Photovoltaic module and method for manufacturing photovoltaic module

Abstract

The present application discloses a photovoltaic module and a method for manufacturing the photovoltaic module. The photovoltaic module comprises cells, ribbons, busbars, and insulating blocks; the back surface of each cell is provided with fine gate electrodes and a first insulating layer; the ribbons include a first ribbon and a second ribbon, the first ribbon is electrically connected to the fine gate electrodes having a first polarity, and the second ribbon is electrically connected to the fine gate electrodes having a second polarity; the insulating blocks are respectively located on the back surfaces of the cells, the insulating blocks and the first insulating layers are alternately arranged in the direction of extension of the fine gate electrodes, and the insulating blocks cover some of the fine gate electrodes having the second polarity and part of the second ribbon; the first insulating layers cover some of the fine gate electrodes having the second polarity; the busbars are respectively located in the regions of the back surfaces of the cells corresponding to the first insulating layers and the insulating blocks, the busbars extend in the length direction of the fine gate electrodes, the length direction of the fine gate electrodes is the same as the direction of extension of the fine gate electrodes, the busbars are electrically connected to the first ribbon, and the busbars are electrically isolated from the second ribbon by means of the insulating blocks; the busbars are electrically isolated from the fine gate electrodes having the second polarity by means of the insulating blocks and the first insulating layers that are alternately arranged.

Description

Photovoltaic modules and photovoltaic module manufacturing methods Technical Field

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

[0002] A photovoltaic module consists of multiple cell strings, and each cell string is composed of multiple cells welded together by solder strips. The solder strips on each cell string and the solder strips between adjacent cell strings are usually electrically connected by busbars.

[0003] To reduce the ineffective area occupied by the busbars in photovoltaic modules, the busbars are placed on the back of the solar cells. This requires insulating the busbars from the electrodes on the solar cells and from the solder strips that have an opposite conductivity to the busbars. Currently, the insulation structure for the busbars on photovoltaic modules is quite complex, and the insulation stability needs further improvement. Summary of the Invention

[0004] The purpose of this application is to provide a photovoltaic module that simplifies the insulation structure and improves insulation stability.

[0005] In a first aspect, this application provides a photovoltaic module, including solar cells, solder ribbons, busbars and insulating blocks, wherein the back side of the solar cells has fine grid electrodes and a first insulating layer;

[0006] The solder strip includes a first solder strip and a second solder strip, wherein the first solder strip is electrically connected to a fine gate electrode of a first polarity, and the second solder strip is electrically connected to a fine gate electrode of a second polarity;

[0007] The insulating block is located on the back of the solar cell. The insulating block and the first insulating layer are arranged alternately along the extension direction of the fine grid electrode. The insulating block covers part of the second polarity fine grid electrode and part of the second solder strip; the first insulating layer covers part of the second polarity fine grid electrode.

[0008] The busbar is located on the back of the battery cell in the area corresponding to the first insulating layer and the insulating block, and the busbar extends along the length direction of the fine grid electrode, the length direction of the fine grid electrode being the same as the extension direction of the fine grid electrode.

[0009] The busbar is electrically connected to the first welding strip, and the busbar is electrically isolated from the second welding strip through an insulating block; the busbar is electrically isolated from the fine grid electrode of the second polarity through alternately arranged insulating blocks and the first insulating layer.

[0010] When the above technical solution is adopted, for the case where a busbar is set on the back of the battery cell, a first insulating layer and an insulating block are alternately arranged along the extension direction of the fine grid electrode at the position corresponding to the busbar on the back of the battery cell. The insulating block covers part of the fine grid electrode of the second polarity and part of the second solder strip, and the first insulating layer covers part of the fine grid electrode of the second polarity. The busbar is electrically connected to the first solder strip, and the busbar is electrically isolated from the second solder strip through the insulating block. The busbar is electrically isolated from the fine grid electrode of the second polarity through the alternately arranged insulating blocks and the first insulating layer.

[0011] First, this application allows the busbar to be positioned at any location on the back of the solar cell, extending along the length of the fine grid electrode. The position of the busbar is flexible and diverse; it only requires printing a first insulating layer and laying an insulating block at the corresponding busbar location to achieve electrical isolation from the second polarity fine grid electrode and the solder strip. The insulating block is placed on the second solder strip. At the connection point between the busbar and the first solder strip, the busbar and the fine grid of the second polarity near the first solder strip are insulated by the first insulating layer. This eliminates any obstruction or spacer between the busbar and the first solder strip, making effective welding easier and reducing the problems of poor soldering and high welding difficulty when an insulating block is present near the first solder strip.

[0012] Furthermore, based on the arrangement of the busbars, solder strips, and insulating blocks on the back of the solar cells, a simpler layout and welding process can be chosen. That is, after all the solar cells are laid on the front encapsulation cover plate, the solder strips, busbars, and insulating blocks are uniformly laid on the back of the solar cells and fixed together. Compared with the original method of first making the solar cell strings, then arranging the solar cell strings and welding the busbars, this method simplifies the process, reduces the process difficulty, improves the manufacturing efficiency of solar modules, and increases the module yield.

[0013] In some possible implementations, the projections of the insulating block and the first insulating layer on the solar cell alternately connect, in which case the projections of the insulating block and the first insulating layer on the solar cell connect but do not overlap; or, the projections of the insulating block and the first insulating layer on the solar cell overlap, in which case the projections of the insulating block and the first insulating layer on the solar cell connect and have overlapping areas. With this configuration, when busbars are positioned corresponding to the areas of the insulating block and the first insulating layer, gaps in the length direction of the fine grid electrode between the insulating block and the first insulating layer are avoided by connecting the insulating block to the first insulating layer or by connecting and overlapping the insulating block to the first insulating layer. This prevents the fine grid electrode of the second polarity from being exposed at the gaps, better avoids conductive contact between the busbar and the underlying fine grid electrode of the second polarity, prevents short circuits, and improves insulation performance.

[0014] In some possible implementations, the length of the overlapping area between the insulating block and the first insulating layer projected onto the solar cell along the length direction of the fine grid electrode is 0.5 mm or more. Since the edges of the insulating block are uneven and some areas are thinner, and the edges of the first insulating layer may be shorter or thinner, ensuring that the overlapping area between the insulating block and the first insulating layer is 0.5 mm or more can prevent a decrease in insulation performance at the edges of the first insulating layer and the insulating block.

[0015] In some possible implementations, the back of the solar cell also has a second insulating layer. The first and second insulating layers are alternately arranged along the length of the busbar, and the second insulating layer covers the fine grid electrode of the first polarity. An insulating block is correspondingly stacked on top of the second insulating layer. By setting the second insulating layer to cover the fine grid electrode of the first polarity, the contact between the second solder strip and the fine grid electrode of the first polarity below can be avoided, improving insulation performance. At the same time, the second insulating layer only needs to be printed by extending the existing insulating adhesive printed on both sides of the second solder strip, without adding any additional process steps. The stacked insulating block enables the placement of the busbar, and the busbar is electrically isolated from the second solder strip through the insulating block. The alternating arrangement of the first and second insulating layers improves the versatility of the solar cell, making it convenient to use busbars of different polarities without the need for cell selection, thus improving manufacturing efficiency.

[0016] In some possible implementations, the difference between the length of the first insulating layer and the length of the second insulating layer along the length direction of the busbar is less than or equal to 2 mm; and / or, the difference between the width of the first insulating layer and the width of the second insulating layer along the width direction of the busbar is less than or equal to 2 mm. Thus, the lengths and / or widths of the first and second insulating layers are similar, improving the versatility of the solar cells and facilitating the use of busbars with different polarities without requiring cell selection, thereby improving manufacturing efficiency.

[0017] And / or, along the width direction of the busbar, the first insulating layer and the second insulating layer intersect; that is, the first insulating layer and the second insulating layer are alternately connected along the length direction of the busbar. The repetitive arrangement simplifies the printing pattern of the first insulating layer and the second insulating layer, improves the versatility of the first insulating layer and the second insulating layer, facilitates the use of busbars with different polarities, eliminates the need to select solar cells, and improves manufacturing efficiency.

[0018] And / or, the first and second insulating layers are made of the same material and have the same thickness. In this way, the first and second insulating layers can be printed simultaneously on the battery using the same printing process, simplifying the manufacturing process and improving manufacturing efficiency.

[0019] And / or, the first and second insulating layers are transparent adhesive layers. Using transparent adhesive layers for the first and second insulating layers can improve the light utilization rate of the solar cells.

[0020] In some possible implementations, the insulating block is a rectangular insulating block; this can prevent the insulating block from intruding between the busbar and the first solder strip, reduce the risk of poor soldering between the busbar and the first solder strip, and at the same time reduce the height difference caused by the insulating block, thus reducing the risk of microcracks.

[0021] Along the width direction of the busbar, the width of the insulating block is 1mm to 5mm wider than the width of the busbar.

[0022] Along the length of the busbar, the length of the insulating block is 0.5 mm to 4 mm longer than the length of the second insulating layer that is stacked with the insulating block.

[0023] With the above technical solution, the width of the insulating block can ensure the insulation effect between the busbar and the second solder strip. The length of the insulating block is longer than the length of the second insulating layer stacked with it, which allows the edge of the insulating block to overlap with the edge of the adjacent first insulating layer. This avoids gaps between the insulating block and the first insulating layer in the length direction of the fine gate electrode, and prevents the fine gate electrode of the second polarity from being exposed at the gap. This can better prevent the busbar from making conductive contact with the fine gate electrode of the second polarity below, prevent short circuits, and improve insulation performance. In addition, the length and width of the insulating block are not too large, reducing light shading and saving materials.

