Packaging box visual detection system for finished wafer and stacking precision measurement method

Abstract

The invention discloses a packaging box visual detection system for finished wafers and a stacking precision measurement method, and relates to the technical field of visual detection. The at least one placement position is arranged on the inner side of the connecting frame, and a collection device facing the detection area is arranged on the placement position; the detection table is arranged on the inner side of the connecting frame, and an acquisition included angle is formed between the detection table and the acquisition equipment; the detection table is rotatably arranged relative to the connecting frame, so that the detection table has a conveying position and a detection position, and when the detection table rotates to the detection position, the included angle between the detection table and the acquisition equipment is the acquisition included angle. According to the method, the placement precision of the wafer in the packaging box can be detected in multiple scenes, and in the detection process, the wafer packaging box is controlled to be switched among multiple detection positions, so that the images of the wafer packaging box at different angles are obtained.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of visual detection, in particular to a packaging box visual detection system for finished wafer and a stacking precision measurement method. BACKGROUND

[0002] Wafer packaging boxes are mainly divided into FOUP / wafer baskets, transport boxes and disposable / anti-static trays, and the selection depends on wafer size, cleanliness level, temperature resistance and automation compatibility.

[0003] Among them, the basket is usually open or semi-closed, suitable for low cleanliness or short-distance transportation within the process; the transport box is front-opening or sealed, designed for high cleanliness and long-distance transportation automation.

[0004] The wafer groove spacing in the transport box has strict specifications, commonly 9-10 mm (about 9.5 mm is commonly used for 300 mm wafers), and SEMI standards are used to ensure clamping, collision and particle control.

[0005] Publication No. CN120495637B discloses a wafer packaging quality identification method and system based on image recognition, which acquires a multi-spectral image of the wafer packaging through a multi-spectral imaging unit and performs fusion processing to obtain a multi-spectral fusion image, acquires an RGB color image of the wafer packaging and a depth image of the wafer packaging through an RGB-D unit, generates a three-dimensional image of the wafer packaging through a three-dimensional reconstruction algorithm, extracts three-dimensional point cloud data from the preprocessed three-dimensional image and reconstructs to generate a three-dimensional point cloud model, detects defect features in the three-dimensional point cloud model through the hybrid attention generation network and outputs information of the defect features, can explain the detection results in detail, output targeted defect feature analysis and processing suggestions, realize the requirement of comprehensive evaluation of wafer packaging quality, and improve the efficiency and accuracy of packaging quality evaluation.

[0006] In the existing detection process, the wafer packaging quality is detected and the packaging quality defects are identified, but for the placement precision of the wafer, a dedicated automated handling equipment (clean room robot or wafer handler) cooperates with a dedicated end effector (vacuum / mechanical clamp) and a vision / laser centering system to accurately place the wafer into the carrier slot. The precision visual detection of the wafer placed in the packaging box must be verified in multiple levels—from "presence / number of pieces" to "slot center / tilt angle / warp" micron-level detection, combined with appropriate light source, camera resolution and algorithm to avoid misjudgment and missed detection. At present, the precision of the wafer in the packaging box is only detected when the wafer is placed, and the placement eccentricity, tilt angle, missing pieces and surface defects are found before shipment / warehousing, which directly protects the yield and the safety of downstream equipment. SUMMARY

[0007] One of the purposes of this application is to provide a visual inspection system for packaging boxes of finished wafers and a method for measuring stacking accuracy. Depending on the driving system, it can be applied to repetitive inspection in most scenarios, and the driving system can be adjusted for different scenarios.

[0008] To achieve the above objectives, this application provides the following technical solution: a visual inspection system for finished wafer packaging boxes, comprising: A connecting frame, the inner side of which forms a detection area; At least one placement position is provided inside the connecting frame, and a data acquisition device facing the detection area is provided thereon; A detection platform is provided inside the connecting frame, and there is a detection angle between the detection platform and the acquisition device; A clamping unit is disposed inside the connecting frame and faces the detection area; The position of the acquisition device can be adjusted so that the acquisition device is located at at least one acquisition position connected to the connecting frame; The detection platform is rotatably arranged relative to the connecting frame so that the detection platform has a conveying position and a detection position. When the detection platform is rotated to the detection position, the angle between the detection platform and the acquisition device is the acquisition angle.

