Cooperative positioning method and device, storage medium and wafer loading method

Abstract

The invention discloses a cooperative positioning method and device, a storage medium and a wafer loading method. According to the cooperative positioning method, first pixel coordinates of a plurality of grinding and polishing stations in the wandering star wheel are determined through a first positioning image collected by a first camera; determining second pixel coordinates of a plurality of positioning stations in a feeding positioning cache table through a second positioning image acquired by a second camera; acquiring a position mapping relation between camera coordinate systems of the first camera and the second camera; based on the first pixel coordinate, the second pixel coordinate and the position mapping relation, determining the alignment adjustment amount of the wafer positioning station; and the relative position relation of the multiple positioning stations is adjusted to be the same as the relative position relation of the multiple grinding and polishing stations. By means of the cooperative positioning method, synchronous alignment of the multiple wafers located on the wafer feeding cache module and the multiple grinding and polishing stations located on the wandering star wheel in the wafer polishing and grinding equipment can be achieved, then one-time wafer feeding of the multiple wafers is achieved, and the grinding and polishing efficiency of the wafers is improved.

Description

Technical Field

[0001] The present application relates to the field of semiconductor processing equipment, and particularly to a collaborative positioning method, device, storage medium, and wafer loading method. Background Art

[0002] In the production process of wafers, double-sided polishing and grinding is an important link in the wafer processing technology. Before polishing and grinding, the wafers need to be placed in a wafer buffer device for positioning and buffering. During the processing, a loading robot needs to take out the wafers in the wafer buffer device and place them in the wafer holes of the planetary wheel for processing.

[0003] In the related art, the automated wafer loading and buffering for wafer polishing and grinding is achieved by the robot sucking multiple wafers one by one from the loading cassette, so as to place multiple wafers on the buffer table, and then another robot intermittently places the buffered multiple wafers into the planetary wheel with the wafer holes positioned. However, in this buffering method, the robot can only load one wafer at a time, resulting in low loading efficiency.

[0004] Aiming at the problem of low wafer loading efficiency in wafer polishing and grinding in the related art, no effective solution has been proposed yet. Summary of the Invention

[0005] To solve the above technical problems, the present application provides a collaborative positioning method for wafer loading to solve the problem of low wafer loading efficiency.

[0006] In a first aspect, a collaborative positioning method for wafer loading is provided, including: obtaining a first positioning image collected by a first camera, and determining first pixel coordinates of a plurality of grinding and polishing stations in a planetary wheel based on the first positioning image; obtaining a second positioning image collected by a second camera, and determining second pixel coordinates of a plurality of positioning stations in a wafer loading positioning buffer table based on the second positioning image; obtaining a position mapping relationship between the camera coordinate system of the first camera and the camera coordinate system of the second camera; determining an alignment adjustment amount of the wafer positioning station based on the first pixel coordinates, the second pixel coordinates, and the position mapping relationship; and adjusting the relative position relationship of the plurality of positioning stations to be the same as the relative position relationship of the plurality of grinding and polishing stations based on the alignment adjustment amount.

[0007] In one embodiment, obtaining the position mapping relationship between the camera coordinate system of the first camera and the camera coordinate system of the second camera includes: obtaining a first mapping relationship between the camera pixels of the first camera and the world coordinates of the upper and lower wafer movement module loading the second camera; obtaining a second mapping relationship between the camera pixels of the second camera and the world coordinates of the upper and lower wafer movement module loading the second camera; and determining the position mapping relationship between the camera coordinate system of the first camera and the camera coordinate system of the second camera based on the first mapping relationship and the second mapping relationship.

[0008] In one embodiment, obtaining the first mapping relationship between the camera pixels of the first camera and the world coordinates of the upper and lower wafer movement module loading the second camera includes: during the process of the upper and lower wafer movement module driving the calibration board to move, obtaining the position of the upper and lower wafer movement module and collecting a first image of the calibration board through the stationary first camera; determining a first calibration matrix according to the position of the upper and lower wafer movement module and the first image; and determining the first mapping relationship based on the first calibration matrix.

[0009] In one embodiment, obtaining the second mapping relationship between the camera pixels of the second camera and the world coordinates of the upper and lower wafer movement module loading the second camera includes: during the process of the upper and lower wafer movement module driving the second camera to move, obtaining the position of the upper and lower wafer movement module and collecting a second image of the stationary calibration board through the second camera; determining a second calibration matrix according to the position of the upper and lower wafer movement module and the second image; and determining... The second mapping relationship.

[0010] In one embodiment, determining the alignment adjustment amount of the positioning station based on the first pixel coordinates, the second pixel coordinates, and the position mapping relationship includes: determining a first relative position of multiple grinding and polishing stations in the planetary gear in the world coordinate system according to the first pixel coordinates and the position mapping relationship; determining a second relative position of multiple positioning stations on the wafer buffer platform in the world coordinate system according to the second pixel coordinates and the position mapping relationship; and comparing the first relative position and the second relative position to determine the alignment adjustment amount.

[0011] In one embodiment, adjusting the relative position relationship of a plurality of the positioning stations to be the same as the relative position relationship of a plurality of the grinding and polishing stations based on the alignment adjustment amount includes: determining the alignment adjustment amount of the positioning stations in a first horizontal direction and the alignment adjustment amount in a second horizontal direction based on the alignment adjustment amount, where the first horizontal direction is perpendicular to the second horizontal direction; and adjusting the relative position relationship of a plurality of the positioning stations to be the same as the relative position relationship of a plurality of the grinding and polishing stations based on the alignment adjustment amount in the first horizontal direction and the alignment adjustment amount in the second horizontal direction.