[0024] In some possible implementations, the pattern of the second insulating layer on all cells in a photovoltaic module is identical, and the pattern of the first insulating layer on all cells in a photovoltaic module is identical. Thus, during production, there is no need to distinguish between cells used to connect to busbars and cells not connected to busbars, improving the versatility of all cells. It also eliminates the need to individually select cells with specific insulating layer patterns, significantly reducing processes and increasing production efficiency.

[0025] In some possible implementations, the end of the insulating region consisting of the first insulating layer and the insulating block extends 1 mm to 5 mm beyond the end of the busbar along the length of the busbar.

[0026] In the width direction of the busbar, the side of the insulating region composed of the first insulating layer and the insulating block extends 1mm to 5mm beyond the side of the busbar;

[0027] Furthermore, in the thickness direction of the battery cell, the insulation distance between the busbar and the second solder strip and the fine grid electrode of the second polarity is greater than or equal to 10 μm.

[0028] With the above technical solution, the dimensional relationship between the insulating region and the busbar meets the insulation requirements while saving material in the insulating region and preventing warping due to the first insulating layer being too large relative to the busbar. The busbar's location within the insulating region ensures more reliable insulation between the busbar and the second polarity fine gate electrode and the second solder strip. The insulation distance between the busbar and the second solder strip and the second polarity fine gate electrode is greater than or equal to 10 μm, guaranteeing reliable insulation between the busbar and the second solder strip and the second polarity fine gate electrode.

[0029] In some possible implementations, the insulating block is made of tape, which is adhered to the solar cell. By adhering it to the solar cell, compared to placing it directly on the solar cell, the insulating block can be pre-fixed to the solar cell, preventing displacement of the insulating block during module movement and lamination, ensuring insulation reliability. Furthermore, the tape is a flexible material, which can reduce the risk of crushing the solar cell.

[0030] In some possible implementations, the busbar is located at a non-edge position of a solar cell.

[0031] In some possible implementations, the busbar is located at the edge of a solar cell. In this case, when setting the busbar, it is not necessary to consider the positions of two solar cells simultaneously in terms of the width of the busbar, and covering only one solar cell can avoid the imbalance of load-bearing force caused by the positional height difference between the two solar cells in the thickness direction, which can easily lead to microcracks in the solar cell.

[0032] In some possible implementations, a busbar covers a portion of the preceding cell and a portion of the following cell; the coverage width of the busbar on the preceding cell is 1mm to 5mm, the coverage width of the busbar on the following cell is 1mm to 5mm, and the spacing between the preceding and following cells is 0.9mm to 2mm.

[0033] With the above technical solution, the busbar can be located at the edge or non-edge position on the back of the solar cell, or simultaneously cover parts of two adjacent solar cells. This expands the selection range of busbar placement positions on the back of the solar cell, facilitating busbar placement. The appropriate position on the back of the solar cell can be selected based on the cell layout and current transmission requirements. Furthermore, the structure described in this application ensures reliable insulation between the busbar and the fine grid electrode and second solder strip of the second polarity on the solar cell. When the busbar simultaneously covers parts of two adjacent solar cells, it can be designed to be thin and wide, ensuring current transmission efficiency while avoiding microcracks caused by excessive thickness. In this case, the busbar can avoid the risk of microcracks or short circuits due to excessive stress on a single solar cell, thus dispersing the stress of busbar stacking and improving module yield.

[0034] In some possible implementations, the first insulating layer comprises a plurality of parallel strip structures, or a plurality of discrete block structures, or a rectangular block; and / or, the second insulating layer comprises a plurality of parallel strip structures, or a plurality of discrete block structures, or a rectangular block. When both the first and second insulating layers are rectangular blocks, they can be connected to form a large, continuous rectangular block.

[0035] In some possible implementations, the connection length between the busbar and a first solder strip is greater than or equal to 20% of the width of the busbar along the width direction of the busbar. This configuration ensures that the welded interconnection area between the first solder strip and the busbar is sufficient to meet conductivity transmission performance and weld reliability, while reducing current loss.

[0036] In some possible implementations, solder strips fixed on the busbar are aligned or connected along the width of the busbar. Aligning the solder strips on the busbar reduces the creepage distance difference of the module along the length of the busbar, reduces the side length of the photovoltaic module, and reduces the blank area of ​​the photovoltaic module. Connecting the solder strips on the busbar reduces current loss.

[0037] In some possible implementations, the photovoltaic module also includes a buffer film located between the busbar and the back sealing film of the photovoltaic module. The buffer film covers the busbar, so that when the busbar is under pressure, the buffer film cushions the area where the busbar is located, reducing the risk of microcracks in the solar cells.

[0038] In some possible implementations, the thickness of the buffer membrane is 200μm to 1000μm, and / or, the width of the buffer membrane is 0 to 100mm wider than the width of the busbar, and / or, the length of the buffer membrane is 0 to 5mm longer than the length of the busbar, and / or, the material of the buffer membrane is POE, EPE, or EVA. In this case, the choice of material ensures good buffering performance on the busbar; the design of the buffer membrane thickness balances buffering performance and layer thickness, avoiding lamination bubbles caused by excessive thickness; and the design of the buffer membrane width and length ensures that the buffer membrane covers the entire busbar, reducing uneven local stress.

[0039] In some possible implementations, the busbar is located on the side of the first and second solder strips facing away from the solar cell. The height difference between the positions of the busbar corresponding to the first solder strip and the corresponding positions to the second solder strip is less than or equal to 100mm; and the cross-sections of both the first and second solder strips are rectangular. The busbar is positioned above the solder strips, which avoids bending of the solder strips when the busbar is below, reducing the risk of microcracks. The height difference between the positions of the two polarity solder strips is not too large, which can prevent uneven stress on the solar cell caused by excessive height difference, thus avoiding microcracks. The solder strips are flat, which increases the contact area with the solar cell and reduces pressure. When the solder strips are under pressure, this reduces the risk of microcracks in the solar cell.

[0040] In some possible implementations, the distance between the cover plate and the backsheet of the photovoltaic module is A, and the sum of the thicknesses of either the first or second solder strip, the solar cell, and the fine grid electrode is B, where B is less than 79% of A. The sum of the thicknesses of the solar cell, the fine grid electrode, and the solder strip being less than 79% of the distance between the cover plate and the backsheet provides sufficient thickness space for the encapsulant layer, which has a buffering and fixing effect, improving the buffering and fixing effect and reducing the risk of microcracks in the solar cell.

[0041] In some possible implementations, the photovoltaic module includes m rows of cells, and each row of cells includes two or more cell strings; the spacing between adjacent cells in a row is 0–2 mm, or multiple cells in a cell string are arranged in shingled configurations, with the width of the overlap area between adjacent cells in each cell string being 0.3 mm–2 mm. This type of photovoltaic module reduces both the cell spacing and string spacing, thereby increasing the power output per unit area of ​​the photovoltaic module.

[0042] In some possible implementations, for each edge of the cover plate of the photovoltaic module, the solar cell assembly, composed of individual cells, has a minimum distance from that edge, with all minimum distances differing by less than 0.5 mm. This results in smaller differences in the distances of the solar cell assembly from the corresponding edges of the cover plate, reducing the side length of the photovoltaic module and increasing its power-to-weight ratio.

[0043] In some possible implementations, the thickness of the encapsulating film of the photovoltaic module corresponding to the busbar is less than the thickness of the encapsulating film at other locations. This ensures uniform stress distribution throughout the cell, reducing the risk of microcracks. And / or, in the thickness direction of the cell, there is a portion of back-side encapsulating material between the busbar and the first insulating layer. This portion of back-side encapsulating material between the busbar and the first insulating layer acts as a buffer between the busbar and the cell, further reducing the risk of microcracks.

[0044] In some possible implementations, at least one end of the busbar is connected to the outermost first solder strip along its length, and the end of the busbar extends more than 1 mm beyond the outermost first solder strip or covers at least 80% of the width of the outermost first solder strip. This allows for sufficient welding with the outermost first solder strip, or leaves sufficient welding process window, with the extended length facilitating connection to other leads of the photovoltaic module.

[0045] Secondly, this application also provides a method for manufacturing a photovoltaic module, comprising:

[0046] Insulating adhesive is printed on the back of the cell at the position corresponding to the busbar to form a first insulating layer that is spaced apart along the extension direction of the fine grid electrodes of the cell. The first insulating layer covers a portion of the fine grid electrodes of the second polarity.

[0047] Conductive adhesive is printed on the back pads of the solar cell;

[0048] Layout and welding: The front cover plate and front encapsulating film are laid out sequentially, and all the photovoltaic cells of the module are laid on the front encapsulating film, with all cells facing downwards. Solder strips, insulating blocks, and busbars are laid out and fixed on the back of all cells. The first solder strip is electrically connected to the fine grid electrode of the first polarity, and the second solder strip is electrically connected to the fine grid electrode of the second polarity. Insulating blocks and the first insulating layer are alternately arranged along the extension direction of the fine grid electrode, with the insulating blocks covering part of the fine grid electrode of the second polarity and part of the second solder strip. The busbar is located on the back of the cell in the area corresponding to the first insulating layer and the insulating block, and extends along the length direction of the fine grid electrode, which is the same as its extension direction. The busbar is electrically connected to the first solder strip, and electrically isolated from the second solder strip by the insulating block. The busbar is electrically isolated from the fine grid electrode of the second polarity by the alternately arranged insulating blocks and the first insulating layer.

[0049] A back-side encapsulation film and backsheet are laid on the back of all the solar cells and then laminated.

