Screen printing plate, solar cell and photovoltaic module

Abstract

The embodiment of the utility model provides a screen printing plate, a solar cell and a photovoltaic module. The screen printing plate comprises a plate which is provided with a plurality of hollow holes; the hollow hole has a first side surface and a second side surface opposite to each other; the first side face comprises a plurality of protrusions, and the protrusions protrude on the first side face in the direction towards the second side face. The second side surface is a plane; and the slurry passes through the hollow holes and is printed on a grid line area on the surface of the battery piece to form a grid line of the battery piece. According to the embodiment of the invention, the plurality of bulges are arranged on the first side surface of the hollow hole in the screen printing plate, slurry seepage caused by inertia occurs at the bulge positions in advance, and the slurry can be printed in the areas, corresponding to the bulge positions, of the surface of the battery piece, so that the grid lines obtained by printing are in the grid line area, and the phenomenon of grid line trailing is relieved.

Description

Technical Field

[0001] The present application relates to the technical field of solar cells, and in particular to a screen, a solar cell, and a photovoltaic module. Background Art

[0002] The metallization process for photovoltaic cells involves forming conductive metal grid lines on the surface of the solar cell. Screen printing is a process where a conductive paste is applied to the cell using a scraper through a screen stencil with a grid line pattern.

[0003] However, when printing the grid lines, the squeegee moves at a high speed, and the cell and screen may not be tightly attached. This can cause excess slurry to seep out from between the surfaces due to inertia. The squeegee presses the excess slurry onto one side of the grid line, causing the grid line to trail along its width. This trailing phenomenon increases the metallization area and the light-shielding area, affecting the photovoltaic conversion efficiency of the cell.

[0004] It should be noted that the above content is not necessarily prior art, nor is it intended to limit the scope of patent protection of this application. Utility Model Content

[0005] The embodiments of the present application provide a screen, a solar cell, and a photovoltaic module to solve or alleviate one or more of the technical problems raised above.

[0006] A first aspect of an embodiment of the present application provides a screen, including:

[0007] A plate, the plate being provided with a plurality of hollow holes;

[0008] The hollow hole has a first side surface and a second side surface opposite to each other; the first side surface includes a plurality of protrusions, and the protrusions protrude from the first side surface in a direction toward the second side surface; the second side surface is a plane;

[0009] The slurry passes through the holes and is printed on the grid line area on the surface of the battery cell to form the grid line of the battery cell.

[0010] Optionally, it further includes a lower knife area and a return knife area, and a plurality of hollow holes are located between the lower knife area and the return knife area; in the case of screen printing, the scraper scrapes from the lower knife area to the return knife area;

[0011] The first side surface is close to the knife receiving area, and the second side surface is close to the knife lowering area.

[0012] Optionally, the protrusion passes through the first side surface along a first direction, and the first direction is a direction from the bottom of the first side surface toward the top of the first side surface.

[0013] Optionally, the plurality of protrusions are distributed on the first side surface at preset intervals along a second direction; the second direction is a direction perpendicular to the first direction.

[0014] Optionally, the cross-section of the protrusion along the second direction is one or more of a triangle, a semicircle, a rectangle and an irregular shape.

[0015] Optionally, when the cross section is triangular, semicircular or irregular in shape, the preset interval is 0 nm to 2 nm.

[0016] Optionally, a first dimension of the protrusion along a direction toward the second side surface is 1 / 10 to 1 / 2 of a width of the gate line region.

[0017] Optionally, the first size is determined based on the gap between the screen and the solar cell, the scraping speed of the scraper, and a preset interval.

[0018] Optionally, the preset interval is 1 / 10 to 1 / 2 of the first size.

[0019] A second aspect of the embodiments of the present application provides a solar cell, comprising a cell and a grid line. A grid line area for printing the grid line is provided on the surface of the cell; the grid line is screen-printed to the grid line area as described above.

