Conductive connectors and photovoltaic modules

Abstract

The utility model discloses a conductive connector and a photovoltaic module. The conductive connector includes a metal conductive substrate and a coating. The metal conductive substrate has a welding area and a non-welding area outside the welding area, and the non-welding area is coated with a coating. The above-mentioned photovoltaic module includes a conductive connector. In the present application, the conductive connector has a simple structure. The non-welding area outside the welding area on the metal conductive substrate is coated with a coating, which reduces the coating on the metal conductive substrate, reduces the content of the coating, and reduces the material cost; the welding area on the metal conductive substrate is vacant, and the absence of a coating can reduce the risk of silver corrosion in the battery welding area and increase the reliability of the welding area. In addition, since the coating of the conductive connector is reduced, the overall thermal expansion coefficient of the conductive connector is reduced to be closer to that of the battery cell, which can effectively improve the warping phenomenon of the battery cell, reduce the risk of hidden cracks in the battery cell, and increase the reliability of the photovoltaic module.

Description

Technical Field

[0001] The utility model relates to the technical field of photovoltaics, in particular to a conductive connector and a photovoltaic assembly. Background Art

[0002] In the photovoltaic field, back-contact cells are a new type of battery technology. The positive and negative electrodes of the cells of back-contact cells are distributed on the back of the cells, and the front of the cells is unobstructed, which can improve the photoelectric conversion efficiency of the cells. The positive and negative electrodes of the cells include positive and negative fine grid lines for collecting current and solder joints for interconnecting the cells. When the cells are interconnected, the solder strips are connected to the solder joints and are both located on the back of the cells. The positive and negative electrodes on the cells are made by screen printing and then sintering. The formed solder joints and fine grid lines have a height difference of 50μm~150μm. Due to the height difference between the fine grid lines and the solder joints, it is difficult for the solder strips to fully contact the solder joints, which is not conducive to the welding between the solder strips and the solder joints, causing welding failure or increasing the contact resistance, affecting the power output of the components.

[0003] In order to solve the welding problem between the solder strip and the solder joint during the interconnection of the back-contact battery, the prior art prints a layer of solder paste or conductive glue on the solder joint of the battery cell. The main component of the solder joint is metal Ag, and the main component of the solder paste is tin-lead alloy and flux. Metal Ag will dissolve in the tin-lead alloy under high temperature conditions. The higher the temperature, the faster the dissolution rate. The solder strip is generally a copper-based tin-lead solder strip, that is, a layer of tin-lead alloy is wrapped around the copper. The temperature used in the welding process is usually greater than 150°C or even 350°C. Under such a high temperature and a large amount of tin content, metal Ag will quickly dissolve in the tin-lead alloy, and the thickness of the Ag at the battery cell solder joint is usually only about 7μm, which will soon be completely dissolved in the solder alloy. At this time, the solder joint will detach from the battery cell, causing welding failure, resulting in a significant attenuation of component power, and affecting product reliability. In addition, the welding or bonding between the battery cell and the soldering ribbon is usually carried out at a higher temperature. After the welding or bonding is completed, the battery cell and the soldering ribbon will return to room temperature from the welding temperature. During this process, the volume of both will shrink. Due to the large difference in the thermal expansion coefficients of the two materials, the battery cell and the soldering ribbon, the battery cell will warp after the welding is completed. The warping will bring the risk of hidden cracks during the lamination of the photovoltaic module, resulting in reduced reliability of the photovoltaic module and affecting the performance of the product. Utility Model Content

[0004] Based on this, it is necessary to provide a conductive connector. The conductive connector of the utility model has a simple structure and low cost, can reduce the risk of silver corrosion in the battery welding area, increase the reliability of the welding area, effectively improve the warping phenomenon of the battery cell, reduce the risk of hidden cracks in the battery cell, and increase the reliability of the photovoltaic module.

[0005] An embodiment of the present application provides a conductive connector.

