KR102483727B1 - Method for forming conductive pattern on dielectric fabric material and electromagnetic wave absorber including conductive pattern coupled to dielectric fabric material - Google Patents

Abstract

A method for forming a conductive pattern on a dielectric fabric comprises the steps of: forming a metal coating layer on a dielectric fabric; arranging a dry photoresist film on at least one surface of the dielectric fabric; providing vacuum to the dry photoresist film arranged on the dielectric fabric to bring the dielectric fabric into close contact with the dry photoresist film; arranging an elastic body on the dry photoresist film, and heating and pressing the dry photoresist film; exposing and developing the dry photoresist film to form a photoresist pattern; and removing the metal coating layer from the exposed area by using the photoresist pattern as a mask. Accordingly, precision in patterns of a dielectric fabric on which conductive patterns are formed can be improved.

Description

A method of forming a conductive pattern on a dielectric fabric material and an electromagnetic wave absorber including a conductive pattern combined with a dielectric fabric material

The present invention relates to an electromagnetic wave absorber, and more particularly, to a method for forming a conductive pattern on a dielectric fabric material and to electromagnetic wave absorption including a conductive pattern combined with a dielectric fabric material.

Electromagnetic wave (electromagnetic wave) absorption technology is a technology that converts incident electromagnetic wave energy into thermal energy and absorbs it. This electromagnetic wave absorption technology has been mainly used for electromagnetic wave stealth technology that is not detected by military radar. In addition, due to the recent development of IoT products and 5G technology, the use of electromagnetic waves of various frequencies has increased, and the problem of electromagnetic interference due to multiple reflections of electromagnetic waves has become an issue. Absorption technology is required.

As a conventional electromagnetic wave absorption technology, there is a method using a paint or sheet material including a magnetic material such as ferrite. However, since these materials contain a high percentage of magnetic particles, their weight and volume increase significantly. In addition, materials such as paint or rubber used as binders for magnetic materials lack mechanical load bearing capability. In order to overcome these disadvantages, research on Radar Absorbing Structures (RAS), which absorbs electromagnetic waves while supporting structural loads using composite materials, has been recently conducted.

Composite materials can have high specific strength and specific stiffness because different materials are used together. Representative composite materials include fiber-reinforced composites in which fibers such as glass fiber and carbon fiber are used as reinforcing materials and polymer materials such as epoxy are used as base materials. this is possible

The principle of the electromagnetic wave absorbing structure is to prevent incident electromagnetic waves from being reflected by matching the characteristic impedance of the material with the characteristic impedance of air. Research on electromagnetic wave absorbing structures using fiber-reinforced composite materials in the early days involved dispersing dielectric loss materials such as Carbon Black (CB) and Carbon Nano-Tube (CNT) in matrix materials to overcome the disadvantages caused by the weight of magnetic materials. has been carried out However, the method of dispersing a material such as CNT in a matrix material greatly increases the viscosity of the matrix material due to aggregation of the material, causing difficulties in manufacturing. In addition, the increase in viscosity causes instability of mechanical and electromagnetic properties of the electromagnetic wave absorbing structure, and makes it difficult to manufacture a structure having a curvature.

Therefore, recently, a method of imparting electrical properties to reinforcing fiber materials has been used. Since carbon fiber has high electrical conductivity, it is difficult to use it as an electromagnetic wave absorbing structure. Accordingly, dielectric fibers such as glass fibers and aramid fibers may be used as materials for the electromagnetic wave absorbing structure. Methods used to impart electromagnetic properties to dielectric fibers include deposition, plating, and the like, but electrolytic plating is difficult because dielectric materials are close to insulators. Therefore, studies on electromagnetic wave absorbing structures using electroless plating have been conducted. However, in order to realize an electromagnetic wave absorbing structure, a nano-level plating thickness is required to have electrical conductivity close to that of a semiconductor. .