[0020] Optionally, the edge of the gate line is flush with the edge of the gate line region.

[0021] A third aspect of the embodiments of the present application provides a photovoltaic assembly, comprising a plurality of solar cells connected in series and / or in parallel; wherein at least one solar cell is the solar cell described above.

[0022] The above technical solution adopted in the embodiments of the present application may have the following advantages:

[0023] By providing multiple protrusions on the first side of the perforated screen, when the scraper drives the slurry across the first side, the slurry seeps out early due to inertia at the protruding locations, and the slurry is printed on the area of ​​the cell surface corresponding to the protruding locations. In other words, the seeping slurry fills the area corresponding to the protruding locations, so that the printed grid lines are within the grid line area, alleviating the phenomenon of grid line tailing. The grid line tailing phenomenon is alleviated, the grid line's light-shielding area is reduced, and the photovoltaic conversion efficiency of the cell is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the multiple drawings represent the same or similar components or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings only depict some embodiments disclosed in this application and should not be construed as limiting the scope of this application.

[0025] Figure 1 It is a schematic diagram of the partial structure of the screen provided in the embodiment of the present application;

[0026] Figure 2 This is a schematic diagram of a partial structure of a screen provided in another embodiment of the present application;

[0027] Figure 3 This is a schematic diagram of the screen-printed grid lines provided in the comparative example of this application;

[0028] Figure 4 This is a schematic diagram of the screen-printed grid lines provided in an embodiment of the present application. DETAILED DESCRIPTION

[0029] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings. In the accompanying drawings, the sizes of layers, regions, and elements and their relative sizes may be exaggerated for clarity. The same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and should not be understood as limiting the present application. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other unless there is a conflict.

[0030] It should be understood that when an element or layer is referred to as being "on," "adjacent to," "connected to," or "coupled to" another element or layer, it can be directly on, adjacent to, connected to, or coupled to the other element or layer, or there can be intervening elements or layers. Conversely, when an element is referred to as being "directly on," "directly adjacent to," "directly connected to," or "directly coupled to" another element or layer, there are no intervening elements or layers. It should be understood that while the terms first, second, third, etc. may be used to describe various elements, components, regions, layers, and / or parts, these elements, components, regions, layers, and / or parts should not be limited by these terms. These terms are merely used to distinguish one element, component, region, layer, or part from another. Thus, without departing from the teachings of the present disclosure, a first element, component, region, layer, or part discussed below may be represented as a second element, component, region, layer, or part. Furthermore, when a second element, component, region, layer, or part is discussed, it does not necessarily mean that the first element, component, region, layer, or part is present in the present disclosure.

[0031] In this application, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0032] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way are interchangeable where appropriate, so that the embodiments of the present application described herein can, for example, be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0033] In the present application, when it comes to a numerical interval (i.e., a numerical range), unless otherwise specified, the distribution of the optional numerical values ​​in the numerical interval is considered to be continuous, and includes the two numerical endpoints (i.e., the minimum and maximum values) of the numerical interval, and each numerical value between the two numerical endpoints. Unless otherwise specified, when the numerical interval only refers to an integer in the numerical interval, including the two endpoint integers of the numerical range, and each integer between the two endpoints, is equivalent to directly enumerating each integer. When multiple numerical ranges are provided to describe a feature or characteristic, these numerical ranges can be merged. In other words, unless otherwise specified, the numerical range disclosed in this application should be understood to include any and all subranges included therein. The "numerical value" in the numerical interval can be any quantitative value, such as a number, a percentage, a ratio, etc. "Numerical interval" allows broadly including quantitative intervals such as percentage intervals, ratio intervals, and ratio intervals.

[0034] Hereinafter, exemplary embodiments according to the present application will be described in more detail with reference to the accompanying drawings. It should be noted that these exemplary embodiments may be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein.

[0035] An embodiment of the present application provides a screen that can be used in a screen printing process.

