CN103763901B - Based on the electromagnetic shielding optical window of the tangent annulus of angular distribution and the sub-circle ring array of inscribe - Google Patents

Abstract

The electromagnetic shielding light window based on the triangular distribution of tangent rings and inscribed sub-ring arrays belongs to the field of electromagnetic shielding technology; the metal rings of the same diameter are arranged in an equilateral triangle to form a grid array and are loaded on the surface of the transparent substrate of the optical window. And the adjacent rings are circumscribed and connected, and each ring has a sub-ring that is inscribed with the ring, and the ring is used as a basic ring and its inscribed connected sub-rings to form a two-dimensional metal grid array structure The basic unit of the basic ring; at the junction of adjacent basic rings and the connection between the basic ring and its inscribed connected sub-rings, ensure that all the rings are connected to each other by overlapping lines or setting metals that ensure reliable electrical connection between the tangent points of the metal rings conduct electricity. The metal grid structure of the invention can significantly reduce the inhomogeneity of the high-order diffraction light intensity distribution of the grid, make the distribution of stray light caused by diffraction more uniform, and have less impact on imaging.

Description

Electromagnetic shielding window based on triangular distribution of tangent rings and inscribed sub-ring arrays

technical field

The invention belongs to the field of electromagnetic shielding of optical transparent parts, in particular to an electromagnetic shielding light window based on triangular distribution of tangent rings and inscribed sub-ring arrays.

Background technique

With the widening and increasing intensity of the electromagnetic wave application spectrum, the requirements for electromagnetic shielding light windows used in aerospace equipment, advanced optical instruments, communication equipment, medical diagnostic instruments and security facilities are getting higher and higher, mainly requiring light windows While having a super strong broadband electromagnetic shielding ability, it also has a very high light transmittance, and the less impact on optical imaging, observation, and detection, the better. For example, the optical window of an aircraft in the field of aerospace equipment must achieve high-quality isolation of electromagnetic signals inside and outside the cabin. On the one hand, it can shield external electromagnetic interference and harmful electromagnetic signals to avoid failure of electronic equipment in the cabin. When working, the electromagnetic signal passes through the light window to cause electromagnetic leakage, but the light transmission of the light window is an essential function. The electromagnetic shielding of the light window should minimize the impact on its transparency, especially as much as possible. Does not affect optical detection or optical imaging capabilities; similarly, light windows for advanced optical instruments must have the highest possible light transmittance and the lowest possible impact on imaging quality in order to achieve high-quality detection and measurement, while preventing The influence of electromagnetic interference on the photoelectric detection device inside the instrument; for the confidential building facilities of party and government organs, military command places, and important scientific research units, it is necessary to carry out electromagnetic shielding design on the window glass of the house while ensuring lighting to prevent indoor When computers and other electronic equipment are working, important information is transmitted to the outside in the form of electromagnetic radiation to cause leakage; the light window of the electromagnetic isolation room for medical use must ensure that most of the electromagnetic waves in the room are shielded to prevent outdoor operators from being radiated by electromagnetic waves for a long time and damage their health, etc. . At present, the electromagnetic shielding of this kind of light window mainly adopts transparent conductive film, metal-induced transmission multilayer film structure, band-stop frequency selective surface and metal grid with millimeter-submillimeter period, etc.

Transparent conductive film is a kind of transparent metal oxide film with indium tin oxide as the main material. It is often used in the occasions where the visible light band is transparent, but it cannot take into account the wider light transmission band. Although it has a wider microwave shielding band, the shielding ability Not strong. The metal-induced transmission multilayer film structure uses a composite structure of multilayer thin metal film and dielectric film to realize the shielding of electromagnetic waves, and has a strong shielding ability for low-frequency microwaves. The light-transmitting area is mainly visible light and ultraviolet light, but the light transmittance is not high. . The frequency selective surface uses a periodic resonant unit structure to realize the function of a bandpass or bandstop filter. Due to its high metal coverage, it can well reflect the interference electromagnetic waves outside the working frequency band, but the optical transmittance is low, which reduces the optical efficiency. The imaging quality of detection brings difficulties to optical image processing, pattern recognition, target search and tracking. To sum up, all the above-mentioned technical solutions have obvious deficiencies in meeting the two requirements of wide-band high light transmittance and wide-band electromagnetic shielding of the light window at the same time. In contrast, the metal grid with a millimeter-submillimeter period can achieve strong low-frequency broadband electromagnetic shielding because its period is much smaller than the interference electromagnetic wavelength; and the metal grid period is much larger than the optical wavelength, which can ensure The light transmittance of the optical band. Therefore, the metal grid with a millimeter-submillimeter period has good transparent and conductive properties, which can meet the requirements of high light transmittance and broadband electromagnetic shielding for light windows, and has been widely used in the field of light window electromagnetic shielding technology:

1. Patent 03135313.5 "an observation window for electromagnetic shielding" uses a single or multiple wire mesh and a semiconductor quantum well structure to form an electromagnetic shielding structure, which can achieve a shielding efficiency of more than 50dB within 10GHz. The light transmittance reaches more than 50%.

