Methods for preparing solar cells and solar cells

Abstract

This application relates to the photovoltaic field, providing a method for preparing solar cells and a solar cell. The method includes: calculating the weight of a single cell before and after printing based on data collected by a weight sensor; calculating wet weight data based on the difference between the pre-printing and post-printing weights; adjusting the printing parameters of the printing press according to the wet weight data to obtain updated printing parameters, and controlling the printing press to print the solar cell using the updated printing parameters to prepare the solar cell. This method eliminates the random errors of traditional single-cell measurement methods through multiple sensor measurements, more accurately reflecting the wet weight of the solar cell. Real-time sensor testing data does not require machine downtime, and adjusting the printing parameters based on the detected data eliminates data lag. It can monitor the production line status in a timely manner and adjust the printing press parameters promptly to ensure optimal production line efficiency and yield.

Description

Technical Field

[0001] This application relates to the field of photovoltaics, and in particular to a method for preparing a solar cell and the solar cell itself. Background Technology

[0002] In the production process of photovoltaic cells, a printing paste needs to be printed onto the surface of the cell. The wet weight of the printing paste determines the electrical performance of the cell to a certain extent and also greatly affects the cost of cell production. Therefore, it is necessary to measure the wet weight of the printed cells regularly during the production process.

[0003] Current methods for measuring the wet weight of solar cells suffer from problems such as large errors, impact on production capacity, and untimely data feedback. Furthermore, existing technologies involve low testing frequency and data lag, making it difficult to detect production line anomalies promptly. This hinders timely adjustments to printing press parameters, resulting in a low yield rate for solar cells. Summary of the Invention

[0004] This application provides a method for preparing a solar cell and a solar cell, which can at least solve the problems in the prior art where the measurement error of the wet weight of the solar cell is large and the data feedback is not timely, resulting in the inability to accurately adjust the printing parameters and thus a low yield.

[0005] According to some embodiments of this application, one aspect of this application provides a method for preparing a solar cell, comprising: obtaining the weight of a single cell before printing and the weight of a single cell after printing, wherein the weight of a single cell before printing is a weight calculated based on multiple pre-printing weight data, and the weight of a single cell after printing is a weight calculated based on multiple post-printing weight data, wherein the pre-printing weight data is the weight of the solar cell before printing collected by a weight sensor in front of the printing machine, and the post-printing weight data is the weight of the solar cell after printing collected by a weight sensor after the printing machine; calculating wet weight data based on the difference between the pre-printing weight and the post-printing weight; adjusting the printing parameters of the printing machine according to the magnitude of the wet weight data to obtain updated printing parameters, and controlling the printing machine to print the solar cell before printing using the updated printing parameters to prepare a solar cell, wherein the yield rate of the solar cell prepared using the updated printing parameters is greater than a preset yield rate.

[0006] In some embodiments, obtaining the pre-printing weight and post-printing weight of a single solar cell during fabrication includes: obtaining multiple first pre-printing weights and multiple first post-printing weights of the solar cell during fabrication, wherein the multiple first pre-printing weights are weight data obtained at different positions of the solar cell during fabrication before passing through the printing press, and the multiple first post-printing weights are weight data obtained at different positions of the solar cell during fabrication after passing through the printing press; a set of corresponding first pre-printing weights and first post-printing weights are weight data obtained at the same position of the solar cell during fabrication; calculating a weighted average of the multiple first pre-printing weights of the solar cell during fabrication to obtain the pre-printing weight of the single solar cell during fabrication; and calculating a weighted average of the multiple first post-printing weights of the solar cell during fabrication to obtain the post-printing weight of the single solar cell during fabrication.

[0007] In some embodiments, the weights of the plurality of first pre-printing weights are different, and the weight of the first pre-printing weights detected at locations closer to the center of the cell being prepared is greater than the weight of the first pre-printing weights detected at locations farther from the center of the cell being prepared.

[0008] In some embodiments, there are multiple solar cells in the fabrication process. Each solar cell in the fabrication process corresponds to a pre-printing weight and a post-printing weight. The wet weight data is calculated based on the difference between the pre-printing weight and the post-printing weight, including: determining the difference between the pre-printing weight and the corresponding post-printing weight as the wet weight of a single cell, wherein each wet weight corresponds one-to-one with a solar cell in the fabrication process; and determining the average of the summation of the wet weights of multiple single cells as the wet weight data.

[0009] In some embodiments, there are multiple solar cells in the fabrication process. Obtaining the pre-printing weight and post-printing weight of a single solar cell in the fabrication process includes: obtaining multiple second pre-printing weights and multiple second post-printing weights, wherein the multiple second pre-printing weights are weight data at different positions of different solar cells in the fabrication process that were detected before passing through the printing machine, and the multiple second post-printing weights are weight data at different positions of different solar cells in the fabrication process that were detected after passing through the printing machine; a set of corresponding second pre-printing weights and second post-printing weights are the weights at the same position of the same solar cell in the fabrication process; calculating the weighted average of the multiple second pre-printing weights to obtain the pre-printing weight of a single cell; and calculating the weighted average of the multiple second post-printing weights to obtain the post-printing weight of a single cell.

[0010] In some embodiments, adjusting the printing parameters of the printing press according to the magnitude of the wet weight data to obtain updated printing parameters includes: calculating the difference between the wet weight data and the standard wet weight, and calculating the ratio of the difference to the standard wet weight to obtain the excess ratio; adjusting the printing parameters of the printing press according to the magnitude of the absolute value of the excess ratio to obtain the updated printing parameters.

[0011] In some embodiments, adjusting the printing parameters of the printing press according to the absolute value of the over-limit ratio to obtain the updated printing parameters includes: when the absolute value of the over-limit ratio is within a first range, keeping the current printing parameters of the printing press unchanged and sending a prompt message, the prompt message being information including the over-limit ratio data; when the absolute value of the over-limit ratio is within a second range, adjusting the printing parameters of the printing press according to the size of the over-limit ratio to obtain the updated printing parameters, the minimum value of the second range being the maximum value of the first range; when the absolute value of the over-limit ratio is within the first range for a first preset number of consecutive times, or within the second range for a second preset number of consecutive times, or within a third range, controlling the printing press to stop and sending an alarm message, the alarm message being information indicating a printing press malfunction, the first preset number of times being greater than the second preset number of times.

[0012] In some embodiments, the printing parameters include printing pressure and squeegee speed. When the absolute value of the excess ratio is within a second range, the printing parameters of the printing press are adjusted according to the magnitude of the excess ratio to obtain updated printing parameters. This includes: obtaining a parameter mapping table, which is a mapping relationship between the wet weight excess value and the printing pressure adjustment value and squeegee speed adjustment value of the printing press, wherein the wet weight excess value is directly proportional to both the printing pressure adjustment value and the squeegee speed adjustment value; determining the corresponding pressure adjustment value and speed adjustment value of the printing press according to the excess ratio and the parameter mapping table; determining the sum of the current printing pressure of the printing press and the pressure adjustment value as the updated pressure value; and / or determining the sum of the current squeegee speed of the printing press and the speed adjustment value as the updated speed value to obtain the updated printing parameters.

[0013] In some embodiments, the printing parameters include printing pressure and squeegee speed. When the absolute value of the over-limit ratio is within a second range, adjusting the printing parameters of the printing press according to the magnitude of the over-limit ratio to obtain updated printing parameters includes: acquiring the equipment parameters of the printing press, the equipment parameters including at least the squeegee usage time, the squeegee hardness, the screen life, the screen tension, and the screen deformation; and adjusting the printing pressure and / or the squeegee speed of the printing press according to the magnitude of the over-limit ratio and the equipment parameters of the printing press to obtain the updated printing parameters.

[0014] In some embodiments, the printing parameters include printing pressure and squeegee speed. When the absolute value of the excess ratio is within a second range, adjusting the printing parameters of the printing press according to the magnitude of the excess ratio to obtain updated printing parameters includes: adjusting a first equipment parameter of the printing press according to the magnitude of the excess ratio in a first manner to obtain a first updated parameter, wherein the first equipment parameter is one of the printing pressure and the squeegee speed, wherein when the excess ratio is positive, the first manner is to increase, and when the excess ratio is negative, the first manner is to decrease; controlling the printing press to print the battery cell under preparation using the first updated parameter; detecting and calculating the updated excess ratio of the battery cell under preparation; and adjusting the printing parameters of the printing press according to the magnitude of the absolute value of the updated excess ratio to obtain the updated printing parameters.

[0015] In some embodiments, adjusting the printing parameters of the printing press according to the magnitude of the absolute value of the updated over-limit ratio to obtain the updated printing parameters includes: when the absolute value of the updated over-limit ratio is within the second range and the sign of the updated over-limit ratio is the same as the sign of the over-limit ratio, continuing to adjust the first equipment parameters of the printing press in the first manner until the absolute value of the updated over-limit ratio is less than the minimum value of the second range; when the absolute value of the updated over-limit ratio is within the second range and the sign of the updated over-limit ratio is different from the sign of the over-limit ratio, adjusting the second equipment parameters of the printing press in a second manner until the absolute value of the updated over-limit ratio is less than the minimum value of the second range, wherein the second manner is the opposite of the first manner.

