Photovoltaic solder strip, photovoltaic solder strip forming method, solar cell string and photovoltaic module

Abstract

The invention relates to a photovoltaic welding strip, a photovoltaic welding strip forming method, a solar cell string and a photovoltaic module. The photovoltaic welding strip comprises a first welding wire, one end of the first welding wire is provided with a first connecting section, and the outer surface of the first welding wire is provided with a first reflecting surface and a first mounting surface; one end of the second welding wire is provided with a second connecting section; wherein the first connecting section and / or the second connecting section are / is arranged in a flat shape, the first connecting section and the second connecting section are arranged in a stacked mode to form an overlapping section, and the photovoltaic welding strip can be connected to the front face of a previous battery piece through the first mounting face of the first welding wire and connected to the back face of an adjacent next battery piece through the second welding wire. Therefore, the photovoltaic solder strip adopts a segmented structural design, and does not need to adopt a mode of flattening or twisting by 180 degrees, so that the process difficulty of the photovoltaic solder strip is reduced, the double-sided rate of the photovoltaic module is improved, meanwhile, the distance between adjacent solder strips can be reduced, and the efficiency of the photovoltaic module is improved.

Description

Technical Field

[0001] The present application relates to the technical field of solar cells, and particularly to a photovoltaic solder ribbon, a method for forming a photovoltaic solder ribbon, a solar cell string, and a photovoltaic module. Background Art

[0002] Photovoltaic modules are the most important part of a photovoltaic power generation system, and their function is to convert solar energy into electrical energy to drive a load to work. The basic unit of a photovoltaic module is a cell, and solder ribbons are used to connect the cells in series. A single solar cell string cannot be directly used as a power source, and several single solar cell strings need to be connected in parallel and tightly encapsulated to form a photovoltaic module.

[0003] With the rapid increase in the market penetration rate of bifacial photovoltaic modules, the performance of the core component, the interconnection solder ribbon, needs to match the bifacial power generation requirements. Currently, a special-shaped solder ribbon is used to connect the front and back of adjacent cells, that is, a composite form of a front wire (enhanced light capture) + a back wire (low-resistance interconnection) is adopted.

[0004] Generally, the special-shaped solder ribbon is a complete triangular solder ribbon. When connecting the front and back of adjacent cells, the bottom surface of the triangular solder ribbon is arranged on the front of the cell, and the top edge of the triangular solder ribbon is arranged on the back of the adjacent cell. However, when the top edge of the triangular solder ribbon contacts the back of the cell, the cell will crack.

[0005] Therefore, the triangular solder ribbon on the back of the cell can be flattened and then connected to the back of the cell. However, this operation will increase the process difficulty of the special-shaped solder ribbon and also increase the light-shielding area of the solder ribbon on the back of the cell, affecting the bifacial ratio of the photovoltaic module.

[0006] It is also possible to twist the triangular solder ribbon by 180°, so that the bottom surface of the triangular solder ribbon is arranged on the back of the cell. However, this method has a large process difficulty and cannot accurately ensure that the bottom surface of the triangular solder ribbon can be aligned with the back of the cell. At the same time, there will be a certain length at the position where the triangular solder ribbon is twisted by 180°, resulting in an increase in the distance between adjacent cells and a decrease in the efficiency of the photovoltaic module. Summary of the Invention

[0007] Based on this, in view of the problems of large process difficulty and low efficiency when a single triangular solder ribbon of the current special-shaped solder ribbon connects the front and back of adjacent cells, it is necessary to provide a photovoltaic solder ribbon, a method for forming a photovoltaic solder ribbon, a solar cell string, and a photovoltaic module, which adopt a segmented structure design to reduce the process difficulty and improve the efficiency of the photovoltaic module.

[0008] A photovoltaic solder ribbon includes:

[0009] A first welding wire, one end of the first welding wire has a first connection section, and the outer surface of the first welding wire has a first reflective surface and a first mounting surface; and

[0010] A second welding wire, one end of the second welding wire has a second connection section;

[0011] Wherein, the first connection section and / or the second connection section are arranged in a flat shape, the first connection section and the second connection section are stacked to form an overlapping section, and the photovoltaic welding strip can be connected to the front of the previous cell through the first mounting surface of the first welding wire and connected to the back of the adjacent next cell through the second welding wire.

[0012] In an embodiment of the present application, the overlapping dimension of the first connection section and the second connection section in the length direction is greater than or equal to 0.5 mm;

[0013] and / or, the dimension of the overlapping section in the thickness direction is less than 0.15 mm;

[0014] and / or, the overlapping section is separated from the front metal electrode of the previous cell and / or the back metal electrode of the next cell.

[0015] In an embodiment of the present application, the first welding wire further includes a first main body section, the first connection section is arranged at one end of the first main body section, and the first main body section can be connected to the front of the previous cell;

[0016] The second welding wire further includes a second main body section, the second connection section is arranged at one end of the second main body section, and the second main body section can be connected to the back of the next cell.

[0017] In an embodiment of the present application, the dimension of the first main body section in the thickness direction is greater than or equal to the dimension of the second main body section in the thickness direction;

[0018] and / or, the thickness of the overlapping section is less than the thickness of the first main body section and / or the second main body section.

[0019] In an embodiment of the present application, the cross-sectional shape of the first main body section is triangular;

[0020] The side length dimension range of the first main body section is 0.1 mm to 0.35 mm.

[0021] In an embodiment of the present application, adjacent two sides in the first main body section are connected by a chamfered portion.

[0022] In an embodiment of the present application, the first main body section further includes a first connection portion and a second connection portion. The first connection portion is disposed along the thickness direction on the second connection portion. The cross-sectional shape of the first connection portion is triangular, and the cross-sectional shape of the second connection portion is rectangular. The second connection portion is connected to the front side of the previous solar cell.

[0023] In an embodiment of the present application, the cross-sectional shape of the second main body section is circular, and the diameter dimension range of the second main body section is 0.1 mm to 0.3 mm;

[0024] Alternatively, the cross-sectional shape of the second main body section is triangular, and the side length dimension range of the second main body section is 0.1 mm to 0.35 mm.

[0025] In an embodiment of the present application, when the cross-sectional shape of the second main body section is triangular, the second welding wire further includes a second reflective surface and a second mounting surface. The second mounting surface is connected to the back side of the subsequent solar cell, and the second reflective surface is used for reflecting light on the back side of the subsequent solar cell.

[0026] In an embodiment of the present application, along the thickness direction, the first connection segment is located on the upper surface of the second connection segment, or the first connection segment is located on the lower surface of the second connection segment.

[0027] In an embodiment of the present application, the first connection segment and the second connection segment are connected by welding.

[0028] In an embodiment of the present application, the first connection segment and the second connection segment are connected by welding using laser welding, ultrasonic welding, infrared welding, or arc welding.

[0029] In an embodiment of the present application, the first welding wire includes a first copper substrate, a first welding coating, and a reflective coating. The first welding coating and the reflective coating are coated on the outer periphery of the first copper substrate. The first welding coating forms the first mounting surface for welding connection with the previous solar cell, and the reflective coating forms the first reflective surface;

[0030] The second welding wire includes a second copper substrate and a second welding coating. The second welding coating is coated on the outer periphery of the second copper substrate, and the second welding coating is welded to the subsequent solar cell.

[0031] In an embodiment of the present application, the first welding coating includes a tin-lead alloy coating, a tin-lead-bismuth alloy coating, or a tin-silver alloy coating;

[0032] And / or, the reflective coating includes a silver coating or an aluminum coating;

[0033] And / or, the second soldering coating includes a tin-lead alloy coating, a tin-lead-bismuth alloy coating, or a tin-silver alloy coating.

[0034] In an embodiment of the present application, when the first soldering coating includes a tin-lead alloy coating or a tin-lead-bismuth alloy coating, the reflective coating includes an aluminum coating or a silver coating, and the second soldering coating includes a tin-lead alloy coating or a tin-lead-bismuth alloy coating, the overlapping section includes at least tin element, lead element, and copper element, and also includes one of aluminum element or silver element.

[0035] In an embodiment of the present application, the overlapping section further includes a first fusion part, and the first soldering coating, the reflective coating, and the second soldering coating are fused to form the first fusion part;

[0036] And / or, the overlapping section further includes a second fusion part, and the first copper substrate and the second copper substrate are fused to form the second fusion part.

[0037] A method for forming a photovoltaic solder ribbon, used for forming the photovoltaic solder ribbon as described in any of the above technical features, the method for forming the photovoltaic solder ribbon at least includes the following steps:

[0038] Use a first feeding mechanism to convey a first raw material, use a first wire drawing mechanism to cut the first raw material to form a first welding wire with a predetermined length, and convey the first welding wire to an interconnection platform;

[0039] Use a second feeding mechanism to convey a second raw material, use a second wire drawing mechanism to cut the second raw material to form a second welding wire with a predetermined length, and convey the second welding wire to the interconnection platform;

[0040] Connect the first welding wire and the second welding wire to form the photovoltaic solder ribbon, the first welding wire can be connected to the front side of a previous battery cell, and the second welding wire can be connected to the back side of a subsequent battery cell.

[0041] In an embodiment of the present application, connecting the first welding wire and the second welding wire to form the photovoltaic solder ribbon at least includes the following steps:

[0042] Flatten one end of the first welding wire to form a first connection section, flatten one end of the second welding wire to form a second connection section, and connect the first connection section and the second connection section to form an overlapping section;

[0043] Or, connect one end of the first welding wire and one end of the second welding wire to form an overlapping section, and flatten the overlapping section;

[0044] Alternatively, one end of the first welding wire is flattened to form a first connection section, one end of the second welding wire is flattened to form a second connection section, the first connection section and the second connection section are connected to form an overlapping section, and the overlapping section is flattened.

[0045] In an embodiment of the present application, the first welding wire includes a first copper substrate, a first welding coating, and a reflective coating. The first welding coating and the reflective coating are coated on the outer periphery of the first copper substrate. The first welding coating forms a first mounting surface, and the reflective coating forms a first reflective surface.

[0046] The second welding wire includes a second copper substrate and a second welding coating. The second welding coating is coated on the outer periphery of the second copper substrate.

[0047] In an embodiment of the present application, connecting the first welding wire and the second welding wire to form the photovoltaic solder ribbon further includes at least the following steps:

[0048] Using laser welding, ultrasonic welding, infrared welding, or arc welding methods to melt the reflective coating, the first welding coating, and the second welding coating;

[0049] Weld and connect the first copper substrate and the second copper substrate.

[0050] In an embodiment of the present application, connecting the first welding wire and the second welding wire to form the photovoltaic solder ribbon further includes at least the following steps:

[0051] Fusion-connect the reflective coating, the first welding coating, and the second welding coating between the first copper substrate and the second copper substrate to form a first fusion part;

[0052] And / or, fusion-connect the first copper substrate and the second copper substrate to form a second fusion part.

