All-black back contact photovoltaic module

Abstract

The utility model relates to the field of photovoltaic power generation, in particular to an all-black back contact photovoltaic assembly, which comprises a plurality of solar cell strings, a first welding strip, an insulating strip and a confluence preassembled piece, the first welding strip and the confluence preassembling piece are arranged on the backlight surface of the solar cell string; the first welding strip is connected with two adjacent back contact battery pieces on the same solar battery string in a first direction; the insulating strip crosses over a first welding strip corresponding to a plurality of solar cell strings along a second direction perpendicular to the first direction; the bus preassembled piece is of an integrated conductive structure and comprises a bus bar arranged in the second direction and a second welding strip arranged in the first direction. And the insulating strip is arranged between the confluence preassembled piece and the solar cell string. According to the utility model, one side assembly of the solder strip and the bus bar is hidden, so that the overall black appearance is ensured, and the probability of hidden crack of the battery piece and short circuit of the assembly is reduced.

Description

Technical Field

[0001] The utility model relates to the field of photovoltaic power generation, in particular to a full black back contact photovoltaic component. Background Art

[0002] Photovoltaics, as a green and clean energy source, also possess certain building material properties in distributed applications. Therefore, their coordinated integration with buildings can truly impress users and encourage them to proactively install solar panels, thereby increasing the supply and utilization of green, clean, and independent, low-carbon energy systems. Black solar panels, due to their darker color, complement building roof tones, blending well with dark roofs, creating a more visually appealing and aesthetically pleasing product.

[0003] Currently, all-black modules on the market use black insulating strips to shield the solder ribbons between cells, and light-shielding strips to shield the busbars. However, using black insulating strips to shield the solder ribbons is a cumbersome process, which can lead to problems such as uneven cutting of the insulating strips and offset placement of the insulating strips, resulting in exposed modules and solder ribbons, which damages the overall black appearance of the module. In addition, in the existing technology, the busbars must be manually placed on the module and then welded to the module's solder ribbons, which is a cumbersome process and can easily cause hidden cracks in the cells and module short circuits. Some existing technologies also use black solder ribbons and black busbars to produce black modules, but black busbars and black solder ribbons are expensive, and the black coating on the solder ribbons and busbars is difficult to weld, posing a risk of cold solder joints.

[0004] Therefore, how to simplify the process, reduce the probability of hidden cracks in the battery cells, component short circuits and cold solder joints, and improve the yield of finished products while ensuring the overall black color of the component appearance is an urgent problem to be solved by technical personnel in this field. Utility Model Content

[0005] The purpose of the utility model is to provide a full black back contact photovoltaic module to solve the problems in the prior art that the overall black color of the module appearance is easily damaged, and the risks of hidden cracks in the battery cells, short circuits and cold solder joints are high, and the yield rate of the finished product is low.

[0006] In order to solve the above technical problems, the utility model provides a full black back contact photovoltaic module, comprising a plurality of solar cell strings, a first welding ribbon, an insulating strip and a busbar pre-assembled component;

[0007] The first soldering ribbon and the busbar pre-assembled component are both arranged on the backlight surface of the solar cell string;

[0008] The first welding ribbon connects two adjacent back contact cells on the same solar cell string in a first direction;

[0009] The insulating strip crosses the first welding strips corresponding to the plurality of solar cell strings along a second direction perpendicular to the first direction;

[0010] The busbar pre-assembly is an integrated conductive structure, comprising a busbar arranged along the second direction and a second welding strip arranged along the first direction;

[0011] The insulating strip is arranged between the busbar pre-assembly and the solar cell string.

[0012] Optionally, in the all-black back-contact photovoltaic module, the back-contact cells of the solar cell string are arranged with negative spacing.

[0013] Optionally, in the all-black back-contact photovoltaic module, the back-contact cell is a cell with a single side chamfered;

[0014] The chamfered edge of the upper cell of two adjacent back contact cells in the same solar cell string is superimposed on the cut edge of the lower cell.

