Solar cell
By designing a multi-busbar connection structure and optimizing the area and shape of the welded parts in solar cells, the problem of welded busbar breakage was solved, ensuring current conduction, reducing shading area, and lowering production costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-19
- Publication Date
- 2026-03-24
AI Technical Summary
In existing technologies, after solar cells are printed using a fully open steel plate screen, weld grid breakage is prone to occur at the weld joints, leading to a break in the current loop and affecting the current conduction effect.
Design a solar cell with a multi-busbar connection structure to ensure that current can form a loop through the main grid lines on both sides when the weld is broken. This includes the first and second main grids being arranged in parallel, the area and shape of the welded part being optimized, the welded part being staggered from the sub-busbar lines, and different parts being printed with the same electrode paste to reduce costs.
It effectively reduces the adverse effects of welded grid breakage, ensures current conduction, reduces the shading area, saves slurry usage, and lowers production costs.
Smart Images
Figure CN224037751U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of photovoltaic power generation, and particularly relates to a solar cell. BACKGROUND
[0002] With the continuous development of photovoltaic power generation technology, the photoelectric conversion efficiency of solar cells is also continuously improved. Solar cells can use clean solar energy to generate electricity and can be installed and used in different terrain environments or roof environments. With the transformation of clean energy, the installed capacity of photovoltaic power generation is continuously increasing in the proportion of clean energy, and the solar cell is an important component for photovoltaic power generation.
[0003] The solar cell will undergo a screen printing process in the production process, and a grid electrode is formed on the surface of the solar cell by screen printing to collect and transmit electrons. The structure of the grid electrode will affect the welding effect in the subsequent component welding process, and the welding fuse phenomenon will cause the electrode to be open-circuited. Therefore, how to design the structure of the grid electrode of the solar cell to reduce the adverse effects of welding fuse is an important problem. CONTENT OF THE INVENTION
[0004] The purpose of the embodiments of the present application is to provide a solar cell which can reduce the adverse effects of welding fuse.
[0005] To solve the above technical problems, the embodiments of the present application provide a solar cell. The solar cell comprises a substrate and a first grid line structure and a second grid line structure located on the surface of the substrate. The first grid line structure has a plurality of first grid line structures, and the plurality of first grid line structures are arranged at intervals along a first direction. Each first grid line structure comprises a first main grid and a second main grid extending along a second direction, and the first main grid and the second main grid have a welding portion arranged at intervals along the second direction. The second grid line structure has a plurality of second grid line structures, and the plurality of second grid line structures are arranged at intervals along the first direction. Each second grid line structure comprises a plurality of second sub-grid lines arranged at intervals along the second direction, each second sub-grid line extends along the first direction, and at least one end of each second sub-grid line is connected to the first main grid or the second main grid. The first direction intersects the second direction.
[0006] The solar cell provided by the embodiments of the present application designs the first grid line structure and the second grid line structure on the surface of the substrate. The first main grid and the second main grid of the first grid line structure form a multi-grid line structure of the main grid. The second sub-grid lines of the plurality of second grid line structures form a vice grid by being connected to the main grid. The plurality of second sub-grid lines of each second grid line structure are connected to the first main grid or the second main grid. The multi-grid line structure of the main grid formed by the first main grid and the second main grid can ensure that the current forms a loop from the two side main grid lines in the case that the grid is fused and broken at the welding position of the welding strip, thereby ensuring the conduction of the current. The adverse effects of welding fuse are reduced.
[0007] In some embodiments, the first main grid and the second main grid are arranged in parallel, and a distance between the first main grid and the second main grid is greater than or equal to 0.6 mm. In this way, by controlling the distance between the first main grid and the second main grid, it can be ensured that the soldering portion has sufficient extension length to ensure the soldering quality.
[0008] In some embodiments, the first main grid and the second main grid are arranged in a curved shape, and the first main grid and the second main grid are equidistantly arranged in the second direction. In this way, by arranging the main grid lines in a curved shape, it can be beneficial to reduce the range of light blocking.
[0009] In some embodiments, the soldering portion includes a first soldering portion and a second soldering portion, and a projection area of the first soldering portion on the substrate is greater than a projection area of the second soldering portion on the substrate. In this way, by arranging soldering portions with different areas, the purpose of ensuring soldering tension and increasing soldering points can be achieved.
