Wide-spectrum anti-reflection film layer and preparation method thereof

Abstract

The invention relates to the technical field of optical thin films, in particular to a wide-spectrum anti-reflection film layer and a preparation method thereof. A wide-spectrum anti-reflection film layer comprises a first high-refraction material layer, a first low-refraction material layer, a second high-refraction material layer, a second low-refraction material layer, a third high-refraction material layer and a third low-refraction material layer which are sequentially arranged in a stacked mode, and the total thickness of the wide-spectrum anti-reflection film layer is 200 nm or above. The thicknesses of the material layers are 10 nm to 12 nm, 30 nm to 35 nm, 25 nm to 35 nm, 15 nm to 25 nm, 25 nm to 30 nm and 90 nm to 100 nm in sequence. The wide-spectrum anti-reflection film layer, the high-refractive-index material layer and the low-refractive-index material layer are alternately arranged, and the appropriate thicknesses of all the layers are matched with one another, so that light rays of the touch screen are subjected to light interference cancellation, the reflectivity of the glass surface can be effectively reduced, and the reflection film layer has ultra-low assembly reflectivity in a wide spectrum.

Description

Technical Field

[0001] This invention relates to the field of optical thin film technology, and more specifically, to a broadband antireflective film and its preparation method. Background Technology

[0002] The development of ultra-low reflection (UDR) coating technology is a key direction in optics, display, and photovoltaic fields. It aims to achieve near-zero reflection optical surfaces through multi-layer thin-film structures, thereby improving light transmittance, reducing stray light, and increasing system efficiency. UDR coatings utilize the interference effect of light, employing multiple thin-film refractive index gradient designs to cancel out reflected light. The core requirements for UDR coatings are: reducing surface reflectivity to minimize ambient light reflection and improve display contrast; increasing transmittance to reduce light loss from the panel surface; and enhancing wide-viewing-angle performance to ensure color and height consistency across large viewing angles.

[0003] Currently, the AR film layer of touch screens has relatively high reflectivity, which cannot meet the requirement of ultra-low reflectivity across a wide spectrum.

[0004] In view of this, the present invention is hereby proposed. Summary of the Invention

[0005] One object of the present invention is to provide a broadband antireflective coating that enables the reflective coating to have an ultra-low overall reflectivity over a broadband spectrum.

[0006] Another object of the present invention is to provide a method for preparing a broadband antireflective film.

[0007] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted: A broadband antireflective coating layer comprises a first high-refractive-index material layer, a first low-refractive-index material layer, a second high-refractive-index material layer, a second low-refractive-index material layer, a third high-refractive-index material layer, and a third low-refractive-index material layer stacked sequentially, wherein the total thickness of the broadband antireflective coating layer is greater than 200 nm.

[0008] The thickness H1 of the first high-refractive-index material layer is 10~12 nm.

[0009] The thickness H2 of the first low-refractive material layer is 30~35nm.

[0010] The thickness H3 of the second high-refractive-index material layer is 25~35nm.

[0011] The thickness H4 of the second low-refractive-index material layer is 15~25nm.

[0012] The thickness H5 of the third high-refractive-index material layer is 25~30nm.

[0013] The thickness H6 of the third low-refractive material layer is 90~100nm.

[0014] In some embodiments, the first high-refractive-index material layer, the second high-refractive-index material layer, and the third high-refractive-index material layer are one or more of Nb2O5 layer, TiO2 layer, Al2O3 layer, Ta2O5 layer, or AZO layer, and the first low-refractive-index material layer, the second low-refractive-index material layer, and the third low-refractive-index material layer are one or more of SiO2 layer or MgF2 layer.

[0015] In some embodiments, the thickness H1 of the first high-refractive-index material layer is 11-12 nm; the thickness H2 of the first low-refractive-index material layer is 31-32 nm; the thickness H3 of the second high-refractive-index material layer is 28-29 nm; the thickness H4 of the second low-refractive-index material layer is 21-22 nm; the thickness H5 of the third high-refractive-index material layer is 27-28 nm; and the thickness H6 of the third low-refractive-index material layer is 94-95 nm.

[0016] In some embodiments, the overall reflectivity of the broadband antireflective film in the wavelength range of 400~700nm is <0.3%.

[0017] The method for preparing the broadband antireflective coating as described above includes the following steps: (a) The substrate is pretreated to obtain a pretreated substrate.

[0018] (b) A first high-refractive-index material layer, a first low-refractive-index material layer, a second high-refractive-index material layer, a second low-refractive-index material layer, a third high-refractive-index material layer and a third low-refractive-index material layer are sequentially prepared on one side surface of the pretreated substrate to form a broadband anti-reflection film.

[0019] In some embodiments, the pretreatment includes cleaning with a cleaning solution, ultrasonic cleaning, brush cleaning, and drying.

[0020] In some embodiments, the cleaning solution used for cleaning includes an alkaline solution with a mass concentration of 4% to 6%; the temperature of the cleaning solution is 40 to 50°C.

[0021] In some embodiments, the ultrasonic cleaning uses an ultrasonic frequency of 23-33 Hz, a temperature of 40-50°C, a power ratio greater than 80%, and a reagent pH of 6-10.

[0022] In some embodiments, the rotation speed of the disc brush cleaning is 200~400 rpm, and the disc brush cleaning uses an alkaline solution with a pH of 7.2~10.

[0023] In some embodiments, the drying is performed by air knife drying, with an exhaust pressure of 45-55 Pa.

[0024] In some embodiments, the broadband antireflective coating is prepared by PVD coating.

[0025] In some embodiments, the working gas for the PVD coating includes Ar.

