Solder ribbon member, manufacturing method thereof, and photovoltaic module

Abstract

The present application provides a solder ribbon member, its manufacturing method, and a photovoltaic module. The solder ribbon member includes a first solder ribbon segment, a second solder ribbon segment, and a connection segment, and the connection segment is located between the first solder ribbon segment and the second solder ribbon segment, and the first solder ribbon segment includes a first solder ribbon body having a recess on its surface, and a first solder coating located at least on the surface of the inner wall of the recess. The solder ribbon member of the present application can increase the solder tensile strength by increasing the thickness of the solder coating, and can rationally control the thickness to prevent cell cracking and achieve high-density mounting.

Description

[Technical Field]

[0001] This application claims priority to a Chinese patent application filed with the China Patent Office on October 27, 2022, bearing application number 202211339959.9 and entitled "Solder ribbon member, manufacturing method thereof, and photovoltaic module," the entire contents of which are incorporated herein by reference.

[0002] This application relates to the field of solar cells, and more particularly to a solder ribbon member, a method for manufacturing the same, and a photovoltaic module. [Background technology]

[0003] Solar cells are devices that absorb sunlight and convert solar radiation energy directly or indirectly into electrical energy through the photovoltaic or photochemical effect. After fabrication, solar cells are soldered together with solder ribbons to form cell strings, which then become solar cell modules. Heterojunction cells have attracted significant attention in recent years as a highly efficient technology. Due to their high photovoltaic conversion efficiency, excellent performance, and significant cost reduction potential, they are recognized as the ultimate solution for future battery technology and are considered cutting-edge technology for next-generation commercial photovoltaic production. However, heterojunction cells are limited by the special properties of conductive layers such as transparent conducting oxides (TCOs). For example, tin-doped indium oxide (ITO) is sensitive to high temperatures, requiring low-temperature soldering techniques. This results in high fabrication costs and limits the development of heterojunction cells. Due to the limitations of the low temperature manufacturing process for heterojunction batteries, only more expensive low-temperature tin-lead-bismuth solder ribbons can be used. However, to reduce costs, companies are focusing on "high density packaging," which improves power generation efficiency by incorporating more cells within a limited size range, and believe that the increased cost per watt will be shared by higher power generation efficiency.

[0004] Conventional solder ribbons are completely round wires, and the contact area between the round wire solder ribbon and the cell is too small, resulting in limited conductivity, insufficient soldering tension, and a tendency for solder voids and sealing-off to occur after soldering, reducing the primary molding rate of solar photovoltaic modules. Furthermore, when the solder coating on the solder ribbon melts, it aggregates at the silver paste spots on the cell, forming molten agglomerates. If there is a gap between the solder ribbon and the cell, these molten agglomerates condense and form irregular foreign points. These foreign points significantly increase the likelihood of the cell being subjected to a single point of force when the cells connected in series by the solder ribbon are covered with a top glass and laminated using a laminator, potentially causing hidden cracks. Therefore, the current method of increasing the thickness of the solder coating to ensure sufficient contact area is commonly adopted. However, the thickness of the tin-lead-bismuth coating of the low-temperature solder ribbon is more than 5 μm thicker than the thickness of the solder ribbon coating for conventional passivated emitter rear cells (abbreviated as PERC). Increasing the thickness of the solder coating increases the volume of foreign matter points, making the problem of cell cracking more serious.

[0005] Therefore, there is a need for a technical solution to soldering that can increase the soldering tensile strength by increasing the thickness of the solder coating, while also rationally controlling the thickness to prevent cracking and enable high-density mounting. Summary of the Invention [Problem to be solved by the invention]

[0006] Therefore, the technical problem that this application aims to solve is to provide a solder ribbon member, a manufacturing method thereof, and a photovoltaic module that solves the problem in the prior art that the soldering tensile force of the solder ribbon member on the cell is insufficient, making the cell prone to cracking, and also realizes high-density mounting technology. [Means for solving the problem]

[0007] In a first aspect of the present application, a first solder ribbon segment, a second solder ribbon segment, and a connecting segment, the connecting segment being located between the first solder ribbon segment and the second solder ribbon segment; The first solder ribbon segment provides a solder ribbon member including a first solder ribbon body having a depression formed on its surface, and a first solder coating located on at least the surface of the inner wall of the depression.

[0008] Optionally, the first solder ribbon body has a first cross section perpendicular to the longitudinal direction of the first solder ribbon body, and the outer edge line of the first cross section includes a first edge section and a second edge section connected to the first edge section, the first edge section being located on the surface of the inner wall of the recess, and the second edge section being located on the outer surface of the first solder ribbon body at both ends of the recess.

[0009] Optionally, the shape of the first edge section comprises an arc, a "V" shape, or a trapezoid.

[0010] Optionally, the shape of the second edge section comprises an arc, a triangle, a trapezoid, or a rectangle.

[0011] Optionally, the depth of the recess is less than or equal to half the maximum distance between any two points on the second edge section.

[0012] Optionally, the maximum distance between any two points on the second edge section is between 250 μm and 350 μm.

[0013] Optionally, the distance between two intersection points of the first edge section and the second edge section is less than or equal to the maximum width of the first solder ribbon body.

[0014] Optionally, the first edge section is "V" shaped, with a base angle of the first edge section being greater than 0° and less than 180°.

[0015] Optionally, the second solder ribbon segment includes a second solder ribbon body having at least a flat soldering surface, the soldering surface and the recess located on the upper and lower surfaces, respectively, in the height direction of the solder ribbon member, and a second solder coating located on at least the soldering surface of the second solder ribbon body.

[0016] Optionally, the shape of the cross section of the second solder ribbon body perpendicular to the longitudinal direction of the second solder ribbon body includes a rectangle or a trapezoid.

[0017] Optionally, the lower surface of the second solder ribbon body in the height direction is an arcuate surface.

[0018] Optionally, the height dimension of the second solder ribbon body is less than the maximum height dimension of the first solder ribbon body.

