A photovoltaic module

Abstract

This disclosure relates to the photovoltaic field, and particularly to a photovoltaic module, comprising: multiple cell strings, each cell string including multiple solar cells arranged along a first direction, each solar cell including a cell body and multiple pads disposed on the cell body; multiple first busbars extending along a second direction, the multiple first busbars being located at opposite ends of the cell strings and electrically connected to the cell strings; at least one electrical connector extending along the first direction and electrically connected to two oppositely disposed first busbars; wherein, the cell body includes a first region, the first region being a region on the cell body near the connection position of the first busbars and the electrical connector, and within the first region, the area of ​​at least one pad is larger than the area of ​​pads located in other regions on the cell body excluding the first region, which can at least improve the reliability and manufacturing yield of the photovoltaic module.

Description

Technical Field

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

[0002] With the rapid development of the photovoltaic industry, photovoltaic modules, as the core component of solar power generation systems, have undergone continuous optimization in structural design and manufacturing processes. Currently, photovoltaic modules typically consist of multiple cells connected in series via solder strips to form a cell string, and then multiple cell strings are connected in parallel or series via busbars. Simultaneously, to address issues such as circuit continuity during the parallel / series connection of cell strings, jumpers are introduced into photovoltaic modules to optimize circuit connections.

[0003] However, the mechanical stress generated by the deformation or displacement of the jumper wire during the encapsulation or use of photovoltaic modules can be transmitted to the busbar and solder strip connection areas, damaging the stability of the solder interface and thus affecting the reliability of the photovoltaic modules. Summary of the Invention

[0004] This disclosure provides a photovoltaic module that can at least improve the reliability and manufacturing yield of the photovoltaic module.

[0005] This disclosure provides a photovoltaic module, comprising: a plurality of cell strings, each cell string including a plurality of solar cells arranged along a first direction, each solar cell including a cell body and a plurality of pads disposed on the cell body; a plurality of first busbars extending along a second direction, the plurality of first busbars being located at opposite ends of the cell strings and electrically connected to the cell strings; and at least one electrical connector extending along the first direction and electrically connected to two oppositely disposed first busbars; wherein the cell body includes a first region, the first region being a region on the cell body near the connection position of the first busbars and the electrical connector, and within the first region, the area of ​​at least one of the pads is larger than the area of ​​pads located in other regions on the cell body other than the first region.

[0006] Optionally, the plurality of pads are arranged on the cell body along the first direction and the second direction; within the first region, along the first direction, the area of ​​the pads closer to the connection position is greater than the area of ​​the pads farther from the connection position, and along the second direction, the area of ​​the pads closer to the connection position is greater than the area of ​​the pads farther from the connection position.

[0007] Optionally, within the first region, the area ratio between two adjacent pads along the first direction is greater than the area ratio between two adjacent pads along the second direction.

[0008] Optionally, along the first direction, the area ratio between two adjacent pads is 0.90 to 0.99.

[0009] Optionally, along the second direction, the area ratio between two adjacent pads is 0.80 to 0.95.

[0010] Optionally, the battery cell body includes a second region, which is the other region on the battery cell body besides the first region; within the second region, along the first direction, the area of ​​the pads closer to the first region is greater than the area of ​​the pads farther from the first region, and along the second direction, the area of ​​the pads closer to the first region is greater than the area of ​​the pads farther from the first region.

[0011] Optionally, along the first direction, the area ratio between two adjacent pads in the first region is greater than the area ratio between two adjacent pads in the second region, and along the second direction, the area ratio between two adjacent pads in the first region is greater than the area ratio between two adjacent pads in the second region.

[0012] Optionally, along the first direction, the area ratio between two adjacent pads in the first region is 0.90 to 0.99, and the area ratio between two adjacent pads in the second region is 0.80 to 0.95.

[0013] Optionally, along the second direction, the area ratio between two adjacent pads in the first region is 0.90 to 0.99, and the area ratio between two adjacent pads in the second region is 0.80 to 0.95.

[0014] Optionally, the area of ​​the pad is 0.15 mm² to 1 mm².

[0015] Optionally, the ratio of the width of the battery cell body in the second direction to its width in the first direction is 2 to 4.