[0012] In one embodiment, further determining the first pixel coordinates of a plurality of grinding and polishing stations in the planetary gear based on the first positioning image further includes: obtaining the taught connection line angle and the taught midpoint position of the taught planetary gear, where the taught connection line angle is the included angle between the connection line of two positioning holes on the taught planetary gear and the first horizontal direction, and the taught midpoint position is the position where the midpoint of the connection line of two positioning holes on the taught planetary gear is located; obtaining the relative distance between the center of each grinding and polishing station in the taught planetary gear and the midpoint of the connection line; storing the taught connection line angle, the taught midpoint position, and a plurality of the relative distances as a taught recipe; obtaining the measured angle information and the measured midpoint position of the connection line of two positioning holes on the planetary gear to be inspected based on the first positioning image; and calculating the first pixel coordinates of any grinding and polishing station in the planetary gear to be inspected based on the measured angle information, the measured midpoint position, and the taught recipe.

[0013] In a second aspect, a wafer loading collaborative positioning device is provided. The device includes: a first acquisition unit configured to acquire a first positioning image collected by a first camera and determine the first pixel coordinates of a plurality of grinding and polishing stations in a planetary gear based on the first positioning image; a second acquisition unit configured to acquire a second positioning image collected by a second camera and determine the second pixel coordinates of a plurality of positioning stations in a wafer loading positioning buffer table based on the second positioning image; a third acquisition unit configured to acquire the position mapping relationship between the camera coordinate system of the first camera and the camera coordinate system of the second camera; a calculation unit configured to determine the alignment adjustment amount of the wafer positioning station based on the first pixel coordinates, the second pixel coordinates, and the position mapping relationship; and an alignment unit configured to adjust the relative position relationship of a plurality of the positioning stations to be the same as the relative position relationship of a plurality of the grinding and polishing stations based on the alignment adjustment amount.

[0014] In a third aspect, a storage medium is provided. The computer-readable storage medium stores computer instructions, and the computer instructions are used to cause a processor to implement the collaborative positioning method described in any embodiment of the first aspect above when executed.

[0015] Fourthly, a wafer loading method is provided. The wafer loading method includes: detecting that a blanking motion module carries a first camera to collect a first positioning image and send it to a collaborative positioning device; the loading and unloading motion module takes out a wafer to be processed from a loading cassette and places it on the loading buffer module; the loading and unloading motion module collects a second positioning image of the loading buffer module and sends it to the collaborative positioning device; the collaborative positioning device is configured to execute the collaborative positioning method described in any one of the embodiments of the first aspect above, so that the relative position relationship between the positioning stations in the loading buffer module is consistent with the relative position relationship between the grinding and polishing stations in the planetary wheel; the loading and unloading motion module sucks the wafers in a plurality of the positioning stations and transfers them to the corresponding grinding and polishing stations in the planetary wheel.

[0016] The collaborative positioning method provided by the present application determines the deviation between the relative positions of the grinding and polishing stations on the planetary wheel and the relative positions of the positioning stations by obtaining the first positioning image of the planetary wheel, the second positioning image of the positioning station, and the position mapping relationship between the camera coordinate systems of the first camera and the second camera, and obtains the alignment adjustment amount for aligning the positioning station with the grinding and polishing station in the world coordinate system. Based on the alignment adjustment amount, the relative position relationship of a plurality of positioning stations is adjusted to be the same as the relative position relationship of a plurality of grinding and polishing stations. The collaborative positioning method provided by the present application solves the alignment problem between each wafer and the grinding and polishing station when multiple wafers are loaded at one time, provides a positioning basis for the one-time adsorption of the multi-wafer loading scheme, and further solves the problem of low loading efficiency of single-wafer loading in the prior art. Description of the Drawings

[0017] Figure 1 is a schematic structural diagram of a wafer polishing and grinding device according to an embodiment of the present application; Figure 2 is a schematic structural diagram of a loading buffer module according to an embodiment of the present application; Figure 3 is a schematic flow chart of a collaborative positioning method according to an embodiment of the present application; Figure 4 is a schematic diagram of the taught points of a planetary wheel according to an embodiment of the present application; Figure 5 is a schematic structural diagram of a collaborative positioning device according to an embodiment of the present application; Figure 6 is a schematic flow chart of a wafer loading method according to an embodiment of the present application; Explanation of the reference numerals in the drawings: 10, polishing and grinding machine; 20, blanking motion detection module; 30, loading buffer module; 40, loading and unloading motion module; 11, planetary wheel; 111, grinding and polishing station; 31, loading positioning buffer table; 32, buffer motion device; 311, positioning station; 312, adjustment platform. Detailed Embodiments

[0018] To make the above objects, features, and advantages of the present invention more apparent and understandable, the following provides a detailed description of the specific embodiments of the present invention in conjunction with the accompanying drawings. Many specific details are set forth in the following description to facilitate a thorough understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the spirit of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0019] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the present invention.

[0020] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, "a plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0021] In the present invention, unless otherwise clearly specified and defined, the terms "mounted", "connected", "coupled", "fixed", etc. should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0022] In the present invention, unless otherwise clearly defined and limited, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may be that the first feature is directly above or obliquely above the second feature, or merely indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "beneath" and "underneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the horizontal height of the first feature is less than that of the second feature.

[0023] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or there may also be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are only for the purpose of illustration and do not represent the only implementation.

[0024] Wafer polishing and grinding is one of the key processes in semiconductor manufacturing, mainly used to planarize the wafer surface and ensure the accuracy and yield of subsequent processes such as lithography and thin film deposition. In related technologies, the automatic loading and unloading method of wafer polishing and grinding mainly uses a manipulator to pick and place wafers one by one. This method has low loading and unloading efficiency. To achieve multi-wafer loading and unloading at one time, how to align the positions of each wafer with the grinding and polishing station has become the primary condition for improving the wafer loading and unloading efficiency.

