Method of manufacturing a photovoltaic module

Abstract

The application relates to the technical field of solar cells, in particular to a manufacturing method of a photovoltaic module. In the embodiment of the application, a plurality of welding bands, a plurality of glue points and a film are arranged on the target side of a cell sheet in a preset order in the process of forming a cell string, each welding band corresponds to at least one glue point, and the film is arranged on the side, away from the cell sheet, of the plurality of welding bands, so that the plurality of welding bands can be fixed to the cell sheet through the glue points and the film, the reliability of the welding connection between the welding bands and the cell sheet is improved, and the reliability of the photovoltaic module is improved.

Description

Technical Field

[0001] This application relates to the field of solar cell technology, and in particular to a method for manufacturing photovoltaic modules. Background Technology

[0002] In the manufacturing process of photovoltaic (PV) modules, multiple solar cells are connected to form a cell string using solder ribbons, followed by lamination, framing, and other related processes to create the PV module. The reliability of the connection between the solder ribbons and the corresponding solar cells affects the reliability of the PV module. Therefore, the reliability of the connection between the solder ribbons and the corresponding solar cells needs further improvement. Summary of the Invention

[0003] Therefore, it is necessary to provide a method for manufacturing photovoltaic modules to improve the connection reliability between the solder ribbon and the solar cells, thereby enhancing the reliability of the photovoltaic modules.

[0004] This application provides a method for manufacturing a photovoltaic module, including:

[0005] Provide battery cells;

[0006] Multiple battery cells are connected to form a battery string according to a preset stringing method;

[0007] In the process of forming the battery string, multiple solder strips, multiple adhesive dots and a coating are set on the target side of the battery cell in a preset order;

[0008] For the same target side, the coating is located on the side of the solder ribbon away from the cell, and the orthographic projection of the coating on the reference surface overlaps with the orthographic projection of the multiple solder ribbons on the reference surface; each solder ribbon corresponds to at least one adhesive dot, and the orthographic projection of the adhesive dot on the reference surface overlaps with the orthographic projection of the corresponding solder ribbon on the reference surface; the target side of the cell is at least one side of the cell along a first direction, the first direction being the thickness direction of the cell, and the reference surface is a plane perpendicular to the first direction.

[0009] In one embodiment, a first target adhesive point exists for all adhesive points on the same target side of the same battery cell;

[0010] Along the first direction, at least a portion of the first target adhesive dot is located between the corresponding solder strip and the battery cell.

[0011] In one embodiment, for the same target side of the same battery cell, at least one first target adhesive dot has an orthographic projection on the reference surface that overlaps with the orthographic projection of the corresponding coating on the reference surface; and / or

[0012] For the same target side of the same battery cell, there exists at least one first target adhesive dot whose orthographic projection on the reference surface does not overlap with the orthographic projection of the corresponding coating on the reference surface.

[0013] In one embodiment, a second target adhesive point exists for all adhesive points on the same target side of all battery cells;

[0014] Along the first direction, at least a portion of the second target adhesive dot is located between the corresponding solder strip and the corresponding coating.

[0015] In one embodiment, for all adhesive dots on the same target side of all solar cells, there is a third target adhesive dot; along a first direction, at least a portion of the third target adhesive dot is located on the side of the corresponding coating opposite to the solar cell; and / or

[0016] For all adhesive dots on the same target side of all solar cells, there is a fourth target adhesive dot; along the first direction, at least a portion of the fourth target adhesive dot is located on the side of the corresponding solder ribbon opposite to the solar cell.

[0017] In one embodiment, for the same target side of all battery cells, a coating is provided such that the orthographic projection of at least a portion of the solder strips on the reference plane overlaps with the orthographic projection of the corresponding coating on the reference plane; or

[0018] For the same target side of all solar cells, multiple coatings are provided, each coating covering at least one solar cell, and all coatings do not overlap each other. At least a portion of the solder strips have an overlapping projection on the reference plane with the corresponding coating's projection on the reference plane; or

[0019] For the same target side of all solar cells, multiple coatings are provided, and all coatings and all solar cells are provided in a one-to-one correspondence. At least some of the solder strips have overlapping projections on the reference surface with the corresponding coatings on the reference surface.

[0020] In one embodiment, each solder strip corresponds to multiple adhesive dots;

[0021] The orthographic projections of the multiple adhesive dots on the reference plane and the orthographic projections of the corresponding solder strips on the reference plane have overlapping projections.

[0022] In one embodiment, the solder strip has a first end and a second end disposed opposite to each other along the longitudinal direction of the solder strip;

[0023] For the multiple adhesive dots, the orthographic projection of one adhesive dot on the reference surface overlaps with the orthographic projection of the first end of the corresponding solder strip on the reference surface; the orthographic projection of another adhesive dot on the reference surface overlaps with the orthographic projection of the second end of the corresponding solder strip on the reference surface.

[0024] In one embodiment, the coating is configured as a single-layer structure, and the pre-crosslinking degree of the coating is 20% to 50%; or

[0025] The coating is configured as a multi-layer structure, comprising multiple sub-coatings stacked together, wherein the pre-crosslinking degree of the sub-coating closest to the solar cell is 20% to 50%.

[0026] In one embodiment, for the same target side of the same battery cell, the orthographic projection of each solder strip on the reference plane overlaps with the orthographic projection of the corresponding coating on the reference plane; and / or

[0027] The minimum torque value ML for coating must satisfy: 0.1 ≤ ML ≤ 0.8; and / or

[0028] The film covering temperature is 100°C to 135°C; and / or

[0029] The coating thickness ranges from 50µm to 500µm; and / or

[0030] The process of forming the battery string includes curing the adhesive dots, and the degree of crosslinking of the cured adhesive dots is greater than 90%; and / or

[0031] The Tg of the glue point is ≥ 59.40℃; Tg is the temperature at which the glue point transitions from the glassy state to the highly solidified state; and / or

[0032] The welding strip includes at least one of round wire welding strip, triangular welding strip, flat welding strip, and irregularly shaped welding strip.

[0033] In the above-mentioned photovoltaic module manufacturing method, multiple solder ribbons, multiple adhesive dots, and a coating are set on the target side of the cell in a preset order during the formation of the cell string, and each solder ribbon corresponds to at least one adhesive dot. The coating is applied to at least one side of the multiple solder ribbons away from the cell, so that the multiple solder ribbons can be fixed to the cell relative to each other via adhesive dots and coating, thereby improving the reliability of the solder ribbon and cell welding connection and thus improving the reliability of the photovoltaic module.

[0034] Additional aspects and advantages of embodiments of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of embodiments of this application. Attached Figure Description

[0035] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the embodiments described below. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0036] Figure 1 A schematic flowchart illustrating a method for manufacturing a photovoltaic module according to some embodiments of this application;

[0037] Figure 2This is a side cross-sectional view of a portion of the structure in which the solder strip, adhesive dots, coating, and battery cell are combined, as provided in some embodiments of this application.

[0038] Figure 3 This is a top view schematic diagram of the partial structure of the solder strip, adhesive dots and battery cell in conjunction with some embodiments of this application;

[0039] Figure 4 A top view schematic diagram of the partial structure of the solder strip, adhesive dots, coating and battery cell in conjunction with some embodiments of this application;

[0040] Figure 5 A top view schematic diagram of the partial structure of the solder strip, adhesive dots, coating and battery cell in cooperation with other embodiments of this application;

[0041] Figure 6 A top view schematic diagram of the partial structure of the solder strip, adhesive dots, coating and battery cell in cooperation with some embodiments of this application;

[0042] Figure 7 A side cross-sectional view of a portion of the structure in which the solder strip, adhesive dots, coating, and battery cell are combined, as provided in other embodiments of this application;

[0043] Figure 8 A side cross-sectional view of a portion of the structure in which the solder strip, adhesive dots, coating, and battery cell are combined, as provided in some embodiments of this application;

[0044] Figure 9 A top view schematic diagram of the partial structure of the solder strip, adhesive dots, coating and battery cell in combination provided in some embodiments of this application;

[0045] Figure 10 A side cross-sectional view of a portion of the structure in which the solder strip, adhesive dots, coating, and battery cell are combined, as provided in some embodiments of this application;

[0046] Figure 11 A top view schematic diagram of the partial structure of the solder strip, adhesive dots, coating and battery cell in cooperation with other embodiments of this application;

[0047] Figure 12 This application also provides side cross-sectional structural diagrams of the partial structures in which the solder strip, adhesive dots, coating, and battery cell cooperate, according to some embodiments.

