Solar cell module and its manufacturing method

Abstract

There are conductive or non-conductive connection points between the solar cells and the interconnected busbars. A gridline adhesion layer and a gridline support layer are provided on the surface of the solar cells. The gridline support layer adheres to the surface of the solar cells by the adhesion effect of the gridline adhesion layer. The gridline support layer is laminated on the interconnected busbars. The method for manufacturing the module includes the steps of first pre-fixing the interconnected busbars on the surface of the solar cells through the conductive or non-conductive connection points, then covering the surface of the solar cells with the gridline support layer and the gridline adhesion layer, applying pressure to the gridline support layer and the gridline adhesion layer, and completely fixing the interconnected busbars to the surface of the solar cells by the gridline support layer.

Description

[Technical field]

[0001] The present invention relates to the technical field of solar cells, and in particular to a solar cell module and a manufacturing method thereof. [Background technology]

[0002] In recent years, solar new energy has been rapidly applied and developed. Combined with energy storage, electric vehicles, charging pile technology, etc., new modes realize local consumption for solar power generation. Therefore, rooftop and building integrated photovoltaics (BIPV) will be the next focus of solar power application.

[0003] Due to the limited application area of ​​rooftop photovoltaics and BIPV, more efficient cells and modules are needed. The most promising new cells among the next generation of cells should be TOPCON and heterojunction cells. Among the next generation module technologies, the most efficient modules are shingle modules.

[0004] Currently, all three technologies suffer from the problem of being too costly. Compared with the mainstream PREC technology, the consumption of Ag paste in heterojunction cells has increased by 150%, and the consumption of Ag paste in TOPCON cells has increased by 50%. When these cells are packaged into modules with single technology, the consumption of Ag paste will further increase. How to reduce Ag paste consumption is the core bottleneck in the development of the photovoltaic industry and the development of BIPV rooftop photovoltaic power generation. Reducing Ag paste consumption and making high-efficiency cell modules better and cheaper is the biggest challenge for the photovoltaic industry.

[0005] At present, the 9BB busbar solar cell commonly used in the industry consumes less Ag paste than the 5BB busbar solar cell. This is because the 9BB busbar solar cell has more cell busbars, the current transmission distance between the two cell busbars is large, and the amplitude is reduced, so the amount of Ag paste for the cell finger can be reduced. If this technological route is still adopted and the number of busbars continues to increase, the amount of Ag paste for the cell finger can be further reduced, but the amount of Ag paste for the cell busbar is increasing. In the electrical connection method of the solar cell with busbar, the busbar of the cell is welded with a welding strip, which has the function of mechanical fixation and current conduction at the same time. Therefore, the total consumption of Ag paste cannot be further reduced.

[0006] In busbarless solar cell technology, there is no cell busbar, which can save the amount of Ag paste for cell busbar. In the prior art, there are two electrical connection methods for busbarless solar cells. The first method is to provide Ag paste pads on the surface of the busbarless solar cell to weld multi-busbar welding strips to the busbarless solar cell.

[0007] Due to the thermal expansion and contraction phenomenon of the multi-busbar welding strip, there will be a back and forth cutting effect on the surface of the solar cell during the cold and hot cycle from -40 degrees to 85 degrees, thereby wearing away the Ag finger lines (such as TOPCON, HJT, and PERC batteries) or ITO conductive layer on the textured surface of the cell (such as HJT batteries), causing failure. Therefore, the number of pads should not be too small to ensure a reliable mechanical fixation between the welding strip and the solar cell. Therefore, in this first scheme of electrical connection of busbarless solar cells, there is still a lot of Ag paste consumption for pads.

[0008] The second method is to realize the electrical connection of busbarless photovoltaic cells by adhesive film electrodes with multi-busbar welding strips. There is no need to provide Ag paste pads on the surface of busbarless solar cells, which further reduces the total Ag paste consumption of the solar cell module.

[0009] Chinese Patent No. 108419433 from Swiss Meyer Burger Co., Ltd. discloses a second scheme of electrical connection for busbarless solar cells, in which the electrical connection between the multi-busbar welding strip and the busbarless solar cell is realized by an adhesive film electrode. The adhesive film electrode with the multi-busbar welding strip includes a layer of adhesive film, and the multi-busbar welding strip is adhered to and embedded in the adhesive film. Then, the adhesive film is used to fix the multi-busbar welding strip to the surface of the cell, as shown in Figure 12, to form a good conductive contact between the multi-busbar welding strip and the busbarless solar cell.

[0010] The disadvantage of the second method of electrical connection of busbarless solar cells is that to produce this kind of adhesive film electrode with multi-busbar welding strip, not only do we need to combine the multi-busbar welding strip and the adhesive film together, but also need to constantly adjust and flip the adhesive surface of the adhesive film in a staggered manner, which leads to the high price of this kind of adhesive film electrode with multi-busbar welding strip. At the same time, the manufacturing cost of the solar cell module using the adhesive film electrode with multi-busbar welding strip is also high, and the actual effect of reducing the module cost is limited.

[0011] In another aspect, there is a market demand to thin the silicon wafer of solar cells to reduce the cost of the silicon wafer. However, as the silicon wafer becomes thinner, the resulting stress and strain between the interconnected busbar and the thin silicon wafer due to the uneven thermal expansion of the welding strip also makes it easier to cause damage to the silicon wafer. In particular, the thermal expansion deformation of the copper welding strip has the greatest effect at its end. According to a research paper [Solar Energy Materials & Solar Cells 215(2020)110667] from the University of New South Wales in Australia, the stress at the end of the copper welding strip can accumulate to more than 150 MPa, which is very easy to cause cracks. Summary of the Invention

[0012] The technical problem to be solved by the present invention is to reduce silver consumption while ensuring a reliable mechanical fixation between the interconnected busbars and the solar cells.

[0013] The technical scheme adopted by the present invention to solve the technical problem is as follows: A solar cell module having a solar cell layer, in which the solar cells in the solar cell layer draw out current through interconnected busbars. Between the solar cells and the interconnected busbars, there are conductive or non-conductive connection points for preliminary fixing of the interconnected busbars and the solar cells. In order to completely fix the interconnected busbars to the surface of the solar cells, a grid line bonding layer and a grid line support layer are provided on the surface of the solar cells. The grid line support layer adheres to the surface of the solar cells by the bonding effect of the grid line bonding layer, and the grid line support layer is laminated to the interconnected busbars.

[0014] In this method of the present invention, the function of mechanically fixing the interconnected busbars is provided by the grid line support layer, which firmly presses the interconnected busbars on the surface of the solar cells, thus restricting the movement of the interconnected busbars and realizing the complete fixation of the interconnected busbars, which helps the module to resist the temperature change of the external environment. The connection points between the interconnected busbars and the solar cells only play a preliminary fixing role, which makes it easy to connect the solar cells to the solar cell string for the later manufacturing process. Therefore, compared with the existing method of electrical connection of busbarless solar cells in which the interconnected busbars are mechanically fixed by a large number of Ag paste pads, the method of the present invention requires a small number of contacts and low or no Ag consumption of the connection points. Compared with the second method of electrical connection of busbarless solar cells by Meyer Burger, Switzerland, the method of the present invention has a lower manufacturing cost and can be implemented by relying on traditional existing equipment or by simple modifications.

