Photovoltaic module

Abstract

Provided in the present disclosure is a photovoltaic module. The photovoltaic module comprises: a solar cell, which has grid lines provided on the surface thereof; a solder ribbon, which is located on the side of the grid lines away from the solar cell; a first intermetallic compound layer, which is located between the surface of the solar cell and the solder ribbon and is formed by means of soldering a first solder paste to the grid lines; and a second intermetallic compound layer, which is located between the first intermetallic compound layer and the solder ribbon and is formed by means of soldering the first solder paste to the solder ribbon. By means of the present disclosure, since the photovoltaic module having the first intermetallic compound layer and the second intermetallic compound layer has excellent soldering pull strength, mass production can be realized; and the problem of the mass production of photovoltaic modules being affected by an excessively wide or narrow soldering window is solved.

Description

Photovoltaic module

[0001] Cross-reference to related applications

[0002] The present disclosure claims priority to the Chinese patent application No. 202422258570.2, filed on September 13, 2024, and entitled “Photovoltaic module”, the entire content of which is incorporated herein by reference. TECHNICAL FIELD

[0003] The present disclosure relates to the technical field of photovoltaic cells, in particular, to a photovoltaic module. BACKGROUND

[0004] In the preparation process of photovoltaic cells, solder strips, grid lines and solder paste are key components of photovoltaic cells. The solder paste is usually used for welding between the grid lines of the cell and the solder strips to form a stable electrical connection.

[0005] In order to realize the welding of the solder strip and the grid line, the existing photovoltaic cell usually adopts low-temperature solder paste + low-temperature solder strip welding material for matching, or adopts high-temperature solder paste + high-temperature solder strip welding material for matching.

[0006] Specifically, in the case of using low-temperature solder paste + low-temperature solder strip welding material matching, the welding temperature in the welding process is low, the lower the welding temperature, the slower the welding reaction speed, the wider the process window, but the longer the welding time, which affects the production rhythm. And the low-temperature material itself has low welding tension, which affects the reliability.

[0007] In the case of using high-temperature solder paste + high-temperature solder strip welding material matching, the welding temperature in the welding process is high, the welding reaction is fast, and the efficiency is high. However, for the current mainstream no-busbar cell, it has too many and small welding points, and the welding time is not easy to control. High temperature can easily cause overwelding, affecting the reliability, the welding window is narrow, and the mass production feasibility is low.

[0008] DISCLOSURE

[0009] The main purpose of the present disclosure is to provide a photovoltaic module to solve the problem of affecting the mass production of the photovoltaic module due to the too wide or too narrow welding window in the prior art.

[0010] In order to achieve the above-mentioned purpose, according to one aspect of the present disclosure, a photovoltaic module is provided, comprising: a cell, the surface of the cell having a grid line; a solder strip located on the side of the grid line away from the cell; a first interlayer compound layer located between the surface of the cell and the solder strip, and the first interlayer compound layer being formed by a first solder paste and the grid line; a second interlayer compound layer located between the first interlayer compound layer and the solder strip, and the second interlayer compound layer being formed by the first solder paste and the solder strip, the melting temperature of the material of the first solder paste being different from the melting temperature of the material of the solder strip.

[0011] In some embodiments, the solder ribbon includes a solder core and a plated tin alloy layer located at the outer periphery of the solder core, and the melting point of the plated tin alloy layer is lower than the melting point of the first tin paste.

[0012] In some embodiments, the photovoltaic module further includes a second tin paste located between the first tin paste and the solder ribbon, and the melting point of the second tin paste is lower than the melting point of the first tin paste.

[0013] In some embodiments, the melting point of the second tin paste is lower than the melting point of the solder ribbon.

[0014] In some embodiments, the melting point of the first tin paste is higher than the melting point of the solder ribbon, and the difference between the melting points of the solder ribbon and the first tin paste is greater than 30℃.

[0015] In some embodiments, the melting point of the solder ribbon is 130-155℃.

[0016] In some embodiments, the melting point of the first tin paste is 160-195℃.

