Solder strip and photovoltaic module

Abstract

The utility model relates to the field of photovoltaic technology, and provides a solder strip and a photovoltaic assembly, the cross section of the solder strip is in a polygonal structure, and at least one edge of the polygonal structure is in fillet connection with two adjacent edges. According to the utility model, the cross section of the solder strip is polygonal, and at least one edge is in fillet connection with the two adjacent edges, so that the placing form of the solder strip can be adjusted by simply applying pressure to the solder strip in the welding process of the solder strip, thereby enabling the solder strip to be in planar contact with a welding spot of a battery piece, and improving the welding quality of the battery piece. The contact area of the welding strip and the welding spot is increased, and the welding spot can be prevented from being damaged by the sharp corner of the welding strip, so that the welding efficiency and the welding stability of the welding strip are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of photovoltaics, and particularly to a welding tape and a photovoltaic module. Background Art

[0002] The welding tape is an important component of a photovoltaic module and is used for connecting and conducting electricity between the battery cells and the junction box in a solar photovoltaic module. In traditional technologies, the welding tape includes a round welding tape and a welding tape with a special-shaped structure. The contact area between the round welding tape and the solder joint of the battery cell is small, making it difficult to weld. Due to the diverse shapes of the special-shaped structure welding tapes, it is difficult to ensure the contact between its specific surface and the solder joint of the battery cell during the welding process. If the welding condition of the welding tape is not ideal, it will directly affect the photoelectric conversion efficiency of the photovoltaic module. Therefore, how to ensure the stable welding of the welding tape has become an urgent technical problem to be solved at present. Summary of the Utility Model

[0003] Based on this, the present application provides a welding tape and a photovoltaic module with stable welding.

[0004] In a first aspect, the present application provides a welding tape. The cross-section of the welding tape has a polygonal structure, and at least one side of the polygonal structure is connected to the two adjacent sides by a rounded corner.

[0005] In some embodiments, any two adjacent sides of the polygonal structure are connected by a rounded corner.

[0006] In some embodiments, the outer surface of the welding tape includes two end faces and a side surface connecting the two end faces. The side surface includes a plurality of sub-surfaces connected in sequence to form the polygonal structure. One of the sub-surfaces is a welding surface for contacting the solder joint of the battery cell, and the welding surface is connected to the two adjacent sub-surfaces by a rounded corner.

[0007] In some embodiments, another sub-surface of the welding tape is a pressing surface, and the pressing surface is disposed opposite to the welding surface.

[0008] In some embodiments, in the polygonal structure, the length of the side formed by the welding surface is 0.12 mm to 0.18 mm.

[0009] In some embodiments, in the rounded corner connection, the radius of the rounded corner is 0.01 mm to 0.02 mm.

[0010] In some embodiments, the number of sides of the polygonal structure is ≥4.

[0011] In some embodiments, the polygonal structure is a regular polygonal structure.

[0012] In some embodiments, a plurality of first grooves are provided on the outer surface of the welding tape.

[0013] In some embodiments, the first groove is formed along the length direction of the solder strip.

[0014] In some embodiments, a plurality of the first grooves are arranged circumferentially along the solder strip.

[0015] In some embodiments, the solder strip includes a metal substrate and a solder layer coated on the surface of the metal substrate.

[0016] In some embodiments, the first groove is provided on the solder layer and does not penetrate the solder layer.

[0017] In some embodiments, a second groove is provided on the surface of the metal substrate, and a part of the solder layer is filled in the second groove and wraps around the surface of the metal substrate.

[0018] In a second aspect, the present utility model provides a photovoltaic module, which includes a plurality of solar cells and the solder strip as described in the first aspect, and the solder strip is connected to the solder joints of the solar cells.

