Photovoltaic module and photovoltaic system

Abstract

The utility model provides a kind of photovoltaic module and photovoltaic system, it is related to photovoltaic technical field, can promote the welding tension between welding point position and welding band, promote welding effect. Photovoltaic module includes: photovoltaic cell piece, at least one welding point position is provided on photovoltaic cell piece;Welding band, welding band is connected with welding point position by the tin paste after melting;After welding point position and welding band are separated, the welding area of the tin paste after melting between welding point position and welding band has multiple tension fracture holes, the number of multiple tension fracture holes is greater than or equal to 6, tension fracture hole is the hole formed by welding band or welding point position and the tin paste after melting are separated, and tension fracture hole is the hole with diameter greater than 3um.

Description

Technical Field

[0001] This utility model relates to the field of welding technology, and in particular to photovoltaic modules and photovoltaic systems. Background Technology

[0002] During the production of photovoltaic modules, molten solder paste is used to weld the solder points on the photovoltaic cells to the solder ribbon.

[0003] In some cases, insufficient welding tension between the welding point and the welding strip makes it easy for the welding point and the welding strip to separate, resulting in insufficient welding effect. Summary of the Invention

[0004] This invention provides a photovoltaic module and a photovoltaic system that can increase the welding pull between the welding point and the welding strip, thereby improving the welding effect.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] In a first aspect, a photovoltaic module is provided, comprising: a photovoltaic cell having at least one soldering point; a solder ribbon connected to the soldering point via molten solder paste; after the soldering point separates from the solder ribbon, the soldering area of ​​the molten solder paste between the soldering point and the solder ribbon has multiple tensile fracture holes, the number of multiple tensile fracture holes being greater than or equal to 6, the tensile fracture holes being holes formed by the separation of the solder ribbon or soldering point from the molten solder paste, and the tensile fracture holes having a diameter greater than 3 μm.

[0007] Based on this scheme, the photovoltaic module of this utility model includes: a photovoltaic cell, on which at least one welding point is provided; a solder ribbon, which is connected to the welding point by molten solder paste. After the welding point separates from the solder ribbon, the welding area of ​​the molten solder paste between the welding point and the solder ribbon has multiple tensile fracture holes formed by the separation of the solder ribbon or welding point from the molten solder paste. The number of multiple tensile fracture holes is greater than or equal to 6, and the tensile fracture holes are holes with a diameter greater than 3 μm. Because there are many tensile fracture holes in the welding area of ​​the molten solder paste, the welding tensile force between the welding point and the solder ribbon is large, thereby improving the welding tensile force between the welding point and the solder ribbon and improving the welding effect.

[0008] In conjunction with the first aspect, in some embodiments of the first aspect, the roughness of the target area of ​​the welding region is less than or equal to 100 μm, the target area does not include tensile fracture holes, and the roughness of the target area is the sum of the diameters of non-tensile fracture holes within a rectangular area of ​​100 μm × 100 μm, wherein the non-tensile fracture holes are holes with a diameter of less than 3 μm.

[0009] In conjunction with the first aspect, in some embodiments of the first aspect, along the direction from the photovoltaic cell to the solder strip, starting from the plane of the molten solder paste that contacts the solder strip, the height of at least one edge region of the molten solder paste is 3mm-10mm, and the edge region is adjacent to the soldering area.

[0010] In conjunction with the first aspect, in some embodiments of the first aspect, the height of at least one edge region of the melted solder paste is 3mm-5mm.

[0011] In conjunction with the first aspect, in some embodiments of the first aspect, the welding pull force between at least one welding point and the welding strip is 4N-15N.

[0012] In conjunction with the first aspect, in some embodiments of the first aspect, the welding pull between the welding point and the welding strip is 5N-8N.

[0013] In conjunction with the first aspect, in some embodiments of the first aspect, the solder paste before melting includes conductive particles, the conductive particles being 5%-30% by mass, and the conductive particles including at least copper.

[0014] In conjunction with the first aspect, in some embodiments of the first aspect, the conductive particles further include at least one of aluminum, iron, nickel, or cobalt.

[0015] In conjunction with the first aspect, in some embodiments of the first aspect, after the solder paste melts before melting, the conductive particles form a columnar support structure or a mesh support structure.

[0016] In conjunction with the first aspect, in some embodiments of the first aspect, the mass percentage of the conductive particles is 5%-20%.