2. Patent 93242068.0 "Electromagnetic shielding glass" sandwiches conductive metal mesh between two layers of glass, and uses conductive transparent film on the outside of the glass to bond it to the metal window frame to form an electromagnetic shielding structure. The structure has certain lighting properties.

3. Patent No. 94231862.5 "Moiré-free electromagnetic shielding observation window" adopts two layers of metal mesh with different numbers placed in parallel, and their warp or weft has a certain angle to overcome the phenomenon of moiré fringes and achieve a clearer view .

4. Patent 02157954.7 "High screen efficiency anti-information leakage glass" has a layer of polycarbonate film on both sides of the wire mesh, and a layer of glass on the outside of the film, and finally heat-pressed to form an electromagnetic shielding structure. When the rate reaches 60%, it has strong shielding efficiency.

5. Patent 200610084149.8 "Electromagnetic wave shielding film and its manufacturing method" describes a highly transparent electromagnetic shielding film with a metal mesh pattern formed by photolithography. The problem of environmental pollution caused by the use of curing glue between the layer and the film substrate.

6. US patent US4871220 "Short wavelength pass filter having a metal mesh on asemiconducting substrate" describes a metal grid with a square structure, which is used to realize the anti-electromagnetic interference performance of the light window.

7. Patent 201010239355.8 "An electromagnetic shielding conformal optical window with latitude and longitude grid structure" describes a conformal electromagnetic shielding with a latitude and longitude metal grid structure realized by metal grid technology and conformal optical window technology The optical window mainly solves the structural design problem of the metal grid of the conformal optical window and improves the electromagnetic shielding performance of the conformal optical window.

8. Patent 200610010066.4 "Electromagnetic shielding optical window with ring metal grid structure" describes a metal grid unit with a ring shape, which is used to realize the electromagnetic shielding function of the optical window; compared with single-layer square metal grid The light transmittance and shielding ability have been improved, and the stray light caused by high order diffraction has also been homogenized to a certain extent.

9. Patent 200810063988.0 "An Electromagnetic Shielding Optical Window with a Double-layer Grid Structure" describes a grid or wire mesh with the same structural parameters placed in parallel on both sides of the optical window or transparent substrate. The electromagnetic shielding optical window formed by the side can greatly improve the electromagnetic shielding efficiency without reducing the light transmittance.

10. Patent 200810063987.6 "An Electromagnetic Shielding Optical Window with a Double-layer Ring Metal Grid Structure" describes an electromagnetic shielding optical window composed of two layers of ring metal grids loaded on both sides of the optical window to solve the problem of high transparency. The problem that light efficiency and strong electromagnetic shielding efficiency cannot be taken into account at the same time.

11. The hub-spoke structure based on the ring unit and the inductive metal grid with multi-ring overlapping structure developed by Jennifer I.Halman et al. a metallic mesh coating". Proc. SPIE, 2009, 7302: 73020Y-1 ~ 73020Y-8), and it is believed that this structure can make the distribution of high-order diffraction of the grid uniform, and achieve low side lobes, which is beneficial to imaging.

12. Ian B.Murray from Exotic Electro-Optics, USA, Victor Densmore from the University of Arizona, Vaibhav Bora and others jointly reported that the inductive grid with hub-spoke structure and multi-ring overlapping structure introduced random distribution of parameters Effects on diffraction characteristics after design (Ian B. Murray, Victor Densmore, Vaibhav Bora et al., "Numerical comparison of grid pattern diffraction effects through measurement and modeling with OptiScan software", Proc.SPIE, 2011, 8016: 80160U-1～80160U -15), pointing out that the distance and diameter of each ring are randomly selected within a certain range, which is conducive to improving the uniformity of the high-order diffraction distribution.

The above schemes can achieve better electromagnetic shielding effect and a certain light transmittance due to the use of metal grids (or wire mesh) as the core shielding device. However, if a metal grid (or wire mesh) is used as the electromagnetic shielding structure, it will inevitably be affected by the diffraction of the grid in the optical band. Since the period of the metal grid is on the order of millimeters or submillimeters, in order to achieve high light transmittance, the width of its metal lines is generally on the order of microns and submicrons. Such structural parameters have a very strong diffraction effect in the optical band. Most of the energy of the incident light is transmitted by the metal grid, and the transmitted part includes zero-order diffracted light and high-order diffracted light. Usually, zero-order diffracted light is useful information for imaging and observation, and high-order diffracted light constitutes stray light. , interfere with imaging and detection. Therefore, the proportion of zero-order diffracted light should be increased as much as possible. At the same time, under the premise that high-order diffracted light is inevitable, the distribution of high-order diffracted light should be made as uniform as possible, and the stray light formed by it becomes relatively uniform. background or noise.