[0050] Using the above technical solution, a photovoltaic module with the same structure as the first aspect can be obtained. The beneficial effects can be found in the description of photovoltaic modules above, and will not be repeated here. In addition, after all the cells are laid on the front encapsulation cover plate, the welding ribbon, busbar and insulating block are uniformly laid on the back of the cells and fixed together. Compared with the original method of first making the cell strings and then arranging the cell strings and welding the busbars, it can simplify the layout and welding process, reduce the process difficulty, improve the photovoltaic module manufacturing efficiency and improve the module yield.

[0051] In some possible implementations, solder strips, insulating blocks, and busbars are laid and secured on the back of all solar cells, including:

[0052] First, solder ribbons are laid on the back of all the solar cells; then, insulating blocks are laid on the back of all the solar cells, partially covering the second solder ribbons; finally, busbars are laid on the back of all the solar cells. This method facilitates the welding of the solder ribbons to the solar cells, as well as the welding of the busbars to the first solder ribbons, improving welding strength. Due to the simple stacked structure of the solder ribbons, insulating blocks, and busbars, the welding joints between the solder ribbons and busbars do not require bending, allowing the first solder ribbons to make flat contact with the solar cells, reducing the risk of microcracks caused by pressure on the first solder ribbons.

[0053] Alternatively, busbars can be laid on the back of all the solar cells first, followed by insulating blocks; finally, solder ribbons can be laid on the back of all the solar cells, with the busbars and the second solder ribbons electrically isolated by the insulating blocks. In this case, the solder ribbons are on top, allowing for convenient and quick visual inspection of the welding effect of the busbars.

[0054] In some possible implementations, the solder ribbon is laid and secured on the back of all solar cells, including: pre-secured with adhesive dots on all solar cells, and then secured with infrared, laser, or lamination methods. Pre-secured with adhesive dots ensures that the solder ribbon is less likely to shift during cell transfer and welding, improving welding accuracy. Attached Figure Description

[0055] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0056] Figure 1 is a schematic diagram of the structure of an insulating region in a photovoltaic module provided in an embodiment of this application;

[0057] Figure 2 is a schematic diagram of the arrangement structure of busbars in a photovoltaic module provided in an embodiment of this application;

[0058] Figure 3 is a schematic cross-sectional view of section AA in Figure 2;

[0059] Figure 4 is a schematic diagram of the arrangement structure of the busbars in another photovoltaic module provided in an embodiment of this application;

[0060] Figure 5 is a schematic cross-sectional view of section BB in Figure 4;

[0061] Figure 6 is a schematic diagram of the arrangement structure of the busbars in another photovoltaic module provided in an embodiment of this application;

[0062] Figure 7 is a schematic cross-sectional view of section CC in Figure 6;

[0063] Figure 8 is a schematic diagram of the arrangement structure of the busbars in another photovoltaic module provided in an embodiment of this application;

[0064] Figure 9 is a schematic diagram of another insulating region provided in an embodiment of this application;

[0065] Figure 10 is a schematic diagram of another insulating region provided in an embodiment of this application;

[0066] Figure 11 is a schematic diagram of another insulating region provided in an embodiment of this application.

[0067] Reference numerals in the attached figures: 1 for battery cell, 2 for insulating area, 21 for first insulating layer, 22 for second insulating layer, 23 for first insulating strip, 24 for insulating layer, 25 for second insulating strip, 3 for welding strip insulating component, 4 for welding strip, 41 for first welding strip, 42 for second welding strip, 5 for busbar, and 6 for insulating block. Detailed Implementation

[0068] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0069] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0070] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise expressly specified. "Several" means one or more, unless otherwise expressly specified.

[0071] In the description of this application, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They 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. Therefore, they should not be construed as limitations on this application.

[0072] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" 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; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0073] As shown in Figures 1-11, this application provides a photovoltaic module including a solar cell 1, solder ribbons 4, busbars 5, and an insulating block 6. The back side of the solar cell 1 has a fine grid electrode and a first insulating layer 21. For a back-contact cell, both the positive and negative electrodes are located on the back side of the solar cell 1. Accordingly, the fine grid electrode includes a positive fine grid electrode and a negative fine grid electrode. The positive and negative fine grid electrodes are each connected to different solder ribbons 4 through electrical connection parts (such as solder pads, thickened sections of the fine grid, or electrical connection points connected to the fine grid, etc.), and the different solder ribbons 4 are connected to the corresponding busbars 5. The first insulating layer 21 is obtained by printing insulating adhesive on the area on the back side of the solar cell where the busbars 5 are to be installed. The first insulating layer 21 covers a portion of the second polarity fine grid electrode. The fine gate electrode covered by the first insulating layer is mainly a second polarity fine gate electrode that is adjacent to the first solder strip. Covering the second polarity fine gate electrode that is adjacent to the first solder strip with the first insulating layer can insulate the first solder strip and the second polarity fine gate electrode and prevent the first solder strip and the second polarity fine gate electrode from being electrically connected. In this sense, the second polarity fine gate electrode covered by the first insulating layer in order to achieve the insulation of the first solder strip and the second polarity fine gate electrode and prevent the first solder strip and the second polarity fine gate electrode from being electrically connected can all be considered as "second polarity fine gate electrode that is adjacent to the first solder strip". The first solder strip 41 is electrically connected to the fine grid electrode of the first polarity, and is insulated from the fine grid electrode of the second polarity. The second solder strip 42 is electrically connected to the fine grid electrode of the second polarity, and is insulated from the fine grid electrode of the first polarity. The insulating block 6 is located on the back side of the cell 1, and the insulating block 6 and the first insulating layer 21 are alternately arranged along the extension direction of the fine grid electrode. On the projection of the cell 1, the insulating block 6 covers part of the fine grid electrode of the second polarity, and on the projection of the cell 1 or the backsheet of the photovoltaic module, the insulating block 6 covers part of the second solder strip 42. The busbar 5 is located on the back side of the cell 1 in the area corresponding to the first insulating layer 21 and the insulating block 6, and the busbar 5 extends along the length direction of the fine grid electrode, the length direction of the fine grid electrode being the same as the extension direction of the fine grid electrode. The busbar 5 is electrically connected to the first solder strip 41, and the busbar 5 is electrically isolated from the second solder strip 42 by the insulating block 6. The busbar 5 is electrically isolated from the fine grid electrode of the second polarity by the alternately arranged insulating blocks 6 and the first insulating layer 21.

[0074] For example, taking a battery string consisting of multiple half-cells connected in series, the busbar 5 extends along the direction parallel to the long side of the half-cell. As shown in Figures 2-8, one busbar 5 is electrically connected to the first solder strip 41 and electrically isolated from the second solder strip 42 by the insulating block 6. The first solder strip 41 is electrically connected to one of the positive and negative fine grid electrodes, and the second solder strip 42 is electrically connected to the other of the positive and negative fine grid electrodes. The solder strip 4 in this application is not limited to metal wire used for welding; it is sufficient to achieve a fixed and conductive connection between the battery cell 1 and the solder strip 4.

[0075] In the above technical solution, to reduce the ineffective area occupied by the busbars in the photovoltaic module, the busbars 5 are disposed on the back side of the cell 1. In this case, a first insulating layer 21 and an insulating block 6 are alternately disposed on the back side of the cell 1 at the position corresponding to the busbar 5 along the extension direction of the fine grid electrode. The insulating block 6 covers part of the second polarity fine grid electrode and part of the second solder strip 42, and the first insulating layer 21 covers part of the second polarity fine grid electrode. The busbar 5 is electrically connected to the first solder strip 41, and the busbar 5 is electrically isolated from the second solder strip 42 by the insulating block 6. The busbar 5 is electrically isolated from the second polarity fine grid electrode by the alternately arranged insulating blocks 6 and the first insulating layer 21. First, this application can place the busbar 5 at any position on the back side of the cell 1, extending along the length direction of the fine grid electrode. The position selection of the busbar 5 is relatively flexible and diverse. It is only necessary to print the first insulating layer 21 and lay the insulating block 6 at the position corresponding to the busbar 5 to achieve electrical isolation from the second polarity fine grid electrode and solder strip 4. The insulating block 6 is placed on the second solder strip 42 at the position where the busbar 5 connects to the first solder strip 41. The fine grid of the second polarity near the busbar 5 and the first solder strip 41 is insulated by the first insulating layer 21, so that there is no obstruction or pad between the busbar 5 and the first solder strip 41, which makes it easier to achieve effective welding and reduces the problems of poor welding and high welding difficulty when there is an insulating block 6 near the first solder strip 41.

[0076] Furthermore, based on the arrangement structure of the busbars 5, solder strips 4, and insulating blocks 6 on the back of the solar cell 1, a simpler layout and welding process can be selected. That is, after all the solar cells 1 are laid on the front encapsulation cover plate, the solder strips 4, busbars 5, and insulating blocks 6 are uniformly laid on the back of the solar cells 1 and fixed together. Compared with the original method of first making the solar cell strings, then arranging the solar cell strings and welding the busbars, this method simplifies the process, reduces the process difficulty, improves the manufacturing efficiency of the solar cell, and increases the yield of the module.

