Electromagnetic shielding protection device and method of manufacturing and use thereof

Abstract

The application relates to an electromagnetic shielding protection device and a preparation method and application thereof. The electromagnetic shielding protection device comprises a substrate layer, a silver nanowire layer, a transparent conductive layer, a first insulating layer and a frequency selective surface layer; the substrate layer has a first surface and a second surface oppositely arranged along the thickness direction thereof; the silver nanowire layer is arranged on the first surface, and the transmittance of the silver nanowire layer to millimeter waves is above 80%; the transparent conductive layer, the first insulating layer and the frequency selective surface layer are sequentially and layerwisely arranged on the second surface; the transparent conductive layer is arranged between the first insulating layer and the substrate layer, and the transmittance of the transparent conductive layer to electromagnetic waves with a frequency of 1 GHz to 100 GHz is above 80%; the frequency selective surface layer comprises periodically arranged ring units, the material of the ring units comprises at least one of a metal or a conductive oxide, and the frequency selective surface layer allows electromagnetic waves with at least one preset frequency to pass.

Description

Technical Field

[0001] This application relates to the field of electromagnetic shielding technology, and in particular to electromagnetic shielding protection devices, their preparation methods, and applications. Background Technology

[0002] Autonomous driving's 5G radar technology achieves environmental perception through a high-frequency electromagnetic wave transmission-reception-signal processing chain, forming a closed loop of "perception-communication-decision" when combined with 5G communication capabilities. In the commonly used frequency bands of vehicle-mounted millimeter-wave radar, the high-frequency bands overlap with some 5G communication frequency bands. Therefore, electromagnetic signal shielding is necessary to reduce interference from 5G communication signals to the radar signal. Simultaneously, a protective structure is required to protect the radar. However, traditional electromagnetic shielding devices struggle to achieve both effective electromagnetic shielding and adequate protection. Summary of the Invention

[0003] Therefore, it is necessary to provide an electromagnetic shielding protection device, its preparation method, and its application. The electromagnetic shielding protection device of this application can achieve both good electromagnetic shielding effect and protection effect.

[0004] In a first aspect, this application provides an electromagnetic shielding protection device, comprising a substrate layer, a silver nanowire layer, a transparent conductive layer, a first insulating layer, and a frequency selective surface layer; the substrate layer has a first surface and a second surface disposed opposite to each other along its thickness direction; the silver nanowire layer is disposed on the first surface, and the silver nanowire layer has a transmittance of more than 80% for millimeter waves; the transparent conductive layer, the first insulating layer, and the frequency selective surface layer are sequentially stacked on the second surface; the transparent conductive layer is disposed between the first insulating layer and the substrate layer, and the transparent conductive layer has a transmittance of more than 80% for electromagnetic waves with frequencies of 1 GHz to 100 GHz; the frequency selective surface layer includes periodically arranged ring units, the material of the ring units including at least one of metal or conductive oxide, and the frequency selective surface layer allows electromagnetic waves of at least one preset frequency to pass through.

[0005] In some embodiments, the frequency-selective surface layer allows electromagnetic waves of 24 GHz and / or 77 GHz to pass through.

[0006] In some embodiments, the frequency-selective surface layer includes a periodically arranged first annular unit; the first annular unit is a circular annular structure with an outer diameter of 3.12 mm to 3.13 mm.

[0007] In some embodiments, the frequency-selective surface layer includes a periodically arranged second annular unit; the second annular unit has a regular hexagonal structure and the outer side length of the second annular unit is 0.973 mm to 0.975 mm.

[0008] In some embodiments, the thickness of the first annular unit is 10µm to 20µm.

[0009] In some embodiments, the minimum distance d1 between two adjacent first ring units is 0.59 mm to 0.61 mm.

[0010] In some embodiments, the thickness of the second annular unit is 10µm to 20µm.

[0011] In some embodiments, the minimum distance d2 between two adjacent second ring units is 0.38 mm to 0.4 mm.