[0006] A conductive connector comprises a metal conductive substrate and a coating. The metal conductive substrate is provided with a welding area and a non-welding area outside the welding area, and the non-welding area is coated with the coating.

[0007] In some embodiments, the metal conductive substrate is a copper substrate.

[0008] In some embodiments, the coating is a solder coating.

[0009] In some embodiments, the coating has a thickness of 10 μm to 100 μm.

[0010] In some embodiments, the metal conductive substrate includes a first surface and a second surface, wherein the second surface is used to match the battery cell, and the second surface has the welding area.

[0011] In some embodiments, the second surface has a plurality of welding areas.

[0012] In some embodiments, the plurality of welding regions on the second surface are spaced apart from each other.

[0013] In some embodiments, the conductive connecting member further includes a filling member, and the filling member is used to fill in the welding area.

[0014] In some embodiments, the filler is solder paste.

[0015] An embodiment of the present application also provides a photovoltaic module.

[0016] A photovoltaic assembly comprises the above-mentioned conductive connecting piece.

[0017] The above-mentioned conductive connector has a coating on the non-welding area outside the welding area on the metal conductive substrate, which reduces the coating on the metal conductive substrate, reduces the content of the coating, reduces the material cost, and has a simple structure; the welding area on the metal conductive substrate is vacant and has no coating, which can reduce the risk of silver corrosion in the battery welding area and increase the reliability of the welding area. In addition, due to the reduction of the coating on the conductive connector, the overall thermal expansion coefficient of the conductive connector is reduced to be closer to the battery cell, which can effectively improve the warping phenomenon of the battery cell, reduce the risk of hidden cracks in the battery cell, and increase the reliability of the photovoltaic module. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application, and those skilled in the art can obtain other drawings based on these drawings without creative work.

[0019] In order to more completely understand the present application and its beneficial effects, the following description will be given in conjunction with the accompanying drawings. In the following description, the same reference numerals represent the same parts.

[0020] Figure 1 This is a schematic diagram of a conductive connecting member according to an embodiment of the utility model;

[0021] Figure 2 This is a schematic diagram of the cooperation between the conductive connector and the battery cell according to an embodiment of the utility model.

[0022] Description of Reference Numerals

[0023] 10. Conductive connector; 100. Metal conductive substrate; 101. Welding area; 102. Non-welding area; 200. Coating; 300. Filler; 20. Battery cell. DETAILED DESCRIPTION

[0024] In order to make the above-mentioned purposes, features and advantages of the utility model more obvious and easy to understand, the specific implementation methods of the utility model are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the utility model. However, the utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the utility model, so the utility model is not limited by the specific embodiments disclosed below.

[0025] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0026] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0027] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0028] In the description of the present utility model, "several" means more than one, "many" means more than two, "greater than", "less than", "exceed" etc. are understood to exclude the number itself, and "above", "below", "within" etc. are understood to include the number itself. If there is a description of "first" or "second", it is only used to distinguish the technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art in the technical field of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0030] The embodiment of the present application provides a conductive connector 10 to solve the problem that the height difference between the fine grid line and the solder joint makes it difficult for the solder strip to fully contact the solder joint, causing welding failure or increasing the contact resistance, affecting the power output of the component; and the problem that the solder joints of the traditional technology of printing solder paste or conductive glue on the solder joints of the battery cell are separated from the battery cell, causing welding failure, a significant attenuation of the component power, and affecting the reliability of the product. The conductive connector 10 will be described below in conjunction with the accompanying drawings.

[0031] The conductive connector 10 provided in the embodiment of the present application is exemplified by referring to Figure 1 As shown, Figure 1 A schematic structural diagram of a conductive connector 10 provided in an embodiment of the present application.

[0032] In order to more clearly illustrate the structure of the conductive connecting member 10 , the conductive connecting member 10 will be introduced below with reference to the accompanying drawings.