[0077] As shown in Figures 1 and 8, in some embodiments, the projections of the insulating block 6 and the first insulating layer 21 on the battery cell 1 alternately connect. In this case, the projections of the insulating block 6 and the first insulating layer 21 on the battery cell 1 connect but do not overlap; or, the projections of the insulating block 6 and the first insulating layer 21 on the battery cell 1 overlap. In this case, the projections of the insulating block 6 and the first insulating layer 21 on the battery cell 1 connect and have an overlapping area. As used herein, "connected" can mean in contact with each other or connected to each other. Exemplarily, the insulating block 6 may directly contact the back side of the battery cell 1 and directly connect with or directly connect with and overlap the first insulating layer 21; or, the insulating block 6 may not contact the back side of the battery cell 1 (related to the stacking order of the insulating block 6, solder strip 4, and busbar 5, the specific stacking structure of which will be described below), and may be spaced apart from the battery cell 1 in the thickness direction of the battery cell 1. Therefore, the projections of the insulating block 6 and the first insulating layer 21 on the battery cell 1 connect and have an overlapping area. With this configuration, when the busbar 5 is correspondingly positioned in the areas of the insulating block 6 and the first insulating layer 21, the connection between the insulating block 6 and the first insulating layer 21, or the connection and overlap between the insulating block 6 and the first insulating layer 21, avoids gaps in the length direction of the fine grid electrode between the insulating block 6 and the first insulating layer 21. This prevents the fine grid electrode of the second polarity from being exposed at the gaps, better preventing conductive contact between the busbar 5 and the fine grid electrode of the second polarity below, preventing short circuits, and improving insulation performance. Of course, in the thickness direction of the battery cell 1, if the insulation distance between the busbar 5 and the fine grid electrode of the second polarity is large enough, the insulating block 6 and the first insulating layer 21 may not be connected, or they may not be connected and may overlap.

[0078] In some embodiments, along the length direction of the fine grid electrode, the length of the overlapping area between the projection of the insulating block 6 and the first insulating layer 21 onto the battery cell 1 is 0.5 mm or more. Specifically, the length of the overlapping area can be 0.5 mm, 0.7 mm, 1 mm, 1.2 mm, 1.5 mm, 2 mm, 3 mm, or greater. Since the edges of the insulating block 6 are uneven and the thickness is relatively thin in some places, the edge position of the first insulating layer 21 may be shorter or less thick. The overlap between the insulating block 6 and the first insulating layer 21, with the length of the overlapping area being 0.5 mm or more, can prevent the insulation performance of the edge positions of the first insulating layer 21 and the insulating block 6 from deteriorating.

[0079] As shown in Figures 1 and 8, in some possible implementations, the back of the battery cell 1 also has a second insulating layer 22. The first insulating layer 21 and the second insulating layer 22 are arranged alternately along the length of the busbar 5. The second insulating layer 22 can also be obtained by printing insulating adhesive on the back of the battery cell 1. The second insulating layer 22 can cover the fine grid electrode of the first polarity. The insulating block 6 is correspondingly stacked on top of the second insulating layer 22. By setting the second insulating layer 22 to cover the fine grid electrode of the first polarity, it is possible to prevent the second solder strip 42 from contacting the fine grid electrode of the first polarity below when the position is shifted, thereby improving the insulation performance. In addition, the second insulating layer 22 only needs to be printed by extending the solder strip insulation 3 printed below the second solder strip 42 on the back of the battery cell 1, without adding any additional process steps. The stacked insulating block 6 can realize the placement of the busbar 5, and the busbar 5 is electrically isolated from the second solder strip 42 through the insulating block 6. It should be understood that the first and second insulating layers are made of the same material as the solder strip insulation on the battery cell. The first insulating layer 21, the second insulating layer 22, and the insulating block 6 form the insulating region 2. The first insulating layer 21 and the second insulating layer 22 are arranged alternately, which improves the versatility of the battery cell 1 and makes it convenient to use the busbars 5 of different polarities. That is, the first insulating layer and the second insulating layer can be interchanged without the need to select the battery cell, thus improving the manufacturing efficiency.

[0080] Exemplarily, the first insulating layer 21 comprises a plurality of parallel strip structures, or the first insulating layer 21 comprises a plurality of discrete block structures, or the first insulating layer 21 is a rectangular block. Alternatively or additionally, the second insulating layer 22 comprises a plurality of parallel strip structures, or the second insulating layer 22 comprises a plurality of discrete block structures, or the second insulating layer 22 is a rectangular block. When both the first insulating layer 21 and the second insulating layer 22 are rectangular blocks, they can be connected to form a large, continuous rectangular block.

[0081] As shown in Figure 1, in some possible implementations, along the length direction of the busbar 5, the difference between the length of the first insulating layer 21 and the length of the second insulating layer 22 is less than or equal to 2 mm. Specifically, the length difference can be 0 mm, 0.2 mm, 0.5 mm, 0.8 mm, 1 mm, 1.2 mm, 1.5 mm, 1.8 mm, 2 mm, etc. Along the width direction of the busbar 5, the difference between the width of the first insulating layer 21 and the width of the second insulating layer 22 is less than or equal to 2 mm. Specifically, the width difference can be 0 mm, 0.2 mm, 0.5 mm, 0.8 mm, 1 mm, 1.2 mm, 1.5 mm, 1.8 mm, 2 mm, etc. The length of the first insulating layer 21 can be longer, shorter, or equal to the length of the second insulating layer 22, and the width of the first insulating layer 21 can be wider, narrower, or equal to the width of the second insulating layer 22. Thus, with the first insulating layer 21 and the second insulating layer 22 having similar lengths and / or widths, when the solder strips connected to the busbar 5 are swapped, the insulating block 6 is moved from above the second insulating layer 22 to above the first insulating layer 21. The second insulating layer 22 can still provide sufficient insulation for the busbar 5 and the fine grid below. The solar cells are highly versatile, eliminating the need for multiple cell designs, processing methods, and selection during production.

[0082] As shown in Figure 1, in some embodiments, the first insulating layer 21 and the second insulating layer 22 intersect along the width direction of the busbar 5; that is, the first insulating layer 21 and the second insulating layer 22 are alternately connected along the length direction of the busbar 5 (e.g., the end interdigitated design). The repetitive arrangement simplifies the printing pattern of the first insulating layer 21 and the second insulating layer 22, improves the versatility of the first insulating layer 21 and the second insulating layer 22, facilitates the use of busbars 5 with different polarities, eliminates the need to select the battery cell 1, and improves the manufacturing efficiency.

[0083] In some embodiments, the first insulating layer 21 and the second insulating layer 22 are made of the same material and have the same thickness. This allows the first insulating layer 21 and the second insulating layer 22 to be printed simultaneously on the battery cell 1 using the same printing process, simplifying the fabrication process and improving efficiency. It should be understood that having the same thickness allows for a certain degree of process error. Of course, the first insulating layer 21 and the second insulating layer 22 can also have different materials and thicknesses, which can be selected as needed.

[0084] In some embodiments, the first insulating layer 21 and the second insulating layer 22 are transparent adhesive layers. Using transparent adhesive layers for the first insulating layer 21 and the second insulating layer 22 can improve the light utilization rate of the solar cell 1.

[0085] As shown in Figure 8, in some possible implementations, along the width direction of the busbar 5, the width of the insulating block 6 is 1mm to 5mm wider than the width of the busbar 5, specifically 1mm, 2mm, 3mm, 4mm, 5mm, etc.; along the length direction of the busbar 5, the length of the insulating block 6 is 0.5mm to 4mm longer than the length of the second insulating layer 22 stacked with the insulating block 6, specifically 0.5mm, 1mm, 2mm, 3mm, 4mm, etc.

[0086] With the above technical solution, the width of the insulating block 6 can ensure the insulation effect between the busbar 5 and the second solder strip 42. The length of the insulating block 6 is longer than the length of the second insulating layer 22 stacked with it, so that there is an overlapping area between the edge of the insulating block 6 and the adjacent first insulating layer 21, so as to avoid the gap between the insulating block 6 and the first insulating layer 21 in the length direction of the fine gate electrode, and to prevent the fine gate electrode of the second polarity from being exposed at the gap. This can better prevent the busbar 5 from making conductive contact with the fine gate electrode of the second polarity below, prevent short circuits, and improve insulation performance. In addition, the length and width of the insulating block 6 are not too large, which can reduce light shading and save materials.

[0087] As shown in Figures 2, 4, and 6, in some embodiments, along the length of the busbar 5, the end of the insulating region 2, composed of the first insulating layer 21 and the insulating block 6, extends beyond the end of the busbar 5 by 1mm to 5mm, specifically 1mm, 2mm, 3mm, 4mm, 5mm, etc. Along the width of the busbar 5, the side of the insulating region 2, composed of the first insulating layer 21 and the insulating block 6, extends beyond the side of the busbar 5 by 1mm to 5mm, specifically 1mm, 2mm, 3mm, 4mm, 5mm, etc. Furthermore, along the thickness of the battery cell 1, the insulating distance between the busbar 5 and the second solder strip 42 and the second polarity fine grid electrode is greater than or equal to 10μm.

[0088] With the above technical solution, the dimensional relationship between the insulating region 2 and the busbar 5 satisfies the insulation requirements while saving material in the insulating region 2 and preventing warping due to the first insulating layer 21 being too large relative to the busbar. The busbar 5 being located within the insulating region 2 ensures more reliable insulation between the busbar 5 and the second polarity fine gate electrode and the second solder strip 42. The insulation distance between the busbar 5 and the second solder strip 42 and the second polarity fine gate electrode is greater than or equal to 10 μm, guaranteeing reliable insulation between the busbar 5 and the second solder strip 42 and the second polarity fine gate electrode. Even if there is incomplete shielding between the busbar 5 and the second polarity fine gate electrode, or between the busbar and the second solder strip 42, sufficient insulation distance can still ensure reliable insulation. The insulation distance between the busbar 5 and the second polarity fine gate electrode can be reflected by the thickness of the second insulating layer, or by the sum of the thicknesses of the second insulating layer and the insulating block. The insulation distance between the busbar 5 and the second solder strip 42 can be reflected by the thickness of the insulating block.

[0089] For example, the thickness of the first insulating layer 21 and the second insulating layer 22 can be 10 μm to 1000 μm.

