Photovoltaic module and soldering jig

Abstract

The application discloses a photovoltaic module and a welding jig. The welding jig comprises an embedding part, the embedding part comprises a supporting surface for supporting a solder strip, and the embedding part is arranged between two cell pieces at least partially when the solder strip is welded, so that the solder strip is partially supported on the supporting surface, and the length of the solder strip between the two cell pieces is greater than the thickness of the cell pieces. The application provides a photovoltaic module and a welding jig. By arranging the embedding part with the supporting surface between the two cell pieces, the solder strip is partially supported on the supporting surface, so that the actual length of the solder strip between the two cell pieces is greater than the thickness of the cell pieces, the additional length allowance and the relaxation space of the solder strip are provided, the thermal stress generated due to the difference in the thermal expansion coefficients of the PET front plate and the metal back plate is effectively absorbed and released when the ambient temperature changes, so that the solder strip is prevented from being fatigued and broken or being separated from the electrode, and the long-term operation reliability and the power stability of the photovoltaic module are finally improved.

Description

Technical Field

[0001] This application relates to the field of photovoltaic power generation technology, and more specifically, to a photovoltaic module and a welding fixture. Background Technology

[0002] In photovoltaic modules, solar cells are primarily connected in series via solder ribbons to form current paths. In related technologies, the solder ribbons are typically in a flat or taut state when soldered onto the solar cells, lacking space for stress release. Furthermore, photovoltaic modules experience complex environmental temperature changes during actual operation, and the thermal expansion coefficients of their PET front sheet and metal back sheet often differ. This results in the solder ribbons being under constant thermal stress during use, easily leading to solder ribbon fatigue or even detachment from the solar cell electrodes, ultimately causing module power degradation or failure. Utility Model Content

[0003] This application provides a photovoltaic module and a welding fixture to solve at least one of the above-mentioned technical problems.

[0004] The photovoltaic module according to the embodiments of this application includes: Multiple battery cells; The welding ribbon has one end extending into and connecting to the first edge of the battery cell, and the other end extending into and connecting to the second edge of another battery cell. The distance between the first edge and the second edge is a first preset value. The welding ribbon includes a buffer section located between the first edge and the second edge. The length of the buffer section is a second preset value. The ratio of the second preset value to the first preset value is greater than or equal to 1.3 and less than or equal to 2.

[0005] The photovoltaic module of this application achieves a relaxed structure with sufficient redundancy between the cells by setting the length of the buffer section between the two cell edges in the solder strip to 1.3 to 2 times the distance between the first edge and the second edge. This provides space for the deformation release of the solder strip caused by thermal stress due to temperature changes, which helps to reduce the accumulation of solder strip fatigue, reduce the risk of desoldering, and thus improve the long-term reliability of the photovoltaic module in complex thermal environments.

[0006] In some embodiments, one end of the solder strip is connected to the top surface of the battery cell, and the other end is connected to the bottom surface of another battery cell.

[0007] In this way, by connecting one end of the welding strip to the top surface of the solar cell and the other end to the bottom surface of another solar cell, a cross-surface connection is achieved in the spatial orientation of the welding strip. This is beneficial to further increase the deformation freedom of the welding strip in the three-dimensional direction, and to more effectively absorb and buffer the multidimensional stress caused by the difference in thermal expansion coefficients between different material layers.

[0008] In some embodiments, the outer surface of the buffer section is provided with a first protective layer.

[0009] Thus, by setting a first protective layer on the outer surface of the solder strip buffer section, environmental protection is achieved for the exposed and easily deformable area of ​​this section, which helps to prevent oxidation, corrosion or mechanical damage, and facilitates the maintenance of the structural integrity and electrical stability of the solder strip during long-term stress cycling, thereby extending the service life of the photovoltaic module.

[0010] Another embodiment of the present application provides a welding fixture for welding the solar cells and the welding strip in a photovoltaic module as described in any of the above claims. The welding fixture includes an embedding part, which includes a support surface for supporting the welding strip. The embedding part is used to be at least partially disposed between two solar cells during welding of the welding strip, so that the buffer section is at least partially laid on the support surface, and the ratio of the second preset value to the first preset value is greater than or equal to 1.3 and less than or equal to 2.

[0011] In this way, by setting an embedded part with a supporting surface between two solar cells, the solder strip is placed on the support, thereby ensuring that the length of the buffer section is set to 1.3 to 2 times the distance between the first edge and the second edge, which improves the long-term operational reliability and power stability of the photovoltaic module.

