Visual alignment method and device for laser transfer printing of photovoltaic cells

Abstract

The invention discloses a laser transfer printing visual alignment method and device for a photovoltaic cell, and the method comprises the steps: collecting a detection image of a silicon wafer and a source substrate in a detection region, and carrying out the preprocessing of the detection image, and the preprocessing comprises the distortion correction; positioning a first position of the silicon wafer in the silicon wafer image coordinate system based on the silicon wafer area detected by the detection image, and positioning a second position of the source substrate in the source substrate image coordinate system based on the source substrate area detected by the detection image; converting the second position to a silicon wafer image coordinate system through image mapping calibration to obtain a third position; the first position and the third position are converted into a WPM table-board coordinate system for visual alignment, the second position is converted into the WPM table-board coordinate system, and a Y-direction difference compensation value of the source substrate is determined through angle calculation; wherein the Y direction is the extension direction of the source substrate slurry tank.

Description

Technical Field

[0001] The present application relates to the field of visual alignment, and more specifically, to a laser transfer visual alignment method and device for photovoltaic cells. Background Art

[0002] In the production process of photovoltaic cells, silicon wafers are the basic materials for the production of photovoltaic cells. Silicon wafers are usually cut from silicon materials and prepared into cells through processes such as functional layer preparation, coating, and laser transfer. Among them, the gate electrode is prepared by laser transfer. When preparing the gate electrode by laser transfer, the electrode slurry is scraped into the slurry tank of the source substrate, and the side with the slurry tank is set downward. The silicon wafer is transported to the bottom of the source substrate, and the laser irradiates the slurry tank carrying the slurry above the source substrate to transfer the slurry in the slurry tank to the silicon wafer. In order to ensure the accuracy of the slurry transfer, the silicon wafer and the source substrate need to be visually aligned.

[0003] In the related art, during the process of aligning the silicon wafer and the source substrate, the accuracy of visual alignment is low and cannot meet the requirements. Summary of the invention

[0004] In response to at least one defect or improvement need in the prior art, the present invention provides a laser transfer visual alignment method and device for photovoltaic cells, which solves the problem of low precision of visual alignment and achieves the purpose of improving production speed and high precision.

[0005] To achieve the above-mentioned purpose, according to the first aspect of the present invention, a laser transfer visual alignment method for photovoltaic cells is provided, the method comprising: collecting detection images of silicon wafers and source substrates in a detection area, and preprocessing the detection images, wherein the preprocessing includes distortion correction; positioning the first position of the silicon wafer in a silicon wafer image coordinate system based on the silicon wafer area detected by the detection image, and positioning the second position of the source substrate in a source substrate image coordinate system based on the source substrate area detected by the detection image; converting the second position to the silicon wafer image coordinate system through image mapping calibration to obtain a third position; converting the first position and the third position to a WPM (wafer positioning module) table coordinate system for visual alignment, and converting the second position to the WPM table coordinate system to determine the Y-direction difference compensation value of the source substrate through angle calculation, wherein the Y direction is the extension direction of the source substrate slurry tank.

[0006] In an exemplary embodiment, locating the first position of the silicon wafer in the silicon wafer image coordinate system based on the silicon wafer area detected by the detection image includes: establishing a silicon wafer contour template for the silicon wafer contour in the detection image, and using the silicon wafer contour template to match the position of the silicon wafer; performing edge detection on the silicon wafer area according to the established silicon wafer contour template, and calculating the intersection points of adjacent edges to obtain the first position, wherein the first position includes the coordinates of four vertices of the silicon wafer; and determining the center coordinates of the silicon wafer and the angle information of the silicon wafer by weighted averaging the first position.

[0007] In an exemplary embodiment, locating the second position of the source substrate in the source substrate image coordinate system based on the source substrate area detected by the detection image includes: establishing a mark point contour template based on the specific mark point contour on the source substrate, and using the mark point contour template to match the mark point position on the source substrate; using straight line detection to locate the slurry slot position and angle corresponding to the mark point on the source substrate, wherein the corresponding slurry slot position is matched one by one with the corresponding slurry slot serial number; calculating the position of the first slurry slot on the source substrate and the angle information of the first slurry slot through the corresponding slurry slot serial number and the slurry slot spacing, wherein the angle information of the first slurry slot is the source substrate angle information.

[0008] In an exemplary embodiment, a pair of specific mark points on the source substrate are set at both ends of the same slurry tank extension direction, and the center line of the mark point is the same as the center line of the slurry tank, and the position and angle of the slurry tank corresponding to the mark point on the source substrate are located by straight line detection, including using binary connected region analysis to extract the connection line area of ​​the pair of specific mark points, wherein the position of the connection line of the pair of mark points is the position of the slurry tank, and the angle of the connection line of the pair of mark points is the source substrate angle;

[0009] Alternatively, straight line detection is used to locate the position and angle of the slurry tank corresponding to the mark point on the source substrate, including using straight line detection to locate the upper and lower edge positions of the slurry tank, and bisectoring the upper and lower edge straight lines to obtain the slurry tank center line, wherein the position of the slurry tank center line is the slurry tank position, and the angle of the slurry tank center line is the source substrate angle information.

[0010] In an exemplary embodiment, calculating the position of the first slurry slot on the source substrate by using the corresponding slurry slot serial number and the slurry slot spacing includes:

[0011] According to the slurry tank position and slurry tank serial number, the coordinates (X, Y) of the center point of the first slurry tank of the source substrate are calculated using the formula:

[0012] X=X1+(N1-N0)×P×sinθ

[0013] Y=Y1+(N1-N0)×P×cosθ

[0014] Wherein, P is the distance between adjacent slurry tanks, N1 is the serial number of the slurry tank corresponding to the mark point, N0 is the serial number of the first slurry tank, X1 is the X-axis coordinate value of the center of the slurry tank numbered N1, Y1 is the Y-axis coordinate value of the center of the slurry tank numbered N1, and θ is the angle of the slurry tank numbered N1.

