Photovoltaic module

Abstract

The embodiment of the present application relates to the photovoltaic field, and provides a kind of photovoltaic module, comprising: at least one cell string, with first surface, and the cell string includes a plurality of solar cell pieces in series;Film, located on the first surface of cell string, film covers the first area of solder strip on cell string;Dispensing part, dispensing part is located in the second area of solder strip, and located in the side of solder strip away from solar cell piece, and the second area of solder strip and target area on the first surface of cell string do not have overlapping part in the first direction, and the first direction is the direction from cell string to film, and target area and the first area of solder strip overlap in the first direction;Encapsulation adhesive film, located on the side of film away from cell string;Cover plate, located on the surface of encapsulation adhesive film away from cell string.The photovoltaic module provided in the embodiment of the present application can reduce the thickness of encapsulation EVA adhesive film by increasing film, so as to reduce the manufacturing cost of EVA adhesive film.

Description

Technical Field

[0001] This application relates to the field of photovoltaics, and in particular to a photovoltaic module. Background Technology

[0002] Traditional photovoltaic (PV) module manufacturing processes typically involve: first, stringing solar cells together using solder ribbons to form a cell string; then, sequentially laying a lower layer of ethylene-vinyl acetate copolymer (EVA) film, a glass cover, an upper layer of EVA film, and a backsheet on both sides of the cell string; and finally, laminating and encapsulating the module under high-temperature vacuum conditions. This process relies on the EVA film having a basis weight of at least 370g to prevent the solder ribbons from puncturing the film during lamination, while the solder ribbon diameter must be maintained at at least 0.22mm to ensure sufficient mechanical strength and prevent tensile breakage. However, this process involves large material consumption, high cost, and limited space optimization. Summary of the Invention

[0003] This application provides a photovoltaic module that at least addresses the problems of high cost and large material usage of EVA film and large cell string thickness in the prior art.

[0004] According to some embodiments of this application, one aspect of this application provides a photovoltaic module, comprising: at least one battery string having a first surface, the battery string including a plurality of solar cells connected in series; a coating located on the first surface of the battery string, the coating covering a first region of a solder ribbon on the battery string; an adhesive dispensing portion located on a second region of the solder ribbon, and on the side of the solder ribbon away from the solar cells, the second region of the solder ribbon and a target region on the first surface of the battery string not overlapping in a first direction, the first direction being the direction from the battery string to the coating, the target region overlapping the first region of the solder ribbon in the first direction; an encapsulating film located on the side of the coating away from the battery string; and a cover plate located on the surface of the encapsulating film opposite to the battery string.

[0005] In some embodiments, the coating includes a plurality of sub-films, one of the sub-films covering the first region of one of the solder strips, the length of the sub-film in a second direction being the same as the length of the first region of the solder strip in the second direction, the length of the sub-film in a third direction being greater than the length of the solder strip in the third direction, any two of the sub-films not contacting each other, the second direction being perpendicular to the third direction, and the third direction being the series connection direction of the plurality of solar cells.

[0006] In some embodiments, the width of the submembrane is 3mm to 6mm.

[0007] In some embodiments, the coating covers a target area on the first surface of the battery string.

[0008] In some embodiments, the coating has a plurality of protrusions, one of which covers the first region of one of the solder strips. The length of the protrusion in a second direction is the same as the length of the first region of the solder strip in the second direction. The length of the protrusion in a third direction is greater than the length of the solder strip in the third direction. The protrusion protrudes along the first direction, and the second direction is perpendicular to the third direction, which is the series direction of the plurality of solar cells.

[0009] In some embodiments, the basis weight of the coating is 50g to 100g, and the basis weight of the encapsulating film is 270g to 330g.

[0010] In some embodiments, the diameter of the solder strip is 0.16 mm to 0.22 mm.

[0011] In some embodiments, the distance between the dispensing portion and the target edge is 2mm-5mm, and the target edge is the edge of the solar cell closest to the dispensing portion.

[0012] In some embodiments, the photovoltaic module further includes: a conductive bump, the conductive bump being located between the second region of the solar cell and the solder strip, the distance between the conductive bump and the target edge being 5mm-7mm, and the target edge being the edge of the solar cell closest to the conductive bump.

