Interconnection component and solar cell assembly

Abstract

The present invention discloses an interconnection component and a solar cell assembly, which relate to the field of photovoltaic technology and are capable of ensuring normal interconnection of cell sheets while suppressing the degree of deformation of back-contact cells during welding. The interconnection component comprises: a flexible insulating substrate and a plurality of structural welding strips spaced apart on the flexible insulating substrate. Each structural welding strip has two welding portions and a connecting portion located between the two welding portions. The connecting portion is respectively connected to the two welding portions. At least part of the connecting portion is located within the flexible insulating substrate, and the two welding portions extend out of the flexible insulating substrate. The solar cell assembly comprises the interconnection component proposed by the above technical solution. The interconnection component provided by the present invention is used for interconnecting back-contact cells.

Description

Technical Field

[0001] The present invention relates to the field of photovoltaic technology, and in particular to an interconnection component and a solar cell assembly. Background Art

[0002] Back-contact cells are solar cells with both the positive and negative electrodes located on the back of the cell, allowing for interconnection using solder ribbons. This eliminates shading losses from the front grid electrodes, improving cell efficiency and making the cell more aesthetically pleasing.

[0003] However, since the positive and negative poles of the back-contact battery are both located on the back of the back-contact battery, the thermal expansion coefficients of the solder ribbon and the battery cell are quite different. Therefore, when the solder ribbon is welded to the pad of the back-contact battery, the heat released by the welding causes the solder ribbon to expand. After the welding is completed, the solder ribbon shrinks due to the temperature drop, causing the back-contact battery to undergo severe bending deformation, thereby affecting the welding stability and increasing the risk of fragments and hidden cracks in the component manufacturing process. Therefore, it is urgent to find an alternative to the solder ribbon to realize the interconnection of the back-contact battery to reduce the degree of deformation of the back-contact battery during welding. Summary of the Invention

[0004] The object of the present invention is to provide an interconnection member and a solar cell assembly, which can ensure normal interconnection of solar cells while suppressing the deformation of back contact cells during welding.

[0005] In a first aspect, the present invention provides an interconnect comprising: a flexible insulating substrate and a plurality of structural welding ribbons spaced apart on the flexible insulating substrate. Each structural welding ribbon has two welding portions and a connecting portion located between the two welding portions. The connecting portion is connected to each of the two welding portions. The two welding portions extend out of the flexible insulating substrate, and at least a portion of the connecting portion is located on the flexible insulating substrate.

[0006] When using the above technical solution, multiple structural welding ribbons are spaced apart on a flexible insulating substrate, with at least a portion of the connecting portion located on the flexible insulating substrate, and two welding portions connected to the connecting portion extending out of the flexible insulating substrate. Based on this, when the structural welding ribbon is subjected to stress due to the welding process, the lamination process, and the high and low temperature differences outdoors, the connecting portion contained in the structural welding ribbon can transfer the stress to the flexible insulating substrate, and release it through the flexible insulating substrate, thereby reducing the degree of bending deformation of the back-contact battery and improving welding stability and long-term use stability. At the same time, the flexible insulating substrate plays a role in fixing and dustproofing the multiple structural welding ribbons during the welding process, preventing the relative position of the structural welding ribbon and the welding pad from shifting during welding, and preventing particulate matter generated by welding from migrating to the front of the battery cell, thereby improving welding accuracy.

[0007] In addition, when the interconnection provided by the present invention is used for interconnection between back-contact batteries, the interconnection can not only serve as a vertical conductive channel to achieve interconnection between back-contact batteries, but also use a flexible insulating substrate to provide electrical isolation for the areas other than the pads of two adjacent back-contact batteries, thereby reducing the possibility of leakage and improving battery efficiency.

[0008] In one possible implementation, the connection portion of each structural solder ribbon has a hollow structure for stress relief. When the structural solder ribbon experiences stress due to welding, lamination, and outdoor high and low temperature variations, the connection portion not only transfers the stress to the flexible insulating substrate, but the hollow structure also partially relieves the stress, further reducing the degree of bending deformation of the back-contact battery and improving welding stability and long-term stability.

[0009] In one possible implementation, the hollow structure includes at least one through-hole. Each through-hole has a closed pattern. Here, the closed pattern refers to a closed outline of the hollow structure. In this case, the edge contour of the connecting portion is complete, ensuring good strength of the structural welding ribbon.

[0010] The pattern of each through hole is a polygonal pattern, a circular pattern, an elliptical pattern or a special-shaped pattern. The polygonal pattern can be a triangle, a rectangle, a square, etc.

[0011] In one possible implementation, the hollow structure includes m rows of through holes, where m is an integer greater than or equal to 1. Each row of through holes includes at least one through hole. The first row of through holes and the mth row of through holes are formed in the connecting portion along any direction parallel to the connecting portion.

[0012] In one possible implementation, two adjacent rows of through holes are staggered. In this case, the m rows of through holes in the connecting portion can relatively evenly release the stress generated by the structural welding ribbon, thereby further reducing the degree of deformation of the back contact battery.

[0013] In one possible implementation, when the above-mentioned through hole is a slit through hole or a rectangular through hole, if the length direction of the through hole is the distribution direction of the two welding parts, then the spacing between the two rows of through holes can be adjusted so that the current of one welding part is transmitted to the other welding part through the connecting part in a straight line as much as possible, thereby reducing current loss.

[0014] In one possible implementation, m is an integer greater than or equal to 3. The number of through-holes included in the first row of through-holes and the m-th row of through-holes is greater than or equal to 2. In this case, along the distribution direction from the first row of through-holes to the m-th row of through-holes, the number of through-holes included in each row of through-holes first decreases and then increases.

[0015] When using the above technical solution, if the length of each row of through-holes first decreases and then increases along the distribution direction of through-holes from the first row to the mth row, the structural strength of the connection first increases and then decreases, and the stress in the connection first gradually decreases and then gradually increases. Based on this, the distribution of through-holes in the connection can be used to adjust the strength and stress-relieving capacity of each area of the connection, so that the strength and stress-relieving capacity of the connection are coordinated.

[0016] In one possible implementation, when m is an integer greater than or equal to 3, the number of through holes included in the first row of through holes and the mth row of through holes is greater than or equal to 1; along the distribution direction from the first row of through holes to the mth row of through holes, the number of through holes included in each row of through holes first increases and then decreases.

[0017] When using the above technical solution, if the length of each row of through-holes first decreases and then increases along the distribution direction of through-holes from the first row to the mth row, the structural strength of the connection first decreases and then increases, and the stress in the connection first gradually increases and then gradually decreases. Based on this, the distribution of through-holes in the connection can be used to adjust the strength and stress release capacity of each area of the connection, so that the strength and stress release capacity of the connection are coordinated.

[0018] In one possible implementation, the central axes of the two welding parts are collinear. In this case, the current flowing from one welding part to the other welding part can be conducted as close to a straight line as possible.

[0019] In one possible implementation, the width of each weld is smaller than the maximum width of the connecting portion. Each weld is connected to the connecting portion using an arc transition. When this arc transition is used, stress concentration is less likely to occur at the arc transition, further reducing stress in the structural weld band due to temperature changes.

[0020] In one possible implementation, the flexible insulating substrate is a light-shielding flexible insulating substrate. When the interconnector interconnects two adjacent back-contact solar cells, if the flexible insulating substrate is partially or completely located in the gap between the two adjacent back-contact solar cells, the flexible insulating substrate can serve as a visual shielding structure. This prevents the structural welding ribbon on the back of the solar cell module from being visible when viewed from the front, thereby improving the aesthetics of the solar cell module.

[0021] In a possible implementation, at least one surface of the flexible insulating substrate is partially or entirely provided with a shielding coating. The effect of the shielding coating is described in detail in the description of the light-shielding flexible insulating substrate and is not described in detail here.

[0022] In a possible implementation, the flexible insulating substrate may be a single-sided tape with a release layer or a double-sided tape with a release layer.

[0023] Using this technical solution, the flexible insulating substrate can be bonded to the back-contact cell, effectively positioning the structured solder ribbon. Furthermore, when the interconnect is used for back-contact cell interconnection, if the flexible insulating substrate is positioned between two adjacent back-contact cells, the release layer of the single-sided or double-sided tape can serve as a visual barrier, enhancing the aesthetics of the solar cell module while also reducing particulate matter contamination.