[0015] In an exemplary embodiment, after calculating the first slurry slot position and the source substrate angle information on the source substrate by using the corresponding slurry slot serial number and the slurry slot spacing, the method further includes: calculating the transformation matrix between the silicon wafer image coordinate system and the source substrate image coordinate system by camera mapping calibration; based on the transformation matrix, converting the second position and the source substrate angle information to the silicon wafer image coordinate system by image mapping calibration to obtain the third position and the first source substrate angle information.

[0016] In an exemplary embodiment, after converting the second position and the source substrate angle information to the silicon wafer image coordinate system through image mapping calibration based on the conversion matrix to obtain the third position and the first source substrate angle information, the method further includes: calibrating the silicon wafer station camera and the WPM table at N points, converting the first position and the third position to the WPM table coordinate system to obtain the fourth position and the fifth position respectively, converting the silicon wafer angle information and the first source substrate angle information to the WPM table coordinate system to obtain the first silicon wafer angle information and the second source substrate angle information; performing visual alignment based on the fourth position and the fifth position, the first silicon wafer angle information and the second source substrate angle information, and determining the X-axis direction, Y-axis direction and angle offset value of the silicon wafer under the WPM table.

[0017] In an exemplary embodiment, the method further includes: performing N-point calibration on the source substrate station camera and the WPM table, converting the source substrate angle information to the WPM table coordinate system, and obtaining the source substrate angle value in the WPM table coordinate system; determining the Y-direction difference compensation value ΔY of the source substrate by the source substrate angle value, the number of gate line electrodes, the silicon wafer gate line electrode spacing, and the source substrate slurry tank spacing, and the formula is,

[0018] ΔY=(p wafer -p segment )×N×tan(θ)

[0019] Where: θ is the angle of the source substrate under the WPM table, N is the number of gate line electrodes, p wafer is the distance between silicon wafer gate lines and electrodes, psegment is the spacing between the source substrate slurry groove lines.

[0020] In an exemplary embodiment, the method further includes that during laser dynamic transfer, the WPM table corrects the silicon wafer according to the offset value and angle offset value of the silicon wafer in the X-axis direction and Y-axis direction under the WPM table, so that the angle and position of the silicon wafer and the source substrate correspond, and when the WPM table moves at a specific speed in the X direction to achieve dynamic printing, compensation is performed according to the Y direction difference compensation value at the same time.

[0021] According to the second aspect of the present invention, there is also provided a laser transfer visual alignment device for photovoltaic cells, comprising: an acquisition unit for acquiring detection images of a silicon wafer and a source substrate in a detection area, and preprocessing the detection images, wherein the preprocessing includes distortion correction; a positioning unit for locating a first position of the silicon wafer in a silicon wafer image coordinate system based on a silicon wafer area detected by the detection image, and locating a second position of the source substrate in a source substrate image coordinate system based on a source substrate area detected by the detection image; a first conversion unit for converting the second position to the silicon wafer image coordinate system through image mapping calibration to obtain a third position; a first determination unit for converting the first position and the third position to a WPM table coordinate system for visual alignment, converting the second position to the WPM table coordinate system, and determining the Y-direction difference compensation value of the source substrate through angle calculation; wherein the Y direction is the extension direction of the source substrate slurry tank.

[0022] According to a third aspect of the present invention, there is also provided a computer-readable storage medium, in which a computer program is stored, wherein the computer program is configured to execute the above-mentioned laser transfer visual alignment method for photovoltaic cells when running.

[0023] According to a fourth aspect of the present invention, there is also provided an electronic device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor executes the above-mentioned laser transfer visual alignment method for photovoltaic cells through the computer program.

[0024] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art:

[0025] The present invention provides a method for laser transfer visual alignment of photovoltaic cells. The method collects images of silicon wafers and source substrates, and performs image preprocessing and distortion correction. Then, the silicon wafer area and source substrate area are detected respectively to locate the positions of the silicon wafer and the source substrate. Thirdly, the source substrate position coordinates are converted to the silicon wafer image coordinate system through image mapping calibration, and are converted to the WPM table coordinate system together with the silicon wafer position coordinates for visual alignment. Finally, the angle value of the source substrate on the WPM table is visually positioned, and the Y direction difference compensation value is calculated by the angle during alignment. The method for laser transfer visual alignment of photovoltaic cell equipment of the present invention is used for the visual alignment of silicon wafers and source substrates in the process of producing battery grid lines of the equipment, and has the characteristics of high precision, high speed, good stability, and full automation. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 A schematic diagram of a flow chart of an optional laser transfer visual alignment method for photovoltaic cells provided in an embodiment of the present application;

[0028] Figure 2 A schematic flow chart of another optional photovoltaic cell laser transfer visual alignment method provided in an embodiment of the present application;

[0029] Figure 3 A schematic diagram of an optional source substrate provided in an embodiment of the present application;

[0030] Figure 4 A schematic structural diagram of an optional photovoltaic cell laser transfer visual alignment device provided in an embodiment of the present application;

[0031] Figure 5 A schematic diagram of the structure of an optional electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0033] The terms "first", "second", "third", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices.

[0034] According to one aspect of the embodiments of the present application, a method for laser transfer visual alignment of photovoltaic cells is provided. Figure 1 The laser transfer visual alignment method for photovoltaic cells provided in an embodiment of the present application is described.

[0035] Figure 1 is a flow chart of an optional laser transfer visual alignment method for photovoltaic cells provided in an embodiment of the present application, such as Figure 1 As shown, the process of the method may include the following steps:

[0036] S102, collecting detection images of the silicon wafer and the source substrate in the detection area, and preprocessing the detection images, wherein the preprocessing includes distortion correction;

[0037] S104, positioning a first position of the silicon wafer in the silicon wafer image coordinate system based on the silicon wafer region detected by the detection image, and positioning a second position of the source substrate in the source substrate image coordinate system based on the source substrate region detected by the detection image;

[0038] S106, converting the second position into a silicon wafer image coordinate system through image mapping calibration to obtain a third position;

[0039] S108, converting the first position and the third position to the wafer positioning module (WPM) table coordinate system for visual alignment, converting the second position to the WPM table coordinate system, and determining the Y-direction difference compensation value of the source substrate by angle calculation; wherein the Y direction is the extension direction of the source substrate slurry tank.

