Back contact cells and photovoltaic modules

Abstract

The application provides a back contact cell and a photovoltaic module, and relates to the technical field of photovoltaics. The back contact cell provided by the application comprises a cell body, a plurality of first fine grids and a plurality of second fine grids extending along a first direction; the plurality of first fine grids and the plurality of second fine grids are sequentially and alternately arranged on a first surface of the cell body along a second direction; the first surface comprises a first region and comprises a first edge and a second edge oppositely arranged along the second direction; a plurality of first sub-pads and a plurality of second sub-pads are arranged on the first fine grids and the second fine grids in the first region; and the area of the first sub-pads is smaller than the area of the second sub-pads. The stability in the soldering process of the solder strip can be improved by the back contact cell provided by the application, and the current collection reliability can be ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of photovoltaic, in particular to a back contact cell and a photovoltaic module. BACKGROUND

[0002] The back contact (BC) cell with no main grid design is usually based on the soldering pad on the fine grid for soldering ribbon, and the soldering ribbon is prone to false soldering phenomenon during soldering, the soldering stability is poor, and the reliability of current collection is severely limited. SUMMARY

[0003] The present application provides a back contact cell and a photovoltaic module, aiming to solve the problem of poor soldering stability and severe limitation of current collection reliability in the soldering process of the back contact cell.

[0004] One aspect of the present application provides a back contact cell, comprising a cell body, a plurality of first fine grids and a plurality of second fine grids extending along a first direction; the plurality of first fine grids and the plurality of second fine grids are sequentially and alternately arranged along a second direction on a first surface of the cell body; the first surface comprises a first region and comprises a first edge and a second edge oppositely arranged along the second direction; in the first region, a plurality of first sub-pads and a plurality of second sub-pads are arranged on the first fine grids and the second fine grids; the area of the first sub-pad is smaller than the area of the second sub-pad; wherein, along the first direction, the plurality of first sub-pads and the plurality of second sub-pads on the first fine grids and / or the second fine grids have a plurality of first repeating units, and the first repeating unit comprises at least one first sub-pad and at least one second sub-pad; and / or, along the second direction, the first sub-pads and the second sub-pads on the first fine grids and the second fine grids are arranged in columns and have a plurality of second repeating units, and the second repeating unit comprises at least one first sub-pad and at least one second sub-pad.

[0005] Optionally, the first repeating unit comprises one first sub-pad and one second sub-pad; and / or, the second repeating unit comprises one first sub-pad and one second sub-pad.

[0006] Optionally, the length of the first sub-pad and the second sub-pad in the first direction, and / or the width of the first sub-pad and the second sub-pad in the second direction, and / or the shape of the first sub-pad and the second sub-pad are different.

[0007] Optionally, the length of the first sub-pad and the second sub-pad in the first direction and the width of the first sub-pad and the second sub-pad in the second direction are the same, but the shape of the first sub-pad and the second sub-pad is different.

[0008] Optionally, the outer contour of the second sub-pad is rectangular or track-shaped; and / or the first sub-pad comprises a middle part and extension parts located on both sides of the middle part in the first direction, the outer contour of the middle part is rectangular or track-shaped, and the outer contour of the extension part is trapezoidal, semi-elliptical or triangular. Optionally, the first surface further comprises a second region located between the first region and the first side and adjacent to the first region in the second direction; in the second region, the first fine grids and the second fine grids are both provided with a plurality of third sub-pads arranged at intervals in the first direction, and the third sub-pads on each first fine grid are arranged in a staggered manner in the second direction with the third sub-pads on the adjacent second fine grid and are arranged in a symmetrical manner in the second direction with the third sub-pads on the adjacent first fine grid; the area of the second sub-pad is smaller than the area of the third sub-pad.

[0009] Optionally, the length of the third sub-pad in the first direction, the width of the third sub-pad in the second direction, and / or the shape of the third sub-pad are different from those of the second sub-pad.

[0010] Optionally, the length of the third sub-pad in the first direction is the same as that of the second sub-pad, and the width of the third sub-pad in the second direction is greater than that of the second sub-pad.

[0011] Optionally, the first surface further comprises a third region located between the first region and the first side and adjacent to the first region in the second direction; in the third region, the first fine grids and the second fine grids are both provided with a plurality of fourth sub-pads arranged at intervals in the first direction, and the fourth sub-pads on each first fine grid are arranged in a staggered manner in the second direction with the fourth sub-pads on the adjacent second fine grid and are arranged in a symmetrical manner in the second direction with the fourth sub-pads on the adjacent first fine grid; the area of the third sub-pad is smaller than the area of the fourth sub-pad.

[0012] Optionally, the length of the fourth sub-pad in the first direction, the width of the fourth sub-pad in the second direction, and / or the shape of the fourth sub-pad are different from those of the third sub-pad.

[0013] Optionally, the length of the fourth sub-pad in the first direction is greater than that of the third sub-pad, and the width of the fourth sub-pad in the second direction is the same as that of the third sub-pad.

[0014] Optionally, the size of the first sub-pad in the first direction is 0.9-1.1 mm, and the size of the first sub-pad in the second direction is 0.19-0.25 mm; and / or, the size of the second sub-pad in the first direction is 0.9-1.1 mm, and the size of the second sub-pad in the second direction is 0.19-0.3 mm; and / or, the size of the third sub-pad in the first direction is 0.9-1.3 mm, and the size of the third sub-pad in the second direction is 0.19-0.4 mm; and / or, the size of the fourth sub-pad in the first direction is 0.9-1.5 mm, and the size of the fourth sub-pad in the second direction is 0.19-0.5 mm.

[0015] Optionally, the back contact cell further comprises a plurality of first doped layers and a plurality of second doped layers; the plurality of first doped layers and the plurality of second doped layers are arranged alternately and spaced apart along the second direction, each first doped layer is arranged between a corresponding first fine grid and the cell body, and each second doped layer is arranged between a corresponding second fine grid and the cell body; wherein the first doped layer and the second doped layer are different in doping type.

[0016] Optionally, in the second region and / or the third region, the first doped layer or the second doped layer at least partially protrudes along the second direction to form a receiving region to accommodate a corresponding third sub-pad or fourth sub-pad.

[0017] Optionally, the first surface further comprises an edge region arranged between the first region or the second region or the third region and the first edge, and the edge region is adjacent to the first edge; in the edge region, a plurality of fifth sub-pads are arranged spaced apart on the first fine grid and the second fine grid adjacent to the first edge, and the area of the fifth sub-pad is greater than that of the fourth sub-pad; an end line is further arranged between the fifth sub-pad and the first edge, and in the second direction, one end of the end line is connected to the corresponding fifth sub-pad, and the other end is connected to the corresponding first fine grid or second fine grid close to the edge of the cell body.

[0018] Optionally, the length of the fifth sub-pad in the first direction is the same as that of the fourth sub-pad, and the width of the fifth sub-pad in the second direction is greater than that of the fourth sub-pad; and / or the size of the fifth sub-pad in the first direction is 0.9-1.1 mm, and the size of the fifth sub-pad in the second direction is 1.1-1.8 mm.

[0019] Optionally, the first fine grid or the second fine grid is in a discontinuous structure or a continuous structure at the positions where the first sub-pad, the second sub-pad, the third sub-pad, the fourth sub-pad or the fifth sub-pad is arranged.

[0020] Another aspect of the present application provides a photovoltaic module comprising the back contact cell and the electrical connector as described above, the electrical connector is connected to the same first fine grid or second fine grid through the first sub-pad and / or the second sub-pad, and an insulating block is arranged between the electrical connector and the different first fine grid or second fine grid.

