JP4359451B2 - Electromagnetic shielding panel and electromagnetic shielding window - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electromagnetic shielding window using an electromagnetic shielding panel in a building, particularly an intelligent building with advanced OA.
[0002]
[Prior art]
In recent years, as represented by the OA / communication field, electronic devices and apparatuses are frequently used in buildings and vehicles. Electromagnetic waves generated from these electronic devices / devices cause other electronic devices and electronic control devices to malfunction or generate noise.
[0003]
In particular, in the advanced information era, electromagnetic waves that enter from the window glass cause a malfunction of computers and communication devices in buildings, and become a source of noise. On the other hand, electromagnetic waves generated from the electronic devices in the building go out of the window glass to the outside, causing malfunctions in the electronic devices outside the building, and causing noise.
[0004]
In order to prevent such malfunctions and noise sources, electromagnetic shielding performance has been demanded on the outer wall surface of the building including the window in order to prevent the leakage of confidential information due to the radio wave coming out of the building.
[0005]
Many proposals have been made to impart electromagnetic shielding performance to a building window. For example, as a method of imparting electromagnetic shielding function to an opening, two sheet glasses are held with a spacer and a peripheral edge is sealed. As a multi-layer glass structure in which an air layer is provided between two sheet glasses, a transparent conductive film is disposed on the air layer side of the sheet glass (Patent Document 1).
[0006]
Further, in order to sufficiently exhibit the electromagnetic shielding performance of the transparent conductive film, the transparent conductive film disposed on the air layer side between the plate glasses in the double glazing structure or the double glazing structure is made of a conductor such as a window frame member. It must be conducted and grounded. Patent Document 2 discloses that a metal foil or a metal tape is used for connection between a transparent conductive film formed on the air layer side and a conductor such as a window frame.
[0007]
In general, the electromagnetic shielding performance of an electromagnetic shielding member, such as an electromagnetic shielding glass, a sash member, a door, or a wall member, used in a building or a room subjected to electromagnetic shielding treatment has a service life of 5 years. That is, in electromagnetic shielding glass, it is necessary to maintain electromagnetic shielding performance as a guarantee period for 5 years.
[0008]
When metal foil or metal tape is used for conduction, moisture enters the transparent conductive film from the metal foil or metal tape, and the conductive film deteriorates to increase resistance, resulting in insufficient electromagnetic shielding performance. In addition, there arises a problem that the transparent conductive film becomes opaque. In order to improve it, the technique protected with the water-resistant tape which uses butyl rubber as an adhesive agent is disclosed (patent documents 3 and 4).
[0009]
[Patent Document 1]
Japanese Patent Laid-Open No. 64-5099 [Patent Document 2]
Japanese Utility Model Publication No. 3-83996 [Patent Document 3]
Japanese Patent Laid-Open No. 11-312892 [Patent Document 4]
Japanese Patent Laid-Open No. 11-31893 [0010]
[Problems to be solved by the invention]
When the conductive film is used to conduct the transparent conductive film and a conductor such as a frame, moisture penetrates and the transparent conductive film deteriorates. In particular, a transparent conductive film is conspicuous in a composite film of Ag and ZnO, an ITO film having no acid resistance, or the like. Further, when the conductive tape is protected with a butyl rubber-based water-resistant tape, there is a problem that the construction is complicated due to the adhesive force of the butyl rubber-based, and a construction error is likely to occur.
[0011]
On the other hand, regarding the electromagnetic shielding performance, the malfunction of the computer system in the building should be reduced to the radio wave intensity of the noise source to the allowable level of malfunction of the device. In general, the intensity of the electromagnetic wave of the noise source is about 150 dB at the maximum level, but the electromagnetic shielding required for the opening in consideration of attenuation due to the distance from the noise source, etc. performance - 10 - if 30 dB, can be used as an electromagnetic shielding window.
[0012]
In addition, when a PHS phone or personal computer (PC) is used in a building for a wireless LAN within a building, and the purpose is to prevent malfunction or wiretapping of the PC or server for the wireless communication, a frequency range for electromagnetic shielding. Can be limited to 20 MHz to 5 GHz.