[0015] Optionally, the all-black back-contact photovoltaic module further includes a carrier film;

[0016] The first soldering ribbon and / or the busbar pre-assembly are covered and fixed on the solar cell through the carrier film.

[0017] Optionally, in the all-black back-contact photovoltaic module, the carrier film is at least one of a pre-crosslinked POE film, a pre-crosslinked EVA film and a pre-crosslinked PVB film.

[0018] Optionally, in the all-black back-contact photovoltaic module, the insulating strip includes a substrate layer and adhesive film layers provided on two surfaces of the substrate layer perpendicular to the thickness direction.

[0019] Optionally, in the all-black back-contact photovoltaic module, the first welding ribbon is an integrated cut welding ribbon.

[0020] Optionally, in the all-black back-contact photovoltaic module, the busbar passes through the solar cell string in the second direction.

[0021] Optionally, in the all-black back-contact photovoltaic module, the insulating strip includes a plurality of openings;

[0022] The busbar pre-assembly is electrically connected to the fine grids of the solar cell string below the insulating strip through the opening.

[0023] Optionally, in the all-black back-contact photovoltaic module, projections of the plurality of openings on the short sides of the insulating strip completely cover the short sides of the insulating strip.

[0024] The all-black back-contact photovoltaic module provided by the present invention includes multiple solar cell strings, a first welding ribbon, an insulating strip and a busbar pre-assembly; the first welding ribbon and the busbar pre-assembly are both arranged on the backlight surface of the solar cell string; the first welding ribbon connects two adjacent back-contact solar cells on the same solar cell string in a first direction; the insulating strip crosses the first welding ribbons corresponding to the multiple solar cell strings along a second direction perpendicular to the first direction; the busbar pre-assembly is an integrated conductive structure, including a busbar arranged along the second direction and a second welding ribbon arranged along the first direction; the insulating strip is arranged between the busbar pre-assembly and the solar cell string.

[0025] In the present invention, since the grid lines of the back contact battery are concentrated on one side of the battery cell, the first welding strip and the second welding strip in the present invention can also be arranged on one side of the solar cell string, specifically towards the side of the back plate. In this way, the side of the solar cell string with the welding strip and the bus bar will be hidden on the back of the solar cell string, and will not be displayed on the light-receiving surface of the component. Therefore, even if there are problems such as uneven cutting of the insulating strip and offset placement of the insulating strip, the overall black color of the component appearance will not be destroyed. In addition, the present invention further combines the bus bar and the second welding strip into a bus pre-assembled part, that is, the bus bar and the second welding strip are welded into a whole in advance, and then directly set on the solar cell string during installation, which greatly reduces the number of welding times required for the solar cell string. While reducing the probability of hidden cracks in the battery cell and short circuit of the component, it also improves the welding quality and reduces the probability of cold welding. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions of the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0027] Figure 1 A specific embodiment of the all-black back-contact photovoltaic module provided by the present invention is a process structure diagram of laying the back-contact cell sheet on the front glass of the film to form the solar cell string;

[0028] Figure 2 A process structure diagram of a specific embodiment of the all-black back-contact photovoltaic module provided by the present invention after the first welding ribbon is arranged on the solar cell string and fixed with a carrier film;

[0029] Figure 3A process structure diagram of a specific embodiment of the all-black back-contact photovoltaic module provided by the present invention after the insulating strips are arranged between the solar cell strings;

[0030] FIG4 (a) and FIG4 (b) are schematic diagrams of the partial structure of the busbar pre-assembly of a specific embodiment of the all-black back-contact photovoltaic module provided by the present invention;

[0031] Figure 5 A schematic structural diagram of a full black back contact photovoltaic module provided by the present invention after the busbar pre-assembled component is arranged on the insulating strip in a specific embodiment;

[0032] Figure 6 A schematic structural diagram of the insulating strip of a specific embodiment of the all-black back-contact photovoltaic module provided by the present invention;

[0033] Figure 7 A schematic diagram of the partial structure of the contact area between the busbar pre-assembled component and the insulating strip in a specific embodiment of the full black back contact photovoltaic module provided by the present invention;

[0034] Figure 8 and Figure 9 A schematic structural diagram of an insulating strip of another specific embodiment of the all-black back-contact photovoltaic module provided by the present invention;

[0035] Figure 10 This is a partial circuit diagram of a specific implementation of the all-black back-contact photovoltaic module provided by the utility model.