[0040] The present application provides an optional laser transfer visual alignment method for photovoltaic cells, which can be used for the visual alignment of silicon wafers and source substrates during the preparation of battery grid electrodes by laser transfer equipment. Those skilled in the art know that the laser transfer equipment includes a source substrate (usually a film), and a laser arranged above the source substrate, and the side of the source substrate facing away from the laser has parallel and spaced linear slurry tanks, the electrode slurry is filled in the slurry tank, the silicon wafer is placed on the WPM table, and the silicon wafer is driven by the WPM table to be transported to the bottom of the source substrate, and the laser irradiates the slurry tank of the source substrate from above to transfer the slurry in the slurry tank to the silicon wafer. The WPM platform can move in the horizontal X-axis, Y-axis and angular directions to complete the transportation and positioning of the silicon wafer. In the present application, the length direction of the grid electrode to be prepared is the Y direction. When the deviation is not considered, the Y direction is the extension direction of the slurry tank, and the X direction is the direction perpendicular to the Y direction. Usually, the silicon wafer is transported to the bottom of the source substrate along the X direction for laser transfer. Exemplarily, Figure 2 A schematic diagram of a flow chart of another optional photovoltaic cell laser transfer visual alignment method provided in an embodiment of the present application, such as Figure 2 As shown, when performing visual alignment, multiple cameras set on the workstation can first collect detection images of the silicon wafer and the source substrate in the detection area, and pre-process the detection images. The pre-processing here can include camera distortion correction, thereby improving the accuracy of image processing and further improving the accuracy of visual alignment.

[0041] Optionally, after collecting the image of the silicon wafer and the image of the source substrate and performing image preprocessing distortion correction, the silicon wafer area and the source substrate area can be detected respectively to locate the position of the silicon wafer and the source substrate. The source substrate position coordinates are converted to the silicon wafer image coordinate system through image mapping calibration to perform a coordinate system conversion. After obtaining the source substrate position and silicon wafer position in the silicon wafer image coordinate system, the position coordinates of the above two are converted together to the WPM table coordinate system for visual alignment to determine the X-axis, Y-axis offset values ​​and angle offset values ​​of the silicon wafer to be aligned under the WPM table. Finally, the angle value of the source substrate on the WPM table is visually positioned, and the Y-direction difference compensation value is calculated by the angle during alignment to complete the visual alignment. Specifically, the movement of the WPM table drives the silicon wafer to move, and the position of the silicon wafer is adjusted according to the aforementioned offset value and angle offset value to align the silicon wafer and the transfer film. During dynamic laser transfer (see the prior art), while the WPM table drives the silicon wafer to move in the X direction to complete dynamic printing, the WPM table moves in the Y direction to compensate for the inherent angle relative to the source substrate.

[0042] Through the above steps S102 to S108, the detection images of the silicon wafer and the source substrate in the detection area are collected and preprocessed, wherein the preprocessing includes distortion correction; positioning the first position of the silicon wafer in the silicon wafer image coordinate system based on the silicon wafer area detected by the detection image, and positioning the second position of the source substrate in the source substrate image coordinate system based on the source substrate area detected by the detection image; converting the second position to the silicon wafer image coordinate system through image mapping calibration to obtain a third position; converting the first position and the third position to the WPM table coordinate system for visual alignment, converting the second position to the WPM table coordinate system for visual alignment, and determining the Y-direction difference compensation of the source substrate through angle calculation, thereby solving the problem of low precision of visual alignment and achieving the purpose of improving production speed and high precision.

[0043] In an exemplary embodiment, collecting detection images of the silicon wafer and the source substrate in the detection area, and preprocessing the detection images includes:

[0044] S11, lighting the silicon wafer through a planar array aperture light source, and lighting the source substrate through a strip light source;

[0045] S12, collecting a detection image of the silicon wafer and the source substrate in the detection area by using an industrial camera, wherein the detection image is a grayscale image;

[0046] S13, obtaining distortion parameters of the industrial camera by using chessboard calibration, and performing distortion correction preprocessing on the detection image according to the distortion parameters.

[0047] In this embodiment, before performing visual alignment of the silicon wafer and the source substrate, detection images of the silicon wafer and the source substrate in the detection area can be collected and pre-processed. For example, a planar array aperture light source can be used to illuminate the silicon wafer, a strip light source can be used to illuminate the source substrate, a silicon wafer industrial camera can be used to collect a grayscale image of the silicon wafer, a source substrate industrial camera can be used to collect a grayscale image of the source substrate, and a checkerboard can be used to calibrate the distortion parameters of the silicon wafer industrial camera and the source substrate industrial camera, and distortion correction pre-processing can be performed on the collected silicon wafer image and the source substrate image.

[0048] Through this embodiment, the collected detection image is pre-processed for distortion correction, which can improve the accuracy of subsequent visual alignment correction through the camera and reduce errors.

[0049] In an exemplary embodiment, it is characterized in that locating a first position of the silicon wafer in the silicon wafer image coordinate system based on the silicon wafer area detected by the detection image includes:

[0050] S21, establishing a silicon wafer outline template for the silicon wafer outline in the detection image, and matching the position of the silicon wafer using the silicon wafer outline template;

[0051] S22, performing edge detection on the silicon wafer region according to the established silicon wafer outline template, respectively calculating intersection points of adjacent edges to obtain a first position, wherein the first position includes coordinates of four vertices of the silicon wafer;

[0052] S23, determining the center coordinates of the silicon wafer and the angle information of the silicon wafer by performing weighted averaging on the first position.

[0053] In an embodiment of the present application, in the process of locating the first position of the silicon wafer in the silicon wafer image coordinate system based on the silicon wafer area detected by the detection image, a template can be established for the silicon wafer contour in the detection image, and the silicon wafer contour template can be used to match the rough position of the silicon wafer. And edge detection is used for the initially detected silicon wafer area (i.e., the aforementioned rough position) to locate the positions of the four sides of the silicon wafer, and the intersections of two adjacent sides of the four sides of the silicon wafer are calculated respectively, so that the four vertex coordinates of the silicon wafer can be obtained, and the weighted average of the four vertex coordinates is calculated to locate the center position of the silicon wafer. At the same time, the angles of the two long sides (two opposite sides) of the located silicon wafer can be weighted averaged to calculate the silicon wafer angle (i.e., silicon wafer angle information).