[0048] Figure 13 A top view schematic diagram of the partial structure of the solder strip, adhesive dots, coating and battery cell in combination provided in some other embodiments of this application;

[0049] Figure 14A top view schematic diagram of the partial structure of the solder strip, adhesive dots, coating and battery cell in conjunction with other embodiments of this application;

[0050] Figure 15 This is a top view schematic diagram of the coating and multiple battery cells in combination provided in some embodiments of this application;

[0051] Figure 16 A top view schematic diagram of the coating and multiple battery cells in combination, provided for some embodiments of this application;

[0052] Figure 17 A top view schematic diagram of the coating and multiple battery cells in combination provided in other embodiments of this application;

[0053] Figure 18 A top view schematic diagram of the partial structure of the solder strip, adhesive dots and battery cell in conjunction with other embodiments of this application;

[0054] Figure 19 A side cross-sectional view of a portion of the structure in which the solder strip, adhesive dots, and battery cell mate, as provided in some embodiments of this application;

[0055] Figure 20 A top view schematic diagram of the partial structure of the solder strip and adhesive dots in conjunction with some embodiments of this application;

[0056] Figure 21 A side cross-sectional view of a portion of the structure in which the solder strip, adhesive dots, and battery cell mate, as provided in some other embodiments of this application;

[0057] Figure 22 A top view schematic diagram of the partial structure of the solder strip and adhesive dots in conjunction with other embodiments of this application;

[0058] Figure 23 This is a schematic diagram of the structure of a photovoltaic module provided in some embodiments of this application;

[0059] Figure 24 This is a schematic diagram of the structure in which the solder strip and the battery cell cooperate with each other, provided in some embodiments of this application;

[0060] Figure 25 This is a schematic diagram of the structure of a battery string provided in some embodiments of this application;

[0061] Figure 26 This is a schematic diagram of the structure of a battery string provided in some other embodiments of this application;

[0062] Figure 27 This is a schematic diagram of the structure of a battery string provided in some embodiments of this application;

[0063] Figure 28This is a schematic diagram of the structure of a battery string provided in some embodiments of this application;

[0064] Figure 29 This is a schematic diagram of the structure in which the solder strip and the battery cell interact with each other, provided for other embodiments of this application;

[0065] Figure 30 This application also provides structural schematic diagrams of battery strings in some embodiments;

[0066] Figure 31 This is a schematic diagram of the structure of a battery string provided in some other embodiments of this application.

[0067] Explanation of reference numerals in the attached figures:

[0068] 10 photovoltaic modules;

[0069] Battery string 100;

[0070] Battery cell 110, solder ribbon 120, first end e1, second end e2, adhesive dot 130, first sub-adhesive dot 131, second sub-adhesive dot 132, first target adhesive dot 130a, second target adhesive dot 130b, third target adhesive dot 130c, fourth target adhesive dot 130d, coating 140.

[0071] Encapsulation layer 200;

[0072] Cover plate 300;

[0073] Steps S110 and S120. Detailed Implementation

[0074] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0075] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0076] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0077] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can be a mechanical connection or an electrical connection; they can be a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly defined. It is worth noting that in the following description, "electrical connection" between one feature and another feature not only includes direct contact between the two features to form a channel for electrical energy transmission or current transfer, but also includes an intermediate feature between the two features, which, along with the intermediate feature, forms an electrical energy transmission or current transfer channel to achieve electrical energy transmission or transfer. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0078] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0079] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0080] When photovoltaic (PV) modules are in use, variations in surface illuminance on the solar cells can lead to differences in localized power generation efficiency and consequently, excessively high temperatures. In such cases, due to the difference in thermal expansion coefficients between the solder ribbon and the solar cell, stress is generated at the interface between them. Prolonged stress can cause the bond between the solder and the solar cell or solder ribbon at the solder joint to gradually loosen. The originally well-formed intermetallic compound bond may be disrupted, making the electrical contact between the solder ribbon and the solar cell unstable, resulting in incomplete soldering. This hinders current transmission between the solar cells, reduces the power generation efficiency of the PV module, and may even cause safety hazards such as localized overheating, ultimately reducing the reliability of the PV module.

[0081] Based on this, the embodiments of this application improve the manufacturing method of photovoltaic modules, enhance the connection reliability between the solder ribbon and the solar cells, and thus improve the reliability of photovoltaic modules.

[0082] Figure 1 The diagram illustrates a process flow diagram of a photovoltaic module manufacturing method provided in some embodiments of this application; for ease of explanation, only the content related to the embodiments of this application is shown.

[0083] Please refer to Figure 1 This application provides a method for manufacturing a photovoltaic module, including the following steps:

[0084] Step S110: Provide battery cells;

[0085] Step S120: Connect multiple battery cells to form a battery string according to a preset stringing method; wherein, during the formation of the battery string, multiple solder ribbons, multiple adhesive dots, and a coating are set on the target side of the battery cells in a preset order; for the same target side, the coating is located on the side of the solder ribbon away from the battery cell, and the orthographic projection of the coating on the reference surface overlaps with the orthographic projection of the multiple solder ribbons on the reference surface; each solder ribbon corresponds to at least one adhesive dot, and the orthographic projection of the adhesive dot on the reference surface overlaps with the orthographic projection of the corresponding solder ribbon on the reference surface; the target side of the battery cell is at least one side of the battery cell along a first direction, the first direction being the thickness direction of the battery cell, and the reference surface is a plane perpendicular to the first direction.

[0086] In step S110, the solar cells can be configured according to actual usage requirements. For example, the solar cells can be TOPCon (Tunnel Oxide Passivating Contacts) cells, BC (Back Contact) cells, HJT (Heterojunction with Intrinsic Thin-layer) cells, perovskite cells, or tandem cells, etc. Tandem cells can be perovskite cells stacked with TOPCon, BC, or HJT cells. No specific limitations are imposed here. The solar cells can be a single piece, a half piece, or even smaller pieces; no specific limitations are imposed here.

[0087] In step S120, the preset stringing method refers to a pre-designed connection method for multiple solar cells, which combines these cells to ensure that the current and voltage generated by them meet the power and electrical characteristic requirements of the photovoltaic module. The preset stringing method includes, but is not limited to, the electrical connection method of the solar cells, the arrangement of the solar cells, the placement of the solder ribbons, and the arrangement of the solder ribbons. The connection method of the solar cells in the string can be that the front electrode of one solar cell is electrically connected to the back electrode of an adjacent solar cell via solder ribbons (e.g., TOPCon cells), or the back electrode of one solar cell is electrically connected to the back electrode of an adjacent solar cell via solder ribbons (e.g., BC cells). These multiple solar cells can be connected in series, in parallel, or in a mixed series-parallel connection; no specific limitations are imposed here.

[0088] The target side of a solar cell can be either the front or the back side. For example, in the case of a TOPCon solar cell, the target side can be at least one of the front and back sides. As another example, in the case of a BC solar cell, the target side can be the back side. The target side can be configured according to the type of solar cell and its intended use.

[0089] It's understandable that the front of a solar cell is the light-receiving surface, and the back is the back-lighting surface. The terms "light-receiving surface" and "back-lighting surface" are relative; the light-receiving surface is specifically the surface of the solar cell that receives the most sunlight. With the development of solar cell technology, the back-lighting surface also receives sunlight energy, primarily from reflected or scattered light from the surrounding environment.

[0090] Solder ribbon is a strip material used for electronic components. It is primarily used to connect solar cells, creating a good electrical connection between them to collect and conduct the current generated by each cell. Solder ribbon is generally a strip-shaped component, typically possessing a certain degree of flexibility to facilitate soldering between solar cells. Materials used for solder ribbon include, but are not limited to, tin-lead alloys and lead-free alloys (such as tin-silver-copper alloys). Coating is a film applied to the surface of the solar cell. Coating materials include, but are not limited to, one or more of EVA (Ethylene-Vinyl Acetate), POE (Polyolefin Elastomer), TPO (Thermoplastic Polyolefin), and TPU (Thermoplastic Polyurethane). Adhesive dots are components formed from materials with a certain adhesive capacity. Adhesive dot materials include at least one of acrylic acid, epoxy resin, and conductive adhesive.

[0091] Multiple solder ribbons, adhesive dots, and a coating are applied to the target side of the solar cell in a preset order. That is, the solder ribbons, adhesive dots, and coating can be applied sequentially, or in a different order. Alternatively, the solder ribbons and adhesive dots can be applied alternately, followed by the coating. The order in which the multiple solder ribbons, adhesive dots, and coating are applied can be configured according to the specific setup requirements; no specific restrictions are imposed here.

[0092] The orthographic projection of the coating on the reference surface overlaps with the orthographic projections of the multiple solder strips on the reference surface. That is, the orthographic projection of the coating on the reference surface and the orthographic projections of the multiple solder strips on the reference surface may or may not overlap completely. As long as the coating and at least some of the solder strips are arranged correspondingly in the thickness direction of the cell, no specific restrictions are imposed here.

[0093] Each solder ribbon corresponds to at least one adhesive dot; that is, in the thickness direction of the solar cell, each solder ribbon is associated with at least one adhesive dot. The orthographic projection of the adhesive dot on the reference surface overlaps with the orthographic projection of the corresponding solder ribbon on the reference surface. In other words, the orthographic projection of the adhesive dot on the reference surface can be entirely within the orthographic projection range of the corresponding solder ribbon on the reference surface, or it can be partially within that range. Depending on different preset sequences and different placement positions, the solder ribbon and the corresponding adhesive dot may or may not be in contact.

