A concealed busbar photovoltaic module

Abstract

The application relates to a hidden busbar photovoltaic module, which comprises a cell piece, a busbar, an insulating strip and a solder strip. The cell piece has a cell edge, a front panel and a back panel; the busbar is arranged on the back panel; the insulating strip is between the busbar and the back panel; and the solder strip is connected with the cell piece and the busbar. Part of the solder strip is arranged in a flat structure with a flat surface, and the flat surface in the flat structure is used for stress contact with the cell edge. The flat surface increases the contact area with the cell edge, reduces stress concentration and reduces the risk of cell piece hidden cracking during lamination.

Description

Technical Field

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

[0002] With the photovoltaic industry's increasing demand for higher module power, current technology hides the busbars at both ends of the module on the back of the cells to improve screen-to-body ratio. There are currently two main solutions: one is to fold the busbars directly to the back of the module after welding, and place insulating strips and adhesive film pads between the busbars and the cells; the other is to directly weld the busbars to the back of the cells in polarity welding, since both the positive and negative electrodes are on the back. However, this solution of placing the busbars on the back of the cells is prone to problems such as excessively high busbar stacking. This problem can lead to stress concentration at the busbar locations during cell lamination, resulting in microcracks and breakage. Furthermore, the stacked busbars on the back of the cells can block light, reducing the bifaciality of the photovoltaic module and affecting product quality. Utility Model Content

[0003] Therefore, it is necessary to provide a hidden busbar photovoltaic module to address the issue of busbar placement on the back of the battery.

[0004] A concealed busbar photovoltaic module, comprising:

[0005] A solar cell, which has connected battery edges, a front panel and a back panel;

[0006] Busbar, located on the rear panel;

[0007] An insulating strip is installed between the busbar and the back panel;

[0008] The welding strip connects the battery cells and busbars.

[0009] In this design, a portion of the welding strip is configured as a flat structure with a flat surface, which is used to contact the edge stress of the battery.

[0010] In some embodiments of this application, the flat surface of the flat structure is also used to contact the edge stress of the busbar.

[0011] In some embodiments of this application, the solder strip has two distinct sections configured as flat structures. One section of the flat structure in the solder strip is used to contact the edge stress of the battery, while the other section of the flat structure in the solder strip is used to contact the edge stress of the busbar; or...

[0012] The welding strip includes a connected main body segment and a flat segment. The main body segment is connected to the front panel, and the flat segment is configured as a flat structure with a flat surface. The flat segment is used to make edge stress contact with the battery edge and the busbar.

[0013] In some embodiments of this application, the flat segment includes a first flat segment, a bent segment, and a second flat segment connected in sequence;

[0014] At least the first and second flat segments in the flat segments are configured as flat structures with flat surfaces;

[0015] The flat surface of the first flat section is spaced or in contact with the front panel, and the flat surface of the second flat section is welded to the busbar.

[0016] In some embodiments of this application, the first flat segment includes a first starting point, which is the boundary position between the main body segment and the flat segment;

[0017] The position where the first flat segment contacts the edge of the battery is called the edge contact portion, and the distance between the first starting point and the edge contact portion is between 1 mm and 2 mm.

[0018] In some embodiments of this application, the first flat segment has two flat surfaces facing away from each other, and the distance between the two flat surfaces of the first flat segment is a first thickness; wherein, the first thickness remains constant along the length direction of the first flat segment; or, the first thickness varies along the length direction of the first flat segment.

[0019] And / or,

[0020] The second flat segment has two flat surfaces facing away from each other, and the distance between the two flat surfaces of the second flat segment is the second thickness; wherein, the second thickness is consistent along the length direction of the second flat segment; or, the second thickness varies along the length direction of the second flat segment.

[0021] In some embodiments of this application, the first thickness is set between 0.08 mm and 0.12 mm; and / or, the second thickness is set between 0.08 mm and 0.12 mm.

[0022] In some embodiments of this application, at least a portion of one side surface of the busbar is configured as a reflective surface, the reflective surface being opposite to the battery cell, and the reflective surface being used to reflect light onto the surface of the back panel.

[0023] In some embodiments of this application, the reflective surface is at least one of a plane, a curved surface, and a folded surface.

[0024] In some embodiments of this application, the main body segment, the first flat segment, the bent segment, and the second flat segment are integrally formed.

