CN109112479B

CN109112479B - Antireflection film for visible and near-infrared light wave band and manufacturing method thereof

Info

Publication number: CN109112479B
Application number: CN201811032940.3A
Authority: CN
Inventors: 刘盛浦; 郭兴忠; 吴兰
Original assignee: Zhejiang Boda Photoelectric Co ltd
Current assignee: Zhejiang Boda Photoelectric Co ltd
Priority date: 2018-09-05
Filing date: 2018-09-05
Publication date: 2020-11-03
Anticipated expiration: 2038-09-05
Also published as: CN109112479A

Abstract

The invention provides a visible and near-infrared band antireflection film which comprises the following components in parts by weight: comprises a first SiO layer arranged from inside to outside in sequence₂Layer, second layer Ti₃O₅Layer, third layer of SiO₂Layer, fourth layer Ti₃O₅Layer, fifth layer of SiO₂Layer, sixth layer Ti₃O₅Layer, seventh layer SiO₂Layer, eighth layer Ti₃O₅Layer, ninth layer of MgF₂Layer and tenth SiO₂And (3) a layer. The invention also provides a manufacturing method of the visible and near-infrared band antireflection film, which comprises the following steps: 1) sequentially plating a first layer to an eighth layer on the substrate by using an ion beam assisted deposition vacuum coating technology; 2) and then a ninth MgF layer is plated by using an ion beam assisted deposition vacuum coating technology without oxygen₂A layer; 3) and plating a tenth SiO layer by using ion beam assisted deposition vacuum coating technology₂And (3) a layer. The invention selects three conventional materials for design, and extremely thin layers are removed, so that the method is easy to control and suitable for stable batch production; and a protective layer is added, so that the subsequent cleaning is facilitated.

Description

Antireflection film for visible and near-infrared light wave band and manufacturing method thereof

Technical Field

The invention relates to an antireflection film, in particular to an antireflection film for visible and near-infrared light bands and a manufacturing method thereof.

Background

An antireflection film, also called an antireflection film, is an optical film with the widest application, and is used for reducing the reflection on the surface of an optical element, improving the light transmittance of light rays in a working waveband and reducing the loss of light energy. Optical elements such as cameras, microscopes and video cameras are plated with antireflection films to improve light energy, increase light transmittance and improve imaging quality of the optical elements. At present, the use of night images and the continuous increase of day and night dual-purpose type image systems put forward higher requirements on antireflection films: the antireflection film is not only limited to visible light or near infrared region, but also has high light transmission and low reflection requirements in the visible light to near infrared ultra-wide spectrum region (400-1100 nm).

However, almost all imaging systems currently capture clear and useful images in the daytime when there is sufficient light, but night imaging is relatively poor. Moreover, most modern imaging systems require the use of an infrared light source at night for concealment, which has a very low illumination level, typically less than 0.1 lux. This requires that the transmittance of the entire imaging system is very good for visible and infrared light sources, and puts forward the requirement for developing high-quality antireflection films with high transmittance and low reflection in the visible to near-infrared region (400-. In addition, with the wide application of military infrared technology in atmospheric optical communication, the spectral region of a military optical system is increasingly wide, and not only the infrared region but also visible light and near infrared are required to be covered, which necessitates the research on high-performance wide-band antireflection films for visible light and near infrared bands with high transmittance, wide band coverage and good reliability.

With the continuous improvement of optical film design and preparation technology, the conventional antireflection film for the visible light region is mature at present, and the actual characteristics can be very close to or even completely reach the theoretical design value. However, due to the fact that the design of the ultra-wideband antireflection film is difficult, or due to the fact that the design thickness of the ultra-wideband antireflection film is irregular, control errors are large, and the theoretical design value is difficult to achieve, or in order to achieve the theoretical design, the selected film layer material can only be used as a theoretical test, and large-scale and stable batch production is difficult to achieve.

Accordingly, there is a need for improvements in the art.

Disclosure of Invention

The invention aims to provide an efficient visible and near-infrared band antireflection film and a manufacturing method thereof.