[0010] In some embodiments, a length of the first soldering portion in the first direction is greater than or equal to 0.6 mm and less than or equal to 1.2 mm, and a width of the first soldering portion in the second direction is greater than or equal to 0.4 mm and less than or equal to 0.8 mm. In this way, by controlling the size range of the first soldering portion, the soldering effect can be ensured while saving the amount of paste.
[0011] In some embodiments, the first soldering portion and the second sub-grid line are arranged staggered in the first direction. In this way, by staggering the first soldering portion and the second sub-grid line, it can be avoided that the second sub-grid line is adversely affected during soldering.
[0012] In some embodiments, a width of the second soldering portion in the second direction gradually decreases from both ends to the middle. In this way, by forming a larger width at both ends of the second soldering portion, the contact effect between the second soldering portion and the main grid lines can be ensured.
[0013] In some embodiments, the width of the second soldering portion in the second direction is greater than the width of the second sub-grid line in the second direction. In this way, by making the width of the second soldering portion greater than the width of the second sub-grid line, the contact effect when the second soldering portion is soldered with the solder strip can be ensured.
[0014] In some embodiments, the number of soldering portions in each first grid line structure is the same as the number of second sub-grid lines in each second grid line structure. In this way, by keeping the number of soldering portions corresponding to the number of second sub-grid lines, positioning during grid printing can be facilitated.
[0015] In some embodiments, the electrode paste of the first main grid, the electrode paste of the second main grid and the electrode paste of the soldering part are the same. In this way, by using the same electrode paste to print different parts of the first grid line structure, it is possible to reduce the manufacturing cost. BRIEF DESCRIPTION OF DRAWINGS
[0016] One or more embodiments are illustrated by way of example in the figures that form a part of this patent document, and which do not limit the scope of embodiments. Like numbers in the figures indicate like elements, unless otherwise noted, and the figures are not necessarily to scale.
[0017] Figure 1 is a schematic diagram of a grid line pattern of a solar cell in a conventional grid line form in some cases;
[0018] Figure 2 is Figure 1 is a schematic diagram of a partial enlarged structure of the grid line pattern shown in FIG. 1;
[0019] Figure 3 is Figure 1 is a schematic diagram of a main grid in the grid line pattern shown in FIG. 1;
[0020] Figure 4 is Figure 1 is a schematic diagram of a partial enlarged structure of the main grid in the grid line pattern shown in FIG. 1;
[0021] Figure 5 is Figure 1 is a schematic diagram of a sub-grid in the grid line pattern shown in FIG. 1;
[0022] Figure 6 is Figure 1 is a schematic diagram of a partial enlarged structure of the sub-grid in the grid line pattern shown in FIG. 1;
[0023] Figure 7 is a schematic diagram of a structure of a solar cell provided by some embodiments of the present application;
[0024] Figure 8 is a schematic diagram of a grid line pattern of a solar cell provided by some embodiments of the present application;
[0025] Figure 9 is Figure 8 is a schematic diagram of a partial enlarged structure of the grid line pattern shown in FIG. 1;
[0026] Figure 10 is Figure 8 is a schematic diagram of a first grid line structure in the grid line pattern shown in FIG. 1;
[0027] Figure 11 is Figure 8 is a schematic diagram of a partial enlarged structure of the first grid line structure in the grid line pattern shown in FIG. 1;
[0028] Figure 12 yes Figure 8 A schematic diagram of the second grid line structure in the grid line pattern shown;
[0029] Figure 13 yes Figure 8 A partially enlarged schematic diagram of the second grid line structure in the grid line pattern shown;
[0030] Figure 14 These are schematic diagrams of the structure of photovoltaic modules provided in some embodiments of this application;
[0031] Figure 15 This is a schematic diagram of the structure of a photovoltaic module provided in some other embodiments of this application. Detailed Implementation
[0032] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the various embodiments of this application will be described in detail below with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been presented in the various embodiments of this application to enable readers to better understand this application. However, even without these technical details and various changes and modifications based on the following embodiments, the technical solutions claimed in this application can be implemented. The division of the various embodiments below is for the convenience of description and should not constitute any limitation on the specific implementation of this application. The various embodiments can be combined with and referenced by each other without contradiction.
[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.
