Photovoltaic module

Abstract

The utility model provides a photovoltaic module. The photovoltaic module comprises a battery piece, wherein the surface of the battery piece is provided with grid lines; the welding strip is positioned on one side of the grid line far away from the battery piece; the first interlayer compound layer is located between the surface of the battery piece and the welding strip, and the first interlayer compound layer is formed by welding a first solder paste and a grid line; the second interlayer compound layer is located between the first interlayer compound layer and the welding strip, and the second interlayer compound layer is formed by welding the first solder paste and the welding strip. Through the application, the photovoltaic module with the first interlayer compound layer and the second interlayer compound layer has good welding tension, so that mass production can be realized, and the problem that the mass production of the photovoltaic module is affected due to the fact that a welding window is too wide or too narrow is solved.

Description

Technical Field

[0001] The present application relates to the technical field of photovoltaic cells, and in particular to a photovoltaic module. Background Art

[0002] In the preparation process of photovoltaic cells, solder ribbons, grid lines and solder paste are key components of photovoltaic cells. Among them, solder paste is usually used to weld between the grid lines of the cell and the solder ribbons to form a stable electrical connection.

[0003] In order to achieve welding of the welding ribbon and the grid line of the existing photovoltaic cells, a combination of low-temperature solder paste and low-temperature solder ribbon is usually used, or a combination of high-temperature solder paste and high-temperature solder ribbon is used.

[0004] Specifically, when using a combination of low-temperature solder paste and low-temperature solder ribbon, the soldering temperature during the soldering process is relatively low. The lower the soldering temperature, the slower the soldering reaction speed, widening the process window, but also increasing soldering time, impacting production cycle time. Furthermore, the low-temperature material itself has low soldering tensile strength, affecting reliability.

[0005] When using a combination of high-temperature solder paste and high-temperature solder ribbon, the welding temperature is high, the welding reaction is fast, and the efficiency is high. However, for the current mainstream busbarless solar cells, there are too many small solder points, the welding time is difficult to control, and high temperatures can easily cause over-soldering, affecting reliability. The welding window is narrow, and the feasibility of mass production is low. Utility Model Content

[0006] The main purpose of the present application is to provide a photovoltaic module to solve the problem in the prior art that the mass production of photovoltaic modules is affected by the welding window being too wide or too narrow.

[0007] In order to achieve the above-mentioned purpose, according to one aspect of the present application, a photovoltaic module is provided, including: a solar cell, wherein the surface of the solar cell has a grid line; a solder strip, located on the side of the grid line away from the solar cell; a first interlayer compound layer, located between the surface of the solar cell and the solder strip, and the first interlayer compound layer is 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 is formed by the first solder paste and the solder strip, and the melting temperature of the material of the first solder paste is different from the melting temperature of the material of the solder strip.

[0008] Optionally, the soldering ribbon includes a solder core and a tin-plated alloy layer located on the 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.

[0009] Optionally, the photovoltaic module further includes: a second solder paste located between the first solder paste and the soldering ribbon, and the melting point of the second solder paste is lower than the melting point of the first solder paste.

[0010] Optionally, the melting point of the second solder paste is lower than the melting point of the solder ribbon.

[0011] Optionally, the melting point of the first solder paste is higher than the melting point of the solder strip, and the difference in melting point between the solder strip and the first solder paste is greater than 30°C.

[0012] Optionally, the melting point of the soldering ribbon is 130-155°C.

[0013] Optionally, the melting point of the first solder paste is 160-195°C.

[0014] Optionally, the melting point of the gate line is higher than the melting point of the first solder paste.

[0015] Optionally, the first interlayer compound layer and the second interlayer compound layer are different.

[0016] Optionally, the photovoltaic module further includes: a front plate, located on a side of the cell away from the welding strip; and a back plate, located on a side of the welding strip away from the cell.