[0026] In some embodiments, the reaction gas for the PVD coating is O2; depending on the different O2 inlet settings, the reaction gas includes main oxygen, lower oxygen, middle oxygen, and upper oxygen.

[0027] In some embodiments, the preparation conditions of the first high-refractive-index material layer include: a power of 8-9.2 kW, a working gas flow rate of 150-170 sccm, a main oxygen flow rate of 50-65 sccm, a lower oxygen flow rate of 15-25 sccm, a middle oxygen flow rate of 8-15 sccm, and an upper oxygen flow rate of 20-30 sccm.

[0028] In some embodiments, the preparation conditions of the first low-refractive material layer include: power of 4.5~5.5KW; working gas flow rate of 150~170sccm; main oxygen flow rate of 60~70sccm, lower oxygen flow rate of 30~40sccm, middle oxygen flow rate of 15~25sccm, and upper oxygen flow rate of 25~35sccm.

[0029] In some embodiments, the preparation conditions of the second high-refractive-index material layer include: a power of 9-10 kW; a working gas flow rate of 150-170 sccm; a main oxygen flow rate of 60-70 sccm; a lower oxygen flow rate of 10-20 sccm; a middle oxygen flow rate of 10-20 sccm; and an upper oxygen flow rate of 8-12 sccm.

[0030] In some embodiments, the preparation conditions of the second low-refractive material layer include: a power of 5-6 kW, a working gas flow rate of 150-170 sccm, a main oxygen flow rate of 75-85 sccm, a lower oxygen flow rate of 8-12 sccm, a middle oxygen flow rate of 10-15 sccm, and an upper oxygen flow rate of 8-12 sccm.

[0031] In some embodiments, the preparation conditions of the third high-refractive-index material layer include: a power of 10-11 kW; a working gas flow rate of 150-170 sccm; a main oxygen flow rate of 55-65 sccm; a lower oxygen flow rate of 8-15 sccm; a middle oxygen flow rate of 10-13 sccm; and an upper oxygen flow rate of 14-20 sccm.

[0032] In some embodiments, the preparation conditions of the third low-refractive material layer include: power of 5~8.5KW; working gas flow rate of 150~170sccm; main oxygen flow rate of 60~70sccm, lower oxygen flow rate of 20~30sccm, middle oxygen flow rate of 19~25sccm, and upper oxygen flow rate of 22~30sccm.

[0033] In some embodiments, a coating shielding device is used in the preparation of the broadband antireflective film; the coating shielding device has a frame structure adapted to the shape of the substrate layer, and the substrate layer is placed inside the frame structure of the coating shielding device to prepare the broadband antireflective film.

[0034] In some embodiments, the gap between the coating shielding device and the substrate layer is 0.5~2mm.

[0035] In some embodiments, the thickness difference between the coating shielding device and the substrate layer is 0~0.2mm.

[0036] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The broadband anti-reflection film of the present invention is formed by alternating high refractive index material layer and low refractive index material layer to form a broadband anti-reflection film with a six-layer structure. The appropriate thickness of each layer is matched with each other so that the light of the touch screen is canceled by light interference, which can effectively reduce the reflectivity of the glass surface and make the reflective film have ultra-low overall reflectivity in the broadband spectrum.

[0037] (2) The method for preparing the broadband antireflective film of the present invention, through the coordinated cooperation of each step, can ensure that the obtained broadband antireflective film has a low reflection effect in a wide spectrum range.

[0038] (3) In the preparation process of the broadband anti-reflection film, the present invention uses a coating shielding device and controls the gap and thickness difference with the substrate to effectively suppress the deposition of the side film. Through the shielding effect of the shielding device, the sputtering and deposition of particles at the glass edge during the coating process are reduced, so that the particles are deposited on the shielding device and the side film accumulation is reduced. Attached Figure Description

[0039] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0040] Figure 1This is a wavelength-reflectivity diagram of the broadband antireflection film in Embodiment 1 of the present invention; Figure 2 This is a schematic diagram showing the placement of the coating shielding device and the substrate layer according to the present invention; Figure 3 Wavelength-reflectivity diagram of the broadband antireflection film in Embodiment 2 of the present invention; Figure 4 Wavelength-reflectivity diagram of the broadband antireflection film in Embodiment 3 of the present invention; Figure 5 Wavelength-reflectivity diagram of the broadband antireflection film in Embodiment 4 of the present invention; Figure 6 This is a wavelength-reflectivity diagram of the reflective film layer in Comparative Example 1 of the present invention. Detailed Implementation

[0041] The embodiments of the present invention will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are for illustrative purposes only and should not be considered as limiting the scope of the invention. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer are followed. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0042] According to one aspect of the present invention, the present invention relates to a broadband antireflective coating layer, the broadband antireflective coating layer comprising a first high-refractive-index material layer, a first low-refractive-index material layer, a second high-refractive-index material layer, a second low-refractive-index material layer, a third high-refractive-index material layer, and a third low-refractive-index material layer stacked sequentially, wherein the total thickness of the broadband antireflective coating layer is greater than 200 nm, for example 202 nm, 205 nm, 208 nm, 210 nm, 212 nm, 215 nm, 220 nm, 225 nm, 230 nm, etc.; the thickness H1 of the first high-refractive-index material layer is 10~12 nm; the thickness H2 of the first low-refractive-index material layer is 30~35 nm; the thickness H3 of the second high-refractive-index material layer is 25~35 nm; the thickness H4 of the second low-refractive-index material layer is 15~25 nm; the thickness H5 of the third high-refractive-index material layer is 25~30 nm; and the thickness H6 of the third low-refractive-index material layer is 90~100 nm.