[0012] In some embodiments, the embedding portion includes a body and a support portion, the support portion being disposed on the top of the body, the support surface being disposed on the side of the support portion away from the body, and when the embedding portion is disposed between two of the battery cells, the support portion is at least partially higher than the battery cells.

[0013] In this way, by setting up the main body and the support part that is higher than the battery cell, the welding strip can obtain a clear and stable lifting support in the gap between the battery cells, which helps to ensure that the welding strip forms a stable and sufficiently long arc-shaped relaxation section between the two battery cells.

[0014] In some embodiments, the body has a first side and a second side located on both sides of the support portion, and the first side and the second side smoothly transition at the connection with the support surface.

[0015] In this way, by making the connection between the two sides of the main body and the support surface smooth, the welding strip is subjected to uniform force when crossing the support, which helps to avoid stress concentration or damage to the welding strip due to sharp corners.

[0016] In some embodiments, the side of the main body away from the support has a placement bottom surface, and the first side surface and the second side surface are provided with transition rounded corners at the connection with the placement bottom surface.

[0017] Thus, by setting a transition rounded corner at the connection between the bottom surface and the first and second sides, smooth contact between the fixture and the battery cell or working surface is achieved when the fixture is placed, which facilitates the placement and removal of the fixture and helps to avoid scratching the surface of the battery cell.

[0018] In some embodiments, the thickness of the body is greater than or equal to the thickness of the battery cell.

[0019] In this way, by making the thickness of the main body greater than or equal to the thickness of the battery cell, the embedded part is stably filled between the two battery cells, which helps to prevent the fixture from shifting during the welding process, thereby ensuring the stable and consistent shape of the loose section of the weld strip.

[0020] In some embodiments, the support surface is an arc surface.

[0021] In this way, by setting the support surface as an arc surface, the weld strip is made to bend naturally along its surface, which is conducive to the formation of a uniform and smooth arc relaxation of the weld strip and further optimizes the stress distribution.

[0022] In some embodiments, the width of the embedded portion is less than the preset distance between the two battery cells during the welding of the solder strip.

[0023] In this way, by making the width of the embedding part smaller than the preset distance between the two battery cells, the fixture can be easily embedded into the gap between the battery cells without interference, which facilitates the welding operation and the positioning of the fixture.

[0024] In some embodiments, a second protective layer is provided on the support surface to protect the solder strip.

[0025] Thus, by setting a second protective layer on the support surface, direct isolation between the surface of the solder strip and the fixture is achieved, which helps to protect the solder strip coating or surface from wear or contamination during the welding process.

[0026] In some embodiments, an insulating layer is provided on the support surface.

[0027] Thus, by setting an insulating layer on the support surface, electrical insulation between the welding strip and the metal fixture is achieved, which helps to prevent accidental electrical short circuits during the welding process and improves operational safety.

[0028] Another embodiment of the welding apparatus of this application includes the welding fixture described in any of the above claims.

[0029] Additional aspects and advantages of embodiments of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of embodiments of this application. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of 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. Wherein: Figure 1 This is an assembly diagram of the photovoltaic module and welding fixture according to an embodiment of this application; Figure 2 This is a schematic diagram of the structure of the solder strip according to an embodiment of this application; Figure 3 This is a schematic diagram of the working process of the welding fixture according to the embodiments of this application; Figure 4 This is a schematic diagram of the welding fixture according to an embodiment of this application; Figure 5 This is a schematic diagram of the welding fixture according to an embodiment of this application; Figure 6 This is a schematic diagram of the welding fixture according to an embodiment of this application.

[0031] Explanation of reference numerals in the attached drawings: welding fixture 100, embedding part 10, main body 11, first side 111, second side 112, top surface 113, placement bottom surface 114, support part 12, support surface 121, second protective layer 13, insulating layer 14, photovoltaic module 200, battery cell 210, first edge 211, second edge 212, welding strip 220, buffer section 221, first protective layer 222. Detailed Implementation

[0032] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," 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 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 limiting this application. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0033] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection. 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, and 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 this application can be understood according to the specific circumstances.

[0034] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0035] This disclosure provides many different embodiments or examples for implementing different structures of this application. To simplify the disclosure, specific examples of components and arrangements are described herein. Of course, these are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, various specific examples of processes and materials are provided in this application, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0036] In photovoltaic modules, solar cells are primarily connected in series via solder ribbons to form current paths. In related technologies, the solder ribbons are typically in a flat or taut state when soldered onto the solar cells, lacking space for stress release. Furthermore, photovoltaic modules experience complex environmental temperature changes during actual operation, and the thermal expansion coefficients of their PET front sheet and metal back sheet often differ. This results in the solder ribbons being under constant thermal stress during use, easily leading to solder ribbon fatigue or even detachment from the solar cell electrodes, ultimately causing module power degradation or failure.