[0021] The back contact cell and the photovoltaic module provided by the present application have at least the following beneficial effects compared with the prior art:

[0022] By optimizing the design of the pad layout on the back contact battery, in the first area, a plurality of first sub-pads and a plurality of second sub-pads are arranged on the first fine grid and the second fine grid, respectively. The first sub-pads have a smaller area than the second sub-pads, which is conducive to reducing the occupation of the surface area of the battery body and reducing the metal composite loss. The second sub-pads have a larger area than the first sub-pads, which is conducive to improving the stability of the solder strip during welding and improving the reliability of current collection.

[0023] In some embodiments, in the first direction, the plurality of first sub-pads and the plurality of second sub-pads on the first fine grid and / or the second fine grid have a plurality of first repeating units each including at least one first sub-pad and at least one second sub-pad. This can minimize the use of metal paste, reduce production costs, and ensure that even if the smaller first sub-pads produce a false weld, the larger second sub-pads in the first direction can still ensure welding reliability and collect current at the false weld position of the first sub-pads, thereby preventing current loss caused by excessive current path transmission. In the second direction, the first sub-pads and the second sub-pads on the first fine grid and the second fine grid are arranged in columns and have a plurality of second repeating units each including at least one first sub-pad and at least one second sub-pad. This can also minimize the use of metal paste, reduce production costs, and help improve the end-to-end contact area of the solder strip in the second direction in the first area, thereby improving the welding tension, ensuring welding stability, and preventing solder strip deviation.

[0024] Thus, by the above design of the back contact battery, the stability of the solder strip during welding can be improved while minimizing the use of metal paste and the metal composite loss of the battery body surface, reducing the occurrence of false welding, and ensuring the reliability of current collection.

[0025] Other features and advantages of the back contact battery and the photovoltaic module provided by the present application are further described in the subsequent specific embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings needed to be used in the specific embodiments or the prior art description. Obviously, the drawings described below are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0027] Figure 1 A structural schematic diagram of a back contact battery according to an embodiment of the present application is provided.

[0028] Figure 2A schematic view of a partial structure of a back contact cell along a second direction according to one of the embodiments of the present application;

[0029] Figure 3 A schematic view of a partial structure of a back contact cell along a first direction according to one of the embodiments of the present application;

[0030] Figure 4 A schematic view of a structure of a first sub-pad according to one of the embodiments of the present application;

[0031] Figure 5 A schematic view of a first doped layer and a second doped layer according to one of the embodiments of the present application;

[0032] Figure 6a A schematic view of a connection of a second sub-pad and a first fine grid according to one of the embodiments of the present application;

[0033] Figure 6b A schematic view of a connection of a second sub-pad and a first fine grid according to one of the embodiments of the present application;

[0034] Figure 7 A schematic view of a structure of a back contact cell according to one of the embodiments of the present application.

[0035] Reference signs are as follows:

[0036] 100, a back contact cell;

[0037] 10, a cell body; 11, a first doped layer; 12, a second doped layer; 20, a first fine grid; 30, a second fine grid; 40, a first sub-pad; 41, an intermediate portion; 42, an extension portion; 50, a second sub-pad; 60, a third sub-pad; 70, a fourth sub-pad; 80, a fifth sub-pad; 81, an end line;

[0038] A, a first region; B, a second region; C, a third region; D, an edge region;

[0039] X, a first direction; Y, a second direction. DETAILED DESCRIPTION

[0040] In order to make the above and other features and advantages of the present application clearer, the following further describes the present application with reference to the accompanying drawings. It should be understood that the specific embodiments given herein are intended for explanatory purposes only and are not limiting.

[0041] In addition, if a feature is described as "first" or "second" only for the purpose of description and is not intended to indicate or imply relative importance or imply the number of the indicated technical features. The features limited by "first" and "second" can explicitly or implicitly include at least one of the features limited. If "multiple" is described, the general meaning is at least two, such as two, three, etc., unless otherwise specifically limited.

[0042] It should be noted that the first direction X and the second direction Y in the embodiments of the present application are perpendicular to each other and perpendicular to the thickness direction of the battery body 10. It should be noted that the first fine grid 20, the second fine grid 30, the first sub-pad 40, the second sub-pad 50, the third sub-pad 60, the fourth sub-pad 70 and the fifth sub-pad 80 in the embodiments of the present application can be made of metal paste by printing process, for example, photovoltaic silver paste material can be used and made by printing process.

[0043] As described above, in order to improve the conversion efficiency of the battery and reduce the use of metal paste, the back contact solar cell in the prior art generally adopts the electrode design form without main grid, and in order to realize effective interconnection welding in the subsequent photovoltaic module manufacturing process, the pad for welding ribbon is arranged on the battery. The welding ribbon at the center position of the battery is prone to partial virtual welding, which causes the reliability of the photovoltaic module to be not guaranteed in subsequent use.

[0044] To this end, the inventive concept of the embodiments of the present application provides a back contact battery 100, which comprises a battery body 10, a plurality of first fine grids 20 and a plurality of second fine grids 30 extending along a first direction X; the plurality of first fine grids 20 and the plurality of second fine grids 30 are sequentially and alternately arranged along a second direction Y on a first surface of the battery body 10; the first surface comprises a first area A and comprises a first edge and a second edge oppositely arranged along the second direction Y; a plurality of first sub-pads 40 and a plurality of second sub-pads 50 are arranged on the first fine grid 20 and the second fine grid 30 in the first area A; the area of the first sub-pad 40 is smaller than the area of the second sub-pad 50.

[0045] It should be noted that the description of the pad arranged on the fine grid in the embodiments of the present application does not represent the positional relationship, but only means that the fine grid is connected with the pad, and cannot be understood as a limitation of the present application. The pad and the fine grid can be replaced up and down, that is, the fine grid can be located above the pad or below the pad, and preferably the pad is below and closer to the battery body 10. For example, in the first area A, a plurality of first sub-pads 40 and a plurality of second sub-pads 50 are arranged on the first fine grid 20 and the second fine grid 30, and the plurality of first sub-pads 40 and the plurality of second sub-pads 50 can be located above or below the corresponding first fine grid 20 or second fine grid 30.

[0046] The battery body 10 in this embodiment can be sheet-shaped. The battery body 10 has two opposing surfaces along its thickness direction. Either of these two surfaces can serve as a first surface. A plurality of first fine grids 20 and a plurality of second fine grids 30 extend along a first direction and are alternately and alternately disposed on the first surface of the battery body 10 along a second direction Y. The first fine grids 20 and the second fine grids 30 have opposite polarities. For example, the first fine grid 20 can be a positive electrode fine grid and the second fine grid 30 can be a negative electrode fine grid, or the first fine grid 20 can be a negative electrode fine grid and the second fine grid 30 can be a positive electrode fine grid. No limitation is made here.

[0047] Therefore, the first surface of the battery body 10 includes a first region A and includes a first side and a second side disposed opposite to each other along the second direction Y. The first region A is located between the first side and the second side along the second direction Y. The first sub-pad 40 and the second sub-pad 50 are both arranged in the first region A. Since the area of ​​the first sub-pad 40 is smaller than the area of ​​the second sub-pad 50, the first sub-pad 40, which has a smaller area than the second sub-pad 50, is beneficial to reducing the area occupied by the pads on the surface of the battery body 10 and can reduce the consumption of metal paste during the manufacturing process, thereby reducing metal composite loss, improving the photoelectric collection efficiency, and reducing production costs. The second sub-pad 50 has a larger area, which is more conducive to improving welding stability, reducing the occurrence of cold solder joints, and further improving the reliability of current collection.