[0094] The orthographic projections of the coating on the reference surface and the orthographic projections of the multiple adhesive dots on the reference surface may or may not overlap; no specific limitation is made here. If the orthographic projections of the coating on the reference surface and the multiple adhesive dots on the reference surface do not overlap, then the orthographic projections of the coating on the reference surface and the orthographic projections of the multiple solder strips on the reference surface partially overlap.

[0095] Therefore, because the solder ribbons and corresponding adhesive dots have the aforementioned overlapping projections in the thickness direction of the solar cell, and the coating and the multiple solder ribbons also have the aforementioned overlapping projections, the multiple solder ribbons can be relatively fixed to the solar cell via the adhesive dots, coating, and solar cell, thus improving the stability between the solder ribbons and the solar cell. Even if the photovoltaic module experiences localized overheating during use, the solder ribbons can still maintain good ohmic contact with the solar cell under the constraint of the adhesive dots and coating, thereby improving the reliability of the solder ribbon and solar cell welding connection, and ultimately improving the reliability of the photovoltaic module.

[0096] In some embodiments, a first target adhesive point exists for all adhesive points on the same target side of the same solar cell. Along a first direction, at least a portion of the first target adhesive point is located between the corresponding solder ribbon and the solar cell.

[0097] Specifically, the first target adhesive dots are first placed on the solar cell, relative to the solder strip. (Refer to reference...) Figure 2 , Figure 2 This illustration shows a side cross-sectional view of a portion of the structure in which the solder ribbon 120, adhesive dots 130, coating 140, and battery cell 110 mate, according to some embodiments of this application. Figure 2 Only one solder ribbon 120 is shown in the diagram. The first target adhesive dot 130a can be located partly between the solder ribbon 120 and the solar cell 110, and partly on the side of the solder ribbon 120. Of course, the first target adhesive dot 130a can also be located between the solder ribbon 120 and the solar cell 110. No specific limitation is made here. Refer to the reference. Figure 3 , Figure 3 This paper shows a top view of the partial structure of the solder ribbon 120, adhesive dots 130, and battery cell 110 in some embodiments of this application. Figure 3The coating 140 is omitted. The first target adhesive point 130a can be any of the adhesive dots 130 on the same target side of the same battery cell 110. Alternatively, one adhesive dot 130 on the same target side of the same battery cell 110 can be the first target adhesive point 130a, or a subset of the adhesive dots 130 on the same target side of the same battery cell 110 can be the first target adhesive point 130a. If there is an adhesive dot 130 on the same target side of the same battery cell 110 that is not the first target adhesive point 130a, the configuration of some adhesive dots 130 shown later can be used as a reference; no specific limitations are made here.

[0098] In this way, by setting the first target adhesive point, not only can the corresponding solder strip be positioned more accurately, but the corresponding solder strip and the battery cell can also be initially fixed together, which helps to improve the tension between the corresponding solder strip and the battery cell and enhance the structural stability between the corresponding solder strip and the battery cell.

[0099] In some embodiments, for the same target side of the same battery cell, the orthographic projection of at least one first target adhesive dot on the reference surface overlaps with the orthographic projection of the corresponding coating on the reference surface; and / or, for the same target side of the same battery cell, the orthographic projection of at least one first target adhesive dot on the reference surface does not overlap with the orthographic projection of the corresponding coating on the reference surface. The overlapping projections can be understood with reference to the situations illustrated in some of the foregoing embodiments, and will not be repeated here.

[0100] For example, in conjunction with reference Figure 4 , Figure 4 This paper shows a top view of a portion of the structure in which the solder ribbon 120, adhesive dots 130, coating 140, and battery cell 110 are coupled, according to some embodiments of this application. Figure 4 The structure covered by the coating 140 in the first direction is illustrated by dashed lines. Viewed from the first direction, a portion of the first target adhesive dots 130a is covered by the coating 140. That is, the orthographic projection of this portion of the first target adhesive dots 130a onto the reference plane lies within the orthographic projection range of the coating 140 onto the reference plane, and the overlapping projection of the two is the orthographic projection of this portion of the first target adhesive dots 130a onto the reference plane. (Continuing to refer to...) Figure 4 Viewed from the first direction, another portion of the first target adhesive dots 130a is not covered by the coating 140. That is, the orthographic projection of the other portion of the first target adhesive dots 130a on the reference surface is outside the orthographic projection range of the coating 140 on the reference surface.

[0101] Furthermore, by way of example, in conjunction with reference Figure 5 , Figure 5This invention provides a top view schematic diagram of the partial structure of the solder ribbon 120, adhesive dots 130, coating 140, and battery cell 110 in cooperation with other embodiments of this application. Figure 5 The structure covered by the coating 140 in the first direction is illustrated by a dashed line. Viewed from the first direction, all first target adhesive dots 130a are not covered by the coating 140. That is, the orthographic projection of all first target adhesive dots 130a onto the reference plane is outside the orthographic projection range of the coating 140 onto the reference plane.

[0102] Another example, in conjunction with reference Figure 6 , Figure 6 This illustration shows a top view of a portion of the structure in which the solder ribbon 120, adhesive dots 130, coating 140, and battery cell 110 mate, according to some embodiments of this application. Figure 6 The structure covered by the coating 140 in the first direction is illustrated by a dashed line. Viewed from the first direction, all first target adhesive dots 130a are covered by the coating 140. That is, the orthographic projection of all first target adhesive dots 130a onto the reference plane lies within the orthographic projection range of the coating 140 onto the reference plane.

[0103] Thus, with the first target adhesive dot located on the side of the coating facing the solar cell and the two having overlapping projections, the first target adhesive dot, the corresponding coating, and the corresponding solder ribbon have corresponding portions in the first direction. This not only helps to provide a support point for coating and further improves the stability of the electrical connection between the solder ribbon and the solar cell under the action of the adhesive dot and the coating, but also helps to absorb and disperse the stress caused by the different coefficients of thermal expansion of the solar cell, solder ribbon, and coating when the temperature changes. This reduces the occurrence of problems such as solar cell cracking and solder ribbon loosening, and enhances the mechanical stability of the photovoltaic module.

[0104] Furthermore, in conjunction with reference Figure 7 , Figure 7 The diagram shows a side cross-sectional view of a portion of the structure in which the solder ribbon 120, adhesive dots 130, film 140, and battery cell 110 cooperate, according to some other embodiments of this application. By controlling the thickness of the first target adhesive dot 130a along the first direction, the film 140 can contact the side of the solder ribbon 120 away from the battery cell 110, and also contact the side of the first target adhesive dot 130a away from the battery cell 110. In this case, the first target adhesive dot 130a can not only improve the stability of the connection between the solder ribbon 120 and the battery cell 110, but also further enhance the fixing force of the film 140 on the solder ribbon 120.

[0105] Therefore, by setting a first target adhesive dot and flexibly configuring the relationship between the first target adhesive dot and the solder ribbon and the coating, the reliability of the electrical connection between the solder ribbon and the solar cell can be further improved, thereby improving the reliability of the photovoltaic module.

[0106] In some embodiments, a second target adhesive dot exists for all adhesive dots on the same target side of all solar cells. Along a first direction, at least a portion of the second target adhesive dot is located between the corresponding solder ribbon and the corresponding coating. Specifically, the second target adhesive dot is subsequently applied to the solar cell relative to the solder ribbon.

[0107] For example, in conjunction with reference Figure 8 , Figure 8 This diagram shows a side cross-sectional view of a portion of the structure in which the solder ribbon 120, adhesive dot 130, coating 140, and battery cell 110 are coupled, according to some embodiments of this application. A portion of the second target adhesive dot 130b is in contact with the corresponding solder ribbon 120, and another portion is in contact with the corresponding coating 140. Furthermore, a further portion of the second target adhesive dot 130b may be in contact with the side edge of the solder ribbon 120.

[0108] Furthermore, by way of example, in conjunction with reference Figure 9 , Figure 9 This is a top view schematic diagram of the partial structure of the solder ribbon 120, adhesive dots 130, coating 140, and battery cell 110 provided in some embodiments of this application, illustrating the case where, along the first direction, the entire second target adhesive dot 130b is located between the corresponding solder ribbon 120 and the corresponding coating 140. Alternatively, along the first direction, a portion of the second target adhesive dot 130b may be located between the corresponding solder ribbon 120 and the corresponding coating 140. Figure 9 In the middle, the structure covered by the film 140 in the first direction is shown by a dashed line.

[0109] In this way, by setting a second target adhesive dot, the fixing force of the coating on the solder ribbon can be further enhanced, thereby improving the reliability of the electrical connection between the solder ribbon and the solar cell. Furthermore, during the manufacturing, transportation, and use of photovoltaic modules, they are subjected to various mechanical stresses (such as pressure during lamination, material expansion and contraction caused by temperature changes, etc.). The second target adhesive dot located between the corresponding solder ribbon and the corresponding coating can act as a buffer component, absorbing and dispersing these stresses. This can improve the situation where stress concentration causes peeling or damage between the solder ribbon and the coating, while also reducing the impact of stress on the solar cell and lowering the risk of cell cracking.