At present, the metal grid is mainly a traditional grid structure, such as the structure mainly used in the above-mentioned patents 1-6 (the structure of patent 7 is a kind of grid structure because it is processed on the curved surface), the grid structure There is an inherent contradiction between light transmission ability and shielding ability, and it is difficult to take into account high light transmission rate and strong electromagnetic shielding efficiency at the same time. In particular, the high-order diffraction energy of the square grid is mainly concentrated on two mutually perpendicular axes, which has a certain impact on the imaging quality. It is even difficult to apply in occasions with high image quality requirements. Changing the grid diffraction characteristics generally requires changing its structural characteristics. The above-mentioned patent 200610010066.4 "Electromagnetic shielding optical window with a ring metal grid structure" proposes to use a metal ring to form a ring metal grid, which improves the advanced quality of the square metal grid. The shortcomings of the concentrated distribution of sub-diffraction energy can alleviate the contradiction between its light transmission ability and shielding ability. In the above-mentioned documents 11 and 12, Jennifer I.Halman et al. and Ian B.Murray et al. also proposed a metal grid structure based on circular ring units to improve the uniformity of the high-order diffraction distribution, but Jennifer I.Halman et al. Human research is also a single-period ring arrangement structure, and the arrangement direction is determined. Its effect on adjusting high-order diffraction is equivalent to the structure proposed in patent 200610010066.4. Although the research of IanB.Murray et al. went further, they proposed random overlapping rings The ring diameter and spacing are randomly distributed within a certain range to further improve the uniformity of the high-order diffraction distribution. However, the random distribution of the ring diameter and spacing changes the uniformity of the mesh distribution, which will damage the electromagnetic shielding efficiency. .

With the increasingly complex electromagnetic environment, the requirements for the light transmission ability and electromagnetic shielding ability of the electromagnetic shielding light window are constantly increasing, especially in the field of aerospace equipment and advanced optical instruments, the light window has been required to reach 95% or even higher While having high light transmittance, it also has extremely low impact on imaging quality, and achieves a shielding efficiency of more than 30dB in the microwave frequency range below 20GHz, which makes it difficult to achieve with existing technologies. Patent 200810063988.0 and Patent 200810063987.6 both adopt double-layer metal grids placed in parallel on both sides of the transparent substrate or substrate of the light window. The two-layer metal grids have the same unit shape and structural parameters. By optimizing the two-layer grids The distance between them can greatly improve the electromagnetic shielding efficiency without reducing the light transmittance. However, the high order diffraction stray light distribution of this double-layer grid structure is still equivalent to that of a single-layer grid with the same light transmittance, which does not fully meet the requirements of future aerospace equipment and advanced optical instruments on low imaging quality.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies of the above-mentioned existing optical window electromagnetic shielding technical solutions, especially for the existence of advanced To solve the problem of relatively concentrated stray light distribution caused by sub-diffraction, an electromagnetic shielding light window based on a triangular distribution of tangent rings and inscribed sub-ring arrays has been developed to achieve depth averaging of high-order diffraction and extremely low impact on imaging quality the goal of.

The purpose of the present invention is achieved like this: based on the electromagnetic shielding light window of the triangular distribution tangent ring and the inscribed sub-ring array, the metal grid in the electromagnetic shielding light window is made of the metal ring of the same diameter as the basic ring by the same Triangular sides are closely arranged to form a two-dimensional grid array, and the adjacent basic rings are circumscribed and connected; each basic ring is provided with a metal sub-ring that is inscribed with it, and the basic rings are connected with each other. The inscribed and connected sub-rings together constitute the basic unit of the two-dimensional grid array structure; the diameter of the basic ring and its inscribed connected sub-rings are on the order of millimeters and submillimeters, and the basic ring and its The width of the metal lines of the inscribed and connected sub-rings is on the order of microns and submicrons; the arrangement of equilateral triangles refers to the connection of the centers of three adjacent basic rings in pairs to form an equilateral triangle; Circumscribed connectivity includes: ①The two rings are circumscribed and the connecting metal connecting the two rings is set at the circumtangent point; ②The lines at the joint of the two rings form a seamless overlapping structure; At the same time of the seamless overlapping structure, a connecting metal connecting the two rings is provided at the overlap; the inscribed connection includes: ① two rings are inscribed and a connecting metal connecting the two rings is set at the inscribed tangent point , ②The lines at the junction of the two rings are in a seamless overlapping structure, ③The lines at the junction of the two rings are in a seamless overlapping structure, and at the same time, a connecting metal connecting the two rings is set at the overlapping place.

In the above-mentioned electromagnetic shielding light window based on triangular distribution of tangent rings and inscribed sub-ring arrays, the number of sub-rings in each basic unit is greater than or equal to 2, and the diameters are the same or different, and the adjacent sub-rings The angle formed by the center of the circle and the line connecting the center of the basic ring is any angle, and the sub-rings in different basic units are rings of equal diameter or non-equal diameter, and the numbers are the same or different.

In the above-mentioned electromagnetic shielding light window based on the triangular distribution of tangent rings and inscribed sub-ring arrays, the adjacent sub-rings in the basic unit can be circumscribed or intersected.

As a preferred structural mode, the above-mentioned electromagnetic shielding light window based on triangular distribution of tangent rings and inscribed sub-ring arrays, the diameters of the sub-rings in the basic unit are the same, and the centers of adjacent sub-rings and The included angles formed by the lines connecting the centers of the basic rings are equal.

As a preferred structure, in the above-mentioned electromagnetic shielding light window based on triangular distribution of tangent rings and inscribed sub-ring arrays, the number of sub-rings in different basic units is the same and the diameters are equal.