[0025] In this application, a wafer polishing and grinding device is provided, as Figure 1 and Figure 2 shown, including a polishing and grinding machine 10, a detection and unloading motion module 20, a wafer loading buffer module 30, and a wafer loading and unloading motion module 40. The polishing and grinding machine 10 includes a plurality of planetary wheels 11, and each planetary wheel 11 has a plurality of grinding and polishing stations 111. The detection and unloading motion module 20 is used to detect the relative position relationship of the plurality of grinding and polishing stations 111 and generate a control signal. The wafer loading buffer module 30 includes a wafer loading positioning buffer table 31 and a buffer motion device 32. The wafer loading positioning buffer table 31 includes a positioning station 311 and an adjustment platform 312. The buffer motion device 32 can transfer the wafers in the wafer loading positioning buffer table 31 to the positioning station 311, and the adjustment platform 312 is used to adjust the wafers in the positioning station 311 in response to the control signal; the wafer loading and unloading motion module 40 is used to transfer the wafers to the grinding and polishing stations 111.

[0026] In this embodiment, a collaborative positioning method for wafer loading is provided, which is applied to the wafer polishing and grinding device described in the previous embodiment, as Figure 3As shown in the figure, the method includes: Step S301: Obtain a first positioning image collected by a first camera, and determine first pixel coordinates of multiple grinding and polishing stations 111 in the planet gear 11 based on the first positioning image.

[0027] Specifically, the first camera is installed on the detection and blanking motion module 20 of the polishing and grinding equipment for collecting planet gear images. The detection and blanking motion module 20 includes a mounting component and a motion component. The mounting component is used for mounting the first camera. Preferably, the mounting component adopts a non-fixed connection method to facilitate adjusting the camera attitude of the first camera. The motion component is used to drive the first camera to move between photographing positions of different planet gears 11. Generally, the polishing and grinding machine 10 includes several planet gears 11. Due to manufacturing processes and other reasons, there are certain deviations in the positions of the grinding and polishing stations 111 in the planet gears 11. Therefore, in this embodiment, the first camera collects a planet gear image at the photographing position, and after the collection is completed, it is driven by the motion component to move to the next photographing position to collect the next planet gear image. In another embodiment, the first camera can also collect a planet gear image including multiple planet gears through one photographing. The first positioning image is the planet gear image. The grinding and polishing station 111 is a wafer hole groove located on the planet gear 11. The pixel coordinate system is a two-dimensional plane composed of pixels, which is commonly used to represent the position and size of an image. Determining the first pixel coordinates of multiple grinding and polishing stations 111 in the planet gear 11 based on the first positioning image means determining the positions of multiple grinding and polishing stations 111 in the image based on the planet gear image. For the convenience of calculation, the first pixel coordinate of each grinding and polishing station 111 can be characterized by the center point of the grinding and polishing station 111.

[0028] Step S302: Obtain a second positioning image collected by a second camera, and determine second pixel coordinates of multiple positioning stations 311 in the positioning buffer table based on the second positioning image.

[0029] Specifically, the second camera is mounted on the wafer loading and unloading motion module 40 of the wafer polishing and grinding equipment. The second camera takes pictures of the loading positioning buffer table 31 of the wafer polishing and grinding equipment to collect images of the positioning stations 311, and obtains a second positioning image. Obtain the second pixel coordinates of multiple positioning stations 311 in the pixel coordinate system of the second positioning image.

[0030] Step S303: Obtain the position mapping relationship between the camera coordinate system of the first camera and the camera coordinate system of the second camera.

[0031] Specifically, the camera coordinate system is a three-dimensional rectangular coordinate system established with the focus center of the camera as the origin and the optical axis as the Z-axis. The optical axis is perpendicular to the graphic plane. Obtaining the position mapping relationship between the camera coordinate system of the first camera and the camera coordinate system of the second camera can achieve the coordinate conversion between the first camera and the second camera.

[0032] Step S304: Determine the alignment adjustment amount of the positioning station 311 based on the first pixel coordinate, the second pixel coordinate, and the position mapping relationship.

[0033] Specifically, based on the first pixel coordinate, the second pixel coordinate, and the position mapping relationship, the relative position relationship between the grinding and polishing stations 111 and the relative position relationship between the positioning stations 311 can be obtained in the same coordinate system. Taking the relative position relationship between the grinding and polishing stations 111 as the reference and comparing the relative position relationship between the positioning stations 311 with it, the alignment adjustment amount of the positioning station 311 of the wafer can be obtained.

[0034] Step S305: Adjust the relative position relationship of the multiple positioning stations 311 to be the same as the relative position relationship of the multiple grinding and polishing stations 111 based on the alignment adjustment amount.

[0035] Specifically, after determining the alignment adjustment amount, a control signal is generated and sent to the wafer loading and positioning buffer table 31. The adjustment platform 312 of the wafer loading and positioning buffer table 31 responds to the control signal to adjust the relative position relationship of the positioning stations 311, so that the relative position relationship of the positioning stations 311 is the same as the relative position relationship of the grinding and polishing stations 111. Further, at this time, the relative position relationship of the wafers located in the positioning stations 311 is the same as the relative position relationship of the grinding and polishing stations 111 in the planetary wheel 11. The upper and lower wafer movement module 40 can suck all the wafers located in the positioning stations 311 at one time and transfer them to the grinding and polishing stations 111.

