Position calibration method, device, equipment and storage medium

Abstract

The present application discloses a position calibration method, device, equipment and storage medium, which relates to the field of machine vision technology, and is at least used to improve the problem of low accuracy when calibrating wafers. The method includes: obtaining the position information of the sampling points after rotation corresponding to each of the multiple turntable rotation angles; determining the target distance and target angle according to the multiple turntable rotation angles and the position information of each sampling point after rotation; the target distance is used to represent the distance between the center of the wafer to be calibrated and the turntable rotation center; the target angle is used to represent the angle between the line between the center of the wafer to be calibrated and the turntable rotation center, and the line between the initial sampling point and the turntable rotation center; according to the target distance and the target angle, determine the position deviation information of the center of the wafer to be calibrated relative to the turntable rotation center, so as to calibrate based on the position deviation information so that the center of the wafer to be calibrated coincides with the turntable rotation center.

Description

Technical Field

[0001] The present application relates to the field of machine vision technology, and in particular to a position calibration method, device, equipment and storage medium. Background Art

[0002] During processes such as wafer manufacturing and processing, the position of the wafer can be calibrated and the wafer can be transferred from one device to another, thereby improving the efficiency and accuracy of the process.

[0003] In the related art, the contour information of the arc segment of the outer edge of the wafer can be collected based on image recognition sensors such as industrial cameras to fit the center of the wafer, thereby calibrating the position of the wafer. However, when the size of the wafer is large, the center angle corresponding to the arc segment of the outer edge of the wafer collected by the image recognition sensor will be smaller. In this case, the contour of the arc segment collected by the image recognition sensor tends to be flat, and when affected by the sampling noise and sampling accuracy of the image recognition sensor, it is easy to cause the accuracy of the fitted wafer center to be low, resulting in the problem of low calibration accuracy. Summary of the invention

[0004] The embodiments of the present application provide a position calibration method, device, equipment and storage medium, which are at least used to improve the problem of low accuracy when calibrating a wafer.

[0005] To achieve the above objectives, the present application provides the following technical solutions:

[0006] In a first aspect, a position calibration method is provided, comprising: obtaining position information of a sampling point after rotation corresponding to each of a plurality of turntable rotation angles. The turntable rotation angle is used to represent the angle between the line between the sampling point after rotation and the rotation center of the turntable and the line between the initial sampling point and the rotation center. The initial sampling point is a point on the arc edge of the wafer to be calibrated that is located within the sampling range of the area array camera when the wafer to be calibrated placed on the turntable is in the initial position. The sampling point after rotation is a point on the arc edge that is located within the sampling range when the wafer to be calibrated is in the position after the turntable rotates by the turntable rotation angle. According to a plurality of turntable rotation angles and the position information of each sampling point after rotation, a target distance and a target angle are determined. The target distance is used to represent the distance between the center of the wafer to be calibrated and the rotation center. The target angle is used to represent the angle between the line between the center of the wafer to be calibrated and the rotation center and the line between the initial sampling point and the rotation center. According to the target distance and the target angle, the position deviation information of the center of the wafer to be calibrated relative to the rotation center is determined, and calibration is performed based on the position deviation information so that the center of the wafer to be calibrated coincides with the rotation center.

[0007] In this technical solution, the computer device can obtain the position information of multiple sampling points after rotation of the wafer to be calibrated during the process of rotating the turntable at multiple turntable rotation angles, so as to accurately determine the distance between the center of the wafer to be calibrated and the rotation center, and the angle between the line connecting the center of the wafer to be calibrated and the rotation center and the line connecting the initial sampling point and the rotation center. Furthermore, the computer device can determine the position deviation information of the center of the wafer to be calibrated relative to the rotation center, so as to calibrate so that the center of the wafer to be calibrated coincides with the rotation center. Based on this, the present application can avoid the problem that the fitting result fluctuates greatly due to the influence of sampling noise and precision when fitting based on the contour of a section of the arc edge of the wafer to be calibrated, and can achieve higher calibration accuracy. Therefore, the present application can be used to improve the problem of low precision when calibrating the wafer.

[0008] In a possible embodiment, a method for determining a target distance and a target angle according to a plurality of turntable rotation angles and position information of each sampling point after rotation specifically includes: determining the sampling point distance of each sampling point after rotation based on the position information of each sampling point after rotation. The sampling point distance is the distance between the sampling point after rotation and the rotation center. According to the plurality of turntable rotation angles and the sampling point distance of each sampling point after rotation, determining the first physical coordinate of each sampling point after rotation in the first coordinate system. The first coordinate system is used to represent a physical rectangular coordinate system whose horizontal axis is a straight line from the rotation center to the initial sampling point and whose origin is the rotation center. The horizontal coordinate of the first physical coordinate is the product of the sampling point distance and the cosine value of the turntable rotation angle. The vertical coordinate of the first physical coordinate is the product of the sampling point distance and the sine value of the turntable rotation angle. Fitting processing is performed based on the first physical coordinates of each sampling point after rotation to determine the center coordinate of the center of the wafer to be calibrated in the first coordinate system. According to the center coordinate, the target distance and the target angle are determined.

[0009] In a possible embodiment, a method for determining the first physical coordinates of each rotated sampling point in a first coordinate system according to a plurality of turntable rotation angles and the sampling point distances of each rotated sampling point specifically includes: determining the polar coordinates of each rotated sampling point in a polar coordinate system according to a plurality of turntable rotation angles and the sampling point distances of each rotated sampling point. The polar angle of the polar coordinates is the turntable rotation angle. The polar diameter of the polar coordinates is the sampling point distance. The polar coordinates of each rotated sampling point are processed based on a first conversion relationship to obtain the first physical coordinates of each rotated sampling point. The first conversion relationship is used to represent the conversion relationship between the polar coordinate system and the first coordinate system.

[0010] In a possible embodiment, the position deviation information includes a deviation in the horizontal axis direction and a deviation in the vertical axis direction. A method for determining the position deviation information of the center of a wafer to be calibrated relative to the rotation center according to a target distance and a target angle specifically includes: obtaining a second physical coordinate of a target sampling point in a second coordinate system. The target sampling point is a point on the arc edge that is located within a sampling range when the wafer to be calibrated is at a target position. The target position is the position of the wafer to be calibrated after the turntable rotates from the initial position to the target angle. The second coordinate system is used to represent a physical rectangular coordinate system whose origin is the rotation center. Based on the second physical coordinate of the target sampling point, the calibration angle is determined. The calibration angle is the angle between the line between the target sampling point and the rotation center and the horizontal axis of the second coordinate system. According to the target distance and the calibration angle, the deviation of the center of the wafer to be calibrated relative to the rotation center in the horizontal axis direction and the deviation of the center of the wafer to be calibrated relative to the rotation center in the vertical axis direction are determined. The deviation in the horizontal axis direction is the product of the target distance and the cosine value of the calibration angle. The deviation in the vertical axis direction is the product of the target distance and the sine value of the calibration angle.

[0011] In a possible embodiment, after the center of the wafer to be calibrated coincides with the rotation center, the method further includes: acquiring a target sampling image. The target sampling image is an image captured by the area array camera during the process of the wafer to be calibrated rotating with the turntable, and the target sampling image includes the notch of the wafer to be calibrated. Determine the position information of the target position point in the notch of the wafer to be calibrated. Based on the position information, determine the angle deviation information of the target position point relative to the preset position point, so as to calibrate based on the angle deviation information so that the target position point coincides with the preset position point. The angle deviation information includes the angle between the line between the target position point and the rotation center and the line between the preset position point and the rotation center.

[0012] In a possible embodiment, the position information is the second physical coordinate of the sampling point after rotation in the second coordinate system. The coordinate origin of the second coordinate system is the rotation center. The method for obtaining the position information of the sampling points after rotation corresponding to the plurality of turntable rotation angles specifically includes: obtaining a sampling image of each sampling point after rotation within the sampling range. Determining the pixel coordinates of each sampling point after rotation in the image coordinate system of the sampling image. Processing the pixel coordinates of each sampling point after rotation based on the second conversion relationship to obtain the second physical coordinates of each sampling point after rotation. The second conversion relationship is used to represent the conversion relationship between the image coordinate system and the second coordinate system.

[0013] In a possible embodiment, the position calibration method further includes: obtaining multiple coordinate pairs of calibration points and pixel coordinates corresponding to multiple calibration angles. The calibration points are points on the calibration object placed on the turntable. The coordinate pairs include the pixel coordinates of the calibration points in the image coordinate system and the physical coordinates of the calibration points in the initial coordinate system. Different coordinate pairs correspond to different positions of the calibration points within the sampling range. The pixel coordinates corresponding to the calibration angle are the pixel coordinates of the calibration point when it is in the position after the turntable rotates the calibration angle. Based on the coordinate pairs corresponding to the multiple calibration points, an initial transformation relationship is determined. The initial transformation relationship is used to represent the transformation relationship between the image coordinate system and the initial coordinate system. Based on the pixel coordinates corresponding to the multiple calibration angles, the pixel coordinates of the rotation center in the image coordinate system are determined. Based on the initial transformation relationship and the pixel coordinates of the rotation center, a second transformation relationship is determined.

[0014] In a second aspect, a position calibration device is provided, including: an acquisition unit and a processing unit.

[0015] The acquisition unit is used to obtain the position information of the sampling points after rotation corresponding to each of the plurality of turntable rotation angles. The turntable rotation angle is used to represent the angle between the line between the sampling point after rotation and the rotation center of the turntable and the line between the initial sampling point and the rotation center. The initial sampling point is a point on the arc edge of the wafer to be calibrated placed on the turntable that is within the sampling range of the area array camera when the wafer to be calibrated is in the initial position. The sampling point after rotation is a point on the arc edge that is within the sampling range when the wafer to be calibrated is in the position after the turntable rotates the turntable by the rotation angle.

[0016] The processing unit is used to determine the target distance and the target angle according to the plurality of turntable rotation angles and the position information of each sampling point after rotation. The target distance is used to represent the distance between the center of the wafer to be calibrated and the rotation center. The target angle is used to represent the angle between the line between the center of the wafer to be calibrated and the rotation center and the line between the initial sampling point and the rotation center.

[0017] The processing unit is also used to determine the position deviation information of the center of the wafer to be calibrated relative to the rotation center according to the target distance and the target angle, so as to perform calibration based on the position deviation information so that the center of the wafer to be calibrated coincides with the rotation center.