[0036] In the figure, it includes 01-film-coated front glass, 02-fine grid, 10-solar cell string, 20-first welding strip, 30-insulating strip, 31-opening, 40-bus pre-assembled part, 41, 41a, 41b-bus bars, 42-second welding strip, and 50-carrier film. DETAILED DESCRIPTION

[0037] To help those skilled in the art better understand the present invention, the present invention is further described below in conjunction with the accompanying drawings and specific embodiments. Obviously, the embodiments described are only a portion of the present invention, not all of the embodiments. All other embodiments derived by those skilled in the art based on the embodiments of the present invention without inventive effort are also within the scope of protection of the present invention.

[0038] The core of the utility model is to provide a full black back contact photovoltaic module, a structural diagram of a specific embodiment of which is shown in FIG. Figures 1 to 5 As shown, it is called specific embodiment 1, which includes multiple solar cell strings 10, a first welding ribbon 20, an insulating strip 30 and a busbar pre-assembled component 40;

[0039] The first soldering ribbon 20 and the busbar pre-assembled component 40 are both disposed on the backlight surface of the solar cell string 10;

[0040] The first soldering ribbon 20 connects two adjacent back contact cells on the same solar cell string 10 in a first direction;

[0041] The insulating strip 30 crosses the first welding ribbons 20 corresponding to the plurality of solar cell strings 10 along a second direction perpendicular to the first direction;

[0042] The busbar pre-assembly 40 is an integrated conductive structure, including a busbar 41 arranged along the second direction and a second welding strip 42 arranged along the first direction;

[0043] The insulating strip 30 is disposed between the busbar pre-assembly 40 and the solar cell string 10 .

[0044] The first solder strip 20 extends in the first direction and includes the first solder strip 20 connecting the positive and negative electrodes of each back contact cell. The bus bars 41 at both ends of the solar cell string 10 are connected to the positive and negative electrodes of the solar cell string 10, respectively. Figure 5 For example, the component includes three bus bars 41 , and the middle bus bar 41 can be set as the positive bus bar 41 and the bus bars 41 at both ends can be set as the negative bus bars 41 , or the middle bus bar 41 can be set as the negative bus bar 41 and the bus bars 41 at both ends can be set as the positive bus bars 41 .

[0045] Figures 1 to 5 Schematic diagram of the process structure of each installation step of the all-black back contact photovoltaic module, wherein: Figure 1 For the front glass with film (the front glass with film is the glass facing the light with film laid on it, Figure 1 The back contact cell is laid on the solar cell string 10 to form the process structure diagram; Figure 2 This is a process structure diagram after the first soldering ribbon 20 is arranged on the solar cell string 10 and fixed with a carrier film 50; Figure 3 Figure 4 (a) and Figure 4 (b) are schematic diagrams of the partial structure of the busbar pre-assembly 40, wherein, since each solar cell string 10 is arranged in series along an S-shape (refer to the corresponding partial circuit diagram of the component Figure 10 ), so the busbars 41 in the reserved pre-assembled part 40 include busbars 41a at the starting point and the end point of the "S-shape" that only penetrate one solar cell string 10, and busbars 41b that penetrate two adjacent solar cell strings 10 at the "S-shaped" bend; Figure 5FIG. 4 is a schematic structural diagram of the insulating strip 30 after the busbar pre-assembly 40 is arranged on the insulating strip 30 .