[0053] A solar cell string includes a previous cell, a subsequent cell, and a photovoltaic solder ribbon as described in any of the above technical features;

[0054] The previous cell and the subsequent cell are arranged along the length direction of the photovoltaic solder ribbon. The first welding wire of the photovoltaic solder ribbon is connected to the front surface of the previous cell, and the second welding wire is connected to the back surface of the subsequent cell, so that the previous cell and the subsequent cell are connected in series.

[0055] In an embodiment of the present application, the overlapping section of the photovoltaic solder ribbon is located on the back surface of the subsequent cell, and / or the overlapping section of the photovoltaic solder ribbon is located on the front surface of the previous cell;

[0056] When the overlapping segment is located on the front side of the previous solar cell and the back side of the subsequent solar cell, the length of the overlapping segment on the back side of the subsequent solar cell is greater than the length of the overlapping segment on the front side of the previous solar cell.

[0057] A photovoltaic module at least includes a cover plate, a back plate, and a plurality of solar cell strings as described in any one of the above technical features;

[0058] A plurality of the solar cell strings are connected in parallel and / or in series. The cover plate and the back plate are disposed on both sides of the plurality of solar cell strings, and the cover plate, the plurality of solar cell strings, and the back plate are encapsulated to form the photovoltaic module.

[0059] After adopting the above technical solution, the present application has at least the following technical effects:

[0060] For the photovoltaic solder ribbon, the photovoltaic solder ribbon forming method, the solar cell string, and the photovoltaic module of the present application, in the photovoltaic solder ribbon, one end of the first solder wire has a first connection segment, one end of the second solder wire has a second connection segment, the first connection segment and / or the second connection segment are arranged in a flat shape, and the first connection segment of the first solder wire and the second connection segment of the second solder wire are stacked and connected to form an overlapping segment, so that the photovoltaic solder ribbon forms an integral body. The first mounting surface of the first solder wire is connected to the previous solar cell and reflects light through the first reflective surface, and the second solder wire is connected to the subsequent solar cell, so that the photovoltaic solder ribbon is connected to the previous solar cell and the subsequent solar cell.

[0061] For this photovoltaic solder ribbon, the first solder wire and the second solder wire are separately arranged. In this way, the photovoltaic solder ribbon is connected to the front side of the previous solar cell through the first solder wire, and is connected to the back side of the previous solar cell through the second solder wire. The first solder wire and the second solder wire are connected in series through the first connection segment and the second connection segment to form an overlapping segment, so as to connect the previous solar cell and the subsequent solar cell in series. In this way, the photovoltaic solder ribbon adopts a segmented structural design, and it does not need to be connected to the back side of the subsequent solar cell by means of flattening or twisting 180°, reducing the process difficulty of the photovoltaic solder ribbon. Moreover, the second solder wire can reflect the sunlight on the back side of the subsequent solar cell, improving the bifaciality of the photovoltaic module. At the same time, the first solder wire and the second solder wire are connected through the overlapping segment, which can reduce the distance between the previous solar cell and the subsequent solar cell and improve the efficiency of the photovoltaic module. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 It is a schematic diagram of a photovoltaic solder ribbon according to an embodiment of the present application.

[0063] Figure 2 For Figure 1 a schematic diagram of the photovoltaic solder ribbon shown applied to a solar cell string from a certain perspective.

[0064] Figure 3 ForFigure 2 Schematic diagram of the solar cell string shown from another perspective.

[0065] Figure 4 For Figure 1 Front view of the disconnection of the photovoltaic ribbon shown.

[0066] Figure 5 For Figure 4 Partial enlarged view of the photovoltaic ribbon at A shown.

[0067] Figure 6 For Figure 2 Front view of the solar cell string shown.

[0068] Figure 7 For Figure 6 Disconnection schematic diagram of the solar cell string shown.

[0069] Figure 8 For Figure 7 Partial schematic diagram of the solar cell string at B shown.

[0070] Figure 9 For Figure 4 Cross-sectional view of the photovoltaic ribbon along the C-C direction shown.

[0071] Figure 10 For Figure 9 First deformation diagram of the cross-section of the first main body segment shown.

[0072] Figure 11 For Figure 9 Second deformation diagram of the cross-section of the first main body segment shown.

[0073] Figure 12 For Figure 9 Third deformation diagram of the cross-section of the first main body segment shown.

[0074] Figure 13 For Figure 4 Cross-sectional view of the photovoltaic ribbon along the D-D direction shown.

[0075] Figure 14 Combined cross-sectional view of one embodiment of the first main body segment and the second main body segment.

[0076] Figure 15 Combined cross-sectional view of another embodiment of the first main body segment and the second main body segment.

[0077] Figure 16 For Figure 1 Forming flow chart of the photovoltaic ribbon shown.

[0078] Wherein: 10, solar cell string; 100, photovoltaic solder ribbon; 110, first welding wire; 111, first connecting section; 112, first main section; 113, first transition section; 114, first reflective surface; 115, first mounting surface; 116, first connecting portion; 117, second connecting portion; 120, second welding wire; 121, second connecting section; 122, second main section; 123, second transition section; 130, overlapping section; 200, previous cell; 300, subsequent cell. Detailed implementation manner

[0079] To make the above objects, features, and advantages of the present application more apparent and understandable, the following will describe the detailed implementation manner of the present application with reference to the accompanying drawings. Many specific details are set forth in the following description to fully understand the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present application. Therefore, the present application is not limited by the specific embodiments disclosed below.

[0080] In the description of the present application, it should be understood that if these terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or positional relationship indicated by these terms is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present application.

[0081] In addition, if these terms "first" and "second" appear, these terms are only for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present application, if the term "plurality" appears, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise specifically and clearly defined.

[0082] In this application, unless otherwise clearly specified or limited, if terms such as "installed", "connected", "joined", "fixed", etc. appear, these terms shall be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components or the interaction relationship between two components, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0083] In this application, unless otherwise clearly specified or limited, if there is a description such as a first feature being "on" or "under" a second feature, its meaning can be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature can be that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is at a higher horizontal level than the second feature. The first feature being "under", "beneath" and "underneath" the second feature can be that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is at a lower horizontal level than the second feature.

[0084] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or there can also be an intermediate element. If an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. If so, the terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used in this application are only for the purpose of illustration and do not represent the only implementation manner.

[0085] It can be understood that currently, an irregular-shaped solder ribbon is used to connect the front and back of adjacent solar cells, that is, a composite form of a front solder wire (enhancing light capture) + a back solder wire (low-resistance interconnection) is adopted. Generally, the irregular-shaped solder ribbon is a complete triangular solder ribbon. When connecting the front and back of adjacent solar cells, the bottom surface of the triangular solder ribbon is arranged on the front of the solar cell, and the top edge of the triangular solder ribbon is arranged on the back of the adjacent solar cell. However, when the top edge of the triangular solder ribbon contacts the back of the solar cell, the solar cell will crack.

[0086] To this end, the triangular solder ribbon on the back of the cell can be flattened and then connected to the back of the cell. However, this operation will increase the process difficulty of the special-shaped solder ribbon and also increase the light-shielding area of the solder ribbon on the back of the cell, affecting the bifaciality of the photovoltaic module. It is also possible to twist the triangular solder ribbon by 180°, so that the bottom surface of the triangular solder ribbon is arranged on the back of the cell. However, this method has a large process difficulty and cannot accurately ensure that the bottom surface of the triangular solder ribbon can be aligned with the back of the cell. At the same time, there will be a certain length at the position where the triangular solder ribbon is twisted by 180°, resulting in an increase in the distance between adjacent cells and reducing the efficiency of the photovoltaic module.

[0087] To this end, referring to Figures 1 to 3 , the present application provides a photovoltaic solder ribbon 100. The photovoltaic solder ribbon 100 is applied to the solar cell string 10 of a photovoltaic module (not shown). Figure 1 FIG. is a schematic diagram of the photovoltaic solder ribbon 100 according to an embodiment of the present application, Figure 2 For Figure 1 FIG. shows a schematic diagram of the photovoltaic solder ribbon 100 applied to the solar cell string 10 from one perspective, Figure 3 For Figure 2 FIG. shows a schematic diagram of the solar cell string 10 from another perspective.

[0088] To better illustrate the structure of the photovoltaic solder ribbon 100, the structures of the photovoltaic module and the solar cell string 10 are briefly introduced here. The photovoltaic module at least includes a cover plate (not shown), a back plate (not shown), and a plurality of solar cell strings 10 in the present application. The plurality of solar cell strings 10 are connected in series and / or in parallel and are arranged between the cover plate and the back plate to protect the plurality of solar cell strings 10 through the cover plate and the back plate. And, sunlight (light rays) enters the surfaces of the plurality of solar cell strings 10 through the cover plate, and the solar cell strings 10 can generate carriers using the photovoltaic effect principle to output current.

[0089] Referring to Figures 1 to 3 , in one embodiment, the solar cell string 10 includes a plurality of cells and a plurality of photovoltaic solder ribbons 100 of the present application. The plurality of cells are arranged in sequence along the length direction, and the plurality of cells are respectively welded and connected through the plurality of photovoltaic solder ribbons 100. It should be noted that the structure and principle of the photovoltaic solder ribbon 100 connecting two adjacent cells are substantially the same as those of the photovoltaic solder ribbon 100 connecting the remaining cells. The present application only takes the photovoltaic solder ribbon 100 connecting two cells as an example for illustration.

[0090] As Figures 1 to 3As shown, the extension direction of the photovoltaic welding strip 100 is the length direction, which is also the arrangement direction of multiple battery cells. The length direction perpendicular to the battery cell is the width direction of the battery cell. The thickness direction of the battery cell is the thickness direction, which is also the up and down direction and the top and bottom direction. The length direction, width direction and thickness direction are not shown in the figure.

[0091] Figure 2 and Figure 3 The photovoltaic ribbon 100 in the solar cell string 10 is shown to connect two solar cells. Figure 2 and Figure 3 The cell on the left side is the previous cell 200, and the cell on the right side is the next cell 300. The surface of the cell facing the sunlight is the front side of the cell, and the surface of the cell facing away from the sunlight is the back side of the cell.

[0092] The photovoltaic welding strip 100 can be connected to the front side of the previous solar cell 200 and the back side of the next solar cell 300, so as to connect the adjacent previous solar cells 200 and the next solar cells 300 in series. Moreover, the connection form between the next solar cell 300 and the next solar cell is the same as the connection form between the previous solar cell 200 and the next solar cell 300. In this way, multiple solar cells are connected in series to form a solar cell string 10.