Another method of implementing an electromagnetic wave absorbing structure is an electromagnetic wave absorber called a Salisbury screen. Salisbury screen is a material composed of a surface resistive layer, a spacer, and a perfect conductor, and uses the resonance of electromagnetic waves to absorb electromagnetic waves in the surface resistive layer. The phase difference between the phase of the electromagnetic wave reflected from the surface resistive layer of the Salisbury screen and the secondary reflected wave that is reflected from the perfect conductor on the back side and returned to the surface through the internal spacer is 180 degrees. This is the principle of the Salisbury screen. At this time, the impedance of the surface resistive layer coincides with the impedance of air, 377 ohm/sq, and the thickness of the spacer must be 1/4 of the wavelength to satisfy the resonance condition. When a resistive material is coated to match the impedance of the surface resistive layer to 377 ohm/sq, it is difficult to accurately match the impedance to 377 ohm/sq only by adjusting the thickness, and many coating materials have high conductivity, making fine adjustment difficult.

If the material has high conductivity, there is a way to make the material into a surface that repeats a specific pattern, and this configuration can be defined as a circuit analog (CA) absorber. In the case of such a CA absorber, it has the advantage of easy control of electromagnetic properties, but in order to form a repeating conductive pattern, a substrate for printing or coating a pattern is required. In general, such a substrate is mainly composed of a polymer film such as polyimide. has been used

However, when such a film is used, it causes deterioration of the mechanical properties of the composite material. The mechanical properties of composite materials tend to increase as the ratio of reinforcing materials in the material increases. To this end, when manufacturing a composite material, heat is applied to the polymer base material to increase fluidity, and then excess polymer resin is removed using a vacuum. However, when a film of polymer material is inserted into a composite material, it is difficult to remove the film because it interferes with the fluidity of the resin, and the film material has poor adhesion to the composite material, so the interlaminar shear strength of the composite material is reduced. cause to decrease

One object of the present invention is to provide a method for forming a conductive pattern in a dielectric fabric.

Another object of the present invention is to provide an electromagnetic wave absorber including a conductive pattern formed on a dielectric fabric and having excellent physical properties.

However, the problem to be solved by the present invention is not limited to the above-mentioned problem, and may be expanded in various ways without departing from the spirit and scope of the present invention.

A method for forming a conductive pattern on a dielectric fabric according to an exemplary embodiment of the present invention for achieving the above-described object of the present invention includes forming a metal coating layer on the dielectric fabric, on at least one surface of the dielectric fabric Disposing a dry photoresist film, supplying a vacuum to the dry photoresist film disposed on the dielectric fabric to bring the dielectric fabric and the dry photoresist film into close contact, disposing an elastic body on the dry photoresist film, Heating and pressing the dry photoresist film, exposing and developing the dry photoresist film to form a photoresist pattern, and using the photoresist pattern as a mask to remove the metal coating layer in the exposed area. include

According to one embodiment, the elastic body includes silicone rubber.

According to one embodiment, the dry photoresist film is heated and pressed by heated air.

A method of forming a conductive pattern on a dielectric fabric according to an exemplary embodiment of the present invention includes disposing a dry photoresist film on at least one side of a dielectric fabric, vacuuming the dry photoresist film disposed on the dielectric fabric. providing an adhesive to bring the dielectric fabric and the dry photoresist film into close contact, disposing an elastic body on the dry photoresist film, heating and pressing the dry photoresist film, exposing and developing the dry photoresist film to Forming a photoresist pattern having an opening, and depositing a metal on a portion of the dielectric fabric through the opening of the photoresist pattern.

An electromagnetic wave absorber according to an exemplary embodiment of the present invention is formed by the above method and includes a conductive patterned dielectric fabric having the same impedance as air.

According to one embodiment, the conductive pattern includes at least one selected from the group consisting of nickel (Ni), cobalt (Co), and iron (Fe).

According to one embodiment, the electromagnetic wave absorber may include a perfect conductor layer spaced apart from the dielectric fabric on which the conductive pattern is formed; and a spacer disposed between the dielectric fabric on which the conductive pattern is formed and the perfect conductor layer.

According to one embodiment, the spacer includes a fiber fabric impregnated with resin, and the spacer and the electromagnetic wave absorber are coupled by the resin of the spacer.