In order to solve the technical problems, the invention provides an antireflection film for visible and near infrared light bands, which comprises the following components in parts by weight:

comprises a first SiO layer arranged from inside to outside in sequence₂Layer, second layer Ti₃O₅Layer, third layer of SiO₂Layer, fourth layer Ti₃O₅Layer, fifth layer of SiO₂Layer, sixth layer Ti₃O₅Layer, seventh layer SiO₂Layer, eighth layer Ti₃O₅Layer, ninth layer of MgF₂Layer and tenth SiO₂And (3) a layer.

As an improvement of the antireflection film of visible and near infrared light bands of the invention:

first layer of SiO₂Layer, second layer Ti₃O₅Layer, third layer of SiO₂Layer, fourth layer Ti₃O₅Layer, fifth layer of SiO₂Layer, sixth layer Ti₃O₅Layer, seventh layer SiO₂Layer, eighth layer Ti₃O₅Layer, ninth layer of MgF₂Layer and tenth SiO₂The physical thicknesses of the layers were 211.29, 9.29, 51.19, 26.1, 21.64, 133.7, 25.53, 21.07, 85.51, and 20nm, in that order.

The invention also provides a manufacturing method of the visible and near-infrared band antireflection film, which comprises the following steps:

1) sequentially plating a first layer of SiO on the substrate by using an ion beam assisted deposition vacuum coating technology₂Layer, second layer Ti₃O₅Layer, third layer of SiO₂Layer, fourth layer Ti₃O₅Layer, fifth layer of SiO₂Layer, sixth layer Ti₃O₅Layer, seventh layer SiO₂Layer and eighth layer of Ti₃O₅A layer;

2) and then a ninth MgF layer is plated by using an oxygen-impermeable ion beam assisted deposition vacuum coating technology₂A layer;

3) and plating a tenth SiO layer by using ion beam assisted deposition vacuum coating technology₂And (3) a layer.

As an improvement of the manufacturing method of the antireflection film in the visible and near infrared light bands, the invention comprises the following steps:

plating a first layer of SiO₂Layer (b): controlling the deposition rate to be 0.8nm/s, the ion source voltage to be 900V, the ion source current to be 900mA, the ion source oxygen to be 50SCCM and the ion source argon to be 8 SCCM;

plating a second layer of Ti₃O₅Layer (b): controlling the deposition rate to be 0.2nm/s, the ion source voltage to be 1200V, the ion source current to be 1100mA, the ion source oxygen to be 70SCCM and the ion source argon to be 15 SCCM;

plating third layer of SiO₂Layer (b): controlling the deposition rate to be 0.8nm/s, the ion source voltage to be 900V, the ion source current to be 900mA, the ion source oxygen to be 50SCCM and the ion source argon to be 8 SCCM;

plating a fourth layer of Ti₃O₅Layer (b): controlling the deposition rate to be 0.4nm/s, the ion source voltage to be 1200V, the ion source current to be 1100mA, the ion source oxygen to be 70SCCM and the ion source argon to be 15 SCCM;

plating fifth layer of SiO₂Layer (b): controlling the deposition rate to be 0.8nm/s, the ion source voltage to be 900V, the ion source current to be 900mA, the ion source oxygen to be 50SCCM and the ion source argon to be 8 SCCM;

plating a sixth layer of Ti₃O₅Layer (b): controlling the deposition rate to be 0.4nm/s, the ion source voltage to be 1200V, the ion source current to be 1100mA, the ion source oxygen to be 70SCCM and the ion source argon to be 15 SCCM;

plating the seventh layer of SiO₂Layer (b): controlling the deposition rate to be 0.8nm/s, the ion source voltage to be 900V, the ion source current to be 900mA, the ion source oxygen to be 50SCCM and the ion source argon to be 8 SCCM;

coating the eighth layer of Ti₃O₅Layer (b): controlling the deposition rate to be 0.4nm/s, the ion source voltage to be 1200V, the ion source current to be 1100mA, the ion source oxygen to be 70SCCM and the ion source argon to be 15 SCCM;

plating a ninth MgF2 layer: controlling the deposition rate to be 0.4nm/s, the ion source voltage to be 200V, the ion source current to be 600mA and the ion source argon to be 40 SCCM;

coating the tenth SiO layer₂Layer (b): the deposition rate was controlled to 0.6nm/s, the ion source voltage was controlled to 900V, the ion source current was controlled to 900mA, the ion source oxygen was controlled to 50SCCM, and the ion source argon was controlled to 8 SCCM.