[0017] In some embodiments, the melting point of the grid line is higher than the melting point of the first tin paste.

[0018] In some embodiments, the first interlayer compound layer and the second interlayer compound layer are different.

[0019] In some embodiments, the photovoltaic module further includes a front plate located at the side of the cell away from the solder ribbon, and a back plate located at the side of the solder ribbon away from the cell.

[0020] According to the technical solution of the present disclosure, a photovoltaic module includes a cell, a solder strip, a first interlayer compound layer and a second interlayer compound layer. The first interlayer compound layer is formed by soldering the cell and the grid line through the first solder paste. The second interlayer compound layer is formed by soldering the cell and the solder strip through the first solder paste. Specifically, the cell has a grid line on its surface. The solder strip can be located on the side of the grid line away from the cell. The first interlayer compound layer can be located between the surface of the cell and the solder strip. The second interlayer compound layer can be located between the first interlayer compound layer and the solder strip, thereby realizing the electrical connection between the solder strip and the cell. As can be seen, after the first solder paste and the grid line are soldered in the photovoltaic module of the present disclosure, the first solder paste and the grid line can form the first interlayer compound layer, so that the first interlayer compound layer can be located between the grid line and the first solder paste first. Then, the soldering of the first solder paste and the solder strip can form the second interlayer compound layer, so that the second interlayer compound layer is located between the first interlayer compound layer and the solder strip. It can be understood that the formation of the interlayer compound can affect the fluidity and wettability of the soldering material, that is, in the formation process of the first interlayer compound layer and the second interlayer compound layer, the solder can fully fill the solder joint, so that the first interlayer compound layer can improve the soldering tension between the first solder paste and the grid line, and the second interlayer compound layer can improve the soldering tension between the first solder paste and the solder strip or between the first interlayer compound layer and the solder strip. In addition, since the melting temperatures of the two materials corresponding to the first solder paste and the solder strip are different, the first interlayer compound layer and the second interlayer compound layer can be formed by step soldering. Moreover, in the process of step soldering, the low-temperature material is placed after the high-temperature material is soldered, thereby reducing the influence of different soldering temperatures on the soldering of the low-temperature material and avoiding over-soldering of the low-temperature material under high-temperature conditions. Therefore, the photovoltaic module with the above-mentioned first interlayer compound layer and second interlayer compound layer in the present disclosure has good soldering tension, so that mass production can be realized. That is, through the present disclosure, the problem of affecting the mass production of photovoltaic modules due to excessively wide or narrow soldering window is solved. BRIEF DESCRIPTION OF DRAWINGS

[0021] The accompanying drawings, which form a part of the present disclosure, are used to provide a further understanding of the present disclosure, and the illustrative embodiments of the present disclosure and their descriptions serve to explain the present disclosure. The accompanying drawings in the present disclosure are as follows:

[0022] FIG. 1 shows a soldering schematic diagram of a grid line and a solder strip of a photovoltaic module according to an embodiment of the present disclosure;

[0023] FIG. 2 shows a cross-sectional structure schematic diagram of a photovoltaic module according to an embodiment of the present disclosure.

[0024] In the above figure, the following reference signs are included: 100, battery piece; 10, grid line; 20, first tin paste; 30, solder strip; 40, first interlayer compound layer; 50, second interlayer compound layer; 60, front plate; 70, back plate; 80, front adhesive film; 90, back adhesive film. DETAILED DESCRIPTION

[0025] It should be noted that the following detailed description is exemplary in nature and is intended to provide further description of the present disclosure. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

[0026] It is to be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments in accordance with the present disclosure. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, steps, operations, elements, components, and / or groups thereof, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof.

[0027] It will be understood that when an element such as a layer, film, region, or substrate is referred to as being "on" another element, it can be directly on the other element or intervening elements can also be present. In addition, it will be understood that when an element is referred to as being "connected" to another element, it can be directly connected to the other element, or electrically connected to the other element via a third element.