[0054] Through this embodiment, it is possible to locate the silicon wafer area and determine the angle information of the silicon wafer in the silicon wafer image coordinate system. First, the rough position of the silicon wafer is located, and then the vertex coordinates of the silicon wafer are located based on edge detection, which facilitates subsequent visual alignment and improves the positioning accuracy.

[0055] In an exemplary embodiment, locating a second position of the source substrate in the source substrate image coordinate system based on the source substrate region detected by the detection image includes:

[0056] S31, establishing a mark point contour template based on a specific mark point contour on the source substrate, and using the mark point contour template to match the mark point position on the source substrate;

[0057] S32, using a straight line detection to locate the position and angle of the slurry tank corresponding to the mark point on the source substrate, wherein the corresponding slurry tank is matched with the corresponding slurry tank serial number one by one;

[0058] S33, calculating the position and angle information of the first slurry slot on the source substrate by corresponding line numbers and line spacings.

[0059] In an embodiment of the present application, after detecting the source substrate area respectively, it is necessary to locate the position of the source substrate. Optionally, the second position of the source substrate in the source substrate image coordinate system can be located based on the source substrate area detected by the detection image. Specifically, a template can be established for the contour of a specific mark point on the source substrate, and the mark point contour template can be used to match the mark point position on the source substrate. The position and angle of the slurry tank corresponding to the mark point on the source substrate are located using straight line detection. This angle is the angle of the source substrate, and the first slurry tank position on the source substrate is calculated by the corresponding slurry tank serial number and the slurry tank spacing that correspond one-to-one to the corresponding slurry tank position.

[0060] See also Figure 3 , Figure 3 Schematic diagram of a source substrate; wherein specific mark points on the source substrate are arranged at both ends of the same slurry tank extension direction, usually at the same distance from the edge of the slurry tank. The connection line of a pair of mark points corresponding to the same slurry tank is the same as the extension direction of the slurry tank. Usually, in order to improve the positioning accuracy, the mark points usually include multiple pairs, corresponding to multiple slurry tanks. It can be understood by those skilled in the art that the slurry tanks are multiple and spaced in parallel, with the first slurry tank at the edge numbered 1, and the rest are numbered in sequence.

[0061] Among them, S32, the position and angle of the slurry tank corresponding to the mark point on the source substrate are located by using straight line detection. Specifically, for the connecting line of a pair of mark points, the line area can be extracted by using binary large object analysis (BLOB). The position of the connecting line of a pair of mark points is the position of the slurry tank, and its angle is the source substrate angle.

[0062] You can also use straight line detection to locate the upper and lower edge positions of the slurry tank, and perform bisector processing on the upper and lower edge straight lines to locate the center line of the slurry tank. The position of the center line is the slurry tank position, and the angle is the source substrate angle information.

[0063] Among them, S33, the position of the first slurry slot on the source substrate is calculated by corresponding to the slurry slot serial number and the slurry spacing. The specific method is to calculate the coordinates (X, Y) of the center point of the first slurry slot of the source substrate according to the slurry slot position and the slurry slot serial number. The formula is as follows:

[0064] X=X1+(N1-N0)×P×sinθ

[0065] Y=Y1+(N1-N0)×P×cosθ

[0066] Wherein, P is the distance between adjacent slurry tanks, N1 is the serial number of the slurry tank corresponding to the mark point, N0 is the serial number of the first slurry tank, X1 is the X-axis coordinate value of the center of the slurry tank with serial number N1, Y1 is the Y-axis coordinate value of the center of the slurry tank with serial number N1, and θ is the angle of the slurry tank with serial number N1. Since the slurry tanks are arranged on the source substrate in parallel and spaced apart, this angle is also the angle of the first slurry tank, that is, the source substrate angle. In an exemplary embodiment, after calculating the position and angle of the first slurry tank on the source substrate by corresponding to the slurry tank serial number and the slurry tank spacing, the above method further includes:

[0067] S41, calculating the conversion matrix between the silicon wafer image coordinate system and the source substrate image coordinate system through camera mapping calibration;

[0068] S42, based on the conversion matrix, convert the second position and the source substrate angle information into a silicon wafer image coordinate system through image mapping calibration to obtain the third position and the first source substrate angle information.

[0069] In this embodiment, after calculating the position and angle of the first slurry slot on the source substrate by corresponding to the slurry slot number and the slurry slot spacing, the source substrate position coordinates (second position) can be converted to the silicon wafer image coordinate system through image mapping calibration, and converted to the WPM table coordinate system together with the silicon wafer position coordinates for visual alignment.

[0070] Optionally, the relationship matrix of the two camera image coordinate systems, i.e., the conversion matrix, can be calculated by performing camera mapping calibration on the wafer station camera and the source substrate station camera. Further, based on the above conversion matrix, the source substrate position coordinates and the source substrate angle information can be converted to the wafer station camera image coordinate system (silicon wafer image coordinate system) to obtain the third position of the source substrate position coordinates in the silicon wafer image coordinate system, and the source substrate angle information is converted to the first source substrate angle information in the silicon wafer image coordinate system.

[0071] In an exemplary embodiment, after converting the second position and the source substrate angle information to the silicon wafer image coordinate system through image mapping calibration based on the conversion matrix to obtain the third position and the first source substrate angle information, the method further includes:

[0072] S51, perform N-point calibration on the wafer station camera and the WPM table, convert the first position and the third position to the WPM table coordinate system, obtain the fourth position and the fifth position respectively, convert the wafer angle information and the first source substrate angle information to the WPM table coordinate system, and obtain the first wafer angle information and the second source substrate angle information;

[0073] S52, performing visual alignment based on the fourth position and the fifth position, the first silicon wafer angle information and the second source substrate angle information, to determine the X-axis direction, Y-axis direction and angle offset value of the silicon wafer under the WPM table.