[0012] In some embodiments, the frequency selective surface layer includes periodically arranged first and second ring units; the distance between two adjacent first and second ring units is greater than d1 or less than d2.

[0013] In some embodiments, the frequency selective surface layer further includes an insulating medium that fills the intra-ring voids of the annular units and the voids between the annular units.

[0014] In some embodiments, a second insulating layer is further included, which is disposed between the substrate layer and the transparent conductive layer.

[0015] In some embodiments, a third insulating layer is also included, which is disposed on the surface of the frequency selective surface layer opposite to the transparent conductive layer.

[0016] In some embodiments, a fourth insulating layer is also included, which is disposed between the silver nanowire layer and the substrate layer.

[0017] In some embodiments, a fifth insulating layer is also included, which is disposed on the surface of the silver nanowire layer opposite to the substrate layer.

[0018] In some embodiments, a protective layer is further included, which is disposed on the surface of the third insulating layer opposite to the frequency selective surface layer; the material of the protective layer includes diamond-like carbon; the dielectric constant of the protective layer is 5 to 7.

[0019] Secondly, this application provides a method for preparing an electromagnetic shielding protection device, comprising the following steps:

[0020] A substrate layer is provided, the substrate layer having a first surface and a second surface disposed opposite to each other along its thickness direction;

[0021] A silver nanowire layer is prepared on the first surface, wherein the silver nanowire layer has a transmittance of more than 80% for millimeter waves;

[0022] A transparent conductive layer, a first insulating layer, and a frequency selective surface layer are sequentially stacked on a second surface; the transparent conductive layer has a transmittance of more than 80% for electromagnetic waves with frequencies from 1 GHz to 100 GHz; the frequency selective surface layer includes periodically arranged ring units, the material of which includes at least one of metal or conductive oxide; the frequency selective surface layer allows electromagnetic waves of at least one preset frequency to pass through.

[0023] Thirdly, this application provides a detection device, including a detection apparatus; the detection device further includes the electromagnetic shielding protection device described in any one of the above-mentioned methods or the electromagnetic shielding protection device prepared by the above-mentioned method; the electromagnetic shielding protection device is disposed on the periphery of the detection apparatus; the silver nanowire layer is closer to the detection apparatus than the substrate layer.

[0024] In the aforementioned electromagnetic shielding protection device, the frequency selective surface layer includes periodically arranged ring-shaped units. By allowing electromagnetic waves of a preset frequency to pass through the frequency selective surface, signals in a specific frequency band can pass through, thus achieving electromagnetic shielding. Simultaneously, the frequency selective surface layer reflects or absorbs other interfering frequency bands, reducing overload heating of internal components and extending their service life. The transparent conductive layer has a transmittance of over 80% for electromagnetic waves with frequencies from 1GHz to 100GHz, ensuring it does not affect radar signal transmission. Furthermore, the transparent conductive layer has high infrared reflectivity, suppressing thermal damage to internal components from radar infrared waves and protecting them. Further, the silver nanowire layer has a transmittance of over 80% for millimeter waves, ensuring it does not affect radar signal transmission. Simultaneously, the silver nanowires have high conductivity and anti-icing properties, enabling rapid defogging and de-icing through Joule heating in cases of icing or fogging, protecting internal components. Therefore, the electromagnetic shielding protection device of this application achieves both good electromagnetic shielding and protective effects. Attached Figure Description

[0025] Figure 1 A schematic diagram of the structure of an electromagnetic shielding protection device provided in one embodiment of this application;

[0026] Figure 2 A schematic diagram of the structure of a ring unit provided in one embodiment of this application;

[0027] Figure 3 A schematic diagram of the structure of a ring unit provided in another embodiment of this application;

[0028] Figure 4This is a partial structural schematic diagram of a ring-shaped unit provided in another embodiment of this application.