[0017] Applying the technical solution of the present application, a photovoltaic module includes a cell, a soldering ribbon, a first interlayer compound layer, and a second interlayer compound layer. The first interlayer compound layer is formed by welding a first solder paste and a grid line, and the second interlayer compound layer is formed by welding the first solder paste and the soldering ribbon. The first solder paste is used to weld the cell and the soldering ribbon. Specifically, the cell has a grid line on its surface, and the soldering ribbon 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 soldering ribbon, and the second interlayer compound layer can be located between the first interlayer compound layer and the soldering ribbon, thereby achieving an electrical connection between the soldering ribbon and the cell. It can be seen that after the first solder paste and the grid line of the photovoltaic module in the present application are welded, the first solder paste and the grid line can form a first interlayer compound layer, so that the first interlayer compound layer can first be located between the grid line and the first solder paste. Furthermore, the welding of the first solder paste and the soldering ribbon can form a second interlayer compound layer, so that the second interlayer compound layer is located between the first interlayer compound layer and the soldering ribbon. It is understandable that the formation of the interlayer compound can affect the fluidity and wettability of the soldering material, that is, during the formation of the first interlayer compound layer and the second interlayer compound layer, since the solder can fully fill the solder joint, the first interlayer compound layer can increase the welding tension between the first solder paste and the grid line, and the second interlayer compound layer can increase the welding tension between the first solder paste and the solder strip or 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-by-step welding, and since the low-temperature material is placed after the high-temperature material is welded during the step-by-step welding process, the effect of different welding temperatures on the welding of the low-temperature material is reduced, and over-welding 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 this application can be mass-produced because it has good welding tension. That is, through this application, the problem of mass production of photovoltaic modules affected by welding windows that are too wide or too narrow is solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings that constitute part of this application are used to provide a further understanding of this application. The illustrative embodiments of this application and their descriptions are used to explain this application and do not constitute an improper limitation on this application. In the drawings:

[0019] Figure 1 A schematic diagram of welding grid lines and welding ribbons of a photovoltaic module according to an embodiment of the present application is shown;

[0020] Figure 2 A schematic cross-sectional structure diagram of a photovoltaic module according to an embodiment of the present application is shown.

[0021] The above drawings include the following reference numerals:

[0022] 100, battery cell; 10, grid line; 20, first solder paste; 30, solder ribbon; 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

[0023] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present application belongs.

[0024] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0025] It should be understood that when an element (such as a layer, film, region, or substrate) is described as being "on" another element, the element may be directly on the other element or intervening elements may be present. Moreover, in the specification and claims, when it is described that an element is "connected to" another element, the element may be "directly connected to" the other element or "connected to" the other element through a third element.

[0026] As described in the background art, existing photovoltaic cells typically use a combination of low-temperature solder paste and low-temperature solder ribbon, or a combination of high-temperature solder paste and high-temperature solder ribbon, to achieve welding between the solder ribbon and the grid line. Specifically, when using the combination of low-temperature solder paste and low-temperature solder ribbon, the welding temperature during the welding process is relatively low. The lower the welding temperature, the slower the welding reaction speed, and the wider the process window, but the welding time is long, affecting the production cycle. In addition, the low-temperature material itself has low welding tensile strength, which affects reliability. When using the combination of high-temperature solder paste and high-temperature solder ribbon, the welding temperature during the welding process is relatively high, the welding reaction is fast, and the efficiency is high. However, for the current mainstream main grid-less solar cells, they have too many small welding points, the welding time is difficult to control, and over-welding is easily caused at high temperatures, affecting reliability. The welding window is narrow, and the feasibility of mass production is low. Therefore, in order to solve the problem in the prior art that the mass production of photovoltaic modules is affected by an overly wide or narrow welding window, the present application proposes a photovoltaic module.