[0090] In some embodiments, the insulating block 6 is an adhesive tape, which is adhered to the solar cell 1. By adhering it to the solar cell 1, compared to placing it directly on the solar cell 1, pre-fixation of the insulating block 6 to the solar cell 1 can be achieved, preventing displacement of the insulating block 6 during component movement and lamination, ensuring insulation reliability. Furthermore, the tape is a flexible material, which reduces the risk of crushing the solar cell 1. The insulating block can be a multilayer composite film, etc., and its color can be white, black, or other colors. The thickness of the insulating block is 50μm to 300μm.

[0091] In some embodiments, the insulating block 6 is a rectangular insulating block 6. In this way, the insulating block 6 can be prevented from encroaching between the busbar 5 and the first solder strip 41, reducing the risk of poor soldering between the busbar 5 and the first solder strip 41, while reducing the height difference caused by the insulating block 6 and reducing the risk of microcracks.

[0092] As shown in Figures 6 and 8, in some embodiments, the busbar 5 is located at a non-edge position of the solar cell 1. In the direction of series connection of the solar cells 1, the solar cell 1 has two edge positions and a non-edge position between the edge positions. Correspondingly, the first insulating layer 21, the second insulating layer 22, and the insulating block 6 are arranged at the non-edge position of the solar cell 1. As used herein, "edge position" refers to the position within the area between the edge pad and the edge of the solar cell; "non-edge position" refers to the position within the area where the edge pad is located and the area within the edge pad. Positions within these areas are all considered non-edge positions. Both the edge busbars and the middle busbars of the photovoltaic module can be located at the non-edge positions of their respective solar cells 1. Specifically, an edge busbar refers to a busbar located on a solar cell near the edge of the photovoltaic module, and a middle busbar refers to a busbar located on a solar cell near the center of the photovoltaic module. The central space of the solar cell 1 is relatively large, reducing the precision requirement for the placement of the busbar 5 and lowering the manufacturing complexity.

[0093] As shown in Figures 2 and 4, in some embodiments, the busbar 5 is located at the edge of the solar cell 1. Correspondingly, the first insulating layer 21, the second insulating layer 22, and the insulating block 6 are arranged at at least one edge of the solar cell 1. Both the edge busbars and the intermediate busbars of the photovoltaic module can be located at the edges of the solar cells 1 to which they are respectively disposed. The busbar 5 can exert a certain pressure on the edge-warped solar cell 1, thereby reducing the degree of warping and decreasing the risk of microcracks or cracks in the solar cell 1.

[0094] In some embodiments, a busbar 5 covers a portion of the preceding battery cell 1 and a portion of the following battery cell 1; the coverage width of the busbar 5 on the preceding battery cell 1 is 1mm to 5mm, specifically 1mm, 2mm, 3mm, 4mm, 5mm, etc.; the coverage width of the busbar 5 on the following battery cell 1 is 1mm to 5mm, specifically 1mm, 2mm, 3mm, 4mm, 5mm, etc.; the width of the busbar 5 covering the preceding battery cell 1 and the width covering the following battery cell 1 can be the same or different; the distance between the preceding battery cell 1 and the following battery cell 1 is 0mm to 2mm, that is, the distance between two adjacent battery cells 1 covered by the busbar is 0mm to 2mm, specifically 0mm, 1mm, 2mm, etc. Preferably, the distance between the preceding battery cell 1 and the following battery cell 1 is 0.9mm to 2mm, that is, the distance between two adjacent battery cells 1 covered by the busbar is 0.9mm to 2mm, specifically 0.9mm, 1mm, 2mm, etc. Specifically, a busbar 5 spans across and connects the preceding solar cell 1 and the following solar cell 1. Correspondingly, a first insulating layer 21 and a second insulating layer 22 are provided on the two adjacent edges of the preceding and following solar cells 1. An insulating block 6 spans and covers the edges of the preceding and following solar cells 1. Both the edge busbars and the middle busbars of the photovoltaic module can be arranged to span across the preceding and following solar cells 1.

[0095] With the above-mentioned busbar arrangements, the busbar 5 can be located at the edge or non-edge position on the back of the solar cell 1, or simultaneously cover parts of two adjacent solar cells 1. This expands the selection range of the busbar 5's placement position on the back of the solar cell 1, facilitating its placement. The appropriate position on the back of the solar cell 1 can be selected based on the cell's layout within the photovoltaic module and current transmission requirements. Furthermore, the structure described in this application ensures reliable insulation between the busbar 5 and the second polarity fine grid electrode and the second solder strip 42 on the solar cell 1. When the busbar 5 simultaneously covers parts of two adjacent solar cells 1, it can be designed to be thin and wide, ensuring current transmission efficiency while avoiding microcracks in the solar cell 1 caused by excessive thickness. In this case, the busbar 5 can avoid the risk of microcracks or short circuits caused by excessive stress on a particular solar cell 1, thus dispersing the stacking stress of the busbar 5 and improving the module yield.

[0096] In some embodiments, in the width direction of the busbar 5, one busbar 5 of the photovoltaic module covers only one solar cell 1. Covering only one solar cell 1 with one busbar 5 of the photovoltaic module facilitates the positioning and fixing of the busbar 5, without having to consider the positions of two solar cells 1 at the same time. Furthermore, covering only one solar cell 1 avoids the imbalance of load-bearing force caused by the positional height difference between the two solar cells 1 in the thickness direction, which can easily lead to microcracks in the solar cell 1.

[0097] In some embodiments, the first insulating layer 21 on all cells 1 in a photovoltaic module has the same pattern. If a cell 1 has a second insulating layer 22, then the pattern of the second insulating layer 22 on all cells 1 is also the same. For example, the patterns of the first and second insulating layers of each cell 1 are shown in Figure 1. With this configuration, during the production process, it is not necessary to distinguish between cell 1s used to connect to the busbar 5 and cell 1s not connected to the busbar, thereby improving the versatility of all cell 1s and eliminating the need to individually select cell 1s with insulating layers of specific patterns, thus improving manufacturing efficiency.

[0098] As shown in Figure 9, this embodiment provides a specific form of the first insulating layer 21 and / or the second insulating layer 22, namely, the first insulating layer 21 and / or the second insulating layer 22 are composed of multiple first insulating strips 23 arranged parallel to each other and spaced apart. The first insulating strips 23 extend continuously along the length direction of the busbar 5. Taking the first insulating layer 21 using the first insulating strips 23 as an example, the first insulating strips 23 cover the second polarity fine grid electrode of the battery cell 1. The fine grid electrode has multiple fine grid electrodes, which are parallel to the length direction of the busbar 5. The multiple fine grid electrodes are arranged at intervals along the width direction of the busbar 5. The fine grid electrodes include alternating positive fine grid electrodes and negative fine grid electrodes. Fine grid electrodes of the same electrical properties (such as one of the positive fine grid electrode and the negative fine grid electrode) are connected by solder ribbon 4. The solder ribbon 4 is electrically isolated from the fine grid electrodes of opposite conductivity (such as the other of the positive fine grid electrode and the negative fine grid electrode) by solder ribbon insulation 3. The solder ribbon insulation 3 can be printed on the cell 1 together with the first insulating layer 21. The solder ribbon insulation 3 is used to cover the fine grid electrodes of opposite conductivity near the solder ribbon 4, so that the solder ribbon 4 is electrically isolated from the fine grid electrodes of opposite conductivity below. The total width of the area between the two outermost first insulating strips 23 in the first insulating layer 21 is greater than the width of the busbar 5. These multiple first insulating strips 23 can support the busbar 5, creating a gap between the busbar 5 and the fine grid electrode of the second polarity of the solar cell 1. The first insulating strips 23 cover the fine grid electrode of the second polarity, achieving electrical isolation between the busbar 5 and the fine grid electrode. Simultaneously, these multiple first insulating strips 23 do not completely cover the edge of the solar cell 1, thus saving material in the insulating layer and reducing solar cell warping caused by the insulating strips. Specifically, the first insulating strips 23 can be insulating adhesive (such as green, black, or transparent insulating adhesive) printed on the back of the solar cell 1. Preparing the first insulating strips 23 through a printing process simplifies the process, improves preparation efficiency, and provides good adhesion to the back of the solar cell, resulting in high insulation stability.

[0099] It should be noted that when the second insulating layer 22 uses the first insulating strip 23, the first insulating strip 23 can cover the fine grid electrode of the first polarity. When both the first insulating layer 21 and the second insulating layer 22 use the first insulating strip 23, since the first insulating layer 21 and the second insulating layer 22 are arranged alternately along the length direction of the busbar 5, an insulating region structure as shown in Figure 1 can be obtained. The lengths of the first insulating strip 23 of the first insulating layer 21 and the first insulating strip 23 of the second insulating layer 22 can be the same, equal to the spacing between the first solder strip 41 and the second solder strip 42. The first insulating strip 23 of the first insulating layer 21 and the first insulating strip 23 of the second insulating layer 22 alternate in the width direction of the busbar 5.

[0100] Alternatively, as shown in Figure 9, the insulating region 2 composed of the first insulating layer 21 is composed of multiple continuous first insulating strips 23, that is, the first insulating layer 21 has a continuous and uninterrupted structure, covering the fine grid electrode of the second polarity, and the insulating block 6 covers the position corresponding to the second solder strip 42. Along the length direction of the fine grid electrode, the first insulating strip can also be a multi-segment structure. For example, depending on the number of solder strips, it can be set to 9 segments, 10 segments, 11 segments, 12 segments, 18 segments, 20 segments, 22 segments, 24 segments, etc.