[0037] Please see Figure 1The photovoltaic module 200 of this application includes a solder ribbon 220 and a plurality of solar cells 210. One end of the solder ribbon 220 extends into the first edge 211 of the solar cell 210 and is connected to the solar cell 210. The other end of the solder ribbon 220 extends into the second edge 212 of another solar cell 210 and is connected to the solar cell 210. The distance between the first edge 211 and the second edge 212 is a first preset value. The solder ribbon 220 includes a buffer section 221 located between the first edge 211 and the second edge 212. The length of the buffer section 221 is a second preset value. The ratio of the second preset value to the first preset value is greater than or equal to 1.3 and less than or equal to 2.

[0038] The photovoltaic module 200 of this application achieves a relaxed structure with sufficient redundant length between the solar cells 210 by setting the length of the buffer section 221 located between the edges of the two solar cells 210 in the solder ribbon 220 to 1.3 to 2 times the distance between the first edge 211 and the second edge 212. This provides deformation release space for the thermal stress caused by temperature changes in the solder ribbon 220, which helps to reduce fatigue accumulation in the solder ribbon 220, reduce the risk of desoldering, and thus improve the long-term reliability of the photovoltaic module 200 in complex thermal environments.

[0039] Specifically, the solar cell 210 is the core power generation unit of the photovoltaic module 200. Essentially a semiconductor device, it has a PET front panel and a metal back panel. It utilizes the photovoltaic effect to directly convert the energy from sunlight into direct current. The solder ribbon 220, also known as the interconnect strip, is a flat copper strip coated with a special flux. In the photovoltaic module 200, it serves to conduct electricity, connect / parallel the solar cells 210, and provide mechanical connections.

[0040] When photovoltaic modules 200 are operated outdoors, they will experience temperature fluctuations. The PET front sheet and metal back sheet of the solar cells 210 have significantly different coefficients of thermal expansion (PET's coefficient of thermal expansion is typically 60-80 × 10⁻⁶). -6 / ℃, while the coefficient of thermal expansion of the aluminum backing plate is approximately 23×10. -6 When the temperature changes, uneven expansion or contraction occurs, which in turn induces alternating tensile and compressive stresses on the solder ribbon 220. If the solder ribbon 220 is taut between the two cells 210 without any redundant length, this stress will concentrate at the solder joint or the bend of the solder ribbon 220, which may lead to fatigue fracture or electrode desoldering in the long term, resulting in module power decay or even failure.

[0041] In this embodiment, the photovoltaic module 200 includes a solder ribbon 220 and a plurality of solar cells 210. A preset distance is maintained between two adjacent solar cells 210 to reserve space for the connection of the solder ribbon 220. The solar cell 210 adopts a conventional rectangular structure, and its first edge 211 is parallel to the second edge 212 of the adjacent solar cell 210 to ensure the straightness and stability of the connection path of the solder ribbon 220.

[0042] In some embodiments, one end of the solder ribbon 220 extends from the first edge 211 of the battery cell 210 along the surface of the battery cell 210 for a predetermined connection length, and is then fixedly connected to the electrode layer of the battery cell 210 by a welding process. The other end of the solder ribbon 220 extends from the second edge 212 of another battery cell 210 in the same direction and with the same connection length, and is also fixedly connected to the electrode layer of the battery cell 210 by a welding process.

[0043] In some embodiments, the distance between the first edge 211 and the second edge 212 is a first preset value. The setting of this distance is usually related to the thermal expansion coefficient of the cell 210, the overall size requirements of the module, and the deformation requirements of the solder strip 220. Its specific value range is adapted to the packaging standard of conventional photovoltaic module 200.

[0044] In some embodiments, the solder strip 220 includes a buffer section 221 located between the first edge 211 and the second edge 212. The buffer section 221 is an intermediate transition portion of the solder strip 220. The length of the buffer section 221 is a second preset value, and the ratio of the second preset value to the first preset value is greater than or equal to 1.3 and less than or equal to 2. Within this ratio range, the buffer section 221 naturally forms a relaxed arc-shaped structure rather than a taut state. When the ambient temperature decreases, the solder strip 220 contracts, and the arc-shaped structure of the buffer section 221 can naturally contract, avoiding excessive stretching. This helps reduce fatigue accumulation in the solder strip 220, reduces the risk of desoldering, and thus improves the long-term reliability of the photovoltaic module 200 in complex thermal environments.

[0045] Please see Figure 1 In some embodiments, one end of the solder strip 220 is connected to the top surface of the battery cell 210, and the other end is connected to the bottom surface of another battery cell 210.