[0033] For example, see Figure 1 As shown, Figure 1 A schematic diagram of the structure of a conductive connector 10 provided in an embodiment of the present application. A conductive connector 10 includes a metal conductive substrate 100 and a coating 200. The metal conductive substrate 100 has a welding area 101 and a non-welding area 102 outside the welding area 101. The non-welding area 102 is coated with the coating 200.

[0034] The conductive connector 10 of the present application reduces the coating 200 such as the tin-lead coating on the metal conductive substrate 100. Specifically, the present application reduces the tin content in the tin-lead coating and improves the distribution of the tin-lead coating. Reducing the tin content in the tin-lead coating can reduce the silver corrosion of the solder paste, and the reduction of tin also makes the metal conductive substrate 100 shrink closer to the battery cell 20, thereby achieving the purpose of improving the warping of the battery cell 20 and reducing the cost at the same time; the purpose of improving the distribution of the tin-lead coating is to prevent the uncoated welding area 101 on the metal conductive substrate 100 from being oxidized.

[0035] In some embodiments, the metal conductive substrate 100 is a copper substrate.

[0036] In some embodiments, the coating 200 is a solder coating.

[0037] In some embodiments, the thickness of the coating 200 is 10 μm to 100 μm. For example, in one example, the thickness of the coating 200 is 10 μm. In another example, the thickness of the coating 200 is 100 μm. It is not difficult to understand that in other specific examples, the thickness of the coating 200 can also be 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm or other values.

[0038] In some embodiments, the metal conductive substrate 100 includes a first surface and a second surface, and the second surface has a welding area 101. Figure 2 As shown, Figure 2This is a schematic diagram of the cooperation between the conductive connector 10 and the battery cell 20 according to an embodiment of the utility model. The second surface is used to cooperate with the battery cell 20. When the conductive connector 10 cooperates with the battery cell 20, the welding area 101 is filled with a filling member 300, and the filling member 300 is used to assist in achieving the connection between the conductive connector 10 and the battery cell 20.

[0039] In some of the embodiments, the second surface has a plurality of welding regions 101 .

[0040] In some embodiments, the plurality of welding regions 101 on the second surface are spaced apart. It should be noted that the distance between the plurality of welding regions 101 on the second surface can be determined according to the required welding interval.

[0041] In some of the embodiments, the plurality of welding regions 101 on the second surface are distributed at equal intervals.

[0042] In some embodiments, the conductive connector 10 further includes a filler 300. The filler 300 is used to fill the welding area 101. The filler 300 is used to assist the connection between the conductive connector 10 and the cell sheet 20 of the solar cell.

[0043] In some embodiments, the filling member 300 is solder paste.

[0044] In some of the embodiments, the metal conductive substrate 100 may be a soldering ribbon of a copper substrate.

[0045] In some of the embodiments, the length and width of the metal conductive substrate 100 can be set according to actual needs.

[0046] In the present application, the external contact surface (first surface) of the metal conductive substrate 100 in the conductive connector 10 is coated with a complete coating 200, such as a solder coating, in order to prevent the Cu in the metal conductive substrate 100 from being oxidized in the air to form CuO during high-temperature welding, and to prevent the conductive connector 10 from being in a humid environment, where Cu is converted into basic copper carbonate (commonly known as verdigris) and thus reducing the conductive performance of the conductive connector 10. Therefore, the first surface of the metal conductive substrate 100 of the conductive connector 10 that contacts the outside needs to be protected by a complete solder coating. The second surface of the conductive connector 10 in contact with the battery cell 20 has a coating 200 such as a solder coating only in the non-welding area 102. The coating 200 on the second surface has the same function as the coating 200 on the first surface, but there is no coating 200 in the welding area 101 of the second surface. Instead, the metal of the metal conductive substrate 100 is exposed. This is because at a welding temperature of about 220°C, the metal in the metal conductive substrate 100, such as copper, and the filler 300, such as Sn in the solder paste, can generate a Cu6Sn5 alloy layer to connect the conductive connector 10 to the solder paste. The welding part of the conductive connector 10 has no solder coating, and Cu will consume part of the Sn. Therefore, the Sn content in the welding area 101 is reduced, the risk of silver corrosion is reduced, and the reliability of the welding area 101 is increased. In addition, the thermal expansion coefficient of the SnPb alloy is 21×10 -6 / K, the thermal expansion coefficient of Cu is 16.1×10 -6 / K, the Si of the cell 20 is 2.6×10 -6 / K, the thermal expansion coefficient of Si is much smaller than that of SnPb alloy and Cu. When the tin-lead coating 200 is reduced, the thermal expansion coefficient of the conductive connector 10 as a whole is reduced, and the expansion and contraction of the conductive connector 10 is closer to the battery cell 20, thereby reducing the warping of the battery cell 20 and the risk of hidden cracks during component lamination, thereby increasing the reliability of the photovoltaic module.