[0024] In a possible implementation, the connection portion of each structural welding strip is exposed away from the surface of the flexible insulating substrate. In this case, each structural welding strip can be pressed onto the flexible insulating substrate using a process such as pressing.

[0025] In one possible implementation, when the connection portion of each structural welding ribbon is embedded in a flexible insulating substrate, the connection portion of each structural welding ribbon is at least partially encased within the flexible insulating substrate. In this case, the interconnect has a sandwich structure, and the flexible insulating substrate can be used to further secure the structural welding ribbon. This not only further reduces or eliminates possible displacement of the structural welding ribbon during welding, but also eliminates the possibility of failure of the connection between the structural welding ribbon and the flexible insulating substrate if a welding portion of the structural welding ribbon is warped under stress, thereby ensuring the stability of the connection between the structural welding ribbon and the flexible insulating substrate.

[0026] In a possible implementation, the flexible insulating substrate has a strip-shaped structure, and a plurality of structural welding strips are spaced apart and distributed along an extending direction of the strip of the flexible insulating substrate.

[0027] In one possible implementation, each structural welding ribbon is heat-pressed or bonded to a flexible insulating substrate. When each structural welding ribbon is heat-pressed and bonded to the flexible insulating substrate, the adhesive may be a polymer adhesive, including but not limited to one or more of polyvinyl acetate, polyvinyl acetal, acrylate, polystyrene, epoxy resin, acrylic resin, polyurethane resin, unsaturated polyester, butyl rubber, nitrile rubber, phenolic-polyvinyl acetal, and epoxy-polyamide.

[0028] In one possible implementation, the flexible insulating substrate includes a conductive layer. The connecting portions of the structural welding strips are electrically connected via the conductive layer. The connecting portions of the structural welding strips are electrically connected via the conductive layer. The conductive layer may be a conductive strip or a conductive particle layer composed of contacting metal particles.

[0029] When using the above technical solution, the conductive layer can electrically connect the conductive layers contained in each structural welding ribbon, allowing the conductive layers to function as a transverse conductive path. If a welding portion of one of the multiple structural welding ribbons fails to weld to the corresponding polarity welding pad, the structural welding ribbon will partially fail as a vertical conductive path. However, the structural welding ribbon can still use the conductive layer to conduct current to other structural welding ribbons that have been properly welded, thus avoiding the problem of reduced battery efficiency caused by local failure of the vertical conductive path, thereby improving the connection reliability of the interconnect.

[0030] In a second aspect, the present invention further provides a solar cell assembly comprising at least two cells and a plurality of interconnecting elements for interconnecting the cells, wherein each interconnecting element is an interconnecting element as described in the first aspect or any one of the first aspects. Each cell has two polarity solder pads on its back surface. Each polarity solder pad is soldered to a soldering portion of a corresponding structural solder ribbon on the corresponding interconnecting element.

[0031] In one possible implementation, there is a gap between two adjacent battery cells. If the gap accommodates a corresponding interconnection component, the two polarity pads on the back of each battery cell are close to the edge of the battery cell, the different polarity pads of two adjacent battery cells are close to the same gap, and the interconnection components corresponding to the different polarity pads of two adjacent electrode sheets are the same interconnection component, thereby using a single interconnection component to interconnect the two adjacent battery cells.

[0032] In one possible implementation, the solar cell assembly further includes at least one busbar. Each busbar is welded to a welding portion of the plurality of structural welding ribbons of the interconnect. In this case, the busbar and the interconnect can collect and conduct the current generated by the solar cells.

[0033] In one possible implementation, when the above-mentioned bus bar is located between two adjacent battery cells, the interconnecting parts corresponding to the different polarity pads of the two adjacent electrode sheets are different interconnecting parts, and the interconnecting parts corresponding to the different polarity pads of the two adjacent battery cells share a bus bar, thereby utilizing two interconnecting parts and a bus bar to realize welding of the two adjacent battery cells.

[0034] In one possible implementation, when multiple battery cells are located on the same side of a busbar and the same polarity pads of the multiple battery cells are close to the busbar, the busbar can be used to weld the welding portions of the interconnecting parts corresponding to the same polarity pads of these electrode sheets to the busbar, thereby connecting multiple battery cells in parallel using one busbar.

[0035] In one possible implementation, the solar cell assembly further includes a vision-blocking layer located between two adjacent cells. The vision-blocking layer is located on a surface of at least one interconnect member that faces the front of the cells. In this case, if the insulating flexible substrate included in the interconnect member is transparent, the vision-blocking layer can be used to conceal the structural welding ribbon, thereby enhancing the appearance of the solar cell assembly.

[0036] In a possible implementation, the welding portion is welded to the corresponding polarity pad of the battery cell by electromagnetic or infrared welding.

[0037] The beneficial effects of the second aspect or any possible implementation of the second aspect are the same as the beneficial effects of the first aspect or any possible implementation of the first aspect, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0039] Figure 1 A schematic structural diagram of a solar cell assembly provided by an embodiment of the present invention;

[0040] Figures 2A to 2C Schematic diagram of the welding structure of different numbers of battery cells and interconnecting components in an embodiment of the present invention;

[0041] Figure 3A and Figure 3B Schematic diagrams of two back side structures of a battery cell according to an embodiment of the present invention;

[0042] Figures 4A to 4C Schematic diagram of the back structure of three battery string groups provided by embodiments of the present invention;

[0043] Figure 4D for Figure 4C A front view of a battery string group is shown;

[0044] Figure 5 Schematic diagram of a cell slice according to an embodiment of the present invention;

[0045] Figure 6 A schematic diagram of the basic structure of an interconnection element provided by an embodiment of the present invention;

[0046] Figure 7A and Figure 7B Schematic diagrams of two basic structures of structural welding strips in embodiments of the present invention;

[0047] Figure 8 A schematic structural diagram of a flexible insulating substrate provided by an embodiment of the present invention;

[0048] Figure 9A is a schematic diagram of an exemplary interconnection structure in an embodiment of the present invention;

[0049] Figure 9B is a schematic diagram of another exemplary interconnection structure according to an embodiment of the present invention;

[0050] Figure 10A is a schematic diagram of another exemplary interconnection structure according to an embodiment of the present invention;

[0051] Figure 10B for Figure 10A A cross-sectional view of the interconnection member shown in the AA direction;

[0052] Figure 10C for Figure 10A Another cross-sectional view of the interconnection member shown in the AA direction;

[0053] Figures 11A to 13A Schematic diagrams of three distributions of multiple rows of through holes distributed along a first direction in an embodiment of the present invention;

[0054] Figures 11B to 13B Schematic diagrams of three distributions of multiple rows of through holes distributed along the second direction in an embodiment of the present invention;

[0055] Figure 14 A schematic structural diagram of an interconnect manufacturing device provided by an embodiment of the present invention;

[0056] Figure 15 A structural flow chart of a method for manufacturing an interconnection component provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0057] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0058] It should be noted that when an element is referred to as being “fixed on” or “disposed on” another element, it may be directly on the other element or indirectly on the other element. When an element is referred to as being “connected to” another element, it may be directly connected to the other element or indirectly connected to the other element.

[0059] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined. "Several" means one or more, unless otherwise specifically defined.

[0060] In the description of the present invention, it should be understood that the terms "up", "down", "front", "back", "left", "right", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0061] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and may encompass internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0062] Figure 1 The following is a schematic diagram of the structure of a solar cell assembly provided by an embodiment of the present invention. Figure 1 As shown, the solar cell assembly provided in the embodiment of the present invention may include a battery module Cell. In addition to the battery module Cell, the solar cell assembly may also include a packaging backsheet BP, a packaging cover sheet TP, and one or two common adhesive layers. For example, the battery module Cell is located between the packaging cover sheet TP and the packaging backsheet BP, a first adhesive layer J1 is provided between the packaging cover sheet TP and the battery module Cell, and a second adhesive layer J2 is provided between the packaging backsheet BP and the battery module Cell. As for the material of the adhesive layer, ethylene-vinyl acetate copolymer (EVA) and other materials are generally selected, but are not limited thereto.

[0063] Figures 2A to 2C The following is a schematic diagram of the welding structure of different numbers of battery cells and interconnecting parts in the embodiment of the present invention. Figures 2A to 2C As shown, Figure 1 The battery module Cell shown includes at least two battery cells 100 and a plurality of interconnecting members 200 for interconnecting the battery cells 100. These battery cells 100 and interconnecting members 200 may constitute Figure 1The battery module Cell is shown.