[0028] As introduced in the background, in order to realize the welding of the solder strip and the grid line, the existing photovoltaic cell usually adopts the welding material of low-temperature tin paste + low-temperature solder strip for matching, or adopts the welding material of high-temperature tin paste + high-temperature solder strip for matching. Specifically, in the case of using the welding material of low-temperature tin paste + low-temperature solder strip for matching, the welding temperature in the welding process is low, the welding reaction speed is slower, the process window is wide, but the welding time is long, which affects the production rhythm. Moreover, the low-temperature material itself has low welding tension, which affects the reliability. In the case of using the welding material of high-temperature tin paste + high-temperature solder strip for matching, the welding temperature in the welding process is high, the welding reaction is fast, and the efficiency is high. However, for the current mainstream no-grid battery piece, the welding points are too many and small, and the welding time is not easy to control, which is easy to cause overwelding under high temperature, affecting the reliability, the welding window is narrow, and the mass production feasibility is low. In order to solve the problem of affecting the mass production of photovoltaic modules due to the too wide or too narrow welding window in the prior art, the present disclosure provides a photovoltaic module.

[0029] In combination with FIG. 1 and FIG. 2, in some optional embodiments, a photovoltaic module can include: a cell sheet 100, a surface of the cell sheet 100 having a grid line 10; a solder strip 30, located on a side of the grid line 10 away from the cell sheet 100; a first interlayer compound layer 40, located between the surface of the cell sheet 100 and the solder strip 30, and the first interlayer compound layer 40 being formed by soldering through a first tin paste 20 and the grid line 10; a second interlayer compound layer 50, located between the first interlayer compound layer 40 and the solder strip 30, and the first interlayer compound layer 40 being formed by soldering through the first tin paste 20 and the solder strip 30, a melting temperature of a material of the first tin paste 20 being different from a melting temperature of a material of the solder strip 30.

[0030] Specifically, in the above embodiments, the cell sheet 100 can include any one of a crystalline silicon cell sheet, a perovskite cell sheet, and a crystalline silicon / perovskite laminated cell sheet. Exemplarily, the crystalline silicon cell sheet can include, but is not limited to, an interdigitated back contact cell sheet (IBC), a heterojunction cell sheet (HJT), a passivated emitter rear contact cell sheet (PERC), and a tunnel oxide passivated contact cell sheet (TOPCon).

[0031] Specifically, the grid line 10 can be at least one of a main grid and a sub-grid of the cell sheet 100.

[0032] Specifically, the grid line 10 is a conductive circuit on the cell sheet 100 for collecting current, and a forming material thereof can include, but is not limited to, at least one of silver, copper, and aluminum. Optionally, the grid line 10 can be printed on the surface of the cell sheet 100 by a screen printing technology. Optionally, the grid line 10 on the surface of the cell sheet 100 can form a grid-like structure, thereby improving the conductivity and current collection efficiency of the cell sheet 100.

[0033] Specifically, the width of the grid line 10, the spacing between two adjacent grid lines 10, and the number of grid lines 10, etc. are not specifically limited in the present disclosure, and can be reasonably set by those skilled in the art according to actual needs.

[0034] Specifically, the solder strip 30 is a conductive material for connecting the cell sheet 100 and an external circuit, and a forming material thereof can include, but is not limited to, at least one of copper, aluminum, and tin. Optionally, the solder strip 30 can be fixed on the surface of the cell sheet 100 by soldering. Optionally, the soldering of the solder strip 30 can use any one of ultrasonic welding, hot air welding, and laser welding technology.

[0035] Specifically, the width of the solder strip 30, the spacing between two adjacent solder strips 30, and the number of solder strips 30, etc. are not specifically limited in the present disclosure, and can be reasonably set by those skilled in the art according to actual needs.

[0036] Specifically, the first solder paste 20 can be a paste-like substance containing metallic tin and other metals (e.g., lead or silver) for metal connection in the soldering process.

[0037] Specifically, the first interlayer compound layer 40 and the second interlayer compound layer 50 are formed in stages, i.e., the first interlayer compound layer 40 and the second interlayer compound layer 50 are soldered in different steps.

