Back contact photovoltaic module and manufacturing method thereof

Abstract

The embodiment of the invention relates to the field of photovoltaic cells, and provides a back contact photovoltaic module and a manufacturing method thereof.The back contact photovoltaic module comprises a back contact photovoltaic cell, and the back contact photovoltaic cell comprises a cell piece body, a grid line arranged on the first surface of the cell piece body and an insulating part; the grid line comprises a first fine grid, a second fine grid, a first main grid and a second main grid, the first fine grid and the second fine grid extend intermittently, the extending directions of the first main grid and the second main grid intersect with the extending directions of the first fine grid and the second fine grid, and the insulating part at least covers the end, close to the second main grid, of the first fine grid and the end, close to the first main grid, of the second fine grid. Wherein the insulating part is a black insulating part. The embodiment of the invention at least can solve the problem of how to improve the utilization rate of light.

Description

Technical Field

[0001] The present application relates to the field of photovoltaic cells, and in particular to a back-contact photovoltaic module and a manufacturing method thereof. Background Art

[0002] In solar photovoltaic technology, the most notable feature of interdigitated back contact (IBC) cells is that the PN junction and contact metal are both located on the back of the IBC cell. The front of the IBC cell completely avoids the obstruction of the metal grid electrode, which can maximize the use of incident light, reduce optical losses, and have a higher short-circuit current, thereby improving the photoelectric conversion efficiency of the IBC cell.

[0003] Therefore, how to improve the utilization efficiency of light is an urgent problem that those skilled in the art need to solve. Summary of the Invention

[0004] The embodiments of the present application provide a back-contact photovoltaic module and a method for manufacturing the same, which at least helps to solve the problem of how to improve light utilization.

[0005] According to some embodiments of the present application, on one hand, a back-contact photovoltaic module is provided, comprising:

[0006] A battery cell body, the battery cell body having a first surface and a second surface opposite to each other in a third direction; the third direction being a thickness direction of the battery cell body;

[0007] A gate line, the gate line being arranged on the first surface, the gate line comprising a plurality of main gates and a plurality of fine gates; the plurality of fine gates comprising a first fine gate and a second fine gate extending intermittently along a first direction and alternately distributed along a second direction; the first direction and the second direction intersecting; the first fine gate and the second fine gate having different polarities; the plurality of main gates comprising a first main gate and a second main gate extending along the second direction and alternately distributed along the first direction, the first main gate being electrically connected to the plurality of the first fine gates, and the second main gate being electrically connected to the plurality of the second fine gates;

[0008] a welding portion, the welding portion being provided on the first main grid or the second main grid;

[0009] an insulating portion, the insulating portion being disposed on the first surface and at least covering an end portion of the first fine grid close to the second main grid and an end portion of the second fine grid close to the first main grid;

[0010] Wherein, the insulating portion is a black insulating portion.

[0011] In some embodiments, the back-contact photovoltaic module further comprises:

[0012] a welding ribbon, the welding ribbon extending along the second direction, a plurality of the welding ribbons being arranged at intervals along the first direction, the welding ribbon being located on the first busbar or the second busbar, the welding ribbon being connected to the welding portion; and at least a portion of the insulating portion being sandwiched between the welding ribbon and the battery cell body;

[0013] Wherein, in the third direction, the insulating portion at least covers a portion where the first fine grid and the second fine grid overlap with a projection of the welding strip.

[0014] In some embodiments, the insulating portion covers the first surface of the battery cell body;

[0015] A window is provided on the insulating portion and passes through the insulating portion along the third direction, and the welding portion is provided in the window.

[0016] In some embodiments, the ratio of the area of ​​the welding portion to the area of ​​the window is 0.5 to 0.8.

[0017] In some embodiments, the area of ​​the weld is 0.8 mm 2 ~1.5mm 2 ;

[0018] The area of ​​the window is 1.15 mm 2 ~1.8mm 2 .

[0019] In some embodiments, the welding ribbon comprises:

[0020] Welding strip body;

[0021] A black coating layer covers a surface of the welding strip body on one side facing the battery cell body.

[0022] In some embodiments, the black coating is provided with an avoidance area exposing the soldering ribbon body, and the soldering ribbon body is connected to the soldering portion through the avoidance area.

[0023] In some embodiments, the system further includes: a back plate, the back plate being arranged on a side of the battery cell body facing the insulating portion, and a black reflective layer being provided on a surface of the back plate facing the battery cell body.

[0024] In some embodiments, the thickness of the insulating portion is 40 μm to 60 μm.

[0025] In some embodiments, the insulating portion includes the following components in parts by weight:

[0026] 35-75 parts of insulating adhesive base material; 0.1-1 part of color filler;

[0027] Wherein, the color filler is a black color filler.

[0028] In some embodiments, the black color filler includes at least one of black masterbatch, carbon black, manganese iron black, perylene black, and iron chrome black.

