JP2002151885A - Radio wave absorbing panel and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radio wave absorbing panel, having nonflammability, being light-weight and thin, capable of keeping stability between first and second conductors to keep insulation state, requiring not so much cost and work, having radio wave absorbing characteristics which are insusceptible to variations in the angle of incidence, and to provide a method for manufacturing the same. SOLUTION: The panel is provided with a first conductor 2 reflecting one part of a radio wave and permeating the other part, a second conductor 6 arranged, so as to be close to the conductor 2 and segmented into a plurality of segments in the magnetic field direction of a radio wave to be absorbed and a third conductor 4, arranged so as to be apart from the conductor 6 according to the frequency of the radio wave to be absorbed for reflecting the radio wave to be absorbed in order from the arrived direction of the radio wave to be absorbed. Also, the panel is provided with a first insulation layer 7 between the conductors 2 and 6, and a second insulation layer 8 between the conductors 6 and 4. Of these conductors 2, 6 and 4, one conductor is provided directly on a sheet glass.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio wave absorbing panel having a characteristic of absorbing radio waves of a specific frequency, and more particularly, to an object of absorbing radio waves arriving at a building to prevent radio wave reflection interference, and BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio wave absorbing panel used for absorbing unnecessary radio waves of wireless communication in an office so as not to deteriorate the electromagnetic wave environment.

[0002]

2. Description of the Related Art In recent years, with the increase of high-rise buildings, VHF
Radio waves in the TV frequency band such as UHF and UHF are reflected by high-rise buildings, and the radio waves directly arriving from the TV station and the radio waves reflected by the buildings are simultaneously incident on the antenna of the TV receiver, resulting in a TV screen. In many cases, reception failures such as ghosts occur, which is a major social problem.

[0003] Recently, Bluetomo has attempted to spread offices using wireless LAN and the like and to standardize wireless LAN.
With the incorporation of oth (communication protocol) as a new communication network, the frequency band of radio waves used is rapidly expanding to 1 GHz or more. In a situation where a large number of radio waves propagate in such a limited space, electromagnetic noise between nearby devices affects each other and causes malfunctions. It is known that the communication speed of the communication may be significantly affected. Further, as the frequency of use (frequency of occurrence) of radio waves increases, the influence of radio waves generated from devices on the human body cannot be ignored.

Conventionally, as a countermeasure against these problems, a radio wave absorbing panel is attached to an outer wall of a building to reduce the reflection of an incoming radio wave, and the radio wave absorbing panel is mounted on a partition wall in an office. It has been proposed to use it to absorb unwanted radio waves.

[0005] As a radio wave absorbing panel used for these, a sheet radio wave absorbing panel in which magnetic powder such as ferrite is mixed in a sheet rubber or urethane resin foam is known. Further, a λ / 4 type radio wave absorber that suppresses reflection due to radio wave interference is disclosed in VIEW (A journal of NHK Engineering Service Friends) Vol. 19, N
o. 1 (issued on Jan. 25, 2000), “Trends in Electromagnetic Absorption Panels” on pages 13 to 15, and EMC 1993.
12.5, No. 68, page 95. Further, a radio wave absorbing panel having a structure in which an insulating substrate having a stripe-shaped or lattice-shaped conductive film formed thereon is arranged in parallel between two insulating substrates having a conductive film formed thereon, is disclosed in No. 275997.

[0006]

However, it has been found that the above-mentioned prior art has the following problems.

That is, a radio wave absorber in which a magnetic powder such as ferrite is mixed into a sheet-like rubber or urethane resin foam is heavy and is not a non-combustible material, so that there are many restrictions in general construction work and it is used. There is a problem that it is difficult. Further, since the ferrite does not transmit light, the radio wave absorber cannot be used as a window.

On the other hand, the λ / 4 type electromagnetic wave absorber can obtain transparency by using a transparent material for two conductive films and a substrate holding them, and can be used as a window. . However, since the λ / 4 type radio wave absorber requires the thickness of the radio wave absorber to be １ ／ of the wavelength, it is 100 to 200 MHz in the case of the VHF band of the TV radio wave.
about 75-38cm corresponding to z, 4 in case of UHF band
A thickness of about 16 to 10 cm is required corresponding to 70 to 770 MHz, and a special wall and sash are required to incorporate the radio wave absorber into a window. Further, even if the target radio wave is, for example, 2.4 GHz used for a wireless LAN, the radio wave absorber has a thickness of about 3 cm. There is a problem that it is bulky because it is too large.

In order to solve the above-mentioned problems, Japanese Patent Application Laid-Open No. 10-275997 mentioned above discloses that the entire structure is made of a transparent material, and a non-combustible material glass is used to form a stripe-shaped or lattice-shaped conductive material. A radio wave absorbing panel having a configuration in which a coating has a large effective relative permittivity to reduce the thickness of the panel is disclosed.

However, as the configuration of the radio wave absorbing panel, the following arrangement has only been specifically proposed in the above-mentioned Japanese Patent Application Laid-Open No. 10-275997. Glass / first conductive film + air layer + second conductive film / glass + air layer + third conductive film / glass or Glass / first conductive film + resin layer + second conductive film / glass + resin layer + third Conductive film / glass Here, the conductive film is a first, second, and third conductive film in order from the arrival direction of the radio wave to be absorbed, and the second conductive film is a stripe-shaped or lattice-shaped conductive film. In the above configuration, an air layer is provided between the first conductive film and the second conductive film. However, a spacer is required to hold the air layer, and the spacer has a minimum thickness. If the thickness of the air layer is less than the above, there is a problem that the central portion of the glass comes into contact and the insulating state between the first conductive film and the second conductive film cannot be maintained. Further, in the above configuration, not only between the first conductive film and the second conductive film, but also between the glass holding the second conductive film and the third conductive film is a resin layer. Because the space for absorption must be secured by the resin layer between the glass and the third conductive film,
Therefore, there is a problem that the amount of resin is increased, and cost and labor are required.

Further, the conventional λ / 4 type radio wave absorber is disclosed in the above-mentioned EMC 1993.12.5, According to 68,
There is a problem that the absorption characteristic of the radio wave changes greatly depending on the incident angle of the radio wave. This is because the radio wave absorption is 2
This is considered to be caused by interference of radio waves reflected by the conductive films, so that the path length of the interfering wave changes depending on the incident angle.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problem by maintaining a non-flammable, lightweight, thin, stable and insulated state between a first conductor and a second conductor. It is an object of the present invention to provide a radio wave absorbing panel and a method for manufacturing the same, which can reduce the cost and labor and whose radio wave absorption characteristics are hardly changed by the incident angle.

[0013]

The radio wave absorbing panel and the method of manufacturing the same according to the present invention are configured as follows to achieve the above object.

The first radio wave absorbing panel (corresponding to claim 1) comprises: a first conductor which reflects a part of the radio wave and transmits the other part in order from the arrival direction of the radio wave to be absorbed; First
The second conductor, which is arranged in close proximity to the conductor and cut at least in the direction of the electric field of the radio wave to be absorbed, is separated from the second conductor in accordance with the frequency of the radio wave to be absorbed. A third conductor that is disposed and reflects a radio wave to be absorbed; and a first insulating layer between the first conductor and the second conductor, and a second conductor and a third conductor. A second insulating layer is provided between the conductors, and at least one of the first conductor, the second conductor, and the third conductor is directly provided on the glass sheet.

According to the first radio wave absorbing panel, the second conductor cut into a plurality in the direction of the electric field of the radio wave to be absorbed is arranged close to the first conductor, Since the conductor is arranged at a distance in accordance with the frequency of the radio wave to be absorbed, the distance between the first conductor and the second conductor found by the present inventors may be reduced by the radio wave absorption characteristics. Based on the finding that if the distance between the second conductor and the third conductor is sufficiently narrower than the distance between the second conductor and the third conductor, the absorption characteristics of the radio wave hardly depend on the incident angle, It is possible to provide a radio wave absorbing panel that does not easily change depending on the incident angle. In addition, since at least one of the first conductor, the second conductor, and the third conductor is provided directly on the glass sheet, the plate shape can be firmly maintained, and nonflammability is also ensured. be able to.

In the above structure, the second radio wave absorbing panel (corresponding to claim 2) preferably has a first conductor, a second conductor, a third conductor, and a first insulating layer. The second insulating layer is characterized by having a property of transmitting visible light.

According to the second radio wave absorbing panel, the first conductor, the second conductor, the third conductor, and the first insulating layer and the second insulating layer transmit visible light. Since it has properties, a radio wave absorbing panel can be used as the window.

A third radio wave absorbing panel (corresponding to claim 3) is characterized in that, in the above configuration, preferably, the second insulating layer comprises a layer formed of a gas.

According to the third radio wave absorbing panel, since the second insulating layer is composed of a layer formed of gas, a space for absorbing a specific radio wave is provided between the glass and the third conductive film. Since it is not necessary to secure with a resin layer, cost and labor are not required. Further, it is easy to make the distance between the second conductor and the third conductor wider than the distance between the first conductor and the second conductor.

A fourth radio wave absorbing panel (corresponding to claim 4) is characterized in that, in the above configuration, preferably, the gas is air.