[0036] The collaborative positioning method of this embodiment collects the image data of the grinding and polishing station 111 on the planet gear 11 through the first camera; collects the image data of the positioning station 311 on the positioning buffer table through the second camera; obtains the position mapping relationship between the camera coordinate system of the first camera and the camera coordinate system of the second camera, and based on the position mapping relationship, converts the image data of the grinding and polishing station 111 and the image data of the positioning station 311 to the same coordinate system. At this time, based on the same coordinate system, taking the relative position relationship between the grinding and polishing stations 111 as the reference, compares the relative position relationship between the positioning stations 311 to determine the alignment adjustment amount of the adjustment platform 312; then, based on the alignment adjustment amount, makes the wafer position correspond to the position of the grinding and polishing station 111 in the planet gear 11, and finally transfers all the wafers at one time through the wafer loading and unloading motion module 40. The collaborative positioning method of this embodiment realizes the precise alignment of multiple wafers and multiple grinding and polishing stations 111, completes the alignment condition for one-time multi-wafer loading, and can significantly improve the wafer loading efficiency compared with the single-wafer loading scheme in the prior art.

[0037] In one of the embodiments, obtaining the position mapping relationship between the camera coordinate system of the first camera and the camera coordinate system of the second camera includes: obtaining the first mapping relationship between the camera pixels of the first camera and the world coordinates of the wafer loading and unloading motion module 40 where the second camera is installed; obtaining the second mapping relationship between the camera pixels of the second camera and the world coordinates of the wafer loading and unloading motion module 40 where the second camera is installed; based on the first mapping relationship and the second mapping relationship, determining the position mapping relationship between the camera coordinate system of the first camera and the camera coordinate system of the second camera.

[0038] Specifically, in the working state of the wafer polishing and grinding equipment, the first camera is installed on the detection and unloading motion module 20; the second camera is installed on the wafer loading and unloading motion module 40. The wafer polishing and grinding equipment can determine the position of the first camera based on the world coordinates of the detection and unloading motion module 20; and can determine the position of the second camera based on the world coordinates of the wafer loading and unloading motion module 40. In order to determine the position deviation between the grinding and polishing station 111 in the planet gear 11 and the positioning station 311 in the wafer loading buffer module 30 in the world coordinate system, the camera coordinate systems of the first camera and the second camera need to be unified. Therefore, in this embodiment, by pre-installing the first camera and the second camera on the wafer loading and unloading motion module 40 respectively for calibration of the mapping relationship, obtaining the first mapping relationship and the second mapping relationship respectively, and determining the position mapping relationship between the camera coordinate system of the first camera and the camera coordinate system of the second camera based on the first mapping relationship and the second mapping relationship.

[0039] Among them, the pixel coordinates (P1x, R1y) of the first camera can obtain the position (R2x, R2y) in the calibration pose of the upper and lower film movement module 40 through the nine-point calibration relationship matrix HomMath2D_2, thereby establishing the first mapping relationship between the camera pixels of the first camera and the world coordinates of the upper and lower film movement module 40; the position (R2x, R2y) in the calibration pose of the upper and lower film movement module 40 obtains the pixel coordinates (P2x, P2y) of the second camera through the inverse relationship of the nine-point calibration relationship matrix HomMath2D_3. Thus, the position mapping relationship between the camera coordinates of the first camera and the camera coordinate system of the second camera is determined.

[0040] In one of the embodiments, obtaining the first mapping relationship between the camera pixels of the first camera and the world coordinates of the upper and lower film movement module 40 loading the second camera includes: during the process of the upper and lower film movement module 40 driving the calibration board to move, obtaining the position of the upper and lower film movement module 40 and the first image of the calibration board collected by the stationary first camera; determining the first calibration matrix according to the position of the upper and lower film movement module 40 and the first image; determining the first mapping relationship based on the first calibration matrix.

[0041] Specifically, based on the first camera, the second camera, and the upper and lower film movement module 40 used in the photographing process, pre-calibration is performed with the help of a calibration board and the nine-point calibration method. During the specific calibration process, the current nine-point coordinates of the camera and the robot are collected as inputs, and the matrix-related parameters are output through the nine-point calibration method. Among them, the first calibration matrix is denoted as HomMath2D_2, and its calibration process is: the first camera is stationary, and the upper and lower film movement module 40 drives the calibration board to move.

[0042] In one of the embodiments, obtaining the second mapping relationship between the pixels of the second camera and the world coordinates of the upper and lower film movement module 40 loading the second camera includes: during the process of the upper and lower film movement module 40 driving the second camera to move, obtaining the position of the upper and lower film movement module 40 and the second image of the stationary calibration board collected by the second camera; determining the second calibration matrix according to the position of the upper and lower film movement module 40 and the second image; determining the second mapping relationship based on the second calibration matrix.

[0043] Specifically, in the calibration process of this embodiment, the current nine-point coordinates of the camera and the robot are collected as inputs, and the matrix-related parameters are output through the nine-point calibration method. Among them, the first calibration matrix is denoted as HomMath2D_3, and its calibration process is: the calibration board is stationary, and the upper and lower film movement module 40 drives the calibration board to move.

[0044] In one embodiment, determining the alignment adjustment amount of the positioning station 311 based on the first pixel coordinates, the second pixel coordinates, and the position mapping relationship includes: determining the first relative positions of multiple grinding and polishing stations 111 in the planetary gear 11 in the world coordinate system according to the first pixel coordinates and the position mapping relationship; determining the second relative positions of multiple positioning stations 311 on the wafer loading positioning buffer table 31 in the world coordinate system according to the penultimate pixel coordinates and the position mapping relationship; comparing the first relative positions with the second relative positions to determine the alignment adjustment amount.

