Photovoltaic module, printing screen

Abstract

This application relates to a photovoltaic module that enhances the tensile strength of the solar cells to the solder ribbons, comprising: a plurality of solar cells, each having a plurality of fine grid lines on its soldering surface, the fine grid lines extending along a first direction and the plurality of fine grid lines spaced apart along a second direction perpendicular to the first direction; a plurality of solder ribbons fixed to the soldering surface, extending along the second direction and electrically connected to the fine grid lines, each solder ribbon being connected to the soldering surface by a plurality of adhesive dots, the adhesive dots being staggered from the fine grid lines; wherein all the adhesive dots are distributed in a central region, two edge regions, an interconnected side region, and a non-interconnected side region, the two edge regions being located on both sides of the central region in the first direction, and the interconnected side region and the non-interconnected side region being located on both sides of the central region in the second direction, wherein the distribution density of adhesive dots in the interconnected side region is greater than the distribution density of adhesive dots in the other regions, and the distribution density of adhesive dots in the edge regions is greater than the distribution density of adhesive dots in the central region. A printing screen is also proposed.

Description

Technical Field

[0001] This application relates to the field of photovoltaic technology, and in particular to a photovoltaic module and a printing screen. Background Technology

[0002] A photovoltaic module includes a first cover plate, a first encapsulant film, a cell string, a second encapsulant film, and a second cover plate stacked along its thickness direction. The cell string is formed by electrically connecting multiple cells. The surface of each cell is provided with multiple fine grids. The fine grids of adjacent cells are connected by solder ribbons to realize the series or parallel connection of adjacent cells.

[0003] When the surface of the solar cell does not have a main grid, the welding tension between the solder ribbon and the cell is reduced. Generally, the tension between the solder wire and the cell is <0.3N. Therefore, the reliability of the module needs to be ensured by printing adhesive dots. By printing adhesive dots of appropriate size above or below the solder wire, the bonding force between the solder wire and the cell is improved, thereby ensuring the reliability of the module.

[0004] The existing design has adhesive dots evenly distributed on the battery surface. On the one hand, the amount of adhesive used is large, which increases the cost of the module. On the other hand, it is not enough to guarantee reliability. Summary of the Invention

[0005] Therefore, it is necessary to provide a photovoltaic module to address the issue that adhesive application cannot guarantee reliability. A printing screen is also proposed.

[0006] According to one aspect of this application, a photovoltaic module includes: a plurality of solar cells, wherein a plurality of fine grid lines are provided on the welding surface of the solar cells, the fine grid lines extending along a first direction, and the plurality of fine grid lines are spaced apart along a second direction, the second direction being perpendicular to the first direction; a plurality of solder strips, the solder strips being fixed to the welding surface, the solder strips extending along the second direction and electrically connected to the fine grid lines, each solder strip being connected to the welding surface by a plurality of adhesive dots, the adhesive dots being staggered from the fine grid lines; wherein all the adhesive dots are distributed in a middle region, two edge regions, an interconnected side region, and a non-interconnected side region, the two edge regions being located on both sides of the middle region in the first direction, the interconnected side region and the non-interconnected side region being located on both sides of the middle region in the second direction, wherein the distribution density of adhesive dots in the interconnected side region is greater than the distribution density of adhesive dots in the other regions, and the distribution density of adhesive dots in the edge regions is greater than the distribution density of adhesive dots in the middle region.

[0007] In this application, the adhesive dots on the welding surface of the solar cell are distributed differently, resulting in more adhesive dots in the interconnected areas where the solder ribbon experiences greater tension, and less adhesive dots in areas where the solder ribbon experiences less tension, thereby reducing the amount of adhesive used. This achieves two goals: firstly, it strengthens the tension on the solder ribbon in areas at risk of detachment; secondly, due to the differentiated use of adhesive, the overall amount of adhesive used is controlled, thus controlling the cost of the photovoltaic module.

[0008] In some embodiments, the number of adhesive dots corresponding to each solder strip in the edge region is N1, and the number of adhesive dots corresponding to each solder strip in the middle region is N2, where N1-N2≥2.

[0009] In some embodiments, in the second direction, the interconnected side region and the non-interconnected side region are located on both sides of the edge region.