[0048] Based on this, by designing the arrangement of multiple first sub-pads 40 and multiple second sub-pads 50 in the first direction X and / or the second direction Y, the stability of the solder strip during welding is fully improved, the occurrence of cold solder joints is reduced, and the reliability of current collection is ensured, while minimizing the use of metal paste and the loss of metal composite on the surface of the battery body 10.

[0049] Based on the above-described inventive concept, the advantages of this application will be described in detail below with reference to specific embodiments. It should be understood that the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. Furthermore, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of those different embodiments or examples.

[0050] refer to Figures 1-3 As shown, Figure 1 This is a schematic diagram of the structure of the back contact battery 100 provided in an embodiment of this application; Figure 2 This is a partial structural schematic diagram of the back contact battery 100 provided in an embodiment of this application; Figure 3 This is a partial structural diagram of the back contact battery 100 provided in an embodiment of this application.

[0051] Please refer to Figure 1 and Figure 3 In an optional embodiment of the present application, the back contact battery 100 comprises a battery body 10, a plurality of first fine grids 20 and a plurality of second fine grids 30 extending along a first direction X; the plurality of first fine grids 20 and the plurality of second fine grids 30 are alternately and spacedly arranged along a second direction Y on a first surface of the battery body 10; the first surface comprises a first region A and comprises a first edge and a second edge oppositely arranged along the second direction Y; in the first region A, a plurality of first sub-pads 40 and a plurality of second sub-pads 50 are arranged on the first fine grids 20 and the second fine grids 30; along the first direction X, the plurality of first sub-pads 40 and the plurality of second sub-pads 50 on the first fine grids 20 and / or the second fine grids 30 have a plurality of first repeating units, and each first repeating unit comprises at least one first sub-pad 40 and at least one second sub-pad 50.

[0052] It should be noted that in the second direction Y, the first sub-pads 40 and the second sub-pads 50 on the first fine grids 20 and the second fine grids 30 are arranged in columns, but do not necessarily have a plurality of second repeating units.

[0053] Since the area of the first sub-pads 40 is smaller than that of the second sub-pads 50, the first sub-pads 40 and the second sub-pads 50 are periodically arranged along the first direction X, which can minimize the use of metal paste, reduce production costs, and ensure the welding reliability of the second sub-pads 50 with larger area along the first direction X even if the first sub-pads 40 with smaller area are welded with the solder ribbon to produce a false weld, so as to collect the current at the false-welded position of the first sub-pads 40 and prevent current loss caused by too large current path transmission.

[0054] It should be noted that in the present embodiment, a single first repeating unit is composed of the first sub-pads 40 and the second sub-pads 50, and the number of the first sub-pads 40 and the second sub-pads 50 constituting a single first repeating unit can be one or more.

[0055] In some embodiments, please refer to Figure 1As shown, the first repeating unit in the embodiment of the present application preferably comprises one first sub-pad 40 and one second sub-pad 50; that is, in the first direction X, the first sub-pad 40 and the second sub-pad 50 in the plurality of first repeating units are arranged in the feature of first sub-pad 40, second sub-pad 50, first sub-pad 40, second sub-pad 50, …; of course, in some unillustrated embodiments, the first repeating unit can also comprise two first sub-pads 40 and one second sub-pad 50, that is, the first sub-pad 40 and the second sub-pad 50 in the plurality of first repeating units are arranged in the feature of first sub-pad 40, second sub-pad 50, second sub-pad 50, first sub-pad 40, second sub-pad 50, second sub-pad 50, …; or, the first repeating unit can also comprise two first sub-pads 40 and two second sub-pads 50, that is, the first sub-pad 40 and the second sub-pad 50 in the plurality of first repeating units are arranged in the feature of first sub-pad 40, first sub-pad 40, second sub-pad 50, second sub-pad 50, first sub-pad 40, first sub-pad 40, second sub-pad 50, second sub-pad 50, …; all of which can minimize the amount of metal paste used, reduce production costs, ensure welding reliability, and prevent current loss caused by excessive current path transmission, which will not be listed here.

[0056] In some embodiments, to ensure that the area of the first sub-pad 40 is smaller than the area of the second sub-pad 50, the length of the first sub-pad 40 and the second sub-pad 50 in the first direction X and / or the width of the first sub-pad 40 and the second sub-pad 50 in the second direction Y and / or the shape of the first sub-pad 40 and the second sub-pad 50 in the embodiment of the present application are different. That is, the length of the first sub-pad 40 and the second sub-pad 50 in the first direction X can be different, the width of the first sub-pad 40 and the second sub-pad 50 in the second direction Y can be different, and the shape of the first sub-pad 40 and the second sub-pad 50 can be different (i.e., the outer contour is different), which can be flexibly designed to minimize the amount of metal paste used, reduce production costs, and maximize welding reliability while preventing current loss caused by excessive current path transmission, while ensuring that the area of the first sub-pad 40 is smaller than the area of the second sub-pad 50.

[0057] In a preferred embodiment of the present application, the length of the first sub-pad 40 and the second sub-pad 50 in the first direction X and the width of the first sub-pad 40 and the second sub-pad 50 in the second direction Y are the same, but the shape of the first sub-pad 40 and the second sub-pad 50 is different. For example, Figure 3 As shown, the second sub-pad 50 is rectangular, and the first sub-pad 40 is a combined shape of two trapezoids and a rectangle. Although the length of the first sub-pad 40 and the second sub-pad 50 in the first direction X and the width of the first sub-pad 40 and the second sub-pad 50 in the second direction Y are the same, the area of the first sub-pad 40 is smaller than that of the second sub-pad 50 due to the different shapes of the first sub-pad 40 and the second sub-pad 50.

[0058] Regarding the shape design of the first sub-pad 40 and the second sub-pad 50, in some embodiments, the outer contour of the second sub-pad 50 can be rectangular or racetrack-shaped. In some embodiments, the first sub-pad 40 includes a middle part 41 and extension parts 42 located on both sides of the middle part 41 in the first direction X, the outer contour of the middle part 41 can be rectangular or racetrack-shaped, and the outer contour of the extension part 42 can be trapezoidal, semi-elliptical or triangular.

[0059] For example, the second sub-pad 50 can preferably adopt a rectangular design to better match the shape of the solder strip and improve the contact area; the first sub-pad 40 can be designed as shown in Figure 4 Figure 4 FIG. 6 is a schematic view of the structure of the first sub-pad 40 in an optional embodiment of the present application. The outer contour of the middle part 41 of the first sub-pad 40 is rectangular, and the extension parts 42 located on both sides of the middle part 41 in the first direction X are trapezoidal, so as to ensure that the length of the first sub-pad 40 in the first direction X and the width of the first sub-pad 40 in the second direction Y are the same as those of the second sub-pad 50, and the area of the first sub-pad 40 is smaller than that of the second sub-pad 50.