[0009] In some embodiments, a sliding plate is provided on one side of the testing platform, and the sliding plate is connected to the connecting frame without interfering with the rotation of the testing platform. The surface of the sliding plate has multiple sets of sliding structures, wherein the multiple sets of sliding structures cover the conveying path of the packaging box on the surface of the sliding plate.

[0010] In some embodiments, the sliding structure includes an air duct, slots, and a wind unit; The air duct is formed inside the slide plate and connected to the wind power unit; the slot extends from the surface of the slide plate into the interior of the slide plate and connects to the ventilation duct. The inner diameter of the air inlet of the air duct is larger than the inner diameter of the air outlet of the air duct.

[0011] In some embodiments, the clamping unit includes a gripper, a drive member, and a gripping assembly. The drive member is located inside the connecting frame, and the drive end of the drive member is connected to the gripper and the gripping assembly. The gripper is wrapped with a rubber pad on its outer side, and the gripping assembly contacts the surface of the packaging box when the gripper clamps the packaging box.

[0012] In some embodiments, the gripping component includes a mounting portion, a hook, and a magnetic suction portion. The mounting portion is connected to the driving end of the driving member. The hook is hinged to one side of the mounting portion and can rotate relative to the mounting portion along the axis of the hinge. The magnetic suction portion is mounted at the connection between the mounting portion and the hook, so that the hook can rotate and fit against the mounting portion when the magnetic suction portion is magnetically attracted.

[0013] In some embodiments, a connecting portion is provided on the outer side of the gripper and connected thereto, the connecting portion is connected to the driving end of the driving member, the gripper is hinged to the outer side of the connecting portion and can rotate relative to the connecting portion, and an electromagnet is provided on the inner side of the connecting portion, the electromagnet attracts the gripper when the electromagnet is powered by electromagnetic force. The grippers on both sides form the gripper working surface on opposite sides, and the working surface is at least partially attached to the packaging box.

[0014] In some embodiments, at least one of the placement positions is provided with a light source, which is positioned toward the detection area.

[0015] In some embodiments, a support structure is provided at the bottom of the detection platform to support the detection platform switching between the conveying position and the detection position. The support structure includes a first magnet matrix and a second magnet matrix. The first magnet matrix is ​​located at the bottom of the detection platform, and the second magnet matrix is ​​located inside the connecting frame. The first magnet matrix and the second magnet matrix are vertically corresponding. Both the first magnet matrix and the second magnet matrix are composed of a number of electromagnetic blocks.

[0016] In some embodiments, the support structure further includes a guide groove, a guide rod, a pressure block, and an elastic element. The guide rod is disposed at the bottom of the mounting platform and connected to the mounting platform. One end of the guide rod extends into the interior of the guide groove, and the pressure block is disposed at the end of the guide rod extending into the interior of the guide groove. The elastic element is located inside the guide rod and supports the pressure block so that the outer wall of the pressure block fits against the inner wall of the guide groove. The inner wall of the guide groove has protrusions forming several support positions, each of which corresponds to a detection position, and the pressure block is adapted to the support position.

[0017] A method for measuring the stacking accuracy of finished wafers includes the following steps: The detection system is installed at the detection location using a connecting bracket; Based on the installation angle of the acquisition equipment, multiple detection positions of the detection station are set and measurements are taken at multiple detection positions of the detection station; The clamping unit drags the packaging box along the slide to the middle of the inspection table, the support structure switches the inspection table from the conveying position to the inspection position, the acquisition device acquires images of the packaging box, and the inspection table switches between multiple inspection positions. Preprocess the images of the packaging boxes captured by the acquisition device at multiple detection locations; The pre-processed packaging and images are segmented to identify the wafer stacking positions; Multiple wafer feature points are identified, and by combining images from multiple detection angles, the wafer feature points are marked for stacking accuracy calculation. After the calculation is completed, the clamping unit re-clamps the packaging box and moves the packaging box to the predetermined position.