[0015] In the method of the present invention, the interconnected busbars are mechanically fixed by the grid line support layer, and the stress caused by thermal expansion is evenly distributed over the entire interconnected busbars of about 100 mm on the surface of the solar cell, and the stress at the ends of the interconnected busbars can be reduced by about 100 times. Therefore, the probability of silicon wafer breakage can be greatly reduced by using the method of the present invention. At the same time, even if the silicon wafer is damaged for other reasons, such as collision during the battery manufacturing process, it is bonded by the grid line bonding layer and the grid line support layer, and does not affect power generation. Therefore, the use of the present invention is beneficial to the thinning of silicon wafers.

[0016] The present invention is generally applicable to a variety of high efficiency cells, such as common heterojunction cells, passivated contact TOPCON cells, IBC back junction cells, perovskite cells, and other thin film and crystalline silicon stack cells. The present invention is particularly beneficial for implementation in heterojunction cells, narrowing the material cost gap between heterojunction cells and traditional PERC cells.

[0017] A specific manner in which the grid line support layer is adhered to the surface of the solar cell by the adhesion effect of the grid line adhesion layer is that the grid line adhesion layer is located between the grid line support layer and the solar cell to adhere the grid line support layer to the surface of the solar cell, and the thickness of the grid line adhesion layer is smaller than the thickness of the interconnected busbars.

[0018] In addition, the interconnected busbars are embedded in the grid line bonding layer, or there is a gap between the interconnected busbars and the grid line bonding layer. When the interconnected busbars are embedded in the grid line bonding layer, the grid line bonding layer and the grid line support layer can mechanically fix the interconnected busbars together, and the fixing effect is relatively good.

[0019] Furthermore, the solar cell module further comprises a packaging structure, the solar cell layer is packaged in the packaging structure, and the gridline bonding layer and the gridline support layer cover the interconnected busbars on the surface of the solar cells. The surface of the interconnected busbars has a low melting point welding layer. Electrical contacts are formed between the interconnected busbars and the solar cells by the low melting point welding layer, and the interconnected busbars are embedded in the gridline bonding layer. Between the gridline support layer and the packaging structure on the same side, there is a packaging bonding layer for bonding the gridline support layer and the packaging structure on the same side together.

[0020] Also, for the smallest coverage unit, both the gridline support layer and the gridline attachment layer are the entire film, or the gridline support layer is the entire film and the gridline attachment layer is in the form of a film strip, or the gridline support layer is in the form of a film strip and the gridline attachment layer is the entire film, or both the gridline attachment layer and the gridline support layer are in the form of a film strip.

[0021] Furthermore, the gridline attachment layer and the gridline support layer are in the form of a composite film strip including the gridline attachment layer and the gridline support layer, considering at least one solar cell as a minimum coverage unit, the composite film strip extending along a first direction and spaced apart along a second direction, or the composite film strip extending along a second direction and spaced apart along the first direction, the first direction being the extension direction of the interconnected busbars, and the second direction being perpendicular to the extension direction of the interconnected busbars.

[0022] The grid line support layer and the grid line bonding layer are polymeric materials, the grid line support layer is PET, EVA, POE, PVB, PVF, PMMA or PC, the grid line bonding layer is silica gel, POE, EVA, TPU or liquid silica gel, the solar cells are busbarless solar cells, and the interconnected busbars are multi-busbar welded strips.

[0023] Another specific manner in which the grid line support layer is adhered to the surface of the solar cell by the adhesion effect of the grid line adhesion layer is that the grid line support layer is located between the grid line adhesion layer and the solar cell, the grid line support layer shields the grid line adhesion layer only in a local area, and the shielded area and the non-shielded area of ​​the grid line adhesion layer shielded by the grid line support layer are respectively bonded to the grid line support layer and the solar cell to adhere the grid line support layer to the surface of the solar cell.

[0024] Also, for the smallest coating unit, both the gridline support layer and the gridline attachment layer are full films, with the gridline support layer having a hollow portion, or the gridline support layer is in the form of a film strip and the gridline attachment layer is a full film.

[0025] In order to ensure a good electrical connection between the interconnected busbars and the solar cells, the surface of the interconnected busbars further has a welding layer or a conductive adhesive, the welding layer being a low melting point welding layer with a melting point lower than the stacking temperature of the module, and the interconnected busbars are in electrical contact with the solar cells through the welding layer or the conductive adhesive. The present invention does not exclude that the interconnected busbars and the solar cells are electrically connected through direct contact to guide the current of the solar cells.

[0026] The manufacturing method of the above solar cell module includes the following steps: first, preliminarily fix the interconnected busbars to the surface of the solar cell through conductive or non-conductive connection points; then, cover the surface of the solar cell with a gridline support layer and a gridline bonding layer, and apply pressure to the gridline support layer and the gridline bonding layer; and completely fix the interconnected busbars to the surface of the solar cell by the gridline support layer.

[0027] The method further includes a solar cell string fabrication step and a module lamination step in that order. In the solar cell string fabrication step, the interconnected busbars are pre-fixed to the surface of the solar cells via conductive or non-conductive connection points. In the module lamination step, lamination pressure is applied to the gridline support layer and the gridline bonding layer such that the interconnected busbars are fully fixed to the surface of the solar cells by the gridline support layer. In the module lamination step, the interconnected busbars are brought into electrical contact with the solar cells.

[0028] Also, the grid line adhesion layer and the grid line support layer are used for sequential coating in a film form, respectively. Or, the grid line adhesion layer and the grid line support layer are used for sequential coating in a composite film form including the grid line adhesion layer and the grid line support layer. Or, the grid line adhesion layer and the grid line support layer are used for sequential coating in a composite film form including the grid line adhesion layer and the grid line support layer. Or, the film-like grid line support layer and the liquid-like grid line adhesion layer are used for sequential coating. Furthermore, the connection points between the interconnected busbars and the solar cells are formed by welding or gluing.

[0029] In the method of manufacturing a solar cell module, first, a solar cell string is manufactured, such that the interconnected busbars of the solar cell string are pre-fixed to the surface of the solar cell through conductive or non-conductive connection points. Then, a grid line bonding layer and a grid line support layer are used to cover the interconnected busbars on the surface of the solar cell, where the grid line bonding layer is located between the grid line support layer and the solar cell. And finally, in a module lamination process, the solar cell is packaged into a packaging structure of a solar cell module, and the interconnected busbars are completely fixed to the surface of the solar cell by the grid line bonding layer and the grid line support layer. The grid line support layer is bonded to the surface of the solar cell by the grid line bonding layer. The thickness of the grid line bonding layer is smaller than the thickness of the interconnected busbars. The grid line bonding layer is heated to flow by the module lamination process, so that the interconnected busbars are embedded in the grid line bonding layer. The grid line support layer is laminated on the interconnected busbars. The surface of the interconnected busbars has low melting point welding layers, which are melted at the lamination temperature to form electrical contacts with the surface of the solar cell.

[0030] Also, the grid line adhesive layer and the grid line support layer are used for sequential coating in a film form, respectively. Alternatively, the grid line adhesive layer and the grid line support layer are used for sequential coating in a composite film form including the grid line adhesive layer and the grid line support layer. Alternatively, the grid line adhesive layer and the grid line support layer are used for sequential coating in a composite film form including the grid line adhesive layer and the grid line support layer. Alternatively, the film-like grid line support layer and the liquid-like grid line adhesive layer are used for sequential coating.

[0031] Furthermore, the grid line attachment layer and the grid line support layer are used to coat at least one solar cell as a minimum coating unit.

[0032] Further, the gridline attachment layer and the gridline support layer are used to coat in the form of a composite film strip including the gridline attachment layer and the gridline support layer, the composite film strip extending along a first direction or a second direction, the first direction being an extension direction of the interconnected bus bars and the second direction being perpendicular to the extension direction of the interconnected bus bars.

