Electromagnetic shielding glass for aircraft canopies and method for producing same

Abstract

This invention relates to the field of electromagnetic shielding technology, and more specifically, to an electromagnetic shielding glass for aircraft cockpit canopies and its preparation method. The glass comprises a transparent substrate made of hyperboloid methyl methacrylate (MMA) acrylic glass with a thickness of 10-20 mm and a basic light transmittance ≥91%. The inner surface of the transparent substrate has grooves with a grid structure etched by laser. Metal paste is filled into the grooves by ultrasonic filling, and the metal paste is sintered and cured to form a metal grid. Anti-reflective and anti-reflective coatings are provided on both sides of the transparent substrate and on the outer side of the metal grid. Compared with traditional transparent conductive oxide thin film materials, this invention significantly improves transmittance and strong electromagnetic wave shielding effectiveness, and has better environmental adaptability.

Description

Technical Field

[0001] This invention relates to the field of electromagnetic shielding technology, and more specifically, to an electromagnetic shielding glass for aircraft cockpit canopies and a method for preparing the same. Background Technology

[0002] With the increasing power of high-power microwave weapons and nuclear pulse weapons, the demand for high-performance, multi-functional electromagnetic shielding materials in aircraft has risen dramatically. Aircraft canopies, in particular, are highly susceptible to external electromagnetic interference in complex electromagnetic environments, leading to malfunctions that can affect internal control systems and crew safety. Currently, transparent shielding film materials used in aircraft canopies suffer from poor electromagnetic shielding performance, allowing electromagnetic waves to penetrate and couple into the cockpit, damaging aircraft control systems and radar detection systems.

[0003] Traditional methods use ITO thin film materials and apply ITO film layers to transparent aircraft parts using physical vapor deposition techniques (magnetron sputtering or evaporation) to achieve electromagnetic shielding. However, the shielding effectiveness of canopies prepared using this method is low (≥20dB, 30MHz~18GHz), and the protection performance against strong electromagnetic pulses is poor, which cannot meet the actual needs of strong electromagnetic fields.

[0004] A novel 3D printing technology that controls conductive silver paste via a needle can fabricate conductive grids, achieving high light transmittance and high shielding performance. However, the conductive layer produced by this method has poor environmental adaptability. Its conductivity deteriorates during high and low temperature, humidity, salt spray, and mold tests, and it is prone to collapse when fabricating grids with high aspect ratios, thus affecting light transmittance and electromagnetic shielding performance. Nanoimprinting technology can fabricate grids of arbitrary shapes on flexible substrates, and the wire diameter ratio can be controlled to achieve high light transmittance and high shielding performance. It can also transfer conductive networks to rigid substrates (inorganic glass, plexiglass, or other materials) using transfer technology. However, aircraft cockpit canopies are irregularly shaped glass with a hyperboloid structure, while nanoimprinting technology can only fabricate planar or single-curved grids, failing to solve the challenge of achieving high light transmittance, high electromagnetic wave shielding, and strong electromagnetic pulse protection for aircraft cockpit canopies.

[0005] Therefore, it is necessary to improve existing technologies. Summary of the Invention

[0006] To overcome the shortcomings of existing technologies, this paper provides an electromagnetic shielding glass for aircraft cockpit canopies with high light transmittance and strong electromagnetic pulse shielding, and a method for its preparation.

[0007] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0008] An electromagnetic shielding glass for an aircraft cockpit canopy, comprising:

[0009] A transparent substrate, wherein the inner surface of the transparent substrate is laser-etched with grooves of a mesh structure, and the grooves are filled with metal paste by ultrasonic filling, and the metal paste is sintered and cured to form a metal mesh.

[0010] Anti-reflective and anti-reflective coatings are provided on both sides of the transparent substrate and on the outer side of the metal mesh, forming a hardened film on the surface of the transparent substrate to prevent scratches and further protect the metal mesh from contact with air.

[0011] To ensure light transmission, the transparent substrate comprises hyperboloid methyl methacrylate acrylic glass with a thickness of 10-20 mm.

[0012] Furthermore, the wire diameter of the mesh structure is 1 to 10 μm, and the groove depth ratio is 2:1 to 3:1.

[0013] Furthermore, the grid structure includes circular grids, hexagonal grids, or random grids.

[0014] Furthermore, the antireflective and anti-reflective coating is made of magnesium fluoride or titanium dioxide using electron beam evaporation to deposit metal or ion beam assisted deposition.

[0015] Furthermore, the metal paste includes nano silver paste, nano gold paste, or nickel-copper powder.