As a preferred structure, the above-mentioned electromagnetic shielding light window based on triangular distribution of tangent rings and inscribed sub-ring arrays, the relative positions of the sub-rings in different basic units are the same, and are copied by one basic unit Afterwards, they are arranged in close contact with equilateral triangles to form a two-dimensional grid array.

As a preferred structure, the above-mentioned electromagnetic shielding light window based on triangular distribution of tangent rings and inscribed sub-ring arrays, in the two-dimensional grid array, the relative positions of the sub-rings in adjacent basic units Different, and a two-dimensional grid array is formed by duplicating a basic unit and arranged closely in an equilateral triangle, in which any one basic unit rotates at a certain angle around the center of its own basic ring in a two-dimensional plane relative to its adjacent basic unit .

As a preferred structure, in the above-mentioned electromagnetic shielding light window based on triangular distribution of tangent rings and inscribed sub-ring arrays, any basic unit in the same row rotates at the same angle relative to adjacent basic units.

In the above-mentioned electromagnetic shielding light window based on the array of tangent rings and inscribed sub-rings in triangular distribution, the basic rings and sub-rings are both made of an alloy with good electrical conductivity, and the thickness of the alloy is greater than 100 nm.

In the electromagnetic shielding light window based on the triangular distribution of tangent rings and inscribed sub-ring arrays, the bonding layer is made of chromium or titanium.

The innovation and good effect of the present invention are:

The innovation of the present invention lies in that the metal grid in the electromagnetic shielding window is composed of metal rings of the same diameter as the basic rings arranged closely in an equilateral triangle to form a two-dimensional grid array, and the adjacent basic rings circumscribe Connected; each basic ring is provided with a metal sub-ring that is inscribed and communicated with it, and the basic ring and its inscribed sub-rings together constitute the basic unit of the two-dimensional grid array structure; The diameter of the sub-ring connected to the basic ring and its inscribed ring is on the order of millimeters and submillimeters, and the width of the metal lines of the sub-rings connected to the basic ring and its inscribed ring is on the order of microns and sub-microns; The arrangement of equilateral triangles refers to the connection of the centers of three adjacent basic rings to form an equilateral triangle; the circumscribed connection includes: 1. two rings are circumscribed and the circumtangent point is set to connect the two rings Connected connecting metal, ②The lines at the joint of the two rings are in a seamless overlapping structure, ③The lines at the joint of the two rings are in a seamless overlapping structure, and at the same time, a connecting metal connecting the two rings is set at the overlap ; The inscribed communication includes: ① the two rings are inscribed and the connecting metal connecting the two rings is set at the inscribed tangent point; ② the lines at the joint of the two rings are in a seamless overlapping structure; While the lines at the connection point are in a seamless overlapping structure, a connecting metal connecting the two rings is set at the overlapping point. The good effect produced by the innovation of the present invention mainly focuses on the high-order diffraction energy distribution of the homogenized metal grid, as follows:

The basic rings in the metal grid are arranged in an equilateral triangle distribution, which can well overcome the shortcomings of the concentrated distribution of high-order diffraction energy in the traditional grid metal grid, and has a good characteristic of homogenizing high-order diffraction energy distribution. , which is one of the reasons for the metal grid of the present invention to homogenize the energy distribution of high-order diffraction.

The sub-ring array in the metal mesh grid, because of the difference in the number, diameter and positional relationship of the sub-rings in each basic unit, makes its structure loose and stray, so the high-order diffraction energy is low, and The higher-order diffraction distribution is relatively uniform, avoiding the concentrated distribution of higher-order diffraction energy that exists in traditional square metal grids. This is the second reason for the metal grid of the present invention to homogenize the distribution of higher-order diffraction energy.

Adding sub-rings to the basic ring to form the basic unit, while ensuring the same light transmittance, compared with the structure with only the basic ring array, it is necessary to increase the diameter of the basic ring, which reduces the advanced level of each array as a whole. Second diffraction energy; and because the superposition probability of the high order diffraction produced by the sub-annular array structure and the high order diffraction of the basic annular array structure is very low, especially after optimizing the structure and parameters, their higher energy high order diffraction does not occur Superposition, thereby homogenizing the distribution of high-order diffraction energy, which is the third reason for the homogenization of high-order diffraction energy distribution by the metal grid of the present invention.

Each basic unit can be rotated at a certain angle around the center of the basic ring without changing the aperture ratio of the metal grid and thus not affecting the light transmittance, but the energy distribution of the higher-order diffraction orders can be further modulated to achieve better This is the fourth reason why the metal grid of the present invention homogenizes the energy distribution of high-order diffraction.

To sum up, the metal grid structure of the present invention can realize the depth homogenization of the high-order diffraction energy distribution of the grid, which is the most prominent effect of the present invention. In addition, adding sub-rings to the basic ring structure effectively improves the uniformity of the metal ring grid structure, and when the basic unit rotates at a certain angle around the center of the basic ring, it will not change the metal grid structure. The uniformity of the structure basically does not affect the electromagnetic shielding effect while effectively modulating the energy distribution of the high-order diffraction order, and even improves the electromagnetic shielding effect in some preferred solutions.

Description of drawings

Fig. 1 is a schematic cross-sectional view of a preferred structure of an electromagnetic shielding light window based on a triangular distribution of tangent rings and inscribed sub-ring arrays.