[0064] Figure 3A and Figure 3B Schematic diagrams of two back structures of the battery cell in the embodiment of the present invention. Figure 3A and Figure 3B As shown, when each of the above-mentioned solar cells 100 is a back-contact solar cell, the front side of each solar cell 100 may be free of any grid lines, or may have some fine grid lines. The back side of each solar cell 100 has a main grid line to conduct holes and electrons. Based on this, the types of solar cells 100 may be interdigitated back contact (IBC cell), metallization wrap-through (MWT) silicon solar cells, emitter-wrap-through (EWT) silicon solar cells, etc., but are not limited to these.

[0065] like Figure 3A and Figure 3B As shown, in order to simultaneously extract holes and electrons on the back side of the battery cell 100, the back side of the battery cell 100 has two polarity pads, namely a first polarity pad 101 and a second polarity pad 102. When the first polarity pad 101 is a positive pad, the second polarity pad 102 is a negative pad. When the first polarity pad 101 is a negative pad, the second polarity pad 102 is a positive pad. In actual applications, the back side of the battery cell 100 has a positive polarity region such as a P-type region and a negative polarity region such as an N-type region. The positive polarity region can be used to extract holes, and the positive pad can be formed in the positive polarity region. The negative polarity region can be used to extract electrons, and the negative pad is formed in the negative polarity region.

[0066] like Figure 3A and Figure 3B As shown, in order to reduce the impact of the stress generated by the interconnect 200 due to alternating hot and cold (welding process or external environment) on the battery cell 100, the two polarity pads contained in the same battery cell 100 are close to the edge of the battery cell 100. Specifically, the battery cell 100 has a first side edge C1 and a second side edge C2. The first polarity pad 101 is formed on the back of the battery cell 100 in a manner close to the first side edge C1, and the second polarity pad 102 is formed on the back of the battery cell 100 in a manner close to the second side edge C2. As long as the first side edge C1 and the second side edge C2 are in different directions, they can be arranged opposite to each other or intersectingly.

[0067] For example, Figure 3A and Figure 3BAs shown, the first side edge C1 and the second side edge C2 are disposed opposite to each other. The first side edge C1 may be a long side of the battery cell 100 , and the second side edge C2 may be another long side of the battery cell 100 .

[0068] like Figure 3A and Figure 3B As shown, for the same battery cell 100, the number of the first polarity pads 101 and the number of the second polarity pads 102 can be one or more. When the number of the first polarity pads 101 and the number of the second polarity pads 102 are more than one, each first polarity pad 101 and the corresponding second polarity pad 102 can be as shown in FIG. Figure 3A The collinear arrangement shown (collinear with respect to the dashed line X) can also be as shown Figure 3B The offset shown (offset relative to the dashed line X) is set.

[0069] like Figure 3A and Figure 3B As shown, the minimum distance d between each polarity pad and the edge of the battery cell can be 0 to 10 mm. Figure 3A and Figure 3B The example shows the minimum distance d between the second polarity pad and the second side edge. When d = 0 mm, the side of the second polarity pad 102 close to the cell edge is flush with the second side edge C2. When d > 0 and ≤ 10 mm, a gap (width d) exists between the side of the second polarity pad 102 close to the cell edge and the second cell edge C2, which can reduce the impact of stress generated during welding on the cell edge.

[0070] Each polarity pad can be welded to the corresponding interconnection part. The interconnection part welded to each polarity pad is defined here as the interconnection part corresponding to the polarity pad. Welding methods include but are not limited to electromagnetic or infrared welding methods. The shape of each polarity pad can be rectangular, circular, elliptical or other shapes, which can be selected according to actual conditions. As for the size of each polarity pad, it can be 0.5mm-5mm (the maximum radial dimension of the pad. For example: when the positive electrode pad is a circular pad, the maximum radial dimension of the circular pad is the diameter of the circular pad. For another example: the positive electrode pad is an elliptical pad, the maximum radial dimension of the elliptical pad is the long axis of the elliptical pad), so that each polarity pad has enough welding area for welding with the corresponding interconnection part. When welding the polarity pad and the corresponding interconnection part, the interconnection part can be welded to the corresponding polarity pad by electromagnetic or infrared welding. For example, when the polarity pad and the interconnection part are welded by electromagnetic welding, the welding temperature is 180° C.-380° C., and the welding time is 1000ms-4000ms.

[0071] In one example, Figure 2AAs shown, for the same interconnection member 100 , the interconnection member 200 welded to the first polarity pad 101 is defined as the first interconnection member 200A corresponding to the first polarity pad 101 , and the interconnection member 200 welded to the second polarity pad 102 is defined as the second interconnection member 200B corresponding to the second polarity pad 102 .

[0072] In another example, Figure 2B and Figure 2C As shown, for two adjacent battery cells, the battery cells corresponding to the different polarity pads of the two adjacent battery cells can be the same interconnecting member 200, or different interconnecting members 200. The two adjacent battery cells can be defined as a first battery cell 100A and a second battery cell 100B. There is a gap between the first battery cell 100A and the second battery cell 100B. The gap accommodates the corresponding interconnecting member 200 (i.e., the interconnecting member 200 corresponding to the gap between the first battery cell 100A and the second battery cell 100B).

[0073] like Figure 2B and Figure 2C As shown, when the first polarity pad 101 and the second polarity pad 102 on the back side of the first cell 100A and the back side of the second cell 100B are both close to the cell edge, and the pads of different polarity on the first cell 100A and the second cell 100B are close to the same gap. In actual applications, when the first polarity pad 101 and the second polarity pad 102 on the first cell 100A and the second cell 100B are arranged opposite to each other, the first polarity pad 101 on the first cell 100A and the second polarity pad 102 on the second cell 100B are close to the gap between the first cell 100A and the second cell 100B.

[0074] If the battery cells corresponding to the two adjacent battery cells with different polarity pads are the same interconnection component, such as Figure 2B As shown, the first polarity pad 101 of the first cell 100A and the second polarity pad 102 of the second cell 100B are welded via the same interconnection member 200. At this time, the first polarity pad 101 of the first cell 100A and the second polarity pad 102 of the second cell 100B are interconnected using the same interconnection member 200.

[0075] If the battery cells corresponding to the two adjacent battery cells with different polarity pads are different interconnects, such as Figure 2CAs shown, the first interconnecting member 200A corresponds to the first polarity pad 101 of the first cell 100A, and the second interconnecting member 200B corresponds to the second polarity pad 102 of the second cell 100B. The end of the first interconnecting member 200A away from the first cell 100A and the end of the second interconnecting member 200B away from the second cell 100B are both welded to the bus bar 300. In this case, the first interconnecting member 200A and the second interconnecting member 200B share a bus bar 300. The first interconnecting member 200A, the bus bar 300, and the second interconnecting member 200A can constitute an interconnection assembly, connecting the first cell 100A and the second cell 100B in series.

[0076] Figures 4A to 4C The following are schematic diagrams of the back structures of three battery strings provided by the embodiments of the present invention. Figures 4A to 4C As shown, the solar cell assembly may further include at least one bus bar 300. Each bus bar 300 may be welded to a corresponding interconnection member 200 to interconnect the cells 100. In practical applications, the bus bar 300 may be welded to the corresponding interconnection member 200 in advance, and then the end of the interconnection member 200 away from the bus bar 300 may be welded to the corresponding polarity pad. Alternatively, one end of the interconnection member 200 may be welded to the corresponding polarity pad first, and then the bus bar 300 may be welded to the end of the interconnection member 200 away from the corresponding polarity pad.

[0077] In one example, Figure 4A As shown, two cells can be welded together in series to form a battery string, and then the two battery strings can be connected in parallel using a bus bar 300 to form a battery string group. For example, in a half-cell battery with 2 rows and 2 columns (a total of 4 cells), the two battery cells 100 in each column are connected in series through an interconnector 200 to form a battery string, and then the two battery strings can be connected in parallel using a bus bar 300 to form a battery string group. Figure 4A The battery string shown.