[0029] In some embodiments, the insulating portion further comprises 20 to 40 parts by mass of a filler, 1 to 10 parts by mass of a curing agent, 1 to 10 parts by mass of a leveling agent, and 0.5 to 2 parts by mass of a wetting and dispersing agent.

[0030] In some embodiments, the filler includes at least one of barite powder, talc powder, mica powder, or glass beads;

[0031] The curing agent includes at least one of an aliphatic amine curing agent, an alicyclic amine curing agent, an HDI curing agent or an IPDI curing agent;

[0032] The leveling agent includes at least one of a fluorocarbon-modified acrylate compound or a polyether-modified polydimethylsiloxane;

[0033] The wetting dispersant includes at least one of a polyacrylate polymer dispersant and a polyester modified polyphosphate compound.

[0034] According to some embodiments of the present application, another aspect of the present application further provides a method for manufacturing a back-contact photovoltaic module, comprising:

[0035] Providing a battery cell body, wherein the battery cell body has a first surface and a second surface opposite to each other in a third direction; the third direction is a thickness direction of the battery cell body;

[0036] A grid line and a welding portion are formed on the first surface; the grid line includes a plurality of main grids and a plurality of fine grids; the plurality of fine grids include a first fine grid and a second fine grid extending along a first direction and alternately distributed along a second direction, the first direction and the second direction being perpendicular and intersecting; the first fine grid and the second fine grid have different polarities; the plurality of main grids include a first main grid and a second main grid extending along the second direction and alternately distributed along the first direction, the first main grid is electrically connected to the plurality of the first fine grids, and the second main grid is electrically connected to the plurality of the second fine grids; the welding portion is provided on the first main grid or the second main grid;

[0037] An insulating portion is formed on the first surface, the insulating portion at least covering an end portion of the first fine gate close to the second main gate and an end portion of the second fine gate close to the first main gate; wherein the insulating portion is a black insulating portion.

[0038] In some embodiments, the method of forming the insulating portion includes: forming the insulating portion at a position of the first surface avoiding the soldering portion using a spray printing process; the insulating portion covers the first surface, and the insulating portion has a window so that the soldering portion is exposed from the window;

[0039] Alternatively, the insulating portion is formed by a screen printing process; in the third direction, the insulating portion at least covers an end portion of the first fine grid close to the second main grid and an end portion of the second fine grid close to the first main grid.

[0040] The technical solution provided by the embodiments of the present application has at least the following advantages: the present application sets the insulating part as a black insulating part, and the black insulating part has a higher reflection efficiency for light than the green insulating part in the related technology. More light that penetrates the cell body and illuminates the insulating part will be reflected to the cell body, so as to improve the utilization rate of light and thereby improve the photoelectric conversion efficiency of the back-contact photovoltaic module. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] One or more embodiments are exemplarily illustrated by the pictures in the corresponding drawings. These exemplified descriptions do not constitute a limitation on the embodiments. Unless otherwise stated, the pictures in the drawings do not constitute a scale limitation. In order to more clearly illustrate the embodiments of the present application or the technical solutions in the traditional technology, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0042] Figure 1 A schematic structural diagram of a back-contact photovoltaic cell in a back-contact photovoltaic module provided in an embodiment of the present application;

[0043] Figure 2 A schematic perspective structural diagram of a back-contact photovoltaic cell connected to a welding ribbon in a back-contact photovoltaic module provided in an embodiment of the present application;

[0044] Figure 3 A schematic structural diagram of a back-contact photovoltaic cell in a back-contact photovoltaic module provided in another embodiment of the present application;

[0045] Figure 4 A flowchart of the steps of a method for manufacturing a back-contact photovoltaic module provided in an embodiment of the present application.

[0046] In the figure: 10, back contact photovoltaic cell; 110, cell body; 120, grid line; 121, first fine grid; 122, second fine grid; 123, first main grid; 124, second main grid; 140, welding part; 150, insulating part; 151, window; 20, welding strip. DETAILED DESCRIPTION

[0047] As known from the background art, improving the utilization rate of light by photovoltaic cells can improve the photoelectric conversion efficiency of the photovoltaic cells.

[0048] In related technologies, the light-receiving surface of a photovoltaic cell is usually made into a velvet surface, so that light can be refracted multiple times between the pyramid-shaped protrusions of the velvet surface, thereby improving light utilization. Therefore, increasing the refractive index of light in a photovoltaic cell is a technical solution to improve light utilization efficiency.

[0049] During the manufacturing process of back-contact photovoltaic cell modules, solder ribbons are used to interconnect multiple cells. During this process, the ribbons are soldered to the cell's solder joints. The gridlines with different polarity from the ribbons are located underneath the ribbons. Therefore, insulating adhesive is applied to the gridlines with different polarity to isolate them from the ribbons.