[0046] In this way, by connecting one end of the welding ribbon 220 to the top surface of the battery cell 210 and the other end to the bottom surface of another battery cell 210, the welding ribbon 220 is connected across surfaces in the spatial direction. This is beneficial to further increase the deformation freedom of the welding ribbon 220 in the three-dimensional direction, and to more effectively absorb and buffer the multidimensional stress caused by the difference in thermal expansion coefficients between different material layers.

[0047] Specifically, in some embodiments, of the two adjacent battery cells 210, one battery cell 210 is placed horizontally with its top surface being the light-receiving surface and having a front electrode layer, and the other battery cell 210 is arranged parallel to the first battery cell 210 with a back electrode layer on its bottom surface.

[0048] In some embodiments, one end of the solder ribbon 220 extends from the first edge 211 of the first battery cell 210, along the top surface to a designated connection area of ​​the front electrode layer, and is fixedly connected by welding or conductive adhesive. The connection area must completely cover the conductive contacts of the electrode layer to ensure current transmission efficiency. The other end of the solder ribbon 220 bends downward, passes through the gap between the two battery cells 210, and extends from the second edge 212 of the second battery cell 210, along the bottom surface to the corresponding connection area of ​​the back electrode layer. A stable connection is formed using the same fixing method as the top surface connection. The bend of the solder ribbon 220 adopts an arc transition structure, and the transition radius is determined according to the gap size and the flexibility of the solder ribbon 220 to avoid creases that could damage the conductive cross section.

[0049] Please see Figure 2 In some embodiments, the outer surface of the buffer section 221 is provided with a first protective layer.

[0050] Thus, by setting a first protective layer on the outer surface of the buffer section 221 of the solder strip 220, environmental protection is achieved for the exposed and easily deformable area of ​​this section, which helps to prevent oxidation, corrosion or mechanical damage, and facilitates the maintenance of the structural integrity and electrical stability of the solder strip 220 during long-term stress cycles, thereby extending the service life of the photovoltaic module 200.

[0051] Specifically, in some embodiments, the first protective layer is usually a film structure with a certain degree of flexibility. Its elongation rate is adapted to the deformation rate of the buffer section 221 of the weld strip 220. When the buffer section 221 undergoes expansion or bending deformation due to thermal stress, the first protective layer can deform synchronously without restricting the normal deformation of the buffer section 221 or breaking due to excessive stretching.

[0052] Optionally, the first protective layer can be made of materials with excellent weather resistance and corrosion resistance, such as polyvinyl fluoride or ethylene-tetrafluoroethylene copolymer. These materials have good high temperature resistance and UV resistance, and can meet the environmental requirements of long-term outdoor use of photovoltaic modules.

[0053] In some embodiments, the first protective layer may also adopt a double-layer protective layer structure, with the inner layer being an insulating and corrosion-resistant layer and the outer layer being a wear-resistant protective layer. For example, the inner layer material may be polyimide and the outer layer material may be fluororubber, further improving the protection level.

[0054] In some embodiments, the first protective layer may be a spray-applied protective coating, in which anti-corrosion and insulating materials are uniformly sprayed onto the outer surface of the buffer section 221 using an electrostatic spraying process, and the coating thickness is precisely controlled by the number of spraying operations.

[0055] In some embodiments, the first protective layer may also be a spiral-wound protective tape instead of a covering film. For example, the protective tape may be made of high-toughness insulating tape, which is tightly wrapped around the outer surface of the buffer section 221 in a spiral manner, with a wrapping overlap rate of not less than 50%, to ensure the continuity of protection.

[0056] Please see Figure 1 This application also proposes a welding fixture 100 for welding the solar cell 210 and the welding strip 220 in the photovoltaic module 200 of any of the above claims. The welding fixture 100 includes an embedding part 10, which includes a support surface 121 for supporting the welding strip 220. The embedding part 10 is at least partially disposed between two solar cells 210 during welding of the welding strip 220, so that the buffer section 221 is at least partially placed on the support surface 121, and the ratio of the second preset value to the first preset value is greater than or equal to 1.3 and less than or equal to 2.

[0057] This application provides a welding fixture 100, which, by setting an embedded part 10 with a support surface 121 between two solar cells 210, allows the welding strip 220 to be partially placed on the support, thereby ensuring that the length of the buffer section 221 is set to 1.3 to 2 times the distance between the first edge and the second edge, thus improving the long-term operational reliability and power stability of the photovoltaic module 200.