[0027] Combine Figure 1 and Figure 2As shown, in some optional embodiments, a photovoltaic module may include: a cell 100, wherein the surface of the cell 100 has a grid line 10; a soldering tape 30, located on a side of the grid line 10 away from the cell 100; a first interlayer compound layer 40, located between the surface of the cell 100 and the soldering tape 30, and the first interlayer compound layer 40 is formed by welding a first solder paste 20 and the grid line 10; a second interlayer compound layer 50, located between the first interlayer compound layer 40 and the soldering tape 30, and the first interlayer compound layer 40 is formed by welding a first solder paste 20 and the soldering tape 30, and the melting temperature of the material of the first solder paste 20 is different from the melting temperature of the material of the soldering tape 30.

[0028] Specifically, in the above embodiment, the cell 100 may include any one of a crystalline silicon cell, a perovskite cell, and a crystalline silicon / perovskite stacked cell. Exemplarily, the above crystalline silicon cell may include, but is not limited to, an interdigitated back contact cell (IBC), a heterojunction cell (HJT), a passivated emitter rear cell (PERC), and a tunnel oxide passivated contact cell (TOPCon).

[0029] Specifically, the grid line 10 may be the main grid and / or the auxiliary grid of the battery cell 100 .

[0030] Specifically, the grid lines 10 are conductive lines on the cell 100 for collecting current. The materials used to form the grid lines 10 may include, but are not limited to, at least one of silver, copper, and aluminum. Alternatively, the grid lines 10 may be screen-printed onto the surface of the cell 100. Alternatively, the grid lines 10 on the surface of the cell 100 may form a grid-like structure, thereby improving the conductivity and current collection efficiency of the cell 100.

[0031] Specifically, the present application does not specifically limit the width of the gate lines 10 , the spacing between two adjacent gate lines 10 , and the number of gate lines 10 , and those skilled in the art may reasonably configure them according to actual needs.

[0032] Specifically, the soldering ribbon 30 is used to connect the battery cell 100 to the conductive material of the external circuit. Its material may include, but is not limited to, at least one of copper, aluminum, and tin. Optionally, the soldering ribbon 30 may be fixed to the surface of the battery cell 100 by welding. Optionally, the soldering ribbon 30 may be welded using ultrasonic welding, hot air welding, or laser welding techniques.

[0033] Specifically, the present application does not specifically limit the width of the above-mentioned welding strips 30, the spacing between two adjacent welding strips 30, and the number of welding strips 30. Those skilled in the art can reasonably set them according to actual needs.

[0034] Specifically, the first solder paste 20 may be a paste containing metallic tin and other metals (such as lead or silver), and is used for metal connection during soldering.

[0035] Specifically, the first interlayer compound layer 40 and the second interlayer compound layer 50 are formed in stages, that is, the first interlayer compound layer 40 and the second interlayer compound layer 50 are formed by welding in different steps.

[0036] Optionally, the first solder paste 20 and the gate line 10 can be welded first. At this time, the first solder paste 20 is heated and melted, and the tin in the first solder paste 20 can contact the gate line 10. The tin in the first solder paste 20 begins to diffuse into the surface of the gate line 10. At the same time, the atoms of the gate line 10 may also diffuse into the first solder paste 20, so that the tin in the first solder paste 20 can react chemically with the atoms of the gate line 10 at the contact interface to form a new compound, and then the first solder paste 20 is cooled and the welding is completed. The above-mentioned new compound, that is, 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 compound corresponding to the first interlayer compound layer 40 is a fixed ratio combination of tin and gate line 10 atoms, usually with a specific chemical composition and crystal structure.

[0037] Optionally, after forming the above-mentioned first interlayer compound layer 40, the soldering tape 30 is placed, and the first solder paste 20 and the soldering tape 30 can be soldered to form a second interlayer compound layer 50. It should be noted that different soldered materials (copper, silver, aluminum and nickel, etc.) have different reactivities with the first solder paste 20, which will affect the type of interlayer compound formed. Therefore, when the materials of the soldering tape 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, that is, 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 soldering tape 30. Furthermore, it should be noted that the second interlayer compound layer 50 may be located between the first solder paste 20 and the solder strip 30 ; or the second interlayer compound layer 50 may penetrate the remaining first solder paste 20 after forming the first interlayer compound layer 40 , so that the second interlayer compound layer 50 may be located between the first interlayer compound layer 40 and the solder strip 30 .