[0019] Optionally, the second solder ribbon body has a height dimension of 130 μm to 200 μm.

[0020] Optionally, the connecting segment has one end connected to one end of the first solder ribbon segment and the other end connected to one end of the second solder ribbon segment.

[0021] Optionally, the thickness of the connecting segment tapers from the first solder ribbon segment to the second solder ribbon segment.

[0022] Optionally, the connecting segment has a sloped surface opposite the recess.

[0023] Optionally, the melting point of the first solder coating is less than the melting point of the first solder ribbon body.

[0024] Optionally, the first solder coating comprises a tin-bismuth-lead solder coating or a tin-bismuth-silver solder coating.

[0025] Optionally, the molar ratio of tin in the tin-bismuth-lead solder coating is greater than or equal to 40% and less than 50%, the molar ratio of bismuth in the tin-bismuth-lead solder coating is greater than or equal to 40% and less than 50%, and the molar ratio of lead in the tin-bismuth-lead solder coating is greater than 0 and less than or equal to 20%.

[0026] Optionally, the molar ratio of tin, bismuth, and lead in the tin-bismuth-lead solder coating is 4:4:2 or 43:43:14.

[0027] Optionally, the molar ratio of tin in the tin-bismuth-silver solder coating is greater than or equal to 40% and less than 50%, the molar ratio of bismuth in the tin-bismuth-silver solder coating is greater than or equal to 40% and less than 50%, and the molar ratio of silver in the tin-bismuth-silver solder coating is greater than 0 and less than or equal to 20%.

[0028] Optionally, the molar ratio of tin, bismuth, and silver in the tin-bismuth-silver solder coating is 4:4:2 or 43:43:14.

[0029] Optionally, the thickness of the first solder coating is between 20 μm and 30 μm.

[0030] Optionally, the melting point of the second solder coating is less than the melting point of the second solder ribbon body.

[0031] Optionally, the second solder coating comprises a second tin-bismuth-lead solder coating or a second tin-bismuth-silver solder coating.

[0032] Optionally, the molar ratio of tin in the second tin-bismuth-lead solder coating is greater than or equal to 40% and less than 50%, the molar ratio of bismuth in the second tin-bismuth-lead solder coating is greater than or equal to 40% and less than 50%, and the molar ratio of lead in the second tin-bismuth-lead solder coating is greater than 0 and less than or equal to 20%.

[0033] Optionally, the molar ratio of tin, bismuth, and lead in the second tin-bismuth-lead solder coating is 4:4:2 or 43:43:14.

[0034] Optionally, the molar ratio of tin in the second tin-bismuth-silver solder coating is greater than or equal to 40% and less than 50%, the molar ratio of bismuth in the second tin-bismuth-silver solder coating is greater than or equal to 40% and less than 50%, and the molar ratio of silver in the second tin-bismuth-silver solder coating is greater than 0 and less than or equal to 20%.

[0035] Optionally, the molar ratio of tin, bismuth, and silver in the second tin-bismuth-silver solder coating is 4:4:2 or 43:43:14.

[0036] Optionally, the thickness of the second solder coating is between 15 μm and 22 μm.

[0037] In a second aspect of the present application, forming a first solder ribbon segment, a second solder ribbon segment, and a connecting segment located between the first solder ribbon segment and the second solder ribbon segment; A method for forming a first solder ribbon segment provides a method for manufacturing a solder ribbon member, including the steps of forming a first solder ribbon body on the first solder ribbon segment, forming a depression on the surface of the first solder ribbon body, and forming a first solder coating on at least the surface of the inner wall of the depression.

[0038] Optionally, the connecting segment has one end connected to one end of the first solder ribbon segment and the other end connected to one end of the second solder ribbon segment.

[0039] Optionally, the method for forming the second solder ribbon segment includes the steps of forming a second solder ribbon body on the second solder ribbon segment, wherein at least the soldering surface of the second solder ribbon body is flat and the soldering surface and the recess are located on the upper and lower surfaces, respectively, in the height direction of the solder ribbon member, and forming a second solder coating on at least the soldering surface of the second solder ribbon body.

[0040] Optionally, the method of forming a second solder coating on the soldering surface of at least the second solder ribbon body includes the steps of forming a second initial solder film on the soldering surface of at least the second solder ribbon body, and curing the second initial solder film to form the second solder coating.

[0041] Optionally, the process of forming the first solder ribbon body and the process of forming the second solder ribbon body and the connecting segment comprises a rolling process.

[0042] Optionally, the method of forming a first solder coating on at least the surface of the interior wall of the recess comprises: forming a first initial solder film on the surface of the inner wall of the depression; Finishing the first initial solder film to make the thickness of the first initial solder film uniform; and after the finishing process, curing the first initial solder film to form a first solder coating.

[0043] In a third aspect of the present application, a plurality of cells are provided. the solder ribbon member connecting adjacent cells in series; For any two adjacent cells, the first solder ribbon body is soldered to the light-receiving surface side of one of the cells via the first solder coating to provide a photovoltaic module.

[0044] Optionally, the solder ribbon member further includes a second solder ribbon segment, the second solder ribbon segment including a second solder ribbon body having at least a flat soldering surface and a soldering surface and a depression located on the upper and lower surfaces, respectively, in the height direction of the solder ribbon member, and a second solder coating located on at least the soldering surface of the second solder ribbon body and having a melting point lower than the melting point of the second solder ribbon body, and in any two adjacent cells, the second solder ribbon body is soldered to the back side of the other cell via the second solder coating. [Effects of the Invention]