[0078] In another example, Figure 4B As shown, 4 cells can be welded together in series to form a battery string, and then the battery strings can be connected in parallel using bus bars 300 to form a battery string group. For example, in a half-cell battery with 4 rows and 2 columns (8 cells in total), in each column of cells, two cells 100 are connected in series through interconnectors 200 to form a battery string, and then two battery strings are connected in parallel using bus bars 300 to form a battery string group. Figure 4B The battery string shown.

[0079] In another example, Figure 4CAs shown, two battery cells 100 can be grouped together and connected in series to form a battery string. Then, each battery string can be connected in series and parallel according to the designed circuit to form a battery string group. For example, in a half-cell battery with 4 rows and 6 columns (a total of 24), two battery cells 100 in each column are first grouped together using an interconnection member 200 to form a battery string. Then, two interconnection bars and a bus bar 300 connecting the two interconnection bars are used to interconnect 12 battery strings. Figure 4C The battery string shown.

[0080] like Figure 4C As shown, when the interconnection member 200 interconnects two adjacent battery cells 100, there is a gap between the two adjacent battery cells 200. The gap accommodates the corresponding interconnection member 200. In order to improve the visual effect of the component, Figure 4D Example Figure 4C The front view of the battery string is shown in Figure 1. Figure 4D As shown, the solar cell assembly further includes a visual shielding layer 400 located between two adjacent cells 100. The visual shielding layer 400 is located on the surface of at least one interconnecting member 200 facing the front of the cell. At this time, the visual shielding layer 400 can scatter the sunlight irradiated on the visual shielding layer to the surrounding cells, thereby improving the light utilization rate of the cells. In addition, the adhesive layer (such as Figure 1 The second adhesive layer J2) shown is a polymer material that is easily discolored due to aging. For example, EVA easily turns brown when in long-term contact with Cu material or other materials. The use of the visual shielding layer 400 can effectively reduce the impact of EVA discoloration on the appearance of the solar cell module.

[0081] In the actual assembly process, Figure 4D As shown, the visual blocking layer 400 can be first attached to the interconnection member 200, and then the interconnection member 200 is welded to the corresponding polarity pads, so that the visual blocking layer 400 faces the front surface of the cell 100. This achieves the purpose of shielding the interconnection and ensures the good appearance of the solar cell module. For example, the material of the visual blocking layer 400 can be a light-shielding material, and its color can be close to or the same as the color of the backplane of the solar cell module. For example, when a white backplane is used, the color of the visual blocking layer used is white, and when a black backplane is used, the color of the visual blocking layer used is black.

[0082] Figures 4A to 4C The battery cell 100 shown can be Figure 5 The complete battery cell BA shown may also be a sliced battery cell. Figure 5 The following is a schematic diagram of a cell slice according to an embodiment of the present invention. Figure 5As shown, these sliced cells can be cut from a complete cell BA, and the cutting process can be implemented using existing cutting processes. The sliced cell is a 1 / N sliced cell, where N is the number of cells formed after cutting a complete cell BA. For example, by forming a scribe line H on the complete cell BA and cutting the complete cell BA along the scribe line H, two cells 100 defined as half-cells can be formed. Of course, the complete cell BA can also be cut into more sub-cells of roughly equal area, which will not be described in detail here.

[0083] When using Figures 4A to 4C The interconnecting member 200 shown interconnects the sliced cells to form a solar cell module. The cells in the solar cell module are often interconnected using a series-parallel structure to ensure that the current of each main grid is reduced to 1 / 2 of the original, and the internal loss is reduced to 1 / 4 of the entire cell, thereby increasing the module power. However, the reduction in cell area here can reduce the resistance loss of the interconnection and improve the energy output efficiency, but there will be multiple cutting damages, which may have an adverse effect on the battery performance. Therefore, it is necessary to make a comprehensive decision on the cutting and series connection design. For example: when multiple sliced cells are connected in series and parallel, the solar photovoltaic module can have a higher output voltage, and more cells can be connected in series. As for the number of cells, it is not limited and depends on actual needs.

[0084] In one example, the backside of the cell can feature a multi-bus bar (MBB) design. This MBB design shortens the current conduction distance on the fine grid, shortening the battery current collection path by more than 50%, reducing lateral resistance losses, and minimizing packaging losses, resulting in higher module efficiency.

[0085] The number of busbars in a multi-busbar system depends primarily on the balance between electrical and optical considerations. Increasing the number of busbars reduces series resistance, but this also increases the shielding area. Based on this, the number of solder pads for each polarity can range from 6 to 15. The solder pads can be rectangular, preferably 2mm x 3mm in size. The minimum distance between each polarity solder pad and the corresponding cell edge is 3mm to prevent cell cracking due to excessive stress.

[0086] In order to improve battery efficiency, a relatively thin main grid can be selected for MBB design plus small-piece battery design. For example, the above-mentioned battery cell can be a rectangular 9BB half-piece IBC battery. At this time, the back of the IBC battery has two opposite long sides (i.e., the first side edge and the second side edge opposite to each other in the previous text), and the 9 first polarity pads are spaced along the length direction and close to one long edge, and the 9 second polarity pads are spaced along the length direction and close to the other long edge. Compared with other numbers of grid lines, the 9BB half-piece IBC battery has the advantages of higher efficiency and lower welding process difficulty.

[0087] In order to achieve the above-mentioned back-contact battery interconnection, an embodiment of the present invention provides an interconnection component to alleviate the stress generated by the welding process and the high and low temperature differences outdoors, thereby reducing the degree of bending deformation of the back-contact battery and improving welding stability and accuracy.

[0088] Figure 6 The following is a basic structural diagram of an interconnection element provided by an embodiment of the present invention. Figure 6 As shown, the interconnection member provided by the embodiment of the present invention includes: a flexible insulating substrate 210 and a plurality of structural welding ribbons 220 formed on the flexible insulating substrate 210 .

[0089] like Figure 6 As shown, the above-mentioned multiple structural welding strips 220 can be arranged at intervals on the flexible insulating substrate 210. The structure of the flexible insulating substrate 210 can be a strip structure, so that the multiple structural welding strips 220 are distributed at intervals along the strip extension direction of the flexible insulating substrate 210.

[0090] When a certain polarity pad on a cell is welded to a corresponding interconnect, the number of polarity pads on the interconnect is related to the number of structural welding ribbons on the interconnect. For example: Figure 4A The illustrated cell has nine first and second polarity pads 101, 102. Therefore, the flexible insulating substrate 210 may have nine structural welding strips 220. Alternatively, the number of structural welding strips 220 may be less than or greater than nine to meet the needs of different circuit designs. Therefore, when a certain polarity pad on a cell is welded to a corresponding interconnect, each polarity pad on the cell is welded to the corresponding structural welding strip on the interconnect.

[0091] Compared with traditional interconnection ribbons, Figure 6The multiple structural welding ribbons 220 shown are spaced apart on the flexible insulating substrate 210, which can reduce the amount of welding ribbon material used. This not only reduces manufacturing costs but also reduces the contact area between the structural welding ribbons 220 contained in the interconnect and the back of the solar cell, reducing the impact of thermal stress during interconnection and improving the reliability of the solar cell module. More importantly, when multiple structural welding ribbons 220 are spaced apart on the flexible insulating substrate 210, the resulting interconnect has excellent flexibility. Therefore, the structural welding ribbons 220 can release thermal stress generated by temperature differences (for example, during the welding process, lamination process, and outdoor environmental changes) through the flexible insulating substrate 210, thereby reducing the degree of bending deformation of the back-contact solar cell and improving welding stability and long-term stability. Furthermore, when the interconnect provided by the embodiments of the present invention is used to interconnect back-contact solar cells, the flexible insulating substrate 210 included in the interconnect can provide electrical isolation between adjacent back-contact solar cells except for the solder pads, thereby reducing the possibility of leakage and improving solar cell efficiency. In other words, the flexible insulating substrate 210 can prevent the structural welding ribbons 220 from forming shunt paths with areas of the solar cell that do not need to be interconnected, thereby improving solar cell conversion efficiency.

[0092] In addition, if Figure 6 As shown, when the interconnection element is welded to the corresponding polarity pad, the flexible insulating substrate 210 can fix the multiple structural welding strips 220 during the welding process, preventing the relative position of the structural welding strips 220 and the pad from shifting during the welding process, thereby improving the welding accuracy and avoiding electrical short circuits caused by misalignment between the structural welding strips 220 and the pad. Figures 2A to 2C As shown, when the interconnection member 200 is located in the gap between two adjacent battery cells or on one side of the battery cell, Figure 6 The flexible insulating substrate 210 shown can be partially or entirely located on one side of the gap or battery cell. If the flexible insulating substrate 210 is partially located on one side of the gap or battery cell, the area of the flexible insulating substrate 210 not located on one side of the gap or battery cell can be attached to the edge of the battery cell.