[0016] In some embodiments, the method further includes: acquiring the transport track speed of the battery cell during fabrication; when the transport track speed is greater than or equal to a first preset speed threshold, the sampling frequency of the weight sensor is a first frequency; when the transport track speed is less than the first preset speed threshold but greater than or equal to a second preset speed threshold, the sampling frequency of the weight sensor is a second frequency, the second frequency being less than the first frequency; when the transport track speed is less than the second preset speed threshold, the sampling frequency of the weight sensor is a third frequency, the third frequency being less than the second frequency.

[0017] In some embodiments, all of the weight sensors are of the same type and have the same operating parameters.

[0018] In some embodiments, the weight sensor is a photoelectric weight sensor or a capacitive weight sensor.

[0019] According to some embodiments of this application, another aspect of this application provides a solar cell, which is prepared using any of the solar cell preparation methods described above.

[0020] The technical solution provided in this application has at least the following advantages: This method uses multiple sensors for measurement, eliminating the random errors of traditional single-cell measurement methods and providing a more accurate reflection of the wet weight of the solar cells. Furthermore, real-time continuous sensor monitoring allows for online acquisition of wet weight data without requiring manual cell removal, reducing the risk of breakage. The real-time sensor testing data and adjustment of printing parameters based on the detected data eliminate data lag, enabling timely monitoring of the production line status and timely adjustment of printing parameters to ensure optimal production line efficiency and yield. This solves the problem in existing technologies where large measurement errors in the wet weight of solar cells and untimely data feedback lead to inaccurate adjustments to printing parameters and lower yield rates. Attached Figure Description

[0021] One or more embodiments are illustrated by way of example with reference to the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Unless otherwise stated, the drawings in the accompanying drawings do not constitute a limitation on scale. In order to more clearly illustrate the technical solutions in the embodiments of this application or in the conventional art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 A schematic flowchart of a method for fabricating a solar cell according to an embodiment of this application is shown;

[0023] Figure 2 A schematic diagram of the mounting position of a weight sensor according to an embodiment of this application is shown;

[0024] Figure 3 A schematic diagram of the mounting location of another weight sensor provided according to an embodiment of this application is shown.

[0025] The above figures include the following reference numerals:

[0026] 01. Printing press; 02. Weight sensor; 021. First weight sensor; 022. Second weight sensor; 023. Third weight sensor; 024. Fourth weight sensor; 025. Fifth weight sensor; 03. Battery cell in preparation; 04. Battery transfer track. Detailed Implementation

[0027] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0028] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0029] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0030] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0031] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A exists, A and B exist simultaneously, and B exists. In addition, the character " / " in this document generally indicates that the related objects before and after it have an "or" relationship.

[0032] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0033] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0034] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0035] In the accompanying drawings corresponding to the embodiments of this application, the thickness and area of ​​the layers are enlarged for better understanding and ease of description. When describing a component (such as a layer, film, region, or substrate) on or on the surface of another component, the component may be "directly" located on the surface of the other component, or there may be a third component between the two components. Conversely, when describing a component on the surface of another component, or when another component is formed or disposed on the surface of a component, it indicates that there is no third component between the two components. Furthermore, when describing a component as being "generally" formed on another component, it means that the component is not formed on the entire surface (or front surface) of the other component, nor is it formed on a portion of the edge of the entire surface.

[0036] In the description of the embodiments of this application, when a component "includes" another component, other components are not excluded unless otherwise stated, and other components may be further included. Furthermore, when a component such as a layer, film, region, or plate is referred to as being "on / located" on another component, it can be "directly on" the other component (i.e., located on the surface of the other component with no other components between them), or another component may be present therein. Moreover, when a component such as a layer, film, region, or plate is "directly located" on another component, or when a component such as a layer, film, region, or plate is located on the surface of another component, it indicates that no other components are located therein.

[0037] The terminology used in the description of the various embodiments herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used in the description of the various embodiments and the appended claims, the term "part" is also intended to include the plural form unless the context clearly indicates otherwise. Components include layers, films, regions, or plates, etc.

[0038] As described in the background section, precise control of wet weight is crucial for optimizing the efficiency, yield, and cost of solar cells during production. Wet weight refers to the extra weight of a solar cell after silver paste printing, directly affecting its electrical performance and manufacturing cost. Traditional wet weight measurement methods rely heavily on manual operation. Before printing, an operator manually removes a solar cell from the production line and records its dry weight using a weighing device. After printing, the same cell is manually removed again for wet weight measurement. The difference between the two weights is considered the wet weight of the silver paste added during printing. Manual wet weight measurement is cumbersome and susceptible to operator technique and environmental factors (such as temperature and humidity changes), leading to high random errors in the test results. Furthermore, manually handling solar cells increases the risk of breakage and interrupts normal production line operation, reducing machine uptime. Traditional wet weight testing is performed every 1 to 3 hours, meaning there is a significant time lag in updating unit consumption data. This lag means that when anomalies in unit consumption occur on the production line, feedback and correction cannot be received in a timely manner. Often, by the time the problem is discovered, the production line has already been running for some time, thus affecting the yield and efficiency of the solar cells and increasing non-silicon costs. Manually measuring and recording wet weight data not only increases the possibility of errors, but also makes it difficult to interface manually recorded data with the company's Manufacturing Execution System (MES) in real time, making data traceability and analysis difficult and hindering continuous optimization of the production process.

[0039] To address the problem that existing technologies suffer from large measurement errors in the wet weight of solar cells and untimely data feedback, which leads to an inability to accurately adjust printing parameters and a low yield rate, embodiments of this application provide a method for preparing solar cells and a solar cell.

[0040] The embodiments of this application will now be described in detail with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been provided in the embodiments of this application to facilitate a better understanding of the application. However, the technical solutions claimed in this application can be implemented even without these technical details and various variations and modifications based on the following embodiments.

[0041] This embodiment provides a method for preparing a solar cell, such as... Figure 1 As shown, it includes the following steps:

[0042] Step S101: Obtain the weight of a single cell before printing and the weight of a single cell after printing during the preparation process. The weight of a single cell before printing is calculated based on multiple pre-printing weight data. The weight of a single cell after printing is calculated based on multiple post-printing weight data. The pre-printing weight data is the weight of the battery cell during preparation collected by a weight sensor in front of the printing machine. The post-printing weight data is the weight of the battery cell during preparation collected by a weight sensor after the printing machine.

[0043] The traditional solar cell screen printing system consists of four printing machines: the front main grid and the back main grid and the back grid, hereinafter referred to as the first, second, third, and fourth printing machines. Each printing machine has at least one set of sensors on its front-end cell transport track and at least one identical set of sensors on its rear-end cell transport track. Multiple sensors within each set are arranged asymmetrically and staggered to cover different areas of the solar cell (edges, center, etc.), reducing measurement errors caused by cell misalignment or surface unevenness.

[0044] The aforementioned weight sensor can be a photoelectric weight sensor or a capacitive weight sensor.

[0045] Photoelectric sensors measure weight by reflecting, blocking, or transmitting light beams, eliminating the need for physical contact with the object. This makes them suitable for fragile, sensitive items or those requiring pollution-free measurement. These sensors offer fast response times, making them ideal for dynamic weight detection or real-time monitoring on high-speed production lines. Due to their non-contact nature, photoelectric sensors are less affected by contaminants, are easy to clean, and have relatively low maintenance costs. They are also unaffected by environmental factors such as temperature and humidity, maintaining stability under a wide range of operating conditions.

[0046] However, strong light or changes in ambient light can affect the accuracy of photoelectric sensors, especially outdoors or under unstable lighting conditions. Obstructions or dust accumulation along the measurement path can also affect the transmission of the light signal, leading to measurement errors. Although fast, photoelectric sensors may not be as accurate as other types of sensors for precise weight measurement, especially in detecting minute weight changes.

[0047] Capacitive sensors offer very high measurement resolution, making them suitable for applications requiring high-precision weight detection. They are flexible enough to perform both static weight measurements and adapt to weight changes in dynamic environments. Compared to other electrical devices, capacitive sensors are less sensitive to electromagnetic interference and can operate stably in environments with electromagnetic noise. They are typically small in size, making them easy to install in limited spaces, especially in applications requiring embedded designs. Compared to other types of high-precision sensors, capacitive sensors are relatively economical for certain mass production needs.