According to the fourth radio wave absorbing panel, since the gas is air, it is not necessary to secure an interval for absorbing a specific radio wave with the resin layer between the glass and the third conductive film. No cost and hassle. In addition, the distance between the second conductor and the third conductor is easily widened as compared with the distance between the first conductor and the second conductor. You can have. Further, since the third conductor faces the air, the heat insulating property is enhanced by the far-infrared reflectivity (= low emissivity) of the conductor. In addition, by using dry air as the air, the second conductor and the third conductor can be isolated from the outside air and held, and radio wave absorption characteristics can be stabilized for a long time.

A fifth radio wave absorbing panel (corresponding to claim 5) is characterized in that, in the above configuration, the gas is preferably any one of argon, krypton, xenon, and SF ₆ gas. Attached.

According to the fifth wave absorbing panel, gas, argon, krypton, xenon, since it is one of the gases of the SF ₆ gas, it is possible to improve the thermal insulation properties, also, SF ₆ In this case, the soundproofing performance can also be improved.

A sixth radio wave absorbing panel (corresponding to claim 6) is characterized in that, in the above configuration, the first insulating layer preferably comprises a layer formed of a resin transmitting visible light. .

According to the sixth radio wave absorbing panel, since the first insulating layer is formed of a layer formed of a resin that transmits visible light, the first and second conductors can be insulated well. They can be placed close together while maintaining their state. Further, fine adjustment of the distance between the first conductor and the second conductor can be easily performed depending on the thickness of the resin layer, and can be kept stable for a long period of time. Further, since the first conductor and the second conductor are sealed with the resin, the conductor does not come into contact with the outside air, and the radio wave absorption characteristics are stabilized for a long time. Furthermore, when the first conductor or the second conductor is provided directly on the plate glass, the glass is bonded to the resin via the conductor, so that even if the glass is broken, the glass does not scatter and is safe.
In the case where the second conductor is provided directly on the glass sheet, by selecting a transparent resin having a value close to the refractive index of the glass sheet, the cutting of the second conductor cut into a plurality of pieces in the direction of the electric field can be performed. Lines are difficult to see and an excellent appearance is easily obtained.

The seventh radio wave absorbing panel (corresponding to claim 7) preferably has a configuration in which the sheet glass is provided on the side of the radio wave arrival direction of the first conductor, and the radio wave of the second conductor is provided. Another glass sheet is provided on the side opposite to the arrival direction of the first and second layers, and the first insulating layer comprises a vacuum layer supported by pillars, and the pillars are at least partially made of an insulating material, or It is characterized by being arranged along the cutting line of the two conductors.

According to the seventh radio wave absorbing panel, the two surfaces of the first conductor and the second conductor are firmly held at a short distance via the pillar, and the two conductors are placed in a vacuum. Since the first and second conductors are retained, the radio wave absorption characteristics of the radio wave absorbing panel are stable for a long time without deterioration. further,
Due to the heat insulating property of the vacuum layer, when used as a window in a building, excellent heat insulating properties can be provided. In addition, since the first conductor and the second conductor that are in contact with the vacuum layer have far-infrared reflectivity (low emissivity), heat insulation can be improved.

An eighth radio wave absorbing panel (corresponding to claim 8) is characterized in that, in the above-described configuration, preferably, the first insulating layer is made of at least one sheet glass.

According to the eighth radio wave absorbing panel, the first insulating layer is made of at least one sheet glass,
A first conductor and a second conductor can be provided on both front and back surfaces of a single sheet of glass. At that time, the total number of glasses can be reduced, and the weight of the radio wave absorbing panel can be reduced. Further, the distance between the first conductor and the second conductor can be stably maintained.

A ninth radio wave absorbing panel (corresponding to claim 9) is characterized in that, in the above configuration, preferably, the first insulating layer comprises at least one inorganic thin film.

According to the ninth radio wave absorbing panel, since the first insulating layer is composed of at least one inorganic thin film,
Forming a first conductor, an inorganic thin film, and a second conductor in this order; or forming a second conductor, an inorganic thin film,
It is possible to continuously form the first conductor in order, and there are many advantages in production. In addition, the first conductor or the second conductor is automatically protected by the upper inorganic thin film and stable for a long time. Is guaranteed. This configuration is one of the means for stably realizing the first insulator in the thinnest and good insulating state.

In a tenth radio wave absorbing panel (corresponding to claim 10), in the above structure, preferably, the first conductor has a surface resistance of 100 Ω / □ or more and 700 Ω / □ or less. Characterized.

According to the tenth radio wave absorbing panel, the first
Has a surface resistance value of 100 Ω / □ or more and 700 Ω / □ or less, so that it is possible to reflect a part of radio waves and transmit the other part in good matching with vacuum impedance.

An eleventh radio wave absorbing panel (corresponding to claim 11) is characterized in that, in the above configuration, preferably, the second conductor has a surface resistance value of 50Ω / □ or less.

According to the eleventh radio wave absorbing panel, the second
Has a surface resistance value of 50Ω / □ or less, and thus has excellent radio wave absorption performance.

A twelfth radio wave absorbing panel (corresponding to claim 12) is characterized in that, in the above-described configuration, preferably, the third conductor has a surface resistance of 50Ω / □ or less.

According to the twelfth radio wave absorbing panel, the third
Since the conductor has a surface resistance of 50Ω / □ or less, the third conductor can favorably reflect radio waves, so that it is possible to obtain a radio wave absorbing panel having excellent radio wave absorption characteristics. .

A thirteenth radio wave absorbing panel (corresponding to claim 13) is characterized in that, in the above structure, the first conductor is preferably a transparent oxide semiconductor or a metal nitride.

According to the thirteenth radio wave absorbing panel, the first
Is 100 Ω / □ or more and 70% or more with respect to the first conductor, because the conductor is a transparent oxide semiconductor or a metal nitride.
A surface resistance value of 0 Ω / □ or less can be obtained relatively stably.

In a fourteenth radio wave absorbing panel (corresponding to claim 14), in the above structure, preferably, the second and / or third conductor is a metal thin film, a transparent oxide semiconductor or a metal-dielectric. It is characterized by comprising a multilayer film.

According to the fourteenth radio wave absorbing panel, the second
And / or the third conductor is made of a metal thin film, a transparent oxide semiconductor or a metal-dielectric multilayer film, so that when a transparent oxide semiconductor is used, a surface resistance of 20 Ω / □ or less can be stably obtained. When a metal-dielectric multilayer film is used, a surface resistance value of 10Ω / □ or less can be stably obtained.

A fifteenth radio wave absorbing panel (corresponding to claim 15) is characterized in that, in the above structure, the oxide semiconductor is preferably tin oxide to which fluorine has been added.

According to the fifteenth radio wave absorbing panel, since the oxide semiconductor is tin oxide to which fluorine has been added, it can be formed by a thermal CVD method, so that it is suitable for mass production and is chemically stable. is there.

In a sixteenth radio wave absorbing panel (corresponding to claim 16), in the above structure, preferably, the first and / or third conductor has a mesh finer than a wavelength of a radio wave to be absorbed. It is characterized by being a conductive fiber woven body.

According to the sixteenth radio wave absorbing panel, the first
And / or the third conductor is a conductive fiber woven body having a mesh finer than the wavelength of the radio wave to be absorbed, so that conductive fibers having various characteristics can be freely selected, and Easy to adjust characteristics. Also, most of the radio waves to be absorbed have sufficiently longer wavelengths than visible light, so they do not affect the visibility of visible light, and are sufficiently fine compared to the radio waves to be absorbed. A mesh size that does not affect the reflection characteristics can be selected.

The seventeenth radio wave absorbing panel (corresponding to claim 17) is characterized in that in the above-described configuration, it preferably has a solar shading property with a solar heat gain of 0.50 or less.

According to the seventeenth radio wave absorbing panel, the solar radiation absorbing property is 0.50 or less, so that solar radiation entering the room can be reduced.

The eighteenth radio wave absorbing panel (corresponding to claim 18) is characterized in that, in the above-described configuration, the heat insulating property preferably has a heat transmission coefficient of 3.0 W / (m ² · K) or less. .

According to the eighteenth radio wave absorbing panel, since it has heat insulation of not more than 3.0 W / (m ² · K), it can absorb radio waves while maintaining heat insulation.

A first method of manufacturing a radio wave absorbing panel (corresponding to claim 19) includes a step of forming a first conductor on one surface of a first sheet glass and a step of forming a second conductor on one surface of a second sheet glass. A step of forming a conductor, a step of forming a third conductor on one surface of a third glass sheet, and a step of forming a first conductor.
Joining the first glass sheet and the second sheet glass on which the second conductor is formed via the first insulating layer, and the first sheet glass forming the first conductor on which the second conductor sheet is joined via the first insulating layer. Joining the plate glass and the second plate glass on which the second conductor is formed to the third plate glass on which the third conductor is formed via a third insulating layer.