[0047] An embodiment of the present application also provides a photovoltaic module.

[0048] A photovoltaic assembly includes the conductive connector 10 mentioned above.

[0049] In some embodiments, the photovoltaic module includes a solar cell packaging component, in which the solar cell is packaged.

[0050] In summary, the conductive connector 10 of the present application has a simple structure, simple production and preparation, and low cost. Specifically, the conductive connector 10 of the present application has a non-welding area 102 outside the welding area 101 on the metal conductive substrate 100 coated with a coating 200, which reduces the coating 200 on the metal conductive substrate 100, reduces the content of the coating 200, and reduces the material cost; the welding area 101 on the metal conductive substrate 100 is vacant, and the absence of the coating 200 can reduce the risk of silver corrosion in the battery welding area 101 and increase the reliability of the welding area 101. In addition, due to the reduction of the coating 200 of the conductive connector 10 of the present application, the overall thermal expansion coefficient of the conductive connector 10 is reduced to be closer to the battery cell 20, which can effectively improve the warping phenomenon of the battery cell 20, reduce the risk of hidden cracks in the battery cell 20, and increase the reliability of the photovoltaic module.

[0051] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0052] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0053] The above-mentioned embodiments only express several implementation methods of the utility model, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the patent of the utility model. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the utility model, and these all belong to the protection scope of the utility model. Therefore, the protection scope of the utility model patent shall be based on the attached claims.

Claims

1. A conductive connector (10), characterized in that: The invention comprises a metal conductive substrate (100) and a coating (200), wherein the metal conductive substrate (100) has a welding area (101) and a non-welding area (102) located outside the welding area (101), and the non-welding area (102) is coated with the coating (200).

2. The conductive connector (10) according to claim 1, characterized in that: The metal conductive substrate (100) is a copper substrate.

3. The conductive connecting piece (10) according to claim 1, characterized in that: The coating (200) is a solder coating (200).

4. The conductive connector (10) according to any one of claims 1 to 3, characterized in that: The coating (200) has a thickness of 10 μm to 100 μm.

5. The conductive connector (10) according to any one of claims 1 to 3, characterized in that: The metal conductive substrate (100) comprises a first surface and a second surface, wherein the second surface is used to match the battery sheet (20), and the second surface has the welding area (101).

6. The conductive connecting piece (10) according to claim 5, characterized in that: The second surface has a plurality of welding areas (101).

7. The conductive connecting piece (10) according to claim 6, characterized in that: The plurality of welding areas (101) on the second surface are distributed at intervals.

8. The conductive connector (10) according to any one of claims 1 to 3, 6 to 7, characterized in that: The conductive connecting member (10) further comprises a filling member (300), wherein the filling member (300) is used to fill the welding area (101).

9. The conductive connecting piece (10) according to claim 8, characterized in that: The filling piece (300) is solder paste.

10. A photovoltaic module, characterized in that: Comprising the conductive connecting piece (10) as claimed in any one of claims 1 to 9.

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