Printing screens, line structures, solar cells and photovoltaic systems

Abstract

The application is suitable for the technical field of solar cells, and particularly relates to a printing screen, a grid line structure, a solar cell and a photovoltaic system. The printing screen comprises a screen body, the screen body is provided with a plurality of interval distributed pad printing areas, and a main grid printing area is arranged between two adjacent pad printing areas. In a first direction, the main grid printing area comprises at least two sections of main grid holes with aperture decreasing in sequence, and a transition section of holes is arranged between two adjacent sections of main grid holes. The opening rate of the transition section of holes is between the opening rates of the two adjacent sections of main grid holes, and the first direction is a direction from the pad printing area to a center point between the two adjacent pad printing areas. The transition section of holes is arranged between the two adjacent sections of main grid holes, the transition is performed by the two adjacent sections of main grid holes with the transition section of holes as a shoulder, the integrity of the printed main grid line is ensured, and thus the quality of the main grid line is ensured.

Description

Technical Field

[0001] This application belongs to the field of solar cell technology, and particularly relates to a printing screen, grid structure, solar cell and photovoltaic system. Background Technology

[0002] Solar cells have photovoltaic grids on their surface, which are a network of metal lines made of conductive materials such as silver and aluminum. Photovoltaic grids are usually divided into main grids and sub-grids. The main grids are responsible for collecting the current collected by the sub-grids and transmitting it to the external circuit, while the sub-grids are distributed in the light-receiving area of ​​the cell to directly capture photogenerated carriers.

[0003] Photovoltaic grid lines are manufactured using photovoltaic printing screens. By precisely controlling the application position and thickness of a metal paste (such as silver or aluminum), photovoltaic grid lines are formed on the surface of the solar cell. The main grid line typically has several pads (PADs), which can be considered as solder pads for bonding with solder ribbons. Adjacent PADs are connected by the main grid line, and the main grid line gradually thickens from the center point of adjacent PADs. Similarly, the mesh size of the photovoltaic printing screen corresponding to the main grid line also gradually increases from the center point to the PAD. However, the variation in the mesh size of the main grid line in existing photovoltaic printing screens can easily lead to poor transitions in the printed main grid lines, affecting the quality of the main grid lines. Utility Model Content

[0004] This application provides a printing screen to solve the problem that changes in the size of the main grid mesh of existing photovoltaic printing screens can easily lead to poor transitions in the printed main grid lines.

[0005] This application embodiment is implemented as follows: a printing screen is provided, comprising:

[0006] The screen version body has several spaced solder pad printing areas, and a main grid printing area is provided between two adjacent solder pad printing areas.

[0007] In the first direction, the main gate printing area includes at least two main gate mesh segments with successively decreasing apertures. A transition mesh segment is provided between two adjacent main gate mesh segments. The aperture ratio of the transition mesh segment is between that of the two adjacent main gate mesh segments. The first direction is the direction from the pad printing area to the center point between two adjacent pad printing areas.

[0008] Furthermore, in the first direction, the width of at least two main grid mesh segments gradually decreases.

[0009] Furthermore, the main grid mesh includes at least one of circular, elliptical, prismatic, polygonal, and irregular shapes.

[0010] Furthermore, the edges of the webpage body are provided with an edge adhesive film.

[0011] Furthermore, the screen printing body includes a sub-grid printing area, which is connected to the main grid printing area.

[0012] Furthermore, a gradient transition edge is provided between the side of the sub-grid printing area and the side of the main grid printing area.

[0013] Furthermore, the gradient transition edge can be any one of a straight line, an arc, or a wavy line.

[0014] Secondly, this application also provides a grid line structure, which is obtained by printing using the printing screen as described above.

[0015] Thirdly, this application also provides a solar cell, including the grid structure as described above.

[0016] Fourthly, this application also provides a photovoltaic system, including the solar cell as described above.