[0058] Specifically, in this embodiment, the welding fixture 100 includes an insert 10, which is designed to be partially or entirely positioned between two solar cells 210 during welding. The insert 10 has a support surface 121 for supporting the solder ribbon 220, such that the solder ribbon 220 partially overlaps the support surface 121, thereby ensuring that the actual length of the solder ribbon 220 between the two solar cells 210 is greater than the thickness of the solar cells 210. Thus, by providing the support surface 121 through the insert 10, the solder ribbon 220 is lifted in the gap between the solar cells 210, forming an additional arc-shaped relaxation section. This relaxation section can absorb and release thermal stress like a spring, avoiding stress peaks and improving the durability of the module.

[0059] In some embodiments, the insert 10 may be made of a high-temperature resistant, low-thermal-conductivity material, such as ceramic (e.g., alumina) or high-temperature engineering plastic (e.g., polyimide), which can remain stable during the welding process and will not stick to the solder ribbon 220.

[0060] In this embodiment, the embedding part 10 is manually or automatically placed in a preset gap between two battery cells 210 before welding. The size of the preset gap is usually determined by the preset distance when the battery cells 210 are arranged, and is usually 0.5 to 2 mm. The placement of the embedding part 10 must ensure that the support surface 121 is parallel to the surface of the battery cell 210. After the solder ribbon 220 is led out from the electrode of one battery cell 210, it crosses the support surface 121 and connects to the electrode of the other battery cell 210, thereby forming a relaxation section in the gap.

[0061] In some embodiments, during welding, the solar cells 210 are first arranged on a fixture platform or conveyor belt, then the insert 10 is inserted into the gap, followed by the welding ribbon 220 being placed on the support surface 121. Finally, the two ends of the welding ribbon 220 are welded to the electrodes of the solar cells 210 using tools such as welding heads. After welding, the insert 10 usually needs to be removed to avoid introducing additional material. In some embodiments, if the insert 10 is compatible with the material of the photovoltaic module 200, it can also be retained in the module.

[0062] In some embodiments, the embedded part 10 may also be integrated into the battery cell 210 support fixture, for example, by providing a raised support strip on the fixture platform.

[0063] Please see Figure 3 In some embodiments, multiple array-arranged embedded portions 10 may be provided to simultaneously process the welding between multiple sets of battery cells 210 and welding ribbons 220, thereby improving efficiency.

[0064] It should be noted that when using the embedded part 10, contaminants such as grease and dust should be avoided to prevent affecting the welding effect of the solder strip 220 or introducing resistance.

[0065] Please see Figure 1 and Figure 4 In some embodiments, the embedded part 10 includes a main body 11 and a support part 12. The support part 12 is disposed on the top of the main body 11, and the support surface 121 is disposed on the side of the support part 12 away from the main body 11. When the embedded part 10 is disposed between two battery cells 210, the support part 12 is at least partially higher than the battery cells 210.

[0066] In this way, by setting the main body 11 and the support part 12 which is higher than the battery cell 210, the welding strip 220 can obtain a clear and stable lifting support in the gap of the battery cell 210, which helps to ensure that the welding strip 220 forms a stable and sufficiently long arc-shaped relaxation section between the two battery cells 210.

[0067] Specifically, in the embodiments of this application, the main body 11 is usually a plate-shaped or block-shaped structure to support the support part 12. Generally speaking, the material of the main body 11 must have sufficient mechanical strength and thermal stability to withstand pressure and temperature during the welding process.

[0068] The support portion 12 is disposed on the top of the main body 11, and the support surface 121 is disposed on the side of the support portion 12 away from the main body 11. The support portion 12 can be connected to the main body 11 by welding, bonding or integral molding. In the embodiment of this application, the support portion 12 is at least partially higher than the upper surface of the battery cell 210 so that the welding strip 220 can form a slack section between the two battery cells 210.

[0069] In some embodiments, the height of the support portion 12 can be calculated based on the actual relaxation requirements of the solder strip 220. The shape of the support portion 12 can be cylindrical, ribbed, or arched, but the top support surface 121 needs to be flat or slightly curved to evenly support the solder strip 220.

[0070] In some embodiments, the support 12 may also be configured as a height-adjustable structure, for example by means of a thread or spring mechanism, to accommodate different cell 210 thicknesses or solder strip 220 specifications.

[0071] In some embodiments, the support portion 12 may also be a plurality of evenly arranged independent small protrusions instead of a continuous strip, in order to reduce the contact area with the solder strip 220, but it is necessary to ensure that the support for the solder strip 220 is uniform.

[0072] In some embodiments, a movable roller may also be used as the support 12, and the welding strip 220 is placed on the roller for rolling adjustment.