[0045] The technical solution of the present application has the following advantages: 1. The solder ribbon member of the present application includes a first solder ribbon segment, the first solder ribbon segment including a first solder ribbon body having a depression on its surface, and a first solder coating located on at least the surface of the inner wall of the depression. The solder ribbon member of the present application has depressions on the surface of the first solder ribbon body that allow the soldered first solder ribbon body to come into surface contact with the cell, increasing the contact area between the solder ribbon member and the cell, thereby solving the problem of poor adhesion between the solder ribbon member and the cell and the likelihood of easy sealing-off. At the same time, during soldering, excess molten first solder coating accumulates inside the depressions, and the first solder coating melts and accumulates between the solder ribbon member and the cell during soldering, preventing the formation of sharp protrusions that could cause the cell to crack. 2. The recess in the first solder ribbon body of the solder ribbon member of the present application may have various shapes, such as an arc shape, a V shape, or a trapezoid shape, and the shape of the recess may be designed according to specific application scenarios, making it highly applicable. 3. The solder ribbon member of the present application further includes a second solder ribbon segment, which includes a second solder ribbon body having at least a flat soldering surface, and a second solder coating located on at least the soldering surface of the second solder ribbon body. The flat soldering surface of the second solder ribbon body increases the contact area between the solder ribbon member and the cell, solving the problem of low adhesion between the solder ribbon member and the cell and the tendency for sealing-off to occur. Meanwhile, even if the second solder coating is formed thinly on the soldering surface, the adhesion between the solder ribbon member and the cell is ensured, saving materials for the second solder coating and reducing costs. 4. The photovoltaic module of the present application includes the above-mentioned solder ribbon member, wherein the height dimension of the second solder ribbon body is smaller than the maximum height dimension of the first solder ribbon body, and the smaller the thickness of the second solder coating, the smaller the overall height dimension of the second solder ribbon segment, thereby reducing the distance between the first solder ribbon segment and the second solder ribbon segment, reducing the spacing between cells, achieving high-density packaging, while achieving the purpose of reducing the cost of using the second solder coating, and increasing the effective area of the photovoltaic module.

[0046] In order to more clearly describe the specific embodiments of the present application or the technical solutions in the prior art, the following will briefly describe the drawings that need to be used to describe the specific embodiments or the prior art. However, the drawings in the following description are only some embodiments of the present application, and it is obvious that those skilled in the art can obtain other drawings based on these drawings without any creative efforts. [Brief explanation of the drawings]

[0047] [Figure 1] 1 is a structural schematic diagram of a solder ribbon member according to an embodiment of the present application. [Figure 2] FIG. 2 is a cross-sectional view of a first solder ribbon segment according to an embodiment of the present application. [Figure 3] FIG. 2 is a cross-sectional view of a first solder ribbon segment according to an embodiment of the present application. [Figure 4] FIG. 2 is a cross-sectional view of a first solder ribbon segment according to an embodiment of the present application. [Figure 5] FIG. 2 is a cross-sectional view of a first solder ribbon segment according to an embodiment of the present application. [Figure 6] FIG. 2 is a cross-sectional view of a first solder ribbon segment according to an embodiment of the present application. [Figure 7] FIG. 2 is a cross-sectional view of a second solder ribbon segment according to an embodiment of the present application. [Figure 8] FIG. 2 is a cross-sectional view of a second solder ribbon segment according to an embodiment of the present application. [Figure 9] FIG. 2 is a cross-sectional view of a second solder ribbon segment according to an embodiment of the present application. [Figure 10] FIG. 2 is a cross-sectional view of a second solder ribbon segment according to an embodiment of the present application. [Figure 11] FIG. 2 is a cross-sectional view of a second solder ribbon segment according to an embodiment of the present application. [Figure 12] FIG. 2 is a cross-sectional view of a second solder ribbon segment according to an embodiment of the present application. [Figure 13] 1 is a structural schematic diagram of a portion of a photovoltaic power generation module according to an embodiment of the present application. DETAILED DESCRIPTION OF THE INVENTION

[0048] The technical solutions of the present application will be described below clearly and completely with reference to the drawings, but it is clear that the described embodiments are only some of the embodiments of the present application, and not all of the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without any creative work fall within the scope of protection of the present application.

[0049] In the description of this application, the orientations or positional relationships indicated by terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" are based on the orientations or positional relationships shown in the drawings, and are intended merely to facilitate and simplify the description of this application, and do not indicate or imply that the device must have a specific orientation, or be configured or operate in a specific orientation, and therefore are not to be understood as limiting this application. Furthermore, the terms "first," "second," and "third" are used for the purpose of description only, and are not to be understood as indicating or implying relative importance.

[0050] In the description of this specification, unless otherwise expressly specified or limited, the terms "attach," "couple," and "connect" should be understood in a broad sense, and may mean, for example, a fixed connection, a detachable connection, or an integral connection, a mechanical connection, an electrical connection, a direct connection, an indirect connection via an intermediate medium, or internal communication between two components. The specific meanings of the above terms in this specification can be understood by those skilled in the art depending on the situation.

[0051] Furthermore, the technical features according to the embodiments of the present application described below may be combined with each other as long as they are not mutually contradictory.

[0052] Example 1 As shown in Figures 1 and 2, this embodiment provides a solder ribbon member including a first solder ribbon segment 100, a second solder ribbon segment 200, and a connection segment 300, where the connection segment 300 is located between the first solder ribbon segment 100 and the second solder ribbon segment 200, and the first solder ribbon segment 100 includes a first solder ribbon body 110 having a depression 120 on its surface, and a first solder coating 130 located on at least the surface of the inner wall of the depression 120.

[0053] The solder ribbon member of the present application uses depressions 120 on the surface of the first solder ribbon body 110 to bring the soldered first solder ribbon body 110 into surface contact with the cell, increasing the contact area between the solder ribbon member and the cell, thereby solving the problem of low adhesion between the solder ribbon member and the cell and the tendency for sealing-off to occur.On the other hand, when soldering, excess molten first solder coating 130 accumulates inside the depressions 120, and when soldering, the first solder coating 130 melts and accumulates between the solder ribbon member and the cell, forming a sharp protruding structure, which prevents the cell from cracking.

