Hard cut-off film, optical device and electric equipment

Abstract

The utility model provides a hard cut-off film, an optical device and electric equipment. The hard cut-off film comprises a substrate, a cut-off layer and a hard layer, the cut-off layer and the hard layer are sequentially stacked on the surface of the substrate, and the hard layer comprises a high-refractive-index hard layer and a second low-refractive-index layer which are alternately stacked. According to the hard cut-off film provided by the utility model, through the special structural design, the hardness, the wear resistance and the mechanical strength of the hard cut-off film are effectively improved while the excellent optical performance caused by an interference phenomenon due to alternate stacking of low refractive indexes and high refractive indexes is ensured, so that the measurement precision of an optical device can be improved, and the service life of the optical device can be prolonged. And the application scene is widened.

Description

Technical Field

[0001] The embodiments of the utility model relate to the technical field of optical devices, and in particular to a hard cut-off film, an optical device and an electrical device. Background Art

[0002] In order to make optical devices meet higher optical performance requirements, optical cutoff filters and similar optical components are often introduced. Common optical cutoff filters usually use two materials with different refractive indices, high refractive index and low refractive index, to alternately stack and deposit, and use the interference principle to achieve an ideal cutoff effect on visible light, thereby improving its optical performance. However, the existing optical cutoff film layer has low hardness, poor mechanical properties and wear resistance. In harsh working environments, the film layer on the surface of optical devices is extremely susceptible to damage. For example, common scratches and bumps on the film surface, as well as high-intensity light pulses from high-power lasers, can easily cause cracks or shedding of the surface film layer, which seriously affects the measurement accuracy and service life of the optical device, and limits the use scenarios of these optical devices. Utility Model Content

[0003] In view of this, the utility model provides a hard cut-off film, an optical device and an electrical device. The hard cut-off film comprises a substrate, and a cut-off layer and a hard layer sequentially stacked on the surface of the substrate, wherein the hard layer comprises a high refractive index hard layer and a second low refractive index layer alternately stacked. The hard cut-off film provided by the utility model has a special structural design, which ensures the excellent optical performance brought by the interference phenomenon caused by the alternating stacking of low refractive index and high refractive index, and effectively improves its hardness, wear resistance and mechanical strength, thereby improving the measurement accuracy and service life of the optical device and broadening its application scenarios.

[0004] The first aspect of the embodiment of the utility model provides a hard cut-off film, which includes a substrate, and a cut-off layer and a hard layer stacked in sequence on the surface of the substrate; the hard layer includes a high refractive index hard layer and a second low refractive index layer alternately stacked.

[0005] In an embodiment of the utility model, the outermost layer of the hard layer on the side away from the substrate is the second low refractive index layer.

[0006] In the embodiment of the present invention, the cut-off layer comprises a high refractive index cut-off layer and a first low refractive index layer which are alternately stacked.

[0007] In an embodiment of the present invention, the difference in refractive index between the high refractive index cut-off layer and the high refractive index hard layer is less than or equal to 0.2.

[0008] In the embodiment of the utility model, the refractive index of the high refractive index cut-off layer is greater than or equal to 2.1, and the absorptivity of light within the wavelength range of 420nm-650nm is less than or equal to 1×10 -4 .

[0009] In the embodiment of the present invention, the refractive index of the first low refractive index layer is 1.36-1.58, and the refractive index of the second low refractive index layer is 1.36-1.58.

[0010] In the embodiment of the utility model, the absorption rate of the first low refractive index layer for light with a wavelength in the range of 420nm-650nm is 1×10 -4 -1×10 -2 The absorption rate of the second low refractive index layer for light in the wavelength range of 420nm-650nm is 1×10 -4 -1×10 -2 .

[0011] In some embodiments of the present invention, the refractive index of the first low refractive index layer and the refractive index of the second low refractive index layer are equal.

[0012] In some embodiments of the present invention, the high refractive index cut-off layer is a Nb2O5 layer, the high refractive index hard layer is a SiN layer, and the first low refractive index layer and the second low refractive index layer are both SiO2 layers.

[0013] In the implementation manner of the utility model, the thickness of the cut-off layer is 1.5 μm-5 μm, and the thickness of the hard layer is 0.5 μm-2 μm.

[0014] In the embodiment of the present invention, the thickness of each high refractive index cut-off layer is 5nm-160nm, and the thickness of each first low refractive index layer is 10nm-180nm; the thickness of each high refractive index hard layer is 10nm-160nm, and the thickness of each second low refractive index layer is 10nm-180nm.

[0015] In an embodiment of the utility model, the total number of layers of the high refractive index cut-off layer and the first low refractive index layer is 20-44 layers; in the hard layer, the total number of layers of the high refractive index hard layer and the second low refractive index layer is 8-16 layers.