[0093] When the interconnect is located in the gap between two adjacent cells or on one side of a cell, Figure 6 The flexible insulating substrate 210 shown can block the gaps at the cell edges, reducing the possibility of particulate matter generated during welding migrating through the cell edges to the front of the cell, thereby reducing contamination of the cell front surface by particulate matter during welding, subsequent processing, or use. Furthermore, the flexible insulating substrate 210 can serve as a spacer for the back contact cells, achieving symmetry and aesthetics in the assembly of the solar cell module.

[0094] In an alternative approach, Figure 6As shown, the structural welding strip 220 can be formed by a stamping process, a chemical etching process, an electrospark machining process, a laser cutting process or other suitable manufacturing processes. Multiple structural welding strips 220 are arranged at intervals on a flexible insulating substrate, which can not only produce interconnects with excellent strain relief capabilities, but also have relatively low manufacturing costs. The thickness of the original welding strip for manufacturing the structural welding strip can be 0.02mm-0.3mm, and the width is 3mm-7mm. For example: the original welding strip is a copper-based material such as oxygen-free copper or T2 copper, with a copper content ≥99.99wt% and a conductivity ≥98%. The welding strip is double-sided coated, the coating material is Sn63Pb37, the coating thickness is 0.02-0.1mm, and the coating melting point is about 183°C. The tensile strength of the welding strip is ≥150N / mm 2 , elongation at break ≥ 20%, yield strength ≤ 65MPa.

[0095] like Figure 6 As shown, each structural welding ribbon 220 can be formed on the flexible insulating substrate 210 by hot pressing or bonding, so that the structural welding ribbon 220 and the flexible insulating substrate 210 form an integral interconnected part. When each structural welding ribbon 220 is formed on the flexible insulating substrate 210 by bonding, the flexible insulating substrate 210 can be an insulating polymer material. The polymer material includes one or more of polyvinyl butyral (PVB), polyolefin (POE), and ethylene-vinyl acetate copolymer (EVA), but is not limited thereto. The adhesive can be a polymer adhesive, including but not limited to one or more of polyvinyl acetate, polyvinyl acetal, acrylate, polystyrene, epoxy resin, acrylic resin, polyurethane resin, unsaturated polyester, butyl rubber, nitrile rubber, phenolic-polyvinyl acetal, and epoxy-polyamide, but is not limited thereto.

[0096] In one example, Figure 6 As shown, when a gap exists between two adjacent solar cells and the interconnection member is accommodated in the gap, the flexible insulating substrate 210 contained in the interconnection member can be a light-shielding flexible insulating substrate or a transparent flexible insulating substrate. If the flexible insulating substrate 210 contained in the interconnection member is a light-shielding flexible insulating substrate, since the flexible insulating substrate 210 is partially or entirely located in the gap between the two adjacent back-contact solar cells, the flexible insulating substrate 210 can be used as a visual shielding structure. When the solar cell module is viewed from the front, the structural welding ribbon 220 on the back of the solar cell module is not visible, thereby improving the aesthetics of the solar cell module.

[0097] like Figure 6As shown, when the flexible insulating substrate 210 is a light-shielding flexible insulating substrate, especially a transparent flexible insulating substrate, in order to improve the visual effect, on the one hand, the aforementioned visual blocking layer can be attached to the surface of the flexible insulating substrate 210 that needs to face the front of the battery cell to block the structural welding strip 220; on the other hand, the flexible insulating substrate 210 can be improved.

[0098] For example, the flexible insulating substrate may have a partial or entire surface with a light-blocking coating. The light-blocking coating may be located on one or both surfaces of the flexible insulating substrate, thereby providing the flexible insulating substrate with a good light-blocking effect. The color of the light-blocking coating can refer to the color of the visual-blocking layer described above, and its effects can also refer to the description of the visual-blocking layer described above.

[0099] For example, the flexible insulating substrate may be a single-sided tape or a double-sided tape with a release layer, which can reduce contamination of the tape surface by the environment or the operating table during the processing of solar cell modules.

[0100] In one application scenario, such as Figures 4A to 4D and Figure 6 As shown, when the above-mentioned interconnection parts are welded to the corresponding polarity pads, if the flexible insulating substrate 210 is located between two adjacent battery cells 100, the surface of the flexible insulating substrate 210 facing the front of the battery cell may have a release layer. The color of the release layer can refer to the color of the visual blocking layer mentioned above, and the effect can also refer to the relevant description of the visual blocking layer mentioned above. At the same time, on the area where the flexible insulating substrate 210 faces the back of the battery cell (i.e., the surface where multiple structural welding strips 220 are formed), the flexible insulating substrate 210 is located between two adjacent structural welding strips 220. A release layer can also be formed to prevent particulate matter contamination (from component processing or subsequent use).

[0101] In one application scenario, the sticky side of the single-sided tape can be attached to the edge of two adjacent battery cells near the same gap, so that the sticky side of the single-sided tape faces the front of the battery cell, and then the structural welding ribbon is welded to the corresponding polarity welding pad. At this time, the single-sided tape acts as a flexible insulating substrate to play a positioning role before welding, so that the position of the structural welding ribbon is not easily offset when welding the structural welding ribbon. Of course, for double-sided tape, as long as any one side is attached to the edge of two adjacent battery cells near the same gap. I will not go into details here.

[0102] Figure 7A and Figure 7B Two basic structural schematic diagrams of the structural welding strip in the embodiment of the present invention are illustrated. Figure 7A and Figure 7BAs shown, each structural welding ribbon 220 has two welding portions and a connecting portion 221 located between the two welding portions. The connecting portion 221 is connected to each of the two welding portions. At least a portion of the connecting portion 221 is located on the flexible insulating substrate 210. The two welding portions extend out of the flexible insulating substrate. For example, each welding portion can be a solid plane, and the two welding portions can extend out of the flexible insulating substrate 210 in opposite directions.

[0103] When each polarity solder ribbon of a cell is welded to the structural solder ribbon corresponding to the corresponding interconnect, each polarity solder ribbon of each polarity solder ribbon is welded to a soldering portion of each structural solder ribbon of the interconnect. Welding methods include, but are not limited to, electromagnetic or infrared welding to the corresponding polarity solder pads of the cell. Furthermore, if thermal stress is generated at the soldering portion during welding, lamination, or subsequent use, the thermal stress can be transferred to the flexible insulating substrate through the connecting portion. The flexible insulating substrate's flexibility can be utilized to release the thermal stress, thereby reducing the degree of bending deformation of the back-contact cell and improving welding stability and long-term stability.

[0104] Specifically, if Figure 7A and Figure 7B As shown, the two welding portions include a first welding portion 221A and a second welding portion 221B. Both the first welding portion 221A and the second welding portion 221B are used to weld to corresponding polarity pads. For example, when the first welding portion 221A is welded to the first polarity pad, the second welding portion 221A is used to conduct current and can be welded to a busbar or the second polarity pad of another battery cell.

[0105] like Figure 6 、 Figure 7A and Figure 7BAs shown, when each structural welding ribbon 220 is formed on the flexible insulating substrate 210 by hot pressing, the thickness of the flexible insulating substrate 210 is as thin as possible, for example, less than 0.02 mm. This can reduce the degree of curvature of the first welding portion 221A and the second welding portion 221B, allowing the first welding portion 221A and the second welding portion 221B to be welded to the corresponding polarity pads as horizontally as possible, thereby improving welding reliability. Of course, if the flexible insulating substrate 210 is thermoplastic, during the lamination process, the flexible insulating substrate 210 can undergo a certain degree of expansion under the lamination heat field environment, thereby allowing the flexible insulating substrate 210 to fill the gap between two adjacent solar cells, thereby completely blocking the gap between the two adjacent solar cells, but not extending to the back area of the solar cells and affecting the solar cell power generation. In addition, the thickness of the structural welding ribbon 220 is less than or equal to 1 / 3 of the thickness of the flexible insulating substrate 210 to avoid the problem of the structural welding ribbon 220 cutting the flexible insulating substrate 210 due to excessive hot pressing pressure during the hot pressing process. Based on this, the thickness of the original welding strip can be 0.12 mm and the width is preferably 5 mm.