As a further improvement of the manufacturing method of the antireflection film in the visible and near infrared light bands, the film coating method in the step 2) comprises the following steps:

MgF film material₂Putting the mixture into a molybdenum crucible, covering the molybdenum crucible with a molybdenum crucible cover, and heating the film material MgF by the electron beam through the heat conduction of the molybdenum crucible cover₂Heating the film material MgF₂Formation of MgF₂Molecules overflow from the evaporation hole in the molybdenum crucible cover and adhere to the substrate to form a coating film.

As a further improvement of the manufacturing method of the antireflection film in the visible and near infrared light bands of the invention:

the substrate was K9 glass.

In the process of the invention, the inventor performs the following experiments:

the design of multilayer broadband antireflection films is quite complex, and according to a large number of design practices, a very useful empirical formula is summarized and induced for designing and estimating the average value of the minimum reflectivity:

Rave(B,L,T,D)＝(4.738/D)(1/T)0.31[exp(B-1.4)-1](L-1)3.5 (1)

rave (B, L, T, D) is the average value of the minimum reflectance, B ═ λ max/λ min, and represents the low reflectance bandwidth (λ max is the maximum value of the wavelength of the low reflectance region, λ min is the minimum value of the wavelength of the low reflectance region); l is the refractive index of the outermost film; d ═ n_H-n_L，n_HAnd n_LThe refractive indexes are respectively high and low except the outermost layer film, and different equipment and processes can be obtained according to experiments and are defined as follows: a difference in high and low refractive indices other than the outermost layer; t is the total optical thickness of the film system, B is the bandwidth, expressed as a multiple of the average wavelength, i.e.:

according to the above functional relationship analysis, if it is necessary to reduce the value of Rave when the bandwidth B is more expensive, the following condition needs to be satisfied: d is as large as possible; n is_HAnd n_LThe difference of (a) is as large as possible; l is as small as possible; t is as large as possible. Meanwhile, Ti is selected in consideration of cost, stability and practical control capability of mass production₃O₅、SiO₂And MgF₂Three materials with refractive indexes of 2.35, 1.46 and 1.38 respectively.

An empirical initial structure G | (0.3H0.3L)40.3HM | a, where G is a low index substrate K9 glass; H. l, M are respectively Ti3O₅、SiO₂、MgF₂The refractive indices of the three materials, the film layer structure obtained preliminarily, are shown in table 1, and the theoretically designed reflection curve thereof is shown in fig. 1.

TABLE 110 layered film systems and optical thicknesses of the respective layers

M is the bandwidth of the membrane system design; b1100/400-2.75, L1.38, D2.35-1.46-0.89, and T740.2/663.3-1.12, the theoretical lowest average reflectance is 0.46% calculated from formula (1), and the average reflectance in the 400-1100nm band obtained from the initial design simulation is about 0.5%, which are slightly different from each other.

According to the initial theoretical design and the actual production experience: adding SiO into the first layer₂As a bonding layer, the low reflection curve can be smoothed at the same time; secondly, the extremely thin layers are not easy to control and can be removed and combined; ③ MgF₂Is a hydrophilic material, is extremely easy to deliquesce at the outermost layer and is difficult to pass a harsher ring test. Therefore, partial SiO is used₂Substitution of MgF₂And serves as a protective layer. And then carrying out secondary optimization to obtain a final 10-layer designed reflection curve as shown in figure 2.

The visible and near-infrared light band antireflection film and the manufacturing method thereof have the technical advantages that:

the invention selects Ti according to the use requirement of day and night dual-purpose monitoring system₃O₅、SiO₂、MgF₂The three optical coating materials are designed, optimized and experimentally optimized and adjusted through a 10-layer film system structure, the loading mode of an evaporation source is improved, the optical performance and environment measurement requirements of a system and the surface requirements of continuous production are met by adopting a mode of all ion source auxiliary electron beam evaporation, and the multilayer broadband antireflection film with high transmittance is prepared and meets the requirements of civil and military image systems on high transmittance of visible to near-infrared bands.

(1) The analysis is carried out according to an empirical formula of the antireflection film, conventional stable materials are selected in combination with production practice, and then the theoretical average reflectivity is 0.46%. And optimizing the film layer by combining with the actual control capability, and substituting into an antireflection film empirical formula to obtain the optimized theoretical average reflectivity of 0.5%.