[0046] Furthermore, the back contact cells of the solar cell string 10 are arranged in a negative pitch.

[0047] In this preferred embodiment, the back contact cell is arranged with a negative spacing, and the bus bar 41 is directly placed on the cell with the insulating strip 30, eliminating the tedious process of placing the insulating strip 30 between the traditional all-black component slices, manually placing the shading strip in the middle, and folding the bus bar 41 of the high-density packaged component. This solves the problems of low mass production yield, low production efficiency, and low component packaging density of high-density packaged all-black components.

[0048] Furthermore, the back contact cell is a cell with a single side chamfered;

[0049] The chamfered edge of the upper cell of two adjacent back contact cells in the same solar cell string 10 is superimposed on the cut edge of the lower cell.

[0050] Please refer to Figure 1 Adjacent back-contact cells in a negative spacing layout will inevitably have one cell partially overlapping the other. The cell on top of the stack is the upper cell, and the cell on the bottom of the stack is the lower cell. In this preferred embodiment, the two overlapping edges of two adjacent back-contact cells are defined as the chamfered edge on the top and the cut edge on the bottom. This minimizes the probability of edge chipping and cracking during the subsequent lamination process, thereby improving the yield rate of the finished product.

[0051] In addition, the all-black back contact photovoltaic module further includes a carrier film 50;

[0052] The first solder ribbon 20 and / or the busbar pre-assembly 40 are covered and fixed on the solar cell through the carrier film 50 .

[0053] After the first soldering ribbon 20 and / or the busbar pre-assembly 40 are arranged on the solar cell string 10, the carrier film 50 can be directly covered on the surface of the first soldering ribbon 20 and / or the busbar pre-assembly 40, and then the carrier film 50 is heated at a low temperature. The carrier film 50 will partially melt during the low-temperature heating, and the first soldering ribbon 20 and / or the busbar pre-assembly 40 will be fixedly connected to the solar cell string 10.

[0054] In a specific embodiment, the coating of the first solder ribbon 20 and / or the coating of the second solder ribbon 42 is at least one of a tin-lead-bismuth alloy solder layer and a tin-bismuth-silver alloy solder layer. These two solder layers have melting points lower than the low-temperature lamination temperature and can form a metallized connection with the back contact cell during the lamination process. After lamination, the soldering force must be ≥ 2.5 N / mm, improving the reliability of the connection between the solder ribbon and the cell surface, and enhancing the operating stability and service life of the module. Of course, other types of solder layers can also be used depending on actual circumstances, and this is not a limitation of the present invention.

[0055] Preferably, the carrier film 50 is at least one of a pre-crosslinked POE film, a pre-crosslinked EVA film, and a pre-crosslinked PVB film. Specifically, the pre-crosslinked POE film is a 45% pre-crosslinked POE film, the pre-crosslinked EVA film is a 48% pre-crosslinked EVA film, and the pre-crosslinked PVB film is a 46% pre-crosslinked PVB film. These three materials can be heated at low temperature (approximately 80 degrees Celsius) under the pressure of a press to secure the first solder ribbon 20 and the busbar pre-assembly 40 to the solar cell string 10.

[0056] Furthermore, the insulating strip 30 includes a base material layer and adhesive film layers provided on two surfaces of the base material layer perpendicular to the thickness direction.

[0057] The substrate layer ensures insulation, while the adhesive film layer prevents delamination of the busbars 41 disposed on the insulating strips 30 and also acts as a buffer, preventing the busbars 41 from crushing the back-contact cell during lamination. The insulating strips 30 are made of a flexible, flame-retardant, and highly reliable insulating material.

[0058] In addition, the first soldering ribbon 20 is an integrally cut soldering ribbon. The first soldering ribbon 20 extends through the solar cell string 10 in its length. Therefore, in this embodiment, the first soldering ribbon 20 is defined as an integrally cut soldering ribbon. This allows for gripping of the entire ribbon during installation, significantly reducing installation difficulty and improving positioning accuracy.