[0016] The technical solution provided in this disclosure has at least the following advantages:

[0017] The photovoltaic module disclosed herein increases the contact area between the pad and the solder strip by designing at least one solder pad area larger than that in other areas in the first region, near the connection point between the cell and the busbar and the electrical connector. This improves the welding strength. As a result, the stress transmitted to the busbar due to the stretching or thermal deformation of the electrical connector can be effectively alleviated, the risk of solder strip desoldering or poor soldering is reduced, and the reliability and manufacturing yield of the photovoltaic module are ultimately improved. Attached Figure Description

[0018] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0019] Figure 1 This is a partial structural diagram of a conventional photovoltaic module in the prior art;

[0020] Figure 2 for Figure 1 An enlarged diagram showing the area circled in the middle;

[0021] Figure 3 This is a schematic diagram of the structure of a photovoltaic module provided in an embodiment of this disclosure;

[0022] Figure 4 This is a partial structural schematic diagram of a photovoltaic module provided in an embodiment of the present disclosure;

[0023] Figure 5 A partial structural schematic diagram of another photovoltaic module provided in an embodiment of this disclosure;

[0024] Figure 6 This is a partial structural schematic diagram of another photovoltaic module provided in an embodiment of the present disclosure.

[0025] Explanation of reference numerals in the attached figures:

[0026] Long jumper 1, busbar 2, solder ribbon 3, battery string 20, first busbar 21, electrical connector 22, solar cell 201, cell body 202, solder pad 203, first zone 204, first sub-cell string 206, second sub-cell string 207, second busbar 24, second zone 208. Detailed Implementation

[0027] refer to Figure 1 and Figure 2 , Figure 1 This is a partial structural diagram of a conventional photovoltaic module in the prior art; Figure 2 for Figure 1 The enlarged diagram shows the area circled in the center. In conventional photovoltaic modules, when a string of cells needs to be connected to the junction box via a long jumper cable 1, the other end of the jumper cable 1 is welded to the busbar 2. In actual production and reliability testing, it was found that during lamination or subsequent use, the long jumper cable 1 experiences continuous tensile force due to its own weight, thermal expansion, or mechanical stretching, causing displacement of the busbar 2 connected to it. Furthermore, this displacement is directly transmitted to the solder strip 3 welded to the busbar, subjecting the solder joint to additional shear or peeling stress. Under stress concentration, the solder strip 3 is prone to pull-out, leading to poor soldering or even open circuits, severely affecting the reliability of the photovoltaic module.

[0028] To address this issue, the industry typically considers increasing the welding area between the solder strip and the busbar or using higher-strength solder to improve connection strength. However, these methods may lead to increased costs, increased process complexity, or thermal damage to other areas. More importantly, the stress source lies in the localized stress concentration in the connection structure, and traditional pad designs cannot specifically address this localized high-stress area.

[0029] Based on an in-depth analysis of the aforementioned technical problems, this disclosure provides a photovoltaic module that increases the welding strength in the area near the connection between the busbar and the electrical connector on the cell, thereby effectively mitigating the stress transmitted to the busbar due to the stretching or thermal deformation of the electrical connector, reducing the risk of solder strip desoldering or incomplete soldering, and ultimately improving the reliability and manufacturing yield of the photovoltaic module.

[0030] In the description of the embodiments of this disclosure, 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 or secondary relationship of the indicated technical features. In the description of the embodiments of this disclosure, "multiple" means two or more, unless otherwise explicitly defined. Similarly, "multiple sets" refers to two or more sets (including two sets), and "multiple pieces" refers to two or more pieces (including two pieces).

[0031] 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 disclosure. 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.

[0032] In the description of the embodiments of this disclosure, 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. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0033] In the description of the embodiments of this disclosure, 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," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the embodiments of this disclosure and simplifying the description. They 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 on the embodiments of this disclosure. For example, if the device or element in the illustration is inverted, then the element described as "below," "under," "below," or "bottom" of other elements or features will be oriented "above" or "top" of said other elements or features. Therefore, the term "below" may, depending on the context in which the term is used, encompass both above and below orientations, which will be obvious to those skilled in the art. Materials may be oriented in other ways (e.g., rotated 90 degrees, inverted, flipped), and the spatial relative descriptive terms used herein may be interpreted accordingly.