(2) During the preparation process, for MgF₂Adopting RF ion source assistance, electron beam evaporation and low-temperature cold plating; for the irregular film system with uneven thickness, the crystal oscillator is adopted for control, and simulation reverse thrust is carried out according to the result, so that continuous adjustment is carried out, and the control error is reduced; MgF₂Electron beam evaporation is adopted, a self-made crucible is used, and the splashing of the material evaporation process is avoided in a technical angle; MgF of hydrophilic film layer can be treated by adding protective layer₂And (6) protecting.

(3) The actually measured average reflectivity of the prepared antireflection film at 400-1100nm is 0.56 percent and is close to the design value. The double-sided transmittance meets the requirement of high transmittance in visible light and near infrared bands. The process is stable through verification, and large-scale production can be realized; the high-performance epoxy resin composition has good mechanical performance and excellent capability of resisting severe environment, can be used for a long time in severe environment, and has wide application prospect.

The technical innovation points comprise the following four points:

1. the design is carried out by selecting three conventional materials (the raw materials selected in the prior art are special, expensive or difficult to control, and difficult to produce stably in large batch);

2. the design process is as follows: 1) the extremely thin layer is removed, so that the control is easier, and the method is suitable for stable batch production; 2) a protective layer is added, so that the subsequent cleaning is facilitated;

3、MgF₂adopts a self-made crucible to solve the problem of MgF during the conventional electron beam evaporation₂The material is easy to splash, so that the problem of poor product surface is caused;

4、MgF₂adopting a low-voltage and high-current mode to ensure that MgF₂The low-temperature cold plating is realized, the production and electricity consumption cost is reduced, and the requirements of environmental tests are met.

Drawings

The following describes embodiments of the present invention in further detail with reference to the accompanying drawings.

FIG. 1 is a schematic diagram of a theoretically designed reflection curve of an antireflection film in the visible and near-infrared light bands in accordance with the present invention;

FIG. 2 is a schematic diagram of the final designed reflection curve of the antireflection film in the visible and near-infrared bands of the present invention;

FIG. 3 is a schematic structural view of a molybdenum crucible 1 of the present invention;

FIG. 4 is a schematic representation of the reflectivity of an antireflection film in the visible and near infrared bands in accordance with the present invention;

FIG. 5 is a schematic diagram of the transmittance of an antireflection film in the visible and near infrared bands according to the present invention;

FIG. 6 is a schematic diagram showing the relationship between the theoretical film structure and the final film structure of the antireflection film in the visible and near-infrared bands.

Detailed Description

The invention will be further described with reference to specific examples, but the scope of the invention is not limited thereto.

Example 1, visible and near infrared band antireflection films, as shown in fig. 1-5, the initial theoretical design was: comprises an initial first layer of Ti which is arranged from inside to outside in sequence₃O₅Layer, initial second layer SiO₂Layer, initial third layer Ti₃O₅Layer, initial fourth layer of SiO₂Layer, initial fifth layer Ti₃O₅Layer, initial sixth layer of SiO₂Layer, initial seventh layer Ti₃O₅Layer, initial eighth layer SiO₂Layer, initial ninth layer Ti₃O₅Layers and the initial tenth layer of MgF₂And (3) a layer.

Initial first layer of Ti₃O₅From layer to the initial tenth layer of MgF₂The physical thicknesses of the layers were 10.6, 45.08, 27.9, 19.47, 92.16, 1.97, 40.19, 27.54, 20.19, and 111.52nm, in that order.

Ti₃O₅Layer, SiO₂Layer and MgF₂The refractive indices of the layers were 2.35, 1.46, and 1.38.

According to actual production experience:

(ii) initial first layer of Ti₃O₅Inserting a layer of SiO in front of the layer₂The layer (the initial zeroth layer) serves as a bonding layer and can smooth a low reflection curve;

② the ultra-thin layer (the sixth SiO2 layer) is not easy to control and can be removed, and the initial fifth Ti layer₃O₅Layer and initial seventh layer of Ti₃O₅Merging layers;

③ the tenth MgF layer₂MgF of the layer₂Is a hydrophilic material, is extremely easy to deliquesce at the outermost layer and is difficult to pass a harsher ring test. Therefore, partial SiO is used₂Substitution of MgF₂As a protective layer; namely the tenth MgF layer₂Layer physical thickness minus 20nm, and MgF at the tenth layer₂An initial eleventh SiO layer is arranged outside the layer₂Layer (as protective layer), initially the eleventh layer of SiO₂The physical thickness of the layer was 20 nm. And then carrying out secondary optimization to obtain a final 10-layer designed reflection curve as shown in figure 2.