[0048] The output of a capacitive sensor is related to the dielectric constant of the material it contacts; changes in the material of the object being measured can affect the measurement results. Capacitive sensors may experience zero-point drift, requiring periodic calibration to maintain measurement accuracy. While capacitive sensors can be made in a small size, their measurement results can be affected by mechanical stress or structural deformation, especially in complex mechanical motion environments. Although relatively inexpensive compared to some high-end sensors, the circuit design and signal processing of capacitive sensors can be more complex, increasing initial design and debugging costs.

[0049] In summary, photoelectric weight sensors, due to their non-contact nature and fast response, have an advantage in measuring the weight of high-speed, non-polluting, or fragile items; while capacitive weight sensors, with their high accuracy and resistance to environmental interference, are more suitable for applications requiring precise measurements and where sensor size is a constraint. The choice of sensor type should be based on a comprehensive consideration of specific measurement requirements, environmental conditions, cost budget, and ease of maintenance.

[0050] Furthermore, all the aforementioned weight sensors are of the same type and operate with the same parameters. Using the same sensors before and after the printing press reduces system design complexity, as it eliminates the need for separate hardware or software configurations for different sensor characteristics. Sensors of the same model perform consistently under identical conditions, ensuring data comparability, which is particularly important for applications requiring data comparison across time or location, such as production line quality control and long-term environmental monitoring. The calibration methods and maintenance procedures for the same sensors are also typically similar, reducing the need for diverse training and operational maintenance, thereby lowering overall costs.

[0051] Before the solar cells reach the printing press, weight sensors located on the transport track collect weight data from multiple solar cells, including their raw weight before printing. From this pre-printing weight data, a representative value is derived using specific calculation methods (such as average, weighted average, etc.) as the standard weight of the solar cells in this process before printing.

[0052] After the solar cells pass through the printing press, weight sensors on the transport track collect weight data from multiple cells again. This data includes the weight of the cells after the silver paste has been printed. Similarly, a representative value is calculated from these post-printing weight data as the standard weight of the printed solar cells in this process.

[0053] By collecting weight data from multiple solar cells before and after printing and calculating the representative weight of a single cell, the accuracy and reliability of wet weight measurement can be improved, reducing errors caused by the randomness of single-cell measurements. Compared to traditional manual sampling and measurement, this continuous online automatic measurement method can more timely reflect the actual unit consumption level of the production line and provide real-time data support for subsequent process control and optimization.

[0054] Step S102: Calculate the wet weight data based on the difference between the weight of the single piece before printing and the weight of the single piece after printing.

[0055] The process involves comparing the weight of a single cell after printing with its weight before printing. This typically means subtracting the pre-printing weight from the post-printing weight; the difference represents the weight increase of the cell due to the printing process. This difference is known as wet weight data, representing the undried weight of the silver paste or conductive paste added to each cell via screen printing. Accurate calculation of wet weight data is crucial for process control, as it directly relates to the cell's electrical performance indicators (such as conversion efficiency and internal resistance) and production costs. The calculated wet weight data is further processed, such as through statistical analysis and comparison with set thresholds, to evaluate the stability and efficiency of the printing process. This data is fed back in real-time to a central processing unit or monitoring system for online adjustments to printing parameters, such as printing speed, printing pressure, and squeegee angle, to ensure the wet weight remains within the ideal range, thereby optimizing cell performance and cost.

[0056] Step S103: Based on the wet weight data, adjust the printing parameters of the printing machine to obtain updated printing parameters, and control the printing machine to print the battery cells in the preparation process using the updated printing parameters to prepare solar cells. The yield of the solar cells prepared using the updated printing parameters is greater than the preset yield.

[0057] Specifically, in the production of solar cells, precise control of wet weight data is crucial for improving cell efficiency, yield, and cost reduction. Wet weight refers to the weight of the silver paste (or other conductive material) printed onto the cell before it dries, directly affecting the cell's electrical performance. After sensors measure and calculate the wet weight data, this data is uploaded to a central processing unit (CPU) or terminal computer. The processor analyzes the data to determine if the wet weight is within the ideal range, i.e., whether it meets the preset upper and lower wet weight warning values. If the wet weight data exceeds the preset range, the system automatically adjusts the printing parameters of the printing press, such as printing speed, printing pressure, squeegee speed, and angle. This automatic adjustment can respond to changes in wet weight in real time, avoiding the lag and inaccuracy of traditional manual adjustments. The system calculates appropriate updated printing parameters to ensure that the wet weight of the next batch of cells returns to the ideal range, thereby improving the cell yield.

[0058] Upon receiving updated printing parameters, the printing press immediately adjusts its operating status and prints according to the new parameters. This real-time adjustment avoids the degradation of cell quality caused by prolonged use of incorrect parameters. The system continuously monitors wet weight data and adjusts printing parameters based on data feedback, forming a closed-loop control process to ensure that the yield rate of cells remains at or above the preset threshold.

[0059] The technical solution provided in this application has at least the following advantages: This method uses multiple sensors for measurement, eliminating the random errors of traditional single-cell measurement methods and providing a more accurate reflection of the wet weight of the solar cells. Furthermore, real-time continuous sensor monitoring allows for online acquisition of wet weight data without requiring manual cell removal, reducing the risk of breakage. The real-time sensor testing data and adjustment of printing parameters based on the detected data eliminate data lag, enabling timely monitoring of the production line status and timely adjustment of printing parameters to ensure optimal production line efficiency and yield. This solves the problem in existing technologies where large measurement errors in the wet weight of solar cells and untimely data feedback lead to inaccurate adjustments to printing parameters and lower yield rates.

[0060] In some embodiments, obtaining the weight of a single cell before printing and the weight of a single cell after printing during the fabrication process includes the following steps:

[0061] Step S201: Obtain multiple first pre-printing weights and multiple first post-printing weights of the battery cell in the above-mentioned preparation. The multiple first pre-printing weights are weight data obtained by detecting different positions of the battery cell in the above-mentioned preparation before passing through the printing machine. The multiple first post-printing weights are weight data obtained by detecting different positions of the battery cell in the above-mentioned preparation after passing through the printing machine. A set of corresponding first pre-printing weights and first post-printing weights are weight data detected at the same position of the battery cell in the above-mentioned preparation.

[0062] Step S202: The weighted average of the multiple first pre-printing weights of the battery cells in the above preparation is calculated to obtain the single pre-printing weight of the battery cells in the above preparation.

[0063] Step S203: The weighted average of the multiple first-printed weights of the battery cells in the above-mentioned preparation is calculated to obtain the single-piece printed weight of the battery cells in the above-mentioned preparation.

[0064] First, by acquiring multiple pre-printing and post-printing weights at different locations on the solar cell (such as edges and centers), this method can more comprehensively reflect the true weight distribution of the solar cell. Because solar cells may exhibit non-uniformity, such as differences in thickness, density, or surface condition, measurements at a single location often cannot accurately represent the overall state of the cell. Multi-location measurements, by integrating information from different locations, make the final wet weight calculation more accurate and reduce the impact of location deviations on the measurement results.

[0065] Secondly, calculating a weighted average of multiple pre- and post-printing weight data points, rather than relying on just one data point, significantly improves data reliability. This is because weighted averaging comprehensively considers measurements from different locations and adjusts the importance of data according to preset weights (e.g., edge sensors may have a lower weight than center sensors), thereby reducing the impact of random errors or local anomalies on the final result. Weighted averaging is a commonly used data processing method that ensures high accuracy in the final wet weight calculation even in cases of abnormal sensor readings.

[0066] Finally, by continuously measuring and feeding back data online in real time, this method significantly improves the efficiency and stability of the production line. Traditional manual measurement methods are not only time-consuming but also susceptible to human error, making it difficult to reflect the production line's status promptly. Real-time wet weight data feedback helps technicians quickly identify any deviations from expectations, such as excessively high or low wet weight, allowing for immediate adjustments to printing press parameters (such as pressure and speed), preventing a decline in product quality and production efficiency due to abnormal wet weight. This immediate response capability helps prevent large-scale problems on the production line, reduces costs, and improves cell yield and line uptime.

[0067] Taking an example where both the weight before and after the first printing are 5 units, such as... Figure 2As shown, five weight sensors 02 are installed before and after the printing machine 01, namely the first weight sensor 021, the second weight sensor 022, the third weight sensor 023, the fourth weight sensor 024, and the fifth weight sensor 025. When the battery cell 03 being prepared is transported from the battery transport track 04 to the weight sensor 02, the weight sensor 02 is used to detect the weight of the battery cell 03 being prepared at this time, and the first pre-printing weight and the first post-printing weight are obtained.

[0068] The specific weighted average formula is shown in Formula 1:

[0069] (Formula 1)

[0070] In calculating the weight of a single sheet before printing, This is the weight of a single sheet before printing. This is the weight before the first printing. Here, n represents the weight corresponding to the first pre-printing weight, and n is the actual pre-printing weight calculated. If no outliers are removed, n is the number of weight sensors in front of the printing press, which is 5 in this embodiment. When calculating the weight of a single sheet after printing... This refers to the weight of a single printed sheet. This is the weight after the first printing. The weight is the weight corresponding to the first printed weight, and n is the actual first printed weight calculated. If no outliers are removed, n is the number of weight sensors in front of the printing press, which is 5 in this embodiment.

