CN116288175A

CN116288175A - Antireflection film and preparation method thereof

Info

Publication number: CN116288175A
Application number: CN202310182815.5A
Authority: CN
Inventors: 尧俊; 林炜杰; 崔志栋; 卢仁; 王文琦; 吴永辉; 张睿智; 刘风雷
Original assignee: Zhejiang Crystal Optech Co Ltd
Current assignee: Zhejiang Crystal Optech Co Ltd
Priority date: 2023-02-21
Filing date: 2023-02-21
Publication date: 2023-06-23

Abstract

The application provides an antireflection film and a preparation method thereof, and relates to the technical field of antireflection film coatings, comprising a substrate, a silicon oxide film layer and a nano porous aluminum oxide film layer which are sequentially laminated; the nano porous alumina film layer is obtained by soaking the alumina film layer in pure water or ultrapure water at the temperature of 65-95 ℃ for 2-30 min, the antireflection film adopts a silicon oxide and porous nano alumina two-layer structure, the reflectivity of the film layer below 0.1% in a wide band can be achieved, the film layer has a simple structure, the manufacturing process is stable, the production yield is high, the stable porous nano alumina film layer can be obtained after being soaked in high-temperature pure water for a few minutes, the industrial batch production requirement is met, the preparation is simple, the method is suitable for large-breadth and batch production, and the method can also be used for hard antireflection film lamination of complex optical surfaces, large-curvature optical elements and the like, and has wide application in optical systems of various lenses, optical panels, microscope precision measuring instruments and the like.

Description

Antireflection film and preparation method thereof

Technical Field

The application relates to the technical field of anti-reflection film coatings, in particular to an anti-reflection film and a preparation method thereof.

Background

The antireflection film is an optical film having the highest use ratio in an optical system. With the upgrading of lens products, the number of lenses in the system is increased, and the use of large-curvature lenses makes the antireflection film one of key factors for reducing stray light of the system and improving imaging quality. In the design of the antireflection film, the refractive index of the outermost film has the greatest influence on the residual reflectivity of the wide-band multilayer antireflection film, but the perfect antireflection effect cannot be realized by matching the natural ultralow refractive index materials in the nature at present. As early as the 60 th century of 20 th, it has been found that the very fine concave-convex structure on the surface of the moth eye can effectively inhibit light reflection, and by using this principle, researchers have introduced a bionic micro-nano structure film layer to optimize the antireflection film.

Based on the nano-structure film layer being a hole structure, lower refractive index can be obtained, so that interface reflection with air is reduced. The combination of the nanostructured low refractive index film layer and the multilayer film stack structure is widely applied to the design of antireflection films, but the design method and the film performance are greatly different. The multilayer film structure mostly adopts modes such as electron beam evaporation, magnetron sputtering and the like, while the nanometer low refractive index film layer adopts reactive ion etching, electrostatic self-assembly, a sol-gel method and the like, and most of the methods have complex preparation processes, long time consumption and expensive required equipment.

Disclosure of Invention

The present application aims to provide an antireflection film, which is simple to prepare, suitable for large-format and mass production, and applicable to complex optical surfaces, large-curvature optical elements and the like, aiming at the defects in the prior art.

In order to achieve the above purpose, the technical solution adopted in the embodiment of the present application is as follows:

in one aspect of the embodiments of the present application, there is provided an antireflection film including: a substrate, a silicon oxide film layer and a nano porous alumina film layer which are sequentially laminated; the nano porous alumina film layer is obtained by soaking the alumina film layer in pure water or ultrapure water at 65-95 ℃ for 2-30 min.

Optionally, the material of the substrate comprises at least one of glass, reinforced glass, organic glass, polypropylene diglycol carbonate, polyethylene carbonate and styrene.

Optionally, the thickness of the silicon oxide film layer is between 30nm and 150nm, and the thickness of the aluminum oxide film layer is between 10nm and 90 nm.

Optionally, the nano porous alumina film layer is a super hydrophilic film layer; the nano porous alumina film layer is also provided with a waterproof film on one side opposite to the silica film layer, and the waterproof film is a super-hydrophobic film layer.