[0017] In conjunction with the first aspect, in some embodiments of the first aspect, the diameter of the conductive particles is 20 μm to 50 μm.

[0018] Secondly, a photovoltaic system is provided, which includes the photovoltaic modules provided in the second aspect above.

[0019] The technical effects brought about by the second aspect can be referred to the technical effects brought about by the different implementation methods of the first aspect mentioned above, and will not be repeated here. Attached Figure Description

[0020] Figure 1 A schematic diagram of the structure of a photovoltaic module provided by this utility model;

[0021] Figure 2 This utility model provides a schematic diagram of the welding point after separation from the welding strip;

[0022] Figure 3A microscopic image of the welding point after separation from the welding strip, provided by this utility model;

[0023] Figure 4 This is a schematic diagram illustrating the state changes of solder paste provided by this utility model. Detailed Implementation

[0024] In this embodiment of the invention, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design described as "exemplary" or "for example" in this embodiment of the invention should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of terms such as "exemplary" or "for example" is intended to present the relevant concepts in a specific manner to facilitate understanding.

[0025] It is understood that the term "embodiment" used throughout the specification means that a specific feature, structure, or characteristic related to an embodiment is included in at least one embodiment of the present invention. Therefore, the various embodiments throughout the specification do not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. It is understood that in the various embodiments of the present invention, the sequence number of each process does not imply the order of execution; the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0026] It is understood that in this utility model, "when," "if," and "if" all refer to the corresponding processing that will be carried out under certain objective circumstances, and are not limited to a specific time, nor do they require a judgment action to be performed, nor do they imply any other limitations.

[0027] It is understood that some optional features in the embodiments of this utility model can be implemented independently in certain scenarios without relying on other features, such as the current solution on which they are based, to solve the corresponding technical problems and achieve the corresponding effects. Alternatively, they can be combined with other features as needed in certain scenarios. Correspondingly, the device given in the embodiments of this utility model can also implement these features or functions, which will not be elaborated here.

[0028] In this utility model, unless otherwise specified, the same or similar parts between the various embodiments can be referred to each other. In the various embodiments and implementation methods of this utility model, unless otherwise specified or logically conflicting, the terminology and / or descriptions between different embodiments and between the implementation methods of different embodiments are consistent and can be mutually referenced. The technical features in different embodiments and between the implementation methods of different embodiments can be combined according to their inherent logical relationships to form new embodiments, implementation methods, implementation methods, or implementation approaches. The following embodiments of this utility model do not constitute a limitation on the scope of protection of this utility model.

[0029] During the production of photovoltaic modules, molten solder paste is used to weld the solder points on the photovoltaic cells to the solder ribbon.

[0030] In some cases, insufficient welding tension between the welding point and the welding strip makes it easy for the welding point and the welding strip to separate, resulting in insufficient welding effect.

[0031] To address the aforementioned problems, this utility model provides a photovoltaic module. Figure 1 A schematic diagram of the structure of a photovoltaic module provided by this utility model is shown below. Figure 1 As shown, the photovoltaic module 10 includes: a photovoltaic cell 101, on which at least one soldering point 1011 is provided; and a solder ribbon 102, which is connected to the soldering point 1011 by molten solder paste 103.

[0032] After the welding point 1011 separates from the welding strip 102, Figure 2 This is a schematic diagram showing the separation of the welding point 1011 from the welding strip 102 provided by this utility model. Figure 3 A microscopic image of the welding point 1011 after separation from the welding strip 102 provided by this utility model, as shown below. Figure 2 or Figure 3 As shown, the soldering area 1031 of the molten solder paste 103 between the soldering point 1011 and the solder strip 102 has multiple tensile fracture holes 1034. The number of multiple tensile fracture holes 1034 is greater than or equal to 6. The tensile fracture holes 1034 are holes formed by the separation of the solder strip 102 or the soldering point 1011 from the molten solder paste 103. The tensile fracture holes 1034 are holes with a diameter greater than 3 μm.

[0033] The photovoltaic cell 101 can be an OBB back contact cell. Of course, the photovoltaic cell 101 can also be other types of cells. This utility model does not impose specific limitations on this.

[0034] Since the orthographic projection of a hole is usually irregular, the diameter of the hole can be defined as the diameter of the largest circumcircle of the orthographic projection of the hole. This will be explained here and will not be repeated later.