[0043] The broadband antireflective film of the present invention forms a six-layer broadband antireflective film by alternating layers of high-refractive-index material and low-refractive-index material. The appropriate thickness of each layer is matched with each other so that the light from the touch screen is canceled by light interference, which can effectively reduce the reflectivity of the glass surface and make the reflective film have an ultra-low overall reflectivity in a broadband spectrum.

[0044] In some embodiments, the thickness H1 of the first high-refractive-index material layer is 10 nm, 10.2 nm, 10.5 nm, 10.8 nm, 11 nm, 11.5 nm, 12 nm, or any value between the two.

[0045] In some embodiments, the thickness H2 of the first low-refractive material layer is 30nm, 31nm, 32nm, 33nm, 34nm, 35nm, or any value between the two.

[0046] In some embodiments, the thickness H3 of the second high-refractive-index material layer is 25nm, 26nm, 27nm, 28nm, 29nm, 30nm, 32nm, 35nm, or any value between the two.

[0047] In some embodiments, the thickness H4 of the second low-refractive material layer is 15nm, 16nm, 17nm, 18nm, 19nm, 20nm, 22nm, 25nm, or any value between the two.

[0048] In some embodiments, the thickness H5 of the third high-refractive-index material layer is 25nm, 26nm, 27nm, 28nm, 29nm, 30nm, or any value between the two.

[0049] In some embodiments, the thickness H6 of the third low-refractive-index material layer is 90nm, 91nm, 92nm, 95nm, 98nm, 100nm, or any value between the two.

[0050] The first high-refractive-index material layer, the first low-refractive-index material layer, the second high-refractive-index material layer, the second low-refractive-index material layer, the third high-refractive-index material layer, and the third low-refractive-index material layer of the present invention have suitable thicknesses, and the layers cooperate with each other to maintain the low reflectivity of the film layer in a wide spectral range.

[0051] In some embodiments, the first high refractive index material layer, the second high refractive index material layer, and the third high refractive index material layer are one or more of Nb2O5 layer, TiO2 layer, Al2O3 layer, Ta2O5 layer, or AZO layer.

[0052] In some embodiments, the first low-refractive-index material layer, the second low-refractive-index material layer, and the third low-refractive-index material layer are one or more of SiO2 layer or MgF2 layer; in some embodiments, the thickness H1 of the first high-refractive-index material layer is 11~12 nm; the thickness H2 of the first low-refractive-index material layer is 31~32 nm; the thickness H3 of the second high-refractive-index material layer is 28~29 nm; the thickness H4 of the second low-refractive-index material layer is 21~22 nm; the thickness H5 of the third high-refractive-index material layer is 27~28 nm; and the thickness H6 of the third low-refractive-index material layer is 94~95 nm.

[0053] In some embodiments, the broadband antireflective film has an overall reflectivity of <0.3% in the wavelength range of 400~700nm. The film of the present invention has a low overall reflectivity in the aforementioned broadband range.

[0054] In some embodiments, a broadband antireflective coating is located on one side surface of the substrate. The substrate is a glass substrate; the thickness of the substrate is 0.4~1.3mm, for example 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 1mm, 1.3mm, etc.

[0055] According to another aspect of the present invention, the present invention also relates to a method for preparing the broadband antireflective coating as described above, comprising the following steps: (a) The substrate is pretreated to obtain a pretreated substrate; (b) A first high-refractive-index material layer, a first low-refractive-index material layer, a second high-refractive-index material layer, a second low-refractive-index material layer, a third high-refractive-index material layer and a third low-refractive-index material layer are sequentially prepared on one side surface of the pretreated substrate to form a broadband anti-reflection film.

[0056] The method for preparing the broadband antireflective film of the present invention, through the coordinated operation of each step, can ensure that the obtained broadband antireflective film has a low reflectance effect over a wide spectral range.

[0057] In some embodiments, the pretreatment includes cleaning with a cleaning solution, ultrasonic cleaning, disc brush cleaning, and drying. This invention, through appropriate pretreatment, can ensure the cleanliness of the substrate surface and improve the adhesion of the broadband antireflective film, thus guaranteeing the broadband low reflectivity effect of the final composite film.

[0058] In some embodiments, the cleaning solution used for cleaning includes: an alkaline solution (e.g., potassium hydroxide) with a mass concentration of 4% to 6% (e.g., 4%, 5%, 6%); and the temperature of the cleaning solution is 40 to 50°C (e.g., 40°C, 45°C, 50°C). A cleaning solution with suitable concentration and temperature can ensure the cleaning effect of surface contaminants.

[0059] In some embodiments, the ultrasonic cleaning uses an ultrasonic frequency of 23-33 Hz (e.g., 23 Hz, 25 Hz, 27 Hz, 30 Hz, 33 Hz, etc.), a temperature of 40-50°C (e.g., 40°C, 42°C, 45°C, 47°C, 50°C, etc.), a power ratio greater than 80% (e.g., 81%, 82%, 85%, 88%, etc.), and a reagent pH of 6-10 (e.g., 6, 7, 8, 9, or 10, etc.).

[0060] In some embodiments, the rotation speed of the disc brush cleaning is 200-400 rpm (e.g., 200 rpm, 250 rpm, 300 rpm, 350 rpm, 400 rpm, etc.), the disc brush cleaning uses an alkaline solution (e.g., potassium hydroxide), and the pH of the disc brush cleaning is 7.2-10 (e.g., 7.2, 8, 9, 10, etc.). Suitable disc brush cleaning combined with cleaning solution cleaning and ultrasonic cleaning can improve the surface condition of the substrate layer, thus facilitating subsequent film preparation.

[0061] In some embodiments, the drying is performed using an air knife, with an exhaust pressure of 45-55 Pa, such as 45 Pa, 48 Pa, 50 Pa, or 55 Pa. Suitable drying conditions can ensure the drying effect, avoid damage to the substrate, and facilitate subsequent film preparation.