Fig. 2 is a schematic diagram of the basic ring distribution of the electromagnetic shielding light window based on the triangular distribution of tangent rings and inscribed sub-ring arrays.

Fig. 3 is a schematic diagram of the circumscribed connected basic units respectively containing 2, 3, 4, and 5 sub-rings of the same diameter.

Fig. 4 is a schematic diagram of basic units respectively containing 3, 4, 5, and 6 sub-rings of the same diameter that are intersected and connected.

Fig. 5 is a schematic diagram of a basic unit composed of sub-rings with different diameters.

Fig. 6 is a schematic diagram of the circumscribed connection mode of two circular rings.

Fig. 7 is a schematic diagram of the inscribed connection mode of two circular rings.

Fig. 8 is a schematic diagram of a rotation mode of a basic unit of the present invention relative to an adjacent basic unit.

Fig. 9 is a schematic diagram of an existing square grid structure.

Fig. 10 is a schematic diagram of the existing square grid high-order diffraction and its relative intensity distribution.

Fig. 11 is a schematic diagram of the existing ring grid structure.

Fig. 12 is a schematic diagram of the high-order diffraction of the existing annular grid and its relative intensity distribution.

Fig. 13 is a schematic diagram of the metal grid structure of preferred solution A in the present invention.

Fig. 14 is a schematic diagram of the high-order diffraction of the metal grid and its relative intensity distribution of the preferred solution A in the present invention.

Fig. 15 is a schematic diagram of the metal grid structure of the preferred solution B in the present invention.

Fig. 16 is a schematic diagram of the high-order diffraction of the metal grid and its relative intensity distribution of the preferred solution B in the present invention.

Fig. 17 is a comparative diagram of the maximum relative intensity of high-order diffraction of four kinds of grid structures.

Part number description in the picture: 1. Adhesive layer 2. Protective layer 3. Anti-reflection film 4. Transparent substrate 5. Metal grid 6. Basic ring 7. Sub-ring 8. Connecting metal

Detailed ways

The present invention will be further described below in conjunction with accompanying drawing and preferred embodiment:

The electromagnetic shielding light window based on triangular distribution of tangent rings and inscribed sub-ring arrays, the metal grid 5 in the electromagnetic shielding light window is composed of metal rings of the same diameter as the basic rings 6 arranged in an equilateral triangle and closely connected. A two-dimensional grid array, and the adjacent basic rings 6 are circumscribed and connected; each basic ring 6 is provided with a metal sub-ring 7 that is inscribed with it, and the basic ring 6 is inscribed with it. The sub-rings 7 together constitute the basic unit of the two-dimensional grid array structure; the diameters of the sub-rings 7 of the basic ring 6 and its inscribed communication are millimeters and submillimeters, and the basic rings 6 The metal line width of the sub-ring 7 connected with it inscribed is micron and sub-micron level; the described circumscribed communication includes: ① two rings are circumscribed and a connecting metal 8 connecting the two rings is set at the circumtangent point , 2. The lines at the junction of the two rings are in a seamless overlapping structure, ③ while the lines at the junction of the two rings are in a seamless overlapping structure, a connecting metal 8 connecting the two rings is set at the overlap; The inscribed connection includes: ①The two rings are inscribed and the connecting metal 8 connecting the two rings is set at the inscribed tangent point; ②The lines at the joint of the two rings are in a seamless overlapping structure; While the lines are in a seamless overlapping structure, the connecting metal 8 connecting the two rings is set at the overlapping place. The transparent substrate 4 can be any transparent material, as long as it can be used as a transparent light window material that meets the requirements of the application, and the metal grid 5 can be processed on it according to a certain process flow; according to the process flow, the metal grid 5 can be Loaded on the surface of the transparent substrate 4 through the adhesive layer 1; the single-layer or multi-layer antireflection film 3 enhances the light transmission ability of the light window, and the single-layer or multi-layer protective layer 2 is used to prevent the metal part from being exposed to the air for a long time Corrosion and oxidation are caused, the shielding ability is reduced, and the metal grid 5 is prevented from being scratched.

The electromagnetic shielding light window based on triangular distribution tangent rings and inscribed sub-ring arrays of the present invention is composed of metal rings of the same diameter as basic rings 6 arranged closely in equilateral triangles to form a grid array 5 and loaded on the The surface of the transparent substrate 4 of the light window is circumscribed and communicated with adjacent basic rings 6 . The arrangement of equilateral triangles means that the connecting lines between the centers of three adjacent basic rings 6 form an equilateral triangle. The distribution of the basic ring 6 is shown in Figure 2. Points A, B, and C in Figure 2 are the centers of any three basic rings 6 that are tangent to each other. ΔABC is an equilateral triangle. This arrangement ensures that all The basic circular rings 6 are arranged in close contact according to equilateral triangles to form the metal mesh grid 5 .

