Solar cell printing screen, solar cell and photovoltaic module

Abstract

The utility model relates to the technical field of photovoltaic equipment, in particular to a solar cell printing screen plate, a solar cell and a photovoltaic assembly, and the solar cell printing screen plate comprises a screen plate and a pattern layer; one surface of the screen plate is covered with a pattern layer; the pattern layer is provided with a partition area, the partition area divides the pattern layer into at least two pattern parts, and each pattern part is provided with an opening area; the opening area comprises main grid openings and harpoon openings, each pattern part is provided with a plurality of main grid openings which are arranged side by side at intervals in the first direction, each main grid opening extends in the second direction, and one end of each main grid opening is provided with a harpoon opening. The solar cell printing screen, the solar cell and the photovoltaic module provided by the utility model can reduce the cost of slurry used during printing, reduce the shading area, and increase the efficiency of the printed solar cell.

Description

Technical Field

[0001] This utility model relates to the field of photovoltaic equipment technology, specifically to a solar cell printing screen, a solar cell, and a photovoltaic module. Background Technology

[0002] Solar cells have metallized grid lines on their surface, which can collect and conduct the current generated by the solar cell. Among the current methods of metallizing solar cells, screen printing technology is widely used to form the grid lines on the surface of solar cells due to its maturity, simplicity, and ease of control.

[0003] Screen printing uses a printing screen to print images. The printing screen forms a pattern on the screen, and then the ink is passed through the screen and the pattern openings to print onto the surface of the solar cell. After drying, the solar cell is formed.

[0004] In recent years, most screen printing on silicon solar cells has adopted a design with harpoon openings at both ends of the main grid. Since the mechanical properties of the edges of solar cells are relatively weak, the harpoon openings can disperse the stress concentration caused by the solder ribbon after welding, thereby avoiding microcracks and breakage at the edges of the solar cells. Without the harpoon opening design, the solder ribbon will pull on the edge of the cell, resulting in microcracks and breakage at the cut edge due to stress. However, the harpoon openings on both ends will increase the basis weight of the printing paste. When the harpoon opening on one side is located in the middle area of ​​the solar cell, it will not play a role and will also block some sunlight, which will increase the cost and reduce the solar energy conversion efficiency. Utility Model Content

[0005] (I) This utility model provides a solar cell printing screen, a solar cell, and a photovoltaic module, which alleviates the technical problems of high cost and low solar energy conversion efficiency of screen printing on the surface of silicon solar cells in the prior art.

[0006] (II) Technical Solution

[0007] To solve the above-mentioned technical problems, embodiments of this utility model provide a solar cell printing screen, including a screen and a pattern layer;

[0008] One side of the stencil is covered with the graphic layer;

[0009] The graphic layer is provided with a dividing area, which divides the graphic layer into at least two graphic parts, and each graphic part has an opening area;

[0010] The opening area includes a main grid opening and a harpoon opening. Each graphic part is provided with a plurality of main grid openings arranged in parallel at intervals along a first direction. Each main grid opening extends along a second direction, and one end of each main grid opening is provided with the harpoon opening.

[0011] Furthermore, the opening area also includes fine grid openings, and each graphic portion is provided with a plurality of fine grid openings arranged in parallel at intervals along the second direction, and each fine grid opening extends along the first direction.

[0012] Furthermore, each of the main gate openings is provided with a plurality of contact point openings that communicate with it along its own extending direction.

[0013] Furthermore, the end of the harpoon opening facing the main gate opening is provided with the contact point opening at the connection between the main gate opening and the end of the harpoon opening.

[0014] Furthermore, the first direction and the second direction are perpendicular to each other.

[0015] Furthermore, the width of the main gate opening is greater than the width of the fine gate opening.

[0016] An embodiment of this utility model also provides a solar cell, including a cell body and a grid structure disposed on the cell body, wherein the grid structure is prepared by a solar cell printing screen as described above;

[0017] The grid structure includes a main grid, fine grids, a harpoon, and contact points. The main grid is spaced out along the first direction and extends along the second direction. The fine grids are spaced out along the second direction and extend along the first direction. The harpoon is provided at one end of the main grid. The main grid has multiple contact points spaced out along its own extension direction.

[0018] Furthermore, the solar cell includes a front side and a back side, both of which are provided with the grid structure.

[0019] An embodiment of this utility model also provides a photovoltaic module, including a battery string, wherein the battery string is formed by welding multiple battery strips together by soldering, and the battery strips are formed by cutting the aforementioned solar cells along the positions corresponding to the printing separation areas.