According to the first method of manufacturing a radio wave absorbing panel, a step of forming a first conductor on one side of a first sheet glass and a step of forming a second conductor on one side of a second sheet glass. A step of forming a third conductor on one surface of the third sheet glass, and a step of forming the first sheet glass on which the first conductor is formed and the second sheet glass on which the second conductor is formed by the first sheet glass. A step of bonding via an insulating layer, and a step of bonding the first sheet glass on which the first conductor is formed and the second sheet glass on which the second conductor is bonded via the first insulating layer to a third insulating layer. Third through the layers
Joining a third sheet glass having the conductor of
, A radio wave absorbing panel having excellent radio wave absorbing characteristics can be manufactured.

In a second method for producing a radio wave absorbing panel (corresponding to claim 20), in the above method, preferably, the step of forming the first conductor on one surface of the first sheet glass comprises the following steps:
The method is characterized by comprising a step of depositing a metal thin film, a transparent oxide semiconductor or a metal nitride on one surface of the first glass sheet.

According to the second method for manufacturing a radio wave absorbing panel, the step of forming the first conductor on one surface of the first sheet glass includes the step of forming a metal thin film, a transparent oxide semiconductor or a transparent oxide semiconductor on one surface of the first sheet glass. Since the method includes a step of depositing a metal nitride, a chemically stable conductor can be mass-produced.

In a third method of manufacturing a radio wave absorbing panel (corresponding to claim 21), in the above method, preferably, the step of forming the second conductor on one surface of the second glass sheet includes the steps of:
A step of depositing a metal thin film, a transparent oxide semiconductor or a metal nitride on one surface of the second glass sheet, and a radio wave to absorb the metal thin film, the transparent oxide or the metal nitride deposited on one surface of the second glass sheet by sandblasting In the direction of the electric field.

According to the third method for manufacturing a radio wave absorbing panel, the step of forming the second conductor on one surface of the second glass sheet includes the step of forming a metal thin film, a transparent oxide semiconductor or a transparent oxide semiconductor on one surface of the second glass sheet. The method includes a step of depositing a metal nitride and a step of performing a plurality of cuts in a direction of an electric field of a radio wave to be absorbed by sandblasting the metal thin film, the transparent oxide or the metal nitride deposited on one surface of the second glass sheet. The second conductor cut into a plurality in the direction of the electric field of the radio wave to be formed can be easily formed.

In a fourth method of manufacturing a radio wave absorbing panel (corresponding to claim 22), in the above method, preferably, the step of forming the second conductor on one surface of the second sheet glass includes:
A step of depositing a metal thin film, a transparent oxide semiconductor or a metal nitride on one surface of the second glass sheet; and a step of absorbing a radio wave to absorb the metal thin film, the transparent oxide semiconductor or the metal nitride deposited on one surface of the second glass sheet. The method is characterized by comprising a step of irradiating and heating a laser along a plurality of lines in the direction of the electric field to evaporate a metal thin film, a transparent oxide semiconductor or a metal nitride on the lines.

According to the fourth method of manufacturing a radio wave absorbing panel, the step of forming the second conductor on one surface of the second glass sheet includes the step of forming a metal thin film, a transparent oxide semiconductor or a transparent oxide semiconductor on one surface of the second glass sheet. A step of depositing a metal nitride, and irradiating and heating a laser along a plurality of lines in a direction of an electric field of a radio wave to absorb the metal thin film, the transparent oxide semiconductor or the metal nitride deposited on one surface of the second sheet glass. Accordingly, the method comprises a step of evaporating the metal thin film, the transparent oxide semiconductor or the metal nitride on the line, so that the second conductor cut into a plurality in the direction of the electric field of the radio wave to be absorbed can be easily formed. . In addition, since a laser is used for evaporating a metal thin film, a transparent oxide semiconductor, or a metal nitride, masking is not required, and dust and waste liquid are not generated and the environmental load is small.
Further, since the cut shape by evaporation can be controlled by computer, the shape can be freely selected.

According to a fifth method for producing a radio wave absorbing panel (corresponding to claim 23), in the above method, preferably, the step of forming the second conductor on one surface of the second glass sheet comprises the following steps:
A step of depositing a metal thin film, a transparent oxide semiconductor or a metal nitride on one surface of the second glass sheet; and a step of absorbing a radio wave to absorb the metal thin film, the transparent oxide semiconductor or the metal nitride deposited on one surface of the second glass sheet. By irradiating and heating a laser along a plurality of lines in the direction of the electric field, the metal thin film, transparent oxide semiconductor or metal nitride on the line is altered and deformed, and the metal thin film, transparent oxide semiconductor or metal nitride on the line is deformed. The method is characterized in that it comprises a step of setting the electrical resistivity of the object to a predetermined value or more.

According to the fifth method of manufacturing a radio wave absorbing panel, the step of forming the second conductor on one surface of the second glass sheet includes the step of forming a metal thin film, a transparent oxide semiconductor or a transparent oxide semiconductor on one surface of the second glass sheet. A step of depositing a metal nitride, and irradiating and heating a laser along a plurality of lines in a direction of an electric field of a radio wave to absorb the metal thin film, the transparent oxide semiconductor or the metal nitride deposited on one surface of the second sheet glass. Transforms metal thin films, transparent oxide semiconductors or metal nitrides on the line,
Deforming the metal thin film, the transparent oxide semiconductor, or the metal nitride on the line to have an electrical resistivity of a predetermined value or more. The body can be easily formed. In addition, since a laser is used for evaporating a metal thin film, a transparent oxide semiconductor, or a metal nitride, masking is not required, and dust and waste liquid are not generated and the environmental load is small. further,
Since the shape of the cut due to evaporation can be controlled by computer, the shape can be freely selected.

According to a sixth method of manufacturing a radio wave absorbing panel (corresponding to claim 24), in the above method, preferably, the step of forming the second conductor on one surface of the second glass sheet includes the steps of:
Depositing a metal thin film, a transparent oxide semiconductor or a metal nitride film on one side of the second glass sheet, and absorbing the metal thin film, the transparent oxide semiconductor or the metal nitride on one side of the second glass sheet; Forming a protective mask having openings along a plurality of lines in the direction of the electric field of a radio wave, and immersing a metal thin film, a transparent oxide semiconductor or a metal nitride deposited on the second plate glass masked by the protective mask in an etchant. And a step of removing the metal thin film, the transparent oxide semiconductor or the metal nitride exposed through the opening by wet etching.

According to the sixth method for manufacturing a radio wave absorbing panel, the step of forming the second conductor on one surface of the second glass sheet includes the step of forming a metal thin film, a transparent oxide semiconductor or a transparent oxide semiconductor on one surface of the second glass sheet. A step of depositing a metal nitride film and a protection having openings along a plurality of lines in the electric field direction of a radio wave to be absorbed on a metal thin film, a transparent oxide semiconductor or a metal nitride deposited on one surface of a second glass sheet Step of forming a mask, wet etching by immersing a metal thin film masked with a protective mask, a second plate glass on which a transparent oxide semiconductor or a metal nitride is deposited in an etchant,
Since the method includes a step of removing the metal thin film, the transparent oxide semiconductor, or the metal nitride exposed through the opening, the second conductor that is cut into a plurality in the direction of the electric field of the radio wave to be absorbed can be easily formed.

According to a seventh method of manufacturing a radio wave absorbing panel (corresponding to claim 25), in the above method, preferably, the step of forming the third conductor on one surface of the third plate glass comprises the following steps:
The method is characterized by comprising a step of depositing a metal thin film, a transparent oxide semiconductor or a metal-dielectric multilayer film on one surface of the third glass sheet.

According to the seventh method of manufacturing the radio wave absorbing panel, the step of forming the third conductor on one surface of the third glass sheet includes the step of forming a metal thin film, a transparent oxide semiconductor or a transparent oxide semiconductor on one surface of the third glass sheet. Since the method comprises a step of depositing a metal-dielectric multilayer film, a chemically stable conductor can be mass-produced.

An eighth method of manufacturing a radio wave absorbing panel (corresponding to claim 26) is a method according to the above method, wherein the first plate glass on which the first conductor is preferably formed and the second conductor are formed. The step of bonding the second glass sheet via the first insulating layer is performed via a pillar between the first glass sheet forming the first conductor and the second glass sheet forming the second conductor. It is characterized by comprising a joining step and a step of evacuating a space formed between the first sheet glass and the second sheet glass by joining via a pillar.

According to the eighth method of manufacturing a radio wave absorbing panel, the first sheet glass on which the first conductor is formed and the second sheet glass on which the second conductor is formed are interposed via the first insulating layer. Joining by a pillar between the first sheet glass on which the first conductor is formed and the second sheet glass on which the second conductor is formed; and joining via the pillar. Vacuuming the space formed between the first glass sheet and the second glass sheet by the first and second glass sheets, so that the two surfaces of the first and second conductors that are firmly held at a short distance are separated from each other. In addition, it is possible to manufacture a radio wave absorbing panel in which the conductor can have stable radio wave absorbing characteristics for a long period of time.

In a ninth method of manufacturing a radio wave absorbing panel (corresponding to claim 27), in the above method, preferably, the first plate glass on which the first conductor is formed and the second conductor are formed. The step of joining the second sheet glass via the first insulating layer includes the step of inserting a resin between the first sheet glass and the second sheet glass and pressing the same, and the step of joining the first sheet glass and the second sheet glass which are inserted and joined by the resin. And a step of heating and pressurizing the sheet glass.