[0054] In one embodiment, the material of the first solder ribbon body 110 of the solder ribbon member is copper, but in other embodiments, the material of the first solder ribbon body 110 is other metals, and the embodiments of the present application are not particularly limited thereto.

[0055] As shown in FIG. 2, in one embodiment, the first solder ribbon body 110 has a first cross section perpendicular to the longitudinal direction of the first solder ribbon body 110, and the outer edge line of the first cross section includes a first edge section and a second edge section connected to the first edge section, the first edge section being located on the surface of the inner wall of the recess, and the second edge section being located on the outer surface of the first solder ribbon body 110 at both ends of the recess 120.

[0056] As shown in FIG. 2, in one embodiment, the depth H1 of the recess 120 is less than or equal to half the maximum distance L1 between any two points on the second edge section.

[0057] The second edge section may have various shapes, such as an arc shape, a triangle shape, a trapezoid shape, a rectangle shape, or other shapes, and the embodiments of the present application are not particularly limited thereto.

[0058] The cross-sectional shape of the depression 120 perpendicular to the longitudinal direction of the first solder ribbon body 110 includes an arc shape, a "V" shape, or a trapezoid shape. The cross-sectional shape of the depression 120 perpendicular to the longitudinal direction of the first solder ribbon body 110 is the shape of the first edge section. The shape of the depression 120 can be set according to specific application scenarios and is highly adaptable.

[0059] 3, in one embodiment, the first solder ribbon segment 100 includes a first solder ribbon body 110A having a depression 120A formed on its surface, and a first solder coating 130A located on at least the inner wall surface of the depression 120A. The first edge section has a "V" shape, and the base angle of the first edge section is an acute angle.

[0060] 4, in one embodiment, first solder ribbon segment 100 includes first solder ribbon body 110B having depression 120B formed on its surface, and first solder coating 130B located on at least the inner wall surface of depression 120B. The first edge section has a "V" shape, and the base angle of the first edge section is obtuse.

[0061] 5, in one embodiment, the first solder ribbon segment 100 includes a first solder ribbon body 110C having a depression 120C formed on its surface, and a first solder coating 130C located on at least the inner wall surface of the depression 120C. The first edge section has an arcuate shape.

[0062] 6, in one embodiment, the first solder ribbon segment 100 includes a first solder ribbon body 110D having a depression 120D formed on its surface, and a first solder coating 130D located on at least the inner wall surface of the depression 120D. The first edge section has a trapezoidal shape.

[0063] As shown in FIG. 2, in one embodiment, the maximum distance L1 between any two points on the second edge section is 250 μm to 350 μm, and for example, the maximum distance L1 between any two points on the second edge section is 250 μm, 270 μm, 290 μm, 310 μm, 330 μm, or 350 μm.

[0064] In one embodiment, the second edge section is arc-shaped, in which case the diameter of the second edge section is between 250 μm and 350 μm, for example 300 μm.

[0065] As shown in FIG. 2, in one embodiment, the distance L2 between the two intersections of the first edge section and the second edge section is 200 μm to 280 μm, and for example, the distance L2 between the two intersections of the first edge section and the second edge section is 200 μm, 220 μm, 240 μm, 260 μm, or 280 μm.

[0066] As shown in FIG. 2, in one embodiment, the depth H1 of the recess is 50 μm to 140 μm, and illustratively, the depth H1 of the recess is 50 μm, 60 μm, 80 μm, 100 μm, 120 μm, or 140 μm.

[0067] 2, in one embodiment, the distance L2 between two intersections of the first edge section and the second edge section is less than or equal to the maximum width of the first solder ribbon body, and in some embodiments, the maximum width of the first solder ribbon body is the maximum distance L1 between any two points on the second edge section.

[0068] The direction of the maximum width of the first solder ribbon body 110 is parallel to the direction of the distance between the two intersection points of the first edge section and the second edge section.

[0069] In one embodiment, the cross section of the depression 120 perpendicular to the longitudinal direction of the first solder ribbon body 110 has a "V" shape. The "V" shape is easier to process than other shapes, and can be formed by, for example, extrusion.

[0070] In one embodiment, the first edge section has a "V" shape and a base angle of the first edge section is greater than 0° and less than 180°. Illustratively, the base angle of the first edge section is 10°, 30°, 60°, 90°, 120°, 150°, or 170°.

[0071] In one embodiment, the melting point of the first solder coating 130 is less than the melting point of the first solder ribbon body 110 .

[0072] In one embodiment, the first solder coating 130 comprises a tin-bismuth-lead solder coating or a tin-bismuth-silver solder coating.

[0073] In one embodiment, the molar ratio of tin in the tin-bismuth-lead solder coating is greater than or equal to 40% and less than 50%, the molar ratio of bismuth in the tin-bismuth-lead solder coating is greater than or equal to 40% and less than 50%, and the molar ratio of lead in the tin-bismuth-lead solder coating is greater than 0 and less than or equal to 20%. Illustratively, the molar ratio of tin, bismuth, and lead in the tin-bismuth-lead solder coating is 4:4:2 or 43:43:14.

[0074] In one embodiment, the molar ratio of tin in the tin-bismuth-silver solder coating is greater than or equal to 40% and less than 50%, the molar ratio of bismuth in the tin-bismuth-silver solder coating is greater than or equal to 40% and less than 50%, and the molar ratio of silver in the tin-bismuth-silver solder coating is greater than 0 and less than or equal to 20%. Illustratively, the molar ratio of tin, bismuth, and silver in the tin-bismuth-silver solder coating is 4:4:2 or 43:43:14.

[0075] In the above embodiment, the first solder coating 130 can be either a tin-bismuth-lead solder coating or a tin-bismuth-silver solder coating, which are both suitable for low-temperature soldering. Because the transparent conductive layer in the cell is sensitive to high temperatures, the use of the first solder coating 130 of the present application can prevent damage to the cell caused by excessively high soldering temperatures.