[0110] In some embodiments, a third target adhesive point exists for all adhesive dots on the same target side of all solar cells; at least a portion of the third target adhesive point is located on the side of the corresponding coating opposite to the solar cell along a first direction; and / or, a fourth target adhesive point exists for all adhesive dots on the same target side of all solar cells; at least a portion of the fourth target adhesive point is located on the side of the corresponding solder ribbon opposite to the solar cell along a first direction. Specifically, the third target adhesive point is applied to the solar cell after the coating. The fourth target adhesive point is applied to the solar cell after the solder ribbon. The fourth target adhesive point can be applied before or after the coating, and no specific limitation is made here.

[0111] For example, in conjunction with reference Figure 10 and Figure 11 , Figure 10 This illustration shows a side cross-sectional view of a portion of the structure in which the solder ribbon 120, adhesive dots 130, coating 140, and battery cell 110 mate, according to some embodiments of this application. Figure 11 This diagram shows a top view of a portion of the structure in which the solder ribbon 120, adhesive dot 130, coating 140, and battery cell 110 cooperate, according to some other embodiments of this application. Along the first direction, the third target adhesive dot 130c is entirely located on the side of the corresponding coating 140 facing away from the battery cell 110. Alternatively, along the first direction, the third target adhesive dot 130c may also be partially located on the side of the corresponding coating 140 facing away from the battery cell 110, with the other part in contact with the solder ribbon 120 or the battery cell 110. In this case, the third target adhesive dot 130c is located in the edge region of the coating 140.

[0112] Furthermore, by way of example, in conjunction with reference Figure 12 and Figure 13 , Figure 12 This illustration shows a side cross-sectional view of a portion of the structure in which the solder ribbon 120, adhesive dots 130, coating 140, and battery cell 110 mate, according to some embodiments of this application. Figure 13 This diagram shows a top view of a portion of the structure in which the solder ribbon 120, adhesive dots 130, coating 140, and battery cell 110 cooperate, according to some other embodiments of this application. The fourth target adhesive dot 130d can be located on the side of the solder ribbon 120 and in contact with the battery cell 110. The fourth target adhesive dot 130d and the corresponding coating 140 are independent of each other. Of course, in other embodiments, the coating 140 can also cover the fourth target adhesive dot 130d, with the fourth target adhesive dot 130d on the side opposite to the battery cell 110 in contact with the coating 140. No specific limitations are made here.

[0113] In this way, by setting a third target adhesive point, both the coating and the solder ribbon can be fixed simultaneously. This allows the coating to work in conjunction with the solar cell to further enhance the fixing force of the coating on the solder ribbon, thereby improving the reliability of the electrical connection between the solder ribbon and the solar cell. Furthermore, during the manufacturing, transportation, and use of photovoltaic modules, they experience various mechanical stresses (such as pressure during lamination, material expansion and contraction caused by temperature changes, etc.). The third target adhesive point can work in conjunction with the coating as a support point to absorb and disperse these stresses, thus improving situations where solder ribbon movement is caused by poor soldering or desoldering between the solder ribbon and the solar cell. By setting a fourth target adhesive point, not only can the order of setting the adhesive points and the coating be made more flexible, allowing for more flexible photovoltaic module manufacturing, but the reliability of the solder ribbon and the solar cell can also be improved. Moreover, even when the fourth target adhesive point and the coating are independent, photovoltaic modules of different thicknesses can be obtained by controlling the dimensions of the fourth target adhesive point and the coating in the first direction.

[0114] Therefore, the first target adhesive dot, the second target adhesive dot, the third target adhesive dot, and the fourth target adhesive dot illustrated in the above embodiments can be set in different preset orders to form a fixed structure that can improve the positional stability of the solder strip to different degrees and in different ways.

[0115] It is understandable that at least two of the four target adhesive dots—the first, second, third, and fourth—can be used in combination. Figure 14 For example, Figure 14 This diagram shows a top view of a partial structure of the bonding strip, adhesive dots, coating, and battery cell provided in some other embodiments of this application. The second and fourth target adhesive dots can be used in combination. No specific limitations are made here. Thus, by combining different types of target adhesive dots, it is beneficial to form a more reliable structure from different perspectives.

[0116] In some embodiments, for the same target side of all battery cells, a coating is provided, wherein at least a portion of the solder ribbons have an orthographic projection on the reference surface that overlaps with the orthographic projection of the corresponding coating on the reference surface; or, for the same target side of all battery cells, multiple coatings are provided, each coating covering at least one battery cell, and all coatings do not overlap each other, wherein at least a portion of the solder ribbons have an orthographic projection on the reference surface that overlaps with the orthographic projection of the corresponding coating on the reference surface; or, for the same target side of all battery cells, multiple coatings are provided, with all coatings and all battery cells corresponding to each other, wherein at least a portion of the solder ribbons have an orthographic projection on the reference surface that overlaps with the orthographic projection of the corresponding coating on the reference surface.

[0117] For example, in conjunction with reference Figures 15 to 17To better illustrate the relationship between the coating 140 and the multiple battery cells 110, Figures 15 to 17 Solder strip 120 and glue dot 130 are omitted. Figure 15 This illustrates a scenario where a covering 140 is located on the same target side. Figure 16 This illustration shows a scenario where multiple films 140, each corresponding to a single battery cell 110, are provided on the same target side. Figure 17 This illustrates a scenario where one coating 140 is applied to one battery cell 110 on the same target side, and where one coating 140 is applied to three battery cells 110. For example, in... Figure 16 In the illustrated scenario, the solder ribbon 120, adhesive dots 130, and film coating 140 can be set in a preset order for each battery cell 110, or the solder ribbon 120 and adhesive dots 130 can be set for each battery cell 110 before applying the film coating 140 together. The adhesive dots 130 can be set according to their structure and position, and no specific restrictions are imposed here.

[0118] When multiple solar cells share a single coating, the shared coating can distribute these forces more evenly across the cells when subjected to external forces or internal stresses (such as material expansion and contraction caused by temperature changes). This reduces the pressure on each cell, decreasing the risk of damage due to excessive localized stress. Simultaneously, it can also simplify the manufacturing process of photovoltaic modules, improving production efficiency.

[0119] With each solar cell covered by a corresponding coating, the independent coating on each cell can independently buffer and disperse external forces. This independent buffering mechanism allows each cell to cope with external forces according to the characteristics and state of its own coating, reducing the probability of cell damage. For example, even if the coating on one cell undergoes localized deformation after an impact, the coatings on other cells and the cell itself can still function normally without significant impact. When facing internal stresses (such as thermal expansion and contraction of the cells due to temperature changes), the independent coatings can also better adapt to the changes in each cell. Because the coatings of each cell are independent, they can adjust accordingly based on the cell's own dimensional changes. This reduces the concentration of internal forces caused by differences in the coefficients of thermal expansion between cells, lowering the risk of damage caused by mutual compression or pulling between cells.

[0120] In cases where a film covers multiple battery cells or a film covers only one battery cell, the advantages of the aforementioned "multiple battery cells sharing a single film" and "each battery cell having its own corresponding film" can be combined.

[0121] In this way, different coating methods can be flexibly configured or different coating methods can be combined according to the specific use case, so as to improve the stress situation in different locations. No specific restrictions are put forward here.

[0122] In some embodiments, each solder strip corresponds to multiple adhesive dots. The orthographic projections of these multiple adhesive dots on the reference plane overlap with the orthographic projections of the corresponding solder strips on the reference plane.

[0123] For example, in conjunction with reference Figures 3 to 6 , Figure 9 , Figure 11 , Figure 13 and Figure 14 This illustrates the situation where each solder strip 120 corresponds to two adhesive dots 130.

[0124] In this way, multiple adhesive dots can be used to further improve the fixation effect on the solder ribbon, thereby further improving the reliability of the electrical connection between the solder ribbon and the battery cell.

[0125] In some embodiments, the solder strip has a first end and a second end disposed opposite to each other along the longitudinal direction of the solder strip. For the plurality of adhesive dots, the orthographic projection of one adhesive dot on the reference surface overlaps with the orthographic projection of the corresponding first end of the solder strip on the reference surface; and the orthographic projection of another adhesive dot on the reference surface overlaps with the orthographic projection of the corresponding second end of the solder strip on the reference surface.

[0126] For example, in conjunction with reference Figures 3 to 6 , Figure 9 , Figure 11 , Figure 13 and Figure 14 The diagram illustrates the situation where each solder strip 120 corresponds to two adhesive dots 130, with the two adhesive dots 130 located at the corresponding first end e1 and the corresponding second end e2, respectively. The longitudinal direction of the solder strip 120 is the second direction shown in the diagram, which is perpendicular to the first direction.