[0034] In the description of the embodiments of this disclosure, unless otherwise expressly specified and limited, 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. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this disclosure according to the specific circumstances.

[0035] In the accompanying drawings corresponding to the embodiments of this disclosure, the thickness and / or area of ​​layers, films, panels, regions, etc., are enlarged for better understanding and ease of description. Throughout the specification, the same reference numerals denote the same elements. It should be understood that 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 an intermediate component between the two components. Conversely, when describing a component on the surface of another component, or a component "directly" on another component, or a component surface on which another component is formed or disposed, it indicates that there is no intermediate component between the two components. Furthermore, when describing a component as "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.

[0036] In the description of the embodiments of this disclosure, when a component "includes" another component, other components are not excluded unless otherwise stated, and may be further included. The formation or placement of a second component above or on a first component, or on the surface of a first component, or on one side of a first component, may include embodiments where the first and second components are in direct contact, and may also include embodiments where an additional component may be placed between the first and second components, thereby preventing direct contact between the first and second components. For simplicity and clarity, various components may be drawn at different scales. In the drawings, some layers / components may be omitted for simplicity. Unless otherwise specified, the formation or placement of a second component on the surface of a first component refers to direct contact between the first and second components. The term "component" can refer to a layer, film, region, portion, structure, etc.

[0037] 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 "component" is also intended to include the plural form unless the context clearly indicates otherwise. Components include layers, films, regions, or plates, etc.

[0038] The embodiments of this disclosure 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 disclosure to facilitate a better understanding of the disclosure. However, the technical solutions claimed in this disclosure can be implemented even without these technical details and various variations and modifications based on the following embodiments.

[0039] Figure 3 This is a schematic diagram of the structure of a photovoltaic module provided in an embodiment of this disclosure.

[0040] refer to Figures 3 to 4 The photovoltaic module includes: multiple cell strings 20, multiple first busbars 21, and at least one electrical connector 22.

[0041] Specifically, the battery string 20 includes a plurality of solar cells 201 arranged along a first direction X. Each solar cell 201 includes a cell body 202 and a plurality of pads 203 disposed on the cell body 202. A plurality of first busbars 21 extend along a second direction Y. The plurality of first busbars 21 are respectively located at opposite ends of the battery string 20 and are electrically connected to the battery string 20. An electrical connector 22 extends along the first direction X and is electrically connected to two oppositely disposed first busbars 21. The cell body 202 includes a first region 204, which is a region on the cell body 202 near the connection position of the first busbars 21 and the electrical connector 22. In the first region 204, the area of ​​at least one pad 203 is larger than the area of ​​the pads 203 located in other regions on the cell body 202 other than the first region 204.

[0042] Photovoltaic modules are used to convert solar energy into electrical energy.

[0043] In some embodiments, the battery string 20 includes solder strips for connecting adjacent solar cells 201.

[0044] The solar cell 201 can be one or any combination of PERC (Passivated Emitter Rear Cell), IBC (Interdigitated Back Contact), TOPCON (Tunnel Oxide Passivated Contact), heterojunction, thin-film solar cell, and tandem solar cell. Thin-film solar cells include, but are not limited to, perovskite thin-film solar cells, copper indium selenide (CIGS) thin-film solar cells, gallium arsenide (GaAs) thin-film solar cells, and cadmium sulfide (CdS) thin-film solar cells. Tandem solar cells include, but are not limited to, perovskite cells stacked with crystalline silicon cells, perovskite cells stacked with perovskite cells, and perovskite cells stacked with thin-film cells.

[0045] Solar cell 201 can be a cell with a main grid. Cells with a main grid can shorten the current conduction path and reduce internal losses, thereby increasing the power of the photovoltaic module.

[0046] This disclosure does not limit the number of solder joints and grid lines. The number of horizontal main grid lines can be 6, 8, etc., and the number of grid lines corresponding to the vertical solder joints can be 10, 12, 14, 16, 18, 20, etc., which can be flexibly adjusted according to the actual battery design.

[0047] Solar cell 201 can also be a gridless cell, in which solder ribbon is used to replace the original grid and is directly connected to the fine grid, which can significantly reduce the consumption of silver paste, thereby reducing the cost of photovoltaic modules.