[0050] The present application provides a back-contact photovoltaic module. By configuring the insulating portion provided on the back of the cell body as a black insulating portion, the black surface of the black insulating portion can improve the reflection efficiency of visible light and short-wavelength invisible light. When light shines on the back-contact photovoltaic module, some of the light will directly pass through the cell body and illuminate the black surface of the black insulating portion. The black insulating portion will reflect this part of the light back to the cell body, thereby improving the utilization rate of light and thereby enhancing the photoelectric conversion efficiency of the back-contact photovoltaic module.

[0051] In the description of the embodiments of the present application, the technical terms "first" and "second" are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined. Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0052] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0053] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists, A and B exist at the same time, and B exists. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0054] In the description of the embodiments of the present application, the orientation or positional relationship indicated by the technical terms "center", "longitudinal", "transverse", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the embodiments of the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the embodiments of the present application. For example, if the device or element in the figure is inverted, then the element described as being "below" or "below" or "below" or "bottom" of other elements or features will be oriented "above" or "top" of the other elements or features. Therefore, the term "below" can cover both above and below orientations depending on the context in which the term is used, which will be obvious to a person skilled in the art. The material can be oriented in other ways (e.g., rotated 90 degrees, inverted, flipped), and the spatially relative descriptors used herein can be interpreted accordingly.

[0055] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.

[0056] In the accompanying drawings corresponding to the embodiments of the present application, the thickness and area of ​​each layer are exaggerated for better understanding and ease of description. In addition, when a component is described as being "substantially" formed on another component, it means that the component is not formed on the entire surface (or front surface) of the other component, nor is it formed on a portion of the edge of the entire surface.

[0057] In the description of the embodiments of the present application, when a certain component "includes" another component, unless otherwise stated, other components are not excluded, and other components may be further included. A second component is formed or provided above or on the first component, or a second component is formed or provided on the surface of the first component, or a second component is formed or provided on one side of the first component. Embodiments in which the first component and the second component are in direct contact may be included, and embodiments in which additional components may be provided between the first component and the second component so that the first component and the second component may not be in direct contact may also be included. For the sake of simplicity and clarity, various components may be arbitrarily drawn in different proportions. In the accompanying drawings, some layers / components may be omitted for simplicity. Unless otherwise specified, a second component is formed or provided on the surface of the first component, which means that the first component is in direct contact with the second component. Among them, the above-mentioned "components" may refer to layers, films, regions, parts, structures, etc.

[0058] The terms used herein in the description of the various embodiments are intended only to describe the specific embodiments and are not intended to be limiting. As used in the description of the various embodiments and the appended claims, "the component" is intended to include the plural form unless the context clearly indicates otherwise. A component includes a layer, film, region, or plate.

[0059] The following detailed description of the various embodiments of the present application is provided in conjunction with the accompanying drawings. However, those skilled in the art will appreciate that many technical details are provided in the various embodiments of the present application to facilitate a better understanding of the present application. However, even without these technical details and the various variations and modifications based on the following embodiments, the technical solutions claimed in the present application can still be implemented.

[0060] Figure 1 This is a schematic structural diagram of a back-contact photovoltaic cell 10 in a back-contact photovoltaic module provided in an embodiment of the present application.

[0061] refer to Figure 1The back-contact photovoltaic module has a first direction X, a second direction Y, and a third direction Z that intersect and are perpendicular to each other. The back-contact photovoltaic module includes a cell body 110, a grid line 120, a welding portion 140, and an insulating portion 150. The cell body 110 has a first surface and a second surface that are opposite to each other in the third direction Z; the third direction is the thickness direction of the cell body 110. The gate lines 120 are arranged on the first surface, and the gate lines 120 include multiple main grids and multiple fine grids; the multiple fine grids include first fine grids 121 and second fine grids 122 that extend intermittently along the first direction X and are alternately distributed along the second direction Y; the first direction X and the second direction Y intersect; the multiple main grids include first main grids 123 and second main grids 124 that extend along the second direction Y and are alternately distributed along the first direction X, the first main grid 123 is electrically connected to the multiple first fine grids 121, and the second main grid 124 is electrically connected to the multiple second fine grids 122; the welding portion 140 is located at the position where the first main grid 123 and the first fine grid 121 are electrically connected or at the position where the second main grid 124 and the second fine grid 122 are electrically connected; the insulating portion 150 is arranged on the first surface, and the insulating portion 150 at least covers the end of the first fine grid 121 close to the second main grid 124 and the end of the second fine grid 122 close to the first main grid 123; wherein the insulating portion 150 is a black insulating portion.

[0062] The present application sets the insulating part 150 on the back of the battery cell body 110 as a black insulating part. Compared with the insulating glue of conventional colors (such as green) in the related art, the black insulating part has a higher light reflection efficiency, especially for invisible light in the short-wave band. The black insulating part has a higher reflection efficiency, and the invisible light in the short-wave band has higher energy. The black insulating part will reflect more light that penetrates the battery cell body 110 back to the battery cell body 110, so as to improve the utilization rate of light and thereby improve the photoelectric conversion efficiency of the present application.