[0013]
In view of such circumstances, the present invention provides an inexpensive electromagnetic shielding window with good durability such that the electromagnetic shielding performance is −10 to −30 dB in the frequency range of 20 MHz to 5 GHz.
[0014]
[Means for solving problems]
The electromagnetic shielding window of the present invention is an electromagnetic shielding window in which an electromagnetic shielding panel is formed with one or more conductive layers between two transparent plates, and the electromagnetic shielding panel is fitted in a frame. The area resistance of the conductive layer is 100Ω / □ or less, and one or more conductive layers are formed between the two transparent plate-like bodies on the surface except between 5 mm to 10 mm from the edge of the transparent plate-like body, provided the surface to the conductive film between the edges of the electromagnetic shielding panel 20 mm, conductive layer and the conductive film are disposed to face each other with a transparent plate-shaped body, said conductive film and frame and is a conductor The area Z where the conductive layer and the conductive film overlap with each other when viewed in the direction perpendicular to the surface of the transparent plate-like body is adjusted, and the impedance Z between the conductive layer and the conductor becomes 0.1 to 10Ω. Thus, the electromagnetic shielding window is provided with a conductive film .
[0016]
Moreover, the electromagnetic shielding window of the present invention is the above-mentioned electromagnetic shielding window, wherein the conductive layer is a transparent conductive film formed on a transparent plate, a metal net, or a resin film coated with a transparent conductive film. The electromagnetic shielding window is characterized by being selected.
[0017]
The electromagnetic shielding window of the present invention is an electromagnetic shielding window characterized in that in the electromagnetic shielding window, two transparent plate-like bodies are bonded with one or more intermediate films.
[0018]
In the electromagnetic shielding window of the present invention, in the electromagnetic shielding window, two transparent plate-like bodies are arranged to face each other via a spacer, and an air layer sealed by the plate-like body and the spacer is formed. It is an electromagnetic shielding window characterized by these.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
There is a high-power track radio (CB radio) in the frequency band of 20 to 30 MHz, a mobile phone in the 800 MHz to 1 GHz, a 1.5 GHz band, a PHS phone in the 1.9 GHz band, and a PDA (information in the 2.45 GHz band). Wireless LAN by a portable terminal) or a PC, and noise waves such as a wireless LAN by a PC are also a problem in the 5 GHz band.
[0021]
The electromagnetic shielding panel used for the electromagnetic shielding window of the present invention has a conductive layer disposed between two transparent plates.
[0022]
Various glass plates such as soda-lime glass, aluminosilicate glass, borosilicate glass, polycarbonate plate, and acrylic plate can be used for the transparent plate-like body.
[0023]
As the conductive layer, a transparent conductive film formed on the surface of the transparent plate, a transparent resin film on which the transparent conductive film is formed, a metal net, or the like can be suitably used.
[0024]
As the transparent conductive film formed on the transparent plate, an Ag film, a laminated film in which an Ag film and a ZnO film are alternately laminated, an ITO film, or the like can be used. The Ag film, the ZnO film, and the ITO film are preferably formed on the transparent plate-like body by a sputtering method, a vacuum evaporation method, an ion plating method, or the like.
[0025]
The resin film on which the transparent conductive film is formed is a film of transparent resin film such as polyethylene terephthalate, polyester, etc. Ag film, laminated film in which Ag film and ZnO film are laminated alternately, ITO film etc., sputtering method, vacuum deposition Metal meshes that are preferably formed by the ion plating method or the like are metal wires such as stainless steel, copper, and monel, and are coated with an insulating coating such as a black dye oxide film for reflection prevention, silicon, and neoprene. Various metal nets can be used, such as those that have been made.
[0026]
For the transparent conductive film formed on the transparent plate, it is desirable for durability that the transparent conductive film is not formed in the range of 5 mm to 10 mm from the edge of the transparent plate. Such a transparent conductive film masks the vicinity of the edge of the transparent plate when forming the transparent conductive film on the transparent plate, or forms a transparent conductive film on the entire transparent plate. After that, the transparent conductive film near the edge can be obtained by polishing or etching.