[0059] As a specific embodiment, a single bus bar 41 passes through a plurality of solar cell strings 10 in the second direction.

[0060] Please refer to Figure 2 A single bus bar 41 runs through all the solar cell strings 10, which facilitates the installation of the bus bar 41 and greatly reduces the internal resistance on the bus bar 41, reduces internal friction, and is conducive to further improving the power of the components.

[0061] Furthermore, the insulating strip 30 includes a plurality of openings 31;

[0062] The busbar pre-assembly 40 is electrically connected to the fine grids of the solar cell string 10 below the insulating strip 30 through the opening 31 .

[0063] In order to ensure that the current collected by the fine grid on the surface of the solar cell string 10 below the insulating strip 30 can also be conducted to the bus bar 41, the first welding ribbon 20 can be extended to below the insulating strip 30, and the first is electrically connected to the fine grid below the insulating strip 30 to conduct the current. However, doing so will greatly increase the thickness of the area where the insulating strip 30 is set, reduce the surface flatness of the cell string before the component is encapsulated, and reduce the yield rate of the finished component.

[0064] Therefore, in this preferred embodiment, an opening 31 is provided on the insulating strip 30, and the busbar pre-assembled component 40 directly contacts the fine grid of the corresponding polarity through the opening 31 ( Figure 7 02 in the figure), which prevents the current collected by the fine grid covered by the insulating strip 30 from being leaked, thereby improving the photoelectric conversion efficiency of the component. A schematic diagram of a specific embodiment of the insulating strip 30 can be referred to. Figure 6 Of course, the openings on the insulating strips 30 only need to expose the fine grids of the same polarity, and avoid exposing the fine grids of the opposite polarity and contacting the busbars to cause a short circuit.

[0065] Furthermore, projections of the plurality of openings 31 on the short sides of the insulating strip 30 completely cover the short sides of the insulating strip 30 .

[0066] Please refer to Figure 7 The projections of the multiple openings 31 on the short sides of the insulating strip 30 completely cover the short sides of the insulating strip 30, which means that all the fine grids located below the insulating strip 30 will be exposed by the openings 31, thereby further ensuring that the busbar pre-assembly 40 is electrically connected to all the fine grids covered by the insulating strip 30, further avoiding current leakage and improving the photoelectric conversion efficiency. Figure 8 , designed as a strip layer composed of multiple S-shaped units connected end to end, the S-shaped units open an opening 31 forward and backward along the first direction to achieve full coverage of the projection on the short side of the insulating strip 30, and can also refer to Figure 9 The insulating strip 30 is designed as a strip layer composed of multiple "string"-shaped units connected end to end, including a closed middle opening 31 and two side openings 31 facing the front and back. The middle opening 31 and the two side openings 31 are alternately arranged to achieve full coverage of the projection on the short side of the insulating strip 30.

[0067] The all-black back-contact photovoltaic module provided by the present invention includes multiple solar cell strings 10, a first welding ribbon 20, an insulating strip 30 and a busbar pre-assembly 40; the first welding ribbon 20 and the busbar pre-assembly 40 are both arranged on the backlight surface of the solar cell string 10; the first welding ribbon 20 connects two adjacent back-contact cells on the same solar cell string 10 in a first direction; the insulating strip 30 crosses the first welding ribbons 20 corresponding to the multiple solar cell strings 10 along a second direction perpendicular to the first direction; the busbar pre-assembly 40 is an integrated conductive structure, including a busbar 41 arranged along the second direction and a second welding ribbon 42 arranged along the first direction; the insulating strip 30 is arranged between the busbar pre-assembly 40 and the solar cell string 10. In the present invention, since the grid lines of the back contact battery are concentrated on one side of the battery cell, the first welding ribbon 20 and the second welding ribbon 42 in the present invention can also be arranged on one side of the solar cell string 10, specifically towards the side of the back plate. In this way, the side of the solar cell string 10 with the welding ribbon and the bus bar 41 will be hidden on the back of the solar cell string 10, and will not be displayed on the light-receiving surface of the component. Therefore, even if there are problems such as uneven cutting of the insulating strip 30 and offset placement of the insulating strip 30, the overall black color of the component appearance will not be destroyed. In addition, the present invention further combines the bus bar 41 and the second welding ribbon 42 into a bus pre-assembled part 40, that is, the bus bar 41 and the second welding ribbon 42 are welded into a whole in advance, and then directly set on the solar cell string 10 during installation, which greatly reduces the number of welding times required for the solar cell string 10. While reducing the probability of hidden cracks in the battery cell and short circuit of the component, it also improves the welding quality and reduces the probability of cold welding.

