Reflective film and solar panel

Abstract

This utility model discloses a reflective film and a solar panel, relating to the field of solar photovoltaic power generation technology. The reflective film includes: an adhesive film layer; a microstructure layer disposed on the adhesive film layer; and a reflective layer disposed on the microstructure layer. The reflective layer, the microstructure layer, and the adhesive film layer are sequentially arranged from top to bottom to form a thin-structured reflective film. This utility model solves the problem that traditional reflective films use a multi-layer structure, resulting in a thicker reflective film product, which is not conducive to assembly in smaller gaps, and the multi-layer bonding structure also causes light energy attenuation.

Description

Technical Field

[0001] This utility model relates to the field of solar photovoltaic power generation technology, and in particular to a reflective film and a solar panel. Background Technology

[0002] Solar photovoltaic (PV) power generation is an important form of utilizing solar energy, which can reduce dependence on and consumption of non-renewable fossil fuels and reduce environmental pollution. Currently, solar power generation modules based on the photovoltaic principle are relatively mature. Conventional solar modules mainly consist of an encapsulating layer, a cell array, a backsheet, and glass. A single cell is insufficient to power the module; they must be connected in series via solder strips to conduct current and achieve power output. However, the presence of the solder strips prevents some sunlight from being absorbed and utilized by the cells, resulting in wasted light energy. To improve the photoelectric conversion efficiency of solar modules, existing technologies utilize the previously wasted sunlight by attaching reflective films to the solder strips.

[0003] Traditional reflective films typically consist of an aluminum layer, a prism-shaped microstructure layer, a PET film layer, and an EVA adhesive layer. The prism structure provides the appropriate reflection angle, the aluminum layer provides the reflective function, the substrate provides the mechanical strength such as load-bearing capacity and rigidity, and the EVA adhesive provides adhesion for easy application. This multi-layered structure results in a relatively thick reflective film product, which is not conducive to assembly in smaller gaps, and the multi-layered bonding structure also causes light energy attenuation. Currently, no effective solution has been proposed to address these problems. Utility Model Content

[0004] Purpose of the utility model: To provide a reflective film and a solar panel to at least solve one of the problems existing in the prior art.

[0005] Technical solution: A reflective film, comprising: Adhesive film layer; A microstructure layer is disposed on the adhesive film layer; and A reflective layer is disposed on the microstructure layer; The reflective layer, the microstructure layer, and the adhesive film layer are arranged sequentially from top to bottom to form a thin reflective film.

[0006] Preferably, the adhesive film layer is a TPU adhesive film layer or an SCA hot melt adhesive film layer.

[0007] Preferably, the thickness of the adhesive film layer is 10-80 μm.

[0008] Preferably, the microstructure layer is a series of triangular cross-sections arranged in an orderly array, and the microstructure layer is cured and molded by UV-cured acrylic adhesive.

[0009] Preferably, the vertex angle of the triangle is 30-160° and its height is 5-30 μm.

[0010] Preferably, the microstructure layer is formed by one or more of the following methods: nanoimprinting, laser processing, microstructure roll transfer, mold forming, 3D printing, or hot pressing.

[0011] Preferably, the reflective layer is a metal coating, which is either aluminum or silver.

[0012] Preferably, the thickness of the reflective layer is 10nm-500nm.

[0013] Preferably, the reflective layer is deposited to a micro-nano thickness using one or more of magnetron sputtering, vacuum evaporation, chemical vapor deposition, or electroplating.

[0014] To achieve the above objectives, according to another aspect of this application, a solar panel is also provided.

[0015] The solar panel according to this application includes the aforementioned reflective film; It also includes: a back sheet and photovoltaic glass, wherein the adhesive layer of the reflective film is directly pasted on the back sheet, and the photovoltaic glass covers the reflective film.

[0016] Beneficial Effects: In this embodiment, an optimized interlayer structure is adopted. The reflective layer, the microstructure layer, and the adhesive film layer are sequentially arranged from top to bottom to form a thin reflective film. This achieves the goal of significantly reducing the overall thickness of the reflective film product, thereby realizing the technical effects of reducing product thickness and improving optical performance. This solves the problem that traditional reflective films are usually composed of an aluminum layer, a prism-type microstructure layer, a PET film layer, and an EVA adhesive film layer. The prism structure provides an appropriate reflection angle, the aluminum layer provides the reflection function, the substrate provides the mechanical strength such as load-bearing capacity and stiffness of the reflective film, and the EVA adhesive film provides adhesion for easy attachment. Such a multi-layer structure results in a high thickness of the reflective film product, which is not conducive to the assembly of smaller gaps. In addition, the multi-layer attachment structure also causes the technical problem of light energy attenuation. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the planar structure of the reflective film of this utility model.