[0016] In an embodiment of the utility model, the average transmittance of the hard cutoff film for light in the wavelength range of 420nm-650nm is greater than or equal to 98%, and the average transmittance for light in the wavelength range of 700nm-1050nm is less than or equal to 0.2%; when the incident angle of the incident light of the hard cutoff film is between 0 degrees and 20 degrees, the offset of the half-value wavelength with the angle is less than 10nm.

[0017] In the implementation manner of the utility model, the nanoindentation hardness of the hard cut-off film is greater than or equal to 12 GPa, and the Mohs hardness is greater than or equal to 9.

[0018] A second aspect of an embodiment of the present utility model provides an optical device, which includes a transparent substrate and a hard cut-off film provided in the first aspect of the embodiment of the present utility model and arranged on the surface of the transparent substrate.

[0019] In some implementations of the utility model, the optical device includes camera protection glass, antenna glass, and a vehicle-mounted laser radar protection cover.

[0020] A third aspect of the embodiment of the utility model provides an electrical device, which includes the hard cut-off film provided in the first aspect of the embodiment of the utility model or the optical device provided in the second aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A schematic diagram of the cross-sectional structure of a hard cut-off film provided in one embodiment of the utility model;

[0022] Figure 2 A schematic diagram of the cross-sectional structure of a hard cut-off film provided in another embodiment of the utility model;

[0023] Figure 3 The spectral variation curve of the hard cut-off film provided in one embodiment of the utility model when the incident angle of the incident light is 0°, 10° and 20°.

[0024] Description of Figure Numbers

[0025] 100 - hard cut-off film; 11 - substrate; 12 - cut-off layer; 121 - high refractive index cut-off layer; 122 - first low refractive index layer; 13 - hard layer; 131 - high refractive index hard layer; 132 - second low refractive index layer. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model and are not used to limit the utility model.

[0027] Common optical cutoff filters usually use two materials with different refractive indices, high refractive index and low refractive index, to alternately stack and deposit, and use the interference principle to achieve an ideal cutoff effect on visible light, thereby improving its optical performance. However, the existing optical cutoff film layer has a low hardness, poor mechanical properties and wear resistance. In harsh working environments, the film layer on the surface of the optical device is extremely susceptible to damage, such as common scratches and bumps on the film surface, and high-intensity light pulses from high-power lasers, which can easily cause cracks or fall off on the surface film layer, thereby seriously affecting the measurement accuracy and service life of the optical device, and limiting the use scenarios of these optical devices. In order to improve the hardness and performance of the film layer, a commonly used method is to use DLC (Diamond-Like Carbon, diamond-like film) technology, but the preparation process for depositing such films is complicated and acetylene gas needs to be introduced during deposition, which poses certain safety hazards.

[0028] In view of this, the utility model provides a hard cut-off film, an optical device and an electrical device. The hard cut-off film comprises a substrate, and a cut-off layer and a hard layer sequentially stacked on the surface of the substrate, wherein the hard layer comprises a high refractive index hard layer and a second low refractive index layer alternately stacked. The hard cut-off film provided by the utility model has a special structural design, which ensures the excellent optical performance brought by the interference phenomenon caused by the alternating stacking of low refractive index and high refractive index, and effectively improves its hardness, wear resistance and mechanical strength, thereby improving the measurement accuracy and service life of the optical device and broadening its application scenarios.

[0029] See also Figure 1 and Figure 2 The embodiment of the utility model provides a hard cut-off film 100, and the hard cut-off film 100 includes a substrate 11, and a cut-off layer 12 and a hard layer 13 sequentially stacked on the surface of the substrate 11. The hard layer 13 includes a high refractive index hard layer 131 and a second low refractive index layer 132 alternately stacked, wherein the refractive index of the high refractive index hard layer 131 is higher than that of the second low refractive index layer 132. The utility model adopts a special structural design of alternatingly stacking high refractive index hard layers 131 and second low refractive index layers 132 with different refractive indices for the hard layer, and utilizes the interference phenomenon to improve the optical performance of the hard cut-off film 100 while effectively improving its hardness and wear resistance. According to optical principles, the high refractive index hard layer 131 and the second low refractive index layer 132 of the hard layer 13 are made of two materials with different refractive indices, n1 and n2 respectively. When visible light is vertically incident, the reflectivity R on the interface of the two materials is (n1-n2) 2 / (n1+n2) 2When the incident visible light passes through the hard layer 13, thin film interference occurs, and the optical path difference of the coherent light satisfies nd=λ / 4. When the optical path difference is an odd multiple of λ / 4, the light intensity is destructively weakened, effectively achieving an ideal cutoff effect on the visible light. In the embodiment of the utility model, the cutoff layer 12 includes a high refractive index cutoff layer 121 and a first low refractive index layer 122 that are alternately stacked, wherein the refractive index of the high refractive index cutoff layer 121 is higher than that of the first low refractive index layer 122. The high refractive index cutoff layer 121 of the cutoff layer 12, the first low refractive index layer 122 and the hard layer 13 utilize the interference principle to achieve an ideal cutoff effect on the visible light.