[0034] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," and "joining" 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. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application according to the specific circumstances.
[0035] Solar cells are printed with grid electrodes on a substrate, usually a silicon substrate. The solar cells have a photovoltaic effect and can generate electric current under the irradiation of sunlight. Further, the solar cells can output electric energy. The grid electrodes on the surface of the solar cells usually include main grids and sub-grids. The grid electrodes can be formed on one side or both sides of the solar cells. According to the number of main grids, the solar cells can be divided into super multi-busbar (SMBB) cells, multi-busbar cells and busbar-less (0BB) cells. The main grids usually play a role in transmitting current, and the sub-grids, also called fine grids, mainly play a role in collecting current.
[0036] The main grids and the sub-grids are usually printed by using different electrode paste systems. Printing is performed by using a screen plate. The screen plate is designed to have openings that can allow the printing of metal paste to pass through. The metal paste is usually silver paste. The metal paste is printed on the surface of the cell to form main grids or sub-grids. After sintering or drying and curing, the required electrode pattern is obtained.
[0037] A full-opening steel plate screen plate is a screen plate with 100% opening rate. The main body is no longer woven by steel wires, but uses alloy steel sheets. The printing openings are obtained by laser grooving. The opening rate of the working area of the screen plate printing is 100%, that is, all the printing patterns are not blocked by steel wires or other similar structures. Since the full-opening steel plate screen plate has no net yarn blocking in the grooving area, the permeability of the paste can be greatly improved, and the consumption of the paste can be saved. At the same time, by using the full-opening steel plate screen plate for screen printing, the width of the grid lines can be optimized, and the shading area on the surface of the cell can be greatly reduced. Moreover, the grid lines printed by the full-opening steel plate screen plate are uniform and flat, and the height fluctuation is significantly lower than that of the traditional screen printing. The resistance of the grid lines can be significantly reduced, and the fill factor of the solar cell can be improved.
[0038] However, the current full-opening steel plate screen plate is mainly used for small-size heterojunction cells and the metallization printing of 0BB (busbar; 0BB means no busbar) cells with special component welding process. When the full-opening steel plate screen plate is applied to multi-busbar cells, such as the mainstream SMBB (super multi-busbar) cell products, the plastic shaping requirement at the main grid lap / welding position of the SMBB cell products does not match, and abnormal problems such as component welding broken grid and poor lap occur. Table 1 below shows the plastic shaping comparison of the main grid lap / welding position of the SMBB cell products in different cases of printing by using a conventional PI (polyimide) screen plate and printing by using a full-opening steel plate screen plate. The conventional grid line form is shown in Figure 1 and Figure 2 The solar cell adopts a form of gradually changing or an I-shaped design on the main grid 100, and the sub-grid 200 is lapped on the main grid 100. Figure 3 and Figure 4The structure of the main grid 100 in the conventional grid line form is shown, which includes a main grid connecting line and a main pad 101 for soldering a solder strip located on the main grid connecting line, and a lap / soldering portion 102. Figure 5 and Figure 6 The structure of the sub-grid 200 in the conventional grid line form is shown, which includes a plurality of sub-grid connecting lines. The thickness of the screen used in the comparative test is 18.5 microns, and the opening width of the slot is 40 microns.
[0039] Table 1, solar cell in the use of different screen grid electrode plastic shape of the lap / soldering place comparison table
[0040] Type Conventional PI screen All open steel screen Height of lap / weld / microns 8.5 3.5 Width of lap / weld / microns 55.4 65.5 Aspect ratio 15.3％ 5.3％
[0041] It can be seen that the conventional grid line form design of the SMBB cell product has a low plastic height performance when using a full opening steel plate screen printing, which can cause soldering to be broken during the soldering of the solder strip of the module, thereby causing the current loop to be broken, which is manifested as EL (Electroluminescence) blackening, which is called soldering broken grid. That is, the full opening steel plate screen does not match the current SMBB cell product process, and the grid line form needs to be optimized to ensure the current conduction effect at the position where the soldering portion of the main grid soldering solder strip is located. That is, the grid line form of the multi-main grid cell needs to be designed so that the full opening steel plate screen pattern based on the multi-main grid cell product can adapt to the multi-main grid cell product process, and solve the adverse effects caused by the soldering broken grid and other problems.