[0017] The beneficial effects of this application are as follows: The printing screen provided by this application includes a screen body, which has a plurality of spaced-apart pad printing areas, and a main grid printing area is provided between two adjacent pad printing areas. In a first direction, the main grid printing area includes at least two main grid mesh segments with successively decreasing apertures, and a transition mesh segment is provided between two adjacent main grid mesh segments. The aperture ratio of the transition mesh segment is between that of the two adjacent main grid mesh segments. The first direction is the direction from the pad printing area to the center point between two adjacent pad printing areas. By providing a transition mesh segment between two adjacent main grid mesh segments, the transition mesh segment overlaps with the two adjacent main grid mesh segments to ensure the integrity of the printed main grid lines, thereby ensuring the quality of the main grid lines. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the grid line structure of one embodiment of the solar cell provided in this application;

[0019] Figure 2 yes Figure 1 Enlarged schematic diagram of section A1 in the middle;

[0020] Figure 3 This is a schematic diagram of the structure of a printing screen provided in this application, showing the main grid mesh and transition section mesh in one embodiment.

[0021] Explanation of reference numerals in the attached figures:

[0022] 100 - Screen body, 110 - Pad printing area, 120 - Main grid printing area, 121 - Main grid mesh, 122 - Transition section mesh. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. Examples of embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. Furthermore, it should be understood that the specific embodiments described herein are merely for explaining this application and are not intended to limit this application.

[0024] In the description of this application, it should be understood that the terms "length", "width", "upper", "lower", "left", "right", "horizontal", "top", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0025] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0026] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0027] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0028] The following disclosure provides numerous different embodiments or examples for implementing various structures of this application. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of this application. Furthermore, reference values ​​and / or reference letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, various specific examples of processes and materials are provided in this application, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0029] The printing screen provided in this application includes a screen body with several spaced-apart pad printing areas and a main grid printing area between adjacent pad printing areas. In a first direction, the main grid printing area includes at least two main grid mesh segments with progressively decreasing apertures. A transition mesh segment is provided between adjacent main grid mesh segments, with the aperture ratio of the transition mesh segment falling between that of the adjacent main grid mesh segments. The first direction is from the pad printing area to the center point between the two adjacent pad printing areas. By providing a transition mesh segment between adjacent main grid mesh segments, the transition mesh segment overlaps with the adjacent main grid mesh segments to ensure the integrity of the printed main grid lines, thereby guaranteeing the quality of the main grid lines.

[0030] like Figures 1 to 3 As shown, this application embodiment provides a printing screen, including:

[0031] The screen version body 100 has a number of spaced pad printing areas 110, and a main grid printing area 120 is provided between two adjacent pad printing areas 110.

[0032] In the first direction, the main gate printing area 120 includes at least two main gate mesh segments 121 with successively decreasing apertures. A transition mesh segment 122 is provided between two adjacent main gate mesh segments 121. The aperture ratio of the transition mesh segment 122 is between the aperture ratios of the two adjacent main gate mesh segments 121. The first direction is the direction from the pad printing area 110 to the center point between two adjacent pad printing areas 110.

[0033] In practice, the printing stencil provided in this application is used to coat and print a metallic conductive pattern at a specified position on the surface of the silicon wafer, including main gate lines and PAD points. The PAD points can be regarded as pads on the main gate lines, which will not be described in detail.

[0034] To form main grid lines and pad dots using a printing screen, the screen body 100 needs to have main grid printing areas 120 and pad printing areas 110 corresponding to the main grid lines and pad dots, respectively. Typically, main grid printing areas 120 of the same polarity are connected to multiple spaced pad printing areas 110. For example, the main grid printing areas 120 can be divided into positive and negative main grid printing areas 120. The positive main grid printing areas 120 correspond to multiple positive pad printing areas 110, and the negative main grid printing areas 120 correspond to multiple negative pad printing areas 110.

[0035] For example, taking the positive gate printing area 120 as an example where it extends vertically, the multiple positive pad printing areas 110 are also distributed vertically at intervals, and adjacent positive pad printing areas 110 are connected by a section of the positive gate printing area 120. Similarly, the negative gate printing area 120 is also distributed vertically, and the positive gate printing areas 120 and the negative pad printing areas 110 are distributed alternately in the horizontal direction. At the same time, the multiple negative pad printing areas 110 are also distributed vertically at intervals, and adjacent negative pad printing areas 110 are connected by a section of the negative gate printing area 120.