[0045] Specifically, the first camera is mounted on the detection and blanking motion module 20, and the second camera is mounted on the wafer loading and unloading motion module 40. Therefore, the world coordinates of the first camera and the world coordinates of the second camera are determined by the world coordinates of the detection and blanking motion module 20 and the wafer loading and unloading motion module 40. The adjustment of the positioning station 311 also uses the first coordinate system. Therefore, to calculate the alignment adjustment amount, it is also necessary to establish the position mapping relationship between the camera pixels of the first camera and the world coordinates of the detection and blanking motion module 20, and the position mapping relationship between the first camera coordinate system and the world coordinates of the adjustment platform 312 on the wafer loading positioning buffer table 31. Finally, the coordinate systems of the detection and blanking motion module 20, the first camera, the second camera, the wafer loading and unloading motion module 40, and the wafer loading positioning buffer table 31 are unified, and the alignment adjustment amount of the wafer loading positioning buffer table 31 is determined based on the planetary gear image collected by the first camera and the image of the positioning station 311 collected by the second camera.

[0046] The first camera is mounted on the detection and blanking motion module 20. Therefore, it is also necessary to establish the mapping relationship between the pixel coordinates of the first camera and the world coordinates of the detection and blanking motion module 20. The pixel points (P1x, P1y) of the first camera are used to obtain the world coordinates of the detection and blanking motion module 20 through the nine-point calibration relationship matrix HomMath2D_1. Among them, the HomMath2D_1 calibration process includes: the calibration plate is stationary, and the detection and blanking motion module 20 moves with the first camera, and the matrix parameters are determined by the nine-point calibration method. When the detection and blanking motion module 20 moves, in order to unify the pixel coordinate systems before and after the movement of the first camera, the coordinates of the first camera before the movement (R1x, R1y) are subtracted from the current (after the movement) robot coordinates (R1x1, R1y1), that is, (R1x - R1x1, R1y - R1y1). Through the inverse relationship matrix operation of HomMath2D_1, the pixel coordinate position (P1x1, P1y1) of the first camera after the movement of the detection and blanking motion module 20 is obtained, thereby establishing the coordinate position relationship between the camera pixels of the first camera and the detection and blanking motion module 20.

[0047] The pixel coordinates (P2x, P2y) of the second camera can obtain the world coordinates (R3x, R3y) in the coordinate system of the upper film buffer module 30 through the nine-point calibration relationship matrix HomMath2D_4. Among them, the HomMath2D_4 matrix can be calibrated by the method of keeping the second camera stationary and driving the calibration plate to move by the upper and lower film movement module 40. So far, by establishing the coordinate position relationship between the detection and blanking movement module 20 and the pixels of the first camera; the coordinate position relationship between the pixels of the first camera and the upper and lower film movement module 40, the position mapping relationship between the camera coordinate systems of the first camera and the second camera can be obtained. Then, through the mapping relationship between the pixels of the second camera and the upper film buffer module 30, the mapping relationship between the camera coordinate system of the first camera and the world coordinates of the positioning station 311 on the upper film buffer module 30 can be obtained.

[0048] During cooperative vision alignment, the relative position information of the grinding and polishing station 111 on the planet gear 11 is obtained by taking a picture with the first camera and sent to the control system. The control system converts this information into a motion control instruction for the adjustment platform 312 in the upper film buffer module 30, driving the X and Y motion actuators of the adjustment platform 312 to move, so as to make the relative position data between the positioning stations 311 in the upper film buffer module 30 the same as the relative position data of the grinding and polishing station 111 on the planet gear 11.

[0049] In one of the embodiments, adjusting the relative position relationship of multiple positioning stations 311 to the relative position relationship of multiple grinding and polishing stations 111 based on the alignment adjustment amount includes: determining the alignment adjustment amount of the positioning station 311 in the first horizontal direction and the alignment adjustment amount in the second horizontal direction based on the alignment adjustment amount, where the first horizontal direction is perpendicular to the second horizontal direction; adjusting the relative position relationship of multiple positioning stations 311 to the relative position relationship of multiple grinding and polishing stations 111 based on the alignment adjustment amount in the first horizontal direction and the alignment adjustment amount in the second horizontal direction.

[0050] In one of the embodiments, determining the first pixel coordinates of multiple grinding and polishing stations in the planet gear based on the first positioning image further includes: obtaining the taught connection line angle and the taught midpoint position of the taught planet gear, where the taught connection line angle is the included angle between the connection line of two positioning holes on the taught planet gear and the first horizontal direction, and the taught midpoint position is the position where the midpoint of the connection line of two positioning holes on the taught planet gear is located; obtaining the relative distance between the center of each grinding and polishing station in the taught planet gear and the midpoint of the connection line; storing the taught connection line angle, the taught midpoint position, and multiple relative distances as a taught formula; obtaining the measured angle information and the measured midpoint position of the connection line of two positioning holes on the planet gear to be inspected based on the first positioning image; calculating the first pixel coordinates of any grinding and polishing station in the planet gear to be inspected based on the measured angle information, the measured midpoint position, and the taught formula.

[0051] Specifically, ideally, when the shooting space and working distance provided by the polishing and grinding equipment for the first camera installed on the blanking detection motion module are sufficient, before each wafer loading, the first camera can directly obtain the relative position of the grinding and polishing station 111 of the planetary gear 11, that is, the entire view of at least one grinding and polishing station 111 in the planetary gear 11 can be covered in one camera shot, so as to determine the center position of the grinding and polishing station 111, and the multi-machine vision collaborative dynamic positioning method described above can be used to guide the movement of the adjustment platform 312, so as to accurately complete a multi-wafer loading task at one time.