[0013] In some embodiments, the length of the conductive bump is 0.5mm to 0.6mm, and the width of the conductive bump is 1.0mm to 1.25mm.

[0014] The technical solution provided in this application has at least the following advantages: The photovoltaic module, by providing a coating on the first surface of the cell string and covering the first area of ​​the solder ribbon with the coating, essentially adding a coating between the existing solder ribbon and encapsulating film, can reduce the thickness of the encapsulating film. Since the encapsulating film is generally made of EVA film, which is expensive to manufacture, while the material cost of the coating is much lower than that of EVA film, reducing the thickness of the encapsulating film significantly reduces the overall manufacturing cost of the photovoltaic module. Furthermore, directly using the coating to hydraulically fix the solder ribbon eliminates the need for solder ribbon welding, thus reducing the solder ribbon diameter. Simultaneously, a dispensing portion is provided on the side of the solder ribbon away from the solar cell in its second area, ensuring that this second area does not overlap with the target area on the first surface of the cell string in the first direction from the cell string to the coating. The target area overlaps with the first area of ​​the solder ribbon in this direction, so that the dispensing portion only acts on the solder ribbon area not covered by the coating. This provides additional local adhesion to the solder ribbon without relying on high-weight encapsulating film or thickened solder ribbon, significantly enhancing the bonding reliability between the solder ribbon and the cell string. Attached Figure Description

[0015] One or more embodiments are illustrated by way of example with reference to the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Unless otherwise stated, the drawings in the accompanying drawings do not constitute a limitation on scale. In order to more clearly illustrate the technical solutions in the embodiments of this application or in the conventional art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 A schematic diagram of the structure of a photovoltaic module according to an embodiment of this application is shown;

[0017] Figure 2 A schematic diagram of the structure of a photovoltaic module is shown when the solar cell provided in the embodiments of this application is a TOPCon cell;

[0018] Figure 3 A schematic diagram of the structure of a photovoltaic module is shown when the solar cell provided in the embodiments of this application is a back-contact cell;

[0019] Figure 4 A schematic diagram of the structure of a first type of coating provided according to an embodiment of this application is shown;

[0020] Figure 5 A schematic diagram of the structure of a second type of coating provided according to an embodiment of this application is shown;

[0021] Figure 6 A schematic diagram of a third type of coating provided according to an embodiment of this application is shown;

[0022] Figure 7 A schematic diagram of the structure of another photovoltaic module provided according to an embodiment of this application is shown.

[0023] The above figures include the following reference numerals:

[0024] 100. Solar cell; 110. Coating; 111. Sub-film; 112. Protrusion; 120. Encapsulating film; 130. Cover plate; 140. Solder ribbon; 150. Dispensing part; 160. Conductive bump. Detailed Implementation

[0025] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0026] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0027] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A exists, A and B exist simultaneously, and B exists. In addition, the character " / " in this document generally indicates that the related objects before and after it have an "or" relationship.

[0028] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0029] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0030] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to 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. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0031] In the accompanying drawings corresponding to the embodiments of this application, the thickness and area of ​​the layers are enlarged for better understanding and ease of description. When describing a component (such as a layer, film, region, or substrate) on or on the surface of another component, the component may be "directly" located on the surface of the other component, or there may be a third component between the two components. Conversely, when describing a component on the surface of another component, or when another component is formed or disposed on the surface of a component, it indicates that there is no third component between the two components. Furthermore, when describing a component as being "generally" formed on another component, it means that the component is not formed on the entire surface (or front surface) of the other component, nor is it formed on a portion of the edge of the entire surface.

[0032] In the description of the embodiments of this application, when a component "includes" another component, other components are not excluded unless otherwise stated, and other components may be further included. Furthermore, when a component such as a layer, film, region, or plate is referred to as being "on / located" on another component, it can be "directly on" the other component (i.e., located on the surface of the other component with no other components between them), or another component may be present therein. Moreover, when a component such as a layer, film, region, or plate is "directly located" on another component, or when a component such as a layer, film, region, or plate is located on the surface of another component, it indicates that no other components are located therein.