[0018] In a possible embodiment, the processing unit is specifically used to: determine the sampling point distance of each sampling point after rotation based on the position information of each sampling point after rotation. The sampling point distance is the distance between the sampling point after rotation and the rotation center. According to multiple turntable rotation angles and the sampling point distances of each sampling point after rotation, determine the first physical coordinates of each sampling point after rotation in the first coordinate system. The first coordinate system is used to represent a physical rectangular coordinate system whose horizontal axis is a straight line from the rotation center to the initial sampling point and whose origin is the rotation center. The horizontal coordinate of the first physical coordinate is the product of the sampling point distance and the cosine value of the turntable rotation angle. The vertical coordinate of the first physical coordinate is the product of the sampling point distance and the sine value of the turntable rotation angle. Fitting processing is performed based on the first physical coordinates of each sampling point after rotation to determine the center coordinates of the center of the wafer to be calibrated in the first coordinate system. According to the center coordinates, the target distance and target angle are determined.

[0019] In a possible embodiment, the processing unit is specifically used to: determine the polar coordinates of each rotated sampling point in the polar coordinate system according to a plurality of turntable rotation angles and the sampling point distances of each rotated sampling point. The polar angle of the polar coordinates is the turntable rotation angle. The polar diameter of the polar coordinates is the sampling point distance. The polar coordinates of each rotated sampling point are processed based on the first conversion relationship to obtain the first physical coordinates of each rotated sampling point. The first conversion relationship is used to represent the conversion relationship between the polar coordinate system and the first coordinate system.

[0020] In a possible embodiment, the position deviation information includes a deviation in the horizontal axis direction and a deviation in the vertical axis direction. The processing unit is specifically used to: obtain the second physical coordinate of the target sampling point in the second coordinate system. The target sampling point is a point on the arc edge that is located within the sampling range when the wafer to be calibrated is at the target position. The target position is the position of the wafer to be calibrated after the turntable rotates from the initial position to the target angle. The second coordinate system is used to represent a physical rectangular coordinate system with the origin as the rotation center. Based on the second physical coordinate of the target sampling point, the calibration angle is determined. The calibration angle is the angle between the line between the target sampling point and the rotation center and the horizontal axis of the second coordinate system. According to the target distance and the calibration angle, determine the deviation of the center of the wafer to be calibrated relative to the rotation center in the horizontal axis direction, and the deviation of the center of the wafer to be calibrated relative to the rotation center in the vertical axis direction. The deviation in the horizontal axis direction is the product of the target distance and the cosine value of the calibration angle. The deviation in the vertical axis direction is the product of the target distance and the sine value of the calibration angle.

[0021] In a possible embodiment, the acquisition unit is further used to acquire a target sampling image. The target sampling image is an image captured by the area array camera when the wafer to be calibrated rotates with the turntable, and the target sampling image includes the notch of the wafer to be calibrated.

[0022] The processing unit is also used to determine the position information of the target position point in the notch of the wafer to be calibrated.

[0023] The processing unit is further used to determine the angle deviation information of the target position point relative to the preset position point based on the position information, so as to calibrate the target position point and the preset position point based on the angle deviation information. The angle deviation information includes the angle between the line between the target position point and the rotation center and the line between the preset position point and the rotation center.

[0024] In a possible embodiment, the position information is the second physical coordinates of the rotated sampling point in the second coordinate system. The coordinate origin of the second coordinate system is the rotation center. The acquisition unit is specifically used to: acquire a sampled image of each rotated sampling point within the sampling range. Determine the pixel coordinates of each rotated sampling point in the image coordinate system of the sampled image. Process the pixel coordinates of each rotated sampling point based on the second conversion relationship to obtain the second physical coordinates of each rotated sampling point. The second conversion relationship is used to represent the conversion relationship between the image coordinate system and the second coordinate system.

[0025] In a possible embodiment, the acquisition unit is further used to acquire multiple coordinate pairs of calibration points and pixel coordinates corresponding to multiple calibration angles. The calibration points are points on the calibration object placed on the turntable. The coordinate pairs include the pixel coordinates of the calibration points in the image coordinate system and the physical coordinates of the calibration points in the initial coordinate system. Different coordinate pairs correspond to different positions of the calibration points within the sampling range. The pixel coordinates corresponding to the calibration angle are the pixel coordinates of the calibration points when they are at the position after the turntable rotates the calibration angle.

[0026] The processing unit is further used to determine an initial transformation relationship based on the coordinate pairs corresponding to the plurality of calibration points. The initial transformation relationship is used to represent the transformation relationship between the image coordinate system and the initial coordinate system.

[0027] The processing unit is further used to determine the pixel coordinates of the rotation center in the image coordinate system based on the pixel coordinates corresponding to each of the multiple calibration angles.

[0028] The processing unit is further used to determine a second conversion relationship based on the initial conversion relationship and the pixel coordinates of the rotation center.

[0029] In a third aspect, a computer device is provided, comprising: a processor and a memory. The processor is connected to the memory, the memory is used to store computer-executable instructions, and the processor executes the computer-executable instructions stored in the memory, thereby implementing any one of the methods provided in the first aspect.

[0030] In a fourth aspect, a readable storage medium is provided, comprising computer execution instructions, which, when executed on a computer device, causes the computer device to execute any one of the methods provided in the first aspect.

[0031] In a fifth aspect, a computer program product is provided, comprising computer execution instructions, which, when executed on a computer device, cause the computer device to execute any one of the methods provided in the first aspect.

[0032] The technical effects brought about by any implementation method in the second to fifth aspects can refer to the technical effects brought about by the corresponding implementation method in the first aspect, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 A schematic diagram of a wafer notch provided in an embodiment of the present application;

[0034] Figure 2 A schematic diagram of the structure of a calibration system provided in an embodiment of the present application;

[0035] Figure 3 A schematic diagram of the structure of a computer device provided in an embodiment of the present application;

[0036] Figure 4 A schematic diagram of a flow chart of a position calibration method provided in an embodiment of the present application;

[0037] Figure 5 A schematic diagram of a wafer rotation process provided in an embodiment of the present application;

[0038] Figure 6 A schematic diagram of a polar coordinate system provided in an embodiment of the present application;

[0039] Figure 7 A schematic diagram of a first coordinate system provided in an embodiment of the present application;

[0040] Figure 8 A schematic diagram of a circle fitting result provided in an embodiment of the present application;

[0041] Fig. 9 A schematic diagram of another circle fitting result provided in an embodiment of the present application;

[0042] Fig.10 A schematic diagram of a flow chart of another position calibration method provided in an embodiment of the present application;

[0043] Fig.11 A schematic diagram of the structure of a position calibration device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0044] In the description of this application, unless otherwise specified, " / " means "or", for example, A / B can mean A or B. "And / or" in this article is merely a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, "at least one" means one or more, and "plurality" means two or more. The words "first", "second", etc. do not limit the quantity and execution order, and the words "first", "second", etc. do not limit them to be different.

[0045] It should be noted that, in this application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in this application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0046] First of all, in order to facilitate the understanding of the present application, the relevant elements involved in the present application are described.

[0047] A wafer is a silicon chip made of silicon material and is used to make integrated circuits.

[0048] Wafer calibration refers to the use of wafer notches to modify and correct the position and direction of the wafer so that the wafer is accurately located in a specific position. It is also called wafer edge patrol, wafer pre-alignment, or wafer pre-positioning. During the wafer production process, when the wafer is transferred from one device to another, the position of the wafer can be calibrated in advance to facilitate the correct handling of the wafer.

[0049] Wafer notches refer to specific marks on the surface of a wafer used as a reference to determine the position and orientation of the wafer. For example, the orientation of a wafer notch can be considered the orientation of the wafer. In some scenarios, wafer notches can also be used to indicate basic information such as the type of wafer. The number of wafer notches can be used to indicate the crystal orientation of the wafer. The position of the wafer notch can be used to indicate the doping type of the wafer.

[0050] For example, Figure 1 As shown in FIG. 1 , a schematic diagram of a wafer notch provided in an embodiment of the present application is provided. For a wafer of smaller size, a smaller plane area can be formed by grinding a wafer surface during the manufacturing and processing process. Figure 1 The wafer notch is obtained by cutting the flat angle shown in (a) in the figure. This flat-angle wafer notch is also called flat. For larger wafers, a notch can be cut on the wafer surface during the manufacturing and processing process. Figure 1 The smaller V-shaped opening shown in (b) or Figure 1The smaller U-shaped opening shown in (c) in the figure is used to obtain a wafer notch. This U-shaped or V-shaped wafer notch is also called a Notch.

[0051] Hand-eye calibration refers to determining the relative position and posture relationship between the pixel coordinate system and the robot coordinate system. The hand can be the motion mechanism at the end of the robot. The eye can be an image recognition sensor such as an area array camera. The setting between the hand and the eye can be "eye outside the hand" or "eye on the hand". "Eye outside the hand" means that the image recognition sensor is installed at a fixed position outside the motion mechanism and is separated from the motion mechanism. "Eye on the hand" means that the image recognition sensor is installed on the motion mechanism and is integrated with the motion mechanism. In a two-dimensional scene, N-point calibration is usually used. N-point calibration is to solve the mapping matrix (or homography matrix) from the image coordinate system of the camera to the second coordinate system of the motion mechanism through N sets of point pair coordinates (N is greater than or equal to 2) in the physical coordinate system of the motion mechanism and the image coordinate system of the camera. The physical coordinate system and the image coordinate system can be rectangular coordinate systems.

[0052] A motion mechanism is a mechanism that has a motion function. When a motion mechanism has a rotation function, the center point of its rotation axis can be called the rotation center.

[0053] Secondly, the application scenarios involved in this application are briefly introduced.

[0054] During wafer manufacturing and processing, wafer alignment can be performed and wafers can be transferred from one device to another, thereby improving the efficiency and accuracy of the process.

[0055] In the related art, a high-frequency (e.g., 16,000 times / second) high-precision laser micrometer is generally used to correct the deviation between the rotation center and the wafer center and the angle of the wafer notch to achieve wafer calibration. However, this method is costly, difficult to effectively calibrate larger wafers, and has poor scalability.

