Through hole type base material laminated cloth as well as preparation method and application thereof

Abstract

The invention provides through hole type base material laminated cloth as well as a preparation method and application thereof, and belongs to the technical field of laminated cloth. Comprising a base material film and a surface functional coating, the surface functional coating comprises an anti-sticking layer and a bottom layer treating agent coating, and the surface of the base material film is drilled through laser. The through hole type base material laminated cloth can effectively improve the problems of exhaust and demolding which are crucial in the lamination of a flexible assembly, and in the lamination process of the flexible photovoltaic assembly, the through hole type base material laminated cloth is usually placed between an assembly lamination layer and a heating plate of a laminating machine or is used as an isolating layer between layers.

Description

Technical Field

[0001] This invention relates to the field of laminated fabric technology, specifically to a perforated substrate laminated fabric, its preparation method, and its application. Background Technology

[0002] With the development of photovoltaic technology, lightweight and flexible monocrystalline silicon photovoltaic modules have gradually emerged. Most of these modules use conventional crystalline silicon solar cells and are encapsulated with flexible substrates and flexible materials, giving them a certain degree of flexibility and bending performance. Previously published patent applications CN202211090758X, CN202310136324.7, and CN202310175757.3 disclosed methods for transforming monocrystalline silicon from brittle to flexible, giving monocrystalline silicon solar cells excellent flexibility. Photovoltaic modules developed based on this original new technology can be rolled and wound, building upon the flexibility of existing market products, further promoting the development of building-integrated photovoltaics and achieving the effect of increasing energy consumption and reducing energy consumption.

[0003] The lamination process is a core encapsulation technology in photovoltaic module manufacturing. Its purpose is to bond the solar cells, upper and lower encapsulating films (usually EVA or POE), and upper and lower substrates (the lower substrate of flexible modules is often a polymer backsheet, and the upper substrate is a transparent front sheet or directly the encapsulating film) together under vacuum, high temperature, and pressure. However, traditional laminated fabrics / silicone sheets face the following significant challenges in flexible module lamination: Firstly, air venting is difficult, as the front panel (sometimes the TPT / TPE backsheet) of flexible modules itself has poor air permeability. When both the upper and lower laminated media (cloth or silicone sheets) are dense structures, it is difficult to completely remove the air between the layers, which can easily lead to the formation of air bubbles at the edges or inside, especially for large-sized or complex-shaped modules.

[0004] Secondly, there's the issue of demolding: the molten encapsulating film may penetrate into the fibers of the traditional laminate, causing severe adhesion after cooling and solidification, leading to difficulty in demolding, damage to the component surface, or the need for frequent cleaning / replacement of the laminate. While silicone sheets offer good demolding properties, they are costly, bulky, and have limited venting efficiency.

[0005] Secondly, there are surface imprints: the texture of traditional laminated fabrics can be imprinted on the surface of soft components, affecting their appearance.

[0006] Finally, there is the heat transfer efficiency: the stacking of multiple layers of fabric may affect the heat transfer efficiency.

[0007] Therefore, it is necessary to develop a perforated substrate laminate and apply it to the lamination process of flexible photovoltaic modules. Summary of the Invention

[0008] The purpose of this invention is to propose a perforated substrate laminate fabric, its preparation method and application, which has a good anti-aging effect.

[0009] The technical solution of this invention is implemented as follows: This invention provides a perforated substrate laminate fabric, comprising a substrate film and a surface functional coating, wherein the surface functional coating is an anti-adhesion coating, and the surface of the substrate film is perforated by laser.

[0010] As a further improvement of the present invention, the substrate film is polyimide, polyetheretherketone, high-temperature polyester, or polytetrafluoroethylene coated glass fiber cloth.

[0011] As a further improvement of the present invention, the thickness of the substrate film is 0.4-0.8 mm; the temperature resistance is stable for a long period of time >200℃; the tensile strength is >150MPa; and the heat shrinkage rate is <1% at 180℃.

[0012] As a further improvement of the present invention, the anti-adhesion layer is a fluoropolymer layer or an organosilicon coating, wherein the fluoropolymer layer is at least one of polytetrafluoroethylene, tetrafluoroethylene and hexafluoropropylene copolymer (FEP), and fusible polytetrafluoroethylene.

