Photovoltaic module, preparation method, and soldering fixture

Abstract

The present application relates to the technical field of photovoltaic modules, and discloses a photovoltaic module, a preparation method, and a soldering fixture. The photovoltaic module comprises one or more cell strings, each cell string comprising a plurality of cells, and a plurality of high-temperature solder ribbons and a plurality of low-temperature solder ribbons connecting the cells in series. Each of the cells is provided with a plurality of first busbars; each of the high-temperature solder ribbons connects two corresponding first busbars of two adjacent cells in series; and each of the low-temperature solder ribbons is disposed between two adjacent first busbars on a cell and connects two adjacent cells in series. In the present embodiment, by providing both high-temperature solder ribbons and low-temperature solder ribbons in the photovoltaic module and retaining a portion of the busbars of the cells, the objectives of reducing silver paste costs and encapsulant film grammage can be achieved, while avoiding the problem of photovoltaic modules being prone to failure during long-term outdoor operation.

Description

A photovoltaic module, its preparation method and welding fixture Technical Field

[0001] This disclosure relates to the field of photovoltaic module technology, and in particular to a photovoltaic module, a preparation method and welding fixture. Background Technology

[0002] Cost reduction and efficiency improvement have become one of the development directions of photovoltaic modules. Currently, the approach is either to increase the number of main grids to reduce the diameter of the solder ribbon and the weight of the encapsulant film, or to omit the main grids and directly use low-temperature solder ribbons to collect current from the fine grids, in order to achieve the goal of cost reduction and efficiency improvement of photovoltaic modules.

[0003] However, the increased number of main grids leads to a greater amount of silver paste required for printing the main grids, resulting in higher costs and significantly limiting the potential for cost reduction. As for structures that collect current directly through low-temperature solder ribbons, the small contact area between the ribbons and the grid limits current collection capacity, and the ribbons are prone to detachment and failure during use. Therefore, there is an urgent need for a photovoltaic module with lower manufacturing costs and a stable structure that is less prone to failure. Summary of the Invention

[0004] In view of this, the present disclosure provides a photovoltaic module, a preparation method and a welding fixture, which can reduce the cost of silver paste and the weight of encapsulant film, and avoid the problem of photovoltaic modules being prone to failure during long-term outdoor operation.

[0005] To achieve the above objectives, according to one aspect of the present disclosure, a photovoltaic module is provided, comprising: one or more cell strings, wherein,

[0006] The aforementioned battery string includes multiple battery cells and multiple high-temperature solder strips and multiple low-temperature solder strips connecting the aforementioned battery cells;

[0007] Each of the above-mentioned solar cells is provided with multiple first main grids;

[0008] Each of the above-mentioned high-temperature welding strips is connected in series with the corresponding two first main grids of two adjacent above-mentioned solar cells.

[0009] Each of the aforementioned low-temperature solder strips is disposed between two adjacent first main grids on the aforementioned solar cell and connected in series with two adjacent solar cells.

[0010] To achieve the above objectives, according to another aspect of the embodiments of this disclosure, a method for manufacturing a photovoltaic module is provided, comprising:

[0011] Repeat steps N1 to N2 until the battery string is laid out:

[0012] N1. Lay one end of the high-temperature solder ribbon on the first main grid of the current cell; and lay one end of the low-temperature solder ribbon between two adjacent first main grids of the current cell, and fix the low-temperature solder ribbon.

[0013] N2, lay another battery cell on the other end of the high-temperature solder strip and the other end of the low-temperature solder strip, and use the other battery cell as the current battery cell, and execute N1;

[0014] Welding fixtures are used to fix the laid battery strings, and the aforementioned high-temperature welding strips in the laid battery strings are welded at high temperature.

[0015] Remove the above welding fixtures, laminate the battery string that has been welded at high temperature, and perform low-temperature welding of the above low-temperature solder strips during the lamination process to obtain the welded battery string.

[0016] Multiple welded battery strings are assembled into a photovoltaic module.

[0017] To achieve the above objectives, according to another aspect of the present disclosure, a welding fixture for photovoltaic modules is provided, applied to the photovoltaic module manufacturing method described above, comprising: a pressure packing component and a welding support component;

[0018] The aforementioned press assembly includes a connecting portion, a plurality of pressing blocks, and a plurality of pressing needle portions, wherein the plurality of pressing needle portions are spaced apart from the connecting portion, and the plurality of pressing blocks are disposed in the connecting portion and located between adjacent pressing needle portions.

[0019] The aforementioned welding support component includes a heating device, a base plate, and a heat-insulating interlayer spaced apart on the base plate; the aforementioned heating device is connected to the aforementioned base plate;

[0020] During the use of the aforementioned welding fixture, the aforementioned pressure plate component is placed above the already laid battery string; the aforementioned welding support component is used to support the laid battery string; wherein, the aforementioned pressure pin portion corresponds to the high-temperature welding strip on the upper surface of the laid battery string; the aforementioned pressure block portion corresponds to the low-temperature welding strip on the upper surface of the laid battery string; the aforementioned heat insulation layer corresponds to the low-temperature welding strip on the lower surface of the laid battery string; the aforementioned heating device provides heat to the aforementioned base plate to perform high-temperature welding on the high-temperature welding strip in the laid battery string.

[0021] One embodiment disclosed above has the following advantages or beneficial effects: by simultaneously setting high-temperature solder ribbons and low-temperature solder ribbons in the photovoltaic module and retaining part of the main busbar in the cell, it is possible to reduce the cost of silver paste and the weight of encapsulant film, and avoid the problem of photovoltaic modules being prone to failure during long-term outdoor operation.

[0022] The further effects of the aforementioned unconventional alternative methods will be explained below in conjunction with specific implementation methods. Attached Figure Description

[0023] The accompanying drawings are provided to better understand this disclosure and do not constitute an undue limitation thereof. Wherein:

[0024] Figure 1 is a schematic diagram of the structure of the solar cell in the first type of photovoltaic module in the prior art;

[0025] Figure 2 is a structural schematic diagram of the location of the main busbar welding contact point in the first type of photovoltaic module in the prior art;

[0026] Figure 3 is a schematic diagram of the connection structure between the low-temperature solder ribbon and the fine grid in the second type of photovoltaic module in the prior art;

[0027] Figure 4 is a schematic diagram of a first structure of a photovoltaic module cell according to an embodiment of the present disclosure;

[0028] Figure 5 is a schematic diagram of a second structure of a photovoltaic module cell according to an embodiment of the present disclosure;

[0029] Figure 6 is a schematic diagram of a third structure of a photovoltaic module cell according to an embodiment of the present disclosure;

[0030] Figure 7 is a schematic diagram of a fourth structure of a photovoltaic module cell according to an embodiment of the present disclosure;

[0031] Figure 8 is a schematic diagram of a fifth structure of a solar cell in a photovoltaic module according to an embodiment of the present disclosure;

[0032] Figure 9 is a schematic diagram of a sixth structure of a solar cell in a photovoltaic module according to an embodiment of the present disclosure;

[0033] Figure 10 is a schematic flowchart of a method for preparing a photovoltaic module according to an embodiment of the present disclosure;

[0034] Figure 11 is a schematic diagram of a battery cell with high-temperature solder strips and low-temperature solder strips laid according to an embodiment of the present disclosure;

[0035] Figure 12 is a schematic diagram of laying battery strings using an adhesive dot bonding method according to an embodiment of the present disclosure;

[0036] Figure 13 is a schematic diagram of laying high-temperature solder ribbons and low-temperature solder ribbons in a battery cell with printed adhesive dots according to an embodiment of the present disclosure.