[0127] Thus, by setting two adhesive dots at each end of the longitudinal direction of the solder strip, the movement of the solder strip in the longitudinal direction can be more effectively restricted, and the risk of solder strip deformation due to thermal stress can be reduced. When the photovoltaic module is subjected to tensile force in the longitudinal direction of the solder strip, such as during module installation due to tension from the mounting structure or during transportation due to improper fixing, the adhesive dots at both ends of the solder strip can more effectively resist this tensile force. At the same time, the adhesive dots at both ends of the solder strip can also change the stress distribution under longitudinal force. Without adhesive dots for fixation, the tensile force will be concentrated at the connection between the solder strip and the solar cell, which can easily lead to loosening of the connection or cracking of the solar cell. With the corresponding adhesive dots, the tensile force is dispersed to the bonding interface between the adhesive dots and the solar cell, and between the adhesive dots and the solder strip. This stress dispersion mechanism reduces the stress in each local area, reducing the risk of damage caused by stress concentration. In the direction perpendicular to the longitudinal direction of the solder strip (e.g., the third direction F3 shown in the figure), when the photovoltaic module is subjected to shear force, such as the lateral wind pressure generated on the module surface when subjected to strong wind or the lateral friction force during transportation, the adhesive dots at both ends of the solder strip can play a role in resisting shear.

[0128] It should be noted that, in conjunction with reference Figures 3 to 6 , Figure 9 , Figure 11 , Figure 13 and Figure 14 The first end e1 and the second end e2 of the solder ribbon 120 are relative. The adhesive dot 130 corresponding to the first end e1 can be directly opposite the edge region of the first end e1 in the first direction, or it can be directly opposite the non-edge region of the first end e1 in the first direction. The adhesive dot 130 corresponding to the second end e2 can also be understood with reference to the adhesive dot 130 corresponding to the first end e1, and will not be elaborated here. The arrangement of the solder ribbon 120 on the battery cell 110 varies depending on the type of battery cell 110 and the electrical connection method of the battery cell 110. Figures 3 to 6 , Figure 9 , Figure 11 , Figure 13 and Figure 14This diagram illustrates a plurality of solder ribbons 120 spaced apart along a third direction, with the first, second, and third directions perpendicular to each other. Of these solder ribbons 120, a portion of the second end e2 extends out of the battery cell 110 on one side along the second direction, while another portion of the first end e1 extends out of the battery cell 110 on the other side along the second direction. For the solder ribbons 120 whose second end e2 extends out of the battery cell 110, the adhesive dot 130 corresponding to the second end e2 is directly opposite the non-edge region of the second end e2 in the first direction. For the solder ribbons 120 whose first end e1 extends out of the battery cell 110, the adhesive dot 130 corresponding to the first end e1 is directly opposite the non-edge region of the first end e1 in the first direction. The positions of the adhesive dots 130 corresponding to the first and second ends e2 of the solder ribbons 120 can be determined based on the position of the solder ribbons 120 relative to the battery cell 110, and are not specifically limited here.

[0129] Furthermore, in some embodiments, please continue to refer to Figure 3 The adhesive dots 130 corresponding to the first end e1 can be arranged at intervals along a third direction, and the adhesive dots 130 corresponding to the second end e2 can also be arranged at intervals along a third direction. At this time, the extension direction of the line connecting the centers of the adhesive dots 130 corresponding to the first end e1 is parallel to each other along the third direction, and the extension direction of the line connecting the centers of the adhesive dots 130 corresponding to the second end e2 is parallel to each other along the third direction.

[0130] This arrangement of adhesive dots not only facilitates more even stress distribution but also minimizes the positional change of each solder strip under external force, thus reducing contact resistance variations caused by solder strip displacement. It also facilitates the formation of adhesive dots through screen printing.

[0131] Of course, in other embodiments, please refer to Figure 18 , Figure 18 This diagram shows a top view of a portion of the structure in which the solder ribbon 120, adhesive dots 130, and battery cell 110 cooperate, according to other embodiments of this application. The adhesive dots 130 corresponding to the first end e1 can be staggered along a third direction, and the adhesive dots 130 corresponding to the second end e2 can also be staggered along a third direction. In this case, the lines connecting the centers of the adhesive dots 130 corresponding to the first end e1 are generally zigzag lines, and the lines connecting the centers of the adhesive dots 130 corresponding to the second end e2 are also generally zigzag lines.

[0132] This arrangement of adhesive dots provides resistance in different directions, creating a mutually restraining structure between the solder ribbons. For example, under torsional force, some adhesive dots experience tensile force while others experience compressive force. This interaction effectively counteracts the torsional force, reducing excessive twisting of the solder ribbon and solar cell, and protecting the structural integrity of the module. This enhances the overall torsional resistance of the photovoltaic module. Simultaneously, it disperses stress to surrounding areas through different transmission paths, better dispersing localized stress and reducing the risk of cell cracking and solder ribbon damage. Furthermore, it improves the tensile strength of the solder ribbon connection to another solar cell, further reducing the risk of solder ribbon misalignment at the cell edge.

[0133] In some embodiments, the coating is configured as a single-layer structure with a pre-crosslinking degree of 20% to 50%; or, the coating is configured as a multi-layer structure, comprising a plurality of sub-coatings stacked together, wherein the sub-coating closest to the battery cell among the plurality of sub-coatings has a pre-crosslinking degree of 20% to 50%.

[0134] Pre-crosslinking degree refers to the extent to which the crosslinking reaction occurs during the coating preparation process. Crosslinking reaction refers to the process by which polymer molecular chains are interconnected through chemical bonds (such as covalent bonds) to form a three-dimensional network structure. Pre-crosslinking degree can be intuitively understood as the relative number of crosslinks formed at a specific stage (usually before the final material molding) or the degree of perfection of the crosslinking structure. At the molecular level, a high pre-crosslinking degree means that more molecular chains are connected together through crosslinks, forming a relatively compact three-dimensional network. Pre-crosslinking degree can be expressed by the proportion of functional groups that have reacted and can form crosslinks. For example, in a polymer system containing double bonds, all double bonds are likely to participate in the crosslinking reaction. If initially there are 100 double bonds in the system, and after the reaction, 60 double bonds participate in the crosslinking reaction, then the pre-crosslinking degree can be expressed as 60%.

[0135] For example, when the coating is configured as a single-layer structure, the pre-crosslinking degree of the coating can be 20%, 30%, 32%, 35%, 37%, 42%, 45%, 48%, or 50%, and the pre-crosslinking degree of the coating can be any value from 20% to 50%. When the coating is configured as a multi-layer structure, the pre-crosslinking degree of the sub-coating closest to the solar cell among the multiple sub-coatings can be 20%, 30%, 32%, 35%, 37%, 42%, 45%, 48%, or 50%, and the pre-crosslinking degree of the sub-coating closest to the solar cell can be any value from 20% to 50%. No specific limitations are imposed here.

[0136] The degree of pre-crosslinking is closely related to the physical and chemical properties of the coating material. A higher degree of pre-crosslinking typically increases the material's hardness and reduces its elasticity. This is because the crosslinked structure restricts the stretching and deformation of the molecular chains, making the material more rigid. For example, the degree of pre-crosslinking is appropriately increased when manufacturing high-hardness plastic coatings. Simultaneously, the degree of pre-crosslinking also affects the material's thermal stability, solvent resistance, and other properties. Materials with a high degree of pre-crosslinking are less prone to softening and deformation at high temperatures because the crosslinked structure requires higher temperatures to be broken down.

[0137] Thus, in a single-layer coating configuration, controlling the pre-crosslinking degree of the coating not only facilitates processing and shortens processing time but also achieves a good balance between strength and toughness, providing certain support and cushioning properties. In a multi-layer coating configuration, controlling the sub-coating closest to the solar cell provides good initial mechanical protection. Simultaneously, due to its flexibility, it can adapt to minor expansion or contraction of the solar cell (such as due to temperature changes), avoiding excessive stress. The remaining sub-coatings can be configured more flexibly, providing additional protection for the solar cell. For example, the remaining sub-coatings can have better weather resistance, corrosion resistance, and other chemical protection properties, blocking ultraviolet rays, moisture, chemical gases, etc., from damaging the solar cell and inner coating. This layered protection mechanism can extend the service life of the entire coating structure and the solar cell. Furthermore, if a quality problem occurs in one of the sub-coating layers during processing, the multi-layer structure helps to isolate the problem. For example, processing defects in the outer coating will not directly affect the sub-coating closest to the solar cell and the solar cell itself, reducing the risk of the entire photovoltaic module being scrapped due to local quality problems and improving the product yield.

[0138] In some embodiments, please continue to refer to Figures 4 to 6 , Figure 9 , Figure 11 , Figure 13 and Figure 14 For the same target side of the same cell 110, the orthographic projection of each solder strip 120 on the reference plane overlaps with the orthographic projection of the corresponding coating 140 on the reference plane.

[0139] In this way, each solder strip has a corresponding coating that provides a certain fixing force, thereby further improving the reliability of the electrical connection between the solder strip and the battery cell.

[0140] Of course, in some other embodiments, for the same target side of the same battery cell, the orthographic projection of a portion of the solder strip on the reference plane may overlap with the orthographic projection of the corresponding coating on the reference plane. No specific limitations are imposed here.

[0141] In some embodiments, the minimum torque value ML of the coating satisfies: 0.1≤ML≤0.8.