According to one embodiment, the electromagnetic wave absorber has a structure of a Dallenbach absorber.

According to one embodiment, the electromagnetic wave absorber has a three-dimensional structure.

According to one embodiment, the dielectric fabric includes glass fibers or aramid fibers.

As described above, according to exemplary embodiments of the present invention, it is possible to improve the pattern accuracy of a dielectric fabric having a conductive pattern formed thereon, and the dielectric fabric can be used as a surface resistance layer or a meta-material of an electromagnetic wave absorber.

The dielectric fabric can be easily combined with other prepregs, and the electromagnetic wave absorber obtained using the same has excellent interlayer bonding strength. In addition, it can be used for manufacturing electromagnetic wave absorbers having various structures.

1 is a plan view illustrating a dielectric fabric used in a method of manufacturing an electromagnetic wave absorber according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view taken along line II′ of FIG. 1 .
3 to 10 are cross-sectional views illustrating a method of forming a dielectric fabric having a conductive pattern according to an embodiment of the present invention.
FIG. 11 is a plan view of a dielectric fabric having the conductive pattern of FIG. 10;
12 and 13 are cross-sectional views illustrating a method of manufacturing an electromagnetic wave absorber according to an embodiment of the present invention.
14 is a plan view illustrating an electromagnetic wave absorber according to an embodiment of the present invention.
15 is a cross-sectional view of an electromagnetic wave absorber according to an embodiment of the present invention.
16 is a perspective view illustrating an electromagnetic wave absorber according to an embodiment of the present invention.
17 and 18 are cross-sectional views illustrating a method of manufacturing an electromagnetic wave absorber according to an embodiment of the present invention.
19 is a graph showing electromagnetic wave absorption performance of the electromagnetic wave absorber of Example 1.
20 is a graph showing interlaminar shear strength (ILSS) of the electromagnetic wave absorber of Example 1 and Comparative Examples.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Since the present invention can have various changes and various forms, specific embodiments are exemplified and described in detail in the text. However, this is not intended to limit the present invention to a specific form disclosed, and should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention. In the accompanying drawings, the dimensions of the structures are shown enlarged than actual for clarity of the present invention.

Terms used in this application are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, the terms "include" or "have" are intended to designate that there is a feature, number, step, operation, component, or combination thereof described in the specification, but one or more other features or numbers However, it should be understood that it does not preclude the presence or addition of steps, operations, components, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related art, and unless explicitly defined in the present application, they should not be interpreted in an ideal or excessively formal meaning. don't

1 is a plan view illustrating a dielectric fabric used in a method of manufacturing an electromagnetic wave absorber according to an embodiment of the present invention. FIG. 2 is a cross-sectional view taken along line II′ of FIG. 1 .

Referring to FIG. 1, the dielectric fabric 100 includes first fibers 100a arranged in a first direction D1 and second fibers 100b arranged in a second direction perpendicular to the first direction D1. can include According to one embodiment, the first fibers 100a and the second fibers 100b may be arranged in a plurality of bundles, and each bundle may be woven with warp and weft yarns to form the dielectric fabric 100. .

For example, the first fiber 100a and the second fiber 100b may include glass fiber, aramid (Kevlar) fiber, or the like. The first fiber 100a and the second fiber 100b may include the same fiber or different fibers, and may be composed of different materials within a bundle if necessary.

3 to 10 are cross-sectional views illustrating a method of forming a dielectric fabric having a conductive pattern according to an embodiment of the present invention. 4 is an enlarged cross-sectional view of the metal-coated fiber shown in FIG. 3;

Referring to FIGS. 3 and 4 , a metal coated fabric 110 is formed by coating the dielectric fabric with a metal. The metal coated fabric 110 may be formed by coating a metal layer ML on a base fiber FB corresponding to the first fiber 100a or the second fiber 100b.

In one embodiment, the metal coating layer (ML) may include a ferromagnetic material such as iron (Fe), cobalt (Co), nickel (Ni), etc., electroless plating, sputtering, chemical vapor deposition, vacuum It may be coated by a method such as vapor deposition or thermal evaporation.