[0052] When the shooting space and working distance provided by the polishing and grinding equipment for the first camera are insufficient, that is, the entire view of one grinding and polishing station 111 cannot be covered in one camera shot of the first camera, it is necessary to determine the positional relationship between the feature positioning holes (i.e., Mark points) in the planetary gear 11 and the centers of each grinding and polishing station 111 through the teaching process, such as Figure 4 shown, and store it in the form of a recipe. Before wafer loading, the first camera takes pictures of the positioning hole features of the planetary gear 11 to determine the corresponding recipe, and the control system controls the movement of the adjustment platform 312 according to the center position information of each grinding and polishing station 111 in the recipe to achieve accurate placement of multiple wafers at one time by the loading and unloading motion module 40. When the planetary gear 11 of the wafer polishing and grinding equipment is updated, it is necessary to re-teach the planetary gear 11 to update the relative pose relationship between the Mark points in the planetary gear 11 and the centers of the wafer holes.

[0053] In one specific embodiment, a rapid teaching method for the grinding and polishing station 111 of the planetary gear 11 is provided. The teaching method includes: Step S501, calculate the angle of the line connecting the two positioning holes Mark1 and Mark2 on the planetary gear 11 and the position of the midpoint P; Step S502, calculate the center point Ci of the i-th wafer Circlei in the planetary gear 11, i = 1, 2... N; for conventional polishing and grinding equipment, N = 3 or 4; when N = 3, the schematic diagram of the teaching point parameters of each part of the planetary gear 11 is as Figure 4 shown; Step S503, calculate and save the distance Di from the midpoint P to the center Ci of the i-th grinding and polishing station 111; Step S504, save the corresponding relationship between the Mark midpoint P, the line connecting the two points angle and D1, D2... DN in the form of a recipe, and this recipe has a one-to-one correspondence with this planetary gear 11.

[0054] In this embodiment, a collaborative positioning device for wafer loading is also provided, as Figure 5 shown, and the device includes: The first acquisition unit 51 is configured to acquire a first positioning image collected by a first camera, and determine first pixel coordinates of a plurality of grinding and polishing stations 111 in the planet gear 11 based on the first positioning image; The second acquisition unit 52 is configured to acquire a second positioning image collected by a second camera, and determine second pixel coordinates of a plurality of positioning stations 311 in the wafer loading positioning buffer table 31 based on the second positioning image; The third acquisition unit 53 is configured to acquire a position mapping relationship between the camera coordinate system of the first camera and the camera coordinate system of the second camera; The calculation unit 54 is configured to determine an alignment adjustment amount of the wafer positioning station 311 based on the first pixel coordinates, the second pixel coordinates, and the position mapping relationship; The alignment unit 55 is configured to adjust the relative position relationship of the plurality of positioning stations 311 to be the same as the relative position relationship of the plurality of grinding and polishing stations 111 based on the alignment adjustment amount.

[0055] The third acquisition unit 53 is further configured to acquire a first mapping relationship between the camera pixels of the first camera and the world coordinates of the wafer loading and unloading motion module 40 loaded with the second camera; acquire a second mapping relationship between the camera pixels of the second camera and the world coordinates of the wafer loading and unloading motion module 40 loaded with the second camera; and determine the position mapping relationship between the camera coordinate system of the first camera and the camera coordinate system of the second camera based on the first mapping relationship and the second mapping relationship.

[0056] In one embodiment, acquiring the first mapping relationship between the camera pixels of the first camera and the world coordinates of the wafer loading and unloading motion module 40 loaded with the second camera includes: during the process of the wafer loading and unloading motion module 40 driving the calibration board to move, acquiring the position of the wafer loading and unloading motion module 40 and collecting a first image of the calibration board through the stationary first camera; determining a first calibration matrix according to the position of the wafer loading and unloading motion module 40 and the first image; and determining the first mapping relationship based on the first calibration matrix.

[0057] In one embodiment, acquiring the second mapping relationship between the camera pixels of the second camera and the world coordinates of the wafer loading and unloading motion module 40 loaded with the second camera includes: during the process of the wafer loading and unloading motion module 40 driving the second camera to move, acquiring the position of the wafer loading and unloading motion module 40 and collecting a second image of the stationary calibration board through the second camera; determining a second calibration matrix according to the position of the wafer loading and unloading motion module 40 and the second image; and determining The second mapping relationship.

[0058] The calculation unit 54 is further configured to determine the first relative positions of multiple grinding and polishing stations 111 in the planetary gear 11 in the world coordinate system according to the first pixel coordinates and the position mapping relationship; determine the second relative positions of multiple positioning stations 311 on the wafer loading and positioning buffer table 31 in the world coordinate system according to the second pixel coordinates and the position mapping relationship; compare the first relative positions with the second relative positions to determine the alignment adjustment amount.

[0059] The alignment unit 55 is further configured to determine the alignment adjustment amount of the positioning station 311 in the first horizontal direction and the alignment adjustment amount in the second horizontal direction based on the alignment adjustment amount, where the first horizontal direction is perpendicular to the second horizontal direction; adjust the relative position relationship of multiple positioning stations 311 to be the same as the relative position relationship of multiple grinding and polishing stations 111 based on the alignment adjustment amount in the first horizontal direction and the alignment adjustment amount in the second horizontal direction.

[0060] The first acquisition unit 51 is further configured to acquire the taught connection line angle and the taught midpoint position of the taught planetary gear, where the taught connection line angle is the included angle between the connection line of two positioning holes on the taught planetary gear and the first horizontal direction, and the taught midpoint position is the position where the midpoint of the connection line of two positioning holes on the taught planetary gear is located; acquire the relative distance between the center of each grinding and polishing station in the taught planetary gear and the midpoint of the connection line; store the taught connection line angle, the taught midpoint position, and multiple relative distances as a taught recipe; acquire the measured angle information and the measured midpoint position of the connection line of two positioning holes on the planetary gear to be inspected based on the first positioning image; calculate the first pixel coordinates of any grinding and polishing station in the planetary gear to be inspected based on the measured angle information, the measured midpoint position, and the taught recipe.