[0038] Alternatively, soldering of the first solder paste 20 and the gate line 10 can be performed first. At this time, the first solder paste 20 is heated and melted, the tin in the first solder paste 20 can come into contact with the gate line 10, the tin in the first solder paste 20 starts to diffuse into the surface of the gate line 10, and at the same time, atoms of the gate line 10 can also diffuse into the first solder paste 20, so that the tin in the first solder paste 20 can chemically react with the atoms of the gate line 10 at the contact interface to form a new compound, and then the first solder paste 20 cools and completes soldering. The above-mentioned new compound, i.e., the first interlayer compound layer 40, is also formed between the gate line 10 and the first solder paste 20. It is mentioned here that the corresponding compound of the first interlayer compound layer 40 is a fixed proportion combination of tin and atoms of the gate line 10, usually having a specific chemical composition and crystal structure.

[0039] Alternatively, after the formation of the above-mentioned first interlayer compound layer 40, the solder strip 30 is placed, and soldering of the first solder paste 20 and the solder strip 30 can be performed to form the second interlayer compound layer 50. It should be noted that different soldered materials (copper, silver, aluminum, nickel, etc.) have different reactivity with the first solder paste 20, which will affect the formation type of the interlayer compound. Therefore, in the case that the materials of the solder strip 30 and the gate line 10 are different, the types of the first interlayer compound layer 40 and the second interlayer compound layer 50 can be different, i.e., the above-mentioned first interlayer compound layer 40 and the above-mentioned second interlayer compound layer 50 can be different. However, it can be understood that the materials of the first interlayer compound layer 40 and the second interlayer compound layer 50 are both alloy materials, wherein the alloy material corresponding to the first interlayer compound layer 40 can be an alloy composed of the metal elements in the first solder paste 20 and the metal elements in the gate line 10, and the alloy material corresponding to the second interlayer compound layer 50 can be an alloy composed of the metal elements in the first solder paste 20 and the metal elements in the solder strip 30. And it should be noted that the above-mentioned second interlayer compound layer 50 can be located between the first solder paste 20 and the solder strip 30; or the second interlayer compound layer 50 can penetrate the remaining first solder paste 20 after the formation of the first interlayer compound layer 40, so that the above-mentioned second interlayer compound layer 50 can be located between the first interlayer compound layer 40 and the solder strip 30.

[0040] In the above embodiments of the present disclosure, a photovoltaic module includes a cell 100, a solder strip 30, a first interlayer compound layer 40 and a second interlayer compound layer 50, the first interlayer compound layer 40 is formed by soldering the first solder paste 20 and the grid line 10, the second interlayer compound layer 50 is formed by soldering the first solder paste 20 and the solder strip 30, and the first solder paste 20 is used to solder the cell 100 and the solder strip 30. Specifically, the surface of the cell 100 has the grid line 10, the solder strip 30 can be located on the side of the grid line 10 away from the cell 100, the first interlayer compound layer 40 can be located between the surface of the cell 100 and the solder strip 30, and the second interlayer compound layer 50 can be located between the first interlayer compound layer 40 and the solder strip 30, so as to realize the electrical connection between the solder strip 30 and the cell 100. It can be seen that, after the first solder paste 20 and the grid line 10 are soldered in the photovoltaic module of the present disclosure, the first solder paste 20 and the grid line 10 can form the first interlayer compound layer 40, so that the first interlayer compound layer 40 can be first located between the grid line 10 and the first solder paste 20. Then the solder strip 30 is placed, and the soldering of the first solder paste 20 and the solder strip 30 can form the second interlayer compound layer 50, so that the second interlayer compound layer 50 is located between the first interlayer compound layer 40 and the solder strip 30. It can be understood that the formation of the interlayer compound can affect the fluidity and wettability of the soldering material, that is, in the formation process of the first interlayer compound layer 40 and the second interlayer compound layer 50, the solder can fully fill the solder joint, so that the first interlayer compound layer 40 can improve the soldering tensile force between the first solder paste 20 and the grid line 10, and the second interlayer compound layer 50 can improve the soldering tensile force between the first solder paste 20 and the solder strip 30 or between the first interlayer compound layer 40 and the solder strip 30; in addition, since the melting temperatures of the two materials corresponding to the first solder paste 20 and the solder strip 30 are different, the first interlayer compound layer 40 and the second interlayer compound layer 50 can be formed by step-by-step soldering, and since the low-temperature material is placed after the high-temperature material is soldered in the process of step-by-step soldering, the influence of different soldering temperatures on the soldering of the low-temperature material is reduced, and over-soldering of the low-temperature material under high-temperature conditions is avoided. Therefore, the photovoltaic module with the above-mentioned first interlayer compound layer 40 and second interlayer compound layer 50 in the present disclosure has good soldering tensile force, so that mass production can be realized, that is, through the present disclosure, the problem of affecting the mass production of photovoltaic modules due to the excessively wide or narrow soldering window is solved.