[0063] The embodiments of the present application will be described in more detail below with reference to the accompanying drawings.

[0064] Reference Figure 1 As shown, Figure 1 The schematic diagram of the structure of a back-contact photovoltaic cell 10 in a back-contact photovoltaic module provided by an embodiment of the present application is shown. The back-contact photovoltaic module includes a back-contact photovoltaic cell 10, a welding ribbon 20, and a backplane. The back-contact photovoltaic cell 10 is electrically connected to form multiple cell strings in the form of a whole piece or slices through the welding ribbon 20. The multiple cell strings are electrically connected in series and / or parallel. The back-contact photovoltaic cell 10 can be a whole cell or a sliced ​​cell. A sliced ​​cell refers to a cell formed by cutting a complete whole cell.

[0065] In some embodiments, the back-contact photovoltaic cell 10 is a BC cell (Back Contact). The BC cell can be an IBC cell (Interdigitated Back Contact), an HPBC cell (Hybrid Passivated Back Contact), a TBC cell that stacks TOPCon (Tunnel Oxide Passivated Contact) technology and IBC technology, or an HBC cell that stacks HIT / HJT (Heterojunction Technology) technology and IBC technology. Of course, it can also be other types of back-contact photovoltaic cells.

[0066] In some embodiments, the type of the back contact photovoltaic cell 10 can be a monocrystalline silicon solar cell, a polycrystalline silicon solar cell, an amorphous silicon solar cell or a multi-compound solar cell. The multi-compound solar cell can specifically be a cadmium sulfide solar cell, a gallium arsenide solar cell, a copper indium selenide solar cell or a perovskite solar cell.

[0067] The back-contact photovoltaic cell 10 includes a cell body 110 , a grid line 120 , a welding portion 140 and an insulating portion 150 .

[0068] The cell body 110 is a sheet-like structure that exhibits a photovoltaic effect. The cell body 110 has a first surface and a second surface that are opposed to each other in the third direction Z. The second surface is the front surface of the final back-contact photovoltaic cell 10, i.e., the second surface can serve as the light-receiving surface, while the first surface is the back surface of the final back-contact photovoltaic cell 10, i.e., the first surface can serve as the backlight surface. The grid lines 120, the welding portion 140, and the insulating portion 150 are all disposed on the second surface of the cell body 110, i.e., the back surface of the back-contact photovoltaic cell 10.

[0069] It should be noted that the final back-contact photovoltaic cell 10 can be a single-sided cell, in which the second surface can be considered the front side of the back-contact photovoltaic cell 10, the second surface being the light-receiving surface for receiving incident light, and the first surface being the backlight surface; alternatively, the final back-contact photovoltaic cell 10 can be a bifacial cell, in which case both the first surface and the second surface can serve as light-receiving surfaces and can both be used to receive incident light. It is understood that the backlight surface described in the embodiments of the present application can also receive incident light, but the degree of its reception of incident light is weaker than that of the light-receiving surface, and therefore is defined as the backlight surface.

[0070] The grid lines 120 are disposed on the first surface of the cell body 110 and include multiple fine grids and multiple main grids. The fine grids include first and second grids 121 and 122 extending intermittently along the first direction X. The first and second grids 121 and 122 are alternately arranged along the second direction Y. The main grids include first and second grids 123 and 124 extending along the second direction Y. The first grid 123 passes through the gap in the second grid 122 and is electrically connected to the first grid 121. The second grid 124 passes through the gap in the first grid 121 and is electrically connected to the second grid 122. The first grid 123 is used to collect carriers collected by the multiple first grids 121 arranged sequentially along the second direction Y. The second grid 124 is used to collect carriers collected by the multiple second grids 122 arranged sequentially along the second direction Y.

[0071] The first main grid 123 passes through the disconnected portion of the second thin grid 122 to insulate the two. Similarly, the second main grid 124 passes through the disconnected portion of the first thin grid 121 to insulate the two.

[0072] It should be noted that the first main gate 123 and the first fine gate 121 have the same polarity, the second main gate 124 and the second fine gate 122 have the same polarity, the first main gate 123 and the second main gate 124 have different polarities, the first main gate 123 is one of the positive polarity or the negative polarity, and the second main gate 124 is the other of the positive polarity or the negative polarity, which is not specifically limited here.

[0073] The welding portion 140 is provided on the busbar and electrically connects to the soldering ribbon 20. The welding portion 140 transfers carriers collected by the busbar to the soldering ribbon 20. The welding portion 140 is larger than the width of the busbar to reduce the transfer resistance of the welding portion 140 itself, thereby improving the carrier transport efficiency of the welding portion 140. The size of the welding portion 140 can be at least one of its diameter, length, or width. Multiple welding portions 140 are arranged in sequence along the second direction Y on a single busbar.