[0033] The terminology used in the description of the various embodiments herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used in the description of the various embodiments and the appended claims, the term "part" is also intended to include the plural form unless the context clearly indicates otherwise. Components include layers, films, regions, or plates, etc.

[0034] As described in the background section, existing photovoltaic modules are mainly manufactured using traditional stringing and lamination processes. The process involves connecting solar cells in series with solder ribbons to form a cell string, then laying EVA (ethylene-vinyl acetate copolymer) encapsulating film on the top and bottom surfaces of the cell string, and finally laminating the glass cover, encapsulating film, and cell string together. In this process, the front encapsulating film basis weight is typically 300–350 g / m², and the back encapsulating film basis weight is 330–380 g / m². The solder ribbon diameter is generally limited to 0.22 mm or more to avoid short circuits caused by the solder ribbon piercing the encapsulating film during lamination due to excessive thinness, or bending and breakage during stretching and welding due to excessive thinness. To ensure welding reliability, the main grid lines of the cell need to be designed as continuous paths. The bonding between the solder ribbon and the cell depends entirely on the adhesion of the encapsulating film and the welding strength of the silver paste; there are no additional reinforcing structures at the beginning and end areas.

[0035] In the aforementioned technologies, the film basis weight and the solder ribbon diameter are mutually restrictive, making it difficult to further reduce the film basis weight (short-circuit risk increases significantly below 370 g / m²), and the solder ribbon diameter cannot break through the lower limit of 0.22 mm, resulting in almost exhausted space for cost reduction in module materials. Simultaneously, in traditional designs, the bonding strength between the solder ribbon and the beginning and end areas of the cell depends on the welding quality of the main busbar silver paste. Under reliability testing conditions such as high temperature and humidity, and thermal cycling, solder ribbon detachment from the main busbar is prone to failure, increasing the risk of module power degradation and microcracks.

[0036] To address the issues of high cost, large material usage, and thick battery strings associated with existing EVA films, embodiments of this application provide a photovoltaic module.

[0037] The embodiments of this application will now be described in detail with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been provided in the embodiments of this application to facilitate a better understanding of the application. However, the technical solutions claimed in this application can be implemented even without these technical details and various variations and modifications based on the following embodiments.

[0038] Figure 1 This is a schematic diagram of the structure of a photovoltaic module according to an embodiment of this application. Figure 1 and Figure 7As shown, the photovoltaic module includes: at least one cell string having a first surface, the cell string including a plurality of solar cells 100 connected in series; a coating 110 located on the first surface of the cell string, the coating 110 covering a first region of a solder ribbon 140 on the cell string; an adhesive dispensing portion 150 located in a second region of the solder ribbon 140, and located on the side of the solder ribbon 140 away from the solar cells 100, the second region of the solder ribbon 140 and a target region on the first surface of the cell string not overlapping in a first direction, the first direction being the direction from the cell string to the coating 110, the target region overlapping the first region of the solder ribbon 140 in the first direction; an encapsulating film 120 located on the side of the coating 110 away from the cell string; and a cover plate 130 located on the surface of the encapsulating film 120 opposite to the cell string.

[0039] In this embodiment, a battery string is formed by connecting multiple solar cells in series via solder ribbons. Therefore, in this application, the solder ribbons on the battery string refer to the solder ribbons on the surface of the solar cells, and the first surface of the battery string refers to the first surface of the solar cells. In some embodiments, the coating material can be EVA adhesive, POE adhesive, or EVA-POE-EVA co-extruded composite film, such as... Figure 1 As can be seen, the coating 110 is applied separately to a single battery cell. In this embodiment, the encapsulating film consists of a coating applied separately to a single battery cell and an encapsulating film covering the entire battery string. In contrast, existing technology involves a single encapsulating film covering the entire battery string. The thickness of this coating applied separately to a single battery cell can be set slightly thinner, effectively reducing the overall thickness of the encapsulating film and lowering its manufacturing cost.