[0041] In some optional embodiments, the solder strip 30 includes a solder core and a tin-plated alloy layer (not shown in the figure) located at the outer periphery of the solder core, and the melting point of the tin-plated alloy layer is lower than the melting point of the first solder paste 20.

[0042] Optionally, the solder core can be copper.

[0043] Specifically, after the first solder paste 20 and the grid line 10 are first soldered, since the first solder paste 20 has cooled, in order to solder the above-mentioned battery piece 100 and the solder strip 30, the present disclosure coats the solder core with a tin-plated alloy layer on the outer periphery and places the solder strip 30 so that the solder strip 30 is in contact with the first solder paste 20, since the melting point of the tin-plated alloy layer is lower than the melting point of the first solder paste 20, during the soldering process of the battery piece 100 and the solder strip 30, the tin-plated alloy layer on the solder strip 30 can be heated to melt, at this time, the tin in the first solder paste 20 can be melted again and mixed with the metal components in the tin-plated alloy layer, and the tin in the tin-plated alloy layer can diffuse into the surface of the solder core, at the same time, the atoms of the solder core can also enter the tin-plated alloy layer, so that the tin in the tin-plated alloy layer and the tin in the first solder paste 20 can chemically react with the atoms of the solder core at the contact interface to form a new compound, and then the tin-plated alloy layer cools and completes the soldering. The above-mentioned new compound, i.e. the second interlayer compound layer 50, is also formed between the first solder paste 20 and the solder strip 30; or the second interlayer compound layer 50 can be formed between the first interlayer compound layer 40 and the solder strip 30. Similarly, it is mentioned here that the corresponding compound of the second interlayer compound layer 50 is a fixed proportion combination of tin and atoms of the solder core, which usually has a specific chemical composition and crystal structure.

[0044] Here, for the case that the second interlayer compound layer 50 is fixed between the first interlayer compound layer 40 and the solder strip 30, it is further explained that in the process of forming the second interlayer compound layer 50, the remaining tin in the first solder paste 20 can be used to form the second interlayer compound layer 50, i.e. the remaining first solder paste 20 after the formation of the first interlayer compound layer 40 can be completely consumed in the process of forming the second interlayer compound layer 50, so that the first interlayer compound layer 40 and the second interlayer compound layer 50 are in contact or at least partially overlap.

[0045] It should be noted that the materials of the above-mentioned first solder paste 20 and the tin-plated alloy layer can include tin and other metal components (lead, silver, copper and antimony, etc.), so that in the process of soldering the first solder paste 20 and the grid line 10, the above-mentioned other metal components in the first solder paste 20 will also affect the formation of the first interlayer compound layer 40 and affect the compound type of the first interlayer compound layer 40; and in the process of soldering the solder strip 30 and the battery piece 100, the above-mentioned other metal components in the tin-plated alloy layer will also affect the formation of the second interlayer compound layer 50 and affect the compound type of the second interlayer compound layer 50.

