Solar cell, silk-screen printing plate and photovoltaic module

Abstract

The embodiment of the utility model provides a solar cell, a silk-screen printing plate and a photovoltaic module. The solar cell comprises a cell piece and an electrode grid line structure arranged on the surface of the cell piece. The electrode grid line structure comprises a plurality of auxiliary grids, and each auxiliary grid is provided with an auxiliary grid welding point or a welding disc used for being welded to a welding strip along a preset welding strip line. Wherein on the solder strip line, the widths of the N auxiliary grid welding points close to the ends are all larger than the width of the auxiliary grid welding points located in the middle, and N is a positive integer larger than or equal to 2. According to the embodiment of the invention, the widths of the N auxiliary grid welding points at the end part are widened, so that the auxiliary grid welding points close to the end part have more tin materials to be welded with the welding strip, and the unsoldering caused by insufficient soldering tin liquid is avoided.

Description

Technical Field

[0001] This application relates to the field of solar cell technology, and more particularly to a solar cell, a screen printing stencil, and a photovoltaic module. Background Technology

[0002] Multiple solar cells are connected in series via solder ribbons to increase output voltage and current. During soldering, the ribbons need to be stretched to ensure straightness. Additionally, the temperature changes before and after soldering cause deformation, making the ribbons prone to grid breakage at the ends of the cells. Utility Model Content

[0003] This application provides a solar cell, a screen printing stencil, and a photovoltaic module to solve or alleviate one or more technical problems in the prior art.

[0004] As a first aspect of the present application, the present application provides a solar cell, including a cell and an electrode grid structure disposed on the surface of the cell; the electrode grid structure includes multiple sub-grids, and each sub-grid is provided with a sub-grid welding point or pad for welding with the welding strip along a preset solder ribbon line; wherein, on the solder ribbon line, the width of the N sub-grid welding points near the end is greater than the width of the sub-grid welding point located in the middle, and N is a positive integer greater than or equal to 2.

[0005] In one embodiment, the total number of sub-gate solder joints on the solder strip line is M; N is 10% to 30% of M, and M is a positive integer greater than or equal to 3.

[0006] In one embodiment, the electrode grid structure further includes a harpoon corner, and the N sub-gate solder points near the end are multiple sub-gate solder points between the solder pad near the end and the harpoon corner.

[0007] In one embodiment, along the solder strip line, the width of the sub-gate solder joints increases in a gradient from the middle sub-gate solder joint towards the end sub-gate solder joints.

[0008] In one embodiment, the width of the sub-gate solder joint near the end is 110% to 200% of the width of the sub-gate solder joint located in the middle, and the width of the sub-gate solder joint located in the middle is 0.04-0.06 mm.

[0009] In one embodiment, on the solder strip line, the width of the S pads near the ends is greater than the width of the pads located in the middle, where S is a positive integer greater than or equal to 2.

[0010] In one implementation, the total number of pads on the solder ribbon is T; S is 10% to 30% of T, and S is a positive integer greater than or equal to 3.

[0011] In one embodiment, the width of the pads on the solder ribbon increases in a gradient along the direction from the middle pad to the end pads.

[0012] In one embodiment, the width of the pads near the ends is 110% to 200% of the width of the pads in the middle, and the width of the pads in the middle is 0.08-0.1 mm.

[0013] As a second aspect of the present application, the present application provides a screen printing stencil for preparing solar cells in any of the above embodiments; wherein the printing stencil includes a film plate with multiple perforations to print multiple sub-grid solder points and multiple pads through the perforations.

[0014] As a third aspect of the present application, the present application provides a photovoltaic module including a plurality of solar cells, at least one of which is a solar cell of any of the above embodiments.

[0015] The embodiments of this application adopt the above technical solution, which widens the width of the N sub-gate solder joints at the end, so that the sub-gate solder joints near the end have more solder material to solder with the solder strip, so as to avoid insufficient solder liquid leading to desoldering.