[0056] Alternatively, calibration can also be performed based on machine vision detection and positioning technology. For example, an image recognition sensor such as an industrial camera can be used to collect the contour of the arc segment on the outer edge of the wafer to fit the center of the wafer, and then the deviation can be solved and calibrated. However, when the size of the wafer is large, the center angle corresponding to the arc segment on the outer edge of the wafer collected by the image recognition sensor will be smaller. In this case, the contour of the arc segment collected by the image recognition sensor tends to be flat, and when affected by the sampling noise and sampling accuracy of the image recognition sensor, it is easy to cause the accuracy of the fitted wafer center to be low, resulting in the problem of low calibration accuracy.

[0057] Next, the implementation environment (implementation architecture) involved in this application is briefly introduced.

[0058] The embodiment of the present application provides a position calibration method, which can be applied to a computer device. The computer device can be used to determine the deviation of the center of a wafer and a notch relative to a position that meets the requirements, thereby realizing a wafer calibration function. For example, the computer device can be used to determine the position deviation of the center of a wafer relative to the rotation center. For another example, the computer device can be used to determine the deviation of the notch of a wafer relative to a preset position on a turntable.

[0059] The embodiments of the present application do not impose any restrictions on the specific form of the computer device. For example, the computer device may be a terminal device for implementing the wafer calibration function, or a network device for implementing the wafer calibration function. Among them, the terminal device may be referred to as: terminal, user equipment (UE), terminal device, mobile device, user terminal, user agent or user device, etc. The terminal device may be a mobile phone, a tablet computer, a laptop computer, an ultra-mobile personal computer (UMPC), a netbook, a personal digital assistant (PDA), etc. The network device may be a server, etc. Among them, the server may be a physical or logical server, or there may be two or more physical or logical servers that share different responsibilities and cooperate with each other to implement the various functions of the server.

[0060] One possible approach is Figure 2 , which is a schematic diagram of a calibration system provided in an embodiment of the present application. The calibration system may include an area array camera 201, a turntable 202, and a computer device 203. The computer device 203 may be connected to the area array camera 201 via a wired network or a wireless network, or may be connected to a controller of the turntable 202 via a wired network or a wireless network ( Figure 2 ) connection.

[0061] The area array camera 201, the turntable 202 and the controller of the turntable 202 may be fixedly arranged on the calibration device.

[0062] The area array camera 201 is used to collect image information within a fixed sampling range.

[0063] The turntable 202 is used to carry the wafer, and can support rotation around the rotation center, translation in the horizontal direction, take-off and landing in the vertical direction, etc.

[0064] In one possible approach, the calibration system may further include an adjustment component ( Figure 2The adjustment component may be fixedly disposed on the calibration device to adjust the position of the wafer placed on the turntable 202. The turntable 202 and the adjustment component may constitute a motion mechanism of the calibration device, and the motion control may be realized by the same controller.

[0065] The computer device 203 is used to implement the wafer calibration function.

[0066] Optionally, the computer device 203 may be a functional module integrated into a calibration device equipped with the area array camera 201 and the turntable 202, or may be a device independently provided from the calibration device, which is not limited in the embodiments of the present disclosure.

[0067] It is easy to understand that when the computer device 203 is a functional module integrated into the calibration device, the communication between the computer device 203 and the controllers of the area array camera 201 and the turntable 202 deployed in the calibration device is the communication between the internal modules of the device. In this case, the communication process between the computer device 203 and the controllers of the area array camera 201 and the turntable 202 is the same as the communication process between them when the computer device 203 and the calibration device are independently arranged.

[0068] For ease of understanding, the present application mainly uses the computer device 203 as an example of a functional module integrated into the calibration device for explanation.

[0069] For example, the computer device 203 can control the rotation of the turntable 202, and control the area array camera 201 to collect image information of the sampling points after rotation within the sampling range. In this way, the computer device 203 can obtain the position information of the sampling points after rotation corresponding to the multiple turntable rotation angles, so as to further determine the position deviation information of the center of the wafer to be calibrated relative to the rotation center. Furthermore, the computer device 203 can control the position of the wafer to be calibrated on the calibration turntable 202 of the adjustment component based on the position deviation information of the center of the wafer to be calibrated relative to the rotation center, so that the center of the wafer to be calibrated coincides with the rotation center.

[0070] In terms of hardware implementation, the above-mentioned computer device can be implemented as follows: Figure 3 The computer device 30 shown is implemented. Figure 3 , which is a schematic diagram of the structure of a computer device 30 provided in an embodiment of the present application. The computer device 30 can be used to implement the functions of the above-mentioned computer devices.

[0071] Figure 3 The computer device 30 shown may include: a processor 301 , a memory 302 , a communication interface 303 , and a bus 304 . The processor 301 , the memory 302 , and the communication interface 303 may be connected via the bus 304 .

[0072] The processor 301 is the control center of the computer device 30, and may be a general-purpose central processing unit (CPU) or other general-purpose processors, etc. The general-purpose processor may be a microprocessor or any conventional processor, etc.

[0073] As an example, the processor 301 may include one or more CPUs, such as Figure 3 CPU 0 and CPU 1 are shown in .

[0074] The memory 302 may be a read-only memory (ROM) or other types of static storage devices that can store static information and instructions, a random access memory (RAM) or other types of dynamic storage devices that can store information and instructions, an electrically erasable programmable read-only memory (EEPROM), a disk storage medium or other magnetic storage device, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and can be accessed by a computer, but is not limited thereto.

[0075] In a possible implementation, the memory 302 may exist independently of the processor 301. The memory 302 may be connected to the processor 301 via a bus 304 and used to store data, instructions, or program codes. When the processor 301 calls and executes the instructions or program codes stored in the memory 302, the state detection method provided in the embodiment of the present application can be implemented.

[0076] In another possible implementation, the memory 302 may also be integrated with the processor 301 .

[0077] The communication interface 303 is used for connecting the computer device 30 with other devices through a communication network, which may be Ethernet, a radio access network (RAN), a wireless local area network (WLAN), etc. The communication interface 303 may include a receiving unit for receiving data and a sending unit for sending data.

[0078] The bus 304 may be an industry standard architecture (ISA) bus, a peripheral component interconnect (PCI) bus, or an extended industry standard architecture (EISA) bus. The bus may be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 3 Only one thick line is used in the diagram, but this does not mean that there is only one bus or only one type of bus.

[0079] It should be pointed out that Figure 3 The structure shown in the figure does not constitute a limitation on the computer device 30, except Figure 3 In addition to the components shown, computer device 30 may include more or fewer components than shown, or combine certain components, or arrange the components differently.

[0080] For ease of understanding, the position calibration method provided in the present application is specifically introduced below with reference to the accompanying drawings.

[0081] like Figure 4 FIG. 4 is a flow chart of a position calibration method provided in an embodiment of the present application. The method includes: S401-S403.

[0082] S401: Acquire position information of sampling points after rotation corresponding to a plurality of rotation angles of the turntable.

[0083] The turntable rotation angle is used to represent the angle between the line between the sampling point and the rotation center after rotation and the line between the initial sampling point and the rotation center. The rotation center can be understood as a point on the turntable whose position does not change during the rotation of the turntable.

[0084] The initial sampling point is a point on the arc edge of the wafer to be calibrated that is within the sampling range of the area array camera when the wafer to be calibrated placed on the turntable is in the initial position.

[0085] The sampling point after rotation is a point on the arc edge of the wafer to be calibrated that is within the sampling range when the wafer to be calibrated is in a position after the turntable rotates by an angle as the turntable rotates.

[0086] The arc edge is the outer edge of the wafer to be calibrated except the notch. For example, the arc edge can be the above Figure 1 The outer edge of the wafer other than the flat-angle wafer notch shown in (a) of FIG. 1 . For another example, the arc edge can be the above Figure 1 The outer edge of the wafer other than the V-shaped wafer notch shown in (b) of FIG. Figure 1 (c) shows the outer edge of the wafer excluding the U-shaped wafer notch.

[0087] The sampling range may be a sampling area within the field of view of the area array camera. The area array camera is generally fixedly mounted on the calibration device, and its field of view is generally fixed. Based on this, the sampling range is generally fixed.

[0088] The sampling image captured by the array camera based on the field of view generally includes a section of the arc edge (e.g., arc edge 1) of the outer edge of the wafer to be calibrated. After the computer device obtains the sampling image captured by the array camera, it can identify the point (e.g., point 11) on the arc edge (e.g., arc edge 1) in the sampling image that is within the sampling area, and determine the identified point on the arc edge that is within the sampling area as the sampling point. In this way, the computer device controls the rotation of the turntable through the controller of the turntable, so that the array camera can capture multiple different arc edges (e.g., arc edge 2, arc edge 3, arc edge 4, etc.) of the outer edge of the wafer to be calibrated, and then the computer device can identify and determine multiple sampling points (e.g., point 21 on arc edge 2 that is within the sampling area, point 31 on arc edge 3 that is within the sampling area, point 41 on arc edge 4 that is within the sampling area, etc.) from the multiple sampling images captured by the array camera, so that the computer device can accurately fit the center of the wafer to be calibrated based on multiple sampling points, avoiding the problem of low accuracy that is easily caused by fitting the center of the wafer based on a section of arc edge.

[0089] For ease of distinction, the first sampling point determined by the computer device in the embodiment of the present application is referred to as an initial sampling point, and the subsequent sampling points determined based on multiple rotations are referred to as rotated sampling points.

[0090] Optionally, the sampling area that divides the sampling range may be an area in the shape of a bar frame, or an area in other shapes that facilitates the computer device to identify the sampling points, without limitation.

[0091] Optionally, the position information of the sampling point after rotation may be the pixel coordinates of the sampling point in the image coordinate system after rotation, or may be the second physical coordinates of the sampling point after rotation. The image coordinate system is the pixel coordinate system of the area array camera, and may be a two-dimensional rectangular coordinate system on the image captured by the area array camera, and its origin may be located at the upper left corner of the image captured by the area array camera. The second physical coordinate is the physical coordinate in the second coordinate system. The second coordinate system may be a physical rectangular coordinate system (such as a two-dimensional rectangular coordinate system) on the horizontal plane where the turntable is located, and its origin may be the rotation center of the motion mechanism, and its horizontal axis or vertical axis is not limited.