[0062] In some embodiments, the broadband antireflective coating is prepared by PVD coating, i.e., vacuum coating.

[0063] In some embodiments, the working gas for the PVD coating includes Ar.

[0064] In some embodiments, the reactive gas for the PVD coating is O2.

[0065] In some embodiments, the reactant gases include main oxygen, lower oxygen, middle oxygen, and upper oxygen, depending on the different O2 inlet configurations. In some embodiments, the first high-refractive-index material layer, the first low-refractive-index material layer, the second high-refractive-index material layer, the second low-refractive-index material layer, the third high-refractive-index material layer, and the third low-refractive-index material layer of the broadband antireflective coating are prepared in their respective independent coating chambers. Each coating chamber is independently provided with a main inlet, a lower inlet, a middle inlet, and an upper inlet, arranged sequentially from bottom to top of the coating chamber; the main oxygen enters through the main inlet, the lower oxygen enters through the lower inlet, the middle oxygen enters through the middle inlet, and the upper oxygen enters through the upper inlet. In some embodiments, the main inlet is located on the top wall of the coating chamber. In some embodiments, the upper inlet is located in the upper region of the coating chamber, close to the top wall. In some embodiments, the middle inlet is located in the middle region of the coating chamber, for example, in the central region. In some embodiments, the lower inlet is located in the bottom region of the coating chamber, close to the bottom wall of the coating chamber. In some embodiments, the upper inlet is 8-15 cm from the top wall of the coating chamber. In some embodiments, the lower inlet is 8-15 cm from the bottom wall of the coating chamber. In some embodiments, the pretreatment substrate is 25-35 cm from the bottom wall of the coating chamber.

[0066] This invention ensures coating effect and improves film quality and performance by setting appropriate main oxygen, lower oxygen, middle oxygen and upper oxygen, thereby helping to make the obtained broadband antireflection film have a low overall reflectivity in the wavelength range of 400~700nm.

[0067] In various embodiments of the present invention, the first high-refractive-index material layer, the first low-refractive-index material layer, the second high-refractive-index material layer, the second low-refractive-index material layer, the third high-refractive-index material layer, and the third low-refractive-index material layer of the broadband antireflective coating are prepared in their respective independent coating chambers. Each coating chamber is independently provided with a main inlet, a lower inlet, a middle inlet, and an upper inlet, arranged sequentially from the bottom to the top of the coating chamber; main oxygen is introduced through the main inlet, lower oxygen through the lower inlet, middle oxygen through the middle inlet, and upper oxygen through the upper inlet. The main inlet is located on the top wall of the coating chamber. The upper inlet is 10 cm away from the top wall of the coating chamber. The lower inlet is 10 cm away from the bottom wall of the coating chamber. The pretreatment substrate is 30 cm away from the bottom wall of the coating chamber.

[0068] In some embodiments, the preparation conditions of the first high-refractive-index material layer include: a power of 8-9.2 kW (e.g., 8 kW, 8.2 kW, 8.5 kW, 8.9 kW, or 9 kW); a working gas flow rate of 150-170 sccm (e.g., 150 sccm, 155 sccm, 160 sccm, 165 sccm, or 170 sccm); a main oxygen flow rate of 50-65 sccm (e.g., 50 sccm, 55 sccm, 60 sccm, or 65 sccm); a lower oxygen flow rate of 15-25 sccm (e.g., 15 sccm, 18 sccm, 20 sccm, or 25 sccm); a middle oxygen flow rate of 8-15 sccm (e.g., 8 sccm, 10 sccm, 12 sccm, or 15 sccm); and an upper oxygen flow rate of 20-30 sccm (e.g., 20 sccm, 22 sccm, 25 sccm, 27 sccm, or 30 sccm).

[0069] In some embodiments, the preparation conditions of the first low-refractive material layer include: a power of 4.5~5.5KW (e.g., 4.5KW, 4.8KW, 5KW, 5.2KW, 5.5KW, etc.), a working gas flow rate of 150~170sccm (e.g., 150sccm, 160sccm, 165sccm, 170sccm, etc.); a main oxygen flow rate of 60~70sccm (e.g., 60sccm, 62sccm, 65sccm, 70sccm, etc.), a lower oxygen flow rate of 30~40sccm (e.g., 30sccm, 32sccm, 35sccm, 38sccm or 40sccm), a middle oxygen flow rate of 15~25sccm (e.g., 15sccm, 18sccm, 20sccm, 22sccm, 25sccm), and an upper oxygen flow rate of 25~35sccm (e.g., 25sccm, 28sccm, 30sccm, 35sccm, etc.).

[0070] In some embodiments, the preparation conditions of the second high-refractive-index material layer include: a power of 9-10 kW (e.g., 9 kW, 9.1 kW, 9.3 kW, 9.5 kW, or 10 kW), a working gas flow rate of 150-170 sccm (e.g., 150 sccm, 155 sccm, 160 sccm, 170 sccm), a main oxygen flow rate of 60-70 sccm (e.g., 60 sccm, 62 sccm, 65 sccm, 68 sccm, 70 sccm), a lower oxygen flow rate of 10-20 sccm (e.g., 10 sccm, 12 sccm, 15 sccm, 18 sccm, 20 sccm), a middle oxygen flow rate of 10-20 sccm (e.g., 10 sccm, 12 sccm, 15 sccm, 18 sccm, or 20 sccm), and an upper oxygen flow rate of 8-12 sccm (e.g., 8 sccm, 10 sccm, 11 sccm, 12 sccm).