[0106] In one example, Figure 7A and Figure 7B As shown, the central axes of the first welding portion 221A and the second welding portion 221B can be collinear. Here, if the first welding portion 221A and the second welding portion 221B are rectangular, the axis along the length of the first welding portion 221A and the second welding portion 221B is the central axis. In this case, the current flowing from the first welding portion 221A to the second welding portion 221B can be conducted in a manner that is as close to a straight line as possible.

[0107] In one example, Figure 7A and Figure 7B As shown, the width of the first welding portion 221A and the width of the second welding portion 221B can both be smaller than the maximum width of the connecting portion 221. For example, when the first welding portion 221A, the second welding portion 221B, and the connecting portion 221 are all rectangular structures, the dimensions of the first welding portion 221A and the second welding portion 221B can be 6 mm × 1 mm, and the dimensions of the connecting portion 221 can be 6 × 3 mm. In this case, the widths of the first welding portion 221A and the second welding portion 221B are both 1 mm, and the width of the connecting portion 221 is 3 mm.

[0108] In one example, Figure 7A and Figure 7B The first welding portion 221A, the second welding portion 221B and the connecting portion 221 are all made of the same Figure 7A The right angle transition shown or Figure 7B When the arc transition method is used as shown. Figure 7BWhen the arc transition is used as shown, stress concentration is not likely to occur at the arc transition, thereby further reducing the stress of the structural welding strip 220 caused by temperature changes (welding temperature changes or external environment temperature changes).

[0109] like Figure 2A 、 Figure 7A and Figure 7B As shown, for the same battery cell, the first welding portion 221A contained in the first interconnecting member 200A is welded to the first polarity pad 101 of the battery cell 100 , and the second welding portion 221B contained in the second interconnecting member 200B is welded to the second polarity pad 102 of the battery cell 100 .

[0110] For two adjacent solar cells, if the solar cells with different polarity pads are the same interconnection component, such as Figure 2B 、 Figure 7A and Figure 7B As shown, the first welding portion 221A of each structural welding ribbon included in the same interconnection member 200 is welded to each first polarity welding pad 101 of the first battery cell 100A in a one-to-one correspondence, and the second welding portion 221B of each structural welding ribbon included in the same interconnection member 200 is welded to each second polarity welding pad 102 of the second battery cell 100B in a one-to-one correspondence. If the battery cells corresponding to the welding pads of different polarities of two adjacent battery cells are different interconnections, such as 2C, Figure 7A and Figure 7B As shown, the first welding portion 221A of each structural welding ribbon included in the first interconnecting member 200A is welded one-to-one with each first polarity welding pad 101 included in the first battery cell 100A, the second welding portion of each structural welding ribbon included in the second interconnecting member 200B is welded one-to-one with the second polarity welding pad 102 included in the second battery cell 100B, and the bus bar 300 is respectively welded to the second welding portion 221B of each structural welding ribbon included in the first interconnecting member 200A and the first welding portion 221A of each structural welding ribbon included in the second interconnecting member 200B.

[0111] Figure 8 A structural schematic diagram of a flexible insulating substrate provided by an embodiment of the present invention is illustrated. Figure 8 As shown, the flexible insulating substrate 210 has a conductive layer 212 therein. Figure 7A and Figure 7B The connection portions 221 of the various structural welding strips 220 are electrically connected via the conductive layer 212. It should be understood that Figure 8 The conductive layer 212 is partially exposed, but in actual practice, Figure 8 The exposed conductive layer 212 is generally embedded in the flexible insulating substrate 210 to reduce unnecessary contamination and loss.

[0112] like Figure 8 As shown, the conductive layer 212 can be a conductive strip or a conductive particle layer composed of contacting metal particles. The conductive strip can be one or more of copper strips, silver strips, aluminum strips, etc., and the conductive particle layer can include one or more of contacting copper particles, silver particles, aluminum particles, etc. In practical applications, a conductive particle slurry can be formed on one side of the flexible insulating layer, and the solvent contained therein can be removed (e.g., by low-temperature drying) without damaging the flexible insulating substrate 210 to form the conductive particle layer. The surface of the flexible insulating layer formed with the conductive particle layer is then covered with another flexible insulating substrate 210, so that the conductive particle layer is formed within the flexible insulating substrate.

[0113] Based on the above structure, Figure 7A 、 Figure 7B and Figure 8 As shown, when the conductive layer 212 electrically connects the connection portions 221 included in each structural welding ribbon 220, the conductive layer 212 can be used as a horizontal conductive path. If the first welding portion 221A included in one of the multiple structural welding ribbons 220 is poorly welded to the first polarity pad, the structural welding ribbon 220 will partially fail as a vertical conductive path. However, the structural welding ribbon 220 can still use the conductive layer to conduct current to other structural welding ribbons 220 with good welding, avoiding the problem of reduced battery efficiency caused by local failure of the vertical conductive path, thereby improving the connection reliability of the interconnect.

[0114] Figure 9A An example schematic diagram of the interconnection structure in an embodiment of the present invention is illustrated. Figure 9B FIG. 1 is a schematic diagram of another example of an interconnection structure in an embodiment of the present invention. Figure 9A and Figure 9B As shown, the connection portion 221 of each structural welding ribbon 220 is exposed away from the surface of the flexible insulating substrate 210. At this time, multiple structural welding ribbons 220 can be placed on the surface of the flexible insulating substrate 210 and pressed onto the flexible insulating substrate 210 under pressure.

[0115] like Figure 9A and 9B As shown, when the flexible insulating substrate 210 includes a conductive layer 212, the flexible insulating substrate 210 includes two flexible insulating layers 211 and the conductive layer 212 located between the two flexible insulating substrates 211. When a plurality of structural welding ribbons 220 are pressed onto one side of the flexible insulating substrate 210 using a hot pressing process, the pressure can be controlled so that the bottom of the connecting portion 221 of the structural welding ribbon 220 contacts the conductive layer 212.

[0116] Figure 10AA schematic diagram of the interconnection structure of another example in an embodiment of the present invention is illustrated. Figure 10B Example Figure 10A A cross-sectional view of the interconnection shown in the AA direction. Figure 10A and Figure 10B As shown, when the connection portion 221 of each structural welding ribbon 220 is embedded in the flexible insulating substrate 210. The connection portion 221 of each structural welding ribbon 220 is at least partially wrapped in the flexible insulating substrate 210. The first welding portion 221A and the second welding portion 221B extend from two opposite directions of the flexible insulating substrate 210. At this time, Figure 10A The interconnection member shown is a sandwich structure, and the flexible insulating substrate 210 can be used to further fix the structural welding ribbon 220. This not only further reduces or eliminates the possible displacement of the structural welding ribbon 220 during the welding process, but also eliminates the possibility of failure of the connection between the structural welding ribbon 220 and the flexible insulating substrate 210 when a welding portion of the structural welding ribbon 220 is warped under force, thereby ensuring the stability of the connection between the structural welding ribbon 220 and the flexible insulating substrate 210.

[0117] Figure 10C Example Figure 10A Another cross-sectional view of the interconnection member in the AA direction is shown. Figure 10C As shown, when a plurality of structural welding strips are pressed between two flexible insulating layers 211 by a hot pressing process, a conductive layer 212 is embedded in the flexible insulating substrate 210. At this time, after the conductive layer 212 is formed on one flexible insulating layer 211, a conductive layer 212 is formed on the surface of the flexible insulating layer 211. Figure 7A or Figure 7B The structural welding ribbon 220 is shown. On this basis, another flexible insulating layer 211 is laminated onto the surface of the flexible insulating layer 211 on which the conductive layer 212 is formed. At this point, the connecting portion 221 of each structural welding ribbon 220 is at least partially wrapped between the two flexible insulating layers 211, ensuring that the connecting portion 221 of each structural welding ribbon 220 is in direct contact with the conductive layer 212.

[0118] In an alternative approach, Figure 7A and Figure 7B As shown, the connection portion 221 has a hollow structure LK for stress relief. Aside from the hollow structure LK, the rest of the connection portion 221 is solid. This hollow structure LK can relieve stress generated during welding, lamination, and outdoor temperature fluctuations, thereby reducing the degree of back-contact cell bending and deformation, improving welding stability and long-term reliability.