[0037] Figure 14 is a schematic diagram of laying battery strings using an adhesive tape method according to an embodiment of the present disclosure;

[0038] Figure 15 is a schematic diagram of a structure for fixing a low-temperature solder ribbon to a battery cell using tape according to an embodiment of the present disclosure;

[0039] Figure 16 is a structural schematic diagram of the press-out component according to an embodiment of the present disclosure;

[0040] Figure 17 is a structural schematic diagram of a welding support component according to an embodiment of the present disclosure;

[0041] Figure 18 is a schematic diagram of the pressure needle portion according to an embodiment of the present disclosure;

[0042] Figure 19 is a schematic diagram of a first structure of the pressing block according to an embodiment of the present disclosure;

[0043] Figure 20 is a schematic diagram of a second structure of the pressing part according to an embodiment of the present disclosure.

[0044] Reference numerals: 1-First main grid; 101-First main grid line; 102-Main grid welding contact point; 2-High-temperature welding strip; 3-Fine grid; 301-Fine grid welding contact point; 302-First fine grid segment; 303-Second fine grid segment; 4-Segmented main grid; 5-Second main grid; 6-Low temperature welding strip; 7-Glue dot; 8-Adhesive tape; 9-Pressure packing component; 901-Connecting part; 9011-First connecting part; 9012-Second connecting part; 902-Pressure block part; 9021-Reflective layer; 9022-Heat insulation pad; 90221-Groove; 903-Pressure needle part; 9031-Elastic component; 90311-Snap ring; 90312-Spring; 9032-Pressure needle body; 904-Frame; 10-Welding support component; 1001-Heating device; 1002-Base plate; 1003-Heat insulation interlayer. Detailed Implementation

[0045] In photovoltaic (PV) modules, an encapsulant film is used to fill the space between the PV cell array (formed by solar cells and solder ribbons) and the glass to reduce vibration and buffer stress on the PV cell array caused by environmental factors such as temperature changes during use, thus providing stable mechanical support for the PV module. While maintaining PV module performance, increasing the number of solder ribbons per unit area of ​​the PV cell array allows for the use of smaller diameter solder ribbons, reducing the gap and height difference between the PV cell array and the glass. Furthermore, thinner solder ribbons exhibit less temperature-induced expansion and contraction, resulting in more uniform stress on the encapsulant film. Therefore, when the solder ribbon diameter is small and the number of ribbons is large, a thinner encapsulant film can be used, thereby reducing the film's basis weight.

[0046] Currently, there are two main types of commonly used photovoltaic modules.

[0047] The first method involves laying high-temperature solder ribbons 2 on solar cells with spaced first main grids 1 and then performing high-temperature welding to obtain a photovoltaic module. In this case, the cell layout can be as shown in Figure 1. The first main grids 1 are evenly distributed at the same intervals on the cell, and each first main grid 1 includes a first main grid line 101 and spaced main grid solder contact points 102 (main grid PAD points). As shown in Figure 2, in this type of photovoltaic module, after high-temperature welding, the high-temperature solder ribbons 2 can be laid out at the positions of the main grid solder contact points 102 and form a firm contact with them. Therefore, this type of photovoltaic module has the advantage of high reliability. However, since all main grids are retained in the cell, the cost reduction potential of the silver paste is greatly limited. Furthermore, due to cost constraints, the first main grid 1 in the cell is generally 16 grids (Busbar, BB), making it impossible to further increase the number of high-temperature solder ribbons 2, and making it difficult to reduce the cost of the encapsulant film weight.

[0048] The second method involves laying low-temperature solder ribbons 6 on solar cells that only have fine grids 3 and no first main grid 1, and then performing low-temperature welding to obtain a photovoltaic module. Because this type of photovoltaic module lacks a main grid, the cost of silver paste is significantly reduced, and the number of low-temperature solder ribbons 6 can reach 24, while also reducing the weight of the encapsulant film. However, as shown in Figure 3, the low-temperature solder ribbons 6 are in direct contact with the fine grids 3, resulting in a small contact area, making alloying difficult and leading to lower reliability. There may even be gaps between the low-temperature solder ribbons 6 and the fine grids 3, causing the low-temperature solder ribbons 6 to easily detach and fail during outdoor use, affecting current collection capacity and the lifespan of the photovoltaic module.

[0049] To address the aforementioned problems in the prior art, this disclosure provides a novel photovoltaic module and its fabrication method, as well as a grid line fabrication fixture.

[0050] The exemplary embodiments of this disclosure are described below with reference to the accompanying drawings, including various details of the embodiments to aid understanding, and should be considered merely exemplary. Therefore, those skilled in the art will recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of this disclosure. Similarly, for clarity and brevity, descriptions of well-known functions and structures are omitted in the following description.

[0051] It should be noted that, unless otherwise specified, the embodiments of this disclosure and the technical features thereof can be combined with each other.

[0052] It should be noted that the electrical connection involved in the embodiments of this disclosure refers to a connection method that can achieve electrical conduction, which can be a direct connection or an indirect connection.

[0053] The photovoltaic module of this disclosure mainly includes one or more cell strings, wherein the cell string includes multiple cells and multiple high-temperature solder ribbons 2 and multiple low-temperature solder ribbons 6 connected in series with the cells. As shown in Figures 4, 5 and 11, each cell is provided with multiple first main grids 1; each high-temperature solder ribbon 2 is connected in series with two corresponding first main grids 1 of two adjacent cells; each low-temperature solder ribbon 6 is disposed between two adjacent first main grids 1 on the cell and is connected in series with two adjacent cells.

[0054] On each solar cell, multiple first main grids 1 extend from one end of the cell to the other along a first direction and are spaced apart. The spacing between the multiple first main grids 1 can be the same or different. Each first main grid 1 may include a first main grid line 101 and a plurality of spaced-apart main grid solder contact points 102. On each solar cell, multiple fine grids 3 are provided, extending from one end of the solar cell to the other along a second direction, wherein the second direction is perpendicular to the first direction.

[0055] High-temperature solder strip 2 covers the first main grid 1, and low-temperature solder strip 6 is disposed between two adjacent first main grids 1. It can be understood that multiple first main grids 1 can exist between two low-temperature solder strips 6, that is, multiple high-temperature solder strips 2 can exist.

[0056] Preferably, for the second structure of the battery cell shown in Figure 5, when high-temperature solder ribbons 2 and low-temperature solder ribbons 6 are provided on its surface to form a battery string, the high-temperature solder ribbons 2 and low-temperature solder ribbons 6 can be arranged alternately, that is, each high-temperature solder ribbon 2 is arranged between two adjacent low-temperature solder ribbons 6 and covers the first main grid 1, and each low-temperature solder ribbon 6 is arranged between two adjacent high-temperature solder ribbons 2, that is, between two adjacent first main grids 1.