[0019] Compared with the traditional technology, the present utility model has at least the following beneficial effects:

[0020] In this application, the cross-sectional shape of the solder strip is set to be polygonal, and the top angles of the polygon are adjusted to a rounded corner structure. During the welding process of the solder strip, by simply applying pressure to the solder strip, the placement form of the solder strip can be adjusted, so that the solder joint between the solder strip and the solar cell is in planar contact. For example, the solder joint between the solder strip and the solar cell is flipped from rounded corner contact to planar contact of the polygon, which not only increases the contact area between the solder strip and the solder joint, but also can avoid damage to the solder joint caused by the sharp corners of the solder strip, and improves the welding efficiency and welding stability of the solder strip. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a schematic cross-sectional structure diagram of a solder strip provided in an embodiment of the present utility model;

[0022] Figure 2 is another schematic cross-sectional structure diagram of a solder strip provided in an embodiment of the present utility model;

[0023] Figure 3 is a schematic structure diagram of the solder strip and the solder joint provided in an embodiment of the present utility model.

[0024] Wherein, 10 - solder strip; 11 - metal substrate; 12 - solder layer; 13 - first groove; 14 - second groove; 20 - solder joint. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] The present utility model will be further described in detail below in conjunction with the accompanying drawings, embodiments and examples. These embodiments and examples are only used to illustrate the present utility model and not to limit the scope of the present utility model. The purpose of providing these embodiments and examples is to make the understanding of the disclosed content of the present utility model more thorough and comprehensive. It should also be understood that the present utility model can be implemented in many different forms and is not limited to the embodiments and examples described herein. Those skilled in the art can make various changes or modifications without departing from the connotation of the present utility model, and the equivalent forms obtained also fall within the protection scope of the present utility model. In addition, in the following description, a large number of specific details are given to provide a more thorough understanding of the present utility model. It should be understood that the present utility model can be implemented without one or more of these details.

[0026] It should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present utility model 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 to the present utility model.

[0027] In the description of the present utility model, unless otherwise clearly defined and limited, the terms "connected", "connected to", "fixed" and "arranged" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; 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 elements or the interaction relationship between two elements. For those of ordinary skill in the art, the meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0028] In the present utility model, "optionally", "optional", "option" mean that it can be present or absent, that is, it refers to any one of the two parallel options of "present" or "absent". If the term "optional" appears in multiple places in a technical solution, unless otherwise specified and there is no contradiction or mutual restriction relationship, each "optional" is independent of each other.

[0029] In the present utility model, for the technical features described in an open-ended manner, it includes a closed technical solution composed of the listed features, and also includes an open technical solution containing the listed features.

[0030] In the present utility model, terms such as "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or quantity, nor can they be construed as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first", "second", etc. only serve the purpose of non-exhaustive enumerative description and should be understood not to constitute a closed limitation on quantity.

[0031] All documents mentioned in the present utility model are cited in the present utility model as references, just as if each document is cited separately as a reference. Unless it conflicts with the utility model purpose and / or technical solution of the present utility model, otherwise, the cited documents related to the present utility model are cited for all contents and all purposes. When the present utility model involves cited documents, the definitions of relevant technical features, terms, nouns, phrases, etc. in the cited documents are also cited together. When the present utility model involves cited documents, the examples and preferred ways of the relevant technical features cited can also be incorporated into the present utility model as references, but only to the extent that the present utility model can be implemented. It should be understood that when the cited content conflicts with the description in the present utility model, the present utility model shall prevail or be amended adaptively according to the description of the present utility model.

[0032] In photovoltaic modules, most of the solder tapes adopt circular solder tapes or solder tapes with special-shaped structures. The contact area between the circular solder tape and the solder joints of the battery cells is small, resulting in problems of unstable soldering. Moreover, the special-shaped structure solder tape has a complex structure, and it is difficult to ensure the contact between a specific surface and the solder joints of the battery cells during the soldering process, which leads to the need to strictly ensure the placement form of the solder tape during the soldering process, seriously affecting the soldering efficiency. In addition, most of the special-shaped structure solder tapes have sharp corner structures, which are likely to cause scratches on the solder joints and affect the soldering effect.

[0033] Based on this, in the first aspect of the present application, a solder tape is provided, as Figure 1 and Figure 3 shown, the cross-section of the solder tape 10 has a polygonal structure, and at least one side of the polygonal structure is connected to its adjacent two sides by a rounded corner. That is, the rounded corner connection is used to replace the vertex connection of the polygonal structure.

