A method, apparatus and storage medium for printing a positive electrode of a solar web

Abstract

A solar screen positive electrode printing method, comprising the following steps: S1, pouring the prepared positive electrode slurry on one end of the solar screen; S2, using a scraper to evenly scrape the slurry across the screen, so that the slurry is printed on the silicon wafer through the pores of the screen; S3, starting the screen printing machine to start printing; S4, after printing is completed, taking out the silicon wafer and drying the silicon wafer; the present application solves the problem caused by the deviation of the scraper angle before and during printing, accurately controls the scraper angle and the slurry content, thereby realizing a solar screen positive electrode printing method without broken line defects and short circuit defects, and the present application determines the slurry weight threshold by calculating the screen subsidence volume and compares the weight, strictly controls the slurry amount, lays a foundation for the uniformity and quality of subsequent printing, and avoids defects caused by improper slurry amount.

Description

Technical Field

[0001] This invention relates to the field of solar screen printing, and in particular to a method, apparatus and storage medium for printing the positive electrode of a solar screen. Background Technology

[0002] With the increasing global demand for clean energy, the optimization of the manufacturing process for solar cells, as a sustainable energy conversion device, is crucial. In solar cell production, positive electrode printing is a key step, and its quality directly affects many aspects of the solar cell, including photoelectric conversion efficiency and performance stability. Traditional positive electrode printing methods often suffer from problems such as difficulty in precisely controlling printing accuracy, susceptibility to various printing defects, and a lack of efficient and flexible quality monitoring and adjustment mechanisms. This results in inconsistent performance of the produced solar cells, limiting the further development of the solar cell industry.

[0003] For example, line breakage defects can occur when lines in the positive electrode pattern are interrupted. For instance, the conductive lines of the electrode, which should be continuous, may be partially missing after printing, forming intermittent breaks. This can be due to factors related to the screen, such as the screen becoming clogged with dried ink after prolonged use, or the screen itself having uneven openings or defects during manufacturing, preventing the ink from passing through evenly and causing line breakage. It can also be due to problems with the squeegee, such as an uneven squeegee blade that misses some ink during squeegeeing, or uneven squeegee pressure that fails to fully compress the ink through the screen openings in areas with finer lines, thus leading to line breakage.

[0004] Alternatively, it could be a short circuit defect. Inappropriate conductive connections appear between different parts of the positive electrodes that should be mutually insulated and independent, disrupting the normal circuit layout of the electrodes. This includes printing accuracy issues, such as excessive speed, pressure, or improper angle of the squeegee when scraping the paste, causing the paste to overflow the originally designed electrode pattern area, connecting adjacent electrode lines with excess paste and causing a short circuit. It also includes screen malfunctions, such as pattern deviations during screen production, or excessively large gaps in the isolation area between electrodes, allowing paste to pass through these gaps that should not be able to pass through, connecting different electrode parts and causing a short circuit.

[0005] In summary, most of the problems are caused by the deviation of the squeegee angle between the pre-printing and printing stages. Therefore, there is an urgent need for a positive electrode printing method for solar screen printing that can achieve unbroken lines and short circuits. Summary of the Invention

[0006] In order to solve the above-mentioned technical problems, the present invention provides a method, apparatus and storage medium for printing the positive electrode of a solar screen.

[0007] The technical solution of the present invention is implemented as follows:

[0008] A positive electrode printing method for a solar screen, comprising the following steps:

[0009] S1: Pour the prepared positive electrode slurry onto one end of the solar screen;

[0010] S2: Use a scraper to evenly scrape the slurry across the screen, so that the slurry passes through the pores of the screen and is printed onto the silicon wafer;

[0011] S3: Start the screen printing machine to begin printing;

[0012] S4: After printing is completed, take out the silicon wafer and dry the silicon wafer.

[0013] Preferably, said S1 further comprises the following sub-steps:

[0014] S11: Calculate the sag volume V of the screen;

[0015] S12: Based on the sag volume V and the weight of the slurry per cubic centimeter, calculate the total required weight K of the slurry with the sag volume V as the total volume of the slurry, and set a threshold for the total slurry amount where 2<K< the set value, in grams;

[0016] S13: Pour the positive electrode slurry onto one end of the solar screen, weigh the total weight of the slurry, perform the next operation after the weight conforms to the threshold range by comparing with the threshold set in step S12; otherwise, use another screen as the printing substrate and reset the aforementioned screen that exceeds the threshold;

[0017] S14: Record the flow condition of the slurry on the solar screen and conduct slurry analysis.