[0057] In a photovoltaic module, each high-temperature solder ribbon 2 connects in series to the two first main grids 1 of two adjacent cells. For example, in cell a, one high-temperature solder ribbon 2 covers the first first main grid 1. In cell b, which is adjacent to cell a, the same high-temperature solder ribbon 2 should also cover its first first main grid 1, thus connecting the corresponding first first main grids 1 in adjacent cells a and b. Similarly, on adjacent cells of a photovoltaic module, each low-temperature solder ribbon 6 is disposed between the two adjacent first main grids 1 of two adjacent cells. For example, in cell a, one low-temperature solder ribbon 6 is disposed between the first first main grid 1 and the second first main grid 1 adjacent to the first first main grid 1. Then, in cell b, which is adjacent to cell a, the same low-temperature solder ribbon 6 should also be disposed between the first first main grid 1 and the second first main grid 1, thus connecting cell a and cell b in series.

[0058] In addition, to ensure the reliability of photovoltaic modules during long-term outdoor operation while reducing costs, the total number of high-temperature solder ribbons 2 and low-temperature solder ribbons 6 on the surface of each cell string of a photovoltaic module can be 16 to 30. As an example, the total number of high-temperature solder ribbons 2 and low-temperature solder ribbons 6 on the surface of each cell string of a photovoltaic module can be 16, 20, 25, or 30, etc.

[0059] By simultaneously incorporating high-temperature solder ribbons 2 and low-temperature solder ribbons 6 into the photovoltaic module, the reliability of the photovoltaic module during long-term outdoor operation is ensured. Even if the low-temperature solder ribbon 6 detaches during long-term operation, the high-temperature solder ribbon 2, which maintains a secure connection, remains in contact and can collect current, thus avoiding the problem of reduced photovoltaic module lifespan due to the detachment of the low-temperature solder ribbon 6. Furthermore, the use of multiple low-temperature solder ribbons 6 reduces the number of main grids, lowers the cost of silver paste and encapsulant film, and achieves cost reduction for the photovoltaic module.

[0060] In an optional embodiment, the number of high-temperature solder strips 2 on the surface of the battery string is greater than or equal to the number of low-temperature solder strips 6.

[0061] To ensure the reliability of photovoltaic modules for long-term outdoor use and to avoid a decrease in current collection capacity due to the detachment of low-temperature solder ribbons 6, the number of high-temperature solder ribbons 2 on the surface of each cell string should be greater than or equal to the number of low-temperature solder ribbons 6.

[0062] In an optional embodiment, the solar cell further includes: fine grid solder contact points 301 disposed between two adjacent first main grids 1. The low-temperature solder strip 6 is electrically connected to the solder contact points between two adjacent first main grids 1.

[0063] Specifically, as shown in Figure 6, one or more fine grid welding contact points 301 are provided between two adjacent first main grids 1. When there are multiple fine grid welding contact points 301, they are spaced apart along the extending direction of the first main grid 1, i.e., the first direction. The total area of ​​all fine grid welding contact points 301 on the upper or lower surface of each solar cell is less than 0.5 mm². 2 This ensures that silver paste costs can be reduced in this situation. For example, the total area of ​​all fine grid solder contact points 301 on the upper or lower surface of each solar cell can be 0.1 mm². 2 0.2mm 2 0.4mm 2 or 0.5mm 2 wait.

[0064] In a photovoltaic module, a low-temperature solder ribbon 6 is electrically connected to a fine grid solder contact point 301 disposed between two adjacent first main grids 1. When there are multiple fine grid solder contact points 301, the low-temperature solder ribbon 6 is deployed along the multiple fine grid solder contact points 301 between two adjacent first main grids 1.

[0065] It should be noted that the fine grid welding contact point 301 should be set in the fine grid 3 to help enhance the contact reliability between the fine grid 3 and the low-temperature welding strip 6, and at the same time improve the current collection capability of the low-temperature welding strip 6.

[0066] In an optional embodiment, as shown in FIG7, the battery cell further includes: a plurality of segmented main grids 4 disposed between two adjacent first main grids 1. The cryogenic solder ribbon 6 is deployed along the plurality of segmented main grids 4 and electrically connected to the plurality of segmented main grids 4.

[0067] Each segment of the main gate 4 can be 2-50 mm long and 10-20 μm wide, and each segment of the main gate 4 should be electrically connected to at least one fine gate 3 to collect the current on the fine gate 3. As an example, the length of each segment of the main gate 4 can be 2 mm, 10 mm, 25 mm or 50 mm, etc., and the width of each segment of the main gate 4 can be 10 μm, 13 μm, 15 μm or 20 μm, etc.

[0068] The segmented main grid 4 extends along a first direction and is arranged parallel to the first main grid 1. The low-temperature solder ribbon 6 is deployed along and covers the segmented main grid 4, collecting current from the fine grid 3 electrically connected to it and the segmented main grid 4 it covers. By setting the segmented main grid 4, the possibility of the low-temperature solder ribbon 6 falling off is reduced, the current collection capacity is improved, and the cost of silver paste is reduced by controlling the length and width of the segmented main grid 4.

[0069] In an optional embodiment, as shown in FIG8, the solar cell further includes a second main grid 5 disposed between two adjacent first main grids 1. The low-temperature solder ribbon 6 is deployed along the second main grid 5 and electrically connected to the second main grid 5.

[0070] The width of the second main gate 5 is smaller than the width of the first main gate 1. Preferably, the width of the second main gate 5 can be 10-20 μm. As an example, the width of the second main gate 5 can be 10 μm, 12 μm, 16 μm, or 20 μm, etc.

[0071] The second main grid 5 extends from one end of the solar cell to the other along a first direction, and is arranged parallel to the first main grid 1. The second main grid 5 is electrically connected to each fine grid 3 on the solar cell to collect the current on the fine grid 3. A low-temperature solder ribbon 6 is deployed along the second main grid 5 and covers the second main grid 5 to collect current from it. By setting the second main grid 5, the possibility of the second solder ribbon detaching is reduced, further improving the current collection capability. Furthermore, by controlling the width of the second main grid 5 to be smaller than the width of the first main grid 1, the cost of the silver paste is reduced.

[0072] In an optional embodiment, as shown in FIG9, the solar cell includes a grid 3 comprising alternating first grid segments 302 and second grid segments 303, wherein the width of the second grid segment 303 is greater than the width of the first grid segment 302; the first main grid 1 is electrically connected to the first grid segment 302. The low-temperature solder ribbon 6 is electrically connected to the second grid segment 303.

[0073] Specifically, the fine grid 3 of the battery cell includes a first fine grid segment 302 and a second fine grid segment 303 with a width greater than the first fine grid segment 302. There may be one or more second fine grid segments 303 in each fine grid 3.

[0074] The width of the second fine gate segment 303 can be 10-80 μm. For example, the width of the second fine gate segment 303 can be 10 μm, 30 μm, 50 μm, or 80 μm. By controlling the width of the second fine gate segment 303, the contact area between the low-temperature solder strip 6 and the second fine gate segment 303 can be increased, while simultaneously improving the current collection capability of the second fine gate segment 303.

[0075] Furthermore, the length of the second fine grid segment 303 can be 1-2 mm, and the total number of the second fine grid segments 303 on the upper or lower surface of each solar cell can be 3-200. For example, the length of the second fine grid segment 303 can be 1 mm, 1.5 mm, or 2 mm, etc.; and the total number of the second fine grid segments 303 on the upper or lower surface of each solar cell can be 3, 20, 80, 150, 200, etc. By controlling the length of the second fine grid segment 303 and the total number of the second fine grid segments 303 on each surface of the solar cell, the cost of silver paste can be reduced.