Referring to FIGS. 5 and 6 , a dry photoresist film 120 is attached to the metal coated fabric 110 to perform a photolithography process.

Since the metal coated fabric 110 has gaps between fibers and between bundles, it cannot be coated with a conventional photoresist composition. Therefore, a dry photoresist film 120 is used to form the photoresist layer. According to one embodiment, the dry photoresist film 120 may be attached to both sides (upper and lower surfaces) of the metal coated fabric 110, but embodiments of the present invention are not limited thereto, and if necessary, The dry photoresist film 120 may be attached to one surface of the metal coated fabric 110 .

Additionally, the metal coated fabric 110 has a structurally uneven surface. When the dry photoresist film 120 is attached to such an uneven surface, a gap is formed between the dry photoresist film 120 and the metal-coated fabric 110, thereby reducing the reliability of the photolithography process, thereby reducing the accuracy of the desired accuracy. It is difficult to obtain a pattern of shapes. Therefore, in the present invention, a process for improving adhesion between the dry photoresist film 120 and the metal coated fabric 110 is performed.

For example, the dry photoresist film 120 may include an epoxy-acrylate resin. However, embodiments of the present invention are not limited thereto, and the dry photoresist film 120 may include an acrylic resin, a styrenic resin, an epoxy resin, an alkyd resin, a phenolic resin, and the like. In addition, the dry photoresist film 120 may further include a crosslinking monomer, a photopolymerization initiator, a photoacid generator, and the like, depending on the type. The dry photoresist film 120 may be of a positive type or a negative type. In the case of the positive type, the solubility of the exposed area is reduced so that the unexposed area remains after development, and in the case of the negative type, a crosslinking reaction proceeds in the exposed area so that the exposed area may remain after development. Hereinafter, the use of the negative type dry photoresist film 120 will be described, but embodiments of the present invention are not limited thereto, and a positive type dry photoresist film may be used.

According to one embodiment, a dry photoresist film 120 is disposed between a flexible elastic body 130 such as silicone rubber and the metal coated fabric 110 . For example, as shown in FIG. 5 , on a substrate 140, an elastomer 130/dry photoresist film 120/metal coated fabric 110/dry photoresist film 120/elastomer 130 can be stacked in the order of

According to one embodiment, a vacuum environment is provided to the laminate. To this end, the stack may be placed in a vacuum bag 150 . When a negative pressure is applied to the vacuum bag 150, the air inside the vacuum bag 150 is discharged to the outside. Accordingly, as the air inside the metal coated fabric 110 escapes to the outside, the dry photoresist film 120 and the metal coated fabric 110 may conformally adhere to each other.

The elastic body 130 applies pressure to the dry photoresist film 120 in the vacuum compression process and deforms it according to the surface shape of the metal-coated fabric 110, so that the dry photoresist film 120 and the metal The coating fabric 110 may assist in adhering.

As the dry photoresist film 120 and the metal coated fabric 110 come into close contact, as shown in FIG. 6, along the uneven surface of the metal coated fabric 110, the dry photoresist film ( 120) can also form uneven surfaces.

Additionally, in order to increase the adhesion between the dry photoresist film 120 and the metal coated fabric 110, after the vacuum pressing process, the metal coated fabric 110 to which the dry photoresist film 120 is attached It can be heated and pressurized with air using an autoclave device or the like. Pressurization by a fluid such as air may be advantageous in adhering the dry photoresist film 120 to an uneven surface.

Referring to FIGS. 7 and 8 , a photoresist pattern 122 is formed by partially exposing and developing the dry photoresist film 120 . A light source LE and a mask MK may be used to expose the dry photoresist film 120 . The mask MK may have a transmissive area (eg, an opening) having a shape corresponding to the exposed area of the dry photoresist film 120 .

For example, as the exposed area of the dry photoresist film 120 remains and the unexposed area is removed by a developing process, the photoresist pattern 122 may be formed.

For example, an alkaline solution such as tetramethylammonium hydroxide (TMAH) may be used as a developing solution in the developing process.