[0029] Explanation of reference numerals in the attached figures:

[0030] 10-Base layer; 20-Silver nanowire layer; 30-Transparent conductive layer; 40-First insulating layer; 50-Frequency selective surface layer; 60-Second insulating layer; 70-Third insulating layer; 80-Fourth insulating layer; 90-Fifth insulating layer; 100-Protective layer; 111-First electrode; 112-Second electrode. Detailed Implementation

[0031] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, a detailed description of specific embodiments of this application is provided below. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0033] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0034] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0035] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0036] Reference Figure 1 As shown, one embodiment of this application provides an electromagnetic shielding protection device, including a substrate layer 10, a silver nanowire layer 20, a transparent conductive layer 30, a first insulating layer 40, and a frequency selective surface layer 50; the substrate layer 10 has a first surface and a second surface disposed opposite to each other along its thickness direction; the silver nanowire layer 20 is disposed on the first surface, and the silver nanowire layer 20 has a transmittance of 80% or more for millimeter waves; the transparent conductive layer 30, the first insulating layer 40, and the frequency selective surface layer 50 are sequentially stacked on the second surface; the transparent conductive layer 30 is disposed between the first insulating layer 40 and the substrate layer 10, and the transparent conductive layer 30 has a transmittance of 80% or more for electromagnetic waves with frequencies of 1 GHz to 100 GHz; the frequency selective surface layer 50 includes periodically arranged ring units, the material of the ring units including at least one of metal or conductive oxide, and the frequency selective surface layer 50 allows electromagnetic waves of at least one preset frequency to pass through.

[0037] In the aforementioned electromagnetic shielding protection device, the frequency selective surface layer 50 includes periodically arranged ring-shaped units. By allowing electromagnetic waves of a preset frequency to pass through the frequency selective surface, signals of a specific frequency band can pass through, thus achieving electromagnetic shielding. Simultaneously, the frequency selective surface layer 50 reflects or absorbs other interfering frequency bands, reducing overload heating of internal components and extending their service life. The transparent conductive layer 30 has a transmittance of over 80% for electromagnetic waves with frequencies from 1 GHz to 100 GHz, ensuring it does not affect radar signal transmission. Furthermore, the transparent conductive layer 30 has high infrared reflectivity, suppressing thermal damage to internal components from radar infrared waves and protecting them. Further, the silver nanowire layer 20 has a transmittance of over 80% for millimeter waves, ensuring it does not affect radar signal transmission. It is understood that millimeter waves refer to electromagnetic waves with wavelengths from 1 mm to 10 mm. Additionally, the silver nanowires have high conductivity and anti-icing properties, enabling rapid defogging and de-icing through Joule heating when dealing with icing or fogging, protecting internal components. That is, the electromagnetic shielding protection device of this application can achieve both good electromagnetic shielding effect and protection effect.

[0038] A frequency selective surface (FSS) is a two-dimensional planar structure composed of periodically arranged conductive units. Its core function is to "filter" electromagnetic waves of different frequencies, allowing electromagnetic waves of specific frequencies to pass through while suppressing electromagnetic waves of other frequencies.

[0039] In some embodiments, the material of the transparent conductive layer 30 includes at least one of ITO, FTO, AZO, and GZO.

[0040] In some embodiments, the material of the ring unit includes at least one of Ag, Cu, Al, and ITO.

[0041] In some embodiments, the substrate layer is made of at least one of PET, PEN, PC, and optical glass.

[0042] In some embodiments, the frequency-selective surface layer 50 allows electromagnetic waves of 24 GHz and / or 77 GHz to pass through.

[0043] The electromagnetic shielding protection device of this application can be used to protect vehicle-mounted radar. Based on the principle of electromagnetic resonance, it selectively transmits electromagnetic waves of 24GHz and / or 77GHz (vehicle-mounted radar frequency band) and can shield other interfering frequency bands, especially the 5G communication frequency band.

[0044] In some implementations, the frequency-selective surface layer 50 allows only 24 GHz electromagnetic waves to pass through.

[0045] Reference Figure 2 As shown, in some embodiments, the frequency selective surface layer 50 includes a periodically arranged first annular unit; the first annular unit is a circular annular structure and the outer diameter of the first annular unit is 3.12 mm to 3.13 mm.