[0016] The above overview is for illustrative purposes only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features of this application will become readily apparent from the accompanying drawings and the following detailed description. Attached Figure Description

[0017] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the various drawings denote the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings depict only some embodiments disclosed in this application and should not be construed as limiting the scope of this application.

[0018] Figure 1 This is a schematic diagram of the electrode grid structure of a solar cell provided in an embodiment of this application.

[0019] Figure 2 Show Figure 1 A magnified schematic diagram of the structure at position A in the middle.

[0020] Figure 3 This diagram illustrates the structure of the electrode grid line structure of a solar cell according to another embodiment of this application.

[0021] Figure 4 Show Figure 3A magnified schematic diagram of the structure at position B in the middle. Detailed Implementation

[0022] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of this application. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0023] This application provides a solar cell, including a cell and an electrode grid structure disposed on the surface of the cell. The purpose of this application is to improve the electrode grid structure in a solar cell to reduce the occurrence of broken grids at the ends during cell stringing. Figure 1 This is a schematic diagram of the electrode grid structure of a solar cell provided in an embodiment of this application. Figure 2 Show Figure 1 A magnified schematic diagram of the structure at position A in the middle. Figure 3 This diagram illustrates the structure of the electrode grid line structure of a solar cell according to another embodiment of this application. Figure 4 Show Figure 3 A magnified schematic diagram of the structure at position B in the middle. (See diagram below.) Figures 1 to 4 As shown, the electrode grid structure includes multiple sub-grids 100. When welding the solder strip, the solder strip is welded along a direction perpendicular or approximately perpendicular to the multiple sub-grids 100. The line of the solder strip to be welded is the preset solder strip line. Along the preset solder strip line, each sub-grid 100 is provided with a sub-grid welding point 110 or a pad 120 for welding with the solder strip. Among them, on the solder strip line, the width of the N sub-grid welding points 110 near the end is greater than the width of the sub-grid welding point 110 located in the middle, and N is a positive integer greater than or equal to 2.

[0024] For existing solar cells, after soldering the solder ribbon, the solder ribbon can be removed to observe the soldering surface. At the middle position, the sub-busbar solder joint 110 has less solder fused with the solder ribbon, and the solder ribbon itself is sufficient to weld and fix it to the sub-busbar 100. At the ends (first or last), because the solder ribbon is stretched before soldering, it can adhere closely to the cell surface. During soldering, the solder ribbon shrinks, leaving less solder at the end. More solder from the sub-busbar solder joint 110 or pad 120 is needed to firmly solder the ribbon to the cell surface. If there is insufficient solder from the sub-busbar solder joint 110 or pad 120, the soldering will be weak and prone to detachment.

[0025] In this embodiment, based on the above phenomenon, by widening the width of the N sub-gate solder joints 110 at the ends, the sub-gate solder joints 110 near the ends have more solder to solder with the solder strip, thus avoiding desoldering due to insufficient solder. In contrast, the width of the sub-gate solder joints 110 in the middle can be narrower to save paste and reduce the manufacturing cost of solar cells.

[0026] In one example, the middle subgate solder point 110 can be the middle subgate solder point 110 among multiple subgate solder points 110 on the solder strip line. If the total number of subgate solder points 110 is even, it can also be the two middle subgate solder points 110.

[0027] In another example, the middle subgate solder point 110 can also be relative to the N subgate solder points 110 near the end, and all the subgate solder points 110 outside the N subgate solder points 110 are the middle subgate solder points 110.

[0028] The solar cell provided in this application embodiment widens the width of the N sub-grid solder points 110 near the end to ensure that the end does not break during soldering; in addition, the width of the sub-grid solder points 110 in the middle position can be reduced to save solder paste and reduce the manufacturing cost of solar cells while ensuring strong soldering.

[0029] In one embodiment, the total number of sub-gate welding points 110 on the solder strip line is M; N is 10% to 30% of M, and M is a positive integer greater than or equal to 3.