[0046] In the above embodiment, the first solder paste 20 has a higher melting point, and the tin-plated alloy layer has a lower melting point. Therefore, the overall temperature of the soldering between the first solder paste 20 and the grid line 10 is higher during the soldering process, while the overall temperature of the soldering between the tin-plated alloy layer on the solder strip 30 and the battery piece 100 is lower after the solder strip 30 is placed. Moreover, the soldering process between the solder strip 30 and the battery piece 100 is divided into two stages in sequence, i.e., the first soldering stage of the first solder paste 20 and the grid line 10 and the second soldering stage of the tin-plated alloy layer and the battery piece 100. Therefore, for the entire photovoltaic module, the low temperature in the second soldering stage can neutralize the soldering problems caused by the high temperature in the first soldering stage, and the high temperature in the first soldering stage can neutralize the soldering problems caused by the low temperature in the second soldering stage. Thus, based on the formation of the first interlayer compound layer 40 and the second interlayer compound layer 50, the temperature difference between the first solder paste 20 and the tin-plated alloy layer further improves the soldering tension between the solder strip 30 and the grid line 10 in the photovoltaic module.

[0047] In some optional embodiments, as shown in FIG. 1, the photovoltaic module can further include a second solder paste (not shown in the figure), which can be located between the first solder paste 20 and the solder strip 30, and the melting point of the second solder paste is lower than that of the first solder paste 20.

[0048] Specifically, as shown in FIG. 2, the photovoltaic module includes a battery piece 100, a solder strip 30, a first solder paste 20, and a second solder paste.

[0049] On this basis, in combination with FIGS. 1 and 2, in an exemplary embodiment, the solder strip 30 can be a copper solder strip. At this time, the solder strip 30 is located on the side of the grid line 10 on the surface of the battery piece 100 away from the battery piece 100, the first solder paste 20 is located between the surface of the battery piece 100 and the solder strip 30, the second solder paste is located between the first solder paste 20 and the solder strip 30, the first interlayer compound layer 40 is formed between the first solder paste 20 and the grid line 10, and the second interlayer compound layer 50 is formed between the second solder paste and the solder strip 30. It can be understood that, in the case where the first solder paste 20 contains metal elements different from those in the second solder paste, an interlayer compound layer can also be formed between the first solder paste 20 and the second solder paste.

[0050] In another exemplary embodiment, in combination with FIG. 1 and FIG. 2, the solder strip 30 can be a solder strip containing tin alloy. For example, the solder strip 30 in this embodiment includes a solder core and a tin alloy plating layer surrounding the solder core. At this time, the solder strip 30 is located on the surface of the battery sheet 100 away from the side of the battery sheet 100, and the tin alloy plating layer of the solder strip 30 is located between the surface of the battery sheet 100 and the solder core of the solder strip 30. The second tin paste (not shown in the figure) is located between the surface of the battery sheet 100 and the tin alloy plating layer of the solder strip 30, the first tin paste 20 is located between the surface of the battery sheet 100 and the second tin paste, the first tin paste 20 and the grid line 10 have a first interlayer compound layer 40, and the second tin paste and the solder strip 30 have a second interlayer compound layer 50. It can be understood that in the case of different metal elements in the first tin paste 20, the tin alloy plating layer and the second tin paste, the interlayer compound layer can also be formed between the first tin paste 20 and the second tin paste, and the interlayer compound layer can also be formed between the tin alloy plating layer and the second tin paste.

[0051] Based on the principle that the melting point of the tin alloy plating layer is lower than the melting point of the first tin paste 20, similarly, the melting point of the second tin paste can be lower than the melting point of the first tin paste 20, which will not be described here.

[0052] In addition, in the case of simultaneously involving the tin alloy plating layer and the second tin paste in the process of manufacturing the photovoltaic module, the melting point of the tin alloy plating layer can be higher than or equal to the melting point of the second tin paste. In other words, the tin alloy plating layer can have the same composition as the second tin paste, at this time the melting point of the tin alloy plating layer can be equal to the melting point of the second tin paste; the tin alloy plating layer can have different composition from the second tin paste, and the melting point of the tin alloy plating layer can be higher than the melting point of the second tin paste, that is, the melting point of the second tin paste can be lower than the melting point of the solder strip 30.