[0027]
When using the resin film in which the transparent conductive film is formed, it is desirable to reduce the size of the resin film by 5 mm to 10 mm from the edge of the transparent plate. Or you may make the size of the resin film which formed the transparent conductive film the same size as a transparent plate-like body, and remove the transparent conductive film currently formed in the range of 5-10 mm from the edge of the resin film.
[0028]
The metal net is used by cutting the metal net so that the edge of the metal net is located 5 mm to 10 mm inside from the transparent plate edge.
[0029]
In the case of a transparent conductive film in which a conductive layer is formed on a transparent plate-like body, a laminated glass structure formed by bonding two transparent plate-like bodies using an intermediate film such as polyvinyl butyral or EVA, or a metal Or two transparent plates using a spacer made of resin or resin, and used in the construction of a double-glazed glass in which a sealed air layer is formed between the spacer and the two transparent plates. Is preferred.
[0030]
FIG. 1 (1) is an electromagnetic shielding panel in which a transparent plate-like body 1 on which a transparent conductive film 3 is formed is bonded to a transparent plate-like body 1 ′ with an intermediate film 2 to form a laminated glass. Reference numeral 1 (2) denotes an electromagnetic shielding panel in which a transparent conductive film 3 'is also formed on the transparent plate 1'. a is preferably 5 to 10 mm. If the value of a is 5 mm or more, sufficient durability can be obtained. The reason why the thickness is 10 mm or less is that it is difficult to dispose the conductive film 24 electrically connected to the conductor 25 facing the conductive layer 23 as shown in FIG. This is because the impedance indicating the state of electrical continuity increases, and as a result, it is difficult to obtain sufficient electromagnetic shielding performance.
[0031]
When the conductive layer is a metal net or a resin film on which a transparent conductive film is formed, in the case of a transparent conductive film in which the conductive layer is formed on the surface of the transparent plate-like body, Using two intermediate films such as polyvinyl butyral and EVA, a conductive layer is disposed between the two intermediate films, and a laminated glass is formed by adhering two transparent plates. It is preferable.
[0032]
3 (1) and 3 (2), the resin film 5 on which the transparent conductive film 4 is formed is used as a conductive layer, and a conductive layer is disposed between the intermediate films 2 and 2 'to form a laminated glass. Is the case. FIG. 3 (1) shows the case where the edge of the resin film 5 is located at the same position as the transparent plate-like body 1, 1 ′, and FIG. 3 (2) shows that the edge of the resin film 5 is the same as the transparent plate-like body. This is the case.
[0033]
The distance b between the edge of the transparent conductive film 3 formed on the conductive film and the edge of the transparent plate-like bodies 1, 1 ′ is preferably 5 to 10 mm as in FIG.
[0034]
FIG. 4 shows a structure in which a metal net is disposed between the intermediate films 2 and 2 ′, and the transparent plate-like bodies 1 and 1 ′ are made of laminated glass. The distance c from the edge of the object. Like distance a and distance b, it is preferable to set it as 5-10 mm.
[0035]
As shown in FIG. 5, when the electromagnetic shielding panel 11 in which the conductive layer 23 is disposed between the two transparent plate-like bodies 21, 21 ′ is fitted into the frame, the frame 20 and the electromagnetic shielding panel 11. In addition, a conductor 25 is provided between them, and a conductive film 24 is further provided around the electromagnetic shielding panel so that the conduction between the conductive layer 23 and the frame body 20 is in a preferable state.
[0036]
When the frame is not made of metal but made of wood or resin, it is preferable to form the conductive film 26 on the frame. Moreover, even if the frame is made of metal, if the surface of the frame is coated and the surface of the frame is insulative, the coating may be peeled off to make it conductive or the conductive film 26 may be formed.
[0037]
Since the edge clearance of the electromagnetic shielding panel is small, the conductive layer 23 and the conductor 25 may not be arranged so as to face each other in the direction perpendicular to the surface of the transparent plate 21 as shown in FIG. For this reason, the impedance between the conductive layer 23 and the conductor 25 increases, and sufficient electromagnetic shielding properties cannot be obtained. In order to solve this problem, a conductive film 24 is provided in the periphery of the electromagnetic shielding panel so as to have a width of 10 to 20 mm from the edge.