[0092] In one possible implementation, after the wafer to be calibrated is placed on a turntable, the computer device can control the turntable to rotate around the rotation center to carry the wafer to be calibrated for rotation. In the process of the wafer to be calibrated rotating with the turntable, the wafer to be calibrated and the turntable remain relatively still, and the wafer to be calibrated and the area array camera move relative to each other. In this case, the arc edge of the wafer to be calibrated within the sampling range will change. Then, the computer device can control the area array camera to collect image information within the sampling range. Furthermore, the computer device can obtain the rotated sampling point from the image information within the sampling range collected by the area array camera, and determine the pixel coordinates of the rotated sampling point in the image coordinate system to obtain the position information of the rotated sampling point.

[0093] Alternatively, the computer device may also convert the pixel coordinates of the rotated sampling point in the image coordinate system into the second physical coordinates of the rotated sampling point through the conversion relationship between the image coordinate system and the second coordinate system to obtain the position information of the rotated sampling point.

[0094] In this way, when the computer device controls the turntable to rotate multiple times around the rotation center, the position information of the sampling points after rotation corresponding to the multiple turntable rotation angles can be obtained.

[0095] It should be understood that the rotation angles corresponding to different rotation processes may be the same or different. Furthermore, the multiple rotations may be continuous or discontinuous.

[0096] In the case where the multiple rotations are continuous, that is, the turntable rotates continuously around the rotation center from the position after the last rotation, the turntable rotation angle can be the sum of the multiple rotation angles. For example, in the case where the rotation angle is a fixed angle ∆α, the turntable rotation angle corresponding to the i-th rotation, that is, the turntable rotation angle corresponding to the sampling point after the i-th rotation can be .

[0097] When the multiple rotations are discontinuous, that is, the turntable returns to the initial position after each rotation and then starts to rotate around the rotation center from the initial position, the turntable rotation angle can be the angle of this rotation around the rotation center.

[0098] For example, Figure 5 As shown, it is a schematic diagram of a wafer rotation process provided in an embodiment of the present application. Figure 5 The two-dimensional rectangular coordinate system shown in is the second coordinate system, and its origin is the rotation center of the turntable. The sampling range is Figure 5 The bar range is shown in . Figure 5The figure shows the rotation of the center of the wafer to be calibrated when the turntable carries the wafer to be calibrated and rotates eight times. The initial position is when the center of the wafer to be calibrated is at point A. After the turntable carries the wafer to be calibrated and rotates counterclockwise for the first time, the center of the wafer to be calibrated is at point A1. After the turntable carries the wafer to be calibrated and rotates counterclockwise for the second time, the center of the wafer to be calibrated is at point A2. Until the turntable carries the wafer to be calibrated and rotates counterclockwise for the eighth time, the center of the wafer to be calibrated is at point A8. A, A1, A2, A3, A4, A5, A6, A7, and A8 are on the edge of a circle with the center of rotation as the center. When the center of the wafer to be calibrated is at point A, the area array camera can collect the initial sampling point within the sampling range. When the center of the wafer to be calibrated is between points A1 and A8, the area array camera can collect the rotated sampling points within the sampling range. Figure 5 K, L, and M marked in are sampling points when the center of the wafer to be calibrated is at positions A, A1, and A2.

[0099] S402: Determine the target distance and target angle according to the plurality of turntable rotation angles and the position information of each sampling point after rotation.

[0100] The target distance is used to represent the distance between the center of the wafer to be calibrated and the rotation center. The target angle is used to represent the angle between the line between the center of the wafer to be calibrated and the rotation center and the line between the initial sampling point and the rotation center.

[0101] In one possible implementation, the computer device can determine the sampling point distance between each rotated sampling point and the rotation center based on the second physical coordinate of each rotated sampling point in the second coordinate system. Then, the computer device can determine the first physical coordinate of each rotated sampling point based on multiple turntable rotation angles and the sampling point distance of each rotated sampling point. The first physical coordinate is the physical coordinate in the first coordinate system. The first coordinate system is used to represent a physical rectangular coordinate system (such as a two-dimensional rectangular coordinate system) whose horizontal axis is a straight line from the rotation center to the initial sampling point and whose origin is the rotation center.

[0102] Furthermore, the computer device can perform fitting processing based on the first physical coordinates of each rotated sampling point according to the standard equation of the circle to determine the center coordinates of the center of the wafer to be calibrated in the first coordinate system. Furthermore, the computer device can determine the target distance and target angle based on the center coordinates.

[0103] S403: Determine the position deviation information of the center of the wafer to be calibrated relative to the rotation center according to the target distance and the target angle, and perform calibration based on the position deviation information so that the center of the wafer to be calibrated coincides with the rotation center.

[0104] The position deviation information of the center of the wafer to be calibrated relative to the rotation center may include a deviation in the horizontal axis direction and a deviation in the vertical axis direction. The deviation in the horizontal axis direction is the distance of the center of the wafer to be calibrated in the horizontal axis direction of the second coordinate system relative to the origin of the second coordinate system. The deviation in the vertical axis direction is the distance of the center of the wafer to be calibrated in the vertical axis direction of the second coordinate system relative to the origin of the second coordinate system.

[0105] In one possible manner, when the multiple turntable rotation angles in S401 are obtained by the computer device controlling the turntable to rotate counterclockwise, the computer device can control the turntable to carry the wafer to be calibrated to rotate clockwise to the target angle. Alternatively, when the multiple turntable rotation angles in S401 are obtained by the computer device controlling the turntable to rotate clockwise, the computer device can control the turntable to carry the wafer to be calibrated to rotate counterclockwise to the target angle.

[0106] In this case, the intersection of the line between the center of the wafer to be calibrated and the origin of the second coordinate system and the arc edge of the wafer to be calibrated can be within the sampling range. In addition, the angle between the line between the center of the wafer to be calibrated and the origin of the second coordinate system and the horizontal axis of the second coordinate system can be regarded as the angle for position calibration to adjust the center of the wafer to be calibrated to the origin of the second coordinate system.

[0107] In this way, the computer device can control the area array camera to acquire a sampled image of the intersection and determine the pixel coordinates of the intersection in the image coordinate system. Then, the computer device converts the pixel coordinates of the intersection in the image coordinate system to obtain the second physical coordinates of the intersection in the second coordinate system, so as to further determine the angle between the line connecting the intersection and the rotation center and the horizontal axis of the second coordinate system. Then, the computer device can determine the deviation in the horizontal axis direction and the deviation in the vertical axis direction based on the target distance and the angle between the line connecting the intersection and the rotation center and the horizontal axis of the second coordinate system.

[0108] Furthermore, the computer device can control the motion mechanism to adjust the position of the wafer to be calibrated in the horizontal axis direction of the second coordinate system and the vertical axis direction of the second coordinate system based on the position deviation information, so that the center of the wafer to be calibrated coincides with the rotation center.

[0109] In one embodiment, in the above S401, that is, when the computer device obtains the position information of the sampling points after rotation corresponding to each of the plurality of rotation angles of the turntable, the embodiment of the present application provides an optional implementation method, including: S4011-S4013.

[0110] S4011: Obtain a sampled image of each rotated sampling point within the sampling range.

[0111] S4012: Determine the pixel coordinates of each rotated sampling point in the image coordinate system of the sampled image.

[0112] S4013: Processing the pixel coordinates of each rotated sampling point based on the second conversion relationship to obtain the second physical coordinates of each rotated sampling point.

[0113] The second conversion relationship is used to represent the conversion relationship between the image coordinate system and the second coordinate system.

[0114] Based on this, the computer equipment can conveniently collect the position information of different positions on the arc edge of the wafer to be calibrated placed on the turntable, so as to accurately fit the center of the wafer to be calibrated.

[0115] In one embodiment, in the above S402, that is, when the computer device determines the target distance and target angle based on multiple turntable rotation angles and the position information of each sampling point after rotation, the embodiment of the present application provides an optional implementation method, including: S4021-S4024.

[0116] S4021: Determine the sampling point distance of each rotated sampling point based on the position information of each rotated sampling point.

[0117] The sampling point distance is the distance between the sampling point and the rotation center after rotation.

[0118] The computer device may determine the distance between the rotated sampling point and the origin of the second coordinate system, that is, the distance between the rotated sampling point and the rotation center, based on the second physical coordinate of the rotated sampling point in the second coordinate system.

[0119] S4022: Determine the first physical coordinate of each rotated sampling point in the first coordinate system according to the plurality of turntable rotation angles and the sampling point distances of each rotated sampling point.

[0120] The first coordinate system is used to represent a physical rectangular coordinate system whose horizontal axis is a straight line from the rotation center to the initial sampling point and whose origin is the rotation center. That is, the horizontal axis of the first coordinate system can be a line connecting the rotation center and the initial sampling point, and whose direction is from the rotation center to the initial sampling point.

[0121] The horizontal coordinate of the first physical coordinate is the product of the sampling point distance and the cosine value of the turntable rotation angle. The vertical coordinate of the first physical coordinate is the product of the sampling point distance and the sine value of the turntable rotation angle. That is, the horizontal coordinate of the rotated sampling point in the first coordinate system is the product of the sampling point distance and the cosine value of the turntable rotation angle, and the vertical coordinate is the product of the sampling point distance and the sine value of the turntable rotation angle. In this way, the computer device can determine the first physical coordinate of each rotated sampling point in the first coordinate system based on the sampling point distance of each rotated sampling point and the turntable rotation angle corresponding to each rotated sampling point.

[0122] In one possible manner, when a computer device determines the first physical coordinates of each rotated sampling point in the first coordinate system based on multiple turntable rotation angles and the sampling point distances of each rotated sampling point, the polar coordinates of each rotated sampling point in the polar coordinate system can be determined based on the multiple turntable rotation angles and the sampling point distances of each rotated sampling point. The polar angle of the polar coordinates in the polar coordinate system is the turntable rotation angle corresponding to the rotated sampling point, and the polar diameter is the sampling point distance corresponding to the rotated sampling point. Furthermore, the computer device can process the polar coordinates of each rotated sampling point based on the first conversion relationship to obtain the first physical coordinates of each rotated sampling point. The first conversion relationship is used to represent the conversion relationship between the polar coordinate system and the first coordinate system.

[0123] Based on this, the computer device can efficiently convert the physical coordinates of the rotated sampling point in the second coordinate system into the physical coordinates in the first coordinate system through the polar coordinate system, so as to accurately fit the center of the wafer to be calibrated.

[0124] For example, it is assumed that the second physical coordinate of the i-th rotated sampling point in the second coordinate system is Among them, X i2 Y is the horizontal coordinate of the i-th rotation sampling point in the second coordinate system. i2 is the horizontal coordinate of the i-th rotation sampling point in the second coordinate system.