[0025] The aforementioned concealed busbar photovoltaic module comprises solar cells, busbars, insulating strips, and solder ribbons. Each solar cell has cell edges, a front panel, and a back panel; the busbars are mounted on the back panel; the insulating strips are located between the busbars and the back panel; and the solder ribbons connect the solar cells and the busbars. A portion of the solder ribbon is designed as a flat structure with a flat surface, which is used to contact the stress points of the cell edges. This flat surface increases the contact area with the cell edges, reduces stress concentration, and decreases the risk of microcracks in the solar cells during lamination. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of the concealed busbar photovoltaic module provided in the embodiments of this application.

[0027] Figure 2 This is a side view of a concealed busbar photovoltaic module provided in an embodiment of this application.

[0028] Figure 3 This is a partial schematic diagram of a concealed busbar photovoltaic module provided in an embodiment of this application.

[0029] Figure 4 This is a side view of the concealed busbar photovoltaic module provided in an embodiment of this application from another perspective.

[0030] Icon labels:

[0031] 1000, Battery cell; 1001, Battery edge; 1002, Front panel; 1003, Back panel;

[0032] 2000, Busbar; 3000, Insulating Strip;

[0033] 4000, Welding strip; 4001, Main body section; 4010, First flat section; 4011, First starting point; 4012, First ending point; 4013, Edge contact section; 4020, Bending section; 4030, Second flat section; 4031, Second starting point; 4032, Second ending point;

[0034] 5000, reflective surface; 6000, adhesive film pad. Detailed Implementation

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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 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, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0039] 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.

[0040] 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.

[0041] See Figure 1 and Figure 2 As shown, Figure 1 This is a schematic diagram of the structure of the concealed busbar photovoltaic module provided in the embodiments of this application. Figure 2 This is a side view of a concealed busbar photovoltaic module provided in an embodiment of this application. The concealed busbar photovoltaic module includes a cell 1000, a busbar 2000, an insulating strip 3000, and a solder ribbon 4000. The cell 1000 has a cell edge 1001, a front panel 1002, and a back panel 1003. The busbar 2000 is disposed on the back panel 1003 via the insulating strip 3000; the insulating strip 3000 is located between the busbar 2000 and the back panel 1003.

[0042] The welding strip 4000 is connected to the battery cell and the busbar, and the connection can be made by contact, welding or a connection with a reasonable gap.

[0043] A portion of the solder ribbon 4000 is designed with a flat structure featuring a flat surface. This flat surface is used for stress contact with the battery edge 1001. Here, "flat" refers to an object or state exhibiting a flat, smooth surface or shape, or a low degree of three-dimensionality. The corresponding flat surface and flat structure are derived concepts, and are understood in general terms. The flat surface significantly increases the contact area between the solder ribbon 4000 and the battery edge 1001, thereby effectively dispersing stress in the welding area, avoiding stress concentration, and greatly reducing the risk of microcracks or breakage of the battery cell 1000 due to stress concentration during lamination.

[0044] Meanwhile, the flat structure reduces the impact of the difference in expansion coefficients between the solder ribbon 4000 and the encapsulant film. When the photovoltaic module is exposed to temperature changes outdoors, it reduces the possibility of the solder ribbon 4000 squeezing and cracking the solar cell 1000 due to inconsistent expansion and contraction between the two, thus improving the stability and reliability of the module during use. In addition, the busbar 2000 is set on the back panel 1003 of the solar cell 1000 through the insulating strip 3000, realizing a hidden layout. This helps to improve the screen ratio of the module, allowing more light to shine on the solar cell 1000, thereby improving the power output of the module. Moreover, the setting of the insulating strip 3000 can prevent short circuits between the busbar 2000 and the solar cell 1000, ensuring the electrical safety of the module. The overall structural design is reasonable and helps to improve the process reliability, product quality and service life of the photovoltaic module.

[0045] In some embodiments of this application, the flat surface of the flat structure is also used to make edge stress contact with the busbar 2000. The flat surface can further increase the contact area between the solder strip 4000 and the edge of the busbar 2000, effectively disperse the stress in the connection area between the two, avoid stress concentration, and reduce the risk of microcracks in the battery cell 1000 or connection failure of the busbar 2000 due to stress concentration during the lamination process.