[0060] In another optional embodiment of the present application, on the basis of the area design concept of the first sub-pad 40 and the second sub-pad 50 in the above-mentioned embodiments, please refer to Figure 1 and Figure 2 FIG. 7 is a schematic view of the structure of the back contact battery 100 in an optional embodiment of the present application. The back contact battery 100 includes a battery body 10, a plurality of first fine grids 20 and a plurality of second fine grids 30 extending in the first direction X; the plurality of first fine grids 20 and the plurality of second fine grids 30 are sequentially and alternately arranged on the first surface of the battery body 10 in the second direction Y; the first surface includes a first region A and includes a first side and a second side oppositely arranged in the second direction Y; in the first region A, a plurality of first sub-pads 40 and a plurality of second sub-pads 50 are arranged on the first fine grid 20 and the second fine grid 30; the area of the first sub-pad 40 is smaller than that of the second sub-pad 50; in the second direction Y, the first sub-pad 40 and the second sub-pad 50 on the first fine grid 20 and the second fine grid 30 are arranged in columns and have a plurality of second repeating units, and each second repeating unit includes at least one first sub-pad 40 and at least one second sub-pad 50.

[0061] It should be noted that in the first direction X, the plurality of first sub-pads 40 and the plurality of second sub-pads 50 on the first fine grid 20 and / or the second fine grid 30 in the present embodiment do not necessarily have a plurality of first repeating units.

[0062] ​It is understood that when the first sub-pads 40 and second sub-pads 50 on the first fine grid 20 and the second fine grid 30 are arranged in a row in the second direction Y, and have multiple second repeating units including at least one first sub-pad 40 and at least one second sub-pad 50, the first sub-pads 40 and second sub-pads 50 in the multiple second repeating units can be welded in the first region A along the second direction Y during soldering. This can minimize the amount of metal paste used and reduce production costs. In addition, since the solder strip bears greater tensile force the closer it is to the edge of the battery body 10 after welding in the first region A, designing multiple second repeating units including at least one first sub-pad 40 and at least one second sub-pad 50 also helps to increase the contact area of ​​the solder strip end along the second direction Y in the first region A, thereby increasing the welding tensile force, ensuring welding stability, and preventing solder strip deviation.

[0063] It should be noted that in the embodiments of this application, a single second repeating unit is composed of a first sub-pad 40 and a second sub-pad 50. The number of the first sub-pad 40 and the second sub-pad 50 constituting a single second repeating unit can be one or more.

[0064] Further, refer to Figure 2 As shown, in the embodiments of this application, the second repeating unit preferably includes a first sub-pad 40 and a second sub-pad 50; that is, in the second direction Y, the first sub-pad 40 and the second sub-pad 50 in the plurality of second repeating units are arranged in a repeating pattern of first sub-pad 40, second sub-pad 50, first sub-pad 40, second sub-pad 50...; of course, in some embodiments not shown, the second repeating unit may also include two first sub-pads 40 and one second sub-pad 50, that is, the first sub-pads 40 and the second sub-pad 50 in the plurality of second repeating units are arranged in a repeating pattern of first sub-pad 40, second sub-pad 50, second sub-pad 50, first sub-pad 40, second sub-pad 50... The first sub-pad 40 and the second sub-pad 50 are arranged in a repeating pattern; or, the second repeating unit may also include two first sub-pads 40 and two second sub-pads 50, that is, the first sub-pads 40 and the second sub-pads 50 in the multiple second repeating units are arranged in a repeating pattern with the features of first sub-pad 40, first sub-pad 40, second sub-pad 50, second sub-pad 50, first sub-pad 40, first sub-pad 40, second sub-pad 50, second sub-pad 50...; all of these can minimize the amount of metal paste used, reduce production costs, increase the contact area of ​​the solder strip at the end along the second direction Y in the first region A, thereby increasing the welding pull, ensuring welding stability, and preventing solder strip deviation, which will not be listed in detail here.

[0065] In some embodiments, the first surface in the embodiments of the present application further comprises a second region B, which is arranged along the second direction Y between the first region A and the first side and is adjacent to the first region A; in the second region B, the first fine grids 20 and the second fine grids 30 are both provided with a plurality of third sub-pads 60 arranged along the first direction X, and the third sub-pads 60 on each first fine grid 20 are arranged in a staggered manner in the second direction Y with the third sub-pads 60 on the adjacent second fine grid 30 and are arranged in a relative manner in the second direction Y with the third sub-pads 60 on the adjacent first fine grid 20; the area of the second sub-pads 50 is smaller than the area of the third sub-pads 60.

[0066] It should be noted that the second region B can also be arranged along the second direction Y between the first region A and the second side and adjacent to the first region A, or as shown, two second regions B are designed, and the two second regions B are arranged along the second direction Y between the first region A and the first side and between the first region A and the second side, respectively, and both of the two second regions B are adjacent to the first region A on one side, so that the first region A can be specifically a middle region of the first surface. Figure 2

[0067] The connection points of the solder ribbons after soldering and the back contact battery 100 can be arranged in a cross manner along the first direction X and the second direction Y in the second region B, so as to effectively avoid stress concentration and facilitate the improvement of the soldering reliability of the solder ribbons; and since the second region B is closer to the edge of the back contact battery, the solder ribbons in this region will bear greater stress after soldering, so that the third sub-pads 60 with a larger area than the second sub-pads 50 are used as the connection points of the solder ribbons, so as to increase the connection area of the solder ribbons in the second region B and further improve the connection stability of the solder ribbons in the second region B.

[0068] In some embodiments, the third sub-pads 60 and the second sub-pads 50 in the embodiments of the present application are different in length along the first direction X, and / or width along the second direction Y, and / or shape. That is, the length of the third sub-pads 60 along the first direction X can be different from that of the second sub-pads 50, the width of the third sub-pads 60 along the second direction Y can be different from that of the second sub-pads 50, and the shape of the third sub-pads 60 can be different from that of the second sub-pads 50 (i.e., the outer contour is different), which can be flexibly designed on the basis of the area of the second sub-pads 50 being smaller than that of the third sub-pads 60, so as to possibly reduce the amount of metal paste used, reduce the production cost, increase the connection area of the solder ribbons in the second region B, and further improve the connection stability of the solder ribbons in the second region B.

[0069] In some embodiments, the length of the third sub-pads 60 along the first direction X is the same as that of the second sub-pads 50, and the width of the third sub-pads 60 along the second direction Y is greater than that of the second sub-pads 50.

[0070] ​Since the solder strip has a width and cannot be offset out of the pad in order to minimize the occlusion of the battery surface, the length of the third sub-pad 60 in the first direction X should not be less than that of the second sub-pad 50, but the width of the third sub-pad 60 in the second direction Y can be greater than that of the second sub-pad 50, so as to possibly minimize the amount of metal paste used and ensure that the area of the third sub-pad 60 is greater than that of the second sub-pad 50.

[0071] Referring to Figure 1 and Figure 2 In some embodiments, the first surface further includes a third region C disposed between the first region B and the first edge in the second direction Y and adjacent to the first region B, and a plurality of fourth sub-pads 70 are disposed on the first fine grid 20 and the second fine grid 30 in the third region C in the first direction X, and the fourth sub-pads 70 on each first fine grid 20 are disposed offset in the second direction Y from the fourth sub-pads 70 on the adjacent second fine grid 30 and disposed opposite the fourth sub-pads 70 on the adjacent first fine grid 20 in the second direction Y, and the area of the third sub-pad 60 is less than the area of the fourth sub-pad 70.

[0072] It should be noted that the third region C can also be disposed between the second region B and the second edge in the second direction Y and adjacent to the second region B, or as shown in Figure 2 two third regions C are disposed between the second region B and the first edge and between the second region B and the second edge in the second direction Y, and both third regions C are adjacent to the second region B on one side, and thus the second region B can be a sub-edge region of the first surface.