[0076] In an optional embodiment, as shown in Figure 4 or Figure 5, no fine grid solder contact point 301, segmented main grid 4, or second main grid 5 may be provided between two adjacent first main grids 1. In addition, the aforementioned fine grid 3 may only include the first fine grid segment 302, so that the low-temperature solder ribbon 6 is directly provided between two adjacent first main grids 1 and electrically connected to the fine grid 3, thereby further reducing the cost of silver paste.

[0077] It is understood that, as described above, several structures, such as fine grids 3, segmented main grids 4, or second main grids 5, can be simultaneously disposed in the same solar cell, including fine grid segments 302 and 303. For example, on the surface of a solar cell, several welding contact points can be disposed between adjacent first main grids 1 and second main grids 1, and a second main grid 5 can be disposed between adjacent second and third main grids 1. As another example, on the surface of a solar cell, several segmented main grids 4 and several fine grid welding contact points 301 can be disposed between adjacent second and third main grids 1, and the fine grid 3 includes first fine grid segments 302 and second fine grid segments 303.

[0078] In one optional embodiment, the thickness of the aforementioned solar cell is 80-140 μm. By simultaneously incorporating low-temperature solder ribbons 6 and high-temperature solder ribbons 2 into the solar cell string of the photovoltaic module, the number of first main busbars 1 is reduced, while the number of solder ribbons is increased. Ultra-fine solder ribbons can be used, making it suitable for thinner solar cells.

[0079] Optionally, the high-temperature solder strip 2 includes, but is not limited to, solder strips with a SnPb alloy coating, with a diameter of 0.1-0.26 mm and a melting point greater than 180°C. As an example, the diameter of the high-temperature solder strip 2 can be 0.1 mm, 0.15 mm, 0.20 mm, or 0.26 mm, etc., and the melting point can be 181°C, 185°C, or 190°C, etc.

[0080] Optionally, the low-temperature solder strip 6 includes, but is not limited to, solder strips with a SnPbBi alloy coating, having a diameter of 0.1-0.26 mm and a melting point of 120-160°C. As an example, the diameter of the low-temperature solder strip 6 can be 0.1 mm, 0.16 mm, 0.22 mm, or 0.26 mm, and the melting point can be 120°C, 130°C, 140°C, or 160°C, etc.

[0081] The solar cells used in photovoltaic modules can be passivated emitter and rear cell (PERC), heterojunction cell (HJT), tunnel oxide passivating contact (TOPCon), or back contact (BC), but are not limited to these.

[0082] According to the photovoltaic module of the present disclosure, by simultaneously setting high-temperature solder ribbon 2 and low-temperature solder ribbon 6 in the photovoltaic module, and only retaining part of the main busbar in the cell, the number of solder ribbons is increased to a certain extent. Both high-temperature solder ribbon 2 and low-temperature solder ribbon 6 can use solder ribbons with smaller diameters, which achieves the purpose of reducing the cost of silver paste and the weight of encapsulant film. At the same time, the retention of high-temperature solder ribbon 2 can also avoid the problem of photovoltaic module failure during long-term outdoor operation, so that the photovoltaic module has good stability.

[0083] Even if the low-temperature solder ribbon 6 falls off during long-term outdoor operation, current can still be collected through the high-temperature solder ribbon 2, which increases the lifespan of the photovoltaic module compared to a photovoltaic module with only the low-temperature solder ribbon 6.

[0084] Figure 10 is a schematic flowchart of a photovoltaic module fabrication method according to an embodiment of the present disclosure. As shown in Figure 10, the photovoltaic module fabrication method according to an embodiment of the present disclosure includes the following steps A1 to A4:

[0085] Step A1: Repeat steps N1 to N2 until the battery string is laid out.

[0086] N1. Lay one end of the high-temperature solder ribbon 2 on the first main grid 1 of the current battery cell; and lay one end of the low-temperature solder ribbon 6 between two adjacent first main grids 1 of the current battery cell, and fix the low-temperature solder ribbon 6.

[0087] N2, lay another battery cell on the other end of the high-temperature solder strip 2 and the other end of the low-temperature solder strip 6, and use the other battery cell as the current battery cell, and execute N1;

[0088] Step A2: Use welding fixtures to fix the laid battery string and perform high-temperature welding on the high-temperature welding strip 2 in the laid battery string.

[0089] Step A3: Remove the above welding fixture, laminate the battery string that has been welded at high temperature, and perform low-temperature welding of the low-temperature welding strip 6 during the lamination process to obtain the welded battery string.

[0090] Step A4: Assemble the welded battery strings into a photovoltaic module.

[0091] To simplify the fabrication process of photovoltaic modules with high-temperature solder ribbons 2 and low-temperature solder ribbons 6, both high-temperature solder ribbons 2 and low-temperature solder ribbons 6 can be laid into adjacent cells in a stringer, interconnecting multiple cells to form a cell string. This allows for direct high-temperature welding of the laid cell strings. During the high-temperature welding process, the high-temperature solder ribbons 2 are also welded at high temperatures, achieving alloying between the high-temperature solder ribbons 2 and the first main grid 1. After high-temperature welding, the welded cell strings can be arranged into the corresponding arrangement structure of the photovoltaic module, and then laminated. During lamination, the low-temperature solder ribbons 6 are welded at low temperatures using the lamination temperature, achieving alloying between the low-temperature solder ribbons 6 and the fine grid 3. After lamination, framing and other operations can be performed to obtain the photovoltaic module. Therefore, this embodiment achieves low-temperature welding during lamination by utilizing the lamination temperature, eliminating the need for additional fabrication processes for photovoltaic modules with both high-temperature solder ribbons 2 and low-temperature solder ribbons 6. The high-temperature welding can be infrared welding, but is not limited to this method.

[0092] Specifically, taking a battery cell with the positive and negative electrodes located on the upper and lower surfaces respectively, and a battery cell with both the positive and negative electrodes located on the lower surface as examples, step A1 will be explained in detail:

[0093] For a battery cell with the positive and negative electrodes located on the upper and lower surfaces respectively, step A1 specifically includes: First, laying high-temperature solder ribbons 2 and low-temperature solder ribbons 6 on the string bonding machine. Referring to Figure 11, the current battery cell is placed on the laid high-temperature solder ribbons 2 and low-temperature solder ribbons 6, so that the high-temperature solder ribbons 2 correspond to the first main grid 1 of the current battery cell, and the low-temperature solder ribbons 6 correspond to the positions between two adjacent first main grids 1, thus completing the solder ribbon laying on the lower surface of the current battery cell. N1, Laying high-temperature solder ribbons 2 and low-temperature solder ribbons 6 at the corresponding positions on the upper surface of the current battery cell. N2, Laying another battery cell, aligning each first main grid 1 of the other battery cell with each first main grid 1 of the current battery cell, so that the two battery cells are placed correspondingly, and the other end of the high-temperature solder ribbons 2 and low-temperature solder ribbons 6 on the upper surface of the current battery cell is located on the lower surface of the other battery cell. Using the other battery cell as the current battery cell, repeating steps N1 and N2 until a battery string is laid.