[0035] Based on this scheme, the photovoltaic module 10 of this utility model includes: a photovoltaic cell 101, on which at least one soldering point 1011 is provided; a solder ribbon 102, which is connected to the soldering point 1011 by molten solder paste 103. After the soldering point 1011 is separated from the solder ribbon 102, the soldering area 1031 of the molten solder paste 103 between the soldering point 1011 and the solder ribbon 102 has multiple solder ribbons 102 or soldering points 1011 and The molten solder paste 103 separates to form tensile fracture holes 1034. The number of tensile fracture holes 1034 is greater than or equal to 6. The tensile fracture holes 1034 are holes with a diameter greater than 3 μm. Since there are a large number of tensile fracture holes 1034 in the soldering area 1031 of the molten solder paste 103, the welding pull between the soldering point 1011 and the solder strip 102 is large, which can improve the welding pull between the soldering point 1011 and the solder strip 102 and improve the welding effect.

[0036] After the soldering point 1011 is connected to the solder ribbon 102 by the melted solder paste 103, the plane in contact between the melted solder paste 103 and the soldering point 1011 or the solder ribbon 102 can be called the soldering area 1031. Since the melted solder paste 103 has a certain fluidity after being heated and melted, after applying soldering pressure to the solder ribbon 102, some of the melted solder paste 103 will overflow the soldering area 1031 and form an edge area 1032 adjacent to the soldering area 1031 along the direction from the photovoltaic cell 101 to the solder ribbon 102.

[0037] like Figure 1As shown, starting from the plane where the melted solder paste 103 contacts the solder ribbon 102, the height d1 of at least one edge region 1032 of the melted solder paste 103 is 3mm-10mm. Thus, starting from the plane where the melted solder paste 103 contacts the solder ribbon 102, since the height of at least one edge region 1032 of the melted solder paste 103 is 3mm-10mm, compared to the height of the edge region 1032 formed by connecting the photovoltaic cell 101 with the solder ribbon 102 using existing methods, the height of the edge region 1032 of the melted solder paste 103 provided by this invention is higher. This allows the melted solder paste 103 to have a larger contact area with the side of the solder ribbon 102, further increasing the tension of the solder ribbon 102 between the solder ribbon 102 and the soldering point 1011 of the cell. Preferably, the height of at least one edge region 1032 of the melted solder paste 103 is 3mm-5mm, for example, the height of at least one edge region 1032 of the melted solder paste 103 is 3mm, 4mm, or 5mm.

[0038] After the solder joint 1011 is connected to the solder ribbon 102 via molten solder paste 103, the tensile strength of the solder ribbon 102 between the solder joint 1011 and the solder ribbon 102 can be tested to determine the strength of the solder joint. Specifically, firstly, the tensile strength of the solder ribbon 102 is tested correctly using a horizontal tensile testing machine according to the operating specifications. Then, after each tensile strength test, the tensile strength is recorded. Based on multiple tensile strengths and the following relationship, the tensile strength of the solder ribbon 102 between the solder ribbon 102 and the solar cell is determined:

[0039]

[0040] Wherein, FA represents the tensile force of the solder strip 102 between the solder strip 102 and the welding point 1011 of the battery cell, n represents the sequence number of the tensile force test of the solder strip 102, and Fi represents the tensile force recorded in the i-th tensile force test of the solder strip 102.

[0041] After the solder joint 1011 is connected to the solder ribbon 102 by the melted solder paste 103, after testing, the tensile force of the solder ribbon 102 between at least one solder joint 1011 and the solder ribbon 102 is 4N-15N. Preferably, the tensile force of the solder ribbon 102 between the solder joint 1011 and the solder ribbon 102 is 5N-8N. For example, the tensile force of the solder ribbon 102 between the solder joint 1011 and the solder ribbon 102 is 5N, 6N, 7N, or 8N.