According to the electromagnetic shielding light window of the present invention based on triangular distribution of tangent rings and inscribed sub-ring arrays, each basic ring 6 has a sub-ring 7 inscribed with the ring, and the basic ring 6 is inscribed with it. The connected sub-rings 7 together form the basic unit of the two-dimensional grid array structure. The diameter of the basic ring 6 and the sub-ring 7 is on the order of millimeters and submillimeters, and the width of the metal lines of the basic ring 6 and the sub-rings 7 is on the order of microns and sub-microns, so as to ensure high light transmittance and good electromagnetic shielding effect . In addition, each ring part is made of a metal with good electrical conductivity, such as gold, silver, copper, aluminum and other pure metals and metal alloys, and the thickness of the metal is greater than 100 nm.

In the electromagnetic shielding light window based on triangular distribution of tangent rings and inscribed sub-ring arrays of the present invention, the number of sub-rings 7 in each basic unit is greater than or equal to 2, and the diameters are the same or different, and adjacent sub-rings The angle formed by the center of circle 7 and the line connecting the center of the basic ring 6 is any angle; the adjacent sub-rings 7 in the basic unit can be tangentially connected or intersected. As shown in Fig. 3 and Fig. 4, the preferred scheme is that the diameter of the sub-annular 7 in the basic unit is the same, and the angle formed by the center of the adjacent sub-annular 7 and the line connecting the centers of the basic annulus 6 is equal: Fig. 3 is the basic The sub-rings 7 of the same diameter in the unit are circumscribed and connected, and Fig. 3 (a) (b) (c) (d) respectively represent the schematic diagrams of the basic units of the 7 sub-rings whose numbers are 2, 3, 4, and 5; 4 is the intersecting connection of the sub-rings 7 of the same diameter in the basic unit, where Figure 4 (a) (b) (c) (d) respectively represent the schematic diagrams of the basic units with 7 sub-rings numbered 3, 4, 5, and 6 . Figure 5 lists a schematic diagram of a basic unit composed of three sub-rings 7 with different diameters, wherein R1, R2, and R3 are the radii of the sub-rings 7, and R1≠R2≠R3, the centers of adjacent sub-rings 7 and the basic The included angles formed by the lines connecting the centers of the rings 6 are different.

Fig. 6 and Fig. 7 show the circumscribed connection and inscribed connection of two circular rings respectively, by overlapping or setting (such as covering) the metal between the tangent points of the metal rings to ensure the reliable electrical connection between the metal rings to ensure the connection between the tangent metal rings Close connection conducts electricity. Among them, Figure 6(a)(b)(c) respectively show the schematic diagrams of the seamless overlapping structure of the two rings when they are circumscribed connected: Figure 6(a) shows the general situation of the seamless overlapping of the two rings, that is, the two circles The center-to-center distance of the rings is less than the distance between the two rings when they are circumscribed, and is greater than the difference between the center-to-center distance when the two rings are circumscribed and the sum of the line widths of the two rings. Figure 6(b) is a seamless overlapping In a special case, the inner and outer contours of the two rings circumscribe each other. Figure 6(c) is another special case of seamless overlap. The center distance of the two rings is equal to the distance between the centers of the two rings and the The difference between the sum of the widths of the ring lines, that is, the inner contours of the two ring lines is circumscribed, and in Figure 6(d) because the two rings are circumscribed, it is necessary to set a reliable electric current between the tangent points of the metal rings at the point of tangency. Jointed metal 8. Figure 7(a) and (b) respectively show the schematic diagrams of the seamless overlapping structure of two rings when inscribed connected: Figure 7(a) shows the general situation of seamless overlapping of two rings when inscribed connected, that is, two The distance between the centers of the rings is greater than the distance between the two rings when they are inscribed, and is smaller than the sum of the distance between the centers of the two rings when they are inscribed and the line width of the ring with a larger diameter. Figure 7(b) shows that when the two rings are inscribed and connected A special case of seamless overlapping of rings, the distance between the centers of two rings is equal to the sum of the distance between the centers of the two rings when they are inscribed and the line width of the ring with a larger diameter, that is, the outer contour of the two rings is inscribed. And Fig. 7 (c) shows that the outer contour of the ring line with smaller diameter is inscribed with the inner contour of the ring line with larger diameter. At this time, it is necessary to set a metal at the tangent point to ensure reliable electrical connection between the tangent points of the metal ring. In addition, if the overlapping area of the two metal rings is small when the two rings overlap seamlessly, it is not enough to ensure a reliable electrical connection between the two metal rings, and it is also necessary to set a guaranteed metal ring tangent point at the tangent point. Metals that can be electrically connected between them to ensure the circumscribed or inscribed communication of the metal rings. Figure 6(d) and Figure 7(c) show a preferred metal connection method at the tangent point, the connecting metal 8 covered at the tangent point is a rectangle, the side length of the rectangle is greater than the line width of the metal ring, and the rectangle covers the cut When pointing the connection, one side of the rectangle should fall completely within a metal ring line, and its opposite side should completely fall within another tangent metal ring line. According to different processing methods and technological levels, other forms of connecting metals can also be used at the tangent point of the rings, as long as the two tangent metal rings can have reliable electrical connection.