[0036] Screen printing is a printing technique that transfers ink or conductive paste onto a substrate using a screen. Using a pre-cut pattern on the screen, a doctor blade is used to apply the ink or conductive paste from one side of the screen to the other. The ink or conductive paste is then pressed through the cutouts onto the substrate surface, creating the desired pattern or structure.

[0037] The screen provided in the embodiment of the present application is used to form conductive metal grid lines on the surface of photovoltaic cells. Figures 1 to 2 As shown, the screen plate includes a plate having a plurality of holes 100 .

[0038] For example, multiple holes 100 are provided corresponding to multiple grid line areas on the cell; one hole 100 corresponds to one grid line area. The grid line area is the area on the cell surface used for printing grid lines. The grid line area can be a set area on the cell for printing grid lines in the specified grid line area, and the holes 100 in the screen correspond to the grid line area. The grid line area can also be any area on the cell surface. Based on the screen adapted to the cell, the position corresponding to the hole 100 of the screen is the grid line area, and the slurry for printing the grid lines falls from the hole 100 onto the cell surface to form the grid lines.

[0039] The hollow hole 100 has a first side surface 300 and a second side surface 400 opposite to each other. The first side surface 300 includes a plurality of protrusions 200 . The protrusions 200 protrude from the first side surface 300 toward the second side surface 400 . The second side surface 400 is a plane.

[0040] The slurry passes through the holes and is printed on the grid line area on the surface of the battery cell to form the grid line of the battery cell.

[0041] In this embodiment, the multiple holes 100 of the screen are arranged corresponding to the multiple grid line areas on the surface of the battery cell, that is, the shape, size and position distribution of the multiple holes 100 correspond to the multiple grid line areas on the battery cell, and the slurry is squeezed onto the battery cell through the multiple holes 100 to form multiple grid lines on the battery cell.

[0042] In one example, the plurality of busbar regions may be busbar regions on the surface of the cell where busbars are to be printed. The busbars are used to collect and conduct charges from the fine busbars.

[0043] In one example, a hole 100 corresponds to a main grid area, so that a main grid line can be printed on the surface of the solar cell using the screen. The shape and size of the hole 100 are adapted to the main grid area. The hole 100 includes a first side 300 and a second side 400 that are opposite to each other. The first side 300 and the second side 400 can be the sides of the hole 100 that extend along the length direction of the grid area. The length direction of the grid area can be the extension direction of the grid line.

[0044] As the scraper moves the slurry from the second side 400 toward the first side 300, the slurry is impressed onto the cell through the perforations 100. Because the scraper moves at a certain speed, and the cell and screen may not fit tightly enough, resulting in gaps, excess slurry can seep out of the gaps due to inertia and be impressed by the moving scraper onto the cell surface beyond the corresponding position on the first side 300, resulting in gate line tailing. Gate line tailing increases the metallized area on the cell surface, increasing the light-shielding area and thus affecting the cell's photoelectric conversion efficiency.

[0045] In an embodiment of the present application, in the perforations 100 of the screen, a plurality of protrusions 200 are provided on the first side 300, and the plurality of protrusions 200 protrude on the first side 300 in a direction toward the second side 400, and the second side 400 is a plane. By providing a plurality of protrusions 200 on the first side 300 of the perforations 100 in the screen, when the scraper drives the slurry through the first side 300, the protrusions 200 have a certain resistance to the scraper, and the slurry seepage caused by inertia occurs in advance at the position of the protrusions 200, and the slurry will be printed on the area corresponding to the position of the protrusions 200 on the surface of the battery cell. That is, the seeping slurry fills the area corresponding to the position of the protrusions 200, so that the side of the finally printed grid line corresponding to the first side 300 tends to be a straight line, thereby alleviating the tailing phenomenon of the grid line. The tailing phenomenon of the grid line is alleviated, the shading area of ​​the grid line is reduced, and the photoelectric conversion efficiency of the battery is improved.