In another aspect of the present application, there is provided a method for preparing an antireflection film, for preparing the antireflection film as described above, comprising: forming a silicon oxide film layer on one side of a substrate; forming an aluminum oxide film layer on the silicon oxide film layer; soaking the substrate in high-temperature pure water to convert the alumina film layer into a nano porous alumina film layer; and drying the substrate.

Optionally, forming the silicon oxide film layer on one side of the substrate includes: forming a silicon oxide film layer by adopting at least one of electron beam evaporation, sputtering, thermal vapor deposition, atomic layer deposition and chemical vapor deposition; the thickness of the silicon oxide film layer is between 30nm and 150 nm.

Optionally, forming an aluminum oxide film layer on the silicon oxide film layer, the method further comprises: forming an aluminum oxide film layer by adopting at least one of electron beam evaporation, sputtering, thermal vapor deposition, atomic layer deposition and chemical vapor deposition; the thickness of the alumina film layer is between 10nm and 90 nm.

Optionally, before forming the silicon oxide film layer on one side of the substrate, the method further includes: and cleaning the substrate.

Optionally, the substrate is soaked in high-temperature pure water to enable the alumina film layer to be converted into a nano porous alumina film layer, and the method further comprises: soaking the alumina film layer in pure water or ultrapure water at 65-95 deg.c for 2-30 min; the thickness of the formed nano porous alumina film layer is between 90nm and 600 nm.

Optionally, after drying the substrate, the method further comprises: and coating a waterproof film on the nano porous alumina film layer to form a super-hydrophobic film layer.

The beneficial effects of this application include:

the application provides an antireflection film, include: the substrate, the silicon oxide film layer and the nano porous alumina film layer are sequentially laminated; the nano porous alumina film layer is obtained by soaking the alumina film layer in pure water or ultrapure water at the temperature of 65-95 ℃, and the soaking time is 2-30 min, and the antireflection film provided by the application has the following beneficial effects: 1) The porous nano structure can be produced by using a hot water soaking process, and the cost is low; 2) The soaking time for converting the alumina film layer into the nano porous alumina structure is short, the production efficiency can be improved, and the method is more suitable for industrial production; 3) The film layer is simple, the reflectivity below 0.1% can be achieved by only two layers, the film layer has a simple structure, the manufacturing process is well controlled, and the film layer is more suitable for industrial mass production; 4) The film layer is simple, the influence of the 3D surface morphology on the uniformity of the film layer is small, the spectrum uniformity of each part of the surface of the lens is good, and the problems of stray light and poor ghost images of the lens with large curvature can be solved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered limiting the scope, and that other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic structural diagram of an antireflection film according to an embodiment of the present disclosure;

FIG. 2 is a flowchart of a method for preparing an antireflection film according to an embodiment of the present disclosure;

fig. 3 is a schematic view of reflectivity of an antireflection film according to an embodiment of the present disclosure.

Icon: 10-an antireflection film; 100-nanometer porous alumina film layer; 200-silicon oxide film layer; 300-substrate; 400-waterproof membrane.

Detailed Description

For the purposes of making the objects, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments. The components of the embodiments of the present application, which are generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present application, as provided in the accompanying drawings, is not intended to limit the scope of the application, as claimed, but is merely representative of selected embodiments of the application. It should be noted that, in the case of no conflict, the features of the embodiments of the present application may be combined with each other, and the combined embodiments still fall within the protection scope of the present application.

It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further definition or explanation thereof is necessary in the following figures.

In the prior art, the structure of the antireflection film is a dielectric multilayer film and nano alumina structure, the nano alumina structure has graded refractive index characteristics, and is combined with a multilayer dielectric film, the influence of small thickness change of each film layer on final reflection change is obvious, the manufactured film is small in Cheng Rongcha property, the production stability is difficult to control, and the production yield is low; and the nanometer alumina structure can be obtained after being soaked for more than 30 minutes by adopting deionized water heated by water bath, the manufacturing process time is longer, and the industrial mass production efficiency is low.