[0048] The battery string 20 includes a first sub-battery string 206 and a second sub-battery string 207 arranged along a first direction X. A first busbar is located on the side of the first sub-battery string opposite to the second sub-battery string, and also on the side of the second sub-battery string opposite to the first sub-battery string 206. The first busbar 21 is an end busbar used for electrical connection with the battery string 20.

[0049] Electrical connector 22 extends along the first direction X and is electrically connected to the first busbar 21.

[0050] It should be noted that the area near the connection point between the electrical connector 22 and the first busbar 21 is a region of concentrated mechanical stress. When the electrical connector 22 is long, such as when it is used to connect a remote junction box, the tension or deformation generated by the electrical connector 22 during lamination, handling, or thermal cycling will be transmitted through the first busbar 21 to the solder strip welded to the first busbar 21, which can easily cause the solder strip to detach or become incompletely welded.

[0051] To address this, the solution increases the area of ​​the pad 203 in the first region corresponding to the connection position on the battery cell body 202, thereby increasing the contact area between the pad 203 and the solder strip, thus improving the welding strength and preventing solder strip detachment or incomplete soldering.

[0052] In some embodiments, the photovoltaic module further includes a second busbar 24, which is located between the first sub-cell string 206 and the second sub-cell string 207 and is electrically connected to the first sub-cell string 206 and the second sub-cell string 207.

[0053] Electrical connector 22 is electrically connected to the second busbar 24.

[0054] The area near the connection point between the electrical connector 22 and the second busbar 24 is also a region of concentrated mechanical stress. Similarly, the area of ​​the pad 203 in the first region corresponding to the connection point between the electrical connector 22 and the second busbar 24 on the cell body 202 can be increased to increase the contact area between the pad 203 and the solder strip, thereby improving the welding strength and preventing solder strip detachment or incomplete soldering.

[0055] The photovoltaic module disclosed herein increases the contact area between the pad and the solder strip by designing at least one solder pad area larger than that in other areas in the first region, near the connection point between the cell and the busbar and the electrical connector. This improves the welding strength. As a result, the stress transmitted to the busbar due to the stretching or thermal deformation of the electrical connector can be effectively alleviated, the risk of solder strip desoldering or poor soldering is reduced, and the reliability and manufacturing yield of the photovoltaic module are ultimately improved.

[0056] The embodiments of this disclosure will now be described in more detail with reference to the accompanying drawings.

[0057] refer to Figure 5 In some embodiments, a plurality of pads 203 are arranged on the cell body 202 along a first direction X and a second direction Y; within the first region 204, along the first direction X, the area of ​​the pads 203 closer to the connection position is larger than the area of ​​the pads 203 farther from the connection position, and along the second direction Y, the area of ​​the pads 203 closer to the connection position is larger than the area of ​​the pads 203 farther from the connection position.

[0058] In other words, the area of ​​the pads 203 in the first region 204 gradually decreases from the connection position outwards, so that the area with the most concentrated stress, namely the pads 203 closest to the connection point between the electrical connector 22 and the first busbar 21, has the largest welding contact area, thereby significantly enhancing the mechanical strength and tensile strength of the local solder joints. At the same time, the gradient distribution of the pads 203 area avoids unnecessary material waste in non-stress concentration areas. Without increasing the overall cost, it effectively suppresses the problem of solder strip desoldering or cold solder joint caused by the displacement of the first busbar 21 due to the stretching of the electrical connector 22, thereby improving the manufacturing yield and long-term operational reliability of the components.

[0059] In some embodiments, within the first region 204, the area ratio between two adjacent pads 203 along the first direction X is greater than the area ratio between two adjacent pads 203 along the second direction Y.

[0060] Specifically, the area of ​​the pad 203 changes relatively gently in the extension direction of the electrical connector 22, while the area gradient change is more significant in the extension direction of the first busbar 21.

[0061] Since the electrical connector 22 extends along the first direction X and is connected to the first busbar 21, the tensile force generated by the electrical connector 22 is mainly transmitted to the pad 203 along the first direction X. Therefore, in this direction, the area of ​​the pad 203 decreases more gradually from the connection position to the outside to maintain a higher welding strength. In the direction of the busbar extension where the force is less, the area of ​​the pad 203 can be reduced more significantly, thereby reducing material usage. This balances connection reliability and manufacturing economy.