[0093] The photovoltaic welding ribbon 100 is a conductive component. After the photovoltaic welding ribbon 100 connects the previous battery cell 200 and the next battery cell 300 in series, the photovoltaic welding ribbon 100 can connect the current of the previous battery cell 200 and the next battery cell 300 in series, and then export the current, so that the current generated by the previous battery cell 200 and the next battery cell 300 under light is transmitted to the external circuit through the photovoltaic welding ribbon 100 to realize the output of current.

[0094] The photovoltaic welding strip 100 of the present application adopts a segmented structural design, and it does not need to be connected to the back of the next cell 300 by flattening or twisting 180 degrees, which reduces the process difficulty of the photovoltaic welding strip 100, and can also reflect the sunlight on the back of the next cell 300, thereby improving the bifaciality of the photovoltaic module. At the same time, the first welding wire 110 and the second welding wire 120 are connected by the overlapping section 130, which can reduce the distance between the previous cell 200 and the next cell 300, thereby improving the efficiency of the photovoltaic module. The specific structure of the photovoltaic welding strip 100 in some embodiments is introduced below.

[0095] See also Figures 1 to 8, in one embodiment, the photovoltaic solder ribbon 100 includes a first solder wire 110 and a second solder wire 120. One end of the first solder wire 110 has a first connection section 111, and the outer surface of the first solder wire 110 has a first reflective surface 114 and a first mounting surface 115. One end of the second solder wire 120 has a second connection section 121. Wherein, the first connection section 111 and / or the second connection section 121 are arranged in a flat shape, and the first connection section 111 and the second connection section 121 are stacked to form an overlapping section 130. The photovoltaic solder ribbon 100 can be connected to the front of the previous cell 200 through the first mounting surface 115 of the first solder wire 110 and connected to the back of the adjacent subsequent cell 300 through the second solder wire 120. Figure 4 is Figure 1 the disconnected front view of the photovoltaic solder ribbon 100 shown in Figure 5 is Figure 4 the partial enlarged view of the photovoltaic solder ribbon 100 at A shown in Figure 6 is Figure 2 the front view of the solar cell string 10 shown in Figure 7 is Figure 6 the disconnected schematic diagram of the solar cell string 10 shown in Figure 8 is Figure 7 the partial schematic diagram of the solar cell string 10 at B shown in

[0096] The first solder wire 110 and the second solder wire 120 extend along the length direction. The first solder wire 110 is placed on the front of the previous cell 200 along the length direction, and the first solder wire 110 is used to collect the current of the previous cell 200. The second solder wire 120 is placed on the back of the subsequent cell 300 along the length direction, and the second solder wire 120 can collect the current of the subsequent cell 300. Moreover, the first solder wire 110 and the second solder wire 120 are connected to connect the previous cell 200 and the subsequent cell 300 in series to realize the collective output of the cells.

[0097] And, one end of the first solder wire 110 facing the subsequent cell 300 has a first connection section 111, and one end of the second solder wire 120 facing the previous cell 200 has a second connection section 121. When the first solder wire 110 and the second solder wire 120 are connected, the first connection section 111 and the second connection section 121 are stacked along the thickness direction to form an overlapping section 130. In this way, the first solder wire 110 and the second solder wire 120 are connected to form an integral photovoltaic solder ribbon 100.

[0098] Refer to Figures 4 to 8, both the first connecting section 111 and the second connecting section 121 are arranged in a flat shape. The flat first connecting section 111 and the flat second connecting section 121 are stacked and connected to form the photovoltaic solder ribbon 100. In this way, the size of the overlapping section 130 in the thickness direction can be reduced, and then the size of the solar cell string 10 in the thickness direction can be reduced, so as to reduce the overall thickness of the photovoltaic module. At the same time, when the flat overlapping section 130 is arranged on the front surface of the previous cell 200 and / or the back surface of the subsequent cell 300, the gap between the previous cell 200 and the subsequent cell 300 can also be reduced, so as to arrange more cells in a limited space and improve the efficiency of the photovoltaic module.

[0099] Of course, in other embodiments of the present application, the first connecting section 111 is arranged in a flat shape, or the second connecting section 121 is arranged in a flat shape. The principle is substantially the same as that when both the first connecting section 111 and the second connecting section 121 are arranged in a flat shape. When describing the structure of the photovoltaic solder ribbon 100 later, only the case where both the first connecting section 111 and the second connecting section 121 are arranged in a flat shape is taken as an example for illustration.

[0100] When the first welding wire 110 is formed, a wire with a uniform cross-sectional shape (here, the cross-section refers to the surface cut along the thickness direction, which will not be elaborated later) is used, and a specified length is intercepted from the wire. The length of the wire is adapted to the length of the first welding wire 110. One end of the wire is flattened to form the flat first connecting section 111, and the rest of the wire remains in its original shape, which is the first main section 112 described later. The second welding wire 120 is made in the same way.

[0101] It can be understood that because the first connecting section 111 and the second connecting section 121 are in a flat structure. When the first welding wire 110 and the second welding wire 120 are formed, the first connecting section 111 and the second connecting section 121 can be flattened first and then connected together to form the overlapping section 130. Or the first connecting section 111 and the second connecting section 121 can be connected together first, and then the first connecting section 111 and the second connecting section 121 are flattened to form the overlapping section 130. Of course, the first connecting section 111 and the second connecting section 121 can also be flattened and connected together, and then the connected first connecting section 111 and the second connecting section 121 are flattened to form the overlapping section 130.

[0102] In Figure 7 and Figure 8 , the upper surface of the previous cell 200 is the front surface of the previous cell 200. The first welding wire 110 is located above the previous cell 200 and is connected to the front surface of the previous cell 200. The lower surface of the subsequent cell 300 is the back surface of the subsequent cell 300. The second welding wire 120 is located below the subsequent cell 300 and is connected to the back surface of the subsequent cell 300.

[0103] Moreover, the outer surface of the first welding wire 110 has a first reflective surface 114 and a first mounting surface 115 (in the following text Figure 9 ), the surface of the first welding wire 110 facing the previous solar cell 200 has a first mounting surface 115, and the first mounting surface 115 is used to realize the connection between the first welding wire 110 and the previous solar cell 200. The surface of the first welding wire 110 facing away from the previous solar cell 200 has a first reflective surface 114, and the first reflective surface 114 is used to reflect sunlight. The first welding wire 110 is connected to the front side of the previous solar cell 200 through the first mounting surface 115, and the first reflective surface 114 faces away from the front side of the previous solar cell 200.

[0104] After sunlight irradiates the first reflective surface 114 of the first welding wire 110, the first reflective surface 114 can reflect the sunlight to the back surface of the cover plate, and then the cover plate can reflect the sunlight to the front surface of the previous solar cell 200. In this way, the sunlight reflected by the first welding wire 110 can be reflected to the front surface of the previous solar cell 200, so as to improve the utilization rate of sunlight and further improve the power of the photovoltaic module.

[0105] At the same time, after the second welding wire 120 is connected to the back surface of the subsequent solar cell 300, the second welding wire 120 can also reflect a part of the sunlight to the backplane, and then through the backplane to the back surface of the subsequent solar cell 300. In this way, the subsequent solar cell 300 can also utilize the sunlight reflected by the second welding wire 120, further improving the utilization rate of sunlight and further improving the bifaciality of the photovoltaic module.

[0106] When forming the solar cell string 10, the first welding wire 110 and the second welding wire 120 are connected through an overlapping section 130. At the same time, the first welding wire 110 is connected to the front surface of the previous solar cell 200, and the second welding wire 120 is connected to the back surface of the subsequent solar cell 300 to connect the previous solar cell 200 and the subsequent solar cell 300 in series. In this way, the photovoltaic solder ribbon 100 has a split (segmented) structure, namely the first welding wire 110 and the second welding wire 120, the first welding wire 110 is connected to the front surface of the previous solar cell 200, and the second welding wire 120 is connected to the back surface of the subsequent solar cell 300.

[0107] In this way, the photovoltaic solder ribbon 100 does not need to be connected to the back surface of the subsequent solar cell 300 by means of flattening or twisting 180°, reducing the process difficulty of the photovoltaic solder ribbon 100. And the second welding wire 120 can reflect the sunlight on the back surface of the subsequent solar cell 300, improving the bifaciality of the photovoltaic module. At the same time, the first welding wire 110 and the second welding wire 120 are connected through the overlapping section 130, which can reduce the distance between the previous solar cell 200 and the subsequent solar cell 300 and improve the efficiency of the photovoltaic module.

[0108] There are two alternative implementation methods for the photovoltaic solder ribbon 100 to connect the previous cell 200 and the subsequent cell 300:

[0109] One implementation method is: connect the first welding wire 110 to the front side of the previous cell 200, connect the second welding wire 120 to the back side of the subsequent cell 300, and then directly connect the first welding wire 110 and the second welding wire 120. However, in the actual process, since the welding connection temperature of the first welding wire 110 and the second welding wire 120 is higher than the connection temperature of the first welding wire 110 and the previous cell 200, and also higher than the connection temperature of the second welding wire 120 and the subsequent cell 300, it will cause the situation of poor welding between the first welding wire 110 and the previous cell 200, and between the second welding wire 120 and the subsequent cell 300, and it is also prone to the risk of hot spots.

[0110] Another implementation method is: when the photovoltaic solder ribbon 100 connects the previous cell 200 and the subsequent cell 300 in series, first connect the first welding wire 110 and the second welding wire 120 together to form the overall photovoltaic solder ribbon 100, and then connect the photovoltaic solder ribbon 100 to the previous cell 200 and the subsequent cell 300. In this way, when the first welding wire 110 is connected to the previous cell 200 and the second welding wire 120 is connected to the subsequent cell 300, it will not be affected by the connection temperature of the first welding wire 110 and the second welding wire 120, thereby avoiding the risks of poor welding and hot spots.

[0111] It should be noted that both of the above implementation methods can achieve the connection between the segmented first welding wire 110 and the second welding wire 120 and the previous cell 200 and the subsequent cell 300. The focus of this application lies in the segmented design of the photovoltaic solder ribbon 100, so as to facilitate the connection of the second welding wire 120 to the back side of the subsequent cell 300, reduce the process difficulty of the photovoltaic solder ribbon 100, and reduce the light-shielding area of the second welding wire 120 on the back side of the subsequent cell 300.

