioning device according to claim 7, characterized in that: The vacuum rotary stage system (200) also includes a photoelectric switch mechanism (230), which includes a photoelectric switch (231) and a second baffle (232). The photoelectric switch (231) is disposed on the fixed shaft (110), and the second baffle (232) is disposed on the central shaft (211); The control module is also used to determine the rotation angle of the wafer when the bearing mechanism (210) drives the wafer to rotate, and when the second baffle (232) reaches the sensing position of the photoelectric switch (231).

9. The wafer positioning device according to claim 7 or 8, characterized in that: The second power mechanism (220) includes a second motor (221), a first pulley (222), a second pulley (223), and a transmission belt (224); The second motor (221) is mounted on the fixed shaft (110), and the first pulley (222) is mounted on the output end of the second motor (221); The second pulley (223) is coaxially mounted on the central shaft (211), and the transmission belt (224) connects the first pulley (222) and the second pulley (223).

10. A wafer grinding apparatus, characterized in that: Includes the wafer positioning device as described in any one of claims 1 to 9.

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