[0076] In one embodiment, the thickness of the first solder coating 130 is between 20 μm and 30 μm, and illustratively the thickness of the first solder ribbon member is 20 μm, 22 μm, 24 μm, 26 μm, 28 μm, or 30 μm.

[0077] In one embodiment, the first solder coating 130 completely covers the entire surface of the inner wall of the recess 120, while in other embodiments, the first solder coating 130 does not completely cover the entire surface of the inner wall of the recess 120, and the first solder coating 130 is not applied to the surface of the inner wall in an area away from the opening of the recess 120. If the area of the first solder coating is large, the thickness of the first solder coating 130 can be appropriately reduced, and if the area of the first solder coating is small, the thickness of the first solder coating 130 can be appropriately increased.

[0078] In one embodiment, the first solder coating 130 is also applied to at least a portion of the surface of the first solder ribbon body 110 other than the depressions 120. The first solder coating 130 in such areas is used only as a surface reflective layer and has a thickness of 5 μm to 10 μm, e.g., 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, or 10 μm. When soldering is performed, the first solder coating 130 on these surfaces melts and collects in the depressions 120 or at the contact positions between the depressions 120 and the cells, increasing the soldering tensile force between the solder ribbon member and the cells.

[0079] In one embodiment, the second solder ribbon segment 200 includes a second solder ribbon body 210 having at least a flat soldering surface, with the soldering surface and depression 120 located on the upper and lower sides, respectively, in the height direction of the solder ribbon member, and a second solder coating 220 located on at least the soldering surface of the second solder ribbon body 210.

[0080] In the above embodiment, the soldering surface of the second solder ribbon body 210 is flat, which increases the contact area between the solder ribbon member and the cell, solving the problem of low adhesive force between the solder ribbon member and the cell and the tendency for sealing-off to occur. On the other hand, even if the second solder coating 220 is formed thinly on the soldering surface, the adhesive force between the solder ribbon member and the cell is ensured, saving the material of the second solder coating 220 and reducing costs.

[0081] In one embodiment, a second solder coating 220 is applied to the surfaces of the second solder ribbon body 210 other than the soldering surface.

[0082] In one embodiment, the cross-sectional shape of the second solder ribbon body 210 perpendicular to the longitudinal direction of the second solder ribbon body 210 includes a rectangle or a trapezoid. In one embodiment, the lower surface of the second solder ribbon body 210 in the height direction is an arc-shaped surface. The shape of the second solder ribbon body 210 can be set according to specific application scenarios, and is highly adaptable.

[0083] 8, in one embodiment, the second solder ribbon segment 200 includes a second solder ribbon body 210A and a second solder coating 220A located on at least the soldering surface of the second solder ribbon body 210A. The cross section of the second solder ribbon body 210A perpendicular to the longitudinal direction of the second solder ribbon body 210A has a rectangular shape.

[0084] 9, in one embodiment, the second solder ribbon segment 200 includes a second solder ribbon body 210B and a second solder coating 220B located on at least the soldering surface of the second solder ribbon body 210B. The cross section of the second solder ribbon body 210B perpendicular to the longitudinal direction of the second solder ribbon body 210B has a rounded rectangular shape.

[0085] 10, in one embodiment, the second solder ribbon segment 200 includes a second solder ribbon body 210C and a second solder coating 220C located on at least the soldering surface of the second solder ribbon body 210C. The cross section of the second solder ribbon body 210C perpendicular to the longitudinal direction of the second solder ribbon body 210C has a trapezoidal shape.

[0086] 11, in one embodiment, the second solder ribbon segment 200 includes a second solder ribbon body 210D and a second solder coating 220D located on at least the soldering surface of the second solder ribbon body 210D. The cross section of the second solder ribbon body 210D perpendicular to the longitudinal direction of the second solder ribbon body 210D has an inverted trapezoidal shape.

[0087] 12, in one embodiment, the second solder ribbon segment 200 includes a second solder ribbon body 210E and a second solder coating 220E located on at least the soldering surface of the second solder ribbon body 210E. The lower surface of the second solder ribbon body 210E in the height direction is an arcuate surface.

[0088] 7, in one embodiment, the dimension H2 in the height direction of the second solder ribbon body 210 of the second solder ribbon body 210 is 130 μm to 200 μm. Illustratively, the dimension H2 in the height direction of the second solder ribbon body 210 of the second solder ribbon body 210 is 130 μm, 140 μm, 160 μm, 180 μm, or 200 μm. The dimension H2 in the height direction of the second solder ribbon body 210 is less than the maximum dimension in the height direction of the first solder ribbon body 110.

[0089] In one embodiment, one end of the connecting segment 300 is connected to one end of the first solder ribbon segment 100 and the other end of the connecting segment 300 is connected to one end of the second solder ribbon segment 200 .

[0090] In one embodiment, the thickness of the connecting segment 300 gradually decreases from the first solder ribbon segment 100 to the second solder ribbon segment 200 .

[0091] As shown in FIG. 1, taken together with FIG. 2, in one embodiment, the side of the connecting segment 300 opposite the recess 120 is an inclined surface.

[0092] In the above embodiment, the distance between the first solder ribbon segment 100 and the second solder ribbon segment 200 connected by the connection segment 300 is reduced, thereby reducing the spacing between adjacent cells to 1.0 mm or less when manufacturing the final photovoltaic module, increasing the number of cells that can be assembled in the same area, achieving the goal of high-density packaging, and increasing the effective area of the photovoltaic module.

[0093] In one embodiment, the melting point of the second solder coating 220 is less than the melting point of the second solder ribbon body 210 .

[0094] In one embodiment, second solder coating 220 comprises a second tin-bismuth-lead solder coating or a second tin-bismuth-silver solder coating.

[0095] In one embodiment, the molar ratio of tin in the second tin-bismuth-lead solder coating is greater than or equal to 40% and less than 50%, the molar ratio of bismuth in the second tin-bismuth-lead solder coating is greater than or equal to 40% and less than 50%, and the molar ratio of lead in the second tin-bismuth-lead solder coating is greater than 0 and less than or equal to 20%. Illustratively, the molar ratio of tin, bismuth, and lead in the second tin-bismuth-lead solder coating is 4:4:2 or 43:43:14.