[0042] In order to reduce the adverse effects caused by the soldering broken grid phenomenon of the solar cell after using the full opening steel plate screen printing process, some embodiments of the present application provide a solar cell. The grid line form of the solar cell is optimized and designed, and the current loop of the main grid soldering portion is optimized. The single main grid connecting line in the conventional grid line form is adjusted to a form in which multiple main grid connecting lines cooperate with each other. Current loops can be formed at different positions of the main grid connecting lines. Even if the lap is broken at a partial position of the solder strip, causing a broken circuit, the current can still be conducted from the two side main grid connecting lines to the nearest soldering point and the solder strip to form a loop. Thus, the adverse effects caused by the soldering broken grid are reduced. That is, by using the grid line form of the multiple main grid connecting lines, the current loop is formed from the two side connecting lines in the case of soldering strip soldering at the soldering position, thereby ensuring current conduction.
[0043] The structure of the solar cell provided by some embodiments of the present application will be described below in conjunction with Figure 7 to Figure 13
[0044] As Figure 7 to Figure 13 As shown, some embodiments of this application provide a solar cell including a substrate 10 and a first grid line structure 11 and a second grid line structure 12 located on the surface of the substrate 10. There are multiple first grid line structures 11, and the multiple first grid line structures 11 are arranged along a first direction (…). Figure 9 The first gate line structure 11 is arranged at intervals along the second direction (as indicated by the middle arrow A), and each first gate line structure 11 includes lines arranged at intervals along the second direction (as indicated by the middle arrow A). Figure 9 The first main gate 111 and the second main gate 112 extend in the direction indicated by the middle arrow B, and there are welded portions 113 spaced apart along the second direction between the first main gate 111 and the second main gate 112. There are multiple second gate line structures 12, which are spaced apart along the first direction. Each second gate line structure 12 includes multiple second sub-gate lines 121 spaced apart along the second direction. Each second sub-gate line 121 extends in the first direction, and at least one end of each second sub-gate line 121 is connected to the first main gate 111 or the second main gate 112. The first direction and the second direction intersect.
[0045] The substrate 10 is the basis for forming the grid electrodes of the solar cell, and is typically a silicon substrate 10. Metal paste can be printed on the front and back sides of the substrate 10 to form grid electrodes with specific patterns. The grid electrodes printed on the front side of the substrate 10 are called front electrodes 110, and the grid electrodes printed on the back side of the substrate 10 are called back electrodes. Generally, the front side of the substrate 10 is the light-receiving surface, receiving solar energy from directly incident light, while the back side of the substrate 10 is the back-lighting surface, receiving solar energy from scattered and refracted light. Grid electrodes can be printed on one or both sides of the substrate 10 to form a single-sided or double-sided cell. Figure 7 Let's take a single-sided battery as an example. Figure 8 and Figure 9 The grid pattern on the surface of a solar cell is shown.
[0046] The first gate line structure 11 and the second gate line structure 12 are formed in different regions on the surface of the substrate 10. Figure 10 and Figure 11 The first gate structure 11 is shown. Figure 12 and Figure 13The second grid line structure 12 is shown. The second grid line structure 12 is formed on both sides of each first grid line structure 11. The first grid line structure 11 and the second grid line structure 12 can be printed by different screens to form the main grid and the auxiliary grid on the surface of the solar cell. In different grid line structures, the first main grid 111 and the second main grid 112 form the main grid of the solar cell, and the solder pad is distributed on the main grid. The second sub-grid line 121 forms the auxiliary grid of the solar cell by connecting with the main grid. The welding part 113 is distributed between the first main grid 111 and the second main grid 112, which facilitates welding with the solder strip and ensures the welding effect of the solder strip. Even if the local position has a welding broken grid phenomenon, the current can be transmitted to the nearest position with good welding of the solder strip through the first main grid 111 or the second main grid 112 at this position, thereby reducing the adverse effects of the welding broken grid.
[0047] The main grid and the auxiliary grid are arranged at intervals on the surface of the substrate 10, and the extension directions of the two, i.e., the first direction and the second direction, can be two directions perpendicular to each other or two directions with other included angles. In actual situations, the number of main grids can be 9, 12, 13, 15, 16, 18, or 20. Each main grid can be designed with two grid lines of the first main grid 111 and the second main grid 112, or more than two grid lines. The number of auxiliary grids can be 45, 50, 55, 60, 65, 70, or 75. In addition, the solar cell provided by some embodiments of the present application can be an integral cell or a half-cell, which is formed by dividing the integral cell along a direction perpendicular to the main grid.