The invention adopts the alumina film to generate the nano porous alumina film layer 100 structure by soaking reaction in high-temperature pure water, does not need complex medium multilayer film, and can reach the reflectivity below 0.1% of a wider band by only using the silica film layer 200 as a transition layer to be matched with the nano porous alumina film layer 100 structure. The antireflection film 10 is simple to prepare, is suitable for large-format and batch production, and can be also used for complex optical surfaces, large-curvature optical elements and the like.

In one aspect of the embodiments of the present application, referring to fig. 1, there is provided an antireflection film 10 including: the substrate 300, the silicon oxide film layer 200 and the nano-porous aluminum oxide film layer 100 are sequentially stacked; the nano-porous alumina film layer 100 is obtained by immersing the alumina film layer in pure water or ultrapure water at a temperature of 65-95 ℃ for 2-30 min.

The application adopts the structure of silicon oxide and nano porous alumina, only two layers are needed, the reflectivity below 0.1% of a broadband can be achieved, the film layer is simple in structure, the manufacturing process is stable, the production yield is high, and the stable nano porous alumina film layer can be obtained after being soaked in high-temperature pure water for a few minutes, so that the requirement of industrial mass production can be met.

Specifically, the nano porous alumina film layer in the embodiment of the application is obtained by a hot water soaking method: soaking the aluminum oxide film in pure water or ultrapure water at 65-95 ℃ for 2-30 min, preferably at 80 ℃ for 7min.

The nanoporous alumina membrane layer 100 provided herein is prepared using a chemical reaction of an alumina thin film with water at high temperature. In high-temperature pure water, aluminum oxide reacts with water and combines with water molecules to generate new substances, which are mainly represented by the increase of the thickness of the nano-structure film; the porosity of the film layer is increased, and the porosity of the film layer is gradually increased from bottom (near the side of the substrate 300) to top, so that a film layer with a spatially-varying graded refractive index is formed, and the refractive index of the film layer is gradually changed from 1.3 to 1, so that the reflection of the nano-porous alumina film layer 100 and an air interface is reduced, and an ultra-low refractive index film layer with an equivalent refractive index of 1.2 to 1.25 and a nano-structure is formed. The thickness of the prepared nano porous alumina film layer 100 is in the range of 90nm-600 nm.

It should be noted that, the preparation methods of the silicon oxide film layer 200 and the aluminum oxide film layer in the present application are not limited, and electron beam evaporation, sputtering, thermal vapor deposition, atomic layer deposition, chemical vapor deposition, other chemical methods, and the like can be adopted; the silicon oxide film 200 and the aluminum oxide film may be designed to have a suitable thickness depending on the desired antireflection band.

In summary, the present application provides an antireflection film 10, comprising: the substrate 300, the silicon oxide film layer 200 and the nano-porous aluminum oxide film layer 100 are sequentially stacked; the nano porous alumina film 100 is obtained by soaking the alumina film in pure water or ultrapure water at the temperature of 65-95 ℃ for 2-30 min, the antireflection film 10 provided by the application adopts a silicon oxide and porous nano alumina two-layer structure, the reflectivity of a wide band below 0.1% can be achieved, the film structure is simple, the process is stable, the production yield is high, the stable porous nano alumina structural film can be obtained after soaking in high-temperature pure water for a few minutes, the requirement of industrial batch production is met, the preparation is simple, the method is suitable for large-format and batch production, and the method can also be used for hardening antireflection film lamination of complex optical surfaces, large-curvature optical elements and the like, and has wide application in optical systems such as various lenses, optical panels, microscopic precision measuring instruments and the like.

Specifically, the material of the substrate 300 includes at least one of glass, reinforced glass, organic glass, polypropylene diglycol carbonate, polyethylene carbonate, and styrene.

Specifically, the thickness of the silicon oxide film layer 200 is between 30nm and 150nm, and the thickness of the aluminum oxide film layer is between 10nm and 90 nm.