[0125] Then, when the computer device converts the second physical coordinates of the i-th rotated sampling point in the second coordinate system into polar coordinates in the polar coordinate system, the following expression can be used:

[0126] .

[0127] .

[0128] Among them, α i is the turntable rotation angle corresponding to the sampling point after the i-th rotation.

[0129] Then the polar coordinates of the i-th rotated sampling point in the polar coordinate system are Ppolar_i =(ρ i ,θ i ). Among them, ρ i θ is the polar diameter of the i-th rotation sampling point in the polar coordinate system. i is the polar angle of the i-th rotational sampling point in the polar coordinate system.

[0130] Furthermore, the computer device may convert the polar coordinates of the i-th rotated sampling point in the polar coordinate system into the first physical coordinates in the first coordinate system based on the first conversion relationship. The first conversion relationship may be expressed as follows:

[0131] .

[0132] in, is the first physical coordinate of the i-th sampling point in the first coordinate system after rotation.

[0133] For example, Figure 6 , which is a schematic diagram of a polar coordinate system provided in an embodiment of the present application. Figure 6 The polar angle of the polar coordinate system shown in is the rotation angle of the turntable corresponding to the sampling point after rotation, and the polar diameter is the distance between the sampling points corresponding to the sampling points after rotation. Figure 6 Shown in is the position of the initial sampling point A and the sampling points B, C, D, E, F, G, H, and I in the polar coordinate system after rotation.

[0134] Combination Figure 6 ,like Figure 7 , which is a schematic diagram of a first coordinate system provided in an embodiment of the present application. Figure 7 The origin of the first coordinate system shown in is the rotation center O, and the horizontal axis is the straight line from the rotation center to the initial sampling point. Figure 7 : shows the positions of the initial sampling point A and the sampling points B, C, D, E, F, G, H, and I after rotation in the first coordinate system. It can be seen that the shape of the wafer to be calibrated relative to the rotation center of the turntable is circular.

[0135] S4023: Perform fitting processing based on the first physical coordinates of each rotated sampling point to determine the center coordinates of the center of the wafer to be calibrated in the first coordinate system.

[0136] In one possible approach, the computer device can use iterative reweighted least squares (IRLS) to fit the first physical coordinates of each rotated sampling point according to the standard equation of the circle and a weight function such as Huber or Tukey, so as to determine the coordinates of the center of the wafer to be calibrated in the first coordinate system.

[0137] The standard equation of a circle is (Xa) 2 +(Yb) 2 =R 2 . Wherein, X is the horizontal coordinate of the center of the wafer to be calibrated. Y is the vertical coordinate of the center of the wafer to be calibrated. a is the horizontal coordinate of the first physical coordinate of the initial sampling point or the sampling point after rotation. b is the vertical coordinate of the first physical coordinate of the initial sampling point or the sampling point after rotation. R is the radius of the wafer to be calibrated.

[0138] For example, in combination Figure 7 ,like Figure 8 The figure is a schematic diagram of a circle fitting result provided in an embodiment of the present application. The computer device is based on Figure 7 After fitting A, B, C, D, E, F, G, H, and I shown in Figure 8 The center of the circle is O'. It can be seen that the shape of the wafer to be calibrated relative to the rotation center of the turntable is circular.

[0139] S4024: Determine the target distance and target angle according to the coordinates of the center of the circle.

[0140] The computer device can determine the distance between the center of the wafer to be calibrated and the origin of the first coordinate system based on the center coordinates of the center of the wafer to be calibrated in the first coordinate system, and obtain the target distance between the center of the wafer to be calibrated and the rotation center. In addition, the computer device can determine the angle between the line connecting the center of the wafer to be calibrated and the origin of the first coordinate system and the horizontal axis of the first coordinate system based on the center coordinates of the center of the wafer to be calibrated in the first coordinate system, and obtain the angle between the line connecting the center of the wafer to be calibrated and the rotation center and the line connecting the initial sampling point and the rotation center.

[0141] Based on this, the present application can accurately determine the distance between the center of the wafer to be calibrated and the rotation center, as well as the angle between the line connecting the center of the wafer to be calibrated and the rotation center and the line connecting the initial sampling point and the rotation center, so as to accurately determine the displacement vector required to adjust the center of the wafer to be calibrated to coincide with the rotation center.

[0142] In one embodiment, in the above S403, that is, when the computer device determines the position deviation information of the center of the wafer to be calibrated relative to the rotation center based on the target distance and the target angle, the embodiment of the present application provides an optional implementation method, including: S4031-S4033.

[0143] S4031: Obtain the second physical coordinates of the target sampling point in the second coordinate system.

[0144] The target sampling point is the point on the arc edge of the wafer to be calibrated that is within the sampling range of the area array camera when the wafer to be calibrated is at the target position. The target position is the position of the wafer to be calibrated after the turntable rotates the target angle from the initial position. The second coordinate system is used to represent a physical rectangular coordinate system with the origin as the rotation center. In other words, the target sampling point, the center of the wafer to be calibrated, and the rotation center are on the same straight line.

[0145] In one possible implementation, when the angle (i.e., the target angle) between the line connecting the center of the circle of the wafer to be calibrated and the rotation center and the line connecting the initial sampling point and the rotation center is determined, the computer device can control the turntable to rotate the target angle so that the wafer to be calibrated rotates with the turntable at the target angle to be in the target position. In this case, the computer device can control the area array camera to capture a sampled image of the target sampling point. In this way, the computer device can obtain the pixel coordinates of the target sampling point in the image coordinate system from the sampled image of the target sampling point, and further convert it to obtain the second physical coordinates of the target sampling point in the second coordinate system.

[0146] Optionally, when the plurality of turntable rotation angles are obtained by the computer device controlling the turntable to rotate counterclockwise, the computer device may control the turntable to carry the wafer to be calibrated to rotate clockwise by a target angle. Alternatively, when the plurality of turntable rotation angles are obtained by the computer device controlling the turntable to rotate clockwise, the computer device may control the turntable to carry the wafer to be calibrated to rotate counterclockwise by a target angle.

[0147] S4032: Determine a calibration angle based on the second physical coordinate of the target sampling point.

[0148] The calibration angle is the angle between the line between the target sampling point and the rotation center and the horizontal axis of the second coordinate system.

[0149] The computer device can determine, based on the second physical coordinates of the target sampling point, the angle between a line connecting the point indicated by the second physical coordinates and the origin of the second coordinate system and the horizontal axis of the second coordinate system, and obtain the angle between a line connecting the target sampling point and the rotation center and the horizontal axis of the second coordinate system.

[0150] S4033: Determine the deviation of the center of the wafer to be calibrated relative to the rotation center in the horizontal axis direction and the deviation of the center of the wafer to be calibrated relative to the rotation center in the vertical axis direction according to the target distance and the calibration angle.

[0151] The deviation in the horizontal axis direction is the product of the target distance and the cosine value of the calibration angle, and the deviation in the vertical axis direction is the product of the target distance and the sine value of the calibration angle.

[0152] For example, in combination Figure 8 ,like Fig. 9 , which is a schematic diagram of another circle fitting result provided in an embodiment of the present application. Fig. 9 The figure shows the situation when the rotation center of the turntable, the center of the wafer to be calibrated (i.e. the wafer center) and the peak point (or trough point) are collinear. The peak point is the point on the arc edge of the wafer to be calibrated that is farthest from the rotation center of the turntable. The trough point is the point on the arc edge of the wafer to be calibrated that is closest to the rotation center of the turntable. The target angle can be Fig. 9 The peak angle φ or the trough angle φ′ between the line connecting the center of the wafer to be calibrated and the rotation center (ie, the origin of the first coordinate system) and the horizontal axis of the first coordinate system is shown in FIG.

[0153] The computer device can control the turntable to carry the wafer to be calibrated to rotate from the initial position to the target angle and then trigger the area array camera to shoot, so as to obtain the pixel coordinates P of the target sampling point on the arc edge of the wafer to be calibrated in the image coordinate system. img_Peak , and obtain the second physical coordinate of the target sampling point in the second coordinate system through the second transformation relationship Then, the computer device can determine the distance from the origin of the second coordinate system to the target sampling point P w_Peak The angle β between the line connecting the two coordinates and the horizontal axis of the second coordinate system. The expression for determining β by the computer device is as follows:

[0154] .

[0155] The computer device can determine the position deviation information of the center of the wafer to be calibrated relative to the rotation center based on the target distance ∆L from the rotation center of the turntable to the center of the wafer to be calibrated and the angle β:

[0156] .

[0157] Where ∆x is the deviation in the horizontal direction and ∆y is the deviation in the horizontal direction.

[0158] Based on this, the computer device can accurately determine the displacement vector required to adjust the center of the wafer to be calibrated to coincide with the rotation center, thereby accurately controlling the motion mechanism to adjust the position of the wafer to be calibrated.

[0159] In one embodiment, after the above S403, that is, after the center of the wafer to be calibrated coincides with the rotation center, the position calibration method provided in the embodiment of the present application further includes: S404-S406.

[0160] S404: Acquire a target sampling image.

[0161] The target sampling image is an image captured by the area array camera when the wafer to be calibrated rotates with the turntable, and the target sampling image includes the notch of the wafer to be calibrated.

[0162] In one possible implementation, after the center of the wafer to be calibrated coincides with the rotation center, the computer device can control the turntable to rotate multiple times in a counterclockwise or clockwise direction at a specific angle, so that the wafer to be calibrated rotates multiple times with the turntable. In this case, the computer device can control the area array camera to capture a sample image after each rotation, and process the captured sample image to determine whether there is a gap of the wafer to be calibrated in the captured sample image.

[0163] If the notch of the wafer to be calibrated does not exist in the sampled image, the computer device can control the turntable to rotate for the next time. If the notch of the wafer to be calibrated exists in the sampled image, the computer device can determine that the sampled image with the notch of the wafer to be calibrated is the target sampled image. In this way, the computer device can collect the target sampled image through the area array camera while the wafer to be calibrated rotates with the turntable.

[0164] Optionally, the specific angle can be flexibly set according to the notch size of the wafer to be calibrated without limitation.

[0165] Optionally, when the computer device processes the captured sampling image, it can input the captured sampling image into a pre-trained machine learning model for recognition processing, or it can match the captured sampling image with a preset gap template, or it can process it in other ways without limitation.