[0048] The solar cell provided by some embodiments of the present application is designed with the first grid line structure 11 and the second grid line structure 12 on the surface of the substrate 10. The first main grid 111 and the second main grid 112 of the first grid line structure 11 form a multi-grid line structure of the main grid. The second sub-grid line 121 of the plurality of second grid line structures 12 forms an auxiliary grid by connecting with the main grid. The plurality of second sub-grid lines 121 of each second grid line structure 12 are connected by the first main grid 111 or the second main grid 112. The multi-grid line structure of the main grid formed by the first main grid 111 and the second main grid 112 can ensure that the current forms a loop from the two-side main grid lines in the case of welding broken grid at the soldering position, thereby ensuring the conduction of the current. The adverse effects caused by welding melting are reduced.
[0049] In some embodiments, the first main grid 111 and the second main grid 112 are arranged in parallel, and the distance between the first main grid 111 and the second main grid 112 is greater than or equal to 0.6 mm.
[0050] The first main grid 111 and the second main grid 112 form a main grid structure in the form of double connection lines. The first main grid 111 and the second main grid 112 are kept in parallel state, facilitating the printing and forming of the grid lines, and being conducive to simplifying the form of the full opening steel screen plate slotting. At the same time, by making the distance between the first main grid 111 and the second main grid 112 greater than or equal to 0.6 millimeters, enough space can be reserved between the first main grid 111 and the second main grid 112 for the setting of the welding part 113. The welding part 113 can form enough extension length to ensure the welding effect with the welding strip. At the same time, even if the middle part of the welding part 113 is welded to be broken, it will not affect the connection effect between the welding strip and the grid lines on both sides of the main grid. In actual cases, the distance between the first main grid 111 and the second main grid 112 can be 0.6 millimeters, 0.7 millimeters, 0.8 millimeters, 0.9 millimeters, 1.0 millimeter, 1.1 millimeter or 1.2 millimeter.
[0051] In some embodiments, the first main grid 111 and the second main grid 112 can be arranged in a curved shape, so that the first main grid 111 and the second main grid 112 are equidistantly arranged in the second direction.
[0052] For example, the first main grid 111 and the second main grid 112 can be arranged in a wave shape or a zigzag shape. By adopting a non-linear main grid structure, part of the main grid can enter the welding area of the welding strip, thereby avoiding the light from reaching the surface of the substrate 10. This is conducive to reducing the light shielding area.
[0053] At the same time, the first main grid 111 and the second main grid 112 are equidistantly arranged in the second direction, that is, in the second direction, the first main grid 111 and the second main grid 112 have the same spacing. This can make the length of each welding part 113 consistent, facilitating the printing and manufacturing of the welding part 113.
[0054] In addition, the width of the first main grid 111 in the first direction can be equal to the width of the second main grid 112 in the first direction.
[0055] The first main grid 111 and the second main grid 112 together form a main grid, and both can play a role in transmitting current in the extension direction of the main grid. By keeping the width of the first main grid 111 and the second main grid 112 the same, it is convenient to control the opening width of the full opening steel screen plate, and facilitate the manufacturing of the screen plate. In actual cases, the width of the first main grid 111 in the first direction can be different from the width of the second main grid 112 in the first direction. When the first main grid 111 or the second main grid 112 is arranged with a larger width, the current transmission capacity of the main grid can be ensured. When the first main grid 111 or the second main grid 112 is arranged with a smaller width, it is conducive to reducing the light shielding area, saving the electrode paste material, and reducing the production cost.
[0056] In some embodiments, the welding portion 113 may include a first welding portion 1131 and a second welding portion 1132, wherein the projected area of the first welding portion 1131 on the substrate 10 is greater than the projected area of the second welding portion 1132 on the substrate 10.