The preparation methods of the silicon oxide film layer 200 and the aluminum oxide film layer of the present invention are not limited, and electron beam evaporation, sputtering, thermal vapor deposition, atomic layer deposition, chemical Vapor Deposition (CVD), other chemical methods, etc. may be used, and a suitable thickness may be designed according to a desired antireflection band.

In one embodiment of the present application, the nanoporous alumina membrane layer 100 is a superhydrophilic membrane layer; the nano-porous alumina film layer 100 is further provided with a waterproof film 400 on one side opposite to the silica film layer 200, and the waterproof film 400 is a super-hydrophobic film layer.

The nanoporous alumina film layer 100 provided herein has a hydrophilic angle below 7 degrees, and the waterproof film 400 coated on the nanoporous alumina film layer 100 may have a hydrophobic angle above 136 degrees.

In another aspect of the embodiments of the present application, there is provided a method of manufacturing an antireflection film 10 for manufacturing the antireflection film 10 as described above. The method of manufacturing the antireflection film 10 includes the same structure and advantageous effects as those of the antireflection film 10 in the foregoing embodiment. The structure and advantageous effects of the antireflection film 10 have been described in detail in the foregoing embodiments, and will not be described in detail here.

As shown in fig. 2, a flowchart of a method for preparing an antireflection film 10 according to an embodiment of the present application is described, where the method for preparing an antireflection film 10 is as follows:

s100: a silicon oxide film layer 200 is deposited on one side of the substrate 300.

S110: an aluminum oxide film layer is deposited on the silicon oxide film layer 200.

The thickness of the silicon oxide film layer 200 and the thickness of the aluminum oxide film layer are designed to be suitable according to the required antireflection wave band.

In the embodiment of the application, a vacuum deposition film is used to deposit a silicon oxide layer and an aluminum oxide layer on a substrate.

S120: the substrate 300 is immersed in high-temperature pure water to convert the alumina film layer into the nano-porous alumina film layer 100.

As shown in fig. 3, the product on which the film layer is deposited is immersed in pure water or ultrapure water at a temperature of about 80 degrees for 7 minutes, and the alumina film layer is formed into the nano-porous alumina film layer 100, thereby obtaining the broadband antireflection film 10.

S130: the substrate 300 is baked.

Specifically, depositing the silicon oxide film layer 200 on one side of the substrate 300 includes: forming a silicon oxide film layer by adopting at least one of electron beam evaporation, sputtering, thermal vapor deposition, atomic layer deposition and chemical vapor deposition; the thickness of the silicon oxide film layer is between 30nm and 150 nm.

Specifically, the substrate 300 may be cleaned by an ultrasonic cleaning apparatus, dried, and the substrate 300 may be cleaned by an ultrasonic cleaning apparatus, and the cleaned substrate 300 may be dried.

Specifically, an aluminum oxide film layer is formed on the silicon oxide film layer, and the method further comprises: forming an aluminum oxide film layer by adopting at least one of electron beam evaporation, sputtering, thermal vapor deposition, atomic layer deposition and chemical vapor deposition; the thickness of the alumina film layer is between 10nm and 90 nm.

Specifically, before forming the silicon oxide film layer on one side of the substrate, the method further includes: and cleaning the substrate.

Cleaning the substrate 300 includes: the substrate 300 is cleaned using an ultrasonic cleaning apparatus, and the cleaned substrate 300 is dried.

Specifically, the substrate 300 is immersed in high-temperature pure water to convert the alumina film layer into the nano-porous alumina film layer 100, and the method further includes: soaking the alumina film layer in pure water or ultrapure water at 65-95 deg.c for 2-30 min; the thickness of the formed nano porous alumina film layer is between 90nm and 600 nm.

In one embodiment of the present application, after the substrate 300 is dried, the method for preparing the anti-reflective film 10 further includes: the nanoporous alumina film layer 100 is coated with a waterproof film 400 to form a superhydrophobic film layer.