[0034] In this way, the cross-sectional shape of the solder tape 10 is set as a polygon, and the vertex of the polygon is adjusted to a rounded corner structure. During the soldering process of the solder tape 10, by simply applying pressure to the solder tape 10, the placement form of the solder tape 10 can be adjusted, so that the solder joint 20 between the solder tape 10 and the battery cell is in planar contact. For example, the solder joint 20 between the solder tape 10 and the battery cell is flipped from rounded corner contact to planar contact of the polygon, which not only increases the contact area between the solder tape 10 and the solder joint 20, but also can avoid damage to the solder joint 20 caused by the sharp corners of the solder tape 10, improving the soldering efficiency and soldering stability of the solder tape 10.

[0035] In some embodiments, any adjacent two sides of the polygonal structure are connected by a rounded corner.

[0036] In some embodiments, the outer surface of the solder ribbon 10 includes two end faces and a side face connecting the two end faces. The side face includes a plurality of sub-surfaces connected in sequence to form a polygonal structure; one of the sub-surfaces in the side face of the solder ribbon 10 is a welding face for contacting the solder joint 20 of the battery cell, and the welding face and the two adjacent sub-surfaces are connected by a fillet. Further, any adjacent sub-surfaces are connected by a fillet.

[0037] Optionally, in the polygonal structure, the side length of the side formed by the welding face is greater than the side lengths of the sides formed by the other sub-surfaces. In the present utility model, setting the side length of the welding face to be the largest can ensure the largest contact area between the solder ribbon 10 and the solder joint 20, thereby improving the welding stability.

[0038] Optionally, in the polygonal structure, the side length of the side formed by the welding face is equal to the side lengths of the sides formed by the other sub-surfaces. That is, all the sub-surfaces in the solder ribbon 10 have the same size, and each sub-surface can be used as a welding face. In the present utility model, setting the sizes of all the sub-surfaces of the solder ribbon 10 to the same structure, during the welding process, as long as the sub-surface in contact with the solder joint 20 is the welding face, the adjustment time of the welding face during the welding process is reduced, effectively ensuring the welding efficiency and welding stability.

[0039] In some embodiments, another sub-surface of the solder ribbon 10 is a pressing face, and the pressing face is disposed opposite to the welding face. It can be understood that the pressing face and the welding face are not directly adjacent, and the pressing face and the welding face are parallel or substantially parallel. In the present utility model, the pressing face and the welding face are disposed opposite to each other on the solder ribbon 10. The pressing face can be used as the supporting face of the glass panel when assembling the photovoltaic module, so as to avoid problems such as hidden cracks in the glass panel caused by a small contact area between the solder ribbon 10 and the glass panel. Moreover, when the solder ribbon 10 needs to be flattened, the pressing face can increase the force-bearing area, and each part of the solder ribbon 10 is more evenly stressed, and the overall relative thickness of the cross-section of the solder ribbon 10 after flattening is uniform.

[0040] In some embodiments, in the polygonal structure, the side length of the side formed by the welding face is 0.12 mm to 0.18 mm, Figure 1 where B represents the side length of the side formed by the welding face. Selecting the above-mentioned size of the welding face can ensure the contact area between the solder ribbon 10 and the solder joint 20 and improve the welding stability.

[0041] In some embodiments, in the fillet connection, the fillet radius is 0.01 mm to 0.02 mm, Figure 1 where R represents the radius of the fillet. Selecting the above-mentioned radius of the fillet can not only reduce the scratch of the solder joint 20 of the battery cell at the fillet, but also easily turn to the side of the sub-surface of the solder ribbon 10 under the action of pressure, effectively ensuring the contact area between the solder ribbon 10 and the solder joint 20.

[0042] In some embodiments, the distance between the center of the polygon structure and the side line of the polygon is 0.12 mm to 0.18 mm. Figure 1 In Figure 1 , A represents the distance between the center of the polygon and the side line of the polygon, which can be, for example, 0.12 mm, 0.13 mm, 0.14 mm, 0.15 mm, 0.16 mm, 0.17 mm, or 0.18 mm. It can be understood that when the polygon is a regular polygon, the distances from the center of the polygon to each side line of the polygon are equal.