[0073] In this way, the connection points of the plurality of solder strips to the back contact battery after soldering can be arranged in the third region C in the first direction X and the second direction Y, so as to effectively avoid stress concentration and facilitate the improvement of the reliability of the soldering of the solder strip; and since the third region C is closer to the edge of the back contact battery 100 than the second region B, the solder strip in this region will bear greater stress after soldering, and therefore using the fourth sub-pad 70 with a larger area than the third sub-pad 60 as the connection site of the solder strip can increase the connection area of the solder strip in the third region C and further improve the stability of the connection of the solder strip in the third region C.

[0074] It should be understood that during the photovoltaic module stringing process, the closer to the edge of the back contact cell 100, the stronger the tensile stress of the solder strip, making it more difficult to achieve a stable weld and increasing the risk of poor soldering. In this embodiment, in the second direction Y, the areas of the first sub-pad 40, the second sub-pad 50, the third sub-pad 60, and the fourth sub-pad 70 increase sequentially. Multiple first sub-pads 40 and multiple second sub-pads 50 form multiple second repeating units distributed along the second direction Y within the first region A located at the center of the back contact cell 100 to ensure the welding stability of the central region of the back contact cell 100. Multiple third sub-pads 60 intersect along the first direction X and the second direction Y. In the second region B, which is distributed in the secondary edge area, multiple fourth sub-pads 70 are alternately distributed along the first direction X and the second direction Y in the third region C near the edge. Thus, along the second direction Y, the pads are densely distributed in the central region of the back contact cell 100, while the pad areas in the secondary and near-edge areas gradually increase. This gradually matches the welding tension between the solder strip and the grid near the edge of the back contact cell 100 during photovoltaic module string bonding, dispersing and resisting the increasing stress and tension as the back contact cell 100 approaches the edge. This improves the tensile strength of the solder strip at the edge, enhances the weld strength, stabilizes the weld, and reduces the risk of incomplete solder joints. In summary, by setting pads of different areas and arrangements in different regions of the back contact cell 100, it is possible to ensure strong welding strength at the edge of the back contact cell 100, effectively achieve effective welding contact between the solder strip and the pad in the middle to collect photocurrent, and minimize the use of metal paste to reduce production costs.

[0075] In some embodiments, the fourth sub-pad 70 and the third sub-pad 60 in this application embodiment have different lengths in the first direction X and / or widths and / or shapes in the second direction Y. That is, the fourth sub-pad 70 and the third sub-pad 60 may have different lengths in the first direction X, different widths in the second direction Y, and different shapes (i.e., different outer contours). Based on the premise that the area of ​​the third sub-pad 60 is smaller than that of the fourth sub-pad 70, the design can be flexible to minimize the amount of metal paste used, reduce production costs, and increase the solder strip connection area within the third region C, thereby further improving the stability of the solder strip connection within the third region C.

[0076] In some embodiments, the third sub-pad 60 and the fourth sub-pad 70 may also have the same shape, and their outer contours may be rectangular or racetrack-shaped; for example, such as Figure 2 As shown, the outer contours of the third sub-pad 60 and the fourth sub-pad 70 are both rectangular. In addition, the shape of each sub-pad can also be trapezoidal, octagonal, or a combination of different shapes.

[0077] In some embodiments, referenceFigure 1 and Figure 2 As shown, in this embodiment of the application, the length of the fourth sub-pad 70 in the first direction X is greater than that of the third sub-pad 60, and the width of the fourth sub-pad 70 in the second direction Y is the same as that of the third sub-pad 60.

[0078] Because the third region C is closer to the battery edge, the solder strip in this region experiences greater tensile force, making it easier to pull off and shift. The design of the fourth sub-pad 70, which is longer than the third sub-pad 60 in the first direction X and has the same width as the third sub-pad 60 in the second direction Y, allows the pads closer to the battery edge to have a larger area. This helps to further offset and disperse the greater stress and tensile force generated by the solder strip being close to the edge of the back contact battery 100, thus significantly improving the stability of the solder strip welding in the third region C and preventing solder strip pull-off. Furthermore, the fourth sub-pad 70 is longer along the first direction X, which helps prevent the solder strip from shifting and failing to bond to the pads in the third region C (i.e., the fourth sub-pad 70).

[0079] In the above embodiments, the size of the first sub-pad 40 in the first direction X can be 0.9-1.1mm, and the size in the second direction Y can be 0.19-0.25mm. For example, the size of the first sub-pad 40 in the first direction X can be any value within the range of 0.9mm, 0.95mm, 1.0mm, 1.05mm, 1.1mm, or 0.9-1.1mm, and the size of the first sub-pad 40 in the second direction Y can be any value within the range of 0.19mm, 0.2mm, 0.21mm, 0.22mm, 0.23mm, 0.24mm, 0.25mm, or 0.19-0.25mm.

[0080] like Figure 4 In the embodiment shown, the size of the middle portion 41 of the first sub-pad 40 in the first direction X can be 0.5-1mm, and the size of the extension portion 42 in the first direction X can be 0.1-0.4mm.

[0081] In each of the above embodiments, the second sub-pad 50 can have a dimension in the first direction X of 0.9-1.1 mm and a dimension in the second direction Y of 0.19-0.3 mm; for example, the second sub-pad 50 can have a dimension in the first direction X of 0.9 mm, 0.95 mm, 1.0 mm, 1.05 mm, 1.1 mm, or any dimension within the range of 0.9-1.1 mm, and a dimension in the second direction Y of 0.19 mm, 0.2 mm, 0.21 mm, 0.22 mm, 0.23 mm, 0.24 mm, 0.25 mm, 0.26 mm, 0.27 mm, 0.28 mm, 0.29 mm, 0.3 mm, or any dimension within the range of 0.19-0.3 mm.

[0082] In each of the above embodiments, the third sub-pad 60 can have a dimension in the first direction X of 0.9-1.3 mm and a dimension in the second direction Y of 0.19-0.4 mm; for example, the third sub-pad 60 can have a dimension in the first direction X of 0.9 mm, 0.95 mm, 1.0 mm, 1.05 mm, 1.1 mm, 1.2 mm, 1.3 mm, or any dimension within the range of 0.9-1.3 mm, and a dimension in the second direction Y of 0.19 mm, 0.2 mm, 0.21 mm, 0.22 mm, 0.23 mm, 0.24 mm, 0.25 mm, 0.26 mm, 0.27 mm, 0.28 mm, 0.29 mm, 0.3 mm, 0.31 mm, 0.32 mm, 0.33 mm, 0.34 mm, 0.35 mm, 0.36 mm, 0.37 mm, 0.38 mm, 0.39 mm, 0.4 mm, or any dimension within the range of 0.19-0.4 mm.

[0083] In the above embodiments, the fourth sub-pad 70 can have a size of 0.9-1.5 mm in the first direction X and a size of 0.19-0.5 mm in the second direction Y. For example, the fourth sub-pad 70 can have a size of 0.9 mm, 0.95 mm, 1.0 mm, 1.05 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, or any size within the range of 0.9-1.5 mm in the first direction X, and a size of 0.19 mm, 0.2 mm, 0.21 mm, 0.22 mm, 0.23 mm, 0.24 mm, 0.25 mm, 0.26 mm, 0.27 mm, 0.28 mm, 0.29 mm, 0.3 mm, 0.31 mm, 0.32 mm, 0.33 mm, 0.34 mm, 0.35 mm, 0.36 mm, 0.37 mm, 0.38 mm, 0.39 mm, 0.4 mm, 0.41 mm, 0.42 mm, 0.43 mm, 0.44 mm, 0.45 mm, 0.46 mm, 0.47 mm, 0.48 mm, 0.49 mm, 0.5 mm, or any size within the range of 0.19-0.5 mm in the second direction Y.