[0040] Specifically, the main function of the individual film coating on the battery cell is to fix the solder ribbon and prevent it from shifting, while also providing a certain degree of encapsulation. Therefore, the original encapsulation film can be made thinner, with its thickness only needing to meet the requirements of encapsulation and sealing. The combination of two films reduces the protective pressure borne by each layer individually, thus allowing for a reduction in the thickness of each layer, resulting in a smaller overall thickness than a single-layer film. If there is only one layer of encapsulation film, this layer needs to meet all protection requirements (e.g., mechanical strength, insulation, waterproofing). To ensure safety redundancy and reliability, this layer is usually designed to be thicker to prevent failure due to localized damage or aging. In other words, the multi-layer thin-film structure has a physical "redundant protection" effect; even if one layer has a small defect, another layer can compensate, so each layer can be made thinner, reducing the overall thickness without compromising safety. Therefore, when using a structure of "individual cell coating + overall encapsulation film for the battery string," both the coating and the encapsulation film can be designed to be thinner, resulting in a smaller overall thickness than a "single-layer overall encapsulation film for the battery string." The single-layer encapsulation film needs to be thick enough to handle all risks.

[0041] The photovoltaic module described in this application adds a coating to the first surface of the cell string, covering the first area of ​​the solder ribbon. This coating provides a localized mechanical protection layer for the solder ribbon, replacing the traditional puncture-resistant function of the encapsulating film in the solder ribbon area. Therefore, the entire encapsulating film no longer needs to be thick, allowing for the safe use of thinner encapsulating films (270–300 g / m²), thus reducing the thickness of the encapsulating film and achieving both material cost reduction and technological breakthroughs. Furthermore, since encapsulating films typically use EVA film, which is expensive to manufacture, while the material cost of the coating is far lower than that of EVA film, reducing the thickness of the encapsulating film significantly reduces the overall manufacturing cost of the photovoltaic module.

[0042] Furthermore, by directly using a coating and hydraulically fixing the solder ribbon, the reliability of the welding no longer relies entirely on the high-strength bond between the solder melt and the intermetallic compound (IMC). Instead, a composite connection mechanism is used, with the coating providing mechanical anchoring and adhesive dispensing providing interfacial bonding. This allows the solder ribbon to achieve a tensile strength of >1.0N even at thinner ribbons and lower welding temperatures, thereby reducing the ribbon diameter. Simultaneously, an adhesive dispensing area is placed on the side of the solder ribbon furthest from the solar cell in its second region. This second region is ensured to not overlap with the target region on the first surface of the cell string in the first direction from the cell string towards the coating, while the target region overlaps with the first region of the solder ribbon in this direction. This means the adhesive dispensing only acts on the area of ​​the solder ribbon not covered by the coating, thus providing additional localized adhesion to the solder ribbon while hydraulically fixing it with the coating, significantly enhancing the bonding reliability between the solder ribbon and the cell string.

[0043] The solar cells include tunnel oxide passivated contact (TOPCon) cells and back contact cells. TOPCon cells have electrodes on both the front and back sides; that is, TOPCon cells have solder ribbons connecting multiple solar cells on both the front and back sides. Therefore, as... Figure 2 As shown, when the battery string is a TOPCon battery, the coating 110 is located on both the front and back sides of the solar cell 100, and both the front and back sides of the solar cell 100 are connected by solder ribbons 140. In this case, the first surface refers to either the front or back side of the solar cell 100. However, back-contact batteries only have electrodes on the back side; that is, back-contact batteries only have solder ribbon connections on the back side of the solar cell. Therefore, as... Figure 3 As shown, when the battery string is a back-contact battery, the solar cell 100 is only connected by the solder strip 140 on the back side, and the coating 110 is only located on the back side of the solar cell 100. The first surface refers to the back side of the solar cell 100.

[0044] In some embodiments, such as Figure 4 As shown, the coating 110 includes a plurality of sub-films 111, one of the sub-films 111 covering the first region of one of the solder ribbons 140. The length of the sub-film 111 in the second direction is the same as the length of the first region of the solder ribbon 140 in the second direction. The length of the sub-film 111 in the third direction is greater than the length of the solder ribbon 140 in the third direction. Any two of the sub-films 111 do not contact each other. The second direction is perpendicular to the third direction. The third direction is the series connection direction of the plurality of solar cells 100.