[0043] In some embodiments, the number of sides of the polygon structure is ≥4, and further is an even number ≥4.

[0044] In some embodiments, the polygon structure is a regular polygon structure. For example, it can be an equilateral triangle, a square, a regular pentagon, or a regular hexagon. It can be selected as a square and a regular hexagon. In this application, the polygon structure is selected as a regular polygon structure. The side lengths of the regular polygon structure are equal, that is, any bottom surface where the solder strip 10 contacts the solder joint 20 is the largest contact surface, effectively ensuring the welding stability and welding efficiency. In addition, in this application, the square and regular hexagon structures are selected, and their bottom surfaces have corresponding bottom surfaces that are directly opposite. When pressing the solder strip 10, it can ensure that the contact areas of the pressing surface and the welding surface are both large.

[0045] In some embodiments, as Figure 2 shown, a plurality of first grooves 13 are provided on the outer surface of the solder strip 10.

[0046] In this application, the first grooves 13 are provided on the surface of the solder strip 10. First, during the flattening process, the first grooves 13 can provide a certain deformation expansion space for the solder strip 10, reduce the planar deformation of the solder strip 10, and thus reduce the light shielding problem of the battery chip. In addition, the structure of the first grooves 13 on the top surface of the solder strip 10 (i.e., the surface facing the sunlight in the photovoltaic module) can increase the diffuse reflection of sunlight during the use of the photovoltaic module, so that more light enters the solar cell and improves the photoelectric conversion efficiency.

[0047] In some embodiments, the first grooves 13 are opened along the length direction of the solder strip 10.

[0048] In some embodiments, a plurality of first grooves 13 are arranged along the circumferential direction of the solder strip 10.

[0049] In some embodiments, the solder ribbon 10 includes a metal substrate 11 and a solder layer 12 coated on the surface of the metal substrate 11. It can be understood that the present utility model does not make specific requirements and special limitations on the materials of the metal substrate 11 and the solder layer 12, and conventional materials in the art can be selected. For example, the material of the metal substrate 11 can be copper, such as oxygen-free copper or T2 copper, which can meet the requirements of precise dimensions, good electrical conductivity, and certain strength. For example, the material of the solder layer 12 can be a tin-lead alloy, such as the mass composition of the tin-lead alloy being 63% Sn and 37% Pb, or 60% Sn and 40% Pb.

[0050] In some embodiments, when the solder ribbon 10 includes the above-mentioned solder layer 12, the cross-sectional shape of the metal substrate 11 can be circular or polygonal. Optionally, the top angles of the polygon can be rounded. As long as the overall cross-section of the outer side of the solder ribbon 10 is the above-mentioned polygonal structure.

[0051] In some embodiments, the thickness of the solder layer 12 is 0.01 mm to 0.02 mm. For example, it can be 0.010 mm, 0.011 mm, 0.012 mm, 0.013 mm, 0.014 mm, 0.015 mm, 0.016 mm, 0.017 mm, 0.018 mm, 0.019 mm, or 0.020 mm. It can be understood that the thickness of the solder layer 12 can be reasonably selected according to the welding requirements of the solder ribbon 10.

[0052] In some embodiments, the first groove 13 is provided on the solder layer 12 and does not penetrate the solder layer 12.

[0053] In some embodiments, a second groove 14 is provided on the surface of the metal substrate 11, and a part of the solder layer 12 is filled in the second groove 14 and wraps around the surface of the metal substrate 11. Optionally, the positions of the first groove 13 and the second groove 14 can correspond or not correspond, that is, the position of the first groove 13 can be arranged staggeredly with the position of the second groove 14, or the positions can be opposite.

[0054] In the present application, by forming the circumferentially arranged second grooves 14 on the surface of the metal substrate 11, the second grooves 14 can improve the bonding force between the solder and the solder ribbon during the welding process, and can reduce the solder that melts and flows onto the surface of the battery cell, avoiding the solder solidifying on the battery cell and causing light shielding.