[0062] In some embodiments, along the first direction X, the area ratio between two adjacent pads 203 is 0.90 to 0.99; for example, it can be 0.90, 0.91, 0.92, 0.93, 0.94, 0.95, 0.96, 0.97, 0.98 or 0.99.

[0063] If the ratio is less than 0.90, the area of ​​pad 203 will decrease too quickly in this direction. Although pad 203 far from the connection point saves material, the solder joints in the high stress area may have reduced strength due to insufficient area, increasing the risk of desoldering.

[0064] By controlling the area ratio between 0.90 and 0.99, it means that for every 203 pad spacing moved away from the connection position, the area decreases by only 1% to 10%, forming a smooth transition. This effectively strengthens high-stress areas while avoiding sudden changes in local stress.

[0065] In some embodiments, along the second direction Y, the area ratio between two adjacent pads 203 is 0.80 to 0.95; for example, it can be 0.80, 0.81, 0.82, 0.83, 0.84, 0.85, 0.86, 0.87, 0.88, 0.89, 0.90, 0.91, 0.92, 0.93, 0.94 or 0.95.

[0066] In the second direction Y, the area of ​​pad 203 can be reduced even more significantly without significantly affecting connection reliability. The ratio is as low as 0.80, which means a 20% reduction in area, while still ensuring sufficient solder strength and significantly reducing the amount of silver paste used.

[0067] A steeper area reduction gradient helps to quickly reduce the size of pad 203 in low-stress areas, reducing conductive paste consumption and improving economy.

[0068] refer to Figure 6 In some embodiments, the battery cell body 202 includes a second region 208, which is the other region on the battery cell body 202 besides the first region 204; within the second region 208, along the first direction X, the area of ​​the pads 203 closer to the first region 204 is larger than the area of ​​the pads 203 farther away from the first region 204, and along the second direction Y, the area of ​​the pads 203 closer to the first region 204 is larger than the area of ​​the pads 203 farther away from the first region 204.

[0069] It is understandable that although the overall stress on the second zone 208 is less than that on the first zone 204, the edge area adjacent to the first zone 204 will still be affected by stress transmission to a certain extent.

[0070] By setting a gradient of pad area 203 decreasing from the inside out within the second region 208, moderate reinforcement can be provided to the second-highest stress region without excessively increasing material costs, further improving the structural robustness of the entire solar cell 201 welding interface. Simultaneously, the moderately reduced area of ​​pad 203 away from the first region 204 helps reduce the consumption of conductive materials such as silver paste, optimizing manufacturing costs.

[0071] refer to Figure 6In some embodiments, along the first direction X, the area ratio between two adjacent pads 203 located in the first region 204 is greater than the area ratio between two adjacent pads 203 located in the second region 208, and along the second direction Y, the area ratio between two adjacent pads 203 located in the first region 204 is greater than the area ratio between two adjacent pads 203 located in the second region 208.

[0072] In the first region 204, where stress concentration is more pronounced, the area of ​​the pad 203 decreases less from the connection point outwards to maintain higher local welding strength; while in the second region 208, where the stress is weaker, the area of ​​the pad 203 is allowed to decrease at a greater gradient, thereby saving material.

[0073] This partitioned, differentiated gradient layout allows the size distribution of the 203 pads to match the actual mechanical load distribution, providing sufficient reinforcement in high-stress areas while controlling costs in low-stress areas, thus balancing the reliability of component connections and manufacturing economy.

[0074] In some embodiments, along the first direction X, the area ratio between two adjacent pads 203 located in the first region 204 is 0.90 to 0.99, for example, it can be 0.90, 0.91, 0.92, 0.93, 0.94, 0.95, 0.96, 0.97, 0.98 or 0.99; the area ratio between two adjacent pads 203 located in the second region 208 is 0.80 to 0.95, for example, it can be 0.80, 0.81, 0.82, 0.83, 0.84, 0.85, 0.86, 0.87, 0.88, 0.89, 0.90, 0.91, 0.92, 0.93, 0.94 or 0.95.