[0020] Furthermore, the openings of the harpoons on both sides of the battery strip are arranged facing each other.

[0021] The beneficial effects of this utility model are:

[0022] This invention provides a printing screen for solar cells, comprising a screen and a pattern layer. One side of the screen is covered with the pattern layer, which is divided into at least two pattern sections by a separating area. The screen and the opening areas provided on the pattern sections cooperate to print paste onto the silicon wafer through the main grid openings and harpoon openings. Since each main grid opening in the opening area has a harpoon opening at only one end, the amount of paste printed through the harpoon openings is reduced. Because the harpoon openings are used to allow the paste to pass through during printing, the amount of printing paste used is further reduced, thereby reducing the paste cost used during printing. Simultaneously, it can also reduce the light-shielding area and increase the efficiency of the printed solar cell. The solar cells printed using this printing screen have harpoon openings on both sides of the edge, thus still providing the function of preventing microcracks and breakage of the solar cell edges under stress after printing.

[0023] This invention provides a method for forming a grid structure printed on the surface of a solar cell using a solar cell printing screen, thereby eliminating the need for a harpoon located in the middle of the solar cell. At the same time, harpoons are formed at the edges on both sides of the solar cell, which also serves to prevent microcracks and breakage. This method can also effectively reduce the weight of the solar cell itself, reduce the shading caused by the harpoon, and improve the cell efficiency of the solar cell.

[0024] The present invention provides a photovoltaic module including a battery string, which is formed by welding multiple solar cells in alternating directions as described above, thereby effectively reducing the weight of the photovoltaic module and improving its conversion efficiency. Attached Figure Description

[0025] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0026] Figure 1 A schematic diagram of the structure of a solar cell printing screen provided for an embodiment of the utility model;

[0027] Figure 2 A schematic diagram of the front printing of a solar cell provided for an embodiment of the utility model;

[0028] Figure 3 A schematic diagram of the reverse side printing of a solar cell provided for an embodiment of the utility model;

[0029] Figure 4A schematic diagram of a photovoltaic module's battery string provided for an embodiment of the utility model;

[0030] Figure 5 This is a partially enlarged view of a schematic diagram of a solar cell printing screen structure provided for an embodiment of the utility model.

[0031] icon:

[0032] 100-Frame; 101-Screen plate; 102-Main grid opening; 103-Fine grid opening; 104-Harpoon opening; 105-Contact point opening; 106-Separation area; 107-Graphic section;

[0033] 200 - Main grid; 201 - Fine grid; 202 - Harpoon; 203 - Contact point;

[0034] 300-Battery cell body. Detailed Implementation

[0035] The technical solution of this utility model will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0036] In the description of this utility model, it should be noted that the terms "upper" and "lower," etc., 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 utility model 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 utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0037] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances. Furthermore, in the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0038] like Figure 1 and Figure 5As shown, this utility model provides a printing screen for solar cells, including a screen 101 and a pattern layer; one side of the screen 101 is covered with the pattern layer; the pattern layer is provided with a dividing area 106, which divides the pattern layer into at least two pattern portions 107, each pattern portion 107 forming an opening area; the opening area includes a main grid opening 102 and a harpoon opening 104, each pattern portion 107 is provided with a plurality of main grid openings 102 arranged in parallel along a first direction, each main grid opening 102 extends along a second direction, and one end of each main grid opening 102 is provided with a harpoon opening 104.

[0039] In this embodiment, the solar cell printing screen includes a screen 101 and a pattern layer. One side of the screen 101 is covered with the pattern layer, which is divided into at least two pattern portions 107 by a partition area 106. The screen 101 and the opening area provided on the pattern portion 107 cooperate to print the paste onto the silicon wafer through the main grid opening 102 and the harpoon opening 104. Since the main grid opening in the opening area is only provided with the harpoon opening 104 at one end, the printing amount of the harpoon opening 104 is reduced. Since the harpoon opening 104 is used to print through the paste, the amount of printing paste used is reduced, thereby reducing the paste cost used during printing. At the same time, it can also reduce the light-shielding area and increase the efficiency of the printed solar cell.

[0040] The number of graphic sections 107 can be set according to the silicon wafers used for printing. There can be two, three or more. Both sides of the solar cell printed by this printing screen will be provided with harpoon openings 104, so the harpoon openings 104 still have the function of preventing the edges of the solar cell from cracking due to stress after printing.

[0041] Optionally, the solar cell printing screen also includes a frame 100, with the frame 100 fixed circumferentially to the screen 101, so that the screen 101 can be fixed by the frame 100 to facilitate printing.