[0018] Through the above technical solution, this application has the following beneficial effects: This application can detect the placement accuracy of wafers inside the packaging box in multiple scenarios. During the detection process, the wafer packaging box is switched between multiple detection positions to obtain images of the wafer packaging box from different angles. The wafer packaging box images are analyzed to obtain feature points and determine the stacking accuracy of the wafers inside the packaging box.

[0019] During the pulling process of the packaging box, multiple sliding structures are set on the slide plate to reduce the friction between the packaging box and the slide plate during movement, reduce the vibration of the wafer inside the packaging box, and improve the stability of the wafer inside the packaging box.

[0020] Other features and advantages of this application will be set forth in the following description, and in part will be apparent from the description, or may be learned by practicing the application. The objectives and other advantages of this application may be realized and obtained by means of the structures particularly pointed out in the written description and the accompanying drawings. Attached Figure Description

[0021] Figure 1 This is a structural diagram of the present application; Figure 2 This is a schematic diagram showing the removal of part of the connecting frame in this application; Figure 3 This is a schematic diagram of the clamp removal unit of this application; Figure 4 This is a schematic diagram of the bottom structure of the skateboard in this application; Figure 5 This is a schematic diagram of the testing station in this application; Figure 6 This is a schematic diagram of the guide groove in this application; Figure 7 This is a schematic diagram of the guide rod in this application; Figure 8 This is a partial schematic diagram of the skateboard in this application; Figure 9 This is a schematic diagram of the sliding structure of this application; Figure 10 This is a schematic diagram of the clamping unit of this application; Figure 11This is a schematic diagram of the gripper and grasping component of this application; Figure 12 This is a schematic diagram of the crawling component in this application; Figure 13 This is a schematic diagram of the hook swing in this application; Figure 14 This is a schematic diagram of the gripper in this application; Figure 15 This is a schematic diagram of the working surface of this application.

[0022] In the diagram: 100 connecting frame, 200 placement position, 300 data acquisition device, 400 detection table, 500 clamping unit; 10 Slide plate, 20 Sliding structure, 21 Air duct, 22 Slots, 23 Wind power unit; 510 Gripper, 511 Connector, 512 Electromagnet, 513 Rubber Pad, 514 Working Surface; 520 drive unit; 530 Gripping component, 531 Mounting part, 532 Hook, 533 Magnetic suction part; 410 Support structure, 411 Guide groove, 412 Guide rod, 413 Pressure block, 414 Elastic element, 415 Support position. Detailed Implementation

[0023] The following describes several embodiments of this application with reference to the accompanying drawings. For clarity, many practical details will be described in the following description. However, it should be understood that these practical details are not intended to limit the application. That is, these practical details are not essential in some embodiments of this application. Furthermore, features of different embodiments can be used interchangeably if feasible.

[0024] Unless otherwise defined, all terms used herein (including technical and scientific terms) have their ordinary meanings, which are understandable to those skilled in the art. Furthermore, the definitions of the aforementioned terms in commonly used dictionaries should be interpreted in the context of this specification as having the meaning consistent with the relevant field of this application. Unless specifically defined, these terms will not be interpreted as having idealized or overly formal meanings.

[0025] The following explains the relationships and terms used in this application: Parallelism: The parallelism defined in this application is not limited to absolute parallelism. This definition of parallelism can be understood as basic parallelism. It allows for situations where the parallelism is not absolute due to factors such as assembly tolerance, design tolerance, and structural flatness. It also allows for errors within a small angular range, such as within 10 degrees of assembly error. These can all be considered as parallel relationships.

[0026] Perpendicularity: The perpendicularity defined in this application is not limited to an absolute perpendicular intersection (with an included angle of 90 degrees). It is permissible for non-absolute perpendicular intersections caused by factors such as assembly tolerances, design tolerances, and structural flatness. It is permissible for errors within a small angular range, such as an assembly error range of 80 to 100 degrees, which can all be understood as a perpendicular relationship.

[0027] Ground: The ground as defined in this application is not limited to a specific material or region, but simply refers to a platform on which this application is supported, and allows for stacking, tilting, and variations in flatness. For example, cement floors, tile floors, work platforms, etc., can all be interpreted as ground.