[0074] Combine Figure 2 As shown, Figure 2A perspective schematic diagram of the back-contact photovoltaic module, provided in an embodiment of the present application, shows the back-contact photovoltaic cell 10 connected to the welding ribbon 20. The welding ribbon 20 is a schematic perspective structure. The welding ribbon 20 extends along a second direction Y and is positioned corresponding to the busbar. The welding ribbon 20 is electrically connected to the busbar via a welding portion 140. In the third direction Z, the ends of some first fine grids 121 or second fine grids 122, which have a different polarity than the welding ribbon 20, overlap with the orthographic projection of the welding ribbon 20 on the cell body 110. The insulating portion 150 is arranged on the first surface of the cell body 110, and at least part of the insulating portion 150 covers the end of the first fine grid 121 close to the second main grid 124 or the end of the second fine grid 122 close to the first main grid 123, so that part of the insulating portion 150 is clamped between the cell body 110 and the welding strip 20. The insulating portion 150 plays an insulating isolation role between the fine grids and the main grid of different polarities, avoiding the contact and connection of the fine grids and the main grid of different polarities to cause a short circuit, which is beneficial to improving the stability of the back-contact photovoltaic module.

[0075] The insulating portion 150 is a black insulating portion, that is, the color of the insulating portion 150 is black, and the surface of the insulating portion 150 is a black surface. The black surface of the insulating portion 150 can improve the reflection efficiency of visible light and short-wave invisible light. The second surface serves as the light-receiving surface of the back-contact photovoltaic cell 10 to receive incident light, and some of the light will penetrate the cell body 110. At least some of the light that penetrates the cell body 110 will be irradiated by the insulating portion 150, and the surface of the insulating portion 150 facing the cell body 110 will reflect this part of the light to the cell body 110. Then, the cell body 110 will be incident with this part of the light and produce a photoelectric effect, thereby improving the utilization rate of light. The insulating part 150 of the embodiment of the present application is a black insulating part. Compared with the insulating glue of conventional colors such as green in the related art, the black insulating part has a higher light reflection efficiency, especially for invisible light in the short-wave band. The black insulating part has a higher reflection efficiency, and the invisible light in the short-wave band has higher energy. The black insulating part reflects more light, further improving the utilization rate of light, thereby improving the photoelectric conversion efficiency of the back-contact photovoltaic cell 10.

[0076] In some embodiments, the thickness of the insulating portion 150 is 40 μm to 60 μm. Optionally, the thickness of the insulating portion 150 is 45 μm to 55 μm, and the thickness of the insulating portion 150 is 45 μm, 48 μm, 50 μm, 53 μm, or 55 μm. The thickness of the insulating portion 150 is set to an appropriate thickness to avoid poor insulation isolation due to excessive thickness, or to avoid excessive thickness causing the welding portion 140 and the welding ribbon 20 to be separated too far in the third direction Z, thereby causing poor welding between the two or breaking the weld due to stress.

[0077] Insulating portion 150 comprises the following components: 35-75 parts by weight of insulating adhesive base material, 0.1-1 parts by weight of color filler, 20-40 parts by weight of filler, 1-10 parts by weight of curing agent, 1-10 parts by weight of leveling agent, and 0.5-2 parts by weight of wetting and dispersing agent. The color filler is black, which gives insulating portion 150 its black color.

[0078] In some embodiments, the material of the color pigment includes at least one of black masterbatch, carbon black, manganese iron black, perylene black, and iron chrome black. The filler includes at least one of barite powder, talc powder, mica powder, or glass beads. The curing agent includes at least one of aliphatic amine curing agent, alicyclic amine curing agent, HDI (hexamethylene diisocyanate) curing agent, or IPDI (isophorone diisocyanate) curing agent. The leveling agent includes at least one of a fluorocarbon-modified acrylate compound or a polyether-modified polydimethylsiloxane. The wetting dispersant includes at least one of a polyacrylate-type polymer dispersant and a polyester-modified polyphosphate compound.

[0079] The soldering ribbon 20 includes a main body and a black coating, with the black coating covering the main body. The main body has a first surface and a second surface facing each other in the third direction Z, with the first surface of the soldering ribbon 20 facing the back-contact photovoltaic cell 10. In some embodiments, the black coating covers at least the first surface of the main body. Light that partially penetrates the cell body 110 will strike the black coating of the soldering ribbon 20 and be reflected back toward the cell body 110, thereby improving light utilization and, in turn, the photoelectric conversion efficiency of the back-contact photovoltaic cell 10.

[0080] In other embodiments, the black coating completely covers the surface of the welding strip body, and the surface of the welding strip body covered by the black coating includes a first surface and a second surface, so that the overall appearance color of the welding strip 20 is black, thereby improving the aesthetics of the back-contact photovoltaic module of the embodiment of the present application.

[0081] In some embodiments, the black coating is made of an insulating material, including at least one of ceramic, rubber, or a photomolecular compound. The black coating provides insulation and protection for the solder ribbon 20, preventing the solder ribbon from contacting and connecting with grid lines 120 of different polarity, which could cause a short circuit, or from rusting or corroding the solder ribbon due to external factors, thereby improving the stability and service life of the back-contact photovoltaic module.