In summary, the embodiments of the present application provide a method for preparing a nanoporous alumina film layer 100: soaking the alumina film in pure water or ultrapure water at 65-95 ℃ for 2-30 min; the embodiment of the application provides an antireflection film 10 layer and a preparation method thereof: the reflective film comprises a silicon oxide film layer 200 and a nano porous aluminum oxide film layer 100, wherein the two layers can achieve reflection of less than 0.1%, the thickness of the silicon oxide film layer 200 is 30nm-150nm, and the thickness of the aluminum oxide film layer is 10nm-90nm (the thickness of the formed porous aluminum oxide film layer is 90nm-600 nm); the embodiment of the application provides a super-hydrophilic film layer and a preparation process thereof: the nanoporous alumina membrane layer 100 described above has a hydrophilic angle of 7 degrees or less; the embodiment of the application provides a super-hydrophobic film layer and a preparation process thereof: the waterproof coating 400 coated on the nano-porous alumina film layer 100 described above may have a hydrophobic angle of 136 degrees or more.

The foregoing is merely a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and variations may be made to the present application by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. An antireflection film (10), characterized by comprising: a substrate (300), a silicon oxide film layer (200) and a nano porous alumina film layer (100) which are sequentially stacked;

the nano porous alumina film layer (100) is obtained by soaking the alumina film layer in pure water or ultrapure water at 65-95 ℃ for 2-30 min.

2. The antireflection film (10) according to claim 1, wherein the material of the substrate (300) comprises at least one of glass, reinforced glass, organic glass, polypropylene-based diglycol carbonate, polyethylene carbonate, and styrene.

3. An antireflection film (10) according to claim 2, characterized in that the thickness of the silicon oxide film layer (200) is between 30nm and 150nm and the thickness of the aluminum oxide film layer is between 10nm and 90 nm.

4. An antireflection film (10) according to claim 1, characterized in that: the nano porous alumina film layer (100) is a super hydrophilic film layer;

the waterproof membrane (400) is further arranged on one side of the nano porous alumina membrane layer (100) opposite to the silica membrane layer (200), and the waterproof membrane (400) is a super-hydrophobic membrane layer.

5. A method of producing an antireflection film (10) for producing an antireflection film (10) as claimed in any one of claims 1 to 4, comprising:

forming a silicon oxide film layer (200) on one side of a substrate (300);

forming an aluminum oxide film layer on the silicon oxide film layer (200);

immersing the substrate (300) in high-temperature pure water to convert the alumina film layer into a nano-porous alumina film layer (100);

drying the substrate (300).

6. The method of manufacturing an antireflection film (10) according to claim 5, characterized in that: the forming of the silicon oxide film layer (200) on one side of the substrate (300) includes:

forming the silicon oxide film layer (200) by at least one of electron beam evaporation, sputtering, thermal evaporation, atomic layer plating, and CVD;

the thickness of the silicon oxide film layer (200) is between 30nm and 150 nm.

7. The method of manufacturing an antireflection film (10) according to claim 5, characterized in that: the forming of the aluminum oxide film layer on the silicon oxide film layer (200) includes:

forming the aluminum oxide film layer by adopting at least one of electron beam evaporation, sputtering, thermal vapor deposition, atomic layer deposition and chemical vapor deposition;

the thickness of the alumina film layer is between 10nm and 90 nm.

8. The method of manufacturing an antireflection film (10) according to claim 5, characterized in that: the method further includes, before forming the silicon oxide film layer (200) on one side of the substrate (300):

the substrate (300) is cleaned.

9. The method of manufacturing an antireflection film (10) according to claim 5, characterized in that: the immersing the substrate (300) in high-temperature pure water to convert the alumina film layer into a nano-porous alumina film layer (100) further comprises:

soaking the alumina film layer in pure water or ultrapure water at 65-95 ℃ for 2-30 min;

the thickness of the formed nano-porous alumina film layer (100) is between 90nm and 600 nm.

10. The method of manufacturing an antireflection film (10) according to claim 5, characterized in that: after the drying of the substrate (300), the method further comprises:

and plating the nano porous alumina film layer (100) with a waterproof film (400) to form a super-hydrophobic film layer.