[0071] In addition, each weight sensor has an initial value, which is the value displayed by the weight sensor when there are no cells being manufactured. Therefore, Formula 1 can also be transformed into Formula 2:

[0072] (Formula 2)

[0073] in, For measurement The initial value of the weight sensor, and the meanings of other parameters in Formula 2 are the same as those in Formula 1.

[0074] Formula 2 above is essentially a zeroing process. This process involves pre-measuring and recording the weight of the container or carrier (such as the support equipment on the cell transport track), and then automatically subtracting this weight from subsequent weight measurements. This ensures that the final weight data reflects only the true weight of the object being measured (such as unprinted and printed cells). This is crucial for weight measurements in complex or dynamic environments because it eliminates interference from the constant factor of carrier weight, making the results closer to the true value. On continuous production lines, the zeroing process ensures that each measurement is based on the same benchmark, i.e., the carrier weight is constantly subtracted. This ensures high comparability between measurement data at different times or locations, facilitating the monitoring of cell weight trends over time or process changes, and forming the basis for quality control and process optimization. In dynamic measurement environments, such as high-speed production lines, cells may move rapidly on the transport track, and the carrier weight may vary slightly due to wear, accumulated substances (such as dust), etc. The zeroing process can automatically adjust the carrier weight benchmark in real time or periodically, ensuring that measurement results remain stable and accurate even in such dynamic environments. Incorporating a zeroing process into the calculation method can significantly improve the accuracy and reliability of weight measurement, ensure the accuracy and comparability of data, simplify the data processing flow, adapt to dynamic measurement environments, and reduce human error.

[0075] In addition, if a test value deviates significantly from other test values, the test value is determined to be abnormal, and it is removed from the calculation to ensure the accuracy of the calculation.

[0076] This involves installing weight sensors on the transport track. When a solar cell reaches the detection position, the sensor is triggered to start high-speed sampling (>1000 times / second), and data acquisition is completed before the solar cell leaves. The central processor incorporates timestamp alignment technology to ensure that the data from the front and back end sensors correspond to the same solar cell. During weighing, multiple areas are detected simultaneously to reduce measurement errors caused by solar cell position offset or surface unevenness. Data from the central area sensor is preferentially selected as the reference value. Data reliability is improved through multi-sensor redundancy design. Outliers are actively rejected. The weighted average is used to calculate the weight of a single cell, with a wet weight measurement accuracy of ±0.01g, and it is compatible with solar cells of different sizes.

[0077] In some embodiments, the weights of the multiple first pre-printing weights are different, and the weight of the first pre-printing weights detected at locations closer to the center of the battery cell being prepared is greater than the weight of the first pre-printing weights detected at locations farther from the center of the battery cell being prepared.

[0078] Specifically, the weight of a solar cell edge may differ from that of the center region due to wear, cutting damage, or uneven slurry accumulation during processing. Therefore, treating edge and center measurements equally may exaggerate the edge effect, leading to inaccurate wet weight calculations. Giving greater weight to center region measurements more accurately reflects the overall wet weight of the cell and reduces interference from edge non-uniformity. The center region is typically considered the core of the cell, with more uniform physical and chemical properties, and is crucial for cell performance. Emphasizing center region weight data in weighted average calculations enhances the overall stability of wet weight calculations. This ensures that even if edge region measurements fluctuate due to environmental or operational factors, it won't excessively affect the final wet weight calculation result, guaranteeing data reliability. Center region weight data better represents the average condition of the entire cell because it represents the most concentrated functional area. By assigning higher weight to the center region, the calculated average wet weight better reflects the overall manufacturing condition of the cell, providing stronger reference value for evaluating and controlling the unit consumption level of the production line.

[0079] By adjusting the weights of measurements taken at different locations, especially by emphasizing the weight of the central region in wet weight calculations, the accuracy and reliability of measurements can be effectively improved, process parameters can be optimized, and cost control and efficiency can be promoted.

[0080] For example Figure 2 In the process of preparing the battery cell 03, the weight value of the weight sensor 02 (i.e., the third weight sensor 023) at the center can be 100%, and the weight values ​​of the weight sensors 02 (i.e., the first weight sensor 021, the second weight sensor 022, the fourth weight sensor 024, and the fifth weight sensor 025) at the four edge corners of the battery cell 03 can be 80%.

[0081] In some embodiments, multiple solar cells are used in the above-described preparation process. Each solar cell corresponds to one pre-printing weight and one post-printing weight. The wet weight data is calculated based on the difference between the pre-printing weight and the post-printing weight, including the following steps:

[0082] Step S1021: The difference between the weight of the single cell before printing and the corresponding weight of the single cell after printing is determined as the wet weight of the single cell, and the wet weight of the single cell corresponds one-to-one with the battery cell in the preparation process.

[0083] Step S1022: The average summation of the wet weights of the multiple individual pieces is determined as the aforementioned wet weight data.

[0084] Specifically, each cell in the manufacturing process corresponds to a precise pre-printing weight and a post-printing weight. The difference between these two values ​​is directly calculated as the wet weight of a single cell. The final wet weight data is obtained by summing and averaging the wet weights of multiple cells. This statistical method effectively reduces the impact of random factors on wet weight measurement, such as anomalies in individual cells, small errors in the measurement process, or minor unevenness in slurry distribution. The average value provides a more stable and representative wet weight indicator, more accurately reflecting the overall wet weight level of the production line. By calculating the wet weight of each cell, wet weight fluctuations during production can be monitored and controlled more accurately. If the wet weight data of a single cell exceeds the preset normal range, the specific cell or production stage can be quickly located, allowing for timely measures to prevent subsequent batches from being affected. Simultaneously, the average wet weight data serves as a key indicator of production line performance, helping to identify and resolve potential production anomalies, such as equipment failures and slurry issues, thereby improving cell yield and production line stability.

[0085] For example, the wet weight of five individual solar cells in the fabrication process is calculated, and then the average of these five wet weights is summed to obtain the aforementioned wet weight data. See Formula 3 for details:

[0086] (Formula 3)

[0087] in, This is wet weight data. This is the weight of a single sheet before printing. denoted as the weight of a single printed cell, and m represents the number of cells being prepared; in this embodiment, m is 5.

[0088] In the above embodiments, the detected first pre-printing weight and first post-printing weight are both from the same battery cell being manufactured. In practical applications, multiple sets of weight sensors can be set, such as... Figure 3 As shown, for example, if it is necessary to collect the pre-printing weight (or post-printing weight) of 5 battery cells 03 under manufacturing, then 5 sets of weight sensors 02 are set up. Each set of weight sensors 02 includes five weight sensors 02, namely, the first weight sensor 021, the second weight sensor 022, the third weight sensor 023, the fourth weight sensor 024, and the fifth weight sensor 025. Each set of weight sensors is used to test the pre-printing weight (or post-printing weight) of one battery cell under manufacturing.

[0089] Alternatively, you can set up only one set of weight sensors, such as... Figure 2As shown, when using this set of weight sensors to detect the weight data of different cells in the manufacturing process, a timestamp technique is needed to determine the correspondence between the weight data and the different cells in the process. When each cell enters the test area (e.g., passing through a weight sensor), the system generates a unique timestamp. This timestamp contains the precise time the cell entered the test area, which can be milliseconds or smaller time units to ensure high accuracy. When the sensor begins measuring the weight or other parameters of the cell, the collected data is closely linked to the generated timestamp. This means that each data acquisition operation records a timestamp to identify the corresponding time point. After receiving the timestamped test data, the central processing unit sorts and processes the data according to the timestamp. Since the transmission track speed at each process is known, the processor can calculate the exact path and position of each cell on the production line based on the timestamp and transmission speed. By analyzing the timestamps of the sensor data before and after, it can be determined that the data collected by the sensors at both ends correspond to the same cell. Specifically, the central processing unit can identify which front-end sensor data and back-end sensor data are closest in time by comparing timestamps, meaning they are likely to correspond to the same batch or the same cell.

[0090] Additionally, if transmission congestion or abnormal situations occur, causing problems with timestamp matching, an anomaly detection mechanism can be set up. For example, if the time difference between two sets of data exceeds a preset threshold for normal transmission time, the system can mark these data as abnormal, which may require manual inspection or recalibration of the sensor's timestamp generation mechanism.

[0091] Ensuring time synchronization across all systems and devices is crucial to avoid timestamp discrepancies. In high-speed production environments, a high-frequency, high-precision timestamp generation mechanism is required to ensure that test data for each solar cell is accurately timestamped. An efficient data storage and management system is essential, capable of rapidly retrieving and processing large volumes of timestamped data.