[0084] In the above embodiments, the first region A is required to exist, while the second region B, the third region C, and the fourth region D can be selected at least one or all of them do not exist. When the second region B, the third region C, and the fourth region D can be selected at least one of them, it can ensure that the pull-out force of the electrical connector (solder strip) is good, and when the second region B, the third region C, and the fourth region D can be selected at least two or three of them, the solder strip has enough buffer zone to ensure enough pull-out force while reducing cost.

[0085] In some embodiments, the back contact battery further comprises a plurality of first doped layers 11 and a plurality of second doped layers 12; referring to Figure 5 , Figure 5 According to the schematic diagram of the first doped layer 11 and the second doped layer 12 provided by one of the embodiments of the present application, the plurality of first doped layers 11 and the plurality of second doped layers 12 are arranged alternately and spaced along the second direction Y, each first doped layer 11 is arranged between a corresponding first fine grid 20 and the battery body 10, and each second doped layer 12 is arranged between a corresponding second fine grid 30 and the battery body 10; wherein the first doped layer 11 and the second doped layer 12 are different in doping type.

[0086] Specifically, the first doped layer 11 can be a P-type doped layer, and the second doped layer 12 can be an N-type doped layer, or the first doped layer 11 can be an N-type doped layer, and the second doped layer 12 can be a P-type doped layer, which can be selected according to actual conditions, and is not limited herein. In some preferred embodiments, the doping manner of the first fine grid 20 and / or the second fine grid 30 closest to the edge of the back contact cell 100 is opposite to the doping manner of the silicon substrate in the back contact cell 100, so as to improve the emitter area of the back contact cell 100, enhance the hole collection capability of the edge part of the back contact cell 100, and optimize the cell efficiency.

[0087] In order to match the size of the larger area solder pad, in some embodiments, in the second region B and / or the third region C, the first doped layer 11 or the second doped layer 12 is at least partially protruded along the second direction Y to form a receiving area to accommodate the corresponding third sub-solder pad 60 or the fourth sub-solder pad 70.

[0088] With reference to Figure 5 As shown, in the second region B and the third region C, the first doped layer 11 or the second doped layer 12 is at least partially protruded along the second direction Y to form a receiving area, and the third sub-solder pad 60 and the fourth sub-solder pad 70 are accommodated in the corresponding receiving area; of course, in some unillustrated embodiments, the first doped layer 11 or the second doped layer 12 can be designed to be at least partially protruded along the second direction Y to form a receiving area only in the third region C to accommodate the larger area fourth sub-solder pad 70.

[0089] In some embodiments, the first surface further comprises an edge region D, the edge region D is arranged between the first region A or the second region B or the third region C and the first side, and the edge region D is adjacent to the first side; in the edge region D, a plurality of fifth sub-solder pads 80 are arranged on the first fine grid 20 and the second fine grid 30 adjacent to the first side, respectively, and the area of the fifth sub-solder pad 80 is larger than that of the fourth sub-solder pad 70; a terminal line 81 is further arranged between the fifth sub-solder pad 80 and the first side, and in the second direction Y, one end of the terminal line 81 is connected to the corresponding fifth sub-solder pad 80, and the other end is connected to the corresponding first fine grid 20 or second fine grid 30 close to the first side.

[0090] It should be understood that when the edge region D is designed as two, it can also be adjacent to the second side. With reference to Figure 7 As shown, it is a structural schematic diagram of the back contact cell 100 provided according to one of the embodiments of the present application. Figure 7 In some embodiments, two edge regions D are arranged between one third region C and the first side and between another third region C and the second side, respectively, and the two edge regions D are adjacent to the first side or the second side, respectively.

[0091] The edge area D is the area closest to the edge of the battery body 10, and the stress and tension of the solder strip are the largest after the solder strip is welded in the edge area D. In the edge area D, a plurality of fifth sub-pads 80 are arranged at intervals on the first fine grid 20 and the second fine grid 30 adjacent to the third area C, respectively. The area of the fifth sub-pad 80 is larger than that of the fourth sub-pad 70, so as to increase the connection area of the solder strip in the edge area D, and further improve the stability of the solder strip connection in the edge area D, and reduce the risk of virtual welding of the solder strip.

[0092] In order to collect the current of the edge part of the back contact battery 100, reference is made to Figure 7 The end line 81 is further arranged between the fifth sub-pad 80 and the first side, and one end of the end line 81 is connected to the corresponding fifth sub-pad 80 in the second direction Y, and the other end is connected to the corresponding first fine grid 20 or second fine grid 30 close to the first side, so that the current of the edge part of the back contact battery 100 can be collected and converged.

[0093] In some embodiments, the length of the fifth sub-pad 80 in the first direction X is the same as that of the fourth sub-pad 70, and the width of the fifth sub-pad 80 in the second direction Y is larger than that of the fourth sub-pad 70. In this way, the area of the fifth sub-pad 80 can be larger than that of the fourth sub-pad 70, and the fifth sub-pad 80 is arranged in the edge area D closest to the edge of the battery, so as to offset and disperse the stress and tension of the solder strip caused by being close to the edge of the back contact battery 100, and effectively improve the stability of the solder strip welding in the edge area D.

[0094] In the above embodiments, the size of the fifth sub-pad 80 in the first direction X can be 0.9-1.1 mm, and the size of the fifth sub-pad 80 in the second direction Y can be 1.1-1.8 mm. For example, the size of the fifth sub-pad 80 in the first direction X can be 0.9 mm, 0.95 mm, 1.0 mm, 1.05 mm, 1.1 mm, or any size value in the range of 0.9-1.1 mm, and the size of the fifth sub-pad 80 in the second direction Y can be 1.1 mm, 1.15 mm, 1.2 mm, 1.25 mm, 1.3 mm, 1.35 mm, 1.4 mm, 1.45 mm, 1.5 mm, 1.55 mm, 1.6 mm, 1.65 mm, 1.7 mm, 1.75 mm, 1.8 mm, or any size value in the range of 1.1-1.8 mm.

[0095] In some embodiments, the first fine grid 20 or the second fine grid 30 is a discontinuous structure or a continuous structure at the positions where the first sub-pad 40, the second sub-pad 50, the third sub-pad 60, the fourth sub-pad 70, or the fifth sub-pad 80 is arranged. For example, the structure design of the first fine grid 20 at the position where the second sub-pad 50 is arranged is taken as an example, as shown in Figure 6aAs shown in Fig. 2, which is a schematic view of the connection between the second sub-pad 50 and the first fine grid 20 according to one of the embodiments of the present application, the first fine grid 20 is in a discontinuous structure at the position where the second sub-pad 50 is arranged, so as to reduce the overall thickness of the fine grid and the pad at this position, and to avoid waste of the metal paste; or as shown in Fig. 3, which is a schematic view of the connection between the second sub-pad 50 and the first fine grid 20 according to one of the embodiments of the present application, the first fine grid 20 is in a continuous structure at the position where the second sub-pad 50 is arranged, the pad at this position is printed first, and then the fine grid is printed on the pad, so that the fine grid can be stacked on the pad. Figure 6b As shown in Fig. 2, which is a schematic view of the connection between the second sub-pad 50 and the first fine grid 20 according to one of the embodiments of the present application, the first fine grid 20 is in a discontinuous structure at the position where the second sub-pad 50 is arranged, so as to reduce the overall thickness of the fine grid and the pad at this position, and to avoid waste of the metal paste; or as shown in Fig. 3, which is a schematic view of the connection between the second sub-pad 50 and the first fine grid 20 according to one of the embodiments of the present application, the first fine grid 20 is in a continuous structure at the position where the second sub-pad 50 is arranged, the pad at this position is printed first, and then the fine grid is printed on the pad, so that the fine grid can be stacked on the pad.