[0074] In this embodiment, after the second position and the source substrate angle information are converted to the silicon wafer image coordinate system through image mapping calibration based on the conversion matrix, and the third position and the first source substrate angle information are obtained, the silicon wafer station camera and the WPM table can be calibrated at N points, and the silicon wafer position and the source substrate position in the image coordinate system are converted to the WPM table coordinate system, that is, the first position and the third position are converted to the WPM table coordinate system, and the fourth position and the fifth position are obtained respectively. Similarly, the silicon wafer angle information and the first source substrate angle information can be converted to the WPM table coordinate system to obtain the first silicon wafer angle information and the second source substrate angle information, and the silicon wafer angle information and the first source substrate angle information can be converted to the WPM table coordinate system. Further, the silicon wafer coordinate position (fourth position) and the source substrate coordinate position (fifth position) in the WPM table coordinate system and the angle information of the two (that is, the first silicon wafer angle information and the second source substrate angle information) can be visually aligned, and the X-axis and Y-axis offset values ​​and angle offsets of the silicon wafer to be aligned under the WPM table are calculated.

[0075] Through this embodiment, the offset value and the angle offset value of the alignment movement of the silicon wafer relative to the source substrate are calculated, and the alignment of the silicon wafer and the source substrate can be controlled based on the above values.

[0076] In an exemplary embodiment, the method further includes: S61, performing N-point calibration on the source substrate station camera and the WPM table, converting the source substrate angle information into the WPM table coordinate system, and obtaining the source substrate angle value in the WPM table coordinate system;

[0077] S62, determining the Y-direction difference compensation value of the source substrate according to the source substrate angle value, the number of gate line electrodes, the distance between silicon wafer gate line electrodes, and the distance between source substrate slurry tanks.

[0078] In this embodiment, the angle value of the source substrate on the WPM table is visually positioned, and the Y-direction difference compensation value is calculated by angle during alignment. N-point calibration is performed between the source substrate station camera and the WPM table, and the first source substrate angle information positioned in the camera image coordinate system is converted to the WPM table to obtain the second source substrate angle information, and then the source substrate angle value in the WPM table coordinate system can be obtained.

[0079] Exemplarily, the difference compensation distance ΔY in the Y direction of the source substrate can be calculated by the source substrate angle value, the number of gate line electrodes, the silicon wafer gate line electrode spacing, and the source substrate slurry tank spacing, and the formula is as follows:

[0080] ΔY=(p wafer -p segment )×N×tan(θ)

[0081] Where: θ is the angle of the source substrate under the WPM table, N is the number of gate line electrodes, p wafer is the distance between silicon wafer gate lines and electrodes, p segment is the spacing between the source substrate slurry groove lines.

[0082] Through this embodiment, the angle value of the source substrate on the WPM table is visually positioned, and the Y-direction difference compensation value is calculated by the angle during alignment, which is used for visual alignment of silicon wafers and source substrates during the equipment production of battery grid lines, thereby improving the accuracy and efficiency of visual alignment.

[0083] When performing laser dynamic transfer, the WPM table first corrects the silicon wafer so that the angle and position of the silicon wafer and the source substrate correspond. Specifically, there is no angle deviation between the silicon wafer and the source substrate, and the position of the first gate electrode to be transferred on the silicon wafer corresponds to the position of the first slurry tank of the source substrate. During transfer, when the WPM table moves at a specific speed in the X direction to achieve dynamic printing, it compensates according to the Y direction difference compensation value to achieve correction of the inherent angle deviation relative to the source substrate, thereby improving the accuracy of dynamic printing.

[0084] According to another aspect of the embodiments of the present application, a laser transfer visual alignment device for implementing the above-mentioned laser transfer visual alignment method for photovoltaic cells is also provided. Figure 4 is a schematic structural diagram of an optional photovoltaic cell laser transfer visual alignment device according to an embodiment of the present application, such as Figure 4 As shown, the device may include:

[0085] The acquisition unit 402 is used to acquire the detection images of the silicon wafer and the source substrate in the detection area, and pre-process the detection images, wherein the pre-processing includes distortion correction;

[0086] A positioning unit 404 is used to position a first position of the silicon wafer in a silicon wafer image coordinate system based on a silicon wafer region detected by the detection image, and to position a second position of the source substrate in a source substrate image coordinate system based on a source substrate region detected by the detection image;

[0087] A first conversion unit 406, configured to convert the second position into the wafer image coordinate system through image mapping calibration to obtain a third position;

[0088] The first determination unit 408 is used to convert the first position and the third position to the WPM table coordinate system for visual alignment, convert the second position to the WPM table coordinate system, and determine the Y-direction difference compensation value of the source substrate by angle calculation; wherein the Y direction is the extension direction of the source substrate slurry tank.

[0089] It should be noted that the collection unit 402 in this embodiment can be used to execute the above step S102, the positioning unit 404 in this embodiment can be used to execute the above step S104, the first conversion unit 406 in this embodiment can be used to execute the above step S106, and the first determination unit 408 in this embodiment can be used to execute the above step S108.

[0090] Through the above module, the detection images of the silicon wafer and the source substrate in the detection area are collected and preprocessed, wherein the preprocessing includes distortion correction; positioning the first position of the silicon wafer in the silicon wafer image coordinate system based on the silicon wafer area detected by the detection image, and positioning the second position of the source substrate in the source substrate image coordinate system based on the source substrate area detected by the detection image; converting the second position to the silicon wafer image coordinate system through image mapping calibration to obtain the third position; converting the first position and the third position to the WPM table coordinate system for visual alignment, converting the second position to the WPM table coordinate system for visual alignment, and determining the Y-direction difference compensation of the source substrate through angle calculation, thereby solving the problem of low precision of visual alignment and achieving the purpose of improving production speed and high precision.

[0091] In an exemplary embodiment, the acquisition unit comprises:

[0092] A lighting module, used to light the silicon wafer through a planar array aperture light source, and to light the source substrate through a strip light source;

[0093] An acquisition module, used for acquiring the detection image of the silicon wafer and the source substrate in the detection area through an industrial camera, wherein the detection image is a grayscale image;

[0094] The preprocessing module is used to obtain the distortion parameters of the industrial camera by using chessboard calibration, and perform distortion correction preprocessing on the detection image according to the distortion parameters.