[0092] In some embodiments, multiple solar cells are used in the above-described preparation process. Obtaining the weight of a single solar cell before printing and the weight of a single solar cell after printing includes the following steps:

[0093] Step S301: Obtain multiple pre-printing weights and multiple post-printing weights. The multiple pre-printing weights are weight data at different positions of different cells in the same process before the printing press. The multiple post-printing weights are weight data at different positions of different cells in the same process after the printing press. A set of corresponding pre-printing weights and post-printing weights are the weights at the same position of the same cell in the same process.

[0094] Step S302: Calculate the weighted average of the multiple pre-printing weights to obtain the pre-printing weight of the single piece.

[0095] Step S303: Calculate the weighted average of the multiple second-printed weights to obtain the single-piece printed weight.

[0096] Specifically, the pre-printing and post-printing weights of different solar cells at different locations are obtained. This means that each data point is collected from an independent solar cell, covering multiple areas of the cell. This method comprehensively reflects the weight variations of solar cells at different locations and in different production batches. Compared to single-location or single-cell measurements, it can more accurately capture potential local anomalies or batch differences in the production line, thereby improving the comprehensiveness and accuracy of wet weight measurements. A weighted average is calculated from the pre-printing and post-printing weights to obtain the average weight of a single cell before and after printing. The weighted average not only combines data from multiple solar cells but also adjusts the importance of each measurement value based on the reliability of the location (e.g., the weight of the central area may be higher than that of the edge area). This method effectively reduces the impact of random errors and local anomalies on the final result, ensuring that the calculated wet weight data is more stable and reliable. By collecting data from multiple solar cells and performing statistical processing, this method is statistically more robust. Even if individual data points are abnormal, the weighted average calculation can largely smooth out the influence of these outliers, avoiding excessive deviation from the wet weight measurement results. This is especially important for industrial production scenarios that require processing large amounts of data and maintaining quality stability.

[0097] This embodiment uses the following method: Figure 2 A set of weight sensors is set up. That is, a set of weight sensors 02 is used to detect the weight at different positions of the battery cell 03 in different manufacturing processes. The set of weight sensors 02 includes a first weight sensor 021, a second weight sensor 022, a third weight sensor 023, a fourth weight sensor 024, and a fifth weight sensor 025.

[0098] For example, if there are five solar cells in the manufacturing process, the following methods are used: a first weight sensor detects the pre-printing weight of the first solar cell (weight at the top left corner), a second weight sensor detects the pre-printing weight of the second solar cell (weight at the top right corner), a third weight sensor detects the pre-printing weight of the third solar cell (weight at the middle position), a fourth weight sensor detects the pre-printing weight of the fourth solar cell (weight at the bottom left corner), and a fifth weight sensor detects the pre-printing weight of the fifth solar cell (weight at the bottom right corner). These five pre-printing weights are then weighted and averaged to obtain the pre-printing weight of each individual cell.

[0099] In some embodiments, adjusting the printing parameters of the printing press based on the wet weight data to obtain updated printing parameters includes the following steps:

[0100] Step S401: Calculate the difference between the above wet weight data and the standard wet weight, and calculate the ratio of the above difference to the above standard wet weight to obtain the excess ratio.

[0101] The excess percentage is obtained by calculating the ratio of wet weight data to standard wet weight. This process can accurately quantify the degree of deviation between wet weight data and standard value.

[0102] Step S402: Adjust the printing parameters of the printing press according to the absolute value of the over-limit ratio to obtain the updated printing parameters.

[0103] Specifically, the control strategy employs a tiered response based on the absolute value of the excess weight percentage. This means that the greater the deviation of the wet weight from the target value, the greater the adjustment range of printing parameters (such as printing pressure and squeegee speed) will be; conversely, when the deviation is small, the parameter adjustments will be more moderate. This tiered response strategy helps achieve precise control, avoiding drastic fluctuations in wet weight caused by over-adjustment, resulting in smoother and more stable wet weight control.

[0104] When the absolute value of the excess percentage is large, the system can quickly identify and make significant parameter adjustments to rapidly correct the wet weight deviation. This rapid response mechanism helps shorten the time for the wet weight to return to the target value, reduces the number of defective products in production, and improves production line efficiency and product qualification rate.

[0105] By adjusting parameters based on the absolute value of the over-limit ratio, rather than solely relying on its sign, the system avoids parameter adjustment oscillations that occur when the wet weight approaches the target value. This reduces the likelihood of repeated adjustments to printing parameters, prevents production fluctuations, and enhances system stability and production continuity.

[0106] When the wet weight deviation is small, minor parameter adjustments are made to avoid unnecessary energy consumption and equipment wear. This mechanism helps reduce production costs and energy consumption, while also extending equipment lifespan, aligning with sustainable production principles.

[0107] Adjusting the printing parameters of the printing press based on the absolute value of the over-limit ratio to obtain the updated printing parameters further includes the following steps:

[0108] Step S4021: If the absolute value of the above-mentioned excess ratio is within the first range, keep the current printing parameters of the printing press unchanged and send a prompt message. The prompt message includes the following information including the data of the above-mentioned excess ratio.

[0109] The first range is within ±3%. When the absolute value of the out-of-range percentage falls within this range, the printing press's current parameters remain unchanged while a warning message is sent. This mechanism avoids overreacting to minor deviations, reduces unnecessary parameter adjustments, and maintains production process stability. Simultaneously, by sending warning messages, operators can monitor changes in wet weight data at any time, taking preventative measures to prevent potential problems from escalating.

[0110] Step S4022: When the absolute value of the above-mentioned over-limit ratio is within the second range, the printing parameters of the printing press are adjusted according to the size of the above-mentioned over-limit ratio to obtain updated printing parameters, wherein the minimum value of the above-mentioned second range is the maximum value of the above-mentioned first range.

[0111] The second range is ±3% to 8%. Automatic adjustment of printing parameters is implemented within this range to respond to larger deviations in wet weight data. This dynamic adjustment mechanism can rapidly adjust the printing press's operating status based on real-time wet weight data, such as increasing or decreasing printing pressure or adjusting printing speed, to achieve the ideal wet weight standard. This instantaneous response capability enhances the production line's adaptability to different material properties and environmental changes, helping to maintain high-quality production levels.

[0112] Step S4023: If the absolute value of the above-mentioned over-limit ratio is within the first range for a first preset number of consecutive times, or within the second range for a second preset number of consecutive times, or within the third range, control the printing press to stop and send an alarm message. The alarm message is a message indicating a fault in the printing press. The first preset number of times is greater than the second preset number of times.

[0113] The first preset number of attempts is three, the second preset number of attempts is two, and the third range is ±8% or more. If the absolute value of the excess percentage falls within the first range for the first preset number of attempts, or within the second range for the second preset number of attempts, or exceeds the third range, the printing machine will automatically stop and send an alarm message. This design not only prevents small deviations from accumulating into major problems, but also allows for immediate action when serious anomalies occur in wet weight data, avoiding production waste, reducing material waste and production costs, and protecting the equipment from potential damage.

[0114] Specifically, by implementing the above steps, wet weight data can be effectively controlled while ensuring production efficiency, avoiding production problems caused by excessively high or low wet weight. This not only reduces the frequency of manual intervention and lowers production costs, but also improves the yield of solar cells and overall production efficiency, ensuring the high-performance operation of the production line.

[0115] In some embodiments, the printing parameters include printing pressure and squeegee speed. When the absolute value of the over-limit ratio is within a second range, the printing parameters of the printing press are adjusted according to the magnitude of the over-limit ratio to obtain updated printing parameters, including the following steps:

[0116] Step S11: Obtain the parameter mapping table. The parameter mapping table is the mapping relationship between the wet weight excess value and the printing pressure adjustment value and the squeegee speed adjustment value of the printing press. The wet weight excess value and the printing pressure adjustment value and the squeegee speed adjustment value are all directly proportional.

[0117] Step S12: Determine the pressure adjustment value and speed adjustment value corresponding to the printing press based on the above-mentioned over-limit ratio and the above-mentioned parameter mapping table.

[0118] Step S13: The sum of the current printing pressure of the printing press and the pressure adjustment value is determined as the updated pressure value, and / or the sum of the current squeegee speed of the printing press and the speed adjustment value is determined as the updated speed value, thereby obtaining the updated printing parameters.

[0119] Specifically, by obtaining the parameter mapping table, the direct proportional relationship between the wet weight exceeding the limit and the adjustment values ​​of printing pressure and squeegee speed was clarified. This means that printing pressure and squeegee speed can be precisely adjusted based on subtle changes in wet weight data, avoiding the production instability and material waste that may result from traditional extensive adjustments, and improving the level of precision control throughout the entire production process.

[0120] In steps S12 and S13, the system automatically determines the printing press's update pressure and update speed values ​​based on the real-time over-limit ratio. This automated decision-making process significantly reduces the need for manual judgment and intervention, improves production efficiency, and also reduces errors caused by human factors, enhancing the automation and intelligence level of the production line. By monitoring changes in wet weight data in real time and immediately adjusting the printing press's printing parameters according to the mapping table, a closed-loop control system is formed.