[0030] The cutoff layer 12 of the hard cutoff film 100 of the embodiment of the utility model is a structure in which a high refractive index cutoff layer 121 and a first low refractive index layer 122 are alternately stacked, and the hard layer 13 is a structure in which a high refractive index hard layer 131 and a second low refractive index layer 132 are alternately stacked, that is, the hard cutoff film 100 as a whole presents a structure in which high refractive index layers and low refractive index layers are alternately stacked on the surface of the substrate. By utilizing its interference principle, an ideal cutoff effect is effectively achieved for visible light, and the optical performance of the hard cutoff film is further improved.

[0031] In the embodiment of the utility model, the refractive index of the high refractive index cut-off layer 121 is greater than or equal to 2.1, and the absorption rate of light within the wavelength range of 420nm-650nm is less than or equal to 1×10 -4 , the difference between the refractive index of the high refractive index cut-off layer 121 and the high refractive index hard layer 131 is less than or equal to 0.2. In some embodiments of the present invention, the refractive index of the high refractive index cut-off layer 121 can be, for example, 2.1, 2.15, 2.2, 2.25, 2.3, 2.35, 2.4, 2.45, 2.5, and the absorption rate for light in the wavelength range of 420nm-650nm can be, for example, 1×10 -5 , 2×10 -5 , 3×10 -5 , 5×10 -5 ,7×10 -5 , 8×10 -5 , 1×10 -4, the difference in refractive index between the high refractive index cut-off layer 121 and the high refractive index hard layer 131 can be, for example, 0.01, 0.02, 0.05, 0.08, 0.1, 0.12, 0.15, 0.18, 0.2. Controlling the difference in refractive index between the high refractive index cut-off layer 121 and the high refractive index hard layer 131 within the smallest possible range can make the transition of the refractive index between the cut-off layer and the hard layer of the hard cut-off film 100 more natural, the optical parameters of the hard cut-off film are more in line with expectations, the overall optical curve of the hard cut-off film is flatter, and the cut-off rate is lower. In some embodiments of the utility model, the high refractive index cut-off layer 121 can be, for example, one or more of a Ti2O5 layer, a Nb2O5 layer, a SiH layer, a PbTe layer, a ZnS layer, a ZnSe layer, and a Ta2O5 layer. The material selection of each high refractive index cut-off layer 121 in the cut-off layer 12 can be the same or different.

[0032] In the embodiment of the present invention, the nanoindentation hardness of the high refractive index hard layer 131 is greater than or equal to 12 GPa, and the Mohs hardness is greater than or equal to 9. In some embodiments of the present invention, the high refractive index hard layer 131 can be, for example, one or more of a SiN layer, a SiON layer, an AlN layer, a ZrO2 layer, a BN layer, and a nano-diamond film layer. The material selection of each high refractive index hard layer 131 in the hard layer 13 can be the same or different.

[0033] In the embodiment of the utility model, the refractive index of the first low refractive index layer 122 is 1.36-1.58. In some embodiments of the utility model, the refractive index of the first low refractive index layer 122 can be, for example, 1.36, 1.38, 1.4, 1.42, 1.44, 1.45, 1.46, 1.48, 1.5, 1.52, 1.54, 1.55, 1.56, 1.58. In the embodiment of the utility model, the absorption rate of the first low refractive index layer 122 for light in the wavelength range of 420nm-650nm is 1×10 -4 -1×10 -2 In some embodiments of the present invention, the absorption rate of the first low refractive index layer 122 for light within the wavelength range of 420nm-650nm can be, for example, 1×10 -4 , 2×10 -4 , 3×10 -4 , 5×10 -4 , 8×10 -4 , 1×10 -3 , 5×10 -3 , 1×10 -2 .

[0034] In the embodiment of the utility model, the refractive index of the second low refractive index layer 132 is 1.36-1.58. In some embodiments of the utility model, the refractive index of the second low refractive index layer 132 can be, for example, 1.36, 1.38, 1.4, 1.42, 1.44, 1.45, 1.46, 1.48, 1.5, 1.52, 1.54, 1.55, 1.56, 1.58. In the embodiment of the utility model, the absorptivity of the second low refractive index layer 132 for light in the wavelength range of 420nm-650nm is 1×10 -4 -1×10 -2 In some embodiments of the present invention, the absorption rate of the second low refractive index layer 132 for light within the wavelength range of 420nm-650nm can be, for example, 1×10 -4 , 2×10 -4 , 3×10 -4 , 5×10 -4 , 8×10 -4 , 1×10 -3 , 5×10 -3 , 1×10 -2 .