[0038]
For the conductive film 24, a conductive tape, a metal tape made of aluminum, stainless steel, or the like can be used.
[0039]
By providing the conductive film 24, the impedance between the conductive layer 23 and the conductor 25 is calculated by the equation (1) based on the capacitor model at a frequency of 2.45 GHz used in the LAN.
[0040]
Z (Ω) = d / (2πf · ε0 · εg · S) (1)
Here, Z is the impedance, f is the frequency (2.45 GHz), .epsilon.0 the dielectric constant of air in ^{- - (2 7 × 10)} (8.854 × 10 12 F / m), εg is the dielectric constant of the glass is there. Further, d is a distance (m), d = L1, and S is an area where the conductive layer 23 and the conductive film 24 overlap each other when viewed in a direction perpendicular to the surface of the transparent plate, and S = L2 × (transparent The width of the plate-like body 21).
[0041]
Further, using the values of impedance Z and air impedance 377, electromagnetic wave reflectance R and shielding performance S are obtained by the following equations (2) and (3).
[0042]
R = ((377−Z) / (377 + Z)) ² (2)
S = 10 log10 (1-R) (3)
Conductive layer and the conductive film are disposed to face each other with a transparent plate-shaped body, the electromagnetic shielding performance - 10dB~ - in order to have an effective electromagnetic shielding performance in the range of 30dB, the transparent plate-shaped object It is preferable that the impedance Z is 0.1 to 10Ω by adjusting the thickness d and the area S where the conductive layer and the conductive film face each other.
[0043]
Although the impedance Z is calculated | required by Formula (1), you may measure using an impedance measuring device.
[0044]
Furthermore, - 10dB~ - to get 30dB range of the electromagnetic shielding performance of the sheet resistance of the conductive layer is desirably 100 [Omega / □ or less.
[0045]
As the conductor, a metal wire or carbon fiber having a mesh structure, a spiral hollow structure, a metal net or a metal film in a pipe shape, or the like can be suitably used.
[0046]
【Example】
Hereinafter, the present invention will be described in detail with reference to the drawings.
[0047]
Example 1
Two transparent glass plates (size 1010 × 1010 mm) having a thickness of 10 mm were used for the transparent plate-like body, and a transparent conductive film 3 in which an Ag film and a ZnO film were alternately laminated was formed on one sheet by a sputtering method to form a conductive layer. . The sheet resistance of the transparent conductive film 3 was 10Ω / □. The transparent conductive film in a range of 10 mm from the edge of the plate glass was removed by polishing.
[0048]
As shown in FIG. 2, two sheets of glass are placed opposite to each other with a spacer 9 filled with a desiccant 10 with the conductive layer 3 positioned on the air layer 12 side, and the electromagnetic shielding is configured as a double-layer glass. Created a panel. Further, this electromagnetic shielding panel is formed by bonding an aluminum tape having a width of 20 mm to the periphery of the electromagnetic shielding panel so that the width of the transparent conductive film 3 and the aluminum tape 4 overlapping the transparent plate-like body in a vertical view is 10 mm. Was mounted on a sash 24 as shown in FIG. 5 to form an electromagnetic shielding window. The conductor 25 is made of a metal wire mesh into a pipe shape and brought into contact with the aluminum tape 24.
[0049]
The impedance Z (Ω) between the conductive layer 23 and the conductive film 26 applied to the conductor 25 and the frame 20 is calculated from the capacitor model with respect to the frequency 2.45 MHz used in the wireless LAN. A value of 1.05Ω was obtained.
[0050]
Relative Dance, from equation (3), the shielding performance - - This Inpi becomes a 20 dB, the result of measurement by the insertion loss method specified in MIL-STD-285 method (US military standards), with a glass surface The shielding performance was -23 dB. Further, a band of 30MHz～5GHz, was measured for electromagnetic shielding performance, - with a value of 23 dB -. 22 to.