Therefore, the visible and near-infrared band antireflection film of the present invention finally includes: modified first layer SiO sequentially arranged from inside to outside₂Layer (initial zero layer), modified second layer Ti₃O₅Layer (initial first layer Ti₃O₅Layer), modified third layer of SiO₂Layer (initial second layer SiO)₂Layer), modified fourth layer Ti₃O₅Layer (initial third layer Ti₃O₅Layer), modified fifth layer of SiO₂Layer (initial fourth layer of SiO₂Layer), modified sixth layer Ti₃O₅Layer (initial fifth layer of SiO₂Layer and initial seventh layer of Ti₃O₅Layer combination), modified seventh layer SiO₂Layer (initial eighth layer SiO)₂Layer), modified eighth layer Ti₃O₅Layer (initial ninth layer Ti₃O₅Layer), modified ninth layer of MgF₂Layer (initial tenth layer of reduced thickness MgF)₂Layer) and modified tenth layer of SiO₂Layer (initial eleventh layer SiO)₂Layers).

Modified first layer of SiO₂Layer to modified tenth layer of SiO₂The physical thicknesses of the layers are 211.29, 9.29, 51.19, 26.1, 21.64, 133.7, 25.53, 21.07, 85.51 and 20nm in this order (with optimization, any layer variation or overall structure, layers of slight thickness variation, all thicknesses slightlyWith a variation). As shown in table 2.

TABLE 2

Modifying and secondarily optimizing to obtain the final film system

The manufacturing method of the antireflection film in visible and near infrared wave bands comprises the following steps:

the antireflection film was prepared using the equipment of Japan SHINCRON MIC-1350. Because the thickness difference of each layer of film is large and irregular, the crystal oscillator is adopted for control, and the control unit is an XTC-3S crystal film thickness meter and a 6-point type rotary controller. In the test, the backstepping simulation is carried out according to the result, the crystal oscillator control coefficient is adjusted, and the control error is eliminated. The experimental apparatus was equipped with a NIS-175-4 type RF ion source having a diameter of 175 mm.

1) And sequentially plating the modified first layer of SiO on the substrate from inside to outside (from near to far away from the basic distance) by using ion beam assisted deposition (IAD) vacuum coating technology and low-temperature cold plating (below 180℃)₂Layer, modified second layer Ti₃O₅Layer, modified third layer of SiO₂Layer, modified fourth layer Ti₃O₅Layer, modified fifth layer of SiO₂Layer, modified sixth layer Ti₃O₅Layer, modified seventh layer SiO₂Layer and modified eighth layer Ti₃O₅A layer and;

the substrate is selected according to the actual use of common K9 glass (Xuanhong K9 glass), and the thickness of the substrate is selected according to the design of an optical system;

this step requires the introduction of oxygen;

in the step 1), a copper crucible (without a crucible cover) of the existing equipment is used, and the materials and the sizes are standardized.

2) And performing low-temperature cold plating on the modified ninth MgF layer by using an ion beam assisted deposition (IAD) vacuum coating technology₂A layer;

oxygen charging is not needed, the voltage of the ion source is 200V, and the current is 600 mA;

3) and cold plating the modified tenth SiO layer by ion beam assisted deposition (IAD) vacuum coating technology at low temperature₂A layer;

this step requires the introduction of oxygen.