[0018] The attached figures are labeled as follows: 10. Adhesive film layer; 20. Microstructure layer; 30. Reflective layer. Detailed Implementation

[0019] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0020] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0021] Furthermore, the terms "installation," "setup," "equipped with," "connection," "linking," and "socketing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this utility model based on the specific circumstances.

[0022] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0023] like Figure 1 As shown, this application relates to a reflective film and a solar panel. The reflective film includes an adhesive film layer 10; it enables direct adhesion, thereby reducing product thickness and enhancing structural stability and protection.

[0024] A microstructure layer 20 is disposed on the adhesive film layer 10; it can control the light propagation path and achieve directional reflection. By adjusting the reflection angle, light can be precisely and directionally reflected to the photovoltaic module, improving energy capture under morning / evening or diffused light conditions.

[0025] A reflective layer 30 is disposed on the microstructure layer 20; it directly reflects incident light and is the core optical medium; the reflective layer 30 achieves high reflectivity through specular reflection.

[0026] The reflective layer 30, the microstructure layer 20, and the adhesive film layer 10 are sequentially arranged from top to bottom to form a thin reflective film. This achieves good product forming results, significantly reduces product thickness, and is easy to implement and operate.

[0027] Specifically, this application addresses the issue that existing reflective film products all have a PET substrate layer with a thickness of 20-38µm, a prism microstructure on the front, and a 70-80µm thick EVA back-coated adhesive layer, resulting in a total thickness of 100-150µm. The novel thin-film gap reflective film product proposed in this invention uses a hot-melt or hot-press adhesive film with good film-forming properties and mechanical strength as the substrate. Its adhesive layer thickness is 10-80µm, which can replace the original combination of PET substrate and EVA adhesive layer in reflective film design. It has a thinner base layer than traditional gap film products, thereby significantly reducing the overall thickness of the gap reflective film product to 20-90µm.

[0028] With the overall thickness reduced, more space can be allocated to the reflective microstructure layer 20, making the microstructure larger and increasing the effective area of ​​the reflective layer 30 to further increase the reflective efficiency.

[0029] This application describes the preparation of a substrate-free solar reflective film product. A triangular microstructure is directly transferred onto the surface of a hot melt adhesive film or a thermoplastic optical adhesive film, and then a thin aluminum or silver metal layer is deposited, which can produce an ultra-thin novel solar reflective film product.

[0030] Of course, the structure of this application can also be configured on both sides according to usage requirements.

[0031] As can be seen from the above description, this application achieves the following technical effects: In this embodiment, an optimized interlayer structure is adopted. The reflective layer 30, the microstructure layer 20, and the adhesive film layer 10 are sequentially arranged from top to bottom to form a thin reflective film. This achieves the goal of significantly reducing the overall thickness of the reflective film product, thereby realizing the technical effects of reducing product thickness and improving optical performance. This solves the problem that traditional reflective films are usually composed of an aluminum layer, a prism-type microstructure layer 20, a PET film layer, and an EVA adhesive film layer 10. The prism structure provides an appropriate reflection angle, the aluminum layer provides the reflection function, the substrate provides the mechanical strength such as load-bearing capacity and stiffness of the reflective film, and the EVA adhesive film provides adhesion for easy attachment. Such a multi-layer structure results in a high thickness of the reflective film product, which is not conducive to the assembly of smaller gaps. In addition, the multi-layer attachment structure also causes the technical problem of light energy attenuation.

[0032] Furthermore, the adhesive film layer 10 is a TPU adhesive film layer 10 or an SCA hot melt adhesive film layer 10. It is understood that TPU adhesive film refers to thermoplastic polyurethane, which has a high elastic modulus (Shore hardness 70A-95A) and low-temperature resistance; it has a highly elastic buffer microstructure layer 20 to prevent the reflective layer 30 from cracking (especially in curved surface bonding scenarios), while also having a light transmittance greater than 90%, avoiding light scattering and loss in the adhesive layer.

[0033] SCA hot melt adhesive film layer 10 has rapid thermal activation characteristics, with a hot melt bonding speed of ≤3 seconds (TPU requires 5-10 seconds), improving production line efficiency. Therefore, both of the above-mentioned adhesive film layers 10 have good adhesion, thereby ensuring good bonding effect.

[0034] Furthermore, the thickness of the adhesive film layer 10 is 10-80 μm. It is understood that by employing processes including but not limited to precision coating or casting to control the thickness tolerance of ±2 μm, good optical performance can be ensured, while also achieving good processing efficiency.

[0035] Specifically, when the thickness of the adhesive film layer 10 is 10-30μm, the ultra-thin design reduces optical path loss (light penetration loss through the adhesive layer <3%) and increases brightness by 15%. When the thickness of the adhesive film layer 10 is 30-60μm, the bonding strength and flexibility are balanced (peel force ≥8N / cm). When the thickness of the film layer 10 is 60-80μm, the thickened buffer layer protects the microstructure from impact.