[0094] For a battery cell where both the positive and negative electrodes are located on the lower surface, step A1 specifically includes: N1, laying high-temperature solder ribbons 2 and low-temperature solder ribbons 6 on a string bonding machine, and then laying the current battery cell on top of the laid high-temperature solder ribbons 2 and low-temperature solder ribbons 6, so that the high-temperature solder ribbons 2 correspond to the first main grid 1 of the current battery cell, and the low-temperature solder ribbons 6 correspond to the positions between two adjacent first main grids 1, thus completing the solder ribbon laying of the current battery cell. N2, laying another battery cell, aligning each first main grid 1 of the other battery cell with each first main grid 1 of the current battery cell, so that the two battery cells are placed correspondingly, with the other ends of the high-temperature solder ribbons 2 and low-temperature solder ribbons 6 of the current battery cell located at corresponding positions on the lower surface of the other battery cell. Using the other battery cell as the current battery cell, laying high-temperature solder ribbons and low-temperature solder ribbons on the surfaces of the current battery cell and the next battery cell, repeating steps N1 and N2 until a battery string is laid.

[0095] It should be noted that for cells not located at the edge of the battery string, one end of each solder strip connects the positive terminal of the current cell to the negative terminal of another cell; for two cells located at the edge of the battery string, the solder strips not connected to adjacent cells are connected to the busbar.

[0096] After the battery strings are laid out on the stringer, welding fixtures are used to fix the battery strings to prevent displacement of the high-temperature welding ribbon 2 and the low-temperature welding ribbon 6. Simultaneously, the low-temperature welding ribbon 6 is provided with heat insulation protection. Through the cooperation of the welding fixtures and the stringer, the battery strings are welded at high temperature, ensuring reliable contact between the high-temperature welding ribbon 2 and the first main grid 1. Furthermore, during the high-temperature welding process, it is necessary to ensure that the low-temperature welding ribbon 6 does not alloy with the fine grid 3, as this could lead to grid breakage and negatively impact the power and reliability of the photovoltaic module.

[0097] After high-temperature welding is completed, the welding fixture is removed, and the high-temperature welded cell strings are arranged into the cell string arrangement structure of the photovoltaic module and laminated. The temperature during the lamination process is used to perform low-temperature welding on the low-temperature solder strip 6, so that the low-temperature solder strip 6 and the fine grid 3 are alloyed to form good contact.

[0098] Alternatively, the lamination temperature can be 135-160°C during the lamination process. As an example, the lamination temperature can be 135°C, 140°C, 150°C, or 160°C.

[0099] In an optional embodiment, step N1 further includes fixing the low-temperature solder strip 6 by adhesive bonding.

[0100] Since the high-temperature welding strip 2 needs to be welded first during the welding process, and the low-temperature welding strip 6 and the high-temperature welding strip 2 have different welding temperatures, in order to prevent the low-temperature welding strip 6 from moving during the high-temperature welding process, the low-temperature welding strip 6 can be fixed to the battery cell by adhesive.

[0101] It is understandable that the method of fixing the low-temperature solder ribbon 6 is not limited to adhesive bonding. Any method that can fix the low-temperature solder ribbon 6 without affecting the preparation of the photovoltaic module can be used, and no specific restrictions are imposed here.

[0102] Furthermore, the adhesive application method can include two methods: glue dot adhesive application and adhesive tape adhesive application.

[0103] The adhesive application method can utilize acrylic thermosetting adhesives, but is not limited to them. The thermosetting adhesive must have a light transmittance greater than or equal to 90%, and the height of the resulting adhesive dots (7) must be less than 150 μm, with an area less than 1 mm². 2 Each low-temperature solder ribbon 6 of each solar cell contains 3-10 adhesive dots 7, with a curing temperature of 80-120℃. Application methods include, but are not limited to, printing and dispensing. As an example, the light transmittance of the thermosetting adhesive in the dot-bonding method can be 90%, 92%, or 95%, etc., and the height of the adhesive dots 7 formed by the thermosetting adhesive can be 150μm, 140μm, 120μm, or 100μm, etc., and the area of ​​the adhesive dots 7 can be 1mm². 2 0.8mm 2 0.5mm 2 or 0.3mm 2 For example, the number of adhesive dots 7 in each low-temperature solder strip 6 of each battery cell can be 3, 5, 8 or 10, etc., and the curing temperature can be 80℃, 90℃, 100℃ or 120℃, etc.

[0104] In the tape bonding method, self-adhesive tape 8 can be used. The light transmittance of tape 8 is greater than or equal to 90%, the width can be 1-5 mm, the thickness can be 10-50 μm, and the length should be consistent with the length of the low-temperature solder ribbon 6 laid in one solar cell. As an example, the light transmittance of tape 8 in the tape bonding method can be 90%, 92%, or 95%, etc., the width can be 1 mm, 2 mm, 3 mm, or 5 mm, etc., and the thickness can be 10 μm, 20 μm, 30 μm, or 50 μm, etc.

[0105] The following two examples illustrate the methods of laying battery strings using adhesive dots and adhesive tape.

[0106] Example 1: In step A1, the battery string is laid out using an adhesive dot bonding method.

[0107] As shown in Figure 12, adhesive dots 7 are printed between adjacent first main grids 1 on the upper and lower surfaces of the battery cell, so that the positions of the adhesive dots 7 correspond to the positions of the low-temperature solder ribbons 6 to be laid. When printing the adhesive dots 7, the adhesive dots 7 on the lower surface of the battery cell can be printed first, followed by the adhesive dots 7 on the upper surface of the battery cell, so that the battery cell does not need to be flipped again when laying the solder ribbons on the surface of the battery cell. High-temperature solder ribbons 2 and low-temperature solder ribbons 6 are laid on the string bonding machine. Referring to Figure 13, the current battery cell with the printed adhesive dots 7 is placed on the laid high-temperature solder ribbons 2 and low-temperature solder ribbons 6, so that the high-temperature solder ribbon 2 corresponds to the first main grid 1 on the lower surface of the current battery cell, and the low-temperature solder ribbon 6 corresponds to the positions between two adjacent first main grids 1 on the lower surface. The adhesive dots 7 on the current battery cell are used to fix the low-temperature solder ribbon 6. High-temperature solder ribbons 2 and low-temperature solder ribbons 6 are then laid at the corresponding positions on the upper surface of the current battery cell with the printed adhesive dots 7. Another battery cell with printed adhesive dots 7 is laid out. Each first main grid 1 of the other battery cell is aligned with each first main grid 1 of the current battery cell, so that the two battery cells are placed correspondingly. The other ends of the high-temperature solder ribbon 2 and the low-temperature solder ribbon 6 on the upper surface of the current battery cell are located on the lower surface of the other battery cell. The low-temperature solder ribbon 6 is fixed by the adhesive dots 7 on the other battery cell. The other battery cell is used as the current battery cell, and the process is repeated until a battery string is laid out.

[0108] Example 2: In step A1, the battery string is laid out using adhesive tape.