[0010] In some embodiments, the number of adhesive dots corresponding to each solder strip in the interconnect side region is N3, and the number of adhesive dots corresponding to each solder strip in the non-interconnect side region is N4, where 1≤N3-N4≤3, and N3≥2.

[0011] In some embodiments, in the second direction, the width of the interconnect side region is greater than the width of the non-interconnect side region.

[0012] In some embodiments, the battery cell has a middle area, two edge areas, an interconnect side area and a non-interconnect side area on both opposite sides, and the two interconnect side areas are located at both ends of the battery cell in a second direction.

[0013] According to another aspect of this application, a printing screen includes a plate body with a plurality of through-holes along its thickness direction. The plurality of holes are distributed in a central region, side regions located on both sides of the central region in a first direction, and connecting and non-connecting regions located on both sides of the central region in a second direction, wherein the second direction is perpendicular to the first direction, and the distribution density of holes in the connecting regions is greater than the distribution density of holes in the other regions, and the distribution density of holes in the side regions is greater than the distribution density of holes in the central region.

[0014] In some embodiments, the plurality of meshes are arranged in multiple columns along a first direction, the number of meshes in each column in the side region is N1, the number of meshes in each column in the central region is N2, and N1-N2≥2.

[0015] In some embodiments, in the second direction, the connecting area and the non-connecting area are located on both sides of the side area.

[0016] In some embodiments, the plurality of meshes are arranged in multiple columns along a first direction, the number of meshes in each column in the connected area is N3, and the number of meshes in each column in the unconnected area is N4, wherein 1≤N3-N4≤3, and N3≥2.

[0017] Using the screen printing plate of this application, differentiated adhesive dots can be printed on the solar cell, resulting in a higher density of adhesive dots in areas where the solder ribbon experiences greater tension and a lower density of adhesive dots in areas where the solder ribbon experiences less tension. This strengthens the tension on the solder ribbon in areas at risk of detachment and, due to the differentiated use of adhesive, controls the overall amount of adhesive used, thereby controlling the cost of the photovoltaic module. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of a photovoltaic module according to some embodiments of this application.

[0019] Figure 2 This is a schematic diagram of the interconnection of adjacent cells in a photovoltaic module according to some embodiments of this application.

[0020] Figure 3 This is a schematic diagram showing the location of adhesive dots on photovoltaic cells according to some embodiments of this application.

[0021] Figure 4 This is a top view of a printing screen for some embodiments of this application.

[0022] Figure label:

[0023] 100. Battery string; 10. Battery cell; 101. Front side; 110. Fine grid line; 120. Solder ribbon; 130. Adhesive dot; 131. Middle area; 132. Edge area; 133. Interconnected side area; 134. Non-interconnected side area; 200. First adhesive film; 300. First cover plate; 400. Second adhesive film; 500. Second cover plate; 600. Printing screen; 610. Plate body; 620. Mesh; 621. Middle area; 622. Side side areas; 623. Connecting area; 624. Non-connecting area. Detailed Implementation

[0024] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0025] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms 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.

[0026] Furthermore, where the terms "first" and "second" appear, these terms are 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 with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0027] In the field of photovoltaic power generation technology, photovoltaic modules are the core components that convert solar energy into electrical energy. For example... Figure 1 As shown, a photovoltaic module typically includes a cell string 100, a first encapsulating film 200, a second encapsulating film 400, and a second cover plate 500. The first cover plate 300, the first encapsulating film 200, the cell string 100, the second encapsulating film 400, and the second cover plate 500 are stacked along their own thickness direction. The first cover plate 300 is sealed and fixed to the cell string 100 by the first encapsulating film 200, and the second cover plate 500 is sealed and fixed to the cell string 100 by the second encapsulating film 400. Other layers may also be provided between the first cover plate 300 and the first encapsulating film 200, between the first encapsulating film 200 and the cell string 100, between the cell string 100 and the second encapsulating film 400, and between the second encapsulating film 400 and the second cover plate 500. This application embodiment does not specifically limit the number of layers in the photovoltaic module.