[0055] In some embodiments, the widths of the first groove 13 and the second groove 14 are independently 0.01 mm to 0.02 mm, for example, they can be 0.010 mm, 0.011 mm, 0.012 mm, 0.013 mm, 0.014 mm, 0.015 mm, 0.016 mm, 0.017 mm, 0.018 mm, 0.019 mm or 0.020 mm. It can be understood that the present utility model can reasonably select the widths of the first groove 13 and the second groove 14 according to the welding requirements and the requirements of refracted light.

[0056] In some embodiments, the depths of the first groove 13 and the second groove 14 are independently 0.01 mm to 0.02 mm, for example, they can be 0.010 mm, 0.011 mm, 0.012 mm, 0.013 mm, 0.014 mm, 0.015 mm, 0.016 mm, 0.017 mm, 0.018 mm, 0.019 mm or 0.020 mm. It can be understood that the present utility model can reasonably select the depths of the first groove 13 and the second groove 14 according to the welding requirements and the requirements of refracted light.

[0057] In some embodiments, the spacing distances between adjacent first grooves 13 and the spacing distances between adjacent second grooves 14 are independently 0.01 mm to 0.02 mm, for example, they can be 0.010 mm, 0.011 mm, 0.012 mm, 0.013 mm, 0.014 mm, 0.015 mm, 0.016 mm, 0.017 mm, 0.018 mm, 0.019 mm or 0.020 mm. Herein, the spacing distance refers to the edge distance between two adjacent grooves. It can be understood that the present utility model can reasonably select the spacing distances of the first groove 13 and the second groove 14 according to the welding requirements and the requirements of refracted light.

[0058] In some embodiments, the cross-sectional shapes of the first groove 13 and the second groove 14 can both be square, conical or bow-shaped. It can be understood that the present utility model can reasonably select the cross-sectional shapes of the grooves according to the welding requirements and the requirements of refracted light.

[0059] In some embodiments, the solder strip 10 first melts and casts a metal substrate 11 through a mold having the corresponding shape of the solder strip 10, and then melts and casts to form a solder layer 12; or, the solder strip 10 is formed by pressing a round solder strip 10 using a mold having the corresponding shape of the solder strip 10.

[0060] The second aspect of the present utility model provides a photovoltaic module. The photovoltaic module includes a plurality of battery cells and the solder strip 10 as in the first aspect. As Figure 3 shown, the solder strip 10 is connected to the solder joints 20 of the battery cells.

[0061] In some embodiments, every two adjacent solar cells are connected by a solder strip 10, and the solder strip is flattened. It can be understood that after the flattening process, the welding surface of the solder strip 10 and its adjacent sub-surface are still connected with rounded corners. In the present utility model, the solder strip 10 has a polygonal structure with rounded corners at the vertices. During the flattening process, the contact area between the solder strip and the solar cell is large, effectively preventing the problem of hidden cracks caused by the extrusion of the solder strip 10.

[0062] In some embodiments, the solar cell can be at least one of HJT solar cells, TOPcon solar cells or PERC solar cells.

[0063] In some embodiments, the photovoltaic module further includes a backsheet, an encapsulation layer and a front panel layer. The encapsulation layer and the backsheet are sequentially stacked on the back side of the solar cell, and the front panel layer is disposed on the front side of the solar cell. Optionally, the encapsulation layer and the backsheet are sequentially disposed on the back side of the solar cell along the direction away from the solar cell. It should be noted that in the present utility model, the back side refers to the side facing away from the sunlight irradiation. Correspondingly, the front side refers to the side directly irradiated by the sunlight.

[0064] In some embodiments, the photovoltaic module further includes a frame. The laminate formed by the front panel layer, the solar cell, the encapsulation layer and the backsheet is disposed within the frame. The frame is used to improve the mechanical strength of the laminate.

[0065] In some embodiments, the photovoltaic module further includes a junction box. The junction box is electrically connected to the solder strip 10. The junction box is used to protect the solar cell and prevent current short circuit, etc.