Referring to FIGS. 9, 10 and 11 , the metal coating of the metal coated fabric 100 is partially removed by providing an etchant to the metal coated fabric 110 on which the photoresist pattern 122 is formed. An area where the metal coating is removed may form a non-conductive area NCA, and an area where the metal coating remains may form a conductive area CA. Accordingly, it is possible to obtain a dielectric fabric 111 having a desired conductive pattern formed thereon.

As the etchant, various etchants may be used depending on the metal material of the metal coated fabric 110 .

FIG. 11 is a plan view of a dielectric fabric having the conductive pattern of FIG. 10; As shown, the conductive pattern CP may have a rectangular frame shape. However, embodiments of the present invention are not limited thereto, and the conductive pattern CP may have various shapes such as a polygonal shape, a circular shape, a loop pattern, a coding pattern, and a partially separated ring pattern.

12 and 13 are cross-sectional views illustrating a method of manufacturing an electromagnetic wave absorber according to an embodiment of the present invention. The dielectric fabric having a conductive pattern obtained according to an embodiment of the present invention may be combined with other components to form an electromagnetic wave absorber.

Referring to FIG. 12 , a dielectric fabric 111 having a conductive pattern formed thereon and a fiber-resin prepreg 200 are combined. The fiber-resin prepreg 200 may have a configuration in which a fiber material 202 such as fabric is impregnated with a resin 204.

For example, the fiber material 202 may include a dielectric fabric made of glass fiber, aramid fiber, etc., and the resin 204 may include epoxy resin, phenol resin, polyimide resin, acrylic resin, polyester resin, etc. can include

For example, a composite may be formed by laminating the dielectric fabric 111 on which the conductive pattern is formed and the fiber-resin prepreg 200, and then heating and pressing using an autoclave or the like.

Since the resin 204 of the fiber-resin prepreg 200 has fluidity and the dielectric fabric 111 has pores due to the fabric structure, the resin 204 of the fiber-resin prepreg 200 has By penetrating into the pores of the dielectric fabric 111, the dielectric fabric 111 on which the conductive pattern is formed and the fiber-resin prepreg 200 may be combined without a separate adhesive.

Referring to FIG. 13, the dielectric fabric 111 on which the conductive pattern is formed may constitute a surface resistance layer of a circuit analog absorber, and the fiber-resin composite formed by the fiber-resin prepreg is a spacer ( 210) can be configured. The spacer may be formed by stacking a plurality of fiber-resin prepregs so that the spacer 210 has an appropriate thickness. For example, the thickness of the spacer 210 or the sum of the thicknesses of the spacer and the dielectric fabric 111 may be designed to be 1/4 of the wavelength of electromagnetic waves to be absorbed.

A fully conductive layer 300 is bonded to the lower surface of the spacer 210 . The fully conductive layer 300 may include various metal materials such as copper, silver, aluminum, nickel, chromium, molybdenum, titanium, or conductive carbon.

14 is a plan view illustrating an electromagnetic wave absorber according to an embodiment of the present invention. When the electromagnetic wave absorber has a configuration of a circuit analog absorber, electromagnetic waves having a wavelength similar to the period (P, cell size) of the conductive pattern CP may be absorbed by resonance.

15 is a cross-sectional view of an electromagnetic wave absorber according to an embodiment of the present invention. 16 is a perspective view illustrating an electromagnetic wave absorber according to an embodiment of the present invention.

Referring to FIG. 15 , a Dallenbach absorber (meta-material absorber) can be manufactured using the dielectric fabric on which the conductive pattern is formed according to an embodiment of the present invention.

For example, a plurality of dielectric fabrics 111 having conductive patterns CP formed thereon may be stacked to form a conductive pattern composite 111 ′, and may be combined with the fully conductive layer 300 . In order to combine the dielectric fabrics 111 on which the conductive patterns CP are formed, a prepreg is formed by using an appropriate adhesive or by impregnating the dielectric fabric 111 on which the conductive patterns CP are formed, and then heating and compressing the prepreg. can

The meta-material absorber as described above has a period of the conductive pattern CP smaller than the wavelength of the electromagnetic wave to be absorbed. Through this, it is possible to have effective permittivity and magnetic permeability ideal for absorbing electromagnetic waves. In addition, the composite 111' may have a thickness smaller than 1/4 of the wavelength of the absorbed electromagnetic wave. Accordingly, it is possible to implement an absorber capable of broadband absorption with a thinner thickness than a circuit analog absorber.