[0028] like Figure 1 and Figure 2 As shown, in the length and width directions of the photovoltaic module, one is denoted as the first direction X, and the other as the second direction Y. The thickness direction of the photovoltaic module is denoted as the third direction Z. The battery string 100 includes multiple battery cells 10 arranged along the second direction Y. Of the first direction X and the second direction Y, one is the length direction of the battery cell 10, and the other is the width direction of the battery cell 10. The first direction X and the second direction Y are perpendicular to each other.

[0029] like Figure 2As shown, the solar cell 10 includes fine grids 110 extending along a first direction X, and multiple fine grids 110 are arranged at intervals along a second direction Y. A solder ribbon 120 extending along the second direction Y is fixed to the solar cell 10. The solder ribbon 120 is electrically connected to at least two fine grids 110, and in the second direction Y, the solder ribbon 120 is simultaneously connected to at least two solar cells 10 to achieve series or parallel connection of adjacent solar cells 10. The solder ribbon 120 is in direct contact with the fine grids 110, thus eliminating the main grid structure in the prior art, making the solar cell 10 a gridless solar cell 10. During the fabrication of the solar cell 10, the gridless solar cell 10 reduces the amount of silver paste used, thereby reducing the printing cost of the solar cell 10. Simultaneously, it reduces the shading area of ​​the grid lines on the surface of the solar cell 10, thereby increasing the area of ​​the solar cell 10 available for contact with sunlight, and thus improving the photoelectric conversion efficiency of the solar cell 10.

[0030] This application does not specifically limit the type of battery cell 10. The types of battery cell 10 include, but are not limited to, passivated emitter rear cell (PERC), tunnel oxide passivated contact (TOPCon), intrinsic thin-film heterojunction (HJT), interdigitated back contact (IBC), perovskite cell, etc.

[0031] Both the front side 101 and the back side (unmarked) of the solar cell 10 are welding surfaces. The front side 101 is the light-receiving surface, and the back side is the back-lighting surface. The front side 101 of the solar cell 10 is stacked and connected to the back side of adjacent solar cells 10. During the fabrication of the busbarless solar cell 10, adhesive dots 130 of appropriate size are printed above or below the solder ribbon to improve the bonding force between the solder ribbon and the cell, thereby ensuring the reliability of the photovoltaic module. Adhesive dots 130 are typically placed on both the front side 101 and the back side.

[0032] like Figure 2 and Figure 3 As shown, taking the setting of adhesive dots 130 on the front side 101 as an example, each solder strip 120 is connected to the front side 101 by multiple adhesive dots 130. The adhesive dots 130 are staggered from the fine grid lines 110 to avoid obscuring the fine grid lines 110.

[0033] In practice, adhesive dots 130 can be pre-defined on the front side 101 of the battery cell 10 and then printed using a screen printing plate 600 (see [link to screen printing]). Figure 4First, apply adhesive to the adhesive dots 130, then apply solder ribbon 120 extending in the second direction Y on the adhesive dots 130. Finally, roll the solder ribbon 120. After the adhesive cures, the solder ribbon 120 is fixed to the front surface 101 through the adhesive dots 130. Alternatively, the solder ribbon 120 can be set first, and then adhesive can be applied through a printing screen 600 at predetermined adhesive dot positions 130, so that the adhesive wraps around the solder ribbon 120. After the adhesive cures, the solder ribbon 120 is fixed to the front surface 101 through the adhesive dots 130.

[0034] Along the first direction X, multiple adhesive dots 130 form multiple rows. Each row of adhesive dots 130 is distributed at intervals along the second direction Y and corresponds to the same solder ribbon 120. That is, along the second direction Y, each solder ribbon 120 corresponds to multiple adhesive dots 130. As can be seen from the above, the adhesive dots 130 can be located below or above the solder ribbon 120.

[0035] In the battery string 100, the solder ribbon 120 connects to two adjacent solar cells 10 simultaneously. Specifically, the solder ribbon 120 connects to the end of the front side 101 of the first solar cell 10 and to the end of the back side of the second solar cell 10. The ends of the front side 101 of the first solar cell 10 and the ends of the back side of the second solar cell 10 are typically stacked. Studies have found that the solder ribbon 120 experiences the greatest tensile force at the ends of the solar cells 10, posing a greater risk of detachment from the solar cells 10 and significantly impacting the reliability of the photovoltaic module.