[0028] The above explanation does not fully encompass the relationship definition given in this application, but only represents a part of it.

[0029] Current inspection processes detect wafer packaging quality and identify defects. However, for wafer placement accuracy, specialized automated handling equipment (cleanroom robots or wafer handlers) combined with dedicated end effectors (vacuum / mechanical clamps) and vision / laser alignment systems precisely place the wafers into carrier slots. Accurate visual inspection of wafers already in their packaging requires multi-level verification—from "presence / count" to micron-level detection of "centering / tilt / warping within the slot," combined with appropriate light sources, camera resolution, and algorithms to avoid false positives and missed detections. Currently, wafer placement accuracy within the packaging is only checked during wafer placement. Detecting placement misalignment, tilting, missing wafers, and surface defects before shipment / warehousing directly protects yield and downstream equipment safety.

[0030] See Figures 1-15 As shown. This application provides a visual inspection system for finished wafer packaging boxes, which can be installed in a wafer packaging line to perform visual inspection of the wafer packaging boxes after the wafers are packaged. It can also be installed in a warehouse, and by changing the drive system, the inspection system can move along the warehouse shelves to perform visual inspection of the wafer packaging boxes.

[0031] The testing system includes a connecting frame 100, a testing table 400, and a clamping unit 500. The connecting frame 100 is connected to the drive system or installed in the wafer packaging line to fix and position the testing system. The connecting frame 100 has at least one placement position 200 in one direction for installing the acquisition device 300, and the placement position 200 is equipped with a light source.

[0032] The inner side of the connecting frame 100 forms the detection area. The light source and the acquisition device 300 are both set towards the detection area. The light source is used to supplement the light of the detection area, and the acquisition device 300 is used to acquire images of the packaging boxes located in the detection area. The detection table 400 is located in the detection area.

[0033] The testing platform 400 can rotate relative to the connecting frame 100. The testing platform 400 has a conveying position and a testing position, which are switched based on the clamping state of the clamping unit 500. When the clamping unit 500 clamps the packaging box and moves it, the testing platform 400 rotates to the conveying position. When the clamping unit 500 pulls the packaging box onto the testing platform 400, the testing platform 400 switches between the testing positions. The angle between the testing platform 400 and the acquisition device 300 is the acquisition angle.

[0034] By capturing changes in the angle, the acquisition device 300 can capture images of packaging boxes from different angles.

[0035] The placement position 200 has multiple mounting holes for mounting the acquisition device 300, so that the acquisition device 300 can be adjusted arbitrarily within the placement position 200. At least one placement position 200 is provided and faces the detection area, while the connecting frame 100 can be provided with multiple placement positions 200 to set up multiple acquisition devices 300 for acquiring packaging box images.

[0036] The clamping unit 500 is provided with at least one pair of grippers 510. The grippers 510 are wrapped with rubber pads 513 to increase the friction on the packaging box during the clamping process.

[0037] A slide plate 10 is provided on one or the opposite side of the testing table 400. The slide plate 10 is inclined to facilitate the transfer of packaging boxes onto the testing table 400. The slide plate 10 extends to the testing table 400 and connects to the connecting frame 100 without interfering with the rotation of the testing table 400. To reduce the vibration generated by the packaging box on the slide plate 10, which could lead to displacement of the wafer inside the packaging box, the surface of the slide plate 10 has multiple sets of sliding structures 20. These multiple sets of sliding structures 20 cover the conveying path of the packaging box on the surface of the slide plate 10. This application does not limit the sliding structure 20; the sliding structure 20 can be any structure such as a ball bearing or roller to reduce the vibration of the packaging box and the slide plate 10 during the sliding process.

[0038] For example, in some embodiments, the sliding structure 20 includes an air duct 21, a slot 22, and a wind unit 23. The air duct 21 is opened inside the slide plate 10 and is tapered. The air duct 21 is connected to the wind unit 23, and the wind unit 23 supplies air into the air duct 21. The inner diameter of the air inlet of the air duct 21 is larger than the inner diameter of the air outlet of the air duct 21. The slot 22 extends from the surface of the slide plate 10 into the slide plate 10 and is connected to the air duct 21. When the wind unit 23 supplies air into the air duct 21, it is sprayed outward from the slot 22, forming an airflow between the bottom wall of the packaging box and the outer wall of the slide plate 10, reducing the friction between the packaging box and the slide plate 10.