Claims 3-6 In the present invention, the sub-rings 7 in different basic units are equal-diameter or non-equal-diameter rings, and the number is the same or different, so as to achieve the purpose of homogenizing the stray light caused by high-order diffraction. As a preferred solution, the diameters of the sub-rings 7 in the basic unit are the same, and the angles formed by the centers of the adjacent sub-rings 7 and the lines connecting the centers of the basic rings 6 are equal; The 7 sub-rings have the same number and equal diameters. As a special example of this preferred solution, the relative positions of the sub-rings 7 in different basic units are the same, and a two-dimensional metal mesh grid 5 is formed by duplicating a basic unit and closely arranged in an equilateral triangle arrangement. In order to achieve a good homogenization of the stray light effect caused by high-order diffraction, as another special case of this preferred solution, the relative positions of the sub-rings 7 in adjacent basic units in the metal grid 5 array in the present invention are different, and After copying a basic unit, it is closely arranged in an equilateral triangle to form a two-dimensional grid array. Any one of the basic units rotates around the center of its own basic ring 6 in a two-dimensional plane relative to its adjacent basic unit at a certain angle, and the same The angle that any basic unit in the row rotates relative to the adjacent basic unit can be the same; for example, Fig. 8 is a schematic diagram of a rotation mode of the basic unit of the present invention relative to the adjacent basic unit, wherein the basic unit of the metal grid 5 is selected from Fig. 4 ( In the structure of b), each basic unit in the same row is rotated by 60° relative to the adjacent basic units.

Fig. 9 and Fig. 10 are the schematic diagrams of the existing square grid structure and its high-order diffraction and its relative intensity distribution in US Patent No. 4871220 respectively. Fig. 11 and Fig. 12 are the schematic diagrams of the existing ring grid structure and Its schematic diagram of high-order diffraction and its relative intensity distribution; Fig. 13 and Fig. 14 are respectively the schematic diagram of the structure of the metal grid 5 of the preferred scheme A in the present invention and its high-order diffraction and its relative intensity distribution schematic diagram, the metal mesh in the preferred scheme A The grid 5 selects the structure of Fig. 3 (c) as the basic unit and there is no relative rotation between each basic unit; Fig. 15 and Fig. 16 are respectively the schematic diagram of the structure of the metal grid 5 of the preferred scheme B in the present invention and its high order diffraction and its Schematic diagram of the relative intensity distribution, the metal grid 5 of the preferred scheme B still selects the structure of Figure 3 (c) as the basic unit, but different from the preferred scheme A, the adjacent basic units of the preferred scheme B rotate according to the rotation shown in Figure 8 The mode is rotated, and the rotation angle is 30°.

In order to illustrate the superiority of the present invention in the homogenization of the high-order diffraction energy distribution, based on the scalar diffraction theory, the theoretical calculations are carried out on the high-order diffraction energy distribution of the above four structures and the maximum relative intensity of the high-order diffraction. During the calculation, each The light transmittance of the structure is the same (both are 95.4%), and their zero-order relative intensities are both 91%, that is, the proportion of useful information for imaging is the same. Compared with the square grid and the circular ring grid, the metal grid 5 structure in the preferred scheme A and B has a significantly lower relative intensity of the highest-order diffraction, and the number of higher-order diffraction spots in the same investigation interval increases significantly, thus avoiding solve the problem that the high-order diffraction energy is concentrated on a few diffraction orders, and make the high-order diffraction energy distribution more uniform; Figure 17 shows the specific values of the maximum relative intensity of the high-order diffraction of the above four structures. It can be seen that the square metal grid structure Compared with other structures, the maximum relative intensity of high-order diffraction is obviously higher than that of other structures. The maximum relative intensity of high-order diffraction of the metal grid structure corresponding to the preferred scheme A of the present invention has been significantly reduced, from 0.0259% (existing ring grid The maximum relative intensity of the higher order diffraction of the structure) drops to 0.0163%, which is 37%, and the homogenization effect of the higher order diffraction is obvious; the maximum relative intensity of the higher order diffraction of the metal grid structure of the preferred scheme B is further reduced, from 0.0259% ( The maximum relative intensity of the high-order diffraction of the existing ring grid structure is reduced to 0.0057%, which is reduced by 78%, and the depth averaging of the high-order diffraction is completed. In summary, the metal grid structure of the present invention has a very significant effect on homogenizing the distribution of high-order diffraction energy, which is not only superior to the existing grid metal grid structure in US Patent No. Ring metal grid structure.

The composition of the basic ring 6 and the sub-ring 7 of the present invention makes the mesh relatively average, and while the depth averages the high-order diffraction energy distribution, it still has good light transmission and shielding performance. When used to construct a double When the single-layer metal grid structure is used, the contradictory problem of light transmittance and shielding efficiency can be improved. At the same time, because the single-layer structure of the present invention is deeply homogenized and the distribution of high-order diffraction energy can be solved, it can also solve the problem in the existing double-layer metal grid structure. Due to the limitation of the single-layer grid structure, it is impossible to further homogenize the distribution of high-order diffraction energy.

The metal grid 5 in the electromagnetic shielding light window based on the triangular distribution tangent ring and the inscribed sub-ring array of the present invention can be processed and manufactured by the following processing method: a mask is made by electron beam direct writing, etc., and the light window is transparent After the substrate 4 is cleaned, it is plated with chrome or titanium as the adhesive layer 1, coated with a metal film, then coated with photoresist, photoetched using a processed mask, and finally dry or wet etched to remove the substrate 4. Get the grid pattern after gluing. It is also possible to omit the mask making process, and directly adopt the method of laser direct writing to make the metal grid pattern based on the triangular distribution of tangent rings and inscribed sub-ring arrays. Other microelectronic processing processes or binary optical element manufacturing processes can also be used to manufacture the metal grid structure of the present invention.