[0142] For example, the minimum torque value ML for coating can be 0.1, 0.2, 0.3, 0.6, or 0.8. The minimum torque value ML for coating can be any value between 0.1 and 0.8, without specific limitation. For example, the minimum torque value ML for coating satisfies: 0.3 ≤ ML ≤ 0.8.

[0143] The torque value of the coating refers to the magnitude of the torsional torque applied to the coating during the torsion operation.

[0144] Thus, by controlling the minimum torque value of the coating, the coating has lower fluidity, allowing it to better provide the fixing force to the solder ribbon. It also further improves the flow of the encapsulating film between the solder ribbon and the cell during subsequent lamination, thereby improving soldering defects. Furthermore, it reduces the occurrence of undissolved air bubbles, thus improving appearance defects and reliability failures.

[0145] In some embodiments, the coating temperature is between 100°C and 135°C. Exemplarily, the coating temperature can be 100°C, 110°C, 120°C, 130°C, or 135°C. The coating temperature can be any value between 100°C and 135°C, and no specific limitation is made herein.

[0146] Thus, by controlling the coating temperature, the molecular chains of the coating material can be adjusted to a certain extent. This temperature range helps to make the material's molecular chains more flexible, thereby enhancing the flexibility of the coating. During subsequent use, a flexible coating can better adapt to the minute deformations of the solar cell under temperature changes and mechanical stress, reducing the risk of cell damage due to material rigidity, such as cell cracking. Simultaneously, a suitable temperature can improve the adhesion between the coating and the solar cell. Within this temperature range, the coating material may undergo some physical and chemical changes, thereby increasing the coating's adhesion to the solder ribbon.

[0147] In some embodiments, the thickness of the coating is from 50µm to 500µm. Exemplarily, the coating thickness can be 50µm, 70µm, 80µm, 90µm, 110µm, 150µm, 200µm, 300µm, 400µm, or 500µm. The coating thickness can be any value between 50µm and 500µm, and no specific limitation is made herein.

[0148] In this way, by controlling the thickness of the coating, the coating can be made easy to manufacture while possessing certain mechanical properties.

[0149] In some embodiments, the process of forming the battery string includes curing the adhesive dots, wherein the degree of crosslinking of the cured adhesive dots is greater than 90%.

[0150] Adhesive dots can be applied to designated locations using a dispensing process. Depending on the material of the adhesive dots, they can be cured using processes such as photocuring. The curing steps can be determined based on the order in which the adhesive dots are applied. For example, if the adhesive dots are applied before the solder strips, curing can be performed after the solder strips are applied, or after the coating is applied; no specific restrictions are imposed here.

[0151] The degree of crosslinking of cured adhesive dots refers to the extent to which the polymer molecular chains within the adhesive dot are interconnected by chemical bonds (covalent bonds) to form a network structure. For example, the degree of crosslinking of cured adhesive dots can be 91%, 92%, 93%, 94%, 95%, 96%, or 99%.

[0152] In this way, a highly cross-linked network structure is formed between the molecular chains of the adhesive dots. This structure gives the adhesive dots high strength and hardness, enabling them to better withstand external pressure and tension. During the use of photovoltaic modules, such as when subjected to wind, vibration, and temperature changes, the highly cross-linked adhesive dots can firmly fix the solder ribbons or other components, improving the situation of displacement or detachment and providing reliable mechanical stability for the photovoltaic modules. At the same time, the highly cross-linked adhesive dots have a low creep tendency, meaning they are not prone to slow deformation under external forces, thus more effectively fixing the solder ribbons and improving the reliability of the photovoltaic modules.

[0153] In some embodiments, the Tg of the adhesive point is ≥ 59.40℃. Tg is the temperature at which the adhesive point transitions from the glassy state to the hypercondensable state.

[0154] For example, the Tg of the adhesive spot can be 59.40℃, 60℃, 65℃, 70℃ or 80℃.

[0155] In this way, the adhesive dots can maintain their glassy or near-glassy properties at higher temperatures. This means that the adhesive dots will not easily soften or flow in high-temperature environments. For example, under some hot climatic conditions or when the temperature rises due to heat generated during operation inside photovoltaic modules, the adhesive dots can still stably fix the solder ribbons or other components.

[0156] In some embodiments, the solder strip includes at least one of round solder strip, triangular solder strip, flat solder strip, and irregularly shaped solder strip.

[0157] Circular wire bonding strips have a uniform circular cross-section, which allows for a uniform distribution of current as it propagates within the conductor. According to electrical principles, a circular conductor exhibits a more uniform current density distribution across its cross-section, effectively reducing current concentration and thus lowering resistance losses. For example, in photovoltaic modules, this uniform current transmission helps improve the electrical connection efficiency between cells, reduces heat generation caused by excessive local resistance, and enhances the overall power generation performance of the module.

[0158] The triangular shape of the solder ribbon allows it to play a role in light capture and guidance in photovoltaic modules. When light shines on the module surface, the edges of the triangle can change the direction of light propagation, reflecting some of the light that would otherwise be reflected or scattered back onto the solar cells, increasing the light-receiving area and light absorption efficiency of the cells. The triangular structure also results in a relatively large contact area between the solder ribbon and the solar cell, allowing for a good mechanical bond at the contact surface. This mechanical bond helps to fix the solder ribbon to the solar cell, reducing the possibility of solder ribbon displacement during production and use.

[0159] The flat solder strip is roughly sheet-like in shape. The larger contact area between the flat solder strip and the solar cell helps improve the stability of their connection. Electrically, the larger contact area reduces contact resistance, ensuring smooth current flow between the solar cell and the solder strip. Mechanically, the flat solder strip better conforms to the surface of the solar cell, resisting displacement under external forces and providing a more reliable connection between the cells.

[0160] The shape of irregularly shaped solder ribbons can be customized according to specific application requirements. For example, they can be designed with special reflective or refractive surfaces to optimize light distribution on the solar cells and improve light absorption efficiency. Simultaneously, in terms of electrical performance, irregularly shaped structures can also be used to adjust current distribution, such as designing wider conductive sections in areas requiring high current density to meet specific electrical connection requirements, thereby improving the overall performance of photovoltaic modules.

[0161] For example, in conjunction with reference Figures 2 to 14 This illustrates the case where the solder strip 120 is a flat solder strip 120. (Refer to the reference.) Figure 19 , Figure 19 This diagram illustrates a side cross-sectional view of a portion of the structure in which the solder ribbon 120, adhesive dots 130, and battery cell 110 mate, according to some embodiments of this application, showing the case where the solder ribbon 120 is a circular solder ribbon 120. Figure 19 The film coating 140 is omitted in the text.

[0162] Therefore, the settings can be configured according to usage requirements, and no specific restrictions are imposed here.

[0163] In some embodiments, the adhesive dot includes a first sub-adhesive dot and a second sub-adhesive dot that are independent of each other. The orthographic projection of the first sub-adhesive dot onto the reference plane is a first projection, and the orthographic projection of the second sub-adhesive dot onto the reference plane is a second projection. The corresponding first and second projections of the same adhesive dot are located on both sides of the central axis of the orthographic projection of the corresponding solder strip onto the reference plane, and both have overlapping projections with the orthographic projection of the corresponding solder strip onto the reference plane. The extending direction of the central axis of the orthographic projection of the solder strip onto the reference plane is parallel to the longitudinal direction of the solder strip.

[0164] For example, in conjunction with reference Figure 20 and Figure 21 ,exist Figure 21 The film coating 140 is omitted in the text. Figure 20 This illustrates the case where the solder strip 120 is a flat solder strip 120. Figure 21 The illustration shows a case where the solder ribbon 120 is a round solder ribbon 120. Of course, in some other embodiments, the adhesive dots 130 located on the coating 140 may be configured to include a first sub-adhesive dot 131 and a second sub-adhesive dot 132 that are independent of each other, without being specifically limited here.

[0165] In this way, because the solder ribbon is fixed and limited on both sides by adhesive dots, the risk of solder ribbon misalignment during lamination is reduced, and the reliability of the electrical connection between the solder ribbon and the solar cells during use in photovoltaic modules is further improved. Simultaneously, since the first and second sub-adhesive dots roughly correspond to the two sides of the solder ribbon, when using, for example... Figure 20 and Figure 21 As shown in the diagram, the adhesive dots 130 are arranged in a way that makes them easier to cure, resulting in a shorter curing time and thus improving the manufacturing efficiency of photovoltaic modules. For example, when the adhesive dots are light-curing adhesives, the curing time of UV-curing adhesive dots can be shortened.

[0166] In some embodiments, the shape of the orthographic projection of all adhesive dots onto the reference plane includes at least one of the following: circular, elliptical, rectangular, elongated, and frame-shaped.