[0038] In the above embodiment of the present application, a photovoltaic module includes a cell 100, a solder ribbon 30, a first interlayer compound layer 40, and a second interlayer compound layer 50. The first interlayer compound layer 40 is formed by soldering a first solder paste 20 and a grid line 10, and the second interlayer compound layer 50 is formed by soldering a first solder paste 20 and a solder ribbon 30. The first solder paste 20 is used to solder the cell 100 and the solder ribbon 30. Specifically, the grid line 10 is provided on the surface of the cell 100, the solder ribbon 30 can be located on a 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 ribbon 30, and the second interlayer compound layer 50 can be located between the first interlayer compound layer 40 and the solder ribbon 30, thereby achieving an electrical connection between the solder ribbon 30 and the cell 100. It can be seen that after the first solder paste 20 and the grid line 10 of the photovoltaic module in this application are welded, the first solder paste 20 and the grid line 10 can form a first interlayer compound layer 40, so that the first interlayer compound layer 40 can first be located between the grid line 10 and the first solder paste 20. Then, the soldering ribbon 30 is placed, and the welding of the first solder paste 20 and the soldering ribbon 30 can form a second interlayer compound layer 50, so that the second interlayer compound layer 50 is located between the first interlayer compound layer 40 and the soldering ribbon 30. It can be understood that the formation of interlayer compounds can affect the fluidity and wettability of the welding material, that is, during the formation of the first interlayer compound layer and the second interlayer compound layer, since the solder can fully fill the solder joints, the first interlayer compound layer 40 can increase the welding tension between the first solder paste 20 and the gate line 10, and the second interlayer compound layer 50 can increase the welding tension between the first solder paste 20 and the solder strip 30 or 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 welding, and since the low-temperature material is placed after the high-temperature material is welded during the step-by-step welding process, the influence of different welding temperatures on the welding of the low-temperature material is reduced, and over-welding of the low-temperature material under high-temperature conditions is avoided. Therefore, the photovoltaic module having the above-mentioned first interlayer compound layer 40 and second interlayer compound layer 50 in this application can be mass-produced due to its good welding tensile strength. That is, through this application, the problem of mass production of photovoltaic modules affected by welding windows that are too wide or too narrow is solved.

[0039] In some optional embodiments, the soldering ribbon 30 includes a solder core and a tin-plated alloy layer (not shown) located at the 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 .

[0040] Optionally, the solder core may be copper.

[0041] Specifically, after the first solder paste 20 and the gate line 10 are first soldered, since the first solder paste 20 has cooled, in order to solder the above-mentioned battery cell 100 and the soldering strip 30, the present application coats a tin-plated alloy layer on the periphery of the soldering core and places the soldering strip 30 so that the soldering strip 30 contacts 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 cell 100 and the soldering strip 30, the tin-plated alloy layer on the soldering 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 soldering core. At the same time, the atoms of the soldering core may 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 soldering core at the contact interface to form a new compound. After that, the tin-plated alloy layer cools and the soldering is completed. The new compound, i.e., the second interlayer compound layer 50, is then formed between the first solder paste 20 and the solder ribbon 30. Alternatively, the second interlayer compound layer 50 may be formed between the first interlayer compound layer 40 and the solder ribbon 30. Similarly, it is mentioned here that the compound corresponding to the second interlayer compound layer 50 is a fixed ratio combination of tin and solder core atoms, and generally has a specific chemical composition and crystal structure.

[0042] Here, the situation in which the second interlayer compound layer 50 is fixed between the first interlayer compound layer 40 and the soldering tape 30 is explained again: in the process of forming the second interlayer compound layer 50, the remaining tin in the first solder paste 20 can all be used to form the second interlayer compound layer 50, that is, the remaining first solder paste 20 after forming 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.