[0046] In an optional embodiment, the screen further includes a lower cutting area and a receiving cutting area, and a plurality of hollow holes 100 are located between the lower cutting area and the receiving cutting area; when screen printing is performed, the scraper scrapes from the lower cutting area to the receiving cutting area; the first side 300 is close to the receiving cutting area, and the second side 400 is close to the lower cutting area.

[0047] The lower knife area and the retracting knife area correspond to the non-printing area in the screen. The non-printing area is a solidified film layer, and the printing paste cannot be pressed onto the battery cell through the non-printing area.

[0048] Multiple holes 100 are located between the lower and return areas. During screen printing, slurry is applied to the lower area, and a scraper moves from the lower area toward the return area, driving the slurry through the holes 100. The slurry falls into the holes 100 and is impressed onto the cell surface by the scraper, forming multiple grid lines made of the slurry on the cell surface.

[0049] The first side surface 300 of the hole 100 is close to the knife receiving area, and the second side surface 400 is close to the knife lowering area. That is, the scraper scrapes from the second side surface 400 of the hole 100 to the first side surface 300, and the scraper completes the imprint of the corresponding grid line when it moves across the first side surface 300.

[0050] In the embodiment of the present application, the first side 300 is brought close to the knife-collecting area and the second side 400 is brought close to the knife-lowering area, and the scraper is scraped from the second side 400 toward the first side 300. The slurry seeps out from the gap between the screen and the cell corresponding to the position of the first side 300 due to inertia, and is printed on the area corresponding to the protrusion 200 on the surface of the cell. Therefore, the seeped slurry can be controlled in the predetermined gate line area, and the edges of the printed gate lines are neater, which alleviates the tailing phenomenon of the gate lines and reduces the shading area of ​​the gate lines, thereby improving the photoelectric conversion efficiency.

[0051] In an optional embodiment, the protrusion 200 penetrates the first side surface 300 along a first direction, where the first direction is a direction from the bottom of the first side surface 300 toward the top of the first side surface 300 .

[0052] The protrusion 200 penetrates the first side surface 300 along a first direction, that is, the protrusion 200 extends from the bottom of the first side surface 300 to the top of the first side surface 300 .

[0053] In this embodiment, the protrusion 200 extends from the bottom of the first side surface 300 to the top of the first side surface 300 , so that the slurry passes through the hole 100 and falls onto the surface of the battery cell in a smooth path, thereby avoiding slurry blockage and other phenomena.

[0054] In an optional embodiment, the plurality of protrusions 200 are distributed on the first side surface 300 at preset intervals along a second direction; the second direction is a direction perpendicular to the first direction.

[0055] In this embodiment, the protrusions 200 are evenly distributed at predetermined intervals on the first side 300. The predetermined intervals are adapted to the scraper speed, the gap between the screen and the cell, and the height of the protrusions 200. This ensures that when the scraper drives the slurry across the first side 300, the size of the slurry that seeps out of the gap due to inertia matches the gridline area, resulting in gridlines of uniform size.

[0056] The intervals between the plurality of protrusions 200 may be uniform or non-uniform.

[0057] The preset interval may be the minimum distance between two edges of two adjacent protrusions 200 that are close to each other.

[0058] In one example, in the middle of the hollow hole 100 , the inertial force of the scraper is relatively large, so the intervals between the multiple protrusions 200 located in the middle can be smaller, and the intervals between the multiple protrusions 200 located at the edge can be relatively larger.

[0059] In an optional embodiment, the cross-section of the protrusion 200 along the second direction is one or more of a triangle, a semicircle, a rectangle and an irregular shape.

[0060] Specifically, the cross section of the protrusion 200 along the second direction may be a cross section parallel to the direction of the battery cell when the screen is placed flat on the battery cell.