According to the ninth method for manufacturing a radio wave absorbing panel, the first sheet glass on which the first conductor is formed and the second sheet glass on which the second conductor is formed are interposed via the first insulating layer. The step of bonding by joining the resin between the first sheet glass and the second sheet glass, and the step of heating and pressurizing the first sheet glass and the second sheet glass sandwiched by the resin, By holding the two conductors at a short distance, it is possible to manufacture a radio wave absorbing panel that has high electrical insulation between the two conductors and is structurally stable.

A tenth method for manufacturing a radio wave absorbing panel (corresponding to claim 28) is a method for manufacturing a radio wave absorbing panel according to the first method, wherein the first conductor is preferably formed by bonding a first conductor through a first insulating layer. A third sheet glass on which a third conductor is formed via a third insulating layer is formed on the second sheet glass on which the sheet glass and the second conductor are formed.
The step of bonding the sheet glass of the above is performed by connecting the first sheet glass formed with the first conductor and the second sheet glass formed with the second conductor, which are bonded via the first insulating layer, to the periphery of the sheet via a spacer. Bonding the third glass sheet having the third conductor formed thereon, and sealing the gas into the space formed by the first and second glass sheets and the third glass sheet bonded via the spacer. , Consisting of:

According to the tenth method for manufacturing a radio wave absorbing panel, the first plate glass on which the first conductor is formed and the second plate on which the second conductor is formed are bonded via the first insulating layer. Bonding the third glass sheet on which the third conductor is formed via the third insulating layer to the third glass sheet via the first insulating layer. A step of joining the sheet glass and the second sheet glass on which the second conductor is formed to the periphery of the sheet with a third sheet glass on which the third conductor is formed via a spacer, and the step of joining the first sheet glass via the spacer And a step of filling a gas into a space formed by the second glass sheet and the third glass sheet, so that the space between the second conductor and the third conductor is wide without cost and labor. A radio wave absorbing panel having excellent heat insulating properties can be manufactured.

An eleventh method of manufacturing a radio wave absorbing panel (corresponding to claim 29) is characterized in that, in the above method, the gas is preferably dry air, argon, krypton, xenon,
Or characterized by an SF _6.

According to the eleventh method for producing a radio wave absorbing panel, since the gas is dry air, argon, krypton, xenon, or SF ₆ , the radio wave absorbing panel having excellent heat insulation and high soundproofing performance is manufactured. can do.

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

A first embodiment of the present invention will be described with reference to FIGS. In FIG. 1 and FIG. 2, a first glass sheet 1, a first conductor 2 uniformly formed on one surface (inner side) of the first glass sheet 1, and a first glass sheet 1 are arranged in parallel to the first glass sheet 1. The illustrated third plate glass 3 and a third conductor 4 for radio wave reflection uniformly formed on one surface (inner surface) of the third plate glass 3 are shown. Further, a second glass sheet 5 arranged in parallel between the first glass sheet 1 and the third glass sheet 3 and one surface of the second glass sheet 5 (the surface on the first glass sheet 1 side) are formed. The second conductor 6 is shown cut at least in the direction of the electric field of the radio wave to be absorbed. Furthermore, a first insulating layer 7 between the first conductor 2 and the second conductor 6, a second conductor 6 and a third conductor 4
The second insulating layer 8 is shown between them. First conductor 2
The distance between the first conductor 4 and the third conductor 4 is indicated by d. The first glass plate 1, the third glass plate 5, and the second glass plate 3 are preferably parallel to each other, but need not be strictly parallel. It is enough if the face-to-face relationship is maintained.

The second glass sheet 5 should have a thickness of about 5 mm and a thickness sufficient to maintain the strength. The thickness of the first sheet glass 1 and the third sheet glass 3 may be any thickness as long as the strength can be maintained.

The first conductor 2 has a function of reflecting a part of the radio wave and transmitting the other part in accordance with the impedance of the vacuum. Although the vacuum impedance is 120π, that is, about 377 Ω / □, in the case of the radio wave absorbing panel of the present invention, the optimum value of the first conductor changes depending on other factors. Value is 1
It is desirable to have a conductivity of 00 to 700 Ω / □.

Since the second conductor 6 is cut at least in the direction of the electric field of the radio wave to be absorbed, the effective dielectric constant becomes large as described in the above-mentioned Japanese Patent Application Laid-Open No. 10-275997. This has the effect of reducing the thickness of the radio wave absorbing panel. The cut shape of the second conductor 6 may be a stripe shape or a lattice shape as shown in FIGS. However, it is not always necessary to use a stripe shape or a grid shape. In such a case, it is necessary to design the film width and the cutting width in accordance with the frequency of the radio wave to be absorbed. Also, the cut shape affects the design of other components. The uncut portion of the second conductor 6 generally has excellent electric wave absorption performance if it has as high conductivity as possible, and therefore has a surface resistance of at least 50 Ω / □.
Or less, preferably 20Ω / □ or less, more preferably 10Ω / □ or less.
It is desirable to have a conductivity of Ω / □ or less.

The third conductor 4 is a radio wave reflection layer.
Radio waves arriving from a direction opposite to the direction of arrival of radio waves to be absorbed first enter this reflective layer, and are almost completely reflected as they are. Since the third conductor 4 has higher electric conductivity as much as possible and generally has better radio wave absorption performance, the third conductor 4 has a surface resistance of at least 50 Ω / □ or less, preferably 20 Ω / □ or less, more preferably 10 Ω / □ or less. , More desirably having a conductivity of 5Ω / □ or less.

The first conductor 2 is desirably formed of a transparent oxide semiconductor or a metal nitride. In addition, although it can be formed by a metal thin film, it is necessary to make the metal thin film very thin in order to obtain conductivity in a region having a surface resistance of 100 to 700 Ω / □. Problems tend to occur in stability and long-term stability. The metal nitride and the transparent oxide semiconductor can obtain the conductivity in this region relatively stably.

The second conductor 6 and the third conductor 4 are
It is desirable to be a metal thin film, a transparent oxide semiconductor or a metal-dielectric multilayer film. When a transparent oxide semiconductor is used, the conductivity having a surface resistance of 20 Ω / □ or less can be obtained stably, and when the metal-dielectric multilayer film is used, the conductivity having a surface resistance of 10 Ω / □ or less can be obtained. It can be obtained stably.

The first conductor 3 and the third conductor 4 are
It is possible to select a conductive fiber woven body having a mesh that is sufficiently fine compared to the wavelength of the radio wave to be absorbed. With such a configuration, conductive fibers having various characteristics can be freely selected, and the characteristics of the conductor with respect to the radio wave absorption performance can be easily adjusted. Also, most of the radio waves to be absorbed have sufficiently longer wavelengths than visible light, so they do not affect the visibility of visible light, and are sufficiently fine compared to the radio waves to be absorbed. Such a mesh size can be selected that does not affect the reflection properties. Since the fibrous woven fabric is not stable in shape as it is, it is preferable that the fibrous woven body is sandwiched between resin layers and finally adhered to a sheet glass to maintain the plate shape.

In the case where an oxide semiconductor is used for the first, second and third conductors, indium oxide, an oxide obtained by doping tin or antimony into indium oxide, zinc oxide, or an oxide obtained by doping aluminum to zinc oxide Or tin oxide to which fluorine is added can be used.

These can be formed by a sol-gel method, a thermal spray method, a thermal CVD method, a vacuum method or the like. However, tin oxide to which fluorine is added can be formed by a thermal CVD method and is suitable for mass production. Most preferably, it has a chemically stable structure. Oxide semiconductors, particularly second and third oxide semiconductors
When used for conductors, because high conductivity is required,
Although the film thickness may exceed 100 nm, the adjustment of the reflection color is limited in the single oxide semiconductor layer; therefore, a layer for adjusting the reflection color is inserted between the oxide semiconductor layer and the glass. It is desirable. By doing so, especially when used for the second conductor 6, the cutting line of the conductor becomes less noticeable, which is desirable in appearance.

When metal nitride is used for the first conductor 2,
In addition to conductivity, it can reflect and absorb solar radiation,
It is possible to provide solar shading and to control the reflection of visible light, so that the design can be improved. These characteristics are particularly desirable when the radio wave absorbing panel of the present invention is used for an exterior window glass of a building.

When a metal nitride is used for the first conductor 2, it is suitable to use a vacuum method for forming a film. In particular, a reactive sputtering method using a metal target and using a nitrogen gas as at least a part of the reactive gas to obtain a metal nitride is preferable because a conductor having stable characteristics can be obtained.

Since the first conductor 2 may be arranged directly facing the outside air, it is desirable to overcoat the metal thin film, the transparent oxide semiconductor or the metal nitride layer with a protective layer. For the protective layer, a transparent metal oxide, gold nitride or metal oxynitride is mainly used.