[0046] In some embodiments, the frequency selective surface layer 50 includes a periodically arranged first ring-shaped unit that allows only 24 GHz electromagnetic waves to pass through.

[0047] A quarter of the wavelength of a 24 GHz electromagnetic wave is approximately 3.125 mm. The outer diameter of a circular ring structure with an outer diameter of 3.12 mm to 3.13 mm corresponds to a quarter of the wavelength of a 24 GHz electromagnetic wave, allowing it to resonate with the 24 GHz electromagnetic wave. A time-varying magnetic field excites a radial electric field within the ring, forming magnetic dipole radiation. Through the magnetic dipole mode ring resonance, only 24 GHz electromagnetic waves are allowed to pass through, thus achieving frequency selectivity. For example, Figure 2In this context, a1 represents the outer diameter of the first annular unit. Optionally, the outer diameter of the first annular unit can be 3.12mm, 3.121mm, 3.122mm, 3.123mm, 3.124mm, 3.125mm, 3.126mm, 3.127mm, 3.128mm, 3.129mm, or 3.13mm. Alternatively, the outer diameter of the first annular unit can be within any two of the aforementioned outer diameters.

[0048] In some implementations, the frequency-selective surface layer 50 allows only 77 GHz electromagnetic waves to pass through.

[0049] Reference Figure 3 As shown, in some embodiments, the frequency selective surface layer 50 includes periodically arranged second annular units; the second annular units are regular hexagonal structures, and the outer side length of the second annular units is 0.973 mm to 0.975 mm.

[0050] In some embodiments, the frequency-selective surface layer 50 includes a periodically arranged second ring-shaped unit that allows only 77 GHz electromagnetic waves to pass through.

[0051] A quarter of the wavelength of a 77 GHz electromagnetic wave is approximately 0.974 mm. The outer side length of a regular hexagonal structure with a side length of 0.973 mm to 0.975 mm corresponds to a quarter of the wavelength of a 77 GHz electromagnetic wave, allowing it to resonate with this wavelength. Each side is equivalent to a short dipole. The symmetrical hexagonal structure supports TE / TM modes, with concentrated electric fields at the edges, forming electric dipole resonance. This electric dipole mode hexagonal resonance allows the passage of 77 GHz electromagnetic waves, thus achieving frequency selectivity. For example, Figure 3 In this context, a2 represents the outer side length of the second annular unit. Optionally, the outer side length of the second annular unit can be 0.973mm, 0.9732mm, 0.9734mm, 0.9736mm, 0.9738mm, 0.974mm, 0.9742mm, 0.9744mm, 0.9746mm, 0.9748mm, or 0.975mm. Alternatively, the outer side length of the second annular unit can also be within the range of any two of the above outer side lengths.

[0052] In some embodiments, the thickness of the first annular unit is 10µm to 20µm.

[0053] It is understandable that the thickness of the first annular element refers to the minimum distance between the outer and inner edges of the first annular element. (Refer to...) Figure 2 As shown, exemplarily, Figure 2In this context, b1 represents the thickness of the first annular unit. Optionally, the thickness of the first annular unit can be 10µm, 11µm, 12µm, 13µm, 14µm, 15µm, 1617µm, 18µm, 19µm, or 20µm, or the thickness of the first annular unit can be within any two of the above thicknesses.

[0054] In some embodiments, the minimum distance d1 between two adjacent first annular units is 0.59 mm to 0.61 mm.

[0055] Reference Figure 2 As shown, exemplarily, Figure 2 In this context, d1 represents the minimum distance between two adjacent first ring units. A minimum distance d1 of 0.59mm to 0.61mm between two adjacent first ring units can reduce high-frequency decoupling. Optionally, the minimum distance d1 between two adjacent first ring units can be 0.59mm, 0.592mm, 0.594mm, 0.596mm, 0.598mm, 0.6mm, 0.602mm, 0.604mm, 0.606mm, 0.608mm, or 0.61mm. Alternatively, the minimum distance between two adjacent first ring units can also be within any two of the above-mentioned distances.