[0036] Therefore, such as Figure 3 As shown in this application, all adhesive dots 130 on the battery cell 10 are distributed into a central region 131, two edge regions 132, an interconnected side region 133, and a non-interconnected side region 134. The two edge regions 132 are located on both sides of the central region 131 in the first direction X, and the interconnected side region 133 and the non-interconnected side region 134 are located on both sides of the central region 131 in the second direction Y. The distribution density of adhesive dots 130 in the interconnected side region 133 is greater than that in the other regions, and the distribution density of adhesive dots 130 in the edge region 132 is greater than that in the central region 131. In this application, the density of adhesive dots 130 can be understood as the number of adhesive dots 130 per unit area, such as the number of adhesive dots 130 per square decimeter.

[0037] The interconnect side region 133 is used for end-to-end lamination with adjacent solar cells 10. The density of adhesive dots 130 in the interconnect side region 133 is relatively high, resulting in more connection points between the solder ribbon 120 and the interconnect side region 133 of the front side 101. The risk of complete separation between the solder ribbon 120 and the interconnect side region 133 is relatively small, thus the solder ribbon 120 can be more reliably fixed to the front side 101.

[0038] Compared to the interconnect side area 133, the solder strip 120 in the middle area 131, the two edge areas 132, and the non-interconnect side area 134 bears relatively less tensile force. Therefore, the distribution density of adhesive dots 130 in these areas is set to be less than that in the interconnect side area 133, thereby reducing the amount of adhesive used.

[0039] Furthermore, analysis revealed that the stress on the solder ribbons 120 at the two edge regions 132 is greater than that on the solder ribbons 120 at the middle region 131. Therefore, the distribution density of adhesive dots 130 in the edge region 132 is greater than that in the middle region 131, resulting in a tighter bond between the solder ribbons 120 and the battery cell 10 at the edge region 132.

[0040] In this application, the adhesive dots 130 on the welding surface of the solar cell 10 are distributed differently, so that more adhesive dots 130 are distributed in the interconnect side 133 where the solder ribbon 120 is under greater tension, and the density of adhesive dots 130 is lower in the area where the solder ribbon 120 is under less tension, thereby reducing the amount of adhesive used. In this way, on the one hand, the tension on the solder ribbon 120 is enhanced in the area with risk of detachment; on the other hand, due to the differentiated use of adhesive, the overall amount of adhesive used can be controlled, thereby controlling the cost of the photovoltaic module.

[0041] In some embodiments, the number of adhesive dots 130 corresponding to each solder strip 120 in the edge region 132 is N1, and the number of adhesive dots 130 corresponding to each solder strip 120 in the middle region 131 is N2, where N1-N2≥2.

[0042] In this way, each solder strip 120 on the edge region 132 has two more adhesive dots 130 than the solder strip 120 in the middle region 131, thus providing two more connection points to the battery cell 10. As a result, the connection between each solder strip 120 in the edge region 132 and the battery cell 10 is more reliable.

[0043] Optionally, the number of adhesive dots 130 corresponding to each solder strip 120 in the edge region 132 is 11, and the number of adhesive dots 130 corresponding to each solder strip 120 in the middle region 131 is 9. That is, the number of adhesive dots 130 in each column in the edge region 132 is 11, and the number of adhesive dots 130 in each column in the middle region 131 is 9.

[0044] Optional, such as Figure 3As shown, in each column of adhesive dots 130 in the intermediate region 131, the adhesive dots 130 are evenly spaced at a distance d1, and the minimum distance d2 between the adhesive dots 130 in the intermediate region 131 and the adhesive dots 130 in the interconnect side region 133 is greater than d1. Thus, the intermediate region 131 has a blank area with a size greater than d1 between it and the interconnect side region 133. This blank area is adjacent to the interconnect side region 133, so although there are no adhesive dots 130 there, its impact on the tension of the solder ribbon 120 is small. At the same time, with the number of adhesive dots 130 in the intermediate region 131 remaining constant, the existence of this blank area makes the adhesive dots 130 more concentrated in the part of the intermediate region 131 outside the blank area, thereby improving the tension of the solder ribbon 120 in the intermediate region 131.