[0043] It should be noted that the materials of the above-mentioned first solder paste 20 and the tin-plated alloy layer may include tin and other metal components (lead, silver, copper and antimony, etc.), so that during the soldering process of the first solder paste 20 and the gate 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 during the soldering process of the soldering ribbon 30 and the battery cell 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.

[0044] In the above embodiment, the melting point of the first solder paste 20 is relatively high, while the melting point of the tin-plated alloy layer is relatively low. Therefore, during the soldering process between the first solder paste 20 and the grid line 10, the overall soldering temperature between the first solder paste 20 and the grid line 10 is relatively high. After the soldering ribbon 30 is placed, the overall soldering temperature between the tin-plated alloy layer on the soldering ribbon 30 and the cell 100 is relatively low. Furthermore, since the soldering process between the soldering ribbon 30 and the cell 100 is divided into two sequential stages, namely, the first soldering stage between the first solder paste 20 and the grid line 10 and the second soldering stage between the tin-plated alloy layer and the cell 100, the low temperature of the second soldering stage can neutralize soldering problems caused by the high temperature in the first soldering stage, and the high temperature of the first soldering stage can neutralize soldering problems caused by the low temperature in the second soldering stage, for the entire photovoltaic module. Thus, based on the formation of the first interlayer compound layer 40 and the second interlayer compound layer 50, the present application further improves the soldering tension between the soldering ribbon 30 and the grid line 10 in the photovoltaic module due to the temperature difference between the first solder paste 20 and the tin-plated alloy layer.

[0045] In some optional embodiments, such as Figure 1 As shown, the photovoltaic module may further include a second solder paste (not shown in the figure), which may 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 .

[0046] Specifically, if Figure 2 As shown, the photovoltaic module includes a cell 100, a solder ribbon 30, a first solder paste 20 and a second solder paste.

[0047] On this basis, combined with Figure 1 and Figure 2 As shown, in one exemplary embodiment, the soldering ribbon 30 may be a copper soldering ribbon. In this case, the soldering ribbon 30 is located on the side of the cell 100 surface facing away from the grid lines 10. The first solder paste 20 is located between the cell 100 surface and the soldering ribbon 30. The second solder paste is located between the first solder paste 20 and the soldering ribbon 30. A first interlayer compound layer 40 is formed between the first solder paste 20 and the grid lines 10, and a second interlayer compound layer 50 is formed between the second solder paste and the soldering ribbon 30. It is understood that if the first solder paste 20 contains a different metallic element than the second solder paste, an interlayer compound layer may also form between the first solder paste 20 and the second solder paste.

[0048] In another exemplary embodiment, in combination Figure 1 and Figure 2As shown, the soldering ribbon 30 may be an alloy soldering ribbon containing tin. For example, the soldering ribbon 30 in this embodiment includes a solder core and a tin-plated alloy layer surrounding the outer periphery of the solder core. In this case, the soldering ribbon 30 is located on the side of the cell 100 surface away from the cell 100, and the tin-plated alloy layer of the soldering ribbon 30 is located between the cell 100 surface and the solder core of the soldering ribbon 30. A second solder paste (not shown) is located between the cell 100 surface and the tin-plated alloy layer of the soldering ribbon 30. The first solder paste 20 is located between the cell 100 surface and the second solder paste. A first interlayer compound layer 40 is formed between the first solder paste 20 and the gate line 10, and a second interlayer compound layer 50 is formed between the second solder paste and the soldering ribbon 30. It is understood that if the first solder paste 20, the tin-plated alloy layer, and the second solder paste contain different metal elements, an interlayer compound layer may also be formed between the first solder paste 20 and the second solder paste, and an interlayer compound layer may also be formed between the tin-plated alloy layer and the second solder paste.

[0049] Based on the principle that the melting point of the tin-plated alloy layer is lower than the melting point of the first solder paste 20 , similarly, the melting point of the second solder paste can be lower than the melting point of the first solder paste 20 , which will not be elaborated here.