[0112] Since the photovoltaic welding strip 100 is connected to the previous cell 200 and the next cell 300 after forming a whole, the problem of cold welding can be avoided, so the specific connection method is also described here. When the photovoltaic welding strip 100 is connected in series with the previous cell 200 and the next cell 300, the first connecting section 111 of the first welding wire 110 and the second connecting section 121 of the second welding wire 120 are first stacked to connect the first welding wire 110 and the second welding wire 120 to form a whole photovoltaic welding strip 100, and then, the first welding wire 110 is connected to the front of the previous cell 200, and the second welding wire 120 is connected to the back of the next cell 300. In this way, the connection between the photovoltaic welding strip 100 and the previous cell 200 and the next cell 300 is realized, and at the same time, the problem of cold welding between the photovoltaic welding strip 100 and the previous cell 200 and the next cell 300 will not occur, and the risk of hot spots can be avoided, thereby ensuring the product quality of the solar cell string 10.

[0113] Moreover, when forming the solar cell string 10, after positioning the previous cell 200 and the next cell 300, the first welding wire 110 can be connected to the front side of the previous cell 200, and the second welding wire 120 can be connected to the back side of the next cell 300. There is no need to calibrate the relative position of the first welding wire 110 and the second welding wire 120 before welding them together, which simplifies the forming process of the solar cell string 10 and improves the forming efficiency of the solar cell string 10.

[0114] See also Figure 1 , Figure 4 and Figure 5 In one embodiment, the first welding wire 110 further includes a first main body section 112, the first connecting section 111 is disposed at one end of the first main body section 112, and the first main body section 112 can be connected to the front side of the previous battery cell 200. The first main body section 112 is disposed at one end of the first connecting section 111 away from the second welding wire 120, and the first main body section 112 is the main part of the first welding wire 110 for collecting current. When the first welding wire 110 is connected to the front side of the previous battery cell 200, the first welding wire 110 is connected to the front side of the previous battery cell 200 through the first main body section 112.

[0115] See also Figure 1 , Figure 4 and Figure 5In one embodiment, the second welding wire 120 further includes a second main body section 122, the second connecting section 121 is disposed at one end of the second main body section 122, and the second main body section 122 can be connected to the back side of the next battery cell 300. The second main body section 122 is disposed at one end of the second connecting section 121 away from the first welding wire 110, and the second main body section 122 is the main part of the second welding wire 120 for collecting current. When the second welding wire 120 is connected to the back side of the next battery cell 300, the second welding wire 120 is connected to the back side of the next battery cell 300 through the second main body section 122.

[0116] See also Figure 5 and Figure 8 In one embodiment, the first welding wire 110 further includes a first transition section 113, which transitionally connects the first main section 112 and the first connecting section 111. One end of the first transition section 113 is connected to the first connecting section 111, and the other end is connected to the first main section 112. It can be understood that after the first connecting section 111 is flattened, the end where the first main section 112 and the first connecting section 111 are connected will be deformed, and the deformed portion is the first transition section 113.

[0117] See also Figure 5 and Figure 8 In one embodiment, the second welding wire 120 further includes a second transition section 123, which transitionally connects the second main section 122 and the second connecting section 121. One end of the second transition section 123 is connected to the second connecting section 121, and the other end is connected to the second main section 122. It can be understood that after the second connecting section 121 is flattened, the end where the second main section 122 and the second connecting section 121 are connected will be deformed, and the deformed portion is the second transition section 123.

[0118] See also Figures 4 to 8 In one embodiment, the overlapping dimension of the first connecting section 111 and the second connecting section 121 along the length direction is greater than or equal to 0.5 mm. In other words, the dimension of the overlapping section 130 along the length direction is greater than or equal to 0.5 mm. In this way, the connection length of the first connecting section 111 and the second connecting section 121 can be ensured, thereby improving the reliability of the connection between the first welding wire 110 and the second welding wire 120. At the same time, the tension between the first welding wire 110 and the second welding wire 120 can also be ensured, and the conductive performance of the photovoltaic welding strip 100 can be ensured.

[0119] See also Figures 4 to 8In one embodiment, the dimension of the overlapping section 130 along the thickness direction is less than 0.15 mm, and the thickness of the overlapping section 130 is less than the thickness of the first main section 112 and / or the second main section 122. In this way, the thickness dimension of the overlapping section 130 is close to the thickness of the first main section 112 and the second main section 122, so that the overlapping section 130 does not protrude from the first main section 112 and the second main section 122, thereby preventing the overlapping section 130 from excessively occupying space and preventing the overlapping section 130 from lifting the next cell 300, thereby preventing the occurrence of cracks during the lamination of the photovoltaic module, thereby ensuring the product quality of the photovoltaic module.

[0120] See also Figures 4 to 8 In one embodiment, the dimension of the first main body section 112 along the thickness direction is greater than or equal to the dimension of the second main body section 122 along the thickness direction. In this way, the dimension of the first welding wire 110 protruding from the front side of the preceding cell 200 is substantially equal to the dimension of the second welding wire 120 protruding from the back side of the following cell 300, so that the overall thickness of the preceding cell 200 provided with the first main body section 112 is substantially equal to the main body thickness of the following cell 300 provided with the second main body section 122, thereby preventing the solar cell string 10 from being uneven.

[0121] See also Figures 4 to 8 In one embodiment, the overlapping section 130 is separated from the front metal electrode of the previous cell 200 and / or the back metal electrode of the next cell 300. In this embodiment, the overlapping section 130 is located on the back of the next cell 300, and there is no conductive connection between the overlapping section 130 and the next cell 300, that is, the overlapping section 130 can contact the back of the next cell 300, but is not welded to the back metal electrode.

[0122] See also Figure 4 and Figure 9 In one embodiment of the present application, the cross-section of the first main body segment 112 (the cross-section here refers to the surface cut along the thickness direction, which will not be repeated later) is triangular in shape. Figure 9 for Figure 4 The sectional view of the photovoltaic welding strip 100 along the CC direction is shown. After the first main body section 112 with a triangular cross section is connected to the front side of the previous battery cell 200, the light shielding area of the first welding wire 110 on the front side of the previous battery cell 200 can be reduced to increase the light receiving area of the previous battery cell 200. At the same time, the first main body section 112 with a triangular cross section has two first light reflecting surfaces 114 to ensure the light reflecting effect and improve the utilization rate of sunlight.

[0123] See also Figure 9, in one embodiment, the side length dimension of the first main body section 112 ranges from 0.1 mm to 0.35 mm. That is to say, the cross-section of the first main body section 112 is triangular, and the side length dimension of the triangle is within the range of 0.1 mm to 0.35 mm. In this way, the resistance can be reduced, the current transmission loss can be lowered, the light-shielding area can be decreased, and the utilization rate of sunlight can be improved. At the same time, the mechanical strength of the first welding wire 110 can be ensured, and the reliability of connection with the previous solar cell 200 can be enhanced.

[0124] Refer to Figure 9 and Figure 10 , in one embodiment, adjacent sides in the first main body section 112 are transitionally connected through a chamfered portion. Figure 10 is Figure 9 the first deformation diagram of the cross-section of the first main body section 112 shown in. That is to say, the three side edges of the triangle are transitionally connected through the chamfered portion, reducing the process processing difficulty.

[0125] In one embodiment, the radius of the chamfered portion is greater than or equal to 5 μm. In this way, the areas of the first reflecting surface 114 and the first mounting surface 115 can be ensured, and at the same time, it is convenient for the forming process of the first welding wire 110.

[0126] Refer to Figure 11 and Figure 12 , in another embodiment of the present application, the first main body section 112 further includes a first connecting portion 116 and a second connecting portion 117. The first connecting portion 116 is arranged along the thickness direction on the second connecting portion 117. The cross-sectional shape of the first connecting portion 116 is triangular, and the cross-sectional shape of the second connecting portion 117 is rectangular. The second connecting portion 117 is connected to the front surface of the previous solar cell 200. Figure 11 is Figure 9 the second deformation diagram of the cross-section of the first main body section 112 shown in, Figure 12 is Figure 9 the third deformation diagram of the cross-section of the first main body section 112 shown in.

[0127] That is to say, the first connecting portion 116 is arranged above the second connecting portion 117, and the shape of the first main body section 112 is a combined structure of a triangle and a rectangle. In this way, the first main body section 112 is connected to the front surface of the previous solar cell 200 through the rectangular second connecting portion 117, and sunlight is reflected by the first reflecting surface 114 on the second connecting portion 117, improving the utilization rate of sunlight. In Figure 11 , the edges of the first main body section 112 are all sharp corners, and in Figure 12 , the edges of the first main body section 112 are transitionally connected through chamfers.

[0128] Refer to Figure 4 and Figure 13 , in one embodiment of the present application, the cross-sectional shape of the second main body section 122 is circular.Figure 13 is Figure 4 The cross-sectional view of the photovoltaic soldering ribbon 100 along the D-D direction as shown. After the second main body segment 122 with a circular cross-section is connected to the back surface of the subsequent cell 300, it can reduce the light-shielding area of the second welding wire 120 on the back surface of the subsequent cell 300. After sunlight is reflected by the cover plate through the ground or other surfaces to the back surface of the subsequent cell 300, the circular second main body segment 122 can reduce its occupied space on the back surface of the subsequent cell 300 to improve the bifaciality rate of the photovoltaic module.

[0129] Referring to Figure 13 , in an embodiment, the diameter dimension range of the second main body segment 122 is 0.1 mm to 0.3 mm. After the diameter dimension of the second main body segment 122 is within the above range, it can reduce the resistance, reduce the current transmission loss, reduce the light-shielding area, improve the utilization rate of sunlight, and at the same time, it can also ensure the mechanical strength of the second welding wire 120 and improve the reliability of connection with the subsequent cell 300.

[0130] In another embodiment of the present application, the cross-sectional shape of the second main body segment 122 is triangular. The side length dimension range of the second main body segment 122 is 0.1 mm to 0.35 mm. That is to say, a wire with a triangular cross-section can be used as the second main body segment 122, which is actually the same as the first main body segment 112 and will not be elaborated here.

[0131] It can be understood that after the first welding wire 110 and the second welding wire 120 are connected to form the photovoltaic soldering ribbon 100, there is partial overlap between the first welding wire 110 and the second welding wire 120 in the side view of the photovoltaic soldering ribbon 100. For the convenience of explaining the cross-sectional shape combination of the first main body segment 112 and the second main body segment 122, the first main body segment 112 and the second main body segment 122 are arranged staggeredly along the thickness direction here, and the cross-sections of the first main body segment 112 and the second main body segment 122 are combined together.

[0132] In an embodiment of the present application, the cross-sectional shape of the first main body segment 112 is triangular, and the cross-sectional shape of the second main body segment 122 is circular, as Figure 14 shown Figure 14 is the combined cross-sectional view of one embodiment of the first main body segment 112 and the second main body segment 122. The first main body segment 112 with a triangular cross-section is connected to the front surface of the previous cell 200, and the second main body segment 122 with a circular cross-section can be connected to the back surface of the subsequent cell 300.