[0121] This real-time response capability enables the production line to quickly adapt to changes in material properties, equipment status, or environmental conditions, maintaining wet weight data within the ideal range, thereby improving the production quality and consistency of solar cells. The parameter mapping table design considers the direct proportional relationship between wet weight exceedances and printing parameter adjustment values, implying that larger wet weight deviations require larger parameter adjustments. When the system detects that the exceedance ratio consistently exceeds a certain threshold, it can trigger preventative maintenance or anomaly handling procedures in advance, avoiding potential production accidents, reducing downtime and maintenance costs, and protecting equipment from damage. By adjusting the printing press's operating status in a timely and precise manner, not only is waste of raw materials such as silver paste reduced, but also production defects caused by improper wet weight control are avoided, thereby lowering production costs.

[0122] The parameter mapping table is shown in Table 1:

[0123] Table 1. Parameter Mapping Table

[0124]

[0125] Table 1 above only shows one linear relationship between the adjustment value and the over-limit ratio. In practical applications, the pressure adjustment value and speed adjustment value are not necessarily strictly linear with the over-limit ratio, and it is necessary to judge according to the actual needs.

[0126] In some embodiments, the printing parameters include printing pressure and squeegee speed. When the absolute value of the over-limit ratio is within a second range, the printing parameters of the printing press are adjusted according to the magnitude of the over-limit ratio to obtain updated printing parameters, including the following steps:

[0127] Step S21: Obtain the equipment parameters of the printing press. The equipment parameters include at least the usage time of the squeegee, the hardness of the squeegee, the lifespan of the screen, the tension of the screen, and the deformation of the screen.

[0128] The above steps not only focused on the percentage of wet weight data exceeding limits, but also obtained multiple equipment parameters of the printing press, such as doctor blade usage time, hardness, screen life, tension, and deformation. These parameters reflect the actual operating status of the printing press and the wear and tear of its components, providing a more comprehensive information basis for subsequent parameter adjustments.

[0129] Step S22: Based on the magnitude of the over-limit ratio and the equipment parameters of the printing press, adjust the printing pressure and / or the squeegee speed of the printing press to obtain the updated printing parameters.

[0130] Based on the extent of the over-limit and the actual condition of the equipment, the system can intelligently adjust the printing pressure and / or squeegee speed. This adjustment is no longer a single-dimensional adjustment, but rather a comprehensive consideration of the equipment's health status, material properties, and other factors that may affect wet weight. This ensures that the updated printing parameters better meet actual production needs, effectively correct wet weight deviations, extend equipment lifespan, and reduce maintenance costs.

[0131] Specifically, by incorporating equipment parameters, this mechanism can also predictively identify equipment aging or wear. For example, when the doctor blade is nearing the end of its lifespan, the system may automatically adjust the printing pressure or doctor blade speed to compensate for changes in wet weight caused by decreased doctor blade performance. This predictive maintenance not only avoids sudden equipment failures but also optimizes resource allocation, avoids unnecessary component replacements, and saves costs. By comprehensively considering the over-limit ratio and adjusting printing parameters based on equipment parameters, wet weight can be controlled more precisely, reducing production anomalies caused by wet weight deviations and improving cell yield. Simultaneously, this intelligent adjustment mechanism reduces the need for manual intervention, avoids production interruptions, maintains the continuity and efficiency of the production line, and contributes to improving overall production efficiency.

[0132] In some embodiments, the printing parameters include printing pressure and squeegee speed. When the absolute value of the over-limit ratio is within a second range, the printing parameters of the printing press are adjusted according to the magnitude of the over-limit ratio to obtain updated printing parameters, including the following steps:

[0133] Step S31: Adjust the first equipment parameter of the printing press according to the magnitude of the above-mentioned over-limit ratio in a first manner to obtain the first updated parameter. The first equipment parameter is one of the printing pressure and the doctor blade speed. When the above-mentioned over-limit ratio is positive, the first manner is to increase it. When the above-mentioned over-limit ratio is negative, the first manner is to decrease it.

[0134] The adjustment method, based on the positive or negative value of the excess ratio, determines whether to increase or decrease the printing pressure or the squeegee speed. This method avoids overcorrection, preventing a blind and drastic reduction in printing pressure due to high wet weight, and vice versa. Gradual adjustment allows for more precise identification of parameter settings suitable for the current production conditions.

[0135] Step S32: Control the printing press to print the battery cells in the preparation process using the first update parameters, and detect and calculate the update over-limit ratio of the battery cells in the preparation process.

[0136] Step S33: Adjust the printing parameters of the printing press according to the absolute value of the updated over-limit ratio to obtain the updated printing parameters.

[0137] Specifically, steps S32 and S33 form a closed-loop control system. In step S32, the first updated parameters are applied during printing, and the updated over-limit ratio is calculated. Step S33 then further adjusts the printing parameters based on the absolute value of this updated over-limit ratio. This closed-loop control mechanism ensures that the printing press parameter adjustments are based on real-time wet weight measurements, improving the accuracy of parameter adjustments and enabling the wet weight to quickly stabilize within the target range.

[0138] Adjusting printing parameters based on the absolute value of the over-limit ratio means the system can flexibly adjust the parameter modification range according to the degree to which the current wet weight deviates from the target value. When the wet weight deviates significantly from the target, the system can make larger adjustments; when it is close to the target, it can make smaller adjustments. This mechanism avoids over-adjustment and improves the system's flexibility and adaptability.

[0139] The updated excess ratio detected and calculated in step S32 provides a basis for readjusting printing parameters in step S33, forming a continuously iterative optimization process. This iterative process continuously optimizes printing parameters, making wet weight control more precise, avoiding instability that may be caused by single adjustments, and ensuring the continuity and efficiency of the production process. This feedback-based dynamic parameter adjustment mechanism, through closed-loop control, dynamic response, and continuous optimization, achieves precision and flexibility in wet weight control, reduces manual intervention, and ultimately improves production yield and efficiency while reducing production costs. It has significant application value for modern manufacturing industries that pursue high precision, high efficiency, and low cost, especially in the production of solar cells.

[0140] Adjusting the printing parameters of the printing press according to the absolute value of the updated over-limit ratio to obtain the updated printing parameters further includes the following steps:

[0141] Step S331: When the absolute value of the above-mentioned update over-limit ratio is within the above-mentioned second range and the sign of the above-mentioned update over-limit ratio is the same as the sign of the above-mentioned over-limit ratio, continue to adjust the first equipment parameter of the printing press in the above-mentioned first manner until the absolute value of the above-mentioned update over-limit ratio is less than the minimum value of the above-mentioned second range.

[0142] Step S332: When the absolute value of the updated over-limit ratio is within the second range and the sign of the updated over-limit ratio is different from the sign of the over-limit ratio, the second equipment parameter of the printing press is adjusted according to the second method until the absolute value of the updated over-limit ratio is less than the minimum value of the second range. The second method is the opposite of the first method.

[0143] Specifically, the above steps allow the system to re-detect and calculate the updated over-limit ratio after each adjustment, and then continue to adjust or change the adjustment strategy based on the updated results. This iterative verification process ensures the effectiveness and relevance of parameter adjustments, helping to quickly optimize to the best state. When the sign of the updated over-limit ratio is the same as the original over-limit ratio, it indicates that the previous adjustment direction was correct but the magnitude was insufficient.

[0144] Therefore, continuing to adjust in the original direction until the absolute value of the updated excess ratio is lower than the set threshold forms a positive feedback mechanism, which helps to accelerate the convergence of the parameter adjustment process and achieve the ideal wet weight control effect more quickly. Conversely, if the sign of the updated excess ratio is different from the original excess ratio, it may mean that the direction of the previous adjustment was incorrect or that environmental conditions have changed. At this time, the system will adjust another parameter in the opposite direction (e.g., if the printing pressure was adjusted before, the doctor blade speed will be adjusted now, and vice versa), to ensure that the adjustment direction is correct and to avoid further expansion of wet weight deviation due to incorrect adjustment. This dynamic adjustment strategy can flexibly respond to sudden changes in material properties, equipment performance fluctuations, or changes in environmental conditions during the production process, improving the robustness of the entire system, that is, its ability to resist external changes and disturbances. Through timely and precise parameter adjustments, wet weight can be maintained within a reasonable range, ensuring that production quality is not affected.

[0145] When the wet weight excess percentage is positive, it indicates that the printed wet weight exceeds the target value and needs to be reduced. Proceed to step S40331 to increase the printing pressure to reduce the printed wet weight. If the updated excess percentage is still positive but the absolute value has decreased to the second range, continue increasing the pressure as in step one until the wet weight meets the target. If the updated excess percentage becomes negative, it indicates that the pressure adjustment has been excessive. In this case, the printing pressure should be reduced to restore it to a reasonable wet weight range.