[0016] A method for preparing electromagnetic shielding glass for aircraft cockpit canopies, comprising:

[0017] S1. Prepare a transparent substrate;

[0018] S2, Etched grid grooves

[0019] S21. Set up a program on the laser etching equipment according to the geometry of the aircraft canopy, and design the groove depth ratio and periodic structure according to the electromagnetic shielding effectiveness and light transmittance.

[0020] S22. Adjust the energy and aperture size of the etching laser beam, and etch the inner surface of the canopy according to the set path;

[0021] S3. Fabricate the metal grating;

[0022] S4. Prepare anti-reflection and anti-reflection coatings by using electron beam evaporation to deposit metals and ion beam-assisted deposition, and using magnesium fluoride or titanium dioxide with high transmittance to prepare anti-reflection and anti-reflection coatings.

[0023] To ensure light transmission performance, in S1, the thickness of the transparent substrate is 10-20mm, the basic light transmittance is ≥91%, and it has a hyperbolic structure.

[0024] Furthermore, S3 includes:

[0025] S31. Fill the groove with conductive metal paste, disperse the conductive paste using ultrasonic vibration, and fill the groove completely. Then scrape off the excess paste on the glass surface to form a continuous metal mesh structure.

[0026] S32. Using laser sintering technology, low-temperature sintering is performed according to the program set by etching the grooves of the mesh, so that it forms good electrical connection performance with the metal mesh.

[0027] Furthermore, in S4, the electron beam power is set to 1500W, a 5000W ion beam is used for assisted deposition, and the fixture for placing the transparent substrate is set to a rotating and revolving structure. The deposition temperature is 90℃, the working pressure is 8Pa, the argon flow rate is 75sccm, and the deposition rate is controlled at 15-20nm / min. Antireflective and antireflective coatings are prepared using crystalline materials with high transmittance such as magnesium fluoride and titanium dioxide.

[0028] The beneficial effects of this invention compared to the prior art are as follows:

[0029] 1. This invention uses conductive metal paste to fill glass groove structures, replacing traditional continuous conductive metal oxide films and nanoimprinted grid films. It combines laser etching and low-temperature laser sintering processes to prepare metal grid structures with good film adhesion on the inner surface of aircraft canopies. The conductive grids with high aspect ratios will not collapse. The operation technology is mature, and the products are consistent and environmentally adaptable.

[0030] 2. Compared with traditional transparent conductive oxide thin film materials, the transmittance and strong electromagnetic wave shielding effectiveness of the present invention are significantly improved, with a light transmittance of ≥90%, strong electromagnetic pulse shielding of ≥50dB, and better environmental adaptability.

[0031] 3. The present invention sets an anti-reflective and anti-reflective film layer on the surface of a transparent substrate, forming a hardened film on the surface of the substrate, which can not only prevent scratches, but also further protect the metal mesh and prevent contact with air. Attached Figure Description

[0032] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0033] Figure 1 This is a schematic diagram of the structure of the present invention;

[0034] Figure 2 This is a schematic diagram of a circular mesh structure;

[0035] Figure 3 This is a schematic diagram of a hexagonal mesh structure;

[0036] Figure 4 This is a schematic diagram of a random mesh structure;

[0037] In the diagram: 1-groove, 2-metal paste, 3-transparent substrate, 4-antireflective coating layer. Detailed Implementation

[0038] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] Example 1:

[0040] like Figures 1 to 4 As shown, an electromagnetic shielding glass for an aircraft cockpit canopy includes a transparent substrate, which may be made of hyperboloid methyl methacrylate organic glass with a thickness of 10-20 mm and a basic light transmittance of ≥91%. The inner surface of the transparent substrate is laser-etched with grooves of a grid structure. The wire diameter of the grid structure is 1-10 μm and the groove depth ratio is 2:1-3:1. The grooves may be circular grids, hexagonal grids, or random grid structures.

[0041] The groove is filled with a metal paste, which can be nano-silver paste or nano-gold paste, using an ultrasonic filling method. The metal paste is then sintered and cured to form a metal mesh. When used for low-frequency electromagnetic shielding, nickel-copper powder can also be used as the conductive material in the metal paste.

[0042] Antireflective coatings with a thickness of 300nm to 500nm are provided on both sides of the transparent substrate and on the outer side of the metal mesh. The antireflective coatings are made of magnesium fluoride or titanium dioxide by electron beam evaporation and ion beam assisted deposition. A hardened film is formed on the outermost layer to increase the hardness of the transparent substrate, prevent scratches, and prevent the metal mesh from oxidizing due to contact with air.