[0133] It can be understood that after the front side of the previous cell 200 is connected by the first welding wire 110 with a triangular cross-section and the back side of the subsequent cell 300 is connected by the second welding wire 120 with a circular cross-section, the first welding wire 110 can reflect sunlight, improving the utilization rate of sunlight, and the second welding wire 120 can reduce the light-shielding area of the back side of the subsequent cell 300, so as to improve the bifaciality of the photovoltaic module, and further improve the power of the photovoltaic module. Moreover, the manufacturing difficulty of the first welding wire 110 and the second welding wire 120 is low, which is convenient for forming and processing, easy to connect with the previous cell 200 and the subsequent cell 300, reduces the hot spot risk, and reduces the production cost of the photovoltaic module.

[0134] In another embodiment of the present application, the cross-sectional shape of the first main body section 112 is triangular, and the cross-sectional shape of the second main body section 122 is also triangular, and the second main body section 122 is arranged upside down relative to the first main body section 112, as Figure 15 shown, Figure 15 is a combined cross-sectional view of another embodiment of the first main body section 112 and the second main body section 122. In this way, the second main body section 122 is inversely connected to the back side of the subsequent cell 300, avoiding the contact between the edges and corners of the triangle and the back side of the subsequent cell 300, and avoiding the situation of cracking of the subsequent cell 300 during the lamination of the photovoltaic module. At the same time, since the first welding wire 110 and the second welding wire 120 are segmented structures, the second welding wire 120 does not need to be formed by twisting 180°, which is convenient for the second welding wire 120 to be connected to the subsequent cell 300.

[0135] Of course, in other embodiments of the present application, the cross-sectional shape of the first main body section 112 can also be other, as long as the first main body section 112 has a small light-shielding area on the front side of the previous cell 200 and can reflect sunlight, and the cross-sectional shape of the second main body section 122 can also be other, as long as the second main body section 122 has a small light-shielding area on the back side of the subsequent cell 300.

[0136] Referring to Figure 15 , in one embodiment, when the cross-sectional shape of the second main body section 122 is triangular, the second welding wire 120 further includes a second reflective surface and a second mounting surface. The second mounting surface is connected to the back side of the subsequent cell 300, and the second reflective surface is used for reflecting sunlight on the back side of the subsequent cell 300. In this way, the second main body section 122 is mounted on the back side of the subsequent cell 300 through the second mounting surface, and the sunlight on the back side of the subsequent cell 300 is reflected through the second reflective surface, so as to improve the utilization rate of sunlight by the photovoltaic module, and further improve the power of the photovoltaic module.

[0137] Referring to Figure 5 and Figure 8 , in one embodiment, in the thickness direction, the first connection section 111 is located on the upper surface of the second connection section 121. That is to say, inFigure 5 and Figure 8 In the direction shown, the first connecting section 111 is located above the second connecting section 121. In this way, it is convenient to connect the first welding wire 110 and the second welding wire 120, and it is also convenient to connect them to the previous cell 200 and the subsequent cell 300. When the overlapping section 130 is located on the back surface of the subsequent cell 300, the first connecting section 111 is located between the second connecting section 121 and the back surface of the subsequent cell 300.

[0138] Of course, in other embodiments of the present application, in the thickness direction, the first connecting section 111 may also be located on the lower surface of the second connecting section 121. That is to say, the first connecting section 111 is located below the second connecting section 121. When the overlapping section 130 is located on the back surface of the subsequent cell 300, the second connecting section 121 is located between the first connecting section 111 and the back surface of the subsequent cell 300.

[0139] Referring to Figures 1 to 8 , in an embodiment, the first connecting section 111 and the second connecting section 121 are connected by welding. That is to say, the first connecting section 111 and the second connecting section 121 are connected together by welding, so as to connect the first welding wire 110 and the second welding wire 120 to form a complete photovoltaic solder ribbon 100. In this way, the reliability of the connection between the first welding wire 110 and the second welding wire 120 can be ensured, and at the same time, the electrical conductivity and heat resistance of the first welding wire 110 and the second welding wire 120 can also be guaranteed.

[0140] It can be understood that the welding method of the first connecting section 111 and the second connecting section 121 is not limited in principle, as long as the electrical connection between the first connecting section 111 and the second connecting section 121 can be realized and the reliability of the connection can be ensured. Optionally, the first connecting section 111 and the second connecting section 121 are connected by laser welding, ultrasonic welding, infrared welding or arc welding, etc., so that the first welding wire 110 and the second welding wire 120 are connected to form the photovoltaic solder ribbon 100, which can ensure the reliability of the connection between the first welding wire 110 and the second welding wire 120, and at the same time, the electrical conductivity and heat resistance of the first welding wire 110 and the second welding wire 120 can also be guaranteed.

[0141] In an embodiment, the first welding wire 110 includes a first copper substrate, a first welding coating and a reflective coating. The first welding coating and the reflective coating are coated on the outer periphery of the first copper substrate. The first welding coating forms a first mounting surface 115 for welding connection with the previous cell 200, and the reflective coating forms a first reflective surface 114. The second welding wire 120 includes a second copper substrate and a second welding coating. The second welding coating is coated on the outer periphery of the second copper substrate, and the second welding coating is welded to the subsequent cell 300.

[0142] The first copper substrate is the conductive substrate in the first welding wire 110, and the electrical conductivity of the first welding wire 110 is ensured by the first copper substrate. The first welding coating and the reflective coating are coated on the surface of the first copper substrate to form the first mounting surface 115 and the first reflective surface 114. When the first main body section 112 is welded and connected to the front side of the previous solar cell 200, the first welding coating can play a role in assisting soldering, facilitating the welding and connection of the first main body section 112 to the front side of the previous solar cell 200. Moreover, the reflective coating can reflect sunlight to improve the utilization rate of sunlight.

[0143] The second copper substrate is the conductive substrate in the second welding wire 120, and the electrical conductivity of the second welding wire 120 is ensured by the second copper substrate. The second welding coating is coated on the surface of the second copper substrate. When the second main body section 122 is welded and connected to the front side of the previous solar cell 200, the second welding coating can play a role in assisting soldering, facilitating the welding and connection of the second main body section 122 to the back side of the subsequent solar cell 300.

[0144] In an embodiment, the first welding coating is coated on the outer wall of the first copper substrate, and the reflective coating is provided on a part of the outer wall of the first welding coating. In this way, the first reflective surface 114 is formed by the reflective coating, and the first mounting surface 115 is formed by the first welding coating exposing the surface of the reflective coating. In this way, only the first welding coating is provided at the first mounting surface 115, and no reflective coating is provided. When the first main body section 112 is welded and connected to the front side of the previous solar cell 200, the reflective coating is not between the first main body section 112 and the previous solar cell 200, and thus will not affect the welding effect between the first main body section 112 and the previous solar cell 200, ensuring the reliability of the connection between the first main body section 112 and the previous solar cell 200. At the same time, the reflective coating can also reflect sunlight.

[0145] Of course, the first welding coating and the reflective coating can also be separately provided on the outer wall of the first copper substrate, and the first welding coating and the reflective coating are separately arranged. That is to say, the reflective coating is not provided on the outer wall of the first welding coating. In this way, while ensuring the reflective effect, the reliability of the connection between the first main body section 112 and the previous solar cell 200 can be ensured.

[0146] It can be understood that the material of the first welding coating is not limited in principle, as long as the first welding coating can play a role in assisting soldering and facilitate the welding and connection of the first main body section 112 to the front side of the previous solar cell 200. In an embodiment, the first welding coating includes a tin-lead alloy coating, a tin-lead-bismuth alloy coating, a tin-silver alloy coating, etc. In this way, the first welding coating does not contain the elements of the reflective coating, that is, the first welding coating does not contain silver elements or aluminum elements. Of course, other trace elements such as antimony elements can also be included in the tin-lead alloy coating.

[0147] It can be understood that the material of the reflective coating is not restricted in principle, as long as the reflective coating can reflect sunlight. In one embodiment, the reflective coating includes a silver coating, an aluminum coating, etc.

[0148] It can be understood that the material of the second welding coating is not restricted in principle, as long as the second welding coating can play a soldering assistance role and facilitate the soldering connection between the second main body section 122 and the back surface of the subsequent solar cell 300. In one embodiment, the second welding coating includes a tin-lead alloy coating, a tin-lead-bismuth alloy coating, a tin-silver alloy coating, etc. Of course, other trace elements such as antimony element can also be included in the tin-lead alloy coating.

[0149] In this way, when the second main body section 122 is connected to the back surface of the subsequent solar cell 300, the second welding coating can facilitate the soldering connection between the second main body section 122 and the subsequent solar cell 300, ensuring the connection effect. At the same time, the surface of the second main body section 122 facing away from the subsequent solar cell 300 can also reflect a certain amount of sunlight to improve the utilization rate of sunlight. Of course, a reflective coating can also be coated on the surface of the second main body section 122 facing away from the subsequent solar cell 300 to further improve the sunlight reflection effect.

[0150] The purpose of the reflective coating is to increase the reflectance and improve the utilization rate of sunlight by the solar cell. In the traditional method, a single welding ribbon is directly used to connect the previous solar cell and the subsequent solar cell, and the double sides of the welding ribbon have reflective coatings. When preparing the welding ribbon, it is necessary to first form a tin layer on the surface of the copper core and then coat a reflective layer on the basis of the tin layer surface. In this way, after the welding ribbon is flattened, at the front surface of the previous solar cell, the lower surface of the welding ribbon will have a situation where the reflective surface faces away from the front surface of the previous solar cell, and the welding ribbon can be reliably connected to the front surface of the previous solar cell. However, at the back surface of the subsequent solar cell, the upper surface of the welding ribbon will have a situation where the reflective surface faces the back surface of the subsequent solar cell. When the welding ribbon is connected to the back surface of the subsequent solar cell, the reflective surface will be connected to the back surface of the subsequent solar cell, affecting the welding performance.

[0151] Therefore, the photovoltaic welding ribbon 100 of the present application adopts a segmented design structure form, and the first welding wire 110 and the second welding wire 120 are independently arranged. In this way, the independent first welding wire 110 and second welding wire 120 can be set according to actual needs, so that the first welding wire 110 and the second welding wire 120 can exhibit different optical and electrical properties to respectively adapt to the front surface of the previous solar cell 200 and the back surface of the subsequent solar cell 300. At the same time, it can also solve the welding problems existing in the traditional process and ensure the welding effect between the second welding wire 120 and the back surface of the subsequent solar cell 300.

[0152] Thus, when manufacturing the first welding wire 110, a reflective coating can be applied to a part of the outer wall of the first copper substrate to form the first mounting surface 115 and the first reflective surface 114. The first welding coating and the reflective coating can also be respectively applied to different positions on the outer wall of the first copper substrate. In this way, the elements in the reflective coating will not exist in the first welding coating, so as not to affect the welding effect between the first main section 112 and the previous solar cell 200.