When a metal-dielectric multilayer film is used as the second and third conductors, optimal characteristics are easily obtained in a combination of transparency and conductivity. Therefore, the metal is a noble metal, particularly a noble metal mainly composed of silver. It is desirable to use. A typical structure of the metal-dielectric multilayer film is a dielectric-metal-dielectric or dielectric-metal-dielectric-metal-dielectric structure. Higher conductivity is easily obtained with a high visible light transmittance in the dielectric structure. As a method for forming a film having these structures, a sputtering method is suitable.

The first insulating layer 7 is a resin that transmits visible light, and the second insulating layer 8 is an air layer. Thus, the first conductor 2, the second conductor 6, the third conductor 4, and the first insulating layer 7 and the second insulating layer 8 have a property of transmitting visible light. ing.

The second conductor 6 is made of the same material as that described in
As described in Japanese Patent Application Publication No. 0-275997,
Between the second conductor 3 and the third conductor 4 has a large relative dielectric constant ε.
This is provided so as to have the same function as in the case where a uniform dielectric film having The distance d between the first conductive film 2 and the third conductive film 4 is such that the distance between the first conductive film 2 and the third conductive film 4 is equal to the distance between the first conductive glass 2 and the third conductive glass 4. 4 are arranged so as to generate resonance due to interference of multiple reflections between them.

Next, in order to explain the operation of the radio wave absorbing panel according to the above embodiment with reference to FIGS. 5 and 6, a case where a radio wave E having a wavelength λ is incident on the radio wave absorbing panel will be considered.

A part of the radio wave E incident on the first glass sheet 1 is reflected on the surface of the first conductor 2, and a part is
Through the conductor 2. The radio wave passes through the resin 7, the second conductor 6, the second glass sheet 5, and the second insulating layer 8,
Third glass sheet 3 arranged parallel to first glass sheet 1
The light is reflected by a third conductor 4 formed by a conductor thereon.

The reflected radio waves are transmitted to the second insulating layer 8,
The light passes through the second glass sheet 5, the second conductor 6, and the first insulating layer 7, and is partially reflected by the first conductor 2 and partially transmitted to the air.

At this time, the dielectric constant of each of the first insulating layer 7, the second insulating layer 8, the second glass plate 5, and the second conductor 6 shortens the wavelength, and the radio wave in the air is reduced. Wavelength λ
Shorter than In particular, the wavelength of the radio wave when passing through the second conductor 6 is greatly reduced because the relative permittivity ε is increased by the action of the second conductor 6.

The distance d between the first conductor 2 and the third conductor 4 is such that resonance occurs due to interference of multiple reflections of radio waves, that is, the first conductor 2 and the third conductor 4.導電 of the wavelength of the radio wave between the first and second conductors 4 and 4, resonance occurs due to interference due to multiple reflections of the radio waves reflected by the first and third conductors 2 and 4. The light is not emitted to the outside from the first conductor 2 and is reflected by the first conductor 2 in the direction of the second conductor 6 by 100%. As a result, the radio wave E incident on the radio wave absorbing panel is confined between the first conductor 2 and the third conductor 4, and between the first conductor 2 and the third conductor 4. It is absorbed by the existing second glass sheet 5, first insulating layer 7 and second insulating layer 8. Thus, the radio wave incident on the radio wave absorbing panel is absorbed by the radio wave absorbing panel.

As shown in FIG. 6, when considering the incident angle of the radio wave E, the electric wave E enters the third conductor 4 at an angle θ and is reflected at an angle θ. At that time, the difference between the path lengths of the radio waves that are multiple-reflected between the first conductor 2 and the third conductor 4 is represented by a distance d between the first conductor 2 and the third conductor 4. When d
(1 / cos θ−1), and the smaller the d, that is, the smaller the distance d between the first conductor 3 and the third conductor 4, the more the difference in the path length difference due to the angle change. Is also smaller. Furthermore, since the relative permittivity between the first conductor 2 and the third conductor 4 is large, the refractive index increases,
Even if the incident angle is increased, the light is largely refracted on the surface of the first conductor 2 of the radio wave absorbing panel, so that the dependence of the difference in path length on the incident angle is reduced. Therefore, even if the incident angle of the radio wave is slightly changed, resonance occurs due to interference of multiple reflections of the radio wave. As a result, a change in the absorptivity of the radio wave due to the incident angle of the radio wave is reduced. Also, as the distance between the first conductor 2 and the second conductor 6 is smaller, the change in the absorptivity of the radio wave due to the incident angle of the radio wave is smaller.

As described above, in the radio wave absorbing panel according to the present embodiment, the second conductor cut into a plurality in the direction of the electric field of the radio wave to be absorbed is close to the first conductor. Since it is arranged and is spaced apart from the third conductor in accordance with the frequency of the radio wave to be absorbed, it is possible to provide a radio wave absorbing panel whose radio wave absorption characteristics are hardly changed by the incident angle. Also, at least one of the conductors
Since the fin is directly provided on the glass sheet, the platy shape can be firmly maintained and the nonflammability can be secured.

Further, since the first insulating layer is a resin that transmits visible light and the second insulating layer is an air layer, the gap between the first conductor and the second conductor is held by the resin. Therefore, they can be arranged close to each other while maintaining a good insulating state. Further, fine adjustment of the distance between the first conductor and the second conductor can be easily performed depending on the thickness of the resin layer, and can be kept stable for a long period of time. In addition, since the first conductor and the second conductor are sealed with the resin, the conductor does not come into contact with the outside air, and the radio wave absorption characteristics are stabilized for a long time. Also,
In the case where the first conductor or the second conductor is directly provided on the sheet glass, the glass is bonded to the resin via the conductor, so that even if the glass is broken, it does not scatter and is safe. In the case where the second conductor is provided directly on the glass sheet, by selecting a transparent resin having a value close to the refractive index of the glass sheet, the cutting of the second conductor cut into a plurality of pieces in the direction of the electric field can be performed. Lines are difficult to see and an excellent appearance is easily obtained. Further, by providing at least one air layer between the second conductor and the third conductor, the distance between the second conductor and the third conductor is larger than the distance between the first conductor and the second conductor. It is easy to widen the distance between the conductors, and when used as a window in a building, it can also have excellent heat insulating properties. When the third conductor faces the air layer, the heat insulating property is further enhanced by the far-infrared reflectivity (= low emissivity) of the conductor. Further, when the air layer is held by a structure in which the periphery of the plate is sealed via a spacer and the dry air is sealed, the conductor can be kept shut off from the outside air, and the electric wave absorption characteristics can be stabilized for a long time. .

In the first embodiment, the second insulating layer is
It was an air layer, but instead of an air layer, argon and crypto
Xenon, SF₆Replace some or all with etc.
be able to. Insulation by replacing these
Can be further enhanced, SF ₆If replaced, soundproof
Performance can also be enhanced.

In the first embodiment, the first insulating layer is made of resin. However, as another configuration of the first insulating layer, a sheet glass is provided on the side of the first conductor on which the radio wave arrives. And
Another sheet glass is provided on the side opposite to the direction of arrival of radio waves of the second conductor, and a first insulating layer, that is, a vacuum layer supported by pillars between the first and second conductors. Yes, the pillars may be at least partially made of an insulating material, or may be arranged along a cutting line of the second conductor.

With this configuration, the two surfaces of the first conductor and the second conductor are firmly held at a short distance via the pillar, and the two conductors are held in a vacuum. Therefore, the characteristics of the film are stable for a long time. In addition, due to the heat insulating property of the vacuum layer, when used as a window of a building, excellent heat insulating properties can be provided. In order to exhibit good heat insulating properties, the degree of vacuum of the vacuum layer is desirably 1 Pa or less. Since the first conductor and the second conductor in contact with the vacuum layer have far-infrared reflectivity (low emissivity),
This also contributes to improving the heat insulation. Since the first conductor and the second conductor need to be kept insulated from each other, the pillar that keeps the space between the two surfaces is electrically insulated at least between the surfaces that are in contact with the two surfaces, or The structure must be arranged along the cutting line of the two conductors and, as a result, keep the insulation of the two conductors.

Further, as another configuration of the first insulating layer,
At least one sheet glass may be arranged between the first and second conductors.

When the first conductor and the second conductor are provided on both the front and back surfaces of such a single sheet of glass, the total number of glass is reduced, so that the weight of the radio wave absorbing panel can be reduced. Is possible. Further, the distance between the first conductor and the second conductor can be stably maintained.

Further, as another configuration of the first insulating layer, at least one insulating inorganic thin film that transmits visible light may be disposed between the first and second conductors. .

With this configuration, the first conductor, the inorganic thin film, and the second conductor are successively formed in this order, or the second conductor, the inorganic thin film, and the first conductor are successively formed in this order. In addition to this, there are many advantages in production, and the first conductor or the second conductor is automatically protected by the upper inorganic thin film, so that long-term stability is easily guaranteed. This configuration is one of the means for stably realizing the first insulating layer in the thinnest and good insulating state.

Further, by making the radio wave absorbing panel have a solar shading property with a solar heat gain of 0.50 or less, the solar radiation entering the room can be reduced. Furthermore, by having heat insulation of not more than 3.0 W / (m ² · K), it is possible to absorb radio waves while maintaining heat insulation.