[0018] Preferably, said S2 further comprises the following sub-steps:

[0019] S21: Measure the angle between the scraper and the plane of the screen, and set the angle threshold at 45-60°;

[0020] S22: Adjust the angle between the scraper and the plane of the screen for the first time, making the adjustment based on the measurement result in step S21 and the threshold;

[0021] S22: Adjust the angle between the scraper and the plane of the screen for the second time, and finely adjust the angle between the scraper and the plane of the screen based on the slurry analysis result in step S14.

[0022] Preferably, step S14 specifically involves: recording video of the slurry flowing on the solar screen using a camera; analyzing the slurry characteristics using image processing technology; and setting the slurry flow speed to v0; recording video of the slurry flowing on the solar screen using a camera; analyzing the forming image of the slurry on the solar screen using image recognition technology; analyzing whether the slurry is fully loaded on the solar screen based on the image; if the analysis result indicates a broken wire defect, adding slurry based on the area t of the broken wire location; if the analysis result indicates a missing part, adding n units of slurry based on the area of ​​the missing part, until the analysis result indicates full loading; if the analysis result indicates overload overflow, using a dropper to remove 1 unit of slurry, until the analysis result indicates full loading.

[0023] Preferably, step S14 specifically involves comparing the video to determine the current slurry flow rate as v1, and the ratio of the current slurry flow rate to the preset slurry flow rate as u, where v0 / v1 = u. At the preset slurry flow rate, the angle between the optimal squeegee and the screen plane is 45°. Through calculation, it is found that the angle between the optimal squeegee and the screen plane at the current slurry flow rate is 45° * u = m°.

[0024] Preferably, in step S3, after printing begins, the printing quality is monitored in real time using high-definition cameras installed around the printing press and a microscopic image acquisition device below the screen. Image data is acquired every 0.1 seconds, and the squeegee angle is observed. The preset squeegee angle is m±1°.

[0025] A positive electrode printing apparatus for a solar screen includes at least one processor, at least one memory, and computer program instructions stored in the memory. When the computer program instructions are executed by the processor, the above-described positive electrode printing method for a solar screen is implemented.

[0026] A storage medium storing computer program instructions, which, when executed by a processor, implement the above-described method for printing the positive electrode of a solar screen.

[0027] This invention solves the problem caused by the deviation of the squeegee angle between pre-printing and printing. It precisely controls the squeegee angle and ink content to achieve a solar cell screen printing method with no broken lines or short circuits. Furthermore, this invention determines the ink weight threshold by calculating the screen's sinking volume and comparing the weights, strictly controlling the ink usage to lay the foundation for uniformity and quality in subsequent printing. This avoids defects caused by unsuitable ink quantity. The squeegee and screen plane angle is adjusted twice based on different references: first, a preliminary calibration using a conventional and reasonable threshold, and then fine-tuning based on actual ink flow analysis. This allows the squeegee angle to be more suitable for the printing process, ensuring uniform ink penetration through the screen apertures. A high-definition camera and microscopic image acquisition device are used to monitor printing quality in real time, acquiring image data every 0.1 seconds. A preset squeegee angle range is also included to facilitate timely detection and rapid adjustment of the squeegee angle, minimizing printing defects, improving yield, and ensuring the printing effect of the solar cell's positive electrode. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of a positive electrode printing method for a solar screen according to the present invention. Detailed Implementation

[0029] The technical means and effects adopted by the present invention to achieve the intended inventive objective will be further elaborated here. Exemplary embodiments will be described in detail, examples of which are illustrated in the accompanying drawings. In the following description referring to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of methods and systems consistent with some aspects of this application as detailed in the appended claims.

[0030] The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The singular forms “a,” “the,” and “the” used in this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any and all possible combinations of one or more of the associated listed items.