[0036] It is important to know that the aforementioned ranges all exhibit good adhesion, thereby ensuring the stability of the structure.

[0037] Furthermore, the microstructure layer 20 is an ordered array of several triangular cross-section structures, and the microstructure layer 20 is cured and molded with UV-cured acrylic adhesive. It can be understood that the microstructure layer 20 is an array structure formed by tiny structures with triangular cross-sections arranged according to a certain pattern. The arrangement is usually periodic and repeating, which helps to achieve specific optical or mechanical properties (such as enhanced reflectivity, anti-adhesion, or light and heat conduction).

[0038] The microstructure is manufactured using UV-cured acrylic adhesive, which is a photosensitive resin that rapidly polymerizes and cures under ultraviolet (UV) light. It offers advantages such as high processing efficiency, high forming precision, and high transparency.

[0039] Therefore, the microstructure layer 20 has a stable structural morphology and good mechanical strength, and can be manufactured quickly, making it suitable for batch processes.

[0040] Furthermore, the microstructure layer 20 can be a regular prism structure or an irregular prism structure. This can meet the needs of various application scenarios, thereby achieving a flexible application effect.

[0041] Furthermore, the apex angle of the triangle is 30-160°, and its height is 5-30 μm. It is understood that the apex angle (i.e., included angle) of each triangular pyramid or wedge in the microstructure is limited to between 30-160 degrees. Angles within this range can achieve a balance between optical performance (such as reflection, refraction, and scattering) and manufacturing difficulty; simultaneously, its height of 5-30 μm effectively allows for optical interference with visible or near-infrared light or enhances reflection. Preferably, the apex angle of the triangle is 120°.

[0042] Therefore, the design parameters of the triangular structure have been optimized to enhance the reflection effect and improve the efficiency of light utilization, while also taking into account the feasibility of manufacturing.

[0043] Furthermore, the microstructure layer 20 is fabricated using one or more of the following methods: nanoimprinting, laser processing, microstructure roll transfer, mold forming, 3D printing, or hot pressing. It is understood that nanoimprinting utilizes a mold to transfer patterns onto the material surface at the micro- and nano-scale, making it suitable for large-scale manufacturing.

[0044] Laser processing uses a laser beam to achieve high-precision etching or ablation of microstructures.

[0045] Microstructure roller transfer printing involves creating a structural pattern on the surface of a roller and then transferring it to an adhesive layer through a rolling motion.

[0046] Mold forming is a traditional thermoplastic material processing method, suitable for high replication precision.

[0047] 3D printing is suitable for prototyping or manufacturing small batches of complex structures.

[0048] Hot pressing refers to shaping a structure under heat and pressure.

[0049] Therefore, the microstructure layer 20 can be prepared using a variety of mature micro-nano fabrication technologies, possessing both technological diversity and mass production feasibility.

[0050] Furthermore, the reflective layer 30 is a metal coating, which is either aluminum or silver. It is understood that the reflective layer 30 is a key functional layer of the entire film, and a metal coating is used to enhance light reflection. Preferably, the metal coating is an aluminum layer.

[0051] Aluminum: It has good reflectivity, low cost, and mature technology.

[0052] Silver: It has extremely high reflectivity, especially in the visible and infrared regions where it performs exceptionally well.

[0053] Therefore, using aluminum or silver as the reflective layer 30 material can effectively improve the reflectivity of the film layer, thereby improving the photoelectric conversion efficiency of the solar panel.

[0054] Furthermore, the thickness of the reflective layer 30 is 10nm-500nm. It is understood that this thickness range falls within the nanoscale coating, which can form an effective light-reflecting interface without affecting the overall flexibility or transparency of the film (depending on the specific design). Preferably, the thickness of the reflective layer 30 is 90nm.

[0055] A lower limit of 10nm can ensure the formation of a continuous film, while 500nm is the upper limit for most metal reflective layers. Exceeding this limit will cause stress cracking or peeling.

[0056] Therefore, this thickness range ensures both good reflective properties and material stability and processability.

[0057] Furthermore, the reflective layer 30 is deposited to a micro-nano thickness using one or more of the following methods: magnetron sputtering, vacuum evaporation, chemical vapor deposition, or electroplating. It is understood that magnetron sputtering refers to the use of a magnetic field to guide plasma to sputter metal atoms, resulting in uniform deposition and making it suitable for large-area film fabrication.

[0058] Vacuum evaporation involves heating a metal until it evaporates and then depositing it onto a substrate in a vacuum, resulting in a high-quality film.

[0059] Chemical vapor deposition (CVD) refers to the generation of solid thin films through gas-phase reactions, which is suitable for complex morphologies.

[0060] Electroplating refers to the deposition of metal on a surface through electrochemical means, and is often used in thick film or conductive enhancement applications.

