Solder strip and photovoltaic module

Abstract

According to the solder strip and the photovoltaic module, one part of a base band of the solder strip is made into a triangular shape, the other part of the base band is embedded into a silver paste electrode on the surface of a photovoltaic cell piece, welding of the base band and the silver paste electrode is achieved through molten solder, and therefore the second part of the triangular shape is exposed out of the photovoltaic cell piece and can be used for reflecting light rays; the first part is embedded into the silver paste electrode, so that the contact area between the silver paste electrode and the base band can be increased, the contact performance is good, and the welding strength is high; in addition, welding strip overturning in the welding process can be avoided, the reflection effect is guaranteed, and the light utilization rate is improved.

Description

Technical Field

[0001] The present application relates to the field of solar power generation technology, and in particular to a welding ribbon and a photovoltaic module. Background Art

[0002] Photovoltaic modules are a key component of photovoltaic power plants. The more effectively they utilize light, the higher their power generation. Improving light utilization is one way to increase a module's power generation. The solder ribbons in photovoltaic modules primarily serve to collect current.

[0003] Currently, the most commonly used welding ribbons include triangular, round, and flat. In terms of light utilization, triangular ribbons can utilize almost all vertical and oblique light, resulting in the highest efficiency. Round ribbons can utilize some vertical light and a small amount of oblique light, resulting in the second highest efficiency. Ordinary flat ribbons cannot utilize all vertical light and most oblique light, resulting in the lowest efficiency. In terms of contact performance, triangular and flat ribbons have a large contact area with the cell, resulting in good contact performance and high weld strength. However, round ribbons have a small contact area with the cell, resulting in poor contact and low weld strength.

[0004] Therefore, a soldering ribbon with a large contact area with the solar cell and good light utilization efficiency is needed. Utility Model Content

[0005] The purpose of this application is to provide a welding strip and a photovoltaic module that can improve light utilization and increase welding strength.

[0006] The embodiments of the present application can be implemented as follows:

[0007] In a first aspect, the utility model provides a soldering strip comprising a base strip and solder wrapped around the outer surface of the base strip, wherein the cross-section of the base strip comprises a first part and a second part connected to each other, wherein the first part is used to be embedded in the silver paste electrode of a photovoltaic cell so that the second part is exposed on the surface of the photovoltaic cell, wherein the second part is triangular.

[0008] In an optional embodiment, the second portion is triangular, so that the cross-section of the base tape is diamond-shaped.

[0009] In an optional embodiment, the top angle of the diamond-shaped cross-section of the base tape is 30 to 60 degrees.

[0010] In an optional embodiment, the width of the diamond-shaped cross section of the base tape is 0.1 to 0.5 mm.

[0011] In an optional embodiment, the surface of the base tape is roughened.

[0012] In an optional embodiment, the surface of the base tape is roughened by flux pickling and etching.

[0013] In an optional embodiment, the solder is attached to the surface of the base tape by a hot-dip process.

[0014] In an optional embodiment, the base tape is made of copper.

[0015] In the second aspect, the utility model provides a photovoltaic module, comprising a photovoltaic cell and the welding strip described in any one of the aforementioned embodiments, wherein the surface of the photovoltaic cell has a silver paste electrode, the silver paste electrode has a placement groove, and the base strip is welded to the silver paste electrode through the melted solder, wherein the first part is embedded in the placement groove, and the second part is exposed on the surface of the photovoltaic cell.

[0016] In an optional embodiment, the surface of the photovoltaic cell has a groove, the silver paste electrode is located in the groove, and the boundary between the first part and the second part is flush with the surface of the photovoltaic cell.

[0017] Compared with the prior art, the beneficial effects of the embodiments of the present application include, for example:

[0018] The base strip of the soldering ribbon is made into a triangle, and the other part is embedded in the silver paste electrode on the surface of the photovoltaic cell. The soldering is then welded to the silver paste electrode through the molten solder. In this way, the second part of the triangle is exposed on the photovoltaic cell and can be used to reflect light. Since the first part is embedded in the silver paste electrode, the contact area between the silver paste electrode and the base strip can be increased, resulting in good contact performance and high welding strength.

[0019] In addition, it can prevent the welding ribbon from flipping during the welding process, ensure the reflective effect, and improve light utilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the specific implementation methods or the description of the prior art. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0021] Figure 1 A cross-sectional view of the layout structure of a photovoltaic module according to an embodiment of the present application;

[0022] Figure 2 for Figure 1 Schematic diagram of the middle welding strip;

[0023] Figure 3A schematic diagram of the reflection of a photovoltaic cell with triangular welding ribbons welded thereto in the prior art;

[0024] Figure 4 for Figure 1 Schematic diagram of reflection;

[0025] Figure 5 for Figure 1 Manufacturing process diagram of the middle welding strip.