[0045] in, Figure 4 The sub-membrane shown is rectangular, but in some embodiments, the shape of the sub-membrane can be any shape, not limited to a rectangle, but can also be an ellipse or an irregularly shaped shape, as long as it covers the first area of ​​the solder strip.

[0046] In this embodiment, the coating is designed as multiple independent sub-films, each sub-film precisely corresponding to and covering the first area of ​​a single solder ribbon, and its length in the second direction is consistent with the length of the first area of ​​the solder ribbon in that direction. This ensures that the coating is perfectly aligned with the length of the first area in the lateral direction, while its length in the third direction is greater than the width of the solder ribbon, allowing the coating to fully cover the critical area of ​​the solder ribbon. Any two sub-films do not contact each other, effectively blocking the connection between the adhesive films of adjacent solder ribbons. This avoids stress concentration, solder ribbon misalignment, and positioning failure caused by material compression during the overall coating process. It also eliminates material waste caused by over-coverage, achieving precise matching and independent encapsulation of the coating and solder ribbon. This not only ensures electrical insulation and mechanical fixation functions but also significantly improves the stability of the encapsulation process and material utilization.

[0047] In some embodiments, the width of the sub-membrane is 3mm to 6mm.

[0048] In this embodiment, the width of the sub-film is set to 3mm~6mm. This range is optimized based on the typical dimensions of the solder ribbon in the third direction and the lamination process tolerance. This ensures that when the sub-film covers the first area of ​​the solder ribbon, it can completely cover the edge of the solder ribbon, avoiding the short circuit risk caused by exposed solder ribbon, while also preventing the sub-film from extending into the adjacent solder ribbon area due to excessive width, causing film material redundancy or contact between adjacent sub-films. This effectively suppresses defects such as bubbles, delamination, or stress concentration caused by film material overlap during the lamination process while maintaining precise alignment between the coating and the solder ribbon. At the same time, this width range matches the length of the solar cell in the second direction, allowing each sub-film to extend completely along the cell, maximizing material utilization and ensuring consistency of the encapsulation structure. Ultimately, under the structural constraints of fixed solder ribbon spacing and limited cell length, it balances encapsulation reliability, process stability, and cost control.

[0049] In some embodiments, such as Figure 5 As shown, the coating 110 covers the target area on the first surface of the battery string.

[0050] The target area on the first surface of the battery string is also the target area on the first surface of the solar cell. The target area is the middle area of ​​the solar cell, that is, the area excluding the edges. The boundary of the target area is about 8mm-10mm away from the edge of the solar cell. Since the edge area of ​​the solar cell needs to be equipped with adhesive dots and conductive bumps, the coating does not need to cover the entire first surface of the solar cell, but only the target area on the first surface of the solar cell.

[0051] In addition, the coating can be as follows: Figure 4 The multiple sub-membranes shown can also be a single, integral membrane, as illustrated. Figure 5 As shown, Figure 5The coating shown is rectangular, but in some embodiments, the shape of the coating can be any shape, not limited to a rectangle, but can also be elliptical or irregularly shaped, as long as it covers the target area.

[0052] In this embodiment, by limiting the coating to cover a target area on the first surface of the battery string, which overlaps with the first area of ​​the solder ribbon in the first direction, the coating ensures a complete and definite coverage and fixation of the contact area between the solder ribbon and the battery cell, thereby effectively suppressing displacement or pull-out of the solder ribbon under thermal cycling or mechanical stress. At the same time, since the adhesive dispensing part is located in the second area of ​​the solder ribbon and does not overlap with the target area in the first direction, the coating and the adhesive dispensing part respectively undertake the bonding function of different areas of the solder ribbon. The two are spatially separated and complementary in function, avoiding the risk of fixation failure caused by the ambiguity of the coating coverage area, improving the overall adhesion reliability between the solder ribbon and the battery cell, and thus solving the problem of insufficient cost reduction space and short circuit and pull-out risks caused by the limited basis weight of the adhesive film and the diameter of the solder ribbon. This achieves the technical effect of significantly enhancing the long-term operational stability of the module without increasing material costs.