[0045] In some embodiments, such as Figure 3 As shown, in the second direction Y, the interconnected side region 133 and the non-interconnected side region 134 are located on both sides of the edge region 132. With this configuration, the interconnected side region 133 and the non-interconnected side region 134 are located at opposite ends of the solar cell 10 in the second direction Y, and the entire area of ​​the end of the solar cell 10 in the first direction X can be used as either the interconnected side region 133 or the non-interconnected side region 134. Therefore, without changing the size of the solar cell 10, the interconnected side region 133 has the potential to accommodate more adhesive dots 130, providing a better foundation for reliable connection of the solder ribbon 120.

[0046] In some embodiments, in the interconnect side region 133, the number of adhesive dots 130 corresponding to each solder ribbon 120 is N3, and in the non-interconnect side region 134, the number of adhesive dots 130 corresponding to each solder ribbon 120 is N4, where 1≤N3-N4≤3, and N3≥2.

[0047] In this way, each solder strip 120 on the interconnected side region 133 is equipped with at least 2 adhesive dots 130, which is at least 1 more adhesive dot 130 than the solder strip 120 in the middle region 131, thus providing at least 1 more connection point to the battery cell 10, making the connection between each solder strip 120 in the interconnected side region 133 and the battery cell 10 more reliable.

[0048] In some embodiments, the width of the interconnect side region 133 is greater than the width of the non-interconnect side region 134 in the second direction Y.

[0049] In this embodiment, the width of the interconnect side area 133 is set to be greater than the width of the non-interconnect side area 134, so that more adhesive dots 130 can be set in the interconnect side area 133.

[0050] like Figure 3As shown, the width d3 of the interconnected side region 133 refers to the distance from the edge of the solar cell 10 to the center line c1 of the gap between the interconnected side region 133 and the edge region 132. The width d4 of the non-interconnected side region 134 refers to the distance from the edge of the solar cell 10 to the center line c2 of the gap between the non-interconnected side region 134 and the edge region 132.

[0051] In some embodiments, the battery cell 10 has a middle region 131, two edge regions 132, an interconnected side region 133 and a non-interconnected side region 134 on both opposite sides, and the two interconnected side regions 133 are located at both ends of the battery cell 10 in the second direction Y.

[0052] As described above, the ends of the front and back sides of two adjacent battery cells 10 in the battery string 100 are stacked on top of each other. Therefore, in this embodiment, on one hand, adhesive dots 130 are provided on both sides of the battery cell 10, i.e., the front side 101 and the back side, and the adhesive dots 130 are divided into a middle area 131, two edge areas 132, an interconnection side area 133, and a non-interconnection side area 134 as described above. On the other hand, the interconnection side area 133 of the front side 101 and the interconnection side area 133 of the back side are located at both ends of the battery cell 10 in the second direction Y.

[0053] With this configuration, when two adjacent battery cells 10 are interconnected, the end of each battery cell 10 used for stacking is an interconnection side area 133. Specifically, the interconnection side area 133 is on the front side 101 of the first battery cell 10 and the interconnection side area 133 is on the back side of the second battery cell 10. In this way, the connection between the solder ribbon 120 and the end of the two adjacent battery cells 10 is more reliable.

[0054] refer to Figure 4 Another aspect of this application proposes a printing screen 600, which can be used to apply adhesive to the surface of the battery cell 10 to form the aforementioned central region 131, two edge regions 132, interconnected side region 133 and non-interconnected side region 134.

[0055] The printing process of this application includes a plate 610, on which a plurality of through-holes 620 are provided along the thickness direction. The plurality of through-holes 620 are distributed in a central region 621, two side regions 622 located on both sides of the central region 621 in a first direction X, and connecting regions 623 and non-connecting regions 624 located on both sides of the central region 621 in a second direction Y. The second direction Y is perpendicular to the first direction X. The distribution density of the through-holes 620 in the connecting regions 623 is greater than the distribution density of the through-holes 620 in the other regions, and the distribution density of the through-holes 620 in the side regions is greater than the distribution density of the through-holes 620 in the central region 621.