[0066] In summary, in the present application, the cross-sectional shape of the solder strip 10 is set to be polygonal, and the vertices of the polygon are adjusted to a rounded corner structure. During the welding process of the solder strip 10, by simply applying pressure to the solder strip 10, the placement form of the solder strip 10 can be adjusted, so that the solder joint between the solder strip and the solar cell is in planar contact. For example, the solder joint 20 between the solder strip 10 and the solar cell is turned from rounded corner contact to planar contact of the polygon, which not only increases the contact area between the solder strip 10 and the solder joint 20, but also can avoid damage to the solder joint 20 caused by the sharp corners of the solder strip 10, improving the welding efficiency and welding stability of the solder strip 10.

[0067] The technical features of the above 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 as the scope recorded in this specification.

[0068] The above embodiments only illustrate several implementation manners of the present utility model. The description thereof is relatively specific and detailed, but it should not be construed as a limitation to the scope of the utility model patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present utility model, several variations and improvements can still be made, and these all fall within the protection scope of the present utility model. Therefore, the protection scope of the present utility model patent shall be subject to the appended claims.

Claims

1. A solder tape, characterized in that, The cross-section of the solder ribbon (10) has a polygonal structure, and at least one side of the polygonal structure is connected to the two adjacent sides by a rounded corner. A plurality of first grooves (13) are provided on the outer surface of the solder ribbon (10).

2. The soldering tape according to claim 1, characterized in that, Any two adjacent sides of the polygonal structure are connected by a rounded corner.

3. The solder ribbon according to claim 1, wherein The outer surface of the solder ribbon (10) includes two end faces and a side face connecting the two end faces. The side face includes a plurality of sub-surfaces connected in sequence to form the polygonal structure. One of the sub-surfaces is a welding surface for contacting the solder joint (20) of the battery cell, and the welding surface is connected to the two adjacent sub-surfaces by a rounded corner.

4. The solder ribbon according to claim 3, characterized in that, Another sub-surface of the solder ribbon (10) is a pressing surface, and the pressing surface is disposed opposite to the welding surface; and / or In the polygonal structure, the side length of the side formed by the welding surface is 0.12 mm to 0.18 mm.

5. The solder ribbon according to claim 1, wherein In the rounded corner connection, the radius of the rounded corner is 0.01 mm to 0.02 mm; and / or The number of sides of the polygonal structure is ≥4; and / or The polygonal structure is a regular polygonal structure.

6. The solder tape according to claim 1, characterized in that, The first grooves (13) are opened along the length direction of the solder ribbon (10); and / or A plurality of the first grooves (13) are arranged circumferentially along the solder ribbon (10).

7. The solder tape according to claim 1, wherein The width of the first grooves (13) is 0.01 mm to 0.02 mm.

8. The solder strip according to claim 1, wherein, The depth of the first grooves (13) is 0.01 mm to 0.02 mm.

9. The solder tape as claimed in claim 1, wherein The spacing distance between adjacent first grooves (13) is 0.01 mm to 0.02 mm.

10. The solder tape according to claim 1, wherein, The solder ribbon (10) includes a metal substrate (11) and a solder layer (12) coated on the surface of the metal substrate (11).

11. The solder tape according to claim 10, wherein, The first grooves (13) are provided on the solder layer (12) and do not penetrate the solder layer (12); and / or The surface of the metal substrate (11) is provided with second grooves (14), and a part of the solder layer (12) is filled in the second grooves (14) and wraps around the surface of the metal substrate (11).

12. The solder ribbon according to claim 11, wherein, The width of the second grooves (14) is 0.01 mm to 0.02 mm.

13. The solder ribbon according to claim 11, wherein The depth of the second grooves (14) is 0.01 mm to 0.02 mm.

14. The solder tape according to claim 11, wherein The spacing distance between adjacent second grooves (14) is 0.01 mm to 0.02 mm.

15. A photovoltaic module, characterized in that, The photovoltaic module includes a plurality of battery cells and the solder ribbon according to any one of claims 1-14, and the solder ribbon (10) is connected to the solder joint (20) of the battery cell.

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