[0013] As a further improvement of the present invention, the undercoating agent is a silane coupling agent. The purpose of the undercoating agent is to enhance the adhesion of the coating.

[0014] This invention further protects a method for preparing the above-mentioned through-hole substrate laminate, comprising the following steps: (1) Substrate pretreatment: plasma cleaning, electrostatic dust removal; (2) Micro-hole processing: Ultraviolet laser drilling or mechanical punching drilling is used; (3) Anti-stick coating: The coating needs to cover the upper and lower surfaces of the substrate film. Double-sided synchronous coating is used. The upper surface is coated by slit extrusion and the lower surface is coated by spray coating. The equipment requires a double-sided coating head. The viscosity is controlled so that the coating can naturally penetrate into the hole wall. (4) High-temperature curing: First, heat the solvent to evaporate, then raise the temperature to perform cross-linking curing; (5) Post-processing: The aperture / position of the hole is detected by machine vision, and the coating thickness is detected by infrared thickness measurement to obtain a through-hole substrate laminate.

[0015] As a further improvement of the present invention, in step (2), the wavelength of the ultraviolet laser is 355nm, the aperture is 0.5-1.0mm, the porosity is 10%-40%, and the hole shape can be cylindrical or conical; the micro-hole processing accuracy is controlled within a position error of ±10μm, and the hole wall smoothness Ra<1.6μm; in step (3), the dry film coating thickness is 5-20μm, the solid content is 20%-40%, the coating speed is 5-20 m / min, and the viscosity is controlled within <100cP.

[0016] As a further improvement of the present invention, the solvent evaporation temperature in step (4) is set to 80-120℃ and the time is 1-2 min. The cross-linking curing varies depending on the film material. For PI substrate, the temperature is 300-350℃ and the time is 30-60s. For PET substrate, the temperature is 180℃ and the time is 2 min. The curing process is controlled by a nitrogen atmosphere. In step (5), diamond tools are used for slitting with an accuracy of ±0.1mm and the winding tension is controlled at 10-20N.

[0017] Specifically, it includes the following steps: (1) Substrate pretreatment: Plasma cleaning is used to increase surface energy and enhance coating adhesion. Electrostatic dust removal is used to remove particulate contamination (cleanroom environment ≥ Class 1000).

[0018] (2) Microhole processing: Ultraviolet laser drilling with the highest precision is preferred. The wavelength is selected as 355nm, the hole diameter is 0.5-1.0mm, the porosity is 10%-40%, and the hole shape can be cylindrical or conical (larger at the top and smaller at the bottom to prevent the adhesive film from penetrating). Mechanical punching drilling can be selected as the second option.

[0019] The micro-hole machining accuracy is controlled within ±10μm of position error and the hole wall smoothness Ra<1.6μm, which can effectively reduce stress concentration.

[0020] (3) Anti-stick coating: The coating needs to cover the upper and lower surfaces of the substrate film. The upper surface contacts the laminator heating plate / silicone pad, and the uncoated substrate film is prone to sintering and sticking to the metal / silicone at high temperatures. The lower surface is prone to direct contact with the photovoltaic encapsulation film (EVA / POE), and the uncoated substrate film is prone to sticking to the molten adhesive film. Double-sided simultaneous coating can be used, with slot die extrusion on the upper surface and spray coating on the lower surface. The equipment requires a double-sided coating head (such as the Nordson double-sided slot die system), and the coating is allowed to naturally penetrate into the pore walls by controlling the viscosity (<100cP). The coating thickness is 5-20μm (dry film), the solid content is 20%-40% (solvent-based / water-based system), and the coating speed can be set to 5-20 m / min.

[0021] (4) High-temperature curing: The solvent evaporation temperature is set to 80-120℃, and the time is 1-2 min. The cross-linking curing time varies depending on the film material. For PI substrates, the temperature can be set to 300-350℃, and the time is 30-60 s. For PET substrates, the temperature can be set to 180℃, and the time is 2 min. The curing process is controlled by a nitrogen atmosphere to prevent oxidation.

[0022] (5) Post-processing: The aperture / position of the holes is detected by machine vision, and the coating thickness is detected by infrared thickness measurement. Diamond tools can be used for slitting, with an accuracy controlled within ±0.1mm. The winding tension is controlled at 10-20N to prevent wrinkles.