[0082] Furthermore, the black coating on the side of the solder strip body facing the cell body 110 has an avoidance area, which is arranged corresponding to the welding portion of the back contact photovoltaic cell 10. The avoidance area exposes the solder strip body so that the solder strip body is connected to the welding portion through the avoidance area.

[0083] In some embodiments, the thickness of the black coating is very thin. During the process of welding the welding strip 20 and the welding portion 140, the heat generated by welding and the mechanical pressure applied can easily destroy the black coating on the surface of the welding strip body to form an avoidance area, so that the welding strip body is welded to the welding portion 140 through the avoidance area.

[0084] In some embodiments, the thickness of the black coating layer is 0.1 μm to 2 μm. Optionally, the thickness of the black coating layer is 0.5 μm to 1 μm, and the thickness of the black coating layer can be 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, or 1 μm.

[0085] The backsheet is disposed on the side of the cell body 110 facing the first surface. A black reflective layer is provided on the side of the backsheet facing the cell body 110. The black reflective layer is black in color and has the same light-reflecting effect as the black insulating portion and the black coating of the solder ribbon 20. Some light that penetrates the cell body 110 and strikes the black reflective layer of the backsheet is reflected back toward the cell body 110, thereby improving light utilization and, in turn, the photoelectric conversion efficiency of the back-contact photovoltaic cell 10.

[0086] In some embodiments, the material of the black reflective layer includes at least one of polyester film (PET), polyvinyl fluoride (PVF), or modified polytetrafluoroethylene (PTFE).

[0087] In some embodiments, the black reflective layer completely covers the surface of the backplane, that is, both sides of the backplane opposite to each other in the third direction Z are covered by the black reflective layer, so that the back side of the back-contact photovoltaic module is black, thereby improving the aesthetics of the back-contact photovoltaic module.

[0088] Furthermore, the back-contact photovoltaic module further includes an encapsulation film, which is used to cover the second surface of the cell body 110. The encapsulation film is made of at least one of polyvinyl butyral (PVB) film, ethylene vinyl acetate copolymer (EVA) film, polyethylene octene co-elastomer (POE) film, or polyester (PET) film.

[0089] Reference Figure 3 As shown, Figure 3A schematic structural diagram of a back-contact photovoltaic cell 10 in a back-contact photovoltaic module provided in another embodiment of the present application is shown, wherein the insulating portion 150 covers the first surface of the cell body 110, the insulating portion 150 has a plurality of windows 151 passing through its body along the third direction Z, and the welding portion 140 is arranged at a position corresponding to the cell body 110 and the window 151 so that the welding portion 140 is exposed from the window 151, thereby preventing the insulating portion 150 from covering the welding portion 140 and causing the welding portion 140 to be unable to be welded to the welding ribbon 20. The insulating portion 150 covers the surface of the first surface of the cell body 110 except the welding portion 140. On the one hand, the coverage area of ​​the insulating portion 150 on the first surface of the cell body 110 is further increased, thereby increasing the amount of light penetrating the cell body 110 and irradiating the insulating portion 150. The black insulating portion improves the light reflection efficiency, further improves the light utilization rate, and thereby improves the photoelectric conversion efficiency of the back-contact photovoltaic cell 10. On the other hand, the insulating portion 150 covers a large area of ​​the first surface of the cell body 110. The precision requirements and process difficulty of forming a large-area insulating portion 150 are less than the precision requirements and process difficulty of forming a small-size insulating portion 150, which simplifies the production process and reduces production costs.

[0090] In some embodiments, a method of forming the insulating portion 150 includes a spray printing process or a screen printing process.

[0091] Furthermore, the area of ​​the window 151 is larger than that of the welding portion 140 to prevent the welding portion 140 from being too close to the surface of the window 151 and the heat generated during the welding process between the welding portion 140 and the welding ribbon 20 from damaging the insulating portion 150 .

[0092] In some embodiments, the ratio of the area of ​​the welding portion 140 to the area of ​​the window 151 is 0.5 to 0.8. Alternatively, the ratio of the area of ​​the welding portion 140 to the area of ​​the window 151 is 0.7 to 0.8, and the ratio of the area of ​​the welding portion 140 to the area of ​​the window 151 can be 0.7, 0.72, 0.78, or 0.8.

[0093] In some embodiments, the area of ​​the welding portion 140 is 0.8 mm 2 ~1.5mm 2 Optionally, the area of ​​the welding portion 140 is 1 mm 2 ~1.4mm 2 , the area of ​​the welding portion 140 is 1mm 2 , 1.1mm 2 , 1.2mm 2 , 1.3mm 2 or 1.4mm 2 .

[0094] In some embodiments, the area of ​​the window 151 is 1.15 mm 2 ~1.8mm 2 Optionally, the area of ​​window 151 is 1.2 mm 2 ~1.7mm 2 , the area of ​​window 151 can be 1.2mm 2 , 1.3mm 2 , 1.4mm 2 or 1.5mm 2 .