[0053] In some optional embodiments, in the case that the melting point of the first tin paste 20 is higher than the melting point of the solder strip 30, the difference between the melting points of the solder strip 30 and the first tin paste 20 is greater than 30℃. At this time, the two soldering stages corresponding to the formation of the first interlayer compound layer 40 and the second interlayer compound layer 50 have a large temperature difference interval, so that they can neutralize the soldering problems different from their own formation stages, thereby improving the overall soldering tension of the photovoltaic module.

[0054] Exemplarily, as shown in FIG. 1, the melting point of the solder strip 30 can be 130-155℃.

[0055] Exemplarily, as shown in FIG. 1, the melting point of the first tin paste 20 can be 160-195℃.

[0056] Optionally, as shown in FIG. 1, the melting point of the grid line 10 can be higher than the melting point of the first tin paste 20.

[0057] Optionally, as shown in FIG. 2, the above photovoltaic module can further comprise: a front plate 60 located on the side of the cell sheet 100 away from the solder strip 30; and a back plate 70 located on the side of the solder strip 30 away from the cell sheet 100.

[0058] Specifically, the front plate 60 and the cell sheet 100 can be bonded by a front adhesive film 80, so that the front plate 60 is located on the side of the cell sheet 100 away from the solder strip 30, and the back plate 70 can be bonded by a back adhesive film 90, so that the back plate 70 is located on the side of the solder strip 30 away from the cell sheet 100.

[0059] Illustratively, the front plate 60 and the back plate 70 can be glass.

[0060] Specifically, the following gives a welding implementation of the grid lines and solder strips in a photovoltaic module:

[0061] First, according to the electrical design, high-temperature tin paste is printed on the cell sheet at the places where welding is needed, so that the printed cell sheet completes the welding of the fine grid and the tin paste. The welding form is heating, and the heating treatment form is not limited, and an oven or an oven heating platform device can be used, the temperature is 160-200℃, and the time is 1-15s. Optionally, the oven heating platform device has good uniformity, short time, and improves the production efficiency. After high-temperature treatment, the cell sheet metal grid line and the high-temperature tin paste complete the first welding in the high-temperature environment to form the first intermetallic compound layer (first IMC layer). The cell sheet metal grid line can be a metal material with good conductivity, such as silver, copper, aluminum, and tin. Then, the pre-processed cell sheet and the solder strip are welded at low temperature to form a cell string, and the welding temperature is 140-160℃. The welding form is not limited, and can be low-temperature string welding or lamination welding. When the low-temperature string welding process is adopted, the front plate / glass, the front adhesive film, the welded cell string, the back adhesive film, and the back plate / glass are sequentially stacked, and then laminated to form a laminated part, and then the junction box and the frame are installed to form a photovoltaic module. When the lamination welding process is adopted, the cell sheet and the solder strip are laid on the combination of the front plate / glass and the front adhesive film, only the relative position is positioned, and no welding is performed, the back adhesive film and the back plate / glass are laid, and then laminated, and the welding of the solder strip and the cell sheet is completed in the lamination process to form an electrically conductive and laminated part. Finally, the junction box and the frame are installed to the laminated part to form a photovoltaic module. Thus, through the above two-stage welding process, the welding requirements of different stages are solved, the welding tension is ensured, the welding window is eliminated, the problem of wide or narrow welding process window affecting mass production is solved, and the problem of different welding temperature requirements of each stage leading to virtual welding / overwelding is also solved.