[0056] In some embodiments, the thickness of the second annular unit is 10µm to 20µm.

[0057] It is understandable that the thickness of the second annular element refers to the minimum distance between the outer and inner edges of the second annular element. (Refer to...) Figure 3 As shown, exemplarily, Figure 3 In this context, b2 represents the thickness of the second annular unit. Optionally, the thickness of the second annular unit can be 10µm, 11µm, 12µm, 13µm, 14µm, 15µm, 1617µm, 18µm, 19µm, or 20µm, or the thickness of the second annular unit can be within any two of the above thicknesses.

[0058] In some embodiments, the minimum distance d2 between two adjacent second ring units is 0.38 mm to 0.4 mm.

[0059] Reference Figure 3 As shown, exemplarily, Figure 3In this context, d2 represents the minimum distance between two adjacent second ring units. A minimum distance d2 of 0.38mm to 0.4mm between two adjacent second ring units can reduce low-frequency interference. Optionally, the minimum distance d2 between two adjacent second ring units can be 0.38mm, 0.382mm, 0.384mm, 0.386mm, 0.388mm, 0.39mm, 0.392mm, 0.394mm, 0.396mm, 0.398mm, or 0.4mm, or it can fall within any of the above two distances.

[0060] In some embodiments, the height of the annular unit along the thickness direction of the substrate 10 is 35µm to 45µm.

[0061] Optionally, the height of the annular unit along the thickness direction of the substrate 10 is 35µm, 36µm, 37µm, 38µm, 39µm, 40µm, 41µm, 42µm, 43µm, 44µm or 45µm, or the height of the annular unit along the thickness direction of the substrate 10 may be within any of the above two heights.

[0062] Reference Figure 4 As shown, in some embodiments, the frequency selective surface layer 50 includes periodically arranged first and second ring units; the distance between two adjacent first and second ring units is greater than d1 or less than d2.

[0063] The frequency-selective surface layer 50 with the above structure can simultaneously allow electromagnetic waves of 24 GHz and 77 GHz to pass through, making the electromagnetic shielding protection device of this application suitable for protecting vehicle-mounted radar. The distance between two adjacent first and second ring units is greater than d1 or less than d2, which can avoid crosstalk. (Refer to...) Figure 4 As shown, exemplarily, Figure 4 In this context, d3 represents the distance between two adjacent first and second ring units.

[0064] In some embodiments, the first annular unit is disposed around the outside of the second annular unit.

[0065] In some embodiments, the frequency selective surface layer 50 further includes an insulating medium that fills the voids within the annular units and the voids between the annular units.

[0066] In some of these embodiments, the insulating medium includes PTFE.

[0067] In some embodiments, a second insulating layer 60 is also included, which is disposed between the substrate layer 10 and the transparent conductive layer 30.

[0068] The second insulating layer 60 disposed between the substrate layer 10 and the transparent conductive layer 30 can provide insulation protection for the transparent conductive layer 30, and can also fill the surface of the substrate layer 10.

[0069] In some embodiments, the material of the second insulating layer 60 includes silicon dioxide.

[0070] In some embodiments, a third insulating layer 70 is also included, which is disposed on the surface of the frequency selective surface layer 50 opposite to the transparent conductive layer 30.

[0071] The third insulating layer 70 disposed on the surface of the frequency selective surface layer 50 that is opposite to the transparent conductive layer 30 can provide insulation protection for the frequency selective surface layer 50.

[0072] In some embodiments, the material of the third insulating layer 70 includes silicon dioxide.

[0073] In some embodiments, a fourth insulating layer 80 is also included, which is disposed between the silver nanowire layer 20 and the substrate layer 10.

[0074] The fourth insulating layer 80 disposed between the silver nanowire layer 20 and the substrate layer 10 can provide insulation protection for the silver nanowire layer 20, and at the same time fill the surface of the substrate layer 10, which facilitates the preparation of the silver nanowire layer 20.