[0109] As shown in Figure 14, tape 8 is laid on the stringer, followed by high-temperature solder ribbon 2 and low-temperature solder ribbon 6, with the low-temperature solder ribbon 6 positioned above tape 8. Referring to Figure 15, the current solar cell is placed on the laid high-temperature solder ribbon 2 and low-temperature solder ribbon 6, so that the high-temperature solder ribbon 2 corresponds to the first main grid 1 of the current solar cell, and the low-temperature solder ribbon 6 corresponds to the position between two adjacent first main grids 1. The low-temperature solder ribbon 6 is fixed to the lower surface of the current solar cell by tape 8 laid below it. Tape 8 is laid next to the current solar cell, and high-temperature solder ribbon 2 and low-temperature solder ribbon 6 are laid at corresponding positions on the upper surface of the current solar cell. One end of high-temperature solder ribbon 2 and low-temperature solder ribbon 6 is located on the upper surface of the current solar cell, the other end of high-temperature solder ribbon 2 is located next to the current solar cell, and the other end of low-temperature solder ribbon 6 is located on the tape 8 laid next to the current solar cell. Tape 8 is laid on the low-temperature solder ribbon 6 on the upper surface of the current solar cell to fix one end of the low-temperature solder ribbon 6 to the upper surface of the current solar cell. Lay out another battery cell, aligning each first main grid 1 of the other battery cell with each first main grid 1 of the current battery cell, so that the two battery cells are placed correspondingly, with the other ends of the high-temperature solder ribbon 2 and the low-temperature solder ribbon 6 on the upper surface of the current battery cell located on the lower surface of the other battery cell. Use the tape 8 below the other end of the low-temperature solder ribbon 6 to fix the other end of the low-temperature solder ribbon 6 to the lower surface of the other battery cell. Use the other battery cell as the current battery cell and repeat the process until a battery string is laid out.

[0110] According to the photovoltaic module manufacturing method of this disclosure, by simultaneously laying low-temperature solder ribbons and high-temperature solder ribbons in the battery cells to form a battery string before high-temperature welding, there is no need to add a low-temperature welding process when manufacturing the battery string into a photovoltaic module. The low-temperature solder ribbons can be directly welded at low temperature through the lamination process. At the same time, the laid battery string is fixed by welding fixtures, which can prevent the high-temperature solder ribbons and low-temperature solder ribbons from shifting during high-temperature welding. It can also provide heat insulation protection for the low-temperature solder ribbons and avoid the problem of grid breakage caused by the low-temperature solder ribbons melting during high-temperature welding.

[0111] In addition, fixing the low-temperature solder ribbon with adhesive further ensures its stability and prevents it from shifting.

[0112] Figure 16 is a structural schematic diagram of the pressure packing component according to an embodiment of the present disclosure; Figure 17 is a structural schematic diagram of the welding support component according to an embodiment of the present disclosure. As shown in Figures 16 and 17, an embodiment of the present disclosure provides a welding fixture for photovoltaic modules, applied to any of the photovoltaic module manufacturing methods described above, including: a pressure packing component 9 and a welding support component 10.

[0113] As shown in Figure 16, the press assembly 9 includes a connecting part 901, a plurality of pressing blocks 902 and a plurality of pressing needles 903, wherein the plurality of pressing needles 903 are spaced apart from the connecting part 901, and the plurality of pressing blocks 902 are disposed in the connecting part 901 and located between adjacent pressing needles 903.

[0114] The connecting portion 901 includes a first connecting portion 9011 and a second connecting portion 9012, which are arranged vertically. Pressure needle portions 903 are spaced apart from the first connecting portion 9011, and pressure block portions 902 are disposed on the second connecting portion 9012, with the pressure block portions 902 and the second connecting portion 9012 located between adjacent pressure needle portions 903.

[0115] In addition, the pressing component 9 also includes a frame 904, which is connected to the connecting portion 901 and is used to support and fix the connecting portion 901. Specifically, the frame 904 is connected to the end of the first connecting portion 9011.

[0116] As shown in Figure 17, the welding support component 10 includes a heating device 1001, a base plate 1002, and a heat insulation interlayer 1003 spaced apart on the base plate 1002; the heating device 1001 is connected to the base plate 1002.

[0117] Several heating devices 1001 can be provided, respectively located at both ends of the base plate 1002, to provide heat to the base plate 1002 during the high-temperature welding process.

[0118] During the use of the above welding fixture, the pressure plate component 9 is placed above the laid battery string; the welding support component 10 is used to support the laid battery string; wherein, the pressure pin part 903 corresponds to the high-temperature welding strip 2 on the upper surface of the laid battery string; the pressure block part 902 corresponds to the low-temperature welding strip 6 on the upper surface of the laid battery string; the heat insulation layer 1003 corresponds to the low-temperature welding strip 6 on the lower surface of the laid battery string; the heating device 1001 provides heat to the base plate 1002 to perform high-temperature welding on the high-temperature welding strip 2 in the laid battery string.

[0119] It should be noted that during the battery string laying process, the welding fixture and the string welding machine work together. The welding support component 10 is placed below the welding light box on the string welding machine platform, serving as the platform for laying the battery strings. After the battery strings are laid, the pressure pack component 9 is placed on top of the laid battery strings. When the welding light box is turned on, it emits infrared rays, and the heating device 1001 of the welding support component 10 is activated, providing heat to the base plate 1002. This heat is then used in conjunction with the light box to perform high-temperature welding on the high-temperature welding strip 2. The heat insulation layer 1003 provided in the base plate 1002 can prevent heat from being transferred to the low-temperature welding strip 6, thereby avoiding the problem of grid breakage caused by alloying between the low-temperature welding strip 6 and the fine grid 3 during the high-temperature welding process.

[0120] In an optional embodiment, as shown in FIG18, the aforementioned pressure needle portion 903 includes an elastic member 9031 and a pressure needle body 9032; the pressure needle body 9032 is elastically connected to the connecting portion 901 through the aforementioned elastic member 9031; during the use of the aforementioned pressure needle portion 903, the position of each pressure needle portion 903 corresponds to the position of the high-temperature solder strip 2 in the laid battery string, the aforementioned pressure needle body 9032 applies pressure to the aforementioned high-temperature solder strip 2, under the action of pressure, the aforementioned elastic member 9031 contracts, driving the aforementioned pressure needle body 9032 to move away from the battery string, wherein the contraction direction of the aforementioned elastic member 9031 is the same as the contraction direction of the aforementioned battery string.

[0121] One end of the pressure needle body 9032 is connected to the elastic element 9031, and the other end can be set as a frustum structure to increase the contact area between the bottom of the pressure needle body 9032 and the high-temperature welding strip 2 during the use of the pressure needle part 903, thereby strengthening the fixation of the high-temperature welding strip 2.

[0122] The elastic element 9031 includes a retaining ring 90311 and a spring 90312. The pressure needle body 9032 passes through the retaining ring 90311 and is engaged with the first connecting part 9011 by the retaining ring 90311. A cavity is provided between the retaining ring 90311 and the connecting part 901, and the spring 90312 is disposed in the cavity. One end of the spring 90312 is fixedly connected to the pressure needle body 9032. When the pressure pack component 9 is placed above the laid battery string, the pressure pack component 9 applies pressure to the laid battery string. The pressure needle body 9032 corresponds to the high-temperature welding ribbon 2 and applies pressure to the high-temperature welding ribbon 2. Under the reaction force of the high-temperature welding ribbon 2, the spring 90312 contracts, driving the pressure needle body 9032 to move away from the battery string. Under the limit of the retaining spring 90311, the pressure needle body 9032 will not fall out of the cavity, thereby preventing the high-temperature welding ribbon 2 from shifting during the high-temperature welding process and making the high-temperature welding ribbon 2 and the first main grid 1 form a more reliable contact.

[0123] In an optional embodiment, as shown in FIG19, the pressing block portion 902 includes a reflective layer 9021 located above the connecting portion 901 and a heat insulation pad 9022 located below the connecting portion 901, wherein the reflective layer 9021 and the heat insulation pad 9022 are respectively disposed.