As described above, in the radio wave absorbing panel of the present invention, the first insulating layer is a vacuum layer, a resin layer, at least one sheet glass, or at least one layer of an inorganic thin film. The gap can be maintained at a short distance while ensuring high electrical insulation and structural stability.

The first conductor, the second conductor,
When the third conductor, the second conductor, and the first conductor are provided, the third conductor can also serve as a reflection layer of radio waves from both directions, so that radio waves absorbing radio waves from both directions can be used. It becomes an absorbent panel. This configuration is also within the scope of the present invention.

Next, a first embodiment of the method for manufacturing a radio wave absorbing panel of the present invention will be described. FIG. 7 is a flowchart illustrating a first embodiment of a method for manufacturing a radio wave absorbing panel. The radio wave absorbing panel has a first sheet glass on one side.
Forming a conductor (ST10) and forming a second conductor on one surface of the second glass sheet (ST11).
Forming a third conductor on one surface of the third glass sheet (ST12); and forming the first glass sheet on which the first conductor is formed and the second glass sheet on which the second conductor is formed by the second step. A step (ST13) of joining via the first insulating layer, and a first sheet glass on which the first conductor is formed and a second sheet glass on which the second conductor is joined via the first insulating layer The third
(ST14) in which the third glass sheet on which the third conductor is formed is joined via the insulating layer.

The step (ST10) of forming the first conductor on one side of the first glass sheet is performed as follows.
FIG. 8 shows one side surface of a normal float glass having a thickness of 3 mm.
A conductive coating made of a metal nitride film was applied by a so-called load-lock type in-line magnetron sputtering apparatus having four sets of cathodes as shown in FIG. The film is applied by loading the washed plate glass 10 from the entrance of the coating apparatus shown in FIG.
4 and evacuated to a predetermined pressure. After being conveyed to the coating chamber 15, a sputtering gas is introduced into the coating chamber 15, adjusted to a predetermined pressure by balancing with an exhaust pump, and then a voltage is applied to the cathode 16. Is applied to generate a discharge, and the material set for each cathode is sputtered. In this embodiment, the glass at the time of coating was applied at room temperature without heating.

The coating was performed as follows. First, a cathode 1 in which nitrogen gas was introduced into the chamber so as to have a pressure of 0.3 Pa and a titanium target was set.
By applying a DC voltage of 460 V to 6c, a titanium nitride film was formed. The thickness of the film was adjusted to 18 nm by adjusting the speed of reciprocating the glass and the number of reciprocations.

The step (ST11) of forming the second conductor on one surface of the second glass sheet is performed as follows.
FIG. 9 shows one side surface of a normal float glass having a thickness of 3 mm.
CV with three sets of coating nozzles as shown in
A low emissivity coating mainly composed of a tin oxide film was applied by a D apparatus. The film is applied to the washed plate glass 10
Is set at the entrance of the coating apparatus, and heated to a predetermined temperature by the heater 11 while being transported to a predetermined coating area, and the raw material gas is introduced into the heated glass surface by the coating nozzle 12, and the gas causes a thermal decomposition reaction. It is implemented by doing. In this embodiment, the heater is controlled so that the glass surface temperature during coating becomes 650 ° C. The details of the coating are described below.

First, the glass was transported to the first nozzle 12a, and a tin oxide film was formed as a first layer. Next, a silicon oxide film was formed as a second layer by the second nozzle 12b, and subsequently, a tin oxide film doped with fluorine was formed as a third layer by the third nozzle 12c. The thickness of the formed film is about 25 nm for the first layer, about 25 nm for the second layer, and about 3 nm for the third layer.
It was 50 nm.

The conditions for producing each film are as follows. The tin oxide film of the first layer is made of monobutyltin trichloride (C ₄ H ₉ SnCl ₃ ) as a tin raw material for 150 minutes.
C., and the vapor is transported using nitrogen gas as a carrier gas at a concentration of 0.001 mol per mol of the carrier gas, introduced into the first nozzle, and oxygen gas as an oxidizing gas is supplied to the same nozzle through another system. And formed by causing a thermal decomposition reaction and an oxidation reaction on the glass surface.

The silicon oxide film of the second layer is formed by introducing monosilane (SiH ₄ ) gas as a silicon raw material directly into the second nozzle from a cylinder and supplying oxygen gas as an oxidizing gas in the same manner as in the case of the above-described tin oxide film. Was formed by introducing a thermal decomposition reaction and an oxidation reaction on a glass surface.

The third fluorine-containing tin oxide film is
The third nozzle was formed basically in the same manner as the first tin oxide film. However, the concentration of the monobutyltin trichloride vapor was 0.01 mol per mol of the carrier gas and 10 times the concentration of the first layer. Further, trifluoroacetate (CF ₃ COOH) was heated as a fluorine raw material, and the vapor was introduced from a separate system into a third nozzle using nitrogen gas as a carrier gas. In order to promote the decomposition reaction of the tin raw material, water vapor was transported using nitrogen gas as a carrier gas at a concentration of 5 mol per mol of the carrier gas, and supplied to the nozzle from another system.

In the fluorinated tin oxide-based coating thus obtained, the first layer of tin oxide and the second layer of silicon oxide are refracted between the glass and the third layer of fluorinated tin oxide film. Since it functions as a rate adjusting layer, it has an effect of reducing a rainbow-like reflected color caused by light interference of the fluorine-added tin oxide layer. The fluorine doped tin oxide film of the third layer has good visible light transmittance and conductivity due to its properties as an oxide semiconductor, and plays an active role in controlling radio waves.

In order to cut the glass coated with the conductive film into a plurality of pieces in the direction of the electric field of a radio wave to be absorbed, first, the conductive film other than the cut portion was protected with a masking tape, and the film at the cut portion was removed by sandblasting. Masking tape is available from Nichiban No. 251 as a sand blasting machine, using an Ascondester spot blaster type 4520 manufactured by Atsushi Tekko Co., Ltd. at a blast pressure of 6
At 000 hPa, 180 grit sand was sprayed. After the operation, it was confirmed visually and by a resistance meter that the cutting was good.

In the step (ST12) of forming the third conductor on one surface of the third glass sheet, four sets of cathodes as shown in FIG. 8 were provided on one surface of a normal float glass having a thickness of 3 mm. A conductor coating composed of a dielectric / silver / dielectric / silver / dielectric sandwich structure film was applied by a so-called load lock type in-line magnetron sputtering apparatus. The film is applied to the washed plate glass 10
Is transported from the entrance of the coating apparatus shown in FIG. 8 to the load lock chamber 14 and evacuated to a predetermined pressure. After the pressure is adjusted to a predetermined value, a voltage is applied to the cathode 16 to generate a discharge and the material set for each cathode is sputtered. In the present embodiment, the glass with the coating was applied at room temperature without heating. The details of the coating are described below.

First, oxygen gas was introduced into the chamber at a pressure of 0.
3 Pa, a DC voltage of 440 V was applied to the cathode 16a on which the zinc target was set to cause reactive sputtering with oxygen gas, and the glass was reciprocated under the cathode, whereby zinc oxide was used as the first layer. A film was formed.

Next, the gas in the chamber was changed to argon (A
r) The gas was switched to a pressure of 0.3 Pa, and a DC voltage of 48 was applied to the cathode 16b on which a silver target was set.
By applying a voltage of 5 V, a silver film was formed as a second layer by sputtering. Next, in the same argon gas atmosphere as the second layer, the cathode 16 with the titanium target set thereon was used.
By applying a DC voltage of 310 V to c, a titanium film was formed as a third layer. Next, the fourth layer zinc oxide film is formed in the same manner as the first layer, the fifth layer silver film is formed in the same manner as the second layer, the sixth layer silver film is formed in the same manner as the third layer. A seventh layer of a zinc oxide film was formed in the same manner as the first layer.

Finally, the gas in the chamber was switched to N ₂ gas so that the pressure became 0.3 Pa, and a DC voltage of 440 V was applied to the cathode 26 d on which a silicon target to which aluminum was added at 10 wt% was set, and sputtering was performed. A silicon nitride film to which aluminum was added was formed as eight layers. The thickness of the film is adjusted by the speed and the number of reciprocations of the glass. The first layer is 16 nm, the second layer is 6 nm, the third layer is 3 nm, the fourth layer is 72 nm, the fifth layer is 13 nm, and the sixth layer. Was 3 nm, the seventh layer was 19 nm, and the eighth layer was 10 nm.

In the coating thus obtained, the zinc oxide film of the first layer functions as a dielectric layer for adjusting the refractive index between the glass and the silver film of the second layer, and reduces the visible light transmittance. Has the effect of increasing. The thin titanium film of the third layer and the sixth layer becomes the second layer when the zinc oxide film of the fourth layer and the seventh layer is deposited.
It has a function of protecting the silver film of the layer and the fifth layer, and at that time, it changes into an oxide. The third layer of oxidized titanium film is
It works as a dielectric cavity layer between the second layer and the fifth layer silver film together with the layer zinc oxide film, and has the effect of increasing the visible light transmittance. The oxidized titanium film of the sixth layer, together with the zinc oxide film of the seventh layer and the silicon nitride film to which aluminum is added, is a dielectric material for adjusting the refractive index between the silver film of the fifth layer and air. Since it functions as a layer, it has an effect of increasing visible light transmittance. The silver films of the second and fifth layers have good conductivity and play a role of controlling radio waves. The eighth layer of aluminum nitride-added titanium nitride also acts as an overcoat to increase the chemical and mechanical durability of the coating.