[0062] From the above description, it can be seen that the above embodiments of the present disclosure achieve the following technical effects:

[0063] The photovoltaic module provided by the present disclosure includes a cell, a solder strip, a first interlayer compound layer and a second interlayer compound layer. The first interlayer compound layer is formed by soldering the first tin paste and the grid line, and the second interlayer compound layer is formed by soldering the first tin paste and the solder strip. The first tin paste is used for soldering the cell and the solder strip. Specifically, the surface of the cell has a grid line, the solder strip can be located on the side of the grid line away from the cell, the first interlayer compound layer can be located between the surface of the cell and the solder strip, and the second interlayer compound layer can be located between the first interlayer compound layer and the solder strip, so as to realize the electrical connection of the solder strip and the cell. It can be seen that after the first tin paste and the grid line of the photovoltaic module in the present disclosure are soldered, the first tin paste and the grid line can form the first interlayer compound layer, so that the first interlayer compound layer can be located between the grid line and the first tin paste first. Further, the soldering of the first tin paste and the solder strip can form the second interlayer compound layer, so that the second interlayer compound layer is located between the first interlayer compound layer and the solder strip. It can be understood that the formation of the interlayer compound can affect the fluidity and wettability of the soldering material, that is, in the formation process of the first interlayer compound layer and the second interlayer compound layer, the solder can fully fill the solder joint, so that the first interlayer compound layer can improve the soldering tension between the first tin paste and the grid line, and the second interlayer compound layer can improve the soldering tension between the first tin paste and the solder strip or between the first interlayer compound layer and the solder strip. In addition, since the melting temperatures of the two materials corresponding to the first tin paste and the solder strip are different, the first interlayer compound layer and the second interlayer compound layer can be formed by step-by-step soldering, and since the low-temperature material is placed after the high-temperature material is soldered in the process of step-by-step soldering, the influence of different soldering temperatures on the soldering of the low-temperature material is reduced, and over-soldering of the low-temperature material under high-temperature conditions is avoided. Therefore, the photovoltaic module with the above-mentioned first interlayer compound layer and second interlayer compound layer in the present disclosure has good soldering tension, so that mass production can be realized, that is, through the present disclosure, the problem of affecting the mass production of the photovoltaic module due to the excessively wide or narrow soldering window is solved.

[0064] The above only describes the preferred embodiments of the present disclosure and is not intended to limit the present disclosure. Those skilled in the art can make various modifications and changes to the present disclosure. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present disclosure shall be included in the protection scope of the present disclosure.

Claims

1. A photovoltaic module comprising: a cell sheet, a surface of the cell sheet having a grid line; a solder strip, located on a side of the grid line away from the cell sheet; a first interlayer compound layer, located between the surface of the cell sheet and the solder strip, and formed by soldering the first tin paste and the grid line; a second interlayer compound layer, located between the first interlayer compound layer and the solder strip, and formed by soldering the first tin paste and the solder strip, a material of the first tin paste having a melting temperature different from a material of the solder strip.

2. The photovoltaic module of claim 1, wherein, the solder strip includes a solder core and a plated tin alloy layer located on a periphery of the solder core, the plated tin alloy layer having a melting point lower than a melting point of the first tin paste.

3. The photovoltaic module of claim 1, wherein, the photovoltaic module further comprises: a second tin paste, located between the first tin paste and the solder strip, and having a melting point lower than a melting point of the first tin paste.

4. The photovoltaic module of claim 3, wherein, the second tin paste has a melting point lower than a melting point of the solder strip.

5. The photovoltaic module according to any of claims 1 to 4, wherein, the first tin paste has a melting point higher than a melting point of the solder strip, and a difference between the melting points of the solder strip and the first tin paste is greater than 30°C.

6. The photovoltaic module of claim 5, wherein, the solder strip has a melting point of 130-155°C.

7. The photovoltaic module of claim 5, wherein, the first tin paste has a melting point of 160-195°C.

8. The photovoltaic module of any of claims 1 to 4, wherein, the grid line has a melting point higher than a melting point of the first tin paste.

9. The photovoltaic module of any of claims 1 to 4, wherein, the first interlayer compound layer and the second interlayer compound layer are different.

10. The photovoltaic module of any of claims 1 to 4, wherein, the photovoltaic module further comprises: a front sheet, located on a side of the cell sheet away from the solder strip; a back sheet, located on a side of the solder strip away from the cell sheet.

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