[0075] In some embodiments, the material of the fourth insulating layer 80 includes at least one of silicon dioxide and organosilane.

[0076] In some embodiments, a fifth insulating layer 90 is also included, which is disposed on the surface of the silver nanowire layer 20 facing away from the substrate layer 10.

[0077] The fifth insulating layer 90 disposed on the surface of the silver nanowire layer 20 away from the substrate layer 10 can provide insulation protection for the silver nanowire layer 20.

[0078] In some embodiments, the material of the fifth insulating layer 90 includes silicon dioxide.

[0079] In some embodiments, a protective layer 100 is also included, which is disposed on the surface of the third insulating layer 70 away from the frequency selective surface layer 50; the material of the protective layer 100 includes diamond-like carbon; and the dielectric constant of the protective layer 100 is 5 to 7.

[0080] Diamond-like carbon (DLC) is a class of amorphous carbon materials or hydrogen-containing amorphous carbon materials that possess some excellent properties similar to diamond (such as high hardness and low coefficient of friction), but whose structure is not entirely the same as diamond. The dielectric constant of the protective layer 100 is 5-7, ensuring its permeability to millimeter waves. Simultaneously, the protective layer 100 also improves the wear resistance and corrosion resistance of the electromagnetic shielding protection device, extending its service life. Optionally, the dielectric constant of the protective layer 100 can be 5, 5.2, 5.4, 5.6, 5.8, 6, 6.2, 6.4, 6.6, 6.8, or 7; alternatively, the dielectric constant of the protective layer 100 can fall within any two of the aforementioned dielectric constants.

[0081] In some embodiments, the material of the protective layer 100 includes doped graphite, wherein the doping element includes at least one of hydrogen, titanium, and tungsten.

[0082] In some embodiments, the sheet resistance of the silver nanowire layer 20 is less than or equal to 100 Ω / sq.

[0083] Optionally, the sheet resistance of the silver nanowire layer 20 is 1Ω / sq to 100Ω / sq. More preferably, the sheet resistance of the silver nanowire layer 20 is 1Ω / sq, 5Ω / sq, 10Ω / sq, 20Ω / sq, 30Ω / sq, 40Ω / sq, 50Ω / sq, 60Ω / sq, 70Ω / sq, 80Ω / sq, 90Ω / sq, or 100Ω / sq. Alternatively, the sheet resistance of the silver nanowire layer 20 can also be within the range between any two of the above sheet resistances.

[0084] In some embodiments, the silver nanowire layer 20 is heated to 40°C to 60°C under an applied voltage of 3V to 12V.

[0085] In some embodiments, the electromagnetic shielding protection device further includes a first electrode 111 and a second electrode 112 spaced apart, both of which are electrically connected to the silver nanowire layer 20.

[0086] A voltage can be applied to the silver nanowire layer 20 through the first electrode 111 and the second electrode 112, thereby raising its surface temperature. By utilizing the conductivity and anti-icing properties of the silver nanowires, de-icing and defogging can be quickly achieved through the Joule heating effect.

[0087] In some embodiments, the thickness of the transparent conductive layer 30 is 50 nm to 300 nm.

[0088] Optionally, the thickness of the transparent conductive layer 30 is 50nm, 80nm, 100nm, 120nm, 150nm, 180nm, 200nm, 220nm, 250nm, 280nm or 300nm, or the thickness of the transparent conductive layer 30 may be within any two of the above thicknesses.

[0089] In some embodiments, the sheet resistance of the transparent conductive layer 30 is 1Ω / sq to 100Ω / sq. Further optionally, the sheet resistance of the transparent conductive layer 30 is 1Ω / sq, 5Ω / sq, 10Ω / sq, 20Ω / sq, 30Ω / sq, 40Ω / sq, 50Ω / sq, 60Ω / sq, 70Ω / sq, 80Ω / sq, 90Ω / sq, or 100Ω / sq. Alternatively, the sheet resistance of the transparent conductive layer 30 may be within the range of any two of the above sheet resistances.