[0030] In this embodiment, the N sub-gate solder points 110 near the end can be the sum of the multiple sub-gate solder points 110 near the head and the multiple sub-gate solder points 110 near the tail. For balance considerations, of the N sub-gate solder points 110, N / 2 are near the head and N / 2 are near the tail.

[0031] For example, when N is 2, the width of the subgate solder point 110 near the head is greater than the width of the subgate solder point 110 in the middle; the width of the subgate solder point 110 near the tail is greater than the width of the subgate solder point 110 in the middle, so that the solder strip can be prevented from detaching at both the head and the tail.

[0032] For example, N is preferably 10-30, so that the multiple sub-gate welding points 110 near the end are widened to prevent the solder strip from detaching.

[0033] In this embodiment, the N widened sub-gate welding points 110 at the end are defined to ensure that the ends of the solder strips can be firmly welded.

[0034] In one example, the ratio of N to M can be adaptively adjusted according to the tension force during soldering and the diameter of the solder strip. The greater the tension force, the more sub-gate solder points 110 need to be widened to ensure that the solder strip will not detach, i.e., the larger the ratio of N to M. The larger the diameter of the solder strip, the fewer sub-gate solder points 110 need to be widened, i.e., the smaller the ratio of N to M.

[0035] N is 10% to 30% of M. Specifically, N can be 10%, 15%, 22% or 30% of M.

[0036] It is understandable that the total number of sub-busbar welding points 110 on a single welding strip line corresponds to the number of sub-busbars 100 set in the solar cell. In actual operation, the value of N can also be set according to the number of sub-busbars 100.

[0037] In one embodiment, the electrode grid structure further includes a harpoon angle 130, and the N sub-gate solder points 110 near the end are multiple sub-gate solder points 110 between the solder pad 120 near the end and the harpoon angle 130.

[0038] Typically, a harpoon angle 130 is set at the head and tail of the solder strip line to optimize current collection at the end and prevent solder strip breakage. Furthermore, when there are multiple sub-gate solder points 110, a solder pad 120 is set. The solder pad 120 contains more solder than the sub-gate solder points 110 to reinforce the solder strip at several designated locations and ensure the stability of the solder strip welding.

[0039] In this embodiment of the application, by widening the multiple sub-gate welding points 110 between the pad 120 near the end and the harpoon angle 130, the pad 120 near the end can be welded to the solder strip more firmly. On this basis, the sub-gate welding points 110 between the pad 120 and the harpoon angle 130 are widened so that the end of the solder strip can be firmly welded to the battery cell, avoiding desoldering.

[0040] In one implementation, such as Figure 1 and Figure 2 As shown, along the solder strip line, the width of the sub-gate solder point 110 increases in a gradient from the middle sub-gate solder point 110 to the end sub-gate solder point 110.

[0041] This embodiment of the application achieves a widening of the width of the sub-gate solder joints 110 at the ends and a narrower width of the sub-gate solder joints 110 in the middle through a gradual width change. This method facilitates the printing or processing of the sub-gate solder joints 110 and simultaneously achieves a design that narrows in the middle and widens at the ends, preventing end desoldering. Furthermore, it can also save solder on the sub-gate solder joints 110 near the middle side of the widened end sub-gate solder joints 110, because relatively speaking, the width of the multiple widened end sub-gate solder joints 110 can be gradually increased.

[0042] Figure 3 and Figure 4 In the electrode grid line structure shown, the width of the multiple sub-grid solder points 110 in the middle is the same, and the width of the sub-grid solder points 110 at the ends is greater than the width of the middle sub-grid solder points 110.

[0043] In one example, the width of the multiple middle subgate solder points 110 can be the same, and the width of the end subgate solder points 110 can be gradually increased along the direction towards the end, which can avoid the width of the middle subgate solder point 110 being too narrow.

[0044] In one embodiment, the width of the sub-gate solder joint 110 near the end is 110% to 200% of the width of the sub-gate solder joint 110 located in the middle, and the width of the sub-gate solder joint 110 located in the middle is 0.04-0.06 mm.