[0101] Furthermore, the length of the first insulating strip 23 is 0.5mm to 1mm shorter than the edge length of the battery cell 1, specifically 0.5mm, 0.7mm, 0.8mm, 1mm, etc. The width of the first insulating strip 23 can be 0.2mm to 1mm, specifically 0.2mm, 0.4mm, 0.6mm, 0.8mm, 1mm, etc. The thickness of the first insulating strip 23 can be 10μm to 100μm, specifically 10μm, 30μm, 50μm, 70μm, 90μm, 100μm, etc. The dimensions of this first insulating strip 23 can meet the insulation requirements while saving on insulating strip material.

[0102] As shown in Figure 10, this embodiment provides a second form of the first insulating layer 21 and / or the second insulating layer 22, namely, the first insulating layer 21 and the second insulating layer 22 are insulating adhesive layers 24 that are integrally covered on the corresponding busbar 5 area of ​​the battery cell 1. The width of the insulating adhesive layer 24 is greater than the width of the busbar 5, and the thickness of the insulating adhesive layer 24 can be 10μm to 100μm, specifically 10μm, 30μm, 50μm, 70μm, 90μm, 100μm, etc. The insulating adhesive layer 24 can be insulating adhesive printed on the battery cell. The insulating adhesive layer 24 can support the entire surface of the busbar 5 and achieve electrical isolation between the busbar 5 and the fine grid electrode of the second polarity on the battery cell 1. At this time, not only is the insulation effect of the busbar 5 better, but it can also play a better role in protecting the fine grid electrode on the battery cell 1 and reducing the adverse effects of the welding heat of the fine grid silver busbar on the fine grid. The first insulating layer 21 and the second insulating layer 22 can be segmented insulating adhesive layers 24 or a continuous whole insulating adhesive layer 24, as shown in Figure 10. The busbar 5 is insulated from the second welding strip 42 by the insulating block 6 (not shown in Figure 10).

[0103] As shown in Figure 11, this embodiment provides a third form of the first insulating layer 21 and the second insulating layer 22, namely, the first insulating layer 21 and / or the second insulating layer 22 are multiple rows and columns of second insulating strips 25 arranged parallel to each other and spaced apart. Regardless of whether it is the first insulating layer 21 or the second insulating layer 22, part of the second insulating strip 25 covers the fine grid electrode of the second polarity, and / or, part of the second insulating strip 25 covers the fine grid electrode of the first polarity, and / or, part of the second insulating strip 25 is located between the fine grid electrode of the first polarity and the fine grid electrode of the second polarity. The third type of insulating layer does not require the second insulating strip 25 to cover the fine grid electrode of the second polarity. This insulating layer can partially support the busbar 5 and can achieve electrical isolation between the busbar 5 and the fine grid electrode of the second polarity on the battery cell 1 through spatial spacing. This insulating layer can save insulating layer material and can disperse the second insulating strip 25 to a large extent, shorten the length of the second insulating strip 25, further reduce the cell warping caused by the second insulating strip 25, and reduce microcracks in the battery cell. The second insulating strip 25 can be insulating adhesive printed on the battery cell. It should be understood that when the busbar 5 is connected to the battery cell 1 in Figure 11, the busbar 5 is electrically connected to the first solder strip 41, insulated from the second solder strip 42 by the insulating block 6, and isolated from the electrodes on the battery cell 1 by the second insulating strip 25.

[0104] Furthermore, the width of the second insulating strip 25 is 0.2mm to 1mm, the length of the second insulating strip 25 can be 0.5mm to 10mm, and the thickness of the second insulating strip 25 is 10μm to 100μm. This size can meet the electrical isolation requirements between the busbar 5 and the fine grid electrode of the second polarity on the battery cell 1, and can save the material of the insulating layer.

[0105] The above three types of insulating layers can be used as the first insulating layer 21 and / or the second insulating layer 22 of the edge busbar of the corresponding photovoltaic module, or as the first insulating layer 21 and / or the second insulating layer 22 of the corresponding middle busbar. All three are applicable and can be equipped with insulating blocks 6. When the solar cell 1 shown in Figures 9, 10, and 11 is connected to the busbar 5, the busbar 5 and the second solder strip 42 are isolated by the insulating block 6, which provides good insulation protection. At this time, the length of the solder strip at the end of the solar cell 1 has a large safety length.

[0106] In some embodiments, along the width direction of the busbar 5, the connection length between the busbar 5 and a first solder strip 41 is greater than or equal to 20% of the width of the busbar 5, specifically 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 100%, etc. This configuration ensures that the welding interconnection area between the first solder strip 41 and the busbar 5 is sufficient to meet conductivity transmission performance and welding reliability, thereby reducing current loss. The busbar 5 and the first solder strip 41 have multiple connection points, with at least two connection points partially overlapping. These connection points can be rectangular, elliptical, or circular. Specifically, laser welding can be used to connect the busbar 5 and the first solder strip 41 and form the connection points.

[0107] As shown in Figures 2, 4, 6, and 8, in some embodiments, the solder ribbons 4 fixed on the busbar 5 are aligned or connected along the width direction of the busbar 5. For example, as shown in Figure 2, taking the connection of the first solder ribbon 41 to the busbar 5 as an example, the first solder ribbon 41 on the preceding cell 1 (left cell 1 in Figure 2) and the first solder ribbon 41 on the following cell 1 (right cell 1 in Figure 2) are aligned or connected horizontally on the busbar 5. Aligning the solder ribbons 4 on the preceding and following cell 1 on the busbar 5 reduces the creepage distance difference between the upper and lower parts of the module, reduces the side length of the photovoltaic module, and reduces the blank area of ​​the photovoltaic module. Connecting the first solder ribbons 41 on the preceding and following cell 1 on the busbar 5 reduces current loss. It should be understood that on the busbar 5, the first solder strip 41 of the previous battery cell 1 and the first solder strip 41 of the next battery cell 1 can also be designed to be staggered.

[0108] In some embodiments, the photovoltaic module further includes a buffer film located between the busbar 5 and the back encapsulation film of the photovoltaic module. The buffer film covers the busbar 5, so that when the busbar 5 is subjected to pressure, the buffer film cushions the location of the busbar 5, reducing the risk of microcracks in the solar cell 1.

[0109] For example, the thickness of the buffer film is 200μm to 1000μm, specifically 200μm, 300μm, 400μm, 500μm, 600μm, 700μm, 800μm, 900μm, 1000μm, etc. And / or, the width of the buffer film is 0 to 100mm wider than the width of the busbar 5, specifically 0mm, 10mm, 20mm, 40mm, 50mm, 70mm, 90mm, 100mm, etc.; and / or, the length of the buffer film is 0 to 5mm longer than the length of the busbar 5, specifically 0mm, 1mm, 2mm, 3mm, 4mm, 5mm, etc.; and / or, the material of the buffer film is a material with elasticity and durability such as POE (polyolefin elastomer), EPE (expandable polyethylene), or EVA (ethylene-vinyl acetate copolymer). At this point, the choice of material can ensure a good buffering effect on the busbar 5; the design of the thickness of the buffer film can balance the buffering effect and the layer thickness, avoiding the problem of lamination bubbles caused by excessive thickness; the design of the width and length of the buffer film can ensure that the buffer film covers the entire busbar 5, reducing the problem of uneven local stress.

[0110] As shown in Figures 2, 3, 6, and 7, in some embodiments, the busbar 5 is located on the side of the first solder strip 41 and the second solder strip 42 away from the battery cell 1. The height difference between the position of the busbar 5 corresponding to the first solder strip 41 and the position corresponding to the second solder strip 42 is less than or equal to 100 mm; and the cross-section of the solder strips 4 is rectangular. As shown in Figure 3, the busbar 5 is located above the solder strips 4. At the position corresponding to the second solder strip 42, the battery cell 1, the second insulating layer 22, the second solder strip 42, the insulating block 6, and the busbar 5 are stacked in sequence. At the position corresponding to the first solder strip 41, the battery cell 1, the first insulating layer 21, the first solder strip 41, and the busbar 5 are stacked in sequence. This structure facilitates the welding of the busbar 5 and the welding ribbon 4, improving welding strength and efficiency. Due to the simple stacked structure of the welding ribbon 4 and busbar 5, the welding joint between the welding ribbon 4 and busbar 5 does not require bending, allowing the welding ribbon 4 to make flat contact with the battery cell 1. This reduces the risk of microcracks in the battery cell 1 caused by pressure on the welding ribbon 4. Furthermore, the height difference between the positions of the two types of welding ribbons 4 on the busbar 5 is less than or equal to 100mm, preventing microcracks in the battery cell 1 due to uneven stress caused by excessive height differences. The welding ribbon 4 is a flat welding ribbon, which increases the contact area with the battery cell 1 and reduces pressure. When the welding ribbon 4 is under pressure, it reduces the risk of microcracks in the battery cell 1.

[0111] Of course, as shown in Figures 4 and 5, the solder strip 4 can also be located above the busbar 5, corresponding to the position of the second solder strip 42, with the battery cell 1, the second insulating layer 22, the busbar 5, the insulating block 6, and the second solder strip 42 stacked sequentially. Corresponding to the position of the first solder strip 41, the battery cell 1, the first insulating layer 21, the busbar 5, and the first solder strip 41 are stacked sequentially. In this case, with the solder strip 4 on top, the welding effect of the busbar 5 can be easily and quickly determined visually.

[0112] In some possible implementations, the distance between the cover plate and the backsheet of the photovoltaic module is A, and the sum of the thicknesses of the solar cell 1, the fine grid electrode, and the solder ribbon 4 is B, where B is less than 79% of A. Since, in addition to the solar cell 1, fine grid electrode, solder ribbon 4, and busbar 5, a film layer is also needed between the cover plate and the backsheet to fix and buffer the solar cell 1, solder ribbon 4, and busbar 5, sufficient thickness space is required for the film layer to improve its fixing and buffering effect and reduce microcracks or misalignments caused to the solar cell 1 during module lamination. Therefore, the sum of the thicknesses of the solar cell 1, fine grid electrode, and solder ribbon 4 is less than 79% of the distance between the cover plate and the backsheet, with the remaining distance reserved for the film layer. That is, the thickness of the film layer, etc., between the cover plate and the backsheet can account for more than 31%.