[0061] The cross-section of the plurality of protrusions 200 may be a combination of a plurality of different shapes, or a single shape, as long as the first side surface 300 has the protrusion 200 structure, which is not limited in the embodiment of the present application.

[0062] In one example, if Figure 1 As shown, the cross section of the protrusion 200 may be semicircular.

[0063] In an optional embodiment, when the cross-section is triangular, semicircular or irregular in shape, the preset interval is 0 nm to 2 nm.

[0064] For example, the preset intervals are 0 nm, 0.5 nm, 1 nm, 1.5 nm, and 2 nm. Figure 2 As shown, when the preset interval is 0 nm, the plurality of protrusions 200 are continuously distributed.

[0065] If the intervals between adjacent protrusions 200 are too large, the resistance encountered by the scraper during the printing process will be reduced, and the slurry will easily flow and diffuse in the gaps between the protrusions 200, reducing the accuracy of controlling the slurry and affecting the edge clarity of the grid lines.

[0066] In this embodiment, by limiting the intervals between the multiple protrusions 200 to no more than 2 nm, it is ensured that the scraper encounters sufficiently large resistance during the printing process to prevent the slurry from seeping out of the grid line area; at the same time, it is avoided that the edges of the grid lines are too thin, resulting in unclear edges of the grid lines, so as to ensure the stability and reliability of the screen printing effect.

[0067] Exemplarily, when the cross section of the protrusion 200 is rectangular, the preset interval is greater than 0, so as to form the structure of the protrusion 200 .

[0068] In an optional embodiment, the first dimension of the protrusion 200 along the direction toward the second side surface 400 is 1 / 10 to 1 / 2 of the width of the gate line region.

[0069] The width of the gridline region is adapted to the maximum width of the hollow hole 100, which can be understood as the distance between the first side and the second side 400. By limiting the first dimension of the protrusion 200 to 1 / 10 to 1 / 2 of the width of the gridline region, a corresponding hollow hole 100 structure is set for the corresponding gridline region. On the one hand, this prevents the protrusion 200 from occupying most of the space in the hollow hole 100, making it difficult for the slurry to fall; on the other hand, it prevents the first dimension of the protrusion 200 from being too small, making it difficult to alleviate the gridline tailing.

[0070] In one example, a first dimension of the protrusion 200 along a direction toward the second side surface 400 is 1 μm to 15 μm. For example, the first dimension may be 1 μm, 5 μm, 10 μm, or 15 μm.

[0071] The first dimension is the distance from the cut surface of the protrusion 200 closest to the second side surface 400 to the first side surface 300 .

[0072] The larger the first dimension, the sooner the scraper encounters resistance, and the sooner the slurry is carried out by inertia. If the first dimension is too large, the slurry will be carried out too early, resulting in thick or blurred edges of the corresponding grid lines, distorted line shape, and thus affecting the grid line's conductivity and reducing overall battery performance. If the first dimension is too small, it will be difficult to alleviate the grid line tailing phenomenon.

[0073] In the embodiment of the present application, by limiting the first size of the protrusion 200, the tailing phenomenon of the gate line can be alleviated while the overall shape of the gate line will not change too much, ensuring that the conductive performance of the gate line is not affected, thereby improving the overall stability and efficiency of the battery.

[0074] In an optional embodiment, the first size is determined based on the gap between the screen and the solar cell, the scraping speed of the scraper, and a preset interval.

[0075] In one example, when the scraper speed is faster, the inertia of the slurry increases, making it easier to drag out a longer "tail". In order to avoid the tailing of the grid line, the protrusion 200 with a larger first size can be set to provide greater resistance to the scraper, reduce the inertia of the slurry, and avoid excessive tailing; at the same time, the first size of the protrusion 200 is larger, and the space corresponding to the position of the protrusion 200 is larger, providing more space to accommodate the slurry generated by the tailing. Therefore, when the scraper speed is faster, setting the protrusion 200 with a larger first size can obtain a grid line with no seepage into the grid line area and uniform slurry distribution.