[0146] If the wet weight excess percentage is negative, it indicates insufficient wet weight, requiring an increase in wet weight. Reduce the scraper speed to allow the silver paste to transfer more fully to the solar cells, thus increasing the wet weight. If the updated excess percentage decreases in absolute value but remains negative, continue reducing the scraper speed until the wet weight meets the requirements. If the updated excess percentage becomes positive, it indicates the adjustment direction is reversed or excessive; the scraper speed should be increased to reduce the wet weight.

[0147] The wet weight control of the production line needs to adapt to different production requirements and changing conditions. The printing pressure or squeegee speed is adjusted based on the positive or negative value of the excess weight, while the second range threshold in steps S331 and S332 is dynamically adjusted to adapt to changes in production conditions. When the wet weight approaches the target value, the second range is narrowed for more precise adjustment. When encountering large fluctuations in wet weight, the second range is appropriately widened to prevent production instability caused by frequent adjustments.

[0148] In some cases, adjusting printing pressure or squeegee speed alone may not be sufficient to effectively control wet weight. Initially, adjust the printing pressure or squeegee speed based on the sign of the excess weight. If the sign of the excess weight reverses after the first adjustment, switch to adjusting the other parameter. As the excess weight gradually approaches zero while the sign remains unchanged, continue adjusting the current parameter until the wet weight meets the target. If wet weight control is difficult, a complex combination of parameters can be introduced, such as first increasing the printing pressure by a certain value and then slightly decreasing the squeegee speed, to achieve the best wet weight control effect.

[0149] Long-term operation requires continuous learning and optimization of parameter adjustment strategies. Over time, the system accumulates historical data to learn the non-linear relationship between the over-limit ratio and printing parameters, and optimizes the adjustment strategy through machine learning algorithms. Learning algorithms, such as neural networks or reinforcement learning, are introduced to adjust the increase or decrease in printing pressure and doctor blade speed based on historical data to achieve the wet weight target more quickly. The model is updated regularly to reflect changes in the production environment and technical parameters.

[0150] In some embodiments, the above method further includes the following steps:

[0151] Step S501: Obtain the transmission trajectory speed of the battery cell in the above preparation process;

[0152] Step S502: When the speed of the transmission track is greater than or equal to the first preset speed threshold, the sampling frequency of the weight sensor is the first frequency.

[0153] Step S503: When the speed of the transmission track is less than the first preset speed threshold and greater than or equal to the second preset speed threshold, the sampling frequency of the weight sensor is the second frequency, which is less than the first frequency.

[0154] In step S504, when the speed of the transmission track is less than the second preset speed threshold, the sampling frequency of the weight sensor is a third frequency, which is less than the second frequency.

[0155] The sensor sampling frequency f is dynamically adjusted according to the transmission track speed v (unit: mm / s). Different sampling frequencies f are set according to different production speeds, such as 5 min / time, 10 min / time, 15 min / time, and 20 min / time.

[0156] Specifically, the above embodiments set different sampling frequencies according to different speed ranges of the transmission track. When the production speed is high (transmission track speed is greater than or equal to a first preset speed threshold), the sampling frequency is higher (first frequency) to ensure that subtle changes in cell weight can still be captured during high-speed production. When the production speed slows down, the sampling frequency is correspondingly reduced. This dynamic matching mechanism ensures that high-quality wet weight data can be obtained at different production speeds. Using a high sampling frequency during high-speed production allows for more detailed tracking of wet weight changes, reduces data omissions that may occur due to excessively long sampling time intervals, and improves data acquisition efficiency.

[0157] Using a lower sampling frequency at slower production speeds maintains data accuracy while avoiding unnecessary data redundancy, saving data processing time and resources, and improving the overall system efficiency. Dynamically adjusting the sampling frequency also effectively reduces hardware wear and tear on the weight sensor, especially at slower production speeds; low-frequency sampling extends sensor lifespan and reduces maintenance costs. Simultaneously, this mechanism helps reduce equipment energy consumption; as production speed decreases, lower sampling frequency means reduced power consumption for the sensor and related electronic equipment, contributing to green manufacturing.

[0158] In addition, a fuzzy algorithm is introduced to dynamically correct the threshold range based on historical data; the system optimizes the priority of response strategies (efficiency or unit consumption) by combining production line efficiency and quality loss cost specifications with unit consumption standards; when the wet weight of a certain process continuously exceeds the limit, the system automatically analyzes upstream process data, such as slurry viscosity and ambient temperature and humidity, and pushes parameter adjustment suggestions to related equipment, supporting a hybrid decision-making process of human experience rules input and AI algorithms; the parameter adjustment response time is shortened from minutes to seconds, reducing unnecessary downtime by more than 30%, reducing silver paste waste while improving overall efficiency and cost.

[0159] Comparative Example

[0160] Before the solar cell passes through the printing press, the machine is stopped and the weight of one solar cell is weighed manually. After the solar cell passes through the printing press, the machine is stopped and the weight of one solar cell is weighed manually again. The difference between the two measurements is determined as the wet weight of the solar cell. The solar cell is then put back into the production line for further processing.

[0161] Example

[0162] Five sets of weight sensors are installed on the battery transport track at the front end of the printing machine. Each set of weight sensors has five sensors. Each set of weight sensors measures the pre-printing weight of a single battery cell at five locations. The weighted average of these five pre-printing weights is then calculated to obtain the pre-printing weight of each battery cell. Since there are five battery cells in production, five sets of weight sensors are used to obtain five pre-printing weights for each cell. The same method is used to obtain five post-printing weights for each cell. The difference between the pre-printing weight and the corresponding post-printing weight is determined as the wet weight of a single battery cell in production, resulting in five wet weights. The sum of these five wet weights is then averaged to determine the wet weight data. The battery cells in production are then placed on the production line for further processing.

[0163] The final data comparison table of the embodiments and comparative examples is shown in Table 2:

[0164] Table 2. Data Comparison Table of Examples and Comparative Examples

[0165]

[0166] The high-speed sampling capability of the sensor and the timestamp-based data matching technology mentioned in the above embodiments enable rapid and accurate data acquisition and processing. Furthermore, by reducing manual intervention (such as manual sampling and parameter adjustment), the production cycle can be significantly shortened, the breakage rate reduced, and the machine uptime increased, thereby significantly improving the efficiency of the entire production line. Precise control of wet weight avoids the overuse or waste of silver paste, effectively controlling non-silicon costs. Simultaneously, it reduces unnecessary equipment adjustment and maintenance time, lowering production costs and improving economic efficiency. The combination of weight data and timestamps mentioned in the embodiments enables precise monitoring of each production stage, facilitating the traceability of the specific production history of each cell, which is crucial for subsequent quality control and problem localization. Simultaneously, the automatic data upload and integration with the MES (Manufacturing Execution System) further enhance the transparency and analyzability of production data. When the wet weight measurement result exceeds a preset threshold, the system can automatically analyze and adjust printing parameters, such as printing pressure and squeegee speed, and even introduce fuzzy algorithms and multi-parameter collaborative adjustment mechanisms to achieve intelligent production process control. This adaptive adjustment mechanism improves the intelligence level of the production line, reduces the occurrence of production anomalies, and ensures stable product quality.

[0167] On the one hand, by continuously testing five cells and averaging the weight difference, the influence of large randomness in single-cell testing is eliminated, providing greater fault tolerance and more accurately reflecting the unit consumption level of the production line. On the other hand, it can continuously monitor fluctuations in unit consumption of the production line, promptly alarming when exceeding the warning value, and realizing online parameter adjustment to control unit consumption. This avoids excessively low unit consumption affecting cell efficiency and yield, or excessively high unit consumption causing an increase in silver costs. Unlike traditional manual measurement methods, which measure at a frequency of 1-3 hours per measurement per channel, the measurement data is subject to human error and has a large lag. By the time an abnormal unit consumption is responded to, the production line has often already been running with the problem for a period of time, resulting in a decrease in yield due to abnormal unit consumption. Furthermore, manual online handling of test cells increases the downtime of the production line due to abnormalities and reduces the response uptime, which is not conducive to further cost reduction. The aforementioned testing method continuously and automatically measures online and provides real-time feedback, improving production line yield and machine uptime, effectively controlling unit consumption within a reasonable range, and further reducing the non-silicon cost of the battery.

[0168] This embodiment also provides a solar cell, which is prepared by any of the above-described methods for preparing solar cells.

[0169] By employing a strategy of dynamically adjusting printing pressure and squeegee speed during the fabrication process, the wet weight of solar cells can be continuously monitored and adjusted in a timely manner, avoiding efficiency and yield reduction issues caused by wet weight fluctuations. Compared to traditional manual monitoring and adjustment methods, this automated approach significantly improves the stability of wet weight control, ensures cell consistency, greatly increases cell yield, and reduces manufacturing costs.