[0036] The pad printing area 110 is provided with pad mesh for printing PAD dots.

[0037] The main gate printing area 120 between two adjacent pad printing areas 110 can be divided into two segments. Each segment of the main gate printing area 120 includes at least two main gate meshes 121 in the first direction, and the aperture of the at least two main gate meshes 121 decreases sequentially in the first direction.

[0038] For ease of understanding, let's denote the center point between two adjacent solder pad printing areas 110 as point D1. Then, the direction from the solder pad printing area 110 to point D1 is the first direction. Figure 2 As shown. That is, when two adjacent solder pad printing areas 110 are vertically distributed, the direction from the upper solder pad printing area 110 to point D1 is recorded as the first direction; similarly, the direction from the lower solder pad printing area 110 to point D1 is also recorded as the first direction, as shown below. Figure 2 As shown by line segment L in the diagram. In the upper pad printing area 110 to point D1, there are at least two main gate mesh segments 121 that are distributed from top to bottom and have decreasing apertures. Similarly, in the lower pad printing area 110 to point D1, there are at least two main gate mesh segments 121 that are distributed from bottom to top and have decreasing apertures.

[0039] A transition section mesh 122 is provided between two adjacent main grid mesh sections 121. The apertures of adjacent main grid mesh sections 121 are different, resulting in different mesh counts and, similarly, different aperture ratios. In implementation, aperture refers to the size of the mesh opening, mesh count refers to the number of mesh openings per unit length (e.g., 1 inch), and aperture ratio refers to the proportion of the mesh area to the total area of ​​the screen. Generally, the conversion relationship between mesh count and aperture (millimeters) is: mesh count = 1 / aperture * 254. For example, if the aperture is 1 millimeter, then according to the formula, the mesh count = 1 / 1 * 254 = 254 meshes. Furthermore, the aperture ratio can be calculated using the following formula: Aperture ratio (m) = [(aperture width b) / (wire diameter a + aperture width b)] 2 ×100%, for example, taking 400 mesh, wire diameter 18, and aperture 45.5 as an example, the aperture ratio is calculated to be 51.3, or taking 290 mesh, wire diameter 20, and aperture 67.6 as an example, the aperture ratio is calculated to be 59.5, which will not be elaborated further.

[0040] By designing the aperture ratio of the transition section mesh 122 to be between that of the two adjacent main grid meshes 121, the transition section mesh 122 can better overlap with the two adjacent main grid meshes 121. The diversified mesh design makes the printed main grid lines smoother and fuller, improves the quality of the main grid, and thus improves the quality of solar cell products.

[0041] Optionally, the main grid mesh 121 includes at least one of circular, elliptical, prismatic, polygonal, and irregular shapes, without limitation.

[0042] Optionally, the pad mesh and transition section mesh 122 can also be designed as at least one of circular, elliptical, prismatic, polygonal and irregular shapes, and the pad mesh and transition section mesh 122 can adopt the same shape as the main gate mesh 121 or a different shape than the main gate mesh 121, without limitation.

[0043] In some alternative embodiments, the width of at least two main grid mesh openings 121 gradually decreases in the first direction. The width of the main grid mesh opening 121 can be considered as the width of the printed main grid. In some possible embodiments, in the first direction, the width ratio of the two ends of the at least two main grid mesh openings 121 is 1:5 to 3:5. For example, the width ratio of the two ends of the at least two main grid mesh openings 121 can be designed as any ratio between 1.5:5, 2:5, 2.5:5, or 1:5 to 3:5, without limitation.

[0044] The above settings enable the printed main grid to be a conductive metal strip with varying width, ensuring connection with the pads while reducing the amount of metal paste used in the main grid, guaranteeing the conductivity of the main grid, and saving costs.