Process parameters of each layer in the manufacturing process

Ti3O5 and SiO2 are selected as coating materials of the antireflection film, and the antireflection film is coated by adopting a conventional IAD parameter auxiliary and low-temperature cold plating mode. MgF₂Because of its hydrophilicity, high temperature coating (above 300 ℃) is generally selected, without the aid of IAD. However, high temperature and high energy consumption inevitably affect production efficiency and shorten equipment life. Theoretical analysis and actual tests confirm that the study is assisted by low-temperature (below 180 ℃) IAD. MgF₂O is not available with IAD assistance₂MgF at high temperature of electron gun₂Can be oxidized (to become MgO after oxidation), and IAD energy can be properly adjusted by low voltage and large current, and MgF is used₂The electron gun evaporation is adopted, the surface of the molybdenum crucible is easy to oxidize and agglomerate, and the molybdenum crucible is easy to splash after being covered by MgO, so the self-made molybdenum crucible 1 (shown in figure 3) is adopted to solve the problems.

The molybdenum material is used as the crucible (the molybdenum crucible 1), the shape of the molybdenum crucible 1 is the same as that of a common molybdenum crucible, the temperature of cooling water of a rotary table of a film plating machine, which is in contact with the molybdenum crucible 1, is isolated, and the crucible can be heated quickly; a molybdenum crucible cover 2 is additionally arranged, so that an electron beam does not directly hit MgF in the heating process₂Surface, and by means of heat conduction, MgF₂The molecules are heated to overflow. The thickness of the molybdenum crucible cover 2 matched with the molybdenum crucible 1 is 0.21cm, the molybdenum crucible cover is also made of molybdenum material, and the right center of the molybdenum crucible 1 is provided with an evaporation hole 21 with the thickness of 6 mm.

The specific using method of the molybdenum crucible 1 in the step 2) comprises the following steps: MgF film material₂Putting into a molybdenum crucible 1, covering with a molybdenum crucible cover 2, and heating MgF by electron beam heat conduction through the molybdenum crucible cover 2₂Heating the film material MgF₂Formation of MgF₂Molecules overflow from the evaporation hole 21 in the center of the molybdenum crucible cover 2 and adhere to the substrate to form a coating film.

Experiment:

and (3) performing spectrum test on the antireflection film:

the method is carried out by using a reflectivity test system of a 723PCS spectrophotometer produced by Shanghai Xin Mao, the test waveband is 360-800nm, and the transmittance in the range of 390-1100nm is tested by matching with Lambda25 of PerkinElmer company because the requirement of testing a wide waveband cannot be met. By the transmittance test, fitting is performed on the reflectance of the wide band, and the reflectance and the transmittance as shown in fig. 4 and fig. 5 are obtained respectively. According to the law of conservation of energy:

R+T+L＝1 (3)

where R and T are reflectance (R includes reflection from both sides) and transmittance, respectively, L ═ a + S, and a and S are two major types of optical loss absorption and scattering in the film. Since the scattering intensity of the evaporation film is obviously dependent on the evaporation material and the preparation process, the Ti selected in the invention is adjusted according to the prior practice of mass production₃O₅、SiO₂Coating material to and assorted conventional IAD parameter, and the whole thickness of product rete is thinner, and the scattering can be ignored, so:

R+T+A＝1 (4)

according to the actual production process, Ti₃O₅Absorption begins in the wavelength band less than 410nm and increases as the wavelength becomes shorter.

According to the above, in the region with both transmission and reflection measurable at 390-800nm, the test data of each waveband is verified: r + T1+ a is 1, where R1+ R2, R1 and R2 are reflectivities of both faces, R1 is a curve shown in fig. 4, and R2 is calculated to be about 4.2 when no film is applied; t1 is the single-sided transmission shown in FIG. 5. According to verification, on the short wave side starting around 410nm, A is larger than 0, namely absorption exists, and other areas A of visible light are approximately equal to 0 and can be ignored. Depending on the material properties, a is also negligible in the near infrared band. Thus, the wavelength band of 800-1100nm is calculated, and R1 is 1-T1-4.2. Based on the above tests and calculations, the measured average reflectance at 400-.

And (3) testing the performance of the antireflection film:

in order to ensure the reliability of the subsequent use process, the following environment test is carried out on the antireflection film:

(1) film firmness test: the film surface (the substrate is not scratched through) is cut into 5 × 5 squares by a glass cutter, the film surface is cleaned, a 3M adhesive tape is stuck on the film surface, air bubbles are extruded out, the adhesive tape is pulled up in the vertical direction at the speed of 10-15cm/s, and whether the film layer falls off or not is checked. The same position is pulled for three times continuously, and the film layer is not separated.