[0033] Furthermore, a method for manufacturing a solar cell module sequentially includes a solar cell string manufacturing step, a module arrangement step, and a module stacking step, in which the grid line bonding layer and the grid line support layer are arranged on the interconnected bus bars on the surface of the solar cells in the module arrangement step.

[0034] Furthermore, the grid line adhesion layer and the grid line support layer sequentially cover the surface of the solar cell layer by forming a film with the solar cell layer as the smallest covering unit, or the grid line adhesion layer and the grid line support layer sequentially cover the surface of the solar cell layer by forming a composite film including the grid line adhesion layer and the grid line support layer with the solar cell layer as the smallest covering unit, or the grid line adhesion layer and the grid line support layer sequentially cover the surface of the solar cell layer by forming the solar cell layer as the smallest covering unit with the film-like grid line support layer and the liquid-like grid line support layer.

[0035] The method for manufacturing the solar cell module further includes a solar cell string manufacturing step, a module arrangement step, and a module stacking step, in which the grid line attachment layer and the grid line support layer are attached to a surface of the solar cell string as a minimum covering unit in the form of a composite film strip including the grid line attachment layer and the grid line support layer, the composite film strip extends along a first direction on the surface of the solar cell string, and is arranged at intervals along a second direction, the first direction being the extension direction of the interconnected bus bars, and the second direction being perpendicular to the extension direction of the interconnected bus bars, and in the module arrangement step, the arrangement is performed on the solar cell strings attached to the composite film strip.

[0036] Furthermore, the manufacturing method of the solar cell module sequentially includes a solar cell string manufacturing step, a solar cell string arrangement step, a module arrangement step, and a module stacking step, in which the solar cell strings are arranged in a solar cell layer as a whole according to module specifications and requirements, and the grid line adhesion layer and the grid line support layer are adhered to the surface of the solar cell layer as the smallest covering unit, and are adhered to the surface of the solar cell layer in the form of a composite film strip including the grid line adhesion layer and the grid line support layer.

[0037] The composite film strips extend along a second direction and are arranged at intervals along a first direction on a surface of the solar cell layer, the first direction being an extension direction of the interconnected bus bars and the second direction being perpendicular to the extension direction of the interconnected bus bars. A module arrangement is performed on the solar cell layer bonded with the composite film strips in a module arrangement step.

[0038] Furthermore, in the solar cell string manufacturing process, the connection points between the interconnected bus bars and the solar cells are formed by welding or bonding. The welding methods include, for example, electromagnetic welding, alloy heat welding, ultrasonic welding, friction welding, resistance welding, laser welding, etc. The bonding methods include, for example, hot melt adhesive bonding, silica gel bonding, acrylic adhesive bonding, epoxy adhesive bonding, etc.

[0039] Also, the grid line adhesive layer and the grid line support layer are used to cover in the form of a composite film including the grid line adhesive layer and the grid line support layer, the composite film is a three-layer composite structure including an adhesive layer, a grid line support layer and a grid line adhesive layer, the packaging adhesive layer is used to attach the grid line support layer with a packaging structure on the same side as the grid line support layer, and the packaging adhesive layer and the grid line adhesive layer are respectively located on the front side and the back side of the grid line support layer.

[0040] The solar cell module includes a solar cell layer packaged in a packaging structure. The solar cells in the solar cell layer draw current through the interconnected busbars. There are conductive or non-conductive connection points between the solar cells and the interconnected busbars for preliminary fixation of the solar cells and the interconnected busbars. The interconnected busbars on the surface of the solar cells are covered with a gridline bonding layer and a gridline support layer to completely fix the interconnected busbars to the surface of the solar cells. The surface of the interconnected busbars has a low melting point welding layer, and electrical contacts are formed between the interconnected busbars and the solar cells by the low melting point welding layer. The gridline support layer is bonded to the surface of the solar cells by the gridline bonding layer. The interconnected busbars are embedded in the gridline bonding layer. The gridline support layer is laminated on the interconnected busbars. There is a packaging bonding layer between the gridline support layer and the packaging structure on the same side to bond the gridline support layer to the packing structure on the same side. Furthermore, the gridline attachment layer and the gridline support layer are in the form of a film, with at least one solar cell being the minimum coverage unit.

[0041] Further, the gridline attachment layer and the gridline support layer are in the form of a composite film strip including the gridline attachment layer and the gridline support layer, with at least one solar cell being a minimum coverage unit, and further, the composite film strip extends along a first direction and is spaced apart along a second direction, or the composite film strip extends along the second direction and is spaced apart along the first direction, the first direction being a direction along which the interconnected busbars extend, and the second direction being perpendicular to the direction along which the interconnected busbars extend.

[0042] Furthermore, for the composite film strip, the solar cell layer is the smallest covering unit, and the solar cell layer is formed by electrically connecting at least one solar cell string. The solar cells in the solar cell string are electrically connected via interconnected bus bars. The solar cells in the solar cell string are arranged in the solar cell layer extending along a first direction and spaced apart along a second direction. The composite film strip is arranged in the surface of the solar cell layer extending along a second direction and spaced apart along the first direction. Here, the first direction is the extension direction of the interconnected bus bars, and the second direction is perpendicular to the extension direction of the interconnected bus bars. The width of the composite film strip is larger than the width of the interconnected bus bars, and each of the interconnected bus bars on the surface of the solar cell is completely fixed by the composite film strip.

[0043] Furthermore, for the composite film strip, the solar cell layer is the smallest covering unit, and the solar cell layer is formed by electrically connecting at least one solar cell string. The solar cells in the solar cell string are electrically connected through interconnected bus bars, and the solar cells in the solar cell string are arranged in the solar cell layer extending along a first direction and spaced apart along a second direction. The composite film strips extend along a second direction and spaced apart along the first direction on the surface of the solar cell layer, where the first direction is the extension direction of the interconnected bus bars, and the second direction is perpendicular to the extension direction of the interconnected bus bars. Each of the interconnected bus bars on the surface of the solar cell is fixed at multiple points by multiple composite film strips intersecting therewith, and the fixed points are the intersections of the interconnected bus bars and the composite film strips.

[0044] The beneficial effects of the present invention are as follows: Compared with the electrical connection method of busbarless solar cells, in which the interconnected busbars are mechanically fixed by pads, the present invention can greatly reduce the Ag consumption at the connection points of the interconnected busbars. Compared with the electrical connection method of solar cells in which the adhesive film electrode does not have a busbar, the present invention has the advantages of simple manufacture and low cost. [Brief description of the drawings]