[0050] Furthermore, when both a tin alloy layer and a second solder paste are used in the photovoltaic module manufacturing process, the melting point of the tin alloy layer can be higher than or equal to the melting point of the second solder paste. In other words, the tin alloy layer can have the same composition as the second solder paste, in which case the melting point of the tin alloy layer can be equal to the melting point of the second solder paste. Alternatively, the tin alloy layer can have a different composition than the second solder paste, and the melting point of the tin alloy layer can be higher than the melting point of the second solder paste, meaning the melting point of the second solder paste can be lower than the melting point of the solder ribbon 30.

[0051] In some optional embodiments, when the melting point of the first solder paste 20 is higher than that of the solder ribbon 30, the difference in melting point between the solder ribbon 30 and the first solder paste 20 is greater than 30°C. In this case, the two soldering stages corresponding to the formation of the first interlayer compound layer 40 and the formation of the second interlayer compound layer 50 have a large temperature difference range, which can neutralize soldering problems that occur during the different formation stages, thereby improving the overall soldering tension of the photovoltaic module.

[0052] For example, Figure 1 As shown, the melting point of the soldering ribbon 30 may be 130-155°C.

[0053] For example, Figure 1 As shown, the melting point of the first solder paste 20 may be 160-195°C.

[0054] Alternatively, as Figure 1 As shown, the melting point of the gate line 10 may be higher than the melting point of the first solder paste 20 .

[0055] Alternatively, as Figure 2 As shown, the photovoltaic module may further include: a front plate 60 located on a side of the cell 100 away from the welding ribbon 30 ; and a back plate 70 located on a side of the welding ribbon 30 away from the cell 100 .

[0056] Specifically, the front panel 60 and the battery cell 100 can be bonded by the front adhesive film 80, so that the front panel 60 is located on the side of the battery cell 100 away from the welding strip 30, and the back panel 70 can be bonded by the back adhesive film 90, so that the back panel 70 is located on the side of the welding strip 30 away from the battery cell 100.

[0057] Exemplarily, the front plate 60 and the back plate 70 may be made of glass.

[0058] Specifically, an implementation method for welding grid lines and welding ribbons in a photovoltaic module is given below:

[0059] First, high-temperature solder paste is printed on the battery cell in the areas where soldering is required, based on the electrical design, so that the printed battery cell completes the soldering of the fine grid and solder paste. The soldering method is heating, and the heat treatment method is not limited. A drying furnace or a drying and heating platform device can be used, with a temperature of 160°C to 200°C and a time of 1 to 15 seconds. Optionally, the drying and heating platform device has good uniformity and a short time, thereby improving production efficiency. After high-temperature treatment, the metal grid lines of the battery cell and the high-temperature solder paste complete the first soldering in a high-temperature environment to form the first interlayer compound layer (first IMC layer). The metal grid lines of the battery cell can be made of metal materials with good conductive properties such as silver, copper, aluminum, and tin. Next, the pre-treated battery cell and the solder ribbon are low-temperature soldered to form a battery string, with a soldering temperature of 140°C to 160°C. The soldering method is not limited and can be low-temperature string soldering or laminated soldering. When using the low-temperature string welding process, the front panel / glass, front adhesive film, welded cell string, back adhesive film, back panel / glass are stacked in sequence, and then laminated to form a laminate. After the junction box and frame are installed, a photovoltaic module is formed. When using the lamination welding process, the cell and the soldering ribbon are laid on the assembly of the front panel / glass and the front adhesive film. Only relative positioning is performed without welding. The back adhesive film and back panel / glass are laid, and then laminated. The lamination process completes the welding of the soldering ribbon and the cell, forming electrical conduction and a laminate. Finally, the junction box and frame are installed on the laminate to form a photovoltaic module. Thus, through the above two-stage welding process, the different welding requirements of different welding stages are solved and the welding tension is guaranteed. Eliminating the welding window solves the problem of wide or narrow welding process window affecting mass production, and also solves the problem of cold welding / over-welding caused by different welding temperature requirements at each stage.