The electromagnetic wave absorber can adjust the effective permittivity and permeability of the entire fabric by adjusting the period, length and line width of the conductive pattern (CP), and accordingly, the electromagnetic wave absorber is designed by matching the impedance value of the electromagnetic wave absorber with the characteristic impedance of air. can do.

Referring to FIG. 16 , an electromagnetic wave absorber having a three-dimensional structure may be formed using a dielectric fabric having a conductive pattern according to an embodiment of the present invention.

When a structure such as a honeycomb is formed using the dielectric fabric on which the conductive pattern is formed, the conductive pattern formed on the outer wall may absorb electromagnetic waves. Also, since it is a three-dimensional pattern, it is possible to implement an impedance gradient absorber whose impedance changes along the thickness direction. This structure can effectively reduce the radar cross section of the structure because it suppresses electromagnetic wave scattering by reflection from the incident surface. In addition, an absorption effect can be expected in various frequency ranges due to a gradual change in impedance, and thus, it is possible to implement an ultra-wideband absorber. In addition, since it is a structure with air gaps like honeycomb, the weight of the electromagnetic wave absorber can be reduced.

Such a three-dimensional structure may be manufactured using a conventional honeycomb manufacturing process such as an expansion process or a corrugation process.

17 and 18 are cross-sectional views illustrating a method of manufacturing an electromagnetic wave absorber according to an embodiment of the present invention.

According to one embodiment, the dielectric fabric on which the conductive pattern is formed may be formed without an etching process.

For example, referring to FIG. 17 , a photoresist pattern 124 having an opening OP is formed on a dielectric fabric 100 that is not coated with metal. As described above, the photoresist pattern 124 may be formed by vacuum pressing the dry photoresist film and the dielectric fabric 100, followed by exposure and development.

Referring to FIG. 18 , a portion of the dielectric fabric 100 is coated with metal through the opening OP of the photoresist pattern 124 . Accordingly, a dielectric fabric 111 having a conductive pattern formed by the conductive area CA and the non-conductive area NCA may be obtained.

According to embodiments of the present invention, it is possible to improve the pattern accuracy of a dielectric fabric on which a conductive pattern is formed, and the dielectric fabric can be used as a surface resistance layer or a meta-material of an electromagnetic wave absorber.

The dielectric fabric can be easily combined with other prepregs, and the electromagnetic wave absorber obtained using the same has excellent interlayer bonding strength. In addition, it can be used for manufacturing electromagnetic wave absorbers having various structures.

Hereinafter, the configuration and effects of the present invention will be described through specific examples and experiments of the present invention.

Example 1

Nickel was plated on a glass fiber fabric (GEP 118, Muhan Composite) by electroless plating. After disposing a dry photoresist film (H-Y900 series, Showa Denko Materials) on both sides of the nickel-coated fabric and placing it between silicon rubber, by providing a vacuum using a vacuum bag, the dry photoresist film and the nickel The coated fabric was brought into close contact.

Next, the nickel-coated fabric to which the dry photoresist film was attached was placed in an autoclave device, and heat-pressed for 15 minutes under conditions of a pressure of 3 bar and a temperature of 90° C.

Next, UV was partially irradiated on the dry photoresist film using an exposure device, and developed (Na ₂ SiO ₃ ) to form a photoresist pattern.

Next, by using FeCl ₃ , nickel in a portion not covered by the photoresist pattern was removed from the nickel-coated fabric to prepare a dielectric fabric having a conductive pattern formed thereon.

Next, an electromagnetic wave absorber specimen was prepared by combining the dielectric fabric on which the conductive pattern was formed, the glass fiber-epoxy resin prepreg, and the copper foil (perfect conductor layer).