[0153] For the first welding wire 110, the back surface of the first welding wire 110 has a first welding coating, and the front surface of the first welding wire 110 has a reflective coating. The back surface of the first welding wire 110 is aligned with the front surface of the previous solar cell 200, and the front surface of the first welding wire 110 faces away from the front surface of the previous solar cell 200. In this way, the functions of different positions of the first welding wire 110 are differentiated, so that the first welding wire 110 is welded and connected to the front surface of the previous solar cell 200 through the first welding coating, and the sunlight is reflected through the reflective coating.

[0154] At the same time, the outer surface of the second welding wire 120 has a second welding coating. The coatings on the first welding wire 110 and the second welding wire 120 are different, so that the first welding wire 110 and the second welding wire 120 exhibit different optical and electrical properties on the front surface of the previous solar cell 200 and the back surface of the subsequent solar cell 300, so as to meet the usage requirements of different installation positions and improve the bifaciality of the photovoltaic module.

[0155] It can be understood that for the conventional solder tape, only a single tin layer can be coated, and the front and back surfaces of the solder tape cannot have different optical and electrical functions. Therefore, in this application, the separate first welding wire 110 and the second welding wire 120 are formed to form a complete photovoltaic solder tape 100. In this way, the elements of the coatings on the first welding wire 110 and the second welding wire 120 can be set according to requirements to exhibit different optical and electrical properties and improve the bifaciality of the photovoltaic module.

[0156] Exemplarily, when the first welding coating includes a tin-lead alloy coating or a tin-lead-bismuth alloy coating, the reflective coating includes an aluminum coating or a silver coating, and the second welding coating includes a tin-lead alloy coating or a tin-lead-bismuth alloy coating, the overlapping section 130 includes tin element, lead element, and copper element, and also includes one of aluminum element or silver element.

[0157] In this way, the first welding coating is welded and connected to the front surface of the previous solar cell 200 through the tin element and lead element in the tin-lead alloy coating, which facilitates the welding connection between the first main section 112 and the previous solar cell 200. At the same time, the reflective coating reflects sunlight through the silver element or aluminum element to ensure the reflection effect. The second welding coating is connected to the back surface of the subsequent solar cell 300 through the tin element and lead element, which facilitates the connection between the second main section 122 and the back surface of the subsequent solar cell 300.

[0158] In one embodiment, the overlapping section 130 further includes a first fusion part, and the first welding coating, the reflective coating, and the second welding coating are fused to form the first fusion part. It can be understood that when the first connecting section 111 and the second connecting section 121 are welded together, the high temperature during welding can melt the first welding coating and the reflective coating on the outer surface of the first connecting section 111, and at the same time, can also melt the second welding coating on the outer surface of the second connecting section 121.

[0159] In this way, the first welding coating, the reflective coating, and the second welding coating can be fused together to form the first fusion part. The tin element and the lead element in the first fusion part are fused and connected, and are also fused and connected with one of the aluminum element or the silver element.

[0160] In one embodiment, the overlapping section 130 further includes a second fusion part, and the first copper substrate and the second copper substrate are fused to form the second fusion part. When the first connecting section 111 and the second connecting section 121 are welded together, in addition to melting the first welding coating, the reflective coating, and the second welding coating, the high temperature during welding can also melt the first copper substrate inside the first connecting section 111 and the second copper substrate inside the second connecting section 121.

[0161] In this way, the first copper substrate and the second copper substrate can be fused and connected to form the second fusion part. In this way, the electrical connection between the first welding wire 110 and the second welding wire 120 can be realized. The tin element, the lead element, and the copper element in the second fusion part are fused and connected, and are also fused and connected with one of the aluminum element or the silver element.

[0162] For the photovoltaic solder strip 100 of the present application, the first connecting section 111 and the second connecting section 121 are stacked and connected to form the overlapping section 130. The photovoltaic solder strip 100 is connected to the front surface of the previous solar cell 200 through the first mounting surface 115 of the first welding wire 110, and is connected to the back surface of the subsequent solar cell 300 through the second welding wire 120 to connect the previous solar cell 200 and the subsequent solar cell 300 in series. In this way, the photovoltaic solder strip 100 does not need to be connected to the back surface of the subsequent solar cell 300 by means of flattening or twisting 180°, reducing the process difficulty of the photovoltaic solder strip 100. Moreover, the second welding wire 120 can reflect the sunlight on the back surface of the subsequent solar cell 300, improving the bifaciality of the photovoltaic module. At the same time, the first welding wire 110 and the second welding wire 120 are connected through the overlapping section, which can reduce the distance between the previous solar cell 200 and the subsequent solar cell 300 and improve the efficiency of the photovoltaic module.

[0163] When using the photovoltaic solder ribbon 100 to connect the previous cell 200 and the subsequent cell 300, the first mounting surface 115 of the first welding wire 110 in the photovoltaic solder ribbon 100 can be directly connected to the front side of the previous cell 200, and the second welding wire 120 in the photovoltaic solder ribbon 100 can be connected to the back side of the subsequent cell 300. In this way, after forming the first welding wire 110 and the second welding wire 120 into an integral photovoltaic solder ribbon 100, then connecting the photovoltaic solder ribbon 100 to the previous cell 200 and the subsequent cell 300. In this way, there will be no problem of loose connection between the photovoltaic solder ribbon 100 and the previous cell 200 and the subsequent cell 300, and the risk of hot spots can also be avoided, ensuring the product quality of the solar cell string 10. At the same time, the connection accuracy between the first welding wire 110 and the second welding wire 120 can also be ensured, making the connection method between the first welding wire 110 and the second welding wire 120 controllable, and improving the reliability of the photovoltaic module.

[0164] Refer to Figures 1 to 4 、 Figure 7 、 Figure 8 and Figure 16 , Figure 16 is Figure 1 the forming flowchart of the photovoltaic solder ribbon 100 shown. The present application also provides a method for forming a photovoltaic solder ribbon, which is used to form the photovoltaic solder ribbon 100 in any of the above embodiments. The method for forming a photovoltaic solder ribbon at least includes the following steps:

[0165] S1, using a first feeding mechanism to convey a first raw material, and using a first wire drawing mechanism to cut the first raw material to form a first welding wire 110 of a predetermined length, and conveying the first welding wire 110 to an interconnection platform;

[0166] S2, using a second feeding mechanism to convey a second raw material, and using a second wire drawing mechanism to cut the second raw material to form a second welding wire 120 of a predetermined length, and conveying the second welding wire 120 to the interconnection platform;

[0167] S3, connecting the first welding wire 110 and the second welding wire 120 to form a photovoltaic solder ribbon 100, the first welding wire 110 can be connected to the front side of the previous cell 200, and the second welding wire 120 can be connected to the back side of the subsequent cell 300.

[0168] When the photovoltaic solder ribbon 100 of the present application is formed, the first welding wire 110 and the second welding wire 120 are respectively made of corresponding raw materials. It can be understood that because the installation positions of the first welding wire 110 and the second welding wire 120 are different, and then the coatings on the outer surfaces of the first welding wire 110 and the second welding wire 120 are different, so different raw materials are used to make the first welding wire 110 and the second welding wire 120 respectively, so that the first welding wire 110 and the second welding wire 120 have different optical and electrical functions.

[0169] To this end, the present application uses a first raw material to prepare a first welding wire 110 and a second raw material to prepare a second welding wire 120. During forming, a first feeding mechanism is used to convey the first raw material, and a first wire drawing mechanism is used to cut the first raw material to a fixed length to form the first welding wire 110 of a predetermined length. Subsequently, the first wire drawing mechanism conveys the first welding wire 110 to an interconnection platform.

[0170] A second feeding mechanism is used to convey the second raw material, and a second wire drawing mechanism is used to cut the second raw material to a fixed length to form the second welding wire 120 of a predetermined length. Subsequently, the second wire drawing mechanism conveys the second welding wire 120 to the interconnection platform. After the first welding wire 110 and the second welding wire 120 are conveyed to the interconnection platform, one end of the first welding wire 110 is connected to the second welding wire 120 to connect the first welding wire 110 and the second welding wire 120 to form a complete photovoltaic solder ribbon 100.

[0171] It can be understood that the process of the first feeding mechanism conveying the first raw material and the process of the second feeding mechanism conveying the second raw material can be operated simultaneously or successively, and the first wire drawing mechanism and the second wire drawing mechanism can also be operated simultaneously or successively. Moreover, the first raw material is the wire material for making the first welding wire 110, and the second raw material is the wire material for making the second welding wire 120. The first raw material and the second raw material can be wound and arranged. It should be noted that the first feeding mechanism, the first wire drawing mechanism, the second feeding mechanism, the second wire drawing mechanism, and the interconnection platform can adopt the current structures for wire conveying and connection, which will not be elaborated here.

[0172] When forming a solar cell string 10, the first welding wire 110 and the second welding wire 120 are connected through an overlapping section 130. At the same time, the first welding wire 110 is used to connect to the front side of the previous cell 200, and the second welding wire 120 is used to connect to the back side of the subsequent cell 300 to connect the previous cell 200 and the subsequent cell 300 in series. In this way, the photovoltaic solder ribbon 100 is a split structure, namely the first welding wire 110 and the second welding wire 1120 respectively. The first welding wire 110 is used to connect to the front side of the previous cell 200, and the second welding wire 120 is used to connect to the back side of the subsequent cell 300.

[0173] In this way, the photovoltaic solder ribbon 100 does not need to be connected to the back side of the subsequent cell 300 by means of flattening or twisting 180°, reducing the process difficulty of the photovoltaic solder ribbon 100. Moreover, the second welding wire 120 can reflect the sunlight on the back side of the subsequent cell 300, improving the bifaciality of the photovoltaic module. At the same time, the first welding wire 110 and the second welding wire 120 are connected through an overlapping section, which can reduce the distance between the previous cell 200 and the subsequent cell 300, improving the efficiency of the photovoltaic module.

[0174] Moreover, after the first welding wire 110 and the second welding wire 120 are connected to form the integral photovoltaic welding ribbon 100, it is then connected to the previous solar cell 200 and the subsequent solar cell 300. In this way, when the photovoltaic welding ribbon 100 is connected to the previous solar cell 200 and the subsequent solar cell 300 as a whole, it will not be affected by the connection temperature of the first welding wire 110 and the second welding wire 120, thereby avoiding the risks of false soldering and hot spots.