[0045] The printing screen provided in this application includes a screen body 100, which has a plurality of spaced-apart pad printing areas 110, and a main grid printing area 120 between two adjacent pad printing areas 110. In a first direction, the main grid printing area 120 includes at least two main grid mesh segments 121 with successively decreasing apertures. A transition mesh segment 122 is provided between two adjacent main grid mesh segments 121, and the aperture ratio of the transition mesh segment 122 is between the aperture ratios of the two adjacent main grid mesh segments 121. The first direction is the direction from the pad printing area 110 to the center point between two adjacent pad printing areas 110. By providing a transition mesh segment 122 between two adjacent main grid mesh segments 121, the transition mesh segment 122 overlaps the two adjacent main grid mesh segments 121 to ensure the integrity of the printed main grid lines, thereby ensuring the quality of the main grid lines.

[0046] In some optional embodiments, the edge of the screen print body 100 is provided with an edge adhesive film, which may be at least one of EVA film, POE film and EPE film, without limitation.

[0047] Optionally, the main component of EVA film is a copolymer of ethylene and vinyl acetate, and it is divided into four types: high transmittance, high cutoff, white, and black. Single-glass modules typically use a combination of high transmittance and white types to improve light transmittance and reflectance; black single-glass modules use high cutoff EVA film to block ultraviolet rays.

[0048] Optionally, POE film uses POE resin as raw material, and its water vapor barrier capacity is one-eighth that of EVA film, making it suitable for humid environments. POE film has excellent anti-aging properties and can avoid PID (potential-induced degradation) phenomenon, making it the preferred material for bifacial modules.

[0049] Alternatively, EPE film is mainly used for encapsulating moisture-sensitive battery cells, but currently, China relies on imports for POE resin, resulting in high costs for EPE film.

[0050] By setting an edge adhesive film on the edge of the screen as an edge reinforcement protective layer of the screen body 100, the wear resistance of the right-angle area where the edge of the screen contacts the battery cell is increased, thereby improving the life of the screen, reducing screen leakage, screen bursting and other phenomena, thus reducing the frequency of screen replacement and improving production efficiency.

[0051] In some alternative embodiments, the screen version body 100 is provided with a sub-grid printing area, which is connected to the main grid printing area 120.

[0052] In practice, the sub-gate printing area is used to print the sub-gate, also called the fine gate. The sub-gate printing area is connected to the main gate printing area 120, so that the printed sub-gate and the main gate are electrically connected.

[0053] The fine gate is mainly responsible for collecting photogenerated carriers (i.e., the current generated by photoelectric conversion). The number and width of the fine gate directly affect the balance between the light-shielding area and the circuit loss. For example, a finer gate can reduce the light-shielding area, but a finer gate will also lead to a larger resistance, requiring finer solder ribbons and solder wires to reduce the resistance.

[0054] The main grid is primarily used to collect the current collected by the sub-grid. The main grid is also welded to the solder strip or interconnect strip via PAD points to transfer the current collected by the fine grid to the solder strip or interconnect strip to achieve series connection between cells.

[0055] In some alternative embodiments, a gradient transition edge is provided between the side of the sub-gate printing area and the side of the main gate printing area 120.

[0056] Optionally, the gradient transition edge can be any one of a straight line, an arc, or a wavy line, without limitation.

[0057] With the above settings, the sides of the main grid printing area 120 and the secondary grid printing area are connected by a gradient transition edge, making the connection between the printed main grid and the secondary grid more stable and reliable, thus ensuring product quality.

[0058] In some embodiments, this application also provides a grid line structure, which is obtained by printing using a screen printing plate as described above.

[0059] In implementation, the grid structure provided in this application includes a main grid and PAD dots. Correspondingly, the printing screen is provided with mesh openings for printing the main grid and PAD dots. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the structure and implementation principle of the grid structure described above can be referred to the corresponding structure and implementation principle in the foregoing embodiments, and will not be repeated here.

[0060] The printing screen provided in this application includes a screen body 100, which has a plurality of spaced-apart pad printing areas 110, and a main grid printing area 120 between two adjacent pad printing areas 110. In a first direction, the main grid printing area 120 includes at least two main grid mesh segments 121 with successively decreasing apertures. A transition mesh segment 122 is provided between two adjacent main grid mesh segments 121, and the aperture ratio of the transition mesh segment 122 is between the aperture ratios of the two adjacent main grid mesh segments 121. The first direction is the direction from the pad printing area 110 to the center point between two adjacent pad printing areas 110. By providing a transition mesh segment 122 between two adjacent main grid mesh segments 121, the transition mesh segment 122 overlaps the two adjacent main grid mesh segments 121 to ensure the integrity of the printed main grid lines, thereby ensuring the quality of the main grid lines.