[0031] Example 1

[0032] The present invention discloses a method for printing the positive electrode of a solar cell screen, comprising the following steps:

[0033] S1, pour the prepared positive electrode paste onto one end of the solar grid;

[0034] Preferably, step S1 further includes the following sub-steps:

[0035] S11, calculating the depression volume V of the screen printing stencil;

[0036] S12, based on the depression volume V and the weight of the paste per cubic centimeter, calculating the total required weight K of the paste with the depression volume V taken as the total volume of the paste, and setting a threshold for the total paste amount where 2 < K < a predetermined value, with the unit being gram;

[0037] S13, pouring the positive electrode paste onto one end of the solar screen printing stencil, weighing the total weight of the paste, performing the next operation after the weight is confirmed to be within the threshold range set in step S12 by comparison, otherwise, taking another stencil as the printing substrate and resetting the aforementioned stencil exceeding the threshold;

[0038] S14, recording the flow condition of the paste on the solar screen printing stencil, and performing paste analysis.

[0039] Preferably, step S14 is specifically: recording the flow video of the paste on the solar screen printing stencil through a camera, analyzing the paste characteristics through an image processing technology, and presetting the paste flow rate as v0; recording the flow video of the paste on the solar screen printing stencil through a camera, analyzing the formed image of the paste on the solar screen printing stencil through an image recognition technology, analyzing whether the paste fully fills the solar screen printing stencil according to the image, adding paste according to the area t of the disconnection position if the analysis result indicates a disconnection defect, adding n units of paste according to the area of the missing position if the analysis result indicates a missing portion, until the analysis result indicates full filling, and sucking out 1 unit of paste with a dropper if the analysis result indicates overflow due to overfilling, until the analysis result indicates full filling.

[0040] Preferably, step S14 is specifically: obtaining the current paste flow rate v1 through video comparison, where the ratio of the current paste flow rate to the preset paste flow rate is u, v O / v1=U, and when the paste flows at the preset flow rate, the optimal included angle between the scraper and the plane of the stencil is 45°, and through calculation, it is obtained that the optimal included angle between the scraper and the plane of the stencil for the current paste flow rate is 45°*u=m°.

[0041] S2, using a scraper to uniformly scrape the paste across the stencil, so that the paste passes through the pores of the stencil and is printed onto the silicon wafer;

[0042] Preferably, said S2 further comprises the following sub-steps:

[0043] S21, measuring the included angle between the scraper and the plane of the stencil, and setting the included angle threshold within 45-60°;

[0044] S22, adjusting the included angle between the scraper and the plane of the stencil for the first time, making the adjustment according to the measurement result of step S21 and the threshold;

[0045] S22, the angle between the second scraper and the screen plane is finely adjusted based on the slurry analysis results in step S14.

[0046] S3, Start the screen printing machine and begin printing; preferably, in step S3, after printing begins, high-definition cameras installed around the printing machine and a microscopic image acquisition device under the screen are used to monitor the printing quality in real time, acquiring image data every 0.1 seconds and observing the squeegee angle, with the preset squeegee angle being m±1°.

[0047] S4. After printing is complete, remove the silicon wafer and dry it.

[0048] Preferably, step S4 further includes the following sub-steps:

[0049] S41 uses a microscope or high-definition camera to observe the electrode patterns printed on the silicon wafer, and counts the number and location of defects such as breaks, cracks and voids in the patterns, which can be quantified as the number of defects per square centimeter of the pattern.

[0050] S42, In pre-press, optical inspection equipment is used to measure the thickness at different positions of the pattern, and the standard deviation of the thickness is calculated to characterize the uniformity.

[0051] S43, compare the deviation between the electrode pattern size required by the design and the actual printed size, and record the deviation value;

[0052] S44, record the actual weight of paste used in each printing and the corresponding printing area, and calculate the paste consumption per unit area.

[0053] Data analysis software (such as Excel with data statistics plugins or professional data analysis tools) is used to organize and analyze the collected data, draw trend charts of various data changes over time or batches, observe data fluctuations, and use statistical methods such as correlation analysis to find the relationship between printing quality data and possible influencing factors (such as raw material batches, paste mixing parameters, screen characteristics, etc.).

[0054] When quality issues related to the squeegee angle are found, such as an increase in breakpoint defects or uneven pattern thickness, the squeegee angle threshold should be adjusted based on the results of correlation factor analysis. For example, if the increased particle size of the conductive powder leads to poorer ink flow, the squeegee needs to apply greater vertical pressure to force the ink through the screen apertures, thus requiring an appropriate increase in the squeegee angle threshold. Conversely, if the screen tension decreases, the squeegee angle threshold should be reduced to avoid excessive pressure on the screen, which could cause deformation and affect printing quality.