[0175] In one embodiment, connecting the first welding wire 110 and the second welding wire 120 to form the photovoltaic welding ribbon 100 includes at least the following steps:

[0176] Flatten one end of the first welding wire 110 to form a first connecting section 111, flatten one end of the second welding wire 120 to form a second connecting section 121, and connect the first connecting section 111 and the second connecting section 121 to form an overlapping section 130. That is to say, the end of the first welding wire 110 facing the second welding wire 120 is the first connecting section 111, and the end of the second welding wire 120 facing the first welding wire 110 is the second connecting section 121. After flattening the first connecting section 111 and the second connecting section 121 respectively, the first connecting section 111 and the second connecting section 121 are stacked and connected to form an overlapping section 130.

[0177] Alternatively, connect one end of the first welding wire 110 and one end of the second welding wire 120 to form an overlapping section 130, and flatten the overlapping section 130. That is to say, after connecting one end of the first welding wire 110 and one end of the second welding wire 120, an overlapping section 130 is formed, and the overlapping section 130 is flattened as a whole.

[0178] Alternatively, flatten one end of the first welding wire 110 to form a first connecting section 111, flatten one end of the second welding wire 120 to form a second connecting section 121, connect the first connecting section 111 and the second connecting section 121 to form an overlapping section 130, and flatten the overlapping section 130. That is to say, the end of the first welding wire 110 facing the second welding wire 120 is the first connecting section 111, and the end of the second welding wire 120 facing the first welding wire 110 is the second connecting section 121. After flattening the first connecting section 111 and the second connecting section 121 respectively, the first connecting section 111 and the second connecting section 121 are stacked and connected to form an overlapping section 130. Then flatten the overlapping section 130.

[0179] In one embodiment, the first welding wire 110 includes a first copper substrate, a first welding coating, and a reflective coating. The first welding coating and the reflective coating are coated on the outer periphery of the first copper substrate. The first welding coating forms a first mounting surface 115, and the reflective coating forms a first reflective surface 114. The second welding wire 120 includes a second copper substrate and a second welding coating. The second welding coating is coated on the outer periphery of the second copper substrate.

[0180] The first copper base material is the conductive base material in the first welding wire 110, and the electrical conductivity of the first welding wire 110 is ensured by the first copper base material. The first welding coating and the reflective coating are coated on the surface of the first copper base material to form the first mounting surface 115 and the first reflective surface 114. When the first main section 112 is welded and connected to the front side of the previous solar cell 200, the first welding coating can play a role in assisting soldering, facilitating the welding and connection of the first main section 112 to the front side of the previous solar cell 200. Moreover, the reflective coating can reflect sunlight to improve the utilization rate of sunlight.

[0181] The second copper base material is the conductive base material in the second welding wire 120, and the electrical conductivity of the second welding wire 120 is ensured by the second copper base material. The second welding coating is coated on the surface of the second copper base material. When the second main section 122 is welded and connected to the front side of the previous solar cell 200, the second welding coating can play a role in assisting soldering, facilitating the welding and connection of the second main section 122 to the back side of the subsequent solar cell 300.

[0182] In one embodiment, connecting the first welding wire 110 and the second welding wire 120 to form the photovoltaic solder ribbon 100 further includes at least the following steps:

[0183] Adopt laser welding, ultrasonic welding, infrared welding or arc welding to melt the reflective coating, the first welding coating and the second welding coating;

[0184] Weld and connect the first copper base material and the second copper base material.

[0185] One end of the first welding wire 110 has a first connection section 111, and one end of the second welding wire 120 has a second connection section 121. When the first welding wire 110 and the second welding wire 120 are connected, the first connection section 111 and the second connection section 121 are stacked and welded together, so that the first welding wire 110 and the second welding wire 120 are welded and connected to form an integral structure, thereby electrically connecting the first welding wire 110 and the second welding wire 120 and ensuring the reliability of the connection between the first welding wire 110 and the second welding wire 120.

[0186] It can be understood that the welding method of the first connection section 111 and the second connection section 121 is not restricted in principle, as long as the electrical connection between the first connection section 111 and the second connection section 121 can be achieved and the reliability of the connection can be ensured. Optionally, the first connection section 111 and the second connection section 121 are welded and connected by laser welding, ultrasonic welding, infrared welding or arc welding, etc., so that the first welding wire 110 and the second welding wire 120 are connected to form the photovoltaic solder ribbon 100, which can ensure the reliability of the connection between the first welding wire 110 and the second welding wire 120. At the same time, it can also ensure the electrical conductivity and heat resistance of the first welding wire 110 and the second welding wire 120.

[0187] When the first connecting section 111 and the second connecting section 121 are welded and connected by means of laser welding, ultrasonic welding, infrared welding, arc welding or the like, the high temperature during welding can weld and connect the first copper substrate and the second copper substrate, so as to realize the electrical connection between the first welding wire 110 and the second welding wire 120, and ensure the electrical conductivity of the first welding wire 110 and the second welding wire 120.

[0188] In one embodiment, when connecting the first welding wire 110 and the second welding wire 120 to form the photovoltaic solder strip 100, at least the following steps are further included:

[0189] A reflective coating, a first welding coating and a second welding coating are fused and connected between the first copper substrate and the second copper substrate to form a first fusion part. It can be understood that when the first connecting section 111 and the second connecting section 121 are welded and connected, the high temperature during welding can melt the first welding coating and the reflective coating on the outer surface of the first connecting section 111. At the same time, it can also melt the second welding coating on the outer surface of the second connecting section 121. In this way, the first welding coating, the reflective coating and the second welding coating can be fused together to form a first fusion part. The tin element and the lead element in the first fusion part are fused and connected, and are also fused and connected with one of the aluminum element or the silver element.

[0190] And / or, the first copper substrate and the second copper substrate are fused and connected to form a second fusion part. When the first connecting section 111 and the second connecting section 121 are welded and connected, in addition to melting the first welding coating, the reflective coating and the second welding coating, the high temperature during welding can also melt the first copper substrate inside the first connecting section 111 and the second copper substrate inside the second connecting section 121. In this way, the first copper substrate and the second copper substrate can be fused and connected to form a second fusion part. In this way, the electrical connection between the first welding wire 110 and the second welding wire 120 can be realized. The tin element, the lead element and the copper element in the second fusion part are fused and connected, and are also fused and connected with one of the aluminum element or the silver element.

[0191] Refer to Figures 1 to 8 , this application also provides a solar cell string 10, including a previous cell 200, a subsequent cell 300 and the photovoltaic solder strip 100 in any of the above embodiments. The previous cell 200 and the subsequent cell 300 are arranged along the length direction of the photovoltaic solder strip 100. The first welding wire 110 of the photovoltaic solder strip 100 is connected to the front surface of the previous cell 200, and the second welding wire 120 is connected to the back surface of the subsequent cell 300, so that the previous cell 200 and the subsequent cell 300 are connected in series.

[0192] When forming the solar cell string 10 using the above-described photovoltaic solder ribbon 100 of the embodiment, since the first solder wire 110 and the second solder wire 120 are designed with a segmented structure, the first solder wire 110 and the second solder wire 120 can be respectively connected to the previous cell 200 and the subsequent cell 300 to form a complete solar cell string 10. In this way, the photovoltaic solder ribbon 100 does not need to be connected to the back of the subsequent cell 300 by means of flattening or twisting 180°, reducing the process difficulty of the photovoltaic solder ribbon 100. Moreover, the second solder wire 120 can reflect the sunlight on the back of the subsequent cell 300, improving the bifaciality of the photovoltaic module. At the same time, the first solder wire 110 and the second solder wire 120 are connected through the overlapping section, which can reduce the distance between the previous cell 200 and the subsequent cell 300 and improve the efficiency of the photovoltaic module.

[0193] In one embodiment, the number of the photovoltaic solder ribbons 100 is multiple. The multiple photovoltaic solder ribbons 100 are arranged at intervals along the width direction of the previous cell 200, and connect the front surface of the previous cell 200 and the back surface of the subsequent cell 300 to connect the previous cell 200 and the subsequent cell 300 using multiple photovoltaic solder ribbons 100. In this way, the multiple photovoltaic solder ribbons 100 can evenly distribute the current, reduce the current-carrying capacity of a single photovoltaic solder ribbon 100, reduce the resistance loss and heat generation. At the same time, it also increases the contact area, reduces the contact resistance of the current transmission path, and improves the overall efficiency of the photovoltaic module.

[0194] In one embodiment, the front surface of the previous cell 200 has a front surface metal electrode along the length direction. The first mounting surface 115 of the first main section 112 is correspondingly connected to the front surface metal electrode. The back surface of the subsequent cell 300 has a back surface metal electrode along the length direction. The second main section 122 is connected to the back surface metal electrode. In this way, the first solder wire 110 can collect the current of the previous cell 200, and the second solder wire 120 can collect the current of the subsequent cell 300.

[0195] Refer to Figures 2 to 8 , in one embodiment of the present application, the overlapping section 130 of the photovoltaic solder ribbon 100 is located on the back surface of the subsequent cell 300. That is to say, the overlapping section 130 is completely located on the back surface of the subsequent cell 300 and will not be provided on the front surface of the previous cell 200. In this way, the overlapping section 130 will not cause occlusion on the front surface of the previous cell 200, thereby avoiding affecting the light-receiving area of the previous cell 200, improving the power of the photovoltaic module, reducing the distance between the previous cell 200 and the subsequent cell 300, and at the same time ensuring the appearance of the front surface of the solar cell string 10.

[0196] In another embodiment of the present application, the overlapping section 130 of the photovoltaic solder ribbon 100 is located on the front side of the previous solar cell 200. That is to say, the overlapping section 130 is completely located on the front side of the previous solar cell 200 and will not be arranged on the back side of the subsequent solar cell 300. In this way, the overlapping section 130 will not cause shading on the back side of the subsequent solar cell 300. At the same time, the overlapping section 130 can also reflect a certain amount of sunlight on the front side of the previous solar cell 200.

[0197] In still another embodiment of the present application, the overlapping section 130 of the photovoltaic solder ribbon 100 may also be partially located on the front side of the previous solar cell 200 and partially located on the back side of the subsequent solar cell 300. That is to say, a part of the overlapping section 130 is on the front side of the previous solar cell 200, and the remaining part is on the back side of the subsequent solar cell 300.

[0198] In one embodiment, when the overlapping section 130 is located on the front side of the previous solar cell 200 and the back side of the subsequent solar cell 300, the length of the overlapping section 130 located on the back side of the subsequent solar cell 300 is greater than the length of the overlapping section 130 located on the front side of the previous solar cell 200. That is to say, the length of the overlapping section 130 on the back side of the subsequent solar cell 300 is greater than the length on the front side of the previous solar cell 200. In this way, the shading of the overlapping section 130 on the front side of the previous solar cell 200 can be reduced.

[0199] A photovoltaic module of the present application includes at least a cover plate, a back plate, and a plurality of solar cell strings 10 as in any of the above embodiments. The plurality of solar cell strings 10 are connected in parallel and / or in series. The cover plate and the back plate are arranged on both sides of the plurality of solar cell strings 10, and the cover plate, the plurality of solar cell strings 10, and the back plate are encapsulated to form a photovoltaic module.