[0023] This invention further protects the application of the above-mentioned through-hole substrate laminate in the lamination process of flexible photovoltaic modules.

[0024] As a further improvement of the present invention, the perforated substrate laminate is used as an isolation layer.

[0025] The present invention has the following beneficial effects: 1. Revolutionary Venting Channels: Gases generated during lamination (air, small molecules from film decomposition) typically need to be slowly expelled along the module edges or through tortuous material gaps. During the melting and vacuuming process of the encapsulating film, gases can reach the through-holes in the substrate lamination fabric through the tiny gaps within the module stack itself. The through-holes apply uneven downward pressure during lamination, increasing the creep of the encapsulating material on the flexible module surface. This downward pressure and increased film melting creep allow for faster and more thorough venting, significantly reducing the risk of bubble formation and improving lamination yield, which is especially crucial for large-size, high-power flexible modules.

[0026] 2. Excellent demolding performance: The polymer film substrate itself has a very smooth surface. The surface of the through-hole substrate laminate is coated with a high-performance anti-adhesion coating (such as fluoropolymer PTFE, PFA, ETFE or silicone coating), which makes the molten encapsulating film almost non-adhesive to the substrate laminate. After the component is laminated, it can be easily and completely peeled off. The component surface is smooth and clean, without residue or damage, which greatly reduces downtime for cleaning and material loss.

[0027] 3. Improved heat transfer and pressure distribution: Compared to traditional multi-layered laminates, single-layer or multi-layer thin-film substrate laminates are thinner and have lower thermal resistance, which helps to transfer heat more evenly and quickly to the module stack. The flat thin-film substrate laminate, together with the heating plate (or silicone plate) underneath, can provide a more uniform pressure distribution and reduce the problem of excessive or insufficient local pressure. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1Core production process flow; Figure 2 Top view of through-hole substrate laminate; Reference numerals: 1-substrate film, 2-through hole; Note: To improve air permeability, the pore array distribution can include hexagonal close-packing.

[0030] Figure 3 Cross-sectional view of through-hole substrate laminate; Figure reference numerals: 3-anti-stick coating, 4-substrate film, 5-through hole, 6-anti-stick coating. Detailed Implementation

[0031] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] Example 1: A method for preparing the above-mentioned through-hole substrate laminate fabric, comprising the following steps: (1) Substrate pretreatment: plasma cleaning, electrostatic dust removal; (2) Microhole processing: Ultraviolet laser drilling or mechanical punching drilling is used; the wavelength of the ultraviolet laser is 355nm, the hole diameter is 0.5mm, the porosity is 10%, and the hole shape can be cylindrical or conical; the microhole processing accuracy is controlled within the position error ±10μm, and the hole wall smoothness Ra<1.6μm; (3) Anti-stick coating: The coating needs to cover the upper and lower surfaces of the substrate film. Double-sided synchronous coating is used. The upper surface is slit extrusion and the lower surface is spray coating. The equipment requires a double-sided coating head. The viscosity is controlled so that the coating can naturally penetrate into the hole wall. The dry film coating thickness is 5μm, the solid content is 20%, the coating speed is 5m / min, and the viscosity is controlled at <100cP. (4) High-temperature curing: First, heat to evaporate the solvent, then raise the temperature to perform cross-linking curing; the solvent evaporation temperature is set at 80℃ for 1 min. The cross-linking curing varies depending on the film material; for PI substrate, the temperature is 300℃ for 30 s, and for PET substrate, the temperature is 180℃ for 2 min. The curing process is controlled by a nitrogen atmosphere. (5) Post-processing: The hole diameter / hole position is detected by machine vision, and diamond tools are used for cutting with an accuracy of ±0.1mm. The winding tension is controlled at 10N. The coating thickness is detected by infrared thickness measurement to obtain a through-hole substrate laminate.

[0033] The prepared first encapsulating film layer, first encapsulating film layer, battery string layer, second encapsulating film layer, and second encapsulating film layer are sequentially and smoothly stacked from bottom to top to obtain a stacked flexible component. The first and second encapsulating film layers are made of 0.1mm thick PET. The stacked flexible component is placed between two pieces of through-hole substrate laminate, and then placed in a laminator with a lamination temperature of 140℃ and a lamination time of 40 minutes. For comparison, the stacked flexible component is also placed between ordinary laminates, and then placed in a laminator with a lamination temperature of 140℃ and a lamination time of 40 minutes. The effect of the laminated component is then observed.