[0096] In one embodiment, the molar ratio of tin in the second tin-bismuth-silver solder coating is greater than or equal to 40% and less than 50%, the molar ratio of bismuth in the second tin-bismuth-silver solder coating is greater than or equal to 40% and less than 50%, and the molar ratio of silver in the second tin-bismuth-silver solder coating is greater than 0 and less than or equal to 20%. Illustratively, the molar ratio of tin, bismuth, and silver in the second tin-bismuth-silver solder coating is 4:4:2 or 43:43:14.

[0097] In the above embodiment, the second tin-bismuth-lead solder coating or the second tin-bismuth-silver solder coating used for the second solder coating 220 can both be soldered at low temperatures. Because the transparent conductive layer commonly used in cells is sensitive to high temperatures, the use of the second solder coating 220 of the present application can prevent damage to the cell caused by soldering at too high a temperature.

[0098] In one embodiment, the thickness of the second solder coating 220 is between 15 μm and 22 μm. Illustratively, the thickness of the second solder coating 220 is 15 μm, 16 μm, 18 μm, 20 μm, or 22 μm.

[0099] In the above embodiment, the thickness of the second solder coating 220 is small, which is advantageous for reducing the overall height dimension of the second solder ribbon segment 200, reducing the distance between the first solder ribbon segment 100 and the second solder ribbon segment 20, reducing the spacing between cells, realizing high-density packaging, and achieving the purpose of reducing the usage cost of the second solder coating 220 and increasing the effective area of the photovoltaic module.

[0100] Example 2 A second aspect of the present application provides a method for manufacturing a solder ribbon member, comprising steps of forming a first solder ribbon segment, a second solder ribbon segment, and a connection segment located between the first solder ribbon segment and the second solder ribbon segment, wherein the method for forming the first solder ribbon segment comprises steps of forming a first solder ribbon body on the first solder ribbon segment and forming a depression on a surface of the first solder ribbon body, and forming a first solder coating on at least the surface of an inner wall of the depression.

[0101] In one embodiment, a method for forming a first solder coating on at least the surface of the inner wall of a recess includes the steps of forming a first initial solder film on the surface of the inner wall of the recess, finishing the first initial solder film to make the thickness of the first initial solder film uniform, and after the finishing process, hardening the first initial solder film to form a first solder coating.

[0102] Specifically, an initial solder ribbon body is provided, a portion of the initial solder ribbon body is subjected to a first rolling process to form a first solder ribbon body having a depression on its surface, and then the surface of the first solder ribbon body having the depression is immersed in a first solder coating liquid, and in one embodiment, the liquid level of the first solder coating liquid reaches a portion of the depth of the depression, and in another embodiment, the liquid level of the first solder coating liquid reaches the entire depth of the depression, and further, the liquid level of the first solder coating liquid covers the entire first solder ribbon body, and then the first solder body is removed from the first solder coating liquid, excess first solder coating liquid is scraped off from the depression, and a first initial solder film is formed, and finally, the first initial solder film is hardened to form a first solder coating.

[0103] In one embodiment, one end of the connecting segment is connected to one end of a first solder ribbon segment, and the other end of the connecting segment is connected to one end of a second solder ribbon segment.

[0104] In one embodiment, the second solder ribbon segment and connecting segment are formed before the first solder coating is formed, and in another embodiment, the second solder ribbon segment and connecting segment are formed after the first solder coating is formed.

[0105] In one embodiment, the process of forming the second solder ribbon body and the connecting segments includes a rolling process.

[0106] In one embodiment, a method for forming a second solder ribbon segment includes the steps of forming a second solder ribbon body on the second solder ribbon segment, wherein at least the soldering surface of the second solder ribbon body is flat and the soldering surface and the depression are located on the upper and lower sides in the height direction of the solder ribbon member, respectively, and forming a second solder coating on at least the soldering surface of the second solder ribbon body.

[0107] Specifically, a second rolling process is performed on a portion of the initial solder ribbon segment away from the first solder ribbon body to form a second solder ribbon body having at least a flat soldering surface, and a connection segment is formed between the first solder ribbon body and the second solder ribbon body when the second rolling process is performed.

[0108] In one embodiment, a method for forming a second solder coating on a soldering surface of at least a second solder ribbon body includes the steps of forming a second initial solder film on the soldering surface of at least the second solder ribbon body, and curing the second initial solder film to form a second solder coating.

[0109] Specifically, a second rolling process is performed on the remaining length of the solder ribbon member other than the first solder ribbon segment to form a second solder ribbon body having a flat soldering surface, and the connecting segment is formed simultaneously with forming the second solder ribbon body, so no additional processing is required. A second soldering film is applied to the soldering surface of the second solder ribbon body, and the second soldering film is cured to form a second solder coating.

[0110] In one embodiment, a second initial soldering film is applied to the soldering surface of the second solder ribbon body and at least a portion of other surfaces other than the soldering surface, and the second initial soldering film is cured to form a second soldering coating.

[0111] In another embodiment, the second solder ribbon body is dipped into a second solder coating liquid, removed and cured to form a second solder coating.

[0112] Example 3 A third aspect of the present application provides a photovoltaic module including a plurality of cells and the above-mentioned solder ribbon member connecting adjacent cells in series, wherein for any two adjacent cells, the first solder ribbon body is soldered to the light-receiving surface side of one of the cells via a first solder coating.

[0113] As shown in FIG. 13, in one embodiment, a first solder ribbon segment 100 of the solder ribbon member contacts the light-receiving surface of a first cell 400 and a second solder ribbon segment 200 of the solder ribbon member contacts the back surface of a second cell 500.