[0060] From the above description, it can be seen that the above embodiments of the present application achieve the following technical effects:

[0061] The photovoltaic module provided in the present application includes a cell, a soldering tape, a first interlayer compound layer and a second interlayer compound layer. The first interlayer compound layer is formed by welding a first solder paste and a grid line, and the second interlayer compound layer is formed by welding a first solder paste and a soldering tape. The first solder paste is used to weld the cell and the soldering tape. Specifically, the cell has a grid line on its surface, and the soldering tape 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 soldering tape, and the second interlayer compound layer can be located between the first interlayer compound layer and the soldering tape, thereby achieving electrical connection between the soldering tape and the cell. It can be seen that after the first solder paste and the grid line of the photovoltaic module in the present application are welded, the first solder paste and the grid line can form a first interlayer compound layer, so that the first interlayer compound layer can first be located between the grid line and the first solder paste. Furthermore, the welding of the first solder paste and the soldering tape can form a second interlayer compound layer, so that the second interlayer compound layer is located between the first interlayer compound layer and the soldering tape. It is understandable that the formation of the interlayer compound can affect the fluidity and wettability of the soldering material, that is, during the formation of the first interlayer compound layer and the second interlayer compound layer, since the solder can fully fill the solder joint, the first interlayer compound layer can increase the welding tension between the first solder paste and the grid line, and the second interlayer compound layer can increase the welding tension between the first solder paste and the solder strip or 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-by-step welding, and since the low-temperature material is placed after the high-temperature material is welded during the step-by-step welding process, the effect of different welding temperatures on the welding of the low-temperature material is reduced, and over-welding 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 this application can be mass-produced because it has good welding tension. That is, through this application, the problem of mass production of photovoltaic modules affected by welding windows that are too wide or too narrow is solved.

[0062] The above description is merely a preferred embodiment of the present application and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A photovoltaic module, characterized in that: include; A battery cell, wherein a grid line is provided on a surface of the battery cell; a welding strip, located on a side of the grid line away from the battery cell; A first interlayer compound layer is located between the surface of the cell and the solder strip, and the first interlayer compound layer is formed by soldering a first solder paste to the grid line; The second interlayer compound layer is located between the first interlayer compound layer and the solder strip, and the second interlayer compound layer is formed by welding the first solder paste and the solder strip, and the melting temperature of the material of the first solder paste is different from the melting temperature of the material of the solder strip.

2. The photovoltaic module according to claim 1, characterized in that The soldering ribbon includes a solder core and a tin-plated alloy layer located on the 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.

3. The photovoltaic module according to claim 1, characterized in that The photovoltaic module further comprises: The second solder paste is located between the first solder paste and the soldering ribbon, and the melting point of the second solder paste is lower than that of the first solder paste.

4. The photovoltaic module according to claim 3, characterized in that The melting point of the second solder paste is lower than the melting point of the soldering ribbon.

5. The photovoltaic module according to any one of claims 1 to 4, characterized in that: The melting point of the first solder paste is higher than that of the soldering strip, and the difference in melting point between the soldering strip and the first solder paste is greater than 30°C.

6. The photovoltaic module according to claim 5, characterized in that: The melting point of the soldering tape is 130-155°C.

7. The photovoltaic module according to claim 5, characterized in that The melting point of the first solder paste is 160-195°C.

8. The photovoltaic module according to any one of claims 1 to 4, characterized in that: The melting point of the gate line is higher than the melting point of the first solder paste.

9. The photovoltaic module according to any one of claims 1 to 4, characterized in that: The first interlayer compound layer and the second interlayer compound layer are different.

10. The photovoltaic module according to any one of claims 1 to 4, characterized in that: The photovoltaic module further comprises: A front plate, located on a side of the battery cell away from the welding ribbon; The back plate is located on a side of the welding ribbon away from the battery cell.

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