[0046] Meanwhile, the larger contact area helps improve the conductivity between the solder ribbon 4000 and the busbar 2000, reduces contact resistance, reduces losses during power transmission, and improves the power generation efficiency of the photovoltaic module. In addition, this contact method makes the connection between the solder ribbon 4000 and the busbar 2000 more stable. Combined with the stress contact between the solder ribbon 4000 and the edge 1001 of the cell 1000, the circuit connection of the entire module is more reliable. With the insulation effect of the insulating strip 3000 between the busbar 2000 and the back panel 1003 of the cell 1000, the electrical performance of the module can be stabilized, the durability and safety of the overall structure can be improved, and it is conducive to the long-term efficient operation of the photovoltaic module.

[0047] In some embodiments of this application, the solder ribbon 4000 has two distinct sections configured as flat structures. One section of the flat structure in the solder ribbon 4000 is used for stress contact with the battery edge 1001, while the other section is used for stress contact with the busbar 2000 edge. By specifically increasing the contact area with the battery edge 1001 and the busbar 2000 edge through two independent flat sections, the stress in their respective connection areas can be precisely dispersed, preventing stress at different connection locations from interfering with each other. This further reduces the risk of microcracks in the battery cell 1000 and connection failure between the solder ribbon 4000 and the busbar 2000 during lamination.

[0048] Alternatively, in some other embodiments, the solder strip 4000 includes a connected main body segment 4001 and a flat segment. The main body segment 4001 is connected to the front panel 1002, and the flat segment is configured as a flat structure with a flat surface. The flat segment is used for edge stress contact with the cell edge 1001 and the busbar 2000. The integrated flat segment design simplifies the structure of the solder strip 4000, ensuring a large contact area with both the cell edge 1001 and the busbar 2000 edges to disperse stress, while facilitating processing and installation. Furthermore, the stable connection between the main body segment 4001 and the front panel 1002 ensures a smooth current conduction path. In both cases, the flat surface of the flat structure enhances contact stability. Combined with the insulation effect of the insulating strip 3000, this improves the overall reliability, conductivity, and resistance to microcracks of the photovoltaic module, ensuring long-term high-efficiency operation of the module.

[0049] In some embodiments of this application, the flat segment includes a first flat segment 4010, a bent segment 4020, and a second flat segment 4030 connected in sequence.

[0050] At least the first flat segment 4010 and the second flat segment 4030 are configured as flat structures with flat surfaces. The flat surface of the first flat segment 4010 is either spaced apart from or in contact with the front panel 1002, while the flat surface of the second flat segment 4030 is welded to the busbar 2000. By spaced apart from or in contact with the front panel 1002, the flat surface of the first flat segment 4010 increases the contact area with the front panel 1002 (when in contact) or provides reasonable space for assembly (when spaced apart), effectively dispersing stress, reducing local pressure on the front panel 1002, and lowering the risk of microcracks in the battery cell 1000. Welding the flat surface of the second flat segment 4030 to the busbar 2000 increases the contact area, improves weld strength, reduces contact resistance, reduces power transmission loss, and simultaneously disperses stress in the welding area, preventing structural damage caused by stress concentration between the busbar 2000 and the back panel 1003 of the battery cell 1000.

[0051] The bending section 4020 achieves a smooth transition between the first flat section 4010 and the second flat section 4030, allowing the solder strip 4000 to adapt to the connection path from the front panel 1002 to the back panel 1003, ensuring smooth current conduction. Combined with the insulating strip 3000's insulating effect between the busbar 2000 and the back panel 1003, the overall structural stability, conductivity, and damage resistance of the photovoltaic module are improved, which is conducive to the long-term reliable operation of the module.

[0052] In some embodiments of this application, the first flat segment 4010 includes a first starting point 4011, which is the boundary position between the main body segment 4001 and the flat segment.

[0053] The contact point between the first flat segment 4010 and the battery edge 1001 is the edge contact portion 4013. The distance between the first starting point portion 4011 and the edge contact portion 4013 is between 1 mm and 2 mm. This distance is equivalent to the contact length between the solder strip 4000 and the battery cell 1000. If the contact length is too short, the shear stress near the battery edge 1001 will be too concentrated, which may lead to microcracks in the battery cell 1000 during lamination. This distance range can effectively disperse stress. Combined with the flat structure of the first flat segment 4010 to increase the contact area, it further reduces the stress concentration and the risk of microcracks. If the contact length is too long, it may lead to problems such as poor soldering or poor conductivity. It should be noted that the first starting point portion 4011 is set to facilitate the understanding of the technical solution and is not a specific limitation on the structure. The first starting point portion 4011 may be a solid structure or an endpoint.