[0034] Flexible components laminated with through-hole substrate laminate have a smooth surface without bubbles, while flexible components laminated with ordinary laminate have a more severe distribution of bubbles on the surface.

[0035] Example 2: A method for preparing the above-mentioned through-hole substrate laminate fabric, comprising the following steps: (1) Substrate pretreatment: plasma cleaning, electrostatic dust removal; (2) Microhole processing: Ultraviolet laser drilling or mechanical punching drilling is used; the wavelength of the ultraviolet laser is 355nm, the hole diameter is 1.0mm, the porosity is 40%, and the hole shape can be cylindrical or conical; the microhole processing accuracy is controlled within the position error ±10μm, and the hole wall smoothness Ra<1.6μm; (3) Anti-stick coating: The coating needs to cover the upper and lower surfaces of the substrate film. Double-sided synchronous coating is used. The upper surface is coated by slit extrusion and the lower surface is coated by spray coating. The equipment requires a double-sided coating head. The viscosity is controlled so that the coating can naturally penetrate into the hole wall. The dry film coating thickness is 20μm, the solid content is 40%, the coating speed is 20m / min, and the viscosity is controlled at <100cP. (4) High-temperature curing: First, heat to evaporate the solvent, then raise the temperature to perform cross-linking curing; the solvent evaporation temperature is set at 120℃ for 2 minutes. The cross-linking curing varies depending on the film material; for PI substrate, the temperature is 350℃ for 60 seconds, and for PET substrate, the temperature is 180℃ for 2 minutes. The curing process is controlled by a nitrogen atmosphere. (5) Post-processing: The hole diameter / hole position is detected by machine vision, and diamond tools are used for cutting with an accuracy of ±0.1mm. The winding tension is controlled at 20N. The coating thickness is detected by infrared thickness measurement to obtain a through-hole substrate laminate.

[0036] The prepared first encapsulating film layer, first encapsulating film layer, battery string layer, second encapsulating film layer, and second encapsulating film layer are sequentially and smoothly stacked from bottom to top to obtain a stacked flexible module. The first and second encapsulating film layers are 50μm thick PI films. The stacked flexible module is placed between two through-hole substrate laminates and then placed in a laminator with a lamination temperature of 150℃ and a lamination time of 20 minutes. For comparison, the stacked flexible module is also placed between ordinary laminates and then placed in a laminator with a lamination temperature of 150℃ and a lamination time of 20 minutes. The effect of the laminated module is then observed.

[0037] Flexible components laminated with through-hole substrate laminate have a smooth surface without bubbles, while flexible components laminated with ordinary laminate have a more severe distribution of bubbles on the surface.

[0038] Example 3: A method for preparing the above-mentioned through-hole substrate laminate fabric, comprising the following steps: (1) Substrate pretreatment: plasma cleaning, electrostatic dust removal; (2) Microhole processing: Ultraviolet laser drilling or mechanical punching drilling is used; the wavelength of the ultraviolet laser is 355nm, the hole diameter is 0.7mm, the porosity is 25%, and the hole shape can be cylindrical or conical; the microhole processing accuracy is controlled within the position error ±10μm, and the hole wall smoothness Ra<1.6μm; (3) Anti-stick coating: The coating needs to cover the upper and lower surfaces of the substrate film. Double-sided synchronous coating is used. The upper surface is coated by slit extrusion and the lower surface is coated by spray coating. The equipment requires a double-sided coating head. The viscosity is controlled so that the coating can naturally penetrate into the hole wall. The dry film coating thickness is 10 μm, the solid content is 30%, the coating speed is 10 m / min, and the viscosity is controlled at <100 cP. (4) High-temperature curing: First, heat to evaporate the solvent, then raise the temperature to perform cross-linking curing; the solvent evaporation temperature is set at 100℃ for 1.5 min. The cross-linking curing varies depending on the film material; for PI substrate, the temperature is 320℃ for 45 s, and for PET substrate, the temperature is 180℃ for 2 min. The curing process is controlled by a nitrogen atmosphere. (5) Post-processing: The aperture / position of the hole is detected by machine vision, and the hole is cut with diamond tools. The accuracy is controlled within ±0.1mm. The winding tension is controlled within 10-20N. The coating thickness is detected by infrared thickness measurement to obtain a through-hole substrate laminate.