[0071] In some embodiments, the preparation conditions of the second low-refractive material layer include: a power of 5-6 kW, such as 5 kW, 5.2 kW, 5.5 kW, 6 kW, etc.; a working gas flow rate of 150-170 sccm (e.g., 150 sccm, 155 sccm, 160 sccm, 165 sccm, 170 sccm, etc.); a main oxygen flow rate of 75-85 sccm (e.g., 75 sccm, 78 sccm, 80 sccm, or 85 sccm, etc.); a lower oxygen flow rate of 8-12 sccm (e.g., 8 sccm, 9 sccm, 10 sccm, 11 sccm, or 12 sccm, etc.); a middle oxygen flow rate of 10-15 sccm (e.g., 10 sccm, 11 sccm, 12 sccm, 13 sccm, 15 sccm, etc.); and an upper oxygen flow rate of 8-12 sccm (e.g., 8 sccm, 9 sccm, 10 sccm, 11 sccm, or 12 sccm, etc.).

[0072] In some embodiments, the preparation conditions of the third high-refractive-index material layer include: a power of 10-11 kW (e.g., 10 kW, 10.2 kW, 10.5 kW, 10.7 kW, 11 kW, etc.), a working gas flow rate of 150-170 sccm (e.g., 150 sccm, 155 sccm, 160 sccm, 165 sccm, 170 sccm, etc.), and a main oxygen flow rate of 55-65 sccm (e.g., 55 sccm, 58 sccm, 60 sccm, etc.). The flow rates for lower oxygen are 8-15 sccm (e.g., 8 sccm, 9 sccm, 10 sccm, 12 sccm or 15 sccm), for middle oxygen is 10-13 sccm (e.g., 10 sccm, 11 sccm, 12 sccm, 13 sccm), and for upper oxygen is 14-20 sccm (e.g., 14 sccm, 15 sccm, 17 sccm, 20 sccm).

[0073] In some embodiments, the preparation conditions of the third low-refractive material layer include: a power of 5~8.5KW (5KW, 6KW, 7KW, 8.5KW); a working gas flow rate of 150~170sccm (e.g., 150sccm, 155sccm, 160sccm, 170sccm, etc.); a main oxygen flow rate of 60~70sccm (e.g., 60sccm, 62sccm, 65sccm, 68sccm, 70sccm, etc.); a lower oxygen flow rate of 20~30sccm (e.g., 20sccm, 22sccm, 25sccm, 28sccm, or 30sccm, etc.); and a middle oxygen flow rate of 19~25sccm (e.g., 19sccm, 20sccm, 21sccm, 22sccm). The oxygen flow rate is 22~30 sccm (e.g., 22 sccm, 23 sccm, 25 sccm, 26 sccm, 30 sccm, etc.).

[0074] In some embodiments, the first, second, and third high-refractive-index material layers are prepared using at least one pair of targets; the first, second, and third low-refractive-index material layers are prepared using at least one pair of targets. In some embodiments, the first high-refractive-index material layer uses one pair of targets; the first low-refractive-index material layer uses two pairs of targets; the second high-refractive-index material layer uses two pairs of targets; the second low-refractive-index material layer uses one pair of targets; the third high-refractive-index material layer uses two pairs of targets; and the third low-refractive-index material layer uses three pairs of targets.

[0075] This invention controls each layer to meet the above-mentioned suitable preparation conditions so that each film layer has suitable thickness and uniformity and excellent performance, so as to obtain a low reflectivity film layer with a wide spectral range through coordinated cooperation.

[0076] In some embodiments, the broadband antireflective film preparation system of the present invention includes a film preparation device and a conveying device; along the conveying direction of the conveying device, the film preparation device includes a first high-refractive-index material layer preparation unit, a first low-refractive-index material layer preparation unit, a second high-refractive-index material layer, a second low-refractive-index material layer, a third high-refractive-index material layer preparation unit, and a third low-refractive-index material layer preparation unit arranged sequentially; the substrate layer passes through the first high-refractive-index material layer preparation unit, the first low-refractive-index material layer preparation unit, the second high-refractive-index material layer, the second low-refractive-index material layer, the third high-refractive-index material layer preparation unit, and the third low-refractive-index material layer preparation unit in the conveying device in sequence, and obtains the corresponding film layer.

[0077] In some embodiments, a coating shielding device is used during the fabrication of the broadband antireflective coating. The coating shielding device has a frame structure adapted to the shape of the substrate layer. The substrate layer is placed inside the frame structure of the coating shielding device, and the broadband antireflective coating is fabricated during this process. In some embodiments, the gap between the coating shielding device and the substrate layer is 0.5~2mm (e.g., 0.5mm, 0.8mm, 1mm, 1.5mm, 2mm, etc.). In some embodiments, the thickness difference between the coating shielding device and the substrate layer is 0~0.2mm (e.g., 0.1mm, 0.12mm, 0.15mm, 0.2mm, etc.).

[0078] During magnetron sputtering, a phenomenon called "wrap-around deposition" occurs. This refers to the phenomenon where particles, during deposition, not only occur on the directly exposed surface of the glass but also wrap around to the sides of the workpiece and other non-direct-view paths. Thick film deposition on the glass sides can lead to yellowing and shine. This invention, by employing the aforementioned film-shielding device and controlling the gap and thickness difference with the substrate, effectively suppresses side film deposition. The shielding effect of the device reduces particle sputtering and deposition at the glass edges during the coating process, causing particles to deposit on the shielding device and reducing side film buildup.

[0079] The following explanation, combined with specific embodiments and comparative examples, further illustrates the point.