[0054] By limiting the distance between the first starting point 4011 and the edge contact portion 4013, problems such as poor soldering or poor conductivity caused by excessive distance can be avoided, and stress concentration caused by excessively short distance can be prevented. This effectively reduces the risk of microcracks in the cell 1000 during the lamination process and improves the reliability and stability of the module manufacturing process.

[0055] Furthermore, the flat structure of the solder ribbon 4000 and the encapsulant film has a smaller difference in their coefficients of thermal expansion. When the photovoltaic module is exposed to temperature changes outdoors, this reduces the risk of the solder ribbon 4000 squeezing and cracking the solar cells due to inconsistent expansion and contraction, thus further improving the stability of the photovoltaic module during use. The placement of the encapsulant film in the laminated photovoltaic module can refer to existing technologies.

[0056] The busbar 2000 is concealed within the back panel 1003 and isolated by the insulating strip 3000, ensuring electrical safety while achieving a concealed structure. The design of the busbar 2000 hidden within the back panel increases the module's screen-to-body ratio. This increased ratio allows more light to reach the solar cells, thereby improving the module's power output and meeting the photovoltaic industry's demand for higher module power. The arrangement of these components makes the module structure more rational, contributing to improved module reliability and increased automation in production.

[0057] In some embodiments of this application, the first flat segment 4010 includes a first starting point 4011 and a first ending point 4012. The first starting point 4011 is connected to the main body segment 4001, and the first ending point 4012 is connected to the bent segment 4020, forming a continuous weld strip structure. A contact point exists on the first flat segment 4010 at the battery edge 1001 of the battery cell 1000; this contact point is defined as an edge contact portion 4013. The distance from the first starting point 4011 to the edge contact portion 4013 is limited to between 1 mm and 2 mm.

[0058] The distance from the first starting point 4011 to the edge contact portion 4013 is the contact length between the welding strip 4000 and the battery cell 1000.

[0059] The main body segment 4001, connected to the first starting point 4011, extends along the length of the solar cell 1000. The circular main body segment 4001 has a line contact with the front panel 1002, which, compared to the surface contact of the flat structure, can form a buffer at the welding start point. When the module is subjected to temperature changes or mechanical stress, the line contact characteristics of the circular segment can absorb some of the stress through its own deformation, preventing the stress from being directly transmitted to the welding interface between the flat segment and the solar cell, further reducing the risk of microcracks. The preset distance needs to be controlled within a reasonable range. If it is too long, it will lead to poor contact between the solar cell 1000 and the solder strip 4000 and poor alloying effect; if it is too short, it will cause excessive shear stress at this point, weakening the effect of improving microcracks.

[0060] In some embodiments of this application, the first flat segment 4010 has two flat surfaces facing away from each other, and the distance between the two flat surfaces is defined as the first thickness. The first thickness has two possible settings in the length direction of the first flat segment 4010: one is to keep it consistent, that is, the overall thickness of the first flat segment 4010 is uniform; the other is to vary, that is, the thickness of the first flat segment 4010 changes gradually or stepwise along the length direction.

[0061] The second flat segment 4030 also has two flat surfaces facing away from each other, and the distance between the two flat surfaces is defined as the second thickness.

[0062] There are two possible settings for the second thickness in the length direction of the second flat segment 4030: one is to keep it consistent, that is, the overall thickness of the second flat segment 4030 is uniform; the other is to vary, that is, the thickness of the second flat segment 4030 changes gradually or stepwise along the length direction.

[0063] The thickness settings of the first flat segment 4010 and the second flat segment 4030 can be selected independently. That is, when the first flat segment 4010 adopts a certain setting, the second flat segment 4030 can adopt the same or different settings, such as the first flat segment 4010 having the same thickness and the second flat segment 4030 having a varying thickness; or both having the same thickness, etc. The flat surface structure itself increases the contact area. Combined with a reasonable thickness setting, such as using a gradual thickness in stress concentration areas, the stress in the welding area can be further dispersed, reducing stress concentration caused by abrupt thickness changes during lamination and lowering the risk of microcracks in the solar cell.