[0053] In some embodiments, such as Figure 6 As shown, the coating has a plurality of protrusions 112, one of the protrusions 112 covering the first region of one of the solder strips 140. The length of the protrusion 112 in the second direction is the same as the length of the first region of the solder strip 140 in the second direction. The length of the protrusion 112 in the third direction is greater than the length of the solder strip 140 in the third direction. The protrusion 112 protrudes along the first direction. The second direction is perpendicular to the third direction. The third direction is the series connection direction of the plurality of solar cells 100.

[0054] In this embodiment, the coating is provided with multiple protrusions, each of which precisely covers the first area of ​​the corresponding solder ribbon. The length of the protrusion in the second direction is consistent with the length of the solar cell in the second direction, ensuring that the coating fully covers the solder ribbon along the width of the cell. At the same time, the length of the protrusion in the third direction is greater than the length of the solder ribbon in the third direction, so that the coating forms an extended covering structure on both sides of the solder ribbon in the series direction, effectively covering the edge area of ​​the solder ribbon and preventing the solder ribbon from being partially suspended or not firmly fixed due to insufficient coating width. Combined with the adhesive part being set in the second area of ​​the solder ribbon away from the cell and not overlapping with the first area covered by the coating in the first direction, the mutual interference between the adhesive film and the adhesive part is avoided, thereby forming a bidirectional limit on the solder ribbon in the series direction. This significantly reduces the risk of lateral displacement or pull-out of the solder ribbon due to thermal stress or external force, improves the positioning stability and mechanical reliability of the solder ribbon in the encapsulation structure, and ultimately solves the problems of incomplete coverage, fixation failure and short circuit risk caused by the limited basis weight of the adhesive film and the diameter of the solder ribbon in the prior art, achieving synergistic optimization of cost reduction and reliability.

[0055] In addition, in some embodiments, the film may not have protrusions, and it can be achieved by simply covering the target area with a flat film.

[0056] In some embodiments, the basis weight of the coating is 50g to 100g, and the basis weight of the encapsulating film is 270g to 330g.

[0057] In the above embodiments, the basis weight of the coating is 50g~100g, and the basis weight of the encapsulating film is 270g~330g. Specifically, if the battery is a TOPCon battery, the first surface is either the front or back of the TOPCon battery, meaning the encapsulating film is distributed on both the front and back of the battery. In this case, the basis weight of the entire encapsulating film on the front is 270-300g, and the basis weight of the entire encapsulating film on the back is 300-330g. In contrast, in the prior art, the lightest basis weight of an encapsulating film on one side can only be controlled at 370g. Therefore, the above embodiments can effectively reduce the basis weight of the encapsulating film. If the battery is a back-contact battery, the first surface is the back of the back-contact battery, and the basis weight of the entire encapsulating film on the back is 300-330g.

[0058] In this embodiment, by limiting the basis weight of the coating to 50g~100g and the basis weight of the encapsulating film to 270g~330g, precise distribution of the encapsulating film material in the module structure is achieved: the coating locally covers the first area of ​​the solder ribbon with a low basis weight, which not only ensures the initial fixation of the solder ribbon and the cell before lamination, reducing material usage and cost, but also avoids short circuits caused by solder ribbon puncture due to excessive film thickness; at the same time, the encapsulating film can still provide sufficient sealing and mechanical support while significantly reducing the basis weight compared to the traditional solution of 370g or more. Since the coating has already undertaken part of the solder ribbon positioning and stress buffering functions, this basis weight range is sufficient to ensure the long-term bonding reliability of the solder ribbon and the cell. Thus, without sacrificing the safety and durability of the module, it effectively breaks through the technical bottleneck of limited cost reduction space and difficulty in balancing reliability in traditional design, and achieves the comprehensive effect of optimizing material cost and synergistically improving electrical reliability.

[0059] In some embodiments, the diameter of the solder strip is 0.16 mm to 0.22 mm.