[0035] In some embodiments of the present invention, the first low refractive index layer 122 and the second low refractive index layer 132 can be, for example, one or more of a SiO2 layer, a MgF2 layer, and an Al2O3 layer. The material selection of each first low refractive index layer 122 in the cut-off layer 12 can be the same or different; the material selection of each second low refractive index layer 132 in the hard layer 13 can be the same or different; the material selection of the first low refractive index layer 122 and the second low refractive index layer 132 can be the same or different.

[0036] In some embodiments of the present invention, in the hard cut-off film 100, the first low refractive index layer 122 and the second low refractive index layer 132 have the same refractive index, which can make the overall structure of the hard cut-off film 100 more uniform, thereby making its optical and mechanical properties more uniform, further improving its optical performance and service life.

[0037] In the embodiment of the utility model, the nanoindentation hardness of the high refractive index cut-off layer 121 is greater than or equal to 12GPa, and the Mohs hardness is greater than or equal to 9. In some embodiments of the utility model, the high refractive index cut-off layer 121 is a Nb2O5 layer, the high refractive index hard layer 131 is a SiN layer, and the first low refractive index layer and the second low refractive index layer are both SiO2 layers. The refractive index of SiN is 2.1, and the absorption rate is less than 1×10 -4It has stable chemical properties, high hardness, good wear resistance, and excellent optical and mechanical properties. Using it as a high refractive index hard layer can make the refractive index closer to that of the high refractive index cut-off layer, making the overall optical performance of the hard cut-off film better while further improving its wear resistance, thereby improving the measurement accuracy and service life of optical devices.

[0038] In the embodiment of the present invention, in the cut-off layer 12 of the hard cut-off film 100, the total number of layers of the high refractive index cut-off layer 121 and the first low refractive index layer 122 is 20-44. In some specific embodiments of the present invention, the total number of layers of the high refractive index cut-off layer 121 and the first low refractive index layer 122 in the cut-off layer 12 can be, for example, 20 layers, 21 layers, 22 layers, 24 layers, 25 layers, 26 layers, 28 layers, 30 layers, 32 layers, 35 layers, 36 layers, 38 layers, 40 layers, 41 layers, 42 layers, 43 layers, 44 layers. The high refractive index cut-off layer 121 and the first low refractive index layer 122 in the cut-off layer 12 are alternately stacked. When the total number of layers is an even number, the number of high refractive index cut-off layers 121 and the number of first low refractive index layers 122 in the cut-off layer 12 are equal; when the total number of layers is an odd number, the number of high refractive index cut-off layers 121 and the number of first low refractive index layers 122 in the cut-off layer 12 differ by 1, and the number of high refractive index cut-off layers 121 may be 1 more than the number of first low refractive index layers 122, or the number of high refractive index cut-off layers 121 may be 1 less than the number of first low refractive index layers 122. In some embodiments of the present invention, the cut-off layer 12 may be directly disposed on the substrate 11, such as Figure 1 As shown, the high refractive index cut-off layer 121 may be in contact with the substrate 11. In other embodiments of the present invention, as Figure 2 As shown, the first low refractive index layer 122 may also be in contact with the substrate 11. The utility model can effectively play its cutoff effect on visible light and improve the optical performance of the hard cutoff film by controlling the total number of high refractive index cutoff layers 121 and first low refractive index layers 122 in the cutoff layer 12 within a suitable range.

[0039] In the embodiment of the present invention, in the hard layer 13 of the hard cut-off film 100, the total number of layers of the high refractive index hard layer 131 and the second low refractive index layer 132 is 8-16 layers. In some specific embodiments of the present invention, the total number of layers of the high refractive index hard layer 131 and the second low refractive index layer 132 in the hard layer 13 can be, for example, 8 layers, 9 layers, 10 layers, 11 layers, 12 layers, 13 layers, 14 layers, 15 layers, 16 layers. The high refractive index hard layer 131 and the second low refractive index layer 132 in the hard layer 13 are alternately stacked, and when the total number of layers is an even number, the number of layers of the high refractive index hard layer 131 and the second low refractive index layer 132 in the hard layer 13 are equal; when the total number of layers is an odd number, the number of layers of the high refractive index hard layer 131 and the second low refractive index layer 132 in the hard layer 13 differ by 1.

[0040] In the embodiment of the present invention, the outermost layer of the hard layer 13 on the side away from the substrate 11 is the second low refractive index layer 132, so when the total number of layers is an even number, such as Figure 1 As shown, the high refractive index hard layer 131 is in contact with the cut-off layer 12; when the total number of layers is an odd number, as shown in Figure 2 As shown, the second low refractive index layer 132 is in contact with the cut-off layer 12. The utility model controls the total number of high refractive index hard layers 131 and second low refractive index layers 132 in the hard layer 13 within a suitable range and arranges the second low refractive index layer 132 with a lower refractive index in the outermost layer, thereby effectively improving the hardness, wear resistance and mechanical strength of the hard cut-off film while ensuring the effective cut-off effect of the hard cut-off film on visible light. Applying it to optical devices can further improve the measurement accuracy and service life of the optical devices.