[0114] The photovoltaic module of the present application includes the above-mentioned solder ribbon member, and the height dimension of the second solder ribbon body is smaller than the maximum height dimension of the first solder ribbon body, and the height dimension of the second solder ribbon segment is small, thereby reducing the distance between the first solder ribbon segment and the second solder ribbon segment, reducing the spacing between cells, and increasing the effective area of the photovoltaic module.

[0115] In one embodiment, the solder ribbon member further includes a second solder ribbon segment, the second solder ribbon segment including a second solder ribbon body having at least a flat soldering surface, the soldering surface and the depression located on the upper and lower sides, respectively, in the height direction of the solder ribbon member, and a second solder coating located on at least the soldering surface of the second solder ribbon body, the second solder coating having a melting point lower than the melting point of the second solder ribbon body, and in any two adjacent cells, the second solder ribbon body is soldered to the back side of another cell by the second solder coating.

[0116] In one embodiment, the cell is a heterojunction cell. The solder ribbon members are directly connected to the bus bars on the surface of the heterojunction cell to form conductive interconnections, and then sequentially stacked and laminated with a photovoltaic module encapsulant to obtain a heterojunction solar cell module, which aims to solve the technical problems of the prior art heterojunction cell, such as low soldering tension between the solder ribbon members, strict requirements for process control, and low success rate.

[0117] In one embodiment, the method for manufacturing the photovoltaic module includes the following steps. 1) Preparation of cell strings The solder ribbon material is set on the solder ribbon reel shaft of the string welding machine, gripped and pulled by the pulling jaws, and then laid on the cells on the belt conveyor. The cells are then stacked one by one in accordance with the laying rhythm of the solder ribbon material, arranging them into a string. The row-arranged cell string is then passed through a lamp box, where it is instantly heated and cooled, and soldered to obtain a string. The string is then cut with a cutter, tested, and those that are found to be defect-free are removed from the string welding machine. This completes the cell string production. 2) Preparation of the lower glass layer and the lower adhesive film 2.1) Using an adhesive film cutter, cut the adhesive film to a certain width and length, and then pull it onto the lower glass to cover it. 2.2) The lower layer glass coated with the lower layer adhesive film is transported to an assembly device or the like through an assembly line for assembly. 3) Fabrication of cell string array 3.1) The laser-cut half cells are arranged and soldered in sequence using a string welding machine, and then connected in series to form a complete cell string. 3.2) The assembly equipment places the serially connected cell strings on the lower adhesive film described in 1) according to the order of the electrodes. After laying out multiple cell strings, the stitch welding machine connects the cell strings with bus bars, leaving leads for attachment to the junction box in a later process. This completes the soldering and forms a cell string array. Next, a tape application device applies fixing tape to specific positions on the array to fix it in place. 4) Preparation of waterproof layer for heterojunction solar cell module 4.1) On the lower glass surface, a waterproof adhesive of a certain thickness and width is coated at a certain interval along the edge of the glass on the inside, and a certain interval is kept between the waterproof adhesive and the lower adhesive film, and the waterproof adhesive is coated uniformly around the entire circumference of the glass surface. 5) Preparation of the top adhesive film and top glass (double glass) or protective layer (single glass) 5.1) Cut the adhesive film to a certain width and length using an adhesive film cutting machine, and pull it over the cell string array to align it with the underlying adhesive film and cover it so that it maintains a certain distance from the surrounding waterproof adhesive. 5.2) An upper layer glass or an upper layer protective layer is coated on the upper layer adhesive film using a glass laminator or a coating machine to prepare a battery module laminate. 6) Cutting test using a cutter, visual inspection The battery module stack is visually inspected to determine whether or not there are any defects, and any stacks detected to be defective are transported to a laminator for lamination and packaging, and any stacks detected to be defective are transported to a return table for repair. 7) Lamination During the lamination process, the top adhesive film and bottom adhesive film fuse together, uniting the bottom glass with the top glass or top protective layer to form an inseparable module laminate. 8) After lamination is complete, the process of visual inspection, trimming, frame mounting, junction box installation, adhesive injection, curing, power testing, and final inspection are carried out in sequence to complete the production of the heterojunction solar cell module.

[0118] Furthermore, in this application, the upper adhesive film and the lower adhesive film are subjected to finish cutting before coating, with a cutting accuracy of ±0.5 mm, and after cutting, are transported and coated by a manipulator.

[0119] Furthermore, in the present application, the adhesive film may be any one of adhesive films such as vinyl acetate copolymer EVA, polyvinyl butyral PVB, EPE, POE polyurethane, PUR, TPO, TPU, and PA.

[0120] Furthermore, in this application, the front and back protective layers are photovoltaic glass or photovoltaic backsheets (any of PP, PC, PET, PE, PMMA, PS, TPT, TPE, KPK, PVF or PVDF materials) for general-purpose component packaging in the photovoltaic industry.

[0121] Furthermore, in the present application, the waterproof adhesive may be a transparent waterproof adhesive or a non-transparent waterproof adhesive, and the component may be either an isobutylene polymer or an isoprene polymer, and has high water vapor barrier capability and anti-aging capability.

[0122] Furthermore, in the present application, the thickness of the waterproof adhesive is 0.5 mm to 3.5 mm, and the width of the waterproof adhesive is 2 mm to 15 mm.

[0123] Furthermore, in the present application, the cell is a double-sided heterojunction solar cell, and a transparent conductive film is provided on the surface thereof, and the transparent conductive film is an ITO film or an AZO film.