[0045] The invention is further explained below in conjunction with the accompanying drawings and embodiments. [Figure 1] 1 is a manufacturing flowchart of a solar cell module according to embodiment 1 of the present invention. [Diagram 2] FIG. 1 is a schematic diagram showing the configuration of a solar cell module according to a first embodiment of the present invention. [Diagram 3] FIG. 1 is a schematic diagram showing the structure of a composite membrane according to a first embodiment of the present invention. [Figure 4] FIG. 2 is a schematic structural diagram showing a preliminary connection between interconnected busbars and busbarless solar cells via connection points according to embodiment 1 of the present invention. [Diagram 5] FIG. 11 is another schematic structural diagram showing a preliminary connection between an interconnected busbar and a busbarless solar cell via a connection point according to embodiment 1 of the present invention. [Figure 6] FIG. 1 is a schematic structural diagram showing that interconnected bus bars are fixed to solar cells via cell bus bar pads in the prior art. [Figure 7] 5 is a schematic diagram showing the configuration of a solar cell module according to a second embodiment of the present invention. FIG. [Figure 8] FIG. 4 is a schematic diagram showing the structure of a composite membrane according to a second embodiment of the present invention. [Figure 9] FIG. 11 is a schematic diagram showing the configuration of a solar cell module according to a fourth embodiment of the present invention. [Figure 10] FIG. 11 is a three-dimensional schematic structural diagram showing the interconnected bus bars fixed by the composite film strip according to embodiment 5 of the present invention. [Figure 11] FIG. 11 is a schematic side view showing the bus bars interconnected by the composite film strip according to the fifth embodiment of the present invention being fixed. [Figure 12]FIG. 1 is a schematic structural diagram showing solar cells being connected in series by an adhesive film electrode with multiple busbar welding strips in the prior art. [Figure 13] FIG. 11 is a three-dimensional schematic structural diagram showing the interconnected bus bars fixed by the composite film strip according to embodiment 6 of the present invention. [Figure 14] FIG. 13 is a side schematic structural view showing interconnected bus bars fixed by a composite film strip according to embodiment 6 of the present invention. [Figure 15] FIG. 13 is a three-dimensional schematic structural diagram showing interconnected bus bars fixed by a composite membrane according to embodiment 7 of the present invention. [Figure 16] FIG. 13 is a side schematic structural view showing interconnected bus bars fixed by a composite membrane according to embodiment 7 of the present invention. [Figure 17] FIG. 13 is a schematic diagram of a first unlaminated laminated structure for fixing interconnected bus bars according to embodiment 13 of the present invention. [Figure 18] FIG. 13 is a schematic diagram of a second unlaminated laminate structure for fixing interconnected bus bars according to a thirteenth embodiment of the present invention. [Figure 19] FIG. 13 is a schematic diagram of a third laminated structure that is not laminated to fix interconnected bus bars according to a thirteenth embodiment of the present invention; [Figure 20] FIG. 15 is a schematic diagram of an unlaminated laminated structure for fixing interconnected bus bars according to embodiment 14 of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0046] In embodiment 1, a method for manufacturing a solar cell module is provided. First, the fabrication of solar cell strings in the solar cell layer of the module is carried out, so that the interconnected busbars 2 of the solar cell strings are preliminarily fixed to the surface of the solar cells 1 through the connection points 4. Then, the interconnected busbars 2 on the surface of the solar cells 1 of the module are covered with a grid line bonding layer 3-1 and a grid line support layer 3-2. The grid line bonding layer 3-1 is located between the grid line support layer 3-2 and the solar cell layer. Finally, in the module lamination process, the solar cells 1 are packaged into the packaging structure of the solar cell module, and the interconnected busbars 2 are completely fixed to the surface of the solar cells 1 by the grid line bonding layer 3-1 and the grid line support layer 3-2.

[0047] Specifically, the thickness of the grid line bonding layer 3-1 is smaller than the thickness of the interconnected busbars 2. The grid line bonding layer 3-1 is heated to flow by the module lamination process, so that the interconnected busbars 2 are embedded in the grid line bonding layer 3-1. The grid line support layer 3-2 is bonded to the surface of the solar cell 1 by the grid line bonding layer 3-1, and the grid line support layer 3-2 is laminated on the interconnected busbars 2, so that the interconnected busbars 2 are completely fixed to the surface of the solar cell by the grid line bonding layer 3-1 and the grid line support layer 3-2. The surface of the interconnected busbars 2 has low melting point weld layers, which are melted at the lamination temperature to form electrical contacts with the surface of the solar cell 1.

[0048] The grid line adhesive layer 3-1 and the grid line support layer 3-2 are used to cover in the form of a composite film 3, which includes the grid line adhesive layer 3-1 and the grid line support layer 3-2. As shown in FIG. 3, the composite film 3 is a three-layer composite structure, which includes a packaging adhesive layer 3-3, a grid line support layer 3-2 and a grid line adhesive layer 3-1. The packaging adhesive layer 3-3 is used to attach the grid line support layer 3-2 to the packaging structure on the same side. The packaging adhesive layer 3-3 and the grid line adhesive layer 3-1 are located on the front side and the back side of the grid line support layer 3-2, respectively.

[0049] The packaging adhesive layer 3-3, the gridline support layer 3-2, and the gridline adhesive layer 3-1 are composed of three layers of different or the same material. Different treatments allow different degrees of polymerization and / or cross-linking to occur between the three layers, resulting in a three-layer composite structure.

[0050] As shown in FIG. 2, FIG. 3 and FIG. 4, the solar cell module manufactured by the manufacturing method of the solar cell module in the embodiment 1 includes a solar cell layer packaged in a packaging structure. The solar cells 1 in the solar cell layer draw out current through the interconnected busbars 2. For preliminary fixation of the interconnected busbars 2 and the solar cells 1, there are conductive connection points 4 between the solar cells 1 and the interconnected busbars 2. The interconnected busbars on the surface of the solar cells are covered with a grid line bonding layer 3-1 and a grid line support layer 3-2 so as to completely fix the interconnected busbars 2 to the surface of the solar cells 1. The surface of the interconnected busbars 2 has a low melting point welding layer, and an electrical contact is formed between the interconnected busbars 2 and the solar cells 1 by the low melting point welding layer. The grid line support layer 3-2 is bonded to the surface of the solar cells 1 by the grid line bonding layer 3-1. The interconnected busbars 2 are embedded in the grid line bonding layer 3-1. The grid line support layer 3-2 is laminated on the interconnected busbars 2. Between the gridline support layer 3-2 and the packaging structure is a packaging bonding layer 3-3 for bonding the packaging structure on the same side to the gridline support layer 3-2.

[0051] The solar cell layer is formed by electrically connecting at least one solar cell string. The solar cells 1 in the solar cell string are electrically connected via interconnected bus bars 2. The solar cells in the string extend along a first direction and are arranged spaced apart along a second direction in the solar cell layer.

[0052] The composite film 3 covers the entire surface of the solar cell layer, with the entire solar cell layer being the smallest covering unit.

[0053] The grid line support layer 3-2 is a polymeric material that does not flow easily at the lamination temperature, such as PET, PVF, PMMA, PC, etc., and has a thickness of about 5 um to 50 um. The grid line support layer 3-2 may be surface-treated to enhance adhesion between the film layers. The grid line bonding layer 3-1 is a polymeric adhesive material that flows easily at the lamination temperature, such as silica gel, POE, EVA, TPU, or other high-temperature adhesives, etc., and has a thickness of 20 um to 150 um. The packaging bonding layer 3-3 is a polymeric adhesive material that flows easily at the lamination temperature, such as EVA, POE, PVB, TPO, or other common film layers, etc., and has a thickness of about 200 um to 600 um. The solar cell 1 is a busbarless solar cell, and the interconnected busbar 2 is a multi-busbar welding strip.

[0054] As shown in FIG. 1, the specific steps of the method for manufacturing the solar cell module in the first embodiment are as follows. (a) The interconnected busbar 2, solar cell 1 and composite membrane 3 are prefabricated. The interconnected busbar 2 is a multi-busbar welded strip with high purity, low expansion coefficient and low melting point weld layer with oxygen-free copper as the metal core. The low melting point weld layer is a tin layer doped with Bi, Ag and other elements to lower the melting point, such as Sn42Bi57Ag1. The solar cell 1 is a busbarless solar cell. There are multiple pads on the busbarless solar cell to connect the multi-busbar welded strip to the busbarless solar cell.

[0055] (b) Manufacturing of solar cell strings The solar cells 1 are placed and aligned on a welding table. The pads are subjected to a local energy treatment, such as local infrared heating or local electromagnetic induction heating, to weld the interconnected busbars 2 onto the pads and form a plurality of connection points 4, so that the interconnected busbars 2 are pre-fixed to the solar cells 1, and the solar cells 1 are connected in series by the interconnected busbars 2 to form a solar cell string.