[0041] In the embodiment of the utility model, the thickness of the cut-off layer 12 is 1.5 μm-5 μm, and the thickness of the hard layer 13 is 0.5 μm-2 μm. In some embodiments of the present invention, the thickness of the cut-off layer 12 can be, for example, 1.5μm, 1.6μm, 1.8μm, 2μm, 2.2μm, 2.4μm, 2.5μm, 2.6μm, 2.8μm, 3μm, 3.2μm, 3.4μm, 3.5μm, 3.6μm, 3.8μm, 4μm, 4.2μm, 4.4μm, 4.5μm, 4.6μm, 4.8μm, 5μm, and the thickness of the hard layer 13 can be, for example, 0.5μm, 0.6μm, 0.7μm, 0.8μm, 0.9μm, 1.0μm, 1.2μm, 1.4μm, 1.5μm, 1.6μm, 1.8μm, 2μm.

[0042] In the embodiment of the present invention, in the cut-off layer 12, the thickness of each high refractive index cut-off layer 121 is 5nm-160nm, and the thickness of each first low refractive index layer 122 is 10nm-180nm. In some specific embodiments of the present invention, the thickness of each high refractive index cut-off layer 121 can be, for example, 5nm, 8nm, 10nm, 15nm, 20nm, 25nm, 30nm, 35nm, 40nm, 45nm, 50nm, 55nm, 60nm, 65nm, 70nm, 75nm, 80nm, 85nm, 90nm, 95nm, 100nm, 110nm, 120nm, 130nm, 140nm, 150nm, 160nm, and the thickness of each first low refractive index layer 122 can be, for example, 1 0nm, 20nm, 30nm, 35nm, 38nm, 40nm, 45nm, 50nm, 51nm, 55nm, 60nm, 61nm, 65nm, 68nm, 70nm, 74nm, 75nm, 80nm, 85nm, 86nm, 90nm, 95nm, 99nm, 100nm, 101nm, 102nm, 110nm, 118nm, 120nm, 122nm, 130nm, 140nm, 150nm, 160nm, 170nm, 176nm, 180nm.

[0043] In the embodiment of the utility model, in the hard layer 13, the thickness of each high refractive index hard layer 131 is 10nm-160nm, and the thickness of each second low refractive index layer 132 is 10nm-180nm. In some specific embodiments of the present invention, the thickness of each high refractive index hard layer 131 can be, for example, 10nm, 20nm, 30nm, 40nm, 50nm, 60nm, 70nm, 80nm, 89nm, 90nm, 96nm, 100nm, 110nm, 116nm, 120nm, 130nm, 140nm, 150nm, 156nm, 160nm, and the thickness of each second low refractive index layer 132 can be, for example, 10nm, 20nm, 30nm, 40nm, 50nm, 60nm, 70nm, 80nm, 90nm, 94nm, 100nm, 110nm, 112nm, 120nm, 122nm, 130nm, 140nm, 150nm, 160nm, 162nm, 170nm, 180nm.

[0044] In the embodiment of the utility model, the average transmittance of the hard cut-off film 100 for light in the range of wavelengths of 420nm-650nm is greater than or equal to 98%, and the average transmittance for light in the range of wavelengths of 700nm-1050nm is less than or equal to 0.2%; when the incident angle of the hard cut-off film 100 is between 0 degrees and 20 degrees, the offset of the half-value wavelength with the angle is less than 10nm. The hard cut-off film provided by the embodiment of the utility model has a high average transmittance for visible light and near-infrared light with an effective cut-off wavelength in the range of 700nm-1050nm, a high overall optical transmittance, a low transmittance in the cut-off band, a small offset, and excellent optical performance.

[0045] In the embodiment of the utility model, the nanoindentation hardness of the hard cut-off film 100 is greater than or equal to 12GPa, and the Mohs hardness is greater than or equal to 9. The nanoindentation hardness and the Mohs hardness are the values ​​measured when the hard cut-off film 100 is measured away from the substrate. The hard cut-off film 100 has a high hardness, which makes it have excellent wear resistance and mechanical strength. When it is used in optical devices, its surface is not easily damaged by scratches, bumps, etc., which effectively improves the measurement accuracy of the optical device and prolongs its service life.

[0046] The hard cutoff film of the embodiment of the utility model is achieved by sequentially stacking a cutoff layer and a hard layer on the surface of a substrate, and the cutoff layer and the hard layer are alternately stacked with high and low refractive indices. While ensuring the excellent optical performance brought about by the interference phenomenon of the alternating stacking of low refractive index and high refractive index, it also effectively improves its hardness, wear resistance and mechanical strength, thereby improving the measurement accuracy and service life of optical devices and broadening their application scenarios.