[0124] Specifically, the pressing block 902 includes a reflective layer 9021 located above the second connecting part 9012 and a heat insulation pad 9022 located below the second connecting part 9012.

[0125] The reflective layer 9021 is a smooth metal coating. When infrared welding is used for high-temperature welding, the reflective layer 9021 is used to reflect infrared light and prevent infrared light from shining on the low-temperature solder strip 6, causing the low-temperature solder strip 6 and the fine grid 3 to alloy during the high-temperature welding process.

[0126] During the use of the pressing section 902, the heat insulation pad 9022 can apply downward pressure, which can better fix the low-temperature solder ribbon 6 in the laid battery string and prevent the low-temperature solder ribbon 6 from shifting during the high-temperature soldering process. At the same time, the heat insulation pad 9022 can further reduce the heat conduction during the high-temperature soldering process and prevent the low-temperature solder ribbon 6 from melting into solder during the high-temperature soldering process.

[0127] Optionally, the heat insulation pad 9022 can be made of a heat insulation material with a thermal conductivity of less than 0.174 W / (m·K); the width of the heat insulation pad 9022 can be 1-5 mm. As an example, the heat insulation pad 9022 can be made of a heat insulation material with a thermal conductivity of 0.170 W / (m·K), 0.100 W / (m·K), 0.050 W / (m·K), or 0.020 W / (m·K), etc.; the width of the heat insulation pad 9022 can be 1 mm, 2 mm, 3 mm, or 5 mm, etc. As another example, the heat insulation pad 9022 can be made of a heat insulation material such as silica aerogel, nano-insulation board, or high-silica fiber felt, but is not limited to these.

[0128] When the low-temperature solder ribbon 6 is fixed by adhesive tape, the end of the heat insulation pad 9022 away from the second connecting part 9012 can be a flat plane so that when pressure is applied to the pressing part 902, uniform pressure can be generated on the tape 8, so that the tape 8 can fix the low-temperature solder ribbon 6 more firmly to the surface of the battery string.

[0129] Furthermore, as shown in FIG20, the heat insulation pad 9022 is provided with grooves 90221 at intervals on the side away from the connecting portion 901; when the low-temperature welding ribbon 6 is fixed by adhesive dots, the grooves 90221 correspond to the adhesive dots 7, so as to accommodate the adhesive dots 7 when the pressing portion 902 applies pressure to the low-temperature welding ribbon 6, and prevent the adhesive dots 7 from being damaged during the use of the pressing portion 902.

[0130] Furthermore, the heat insulation pad 9022 of the pressing block 902 is detachably connected to the second connecting part 9012, so that the heat insulation pad 9022 with corresponding intervals can be replaced for adhesive dots 7 with different intervals, further increasing the practicality of the pressing and assembling component 9.

[0131] According to the photovoltaic module welding fixture of this disclosure, the laid cell strings can be fixed by the cooperation of the pressure packing component and the welding support component, preventing the displacement of high-temperature and low-temperature solder strips during high-temperature welding. Furthermore, by providing a pressure block containing heat-insulating pads in the pressure packing component and a heat-insulating interlayer in the welding support component, heat insulation protection can be provided for the low-temperature solder strips during high-temperature welding, preventing the low-temperature solder strips from melting and causing grid breakage.

[0132] The photovoltaic module and its preparation method provided in this disclosure will be further described below based on specific embodiments. The following description is only used to explain the relevant disclosure of this application and is not intended to limit this disclosure.

[0133] The battery cell with the structure shown in Figure 4 has 20 solder ribbons on its surface, including 15 high-temperature solder ribbons 2 and 5 low-temperature solder ribbons 6. High-temperature solder ribbons are laid on the first main grid 1 on the lower surface of the first battery cell, and low-temperature solder ribbons 6 are laid between the first main grids 1. The second battery cell is placed correspondingly to the first battery cell, aligning each first main grid 1 in the second battery cell with each first main grid 1 in the first battery cell. The other end of the high-temperature solder ribbons 2 laid on the lower surface of the first battery cell is laid onto the first main grid 1 on the upper surface of the second battery cell, and the other end of the low-temperature solder ribbons 6 laid on the upper surface of the first battery cell is laid between the first main grids 1 on the upper surface of the second battery cell. This process is repeated until a battery string is formed. The low-temperature solder ribbons 6 in the battery string are fixed using adhesive tape.

[0134] The high-temperature solder ribbon 2 can be Sn60Pb40 solder ribbon with a diameter of 0.2mm and a melting point of 183℃; the low-temperature solder ribbon 6 can be Sn32Pb42Bi26 solder ribbon with a diameter of 0.2mm and a melting point of 135℃.

[0135] In the string welding machine, the pressure packing component 9 (as shown in Figure 16) and the welding support component 10 (as shown in Figure 17) are used to fix the laid battery strings. Infrared rays emitted from the welding lamp box and heat provided by the welding support component 10 are used to perform high-temperature welding on the high-temperature welding strips 2 in the laid battery strings, ensuring good contact between the high-temperature welding strips 2 and the first main grid 1. The welding temperature of the welding lamp box is 280℃, and the temperature of the welding support component is 100℃.

[0136] Specifically, the pressure pin 903 in the pressure assembly 9 applies pressure to the high-temperature solder ribbon 2 in the laid battery string, the pressure block 902 applies pressure to the low-temperature solder ribbon 6 in the laid battery string, the welding support component 10 provides support for the laid battery string, and the heat insulation layer 1003 corresponds to the low-temperature solder ribbon 6. When the high-temperature solder ribbon 2 in the laid battery string is subjected to high-temperature welding by the infrared rays emitted by the welding lamp box and the heat provided by the welding support component 10, the heat is transferred to the position of the high-temperature solder ribbon 2, causing the high-temperature solder ribbon 2 to melt and thus alloy with the first main grid 1, forming a stable connection between the high-temperature solder ribbon 2 and the first main grid 1; the reflective layer 9021 in the pressure block 902 can reflect the infrared rays emitted by the welding lamp box, and the heat insulation pad 9022 in the pressure block 902 and the heat insulation layer 1003 in the welding support component 10 can prevent heat from being transferred to the position of the low-temperature solder ribbon 6, avoiding the problem of the low-temperature solder ribbon 6 melting and alloying with the fine grid 3 during the high-temperature welding process, which would lead to grid breakage.

[0137] It should be noted that both the high-temperature solder strip 2 and the low-temperature solder strip 6 have a tin-plated layer on their surface. During the soldering process, the tin-plated layer melts and transforms into liquid tin, which is called tin melting. Liquid tin can alloy with the gate line.

[0138] After high-temperature soldering, the defects in the battery string were identified by electroluminescence (EL) testing. It was found that the battery string performed well after the above process, no microcracks were observed, the low-temperature solder ribbon 6 did not melt, and there was no grid breakage at the fine grid. After being fixed with tape, the low-temperature solder ribbon 6 did not shift.

[0139] The battery strings, which have undergone high-temperature welding, are stacked together. The adhesive film used in the stacking process has a basis weight of 360 g / m³. 2 Compared to conventional 16BB photovoltaic modules, the photovoltaic module manufacturing method of this embodiment uses a lower basis weight of encapsulant film, thus reducing encapsulant film consumption.