[0056] The mesh 620 of the central region 621 is used for the middle region 321 where adhesive dots 130 are formed on the solar cell 10; the mesh 620 of the two side regions 622 is used for the two edge regions 132 where adhesive dots 130 are formed on the solar cell 10; the mesh 620 of the connecting region 623 is used for the interconnecting side region 133 where adhesive dots 130 are formed on the solar cell 10; and the mesh 620 of the non-connecting region 624 is used for the non-interconnecting side region 134 where adhesive dots 130 are formed on the solar cell 10.

[0057] The printing of adhesive onto the solar cell 10 is achieved by a printing apparatus, which includes a substrate for supporting the solar cell 10, a printing screen mounted on the substrate, and a squeegee mounted on the substrate. The solar cell 10 and the squeegee are located on opposite sides of the printing screen. The squeegee is used to press down on the printing screen and to scrape the adhesive on the printing screen into the mesh openings 620. This technology is well known in the art and is not the focus of this application, so it will not be described in detail here.

[0058] Using the printing screen 310 of this application, differentiated adhesive dots 130 can be printed on the solar cell 10, resulting in a higher density of adhesive dots 130 in areas of the solder ribbon 120 where the tension is greater, and a lower density of adhesive dots 130 in areas where the tension is less. This strengthens the tension on the solder ribbon 120 in areas at risk of detachment, and also controls the overall amount of adhesive used due to the differentiated adhesive, thus controlling the cost of the photovoltaic module.

[0059] In some embodiments, each mesh 620 has the same shape and size; this facilitates the fabrication of the mesh 620; however, the shape and size of the mesh 620 are not limited thereto. For example, in other embodiments, the mesh 620s on both side regions 622 may be completely identical, and the mesh 620s in the middle region 621 may be smaller than the mesh 620s in the connecting region 623.

[0060] In some embodiments, the plurality of meshes 620 are arranged in multiple columns along a first direction X, the number of meshes 620 in each column in the side region is N1, the number of meshes 620 in each column in the central region 621 is N2, and N1-N2≥2.

[0061] With the above settings, each solder strip 120 on the edge region 132 of the battery cell 10 has two more adhesive dots 130 than the solder strip 120 in the middle region 131, thus providing two more connection points to the battery cell 10, making the connection between each solder strip 120 on the edge region 132 and the battery cell 10 more reliable.

[0062] In some embodiments, in the second direction Y, the connecting region 623 and the non-connecting region 624 are located on both sides of the side region. With the above arrangement, after forming the interconnecting side region 133 and the non-interconnecting side region 134 on the battery cell 10, the interconnecting side region 133 and the non-interconnecting side region 134 are respectively located at both ends of the battery cell 10 in the second direction Y, and the entire area of ​​the end of the battery cell 10 in the first direction X is used as the interconnecting side region 133 or the non-interconnecting side region 134. Therefore, without changing the size of the battery cell 10, a larger number of adhesive dots 130 can be provided in the interconnecting side region 133.

[0063] In some embodiments, the plurality of meshes 620 are arranged in multiple columns along a first direction X. The number of meshes 620 in each column in the connection area 623 is N3, and the number of meshes 620 in each column in the non-connection area 624 is N4, where 1≤N3-N4≤3 and N3≥2. With the above configuration, after the interconnection side area 133 and the non-interconnection side area 134 are formed on the battery cell 10, each solder ribbon 120 on the interconnection side area 133 corresponds to at least 2 adhesive dots 130, which is at least 1 more adhesive dot 130 than the solder ribbon 120 in the middle area 131. This results in at least 1 more connection point to the battery cell 10, thus making the connection between each solder ribbon 120 in the interconnection side area 133 and the battery cell 10 more reliable.

[0064] In some embodiments, such as Figure 4 As shown, in the second direction Y, the width of the connecting area 623 is greater than the width of the non-connecting area 624. In this embodiment, the width d5 ​​of the connecting area 623 refers to the distance from the edge of the screen to the center line c3 of the gap between the connecting area 623 and the side area. The width d6 of the non-connecting area 624 refers to the distance from the edge of the screen to the center line c4 of the gap between the non-connecting area 624 and the side area.