[0076] In one example, when the gap between the screen and the cell is larger, the slurry is more likely to seep out of the gap, and more slurry seeps out; the protrusion 200 with a larger first size can be set to increase the resistance provided by the protrusion 200, thereby reducing the amount of slurry seeping out due to inertia and alleviating the tailing phenomenon of the gate line.

[0077] In one example, the preset intervals between the plurality of protrusions 200 may be adapted to the first size, so as to obtain gate lines with uniform slurry distribution and ensure the stability of the conductive properties of the gate lines.

[0078] In this embodiment, the appropriate first size is determined by taking into account factors such as the gap between the cells, the scraping speed of the scraper, and the preset interval. The resulting first size of the protrusion 200 can improve the printing quality of the gate lines, ensure the stability of the gate line shape and size, effectively alleviate the gate line tailing phenomenon, and improve the photoelectric conversion efficiency and battery performance.

[0079] In an optional embodiment, the preset interval is 1 / 10 to 1 / 2 of the first size.

[0080] The preset interval is adapted to the first size so as to obtain a gate line with uniform slurry distribution, thereby ensuring the stability of the conductive properties of the gate line.

[0081] In an example, when the first size is relatively large, a smaller preset interval may be set to avoid obvious blank spaces or depressions at the edges of the gate lines.

[0082] The present application also provides a solar cell comprising a cell and a grid line, wherein a grid line region for printing the grid line is provided on the surface of the cell; the grid line is screen-printed onto the grid line region using any of the above embodiments.

[0083] In an optional embodiment, the edge of the gate line is flush with the edge of the gate line region.

[0084] The grid line area can be an area with an edge marking line for indicating the limit of the grid line printing. The edge of the grid line is flush with the edge of the grid line area, so that the grid line can be printed on the surface of the solar cell according to the area of ​​the preset mark, without burrs or tailing that exceed the edge marking line. The grid line area can also be an area prepared for printing grid lines according to preset rules, and the preset rules can be including a specified grid line spacing, a specified grid line width, etc. The edge of the grid line is flush with the edge of the grid line area, so that the printed grid line meets the preset rules, without burrs or tailing that exceed the preset rules.

[0085] For example, see Figure 3 . Figure 3This is a schematic diagram of a grid line that exhibits tailing. The first side 500 corresponds to the lower cutter side of the screen, while the second side 502 corresponds to the lower cutter side. Because the screen used for printing the grid lines lacks a raised structure on the lower cutter side, excess printing paste seeps out of the gaps in the lower cutter due to inertia, causing burrs on the second side 502 of the grid lines.

[0086] For example, see Figure 4 . Figure 4 This is a schematic diagram of a grid line without the tailing phenomenon, which is printed using the screen provided by the embodiment of the present application. The fourth side 506 of the grid line corresponds to the lower cutter side of the perforation in the screen, and the third side 504 corresponds to the lower cutter side of the perforation. The screen of the embodiment of the present application, such as Figure 1 As shown, a plurality of protrusions 200 are provided on the first side 300 of the hollow hole 100, and the plurality of protrusions 200 protrude on the first side 300 in the direction toward the second side 400, and the second side 400 is a plane. By providing a plurality of protrusions 200 on the first side 300 of the hollow hole 100 in the screen, when the scraper drives the slurry through the first side 300, the protrusions 200 have a certain resistance to the scraper, and the slurry seepage caused by inertia occurs in advance at the position of the protrusions 200, and the slurry will be printed on the area corresponding to the position of the protrusions 200 on the surface of the battery cell. That is, the seeping slurry fills the area corresponding to the position of the protrusions 200, so that the corresponding third side 504 of the finally printed grid line tends to be a straight line, thereby alleviating the tailing phenomenon of the grid line. The tailing phenomenon of the grid line is alleviated, the shading area of ​​the grid line is reduced, and the photoelectric conversion efficiency of the battery is improved.