[0090] Another embodiment of this application provides a method for preparing an electromagnetic shielding protection device, comprising the following steps:

[0091] A substrate layer 10 is provided, the substrate layer 10 having a first surface and a second surface disposed opposite to each other along its thickness direction;

[0092] A silver nanowire layer 20 is prepared on the first surface, and the silver nanowire layer 20 has a transmittance of more than 80% for millimeter waves.

[0093] A transparent conductive layer 30, a first insulating layer 40, and a frequency selective surface layer 50 are sequentially stacked on a second surface; the transparent conductive layer 30 has a transmittance of more than 80% for electromagnetic waves with frequencies of 1 GHz to 100 GHz; the frequency selective surface layer 50 includes periodically arranged ring units, the material of which includes at least one of metal or conductive oxide; the frequency selective surface layer 50 allows electromagnetic waves of at least one preset frequency to pass through.

[0094] In some embodiments, the method for preparing the silver nanowire layer 20 includes:

[0095] The silver source and surfactant are dissolved in an organic solvent to obtain a mixed solution;

[0096] The mixed solution was applied to the substrate layer 10 and then dried.

[0097] In some embodiments, the silver source includes silver nitrate.

[0098] In some of these embodiments, the organic solvent includes ethylene glycol.

[0099] In some of these embodiments, the surfactant includes PVP.

[0100] In some embodiments, the method for preparing the silver nanowire layer 20 includes:

[0101] PVP is dissolved in ethylene glycol and heated to 160℃~180℃ to dissolve PVP.

[0102] Slowly add AgNO3 solution dropwise to ethylene glycol and react for 1 to 4 hours to obtain a mixed solution;

[0103] The mixed solution was centrifuged to remove byproducts, yielding silver nanowires;

[0104] Silver nanowires were dispersed in a dispersion medium to obtain a dispersion.

[0105] The dispersion was applied to the substrate layer 10 and then dried.

[0106] In some embodiments, the transparent conductive layer 30 is prepared by magnetron sputtering.

[0107] In some embodiments, the protective layer 100 is prepared by physical vapor deposition.

[0108] In some implementations, the bias voltage for physical vapor deposition is 50V to 500V.

[0109] Optionally, the bias voltage for physical vapor deposition is 50V to 500V, or the bias voltage for physical vapor deposition can be within any two of the above bias voltages.

[0110] In some embodiments, the temperature for physical vapor deposition is 25°C to 200°C.

[0111] Optionally, the physical vapor deposition temperature is 25°C, 50°C, 75°C, 100°C, 125°C, 150°C, 175°C, or 200°C, or the physical vapor deposition temperature may be within any two of the above temperatures.

[0112] Another embodiment of this application provides a detection device, including a detection apparatus; the detection device further includes an electromagnetic shielding protection device according to any one of the above claims or an electromagnetic shielding protection device prepared by the above-described method; the electromagnetic shielding protection device is disposed on the periphery of the detection apparatus; the silver nanowire layer 20 is closer to the detection apparatus than the substrate layer 10.

[0113] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0114] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims, and the specification and drawings can be used to interpret the content of the claims.

Claims

1. An electromagnetic shielding protection device, characterized in that, The system comprises a substrate layer, a silver nanowire layer, a transparent conductive layer, a first insulating layer, and a frequency-selective surface layer. The substrate layer has a first surface and a second surface disposed opposite each other along its thickness direction. The silver nanowire layer is disposed on the first surface and has a transmittance of over 80% for millimeter waves. The transparent conductive layer, the first insulating layer, and the frequency-selective surface layer are sequentially stacked on the second surface. The transparent conductive layer is disposed between the first insulating layer and the substrate layer and has a transmittance of over 80% for electromagnetic waves with frequencies from 1 GHz to 100 GHz. The frequency-selective surface layer includes periodically arranged ring units, the material of which is... The material includes at least one of a metal or a conductive oxide, and the frequency selective surface layer allows electromagnetic waves of at least one preset frequency to pass through; the frequency selective surface layer includes a periodically arranged first annular unit; the first annular unit has a circular structure and an outer diameter of 3.12 mm to 3.13 mm; and / or, the frequency selective surface layer includes a periodically arranged second annular unit; the second annular unit has a regular hexagonal structure and an outer side length of 0.973 mm to 0.975 mm; the electromagnetic shielding protection device further includes a first electrode and a second electrode spaced apart, both of which are electrically connected to the silver nanowire layer.