The step (ST13) of joining the first sheet glass on which the first conductor is formed and the second sheet glass on which the second conductor is formed via the first insulating layer (ST13) is as follows. Done. A 0.38-mm-thick polyvinyl butyral sheet serving as a first insulator, with a metal nitride film produced as a first conductor and a cut tin oxide film produced as a second conductor inside. Was sandwiched between two sheets of glass and pressed with a roller. Next, pressure was applied while applying heat with an autoclave apparatus. By this step, the polyvinyl butyral sheet was made transparent and adhered to the conductor.

The first glass sheet on which the first conductor is formed and the second glass sheet on which the second conductor is formed are bonded via the first insulating layer to the third glass sheet via the third insulating layer. In the step (ST14) of joining the third sheet glass on which the conductor is formed, the two sheet glasses integrated with the resin and the third sheet glass are joined together.
The electric wave-absorbing panel of FIG. 1 was completed by combining a sheet glass coated with the above-mentioned conductor with an air layer serving as a part of the third insulator provided therebetween. At this time, the surface coated with the third conductor is arranged to be on the air layer side,
The direction of the integrated first and second conductors must be selected so that the first, second, and third conductors are arranged in this order. An aluminum spacer was bonded to the periphery of the glass with butyl rubber to maintain the shape of the air layer.
The spacer was filled with a desiccant for keeping the air layer in a dry atmosphere. Further, since the third conductor uses a silver layer, the film at the spacer contact portion was removed so that corrosion from the periphery did not occur. The radio wave absorbing panel produced in this way has stable radio wave absorption characteristics independent of the angle of incidence, and has sufficient durability to be used for the exterior of buildings. He also had sex.

Next, a second method of manufacturing the radio wave absorbing panel will be described.
An embodiment will be described. In this embodiment, a method for forming the second conductor is performed using a laser.
Other steps are the same as in the first embodiment. First,
A conductor is uniformly formed on one side of the glass sheet. After that, a cut portion of the conductive film is irradiated with a YAG laser or a CO ₂ laser. Thereby, the laser beam is absorbed and locally heated. Due to the local heating by the laser, the conductive film is altered, deformed, and evaporated. When the conductive film evaporates, it is completely cut, and the second conductive film is formed. In addition, even if the conductive film cannot be completely removed,
By the deformation, the predetermined electrical insulation of the cut portion is ensured, so that the same effect as that of the cut can be obtained, and the second conductive film can be formed.

The cutting method using a laser is excellent in that a mask is not required, dust and waste liquid are not generated, and an environmental load is small. Further, since the cutting shape can be controlled by a computer, the shape can be freely selected.

Next, the third method of manufacturing the radio wave absorbing panel will be described.
An embodiment will be described. In this embodiment, the method for forming the second conductive film is performed by wet etching. Other steps are performed in the same manner as in the first embodiment. The conductor 18 is uniformly deposited on one surface of the glass plate 17 (FIG. 10A). Thereafter, as shown in FIG. 10B, a photoresist 19 is uniformly applied. A mask that exposes the part to be etched is adhered to it,
Expose. Thereafter, by performing development and rinsing, the resist at the portion to be etched is removed as shown in FIG. By immersing in the etchant in this state, the conductor exposed by the opening 20 of the resist is etched (FIG. 10D) and removed. Thereafter, a second conductor is formed by removing the photoresist (FIG. 10e).

In this embodiment, since the second conductor is cut after the formation of the conductive film, the cut portion may be mechanically, chemically or thermally removed after the formation of the film. There is the advantage that the degree is relatively large. When mechanically removed, if the second conductor is a metal-dielectric multilayer film,
By simply rubbing the portion where the metal or ceramic is desired to be removed, the upper layer film including the lowermost metal can be removed, so that the necessary insulation of the cut portion can be secured. In the case where the second conductor is an oxide semiconductor, sand blasting is performed in this embodiment, but it may be removed by polishing with a grindstone.

In this embodiment, the cutting of the second conductor is performed after the formation of the conductive film. However, the cutting may be performed when the conductor is formed. In this case, it is necessary to mask the cut portion before forming the conductor.

Although the first insulating layer is made of resin in the present embodiment, a vacuum may be formed by using pillars. At that time, the heat insulation becomes better. In addition, the second conductor and the third conductor
Although air is filled in the space of the conductor, another gas such as argon may be used. At that time, heat insulation and soundproofing are improved.

[0129]

As apparent from the above description, the present invention has the following effects.

A second conductor cut into a plurality of pieces in the direction of the electric field of the radio wave to be absorbed is disposed close to the first conductor, and the third conductor is defined by the frequency of the radio wave to be absorbed. Since they are arranged at a distance from each other, it is possible to provide a radio wave absorbing panel in which the radio wave absorption characteristics are hardly changed by the incident angle. In addition, since at least one of the first conductor, the second conductor, and the third conductor is provided directly on the glass sheet, the plate shape can be firmly maintained, and nonflammability is also ensured. be able to.

Further, the first conductor, the second conductor, and the third
Since the conductor and the first insulating layer and the second insulating layer have a property of transmitting visible light, a radio wave absorbing panel can be used as a window.

Further, since the second insulating layer is composed of a layer formed of gas, it is not necessary to secure an interval for absorbing a specific radio wave with the resin layer between the glass and the third conductive film. So it is not costly and troublesome. Also, the first
The distance between the second conductor and the third conductor can be made wider than the distance between the second conductor and the second conductor.

Further, the method for manufacturing a radio wave absorbing panel includes a step of forming a first conductor on one surface of a first sheet glass;
A step of forming a second conductor on one side of the second glass sheet, a step of forming a third conductor on one side of the third glass sheet, and a step of forming the first glass sheet on which the first conductor is formed, Bonding the second glass sheet on which the second conductor is formed via the first insulating layer; and bonding the first glass sheet via the first insulating layer to the first glass sheet.
Bonding the first sheet glass having the conductor formed thereon and the second sheet glass having the second conductor formed thereon via a third insulating layer to a third sheet glass having the third conductor formed thereon; , A radio wave absorbing panel having excellent radio wave absorbing characteristics can be manufactured.

In addition, since a vacuum layer, a resin layer, at least one sheet of glass, or at least one layer of an inorganic thin film is provided between the first conductor and the second conductor, high electrical insulation and high structural stability can be obtained. And the two conductors can be held at a short distance.

When the space between the first conductor and the second conductor is a vacuum layer or the space between the second conductor and the third conductor is an air or heat-insulating gas layer, the material may be used as a building material. Excellent heat insulation can be ensured.

Further, when the first conductor is formed of metal nitride, it is possible to have both excellent solar shading and design properties as a building material.

[Brief description of the drawings]

FIG. 1 is an external perspective view of a part of a radio wave absorbing panel of the present invention.

FIG. 2 is a vertical sectional view of a main part showing an internal structure of the radio wave absorbing panel of the present invention.

FIG. 3 is a pattern diagram of a stripe-shaped second conductor of the radio wave absorbing panel of the present invention.

FIG. 4 is a pattern diagram of a grid-shaped second conductor of the radio wave absorbing panel of the present invention.

FIG. 5 is a longitudinal sectional view for explaining the operation of the radio wave absorbing panel of the present invention.

FIG. 6 is a longitudinal sectional view for explaining the operation of the radio wave absorbing panel of the present invention.

FIG. 7 is a flowchart showing a method for manufacturing a radio wave absorbing panel of the present invention.

FIG. 8 is a schematic sectional view of a sputtering apparatus used for applying a conductor coating.

FIG. 9: C used to apply a conductor coating
It is a schematic cross section of a VD device.