[0065] With the above settings, after the interconnected side region 133 and the non-interconnected side region 134 are formed on the battery cell 10, the width of the interconnected side region 133 is set to be greater than the width of the non-interconnected side region 134. This allows more adhesive dots 130 to be set in the interconnected side region 133.

[0066] It is easy to understand that, using the printing screen 600 of this application, adhesive dots 130 can be printed on the front side 101 and the back side of the battery cell 10 respectively. Furthermore, by rotating the printing screen 600, the interconnection side area 133 of the front side 101 of the battery cell 10 and the interconnection side area 133 of the battery cell 10 can be located at both ends of the battery cell 10 in the second direction Y.

[0067] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," 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 or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0068] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0069] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0070] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0071] The above embodiments merely illustrate several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A photovoltaic module, characterized in that, include: A plurality of battery cells, wherein the welding surface of the battery cells is provided with a plurality of fine grid lines, the fine grid lines extend along a first direction, the plurality of fine grid lines are arranged at intervals along a second direction, the second direction being perpendicular to the first direction, and the plurality of battery cells are arranged along the second direction; Multiple solder strips are fixed to the welding surface. The solder strips extend along a second direction and are electrically connected to the fine grid lines. Each solder strip is connected to the welding surface by multiple adhesive dots, and the adhesive dots are staggered from the fine grid lines. The adhesive dots are distributed in a middle region, two edge regions, an interconnected side region, and a non-interconnected side region. The two edge regions are located on both sides of the middle region in a first direction, and the interconnected side region and the non-interconnected side region are located on both sides of the middle region in a second direction. The distribution density of adhesive dots in the interconnected side region is greater than that in the other regions, and the distribution density of adhesive dots in the edge regions is greater than that in the middle region. The interconnected side region is located at the end of the solar cell in the second direction.

2. The photovoltaic module according to claim 1, characterized in that, The number of adhesive dots corresponding to each solder strip in the edge region is N1, and the number of adhesive dots corresponding to each solder strip in the middle region is N2, where N1-N2≥2.

3. The photovoltaic module according to claim 1, characterized in that, In the second direction, the interconnected side area and the non-interconnected side area are located on both sides of the edge area.

4. The photovoltaic module according to claim 1, characterized in that, In the interconnection side area, the number of adhesive dots corresponding to each solder strip is N3, and in the non-interconnection side area, the number of adhesive dots corresponding to each solder strip is N4, where 1≤N3-N4≤3, and N3≥2.

5. The photovoltaic module according to claim 1, characterized in that, In the second direction, the width of the interconnected side region is greater than the width of the non-interconnected side region.

6. The photovoltaic module according to claim 1, characterized in that, The battery cell has a middle area, two edge areas, an interconnected side area and a non-interconnected side area on both sides opposite to each other, and the two interconnected side areas are located at both ends of the battery cell in the second direction.

7. A printing screen, comprising a plate body, characterized in that, The plate has multiple through-holes along its thickness direction. These holes are distributed in a central region, two side regions located on either side of the central region in a first direction, and connecting and non-connecting regions located on either side of the central region in a second direction. The second direction is perpendicular to the first direction. The distribution density of the holes in the connecting regions is greater than that in the other regions, and the distribution density of the holes in the side regions is greater than that in the central region. The mesh in the central area is used to form adhesive dots in the middle area of ​​the solar cell, the mesh in the two side areas is used to form adhesive dots in the two edge areas of the solar cell, the mesh in the connecting area is used to form adhesive dots in the interconnecting side areas of the solar cell, and the mesh in the non-connecting area is used to form adhesive dots in the non-interconnecting side areas of the solar cell.

8. The printing screen according to claim 7, characterized in that, The plurality of meshes are arranged in multiple columns along a first direction, the number of meshes in each column in the side region is N1, the number of meshes in each column in the central region is N2, and N1-N2≥2.

9. The printing screen according to claim 7, characterized in that, In the second direction, the connecting area and the non-connecting area are located on both sides of the side area.

10. The printing screen according to claim 7, characterized in that, The plurality of meshes are arranged in multiple columns along a first direction. The number of meshes in each column in the connected area is N3, and the number of meshes in each column in the unconnected area is N4, wherein 1≤N3-N4≤3, and N3≥2.

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