[0056] As shown in Figure 6, in existing electrical connection technologies for busbarless solar cells, a solar cell 1 having 18 interconnected busbars 2 on its surface typically requires 180 connection points 4 to meet the technical requirements for reliable mechanical fixation between the interconnected busbars 2 and the solar cell 1.

[0057] However, in the present invention, as shown in Fig. 4, the solar cells 1 are connected to the interconnected busbars 2 through 36 connection points 4, thereby producing the solar cell string required in embodiment 1. In Fig. 5, the solar cells 1 are connected to the interconnected busbars 2 through 54 connection points 4, thereby producing the solar cell string required in embodiment 1. The number of connection points 4 required is much less than the number of connection points 4 required in the existing electrical connection technology for busbarless solar cells, in which the interconnected busbars 2 are welded by pads, so that the consumption of Ag paste on the pads can be saved.

[0058] (c) Module arrangement The packaging backplane 6, the composite film 3, the solar cell string, the composite film 3, and the packaging panel 5 are laid in sequence to obtain a stack for module stacking. The packaging backplane 6 and the packaging panel 5 are the packaging structure of the module.

[0059] The composite film 3 in embodiment 1 has a three-layer composite structure of the packaging adhesive layer 3-3, the grid line support layer 3-2, and the grid line adhesive layer 3-1. Therefore, the arrangement process of the packaging adhesive layer 3-3 can be omitted, and the manufacturing process can be simplified.

[0060] (d) Module stacking The lamination is performed at a lamination temperature higher than the melting point of the low melting point weld layer of the interconnected busbars 2. During lamination, the low melting point weld layer of the interconnected busbars 2 is melted to form a good conductive relationship with the Ag finger lines on the surface of the solar cell 1. If the solar cell 1 is a heterojunction cell, during lamination, the low melting point weld layer melts, which not only forms a good conductive relationship with the Ag finger lines on the surface of the solar cell 1, but also adheres to the 2um-7um textured surface of the solar cell 1 to form a good physical contact and a certain conductive contact.

[0061] During lamination, the gridline bonding layer 3-1 is heated to flow, so that the interconnected busbars 2 are embedded in the gridline bonding layer 3-1. The gridline supporting layer 3-2 is laminated onto the interconnected busbars 2. After lamination and cooling, the gridline bonding layer 3-1 and the gridline supporting layer 3-2 firmly press the interconnected busbars 2 onto the surface of the solar cells 1, thereby restricting the movement of the interconnected busbars 2 and achieving a perfect fixation of the interconnected busbars 2. This helps the module to resist temperature changes in the external environment.

[0062] In the second embodiment, a method for manufacturing a solar cell module is provided that is basically similar to that in the first embodiment, except that the composite film 3 has a two-layer composite structure of a grid line support layer 3-2 and a grid line bonding layer 3-1, as shown in Figs. 7 and 8.

[0063] Specific steps (a), (b), and (d) in embodiment 2 are the same as those in embodiment 1, but differ in step (c).

[0064] In step (c), the packaging backplane 6, the packaging adhesive layer 3-3, the composite film 3, the solar cell string, the composite film 3, the packaging adhesive layer 3-3, and the packaging panel 5 are laid in order.

[0065] The third embodiment is basically the same as the first embodiment, with the difference being that the interconnected busbars 2 of the solar cell strings are pre-fixed to the surface of the solar cell 1 via non-conductive connection points 4. The non-conductive connection points 4 are usually formed by gluing with an adhesive, such as hot melt adhesive, silica gel, acrylic adhesive, epoxy adhesive, etc. A part of the adhesive needs to be cured by local UV light irradiation to produce an adhesive effect.

[0066] Compared with the existing electrical connection technology for busbar-less solar cells shown in FIG. 6, the consumption of Ag paste on the pads is zero in embodiment 3.

[0067] In the fourth embodiment, as shown in FIG. 9, a method for manufacturing a solar cell module is provided, which is basically the same as that in the first embodiment, except that a grid line bonding layer 3-1 and a grid line supporting layer 3-2 sequentially cover the entire surface of the solar cell layer in a film-like manner, with the entire solar cell layer being the smallest covering unit.

[0068] Specific steps (a), (b), and (d) in the fourth embodiment are similar to those in the first embodiment, with the exception of steps (a) and (c).

[0069] In step (a), the steps of combining and preparing the grid line bonding layer 3-1 and the grid line support layer 3-2 are omitted.

[0070] In step (c), the packaging backplane 6, the packaging adhesive layer 3-3, the grid line support layer 3-2, the grid line adhesive layer 3-1, the solar cell string, the grid line adhesive layer 3-1, the grid line support layer 3-2, the packaging adhesive layer 3-3, and the packaging panel 5 are laid out in this order.

[0071] In embodiment 5, a method for manufacturing a solar cell module is provided. This manufacturing method is basically the same as embodiment 1, with the difference being that the grid line bonding layer 3-1 and the grid line support layer 3-2 are bonded to the surface of the solar cell string in the form of a composite film strip 3' including the grid line bonding layer 3-1 and the grid line support layer 3-2. The composite film strip 3' is a two-layer composite structure of the grid line support layer 3-2 and the grid line bonding layer 3-1, as shown in FIG. 8. For the composite film strip 3', the solar cell string is taken as the smallest covering unit. The composite film strip 3' extends along a first direction and is spaced apart and arranged along a second direction on the surface of the solar cell string. The first direction is the extension direction of the interconnected busbars 2. The second direction is perpendicular to the extension direction of the interconnected busbars 2.

[0072] The specific steps of the method for producing a solar cell module in embodiment 5 are the following steps (a) to (d).

[0073] In step (a), the interconnected busbars 2, solar cells 1 and composite film strips 3' are pre-fabricated. The solar cells 1 are busbarless solar cells, which have multiple pads.

[0074] (b) Manufacturing of solar cell strings The solar cells 1 are placed and arranged on a welding table. The interconnected bus bars 2 are welded on the pads to form a plurality of connection points 4, so that the interconnected bus bars 2 are pre-fixed to the solar cells 1, and the solar cells 1 are connected in series by the interconnected bus bars 2 to form a solar cell string.

[0075] As shown in Figures 10 and 11, the composite film strips 3' are bonded to the surface of the solar cell string in a manner that they extend along a first direction and are spaced apart along a second direction on the surface of the solar cell string. In a module alignment step, alignment is performed on the solar cell string bonded with the composite film strips 3'. The composite film strips 3' are bonded to the surface of the solar cell string by slightly heating the grid line bonding layer 3-1.

[0076] (c) Module arrangement A packaging backplane 6, a packaging adhesive layer 3-3, a solar cell string with a composite film strip 3' bonded thereto, a packaging adhesive layer 3-3, and a packaging panel 5 are laid out in this order to obtain a stack for stacking modules.

[0077] (d) Module stacking The lamination is performed at a lamination temperature higher than the melting point of the low melting point weld layer of the interconnected busbars 2. During lamination, the low melting point weld layer of the interconnected busbars 2 is melted to form a good conductive connection with the Ag finger lines on the surface of the solar cells 1.

[0078] During lamination, the gridline adhesion layer 3-1 is heated to flow so that the interconnected busbars 2 become embedded in the gridline adhesion layer 3-1. Gridline supporting layer 3-2 is laminated onto the interconnected busbars 2. After lamination and cooling, the gridline adhesion layer 3-1 and gridline support layer 3-2 press the interconnected busbars 2 firmly against the surface of the solar cell 1, thereby limiting movement of the interconnected busbars 2.