[0047] In some embodiments of the utility model, the hard cutoff film obtains the corresponding specific film layer structure by magnetron sputtering, which can be specifically: the reaction gas and sputtering gas are filled into the vacuum chamber and ionized, and under the action of a strong magnetic field, the target material surface is bombarded, and a certain thickness of high and low refractive index materials are alternately deposited on the substrate surface, and the coating can be carried out by inductively coupled plasma assistance to improve the bonding strength of the film layer.

[0048] In the embodiment of the utility model, a cut-off layer 12 is first deposited on the surface of the substrate, that is, a high refractive index cut-off layer and a first low refractive index layer of a certain thickness are alternately deposited. After the cut-off layer 12 is prepared, a hard layer 13 is deposited on its surface, that is, a high refractive index hard layer and a second low refractive index layer of a certain thickness are alternately deposited.

[0049] In some embodiments of the utility model, after the cut-off layer 12 is prepared, annealing treatment is required to reduce the surface energy of the film layer and reduce the crystal defects of the thin film. After the cut-off layer 12 is prepared, when preparing the hard layer 13, each layer of the high refractive index hard layer needs to be air-plated, and a constant temperature is maintained to reduce the surface stress of the film layer. The annealing treatment between the deposition of the cut-off layer 12 and the hard layer 13 effectively reduces the defects on the crystal surface, thereby reducing the surface stress of the film layer, which is more conducive to the combination between the cut-off layer 12 and the hard layer 13. The subsequent air plating and heat preservation treatment accelerates the release of the interlayer stress of the hard cut-off film 100 as a whole. When each layer of the high refractive index hard layer 131 is deposited, the air plating and heat preservation can further increase the refractive index of the high refractive index hard layer 131, reduce its absorption coefficient, and be more conducive to its matching with the cut-off layer 12, so that the hard cut-off film 100 as a whole further exerts better optical properties, higher optical transmittance, larger spectral range, and lower cut-off rate.

[0050] The utility model also provides an optical device, which includes a transparent substrate and a hard cut-off film as provided in the utility model above, which is arranged on the transparent substrate. Among them, the transparent substrate can be a glass substrate. The optical device can be, for example, an optical element such as a polarizer, an optical lens, a color filter, a prism, a camera module, etc., and can also be an optical detection and measurement instrument. In some embodiments of the utility model, the optical device can be, for example, a camera protection glass, an antenna glass, and a vehicle-mounted laser radar protection cover.

[0051] The utility model also provides an electrical device, including the optical device provided above. The electrical device may be, for example, an electric car, a mobile phone, a tablet computer, a notebook computer, a wearable device (a watch, a bracelet), a digital camera, etc.

[0052] The technical solution of the utility model is further described below through specific embodiments:

[0053] Example 1

[0054] A vacuum magnetron sputtering machine is used for coating. The coating machine is equipped with a three-stage exhaust system of a mechanical pump, a Roots pump, and a molecular pump. Three pairs of target materials can be installed, and inductively coupled plasma ionization is used for auxiliary deposition. A hard cutoff film is prepared. The substrate is a k9 glass with a thickness of 1 mm. The design reference wavelength is 550 nm. The average transmittance of visible light in the wavelength range of 420 nm-650 nm can reach more than 98%. The cutoff transmittance of near-infrared light in the wavelength range of 700 nm-1050 nm is less than 0.2%. The cutoff depth can be increased with the increase of the film layer. When the incident angle is between 0 degrees and 20 degrees, the offset of the half-value wavelength with the angle is less than 10 nm.

[0055] The specific preparation method is as follows:

[0056] 1. Clean the carrier with a dust-free cloth containing alcohol, then put the cleaned 1mm thick K9 glass into the carrier and fix it, put the carrier with the parts to be plated into the trolley of the vacuum coating machine, and wait for the robot to grab it and put it into the vacuum chamber;

[0057] 2. After the glass carrier is placed in the sputtering coating machine chamber, close the chamber door and exhaust the air until the minimum vacuum in the chamber reaches 2.0×10 -2 -3.0×10 -6 When the pressure is 1000 Pa, the inductively coupled plasma spectrometer ion cleaning is performed for 10s-300s. After the cleaning is completed, the thin film deposition begins. The inductively coupled plasma ion assist is used throughout the coating process.