[0170] Those skilled in the art will understand that the above embodiments are specific examples of implementing this application, and in practical applications, various changes in form and detail can be made without departing from the spirit and scope of this application. Any person skilled in the art can make various alterations and modifications without departing from the spirit and scope of this application; therefore, the scope of protection of this application should be determined by the scope defined in the claims.

Claims

1. A method for preparing a solar cell, characterized in that, include: The pre-printing weight and post-printing weight of a single solar cell during the manufacturing process are obtained. The pre-printing weight is calculated from multiple pre-printing weight data, and the post-printing weight is calculated from multiple post-printing weight data. The pre-printing weight data is the weight of the solar cell during the manufacturing process collected by a weight sensor in front of the printing press, and the post-printing weight data is the weight of the solar cell during the manufacturing process collected by a weight sensor after the printing press. The wet weight data is calculated based on the difference between the weight of the single piece before printing and the weight of the single piece after printing. Based on the wet weight data, the printing parameters of the printing press are adjusted to obtain updated printing parameters, and the printing press is controlled to print the battery cells in preparation using the updated printing parameters to prepare solar cells. The yield rate of the solar cells prepared using the updated printing parameters is greater than the preset yield rate. Obtain the weight of a single solar cell before and after printing during the fabrication process, including: Multiple first pre-printing weights and multiple first post-printing weights of the battery cell in the process of preparation are obtained. The multiple first pre-printing weights are weight data obtained by detecting different positions of the battery cell in the process of preparation before passing through the printing machine. The multiple first post-printing weights are weight data obtained by detecting different positions of the battery cell in the process of preparation after passing through the printing machine. A set of corresponding first pre-printing weights and first post-printing weights are weight data detected at the same position of the battery cell in the process of preparation. The weighted average of the multiple first pre-printing weights of the battery cells in the preparation process is calculated to obtain the pre-printing weight of a single battery cell in the preparation process. The weighted average of the multiple first-printed weights of the battery cells in the preparation process is calculated to obtain the single-cell printed weight of the battery cells in the preparation process. The weights of the first pre-printing weights are different, and the weight of the first pre-printing weights whose detection position is closer to the center of the battery cell being prepared is greater than the weight of the first pre-printing weights whose detection position is farther from the center of the battery cell being prepared.

2. The method for preparing a solar cell according to claim 1, characterized in that, The preparation process involves multiple solar cells. Each solar cell corresponds to a pre-printing weight and a post-printing weight. Wet weight data is calculated based on the difference between the pre-printing weight and the post-printing weight, including: The difference between the weight of the single cell before printing and the corresponding weight of the single cell after printing is determined as the wet weight of the single cell, and the wet weight of the single cell corresponds one-to-one with the battery cell in the preparation process. The average sum of the wet weights of multiple individual pieces is determined as the wet weight data.

3. The method for preparing a solar cell according to claim 1, characterized in that, The preparation process involves multiple solar cells. The weight of a single solar cell before printing and the weight of a single solar cell after printing are obtained, including: Multiple pre-printing weights and multiple post-printing weights are obtained. The multiple pre-printing weights are weight data at different positions of different cells in the same process before the printing press is used. The multiple post-printing weights are weight data at different positions of different cells in the same process after the printing press is used. A set of corresponding pre-printing weights and post-printing weights are the weights at the same position of the same cell in the same process. The weighted average of the multiple second pre-printing weights is used to obtain the pre-printing weight of the single piece. The weight of a single printed piece is obtained by weighted averaging of multiple second-printed weights.

4. The method for preparing a solar cell according to claim 1, characterized in that, Based on the wet weight data, the printing parameters of the printing press are adjusted to obtain updated printing parameters, including: Calculate the difference between the wet weight data and the standard wet weight, and calculate the ratio of the difference to the standard wet weight to obtain the excess ratio; Based on the absolute value of the over-limit ratio, the printing parameters of the printing press are adjusted to obtain the updated printing parameters.

5. The method for preparing a solar cell according to claim 4, characterized in that, Based on the absolute value of the excess ratio, the printing parameters of the printing press are adjusted to obtain the updated printing parameters, including: If the absolute value of the excess ratio is within a first range, the current printing parameters of the printing press are kept unchanged, and a prompt message is sent, the prompt message including information about the excess ratio. When the absolute value of the over-limit ratio is within the second range, the printing parameters of the printing press are adjusted according to the size of the over-limit ratio to obtain updated printing parameters, wherein the minimum value of the second range is the maximum value of the first range. If the absolute value of the excess ratio is within the first range for a first preset number of consecutive times, or within the second range for a second preset number of consecutive times, or within the third range, the printing press is controlled to stop and an alarm message is sent. The alarm message indicates a fault in the printing press, and the first preset number of times is greater than the second preset number of times.

6. The method for preparing a solar cell according to claim 5, characterized in that, The printing parameters include printing pressure and squeegee speed. When the absolute value of the out-of-limit ratio is within a second range, the printing parameters of the printing press are adjusted according to the magnitude of the out-of-limit ratio to obtain updated printing parameters, including: Obtain a parameter mapping table, which shows the mapping relationship between the wet weight excess value and the printing pressure adjustment value and the doctor blade speed adjustment value of the printing press. The wet weight excess value is directly proportional to both the printing pressure adjustment value and the doctor blade speed adjustment value. Based on the over-limit ratio and the parameter mapping table, determine the pressure adjustment value and speed adjustment value corresponding to the printing press; The updated printing parameters are obtained by determining the sum of the current printing pressure of the printing press and the pressure adjustment value, and / or by determining the sum of the current squeegee speed of the printing press and the speed adjustment value.

7. The method for preparing a solar cell according to claim 5, characterized in that, The printing parameters include printing pressure and squeegee speed. When the absolute value of the out-of-limit ratio is within a second range, the printing parameters of the printing press are adjusted according to the magnitude of the out-of-limit ratio to obtain updated printing parameters, including: Obtain the equipment parameters of the printing press, which include at least the usage time of the squeegee, the hardness of the squeegee, the lifespan of the screen, the tension of the screen, and the deformation of the screen. Based on the magnitude of the over-limit ratio and the equipment parameters of the printing press, the printing pressure and / or the squeegee speed of the printing press are adjusted to obtain the updated printing parameters.

8. The method for preparing a solar cell according to claim 5, characterized in that, The printing parameters include printing pressure and squeegee speed. When the absolute value of the out-of-limit ratio is within a second range, the printing parameters of the printing press are adjusted according to the magnitude of the out-of-limit ratio to obtain updated printing parameters, including: According to the magnitude of the over-limit ratio, the first equipment parameter of the printing press is adjusted in a first manner to obtain the first updated parameter. The first equipment parameter is one of the printing pressure and the squeegee speed. When the over-limit ratio is positive, the first manner is to increase it; when the over-limit ratio is negative, the first manner is to decrease it. The printing press is controlled to print the battery cells in preparation using the first update parameters, and the update over-limit ratio of the battery cells in preparation is detected and calculated. The printing parameters of the printing press are adjusted according to the absolute value of the updated over-limit ratio to obtain the updated printing parameters.

9. The method for preparing a solar cell according to claim 8, characterized in that, The printing parameters of the printing press are adjusted according to the absolute value of the updated over-limit ratio to obtain the updated printing parameters, including: If the absolute value of the updated excess ratio is within the second range and the sign of the updated excess ratio is the same as the sign of the excess ratio, continue to adjust the first equipment parameter of the printing press in the first manner until the absolute value of the updated excess ratio is less than the minimum value of the second range. If the absolute value of the updated over-limit ratio is within the second range and the sign of the updated over-limit ratio is different from the sign of the over-limit ratio, the second equipment parameter of the printing press is adjusted in a second manner until the absolute value of the updated over-limit ratio is less than the minimum value of the second range. The second manner is the opposite of the first manner.

10. The method for preparing a solar cell according to any one of claims 1 to 9, characterized in that, The method further includes: Obtain the transport trajectory speed of the battery cells during the fabrication process; When the speed of the transmission track is greater than or equal to a first preset speed threshold, the sampling frequency of the weight sensor is a first frequency; When the speed of the transmission track is less than the first preset speed threshold and greater than or equal to the second preset speed threshold, the sampling frequency of the weight sensor is the second frequency, which is less than the first frequency; When the speed of the transmission track is less than the second preset speed threshold, the sampling frequency of the weight sensor is a third frequency, which is less than the second frequency.

11. The method for preparing a solar cell according to any one of claims 1 to 9, characterized in that, All of the aforementioned weight sensors are of the same type and have the same operating parameters.

12. The method for preparing a solar cell according to any one of claims 1 to 9, characterized in that, The weight sensor is either a photoelectric weight sensor or a capacitive weight sensor.

13. A solar cell, characterized in that, The solar cell is prepared by the method for preparing a solar cell according to any one of claims 1 to 12.

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