[0166] S405: Determine the position information of the target position point in the notch of the wafer to be calibrated.

[0167] Optionally, the target position point may be the center point or vertex of the notch of the wafer to be calibrated. For example, the target position point may be Figure 1 The center point of the V-shaped mouth shown in (b) in FIG. Another example is that the target position point can be Figure 1 The V-shaped opening shown in (b) is concave inward. For another example, the target position point can be Figure 1 The center point of the U-shaped mouth shown in (c).

[0168] In one possible manner, the computer device may match the target sampling image with a notch template marked with the target position point to identify the target position point in the notch of the wafer to be calibrated in the target sampling image.

[0169] Alternatively, the computer device may also perform vertex detection processing on the target sampling image to identify the target position point in the notch of the wafer to be calibrated in the target sampling image.

[0170] Alternatively, the computer device may first perform matching processing on the notch of the wafer to be calibrated in the target sampling image, then perform position correction processing to reduce the impact of wafer position change, and then perform vertex detection processing on the target sampling image to identify the target position point in the notch of the wafer to be calibrated in the target sampling image. The embodiments of the present application are not limited to this.

[0171] Furthermore, the computer device may determine the pixel coordinates of the target location point in the image coordinate system, and further convert them to obtain the second physical coordinates of the target location point in the second coordinate system.

[0172] S406: Based on the position information, determine the angle deviation information of the target position point relative to the preset position point, and perform calibration based on the angle deviation information to make the target position point coincide with the preset position point.

[0173] The angle deviation information includes the angle between the line between the target position point and the rotation center and the line between the preset position point and the rotation center. The preset position point can be a position point on the longitudinal axis of the second coordinate system, or a position point on the transverse axis of the second coordinate system, or other position points in the second coordinate system. The distance between the preset position point and the origin of the second coordinate system is the same as the distance between the target position point in the notch and the center of the wafer to be calibrated.

[0174] In one possible implementation, the computer device can determine the angle deviation information of the target position point relative to the preset position point based on the second physical coordinate of the target position point in the second coordinate system and the second physical coordinate of the preset position point in the second coordinate system. Furthermore, the computer device can control the turntable to carry the wafer to be calibrated to rotate based on the angle deviation information so that the target position point coincides with the preset position point.

[0175] Based on this, the computer equipment can accurately identify the notch of the wafer to be calibrated, and by adjusting the target position point in the notch of the wafer to be calibrated to coincide with the preset position point, accurately adjust the notch direction of the wafer to be calibrated to the required direction, so as to facilitate processing of the wafer to be calibrated.

[0176] For example, assume that the pixel coordinates of the target position point in the image coordinate system are P img_Notch , and the preset position point is a position point on the vertical axis of the second coordinate system. Then the computer device can convert the second physical coordinate of the target position point in the second coordinate system by the second conversion relationship as P world_Notch =(x w_Notch ,y w_Notch ) T Then, the computer device can determine that the angle γ between the line between the target position point and the rotation center and the line between the preset position point and the rotation center is:

[0177] .

[0178] In one embodiment, when the arrangement between the area array camera and the motion mechanism is "eye outside the hand", when the computer device performs hand-eye calibration, that is, calibrates the conversion relationship between the image coordinate system of the area array camera and the second coordinate system of the motion mechanism, the position calibration method provided in the embodiment of the present application also includes: S501-S505.

[0179] S501: Acquire multiple coordinate pairs of calibration points.

[0180] The calibration point is a point on a calibration object placed on the turntable. The calibration object may be a reference object or a calibration plate that supports rotation with the turntable. The reference object may be a wafer provided with calibration points such as circular marking points or square marking points. The calibration plate may be a flat plate provided with calibration points such as circular marking points or square marking points.

[0181] The coordinate pair of the calibration point may include the pixel coordinates of the calibration point in the image coordinate system and the physical coordinates of the calibration point in the initial coordinate system. Different coordinate pairs in the plurality of coordinate pairs may correspond to different positions of the calibration point within the sampling range. That is, different coordinate pairs may be collected when the calibration point is at different positions within the sampling range.

[0182] Optionally, the initial coordinate system may be a two-dimensional rectangular coordinate system on the horizontal plane where the turntable is located, and the origin thereof may be any position on the horizontal plane where the turntable is located that is convenient for the staff to measure.

[0183] In one possible implementation, the computer device can control the turntable to translate multiple times, so that the calibration object translates multiple times with the turntable within the sampling range. In addition, after each control of the turntable to translate, the computer device can control the area array camera to capture a sampled image, and extract the pixel coordinates of the calibration points on the calibration object in the sampled image in the image coordinate system. At the same time, the staff can determine the physical coordinates of the calibration points on the calibration object in the initial coordinate system, and set the physical coordinates of the calibration points in the initial coordinate system and the pixel coordinates of the calibration points in the image coordinate system in the computer device. In this way, the computer device can obtain multiple coordinate pairs of the calibration points.

[0184] S502: Determine an initial transformation relationship based on the coordinate pairs corresponding to the plurality of calibration points.

[0185] The initial transformation relationship is used to represent the transformation relationship between the image coordinate system and the initial coordinate system. The initial transformation relationship can be a transformation matrix, which can also be called a hand-eye calibration matrix.

[0186] When coordinate pairs corresponding to multiple calibration points are obtained, the computer device can determine the conversion relationship between the image coordinate system and the initial coordinate system through N-point calibration such as 9-point calibration or 12-point calibration.

[0187] S503: Obtain pixel coordinates corresponding to each of the multiple calibration angles.

[0188] The pixel coordinates corresponding to the calibration angle are the pixel coordinates when the calibration point is at the position after the turntable rotates by the calibration angle.

[0189] In one possible implementation, the computer device can control the turntable to carry the calibration object to rotate continuously multiple times in the counterclockwise direction or clockwise direction within the sampling range, and record the angle of each rotation. In addition, the computer device can control the area array camera to collect each sampling image before the start of rotation and at the end of each rotation, and obtain sampling images corresponding to multiple calibration angles.

[0190] In this way, the computer device can record the calibration angle corresponding to each rotation based on the angle of each rotation. For example, assume that the turntable rotates 15 degrees each time and the number of rotations is 2. Then the multiple calibration angles are 0 degrees before the turntable starts to rotate within the sampling range, 15 degrees when the turntable rotates once within the sampling range, and 30 degrees when the turntable rotates twice within the sampling range. That is, the computer device can control the area array camera to collect the sampling image when the calibration point is at the position after the turntable rotates 0 degrees, the sampling image when the calibration point is at the position after the turntable rotates 15 degrees, and the sampling image when the calibration point is at the position after the turntable rotates 30 degrees, and obtain the sampling images corresponding to the multiple calibration angles.

[0191] Furthermore, the computer device may determine the pixel coordinates of the calibration point in each sampled image to obtain the pixel coordinates corresponding to each of the multiple calibration angles.

[0192] It should be understood that the above numbering does not limit the execution order between S501 and S503. For example, S501 and S503 can be executed at the same time. For another example, S501 can be executed before S503. For another example, S503 can be executed before S501.

[0193] S504: Determine the pixel coordinates of the rotation center in the image coordinate system based on the pixel coordinates corresponding to each of the multiple calibration angles.

[0194] It should be understood that when the turntable rotates with the calibration object, the calibration point on the calibration object rotates with the rotation center as the center of the circle.

[0195] In this case, for the area array camera, the calibration point is on a circle with the rotation center as the center in the image coordinate system. The computer device can determine the pixel coordinates corresponding to each calibration angle as the coordinates of the point on the circle with the rotation center as the center. Moreover, the computer device can determine the center angle between the points on these circles based on each calibration angle. Furthermore, the computer device can determine the pixel coordinates of the center of the circle in the image coordinate system, that is, the pixel coordinates of the rotation center in the image coordinate system.

[0196] S505: Determine a second transformation relationship based on the initial transformation relationship and the pixel coordinates of the rotation center.

[0197] The computer device can process the translation component of the initial transformation relationship based on the initial transformation relationship and the pixel coordinates of the rotation center in the image coordinate system to obtain a second transformation relationship. In this way, the origin of the initial coordinate system is replaced by the rotation center and is converted into a second coordinate system with the rotation center as the origin. In other words, the second transformation relationship is a transformation relationship between the image coordinate system and the second coordinate system with the rotation center as the origin.

[0198] For example, assuming that the initial conversion relationship is , the pixel coordinates of the rotation center in the image coordinate system are , then the expression for zeroing the coordinates of the rotation center is:

[0199] .

[0200] The second transformation relationship obtained after processing the translation component of the initial transformation relationship is:

[0201] .

[0202] Based on this, the computer equipment can accurately calibrate the conversion relationship between the pixel coordinate system of the area array camera and the physical coordinate system with the turntable rotation center as the origin, so as to accurately collect the position information of different points on the arc edge of the wafer to be calibrated through the area array camera.

[0203] It should be noted that when the setting mode between the area array camera and the motion mechanism is "eye in hand", when the computer equipment performs hand-eye calibration, it can control the turntable carrying the area array camera to translate and rotate, so that the area array camera and the calibration object move relative to each other, thereby realizing hand-eye calibration based on a processing method similar to the above process, which will not be repeated here.

[0204] It should be understood that when the displacement axis of the calibration device is only the X-axis or the Y-axis, the computer device can also implement single-axis hand-eye calibration based on the above process.

[0205] In one embodiment, Fig.10 , which is a flow chart of another position calibration method provided in an embodiment of the present application. Fig.10 The position calibration method shown may include: S601 - S612 .

[0206] S601: Acquire sampling images corresponding to multiple turntable rotation angles.

[0207] In one possible implementation, the computer device can control the turntable to rotate multiple times at a fixed angle, and after each rotation, control the area array camera to shoot the arc edge of the wafer to be calibrated within the sampling range to obtain a sampling image. In this way, the computer device can obtain sampling images corresponding to multiple turntable rotation angles.

[0208] S602: Determine the pixel coordinates of the rotated sampling points in each sampled image.

[0209] In one implementation, the computer device may use an edge point extraction algorithm to extract pixel coordinates of edge points on the outer edge of the wafer to be calibrated within a sampling range.

[0210] S603: Processing the pixel coordinates of each rotated sampling point based on the second conversion relationship to obtain the second physical coordinates of each rotated sampling point.