[0042] According to one embodiment provided by this utility model, such as Figure 1 As shown, the opening area also includes fine grid openings 103. Each graphic part 107 is provided with a plurality of fine grid openings 103 arranged in parallel at intervals along the second direction, and each fine grid opening 103 extends along the first direction.

[0043] The graphic layer is formed by coating photosensitive emulsion onto a screen 101 to create a pattern. Before making the printing screen, the screen 101 needs to be cleaned to remove surface oil and impurities, ensuring uniform adhesion of the photosensitive emulsion. A layer of photosensitive emulsion is then uniformly coated onto the cleaned screen 101. Photosensitive emulsion is a material sensitive to ultraviolet light and cures upon exposure. The screen 101 coated with photosensitive emulsion is aligned with a mask, which has the required pattern (i.e., main grid opening 102, fine grid opening 103, and harpoon opening 104). When ultraviolet light is irradiated onto the screen 101, the pattern on the mask blocks some of the ultraviolet light, causing the photosensitive emulsion to cure in the exposed areas, while the photosensitive emulsion in the unexposed areas remains soluble. After exposure, the screen 101 is placed in a developing solution, where the unexposed photosensitive emulsion dissolves, forming the pattern corresponding to the opening areas, thus completing the graphic layer covering the screen 101. The ink then passes through the screen 101 and the opening areas sequentially to complete the printing process.

[0044] According to one embodiment provided by this utility model, such as Figure 1 and Figure 5 As shown, each main gate opening 102 is provided with a plurality of contact point openings 105 that communicate with it along its own extension direction.

[0045] In this embodiment, each main gate opening 102 of the pattern layer is provided with multiple contact point openings 105 at intervals along its own direction to facilitate subsequent welding with the solder strip.

[0046] Preferably, the number of contact point openings 105 is set to six, and the six contact point openings 105 are evenly spaced. The number of contact point openings 105 can also be increased according to actual usage requirements, without departing from the design concept of this utility model, and should fall within the protection scope of this utility model.

[0047] According to one embodiment provided by this utility model, such as Figure 1 and Figure 5 As shown, the end of the harpoon opening 104 facing the main gate opening 102 is provided with a contact point opening 105 at the connection between the main gate opening 102 and the harpoon opening 104.

[0048] In this embodiment, a contact point opening 105 is provided at the connection point of the harpoon opening 104 at the end of the main grid opening 102 near the end of the main grid opening 102. After printing the solar cell using the printing screen provided in this embodiment, it can be connected to the solder ribbon through the printing point of the contact point opening 105.

[0049] According to one embodiment provided by this utility model, such as Figure 1 As shown, the first direction and the second direction are perpendicular to each other.

[0050] In this embodiment, the first direction and the second direction are set perpendicular to each other to optimize current collection efficiency, reduce resistance loss, and simplify the manufacturing process.

[0051] According to one embodiment provided by this utility model, such as Figure 1 As shown, the width of the main gate opening 102 is greater than the width of the fine gate opening 103.

[0052] In this embodiment, the main gate opening 102 has a larger width to efficiently transmit current, therefore the width of the main gate opening 102 is greater than the width of the fine gate opening 103.

[0053] The mesh count of printing stencils for solar cells ranges from 280 to 350 mesh.

[0054] In this embodiment, by using a printing screen with a mesh count between 280 and 350, the paste can be evenly distributed, improving the performance and efficiency of the solar cells. Consequently, the printing efficiency can also be effectively accelerated.

[0055] Preferably, the mesh size of the printing screen for solar cells is 300 mesh.

[0056] like Figure 2 and Figure 3 As shown, this utility model provides a solar cell, including a cell body 300 and a grid structure disposed on the cell body 300. The grid structure is prepared by a solar cell printing screen as described above. The grid structure includes a main grid 200, fine grids 201, a harpoon 202 and contact points 203. The main grid 200 is spaced apart along a first direction and extends along a second direction. The fine grids 201 are spaced apart along the second direction. A harpoon 202 is provided at one end of the main grid 200. The main grid 200 is provided with a plurality of contact points 203 spaced apart along its own extension direction.

[0057] In this embodiment, the surface of the solar cell is formed with the grid structure printed by the solar cell printing screen, thereby eliminating the need for the harpoon located in the middle of the solar cell. At the same time, the harpoons 202 on both sides used for soldering during the stringing of solar cells are retained, which also serves to prevent microcracks and breakage. This also effectively reduces the amount of paste used and minimizes the shading caused by the harpoons 202, thus improving the cell efficiency of the solar cell. The printed solar cell is directly soldered to the soldering strip through contact points 203, which can be PAD points.