[0119] Figure 7A and Figure 7BThe hollow structure LK shown may include at least one through hole T. The pattern of each through hole T is a closed pattern. In this case, the closed pattern here means that the outline pattern of the hollow structure LK is closed. In this case, the edge contour of the connecting portion 221 is complete, which can ensure that the structural welding strip 220 has good strength. The pattern of each through hole is a polygonal pattern, a circular pattern, an elliptical pattern or an irregular pattern. The polygonal pattern can be a triangle, a rectangle, a square, etc. For example, the shape of the through hole is a rectangle and the length can be 1mm-10mm.

[0120] Figures 11A to 13A Three distribution diagrams of multiple rows of through holes distributed along a first direction in an embodiment of the present invention are illustrated; Figures 11B to 13B Three distribution diagrams of multiple rows of through holes distributed along the second direction in an embodiment of the present invention are illustrated. Figures 11A to 13A and Figures 11B to 13B As shown, Figure 7A and Figure 7B The hollow structure LK shown includes m rows of through holes, where m is an integer greater than or equal to 1. Each row of through holes includes at least one through hole. The first row of through holes and the mth row of through holes are formed in the connecting portion 221 along any direction parallel to the connecting portion 221. For example: when m is an integer greater than or equal to 2, the first row of through holes to the mth row of through holes are distributed along the distribution direction (first direction A) of the first welding portion 221A and the second welding portion 221B. For another example: when m is an integer greater than or equal to 2, the first row of through holes to the mth row of through holes are distributed along the distribution direction (second direction B) perpendicular to the first welding portion 221A and the second welding portion 221B.

[0121] When the first row of through holes to the mth row of through holes are arranged along the Figures 11A to 13A When distributed in the first direction A shown, the through hole T is a slit-type through hole or a rectangular through hole. The distribution of the through holes T in two adjacent rows can be appropriately adjusted to ensure that there is a shorter circuit path between the first welding portion 221A and the second welding portion 221B while ensuring appropriate strength and stress relief capabilities.

[0122] When the first row of through holes to the mth row of through holes are arranged along the Figures 11B to 13B When distributed in the second direction B shown, the through hole T is a slit-type through hole or a rectangular through hole. If the length direction of the through hole T is distributed perpendicular to the distribution direction of the first welding portion 221A and the second welding portion 221B, then the spacing between the two rows of through holes can be adjusted so that the current of the first welding portion 221A and the second welding portion 221B is transmitted to the other welding portion through the connecting portion 221 in a straight line as much as possible, thereby reducing current loss.

[0123] For example, two adjacent rows of through holes are staggered. In this case, the m rows of through holes in the connection portion can release the stress generated by the structural welding strip more evenly, thereby further reducing the degree of deformation of the back contact battery. Of course, the distribution of each row of through holes can also be adjusted to balance the structural strength and stress release capacity of the connection portion. For example, Figure 11A and Figure 11B As shown, the connection portion 221 of the structural welding strip 220 has two rows of slit-type through holes with staggered distribution, and each row of slit-type through holes contains one slit-type through hole. The two rows of slit-type through holes can be arranged along Figure 11A The first direction A shown can also be distributed along Figure 11B The second direction B is shown.

[0124] like Figure 11A As shown, when the two rows of through holes are distributed in the first direction A, the ends of the first row of through holes and the ends of the second row of through holes are staggered, so that the current conducted by the first welding portion 221A and the second welding portion 221B can flow along the connecting portion. Figure 11A Conductivity occurs in the direction of the dotted line shown.

[0125] like Figure 11B As shown, when the two rows of through holes are distributed in the second direction B, each row of through holes is a slit-type through hole. The length direction of the slit-type through hole is the same as the first direction A. At this time, the distance between the two adjacent rows of slit-type through holes can be adjusted to be the first welding portion 221A and the second welding portion 221B. Figure 11B The dotted lines shown conduct current in the direction provided the hardware basis.

[0126] For example, Figure 12A and Figure 12B As shown, when m is an integer greater than or equal to 3. The number of through holes included in the 1st row of through holes and the mth row of through holes is greater than or equal to 2. At this time, along the distribution direction from the 1st row of through holes to the mth row of through holes, the number of through holes included in each row of through holes first decreases and then increases. Along the distribution direction from the 1st row of through holes to the mth row of through holes, if the length of each row of through holes along the row direction first decreases and then increases, then along the distribution direction from the 1st row of through holes to the mth row of through holes, the structural strength of the connection portion 221 first increases and then decreases, and the stress of the connection portion 221 first gradually decreases and then gradually increases. Based on this, the distribution mode of the through holes in the connection portion 221 can be used to adjust the strength and stress release capacity of each area of the connection portion 221, so that the strength and stress release capacity of the connection portion 221 are coordinated.

[0127] like Figure 12A and Figure 12BAs shown, when the first row of through holes and the mth row of through holes are formed in the connecting portion 221 along the distribution direction of the two welding portions, along the distribution direction from the first row of through holes to the mth row of through holes, if the number of through holes included in each row of through holes first decreases and then increases, and the distances between the first and tail ends of each row of through holes and the edge of the connecting portion 221 first decrease and then increase, then the current path of the current conducted between the first welding portion 221A and the second welding portion 221B in the connecting portion 221 is as short as possible.

[0128] For example, Figure 12A and 12B As shown, the connection portion 221 of the structural welding strip 220 has three rows of slit-type through holes. The first and third rows of through holes each include two slit-type through holes, and the second row of through holes includes one slit-type through hole. Furthermore, the length of one slit-type through hole included in the second row of through holes is longer than the length of the slit-type through hole included in the first row of through holes, but does not exceed the ends of the first and third rows of through holes. In this case, the first and third rows of through holes contain a relatively large number of slit-type through holes at the ends, while the second row of through holes contains a relatively small number of slit-type through holes. This can result in a relatively high strain relief capability at the ends of the connection portion 221, but relatively weak strength, while the middle portion has poor strain relief capability but relatively high strength. Therefore, the distribution of m rows of through holes can balance the strain relief capability and strength of each area of the connection portion 221, so that the structural welding strip has a high strain relief capability while ensuring strength.

[0129] like Figure 12A As shown, when the three rows of through holes are distributed according to the first direction A, the end of the second row of through holes does not exceed the end of the first row of through holes and the third row of through holes, so that the current conducted by the first welding portion 221A and the second welding portion 221B in the current path of the connecting portion 221 is as follows: Figure 12A The dotted lines shown are conducting.

[0130] like Figure 12B As shown, when the three rows of through holes are distributed along the second direction B, each row of through holes is a slit-type through hole, and the length of the slit-type through holes is distributed along the first direction. At this time, the distance between two adjacent rows of slit-type through holes can be adjusted so that the current path of the current conducted by the first welding portion 221A and the second welding portion 221B in the connecting portion 221 is arranged in the same direction. Figure 12B The dotted lines shown are conducting.

[0131] For example, Figure 13A and Figure 13B As shown, when m is an integer greater than or equal to 3, the number of through holes included in the first row of through holes and the mth row of through holes is greater than or equal to 1. Along the distribution direction from the first row of through holes to the mth row of through holes, the number of through holes included in each row of through holes first increases and then decreases.

[0132] like Figure 13A and Figure 13B As shown, along the distribution direction of through-holes from the first row to the mth row, if the length of each row of through-holes along the row direction first increases and then decreases, then along the distribution direction of through-holes from the first row to the mth row, the structural strength of the connection portion 221 first decreases and then increases, and the stress in the connection portion 221 first gradually increases and then gradually decreases. Based on this, the distribution of through-holes in the connection portion 221 can be used to adjust the strength and stress release capacity of each area of the connection portion 221, so that the strength and stress release capacity of the connection portion 221 are coordinated.

[0133] For example, Figure 13A and Figure 13B As shown, the connection portion 221 of the structural welding strip 220 has three rows of slit-type through holes. The first and third rows of through holes each include one slit-type through hole, and the second row of through holes includes two slit-type through holes. Furthermore, the length of one slit-type through hole in the first row of through holes is longer than the length of the slit-type through hole in the second row of through holes, but the ends of the first and third rows of through holes do not exceed the ends of the second row of through holes. In this case, the number of slit-type through holes in the first and third rows of through holes is relatively small, while the number of slit-type through holes in the second row of through holes is relatively large. This can result in higher strength at both ends of the connection portion 221, but lower stress relief capability, while the middle portion has higher strain relief capability but lower strength. Therefore, the distribution of m rows of through holes T can balance the strain relief capability and strength of each region of the connection portion 221, allowing the structural welding strip 220 to have higher strain relief capability while ensuring strength.