[0055] For example, after numerous experiments and data analysis, the following linear relationship was found between the squeegee angle and pattern integrity: for every 1° increase in the squeegee angle, the number of breakpoint defects decreases by 0.5 per square centimeter. If a current batch of printing has an average of 5 breakpoint defects per square centimeter, and the goal is to reduce this to less than 2, calculate the required increase in the squeegee angle, Δθ:

[0056]

[0057] Therefore, the scraper angle threshold needs to be increased by 6° from the original value.

[0058] A positive electrode printing apparatus for a solar screen includes at least one processor, at least one memory, and computer program instructions stored in the memory. When the computer program instructions are executed by the processor, the above-described positive electrode printing method for a solar screen is implemented.

[0059] A storage medium storing computer program instructions, which, when executed by a processor, implement the above-described method for printing the positive electrode of a solar screen.

[0060] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for printing the positive electrode of a solar screen, characterized in that, Includes the following steps: S1, pour the prepared positive electrode paste onto one end of the solar grid; S2, Use a squeegee to evenly spread the positive electrode paste across the solar screen, so that the positive electrode paste is printed onto the silicon wafer through the apertures of the solar screen; S3, start the screen printing machine and begin printing; S4, After printing is complete, remove the silicon wafer and dry it; S1 further includes the following sub-steps: S11, calculate the sunken volume V of the solar grid; S12. Based on the depression volume V and the weight of the positive electrode slurry per cubic centimeter, the depression volume V is taken as the total volume of the positive electrode slurry, and the total weight K required for the positive electrode slurry is calculated. The threshold for the total weight of the positive electrode slurry is set in grams. S13, pour the positive electrode paste onto one end of the solar screen and weigh the total weight of the positive electrode paste. If the weight meets the threshold set in step S12, proceed to the next step. Otherwise, use another solar screen as the printing substrate and reset the solar screen that exceeds the threshold. S14, record the flow of the positive electrode slurry on the solar screen and perform positive electrode slurry analysis; S2 further includes the following sub-steps: S21, Measure the angle between the scraper and the plane of the solar grid, and set the angle threshold between 45-60°; S22, the angle between the scraper and the solar screen plane is adjusted for the first time, based on the measurement results of step S21 and the threshold. S23, the angle between the scraper and the solar screen plane is adjusted for the second time. Based on the positive electrode slurry analysis results in step S14, the angle between the scraper and the solar screen plane is finely adjusted. Step S14 specifically involves recording a video of the positive electrode slurry flowing on the solar screen using a camera, analyzing the characteristics of the positive electrode slurry using image processing technology, and setting the flow rate of the positive electrode slurry to v0; recording a video of the positive electrode slurry flowing on the solar screen using a camera, analyzing the forming image of the positive electrode slurry on the solar screen using image recognition technology, analyzing whether the positive electrode slurry is fully loaded on the solar screen based on the image, and if the analysis result is a broken wire defect, adding positive electrode slurry according to the area t of the broken wire location; if the analysis result is a missing part, adding n units of positive electrode slurry according to the area of ​​the missing part, until the analysis result is full loading; If the analysis result indicates overload overflow, use a dropper to remove one unit of positive electrode slurry until the analysis result indicates full load. By comparing the video, we found that the current positive electrode slurry flow rate is v1, and the ratio of the current positive electrode slurry flow rate to the preset positive electrode slurry flow rate is u, v0 / v1=u. When the positive electrode slurry flow rate is preset, the angle between the optimal scraper and the solar screen plane is 45°. Through calculation, we found that the optimal angle between the scraper and the solar screen plane when the positive electrode slurry flow rate is 45°*u=m°. In step S3, after printing begins, the printing quality is monitored in real time using high-definition cameras installed around the printing press and a microscopic image acquisition device under the solar screen. Image data is acquired every 0.1 seconds, and the squeegee angle is observed. The preset squeegee angle is m±1°.

2. A positive electrode printing device for a solar screen printing plate, characterized in that, It includes at least one processor, at least one memory, and computer program instructions stored in the memory, which, when executed by the processor, implement the method of claim 1.

3. A storage medium, characterized in that, It stores computer program instructions, which, when executed by a processor, implement the method described in claim 1.

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