[0200] By connecting the plurality of solar cell strings 10 in series and / or in parallel, subsequent processes such as typesetting, lamination, and framing can be used to encapsulate and form the cover plate, the plurality of solar cell strings 10, and the back plate to form a photovoltaic module. After adopting the solar cell string 10 of the above embodiment in the photovoltaic module of the present application, the process difficulty of the photovoltaic solder ribbon 100 is reduced, the bifaciality of the photovoltaic module is improved. At the same time, the distance between the previous solar cell 200 and the subsequent solar cell 300 can also be reduced, and the efficiency of the photovoltaic module is improved.

[0201] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered to be within the scope described in this specification.

[0202] The above-described embodiments merely represent several implementation manners of the present application. The description thereof is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patented application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all fall within the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the appended claims.

Claims

1. A kind of photovoltaic welding ribbon, characterized in that, Comprising: A first welding wire (110), one end of the first welding wire (110) has a first connection section (111), and the outer surface of the first welding wire (110) has a first reflective surface (114) and a first mounting surface (115); and A second welding wire (120), one end of the second welding wire (120) has a second connection section (121); Wherein, the first connection section (111) and / or the second connection section (121) are arranged in a flat shape, the first connection section (111) and the second connection section (121) are stacked to form an overlapping section (130), and the photovoltaic welding tape (100) can be connected to the front surface of the previous cell (200) through the first mounting surface (115) of the first welding wire (110), and connected to the back surface of the adjacent subsequent cell (300) through the second welding wire (120).

2. The photovoltaic solder ribbon according to claim 1, wherein, The overlapping dimension of the first connection section (111) and the second connection section (121) in the length direction is greater than or equal to 0.5 mm; And / or, the dimension of the overlapping section (130) in the thickness direction is less than 0.15 mm; And / or, the overlapping section (130) is separated from the front metal electrode of the previous cell (200) and / or the back metal electrode of the subsequent cell (300).

3. The PV ribbon according to claim 1, wherein The first welding wire (110) further includes a first main body section (112), the first connection section (111) is arranged at one end of the first main body section (112), and the first main body section (112) can be connected to the front surface of the previous cell (200); The second welding wire (120) further includes a second main body section (122), the second connection section (121) is arranged at one end of the second main body section (122), and the second main body section (122) can be connected to the back surface of the subsequent cell (300).

4. The PV ribbon according to claim 3, wherein, The dimension of the first main body section (112) in the thickness direction is greater than or equal to the dimension of the second main body section (122) in the thickness direction; And / or, the thickness of the overlapping section (130) is less than the thickness of the first main body section (112) and / or the second main body section (122).

5. The photovoltaic solder ribbon according to claim 3, wherein The cross-sectional shape of the first main body section (112) is triangular; The side length dimension range of the first main body section (112) is 0.1 mm to 0.35 mm.

6. The photovoltaic solder ribbon according to claim 5, wherein, Adjacent sides in the first main body section (112) are connected by a chamfered portion.

7. The PV ribbon according to claim 3, wherein, The first main body section (112) further includes a first connection portion (116) and a second connection portion (117), the first connection portion (116) is arranged in the thickness direction on the second connection portion (117), the cross-sectional shape of the first connection portion (116) is triangular, the cross-sectional shape of the second connection portion (117) is rectangular, and the second connection portion (117) is connected to the front surface of the previous cell (200).

8. The PV ribbon according to claim 3, wherein, The cross-sectional shape of the second main body section (122) is circular, and the diameter dimension range of the second main body section (122) is 0.1 mm to 0.3 mm; Alternatively, the cross-sectional shape of the second main body section (122) is triangular, and the side length dimension of the second main body section (122) ranges from 0.1 mm to 0.35 mm.

9. The PV ribbon according to claim 3, wherein, When the cross-sectional shape of the second main body section (122) is triangular, the second welding wire (120) further includes a second reflective surface and a second mounting surface. The second mounting surface is connected to the back surface of the latter solar cell (300), and the second reflective surface is used for reflecting light on the back surface of the latter solar cell (300).

10. The PV ribbon according to any one of claims 1 to 9, characterized in that, In the thickness direction, the first connecting section (111) is located on the upper surface of the second connecting section (121), or the first connecting section (111) is located on the lower surface of the second connecting section (121).

11. The PV ribbon according to any one of claims 1 to 9, characterized in that, The first connecting section (111) and the second connecting section (121) are welded together.

12. The photovoltaic solder ribbon according to claim 11, wherein, The first connecting section (111) and the second connecting section (121) are welded together by laser welding, ultrasonic welding, infrared welding or arc welding.

13. The PV ribbon according to any one of claims 1 to 9, characterized in that, The first welding wire (110) includes a first copper substrate, a first welding coating and a reflective coating. The first welding coating and the reflective coating cover the outer periphery of the first copper substrate. The first welding coating forms the first mounting surface (115) for welding connection with the previous solar cell (200), and the reflective coating forms the first reflective surface (114); The second welding wire (120) includes a second copper substrate and a second welding coating. The second welding coating covers the outer periphery of the second copper substrate, and the second welding coating is welded to the back surface of the latter solar cell (300).

14. The PV ribbon according to claim 13, wherein The first welding coating includes a tin-lead alloy coating, a tin-lead-bismuth alloy coating or a tin-silver alloy coating; And / or, the reflective coating includes a silver coating or an aluminum coating; And / or, the second welding coating includes a tin-lead alloy coating, a tin-lead-bismuth alloy coating or a tin-silver alloy coating.

15. The PV ribbon according to claim 14, wherein When the first welding coating includes a tin-lead alloy coating or a tin-lead-bismuth alloy coating, the reflective coating includes an aluminum coating or a silver coating, and the second welding coating includes a tin-lead alloy coating or a tin-lead-bismuth alloy coating, the overlapping section (130) at least includes tin, lead and copper elements, and also includes one of aluminum or silver elements.

16. The PV ribbon according to claim 13, wherein, The overlapping section (130) further includes a first fusion part, and the first welding coating, the reflective coating and the second welding coating are fused to form the first fusion part; And / or, the overlapping section (130) further includes a second fusion part, and the first copper substrate and the second copper substrate are fused to form the second fusion part.

17. A method for forming a photovoltaic welding ribbon, characterized in that, For forming the photovoltaic welding ribbon (100) according to any one of claims 1 to 16, the method for forming the photovoltaic welding ribbon at least includes the following steps: Using a first feeding mechanism to convey a first raw material, using a first wire drawing mechanism to cut the first raw material to form a first welding wire (110) of a predetermined length, and conveying the first welding wire (110) to an interconnection platform; The second feeding mechanism is adopted to convey the second raw material, and the second wire drawing mechanism is adopted to cut the second raw material to form the second welding wire (120) with a predetermined length, and the second welding wire (120) is conveyed to the interconnection platform; The first welding wire (110) and the second welding wire (120) are connected to form the photovoltaic welding tape (100). The first welding wire (110) can be connected to the front side of the previous cell (200), and the second welding wire (120) can be connected to the back side of the next cell (300).

18. The method for forming a photovoltaic solder ribbon according to claim 17, wherein Connecting the first welding wire (110) and the second welding wire (120) to form the photovoltaic welding tape (100) includes at least the following steps: One end of the first welding wire (110) is flattened to form a first connecting section (111), one end of the second welding wire (120) is flattened to form a second connecting section (121), and the first connecting section (111) and the second connecting section (121) are connected to form an overlapping section (130); Alternatively, one end of the first welding wire (110) and one end of the second welding wire (120) are connected to form an overlapping section (130), and the overlapping section (130) is flattened; Alternatively, one end of the first welding wire (110) is flattened to form a first connecting section (111), one end of the second welding wire (120) is flattened to form a second connecting section (121), the first connecting section (111) and the second connecting section (121) are connected to form an overlapping section (130), and the overlapping section (130) is flattened.

19. The method for forming a photovoltaic solder ribbon according to claim 17 or 18, wherein The first welding wire (110) includes a first copper base material, a first welding coating, and a reflective coating. The first welding coating and the reflective coating are coated on the outer periphery of the first copper base material. The first welding coating forms a first mounting surface (115), and the reflective coating forms a first reflective surface (114); The second welding wire (120) includes a second copper base material and a second welding coating. The second welding coating is coated on the outer periphery of the second copper base material.

20. The method for forming a photovoltaic solder ribbon according to claim 19, wherein, Connecting the first welding wire (110) and the second welding wire (120) to form the photovoltaic welding tape (100) further includes at least the following steps: Adopting a laser welding method, an ultrasonic welding method, an infrared welding method, or an arc welding method to melt the reflective coating, the first welding coating, and the second welding coating; Welding and connecting the first copper base material and the second copper base material.

21. The method for forming a photovoltaic solder ribbon according to claim 20, characterized in that, characterized in that, Connecting the first welding wire (110) and the second welding wire (120) to form the photovoltaic welding tape (100) further includes at least the following steps: Fusing and connecting the reflective coating, the first welding coating, and the second welding coating between the first copper base material and the second copper base material to form a first fusion part; And / or fusing and connecting the first copper base material and the second copper base material to form a second fusion part.

22. A solar cell string, characterized in that, Including a previous cell (200), a next cell (300), and the photovoltaic welding tape (100) according to any one of claims 1 to 16; The previous solar cell (200) and the subsequent solar cell (300) are arranged along the length direction of the photovoltaic solder ribbon (100). The first solder wire (110) of the photovoltaic solder ribbon (100) is connected to the front side of the previous solar cell (200), and the second solder wire (120) is connected to the back side of the subsequent solar cell (300), so that the previous solar cell (200) and the subsequent solar cell (300) are connected in series.

23. The solar cell string according to claim 22, wherein, The overlapping section (130) of the photovoltaic solder ribbon (100) is located on the back side of the subsequent solar cell (300), and / or the overlapping section (130) of the photovoltaic solder ribbon (100) is located on the front side of the previous solar cell (200); When the overlapping section (130) is located on the front side of the previous solar cell (200) and the back side of the subsequent solar cell (300), the length of the overlapping section (130) located on the back side of the subsequent solar cell (300) is greater than the length of the overlapping section (130) located on the front side of the previous solar cell (200).

24. A photovoltaic module, characterized in that, It at least includes a cover plate, a back plate, and a plurality of solar cell strings (10) as described in claim 22 or 23; A plurality of the solar cell strings (10) are connected in parallel and / or in series. The cover plate and the back plate are arranged on both sides of the plurality of solar cell strings (10), and the cover plate, the plurality of solar cell strings (10), and the back plate are encapsulated to form the photovoltaic module.

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