[0079] The solar cell module manufactured by the manufacturing method of the solar cell module in the embodiment 5 includes a solar cell layer packaged in a packaging structure. The solar cells 1 in the solar cell layer draw out current through the interconnected busbars 2. For preliminary fixation of the interconnected busbars 2 and the solar cells 1, there are conductive connection points 4 between the solar cells 1 and the interconnected busbars 2. The interconnected busbars 2 on the surface of the solar cells 1 are covered with a grid line bonding layer 3-1 and a grid line support layer 3-2 so as to completely fix the interconnected busbars 2 to the surface of the solar cells 1. The surface of the interconnected busbars 2 has a low melting point welding layer, and an electrical contact is formed between the interconnected busbars 2 and the solar cells 1 by the low melting point welding layer. The grid line support layer 3-2 is bonded to the surface of the solar cells 1 by the grid line bonding layer 3-1. The interconnected busbars 2 are embedded in the grid line bonding layer 3-1. The grid line support layer 3-2 is laminated on the interconnected busbars 2. Between the grid line support layer 3-2 and the packaging structure on the same side is a packaging bonding layer 3-3, which is for bonding the grid line support layer 3-2 to the packaging structure on the same side.

[0080] The solar cell layer is formed by electrically connecting at least one solar cell string. Solar cells 1 in the solar cell string are electrically connected via interconnected bus bars 2. The solar cells in the string are arranged in the solar cell layer extending along a first direction and spaced apart along a second direction. Grid line attachment layers 3-1 and grid line support layers 3-2 are coated on the surface of the solar cell layer in a spaced apart manner in the form of composite film strips 3' comprising the grid line attachment layers 3-1 and grid line support layers 3-2.

[0081] Since the solar cells in the string extend along a first direction and are arranged at intervals along a second direction in the solar cell layer, the solar cell string can be regarded as the smallest covered unit for the composite membrane strip 3', or the solar cell layer can be regarded as the smallest covered unit. The composite membrane strip 3' extends along a first direction and is arranged at intervals along a second direction on the surface of the solar cell layer. The width of the composite membrane strip 3' is greater than the width of the interconnected busbar 2. Each of the interconnected busbars 2 on the surface of the solar cell 1 is fixed integrally by the composite membrane strip 3'. In FIG. 10, each of the interconnected busbars 2 corresponds to the composite membrane strip 3', but it is not excluded that multiple interconnected busbars 2 correspond to the composite membrane strip 3'.

[0082] In embodiment 5, when the width of the interconnected busbars 2 is 0.27 mm and the spacing between the interconnected busbars 2 is 8.75 mm, the width of the composite film strips 3' may be about 4 mm, and the spacing between the composite film strips 3' is about 4.75 mm. The amount of the composite film strips 3' is about 45% of the area of ​​the solar cell layer.

[0083] In the prior art of connecting solar cells in series by adhesive film electrodes 7 with multi-busbar welding strips as shown in Fig. 12, the amount of adhesive film is more than 90% of the area of ​​the solar cell layer, which has high cost and shading effects. Compared with the prior art, the technical scheme in embodiment 5 can reduce the amount of composite adhesive strips 3', which has the advantages of cost-effectiveness, reduced shading effects, and increased power.

[0084] In embodiment 6, a method for manufacturing a solar cell module is provided which is basically the same as that in embodiment 5, with the difference being that it sequentially includes a solar cell string manufacturing step, a solar cell string arrangement step, a module arrangement step, and a module stacking step. In the solar cell string arrangement step, solar cell strings are arranged on the entire solar cell layer according to module specifications and requirements. A composite film strip 3' is adhered to the surface of the solar cell layer with the solar cell layer as the smallest covering unit, and the composite film strip 3' is extended along a second direction and arranged at intervals along a first direction on the surface of the solar cell layer. In the module arrangement step, a module arrangement is performed on the solar cell layer with the composite film strip 3' adhered thereto. The composite film strip 3' is used to attach the grid line bonding layer 3-1 by slightly heating it.

[0085] The specific steps of the method for producing a solar cell module in embodiment 6 are the following steps (a) to (d).

[0086] In step (a), the interconnected busbars 2, solar cells 1 and composite film strips 3' are pre-fabricated. The solar cells 1 are busbarless solar cells, which have multiple pads.

[0087] (b) Manufacturing of solar cell strings The solar cells 1 are placed and arranged on a welding table. The interconnected bus bars 2 are welded on the pads to form a plurality of connection points 4, so that the interconnected bus bars 2 are pre-fixed to the solar cells 1, and the solar cells 1 are connected in series by the interconnected bus bars 2 to form a solar cell string.

[0088] (c) Solar cell string device The solar cell strings are arranged in the solar cell layer as a whole according to the specifications and requirements of the module, the composite film strips 3' are adhered to the surface of the solar cell layer together with the solar cell layer as the smallest covering unit, the composite film strips 3' extend along the second direction and are arranged at intervals along the first direction on the surface of the solar cell layer, and a module arrangement step is performed on the solar cell layer adhered together with the composite film strips 3'.

[0089] (d) Module arrangement The packaging backplane 6, the packaging adhesive layer 3-3, the solar cell layer bonded with the composite film strip 3', the packaging adhesive layer 3-3, and the packaging panel 5 are arranged in sequence to obtain a stack for module stacking.

[0090] (e) Module stacking The lamination is performed at a lamination temperature higher than the melting point of the low melting point weld layer of the interconnected busbars 2. During lamination, the low melting point weld layer of the interconnected busbars 2 is melted to form a good conductive connection with the Ag finger lines on the surface of the solar cells 1.

[0091] During lamination, the gridline bonding layer 3-1 is heated to flow so that the interconnected busbars 2 become embedded in the gridline bonding layer 3-1. The gridline support layer 3-2 is laminated over the interconnected busbars 2. After lamination and cooling, the gridline bonding layer 3-1 and the gridline support layer 3-2 press the interconnected busbars 2 firmly against the surface of the solar cell 1, thereby limiting movement of the interconnected busbars 2.

[0092] As shown in Figures 13 and 14, the solar cell module manufactured by the solar cell module manufacturing method in embodiment 6 is basically the same as that of embodiment 5, with the difference being that the composite film strips 3' extend along the second direction on the surface of the solar cell layer and are arranged at intervals along the first direction, and each of the interconnected bus bars 2 on the surface of the solar cell 1 is fixed at multiple points by multiple composite film strips 3' intersecting with them, and the fixing points are the intersections of the interconnected bus bars 2 and the composite film strips 3'.

[0093] In embodiment 6, when the width of the interconnected busbars 2 is 0.27 mm and the interval between the interconnected busbars 2 is 8.75 mm, the width of the composite film strips 3' can be about 4 mm. The interval between the composite film strips 3' is about 8 mm. The amount of the composite film strips 3' is about 30% of the area of ​​the solar cell layer. Compared with embodiment 5, it has advantages in terms of cost and shading.

[0094] Embodiment 7 is essentially the same as embodiment 2, with the difference being that the solar cells 1 are busbar-less IBC back-to-back junction cells, the interconnected busbars 2 are all located on one side of the solar cell string, and the composite film 3 is used to coat with a single solar cell as the smallest coating unit, as shown in Figures 15 and 16.

[0095] The eighth embodiment is basically the same as the seventh embodiment, except that the composite film 3 covers the entire surface of the solar cell layer, with the entire solar cell layer being the smallest covering unit.