19 is a graph showing electromagnetic wave absorption performance of the electromagnetic wave absorber of Example 1. When the unit cell size (D) was designed to be 10.65mm, the outer size (a) of the loop pattern to be 6.40mm, and the inner size (b) to be 5.45mm, the optimal thickness by simulation was 3.564mm, which was actually obtained as a target. The thickness of the specimen was measured to be 3.420 mm.

Referring to FIG. 19 , the predicted electromagnetic wave absorption performance by simulation and the performance of the electromagnetic wave absorber of Example 1 were similar, and through this, it can be seen that the electromagnetic wave absorber of the present invention formed a relatively precise conductive pattern.

20 is a graph showing interlaminar shear strength (ILSS) of the electromagnetic wave absorber of Example 1 and Comparative Examples.

A composite (same thickness as Example 1) formed of glass fiber fabric (GEP 118, Muhan Composite) impregnated with epoxy resin was prepared as Comparative Example 1, and a composite bonded to prepreg (same thickness as Example 1) without nickel patterning. ) was prepared as Comparative Example 2.

Referring to FIG. 20, Example 1 (This work) was able to have superior interlaminar shear strength than Comparative Example 2, and it can be seen that as nickel is partially removed, bonding strength with the prepreg is increased.

Although the above has been described with reference to the embodiments of the present invention, those skilled in the art can variously modify and change the present invention without departing from the spirit and scope of the present invention described in the claims below. You will understand that you can.

The electromagnetic wave absorber according to the above exemplary embodiments can be applied to the aerospace field to which stealth technology is applied, and the dielectric fabric on which the conductive pattern is formed can be used as a variety of smart fabrics such as frequency selective surfaces, sensing fabrics, and wearable devices. can be expanded

Claims (11)

forming a metal coating layer on the dielectric fabric;
disposing a dry photoresist film on at least one side of the dielectric fabric;
applying a vacuum to the dry photoresist film disposed on the dielectric fabric to bring the dielectric fabric into close contact with the dry photoresist film;
disposing an elastic body on the dry photoresist film and heating and pressing the dry photoresist film;
forming a photoresist pattern by exposing and developing the dry photoresist film; and
A method of forming a conductive pattern on a dielectric fabric comprising the step of removing the metal coating layer in the exposed area using the photoresist pattern as a mask. The method of claim 1 , wherein the elastic body comprises silicone rubber. The method of claim 1 , wherein the dry photoresist film is pressed by heated air. disposing a dry photoresist film on at least one side of the dielectric fabric;
applying a vacuum to the dry photoresist film disposed on the dielectric fabric to bring the dielectric fabric into close contact with the dry photoresist film;
disposing an elastic body on the dry photoresist film and heating and pressing the dry photoresist film;
forming a photoresist pattern having an opening by exposing and developing the dry photoresist film; and
A method of forming a conductive pattern on a dielectric fabric comprising depositing a metal on a portion of the dielectric fabric through an opening in the photoresist pattern. An electromagnetic wave absorber comprising a conductive patterned dielectric fabric formed by any one of claims 1 to 4 and having the same impedance as air. The electromagnetic wave absorber of claim 5, wherein the conductive pattern includes at least one selected from the group consisting of nickel (Ni), cobalt (Co), and iron (Fe). The method of claim 5, further comprising: a perfect conductor layer spaced apart from the dielectric fabric on which the conductive pattern is formed; and
The electromagnetic wave absorber further comprises a spacer disposed between the dielectric fabric on which the conductive pattern is formed and the perfect conductor layer. The electromagnetic wave absorber according to claim 7, wherein the spacer includes a fiber fabric impregnated with resin, and the spacer and the electromagnetic wave absorber are bonded by the resin of the spacer. The electromagnetic wave absorber according to claim 5, wherein the electromagnetic wave absorber has a structure of a Dallenbach absorber. The electromagnetic wave absorber according to claim 5, wherein the electromagnetic wave absorber has a three-dimensional structure. [6] The electromagnetic wave absorber according to claim 5, wherein the dielectric fabric includes glass fibers or aramid fibers.

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