[0043] Example 2:

[0044] A method for preparing electromagnetic shielding glass for aircraft cockpit canopies, comprising:

[0045] S1. Prepare a transparent substrate using methyl methacrylate glass with a thickness of 20.0 mm, a basic light transmittance of ≥91%, and a hyperbolic structure.

[0046] S2, Etched grid grooves

[0047] The grooves of the metal mesh structure are prepared by laser etching technology. The program is set on the laser etching equipment according to the geometry of the aircraft canopy. Then, the depth ratio and periodic structure of the groove are designed according to the electromagnetic shielding effectiveness and light transmittance. The depth ratio is 2:1 to 3:1 and the periodic structure is 200μm to 300μm.

[0048] The etching laser beam energy and aperture size are adjusted to etch the inner surface of the canopy according to the set path. A helium-neon laser beam is used with an energy density of 30-50 J / cm2 / s and an aperture size of 1-5 μm.

[0049] S3. Fabricate the metal grating;

[0050] Conductive silver paste is filled into the groove, and the conductive paste is dispersed by ultrasonic vibration to fill the groove. Then, the excess paste on the glass surface is scraped clean with a flexible scraper, and the glass is heated to 80℃-90℃ in an oven to semi-cur it, forming a continuous metal mesh structure.

[0051] Using laser sintering technology, based on the etching program set for the grooved grid structure, the energy and aperture size of the ultraviolet low-temperature sintering laser beam are adjusted to perform low-temperature sintering at 120℃ to 150℃, enabling good electrical bonding of the metal inside the conductive paste. The laser beam energy density is 15-25 J / cm² / s, and the aperture size is consistent with the laser etching aperture.

[0052] S4. Based on the optical performance requirements of the aircraft cockpit canopy, anti-reflection and anti-reflection coatings are designed using optical design software. Electron beam evaporation is used to deposit metal, and ion beam assisted deposition is used. The electron beam power is 1500W, and the ion beam assisted deposition is 5000W. The fixture for placing methyl methacrylate glass is set to rotate 60-80 s / r and revolve 2 min / r. The deposition temperature is 90℃, the working pressure is 8Pa, the argon flow rate is 75 sccm, and the deposition rate is controlled at 15-20 nm / min. Anti-reflection and anti-reflection coatings are prepared using high-transmittance crystalline materials such as magnesium fluoride or titanium dioxide to protect the metal grid. An anti-reflection coating of 300nm-500nm is deposited on the inner surface of the hyperboloid methyl methacrylate acrylic glass. TiO2 is prepared on the outermost layer to form a hardened film, which increases the hardness of the acrylic glass, prevents scratches on the acrylic glass, and also prevents the conductive silver paste from oxidizing upon contact with air.

[0053] Example 3:

[0054] A method for preparing electromagnetic shielding glass for aircraft cockpit canopies, comprising:

[0055] S1. Prepare a transparent substrate using methyl methacrylate glass with a thickness of 20.0 mm, a basic light transmittance of ≥91%, and a hyperbolic structure.

[0056] S2, Etched grid grooves

[0057] The grooves of the metal mesh structure are prepared by laser etching technology. The program is set on the laser etching equipment according to the geometry of the aircraft canopy. Then, the depth ratio and periodic structure of the groove are designed according to the electromagnetic shielding effectiveness and light transmittance. The depth ratio is 2:1 to 3:1 and the periodic structure is 200μm to 300μm.

[0058] The etching laser beam energy and aperture size are adjusted to etch the inner surface of the canopy according to the set path. A helium-neon laser beam is used with an energy density of 30-50 J / cm2 / s and an aperture size of 1-5 μm.

[0059] S3. Fabricate the metal grating;

[0060] The conductive gold paste is filled into the groove, and the conductive paste is dispersed by ultrasonic vibration to fill the groove. Then, the excess paste on the glass surface is scraped clean with a flexible scraper, and the glass is heated to 80℃-90℃ in an oven to semi-cur it, forming a continuous metal mesh structure.

[0061] Using laser sintering technology, based on the etching program set for the grooved grid structure, the energy and aperture size of the ultraviolet low-temperature sintering laser beam are adjusted to perform low-temperature sintering at 100℃ to 140℃, enabling good electrical bonding of the metal inside the conductive paste. The laser beam energy density is 12-20 J / cm². 2 / s, the aperture size is consistent with the laser etching aperture.