[0045] In one example, in existing solar cells, the width of multiple sub-grid welding points 110 is all the same, for example, 0.07 mm. In this embodiment of the application, compared with existing solar cells, the width of the sub-grid welding point 110 at the middle position can be less than 0.07 mm, for example, 0.04 mm, 0.044 mm, 0.051 mm, 0.058 mm or 0.06 mm, etc.

[0046] The width of the sub-gate solder joint 110 near the end is 110% to 200% of the width of the sub-gate solder joint 110 in the middle, so as to avoid the sub-gate solder joint 110 at the end being too wide and causing waste of solder.

[0047] In one example, the width of the subgate solder point 110 near the end can also be smaller than the width of the end pad 120, and can be 1 / 4 to 2 / 3 of the width of the end pad 120.

[0048] In one embodiment, on the solder strip line, the width of the S pads 120 near the end is greater than the width of the pad 120 located in the middle, where S is a positive integer greater than or equal to 2.

[0049] The pads 120 are used to reinforce the solder strength of the solder strip at designated locations. For the same reason, the solder strip needs to be reinforced at its ends to prevent end desoldering. Therefore, in the arrangement of the pads 120 in this embodiment, the width of the end pads 120 is widened, while the width of the middle pads 120 can be reduced, thereby saving solder and reducing the manufacturing cost of solar cells.

[0050] The width of the end pad 120 is increased to accommodate the shrinkage of the solder strip end. By widening the pad 120, more molten solder can be fused with the molten solder strip to form a stable solid solder.

[0051] In some examples, solder leads 121 extending from the pad 120 can be added in the width direction of the pad 120 to enhance the soldering with the solder strip near the pad 120.

[0052] In this embodiment, the width involved can be understood as the dimension along the direction perpendicular to the sub-gate 100 line.

[0053] In one embodiment, the total number of pads 120 on the solder ribbon line is T; S is 10% to 30% of T, and S is a positive integer greater than or equal to 3.

[0054] In this embodiment, the S pads 120 near the end can be the sum of the multiple pads 120 near the head and the multiple pads 120 near the tail. For balance, S / 2 of the S pads 120 are near the head and S / 2 are near the tail.

[0055] For example, when S is 2, the width of the pad 120 near the head is greater than the width of the pad 120 in the middle; the width of the pad 120 near the tail is greater than the width of the pad 120 in the middle, so that the solder strip can be prevented from detaching at both the head and the tail.

[0056] For example, S is preferably set to 2-8, so that the multiple pads 120 near the end are widened to prevent the solder strip from detaching.

[0057] In one embodiment, along the solder strip line, the width of the solder pad 120 increases in a gradient from the middle solder pad 120 toward the end solder pad 120.

[0058] This embodiment of the application achieves a gradient width by widening the pads 120 at the ends and narrowing the pads 120 in the middle. This facilitates the printing or processing of the pads 120 and also achieves a design that narrows in the middle and widens at the ends, preventing end desoldering. Furthermore, the sub-gate solder joints 110 also gradually widen from the middle sub-gate solder joints 110 towards the end sub-gate solder joints 110. This facilitates the printing or processing of the sub-gate solder joints 110 and the pads 120, and the overall structure is more harmonious and aesthetically pleasing.

[0059] In one embodiment, the width of the pad 120 near the end is 110% to 200% of the width of the pad 120 in the middle, and the width of the pad 120 in the middle is 0.08-0.1 mm.

[0060] In one example, in existing solar cells, the width of multiple pads 120 is all the same, for example, 0.11 mm. In this embodiment of the application, compared with existing solar cells, the width of the pad 120 in the middle position can be less than 0.11 mm, for example, 0.08 mm, 0.084 mm, 0.091 mm, 0.098 mm or 0.1 mm, etc.

[0061] The width of the pads 120 near the ends is 110% to 200% of the width of the pads 120 in the middle, to avoid the pads 120 at the ends being too wide and causing waste of solder.