[0064] In some embodiments of this application, the first flat segment 4010 has a first thickness ranging from 0.08 mm to 0.12 mm, and the second flat segment 4030 has a second thickness, also ranging from 0.08 mm to 0.12 mm. It should be noted that the thickness of the solder strip 4000 was originally between 0.02 mm and 0.26 mm, but here the thicknesses of the first flat segment 4010 and the second flat segment 4030 are explicitly defined. In the lamination of photovoltaic modules, the first thickness and the second thickness refer to the thickness of the first flat segment 4010 and the second flat segment 4030 in the lamination direction.

[0065] For the first flat segment 4010, its thickness is controlled within the range of 0.08 mm to 0.12 mm through processing techniques, thus reducing the thickness of the solder strip 4000, which originally ranged from 0.02 mm to 0.26 mm, to this range. Similarly, the second flat segment 4030 is processed in the same way, precisely controlling its thickness between 0.08 mm and 0.12 mm. This setup can be applied to either the first flat segment 4010 or the second flat segment 4030 individually, or to both simultaneously.

[0066] By limiting the thickness of the first flat segment 4010 and the second flat segment 4030 to between 0.08 mm and 0.12 mm, compared to the previously thicker solder strip 4000, the contact area between the second flat segment and the front panel 1002 of the solar cell 1000 and the busbar 2000 can be effectively increased. A larger contact area reduces stress concentration in this area, decreasing the risk of microcracks in the solar cell 1000 due to stress concentration during lamination. Simultaneously, the appropriate thickness reduces the difference in the coefficient of thermal expansion between the second flat segment and the encapsulant film, reducing the likelihood of the solder strip 4000 causing cracking of the solar cell 1000 due to inconsistent expansion and contraction during outdoor temperature changes, thereby improving the reliability and lifespan of the photovoltaic module.

[0067] In some embodiments of this application, for ease of understanding, the second flat segment 4030 is provided to have a second starting point 4031 and a second ending point 4032. The provision of the second starting point 4031 and the second ending point 4032 is to facilitate the understanding of the technical solution and is not to specifically limit the structure. The first starting point 4011 may be a solid structure or an endpoint.

[0068] The second starting point 4031 of the second flat segment 4030 is connected to the bent segment 4020 to form a continuous solder strip structure, allowing current to be conducted from the first flat segment 4010 through the bent segment 4020 to the second flat segment 4030. The second ending point 4032 of the second flat segment 4030 is welded to the surface of the busbar 2000, and this surface is the side of the busbar 2000 facing away from the solar cell 1000, that is, the other side of the busbar 2000 that contacts the insulating strip 3000. The second ending point 4032 is directly welded to the surface of the busbar 2000 facing away from the solar cell 1000, shortening the current conduction distance from the solder strip 4000 to the busbar 2000, reducing resistance loss, and improving the conductivity efficiency of the photovoltaic module. An insulating strip 3000 is provided between the busbar 2000 and the back panel 1003 of the solar cell 1000. The welding position of the second flat section 4030 is located on the surface of the busbar 2000 away from the solar cell 1000, further preventing direct contact between the second flat section 4030 and the solar cell 1000, reducing the possibility of short circuits, and ensuring the electrical safety of the module. The second flat section 4030 is connected to the bent section 4020 through the second starting point 4031, and the second ending point 4032 is directly welded to the surface of the busbar 2000, making the connection between the solder strip 4000 and the busbar 2000 more direct, reducing redundant structures, and making the overall layout of the module more compact.

[0069] In some embodiments of this application, reference is made to the appended specification. Figure 3 and attached Figure 4 , Figure 3 This is a partial schematic diagram of a concealed busbar photovoltaic module provided in an embodiment of this application.

[0070] Figure 4 This is a side view of the concealed busbar photovoltaic module provided in an embodiment of this application from another perspective. At least a portion of one side surface of the busbar 2000 is configured as a reflective surface 5000, which faces away from the solar cell 1000 and is used to reflect light onto the surface of the back panel 1003.

[0071] The reflective surface 5000 reflects light that would otherwise be blocked by the busbar 2000 back onto the back panel 1003, reducing light loss and allowing the back panel 1003 to absorb more light energy, thereby improving the bifaciality and overall power generation efficiency of the photovoltaic module. Traditional busbars reduce module performance by blocking light from the back panel, but the reflective surface 5000 offsets some of the shading through directional reflection, balancing the trade-off between the busbar's conductivity and light utilization. The reflective surface 5000's placement away from the solar cell 1000 is compatible with the installation position of the busbar 2000 on the back panel 1003, without interfering with the connection structure between the busbar, insulating strip 3000, and solder ribbon 4000, ensuring the synergistic optimization of the module's overall electrical and optical performance.