[0058] 3. Deposit the cut-off layer first, the total number of the cut-off layer is 30 layers, wherein the 30 layers are specifically 15 layers of Nb2O5 and 15 layers of SiO2 alternately deposited; the deposition thickness of the 1st to 15th layers of Nb2O5 is 5nm, 56nm, 12nm, 34nm, 41nm, 18nm, 46nm, 75nm, 45nm, 61nm, 37nm, 19nm, 28nm, 54nm, 79nm; the deposition thickness of the 1st to 15th layers of SiO2 is 101nm, 38nm, 176nm, 99nm, 118nm, 122nm, 86nm, 102nm, 45nm, 61nm, 74nm, 51nm, 95nm, 68nm, 51nm;

[0059] When depositing Nb2O5, a metal Nb target is selected as a sputtering target, the reaction gas is O2, and the sputtering gas is Ar; the target power supply power is 5kw-10kw, O2 and Ar are filled in the inductively coupled plasma spectrometer, the power of the inductively coupled plasma spectrometer is 0.3kW-5kW, the Ar flow rate is 40sccm-300sccm, and the O2 flow rate is 40sccm-300sccm;

[0060] When depositing SiO2, Si target is selected as sputtering target, reaction gas is O2, sputtering gas is Ar; target power source power is 5kw-10kw, target Ar flow rate is 40sccm-200sccm, inductively coupled plasma spectrometer power is 0.3kW-5kW, Ar flow rate is 40sccm-300sccm, O2 flow rate is 20sccm-200sccm;

[0061] 4. After the cut-off layer is deposited, annealing is performed, and after the treatment, the hard layer is deposited;

[0062] 5. The total number of hard layers is 10 layers, wherein the 10 layers are specifically 5 layers of SiN and 5 layers of SiO2 deposited alternately; the deposition thickness of the 1st to 5th layers of SiN is 116nm, 89nm, 116nm, 96nm, and 156nm, respectively; the deposition thickness of the 1st to 5th layers of SiO2 is 80nm, 162nm, 94nm, 122nm, and 112nm, respectively;

[0063] When depositing SiN, the reaction gas is N2 and the sputtering gas is Ar; the target power supply power is 6kw-10kw, the target Ar flow rate is 40sccm-200sccm, the inductively coupled plasma spectrometer power is 0.3kW-5kW, the Ar flow rate is 40sccm-300sccm, and the N2 flow rate is 20sccm-200sccm;

[0064] Deposit SiO2, select Si target as sputtering target, the reaction gas is O2, the sputtering gas is Ar; the target power supply power is 5SiO2-10 kw, the target Ar flow rate is 40sccm-200sccm, the inductively coupled plasma spectrometer power is 0.3kW-5kW, the Ar flow rate is 40-300sccm, and the O2 flow rate is 20-200sccm;

[0065] 6. After all the film layers are plated, let them stand until the sample temperature cools down and then take them out to obtain a hard cut-off film.

[0066] Optical performance test:

[0067] The transmittance curve of the sample was tested using an ultraviolet-visible-near infrared spectrophotometer, and all parameters were calibrated before use. The specific process is as follows: the prepared hard cut-off film is mounted on a fixed special fixture, the reference film and the aperture for mounting the sample to be tested are placed on the main fixed bracket, the incident light passes through the reference film and the sample to be tested in turn, and then reaches the detector, a target wavelength is set, the reference film is rotated, the angle of the reference film when the transmittance is minimum is found, the baseline is scanned, and the sample transmittance curve can be obtained. When the incident angle changes from 0° to 10°, the center wavelength drift amplitude of the passband band is less than 2nm, and the center wavelength drift amplitude of the passband band is less than 0.5nm for every 1° change in the incident angle. When the incident angle changes from 0° to 20°, the center wavelength drift amplitude of the passband band is less than 10nm. In the range of the incident angle from 10° to 20°, the center wavelength drift amplitude of the passband band is less than 5nm for every 1° change in the incident angle. Figure 3 The spectrum change curve of the hard cut-off film when the incident light angle is 0°, 10°, and 20°. The average transmittance of visible light in the wavelength range of 420nm-650nm is greater than or equal to 98%, and the average transmittance of near-infrared light in the wavelength range of 700nm-1050nm is less than 0.2%.

[0068] Stability and reliability test:

[0069] Vibration wear test:

[0070] The hard cut-off film was weighed 200 grams and put into the vibration wear tester for testing. The test sample was inserted into the abrasive with the head facing upward, ensuring that at least half of the body was immersed in the abrasive. After 30 minutes, the test sample was taken out and photographed. The sample was recorded every 30 minutes. The sample was taken out for observation and photographed at 60 minutes, 90 minutes and 120 minutes respectively. The film layer of the sample had no scratch damage.

[0071] Adhesion test:

[0072] The prepared hard cut-off film was tested on both sides. Before the test, the product appearance was checked for discoloration, bubbles, cracks, shedding and other defects, and the sample surface was wiped clean with a dust-free cloth; the pure water was heated to 80°C, and the product was put into a water bath to ensure that the product would not overlap, collide or directly contact the heating rod; the water bath time was 30 minutes, and after the test was completed, it was naturally cooled to room temperature under room temperature; the appearance of the hard cut-off film was checked, and the "hundred grid method" was used for adhesion test on the test surface. The hard cut-off film sample had no abnormal appearance, the coating shedding area was less than 5%, and the adhesion was judged to be 5B, that is, there was no peeling at the grid edge, and the cut edge was completely smooth.