[0134] like Figure 13A As shown, when the three rows of through holes are distributed in the first direction A, the ends of the first row of through holes and the third row of through holes do not exceed the second row of through holes, so that the current conducted by the first welding portion 221A and the second welding portion 221B can flow along the connecting portion 221. Figure 13A Flow is shown in the dashed direction.

[0135] like Figure 13B As shown, when the three rows of through holes are distributed along the second direction B, each row of through holes is a slit-type through hole, and the length direction of the slit-type through holes is distributed along the first direction A. At this time, the distance between two adjacent rows of slit-type through holes can be adjusted so that the current conducted by the first welding portion 221A and the second welding portion 221B can be distributed along the connecting portion 221. Figure 13A Flow is shown in the dashed direction.

[0136] Figure 14The following is a schematic structural diagram of a manufacturing device for an interconnection part provided by an embodiment of the present invention. The manufacturing device for the interconnection part includes a first feeding mechanism S1, a stamping and forming mechanism S2, a cutting mechanism S3, a second feeding mechanism S4, a material compounding mechanism S5 and a winding mechanism S6. The stamping and forming mechanism S2 has a stamping head and a forming die. The forming die includes an upper die and a lower die. The upper die and the lower die have a structural welding strip forming portion corresponding to the structural welding strip 220. The structural diagram of the structural welding strip forming portion can refer to the structure of the structural welding strip in the previous text, specifically including two welding forming portions and a connection forming portion located between the two welding forming portions. The connection forming portion is respectively connected to the two welding forming portions, and the connection forming portion has a function of forming a perforated structure on the welding strip. The following is combined with Figure 15 The structural flow diagrams of the interconnection component manufacturing method at various stages are shown to describe the manufacturing process of the interconnection component provided by the embodiment of the present invention.

[0137] like Figure 14 and Figure 15 As shown, the first feeding mechanism S1 can provide the stamping mechanism with Figure 14 The stamping mechanism S2 includes a punch head that controls the lower and upper dies to close and release the die, and stamps the solder strip W to obtain the following: Figure 14 The connecting structural welding strip LX shown. The connecting structural welding strip LX is an integrated structure formed by multiple structural welding strips 220 described above. The welding portion contained in two adjacent structural welding strips 220 is connected. The cutting mechanism S3 is used to cut the welding portion connecting two adjacent structural welding strips 220 together to form multiple independent structural welding strips 220. The second feeding mechanism S4 can provide the flexible insulating substrate 210 to the material compounding mechanism S5. The material compounding mechanism S5 can be a hot pressing roller mechanism, which can hot press the flexible insulating substrate 210 to the multiple structural welding strips 220 onto the flexible insulating substrate at 50 to 120°C for 5s to 30s (for example, 100°C) to form an interconnection. The winding mechanism winds the interconnection together.

[0138] It should be noted that if the interconnection component adopts a sandwich structure, the second feeding mechanism S4 may include two feeding rollers, each for providing the flexible insulating substrate 210 to the material laminating mechanism S5. The material laminating mechanism S5 can achieve not only two-layer structure lamination, but also three-layer structure lamination. For example, multiple structural welding ribbons are spaced along the length of the flexible insulating substrate, and the flexible insulating substrate is distributed on the surface of the structural welding ribbons by hot pressing to form a flexible insulating substrate, thereby forming a sandwich-structured interconnection component.

[0139] In the description of the above embodiments, specific features, structures, materials or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.

[0140] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. An interconnection component, characterized in that: Applicable to back-contact battery interconnection, the interconnection component comprises: a flexible insulating substrate and a plurality of structural welding strips spaced apart on the flexible insulating substrate; each structural welding strip has two welding portions and a connecting portion located between the two welding portions, the connecting portion being connected to the two welding portions respectively; at least a portion of the connecting portion is located on the flexible insulating substrate, and the two welding portions extend out of the flexible insulating substrate; The flexible insulating substrate has a conductive layer, and the connection portions of the structural welding strips are electrically connected through the conductive layer; wherein the conductive layer is a conductive strip or a conductive particle layer composed of metal particles in contact with each other; The connection portion of each of the structural welding strips is exposed away from the surface of the flexible insulating substrate; or, at least a portion of the connection portion of each of the structural welding strips is wrapped in the flexible insulating substrate; or, each of the structural welding strips is hot-pressed or bonded to the flexible insulating substrate; The flexible insulating substrate comprises two flexible insulating layers and the conductive layer located between the two flexible insulating layers; The thickness of the structural welding strip is less than or equal to 1 / 3 of the thickness of the flexible insulating substrate.

2. The interconnection member according to claim 1, wherein: The connecting portion has a hollow structure for relieving stress.

3. The interconnection member according to claim 2, wherein: The hollow structure includes at least one through hole; wherein, The pattern of each through hole is a closed pattern; and / or, The pattern of each through hole is a polygonal pattern, a circular pattern, an elliptical pattern or a special-shaped pattern.

4. The interconnection member according to claim 2, wherein: The hollow structure includes m rows of through holes, where m is an integer greater than or equal to 1; each row of through holes includes at least one through hole, and the first row of through holes and the mth row of through holes are formed in the connecting portion along any direction parallel to the connecting portion.

5. The interconnection member according to claim 4, characterized in that The through holes in two adjacent rows are staggered; wherein, m is an integer greater than or equal to 3, the number of through holes in the first row of through holes and the mth row of through holes are both greater than or equal to 2; along the distribution direction from the first row of through holes to the mth row of through holes, the number of through holes in each row of through holes first decreases and then increases; and / or, The m is an integer greater than or equal to 3, and the number of through holes included in the first row of through holes and the mth row of through holes is greater than or equal to 1; along the distribution direction from the first row of through holes to the mth row of through holes, the number of through holes included in each row of through holes first increases and then decreases.

6. The interconnection element according to any one of claims 1 to 5, characterized in that: The central axes of the two welding portions are collinear; and / or, The width of each welding portion is smaller than the maximum width of the connecting portion, and each welding portion is connected to the connecting portion in an arc transition manner.

7. The interconnection element according to any one of claims 1 to 5, characterized in that: The flexible insulating substrate is a light-shielding flexible insulating substrate; or At least one surface of the flexible insulating substrate is partially or entirely coated with a shielding coating; or The flexible insulating substrate is a single-sided adhesive tape with a release layer or a double-sided adhesive tape with a release layer.

8. A solar cell module, characterized in that: The invention comprises at least two battery cells and a plurality of interconnecting members for interconnecting the battery cells, wherein each of the interconnecting members is an interconnecting member according to any one of claims 1 to 7; wherein, The back side of each of the battery cells has two polarity pads, and each polarity pad contained in each of the polarity pads is welded to a welding portion of a corresponding structural welding ribbon contained in the corresponding interconnection member.

9. The solar cell assembly according to claim 8, characterized in that There is a gap between two adjacent battery cells, and the gap accommodates the corresponding interconnection parts. The two polarity pads on the back of each battery cell are close to the edge of the battery cell. The different polarity pads of two adjacent battery cells are close to the same gap, and the corresponding interconnection parts of the different polarity pads of two adjacent battery cells are the same interconnection parts.

10. The solar cell assembly according to claim 8, characterized in that The solar cell assembly further includes at least one bus bar; each of the bus bars is welded to a welding portion of the plurality of structural welding ribbons of the corresponding interconnector.

11. The solar cell assembly according to claim 10, wherein: When the bus bar is located between two adjacent battery cells, the interconnecting parts corresponding to the different polarity pads of the two adjacent battery cells are different interconnecting parts, and the interconnecting parts corresponding to the different polarity pads of the two adjacent battery cells share one bus bar.

12. The solar cell module according to any one of claims 8 to 11, characterized in that: The solar cell assembly further includes a visual shielding layer located between two adjacent solar cells. The visual shielding layer is located on a surface of at least one of the interconnecting members facing the front side of the solar cell.

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