[0060] In this embodiment, by limiting the diameter of the solder ribbon to 0.16mm~0.22mm, and combining it with a structural design where the coating only covers the first area of ​​the solder ribbon, the adhesive dispensing part is located in the second area of ​​the solder ribbon and does not overlap with the target area on the first surface of the battery string in the first direction, the thinner solder ribbon is stably fixed under the local support of the coating. At the same time, the adhesive dispensing part is located above the solder ribbon side in the non-target area, which effectively avoids stress concentration at the junction of the solder ribbon and the battery cell due to adhesive dispensing. Thus, without increasing the basis weight of the adhesive film, the tensile strength and puncture resistance of the thin solder ribbon are significantly improved, preventing the risk of pull-out or perforation short circuit caused by the excessively thin solder ribbon. This achieves the goal of reducing the cost of solder ribbon materials and the amount of adhesive film used while ensuring the electrical reliability and mechanical stability of the module during long-term operation.

[0061] In some embodiments, such as Figure 7 As shown, the dispensing portion 150 is located in the second region of the solder ribbon 140 and is located on the side of the solder ribbon 140 away from the solar cell 100. The distance between the dispensing portion 150 and the target edge is 2mm-5mm. The target edge is the edge of the solar cell 100 that is closest to the dispensing portion 150.

[0062] In this embodiment, by placing the dispensing portion on the side of the solder ribbon away from the solar cell and in its second region, and limiting the distance between the dispensing portion and the nearest edge of the solar cell to 2mm-5mm, while ensuring that the second region does not overlap with the target region on the first surface of the cell string in the first direction, and the target region overlaps with the first region of the solder ribbon in the first direction, the dispensing portion is precisely positioned in the transition area between the end of the solder ribbon and the edge of the cell. This avoids the adhesive overflowing into the first region of the solder ribbon covered by the film, which would interfere with the welding stability, and also prevents the adhesive from being unable to effectively anchor the joint between the end of the solder ribbon and the edge of the cell due to the dispensing position being too far away. Thus, while ensuring that the adhesive distribution is controllable and there is no risk of adhesive overflow during the lamination process, the mechanical bonding force between the solder ribbon and the edge of the cell is significantly enhanced, effectively suppressing the risk of solder ribbon pull-out and short circuit, and improving the long-term reliability and encapsulation yield of the module.

[0063] In some embodiments, such as Figure 7 As shown, the photovoltaic module further includes a conductive bump 160, which is located between the second region of the solar cell 100 and the solder strip 140. The distance between the conductive bump 160 and the target edge is 5mm-7mm, and the target edge is the edge of the solar cell 100 that is closest to the conductive bump 160.

[0064] The conductive bumps are actually solder pads, and the material can be silver paste. The conductive bumps can ensure that the silver paste points at the beginning and end of the cell are welded to the solder strip. The tensile force is greater than 1N, and the solder strip is pulled off the main busbar after the reliability of the module is ensured.

[0065] In this embodiment, by setting conductive bumps between the second region of the solar cell and the solder ribbon, and limiting the distance between the conductive bumps and the nearest edge of the solar cell to 5mm-7mm, the conductive bumps act as a physical reinforcement structure directly located at the interface between the solder ribbon and the cell. This significantly improves the mechanical anchoring strength and electrical connection reliability between the second region of the solder ribbon and the cell without increasing the basis weight of the adhesive film or the diameter of the solder ribbon. Simultaneously, the design of non-overlapping of the second region of the solder ribbon and the target region on the first surface of the cell string in the first direction ensures that the solder ribbon contacts the cell only through the conductive bumps. This avoids the risk of pull-out due to insufficient interfacial bonding force in traditional dispensing or adhesive film bonding methods. Experimental verification shows that this distance range effectively balances stress concentration and current conduction path, prevents edge crack propagation, and ensures the structural stability of the conductive bumps during reliability tests such as thermal cycling and damp heat aging. Thus, while maintaining the lightweight and low-cost design of the module, this completely solves the technical problem of easy pull-out of the solder ribbon in the second region, achieving a substantial improvement in the long-term operational reliability of the module.

[0066] In some embodiments, the length of the conductive bump is 0.5mm to 0.6mm, and the width of the conductive bump is 1.0mm to 1.25mm.