[0039] In some embodiments, the clamping unit 500 is provided with a drive member 520 and a gripping component 530. The drive member 520 is installed in the connecting frame 100. The position of the gripper 510 and the gripping component 530 is adjusted by the drive member 520, and the packaging box is pulled by the gripper 510 and the gripping component 530.

[0040] The driving end of the driving component 520 is connected to the gripper 510 and the grasping assembly 530. The grasping assembly 530 includes a mounting part 531, a hook 532, and a magnetic attraction part 533. The mounting part 531 is connected to the driving end of the driving component 520. The hook 532 is hinged to one side of the mounting part 531 and can rotate relative to the mounting part 531 along the hinge. The magnetic attraction part 533 is located at the connection between the mounting part 531 and the hook 532. The magnetic attraction part 533 includes a first electromagnet and a second electromagnet. The first electromagnet is fixed at the mounting part 531, and the second electromagnet is fixed at the hook 532. The first electromagnet and the second electromagnet attract each other magnetically, so that the hook 532 can hook the packaging box. When the first electromagnet and the second electromagnet repel each other, the hook 532 disengages from the packaging box.

[0041] In some embodiments, a connecting portion 511 is provided on the outer side of the gripper 510, and the gripper 510 is connected to the connecting portion 511. The connecting portion 511 is connected to the driving end of the driving member 520. The gripper 510 is hinged to the connecting portion 511 and can rotate relative to the connecting portion 511. An electromagnet 512 is provided on the inner side of the connecting portion 511. The electromagnet 512 attracts the gripper 510 through electromagnetic induction, so that the gripper 510 clamps the packaging box.

[0042] The drive unit 520 is a slide table, which is installed in the direction of conveying the packaging box. The slide table is connected to the connecting part 511 and the mounting part 531, and drives the connecting part 511 and the mounting part 531 to move in the direction of conveying the packaging box.

[0043] The opposite side of the two grippers 510 is the working surface 514 of the gripper 510. When the gripper 510 clamps the packaging box, at least part of the working surface 514 is in contact with the packaging box to ensure the stability of the gripper 510 in clamping the packaging box and driving the packaging box to move.

[0044] The working surface 514 of the gripper 510 includes multiple surfaces, so that the gripper 510 can stably contact the outer wall of the packaging box when gripping different parts of the packaging box. The electromagnet 512 magnetically attracts the gripper 510. By adjusting the magnetic force of the electromagnet 512, the gripper 510 can maintain the gripping of the packaging box in a state that can pull and drag the packaging box without causing the packaging box to deform.

[0045] The bottom of the testing table 400 is provided with a support structure 410, which supports the testing table 400 to switch between the conveying position and the testing position. The support structure 410 includes a first magnet matrix and a second magnet matrix, which are vertically aligned. Both the first magnet matrix and the second magnet matrix are composed of several electromagnetic blocks. When the testing table 400 needs to change position, the electromagnetic blocks at different positions adjust the magnetic force to tilt the testing table 400, thereby causing the packaging boxes on the testing table 400 to change multiple directions and switch between testing positions.

[0046] The testing platform 400 is tilted to different positions, and the acquisition device 300 can acquire images of the packaging box from multiple angles. By acquiring images of the packaging box from multiple angles, the wafer placement accuracy inside the packaging box is tested.

[0047] In some embodiments, the support structure 410 further includes a guide groove 411, a guide rod 412, a pressure block 413, and an elastic member 414. The guide rod 412 is rotatably mounted on the bottom of the mounting platform and can rotate relative to the mounting platform. The guide groove 411 is mounted inside the connecting frame 100 and cooperates with the guide rod 412. The pressure block 413 is disposed at one end of the guide rod 412 extending into the guide groove 411. The elastic member 414 supports the pressure block 413 inside the guide rod 412, so that the outer wall of the pressure block 413 fits against the inner wall of the guide groove 411.