[0080] Example 1 A broadband antireflective coating is located on one side surface of a substrate layer. Along a direction away from the substrate layer, the broadband antireflective coating layer comprises a first Nb₂O₅ layer, a first SiO₂ layer, a second Nb₂O₅ layer, a second SiO₂ layer, a third Nb₂O₅ layer, and a third SiO₂ layer, sequentially stacked. The substrate layer has a thickness of 0.8 mm.

[0081] The thickness H1 of the first Nb2O5 layer is 12 nm.

[0082] The thickness H2 of the first SiO2 layer is 31 nm.

[0083] The thickness H3 of the second Nb2O5 layer is 29 nm.

[0084] The thickness H4 of the second SiO2 layer is 21 nm.

[0085] The thickness H5 of the third Nb2O5 layer is 28 nm.

[0086] The thickness H6 of the third SiO2 layer is 95 nm.

[0087] The method for preparing the broadband antireflective film in this embodiment includes the following steps: (a) The substrate is pretreated, including cleaning with a cleaning solution, ultrasonic cleaning, disc brush cleaning, and drying. The cleaning solution used is a 5% potassium hydroxide solution at a temperature of 45°C. The ultrasonic cleaning uses an ultrasonic frequency of 25Hz, a temperature of 45°C, a power ratio of 85%, and a reagent pH of 8. The disc brush cleaning operates at a rotation speed of 300 rpm and a pH of 7.5. Drying is performed using an air knife with an exhaust pressure of 50 Pa. The pretreated substrate is obtained through this pretreatment process.

[0088] (b) A first Nb₂O₅ layer, a first SiO₂ layer, a second Nb₂O₅ layer, a second SiO₂ layer, a third Nb₂O₅ layer, and a third SiO₂ layer are sequentially prepared on one side surface of the pretreated substrate by PVD, specifically including: A first Nb2O5 layer is deposited on one side of the pretreated substrate: there is one pair of targets, the power is 8.96KW, the flow rate of the working gas is 160sccm; the flow rate of the main oxygen is 60sccm, the flow rate of the lower oxygen is 20sccm, the flow rate of the middle oxygen is 10sccm, and the flow rate of the upper oxygen is 25sccm.

[0089] A first SiO2 layer is deposited on the surface of the first Nb2O5 layer: two pairs of targets are used, with power of 5.06KW and 5.07KW respectively; the flow rate of the working gas is 160sccm; the flow rate of the main oxygen is 65sccm, the flow rate of the lower oxygen is 32sccm, the flow rate of the middle oxygen is 19sccm, and the flow rate of the upper oxygen is 27sccm.

[0090] A second Nb2O5 layer is deposited on the surface of the first SiO2 layer by vapor deposition: two pairs of targets are used, with power of 9.6KW and 9.7KW respectively; the flow rate of the working gas is 160sccm; the flow rate of the main oxygen is 60sccm, the flow rate of the lower oxygen is 15sccm, the flow rate of the middle oxygen is 15sccm, and the flow rate of the upper oxygen is 10sccm.

[0091] A second SiO2 layer is deposited on the surface of the second Nb2O5 layer: a pair of targets are used, the power is 5.56KW, the flow rate of the working gas is 160sccm; the flow rate of the main oxygen is 80sccm, the flow rate of the lower oxygen is 11sccm, the flow rate of the middle oxygen is 12sccm, and the flow rate of the upper oxygen is 11sccm.

[0092] A third Nb2O5 layer is deposited on the surface of the second SiO2 layer: two pairs of targets are used, with a power of 10.35KW; the flow rate of the working gas is 160sccm; the flow rate of the main oxygen is 60sccm, the flow rate of the lower oxygen is 10sccm, the flow rate of the middle oxygen is 12sccm, and the flow rate of the upper oxygen is 15sccm.

[0093] A third SiO2 layer was deposited on the surface of the third Nb2O5 layer by vapor deposition: three pairs of targets were used, with power of 8.36KW, 8.26KW and 8.36KW respectively; the flow rate of the working gas was 160sccm; the flow rate of the main oxygen was 65sccm, the flow rate of the lower oxygen was 27sccm, the flow rate of the middle oxygen was 24sccm and the flow rate of the upper oxygen was 23sccm.

[0094] The fabrication process of broadband antireflective coatings employs coating shielding devices, such as... Figure 2 As shown, the coating masking device has a frame structure adapted to the shape of the substrate. The substrate is placed inside the frame structure of the coating masking device, and a broadband antireflective film is prepared. The gap between the coating masking device and the substrate is 0.6 mm. The thickness difference between the coating masking device and the substrate is 0.1 mm.

[0095] Example 2 A broadband antireflective coating layer, which differs from Example 1 in that: The thickness H1 of the first Nb2O5 layer is 11.5 nm.

[0096] The thickness H2 of the first SiO2 layer is 31.5 nm.

[0097] The thickness H3 of the second Nb2O5 layer is 28.5 nm.

[0098] The thickness H4 of the second SiO2 layer is 21 nm.

[0099] The thickness H5 of the third Nb2O5 layer is 27.5 nm.

[0100] The thickness H6 of the third SiO2 layer is 94.5 nm.

[0101] The method for preparing the broadband antireflective film in this embodiment differs from that in Example 1 in that it is prepared according to the thickness described above in this embodiment.

[0102] The power consumption during the preparation of the first Nb2O5 layer was 9.15 kW.

[0103] The power consumption during the preparation of the first SiO2 layer was 5.06KW and 5.07KW, respectively.

[0104] The power consumption during the preparation of the second Nb2O5 layer was 9.7KW and 9.6KW, respectively.

[0105] The power consumption during the preparation of the second SiO2 layer was 5.56 kW.

[0106] The power consumption during the preparation of the third Nb2O5 layer was 10.35 kW.

[0107] The power consumption during the preparation of the third SiO2 layer was 8.36KW, 8.26KW, and 8.36KW, respectively.