[0167] For example, in Figures 3 to 6 , Figure 9 , Figure 11 , Figure 13 , Figure 14 and Figure 18 In the illustrated scenario, the orthographic projection of the adhesive dot 130 onto the reference plane is rectangular. Furthermore, by way of example, in conjunction with the reference... Figure 22 , Figure 22 This invention provides a top view schematic diagram of a portion of the structure in which the solder strip 120 and adhesive dots 130 mate, according to other embodiments of this application. Figure 22In this design, adhesive dots 130 include a first sub-adhesive dot 131 and a second sub-adhesive dot 132. The orthographic projections of the first sub-adhesive dot 131 and the second sub-adhesive dot 132 onto the reference plane are both elongated. The orthographic projections of all adhesive dots 130 onto the reference plane can have one or more shapes, and no specific limitation is made here. As another example, frame-shaped adhesive dots 130 can reduce the amount of adhesive dots 130 used compared to other forms of adhesive dots 130.

[0168] In this way, the structure of the adhesive dots can be flexibly combined and configured according to the stress conditions of the solder strips at different locations and the usage requirements of the photovoltaic modules, thereby improving the reliability of the photovoltaic modules to varying degrees and in different ways. When using a printing screen to print the adhesive dots, the mesh size on the printing screen is also set according to the structure of the adhesive dots, without specific restrictions here.

[0169] In some embodiments, please continue to refer to Figure 3 The tensile force between the welding strip 120, the adhesive dot 130, and the battery cell 110 is greater than or equal to 0.3N. Specifically, this includes, but is not limited to, controlling the corresponding tensile force by configuring the size and material of the adhesive dot 130.

[0170] For example, with Figure 4 For example, when the solder strip 120 is a flat solder strip 120, the dimension of the solder strip 120 along the third direction can be 0.4mm to 2mm, the dimension of the adhesive dot 130 along the second direction can be 0.4mm, and the dimension of the adhesive dot 130 along the third direction can be 1mm to 4mm.

[0171] For example, with Figure 20 For example, the distance between the first sub-adhesive dot 131 and the second sub-adhesive dot 132 along the third direction is greater than or equal to 0.4 mm. The dimensions of the first sub-adhesive dot 131 and the second sub-adhesive dot 132 along the second direction can both be 0.4 mm, and the dimensions along the third direction can both be 1 mm to 4 mm. The maximum value of the distance between the first sub-adhesive dot 131 and the second sub-adhesive dot 132 along the third direction can be determined based on the dimensions of the solder strip 120, the first sub-adhesive dot 131, and the second sub-adhesive dot 132 along the third direction, and no specific restrictions are imposed here.

[0172] For another example, with Figure 22 For example, the distance between the first sub-adhesive dot 131 and the second sub-adhesive dot 132 along the third direction is greater than or equal to 0.4 mm. The dimensions of the first sub-adhesive dot 131 and the second sub-adhesive dot 132 along the second direction can both be 2 mm, and the dimensions along the third direction can both be 4 mm to 10 mm. The maximum value of the distance between the first sub-adhesive dot 131 and the second sub-adhesive dot 132 along the third direction can be determined based on the dimensions of the solder strip 120, the first sub-adhesive dot 131, and the second sub-adhesive dot 132 along the third direction, and no specific restrictions are imposed here.

[0173] Continuing with the example, Figure 21 For example, when the solder strip 120 is a round solder strip 120, the dimension of the solder strip 120 along the third direction (i.e., the diameter of the solder strip 120) can be from 0.18 mm to 0.3 mm. The distance between the first sub-adhesive dot 131 and the second sub-adhesive dot 132 along the third direction is greater than or equal to 0.2 mm. The maximum value of the distance between the first sub-adhesive dot 131 and the second sub-adhesive dot 132 along the third direction can be determined based on the dimensions of the solder strip 120, the first sub-adhesive dot 131, and the second sub-adhesive dot 132 along the third direction, and is not specifically limited here.

[0174] Continuing with the example, Figure 19 For example, when the solder strip 120 is a round solder strip 120, the dimension of the solder strip 120 along the third direction (i.e., the diameter of the solder strip 120) can be 0.18 mm to 0.3 mm. The dimension of the adhesive dot 130 along the second direction can be 0.2 mm, and the dimension of the adhesive dot 130 along the third direction can be 1.5 mm to 3 mm.

[0175] In this way, by controlling the structure and size of the solder strip and adhesive dots, not only can the solder strip have a certain tensile strength, but the risk of adhesive dots penetrating between the solder strip and the battery cell and causing poor soldering can also be reduced.

[0176] In some embodiments, prior to step S120, the method includes: printing and curing an insulating adhesive layer on the battery cell.

[0177] Specifically, an insulating pattern is designed based on the electrode distribution and insulation requirements of the solar cell, and a corresponding screen is fabricated based on this pattern. An insulating adhesive layer is then formed on the corresponding positions of the solar cell using screen printing. Subsequently, the insulating adhesive layer undergoes a curing process.

[0178] This improves the prevention of short circuits between solar cells and between solar cells and other components (such as metal frames). By printing insulating adhesive at the corresponding locations, an effective insulating barrier can be formed between the conductive areas of the solar cells, allowing current to flow along the designed circuit path.

[0179] In some embodiments, prior to step S120, the method includes: printing and curing solder on the battery cell.

[0180] Specifically, the solder positions are determined based on the electrode distribution of the solar cell, and corresponding printing stencils are prepared according to these positions. The solder can be solder paste, which mainly consists of tin alloy powder (such as tin-silver-copper alloy) and flux. The printing stencil is placed above the solar cell, and the solder paste is scraped onto the stencil using a squeegee. After printing, the solder paste is deposited onto the electrodes of the solar cell through the openings in the printing stencil, forming a solder paste layer. Subsequently, the solder paste layer undergoes a curing process.

[0181] In some embodiments, after step S120, the method includes: providing a cover plate and an encapsulation layer, and processing the cover plate, encapsulation layer, and cell string using a lamination process to form a photovoltaic module.

[0182] Specifically, before lamination, the cover plate, encapsulation layer, and cover plate can be stacked together. (Refer to reference...) Figure 23 The encapsulation layer 200 is used to cover the surface of the battery string 100. The cover plate 300 is used to cover the surface of the encapsulation layer 200 away from the battery string 100. Further, the battery cells 110 are electrically connected in a single piece or in multiple pieces in the manner of forming battery strings 100 in any of the foregoing embodiments to form multiple battery strings 100, and the multiple battery strings 100 are electrically connected in series and / or parallel. The encapsulation layer 200 covers the front and back sides of the battery cells 110, thus obtaining the photovoltaic module 10.

[0183] For example, the encapsulation layer 200 can be an organic encapsulation film such as ethylene-vinyl acetate copolymer (EVA) film, polyethylene octene coelastomer (POE) film, or polyethylene terephthalate (PET) film.

[0184] For example, the cover plate 300 can be a glass cover plate, a plastic cover plate, or other cover plate with light transmission function.

[0185] For example, the surface of the cover plate 300 facing the encapsulation layer 200 can be an uneven surface, thereby increasing the utilization of incident light.

[0186] During the lamination process, the lamination temperature can be determined based on the crosslinking temperature of the encapsulation layer and the solder melting point mentioned in some of the foregoing embodiments. For example, the lamination temperature can be between 100°C and 150°C.

[0187] Thus, during the lamination process, lamination temperature and lamination pressure can be used to achieve electrical connection between the solder ribbon and the solar cell, and to form a photovoltaic module.

[0188] The following description, in conjunction with the processes illustrated in the above embodiments, provides an exemplary explanation of the photovoltaic module manufacturing method provided in this application, but it is not intended to be limited thereto.

[0189] Taking a gridless solar cell as an example, depending on the type of solar cell, one type of solar cell (such as TOPCon cells) has electrodes (i.e., sub-grid lines) on both the front and back sides, and solder ribbons need to be set on both the front and back sides. In this case, the target side of the solar cell is at least one side of the front and back sides. Another type of solar cell (such as BC cells) has electrodes (i.e., sub-grid lines) on the back side, and solder ribbons need to be set on the back side. In this case, the target side of the solar cell is the back side.

[0190] In one example scenario, assuming the solar cell has electrodes on both the front and back sides, and both the front and back sides are target sides, refer to... Figure 24 , Figure 24 The diagram only illustrates the relationship between the solder ribbons 120 and the solar cells 110. The first solar cell 110 is positioned above the rear half of the first solder ribbon group; the front half of the second solder ribbon group is positioned on top of the first solar cell 110; the second solar cell 110 is positioned above the rear half of the second solder ribbon group; the front half of the third solder ribbon group is positioned on top of the second solar cell 110; the third solar cell 110 is positioned above the rear half of the third solder ribbon group, and so on. Each solder ribbon group includes multiple solder ribbons 120.