[0073] Please see Figure 1 and Figure 4 In some embodiments, the main body 11 has a first side surface 111 and a second side surface 112 located on both sides of the support portion 12, and the first side surface 111 and the second side surface 112 are smoothly connected to the support surface 121.

[0074] In this way, by making the two sides of the main body 11 smoothly transition to the support surface 121, the welding strip 220 is subjected to uniform force when crossing the support part 12, which helps to avoid stress concentration or damage to the welding strip 220 due to sharp corners.

[0075] Specifically, in this embodiment, the main body 11 is rectangular and includes a top surface 113, a bottom surface 114, a front side, a rear side, a first side 111, and a second side 112. The support part 12 is disposed on the top surface 113. The bottom surface 114 is parallel to the top surface 113. The first side 111 and the second side 112 are both perpendicular to the top surface 113 and the bottom surface 114, and respectively connect the top surface 113 and the bottom surface 114 and are located on both sides of the support part 12. The connection between the first side 111 and the second side 112 and the support surface 121 should be a smooth transition.

[0076] Smooth transition refers to the use of rounded or chamfered edges at the joint to avoid sharp corners, thereby ensuring that the bending radius of the welding strip 220 changes continuously when it crosses from the support surface 121 to the side area, without creating stress concentration points or scratching the welding strip 220.

[0077] In this embodiment, when the embedding part 10 is placed in the gap between the battery cells 210, the first side 111 and the second side 112 face the edges of the two battery cells 210 respectively. The smooth transition area is close to the starting point of the solder ribbon 220 after it is led out from the electrode of the battery cell 210 and contacts the embedding part 10. During the placement of the solder ribbon 220, the solder ribbon 220 is straightened and lowered to the support surface 121. Due to the smooth transition, the solder ribbon 220 naturally conforms to the curved surface and will not generate stress concentration points. When welding, the head of the solder ribbon 220 is pressed down and the solder ribbon 220 may slide slightly. The smooth transition helps to reduce frictional resistance and prevent the coating on the surface of the solder ribbon 220 from being scratched.

[0078] Please see Figure 1 and Figure 4 In some embodiments, the side of the main body 11 away from the support portion 12 has a placement bottom surface 114, and the first side surface 111 and the second side surface 112 are provided with transition rounded corners at the connection with the placement bottom surface 114.

[0079] Thus, by setting a transition rounded corner at the connection between the bottom surface 114 of the main body 11 and the first side surface 111 and the second side surface 112, smooth contact between the fixture and the battery cell 210 or the working surface is achieved when the fixture is placed, which facilitates the placement and removal of the fixture and helps to avoid scratching the surface of the battery cell 210.

[0080] Specifically, in the embodiments of this application, the placement bottom surface 114 is the area where the embedded part 10 contacts the bearing surface of the battery cell 210 or the worktable. It is usually designed as a flat surface, but in order to facilitate picking up and putting down and avoid damage, the junction of the placement bottom surface 114 with the first side surface 111 and the second side surface 112 is usually processed into a rounded corner.

[0081] On the other hand, in this embodiment of the application, one end of the solder ribbon 220 is soldered to the top surface 113 of the first battery cell 210, and the other end needs to be soldered to the bottom surface of another battery cell 210. At this time, when the embedded part 10 is disposed between the two battery cells 210, the connection between the first side surface 111 or the second side surface 112 and the placement bottom surface 114 will be close to the solder ribbon 220 and the soldering point of one of the battery cells 210. At this time, the transition rounded corner can prevent the sharp corner from contacting the solder ribbon 220, scratching the coating of the solder ribbon 220 or even damaging the body of the solder ribbon 220.

[0082] In some embodiments, the transition fillet can also be a full chamfer, that is, the bottom edge is machined into a bevel, but the bevel angle needs to be controlled.

[0083] In some embodiments, soft pads, such as silicone pads, can be attached to the connection between the first side 111 and the second side 112 and the placement bottom surface 114 for direct cushioning contact. It should be noted that when setting soft pads, attention should be paid to controlling the dimensional accuracy.

[0084] Please see Figure 1 and Figure 4 In some embodiments, the thickness of the body 11 is greater than or equal to the thickness of the battery cell 210.

[0085] In this way, by making the thickness of the main body 11 greater than or equal to the thickness of the battery cell 210, the embedded part 10 is stably filled between the two battery cells 210, which helps to prevent the fixture from shifting during the welding process, thereby ensuring the stable and consistent shape of the relaxed section of the welding strip 220.