10A and 10B are cross-sectional views of a sheet glass when a second conductor is formed by wet etching. FIG. 10A is a cross-sectional view after a conductor is uniformly deposited on one surface of the sheet glass. )
Is a cross-sectional view when a photoresist is uniformly applied on a conductor, (c) is a cross-sectional view when a portion of the photoresist to be etched is removed, and (d) is
FIG. 4 is a cross-sectional view when a conductor exposed through an opening of a photoresist is etched.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st sheet glass 2 1st conductor 3 3rd sheet glass 4 3rd conductor 5 2nd sheet glass 6 2nd conductor 7 1st insulating layer 8 2nd insulating layer 10 sheet glass 11 heater 12 Coating nozzle 13 CVD equipment 14 Load lock chamber 15 Coating chamber 16 Cathode C Glass transport direction D Glass transport direction

Continued on the front page (72) Inventor Kenji Murata 4-7-28 Kitahama, Chuo-ku, Osaka-shi, Osaka Inside Nippon Sheet Glass Co., Ltd. (72) Michihiro Masakage 4- 7-28 Kitahama, Chuo-ku, Osaka-shi, Osaka Inside Nippon Sheet Glass Co., Ltd. (72) Inventor Motoyasu Togashi 1-1-11, Shiba, Minato-ku, Tokyo Nippon Sheet Glass Environmental Amenity Co., Ltd. (72) Inventor Yasushi Hoshino 1-11-11, Shiba, Minato-ku, Tokyo Nippon Sheet Glass Inside Environmental Amenity Co., Ltd. (72) Inventor Kenichi Harakawa 1-5-1, Otsuka, Inzai City, Chiba Prefecture Inside the Research Institute of Takenaka Corporation (72) Inventor Toshio Saito 1-5-1, Otsuka 1, Inzai City, Chiba Prefecture Stock Company 4G061 AA01 AA29 BA01 CB02 CB05 CB06 CB19 CD02 CD19 CD21 5E321 AA46 BB23 BB25 BB41 BB60 GG05 GG11 GG12 GH01

Claims (29)

[Claims] 1. A first conductor which reflects a part of a radio wave and transmits another part thereof in order from the arrival direction of a radio wave to be absorbed; A second conductor cut into a plurality in the direction of the electric field of the radio wave to be absorbed, and a second conductor which is arranged at a distance from the second conductor according to the frequency of the radio wave to be absorbed and reflects the radio wave to be absorbed. 3
And a first insulating layer between the first conductor and the second conductor, and a second insulating layer between the second conductor and the third conductor. A radio wave absorbing panel, wherein at least one of the first conductor, the second conductor, and the third conductor is provided directly on a sheet glass. 2. The first conductor, the second conductor, the third conductor, and the first insulating layer and the second insulating layer have a property of transmitting visible light. The radio wave absorbing panel according to claim 1, wherein 3. The radio wave absorbing panel according to claim 1, wherein said second insulating layer comprises a layer formed of a gas. 4. The radio wave absorbing panel according to claim 3, wherein the gas is air. 5. The radio wave absorbing panel according to claim 3, wherein the gas is one of argon, krypton, xenon, and SF ₆ gas. 6. The method according to claim 1, wherein the first insulating layer is formed of a layer formed of a resin transmitting visible light.
The radio-absorbing panel described. 7. A sheet glass is provided on the direction of arrival of radio waves of the first conductor, and another sheet of glass is provided on a side opposite to the direction of arrival of radio waves of the second conductor. Wherein the first insulating layer comprises a vacuum layer supported by pillars, wherein the pillars are at least partially made of an insulating material or are arranged along cutting lines of the second conductor. The radio wave absorbing panel according to claim 1, wherein: 8. The radio wave absorbing panel according to claim 1, wherein the first insulating layer is made of at least one sheet glass. 9. The radio wave absorbing panel according to claim 1, wherein the first insulating layer comprises at least one inorganic thin film. 10. The radio wave absorbing panel according to claim 1, wherein the first conductor has a surface resistance of 100 Ω / □ or more and 700 Ω / □ or less. 11. The radio wave absorbing panel according to claim 1, wherein the second conductor has a surface resistance value of 50Ω / □ or less. 12. The radio wave absorbing panel according to claim 1, wherein the third conductor has a surface resistance of 50Ω / □ or less. 13. The radio wave absorbing panel according to claim 1, wherein the first conductor is a transparent oxide semiconductor or a metal nitride. 14. The radio wave absorbing panel according to claim 1, wherein the second and / or third conductor is made of a metal thin film, a transparent oxide semiconductor, or a metal-dielectric multilayer film. 15. The oxide semiconductor according to claim 13, wherein the oxide semiconductor is tin oxide to which fluorine is added.
4. The radio wave absorbing panel according to 4. 16. The radio wave absorbent according to claim 1, wherein the first and / or third conductor is a conductive fiber woven fabric having a mesh finer than a wavelength of a radio wave to be absorbed. panel. 17. The radio wave absorbing panel according to claim 1, wherein the panel has solar radiation shielding properties with a solar radiation heat acquisition rate of 0.50 or less. 18. The radio wave absorbing panel according to claim 1, wherein the panel has heat insulation properties of not more than 3.0 W / (m ² · K). 19. A step of forming a first conductor on one side of a first sheet glass, a step of forming a second conductor on one side of a second sheet glass, and a step of forming a third conductor on one side of a third sheet glass. Forming the first conductor and bonding the first glass sheet on which the first conductor is formed and the second glass sheet on which the second conductor is formed via a first insulating layer. And the first sheet glass on which the first conductor is formed and the second sheet glass on which the second conductor is formed, which are joined via the first insulating layer, via a third insulating layer. Bonding a third glass sheet having a third conductor formed thereon by using a third conductor. 20. The step of forming a first conductor on one surface of the first plate glass comprises a step of depositing a transparent oxide semiconductor or a metal nitride on one surface of the first plate glass. The method for manufacturing a radio wave absorbing panel according to claim 19, wherein 21. A step of forming a second conductor on one surface of the second plate glass, comprising: depositing a metal thin film, a transparent oxide semiconductor or a metal nitride on one surface of the second plate glass; 20. The radio wave absorption according to claim 19, comprising a step of performing a plurality of cuttings in a direction of an electric field of a radio wave to be absorbed by sandblasting the metal thin film, the transparent oxide or the metal nitride deposited on one surface of the second sheet glass. Manufacturing method of flexible panel. 22. A step of forming a second conductor on one surface of the second plate glass, comprising: depositing a metal thin film, a transparent oxide semiconductor or a metal nitride on one surface of the second plate glass; A metal thin film deposited on one surface of the second glass sheet, a metal thin film on the line by irradiating a laser along a plurality of lines in the electric field direction of a radio wave to absorb a transparent oxide semiconductor or a metal nitride and heating the line, 20. The method according to claim 19, comprising a step of evaporating the transparent oxide semiconductor or the metal nitride. 23. A step of forming a second conductor on one surface of the second glass sheet, comprising: depositing a metal thin film, a transparent oxide semiconductor or a metal nitride on one surface of the second glass sheet; A metal thin film deposited on one surface of the second glass sheet, a metal thin film on the line by irradiating a laser along a plurality of lines in the electric field direction of a radio wave to absorb a transparent oxide semiconductor or a metal nitride and heating the line, The method according to claim 1, further comprising the step of transforming and deforming the transparent oxide semiconductor or the metal nitride to make the electrical resistivity of the metal thin film, the transparent oxide semiconductor or the metal nitride on the line equal to or higher than a predetermined value. 20. The method for producing a radio wave absorbing panel according to item 19. 24. The step of forming a second conductor on one surface of the second plate glass, comprising: depositing a metal thin film, a transparent oxide semiconductor or a metal nitride film on one surface of the second plate glass; Forming a protective mask having openings along a plurality of lines in a direction of an electric field of a radio wave to be absorbed on a metal thin film, a transparent oxide semiconductor, or a metal nitride deposited on one surface of a second glass sheet; The metal thin film masked by the mask, the second glass sheet on which the transparent oxide semiconductor or metal nitride is deposited is wet-etched by dipping in an etchant, and the metal thin film, transparent oxide semiconductor or metal nitride exposed through the opening is removed. 20. The method for manufacturing a radio wave absorbing panel according to claim 19, comprising a step of removing. 25. The step of forming a third conductor on one surface of the third glass sheet includes depositing a metal thin film, a transparent oxide semiconductor, or a metal-dielectric multilayer film on one surface of the third glass sheet. The method for manufacturing a radio wave absorbing panel according to claim 19, comprising: 26. The method according to claim 26, wherein the first conductor is formed on the first conductor.
The step of bonding the plate glass and the second plate glass on which the second conductor is formed via a first insulating layer includes the step of joining the first plate glass on which the first conductor is formed and the second plate glass A step of bonding via a pillar between the second glass sheets on which the conductor is formed; and a space formed between the first glass sheet and the second glass sheet by bonding via the pillars. 20. The step of applying a vacuum.
A method for producing the radio wave absorbing panel according to the above. 27. The method according to claim 27, wherein the first conductor is formed on the first conductor.
The step of joining the first glass sheet and the second glass sheet, on which the second conductor is formed, via a first insulating layer, comprises sandwiching a resin between the first glass sheet and the second glass sheet and pressing them together. 20. The method of manufacturing a radio wave absorbing panel according to claim 19, comprising: a step of heating and pressurizing the first glass sheet and the second glass sheet that have been sandwiched and pressed with the resin. 28. A method according to claim 27, wherein the first glass sheet on which the first conductor is formed and the second glass sheet on which the second conductor is formed are joined by a third insulating layer. The step of bonding the third glass sheet having the third conductor formed thereon via a layer includes the step of bonding the first glass sheet having the first conductor formed via the first insulating layer and the third glass sheet. 2
Bonding the second plate glass having the conductor formed thereon to a third plate glass having a third conductor formed around the plate via a spacer; and bonding the first plate glass having the third conductor formed via the spacer and the 20. The method of manufacturing a radio wave absorbing panel according to claim 19, comprising: a step of filling a gas into a space formed by the second glass sheet and the third glass sheet. 29. The method according to claim 28, wherein the gas is dry air, argon, krypton, xenon, or SF ₆ .