[0095] Accordingly, an embodiment of the present application further provides a method for manufacturing a back-contact photovoltaic module, which can be used to manufacture the back-contact photovoltaic module provided in the above embodiment. The following detailed description of the method for manufacturing a semiconductor structure provided in another embodiment of the present application is provided in conjunction with the accompanying drawings. For parts that are identical or corresponding to the previous embodiment, reference can be made to the corresponding description of the previous embodiment and will not be repeated in detail below.

[0096] like Figure 4 As shown, Figure 4 A flowchart of the steps of a method for manufacturing a back-contact photovoltaic module provided in an embodiment of the present application is shown. The method for manufacturing a back-contact photovoltaic module includes:

[0097] In step S1 , a battery cell body 110 is provided. The battery cell body 110 has a first surface and a second surface opposite to each other in a third direction Z.

[0098] Step S2, forming a gate line 120 and a welding portion 140 on the first surface; the gate line 120 includes multiple main grids and multiple fine grids; the multiple fine grids include first fine grids 121 and second fine grids 122 extending along the first direction X and alternately distributed along the second direction Y, the first direction X and the second direction Y are perpendicular and intersecting; the first fine grids 121 and the second fine grids 122 have different polarities; the multiple main grids include first main grids 123 and second main grids 124 extending along the second direction Y and alternately distributed along the first direction X, the first main grid 123 is electrically connected to the multiple first fine grids 121, and the second main grid 124 is electrically connected to the multiple second fine grids 122; the welding portion 140 is provided at a position where the first fine grid 121 is electrically connected to the first main grid 123 or at a position where the second fine grid 122 is electrically connected to the second main grid 124.

[0099] In step S3 , an insulating portion 150 is formed on the first surface. The insulating portion 150 covers at least the end of the first fine gate 121 close to the second main gate 124 and the end of the second fine gate 122 close to the first main gate 123 . The insulating portion 150 is a black insulating portion.

[0100] In some embodiments, the method for forming insulating portion 150 includes a spray printing process or a screen printing process. In the method of forming insulating portion 150 using the spray printing process, insulating portion 150 is formed at a location on the first surface away from solder portion 140; insulating portion 150 covers the first surface and has a window 151 through which solder portion 140 is exposed. Using the spray printing process to form insulating portion 150 over a large area reduces precision requirements and process complexity, simplifies the production process, and thus reduces production costs.

[0101] In the method of forming the insulating portion 150 using a screen printing process, the insulating portion 150 covers at least the end of the first fine grid 121 near the second busbar 124 and the end of the second fine grid 122 near the first busbar 123 in the thickness direction. The area of ​​the insulating portion 150 formed using the screen printing process can be adjusted according to actual needs. This method has the advantages of flexibility and wide applicability.

[0102] Those skilled in the art will appreciate that the above-described embodiments are specific examples for implementing the present application, and that in actual applications, various changes in form and detail may be made thereto without departing from the spirit and scope of the present application. Any person skilled in the art may make various changes and modifications without departing from the spirit and scope of the present application. Therefore, the scope of protection of the present application shall be based on the scope defined in the claims.

Claims

1. A back contact photovoltaic module, characterized in that: include: A back-contact photovoltaic cell (10), the back-contact photovoltaic cell (10) comprising: A battery cell body (110), the battery cell body (110) having a first surface and a second surface opposite to each other in a third direction (Z); the third direction (Z) being a thickness direction of the battery cell body (110); A gate line (120), the gate line (120) being arranged on the first surface, the gate line (120) comprising a plurality of main gates and a plurality of fine gates; the plurality of fine gates comprising a first fine gate (121) and a second fine gate (122) extending discontinuously along a first direction (X) and alternately distributed along a second direction (Y); the first direction (X) and the second direction (Y) intersect; the first fine gate (121) and the second fine gate (122) have different polarities; the plurality of main gates comprising a first main gate (123) and a second main gate (124) extending along the second direction (Y) and alternately distributed along the first direction (X); the first main gate (123) being electrically connected to the plurality of first fine gates (121), and the second main gate (124) being electrically connected to the plurality of second fine gates (122); a welding portion (140), the welding portion (140) being arranged on the first main grid (123) or the second main grid (124); an insulating portion (150), the insulating portion (150) being arranged on the first surface, the insulating portion (150) at least covering an end portion of the first fine grid (121) close to the second main grid (124) and an end portion of the second fine grid (122) close to the first main grid (123); Wherein, the insulating portion (150) is a black insulating portion.

2. The back contact photovoltaic module according to claim 1, characterized in that: Also includes: a welding ribbon (20), the welding ribbon (20) extending along the second direction (Y), a plurality of the welding ribbons (20) being arranged at intervals along the first direction (X), the welding ribbon (20) being located on the first main grid (123) or the second main grid (124), the welding ribbon (20) being connected to the welding portion (140); and at least a portion of the insulating portion (150) being sandwiched between the welding ribbon (20) and the battery cell body (110); Wherein, in the third direction (Z), the insulating portion (150) at least covers a portion where the first fine grid (121) and the second fine grid (122) overlap with the projection of the welding strip (20).