2. The electromagnetic shielding protection device according to claim 1, characterized in that, The frequency-selective surface layer allows electromagnetic waves of 24 GHz and / or 77 GHz to pass through.

3. The electromagnetic shielding protection device according to claim 2, characterized in that, The frequency-selective surface layer satisfies at least one of the following characteristics: (1) The thickness of the first annular unit is 10µm~20µm; (2) The minimum distance d1 between two adjacent first ring units is 0.59mm~0.61mm; (3) The thickness of the second annular unit is 10µm~20µm; (4) The minimum distance d2 between two adjacent second ring units is 0.38mm~0.4mm.

4. The electromagnetic shielding protection device according to claim 3, characterized in that, The frequency selective surface layer includes periodically arranged first ring units and second ring units; the distance between two adjacent first ring units and second ring units is greater than d1 or less than d2.

5. The electromagnetic shielding protection device according to claim 1, characterized in that, The frequency selective surface layer further includes an insulating medium that fills the gaps within the annular units and the gaps between the annular units.

6. The electromagnetic shielding protection device according to any one of claims 1 to 5, characterized in that, It also includes a second insulating layer disposed between the substrate layer and the transparent conductive layer; and / or, It also includes a third insulating layer disposed on the surface of the frequency selective surface layer opposite to the transparent conductive layer; and / or, It also includes a fourth insulating layer disposed between the silver nanowire layer and the substrate layer; and / or, It also includes a fifth insulating layer disposed on the surface of the silver nanowire layer opposite to the substrate layer.

7. The electromagnetic shielding protection device according to claim 6, characterized in that, It also includes a protective layer disposed on the surface of the third insulating layer away from the frequency selective surface layer; the material of the protective layer includes diamond-like carbon; the dielectric constant of the protective layer is 5 to 7.

8. A method for preparing an electromagnetic shielding protection device, characterized in that, Includes the following steps: A substrate layer is provided, the substrate layer having a first surface and a second surface disposed opposite to each other along its thickness direction; A silver nanowire layer is prepared on the first surface, wherein the silver nanowire layer has a transmittance of more than 80% for millimeter waves; A transparent conductive layer, a first insulating layer, and a frequency selective surface layer are sequentially stacked on a second surface; the transparent conductive layer has a transmittance of over 80% for electromagnetic waves with frequencies from 1 GHz to 100 GHz; the frequency selective surface layer includes periodically arranged annular units, the material of which includes at least one of metal or conductive oxide; the frequency selective surface layer allows electromagnetic waves of at least one preset frequency to pass through; the frequency selective surface layer includes periodically arranged first annular units; the first annular unit has a circular annular structure and an outer diameter of 3.12 mm to 3.13 mm; and / or, the frequency selective surface layer includes periodically arranged second annular units; the second annular unit has a regular hexagonal structure and an outer side length of 0.973 mm to 0.975 mm; A first electrode and a second electrode are prepared at intervals, and both the first electrode and the second electrode are electrically connected to the silver nanowire layer.

9. A detection device, characterized in that, The device includes a detection device; the detection device further includes an electromagnetic shielding protection device according to any one of claims 1 to 7 or an electromagnetic shielding protection device prepared by the method of preparing the electromagnetic shielding protection device according to claim 8; the electromagnetic shielding protection device is disposed on the periphery of the detection device; the silver nanowire layer is closer to the detection device than the substrate layer.

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