[0191] During this process, when setting relevant components on the target side of the corresponding solar cell, the target side of the solar cell is facing upwards. The order can be: first setting the adhesive dots, then the solder ribbons, and finally the coating; or first setting the solder ribbons, then the adhesive dots, and finally the coating; or first setting the solder ribbons, then the coating, and finally the adhesive dots. Alternatively, the solder ribbons, adhesive dots, and coating can be set for each solar cell before arranging the cells; or the solder ribbons and adhesive dots can be set on all the solar cells before applying the coating together. This can result in a structure like... Figure 25 , Figure 26 , Figure 27 and Figure 28 The different structural forms shown are illustrated. Among them, Figure 25 In the illustrated scenario, both the front and back sides of the battery cell 110 are target sides, and a coating 140 is provided on both the front and back sides of the overall structure. Figure 26 In the illustrated scenario, both the front and back sides of the battery cell 110 are target sides, the front side of the overall structure is provided with multiple coatings 140, and the back side of the overall structure is provided with one coating 140. Figure 27 In the illustrated scenario, both the front and back sides of the battery cell 110 are target sides, and multiple coatings 140 are provided on both the front and back sides of the overall structure. Figure 28 In the illustrated scenario, both the front and back sides of the battery cell 110 are target sides. The front side of the overall structure has a coating 140, and the back side of the overall structure has multiple coatings 140. The arrangement of the solder ribbon 120, adhesive dots 130, and coatings 140 can be as illustrated in the aforementioned embodiments. Figures 25 to 28 The adhesive dot 130 is omitted. The arrangement of the adhesive dot 130, adhesive strip 120, and coating 140 can be varied according to different combinations; no specific limitations are specified here.

[0192] In another example, assuming the back of the solar cell has electrodes and the back side of the solar cell is the target side, refer to [reference needed]. Figure 29 , Figure 29 The diagram only illustrates the relationship between the solder ribbons 120 and the solar cells 110. Multiple solar cells 110 can be first laid on their respective support devices, with the back sides of the solar cells 110 facing upwards. Subsequently, multiple solder ribbon groups are placed on the back sides of the multiple solar cells 110, each solder ribbon group comprising multiple solder ribbons 120, forming a structure as shown below. Figure 29 The structure shown is as follows.

[0193] It should be noted that the placement of the solder ribbon 120 includes, but is not limited to, the situations described above. It can also be that the first or second half of the solder ribbon group is located on the corresponding battery cell 110; that is, the positional relationship between each solder ribbon 120 and its corresponding battery cell 110 within the solder ribbon group is approximately the same. In this process, the order of the adhesive dots 130, solder ribbons 120, and coating 140 can be understood by referring to the situations illustrated in some of the above embodiments, and will not be repeated here. In this way, a structure can be formed as follows... Figure 30 and Figure 31 The different structural forms shown. Figure 30 and Figure 31 In the illustrated scenario, the back side of the battery cell 110 is the target side. Figure 30 The diagram illustrates a configuration where a film 140 is provided on the rear side of the overall structure. Figure 31 The diagram illustrates a configuration where multiple films 140 are provided on the rear side of the overall structure. Figure 29 and Figure 30 The glue point 130 is omitted. Furthermore, in... Figures 25 to 28 , Figure 30 and Figure 31 The diagram illustrates the relative positions of the solder strip 120, the coating 140, and the battery cell 110.

[0194] It is understood that when the solar cells are gridless, a low-temperature lamination process can be used to manufacture photovoltaic modules. The solder ribbon can be a low-temperature solder ribbon, and its surface can be coated with a low-melting-point alloy or metal coating, for example, the melting point of the low-melting-point alloy or metal coating can be 140°C. During this process, because the encapsulation layer is a buffering layer, the reliability of the electrical connection between the solder ribbon and the solar cell is affected by the expansion and contraction of the material caused by temperature changes. However, in this embodiment, by setting a coating with different buffering properties than the encapsulation layer and using adhesive dots, the positional stability of the solder ribbon relative to the solar cell can be improved, thereby improving the reliability of the electrical connection between the solder ribbon and the solar cell. Furthermore, the coating allows for a thinner encapsulation layer, which is beneficial for the thinner design of photovoltaic modules. Therefore, by using the manufacturing methods illustrated in the above embodiments of this application, the reliability of the photovoltaic module can be improved during the lamination stage, TC (Thermal Cycling) reliability testing, the use of the photovoltaic module, and the transportation of the photovoltaic module.

[0195] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0196] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A method for manufacturing a photovoltaic module, characterized in that, include: Provide battery cells; Multiple battery cells are connected to form a battery string according to a preset stringing method; In the process of forming the battery string, multiple solder strips, multiple adhesive dots and a coating are set on the target side of the battery cell in a preset order; For the same target side, the coating is located on the side of the solder strip opposite to the battery cell, and the orthographic projection of the coating on the reference plane overlaps with the orthographic projection of the plurality of solder strips on the reference plane; each solder strip corresponds to at least one adhesive dot, and the orthographic projection of the adhesive dot on the reference plane overlaps with the orthographic projection of the corresponding solder strip on the reference plane. On the same target side of the same battery cell, at least some of the adhesive dots are arranged alternately in a direction that intersects both the first direction and the longitudinal direction of the solder strip. The target side of the battery cell is at least one side of the battery cell along a first direction, the first direction being the thickness direction of the battery cell, the first direction intersecting the longitudinal direction of the solder strip, and the reference surface being a plane perpendicular to the first direction.

2. The method for manufacturing a photovoltaic module according to claim 1, characterized in that, For all the adhesive dots on the same target side of the same battery cell, there exists a first target adhesive dot; Along the first direction, at least a portion of the first target adhesive dot is located between the corresponding solder strip and the battery cell.

3. The method for manufacturing a photovoltaic module according to claim 2, characterized in that, For the same target side of the same battery cell, at least one of the first target adhesive dots has an orthographic projection on the reference surface that overlaps with the orthographic projection of the corresponding coating on the reference surface; and / or For the same target side of the same battery cell, at least one of the first target adhesive dots has an orthographic projection on the reference surface that does not overlap with the orthographic projection of the corresponding coating on the reference surface.

4. The method for manufacturing a photovoltaic module according to claim 1, characterized in that, For all the adhesive dots on the same target side of all the said battery cells, there exists a second target adhesive dot; Along the first direction, at least a portion of the second target adhesive dot is located between the corresponding solder strip and the corresponding coating.

5. The method for manufacturing a photovoltaic module according to claim 1, characterized in that, For all the adhesive dots on the same target side of all the solar cells, there exists a third target adhesive dot; along the first direction, at least a portion of the third target adhesive dot is located on the corresponding side of the coating opposite to the solar cell; and / or For all the adhesive dots on the same target side of all the solar cells, there is a fourth target adhesive dot; along the first direction, at least a portion of the fourth target adhesive dot is located on the side of the corresponding solder ribbon opposite to the solar cell.

6. The method for manufacturing a photovoltaic module according to any one of claims 1-5, characterized in that, For the same target side of all the solar cells, the coating has a projection where at least a portion of the solder strips' orthogonal projection on the reference plane overlaps with the corresponding orthogonal projection of the coating on the reference plane; or For the same target side of all the solar cells, multiple coatings are provided, each coating covering at least one solar cell, and all coatings do not overlap each other. At least a portion of the solder strips have overlapping projections on the reference plane with the corresponding coating's projection on the reference plane; or For the same target side of all the solar cells, multiple coatings are provided, and all the coatings and all the solar cells are provided in a one-to-one correspondence. At least some of the solder strips have an overlapping projection on the reference surface with the corresponding coating on the reference surface.

7. The method for manufacturing a photovoltaic module according to any one of claims 1-5, characterized in that, Each of the solder strips corresponds to a plurality of adhesive dots; The orthographic projections of the plurality of adhesive dots on the reference surface and the orthographic projections of the corresponding solder strips on the reference surface have overlapping projections.

8. The method for manufacturing a photovoltaic module according to claim 7, characterized in that, The welding strip has a first end and a second end that are disposed opposite to each other along the longitudinal direction of the welding strip; For the plurality of adhesive dots, the orthographic projection of one of the adhesive dots on the reference surface overlaps with the orthographic projection of the first end of the corresponding solder strip on the reference surface; The orthographic projection of one of the adhesive dots on the reference surface overlaps with the orthographic projection of the second end of the corresponding solder strip on the reference surface.

9. The method for manufacturing a photovoltaic module according to any one of claims 1-5, characterized in that, The coating is configured as a single-layer structure, and the pre-crosslinking degree of the coating is 20% to 50%; or The coating is configured as a multilayer structure, comprising multiple sub-coatings stacked together, wherein the pre-crosslinking degree of the sub-coating closest to the battery cell is 20% to 50%.

10. A method for manufacturing a photovoltaic module according to any one of claims 1-5, characterized in that, For the same target side of the same battery cell, the orthographic projection of each of the solder strips on the reference plane overlaps with the orthographic projection of the corresponding coating on the reference plane; and / or The minimum torque value ML of the coating satisfies: 0.1 ≤ ML ≤ 0.8; and / or The coating temperature for applying the coating is 100°C to 135°C; and / or The thickness of the coating is 50µm to 500µm; and / or The process of forming the battery string includes a curing process for the adhesive dots, wherein the degree of crosslinking of the cured adhesive dots is greater than 90%; and / or The Tg of the adhesive point is ≥ 59.40℃; Tg is the temperature at which the adhesive point transitions from a glassy state to a highly solidified state; and / or The welding strip includes at least one of round wire welding strip, triangular welding strip, flat welding strip, and irregularly shaped welding strip.

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