[0086] Specifically, the thickness of the main body 11 refers to the vertical distance from the placement bottom surface 114 to the bottom surface of the support portion 12, which can be precisely set according to the specifications of the battery cell 210. In the embodiments of this application, the thickness of the main body 11 is usually equal to the thickness of the battery cell 210. For example, for a standard battery cell 210 with a thickness of 0.2 mm, the thickness of the main body 11 is also 0.2 mm.

[0087] In some embodiments, the thickness of the body 11 can also be adjustable, for example, by combining stacked sheets to accommodate different cell thicknesses 210.

[0088] Please see Figure 1 and Figure 4 In some embodiments, the support surface 121 is an arc surface.

[0089] Thus, by setting the support surface 121 as an arc surface, the welding strip 220 is naturally bent along its surface, which is conducive to the formation of a uniform and smooth arc relaxation of the welding strip 220 and further optimizes the stress distribution.

[0090] Specifically, the radius of curvature of the arc surface needs to be calculated based on the relaxation length of the welding strip 220. Typically, the radius R is set to 1 / 2 to 1 times the span of the welding strip 220 between the two battery cells 210. This ensures that the welding strip 220 fits the arc after being laid, and the bending strain can be controlled within the elastic range, avoiding plastic deformation. In this embodiment, the support surface 121 is a semi-circular arc surface; that is, the support portion 12 is semi-cylindrical.

[0091] In some embodiments, the coefficient of friction of the support surface 121 should be controlled during processing to reduce friction and avoid damaging the coating. For example, the surface roughness of the support surface 121 should be less than Ra0.8μm.

[0092] In some embodiments, the highest point of the arc surface needs to be aligned with the center of the gap between the battery cells 210, and the two ends of the arc surface are smoothly connected to the first side surface 111 and the second side surface 112 to ensure a continuous transition of the solder ribbon 220 from the electrode of the battery cell 210 to the arc surface.

[0093] In some embodiments, the arc surface can also be replaced by a multi-segment folded surface, but the fold points need to be rounded to simulate the arc effect.

[0094] In some embodiments, the support surface 121 may be a flat or slightly curved surface, but it is necessary to ensure that a continuous, smooth contact area is provided so that the welding strip 220 can sag naturally during installation without stress concentration.

[0095] Please see Figure 1 and Figure 4 In some embodiments, the width of the embedded portion 10 is less than the preset distance between the two battery cells 210 when the solder strip 220 is welded.

[0096] Thus, by making the width of the insert 10 smaller than the preset distance between the two battery cells 210, the fixture can be easily inserted into the gap between the battery cells 210 without interference, which facilitates the welding operation and the positioning of the fixture.

[0097] Specifically, for example, the preset distance between the two battery cells 210 is 1.5mm, and the width of the insert 10 can be designed to be 1.2 to 1.4mm, leaving a gap of 0.1 to 0.3mm so that the fixture can finely adjust the centering in the gap.

[0098] Thus, during the welding operation, after the insert 10 is inserted into the gap between the two battery cells 210, the main body 11 is partially or mostly located within the gap, with its width aligned with the gap between the battery cells 210. The clearance allows the insert 10 to float horizontally within the gap, facilitating positional adjustments. Simultaneously, the width being smaller than the gap prevents the insert 10 from compressing the edges of the battery cells 210, protecting the brittle coating of the battery cells 210. Furthermore, during use, the insert 10 is inserted into the gap via a guide rail or robotic arm; the smaller width helps reduce insertion resistance and increase speed. After welding, when the insert 10 is withdrawn, the clearance also prevents the friction from carrying away the weld strip 220.

[0099] In some embodiments, the width of the embedded portion 10 may also be adjustable, for example, by means of a telescopic slider or a combination of stacked sheets to accommodate different gaps.

[0100] In some embodiments, the width of the embedded portion 10 may vary due to the thermal expansion of the material. To avoid excessive thermal expansion causing the embedded portion 10 to squeeze the battery cell 210 or the solder ribbon 220, a low-expansion material such as ceramic must be selected.

[0101] Please see Figure 1 and Figure 5In some embodiments, a second protective layer 13 for protecting the solder strip 220 is provided on the support surface 121.

[0102] Thus, by setting a second protective layer 13 on the support surface 121, direct isolation between the surface of the welding strip 220 and the fixture is achieved, which is beneficial to protect the coating or surface of the welding strip 220 from wear or contamination during the welding process.

[0103] Specifically, in this embodiment, the second protective layer 13 can be a thin film or coating with a thickness of 0.01–0.1 mm. During welding, the second protective layer 13 acts as a buffer medium, allowing the solder ribbon 220 to directly contact the second protective layer 13 rather than the fixture substrate, which is beneficial for protecting the solder ribbon 220. It should be noted that the second protective layer 13 needs to be replaced or repaired periodically.