[0075] Along the first direction X, the gradient change of the pad area in the first region 204 is relatively gentle to maintain the welding strength of the high stress area and ensure that the key solder joints have sufficient mechanical anchoring force and electrical contact area to resist the stress caused by the stretching or thermal deformation of the electrical connector.

[0076] Along the first direction X, the pad area gradient in the second region 208 changes significantly, so as to effectively save conductive materials such as silver paste and reduce manufacturing costs while ensuring basic welding reliability.

[0077] In some embodiments, along the second direction Y, the area ratio between two adjacent pads 203 located in the first region 204 is 0.90 to 0.99, for example, it can be 0.90, 0.91, 0.92, 0.93, 0.94, 0.95, 0.96, 0.97, 0.98 or 0.99; the area ratio between two adjacent pads 203 located in the second region 208 is 0.80 to 0.95, for example, it can be 0.80, 0.81, 0.82, 0.83, 0.84, 0.85, 0.86, 0.87, 0.88, 0.89, 0.90, 0.91, 0.92, 0.93, 0.94 or 0.95.

[0078] Along the second direction Y, the gradient change of the pad area in the first region 204 is relatively gentle to maintain the welding strength of the high-stress area and ensure that the key solder joints have sufficient mechanical anchoring force and electrical contact area to resist the stress caused by the stretching or thermal deformation of the electrical connector.

[0079] Along the second direction Y, the pad area gradient changes significantly within the second region 208, which effectively saves conductive materials such as silver paste and reduces manufacturing costs while ensuring basic welding reliability.

[0080] In some embodiments, the area of ​​the pad 203 is 0.15 mm² to 1 mm²; for example, it can be 0.15 mm², 0.2 mm², 0.25 mm², 0.3 mm², 0.35 mm², 0.4 mm², 0.45 mm², 0.5 mm², 0.55 mm², 0.6 mm², 0.65 mm², 0.7 mm², 0.75 mm², 0.8 mm², 0.85 mm², 0.9 mm², 0.95 mm², or 1 mm².

[0081] It is worth noting that in the aforementioned design of decreasing pad area, if the area of ​​a certain pad 203 calculated according to the gradient is less than 0.15 mm², then the area of ​​that pad 203 is limited to 0.15 mm². Simultaneously, the area of ​​all pads 203 located on the side furthest from the connection point between the first busbar 21 and the electrical connector 22 is also uniformly set to 0.15 mm². This lower limit is designed to ensure that even in low-stress areas, the pads 203 still have sufficient area to maintain reliable soldering strength and electrical connection performance, avoiding problems such as poor soldering, inadequate wetting, or insufficient mechanical strength due to excessively small area.

[0082] Within the first zone 204, the area of ​​the pad 203 closest to the connection point between the first busbar 21 and the electrical connector 22 can be 0.48 mm² to 1 mm².

[0083] Since the area near the connection point is subjected to tensile or thermal stress from the electrical connector 22, if the area of ​​the solder pad 203 is too small, it can easily lead to insufficient solder strength, causing desoldering or cold solder joints. Increasing the area of ​​the nearest solder pad 203 to more than 0.48 mm² can significantly increase the solder wetting area and mechanical anchoring force, effectively resisting the transmission of external stress. At the same time, setting the upper limit to 1 mm² can avoid excessively increasing the size of the solder pad 203, which would cause silver paste waste or light-shielding loss.

[0084] In some embodiments, the ratio of the width of the battery cell body 202 in the second direction Y to the width in the first direction X is 2 to 4.

[0085] Specifically, a standard monolithic crystalline silicon solar cell is typically approximately square. If it is cut into two pieces along the first direction X, the aspect ratio of the resulting individual cell is approximately 1.7:1, which is less than the lower limit of 2 defined in this embodiment. This aspect ratio range is intended to explicitly limit the applicability of the embodiments of this disclosure to multi-slice solar cell structures and exclude conventional bi-slice solar cells.

[0086] The solar cell 201 can be a three-slice cell, a four-slice cell, or an eight-slice cell, etc.

[0087] It should be noted that the multi-segmented cells mentioned here can be obtained by cutting a standard whole cell or directly fabricated from crystalline silicon wafers that meet the corresponding size specifications.