[0096] Since the pads arranged on the fine grid are mainly used for the electrical connection between the solder strip and the fine grid of the same polarity, in some embodiments, each of the sub-pads on the first fine grid 20 and the second fine grid 30 is used to load the solder paste layer, the area of the solder paste layer is equal to or smaller than the area of the corresponding sub-pad, and the outer contour of the solder paste layer can be set as a trapezoidal shape, a circular shape, a rectangular shape, an octagonal shape, or other irregular shapes, so as to ensure the electrical connection between the solder strip and the fine grid.

[0097] In addition, considering the insulation between the solder strip and the fine grid of different polarity, since the pads on the fine grid are arranged opposite to the pads on the fine grid of the same polarity adjacent thereto in the second direction Y, and are misaligned with the pads on the fine grid of different polarity adjacent thereto in the second direction Y, the insulation block can be arranged on the fine grid of different polarity between two fine grids of the same polarity in the second direction Y, that is, the insulation block is opposite to the pads on the fine grid of different polarity adjacent thereto in the second direction Y, so as to realize the insulated connection between the solder strip and the fine grid of different polarity.

[0098] As shown in Fig. 2, which is a schematic view of the connection between the second sub-pad 50 and the first fine grid 20 according to one of the embodiments of the present application, the first fine grid 20 is in a discontinuous structure at the position where the second sub-pad 50 is arranged, so as to reduce the overall thickness of the fine grid and the pad at this position, and to avoid waste of the metal paste; or as shown in Fig. 3, which is a schematic view of the connection between the second sub-pad 50 and the first fine grid 20 according to one of the embodiments of the present application, the first fine grid 20 is in a continuous structure at the position where the second sub-pad 50 is arranged, the pad at this position is printed first, and then the fine grid is printed on the pad, so that the fine grid can be stacked on the pad. Figures 1-3 As shown in Fig. 2, which is a schematic view of the connection between the second sub-pad 50 and the first fine grid 20 according to one of the embodiments of the present application, the first fine grid 20 is in a discontinuous structure at the position where the second sub-pad 50 is arranged, so as to reduce the overall thickness of the fine grid and the pad at this position, and to avoid waste of the metal paste; or as shown in Fig. 3, which is a schematic view of the connection between the second sub-pad 50 and the first fine grid 20 according to one of the embodiments of the present application, the first fine grid 20 is in a continuous structure at the position where the second sub-pad 50 is arranged, the pad at this position is printed first, and then the fine grid is printed on the pad, so that the fine grid can be stacked on the pad.

[0099] It is understood that in this embodiment, in the first direction X, the plurality of first sub-pads 40 and the plurality of second sub-pads 50 on the first fine gate 20 and / or the second fine gate 30 have a plurality of first repeating units; and in the second direction Y, the first sub-pads 40 and the second sub-pads 50 on the first fine gate 20 and the second fine gate 30 are arranged in a row and have a plurality of second repeating units.

[0100] like Figure 1 As shown, in the first direction X, each first repeating unit includes a first sub-pad 40 and a second sub-pad 50, such that the first sub-pad 40 and the second sub-pad 50 on a single first fine gate 20 and a second fine gate 30 within the first region A are alternately arranged along the first direction X; and as... Figure 3 As shown, the first sub-pad 40 on each first fine gate 20 is offset from the second sub-pad 50 on its adjacent second fine gate 30 in the second direction Y, and the second sub-pad 50 on each first fine gate 20 is opposite to its adjacent first fine gate 20 in the second direction Y; Figure 2 As shown, in the second direction Y, each second repeating unit includes a first sub-pad 40 and a second sub-pad 50, so that when soldering, the first sub-pad 40 and the second sub-pad 50 can be alternately soldered in the first region A along the second direction Y.

[0101] This design minimizes the amount of metal paste used, reducing production costs. Even when a smaller area of ​​the first sub-pad 40 experiences a cold solder joint, the larger area of ​​the second sub-pad 50 in the first direction X can still ensure welding reliability. Current at the cold solder joint location of the first sub-pad 40 is collected, preventing current loss due to excessive current path transmission. Furthermore, in the second direction Y, the first sub-pads 40 and 50 on the first and second fine grids 20 and 30 are arranged in a row, with multiple second repeating units including at least one first sub-pad 40 and at least one second sub-pad 50. This also minimizes the amount of metal paste used, reducing production costs. It also helps increase the contact area of ​​the solder strip along the second direction Y within the first region A, thereby increasing welding tensile strength, ensuring welding stability, and preventing solder strip misalignment. In addition, the connection points of the multiple solder strips to the back contact battery 100 after welding are arranged crosswise in the first direction X and the second direction Y, facilitating uniform stress distribution after welding. This effectively reduces cold solder joints and significantly improves welding reliability.

[0102] Another embodiment of this application also provides a photovoltaic module, including a back contact cell 100 as described above and an electrical connector. The electrical connector is connected to a first fine grid 20 or a second fine grid 30 of the same polarity through a first sub-pad and / or a second sub-pad. An insulating block is provided between the electrical connector and the first fine grid 20 or the second fine grid 30 of different polarity.

[0103] It can be understood that the electrical connecting member can be a solder strip, the electrical connecting member is connected with the first fine grid 20 or the second fine grid 30 through the sub-pad (for example, the first sub-pad and / or the second sub-pad), and specifically can be connected through a tin paste layer formed by tin paste on the sub-pad; an insulating block is arranged between the electrical connecting member and the first fine grid 20 or the second fine grid 30, the insulating block can be formed by insulating glue, and when the insulating block is arranged, the adjacent two first fine grids 20 can be arranged with the insulating block at the second fine grid 30 between the two sub-pads in the second direction Y, or the adjacent two second fine grids 30 can be arranged with the insulating block at the first fine grid 20 between the two sub-pads in the second direction Y, so that the electrical connecting member can be insulated from the fine grid of different polarity while being connected with the fine grid of the same polarity.

[0104] In addition, the photovoltaic module in the embodiment of the present application can include a plurality of cell strings, and the cell string can include a plurality of back contact cells 100 in the embodiment of the present application. The plurality of back contact cells 100 in the photovoltaic module can be sequentially connected in series by solder strips to form a cell string. Each cell string in the photovoltaic module can be connected in series, in parallel, or in a combination of series and parallel to realize the current collection output, for example, the connection between each cell string can be realized by a bus bar.

[0105] In summary, the embodiment of the present application optimizes the design of the pad arrangement on the back contact cell 100, maximally reduces the use of metal paste and the loss of metal composite on the surface of the cell body 10, fully improves the stability of the solder strip welding, reduces the occurrence of false welding, and ensures the reliability of current collection.

[0106] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above embodiments within the scope of the present application.

