Photovoltaic solder strip with segmented thermoplastic conductive coating

Abstract

The utility model provides a photovoltaic solder strip with a segmented thermoplastic conductive coating. The photovoltaic solder strip comprises a copper core; a silver layer covering the copper core; the conductive coating covers the silver layer, the conductive coating comprises a thermoplastic conductive coating section and alloy coating sections, the alloy coating sections are arranged on the two sides of the thermoplastic conductive coating section, and the thermoplastic conductive coating section is arranged between adjacent bonding pads of the two battery pieces which are connected in series. Through the processing scheme of the utility model, the cost of the solder strip is reduced, and the thermoplastic conductive coating solder strip can be directly attached to the surface of the battery piece and can form mechanical combination and electrical connection with the TCO layer through low-temperature curing, thereby preventing the solder strip from shifting.

Description

Technical Field

[0001] The utility model belongs to the field of solar photovoltaics, and in particular relates to a photovoltaic welding strip with a segmented thermoplastic conductive coating. Background Art

[0002] With the continuous development of photovoltaic energy technology, cost reduction and efficiency improvement have become the focus of current industry development. Photovoltaic modules involve a variety of materials, among which photovoltaic welding ribbons are an indispensable material in photovoltaic modules, and the cost of welding ribbons accounts for a large proportion of the entire photovoltaic module cost. At present, flux must be used on the surface of string welding technology, and only certain metal surfaces can be welded. Traditional SnPb and SnBi alloy coatings are widely used in standard solar cell interconnections, but their cost is relatively high, and the existing welding ribbon alloy coating has poor bonding ability with the edge without silver paste, and it is difficult for the welding ribbon to be firmly bonded to the edge of the battery cell, resulting in welding ribbon deviation. Under the pressure of reducing the cost of photovoltaic modules, improving the cost of welding ribbon coating is currently a key. Utility Model Content

[0003] In view of this, the utility model provides a photovoltaic welding strip with a segmented thermoplastic conductive coating, which at least partially solves the problems existing in the prior art.

[0004] The utility model discloses a photovoltaic welding strip with a segmented thermoplastic conductive coating, comprising:

[0005] Copper core;

[0006] a silver layer covering the copper core; and

[0007] A conductive coating covering the silver layer, wherein

[0008] The conductive coating comprises a thermoplastic conductive coating segment and an alloy coating segment. The alloy coating segment is arranged on both sides of the thermoplastic conductive coating segment, and the thermoplastic conductive coating segment is arranged between adjacent pads of two battery cells connected in series.

[0009] In one specific implementation, the thermoplastic conductive coating includes a matrix and conductive particles.

[0010] In a specific implementation, the substrate is made of polyolefin material, and the conductive particles are metal powder.

[0011] In a specific implementation, the diameter of the metal powder is between 5 and 20 μm.

[0012] In a specific implementation, the alloy coating is a SnPb alloy coating or a SnBi alloy coating.

[0013] In a specific implementation, a transparent conductive oxide layer is disposed on the surface of the cell, and the thermoplastic conductive coating is in direct contact with the transparent conductive oxide layer.

[0014] In a specific implementation, a metal electrode is disposed on the surface of the battery cell, and the alloy coating is connected to the metal electrode.

[0015] The utility model discloses a photovoltaic welding strip with segmented thermoplastic conductive coating, comprising: a copper core; a silver layer covering the copper core; and a conductive coating covering the silver layer, wherein the conductive coating comprises a thermoplastic conductive coating segment and an alloy coating segment, the alloy coating segment is arranged on both sides of the thermoplastic conductive coating segment, and the thermoplastic conductive coating segment is arranged between adjacent pads of two battery cells connected in series. Through the processing scheme of the utility model, the cost of the welding strip is reduced, and the thermoplastic conductive coating welding strip can be directly attached to the surface of the battery cell, and can form a mechanical bond and electrical connection with the TCO layer through low temperature curing, thereby preventing the welding strip from deviating. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solution of the present utility model, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 A schematic diagram of the structure of the welding strip provided by the utility model;

[0018] Figure 2 A schematic diagram of the arrangement of the segmented thermoplastic conductive coating welding strip provided by the utility model;

[0019] Figure 3 This is a schematic diagram of the thermoplastic conductive coating provided by the present invention in direct contact with the TCO layer on the surface of the battery. DETAILED DESCRIPTION

[0020] The utility model is described in detail below in conjunction with the accompanying drawings.

[0021] The following describes the implementation methods of the present invention through specific concrete examples. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. The present invention can also be implemented or applied through other different specific implementation methods, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0022] It should be noted that various aspects of the embodiments within the scope of the appended claims are described below. It should be apparent that the aspects described herein can be embodied in a wide variety of forms, and any specific structure and / or function described herein is merely illustrative. Based on the utility model, it should be understood by those skilled in the art that an aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects described herein can be used to implement the device and / or practice the method. In addition, other structures and / or functionalities other than one or more of the aspects described herein can be used to implement this device and / or practice this method.

[0023] It should also be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention. The drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed at will, and the component layout may also be more complicated.

[0024] Additionally, in the following description, specific details are provided to facilitate a thorough understanding of the examples. However, it will be understood by those skilled in the art that the aspects described may be practiced without these specific details.