[0073] Hardness test:

[0074] A rigid indenter with a regular shape (standard reference indenter) is pressed into the surface of the sample to be tested under the action of gradually increasing external force. After the external force (or external force) reaches a predetermined peak value, the external force is gradually removed, and the displacement H of the indenter and the pressure P on the indenter are recorded. The hardness of the sample to be tested can be obtained by analyzing the PH curve. Through the analysis of the sample PH curve, the nanoindentation hardness is greater than 12Gpa.

[0075] The surface of the hard cut-off film is scratched by a pyramidal diamond needle using the scratch method, and the depth of the scratch is measured. The depth of the scratch is the Mohs hardness. The sample has scratches when the pyramidal diamond needle is scratched at a Mohs hardness of 9, while there are no scratches when the pyramidal diamond needle is scratched at a Mohs hardness of 9. The Mohs hardness of the hard cut-off film sample reaches 9.

[0076] The above is an exemplary embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A hard cut-off film, characterized in that: The hard cut-off film comprises a substrate, and a cut-off layer and a hard layer sequentially stacked on the surface of the substrate; the cut-off layer comprises a high refractive index cut-off layer and a first low refractive index layer alternately stacked; the hard layer comprises a high refractive index hard layer and a second low refractive index layer alternately stacked.

2. The hard cut-off film according to claim 1, characterized in that The outermost layer of the hard layer on the side away from the substrate is the second low refractive index layer.

3. The hard cut-off film according to claim 1, characterized in that: The difference in refractive index between the high refractive index cut-off layer and the high refractive index hard layer is less than or equal to 0.

2.

4. The hard cut-off film according to claim 1, characterized in that: The refractive index of the high refractive index cut-off layer is greater than or equal to 2.1, and the absorptivity of light within the wavelength range of 420nm-650nm is less than or equal to 1×10 -4 .

5. The hard cut-off film according to claim 1, characterized in that: The refractive index of the first low refractive index layer is 1.36-1.58, and the refractive index of the second low refractive index layer is 1.36-1.58; the absorptivity of the first low refractive index layer for light in the wavelength range of 420nm-650nm is 1×10 -4 -1×10 -2 The absorption rate of the second low refractive index layer for light in the wavelength range of 420nm-650nm is 1×10 -4 -1×10 -2 .

6. The hard cut-off film according to claim 1, characterized in that: The first low-refractive index layer and the second low-refractive index layer have the same refractive index.

7. The hard cut-off film according to claim 1, characterized in that: The high refractive index cut-off layer is a Nb2O5 layer, the high refractive index hard layer is a SiN layer, and the first low refractive index layer and the second low refractive index layer are both SiO2 layers.

8. The hard cut-off film according to claim 1, characterized in that: The thickness of the cut-off layer is 1.5 μm-5 μm, and the thickness of the hard layer is 0.5 μm-2 μm.

9. The hard cut-off film according to claim 1, characterized in that: The thickness of each high refractive index cut-off layer is 5nm-160nm, and the thickness of each first low refractive index layer is 10nm-180nm; the thickness of each high refractive index hard layer is 10nm-160nm, and the thickness of each second low refractive index layer is 10nm-180nm.

10. The hard cut-off film according to claim 1, characterized in that: In the cut-off layer, the total number of layers of the high refractive index cut-off layer and the first low refractive index layer is 20-44 layers; in the hard layer, the total number of layers of the high refractive index hard layer and the second low refractive index layer is 8-16 layers.

11. The hard cut-off film according to claim 1, characterized in that: The hard cutoff film has an average transmittance greater than or equal to 98% for light in the wavelength range of 420nm-650nm, and an average transmittance less than or equal to 0.2% for light in the wavelength range of 700nm-1050nm; when the incident angle of the incident light of the hard cutoff film is between 0 degrees and 20 degrees, the offset of the half-value wavelength with the angle is less than 10nm.

12. The hard cut-off film according to claim 1, characterized in that: The hard cut-off film has a nanoindentation hardness greater than or equal to 12 GPa and a Mohs hardness greater than or equal to 9.

13. An optical device, characterized in that: The optical device comprises a transparent substrate and a hard cut-off film according to any one of claims 1 to 12 disposed on the surface of the transparent substrate.

14. The optical device according to claim 13, characterized in that Including camera protection glass, antenna glass, or vehicle-mounted lidar protection cover.

15. An electrical equipment, characterized in that: The electrical equipment comprises the hard cut-off film according to any one of claims 1 to 12 or the optical device according to claim 13 or 14.

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