[0061] In some embodiments, this application also provides a solar cell, including the grid structure as described above.

[0062] In practice, a solar cell is a photoelectric semiconductor wafer that generates electricity directly using sunlight. As long as the illuminance meets certain conditions, it can instantly output voltage and generate current when there is a circuit.

[0063] Generally, there are two ways to generate solar power: one is the light-to-heat-to-electricity conversion method, and the other is the direct light-to-electricity conversion method.

[0064] Alternatively, the light-heat-electricity conversion method generates electricity by utilizing the heat energy produced by solar radiation. Generally, a solar collector converts the absorbed heat energy into steam, which then drives a steam turbine to generate electricity.

[0065] Alternatively, direct photo-to-electricity conversion utilizes electromagnetic waves of different wavelengths (corresponding to different frequencies) radiated by the sun, such as infrared, ultraviolet, and visible light. When these rays irradiate different conductors or semiconductors, photons interact with free electrons in the conductors or semiconductors to generate an electric current. The shorter the wavelength and the higher the frequency of the rays, the higher their energy; for example, ultraviolet light has much higher energy than infrared light. However, not all wavelengths of radiation can be converted into electrical energy. It is worth noting that the photovoltaic effect is independent of the intensity of the radiation; current can only be generated when the frequency reaches or exceeds the threshold for the photovoltaic effect. The maximum wavelength of light that can cause a semiconductor to produce a photovoltaic effect is related to the bandgap of the semiconductor. For example, the bandgap of crystalline silicon is approximately 1.155 eV at room temperature, therefore light with a wavelength less than 1100 nm is required to cause a photovoltaic effect in crystalline silicon.

[0066] Optionally, solar cells can be categorized according to their manufacturing materials into silicon-based semiconductor cells, CdTe thin-film cells, CIGS thin-film cells, dye-sensitized thin-film cells, and organic material cells. Silicon cells are further divided into monocrystalline cells, polycrystalline cells, and amorphous silicon thin-film cells. The conversion efficiency of monocrystalline silicon cells is 25.0%, polycrystalline silicon cells are 20.4%, CIGS thin-film cells reach 19.6%, CdTe thin-film cells reach 16.7%, and amorphous silicon thin-film cells have a conversion efficiency of 10.1%, which will not be elaborated further.

[0067] The basic structure of a solar cell is made by combining P-type and N-type semiconductors. The most basic material of semiconductors is silicon, which is non-conductive. However, by doping semiconductors with different impurities, P-type and N-type semiconductors can be created. The potential difference between the P-type semiconductor (which has one less negatively charged electron, essentially one more positively charged electron) and the N-type semiconductor (which has one more free electron) generates current. When sunlight shines on the silicon, the light excites electrons in the silicon atoms, creating convection currents between electrons and holes. These electrons and holes are influenced by the built-in potential and are attracted to the N-type and P-type semiconductors respectively, accumulating at their ends. If these are connected by electrodes to form a circuit, this is the principle behind solar cell power generation.

[0068] Simply put, the principle of solar cell power generation is to use solar cells to absorb sunlight with wavelengths of 0.4μm to 1.1μm (for silicon crystals) and directly convert light energy into electrical energy output.

[0069] In implementation, a solar cell includes a front panel, EVA adhesive, solar cells, and a back panel. The front panel, EVA adhesive, solar cells, and back panel form a laminate. The front panel can be made of tempered glass, which protects the power generation component (such as the solar cells). The EVA adhesive is used to bond and fix the tempered glass and the power generation component. The main function of the solar cells is to generate electricity. The solar cells are equipped with the grid structure mentioned above. The back panel is used for sealing, insulation, and waterproofing, which will not be elaborated further.

[0070] It should be noted that the solar cells described above, including the front panel, EVA adhesive, solar cells, and back panel, are illustrative examples of embodiments of this application and not specific limitations thereof. In some other embodiments, the solar cell also includes a frame and a junction box. The frame protects the laminated components and provides sealing and support. The junction box protects the entire power generation system and acts as a current relay station.