[0095] In an exemplary embodiment, the positioning unit comprises:

[0096] A first establishing module is used to establish a silicon wafer outline template for the silicon wafer outline in the detection image, and use the silicon wafer outline template to match the position of the silicon wafer;

[0097] An edge detection module, used to perform edge detection on the silicon wafer area according to the established silicon wafer outline template, and calculate intersection points of adjacent edges to obtain the first position, wherein the first position includes coordinates of four vertices of the silicon wafer;

[0098] A determination module is used to determine the center coordinates of the silicon wafer and the angle information of the silicon wafer by performing weighted averaging on the first position.

[0099] In an exemplary embodiment, the positioning unit comprises:

[0100] A second establishing module is used to establish a mark point contour template based on the specific mark point contour on the source substrate, and use the mark point contour template to match the mark point position on the source substrate;

[0101] A detection and positioning module, used for using straight line detection to locate the position and angle of the slurry slot corresponding to the mark point on the source substrate, wherein the corresponding slurry slot position is matched with the corresponding slurry slot serial number one by one;

[0102] A calculation module is used to calculate the position of the first slurry slot on the source substrate and the source substrate angle information according to the corresponding line sequence number and line spacing.

[0103] In an exemplary embodiment, a pair of specific mark points on the source substrate are arranged at two ends of the same slurry tank extension direction, and the center line of the mark point is the same as the center line of the slurry tank, and the detection and positioning module includes: an analysis and extraction submodule, which is used to extract a connection line area of ​​a pair of specific mark points by using a binary connected region analysis, wherein the position of the connection line of the pair of mark points is the position of the slurry tank, and the angle of the connection line of the pair of mark points is the source substrate angle;

[0104] Alternatively, the detection and positioning module includes: a detection and positioning sub-module, which is used to use straight line detection to locate the upper and lower edge positions of the slurry tank, and to perform bisector processing on the upper and lower edge straight lines to obtain the center line of the slurry tank, wherein the position of the center line of the slurry tank is the slurry tank position, and the angle of the center line of the slurry tank is the source substrate angle information.

[0105] In an exemplary embodiment, the computing module includes,

[0106] The calculation submodule is used to calculate the coordinates (X, Y) of the center point of the first slurry tank of the source substrate according to the slurry tank position and the slurry tank sequence number. The formula is:

[0107] X=X1+(N1-N0)×P×sinθ

[0108] Y=Y1+(N1-N0)×P×cosθ

[0109] Wherein, P is the distance between adjacent slurry tanks, N1 is the serial number of the slurry tank corresponding to the mark point, N0 is the serial number of the first slurry tank, X1 is the X-axis coordinate value of the center of the slurry tank numbered N1, Y1 is the Y-axis coordinate value of the center of the slurry tank numbered N1, and θ is the angle of the slurry tank numbered N1.

[0110] In an exemplary embodiment, the apparatus further comprises:

[0111] A calculation unit, used for calculating a transformation matrix between the silicon wafer image coordinate system and the source substrate image coordinate system through camera mapping calibration;

[0112] The second conversion unit is used to convert the second position and the source substrate angle information into the silicon wafer image coordinate system through image mapping calibration based on the conversion matrix to obtain the third position and the first source substrate angle information.

[0113] In an exemplary embodiment, the apparatus further comprises:

[0114] A first calibration unit is used to perform N-point calibration on the wafer station camera and the WPM table, convert the first position and the third position to the WPM table coordinate system, obtain the fourth position and the fifth position respectively, convert the wafer angle information and the first source substrate angle information to the WPM table coordinate system, and obtain the first wafer angle information and the second source substrate angle information;

[0115] The visual alignment unit is used to perform visual alignment based on the fourth position and the fifth position, the first silicon wafer angle information and the second source substrate angle information, and determine the X-axis direction, Y-axis direction and angle offset value of the silicon wafer under the WPM table.

[0116] In an exemplary embodiment, the apparatus further comprises:

[0117] A second calibration unit is used to perform N-point calibration on the source substrate station camera and the WPM table, convert the source substrate angle information into the WPM table coordinate system, and obtain the source substrate angle value in the WPM table coordinate system;

[0118] The second determination unit is used to determine the Y-direction difference compensation value ΔY of the source substrate according to the source substrate angle value, the number of gate line electrodes, the silicon wafer gate line electrode spacing and the source substrate slurry tank spacing, and the formula is:

[0119] ΔY=(p wafer -p segment )×N×tan(θ)

[0120] Where: θ is the angle of the source substrate under the WPM table, N is the number of gate line electrodes, p wafer is the distance between silicon wafer gate lines and electrodes, p segment is the spacing between the source substrate slurry groove lines.

[0121] In an exemplary embodiment, the device further includes an execution unit, which is used for laser dynamic transfer. The WPM table corrects the silicon wafer according to the offset value and angle offset value of the silicon wafer in the X-axis direction and Y-axis direction under the WPM table, so that the angle and position of the silicon wafer and the source substrate correspond. When the WPM table moves at a specific speed in the X direction to realize dynamic printing, compensation is performed according to the Y direction difference compensation value at the same time.

[0122] It should be noted here that the examples and scenarios implemented by the above-mentioned modules and corresponding steps are the same, but are not limited to the contents disclosed in the above-mentioned embodiments. It should be noted that the above-mentioned modules as part of the device can run in a hardware environment and can be implemented by software or hardware, wherein the hardware environment includes a network environment.

[0123] According to another aspect of the embodiments of the present application, a storage medium is further provided. Optionally, in this embodiment, the storage medium can be used to execute the program code of any of the above photovoltaic cell laser transfer visual alignment methods in the embodiments of the present application.

[0124] Optionally, in this embodiment, the storage medium is configured to store program codes for executing the following steps:

[0125] S1, collecting detection images of the silicon wafer and the source substrate in the detection area, and preprocessing the detection images, wherein the preprocessing includes distortion correction.

[0126] S2, positioning a first position of the silicon wafer in the silicon wafer image coordinate system based on the silicon wafer region detected by the detection image, and positioning a second position of the source substrate in the source substrate image coordinate system based on the source substrate region detected by the detection image.

[0127] S3, converting the second position into a silicon wafer image coordinate system through image mapping calibration to obtain a third position.