[0096] The ninth embodiment is basically the same as the fourth embodiment, except that a film-like grid line supporting layer and a liquid grid line bonding layer are successively coated.

[0097] The packaging adhesive layer 3-3 and the grid line adhesive layer 3-1 are liquid silica gel, and the grid line support layer 3-2 is PET, PVF, PMMA or PC.

[0098] Specific steps of the method for manufacturing a solar cell module in embodiment 9 are the following steps (a) to (d). In step (a), interconnected busbars 2 and solar cells 1 are manufactured in advance. Solar cells 1 are busbarless solar cells, and the busbarless solar cells have a plurality of pads.

[0099] (b) Manufacturing of solar cell strings The solar cells 1 are placed and arranged on a welding table. The interconnected bus bars 2 are welded on the pads to form a plurality of connection points 4, so that the interconnected bus bars 2 are pre-fixed to the solar cells 1, and the solar cells 1 are connected in series by the interconnected bus bars 2 to form a solar cell string.

[0100] (c) Module arrangement The laminate for module stacking is obtained by sequentially stacking a packaging backplane 6, applying liquid silica gel, stacking a grid line support layer 3-2, applying liquid silica gel, stacking a solar cell string, applying liquid silica gel, stacking a grid line support layer 3-2, applying liquid silica gel, and stacking a packaging panel 5. The method of applying liquid silica gel is to mix and apply the A / B components of liquid silica gel to the solar cell layer as the smallest coating unit.

[0101] (d) Module stacking The lamination is performed at a lamination temperature higher than the melting point of the low melting point weld layer of the interconnected busbars 2. During lamination, the low melting point weld layer of the interconnected busbars 2 is melted to form a good conductive connection with the Ag finger lines on the surface of the solar cells 1.

[0102] During lamination, the gridline support layer 3-2 is laminated onto the interconnected busbars 2 and the gridline bonding layer 3-1 is heated to a solid state. After lamination and cooling, the gridline bonding layer 3-1 and gridline support layer 3-2 firmly press the interconnected busbars 2 against the surface of the solar cell 1, thereby limiting movement of the interconnected busbars 2.

[0103] The tenth embodiment is essentially the same as the first embodiment, except that the cell grid line surface of the solar cell 1 has a low melting point weld layer, which melts at the lamination temperature and forms good electrical contact with the interconnected busbar 2.

[0104] Specifically, the interconnected busbars 2 are metal welded strips with a Sn coating layer, and the melting point of the Sn coating layer is about 230°C. The surface of the solar cells 1 is electroplated with Cu finger lines. Then, the surface of the Cu finger lines is electroplated with SnBi alloy, whose melting point is lower than 150°C. During lamination, the temperature of the module is raised to above 150°C, and the Sn-Bi alloy on the surface of the Cu finger lines melts and forms a good electrical connection with the interconnected busbars 2.

[0105] Embodiment 11 is essentially the same as embodiment 1, with the difference being that the surface of the interconnected busbar 2 has a conductive adhesive, which deforms under lamination pressure to form good electrical contact with the solar cell 1.

[0106] Specifically, the interconnected busbars 2 are metal weld strips with an electroconductive adhesive (ECA) coating layer, which may be deformed under lamination pressure to form good electrical connections with the metal finger lines on the surface of the solar cells 1. The metal weld strips are Cu weld strips, and the metal finger lines are Cu or Ag finger lines.

[0107] The embodiment 12 is basically the same as the embodiment 1, except that the grid line support layer 3-2 may use crosslinked EVA, POE, PVB and other materials. When the crosslinked EVA, POE, PVB and other materials are used as the grid line support layer 3-2, they are first crosslinked, and the crosslinking rate is preferably 80% to 100%. For example, the grid line support layer 3-2 and the grid line bonding layer 3-1 are both made of EVA material, because the light transmittance of the EVA film is much better than that of the PET film, so there is no need to limit the thickness of the EVA film used as the grid line support layer 3-2. In general, the grid line support layer 3-2 may be made by using a 300 um crosslinked EVA film after being fully crosslinked by radiation or heating, while the grid line bonding layer 3-1 may be made from a conventional EVA adhesive film with a thickness of 50 um.

[0108] In embodiment 13, a solar cell module includes a packaging structure and a solar cell layer packaged in the packaging structure. The solar cells 1 in the solar cell layer draw out current through the interconnected busbars 2. There are conductive or non-conductive connection points 4 between the solar cells 1 and the interconnected busbars 2 for preliminary fixation of the interconnected busbars 2 and the solar cells 1. The grid line bonding layer 3-1 and the grid line support layer 3-2 are provided on the surface of the solar cells 1 to completely fix the interconnected busbars 2 to the surface of the solar cells 1. The grid line support layer 3-2 adheres to the surface of the solar cells 1 by the bonding effect of the grid line bonding layer 3-1. The grid line support layer 3-2 is laminated on the interconnected busbars 2. The grid line bonding layer 3-1 is located between the grid line support layer 3-2 and the solar cells 1 for bonding the grid line support layer 3-2 to the surface of the solar cells 1. The thickness of the grid line bonding layer 3-1 is smaller than the thickness of the interconnected busbars 2. A packaging adhesive layer 3-3 is present between the grid line support layer 3-2 and the packaging structure on the same side, bonding the grid line support layer 3-2 and the packaging structure on the same side.

[0109] Compared with embodiment 1, the difference is that for the smallest covered unit such as solar cell 1, grid line support layer 3-2 is a whole film, and grid line bonding layer 3-1 is in the form of a film strip, as shown in FIG. 17. There is a gap between interconnected busbars 2 and grid line bonding layer 3-1. Since there is a gap between interconnected busbars 2 and grid line bonding layer 3-1, it is not excluded that the thickness of grid line bonding layer 3-1 may be slightly larger than the thickness of interconnected busbars 2 before the module is stacked. After stacking, grid line bonding layer 3-1 becomes thinner due to compression.

[0110] Of course, there may be variations in that the gridline support layer 3-2 is in the form of a membrane strip and the gridline attachment layer 3-1 is the entire membrane, as shown in FIG. 18, or that both the gridline attachment layer 3-1 and the gridline support layer 3-2 are in the form of membrane strips, as shown in FIG. 19.

[0111] In comparison with the thirteenth embodiment, the fourteenth embodiment differs from the thirteenth embodiment in that, as shown in FIG. 20 , the grid line support layer 3-2 is located between the grid line contact layer 3-1 and the solar cell 1, and the grid line support layer 3-2 only locally shields the grid line contact layer 3-1, and the shielded and non-shielded areas of the grid line contact layer 3-1 shielded by the grid line support layer 3-2 are respectively bonded to the grid line support layer 3-2 and the solar cell 1, thereby adhering the grid line support layer 3-2 to the surface of the solar cell 1.

[0112] 20, for the smallest covered unit such as solar cell 1, grid line support layer 3-2 is in the form of a film strip, grid line bonding layer 3-1 is the whole film, and grid line bonding layer 3-1 may be exactly the packaging bonding layer 3-3. The structure of the solar cell module includes packaging panel 5, grid line bonding layer 3-1, grid line support layer 3-2, solar cell layer, grid line support layer 3-2, grid line bonding layer 3-1, and packaging backplane 6.