[0211] In one achievable manner, the computer device may convert the pixel coordinates of each rotated sampling point into second physical coordinates in the second coordinate system based on the second conversion relationship.

[0212] S604: Determine the polar coordinates of each rotated sampling point based on each turntable rotation angle and the second physical coordinates of each rotated sampling point.

[0213] S605: Processing the polar coordinates of each rotated sampling point based on the first conversion relationship to obtain a first physical coordinate of each rotated sampling point in the first coordinate system.

[0214] S606: Perform fitting processing based on the first physical coordinates of each rotated sampling point to obtain a target distance and a target angle.

[0215] S607: Obtain the second physical coordinates of the target sampling point in the second coordinate system.

[0216] The computer device can control the turntable to rotate from the initial position to the target angle, so that the wafer to be calibrated is at the target position after the turntable rotates from the initial position to the target angle. In this case, the computer device can control the area array camera to capture a sampling image, and obtain the pixel coordinates of the target sampling point in the image coordinate system from the captured sampling image, so as to further convert and obtain the second physical coordinates of the target sampling point in the second coordinate system.

[0217] S608: Determine position deviation information according to the target distance and the second physical coordinates of the target sampling point.

[0218] The computer device may determine a calibration angle based on the second physical coordinates of the target sampling point, and determine a deviation in the horizontal axis direction and a deviation in the vertical axis direction according to the target distance and the calibration angle.

[0219] S609: Calibrate based on the position deviation information.

[0220] The computer device can control the motion mechanism to correct the coordinate deviation based on the position deviation information, thereby achieving accurate calibration of the center of the wafer to be calibrated.

[0221] S610: Determine the second physical coordinates of the target location point in the second coordinate system.

[0222] S611: Determine angle deviation information of the target position point relative to the preset position point based on the second physical coordinates of the target position point.

[0223] S612: Perform calibration based on the angle deviation information.

[0224] The computer device can control the motion mechanism to correct the angle deviation based on the angle deviation information, thereby achieving accurate calibration of the notch orientation of the wafer to be calibrated.

[0225] The position calibration method proposed in the above embodiment of the present application can overcome the pain point of large fluctuations in the results when fitting a circle with the outer edge contour of the wafer in the related art, and can support the realization of higher calibration accuracy when sampling a smaller number of sampling points. It has higher production efficiency in actual application, and the deployment cost of the area array camera is low, and it has strong applicability. In addition, multiple test results show that the calibration accuracy can be improved by an order of magnitude by using the position calibration method proposed in the above embodiment of the present application when the hardware equipment such as the area array camera is the same.

[0226] It should be understood that the position calibration method proposed in the above embodiment of the present application can be used for Figure 1 The wafers with various types of notches shown in FIG. can be calibrated. When the notch types are different, different templates can be flexibly set for matching.

[0227] The above mainly introduces the scheme of the embodiment of the present application from the perspective of the method. It is understandable that in order to realize the above functions, the computer device includes at least one of the hardware structure and software modules corresponding to the execution of each function. It should be easily appreciated by those skilled in the art that, in combination with the units and algorithm steps of each example described in the embodiments disclosed herein, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed in the form of hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present application.

[0228] The embodiment of the present application can divide the computer device into functional units according to the above method example. For example, each functional unit can be divided according to each function, or two or more functions can be integrated into one processing unit. The above integrated unit can be implemented in the form of hardware or in the form of software functional units. It should be noted that the division of units in the embodiment of the present application is schematic and is only a logical function division. There may be other division methods in actual implementation.

[0229] For example, Fig.11 , which is a schematic diagram of the structure of a position calibration device provided in an embodiment of the present application. The position calibration device 40 can be used to execute the method involved in the above embodiment. The position calibration device 40 includes: an acquisition unit 701 and a processing unit 702.

[0230] The acquisition unit 701 is used to obtain the position information of the sampling points after rotation corresponding to each of the plurality of turntable rotation angles. The turntable rotation angle is used to represent the angle between the line between the sampling point after rotation and the rotation center of the turntable and the line between the initial sampling point and the rotation center. The initial sampling point is a point on the arc edge of the wafer to be calibrated placed on the turntable that is within the sampling range of the area array camera when the wafer to be calibrated is in the initial position. The sampling point after rotation is a point on the arc edge that is within the sampling range when the wafer to be calibrated is in the position after the turntable rotates the turntable by the rotation angle.

[0231] The processing unit 702 is used to determine the target distance and the target angle according to the plurality of turntable rotation angles and the position information of each sampling point after rotation. The target distance is used to represent the distance between the center of the wafer to be calibrated and the rotation center. The target angle is used to represent the angle between the line between the center of the wafer to be calibrated and the rotation center and the line between the initial sampling point and the rotation center.

[0232] The processing unit 702 is further used to determine the position deviation information of the center of the wafer to be calibrated relative to the rotation center according to the target distance and the target angle, so as to perform calibration based on the position deviation information so that the center of the wafer to be calibrated coincides with the rotation center.

[0233] In a possible embodiment, the processing unit 702 is specifically used to: determine the sampling point distance of each sampling point after rotation based on the position information of each sampling point after rotation. The sampling point distance is the distance between the sampling point after rotation and the rotation center. According to multiple turntable rotation angles and the sampling point distances of each sampling point after rotation, determine the first physical coordinates of each sampling point after rotation in the first coordinate system. The first coordinate system is used to represent a physical rectangular coordinate system whose horizontal axis is a straight line from the rotation center to the initial sampling point and whose origin is the rotation center. The horizontal coordinate of the first physical coordinate is the product of the sampling point distance and the cosine value of the turntable rotation angle. The vertical coordinate of the first physical coordinate is the product of the sampling point distance and the sine value of the turntable rotation angle. Fitting processing is performed based on the first physical coordinates of each sampling point after rotation to determine the center coordinates of the center of the wafer to be calibrated in the first coordinate system. According to the center coordinates, the target distance and target angle are determined.

[0234] In a possible embodiment, the processing unit 702 is specifically used to: determine the polar coordinates of each rotated sampling point in the polar coordinate system according to multiple turntable rotation angles and the sampling point distances of each rotated sampling point. The polar angle of the polar coordinates is the turntable rotation angle. The polar diameter of the polar coordinates is the sampling point distance. The polar coordinates of each rotated sampling point are processed based on the first conversion relationship to obtain the first physical coordinates of each rotated sampling point. The first conversion relationship is used to represent the conversion relationship between the polar coordinate system and the first coordinate system.

[0235] In a possible embodiment, the position deviation information includes a deviation in the horizontal axis direction and a deviation in the vertical axis direction. The processing unit 702 is specifically used to: obtain the second physical coordinate of the target sampling point in the second coordinate system. The target sampling point is a point on the arc edge that is located within the sampling range when the wafer to be calibrated is at the target position. The target position is the position of the wafer to be calibrated after the turntable rotates from the initial position to the target angle. The second coordinate system is used to represent a physical rectangular coordinate system with the origin as the rotation center. Based on the second physical coordinate of the target sampling point, the calibration angle is determined. The calibration angle is the angle between the line between the target sampling point and the rotation center and the horizontal axis of the second coordinate system. According to the target distance and the calibration angle, determine the deviation of the center of the wafer to be calibrated relative to the rotation center in the horizontal axis direction, and the deviation of the center of the wafer to be calibrated relative to the rotation center in the vertical axis direction. The deviation in the horizontal axis direction is the product of the target distance and the cosine value of the calibration angle. The deviation in the vertical axis direction is the product of the target distance and the sine value of the calibration angle.

[0236] In a possible embodiment, the acquisition unit 701 is further configured to acquire a target sampling image, which is an image captured by the area array camera when the wafer to be calibrated rotates with the turntable, and the target sampling image includes the notch of the wafer to be calibrated.

[0237] The processing unit 702 is further configured to determine the position information of the target position point in the notch of the wafer to be calibrated.

[0238] The processing unit 702 is further configured to determine, based on the position information, the angle deviation information of the target position point relative to the preset position point, so as to calibrate based on the angle deviation information so that the target position point coincides with the preset position point. The angle deviation information includes the angle between the line between the target position point and the rotation center and the line between the preset position point and the rotation center.

[0239] In a possible embodiment, the position information is the second physical coordinates of the rotated sampling point in the second coordinate system. The coordinate origin of the second coordinate system is the rotation center. The acquisition unit 701 is specifically used to: acquire a sampled image of each rotated sampling point within the sampling range. Determine the pixel coordinates of each rotated sampling point in the image coordinate system of the sampled image. Process the pixel coordinates of each rotated sampling point based on the second conversion relationship to obtain the second physical coordinates of each rotated sampling point. The second conversion relationship is used to represent the conversion relationship between the image coordinate system and the second coordinate system.

[0240] In a possible embodiment, the acquisition unit 701 is further used to acquire multiple coordinate pairs of calibration points and pixel coordinates corresponding to multiple calibration angles. The calibration points are points on the calibration object placed on the turntable. The coordinate pairs include the pixel coordinates of the calibration points in the image coordinate system and the physical coordinates of the calibration points in the initial coordinate system. Different coordinate pairs correspond to different positions of the calibration points within the sampling range. The pixel coordinates corresponding to the calibration angle are the pixel coordinates of the calibration points when they are in the position after the turntable rotates the calibration angle.

[0241] The processing unit 702 is further configured to determine an initial transformation relationship based on the coordinate pairs corresponding to the plurality of calibration points. The initial transformation relationship is used to represent the transformation relationship between the image coordinate system and the initial coordinate system.

[0242] The processing unit 702 is further configured to determine the pixel coordinates of the rotation center in the image coordinate system based on the pixel coordinates corresponding to each of the multiple calibration angles.

[0243] The processing unit 702 is further configured to determine a second transformation relationship based on the initial transformation relationship and the pixel coordinates of the rotation center.

[0244] For the specific description of the above optional manner, please refer to the above method embodiment, which will not be repeated here. In addition, the explanation of any of the above computer devices and the description of the beneficial effects can refer to the above corresponding method embodiment, which will not be repeated here.

[0245] As an example, combining Figure 3 , the functions partially or completely implemented by the acquisition unit 701 and the processing unit 702 in the position calibration device 40 can be Figure 3 Processor 301 in the Figure 3 The program code in the memory 302 is implemented.

[0246] An embodiment of the present application further provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed on a computer, the computer is enabled to execute any of the methods executed by the computer devices provided above.