[0128] S4, converting the first position and the third position to the WPM table coordinate system for visual alignment, converting the second position to the WPM table coordinate system, and determining the Y direction difference compensation value of the source substrate by angle calculation; wherein the Y direction is the extension direction of the source substrate slurry tank.

[0129] Optionally, the specific examples in this embodiment may refer to the examples described in the above embodiments, which will not be described in detail in this embodiment.

[0130] Among them, computer-readable storage media may include, but are not limited to, any type of disk, including floppy disks, optical disks, DVDs, CD-ROMs, microdrives and magneto-optical disks, ROMs, RAMs, EPROMs, EEPROMs, DRAMs, VRAMs, flash memory devices, magnetic or optical cards, nanosystems (including molecular memory ICs), or any type of medium or device suitable for storing instructions and / or data.

[0131] According to another aspect of the embodiments of the present application, an electronic device for implementing the above-mentioned laser transfer visual alignment method for photovoltaic cells is also provided. The electronic device may be a server, a terminal, or a combination thereof.

[0132] Figure 5 is a schematic diagram of the structure of an optional electronic device according to an embodiment of the present application, such as Figure 5 As shown, it includes a processor 502, a communication interface 504, a memory 506 and a communication bus 508, wherein the processor 502, the communication interface 504, and the memory 506 communicate with each other through the communication bus 508, wherein:

[0133] Memory 506, used for storing computer programs;

[0134] The processor 502 is used to execute the computer program stored in the memory 506 to implement the following steps:

[0135] S1, collecting detection images of the silicon wafer and the source substrate in the detection area, and preprocessing the detection images, wherein the preprocessing includes distortion correction.

[0136] S2, positioning a first position of the silicon wafer in the silicon wafer image coordinate system based on the silicon wafer region detected by the detection image, and positioning a second position of the source substrate in the source substrate image coordinate system based on the source substrate region detected by the detection image.

[0137] S3, converting the second position into a silicon wafer image coordinate system through image mapping calibration to obtain a third position.

[0138] S4, converting the first position and the third position to the WPM table coordinate system for visual alignment, converting the second position to the WPM table coordinate system, and determining the Y direction difference compensation value of the source substrate by angle calculation; wherein the Y direction is the extension direction of the source substrate slurry tank.

[0139] Optionally, the communication bus may be a PCI (Peripheral Component Interconnect) bus, or an EISA (Extended Industry Standard Architecture) bus, etc. The communication bus may be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 5 The communication interface is used for communication between the electronic device and other devices.

[0140] The memory may include RAM, or may include non-volatile memory, such as at least one disk memory. Optionally, the memory may also be at least one storage device located away from the aforementioned processor.

[0141] As an example, the memory 506 may include, but is not limited to, the acquisition unit 402, the positioning unit 404, the first conversion unit 406, and the first determination unit 408 in the laser transfer visual alignment device for the photovoltaic cell. In addition, it may also include, but is not limited to, other module units in the laser transfer visual alignment device for the photovoltaic cell, which will not be described in detail in this example.

[0142] The above-mentioned processor can be a general-purpose processor, which can include but not be limited to: CPU (Central Processing Unit), NP (Network Processor), etc.; it can also be DSP (Digital Signal Processing), ASIC (Application Specific Integrated Circuit), FPGA (Field-Programmable Gate Array) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components.

[0143] Optionally, the specific examples in this embodiment may refer to the examples described in the above embodiments, and this embodiment will not be described in detail here.

[0144] It should be noted that, for the aforementioned method embodiments, for the sake of simplicity, they are all expressed as a series of action combinations, but those skilled in the art should be aware that the present application is not limited by the described order of actions, because according to the present application, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present application.

[0145] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0146] In the several embodiments provided in the present application, it should be understood that the disclosed devices can be implemented in other ways. For example, the device embodiments described above are only schematic, such as the division of the units, which is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some service interfaces, and the indirect coupling or communication connection of devices or units can be electrical or other forms.

[0147] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0148] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0149] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable memory. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a memory, including a number of instructions to enable a computer device (which can be a personal computer, server or network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned memory includes: U disk, read-only memory (ROM), random access memory (RAM), mobile hard disk, disk or optical disk and other media that can store program code.

[0150] A person of ordinary skill in the art can understand that all or part of the steps in the various methods of the above embodiments can be completed by instructing related hardware through a program, and the program can be stored in a computer-readable memory, which can include: a flash drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, etc.

[0151] The above is only an exemplary embodiment of the present disclosure, and the scope of the present disclosure cannot be limited thereto. That is, any equivalent changes and modifications made according to the teachings of the present disclosure are still within the scope of the present disclosure. After considering the specification and practicing the disclosure here, those skilled in the art will easily think of the implementation scheme of the present disclosure. This application is intended to cover any modification, use or adaptation of the present disclosure, which follows the general principles of the present disclosure and includes common knowledge or customary technical means in the technical field not recorded in the present disclosure. The description and examples are regarded as exemplary only, and the scope and spirit of the present disclosure are defined by the claims.

[0152] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, 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, they should be considered to be within the scope of this specification.

[0153] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A laser transfer visual alignment method for photovoltaic cells, characterized in that: include: Collecting detection images of the silicon wafer and the source substrate in the detection area, and preprocessing the detection images, wherein the preprocessing includes distortion correction; Positioning a first position of the silicon wafer in a silicon wafer image coordinate system based on a silicon wafer region detected by the detection image, and positioning a second position of the source substrate in a source substrate image coordinate system based on a source substrate region detected by the detection image; Converting the second position to the silicon wafer image coordinate system through image mapping calibration to obtain a third position; The first position and the third position are converted to the WPM table coordinate system for visual alignment, and the second position is converted to the WPM table coordinate system, and the Y-direction difference compensation value of the source substrate is determined by angle calculation; The Y direction is the extension direction of the source substrate slurry tank.

2. The laser transfer visual alignment method for photovoltaic cells according to claim 1, characterized in that: The step of locating a first position of the silicon wafer in a silicon wafer image coordinate system based on the silicon wafer region detected by the detection image comprises: Establishing a silicon wafer outline template for the silicon wafer outline in the detection image, and matching the position of the silicon wafer using the silicon wafer outline template; Perform edge detection on the silicon wafer region according to the established silicon wafer outline template, calculate intersection points of adjacent edges respectively, and obtain the first position, wherein the first position includes coordinates of four vertices of the silicon wafer; The center coordinates of the silicon wafer and the angle information of the silicon wafer are determined by performing weighted averaging on the first positions.