[0051]
Moreover, when the outdoor exposure test (one year) and the durability test prescribed | regulated to JISR3209 were done with respect to the electromagnetic shielding window of a present Example, it confirmed that it had sufficient durability.
[0052]
Comparative Example 1
An electromagnetic shielding panel was produced in the same manner as in Example 1 except that the aluminum tape used in Example 1 was not used. Further, as shown in FIG. 6, this electromagnetic shielding panel was fitted into the frame body 20 to produce an electromagnetic shielding window.
[0053]
Moreover, when the outdoor exposure test (one year) and the durability test prescribed | regulated to JISR3209 were done with respect to the electromagnetic shielding window of this comparative example, it confirmed that it had sufficient durability.
[0054]
However, impedance is 18Omu, results of measurement by the insertion loss method specified shielding performance MIL-STD-285 method (US military standards), a band of 30MHz~5GHz, - 7~ - the value of 8 dB, The performance was almost unusable.
[0055]
【The invention's effect】
The electromagnetic shielding panel and electromagnetic shielding window of the present invention can provide a simple electromagnetic shielding opening.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of an essential part of an electromagnetic shielding panel in which a transparent plate-like body on which a transparent conductive film is formed is made of laminated glass using an intermediate film.
FIG. 2 is a cross-sectional view of an essential part of an electromagnetic shielding panel in which a transparent plate-like body on which a transparent conductive film is formed is arranged to face each other using a spacer to form a multilayer glass.
FIG. 3 is a cross-sectional view of a main part of an electromagnetic shielding panel using a resin film on which a transparent conductive film is formed.
FIG. 4 is a cross-sectional view of a main part of a transparent electromagnetic shielding panel using a metal net.
FIG. 5 is a cross-sectional view of a main part in a state in which an electromagnetic shielding panel having a multilayer glass configuration using a transparent plate-like body on which a transparent conductive film is formed is fitted to a frame.
6 is a cross-sectional view of the main part of an electromagnetic shielding window of Comparative Example 1. FIG.
FIG. 7 is a cross-sectional view of the main part of the electromagnetic shielding window when the conductive layer is provided more than 10 mm from the edge of the transparent plate-like body.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1, 1 'Transparent plate-like body 2, 2' Intermediate film 3, 3 'Transparent electrically conductive film 4, 4' Conductive film 5 Resin film 6 Metal net | network 7 Primary sealing material 8 Secondary sealing material 9 Spacer 10 Desiccant 20 Frame 21, 21 'transparent plate,
23 transparent conductive film 24 conductive film 25 conductor 26 conductive film 27 setting block 28 pressing edge 29 backup material 30 sealing material

Claims (4)

In an electromagnetic shielding window in which an electromagnetic shielding panel is formed by forming one or more conductive layers between two transparent plates, and the electromagnetic shielding panel is fitted in a frame, the area resistance of the conductive layer is 100Ω. / □ or less, and one or more conductive layers are formed between the two transparent plate-like bodies on the surface except between 5 mm to 10 mm from the edge of the transparent plate-like body, and 20 mm from the edge of the electromagnetic shielding panel. side conductive film is provided between the conductive layer and the conductive film are disposed to face each other with a transparent plate-shaped body, and with said conductive layer and the frame body is conductive with a conductive material, a conductive layer and The conductive film is provided such that the area S when the conductive film overlaps with the surface of the transparent plate in the direction perpendicular to the surface is adjusted so that the impedance Z between the conductive layer and the conductor is 0.1 to 10Ω. An electromagnetic shielding window. 3. The conductive layer is selected from a transparent conductive film formed on a transparent plate, a metal net, and a resin film coated with a transparent conductive film. The electromagnetic shielding window described in 1. The electromagnetic shielding window according to claim 1, wherein the two transparent plate-like bodies are bonded with one or more intermediate films. 2. The electromagnetic shielding window according to claim 1, wherein two transparent plate-like bodies are arranged to face each other via a spacer, and an air layer sealed by the plate-like body and the spacer is formed.