[0113] In some embodiments, the photovoltaic module includes a battery pack composed of all the cells 1, the battery pack comprising m columns of cells, where m is an integer greater than or equal to 2, and one column of cells comprising two or more cell strings; for each edge of the cover plate of the photovoltaic module, the battery pack has a minimum distance from that edge, and the difference between all minimum distances is less than 0.5 mm, specifically 0 mm, 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, and 0.5 mm, etc. Thus, the distances of the battery pack from the corresponding edges of the cover plate are relatively small, which can reduce the side length of the photovoltaic module and improve the unit power of the photovoltaic module.

[0114] In some embodiments, for photovoltaic modules with inter-cell spacing, the spacing between adjacent cells in a row of cells is 0–2 mm, specifically 0 mm, 0.5 mm, 1 mm, 2 mm, etc. The spacing between adjacent cells in a row can be the spacing between two adjacent cells in a single cell string within that row; it can also be the spacing between two adjacent cell strings within that row after the busbars are hidden. These two spacings can be substantially the same. For another type of photovoltaic module, multiple cells in a cell string are arranged in a shingled configuration, meaning that multiple cells in a cell string are arranged like overlapping tiles. The width of the overlapping area between adjacent cells in each cell string is 0.3 mm–2 mm, specifically 0.3 mm, 0.5 mm, 1 mm, 1.3 mm, 1.6 mm, 2 mm, etc. This type of photovoltaic module reduces both the inter-cell spacing and the cell-to-string spacing, thereby increasing the power-to-weight ratio of the photovoltaic module.

[0115] In some possible implementations, the thickness of the encapsulating film of the photovoltaic module at the location corresponding to the busbar 5 is less than the thickness of the encapsulating film at other locations besides the location corresponding to the busbar 5. This ensures that the stress on the solar cell 1 is uniform throughout, reducing the risk of microcracks in the solar cell 1.

[0116] In some possible implementations, a portion of the back-side encapsulation material is present between the busbar 5 and the first insulating layer 21 in the thickness direction of the battery cell 1. This portion of the back-side encapsulation material between the busbar 5 and the first insulating layer 21 acts as a buffer between the busbar 5 and the battery cell 1, reducing the risk of microcracks in the battery cell 1. If the battery cell has a second insulating layer 22, a portion of the back-side encapsulation material can also be present between the busbar and the second insulating layer 22, with the same beneficial effect.

[0117] In some possible implementations, at least one end of the busbar 5 is connected to the outermost first solder strip 41 along its length, and the end of the busbar 5 extends beyond the outermost first solder strip 41 by more than 1 mm or covers at least 80% of the width of the outermost first solder strip 41. Specifically, it can extend by 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, etc., or cover 80%, 85%, 90%, 95%, 100%, etc. For example, as shown in Figures 2, 4, and 6, the length direction of the busbar 5 is perpendicular to the length direction of the first solder strip 41, and multiple first solder strips 41 are arranged at intervals along the length direction of the busbar 5. The busbar 5 is connected to one end of the multiple first solder strips 41 or between the two ends of the multiple first solder strips 41, and the end of the busbar 5 extends beyond the outermost first solder strip 41 by more than 1 mm along its length. This allows for full welding with the outermost first solder strip 41, or leaves sufficient welding process window, with the excess length facilitating connection with other leads of the photovoltaic module.

[0118] Based on the photovoltaic module described in any of the above embodiments, this application also provides a method for preparing a photovoltaic module, including the following steps:

[0119] In step S100, insulating adhesive is printed on the back of the solar cell 1 at the position corresponding to the busbar 5 to form a first insulating layer 21 spaced along the extension direction of the fine grid electrodes of the solar cell 1. The first insulating layer 21 covers a portion of the length of the second polarity fine grid electrodes to prevent conductive short circuits, protect the pad positions, prevent overheating and grid breakage during soldering, and prevent short circuits. Through layout optimization, short circuits caused by solder ribbon misalignment or slippage are prevented. It should be noted that when the solar cell 1 has a second insulating layer 22, insulating adhesive is also printed in step S100 to form the second insulating layer 22. The printing patterns of the first insulating layer 21 and the second insulating layer 22 can be arbitrarily selected from the patterns in Figures 1, 9-11.

[0120] In step S200, conductive adhesive is printed on the back pads of the battery cell 1 to meet the welding requirements between the pads and the solder strips 4, thereby improving welding performance and conductivity.

[0121] Step S300, Layout and Welding: Lay out the front cover plate and the front encapsulation film in sequence, and lay out all the solar cells 1 of the photovoltaic module on the front encapsulation film, with the front of all solar cells 1 facing down; lay out and fix the welding ribbon 4, the insulating block 6 and the busbar 5 on the back of all solar cells 1.

[0122] The first solder strip 41 is electrically connected to the fine grid electrode of the first polarity, and the second solder strip 42 is electrically connected to the fine grid electrode of the second polarity. The insulating block 6 and the first insulating layer 21 are alternately arranged along the extension direction of the fine grid electrode, and the insulating block 6 covers part of the fine grid electrode of the second polarity and part of the second solder strip 42. The busbar 5 is located on the back of the cell in the area corresponding to the first insulating layer 21 and the insulating block 6, and the busbar 5 extends along the length direction of the fine grid electrode, which is the same as the extension direction of the fine grid electrode. The busbar 5 is electrically connected to the first solder strip 41, and the busbar 5 is electrically isolated from the second solder strip 42 by the insulating block 6. The busbar 5 is electrically isolated from the fine grid electrode of the second polarity by the alternately arranged insulating blocks 6 and the first insulating layer 21.

[0123] In step S400, a back sealing film and a backplate are laid on the back of all the battery cells 1 and laminated to obtain a laminate.

[0124] By adopting the above technical solution, a photovoltaic module with the same structure as any of the above embodiments can be obtained. The beneficial effects can be found in the above description of photovoltaic modules, which will not be repeated here. In addition, after all the cells are laid on the front encapsulation cover plate, the welding ribbon, busbar and insulating block are uniformly laid on the back of the cells and fixed together. Compared with the original method of first making the cell strings and then arranging the cell strings and welding the busbars, it can simplify the layout and welding process, reduce the process difficulty, improve the photovoltaic module manufacturing efficiency and improve the module yield.

[0125] For example, step S300, which involves laying and fixing the solder strip 4, insulating block 6, and busbar 5 on the back of all battery cells 1, specifically includes the following steps:

[0126] Step S311: First, solder ribbons 4 are laid on the back of all the battery cells 1. Exemplarily, a first solder ribbon 41 and a second solder ribbon 42 are laid on the back of the battery cells 1 respectively. The first solder ribbon 41 connects the positive electrode of the back of the preceding battery cell 1 to the negative electrode of the back of the following battery cell 1, and the second solder ribbon 42 connects the negative electrode of the back of the preceding battery cell 1 to the positive electrode of the back of the following battery cell 1, forming a series circuit. Alternatively, adhesive dots for fixing the solder ribbons 4 can be set on the battery cells 1 before laying the solder ribbons 4, then the solder ribbons are laid, and then the adhesive dots are cured to fix the solder ribbons 4. Or, the solder ribbons can be laid on the battery cells 1 first, and then adhesive dots are applied and cured to fix the solder ribbons 4.

[0127] In this step, laser or infrared heating can be used to weld the solder ribbon 4 to the electrode on the battery cell 1. Alternatively, after laying the busbar 5 in step S313, the welding of the solder ribbon 4 to the battery cell 1 and the welding ribbon 4 to the busbar 5 can be achieved simultaneously.

[0128] In step S312, an insulating block 6 is then laid on the back of all the battery cells 1, covering a portion of the second solder strip 42. For example, when the insulating block 6 is insulating tape, the insulating tape is adhered to the back of the battery cell 1 and positioned above the second solder strip 42.

[0129] In step S313, finally, busbars 5 are laid on the back of all the battery cells 1. The busbars 5 are located above the insulating block 6, and the busbars 5 are welded to the first solder strip 41.

[0130] The fixed welding strip 4, insulating block 6 and busbar 5 can facilitate the welding of welding strip 4 to battery cell 1, as well as the welding of busbar 5 to the first welding strip 41, and improve the welding strength. Since the stacked structure of welding strip 4, insulating block 6 and busbar 5 is simple, the welding point between welding strip 4 and busbar 5 does not need to be bent, so that the first welding strip 41 can make flat contact with battery cell 1, which can reduce the risk of microcracks caused to battery cell 1 by the pressure of the first welding strip 41.

[0131] Exemplarily, another specific method of laying and securing the solder ribbon 4, insulating block 6, and busbar 5 on the back of all battery cells 1 in step S300 includes the following steps:

[0132] Step S321: First, lay busbars 5 on the back of all battery cells 1.

[0133] In step S322, an insulating block 6 is then laid on the back of all the battery cells 1. For example, when the insulating block 6 is insulating tape, the insulating tape is pasted on the back of the battery cells 1 and located above the busbar 5.

[0134] In step S323, solder ribbons 4 are finally laid on the back of all battery cells 1, and the busbar 5 and the second solder ribbon 42 are electrically isolated by the insulating block 6. Exemplarily, the first solder ribbon 41 is located above the busbar 5 and welded to it, while the second solder ribbon 42 is located above the insulating block 6. At this time, with the solder ribbons 4 positioned above, the welding effect of the busbar 5 can be easily and quickly determined visually.