(2) And (3) friction resistance test: after the film surface was cleaned, the surface of the film was rubbed with gauze with alcohol at a force of 5N/cm2 for 50 cycles with 30mm each time, and no surface abnormality was observed.

(3) Boiling test: the product is placed in boiling purified water and boiled for one hour (note that the product can be wrapped with gauze and placed in contact with the bottom or side walls of the pan). Taking out the product, wiping the product dry, and performing a firmness test until the film layer does not fall off;

(4) PCT (high pressure accelerated aging) test: and (3) putting the product into a PCT test box, setting the temperature at 120 ℃ and the humidity at 100% R.H., and after aging for 3 hours, taking out the product without surface abnormality.

(5) Ultrasonic cleaning test: according to the method for cleaning the finished product film layer, the product is rinsed by alkaline solution with the pH value of 12 (the ratio of the solution to water is 1:100) in a tank, then rinsed by clean water in 5 tanks, slowly pulled and cut, and then dried by spin. The single-tank ultrasonic power is 900 KW. The product characteristics are not obviously changed after three times of continuous cleaning.

(6) The subsequent continuous production process has stable product surface and no MgF₂A splash phenomenon.

The tests show that the improvement of the MgF2 crucible cleaning tester directly shows the feasibility and stability of mass production of products and meets the process requirements of mass production; the firmness and the friction resistance test result are the embodiment of good mechanical property of the optical film; the boiling test and the PCT (high pressure accelerated aging) test show that the product has good capability of resisting severe environment and meets the requirement of military and civil camera systems for use in severe environment.

In summary, the 10-layer antireflection film is analyzed according to an empirical formula of the antireflection film, a common coating material is selected, a conventional RF ion source assistance, electron beam evaporation and low-temperature cold plating are used, and a batch production process is modified, so that large-scale stable production can be realized, high transmittance in 400-1100nm visible light and near infrared light bands is achieved, and the 10-layer antireflection film has good mechanical properties and severe environment resistance. The multilayer broadband antireflection film meets the requirement of high permeability of an image system to visible to near-infrared wave bands in a severe environment in military affairs, and meets the requirements of large demand, large-scale and low-cost production in civil use.

Finally, it is also noted that the above-mentioned lists merely illustrate a few specific embodiments of the invention. It is obvious that the invention is not limited to the above embodiments, but that many variations are possible. All modifications which can be derived or suggested by a person skilled in the art from the disclosure of the present invention are to be considered within the scope of the invention.

Claims

1. The visible and near-infrared light band antireflection film is characterized in that:

comprises sequentially arranging a first SiO layer on a substrate from inside to outside₂Layer, second layer Ti₃O₅Layer, third layer of SiO₂Layer, fourth layer Ti₃O₅Layer, fifth layer of SiO₂Layer, sixth layer Ti₃O₅Layer, seventh layer SiO₂Layer, eighth layer Ti₃O₅Layer, ninth layer of MgF₂Layer and tenth SiO₂A layer;

first layer of SiO₂Layer, second layer Ti₃O₅Layer, third layer of SiO₂Layer, fourth layer Ti₃O₅Layer, fifth layer of SiO₂Layer, sixth layer Ti₃O₅Layer, seventh layer SiO₂Layer, eighth layer Ti₃O₅Layer, ninth layer of MgF₂Layer and tenth SiO₂The physical thickness of the layers is 211.29, 9.29, 51.19, 26.1, 21.64, 133.7, 25.53, 21.07, 85.51 and 20nm in that order;

the substrate was K9 glass.

2. The method of manufacturing an antireflection film in the visible and near-infrared wavelength bands of claim 1, comprising the steps of:

the coating method comprises the following steps:

MgF film material₂Putting the mixture into a molybdenum crucible (1), covering a molybdenum crucible cover (2), and heating the film material MgF by the electron beam through the heat conduction of the molybdenum crucible cover (2)₂Heating the film material MgF₂Formation of MgF₂Molecules overflow from an evaporation hole (21) on the molybdenum crucible cover (2) and are attached to the base material to form a coating film;

3. The method of claim 2, wherein the antireflection film is formed by:

plating a ninth MgF layer₂Layer (b): controlling the deposition rate to be 0.4nm/s, the ion source voltage to be 200V, the ion source current to be 600mA and the ion source argon to be 40 SCCM;