[0113] Of course, the grid line supporting layer 3-2 and the grid line bonding layer 3-1 are both whole films, and the grid line supporting layer 3-2 has a hollow portion. The area, shape and distribution density of the hollow portion can be arbitrarily designed under the condition that the packaging quality of the module is ensured and the interconnected busbars 2 are securely fixed. [Explanation of symbols]

[0114] 1...Solar cell, 2…Interconnecting busbars 3…Composite membrane 3' Composite membrane strip 3-1…Grid line bonding layer 3-2…Grid line support layer 3-3…Packaging bonding layer 4…Connection point 5…Packaging panel 6…Packaging backplane 7…Adhesive film electrode with multi-busbar welding strip

Claims

1. A solar cell module comprising a solar cell layer, The solar cells in the solar cell layer conduct current through interconnected bus bars; a plurality of connection points between the solar cells and the interconnected busbars for pre-securing the interconnected busbars and the solar cells, and a linear contact between a surface of the interconnected busbars and the solar cells; a gridline adhesion layer and a gridline support layer are provided on the surface of the solar cell to securely attach the interconnected busbars to the surface of the solar cell; the interconnected bus bars are embedded in the gridline bonding layer; the grid line support layer is adhered to the surface of the solar cell by the adhesion effect of the grid line adhesion layer; The gridline support layer is laminated over the interconnected busbars. A solar cell module characterized by:

2. the gridline adhesion layer is positioned between the gridline support layer and the solar cell for adhering the gridline support layer to a surface of the solar cell; The solar module of claim 1 , wherein the gridline bonding layer has a thickness less than a thickness of the interconnected busbars.

3. 3. The solar cell module of claim 2, further comprising a packaging structure, the solar cell layer being packaged in the packaging structure, the gridline bonding layer and the gridline support layer covering the interconnected busbars on a surface of the solar cells, the surface of the interconnected busbars being bonded to a surface of the solar cells by a molten low melting point weld layer, and a packaging bonding layer being present between the gridline support layer and the packaging structure for bonding the gridline support layer and the packaging structure on the same side to each other.

4. The solar cell module according to claim 2, wherein the minimum covering unit is: the gridline support layer and the gridline attachment layer are both integral films; or the gridline support layer is an entire membrane and the gridline attachment layer is a membrane strip; or the gridline support layer is a membrane strip and the gridline attachment layer is the entire membrane; or A solar cell module, wherein both the gridline attachment layer and the gridline support layer are film strips.

5. 3. The solar cell module of claim 2, wherein the grid line attachment layer and the grid line support layer are in the form of a composite film strip including a grid line attachment layer and a grid line support layer, and at least one solar cell is considered as a minimum covered unit; The composite membrane strips extend along a first direction and are spaced apart along a second direction; or the composite membrane strips extend along the second direction and are spaced apart along the first direction; The solar cell module, wherein the first direction is an extension direction of the interconnected bus bars, and the second direction is perpendicular to the extension direction of the interconnected bus bars.

6. the grid line support layer is located between the grid line contact layer and the solar cell; the grid line support layer shields the grid line bonding layer only in a localized area; the shielded and unshielded areas of the grid line bonding layer shielded by the grid line support layer are bonded to the grid line support layer and the solar cell, respectively, to bond the grid line support layer to a surface of the solar cell; The solar cell module according to claim 1 .

7. For the smallest covering unit, the grid line support layer and the grid line attachment layer are both full films, and the grid line support layer has a hollow, or 7. The solar cell module of claim 6, wherein the gridline support layer is a film strip and the gridline attachment layer is the entire film.

8. A method for manufacturing the solar cell module according to claim 1, comprising the steps of: First, the interconnected bus bars are pre-fixed on the surface of the solar cell via conductive or non-conductive connection points; followed by covering the surface of the solar cell with a gridline support layer and a gridline adhesion layer; applying pressure to the gridline support layer and the gridline attachment layer; securing the interconnected bus bars to a surface of the solar cell by the gridline support layer; A method for providing the above.

9. The method includes a solar cell string manufacturing step and a module stacking step, In the solar cell string manufacturing step, the interconnected bus bars are pre-fixed to the surface of the solar cells via conductive or non-conductive connection points; during the module lamination step, lamination pressure applied to the grid line support layer and the grid line bonding layer ensures that the interconnected bus bars are fully secured to the surface of the solar cells by the grid line support layer; The method of claim 8 , wherein the interconnected bus bars are brought into electrical contact with the solar cells during the module stacking step.

10. The grid line attachment layer and the grid line support layer are each used for coating in succession in the form of a film, or The grid line attachment layer and the grid line support layer are used to coat in the form of a composite film comprising the grid line attachment layer and the grid line support layer; or The grid line bonding layer and the grid line support layer are used for coating in the form of a composite membrane strip including a lid wire support layer, or The method of claim 8 , wherein the gridline support layer in the form of a film and the gridline attachment layer in the form of a liquid are used for coating in sequence.

11. 9. The method of claim 8, wherein the connection points between the interconnected bus bars and the solar cells are formed by welding or gluing.

12. 1. A method for manufacturing a solar cell module, comprising: First, manufacturing a solar cell string such that the interconnected bus bars of the solar cell string are pre-fixed to a surface of the solar cell via conductive or non-conductive connection points; then covering the interconnected bus bars on a surface of the solar cell with a gridline adhesion layer and a gridline support layer, the gridline adhesion layer being between the gridline support layer and the solar cell; Finally, packaging the solar cells in a solar cell module packaging structure using a module lamination process, and completely fixing the interconnected bus bars to the surface of the solar cells using the gridline attachment layer and the gridline support layer. Including, the grid line bonding layer is bonded to a surface of the solar cell using the grid line bonding layer; the thickness of the grid line bonding layer is less than the thickness of the interconnected bus bars; the gridline bonding layer is heated to flow through the module lamination process, such that the interconnected bus bars are embedded within the gridline bonding layer and the gridline support layer is laminated onto the interconnected bus bars; A method of manufacturing a solar cell module, wherein the surfaces of the interconnected bus bars have low melting point weld layers that melt at lamination temperatures to form electrical contacts with the surfaces of the solar cells.

13. The method includes a solar cell string manufacturing step, a module arrangement step, and a module stacking step, the grid line attachment layer and the grid line support layer are adhered to a surface of the solar cell string as a smallest coated unit, forming a composite film strip including the grid line attachment layer and the grid line support layer; the composite film strips extend along a first direction and are arranged at intervals along a second direction on a surface of the solar cell string, the first direction being an extension direction of the interconnected bus bars and the second direction being perpendicular to the extension direction of the interconnected bus bars; In the module arrangement step, the composite film strip is arranged on the solar cell string bonded together; or The method includes a solar cell string manufacturing step, a solar cell string arrangement step, a module arrangement step, and a module stacking step, In the solar cell string arrangement step, the solar cell strings are arranged in a solar cell layer as a whole according to module specifications and requirements; the grid line attachment layer and the grid line support layer are adhered to a surface of the solar cell layer as a smallest covering unit, and are in the form of a composite film strip including the grid line attachment layer and the grid line support layer; the composite film strips extend along a second direction and are arranged at intervals along a first direction on a surface of the solar cell layer, the first direction being an extension direction of the interconnected bus bars and the second direction being perpendicular to the extension direction of the interconnected bus bars; The method for manufacturing a solar cell module according to claim 12 , wherein in the module arranging step, module arrangement is performed on the solar cell layer adhered with the composite film strip.

14. The grid line adhesive layer and the grid line support layer are used for covering in the form of a composite film including the grid line adhesive layer and the grid line support layer, and the composite film is a three-layer composite structure including a packaging adhesive layer, the grid line support layer and the grid line adhesive layer; 13. The method for manufacturing a solar cell module according to claim 12, wherein the packaging adhesive layer is used to attach the grid line support layer to a packaging structure on the same side, and the packaging adhesive layer and the grid line adhesive layer are located on the front side and the back side of the grid line support layer, respectively.

Images