[0072] In some embodiments of this application, the reflective surface 5000 may take one or more combinations of planar, curved, and folded surfaces to adapt to different light incident angles and reflection requirements.

[0073] The reflective surface 5000 may include at least one inclined reflective surface, which is designed to face a specific direction according to the incident direction of light and the position of the back panel 1003, so as to ensure that the light can be directed onto the surface of the back panel 1003 after being reflected by it.

[0074] The combined design of planar, curved, and folded surfaces covers a wider range of light incidence angles. Regardless of the direction from which light strikes the busbar 2000 surface, it can be reflected by the adapted reflective surface shape. The directional design of the tilted reflective surface precisely controls the path of reflected light, ensuring more light is focused onto the back panel 1003 and reducing light waste. The tilted reflective surface can specifically reflect light from areas blocked by the busbar 2000 to the back panel 1003, compensating for the busbar's shading effect and significantly improving the light absorption rate of the back panel 1003, thereby increasing the bifaciality of the photovoltaic module. The diverse shape design of the reflective surface can flexibly adapt to the installation space of the busbar 2000 on the back panel 1003 without affecting the connection structure between the busbar and the insulating strip 3000 and solder ribbon 4000, ensuring synergistic optimization of the module's electrical and optical performance. Additionally, a V-shaped recessed structure can be formed from the reflective surface.

[0075] In some embodiments of this application, the main body segment 4001, the first flat segment 4010, the bent segment 4020, and the second flat segment 4030 are manufactured as a single piece. Through specific processing techniques such as stamping, rolling, or die forming, the original welding strip 4000 is directly processed into a welding strip 4000 with a continuous structure, making the main body segment 4001, the first flat segment 4010, the bent segment 4020, and the second flat segment 4030 completely integrated in material and structure. During processing, there is no need to separately manufacture and reassemble each segment; instead, a complete welding strip 4000 shape is formed in one go, ensuring a natural and smooth transition between segments.

[0076] In some embodiments of this application, an adhesive film pad 6000 is provided between the insulating strip 3000 and the back panel 1003 of the battery cell 1000. Specifically, the adhesive film pad 6000 is located between the contact surfaces of the back panel 1003 and the insulating strip 3000, forming an intermediate sandwich structure. The insulating strip 3000 itself already provides electrical isolation between the busbar 2000 and the back panel 1003. The addition of the adhesive film pad 6000 further enhances the insulation performance between the two, reducing the risk of short circuits caused by damage or aging of the insulating strip 3000 and ensuring the electrical safety of the module.

[0077] The adhesive film pad 6000 has a certain degree of elasticity, which can absorb some pressure during the lamination process, reducing the stress transmitted from the busbar 2000 to the back panel 1003 through the insulating strip 3000. This prevents the back panel 1003 from developing microcracks or damage due to stress concentration, thus improving the reliability of the lamination process. The busbar 2000 is laminated on the surface of the insulating strip 3000 away from the back panel 1003. Combined with the adhesive effect of the adhesive film pad 6000, the back panel 1003, adhesive film pad 6000, insulating strip 3000, and busbar 2000 form a stable integral structure, reducing component loosening during transportation or use and enhancing structural durability.

[0078] In some embodiments of this application, during the assembly of photovoltaic modules, an adhesive film is filled into the gap between the cell edge 1001 and the bending section 4020. During filling, it is ensured that the adhesive film is evenly distributed in this area, completely covering the gap between the cell edge 1001 and the bending section 4020, forming a continuous filling layer to achieve effective filling of this area.

[0079] The adhesive film filling between the cell edge 1001 and the bending section 4020 acts as a stress buffer, reducing the direct pressure of the bending section 4020 on the cell edge 1001, thereby reducing the risk of microcracks in the cell 1000 due to stress concentration. Simultaneously, the adhesive film filling also enhances the sealing and insulation of this area, preventing external environmental factors from affecting the internal structure of the module, and improving the module's reliability and lifespan.