[0026] Icon: 100-solder ribbon; 110-base ribbon; 111-first part; 112-second part; 120-solder; 200-photovoltaic cell; 210-groove; 220-silver paste electrode; 230-placement groove. DETAILED DESCRIPTION

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Generally, the components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0028] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for protection, but merely represents selected embodiments of the present application. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments in the present application without creative work are within the scope of protection of the present application.

[0029] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0030] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the product of this application is typically placed when in use. These terms are intended only to facilitate the description of this application and simplify the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0031] Furthermore, terms such as "horizontal," "vertical," and "overhanging" do not necessarily imply that a component must be absolutely horizontal or overhanging, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but rather that it can be slightly tilted.

[0032] It should also be noted that, in the description of this application, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0033] The following describes some embodiments of the present application in detail with reference to the accompanying drawings. In the absence of conflict, the following embodiments and features therein may be combined with each other.

[0034] refer to Figure 1 The present invention discloses a photovoltaic module comprising a photovoltaic cell 200 and a solder ribbon 100. Photovoltaic cells 200, also known as solar cells, are semiconductor devices that convert sunlight directly into electrical energy. They are core components in solar power generation systems and are widely used in rooftop solar panels, large-scale solar power plants, and various portable devices.

[0035] Photovoltaic cells 200 operate based on the photovoltaic effect (PE), which states that certain materials can generate an electric current when exposed to light. The basic operating process is as follows: When sunlight strikes a photovoltaic cell 200, photons are absorbed by the semiconductor material (typically silicon). The absorbed photon energy causes electrons in the semiconductor material to transition from the valence band to the conduction band, forming free electron-hole pairs. Under the action of a PN junction or heterojunction, the electrons and holes are separated, with electrons migrating to the N region and holes to the P region. Then, through an external circuit, the electrons and holes flow to the positive and negative electrodes, respectively, forming a current.

[0036] Silver paste electrodes 220 are located on the surface of the photovoltaic cell 200, and the soldering ribbon 100 is welded to the silver paste electrodes 220. The soldering ribbon 100 primarily collects current, allowing it to flow from one photovoltaic cell 200 to the next, ultimately forming a high-voltage circuit. The soldering ribbon 100 also enhances the mechanical strength of the photovoltaic module, preventing damage to the cells due to external forces. Furthermore, the soldering ribbon 100 exhibits a certain degree of flexibility, absorbing some thermal stress during temperature fluctuations and reducing mechanical stress between the cells.

[0037] refer to Figure 1 and Figure 2 The soldering tape 100 includes a base tape 110 and a solder 120 wrapped around the outer surface of the base tape 110. The shape of the solder 120 is adapted to the shape of the base tape 110. The cross section of the base tape 110 includes a first portion 111 and a second portion 112 connected to each other. The first portion 111 is used to be embedded in the silver paste electrode 220 of the photovoltaic cell 200 so that the second portion 112 is exposed on the surface of the photovoltaic cell 200, wherein the second portion 112 is triangular.

[0038] In this way, the base strip 110 of the welding strip 100 is made into a triangle in part, and the other part is embedded in the silver paste electrode 220 on the surface of the photovoltaic cell 200, and the welding with the silver paste electrode 220 is achieved through the melted solder 120. In this way, the second part 112 of the triangle is exposed on the photovoltaic cell 200 and can be used to reflect light. Since the first part 111 is embedded in the silver paste electrode 220, the contact area between the silver paste electrode 220 and the base strip 110 can be increased, the contact performance is good, and the welding strength is high.

[0039] In the prior art, the welding of the triangular welding strip 100 and the photovoltaic cell 200 is as follows: Figure 3 As shown, since one side of the triangular welding ribbon 100 contacts the silver paste electrode 220, the contact area is small, and it is easy to flip over during the welding process, causing the side of the triangular welding ribbon 100 close to the photovoltaic cell 200 to be tilted from the surface of the photovoltaic cell 200, affecting the reflective effect and thus affecting the light utilization rate. In addition, the amount of silver paste used is also greater, and the cost is higher.

[0040] In this embodiment, again referring to Figure 1 Since the second part 112 is embedded with the silver paste electrode 220, a placement groove 230 can be formed after the silver paste is sintered when manufacturing the photovoltaic cell 200. In this way, the first part 111 is embedded with the placement groove 230 and the base strip 110 and the silver paste electrode 220 are welded through the melted solder 120, thereby ensuring contact performance and welding strength. At the same time, it can avoid the flipping of the welding strip 100 during the welding process, ensure the reflective effect, improve light utilization, and reduce the amount of silver paste used.