[0061] Therefore, a variety of preparation methods can be selected according to production needs and performance targets, providing flexible process options.

[0062] The following examples further illustrate this point: Example 1 A novel ultra-thin metallic gap reflective film product is obtained by coating and curing UV-type acrylic adhesive onto a 25µm TPU adhesive substrate layer using a microstructure transfer method, forming an array of isosceles triangular microstructures with a vertices of 120 degrees and a height of 10µm. Then, a 90nm thick aluminum layer is fabricated on the triangular microstructures using magnetron sputtering.

[0063] Example 2 UV-type acrylic adhesive is coated and cured onto the surface of a 30µm SCA hot melt adhesive film using a microstructure transfer method, forming an array of isosceles triangular microstructures with a vertices of 120 degrees and a height of 8µm. Then, a 90nm thick aluminum layer is fabricated on the triangular microstructures using magnetron sputtering, resulting in another ultrathin, PET-free, novel metallic gap reflective film product.

[0064] In summary, the novel PET-free metal-type gap reflective film replaces the original PET plus EVA adhesive layer structure with a single-layer TPU film or SCA hot melt adhesive film with adhesive properties. Microstructures are directly made on the surface of the TPU or SCA film and a metal layer is deposited, which greatly reduces the total thickness of the product and achieves a thin design.

[0065] This application also relates to a solar panel, including the aforementioned reflective film; It also includes: a back sheet and photovoltaic glass, wherein the adhesive film layer 10 of the reflective film is directly pasted on the back sheet, and the photovoltaic glass covers the reflective film.

[0066] Specifically, by attaching the adhesive film layer 10 to the backplate, light reflection is enhanced and guided into the solar cell, thereby improving the light reuse rate. At the same time, photovoltaic glass, as a protection for the surface of the solar cell and a light-incoming interface, covers the reflective film. Therefore, the above structure can optimize the light-capturing ability of the solar cell and effectively improve the photoelectric conversion efficiency.

[0067] This application has the following beneficial effects: 1. The new structure eliminates the traditional substrate layer, replacing the combination of substrate and adhesive layer with a single adhesive layer, thus significantly reducing the overall thickness of the gap reflective film product. 2. Under the premise of the same total thickness, the reflective prism structure can be enlarged, which increases the effective area of ​​the reflective layer and improves the light reflection efficiency.

[0068] In summary, the metallic gap reflective film product of this invention replaces the PET substrate layer plus the back-coated EVA adhesive layer with a single adhesive film layer 10, directly preparing the reflective microstructure on the adhesive layer. This reduces the total thickness of the gap reflective film and expands its application scenarios in narrower spaces. Furthermore, while maintaining the same total thickness, the metallic reflective film product of this application can increase the size of the reflective microstructure to further increase the effective area of ​​the reflective layer and improve the light energy utilization rate of the gap reflective film product.

[0069] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various equivalent transformations can be made to the technical solutions of the present invention, and all such equivalent transformations fall within the protection scope of the present invention.

Claims

1. A reflective film, characterized in that, include: Adhesive film layer (10); A microstructure layer (20) is disposed on the adhesive film layer (10); and A reflective layer (30) is disposed on the microstructure layer (20); The reflective layer (30), the microstructure layer (20) and the adhesive film layer (10) are arranged sequentially from top to bottom to form a thin reflective film. The adhesive film layer (10) is a TPU adhesive film layer (10) or an SCA hot melt adhesive film layer (10).

2. The reflective film according to claim 1, characterized in that, The thickness of the adhesive film layer (10) is 10-80 μm.

3. The reflective film according to claim 1, characterized in that, The microstructure layer (20) is a series of triangular cross-sections arranged in an orderly array, and the microstructure layer (20) is cured and formed by UV-cured acrylic adhesive.

4. The reflective film according to claim 3, characterized in that, The vertex angle of the triangle is 30-160°, and its height is 5-30 μm.

5. The reflective film according to claim 1, characterized in that, The microstructure layer (20) is formed by one or more of the following methods: nanoimprinting, laser processing, microstructure roll transfer, mold forming, 3D printing, or hot pressing.

6. The reflective film according to claim 1, characterized in that, The reflective layer (30) is a metal coating, which is either aluminum or silver.

7. The reflective film according to claim 1, characterized in that, The thickness of the reflective layer (30) is 10nm-500nm.

8. The reflective film according to claim 1, characterized in that, The reflective layer (30) is deposited with a micro-nano thickness by one or more of magnetron sputtering, vacuum evaporation, chemical vapor deposition or electroplating.

9. A solar panel, characterized in that, Includes the reflective film according to any one of claims 1-8; It also includes: a back sheet and photovoltaic glass, wherein the adhesive film layer (10) of the reflective film is directly pasted on the back sheet, and the photovoltaic glass covers the reflective film.

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