[0247] For the explanation of the relevant contents and description of the beneficial effects in any of the above-mentioned computer-readable storage media, reference may be made to the above-mentioned corresponding embodiments, which will not be repeated here.

[0248] The embodiment of the present application also provides a computer program product including instructions, when the instructions are run on a computer, the computer executes any one of the methods in the above embodiments. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on the computer, the process or function according to the embodiment of the present application is generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions may be transmitted from one website site, computer, server or data center to another website site, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium may be any available medium that can be accessed by the computer or a data storage device such as a server or data center that includes one or more servers that can be integrated with the medium. The available medium may be a magnetic medium (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), etc.

[0249] It should be noted that the above-mentioned devices for storing computer instructions or computer programs provided in the embodiments of the present application, such as but not limited to the above-mentioned memories, computer-readable storage media, etc., are all non-transitory.

[0250] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using a software program, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function according to the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from a website site, a computer, a server or a data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (digital subscriber line, DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode to another website site, computer, server or data center. The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server, a data center, etc. that contains one or more servers that can be integrated with the medium. The available medium can be a magnetic medium (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), etc.

[0251] Although the present application is described herein in conjunction with various embodiments, in the process of implementing the claimed application, those skilled in the art may understand and implement other changes to the disclosed embodiments by viewing the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other components or steps, and "one" or "an" does not exclude multiple situations. A single processor or other unit may implement several functions listed in a claim. Certain measures are recorded in different dependent claims, but this does not mean that these measures cannot be combined to produce good results.

[0252] Although the present application has been described in conjunction with specific features and embodiments thereof, it is obvious that various modifications and combinations may be made thereto without departing from the spirit and scope of the present application. Accordingly, this specification and the drawings are merely exemplary illustrations of the present application as defined by the appended claims, and are deemed to have covered any and all modifications, variations, combinations or equivalents within the scope of the present application. Obviously, those skilled in the art may make various modifications and variations to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A position calibration method, characterized in that: include: Obtain position information of the sampling points after rotation corresponding to each of the rotation angles of the turntable; The turntable rotation angle is used to represent the angle between the line between the sampling point after rotation and the rotation center of the turntable and the line between the initial sampling point and the rotation center; the initial sampling point is a point on the arc edge of the wafer to be calibrated placed on the turntable that is within the sampling range of the area array camera when the wafer to be calibrated is in the initial position; The post-rotation sampling point is a point on the arc edge that is within the sampling range when the wafer to be calibrated is in a position after the turntable rotates by the turntable rotation angle; According to the plurality of turntable rotation angles and the position information of each sampling point after rotation, a target distance and a target angle are determined; the target distance is used to represent the distance between the center of the wafer to be calibrated and the rotation center; the target angle is used to represent the angle between the line between the center of the wafer to be calibrated and the rotation center and the line between the initial sampling point and the rotation center; Determine, according to the target distance and the target angle, position deviation information of the center of the wafer to be calibrated relative to the rotation center, and perform calibration based on the position deviation information so that the center of the wafer to be calibrated coincides with the rotation center; Acquire a target sampling image; the target sampling image is an image captured by the area array camera during the process of the wafer to be calibrated rotating with the turntable, and the target sampling image includes a notch of the wafer to be calibrated; Determining position information of a target position point in the notch of the wafer to be calibrated; Based on the position information, determine the angle deviation information of the target position point relative to the preset position point, and perform calibration based on the angle deviation information so that the target position point coincides with the preset position point; The angle deviation information includes an angle between a line between the target position point and the rotation center and a line between the preset position point and the rotation center.

2. The position calibration method according to claim 1, characterized in that: Determining the target distance and the target angle according to the plurality of turntable rotation angles and the position information of each sampling point after the rotation includes: Based on the position information of each of the rotated sampling points, determining the sampling point distance of each of the rotated sampling points; the sampling point distance is the distance between the rotated sampling point and the rotation center; Determine, according to the plurality of turntable rotation angles and the sampling point distances of the sampling points after rotation, the first physical coordinates of each of the sampling points after rotation in the first coordinate system; the first coordinate system is used to represent a physical rectangular coordinate system whose horizontal axis is a straight line from the rotation center to the initial sampling point and whose origin is the rotation center; the horizontal coordinate of the first physical coordinate is the product of the sampling point distance and the cosine value of the turntable rotation angle; the vertical coordinate of the first physical coordinate is the product of the sampling point distance and the sine value of the turntable rotation angle; Perform fitting processing based on the first physical coordinates of each of the rotated sampling points to determine the center coordinates of the center of the wafer to be calibrated in the first coordinate system; The target distance and the target angle are determined according to the circle center coordinates.

3. The position calibration method according to claim 2, characterized in that: Determining the first physical coordinates of each of the rotated sampling points in the first coordinate system according to the plurality of turntable rotation angles and the sampling point distances of each of the rotated sampling points comprises: Determine the polar coordinates of each of the rotated sampling points in a polar coordinate system according to the plurality of turntable rotation angles and the sampling point distances of each of the rotated sampling points; the polar angle of the polar coordinates is the turntable rotation angle; the polar diameter of the polar coordinates is the sampling point distance; The polar coordinates of each of the rotated sampling points are processed based on a first conversion relationship to obtain a first physical coordinate of each of the rotated sampling points; the first conversion relationship is used to represent a conversion relationship between the polar coordinate system and the first coordinate system.

4. The position calibration method according to claim 1, characterized in that: The position deviation information includes a deviation in the horizontal axis direction and a deviation in the vertical axis direction; the determining, based on the target distance and the target angle, the position deviation information of the center of the wafer to be calibrated relative to the rotation center includes: Acquire the second physical coordinates of the target sampling point in the second coordinate system; the target sampling point is a point on the arc edge within the sampling range when the wafer to be calibrated is at the target position; the target position is the position of the wafer to be calibrated after the turntable rotates from the initial position to the target angle; the second coordinate system is used to represent a physical rectangular coordinate system with the origin as the rotation center; Based on the second physical coordinate of the target sampling point, determining a calibration angle; the calibration angle is the angle between a line between the target sampling point and the rotation center and a horizontal axis of the second coordinate system; According to the target distance and the calibration angle, determine the deviation of the center of the wafer to be calibrated relative to the rotation center in the horizontal axis direction, and the deviation of the center of the wafer to be calibrated relative to the rotation center in the vertical axis direction; the deviation in the horizontal axis direction is the product of the target distance and the cosine value of the calibration angle; the deviation in the vertical axis direction is the product of the target distance and the sine value of the calibration angle.

5. The position calibration method according to claim 1, characterized in that: The position information is the second physical coordinate of the rotated sampling point in the second coordinate system; the origin of the second coordinate system is the rotation center; The step of obtaining position information of the sampling points after rotation corresponding to the plurality of rotation angles of the turntable includes: Acquire a sampling image of each of the rotated sampling points within the sampling range; Determine the pixel coordinates of each of the rotated sampling points in the image coordinate system of the sampled image; The pixel coordinates of each of the rotated sampling points are processed based on a second conversion relationship to obtain second physical coordinates of each of the rotated sampling points; the second conversion relationship is used to represent a conversion relationship between the image coordinate system and the second coordinate system.

6. The position calibration method according to claim 5, characterized in that: Also includes: Obtain multiple coordinate pairs of calibration points and pixel coordinates corresponding to multiple calibration angles; The calibration point is a point on the calibration object placed on the turntable; the coordinate pair includes the pixel coordinate of the calibration point in the image coordinate system and the physical coordinate of the calibration point in the initial coordinate system; different coordinate pairs correspond to different positions of the calibration point within the sampling range; the pixel coordinate corresponding to the calibration angle is the pixel coordinate of the calibration point when it is at the position after the turntable rotates by the calibration angle; Determining an initial transformation relationship based on the coordinate pairs corresponding to the plurality of calibration points; the initial transformation relationship is used to represent the transformation relationship between the image coordinate system and the initial coordinate system; Determining the pixel coordinates of the rotation center in the image coordinate system based on the pixel coordinates corresponding to each of the multiple calibration angles; The second transformation relationship is determined based on the initial transformation relationship and the pixel coordinates of the rotation center.

7. A position calibration device, characterized in that: include: Acquisition unit and processing unit; The acquisition unit is used to acquire position information of the sampling points after rotation corresponding to each of the plurality of rotation angles of the turntable; The turntable rotation angle is used to represent the angle between the line between the sampling point after rotation and the rotation center of the turntable and the line between the initial sampling point and the rotation center; the initial sampling point is a point on the arc edge of the wafer to be calibrated placed on the turntable that is within the sampling range of the area array camera when the wafer to be calibrated is in the initial position; The post-rotation sampling point is a point on the arc edge that is within the sampling range when the wafer to be calibrated is in a position after the turntable rotates by the turntable rotation angle; The processing unit is used to determine a target distance and a target angle according to the plurality of turntable rotation angles and the position information of each sampling point after rotation; the target distance is used to represent the distance between the center of the wafer to be calibrated and the rotation center; the target angle is used to represent the angle between the line between the center of the wafer to be calibrated and the rotation center and the line between the initial sampling point and the rotation center; The processing unit is further used to determine the position deviation information of the center of the wafer to be calibrated relative to the rotation center according to the target distance and the target angle, so as to perform calibration based on the position deviation information so that the center of the wafer to be calibrated coincides with the rotation center; The acquisition unit is further used to acquire a target sampling image; the target sampling image is an image captured by the area array camera during the process of the wafer to be calibrated rotating with the turntable, and the target sampling image includes the notch of the wafer to be calibrated; The processing unit is further used to determine the position information of the target position point in the notch of the wafer to be calibrated; The processing unit is further configured to determine, based on the position information, angle deviation information of the target position point relative to the preset position point, so as to perform calibration based on the angle deviation information so that the target position point coincides with the preset position point; The angle deviation information includes an angle between a line between the target position point and the rotation center and a line between the preset position point and the rotation center.

8. A computer device, characterized in that: include: processor; The processor is connected to a memory, the memory is used to store computer-executable instructions, and the processor executes the computer-executable instructions stored in the memory, so that the computer device implements the method according to any one of claims 1 to 6.

9. A readable storage medium, characterized in that: Used to store computer instructions, when the computer instructions are executed on a computer device, the computer device is caused to execute the method according to any one of claims 1 to 6.

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