[0041] Specifically, the second part 112 is triangular, so that the cross-section of the base band 110 is roughly diamond-shaped as a whole. In this way, the overall shape of the base band 110 is relatively regular and easy to mold and manufacture. At the same time, the placement groove 230 is a V-shaped groove to ensure the tightness of the fit between the second part 112 and the placement groove 230, and at the same time better avoid the flipping problem during the welding process. In addition, it can save the amount of silver paste and reduce costs.

[0042] In addition, the surface of the photovoltaic cell 200 has a groove 210, and the silver paste electrode 220 is located in the groove 210. The boundary between the first part 111 and the second part 112 is flush with the surface of the photovoltaic cell 200. This can further ensure the reflective effect, improve light utilization, and reduce the amount of silver paste used to reduce costs.

[0043] It should also be noted that the reflective effect of the triangular welding strip 100 in the prior art is as follows: Figure 4 As shown, since the surface of the triangular welding strip 100 is smooth, light will partially escape after being irradiated onto the triangular welding strip 100 , resulting in poor reflective effect and low light utilization efficiency.

[0044] In this embodiment, combined with Figure 4 and Figure 5 The surface of the base tape 110 is roughened. Specifically, the surface of the base tape 110 can be roughened by flux pickling and etching. This can further increase the contact area between the base tape 110 and the silver paste, and also cause diffuse reflection after light is irradiated onto the base tape 110, thereby increasing the amount of light reaching the surface of the photovoltaic cell 200.

[0045] In addition, the top angle α of the diamond cross-section of the base band 110 is 30 to 60°, that is, the top angle α of the first part 111 and the second part 112 facing each other is 30 to 60°, and the width D of the diamond cross-section of the base band 110 is 0.1 to 0.5 mm, that is, the length D at the junction of the first part 111 and the second part 112 is 0.1 to 0.5 mm, so as to ensure the reflective effect and improve the light utilization rate.

[0046] The material of the base band 110 can be copper, which has good conductivity, toughness and low cost. Figure 5 To manufacture solder ribbon 100, copper raw material is first molded into a diamond shape. The hard base material is then annealed to a soft state at a temperature of 400-600°C. The copper ribbon is then pickled and etched using a flux pickling agent (using a rosin, resin, organic, or inorganic flux). The pickling time ranges from 0.5s to 3s. Finally, solder 120 is applied to the surface of base ribbon 110 via a hot-dip process, completing the manufacture of solder ribbon 100.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A welding strip, characterized in that: The invention comprises a base tape (110) and a solder (120) wrapped around the outer surface of the base tape (110); the cross section of the base tape (110) comprises a first portion (111) and a second portion (112) connected to each other; the first portion (111) is used to be embedded in a silver paste electrode (220) of a photovoltaic cell (200) so that the second portion (112) is exposed on the surface of the photovoltaic cell (200); and the second portion (112) is triangular in shape.

2. The welding strip according to claim 1, characterized in that The second portion (112) is triangular in shape, so that the cross section of the base tape (110) is diamond-shaped.

3. The welding strip according to claim 2, characterized in that The base tape (110) has a rhombus cross-section with a top angle of 30 to 60 degrees.

4. The welding strip according to claim 2, characterized in that The base tape (110) has a diamond-shaped cross-section with a width of 0.1 to 0.5 mm.

5. The welding strip according to claim 1, characterized in that The surface of the base tape (110) is roughened.

6. The welding strip according to claim 5, characterized in that The surface of the base tape (110) is roughened by flux pickling and etching.

7. The welding strip according to claim 1, characterized in that The solder (120) is attached to the surface of the base tape (110) through a hot-dip process.

8. The welding strip according to claim 1, characterized in that The base tape (110) is made of copper.

9. A photovoltaic module, characterized in that: The invention comprises a photovoltaic cell (200) and a soldering tape according to any one of claims 1 to 8, wherein a silver paste electrode (220) is provided on the surface of the photovoltaic cell (200), the silver paste electrode (220) having a placement groove (230), the base tape (110) being soldered to the silver paste electrode (220) through the melted solder (120), wherein the first portion (111) is engaged with the placement groove (230), and the second portion (112) is exposed on the surface of the photovoltaic cell (200).

10. The photovoltaic module according to claim 9, characterized in that: The surface of the photovoltaic cell (200) has a groove (210), the silver paste electrode (220) is located in the groove (210), and the boundary between the first part (111) and the second part (112) is flush with the surface of the photovoltaic cell (200).

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