[0042] In some embodiments, the target area 1033 of the welding area 1031 includes non-tensile fracture holes 1034, but does not include tensile fracture holes 1034. A non-tensile fracture hole 1034 refers to a hole with a diameter less than 3 μm. The roughness of the target area 1033 is the sum of the diameters of the non-tensile fracture holes 1034 within an area of ​​100 μm × 100 μm. The roughness of the target area 1033 is less than or equal to 100 μm; for example, the roughness of the target area 1033 may be 100 μm, 90 μm, 80 μm, or 70 μm. This invention does not impose specific limitations in this regard. Thus, since the roughness of the target area 1033 of the welding area 1031 is less than or equal to 100 μm, compared with the roughness of the target area 1033 of the welding area 1031 formed by connecting the photovoltaic cell 101 with the solder ribbon 102 through the existing melted solder paste 103, the roughness of the target area 1033 of the welding area 1031 of the melted solder paste 103 provided by this utility model is lower, and the welding area 1031 can have a larger contact area with the solder ribbon 102, further increasing the solder ribbon 102 tension between the solder ribbon 102 and the welding point 1011 of the cell.

[0043] In addition to tin-based solder, the solder paste 103 before melting may also include conductive particles, with a mass percentage of 5%-30%, and the conductive particles include at least copper.

[0044] Preferably, the mass percentage of conductive particles is 5%-20%. For example, the mass percentage of conductive particles is 5%, 10%, 15%, or 20%.

[0045] The conductive particles have a diameter of 20µm to 50µm, which increases the bonding stability between them. Preferably, the conductive particles have a diameter of 30µm to 40µm. For example, the conductive particles have a diameter of 30µm, 35µm, or 40µm.

[0046] Optionally, the conductive particles may also include at least one of aluminum, iron, nickel, or cobalt.

[0047] At this point, the mass percentage of copper in the conductive particles is 60%-80%. For example, if the conductive particles also include aluminum, the conductive particles may include 80% copper and 20% aluminum; if the conductive particles also include iron and cobalt, the conductive particles may include 80% copper, 10% cobalt, and 10% iron.

[0048] It should be noted that the mass percentage of conductive particles refers to the mass percentage of solder paste 103 before it has been melted and soldered.

[0049] After the solder paste 103 melts, the conductive particles form a columnar or mesh-like support structure. In this way, the molten tin-based solder can adhere to the support structure formed by the conductive particles, thereby reducing the height of the solder paste 103 that drops due to melting and increasing the welding pull between the solder joint 1011 and the solder ribbon 102, thus improving the welding effect. Figure 4 A schematic diagram illustrating the state changes of solder paste 103 provided by this utility model, as shown below. Figure 4 As shown in Figure a, before the solder paste 103 melts, the distribution of conductive particles in the solder paste 103 before melting is consistent, that is, the conductive particles are evenly distributed in the solder paste 103 before melting. Figure 4 As shown in b, after the solder paste 103 melts, the conductive particles form a mesh support structure, and the solder beads formed by the melting of the tin-based solder adhere to the support structure to maintain the same height before and after melting.

[0050] The photovoltaic module 10 may also include a metal frame, a backsheet, photovoltaic glass, and an encapsulating film. The encapsulating film can be filled between the front and back of the photovoltaic cells 101, the photovoltaic glass, and adjacent photovoltaic cells 101. As a filler, it can be a transparent colloid with good light transmission and aging resistance. For example, the encapsulating film can be EVA film or POE film. The specific choice can be made according to the actual situation and is not limited here.

[0051] Photovoltaic glass can be applied to the encapsulant film on the front side of the photovoltaic cell 101. The photovoltaic glass can be ultra-clear glass, which has high light transmittance, high transparency, and superior physical, mechanical, and optical properties. For example, the light transmittance of ultra-clear glass can reach over 9%. It can protect the photovoltaic cell 101 while minimizing impact on its efficiency. Simultaneously, the encapsulant film bonds the photovoltaic glass and the photovoltaic cell 101 together, providing sealing, insulation, waterproofing, and moisture protection for the photovoltaic cell 101.

[0052] The backsheet can be attached to the adhesive film on the back of the photovoltaic cell 101. The backsheet protects and supports the photovoltaic cell 101, and has reliable insulation, water resistance, and aging resistance. Multiple options are available for the backsheet, typically tempered glass, acrylic glass, aluminum alloy TPT composite adhesive film, etc., and the specific choice depends on the specific circumstances and is not limited here. The backsheet, photovoltaic cell 101, adhesive film, and photovoltaic glass together can be mounted on a metal frame. The metal frame serves as the main external support structure for the entire photovoltaic module 10, providing stable support and installation for the photovoltaic module 10. For example, the photovoltaic module 10 can be installed at the desired location using the metal frame.

[0053] This utility model embodiment provides a photovoltaic system, including the photovoltaic module 10 described above.