3. The laser transfer visual alignment method for photovoltaic cells according to claim 1, characterized in that: The positioning of the second position of the source substrate in the source substrate image coordinate system based on the source substrate region detected by the detection image comprises: Establishing a mark point contour template based on the specific mark point contour on the source substrate, and matching the mark point position on the source substrate using the mark point contour template; Using straight line detection to locate the position and angle of the slurry tank corresponding to the mark point on the source substrate, wherein the corresponding slurry tank position is matched with the corresponding slurry tank serial number one by one; The position of the first slurry slot on the source substrate and the angle information of the first slurry slot are calculated by the corresponding slurry slot serial number and the slurry slot spacing, wherein the angle information of the first slurry slot is the angle information of the source substrate.

4. The laser transfer visual alignment method for photovoltaic cells according to claim 3, characterized in that: A pair of specific mark points on the source substrate are set at the two ends of the same slurry tank extension direction, and the center line of the mark point is the same as the center line of the slurry tank, and the position and angle of the slurry tank corresponding to the mark point on the source substrate are located by straight line detection, including using binary connected region analysis to extract the connection line area of ​​the pair of specific mark points, wherein the position of the connection line of the pair of mark points is the position of the slurry tank, and the angle of the connection line of the pair of mark points is the source substrate angle; Alternatively, straight line detection is used to locate the position and angle of the slurry tank corresponding to the mark point on the source substrate, including using straight line detection to locate the upper and lower edge positions of the slurry tank, and bisectoring the upper and lower edge straight lines to obtain the slurry tank center line, wherein the position of the slurry tank center line is the slurry tank position, and the angle of the slurry tank center line is the source substrate angle information.

5. The laser transfer visual alignment method for photovoltaic cells according to claim 3, characterized in that: Calculating the position of the first slurry slot on the source substrate by using the corresponding slurry slot serial number and the slurry slot spacing includes: According to the slurry tank position and slurry tank serial number, the coordinates (X, Y) of the center point of the first slurry tank of the source substrate are calculated using the formula: X=X1+(N1-N0)×P×sinθ Y=Y1+(N1-N0)×P×cosθ Wherein, P is the distance between adjacent slurry tanks, N1 is the serial number of the slurry tank corresponding to the mark point, N0 is the serial number of the first slurry tank, X1 is the X-axis coordinate value of the center of the slurry tank numbered N1, Y1 is the Y-axis coordinate value of the center of the slurry tank numbered N1, and θ is the angle of the slurry tank numbered N1.

6. The laser transfer visual alignment method for photovoltaic cells according to claim 3, characterized in that: After calculating the first slurry slot position on the source substrate and the source substrate angle information by using the corresponding line slurry slot number and line spacing, the method further includes: Calculating the transformation matrix between the silicon wafer image coordinate system and the source substrate image coordinate system through camera mapping calibration; Based on the conversion matrix, the second position and the source substrate angle information are converted to the silicon wafer image coordinate system through image mapping calibration to obtain the third position and the first source substrate angle information.

7. The laser transfer visual alignment method for photovoltaic cells according to claim 6, characterized in that: After converting the second position and the source substrate angle information to the silicon wafer image coordinate system through image mapping calibration based on the conversion matrix to obtain the third position and the first source substrate angle information, the method further includes: Perform N-point calibration on the wafer station camera and the WPM table, convert the first position and the third position to the WPM table coordinate system, obtain the fourth position and the fifth position respectively, convert the wafer angle information and the first source substrate angle information to the WPM table coordinate system, and obtain the first wafer angle information and the second source substrate angle information; Based on the fourth position and the fifth position, the first silicon wafer angle information and the second source substrate angle information, visual alignment is performed to determine the X-axis direction, Y-axis direction and angle offset value of the silicon wafer under the WPM table.

8. The laser transfer visual alignment method for photovoltaic cells according to any one of claims 1 to 7, characterized in that: The method further comprises: Performing N-point calibration on the source substrate station camera and the WPM table, converting the source substrate angle information into the WPM table coordinate system, and obtaining the source substrate angle value in the WPM table coordinate system; The Y-direction difference compensation value ΔY of the source substrate is determined by the source substrate angle value, the number of gate line electrodes, the silicon wafer gate line electrode spacing and the source substrate slurry tank spacing, and the formula is: ΔY=(p wafer -p segment )×N×tan(θ) Where: θ is the angle of the source substrate under the WPM table, N is the number of gate line electrodes, p wafer is the distance between silicon wafer gate lines and electrodes, p segment is the spacing between the source substrate slurry groove lines.

9. The laser transfer visual alignment method for photovoltaic cells according to claim 8, characterized in that: The method also includes that during laser dynamic transfer, the WPM table corrects the silicon wafer according to the offset value and angle offset value of the silicon wafer in the X-axis direction and Y-axis direction under the WPM table, so that the angle and position of the silicon wafer and the source substrate correspond, and when the WPM table moves at a specific speed in the X direction to realize dynamic printing, compensation is performed according to the Y direction difference compensation value at the same time.

10. A laser transfer visual alignment device for photovoltaic cells, characterized in that: include: A collection unit, used for collecting the detection images of the silicon wafer and the source substrate in the detection area, and preprocessing the detection images, wherein the preprocessing includes distortion correction; a positioning unit, configured to position a first position of the silicon wafer in a silicon wafer image coordinate system based on a silicon wafer region detected by the detection image, and to position a second position of the source substrate in a source substrate image coordinate system based on a source substrate region detected by the detection image; A first conversion unit, used for converting the second position into the silicon wafer image coordinate system through image mapping calibration to obtain a third position; The first determination unit is used to convert the first position and the third position to the WPM table coordinate system for visual alignment, convert the second position to the WPM table coordinate system, and determine the Y-direction difference compensation value of the source substrate by angle calculation; wherein the Y direction is the extension direction of the source substrate slurry tank.

Images