[0062] Other configurations of the solar cells in the above embodiments can be derived from various technical solutions now and in the future known to those skilled in the art, and will not be described in detail here.

[0063] This application provides a screen printing stencil for preparing solar cells according to any of the above embodiments; wherein the printing stencil includes a film plate with multiple perforations to print multiple sub-grid solder points and multiple pads through the perforations.

[0064] Multiple perforations on the film sheet are used to print multiple sub-grid solder joints and multiple pads. The perforation is set to correspond to the position of the sub-grid on the solar cell, so that the paste leaking from the perforations falls onto the sub-grid and forms sub-grid solder joints or pads on the sub-grid.

[0065] Other components of the screen printing stencil in the above embodiments can be derived from various technical solutions known now and in the future to those skilled in the art, and will not be described in detail here.

[0066] This application provides a photovoltaic module, including multiple solar cells, at least one of which is a solar cell according to any of the above embodiments.

[0067] Other components of the photovoltaic modules in the above embodiments can be derived from various technical solutions that are now and will be known to those skilled in the art, and will not be described in detail here.

[0068] In the description of this specification, it should be understood that the terms "center," "longitudinal," "transverse," "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 used 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. Therefore, they should not be construed as limitations on this application.

[0069] 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. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0070] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., 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, an electrical connection, or a communication 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. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0071] 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 above or diagonally above the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0072] The foregoing disclosure provides many different implementations or examples for carrying out different structures of this application. To simplify the disclosure, specific examples of components and arrangements are described above. Of course, these are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or 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 implementations and / or arrangements discussed.

[0073] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various variations or substitutions within the technical scope disclosed in this application, and these should all be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A solar cell, characterized by, The battery piece and the electrode grid line structure arranged on the surface of the battery piece are included; the electrode grid line structure includes a plurality of sub-grids, and each sub-grid is provided with a sub-grid welding point or a welding pad for welding with a solder strip along a preset solder strip line; wherein the width of the N sub-grid welding points close to the end of the solder strip line is greater than the width of the sub-grid welding points in the middle, and N is a positive integer greater than or equal to 2.

2. The solar cell according to claim 1, characterized in that, The total number of the sub-grid welding points on the solder strip line is M; N is 10%-30% of M, and M is a positive integer greater than or equal to 3.

3. The solar cell according to claim 1, characterized in that, The electrode grid line structure further includes a fishhook corner, and the N sub-grid welding points close to the end are a plurality of sub-grid welding points between the welding pad close to the end and the fishhook corner.

4. The solar cell of claim 1, wherein The width of the sub-grid welding points increases in a gradient along the direction from the sub-grid welding points in the middle to the sub-grid welding points close to the end on the solder strip line.

5. The solar cell according to any one of claims 2 to 4, characterized in that, The width of the sub-grid welding points close to the end is 110%-200% of the width of the sub-grid welding points in the middle, and the width of the sub-grid welding points in the middle is 0.04-0.06 mm.

6. The solar cell according to claim 1 or 4, characterized in that, The width of the S welding pads close to the end on the solder strip line is greater than the width of the welding pads in the middle, and S is a positive integer greater than or equal to 2.

7. The solar cell of claim 5, wherein, The total number of the welding pads on the solder strip line is T; S is 10%-30% of T, and S is a positive integer greater than or equal to 3.

8. The solar cell of claim 5, wherein, The width of the welding pads increases in a gradient along the direction from the welding pads in the middle to the welding pads close to the end on the solder strip line.

9. The solar cell of claim 5, wherein, The width of the welding pads close to the end is 110%-200% of the width of the welding pads in the middle, and the width of the welding pads in the middle is 0.08-0.1 mm.

10. A screen printing screen, characterized by The printing screen plate includes a film plate provided with a plurality of perforations for printing a plurality of sub-grid welding points and a plurality of welding pads through the plurality of perforations.

11. A photovoltaic module, characterized by The solar cell includes a plurality of solar cells, and at least one of the solar cells is the solar cell according to any one of claims 1-9.

Images