[0048] The elastic element 414 is a compression spring. The opening of the guide groove 411 contracts to ensure that the guide rod 412 is confined inside the guide groove 411, preventing the guide rod 412 from slipping out of the guide groove 411 and causing inaccurate positioning between the guide rod 412 and the guide groove 411. The support of the compression spring for the pressure block 413 can ensure stable friction between the pressure block 413 and the guide groove 411, thereby improving the support stability during the cooperation between the guide rod 412 and the guide groove 411.

[0049] The inner wall of the guide groove 411 has protrusions forming several support positions 415, each support position 415 corresponding to a detection position. The magnetic force changes of the first magnet matrix and the second magnet matrix cause the detection stage 400 to tilt. At the same time, the cooperation between the guide rod 412 and the guide groove 411 also changes accordingly. The pressure block 413 moves inside the guide groove 411 and cooperates with the support position 415 to further improve the stability when the guide rod 412 cooperates with the guide groove 411.

[0050] This application also provides a method for measuring the stacking accuracy of finished wafers, used in the above-mentioned detection system, the steps of which are as follows: The detection system is installed at the detection location via the connecting bracket 100; Based on the installation angle of the acquisition device 300, multiple detection positions of the detection station 400 are set, and the multiple detection positions of the detection station 400 are measured through the support structure 410. Based on changes in ambient light, the acquisition device 300 can clearly capture the light source intensity of the packaging box image; The clamping unit 500 drags the packaging box along the slide plate 10 to the middle of the inspection table 400, the support structure 410 switches the inspection table 400 from the conveying position to the inspection position, the acquisition device 300 acquires images of the packaging box, and the support structure 410 supports the inspection table 400 to switch between multiple inspection positions. The images of the packaging boxes acquired by the acquisition device 300 at multiple detection locations are preprocessed; The pre-processed packaging and images are segmented to identify the wafer stacking positions; Multiple wafer feature points are identified, and by combining images from multiple detection angles, the wafer feature points are marked for stacking accuracy calculation. After the calculation is completed, the clamping unit 500 re-clamps the packaging box and moves the packaging box to the predetermined position.

[0051] Although this application has been disclosed in conjunction with the above embodiments, it is not intended to limit this application. Any person skilled in the art may make various modifications and refinements without departing from the spirit and scope of this application. Therefore, the scope of protection of this application shall be determined by the appended claims.

Claims

1. A visual inspection system for packaging boxes of finished wafers, characterized in that, include: A connecting frame (100) has a detection area formed on its inner side; At least one placement position (200) is provided inside the connecting frame (100), and a data acquisition device (300) facing the detection area is provided thereon. A detection platform (400) is located inside the connecting frame (100), and there is a collection angle between the detection platform (400) and the acquisition device (300); A clamping unit (500) is disposed inside the connecting frame (100) and the clamping unit (500) is arranged facing the detection area; The acquisition device (300) is positioned adjustablely so that it is located at at least one acquisition position where the placement position (200) is connected to the connecting frame (100). The detection platform (400) is rotatably arranged relative to the connecting frame (100) so that the detection platform (400) has a conveying position and a detection position. When the detection platform (400) rotates to the detection position, the angle between the detection platform (400) and the acquisition device (300) is the acquisition angle.

2. The visual inspection system for packaging boxes of finished wafers according to claim 1, characterized in that, The testing platform (400) is provided with a sliding plate (10) on one side, and the sliding plate (10) is connected to the connecting frame (100) without interfering with the rotation of the testing platform (400). The surface of the sliding plate (10) has multiple sets of sliding structures (20), wherein the multiple sets of sliding structures (20) cover the conveying path of the packaging box on the surface of the sliding plate (10).

3. The visual inspection system for packaging boxes of finished wafers according to claim 2, characterized in that, The sliding structure (20) includes an air duct (21), a slot (22), and a wind unit (23); The air duct (21) is opened inside the slide plate (10) and connected to the wind unit (23). The slot (22) extends from the surface of the slide plate (10) into the interior of the slide plate (10) and connects to the air duct (21). The inner diameter of the air inlet of the air duct (21) is larger than the inner diameter of the air outlet of the air duct (21).