[0135] Furthermore, step S300, which involves laying and fixing the solder ribbon 4 on the back of all the battery cells 1, also includes the steps of: first pre-fixing the solder ribbon 4 using the fixing adhesive dots on the battery cells 1, and then fixing the solder ribbon 4 using infrared, laser or lamination.

[0136] For example, UV adhesive is applied to the outer side of each large pad on all solar cells 1. Large pads refer to those with a larger area near the edge of the solar cell 1, used to improve the welding strength with the solder ribbon 4. The UV adhesive has a diameter of 1mm to 3mm, and its edge is 0.5mm to 2mm from the edge of the large pad. All solder ribbons 4 are then placed on the back of the solar cell 1, with the ends of the solder ribbons 4 protruding 0mm-2mm beyond the UV adhesive. UV lamp curing is then used to pre-fix the solder ribbons 4. Finally, the solder ribbons 4 are fixed by infrared irradiation, laser welding, or lamination temperature. Pre-fixing the solder ribbons 4 with adhesive dots ensures that they are less likely to shift during solar cell transfer and welding, improving the welding accuracy of the solder ribbons 4.

[0137] In the description of the above embodiments, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0138] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A photovoltaic module, comprising solar cells, solder ribbons, busbars and insulating blocks, wherein the back side of the solar cells has fine grid electrodes and a first insulating layer; The solder strip includes a first solder strip and a second solder strip, wherein the first solder strip is electrically connected to the fine gate electrode of the first polarity, and the second solder strip is electrically connected to the fine gate electrode of the second polarity; The insulating block is located on the back side of the battery cell. The insulating block and the first insulating layer are arranged alternately along the extension direction of the fine grid electrode. The insulating block covers a portion of the second polarity fine grid electrode and a portion of the second solder strip. The first insulating layer covers a portion of the second polarity fine grid electrode. The busbar is located on the back of the battery cell in the region corresponding to the first insulating layer and the insulating block, and the busbar extends along the length direction of the fine grid electrode, the length direction of the fine grid electrode being the same as the extension direction of the fine grid electrode; The busbar is electrically connected to the first solder strip, and the busbar is electrically isolated from the second solder strip through the insulating block; the busbar is electrically isolated from the fine grid electrode of the second polarity through the alternately arranged insulating blocks and the first insulating layer.

2. The photovoltaic module according to claim 1, wherein, The projections of the insulating block and the first insulating layer on the solar cell alternately connect, in which case the projections of the insulating block and the first insulating layer on the solar cell connect but do not overlap; or... The projections of the insulating block and the first insulating layer on the battery cell overlap and are in contact. In this case, the projections of the insulating block and the first insulating layer on the battery cell are in contact and have an overlapping area.

3. The photovoltaic module according to claim 2, wherein, Along the length direction of the fine grid electrode, the length of the overlapping area between the projection of the insulating block and the first insulating layer on the battery cell is 0.5 mm or more.

4. The photovoltaic module according to claim 1, wherein, The back of the battery cell also has a second insulating layer. The first insulating layer and the second insulating layer are arranged alternately along the length of the busbar. The second insulating layer covers the fine grid electrode of the first polarity. The insulating block is correspondingly stacked on top of the second insulating layer.

5. The photovoltaic module according to claim 4, wherein, Along the length direction of the busbar, the difference between the length of the first insulating layer and the length of the second insulating layer is less than or equal to 2 mm; And / or, along the width direction of the busbar, the difference between the width of the first insulating layer and the width of the second insulating layer is less than or equal to 2 mm; And / or, along the width direction of the busbar, the first insulating layer and the second insulating layer intersect; And / or, the first insulating layer and the second insulating layer are made of the same material and have the same thickness; And / or, the first insulating layer and the second insulating layer are transparent adhesive layers; And / or, along the length direction of the busbar, the length of the insulating block is 0.5 mm to 4 mm longer than the length of the second insulating layer stacked with the insulating block; And / or, the pattern of the second insulating layer on all cells in the photovoltaic module is the same and the pattern of the first insulating layer on all cells in the photovoltaic module is the same.

6. The photovoltaic module according to claim 1, wherein, Along the length of the busbar, the end of the insulating region formed by the first insulating layer and the insulating block extends 1 mm to 5 mm beyond the end of the busbar. In the width direction of the busbar, the side of the insulating region composed of the first insulating layer and the insulating block extends 1mm to 5mm beyond the side of the busbar; Furthermore, in the thickness direction of the battery cell, the insulation distance between the busbar and the second solder strip, and the fine grid electrode of the second polarity, is greater than or equal to 10 μm.

7. The photovoltaic module according to claim 1, wherein, The insulating block is adhesive tape, which is adhered to the battery cell. And / or, the insulating block is a rectangular insulating block.

8. The photovoltaic module according to any one of claims 1-7, wherein, The busbar is located at a non-edge position of one of the battery cells.

9. The photovoltaic module according to any one of claims 1-7, wherein, The busbar is located at the edge of one of the battery cells.

10. The photovoltaic module according to any one of claims 1-7, wherein, The busbar covers a portion of the preceding battery cell and a portion of the following battery cell; the coverage width of the busbar on the preceding battery cell is 1mm to 5mm, and the coverage width of the busbar on the following battery cell is 1mm to 5mm.

11. The photovoltaic module according to claim 4, wherein, The first insulating layer comprises a plurality of parallel strip structures, or the first insulating layer comprises a plurality of discrete block structures, or the first insulating layer is a rectangular block; and / or The second insulating layer comprises a plurality of parallel strip structures, or the second insulating layer comprises a plurality of discrete block structures, or the second insulating layer is a rectangular block.

12. The photovoltaic module according to any one of claims 1-7, wherein, Along the width direction of the busbar, the connection length between the busbar and a first solder strip is greater than or equal to 20% of the width of the busbar.

13. The photovoltaic module according to any one of claims 1-7, wherein, The photovoltaic module also includes a buffer film located between the busbar and the back sealing film of the photovoltaic module.

14. The photovoltaic module according to claim 13, wherein, The thickness of the buffer membrane is 200μm to 1000μm, and / or the width of the buffer membrane is 0 to 100mm wider than the width of the busbar, and / or the length of the buffer membrane is 0 to 5mm longer than the length of the busbar, and / or the material of the buffer membrane is POE, EPE or EVA.

15. The photovoltaic module according to any one of claims 1-7, wherein, The busbar is located on the side of the first and second solder strips away from the battery cell. The height difference between the position of the busbar corresponding to the first solder strip and the position of the busbar corresponding to the second solder strip is less than or equal to 100mm. The cross-sections of the first and second solder strips are both rectangular.

16. The photovoltaic module according to any one of claims 1-7, wherein, The distance between the cover plate and the back plate of the photovoltaic module is A, and the sum of the thicknesses of either the first solder strip and the second solder strip, the cell and the grid electrode is B, where B is less than 79% of A.

17. The photovoltaic module according to any one of claims 1-7, wherein, The photovoltaic module includes m columns of solar cells, and each column of solar cells includes two or more cell strings; the spacing between adjacent solar cells in a column of solar cells is 0 to 2 mm, or, multiple solar cells in a cell string are arranged in a shingled manner, and the width of the overlapping area between adjacent solar cells in each cell string is 0.3 mm to 2 mm. And / or, for each edge of the cover plate of the photovoltaic module, the battery pack in the photovoltaic module, composed of each of the solar cells, has a minimum distance from that edge, and the difference between all the minimum distances is less than 0.5 mm.

18. The photovoltaic module according to any one of claims 1-7, wherein, The thickness of the encapsulating film of the photovoltaic module corresponding to the busbar position is less than the thickness of the encapsulating film at other positions besides the busbar position; and / or, In the thickness direction of the battery cell, there is a portion of back-side encapsulation material between the busbar and the first insulating layer.

19. The photovoltaic module according to any one of claims 1-7, wherein, Along the length of the busbar, at least one end of the busbar is connected to the outermost first weld strip, and the end of the busbar extends beyond the outermost first weld strip by more than 1 mm or the end of the busbar covers at least 80% of the width of the outermost first weld strip.

20. A method for preparing a photovoltaic module according to claim 1, comprising: Insulating adhesive is printed on the back of the battery cell at the position corresponding to the busbar to form a first insulating layer spaced apart along the extension direction of the fine grid electrodes of the battery cell. Conductive adhesive is printed on the pads on the back of the battery cell; Layout and welding: Lay out the front cover plate and the front encapsulation film in sequence, and lay out all the solar cells of the photovoltaic module on the front encapsulation film, with the front of all the solar cells facing down; lay out and fix the welding ribbon, insulating block and the busbar on the back of all the solar cells; A back-side encapsulating film and a backsheet are laid on the back of all the solar cells and then laminated.

21. The method for preparing a photovoltaic module according to claim 20, wherein, Laying and securing solder strips, insulating blocks, and busbars on the back of all said solar cells, including: First, the solder strip is laid on the back of all the solar cells; then, the insulating block is laid on the back of all the solar cells, the insulating block covering part of the second solder strip; finally, the busbar is laid on the back of all the solar cells. Alternatively, the busbar is first laid on the back of all the battery cells, then the insulating block is laid on the back of all the battery cells; finally, the solder ribbon is laid on the back of all the battery cells, and the busbar and the second solder ribbon are electrically isolated from each other by the insulating block.

22. The method for preparing a photovoltaic module according to claim 21, wherein, Laying and securing the solder ribbon on the back of all the solar cells includes: first pre-fixing the solder ribbon using adhesive dots on all the solar cells, and then fixing the solder ribbon using infrared, laser or lamination.

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