[0039] The prepared first encapsulating film layer, first encapsulating film layer, battery string layer, second encapsulating film layer, and second encapsulating film layer are sequentially and smoothly stacked from bottom to top to obtain a stacked flexible module. The first and second encapsulating film layers are ETFE films with a thickness of 35μm. The stacked flexible module is placed between two through-hole substrate laminates and then placed in a laminator with a lamination temperature of 165℃ and a lamination time of 55 minutes. For comparison, the stacked flexible module is also placed between ordinary laminates and then placed in a laminator with a lamination temperature of 165℃ and a lamination time of 55 minutes; the module effect after lamination is then observed.

[0040] Flexible components laminated with through-hole substrate laminates have a smooth, bubble-free surface, as do flexible components laminated with ordinary laminates. The reason for this is that the ETFE film used is thin and flexible enough to remove bubbles in time when the film layer melts.

[0041] Test Example 1: The performance of the flexible components laminated with the through-hole substrate laminates prepared in Examples 1-3 was tested, and the results are shown in Table 1.

[0042] Table 1 .

[0043] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A via substrate laminate fabric, characterized by, The substrate film and the surface functional coating layer including an anti-adhesion layer and a primer coating, the substrate film surface is laser punched.

2. The via substrate laminate fabric of claim 1, wherein, The substrate film is polyimide, polyether ether ketone, high-temperature polyester or polytetrafluoroethylene coated glass fiber cloth.

3. The via substrate laminate of claim 2, wherein, The substrate film thickness is 0.4-0.8mm; temperature resistance is long-term stable >200℃; tensile strength is >150MPa; thermal shrinkage rate is <1% at 180℃.

4. The via substrate laminate fabric of claim 1, wherein, The anti-adhesion layer is a fluoropolymer layer or a silicone coating, the fluoropolymer layer is at least one of polytetrafluoroethylene, tetrafluoroethylene and hexafluoropropylene copolymer FEP, and meltable polytetrafluoroethylene.

5. The via substrate laminate fabric of claim 1, wherein, The primer is a silane coupling agent.

6. A method of making a via substrate laminate according to any one of claims 1 to 5, characterized in that, The steps include: (1) substrate pretreatment: plasma cleaning, electrostatic dust removal; (2) micropore processing: using ultraviolet laser punching or mechanical punching; (3) anti-adhesion coating: the coating needs to cover the upper and lower surfaces of the substrate film, using double-sided synchronous coating, the upper surface uses slot extrusion, the lower surface uses spray coating, the equipment requires double-sided coating head, and the coating is naturally infiltrated into the hole wall by controlling the viscosity; (4) high temperature curing: first heating to volatilize the solvent, and then heating to crosslink and cure; (5) post-processing: detecting the hole diameter / hole position through machine vision, and detecting the coating thickness through infrared thickness measurement, to obtain a through-hole substrate laminated cloth.

7. The production method according to claim 6, characterized by, In step (2), the wavelength of the ultraviolet laser is 355nm, the hole diameter is 0.5-1.0mm, the porosity is 10%-40%, and the hole type can be cylindrical or conical; the micropore processing precision is controlled within a position error of ±10μm, and the hole wall smoothness Ra is <1.6μm; in step (3), the dry film coating thickness is 5-20μm, the solid content is 20%-40%, the coating speed is 5-20m / min, and the viscosity is controlled to be <100cP.

8. The preparation method according to claim 6, characterized in that, In step (4), the temperature for solvent volatilization is set to 80-120℃, and the time is 1-2min. The crosslinking and curing temperature is different according to the film material, the PI substrate temperature is 300-350℃, the time is 30-60s, the PET substrate temperature is 180℃, the time is 2min, and the curing process is set to nitrogen atmosphere control; in step (5), diamond knives are used for slitting, the precision is controlled within ±0.1mm, and the winding tension is controlled within 10-20N.

9. The application of the through-hole substrate laminated cloth according to any one of claims 1-5 in the lamination process of a flexible photovoltaic module.

10. Use according to claim 9, characterized in that, The through-hole substrate laminated cloth is used as a separation layer.

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