[0057] The first welding portion 1131 forms the main pad of the main gate. The first welding portion 1131 can be set in a regular shape such as square, rectangle, or trapezoid, or it can be set in an irregular shape. The first welding portion 1131 can ensure that there is a sufficient welding area between it and the solder strip, and ensure the local connection strength of the solder strip. The second welding portion 1132 forms the local solder joint of the main gate. The second welding portion 1132 has a smaller area, which helps to increase the number of solder joints and ensure the overall welding effect of the solder strip.
[0058] In practice, the length of the first welded part 1131 in the first direction can be greater than or equal to 0.6 mm and less than or equal to 1.2 mm, and the width of the first welded part 1131 in the second direction can be greater than or equal to 0.4 mm and less than or equal to 0.8 mm.
[0059] like Figure 11 As shown, the first welding portion 1131 is rectangular. By controlling the area of the first welding portion 1131, it can be ensured that the welding tensile strength after welding the weld strip meets or exceeds the qualified standard. The length of the long side of the first welding portion 1131 can be controlled between 0.6 mm and 1.2 mm, for example, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, or 1.2 mm. The length of the short side of the first welding portion 1131 can be controlled between 0.4 mm and 0.8 mm, for example, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, or 0.8 mm. By controlling the size range of the first welding portion 1131, it is possible to avoid the first welding portion 1131 being too large, thus increasing the light-blocking area, and also to avoid the first welding portion 1131 being too small, thus failing to ensure the welding strength of the weld strip.
[0060] In some embodiments, the first welding portion 1131 and the second sub-gate line 121 may be offset in a first direction.
[0061] By staggering the first weld portion 1131 from the second sub-gate line 121, i.e., by placing the first weld portion 1131 between two adjacent sub-gates, the sub-gates can avoid the welding range of the first weld portion 1131. This reduces the possibility of the sub-gate melting during the welding of the solder strip and the first weld portion 1131.
[0062] In practice, the projection shape of the first welding part 1131 on the surface of the substrate 10 can be any one of rectangle, square, circle, ellipse and trapezoid.
[0063] That is, the first soldering portion 1131 can adopt different shape designs. When the pad formed by the first soldering portion 1131 adopts different shape designs, the application requirements in different situations can be adapted while facilitating the connection of the solder strip. For example, the first soldering portion 1131 can be set to be rectangular or square to simplify the printing manufacturing of the first soldering portion 1131. The first soldering portion 1131 can also be set to be circular or elliptical to save the use of paste and reduce the production cost.
[0064] In some embodiments, the width of the second soldering portion 1132 in the second direction can gradually decrease from both ends to the middle.
[0065] The second soldering portion 1132 forms the part of the sub-grid between the first main grid 111 and the second main grid 112. By making the part of the second soldering portion 1132 close to the two main grids have a larger width, it can be ensured that the second soldering portion 1132 forms good contact with the first main grid 111 and the second main grid 112. Even if the middle part of the second soldering portion 1132 has a soldering fuse phenomenon, it can also ensure that the solder strip forms a current path with different main grids.
[0066] In addition, the shape of the second soldering portion 1132 can be any one of a straight line type, a wave type, a curve type, and a broken line type.
[0067] By setting the second soldering portion 1132 to be linearly extended, the printing manufacturing of the second soldering portion 1132 can be facilitated. At the same time, the use of paste is reduced. In actual situations, the second soldering portion 1132 can also be thickened to facilitate soldering with the solder strip. Or the second soldering portion 1132 can be set to an elliptical or rhombus shape, etc., which is wide in the middle and narrow at both ends, to increase the contact area during soldering. The second soldering portion 1132 can also be set to be point-shaped arranged in sequence along a straight line. The shape of the point can be a regular shape such as a circle, or other irregular shapes. Similarly, the contact area at the local position during soldering can be increased to facilitate soldering with the solder strip.
[0068] In some embodiments, the width of the second soldering portion 1132 in the second direction can be greater than the width of the second sub-grid line 121 in the second direction.
[0069] By making the width of the second soldering portion 1132 in the second direction greater than the width of the second sub-grid line 121 in the second direction, the soldering performance of the second soldering portion 1132 can be ensured. In the first direction, different second sub-grid lines 121 can form a complete sub-grid together with the second soldering portion 1132. Compared with the second sub-grid line 121 being set to be narrow, by widening the second soldering portion 1132, the contact area during soldering of the solder strip can be increased to facilitate soldering with the solder strip while ensuring the current transmission capability.