3. The back contact photovoltaic module according to claim 2, characterized in that: The insulating portion (150) covers the first surface of the battery cell body (110); A window (151) is provided on the insulating portion (150) and passes through the insulating portion (150) along the third direction (Z), and the welding portion (140) is provided in the window (151).

4. The back contact photovoltaic module according to claim 3, characterized in that: The ratio between the area of ​​the welding portion (140) and the area of ​​the window (151) is 0.5 to 0.

8.

5. The back contact photovoltaic module according to claim 4, characterized in that: The area of ​​the welding portion (140) is 0.8 mm 2 ~1.5mm 2 ; The area of ​​the window (151) is 1.15 mm 2 ~1.8mm 2 .

6. The back contact photovoltaic module according to claim 2 or 3, characterized in that: The welding strip (20) comprises: Welding strip body; A black coating layer covers a surface of the welding strip body on one side facing the battery cell body (110).

7. The back contact photovoltaic module according to claim 6, characterized in that: The black coating is provided with an avoidance area for exposing the welding strip body, and the welding strip body is connected to the welding portion (140) through the avoidance area.

8. The back-contact photovoltaic module according to any one of claims 1 to 3, characterized in that: Also includes: A back plate is provided on a side of the battery cell body (110) facing the insulating portion (150), and a black reflective layer is provided on a surface of the back plate facing the battery cell body (110).

9. The back contact photovoltaic module according to claim 1, characterized in that: The thickness of the insulating portion (150) is 40 μm to 60 μm.

10. The back contact photovoltaic module according to claim 1, characterized in that: The insulating part (150) comprises the following components in parts by mass: 35 to 75 parts of insulating adhesive base material; 0.1 to 1 part of color filler; Wherein, the color filler is a black color filler.

11. The back contact photovoltaic module according to claim 10, characterized in that: The black color filler includes at least one of black masterbatch, carbon black, ferromanganese black, perylene black, and ferrochrome black.

12. The back contact photovoltaic module according to claim 10, characterized in that: The insulating part (150) further comprises 20 to 40 parts by mass of a filler, 1 to 10 parts by mass of a curing agent, 1 to 10 parts by mass of a leveling agent, and 0.5 to 2 parts by mass of a wetting dispersant.

13. The back contact photovoltaic module according to claim 12, characterized in that: The filler includes at least one of barite powder, talc powder, mica powder or glass beads; The curing agent includes at least one of an aliphatic amine curing agent, an alicyclic amine curing agent, an HDI curing agent or an IPDI curing agent; The leveling agent includes at least one of a fluorocarbon-modified acrylate compound or a polyether-modified polydimethylsiloxane; The wetting dispersant includes at least one of a polyacrylate polymer dispersant and a polyester modified polyphosphate compound.

14. A method for manufacturing a back-contact photovoltaic module, characterized in that: A battery cell body (110) is provided, wherein the battery cell body (110) has a first surface and a second surface opposite to each other in a third direction (Z); the third direction (Z) is a thickness direction of the battery cell body (110); A grid line (120) and a welding portion (140) are formed on the first surface; the grid line (120) includes a plurality of main grids and a plurality of fine grids; the plurality of fine grids include a first fine grid (121) and a second fine grid (122) extending discontinuously along a first direction (X) and alternately distributed along a second direction (Y), wherein the first direction (X) and the second direction (Y) intersect; the first fine grid (121) and the second fine grid (122) have different polarities; the plurality of main grids include a first main grid (123) and a second main grid (124) extending along the second direction (Y) and alternately distributed along the first direction (X), wherein the first main grid (123) is electrically connected to the plurality of first fine grids (121), and the second main grid (124) is electrically connected to the plurality of second fine grids (122); the welding portion (140) is provided on the first main grid (123) or the second main grid (124); An insulating portion (150) is formed on the first surface, the insulating portion (150) at least covering an end portion of the first fine grid (121) close to the second main grid (124) and an end portion of the second fine grid (122) close to the first main grid (123); wherein the insulating portion (150) is a black insulating portion (150).

15. The method for manufacturing a back-contact photovoltaic module according to claim 14, characterized in that: The method for forming the insulating portion (150) comprises: forming the insulating portion (150) at a position of the first surface avoiding the welding portion (140) by a spray printing process; the insulating portion (150) covers the first surface, and the insulating portion (150) has a window (151) so that the welding portion (140) is exposed from the window (151); Alternatively, the insulating portion (150) is formed by a screen printing process; in the third direction (Z), the insulating portion (150) at least covers the end of the first fine grid (121) close to the second main grid (124) and the end of the second fine grid (122) close to the first main grid (123).

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