[0068] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from the other embodiments. Reference can be made to the descriptions of the identical or similar parts between the various embodiments. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple, and the relevant parts can be referred to the descriptions of the methods.

[0069] It should be noted that, in this specification, relational terms such as first and second, etc. are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprises", "comprising" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprising a ..." does not exclude the presence of other identical elements in the process, method, article or device comprising the element.

[0070] The above describes in detail the all-black back-contact photovoltaic module provided by the present invention. This article uses specific examples to illustrate the principles and implementation methods of the present invention. The description of the above examples is intended only to facilitate understanding of the method and core concept of the present invention. It should be noted that those skilled in the art may make various improvements and modifications to the present invention without departing from the principles of the present invention, and such improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. An all-black back-contact photovoltaic module, characterized in that: It includes a plurality of solar cell strings, a first welding ribbon, an insulating strip and a busbar pre-assembly; The first soldering ribbon and the busbar pre-assembled component are both arranged on the backlight surface of the solar cell string; The first welding ribbon connects two adjacent back contact cells on the same solar cell string in a first direction; The insulating strip crosses the first welding strips corresponding to the plurality of solar cell strings along a second direction perpendicular to the first direction; The busbar pre-assembly is an integrated conductive structure, comprising a busbar arranged along the second direction and a second welding strip arranged along the first direction; The insulating strip is arranged between the busbar pre-assembly and the solar cell string.

2. The all-black back contact photovoltaic module according to claim 1, characterized in that: The back contact cells of the solar cell string are arranged with a negative spacing.

3. The all-black back contact photovoltaic module according to claim 2, characterized in that: The back contact cell is a cell with a single side chamfered; The chamfered edge of the upper cell of two adjacent back contact cells in the same solar cell string is superimposed on the cut edge of the lower cell.

4. The all-black back-contact photovoltaic module according to claim 1, wherein: Also included is a carrier film; The first soldering ribbon and / or the busbar pre-assembly are covered and fixed on the solar cell through the carrier film.

5. The all-black back contact photovoltaic module according to claim 4, characterized in that: The carrier film is at least one of a pre-crosslinked POE film, a pre-crosslinked EVA film and a pre-crosslinked PVB film.

6. The all-black back contact photovoltaic module according to claim 1, wherein: The insulating strip includes a base material layer and adhesive film layers arranged on two surfaces of the base material layer perpendicular to the thickness direction.

7. The all-black back-contact photovoltaic module according to claim 1, wherein: The first welding ribbon is an integrated cut welding ribbon.

8. The all-black back-contact photovoltaic module according to claim 1, wherein: The bus bar passes through the solar cell string in the second direction.

9. The all-black back-contact photovoltaic module according to any one of claims 1 to 8, characterized in that: The insulating strip includes a plurality of openings; The busbar pre-assembly is electrically connected to the fine grids of the solar cell string below the insulating strip through the opening.

10. The all-black back contact photovoltaic module according to claim 9, characterized in that: Projections of the plurality of openings on the short sides of the insulating strip completely cover the short sides of the insulating strip.

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