[0061] The present application further provides a storage medium. The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable the processor to implement the collaborative positioning method described in any of the above embodiments when executed.

[0062] The present application further provides a wafer loading method, as Figure 6 shown, the wafer loading method includes: Step S601, detecting that the blanking motion module 20 carries the first camera to acquire the first positioning image and send it to the collaborative positioning device; Step S602, the wafer loading and unloading motion module 40 takes out the wafer to be processed from the loading cassette and places it on the wafer loading buffer module 30; Step S603, the wafer loading and unloading motion module 40 acquires the second positioning image of the wafer loading buffer module 30 and sends it to the collaborative positioning device; Step S604, the collaborative positioning device is configured to execute the collaborative positioning method described in any of the embodiments of the first aspect above, so that the relative position relationship of each positioning station 311 in the wafer loading buffer module 30 is the same as the relative position relationship of each grinding and polishing station 111 in the planetary gear 11. In step S605, the upper and lower wafer movement module 40 sucks the wafers in multiple positioning stations 311 and transfers them to the corresponding grinding and polishing stations 111 of the planetary wheel 11.

[0063] In the wafer loading method of this embodiment, on the basis of realizing visual collaborative positioning, the upper and lower wafer movement module 40 adsorbs multiple wafers to the grinding and polishing station 111 at one time. Compared with the single-wafer loading scheme in the prior art, the wafer loading efficiency is greatly improved.

[0064] In one specific embodiment, a method for automatic buffering, positioning and loading of wafer polishing and grinding is provided. Taking an example where there are 3 wafer holes in 1 planetary wheel 11 and 1 polishing and grinding machine can accommodate 5 planetary wheels 11 at the same time: In step S701, the upper and lower wafer movement module 40 takes out the wafers from the loading wafer cassette FOUP and places them on the wafer loading buffer module 30. When the uppermost layer of the wafer loading buffer module 30 is full of 3 wafers, the double-wafer buffer movement device 32 and the single-wafer buffer movement device 32 move to place the 3 wafers in the lower buffer station until the wafer loading buffer module 30 is full of 15 wafers.

[0065] In step S702, when receiving the wafer loading instruction, the unloading movement module 20 equipped with the first camera is detected to move above the mark1 point of the positioning hole of the i-th (i = 1, 2, 3, 4, 5) planetary wheel 11 of the polishing and grinding machine 10, and the position information of the mark1 point is obtained. In step S703, it is detected to move above the mark2 point of the positioning hole of the planetary wheel 11 of the polishing and grinding machine 10, and the position information of the mark2 point is obtained.

[0066] In step S704, the midpoint P of the line connecting the mark1 and mark2 points and the angle of the line connecting the two points are calculated. In step S705, the teaching formula is loaded, and the relative position relationship of each grinding and polishing station 111 in the planetary wheel 11 is deduced from the data calculated in step S704.

[0067] In step S706, the multi-machine vision collaborative dynamic positioning method is adopted to control the wafer loading adjustment platform 312 to realize the dynamic adjustment of the relative positions between the positioning stations 311 to make them consistent with the relative position data of the grinding and polishing stations 111. In step S707, the wafer loading robot moves to the wafer loading buffer module 30 and simultaneously sucks 3 wafers at one time and places them in the planetary wheel 11 of the polishing and grinding equipment; the wafer loading buffer module 30 takes out 3 wafers from the buffer station and places them on the wafer loading positioning station 311.

[0068] Step S708: Repeat steps S702 to S707 until all the planetary wheels 11 of the polishing and grinding machine 10 are fully filled with wafers (i = 5), completing the wafer loading operation.

[0069] It can be understood that in this embodiment, it is described that there are 3 wafer holes in one planetary wheel 11 and one polishing and grinding machine 10 can accommodate 5 planetary wheels 11 simultaneously to illustrate the wafer loading process. In some other specific embodiments, the number of planetary wheels 11 and the grinding and polishing stations 111 can also be adjusted according to the processing technology.

[0070] The wafer loading method of this embodiment stores the teaching recipe by means of the positions of the grinding and positioning station 311 and the positioning points on the planetary wheel 11, improving the positioning accuracy of the grinding and polishing station 111. With the visual collaborative positioning method, it can dynamically adjust the center distance of the buffered wafers in the positioning station 311 according to the difference in the center distance of each grinding and polishing station 111 within each planetary wheel 11, improving the positioning accuracy. Finally, based on the positioning station 311 after position alignment, the wafer loading and unloading motion module 40 can pick up multiple wafers to the planetary wheel 11 at one time, greatly shortening the wafer loading cycle.

[0071] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0072] The above-described embodiments only represent several implementation manners of the present invention. Their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent should be subject to the appended claims.

Claims

1. A collaborative positioning method for wafer loading, characterized in that, The method includes: Obtaining a first positioning image collected by a first camera, and determining first pixel coordinates of a plurality of grinding and polishing stations in the planetary gear based on the first positioning image; Obtaining a second positioning image collected by a second camera, and determining second pixel coordinates of a plurality of positioning stations in the wafer loading positioning buffer table based on the second positioning image; Obtaining a position mapping relationship between the camera coordinate system of the first camera and the camera coordinate system of the second camera; Determining an alignment adjustment amount of the wafer positioning station based on the first pixel coordinates, the second pixel coordinates, and the position mapping relationship; Adjusting the relative position relationship of the plurality of positioning stations to be the same as the relative position relationship of the plurality of grinding and polishing stations based on the alignment adjustment amount.