[0088] The photovoltaic module disclosed herein improves welding strength by designing at least one pad with a larger area than pads in other areas within the first region (the region near the connection between the cell and the busbar and electrical connector). This increases the contact area between the pad and the solder ribbon, effectively mitigating stress transmitted to the busbar due to tensile or thermal deformation of the electrical connector, reducing the risk of solder ribbon desoldering or incomplete soldering, and ultimately improving the reliability and manufacturing yield of the photovoltaic module. Furthermore, by employing a differentiated area reduction strategy in high-stress and low-stress regions, a relatively gentle area reduction gradient is maintained in high-stress regions to ensure sufficient mechanical anchoring force and electrical contact area for critical solder joints to effectively resist external stress. In low-stress regions, a more significant area reduction is allowed, significantly reducing the use of conductive materials such as silver paste while ensuring basic welding reliability, thus lowering manufacturing costs. This zoned optimization design achieves a synergistic improvement in reliability and economy. In addition, limiting the area range of the pads significantly increases the solder wetting area and mechanical anchoring force, effectively resisting external stress transmission, while avoiding excessive pad enlargement that could lead to silver paste waste or shading loss.

[0089] Those skilled in the art will understand that the above embodiments are specific examples of implementing this disclosure, and in practical applications, various changes in form and detail may be made without departing from the spirit and scope of this disclosure. Any person skilled in the art can make various alterations and modifications without departing from the spirit and scope of this disclosure; therefore, the scope of protection of this disclosure should be determined by the scope defined in the claims.

Claims

1. A photovoltaic module, characterized in that, include: Multiple battery strings, each battery string including multiple solar cells arranged along a first direction, each solar cell including a cell body and multiple pads disposed on the cell body; Multiple first busbars extend along a second direction and are located at opposite ends of the battery string and electrically connected to the battery string. At least one electrical connector extends along the first direction and is electrically connected to two opposing first busbars; The battery cell body includes a first region, which is a region on the battery cell body near the connection position between the first busbar and the electrical connector. In the first region, the area of ​​at least one of the solder pads is larger than the area of ​​solder pads located in other regions on the battery cell body other than the first region. The plurality of pads are arranged on the cell body along the first direction and the second direction; within the first region, along the first direction, the area of ​​the pads closer to the connection position is greater than the area of ​​the pads farther from the connection position, and along the second direction, the area of ​​the pads closer to the connection position is greater than the area of ​​the pads farther from the connection position.

2. The photovoltaic module according to claim 1, characterized in that, Within the first region, along the first direction, the area ratio between two adjacent pads is greater than the area ratio between two adjacent pads along the second direction.

3. The photovoltaic module according to claim 2, characterized in that, Along the first direction, the area ratio between two adjacent pads is 0.90 to 0.

99.

4. The photovoltaic module according to claim 2, characterized in that, Along the second direction, the area ratio between two adjacent pads is 0.80 to 0.

95.

5. The photovoltaic module according to claim 1, characterized in that, The battery cell body includes a second region, which is the other region on the battery cell body besides the first region; Within the second region, along the first direction, the area of ​​the pads closer to the first region is greater than the area of ​​the pads farther from the first region, and along the second direction, the area of ​​the pads closer to the first region is greater than the area of ​​the pads farther from the first region.

6. The photovoltaic module according to claim 5, characterized in that, Along the first direction, the area ratio between two adjacent pads in the first region is greater than the area ratio between two adjacent pads in the second region, and along the second direction, the area ratio between two adjacent pads in the first region is greater than the area ratio between two adjacent pads in the second region.

7. The photovoltaic module according to claim 6, characterized in that, Along the first direction, the area ratio between two adjacent pads in the first region is 0.90 to 0.99, and the area ratio between two adjacent pads in the second region is 0.80 to 0.

95.

8. The photovoltaic module according to claim 6, characterized in that, Along the second direction, the area ratio between two adjacent pads in the first region is 0.90 to 0.99, and the area ratio between two adjacent pads in the second region is 0.80 to 0.

95.

9. The photovoltaic module according to claim 1, characterized in that, The area of ​​the pad is 0.15mm² to 1mm².

10. The photovoltaic module according to claim 1, characterized in that, The ratio of the width of the battery cell body in the second direction to its width in the first direction is 2 to 4.

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