[0104] In this embodiment, since the welding strip 220 and its surrounding area are usually at high temperatures during welding, the material of the second protective layer 13 must have high temperature resistance. Furthermore, the welding strip 220 will frequently rub against the support surface 121 during welding, so the material of the second protective layer 13 must have high wear resistance to reduce wear. In addition, to reduce the friction between the second protective layer 13 and the welding strip 220, the material of the second protective layer 13 is usually required to have a low coefficient of friction to reduce the sliding resistance of the welding strip 220.

[0105] In this embodiment, the second protective layer 13 needs to completely cover the support surface 121 and may extend to the smooth transition area to form continuous protection; in some embodiments, the second protective layer 13 may also completely cover the entire embedded part 10.

[0106] In some embodiments, the second protective layer 13 may also be temporarily applied with silicone oil or high-temperature grease, but the amount used must be controlled to prevent contamination of the solder joints of the solder ribbon 220.

[0107] Please see Figure 1 and Figure 6 In some embodiments, an insulating layer 14 is provided on the support surface 121.

[0108] Thus, by setting an insulating layer 14 on the support surface 121, electrical insulation between the welding strip 220 and the metal fixture is achieved, which helps to prevent accidental electrical short circuits during the welding process and improves operational safety.

[0109] Specifically, in this embodiment, the insulating layer 14 can be a dielectric material layer with a thickness of 0.05–0.2 mm, requiring high insulation strength and high temperature resistance. For example, it can be bonded with alumina ceramic sheets or coated with silicon nitride, or a mica sheet pad can be used, but the mica sheet pad must be flat and adhered properly. It should be noted that, similar to the second protective layer 13, the insulating layer 14 also needs to be replaced or repaired periodically.

[0110] In this embodiment, the insulating layer 14 covers the entire support surface 121 and the area that may come into contact with the solder strip 220 to ensure complete isolation of the metal fixture substrate during welding; if the fixture itself is a non-metal such as ceramic, the insulating layer 14 may be omitted.

[0111] In some embodiments, the insulating layer 14 may be a curable resin such as epoxy resin that can be applied on-site, but the thickness must be controlled to be uniform.

[0112] In some embodiments, the second protective layer 13 and the insulating layer 14 can also serve both protective and insulating functions by providing a coating.

[0113] In the description of this specification, the references to "certain embodiments," "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples" refer to specific features, structures, materials, or characteristics described in connection with the described embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0114] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the stated features. In the description of this application, "multiple" means at least two, such as two or three, unless otherwise explicitly specified.

[0115] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A photovoltaic module, characterized in that, include: Multiple battery cells; The welding ribbon has one end extending into and connecting to the first edge of the battery cell, and the other end extending into and connecting to the second edge of another battery cell. The distance between the first edge and the second edge is a first preset value. The welding ribbon includes a buffer section located between the first edge and the second edge. The length of the buffer section is a second preset value. The ratio of the second preset value to the first preset value is greater than or equal to 1.3 and less than or equal to 2.

2. The photovoltaic module according to claim 1, characterized in that, One end of the welding strip is connected to the top surface of the battery cell, and the other end is connected to the bottom surface of another battery cell.

3. The photovoltaic module according to claim 1, characterized in that, The outer surface of the buffer section is provided with a first protective layer.

4. A welding fixture for welding the solar cells and the welding strip in a photovoltaic module according to any one of claims 1-3, characterized in that, The welding fixture includes an embedding part, which includes a support surface for supporting the welding strip. The embedding part is used to be at least partially disposed between two of the battery cells when the welding strip is being welded, so that the buffer section is at least partially placed on the support surface, and the ratio of the second preset value to the first preset value is greater than or equal to 1.3 and less than or equal to 2.

5. The welding fixture according to claim 4, characterized in that, The embedded part includes a main body and a support part. The support part is disposed on the top of the main body, and the support surface is disposed on the side of the support part away from the main body. When the embedded part is disposed between two of the battery cells, the support part is at least partially higher than the battery cells.

6. The welding fixture according to claim 5, characterized in that, The main body has a first side and a second side located on both sides of the support portion, and the first side and the second side are smoothly connected to the support surface.

7. The welding fixture according to claim 4, characterized in that, The supporting surface is an arc surface.

8. The welding fixture according to claim 4, characterized in that, The width of the embedded part is less than the preset distance between the two battery cells when the welding strip is welded.

9. The welding fixture according to claim 4, characterized in that, The support surface is provided with a second protective layer for protecting the welding strip.

10. The welding fixture according to claim 4, characterized in that, An insulating layer is provided on the support surface.

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