[0054] In this embodiment, the photovoltaic system can be applied in photovoltaic power plants, such as ground-mounted power plants, rooftop power plants, and floating power plants. It can also be applied to equipment or devices that utilize solar energy to generate electricity, such as user solar power supplies, solar streetlights, solar cars, and solar buildings. Of course, it is understood that the application scenarios of the photovoltaic system are not limited to these; that is, the photovoltaic system can be applied in all fields that require solar energy to generate electricity. Taking a photovoltaic power generation system network as an example, the photovoltaic system may include a photovoltaic array, a combiner box, and an inverter. The photovoltaic array may be an array combination of multiple photovoltaic modules 10. For example, multiple photovoltaic modules 10 can form multiple photovoltaic arrays. The photovoltaic array is connected to the combiner box, which can collect the current generated by the photovoltaic array. The collected current flows through the inverter and is converted into AC power required by the mains power grid before being connected to the mains power grid to achieve solar power supply.

[0055] Although the present invention has been described herein in conjunction with various embodiments, those skilled in the art will understand and implement other variations of the disclosed embodiments by reviewing the accompanying drawings, the disclosure, and the appended claims in carrying out the claimed invention. In the claims, the word "comprising" does not exclude other components or steps, and "a" or "an" does not exclude a plurality. A single processor or other unit can implement several functions listed in the claims. While different dependent claims may recite certain measures, this does not mean that these measures cannot be combined to produce good results.

[0056] Although the present invention has been described in conjunction with specific features and embodiments, it is obvious that various modifications and combinations can be made thereto without departing from the spirit and scope of the present invention. Accordingly, this specification and drawings are merely exemplary descriptions of the present invention as defined by the appended claims, and are considered to cover any and all modifications, variations, combinations, or equivalents within the scope of the present invention. Clearly, those skilled in the art can make various alterations and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such modifications and modifications of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and modifications.

Claims

1. A photovoltaic module, characterized in that, The photovoltaic module includes: A photovoltaic cell, wherein at least one welding point is provided on the photovoltaic cell; Solder strip, wherein the solder strip is connected to the soldering point by molten solder paste; After the soldering point separates from the solder strip, the soldering area of ​​the molten solder paste between the soldering point and the solder strip has multiple tensile fracture holes. The number of the multiple tensile fracture holes is greater than or equal to 6. The tensile fracture holes are holes formed by the separation of the solder strip or soldering point from the molten solder paste. The tensile fracture holes are holes with a diameter greater than 3 μm.

2. The photovoltaic module according to claim 1, characterized in that, The roughness of the target area of ​​the welding region is less than or equal to 100 μm. The target area does not include the tensile fracture hole. The roughness of the target area is the sum of the diameters of the non-tensile fracture holes within a rectangular area of ​​100 μm × 100 μm. The non-tensile fracture hole is a hole with a diameter of less than 3 μm.

3. The photovoltaic module according to claim 1, characterized in that, Along the direction from the photovoltaic cell to the solder strip, starting from the plane of the molten solder paste that contacts the solder strip, the height of at least one edge region of the molten solder paste is 3mm-10mm, and the edge region is adjacent to the soldering area.

4. The photovoltaic module according to claim 3, characterized in that, The height of at least one edge region of the melted solder paste is 3mm-5mm.

5. The photovoltaic module according to claim 1, characterized in that, The welding pull between at least one welding point and the welding strip is 4N-15N.

6. The photovoltaic module according to claim 5, characterized in that, The welding tension between the welding point and the welding strip is 5N-8N.

7. The photovoltaic module according to any one of claims 1-6, characterized in that, The solder paste before melting contains conductive particles, which account for 5%-30% by mass, and the conductive particles include at least copper.

8. The photovoltaic module according to claim 7, characterized in that, The conductive particles also include at least one of aluminum, iron, nickel, or cobalt.

9. The photovoltaic module according to claim 7, characterized in that, After the solder paste melts, the conductive particles form a columnar support structure or a mesh support structure.

10. The photovoltaic module according to claim 7, characterized in that, The mass percentage of the conductive particles is 5%-20%.

11. The photovoltaic module according to claim 7, characterized in that, The diameter of the conductive particles is 20µm to 50µm.

12. A photovoltaic system, characterized in that, The photovoltaic system includes the photovoltaic module according to any one of claims 1-11.

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