Claims

1. A back-contact battery, characterized in that, It includes a battery body (10), a plurality of first fine grids (20) extending along a first direction (X) and a plurality of second fine grids (30). A plurality of first fine grids (20) and a plurality of second fine grids (30) are sequentially and alternately arranged at intervals along a second direction (Y) on the first surface of the battery body (10); The first surface includes a first region (A) and includes a first side and a second side disposed opposite to each other along the second direction (Y); Within the first region (A), both the first fine gate (20) and the second fine gate (30) are provided with a plurality of first sub-pads (40) and a plurality of second sub-pads (50); the area of ​​the first sub-pad (40) is smaller than the area of ​​the second sub-pad (50); In the first direction (X), a plurality of first sub-pads (40) and a plurality of second sub-pads (50) on the first fine gate (20) and / or the second fine gate (30) have a plurality of first repeating units, each of which includes at least one first sub-pad (40) and at least one second sub-pad (50); and in the second direction (Y), the first sub-pads (40) and the second sub-pads (50) on the first fine gate (20) and the second fine gate (30) are arranged in a row and have a plurality of second repeating units, each of which includes at least one first sub-pad (40) and at least one second sub-pad (50). The first sub-pad (40) has a different shape than the second sub-pad (50).

2. The back contact battery according to claim 1, characterized in that, The first repeating unit includes a first sub-pad (40) and a second sub-pad (50); and / or, the second repeating unit includes a first sub-pad (40) and a second sub-pad (50).

3. The back contact battery according to claim 1, characterized in that, The first sub-pad (40) and the second sub-pad (50) have different lengths in the first direction (X) and / or widths in the second direction (Y).

4. The back contact battery according to claim 3, characterized in that, The first sub-pad (40) and the second sub-pad (50) have the same length in the first direction (X) and width in the second direction (Y), but the first sub-pad (40) and the second sub-pad (50) have different shapes.

5. The back contact battery according to claim 4, characterized in that, The outer contour of the second sub-pad (50) is rectangular or racetrack-shaped; and / or The first sub-pad (40) includes a middle portion (41) and extension portions (42) located on both sides of the middle portion (41) in the first direction (X). The outer contour of the middle portion (41) is rectangular or racetrack-shaped, and the outer contour of the extension portions (42) is trapezoidal, semi-elliptical or triangular.

6. The back contact battery according to claim 1, characterized in that, The first surface further includes a second region (B) disposed between the first region (A) and the first edge along the second direction (Y) and adjacent to the first region (A); in the second region (B), a plurality of third sub-pads (60) are provided on the first fine gate (20) and the second fine gate (30) at intervals along the first direction (X), and the third sub-pad (60) on each of the first fine gates (20) is staggered with the third sub-pad (60) on the adjacent second fine gate (30) in the second direction (Y), and the third sub-pad (60) on the adjacent first fine gate (20) is opposite to the third sub-pad (60) in the second direction (Y); The area of ​​the second sub-pad (50) is smaller than the area of ​​the third sub-pad (60).

7. The back contact battery according to claim 6, characterized in that, The third sub-pad (60) differs from the second sub-pad (50) in length in the first direction (X), and / or width in the second direction (Y), and / or shape.

8. The back contact battery according to claim 7, characterized in that, The length of the third sub-pad (60) in the first direction (X) is the same as that of the second sub-pad (50), and the width of the third sub-pad (60) in the second direction (Y) is greater than that of the second sub-pad (50).

9. The back contact battery according to claim 6, characterized in that, The first surface further includes a third region (C) disposed between the first region (B) and the first edge along the second direction (Y) and adjacent to the first region (B). Within the third region (C), both the first fine gate (20) and the second fine gate (30) are provided with a plurality of fourth sub-pads (70) arranged at intervals along the first direction (X), and the fourth sub-pad (70) on each of the first fine gate (20) and the fourth sub-pad (70) on the adjacent second fine gate (30) are staggered in the second direction (Y), and are opposite to the fourth sub-pad (70) on the adjacent first fine gate (20) in the second direction (Y); The area of ​​the third sub-pad (60) is smaller than the area of ​​the fourth sub-pad (70).

10. The back contact battery according to claim 9, characterized in that, The fourth sub-pad (70) differs from the third sub-pad (60) in length in the first direction (X), and / or width in the second direction (Y), and / or shape.

11. The back contact battery according to claim 10, characterized in that, The fourth sub-pad (70) is longer than the third sub-pad (60) in the first direction (X), and the width of the fourth sub-pad (70) in the second direction (Y) is the same as that of the third sub-pad (60).

12. The back contact battery according to any one of claims 9-11, characterized in that, The first sub-pad (40) has a dimension of 0.9-1.1 mm in the first direction (X) and a dimension of 0.19-0.25 mm in the second direction (Y); and / or, The second sub-pad (50) has a dimension of 0.9-1.1 mm in the first direction (X) and a dimension of 0.19-0.3 mm in the second direction (Y); and / or, The third sub-pad (60) has a dimension of 0.9-1.3 mm in the first direction (X) and a dimension of 0.19-0.4 mm in the second direction (Y); and / or, The fourth sub-pad (70) has a size of 0.9-1.5 mm in the first direction (X) and a size of 0.19-0.5 mm in the second direction (Y).

13. The back contact battery according to claim 9, characterized in that, It also includes multiple first doped layers (11) and multiple second doped layers (12); Multiple first doped layers (11) and multiple second doped layers (12) are arranged alternately along the second direction (Y). Each first doped layer (11) is disposed between a corresponding first fine gate (20) and the battery body (10), and each second doped layer (12) is disposed between a corresponding second fine gate (30) and the battery body (10). The first doped layer (11) and the second doped layer (12) have different doping types.

14. The back contact battery according to claim 13, characterized in that, Within the second region (B) and / or the third region (C), the first doped layer (11) or the second doped layer (12) protrudes at least partially along the second direction (Y) to form a receiving region to accommodate the corresponding third sub-pad (60) or fourth sub-pad (70).

15. The back contact battery according to any one of claims 9-11, characterized in that, The first surface further includes an edge region (D), which is disposed between the first region (A), the second region (B), or the third region (C) and the first edge, and the edge region (D) is adjacent to the first edge; Within the edge region (D), a plurality of fifth sub-pads (80) are respectively provided on the first fine gate (20) and the second fine gate (30) adjacent to the first edge, and the area of ​​the fifth sub-pad (80) is larger than that of the fourth sub-pad (70). An end line (81) is also provided between the fifth sub-pad (80) and the first side, and in the second direction (Y), one end of the end line (81) is connected to the corresponding fifth sub-pad (80), and the other end is connected to the corresponding first fine gate (20) or second fine gate (30) near the first side.

16. The back contact battery according to claim 15, characterized in that, The fifth sub-pad (80) has the same length as the fourth sub-pad (70) in the first direction (X), and its width in the second direction (Y) is greater than that of the fourth sub-pad (70); and / or The fifth sub-pad (80) has a size of 0.9-1.1 mm in the first direction (X) and a size of 1.1-1.8 mm in the second direction (Y).

17. The back contact battery according to claim 15, characterized in that, The first fine gate (20) or the second fine gate (30) is either a broken structure or a continuous structure at the location where the first sub-pad (40), the second sub-pad (50), the third sub-pad (60), the fourth sub-pad (70), or the fifth sub-pad (80) are set.

18. A photovoltaic module, characterized in that, Includes a back contact battery (100) as described in any one of claims 1 to 17 and an electrical connector, wherein the electrical connector is connected to the same-type first fine grid (20) or second fine grid (30) via a first sub-pad and / or a second sub-pad, and an insulating block is provided between the electrical connector and the opposite-type first fine grid (20) or second fine grid (30).

Images