[0067] In this embodiment, by limiting the length of the conductive bump to 0.5mm~0.6mm and the width to 1.0mm~1.25mm, the conductive bump forms a stable and controllable physical contact and electrical connection structure in the tiny gap between the second region of the solder ribbon and the edge of the solar cell. This ensures sufficient contact area to improve the mechanical adhesion strength and conductivity reliability between the solder ribbon and the edge region of the solar cell, while avoiding encroachment on adjacent structural space or short circuit risks due to excessive size. At the same time, it ensures that under the edge distance constraint of 5mm~7mm, the conductive bump acts precisely on the stress concentration area where solder ribbon pull-off is prone to occur, significantly enhancing the solder ribbon's resistance to pull-off and maintaining a welding bond force greater than 1N. Thus, without changing the original coating, dispensing section and solder ribbon layout, it achieves precise reinforcement of the electrical-mechanical dual connection of the beginning and end regions of the solar cell, effectively solving the problems of insufficient bonding force and decreased reliability caused by the limited basis weight of the adhesive film and the diameter of the solder ribbon.

[0068] Those skilled in the art will understand that the above embodiments are specific examples of implementing this application, and in practical applications, various changes in form and detail can be made without departing from the spirit and scope of this application. Any person skilled in the art can make various alterations and modifications without departing from the spirit and scope of this application; therefore, the scope of protection of this application should be determined by the scope defined in the claims.

Claims

1. A photovoltaic module, characterized in that, include: At least one battery string having a first surface, the battery string comprising a plurality of solar cells connected in series; A coating is located on the first surface of the battery string, the coating covering a first area of ​​the solder strips on the battery string; The adhesive dispensing section is located in the second region of the solder ribbon and on the side of the solder ribbon away from the solar cell. The second region of the solder ribbon does not overlap with the target region on the first surface of the battery string in a first direction, where the first direction is from the battery string to the coating. The target region overlaps with the first region of the solder ribbon in the first direction. An encapsulating film is located on the side of the coating away from the battery string; A cover plate is located on the surface of the encapsulating film facing away from the battery string; The coating includes multiple sub-films, one of the sub-films covering the first region of one of the solder strips, the length of the sub-film in the third direction is greater than the length of the solder strip in the third direction, any two sub-films do not contact each other, and the third direction is the series connection direction of the multiple solar cells; The photovoltaic module further includes a conductive bump located between the solar cell and the second region of the solder strip.

2. The photovoltaic module according to claim 1, characterized in that, The length of the sub-film in the second direction is the same as the length of the first region of the solder strip in the second direction, and the second direction is perpendicular to the third direction.

3. The photovoltaic module according to claim 2, characterized in that, The width of the submembrane is 3mm to 6mm.

4. The photovoltaic module according to claim 1, characterized in that, The coating covers the target area on the first surface of the battery string.

5. The photovoltaic module according to claim 4, characterized in that, The coating has a plurality of protrusions, one of which covers the first region of one of the solder strips. The length of the protrusion in the second direction is the same as the length of the first region of the solder strip in the second direction. The length of the protrusion in the third direction is greater than the length of the solder strip in the third direction. The protrusion protrudes along the first direction. The second direction is perpendicular to the third direction, which is the series direction of the plurality of solar cells.

6. The photovoltaic module according to claim 1, characterized in that, The basis weight of the coating is 50g~100g, and the basis weight of the encapsulating film is 270g~330g.

7. The photovoltaic module according to claim 1, characterized in that, The diameter of the welding strip is 0.16mm to 0.22mm.

8. The photovoltaic module according to claim 1, characterized in that, The distance between the dispensing part and the target edge is 2mm-5mm, and the target edge is the edge of the solar cell closest to the dispensing part.

9. The photovoltaic module according to claim 1, characterized in that, The distance between the conductive bump and the target edge is 5mm-7mm, and the target edge is the edge of the solar cell closest to the conductive bump.

10. The photovoltaic module according to claim 9, characterized in that, The length of the conductive bump is 0.5mm to 0.6mm, and the width of the conductive bump is 1.0mm to 1.25mm.

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