[0058] In this embodiment, the main grid 200 of the grid structure formed on the surface of the solar cell is printed through the main grid opening 102 in the solar cell printing screen, the fine grid 201 is printed through the main grid opening 102 in the solar cell printing screen, the harpoon 202 is printed through the harpoon opening 104 in the solar cell printing screen, and the contact point 203 is printed through the contact point opening 105 in the solar cell printing screen.

[0059] According to one embodiment provided by this utility model, such as Figure 2 and Figure 3 As shown, the solar cell includes a front side and a back side, both of which are provided with grid structures.

[0060] In this embodiment, optionally, grid lines can be provided on both the front and back sides of the solar cell, or grid lines can be provided only on the front or only on the back side.

[0061] like Figure 4 As shown, this utility model provides a photovoltaic module, including a battery string. The battery string is formed by welding multiple small battery strips together with solder strips. The small battery strips are formed by cutting the aforementioned solar cells along the positions corresponding to the printed separation areas.

[0062] In this embodiment, the photovoltaic module includes a battery string. The printed battery cells are cut along the positions corresponding to the dividing areas in the solar cell printing screen to form battery strips. The battery strips are then welded together with solder ribbons to form a battery string. Since the main grid in the grid structure of the battery strips only has a fork at one end, the amount of paste used during printing can be effectively reduced, and the conversion efficiency of the photovoltaic module can also be improved.

[0063] According to one embodiment provided by this utility model, such as Figure 4 As shown, the openings of the harpoons 202 on both sides of the battery strip are arranged facing each other.

[0064] In this embodiment, as Figure 4 As shown, the grid structure on both sides of the battery strip formed by cutting the solar cell as described above needs to be set so that the openings of the harpoon 202 face opposite directions, so that the battery strip can be welded to the solder strip to form a battery string, that is, as shown in the figure. Figure 4 As shown, harpoon 202 is removed at point A, and harpoon 202 is retained at point B and welded by welding strips.

[0065] The above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A printing screen for solar cells, characterized in that, Includes a stencil (101) and a graphics layer; One side of the stencil (101) is covered with the graphic layer; The graphic layer is provided with a partition area (106), which divides the graphic layer into at least two graphic sections (107), and each graphic section (107) is provided with an opening area. The opening area includes a main gate opening (102) and a harpoon opening (104). Each graphic part (107) is provided with a plurality of main gate openings (102) arranged in parallel along a first direction at intervals. Each main gate opening (102) extends along a second direction, and one end of each main gate opening (102) is provided with the harpoon opening (104).

2. The solar cell printing screen according to claim 1, characterized in that, The opening area also includes fine grid openings (103), and each graphic part (107) is provided with a plurality of fine grid openings (103) arranged side by side at intervals along the second direction, and each fine grid opening (103) extends along the first direction.

3. The solar cell printing screen according to claim 1, characterized in that, Each of the main gate openings (102) is provided with a plurality of contact point openings (105) connected to it along its own extension direction.

4. The solar cell printing screen according to claim 3, characterized in that, The harpoon opening (104) is provided with the contact point opening (105) at the connection between the end of the harpoon opening (104) facing the main gate opening (102) and the main gate opening (102).

5. The solar cell printing screen according to claim 1, characterized in that, The first direction and the second direction are perpendicular to each other.

6. The solar cell printing screen according to claim 2, characterized in that, The width of the main gate opening (102) is greater than the width of the fine gate opening (103).

7. A solar cell, characterized in that, It includes a solar cell body (300) and a grid line structure disposed on the solar cell body (300), the grid line structure being prepared by a solar cell printing screen as described in any one of claims 1 to 6; The grid structure includes a main grid (200), fine grids (201), a harpoon (202), and contact points (203). The main grid (200) is spaced out along the first direction and extends along the second direction. The fine grids (201) are spaced out along the second direction and extend along the first direction. One end of the main grid (200) is provided with the harpoon (202). The main grid (200) is provided with a plurality of contact points (203) spaced out along its own extension direction.

8. The solar cell according to claim 7, characterized in that, The solar cell includes a front side and a back side, both of which are provided with the grid structure.

9. A photovoltaic module, characterized in that, It includes a battery string, which is formed by welding multiple battery strips together with solder strips. The battery strips are formed by cutting the solar cell according to any one of claims 7-8 along the position corresponding to the printed separation area (106).

10. The photovoltaic module according to claim 9, characterized in that, The openings of the harpoons (202) on both sides of the battery strip are arranged facing each other.

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