[0108] Example 3 A broadband antireflective coating layer, which differs from Example 1 in that: The thickness H1 of the first Nb2O5 layer is 11 nm.

[0109] The thickness H2 of the first SiO2 layer is 32 nm.

[0110] The thickness H3 of the second Nb2O5 layer is 29 nm.

[0111] The thickness H4 of the second SiO2 layer is 22 nm.

[0112] The thickness H5 of the third Nb2O5 layer is 28 nm.

[0113] The thickness H6 of the third SiO2 layer is 94 nm.

[0114] The method for preparing the broadband antireflective film in this embodiment differs from that in Example 1 in that it is prepared according to the thickness described above in this embodiment.

[0115] The power consumption during the preparation of the first Nb2O5 layer was 8.96 kW.

[0116] The power consumption during the preparation of the first SiO2 layer was 5.06KW and 5.07KW, respectively.

[0117] The power consumption during the preparation of the second Nb2O5 layer was 9.9KW and 9.98KW, respectively.

[0118] The power consumption during the preparation of the second SiO2 layer was 5.56 kW.

[0119] The power consumption during the preparation of the third Nb2O5 layer was 10.35 kW.

[0120] The power consumption during the preparation of the third SiO2 layer was 8.36KW, 8.26KW, and 8.36KW, respectively.

[0121] Example 4 A broadband antireflective coating layer, which differs from Example 1 in that: The thickness H1 of the first Nb2O5 layer is 10 nm; The thickness H2 of the first SiO2 layer is 30 nm; The thickness H3 of the second Nb2O5 layer is 25 nm; The thickness H4 of the second SiO2 layer is 15 nm; The thickness H5 of the third Nb2O5 layer is 30 nm; The thickness H6 of the third SiO2 layer is 100 nm.

[0122] The method for preparing the broadband antireflective film in this embodiment differs from that in Example 1 in that: The material is prepared according to the thickness described in this embodiment.

[0123] The power consumption during the preparation of the first Nb2O5 layer was 8.96 kW.

[0124] The power consumption during the preparation of the first SiO2 layer was 5.06KW and 5.07KW, respectively.

[0125] The power consumption during the preparation of the second Nb2O5 layer was 9.9KW and 10KW, respectively.

[0126] The power consumption during the preparation of the second SiO2 layer was 5.56 kW.

[0127] The power consumption during the preparation of the third Nb2O5 layer was 10.35 kW.

[0128] The power consumption during the preparation of the third SiO2 layer was 8.36KW, 8.26KW, and 8.36KW, respectively.

[0129] The gap between the coating shielding device and the substrate is 0.7 mm. The thickness difference between the coating shielding device and the substrate is 0.15 mm.

[0130] Comparative Example 1 An anti-reflective film layer, differing from Example 1 in that: The thickness H1 of the first Nb2O5 layer is 15 nm.

[0131] The thickness H2 of the first SiO2 layer is 25 nm.

[0132] The thickness H3 of the second Nb2O5 layer is 37 nm.

[0133] The thickness H4 of the second SiO2 layer is 10 nm.

[0134] The thickness H5 of the third Nb2O5 layer is 20 nm.

[0135] The thickness H6 of the third SiO2 layer is 85 nm.

[0136] The preparation method of the broadband antireflective film in this comparative example differs from that in Example 1 in that: The power consumption during the preparation of the first Nb2O5 layer was 10.28 kW.

[0137] The power consumption during the preparation of the first SiO2 layer was 5.2KW and 5.3KW, respectively.

[0138] The power consumption during the preparation of the second Nb2O5 layer was 12.3KW and 12.4KW, respectively.

[0139] The power consumption during the preparation of the second SiO2 layer is 6KW.

[0140] The power consumption during the preparation of the third Nb2O5 layer was 8KW and 8.1KW, respectively.

[0141] The power consumption during the preparation of the third SiO2 layer was 7.5 kW.

[0142] The sample was prepared according to the thickness described above in this comparative example. No coating shielding device was used.

[0143] Experimental Example The reflectivity of the broadband antireflective coatings of Examples 1-4 and the reflective coating of Comparative Example 1 was tested at different wavelengths. The wavelength-reflectivity diagram of the reflective coating of Example 1 of this invention is shown below. Figure 1 As shown. The wavelength-reflectivity diagram of the broadband antireflective coating in Example 2 is shown below. Figure 3 As shown; the wavelength-reflectivity diagram of the broadband antireflection film in Example 3 is shown below. Figure 4 As shown; the wavelength-reflectivity diagram of the broadband antireflective film in Example 4 is shown below. Figure 5 As shown. The wavelength-reflectivity diagram of the reflective film in Comparative Example 1 is shown below. Figure 6 As shown.

[0144] The test was conducted using a CM700d optical tester; a PAINT-MOP-200MZ-black Indonesian pen was used for blackening the test, and the overall reflectivity in the 400-700nm range was measured.

[0145] The results of the overall reflectivity of the antireflective films in the 400-700nm range for each embodiment and comparative example are shown in Table 1.

[0146] Table 1 Test Results

[0147] As shown in Table 1, the broadband antireflective coating obtained by the method of the present invention has an ultra-low overall reflectivity across a wide spectrum; and it can effectively suppress side layer deposition. The antireflective coating obtained by the method in Comparative Example 1 has a relatively high overall reflectivity, and the antireflective coating layer accumulates on the side.