[0025] The utility model discloses a photovoltaic welding strip with a segmented thermoplastic conductive coating, in which the welding strip coating between the last welding pad PAD point of the previous battery sheet and the first welding pad PAD point of the next battery sheet is replaced by a thermoplastic conductive coating; this can reduce costs on the one hand, and on the other hand, the raw material material and proportion of the thermoplastic conductive coating can be controlled to adjust its melting temperature between 130°C and 200°C, so that it can be tightly bonded to the edge of the battery sheet, which can effectively inhibit the welding strip from deviating during the movement or lamination of the battery string.

[0026] Next, with reference to the accompanying drawings, the photovoltaic welding strip with segmented thermoplastic conductive coating of the present invention will be described in detail. Figure 1 , describing the structure of the welding strip of the utility model. Figure 1 As shown, the conductor of the photovoltaic welding ribbon is composed of a round copper core, the surface of which is covered with a silver layer for corrosion protection and diffusion protection, and then the outermost layer is coated with a conductive coating. In the utility model, the conductive coating can be divided into a thermoplastic conductive coating and an alloy coating, that is, the conductive coating of the photovoltaic welding ribbon includes a thermoplastic conductive coating segment and an alloy coating segment.

[0027] In the utility model, the thermoplastic conductive coating is mainly composed of a substrate and conductive particles. The substrate is generally made of polyolefin; the conductive particles are metal powders with a diameter of 5 to 20 μm, and are made of copper, nickel, silver, etc. The melting temperature of the thermoplastic conductive coating can be adjusted between 130°C and 200°C by controlling the raw material and ratio of the thermoplastic conductive coating to meet the requirements of bonding the coating to the edge of the battery cell.

[0028] Specifically, Figure 2 As shown, the surface of the soldering strip with segmented thermoplastic conductive coating of the utility model between the last soldering pad PAD point of the previous battery sheet and the first soldering pad PAD point of the next battery sheet is replaced by a thermoplastic conductive coating (such as Figure 2 The dark part between the cells), the rest of the solder strip is coated with an alloy coating (such as Figure 2 That is, the conductive coating of the present invention comprises a thermoplastic conductive coating segment and an alloy coating segment, the alloy coating segment is arranged on both sides of the thermoplastic conductive coating segment, and the thermoplastic conductive coating segment is arranged between adjacent pads of two battery cells connected in series.

[0029] In addition, if Figure 2 As shown, it shows two adjacent cells, where the gray rectangular portion on the left is the first cell, and the gray rectangular portion on the right is the second cell, and the two cells are electrically connected via a photovoltaic ribbon. Figure 2 As shown, the photovoltaic welding ribbon adopts different conductive coatings in the part between the two cells and the part inside the cell. Specifically, the part between the first cell and the second cell adopts a thermoplastic conductive coating, and the inside of the cell adopts an alloy coating.

[0030] So set up, such as Figure 3As shown, when the cells are connected in series, the thermoplastic conductive coating can be directly attached to the transparent conductive oxide layer TCO layer on the surface of the solar cell, and the thermoplastic conductive coating melts at a certain temperature, and after solidification, it can form a mechanical bond and electrical connection with the TCO layer. In addition, the melting temperature of the thermoplastic conductive coating welding strip can be adjusted between 130°C and 200°C by changing the raw material and ratio of the thermoplastic coating. This can reduce material costs and reduce the string welding temperature.

[0031] That is, in the present invention, a transparent conductive oxide layer is provided on the surface of the cell, and the thermoplastic conductive coating is in direct contact with the transparent conductive oxide layer. On the other hand, a metal electrode is provided on the surface of the cell, and the alloy coating is connected to the metal electrode. The reason for such a setting is that the alloy coating is more firmly connected to the metal electrode, but not firmly connected to the TCO layer. Therefore, in the present invention, a thermoplastic conductive coating is used to connect to the transparent conductive oxide layer, thereby providing a firm mechanical and electrical connection.

[0032] The above is only a specific implementation of the utility model, but the protection scope of the utility model is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the utility model should be included in the protection scope of the utility model. Therefore, the protection scope of the utility model should be based on the protection scope of the claims.

Claims

1. A photovoltaic welding ribbon with a segmented thermoplastic conductive coating, characterized in that: include: Copper core; a silver layer covering the copper core; as well as A conductive coating covering the silver layer, wherein The conductive coating comprises a thermoplastic conductive coating segment and an alloy coating segment. The alloy coating segment is arranged on both sides of the thermoplastic conductive coating segment, and the thermoplastic conductive coating segment is arranged between adjacent pads of two battery cells connected in series.

2. The photovoltaic welding ribbon with segmented thermoplastic conductive coating according to claim 1, characterized in that: The alloy coating is a SnPb alloy coating or a SnBi alloy coating.

3. The photovoltaic welding ribbon with segmented thermoplastic conductive coating according to claim 1, characterized in that: A transparent conductive oxide layer is disposed on the surface of the cell, and the thermoplastic conductive coating is in direct contact with the transparent conductive oxide layer.

4. The photovoltaic welding ribbon with segmented thermoplastic conductive coating according to claim 3, characterized in that: A metal electrode is disposed on the surface of the battery cell, and the alloy coating is connected to the metal electrode.

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