[0124] Obviously, the above examples are merely illustrative examples for the purpose of clarity and are not intended to limit the scope of the present invention. Those skilled in the art may make various other changes or modifications based on the above description. It is not necessary to, and cannot, cover all embodiments herein. Any obvious changes or modifications derived in this manner are also within the scope of protection of the present invention. [Explanation of symbols]

[0125] 100 First solder ribbon segment 110 First solder ribbon body 110A First solder ribbon body 110B First solder ribbon body 110C First solder ribbon body 110D First solder ribbon body 120 depression 120A recess 120B recess 120C recess 120D recess 130 First solder coating 130A 1st solder coating 130B 1st solder coating 130C 1st solder coating 130D First solder coating 200 Second solder ribbon segment 210 Second solder ribbon body 210A Second solder ribbon body 210B Second solder ribbon body 210C Second solder ribbon body 210D Second solder ribbon body 210E Second solder ribbon body 220 Second solder coating 220A Second Solder Coating 220B Second Solder Coating 220C Second Solder Coating 220D Second Solder Coating 220E Second Solder Coating 300 connection segments L1: The maximum distance between any two points on the second edge section L2: The distance between the two intersections of the first and second edge sections H1 Depth of depression H2 Height dimension of the second solder ribbon body 400 Cell 1 500 Second Cell

Claims

1. A solder ribbon member, a first solder ribbon segment, a second solder ribbon segment, and a connecting segment, the connecting segment being located between the first solder ribbon segment and the second solder ribbon segment; the first solder ribbon segment includes a first solder ribbon body having a depression on its surface, and a first solder coating located only on the surface of the inner wall of the depression; The second solder ribbon segment has a second solder ribbon body, the soldering surface of the second solder ribbon body is at least flat, the soldering surface and the recess are respectively located above and below in the height direction of the solder ribbon member, and includes a second solder coating provided at least on the soldering surface of the second solder ribbon body, one end of the connecting segment is connected to one end of the first solder ribbon segment; the other end is connected to one end of the second solder ribbon segment; a thickness of the connection segment gradually decreases in a direction from the first solder ribbon segment to the second solder ribbon segment; A solder ribbon member, characterized in that the melting point of the first solder coating is lower than the melting point of the first solder ribbon body.

2. the first solder ribbon body has a first cross section perpendicular to the longitudinal direction of the first solder ribbon body, and an outer edge line of the first cross section includes a first edge section and a second edge section connected to the first edge section, the first edge section being located on the surface of an inner wall of the depression, and the second edge sections being located on the outer surface of the first solder ribbon body at both ends of the depression; the shape of the first edge section comprises an arc shape, a "V" shape, or a trapezoid shape; The solder ribbon member according to claim 1 , wherein the shape of the second edge section comprises an arc, a triangle, a trapezoid, or a rectangle.

3. The depth of the recess is less than half the maximum distance between two points in the second edge section, 3. The solder ribbon member according to claim 2, wherein the maximum distance is in the range of 250 μm to 350 μm.

4. 4. A solder ribbon member according to claim 1, wherein the cross-sectional shape of the second solder ribbon body perpendicular to the longitudinal direction is rectangular, trapezoidal, or partially arc-shaped.

5. A solder ribbon member described in any one of claims 1 to 4, characterized in that the height dimension of the second solder ribbon body is smaller than the maximum height dimension of the first solder ribbon body.

6. A solder ribbon member described in any one of claims 1 to 5, characterized in that the height dimension of the second solder ribbon body is 130 μm to 200 μm.

7. A solder ribbon member described in any one of claims 1 to 6, characterized in that the side opposite the recess of the connection segment is an inclined surface.

8. 8. The solder ribbon member according to claim 1, wherein the melting point of the second solder coating is lower than the melting point of the second solder ribbon body.

9. A solder ribbon member described in any one of claims 1 to 8, characterized in that the first soldering coating includes a first tin-bismuth-lead soldering coating or a first tin-bismuth-silver soldering coating, and the second soldering coating includes a second tin-bismuth-lead soldering coating or a second tin-bismuth-silver soldering coating.

10. A solder ribbon member as described in claim 1, characterized in that the thickness of the first solder coating is 20 μm to 30 μm, and the thickness of the second solder coating is 15 μm to 22 μm.

11. A method for manufacturing a solder ribbon member, comprising: forming a first solder ribbon segment, a second solder ribbon segment, and a connecting segment located between the first solder ribbon segment and the second solder ribbon segment; forming the first solder ribbon segment includes forming a first solder ribbon body on the first solder ribbon segment and forming a depression on a surface of the first solder ribbon body; and forming a first solder coating only on a surface of an inner wall of the depression; The step of forming the second solder ribbon segment includes the steps of: forming a second solder ribbon body on the second solder ribbon segment, the soldering surface of the second solder ribbon body being at least flat, and the soldering surface and the depression being located on the upper and lower sides of the solder ribbon member in the height direction, respectively; and forming a second solder coating on at least the soldering surface of the second solder ribbon body. A method for manufacturing a solder ribbon member, characterized in that one end of the connection segment is connected to one end of the first solder ribbon segment and the other end is connected to one end of the second solder ribbon segment, and the thickness of the connection segment gradually decreases from the first solder ribbon segment to the second solder ribbon segment.

12. A method for manufacturing a solder ribbon member as described in Claim 11, characterized in that the step of forming a second solder coating on at least the soldering surface of the second solder ribbon body includes the steps of forming a second initial soldering film on at least the soldering surface of the second solder ribbon body, and hardening the second initial soldering film to form the second solder coating.

13. A method for manufacturing a solder ribbon member as described in Claim 11, characterized in that the process of forming the first solder ribbon body and the process of forming the second solder ribbon body and the connection segment include a rolling process.

14. The step of forming a first solder coating on at least the surface of the inner wall of the recess includes: forming a first initial solder film on the surface of the inner wall of the depression; Finishing the first initial solder film to make the thickness of the first initial solder film uniform; 12. The method of claim 11, further comprising the step of: after the finishing process, curing the first initial solder film to form the first solder coating.

15. A photovoltaic module, A plurality of cells; and a solder ribbon member according to any one of claims 1 to 10, which connects adjacent cells in series, wherein adjacent cells are connected in series via the solder ribbon member; In two adjacent cells, the first solder ribbon body is soldered to the light-receiving surface side of one cell via a first solder coating; A photovoltaic module, characterized in that the second solder ribbon body is soldered to the back side of the other cell via a second solder coating.

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