[0140] The stacked battery strings were laminated at a temperature of 145℃. During lamination, the low-temperature solder ribbon 6 was de-tinned at the lamination temperature, alloying it with the fine grid 3 and completing the low-temperature welding. Because the high-temperature solder ribbon has a higher melting point, secondary de-tinning of the high-temperature solder ribbon was avoided during lamination, preventing a weak connection between the high-temperature solder ribbon 2 and the first main grid 1 caused by secondary de-tinning. After lamination, EL testing showed that the laminated battery strings performed well.

[0141] After steps such as framing, photovoltaic modules are obtained.

[0142] After testing, the photovoltaic module of this embodiment has basically the same power as the conventional 16BB photovoltaic module. However, compared with the conventional 16BB photovoltaic module, the photovoltaic module of this embodiment has a 20μm reduction in cell thickness, saves 40mg of silver paste per photovoltaic module, reduces the solder ribbon diameter by 0.06mm, and reduces the encapsulant film weight by 60g / m³. 2 Cost reduction can reach 0.2 cents / W. Furthermore, the photovoltaic modules of this embodiment were subjected to TC-400 testing according to the IEC61215 standard. After the test, the power loss was less than 2%, indicating that the photovoltaic modules of this embodiment can still maintain a high power output capacity after undergoing relatively stringent temperature changes. The structure and manufacturing process of the photovoltaic modules have good stability, enabling long-term stable outdoor power generation.

[0143] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can occur depending on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A photovoltaic module, comprising: One or more battery strings, wherein, The battery string includes multiple battery cells and multiple high-temperature solder strips (2) and multiple low-temperature solder strips (6) that connect the battery cells in series; Each of the aforementioned solar cells is provided with multiple first main grids (1); Each of the high-temperature welding strips (2) is connected in series with the two corresponding first main grids (1) of two adjacent battery cells; Each of the low-temperature solder strips (6) is disposed between two adjacent first main grids (1) on the solar cell and connected in series with two adjacent solar cells.

2. The photovoltaic module according to claim 1, wherein, The number of high-temperature solder strips (2) on the surface of the battery string is greater than or equal to the number of low-temperature solder strips (6).

3. The photovoltaic module according to claim 1, wherein, The battery cell further includes: fine grid welding contact points (301) provided between two adjacent first main grids (1); The low-temperature welding strip (6) is electrically connected to the fine grid welding contact point (301) between two adjacent first main grids (1); or, The battery cell further includes: a plurality of segmented main grids (4) disposed between two adjacent first main grids (1); The low-temperature welding strip (6) is deployed along the plurality of segmented main grids (4) and electrically connected to the plurality of segmented main grids (4); or, The battery cell further includes: a second main grid (5) disposed between two adjacent first main grids (1), wherein the width of the second main grid (5) is smaller than the width of the first main grid (1); The low-temperature welding strip (6) is deployed along the second main gate (5) and electrically connected to the second main gate (5); And / or, The battery cell includes a fine grid (3) comprising alternating first fine grid segments (302) and second fine grid segments (303), wherein the width of the second fine grid segment (303) is greater than the width of the first fine grid segment (302); The first main gate (1) is electrically connected to the first fine gate segment (302); The low-temperature solder strip (6) is electrically connected to the second fine grid segment (303).

4. The photovoltaic module according to claim 3, wherein, When the battery cell includes fine grid solder contact points (301) disposed between two adjacent first main grids (1), the total area of ​​the fine grid solder contact points (301) disposed between two adjacent first main grids (1) is less than 0.5 mm. 2 ; or, When the battery cell includes the segmented main grid (4), the length of each segmented main grid (4) is 2-50 mm; or, When the battery cell includes the second main grid (5), the width of each second main grid (5) is 10-20 μm; And / or, When the fine grid (3) of the battery cell includes the first fine grid segment (302), the width of the second fine grid segment is 10-80 μm.

5. The photovoltaic module according to any one of claims 1-4, wherein, The thickness of the battery cell is 80-140 μm.

6. A method for manufacturing a photovoltaic module, comprising: Repeat steps N1 to N2 until the battery string is laid out: N1. Lay one end of the high-temperature solder ribbon on the first main grid of the current cell; and lay one end of the low-temperature solder ribbon between two adjacent first main grids of the current cell, and fix the low-temperature solder ribbon. N2. Lay another battery cell at the other end of the high-temperature solder strip and the other end of the low-temperature solder strip, and use the other battery cell as the current battery cell, and execute N1. Welding fixtures are used to fix the laid battery strings, and the high-temperature welding strips in the laid battery strings are welded at high temperature. Remove the welding fixture, laminate the battery string that has been welded at high temperature, and perform low-temperature welding of the low-temperature solder strip during the lamination process to obtain the welded battery string. Multiple welded battery strings are assembled into a photovoltaic module.

7. The method for preparing a photovoltaic module according to claim 6, wherein, Step N1 includes: The low-temperature welding strip is fixed by adhesive bonding.

8. A welding fixture for photovoltaic modules, applied to the method for manufacturing photovoltaic modules as described in any one of claims 6 to 7, comprising: Pressing component (9) and welding support component (10); The press assembly (9) includes a connecting part (901), a plurality of pressing blocks (902) and a plurality of pressing needles (903), wherein the plurality of pressing needles (903) are spaced apart from the connecting part (901), and the plurality of pressing blocks (902) are disposed in the connecting part (901) and located between adjacent pressing needles (903); The welding support component (10) includes a heating device (1001), a base plate (1002), and a heat insulation interlayer (1003) spaced apart on the base plate (1002); the heating device (1001) is connected to the base plate (1002); During the use of the welding fixture, the pressure pack component (9) is placed above the laid battery string; the welding support component (10) is used to support the laid battery string; wherein, the pressure pin part (903) corresponds to the high-temperature welding strip (2) on the upper surface of the laid battery string; the pressure block part (902) corresponds to the low-temperature welding strip (6) on the upper surface of the laid battery string; the heat insulation layer (1003) corresponds to the low-temperature welding strip (6) on the lower surface of the laid battery string; the heating device (1001) provides heat to the base plate (1002) to perform high-temperature welding on the high-temperature welding strip (2) in the laid battery string.

9. The welding fixture for photovoltaic modules according to claim 8, wherein, The pressure needle part (903) includes an elastic element (9031) and a pressure needle body (9032); The pressure needle body (9032) is elastically connected to the connecting part (901) through the elastic member (9031); During the use of the pressure needle (903), the pressure needle body (9032) applies pressure to the high-temperature welding strip (2). Under the pressure, the elastic member (9031) contracts, causing the pressure needle body (9032) to move away from the battery string. The contraction direction of the elastic member (9031) is the same as the contraction direction of the battery string.

10. The welding fixture for photovoltaic modules according to claim 8, wherein, The pressing block (902) includes a reflective layer (9021) located above the connecting part (901) and a heat insulation pad (9022) located below the connecting part (901), wherein the reflective layer (9021) and the heat insulation pad (9022) are respectively provided.

11. The welding fixture for photovoltaic modules according to claim 10, wherein, The heat insulation pad (9022) has grooves (90221) spaced apart on the side away from the connecting part (901); When the low-temperature solder ribbon (6) is fixed by adhesive dots, the groove (90221) corresponds to the adhesive dots (7) to accommodate the adhesive dots (7) when the pressure block (902) applies pressure to the low-temperature solder ribbon (6).

Images