[0148] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A broadband antireflective coating, characterized in that, The broadband antireflective coating layer comprises a first high-refractive-index material layer, a first low-refractive-index material layer, a second high-refractive-index material layer, a second low-refractive-index material layer, a third high-refractive-index material layer, and a third low-refractive-index material layer stacked sequentially, and the total thickness of the broadband antireflective coating layer is greater than 200 nm; The thickness H1 of the first high-refractive-index material layer is 10~12 nm; The thickness H2 of the first low-refractive material layer is 30~35nm; The thickness H3 of the second high-refractive-index material layer is 25~35 nm; The thickness H4 of the second low-refractive material layer is 15~25nm; The thickness H5 of the third high-refractive-index material layer is 25~30nm; The thickness H6 of the third low-refractive material layer is 90~100nm.

2. The broadband antireflective coating according to claim 1, characterized in that, The first high refractive index material layer, the second high refractive index material layer, and the third high refractive index material layer are one or more of Nb2O5 layer, TiO2 layer, Al2O3 layer, Ta2O5 layer, or AZO layer; The first low-refractive-index material layer, the second low-refractive-index material layer, and the third low-refractive-index material layer are one or more of SiO2 layer or MgF2 layer.

3. The broadband antireflective coating according to claim 1, characterized in that, The thickness H1 of the first high-refractive-index material layer is 11~12 nm; The thickness H2 of the first low-refractive material layer is 31~32 nm; The thickness H3 of the second high-refractive-index material layer is 28~29 nm; The thickness H4 of the second low-refractive-index material layer is 21~22 nm; The thickness H5 of the third high-refractive-index material layer is 27~28 nm; The thickness H6 of the third low-refractive material layer is 94~95nm.

4. The broadband antireflective coating according to claim 1, characterized in that, The overall reflectivity of the broadband antireflective film in the wavelength range of 400~700nm is <0.3%.

5. The method for preparing the broadband antireflective coating as described in any one of claims 1 to 4, characterized in that, Includes the following steps: (a) The substrate is pretreated to obtain a pretreated substrate; (b) A first high-refractive-index material layer, a first low-refractive-index material layer, a second high-refractive-index material layer, a second low-refractive-index material layer, a third high-refractive-index material layer and a third low-refractive-index material layer are sequentially prepared on one side surface of the pretreated substrate to form a broadband anti-reflection film.

6. The method for preparing the broadband antireflective film according to claim 5, characterized in that, The pretreatment includes cleaning with cleaning solution, ultrasonic cleaning, brush cleaning, and drying.

7. The method for preparing the broadband antireflective film according to claim 6, characterized in that, It includes at least one of the following features (1) to (4): (1) The cleaning solution used for cleaning includes: an alkaline solution with a mass concentration of 4% to 6%; the temperature of the cleaning solution is 40 to 50°C; (2) The ultrasonic cleaning process has an ultrasonic frequency of 23~33Hz, a temperature of 40~50℃, a power ratio of more than 80%, and a pH of 6~10. (3) The rotation speed of the disc brush cleaning is 200~400 rpm, and the disc brush cleaning uses an alkaline solution with a pH of 7.2~10; (4) The drying is air knife drying, and the exhaust pressure is 45~55Pa.

8. The method for preparing the broadband antireflective film according to claim 5, characterized in that, The broadband antireflective coating was prepared by PVD coating. The working gas for the PVD coating includes Ar; The reaction gas for the PVD coating is O2; depending on the different O2 inlets, the reaction gas includes main oxygen, lower oxygen, middle oxygen and upper oxygen.

9. The method for preparing the broadband antireflective film according to claim 8, characterized in that, The preparation conditions of the first high refractive material layer include: power of 8~9.2KW, working gas flow rate of 150~170sccm; main oxygen flow rate of 50~65sccm, lower oxygen flow rate of 15~25sccm, middle oxygen flow rate of 8~15sccm, and upper oxygen flow rate of 20~30sccm. The preparation conditions of the first low-refractive material layer include: power of 4.5~5.5KW; working gas flow rate of 150~170sccm; main oxygen flow rate of 60~70sccm, lower oxygen flow rate of 30~40sccm, middle oxygen flow rate of 15~25sccm, and upper oxygen flow rate of 25~35sccm. The preparation conditions for the second high-refractive-index material layer include: power of 9~10KW; working gas flow rate of 150~170sccm; main oxygen flow rate of 60~70sccm; lower oxygen flow rate of 10~20sccm; middle oxygen flow rate of 10~20sccm; and upper oxygen flow rate of 8~12sccm. The preparation conditions for the second low-refractive material layer include: power of 5~6KW, working gas flow rate of 150~170sccm; main oxygen flow rate of 75~85sccm, lower oxygen flow rate of 8~12sccm, middle oxygen flow rate of 10~15sccm, and upper oxygen flow rate of 8~12sccm. The preparation conditions of the third high-refractive-index material layer include: power of 10~11KW; working gas flow rate of 150~170sccm; main oxygen flow rate of 55~65sccm; lower oxygen flow rate of 8~15sccm; middle oxygen flow rate of 10~13sccm; and upper oxygen flow rate of 14~20sccm. The preparation conditions for the third low-refractive material layer include: power of 5~8.5KW; working gas flow rate of 150~170sccm; main oxygen flow rate of 60~70sccm; lower oxygen flow rate of 20~30sccm; middle oxygen flow rate of 19~25sccm; and upper oxygen flow rate of 22~30sccm.

10. The method for preparing the broadband antireflective film according to claim 5, characterized in that, The preparation of the broadband antireflective coating is carried out using a coating shielding device; the coating shielding device has a frame structure adapted to the shape of the substrate layer, and the substrate layer is placed inside the frame structure of the coating shielding device to prepare the broadband antireflective coating layer; Preferably, the gap between the coating shielding device and the substrate layer is 0.5~2mm; Preferably, the thickness difference between the coating shielding device and the substrate layer is 0~0.2mm.

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