[0087] The present application also provides a photovoltaic module comprising a plurality of solar cells connected in series and / or in parallel, wherein the grid lines on the cell of at least one solar cell are screen-printed as described above. The plurality of solar cells connected in series form a cell string, and adjacent solar cells can be connected together by string soldering.

[0088] It should be noted that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. are only for the convenience of describing the present 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, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present application. The directional terms "inside" and "outside" refer to the inside and outside relative to the outline of the component itself. For example, if the device in the drawing is inverted, the device described as "above other devices or structures" or "on top of other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Therefore, the exemplary term "above..." can include both "above..." and "below..." orientations. The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used here will be interpreted accordingly.

[0089] It should also be noted that references to "one embodiment," "another embodiment," "an embodiment," etc., in this application refer to specific features, structures, or characteristics described in conjunction with that embodiment as included in at least one embodiment generally described in this application. The appearance of the same expression in multiple places in the specification does not necessarily refer to the same embodiment. Furthermore, when a specific feature, structure, or characteristic is described in conjunction with any embodiment, it is intended that such feature, structure, or characteristic, when implemented in conjunction with other embodiments, also fall within the scope of this application.

[0090] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0091] It should also be noted that the above are only preferred embodiments of the present application and do not limit the scope of patent protection of the present application. Any equivalent structure or equivalent process transformation made using the contents of the description and drawings of this application, or directly or indirectly applied in other related technical fields, are also included in the scope of patent protection of the present application.

Claims

1. A screen, characterized in that: include: A plate, wherein the plate is provided with a plurality of hollow holes; The hollow hole has a first side surface and a second side surface opposite to each other; the first side surface includes a plurality of protrusions, and the protrusions protrude from the first side surface toward the second side surface; the second side surface is a plane; The slurry passes through the holes and is printed on the grid line area on the surface of the battery cell to form the grid lines of the battery cell.

2. The screen according to claim 1, wherein: The scraper also includes a lower blade area and a receiving blade area, wherein the plurality of hollow holes are located between the lower blade area and the receiving blade area; when screen printing is performed, the scraper scrapes from the lower blade area to the receiving blade area; The first side surface is close to the knife receiving area, and the second side surface is close to the knife lowering area.

3. The screen according to claim 1 or 2, characterized in that: The protrusion passes through the first side surface along a first direction, where the first direction is a direction from the bottom of the first side surface toward the top of the first side surface.

4. The screen plate according to claim 3, wherein: The plurality of protrusions are distributed on the first side surface at preset intervals along a second direction; the second direction is a direction perpendicular to the first direction.

5. The screen plate according to claim 4, characterized in that: The cross section of the protrusion along the second direction is one or more of a triangle, a semicircle, a rectangle and an irregular shape.

6. The screen plate according to claim 5, characterized in that: When the cross section is triangular, semicircular or irregular in shape, the preset interval is 0 nm to 2 nm.

7. The screen plate according to claim 4, wherein: A first dimension of the protrusion along a direction toward the second side surface is 1 / 10 to 1 / 2 of a width of the gate line region.

8. The screen plate according to claim 7, wherein: The first size is determined based on the gap between the screen and the battery sheet, the scraping speed of the scraper, and the preset interval.

9. The screen plate according to claim 7, wherein: The preset interval is 1 / 10 to 1 / 2 of the first size.

10. A solar cell, characterized in that: The invention comprises a battery cell and a gate line, wherein the surface of the battery cell is provided with a gate line area for printing the gate line; the gate line is printed on the gate line area by using the screen printing according to any one of claims 1 to 9.

11. The solar cell according to claim 10, characterized in that The edge of the gate line is flush with the edge of the gate line region.

12. A photovoltaic module, characterized in that: The photovoltaic module includes a plurality of solar cells connected in series and / or in parallel; wherein at least one solar cell is the solar cell according to any one of claims 10 to 11.

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