[0070] In practice, the number of welded portions 113 in each first gate structure 11 can be the same as the number of second sub-gate lines 121 in each second gate structure 12.
[0071] That is, each of the multiple second sub-gate lines 121 distributed along the second direction corresponds one-to-one with a multiple welding portion 113 distributed along the second direction. The ends of the second sub-gate lines 121 are set with different welding portions 113. This facilitates positioning during gate line printing and also helps ensure the formation of a complete sub-gate extending in a straight direction.
[0072] In some embodiments, the electrode paste of the first main gate 111, the electrode paste of the second main gate 112, and the electrode paste of the welding portion 113 may be the same.
[0073] In other words, all parts of the first grid structure 11 use the same electrode paste system, that is, they are printed using the main grid paste. This helps to reduce the cost of paste usage. Furthermore, using the main grid paste to print the welded part 113 allows for the utilization of the welding characteristics of the main grid paste to ensure that the welding pull force after welding the welded strip in the welded part 113 reaches the qualified pull force value.
[0074] like Figure 14 and Figure 15 As shown, some embodiments of this application also provide a photovoltaic module. The photovoltaic module includes a cell string 120, an encapsulating film 130, and a cover plate 140. The cell string 120 is formed by connecting multiple of the above-described solar cells. The encapsulating film 130 is used to cover the surface of the cell string 120. The cover plate 140 is used to cover the surface of the encapsulating film 130 facing away from the surface of the cell string 120.
[0075] in, Figure 14 The solar cells are arranged in a direction parallel to the cover plate 140. Figure 15 The solar cells are arranged in a direction that is inclined relative to the cover plate 140°.
[0076] In the cell string 120 used in the photovoltaic module, the main grid in the surface grid structure of each solar cell adopts a multi-connection line form. When a grid breakage occurs in part of the weld 113 of the grid structure, different main grids can still guide the current through the nearest weld 113 to the solder strip, thereby improving the reliability of the grid structure.
[0077] Those skilled in the art will understand that the above embodiments are specific implementations of this application, and in practical applications, various changes can be made in form and detail without departing from the spirit and scope of this application.
Claims
1. A solar cell, characterized in that, It includes a substrate and a first gate line structure and a second gate line structure located on the surface of the substrate; There are multiple first gate line structures, and the multiple first gate line structures are arranged at intervals along a first direction. Each first gate line structure includes a first main gate and a second main gate extending along a second direction, and there are welded portions arranged at intervals along the second direction between the first main gate and the second main gate. There are multiple second gate line structures, which are spaced apart along the first direction. Each second gate line structure includes multiple second sub-gate lines spaced apart along the second direction. Each second sub-gate line extends along the first direction, and at least one end of each second sub-gate line is connected to the first main gate or the second main gate. The first direction intersects the second direction.
2. The solar cell according to claim 1, characterized in that, The first main gate and the second main gate are arranged in parallel, and the distance between the first main gate and the second main gate is greater than or equal to 0.6 mm.
3. The solar cell according to claim 1, characterized in that, The first main gate and the second main gate are configured in a curved shape, and the first main gate and the second main gate are equidistant in the second direction.
4. The solar cell according to claim 1, characterized in that, The welding part includes a first welding part and a second welding part, wherein the projected area of the first welding part on the substrate is greater than the projected area of the second welding part on the substrate.
5. The solar cell according to claim 4, characterized in that, The length of the first welded part in the first direction is greater than or equal to 0.6 mm and less than or equal to 1.2 mm, and the width of the first welded part in the second direction is greater than or equal to 0.4 mm and less than or equal to 0.8 mm.
6. The solar cell according to claim 4, characterized in that, The first welding portion and the second sub-gate line are offset from each other in the first direction.
7. The solar cell according to claim 4, characterized in that, The width of the second welded portion in the second direction gradually decreases from both ends toward the middle.
8. The solar cell according to claim 4, characterized in that, The width of the second welded portion in the second direction is greater than the width of the second sub-gate line in the second direction.
9. The solar cell according to claim 1, characterized in that, The number of welded portions in each of the first grid structures is the same as the number of second sub-grid lines in each of the second grid structures.
10. The solar cell according to claim 1, characterized in that, The electrode paste of the first main grid and the electrode paste of the second main grid are the same as the electrode paste of the welding part.