[0080] The solder ribbon 4000 is flattened through mechanical processing such as rolling and stamping, increasing the local contact area between the solder ribbon 4000 and the solar cell 1000. The flattening operation requires precise control to ensure that the solder ribbon 4000 forms a flat structure in the area of ​​contact with the solar cell 1000, thereby effectively expanding the contact area. On the one hand, the increased contact area significantly reduces stress concentration in this area, thus reducing the risk of microcracks in the solar cell 1000 due to stress concentration during processes such as lamination. On the other hand, due to the difference in expansion coefficients between the solder ribbon 4000 and the encapsulant film, in conventional solutions, when the module is exposed to outdoor temperature changes, the solder ribbon 4000 is prone to cracking the solar cell 1000 due to inconsistent expansion and contraction. Flattening the solder ribbon 4000 to increase the contact area effectively disperses the stress caused by this difference in expansion coefficients, reducing such risks and improving the reliability of the module when used outdoors.

[0081] 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.

[0082] The above embodiments merely illustrate 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 concealed busbar photovoltaic module, characterized in that, The concealed busbar photovoltaic module includes: A battery cell (1000) having a connected battery edge (1001), a front panel (1002) and a back panel (1003). Busbar (2000) is disposed on the back panel (1003); An insulating strip (3000) is disposed between the busbar (2000) and the back panel (1003); The solder strip (4000) is connected to the battery cell and the busbar; In this embodiment, a portion of the welding strip (4000) is configured as a flat structure with a flat surface, the flat surface of which is used to stress contact the edge (1001) of the battery.

2. The concealed busbar photovoltaic module according to claim 1, characterized in that, The flat surface of the flat structure is also used to make edge stress contact with the busbar (2000).

3. The concealed busbar photovoltaic module according to claim 2, characterized in that, The solder strip (4000) has two distinct sections configured as the flat structure. The flat structure in one section of the solder strip (4000) is used for stress contact with the edge (1001) of the battery, and the flat structure in the other section of the solder strip (4000) is used for stress contact with the edge of the busbar (2000); or, The solder strip (4000) includes a connected main body segment (4001) and a flat segment. The main body segment (4001) is connected to the front panel (1002). The flat segment is configured as a flat structure with a flat surface and is used for edge stress contact with the battery edge (1001) and the busbar (2000).

4. The concealed busbar photovoltaic module according to claim 3, characterized in that, The flat segment includes a first flat segment (4010), a bent segment (4020), and a second flat segment (4030) connected in sequence. At least the first flat segment (4010) and the second flat segment (4030) are configured as flat structures with flat surfaces; The flat surface of the first flat segment (4010) is spaced apart from or in contact with the front panel (1002), and the flat surface of the second flat segment (4030) is welded to the busbar (2000).

5. The concealed busbar photovoltaic module according to claim 4, characterized in that, The first flat segment (4010) includes a first starting point (4011), which is the boundary between the main body segment (4001) and the flat segment; The position where the first flat segment (4010) and the edge of the battery (1001) come into contact is the edge contact portion (4013), and the distance between the first starting point portion (4011) and the edge contact portion (4013) is between 1 mm and 2 mm.

6. The concealed busbar photovoltaic module according to claim 5, characterized in that, The first flat segment (4010) has two flat surfaces facing away from each other, and the distance between the two flat surfaces of the first flat segment is a first thickness; wherein, the first thickness is consistent along the length direction of the first flat segment (4010); or, the first thickness varies along the length direction of the first flat segment (4010). And / or, The second flat segment (4030) has two flat surfaces facing away from each other, and the distance between the two flat surfaces of the second flat segment (4030) is the second thickness; wherein, the second thickness is consistent along the length direction of the second flat segment (4030); or, the second thickness varies along the length direction of the second flat segment (4030).

7. The concealed busbar photovoltaic module according to claim 6, characterized in that, The first thickness is set between 0.08 mm and 0.12 mm; and / or, the second thickness is set between 0.08 mm and 0.12 mm.

8. The concealed busbar photovoltaic module according to claim 1, characterized in that, At least a portion of one side surface of the busbar (2000) is configured as a reflective surface (5000), the reflective surface (5000) being opposite to the battery cell (1000), the reflective surface (5000) being used to reflect light onto the surface of the back panel (1003).

9. The concealed busbar photovoltaic module according to claim 8, characterized in that, The reflective surface (5000) is at least one of a plane, a curved surface, and a folded surface.

10. The concealed busbar photovoltaic module according to claim 4, characterized in that, The main body segment (4001), the first flat segment (4010), the bent segment (4020), and the second flat segment (4030) are integrally formed.

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