2. The co-localization method according to claim 1, wherein The obtaining the position mapping relationship between the camera coordinate system of the first camera and the camera coordinate system of the second camera includes: Obtaining a first mapping relationship between the camera pixels of the first camera and the world coordinates of the wafer loading and unloading motion module loading the second camera; Obtaining a second mapping relationship between the camera pixels of the second camera and the world coordinates of the wafer loading and unloading motion module loading the second camera; Determining the position mapping relationship between the camera coordinate system of the first camera and the camera coordinate system of the second camera based on the first mapping relationship and the second mapping relationship.

3. The co-localization method according to claim 2, wherein The obtaining the first mapping relationship between the camera pixels of the first camera and the world coordinates of the wafer loading and unloading motion module loading the second camera includes: During the process of the wafer loading and unloading motion module driving the calibration board to move, obtaining the position of the wafer loading and unloading motion module and collecting a first image of the calibration board through the stationary first camera; Determining a first calibration matrix according to the position of the wafer loading and unloading motion module and the first image; Determining the first mapping relationship based on the first calibration matrix.

4. The co-localization method according to claim 2, wherein The obtaining the second mapping relationship between the camera pixels of the second camera and the world coordinates of the wafer loading and unloading motion module loading the second camera includes: During the process of the wafer loading and unloading motion module driving the second camera to move, obtaining the position of the wafer loading and unloading motion module and collecting a second image of the stationary calibration board through the second camera; Determining a second calibration matrix according to the position of the wafer loading and unloading motion module and the second image; Determining the second mapping relationship based on the second calibration matrix.

5. The co-localization method according to claim 1, wherein The determining the alignment adjustment amount of the positioning station based on the first pixel coordinates, the second pixel coordinates, and the position mapping relationship includes: Determining a first relative position of a plurality of the grinding and polishing stations in the planetary gear in the world coordinate system according to the first pixel coordinates and the position mapping relationship; Determining a second relative position of a plurality of the positioning stations on the wafer buffer platform in the world coordinate system according to the second pixel coordinates and the position mapping relationship; Comparing the first relative position and the second relative position to determine the alignment adjustment amount.

6. The co-localization method according to claim 1, wherein The adjusting the relative position relationship of the plurality of positioning stations to be the same as the relative position relationship of the plurality of grinding and polishing stations based on the alignment adjustment amount includes: Determine the alignment adjustment amount of the positioning station in the first horizontal direction and the alignment adjustment amount in the second horizontal direction based on the alignment adjustment amount, where the first horizontal direction is perpendicular to the second horizontal direction; Based on the alignment adjustment amount in the first horizontal direction and the alignment adjustment amount in the second horizontal direction, adjust the relative position relationship of multiple positioning stations to be the same as the relative position relationship of multiple grinding and polishing stations.

7. The co-localization method according to claim 1, wherein The determining the first pixel coordinates of multiple grinding and polishing stations in the planetary gear based on the first positioning image further includes: Obtain the taught connection line angle and the taught midpoint position of the taught planetary gear, where the taught connection line angle is the included angle between the connection line of two positioning holes on the taught planetary gear and the first horizontal direction, and the taught midpoint position is the position where the midpoint of the connection line of two positioning holes on the taught planetary gear is located; Obtain the relative distance between the center of each grinding and polishing station in the taught planetary gear and the midpoint of the connection line; Store the taught connection line angle, the taught midpoint position, and multiple relative distances as a taught recipe; Based on the first positioning image, obtain the measured angle information and the measured midpoint position of the connection line of two positioning holes on the planetary gear to be inspected; Calculate the first pixel coordinates of any grinding and polishing station in the planetary gear to be inspected based on the measured angle information, the measured midpoint position, and the taught recipe.

8. A collaborative positioning device for wafer loading, characterized in that, The device includes: A first acquisition unit for acquiring a first positioning image collected by a first camera and determining the first pixel coordinates of multiple grinding and polishing stations in the planetary gear based on the first positioning image; A second acquisition unit for acquiring a second positioning image collected by a second camera and determining the second pixel coordinates of multiple positioning stations in the wafer loading positioning buffer table based on the second positioning image; A third acquisition unit for acquiring the position mapping relationship between the camera coordinate system of the first camera and the camera coordinate system of the second camera; A calculation unit for determining the alignment adjustment amount of the wafer positioning station based on the first pixel coordinates, the second pixel coordinates, and the position mapping relationship; An alignment unit for adjusting the relative position relationship of multiple positioning stations to be the same as the relative position relationship of multiple grinding and polishing stations based on the alignment adjustment amount.

9. A storage medium, characterized in that, The computer-readable storage medium stores computer instructions, and the computer instructions are used to cause the processor to implement the collaborative positioning method according to any one of claims 1-7 when executed.

10. A wafer loading method, characterized in that, The wafer loading method includes: The blanking motion module detects and the first camera collects a first positioning image and sends it to the collaborative positioning device; The wafer loading and unloading motion module takes out the wafer to be processed from the loading cassette and places it in the wafer loading buffer module; The wafer loading and unloading motion module collects the second positioning image of the wafer loading buffer module and sends it to the collaborative positioning device; The collaborative positioning device is used to execute the collaborative positioning method according to any one of claims 1 to 7, so that the relative position relationship of each positioning station in the wafer loading buffer module is consistent with the relative position relationship of each grinding and polishing station in the planetary gear; The wafer loading and unloading motion module sucks the wafers in multiple positioning stations and transfers them to the corresponding grinding and polishing stations of the planetary gear.

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