4. The visual inspection system for packaging boxes of finished wafers according to claim 1, characterized in that, The clamping unit (500) includes a gripper (510), a drive member (520), and a gripping component (530). The drive member (520) is located inside the connecting frame (100), and the drive end of the drive member (520) is connected to the gripper (510) and the gripping component (530). The gripper (510) is wrapped with a rubber pad (513) on its outside. The gripping component (530) contacts the surface of the packaging box when the gripper (510) clamps the packaging box.

5. The visual inspection system for packaging boxes of finished wafers according to claim 4, characterized in that, The gripping component (530) includes a mounting part (531), a hook (532), and a magnetic suction part (533). The mounting part (531) is connected to the driving end of the driving member (520). The hook (532) is hinged to one side of the mounting part (531) and can rotate relative to the mounting part (531) along the axis of the hinge. The magnetic suction part (533) is installed at the connection between the mounting part (531) and the hook (532) so that when the magnetic suction part (533) magnetically attracts, the hook (532) can rotate and fit against the mounting part (531).

6. The visual inspection system for packaging boxes of finished wafers according to claim 4, characterized in that, The gripper (510) has a connecting part (511) on its outer side and is connected thereto. The connecting part (511) is connected to the driving end of the driving member (520). The gripper (510) is hinged to the outside of the connecting part (511) and can rotate relative to the connecting part (511). An electromagnet (512) is provided on the inner side of the connecting part (511). The electromagnet (512) attracts the gripper (510) by electromagnetic induction. The grippers (510) on both sides form a working surface (514) on opposite sides, and the working surface (514) is at least partially attached to the packaging box.

7. The visual inspection system for packaging boxes of finished wafers according to claim 1, characterized in that, At least one of the placement positions (200) is provided with a light source, which is positioned toward the detection area.

8. The visual inspection system for packaging boxes of finished wafers according to claim 1, characterized in that, The bottom of the testing platform (400) is provided with a support structure (410) to support the testing platform (400) to switch between the conveying position and the testing position. The support structure (410) includes a first magnet matrix and a second magnet matrix. The first magnet matrix is ​​located at the bottom of the testing platform (400), and the second magnet matrix is ​​located inside the connecting frame (100). The first magnet matrix and the second magnet matrix are vertically corresponding. Both the first magnet matrix and the second magnet matrix are composed of several electromagnetic blocks.

9. The visual inspection system for packaging boxes of finished wafers according to claim 8, characterized in that, The support structure (410) further includes a guide groove (411), a guide rod (412), a pressure block (413), and an elastic element (414). The guide rod (412) is located at the bottom of the testing table (400) and connected to the testing table (400). One end of the guide rod (412) extends into the interior of the guide groove (411), and the pressure block (413) is located at the end of the guide rod (412) that extends into the interior of the guide groove (411). The elastic element (414) is located inside the guide rod (412) and supports the pressure block (413) so that the outer wall of the pressure block (413) fits against the inner wall of the guide groove (411). The inner wall of the guide groove (411) protrudes to form a number of support positions (415), each of the support positions (415) corresponds to a detection position, and the pressure block (413) is adapted to the support position (415).

10. A method for measuring the stacking accuracy of finished wafers, used in the packaging box visual inspection system as described in any one of claims 1-9, characterized in that, Includes the following steps: The detection system is installed at the detection location via the connecting bracket (100); Based on the installation angle of the acquisition device (300), multiple detection positions of the detection station (400) are set and the multiple detection positions of the detection station (400) are measured; The clamping unit (500) drags the packaging box along the slide plate (10) to the middle of the inspection table (400), the support structure (410) switches the inspection table (400) from the conveying position to the inspection position, the acquisition device (300) acquires images of the packaging box, and the inspection table (400) switches between multiple inspection positions; The images of the packaging boxes acquired by the acquisition device (300) at multiple detection locations are preprocessed; The pre-processed packaging and images are segmented to identify the wafer stacking positions; Multiple wafer feature points are identified, and by combining images from multiple detection angles, the wafer feature points are marked for stacking accuracy calculation. After the calculation is completed, the clamping unit (500) clamps the packaging box again and moves the packaging box to the predetermined position.

Images