The transparent substrate 4 involved in the present invention is determined by the actual application, and can be ordinary glass, quartz glass, infrared material, transparent resin material and the like. The metal structure of the basic ring 6 and the sub-ring 7 of the present invention should be based on the transparent substrate 4 to take a suitable processing process to make it completely covered on the transparent substrate 4, and can realize reliable electrical connection or connection with the window frame or the like. Sealed to ensure excellent electromagnetic shielding function. In practical application, the surface of the transparent substrate 4 with the grid structure of the present invention can be plated with an anti-reflection film to increase the light transmission capacity, and can also be coated with a protective layer on the surface of the grid layer to prevent the metal structure from being corroded in the air for a long time Or oxidation to reduce the shielding ability, and also prevent the grid layer from being scratched, worn or otherwise damaged.

Claims (9)

1. Based on the electromagnetic shielding light window of triangular distribution tangent ring and inscribed sub-ring array, it is characterized in that: the metal grid (5) in the electromagnetic shielding light window is made of the metal ring of the same diameter as the basic ring (6 ) are arranged in close contact with equilateral triangles to form a two-dimensional grid array, and the adjacent basic rings (6) are circumscribed and connected; each basic ring (6) is provided with a sub-circle connected with it and metal Ring (7), the basic ring (6) and its inscribed sub-rings (7) together constitute the basic unit of the two-dimensional grid array structure; the basic ring (6) is connected with its inscribed The diameter of the sub-annulus (7) is millimeter and sub-millimeter order, and the metal line width of the sub-annulus (7) of the described basic annulus (6) and its inscribed communication is micron and sub-micron order; Described equilateral triangle arrangement refers to that the center line of three two adjacent basic circular rings (6) forms an equilateral triangle; Described circumscribed connection comprises: 1. two circular rings are circumscribed and the circumtangent points are set The connecting metal (8) that connects the two rings, ② the lines at the joint of the two rings are in a seamless overlapping structure, ③ the lines at the connecting point of the two rings are in a seamless overlapping structure, and at the same time, a The connection metal (8) connecting the two rings; the inscribed communication includes: 1. the two rings are inscribed and the connecting metal (8) connecting the two rings is set at the inscribed tangent point; 2. the two rings are connected at the joint The lines are in a seamless overlapping structure, ③ when the lines at the joint of the two rings are in a seamless overlapping structure, a connecting metal (8) connecting the two rings is arranged at the overlapping position. 2. The electromagnetic shielding light window based on triangular distribution tangent ring and inscribed sub-ring array according to claim 1, characterized in that: the number of sub-rings (7) in each basic unit is greater than or equal to 2, And the diameters are the same or different, the angle formed by the center of the adjacent sub-rings (7) and the line connecting the centers of the basic rings (6) is any angle, and the sub-rings (7) in different basic units are equal diameters or Rings of unequal diameter, the number is the same or different. 3. The electromagnetic shielding light window based on triangular distribution tangent rings and inscribed sub-ring arrays according to claim 1 or 2, characterized in that: the adjacent sub-rings (7) in the basic unit are circumscribed or intersected . 4. the electromagnetic shielding light window based on triangular distribution tangent ring and inscribed sub-ring array according to claim 2, characterized in that: the diameters of the sub-rings (7) in the basic unit are the same, and the adjacent sub-rings The included angle formed by the center of circle of (7) and the connecting line of the center of circle of basic annulus (6) is equal. 5. The electromagnetic shielding light window based on triangular distribution of tangent rings and inscribed sub-ring arrays according to claim 4, characterized in that: the number of sub-rings (7) in different basic units is the same, and the diameters are equal. 6. The electromagnetic shielding light window based on triangular distribution tangent ring and inscribed sub-ring array according to claim 5, characterized in that: the relative positions of the sub-rings (7) in different basic units are the same, and are formed by a After the basic units are copied, they are closely arranged in an equilateral triangle arrangement to form a two-dimensional grid array. 7. the electromagnetic shielding light window based on triangular distribution tangent ring and inscribed sub-ring array according to claim 5, is characterized in that: in the two-dimensional grid array, the sub-rings ( 7) The relative positions are different, and a two-dimensional grid array is formed by duplicating a basic unit and closely arranged in an equilateral triangle arrangement, wherein any one basic unit surrounds itself in a two-dimensional plane with respect to its adjacent basic units. (6) The center of the circle is rotated by a certain angle. 8 . The electromagnetic shielding light window based on triangular distribution of tangent rings and inscribed sub-ring arrays according to claim 7 , wherein any basic unit in the same row rotates at the same angle relative to adjacent basic units. 9. The electromagnetic shielding light window based on the triangular distribution tangent ring and the inscribed sub-ring array according to claim 1, characterized in that: the basic ring (6) and the sub-ring (7) are all made of good electrical conductivity The alloy composition, and the thickness of the alloy is greater than 100nm.