[0071] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the structure and implementation principle of the solar cell described above can be referred to the corresponding structure and implementation principle in the foregoing embodiments, and will not be repeated here.

[0072] The printing screen provided in this application includes a screen body 100, which has a plurality of spaced-apart pad printing areas 110, and a main grid printing area 120 between two adjacent pad printing areas 110. In a first direction, the main grid printing area 120 includes at least two main grid mesh segments 121 with successively decreasing apertures. A transition mesh segment 122 is provided between two adjacent main grid mesh segments 121, and the aperture ratio of the transition mesh segment 122 is between the aperture ratios of the two adjacent main grid mesh segments 121. The first direction is the direction from the pad printing area 110 to the center point between two adjacent pad printing areas 110. By providing a transition mesh segment 122 between two adjacent main grid mesh segments 121, the transition mesh segment 122 overlaps the two adjacent main grid mesh segments 121 to ensure the integrity of the printed main grid lines, thereby ensuring the quality of the main grid lines.

[0073] In some embodiments, this application also provides a photovoltaic system, including the solar cells described above.

[0074] A photovoltaic (PV) system is a clean energy system that converts solar energy into electrical energy. A PV system consists of solar cells, a controller, and an inverter. Several solar cells form a PV array to generate electricity, the controller regulates the power and monitors the voltage, and the inverter is responsible for AC / DC conversion. These details will not be elaborated further.

[0075] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the structure and implementation principle of the photovoltaic system described above can be referred to the corresponding structure and implementation principle in the foregoing embodiments, and will not be repeated here.

[0076] The printing screen provided in this application includes a screen body 100, which has a plurality of spaced-apart pad printing areas 110, and a main grid printing area 120 between two adjacent pad printing areas 110. In a first direction, the main grid printing area 120 includes at least two main grid mesh segments 121 with successively decreasing apertures. A transition mesh segment 122 is provided between two adjacent main grid mesh segments 121, and the aperture ratio of the transition mesh segment 122 is between the aperture ratios of the two adjacent main grid mesh segments 121. The first direction is the direction from the pad printing area 110 to the center point between two adjacent pad printing areas 110. By providing a transition mesh segment 122 between two adjacent main grid mesh segments 121, the transition mesh segment 122 overlaps the two adjacent main grid mesh segments 121 to ensure the integrity of the printed main grid lines, thereby ensuring the quality of the main grid lines.

[0077] The above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A printing screen, characterized in that, include: The screen printing body has a plurality of spaced pad printing areas, and a main grid printing area is provided between two adjacent pad printing areas. In a first direction, the main gate printing area includes at least two main gate mesh segments with successively decreasing apertures, and a transition mesh segment is provided between two adjacent main gate mesh segments. The aperture ratio of the transition mesh segment is between that of the two adjacent main gate mesh segments. The first direction is the direction from the pad printing area to the center point between two adjacent pad printing areas.

2. The printing screen as described in claim 1, characterized in that, In the first direction, the width of at least two of the main grid mesh openings gradually decreases.

3. The printing screen as described in any one of claims 1 to 2, characterized in that, The main grid mesh includes at least one of the following shapes: circular, elliptical, prismatic, polygonal, and irregular.

4. The printing screen as described in claim 1, characterized in that, The edges of the screen printing body are provided with an edge adhesive film.

5. The printing screen as described in claim 1, characterized in that, The screen printing body includes a sub-grid printing area, which is connected to the main grid printing area.

6. The printing screen as described in claim 5, characterized in that, A gradient transition edge is provided between the side of the sub-gate printing area and the side of the main gate printing area.

7. The printing screen as described in claim 6, characterized in that, The gradient transition edge can be any one of a straight line, an arc, or a wavy line.

8. A grid line structure, characterized in that, The grid structure is obtained by printing using a screen printing plate as described in any one of claims 1 to 7.

9. A solar cell, characterized in that, Includes the gate structure as described in claim 8.

10. A photovoltaic system, characterized in that, Including the solar cell as described in claim 9.

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