[0062] S4. Based on the optical performance requirements of the aircraft cockpit canopy, anti-reflection and anti-reflection coatings are designed using optical design software. Electron beam evaporation is used to deposit metal, and ion beam assisted deposition is used. The electron beam power is 1500W, and the ion beam assisted deposition is 5000W. The fixture for placing methyl methacrylate glass is set to rotate 60-80 s / r and revolve 2 min / r. The deposition temperature is 90℃, the working pressure is 8Pa, the argon flow rate is 75 sccm, and the deposition rate is controlled at 15-20 nm / min. Anti-reflection and anti-reflection coatings are prepared using high-transmittance crystalline materials such as magnesium fluoride or titanium dioxide to protect the metal grid. An anti-reflection coating of 300nm-500nm is deposited on the inner surface of the hyperboloid methyl methacrylate acrylic glass. TiO2 is prepared on the outermost layer to form a hardened film, which increases the hardness of the acrylic glass, prevents scratches on the acrylic glass, and also prevents the conductive silver paste from oxidizing upon contact with air.

[0063] The above description only illustrates the preferred embodiments of the present invention. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention, and all such changes should be included within the protection scope of the present invention.

Claims

1. A method for preparing electromagnetic shielding glass for aircraft cockpit canopies, characterized in that, include: S1. Prepare a transparent substrate; S2, Etched grid grooves S21. Set up a program on the laser etching equipment according to the geometry of the aircraft canopy, and design the groove depth ratio and periodic structure according to the electromagnetic shielding effectiveness and light transmittance. S22. Adjust the etching laser beam energy and aperture size, and perform etching on the inner surface of the transparent substrate according to the set path; S3. Fabricate the metal grating; S31. The conductive metal paste is filled into the groove, and the conductive paste is dispersed by ultrasonic vibration to fill the groove. Then, the excess paste on the glass surface is scraped clean to form a continuous metal mesh structure. S32. Using laser sintering technology, according to the program set by etching the grooves of the mesh, low-temperature sintering is performed to make it form good electrical connection performance with the metal mesh. S4. Prepare anti-reflection and anti-reflection coatings by electron beam evaporation to deposit metals and ion beam-assisted deposition, using magnesium fluoride or titanium dioxide with high transmittance to prepare anti-reflection and anti-reflection coatings. The electron beam power was set to 1500W, and a 5000W ion beam was used for assisted deposition. The fixture for placing the transparent substrate was set to a rotating and revolving structure. The deposition temperature was 90℃, the working pressure was 8Pa, the argon flow rate was 75sccm, and the deposition rate was controlled at 15-20nm / min. Antireflective and anti-reflective coatings were prepared using magnesium fluoride or titanium dioxide with high transmittance.

2. The method for preparing electromagnetic shielding glass for aircraft cockpit canopies according to claim 1, characterized in that: In S1, the thickness of the transparent substrate is 10-20mm, the basic light transmittance is ≥91%, and it has a hyperbolic structure.

3. The method for preparing electromagnetic shielding glass for aircraft cockpit canopies according to claim 1, characterized in that: include: A transparent substrate, wherein the inner surface of the transparent substrate is laser-etched with grooves of a mesh structure, and the grooves are filled with metal paste by ultrasonic filling, and the metal paste is sintered and cured to form a metal mesh. Anti-reflective coatings are provided on both sides of the transparent substrate and on the outer side of the metal mesh.

4. The method for preparing electromagnetic shielding glass for aircraft cockpit canopies according to claim 3, characterized in that: The transparent substrate includes hyperboloid methyl methacrylate acrylic glass, and the thickness of the transparent substrate is 10-20mm.

5. A method for preparing electromagnetic shielding glass for an aircraft cockpit canopy according to claim 3, characterized in that: The wire diameter of the grid structure is 1 to 10 μm, and the groove depth ratio is 2:1 to 3:

1.

6. A method for preparing electromagnetic shielding glass for an aircraft cockpit canopy according to claim 3, characterized in that: Mesh grid structures include circular mesh grids, hexagonal mesh grids, or random mesh grids.

7. A method for preparing electromagnetic shielding glass for an aircraft cockpit canopy according to claim 3, characterized in that: The antireflective and anti-reflective coating is made of magnesium fluoride or titanium dioxide using electron beam evaporation to deposit metal or ion beam assisted deposition.

8. A method for preparing electromagnetic shielding glass for an aircraft cockpit canopy according to claim 3, characterized in that: The metal paste includes nano silver paste, nano gold paste, or nickel-copper powder.

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