JP2004253675A - Electromagnetic wave shielding material and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electromagnetic wave shielding material which can avoid deterioration of its visibility, and to provide a method for manufacturing the material. <P>SOLUTION: The method comprises the steps of stacking the black color layer 34 of an ultraviolet curing type and a conductive layer 35 on one surface of a transparent glass 30, exposing and developing a pattern provided to a mask 36 on the black color layer 34 and the conductive layer 35 via the patterned mask 36, and also exposing on the black color layer 34 from the rear side of the transparent glass 30 to form an intermediate and subjecting the intermediate to heat treatment to make an electromagnetic wave shielding layer conductive. Since the black color layer 34 of chromatic color for absorbing light is provided between the transparent glass 30 and the conductive layer 35, the visibility of the glass 30 can be improved without causing the entire glass 30 to be clouded. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【００４３】
試験結果
実施例１，２，３の電磁波シールド体に関しては、非常に良好なシールド効果、透光性、視認性を確認した。
これに対し、比較例１の電磁波シールド体に関しては、黒色層と導電層をスクリーン印刷したが、これら黒色層と導電層の重ねあわせが非常に困難であり、結果として位置ずれを招き、十分な透光性や視認性を得ることができなかった。
【００４４】
比較例２の電磁波シールド体については、十分なシールド効果と透光性を得ることができたものの、導電層が銀色のために全体として曇り、十分な視認性を確認することができなかった。このため、実用可能な品質レベルに到達しなかった。
さらに、比較例３の電磁波シールド体については、実用上問題のないシールド効果と透光性を得ることができたが、導電層が銀色のために全体として曇り、十分な視認性を得られなかった。このため、実用可能な品質レベルに達しなかった。
【００４５】
【発明の効果】
以上のように本発明によれば、透明基板に感光性の視認性保持層を形成し、この視認性保持層に感光性の導電層を重ねて形成するので、視認性等を損なうことがないという効果がある。
【図面の簡単な説明】
【図１】本発明に係る電磁波シールド体の製造方法の実施形態における透明ガラスを示す模式説明図である。
【図２】本発明に係る電磁波シールド体の製造方法の実施形態における透明ガラスの全表面に黒色層を塗布して乾燥させ、この全黒色層上に導電層を塗布する状態を示す模式説明図である。
【図３】本発明に係る電磁波シールド体の製造方法の実施形態における導電層上にマスクをセットし、黒色層と導電層を紫外線により露光する状態を示す模式説明図である。
【図４】本発明に係る電磁波シールド体の製造方法の実施形態における黒色層及び導電層が所定のパターンに形成された中間体を示す模式説明図である。
【図５】本発明に係る電磁波シールド体及びその製造方法の実施形態における電磁波シールド層を完全に導電化した電磁波シールド体を示す模式説明図である。
【図６】プラズマディスプレイを示す全体斜視説明図である。
【図７】プラズマディスプレイの前面パネルを示す説明図である。
【符号の説明】
１ プラズマディスプレイパネル（ＰＤＰ）
２ パネル本体
３ 前面パネル
３０ 透明ガラス（透明基板）
３１ 電磁波シールド層
３４ 黒色層（視認性保持層）
３５ 導電層
３６ マスク
３７ 中間体
３８ 電磁波シールド体[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an electromagnetic wave shield that shields electromagnetic waves radiated from a display screen of a plasma display panel (hereinafter, referred to as a PDP) and a method of manufacturing the same.
[0002]
[Prior art]
There are various types of color televisions, and in recent years, color PDPs 1 as shown in FIG. 6 have attracted attention. The PDP 1 includes a panel main body 2 as a light emitting unit and a front panel 3 mounted on a front surface of the panel main body 2, and has a feature of being excellent in a viewing angle, a response speed, and low power consumption.
[0003]
As shown in FIG. 7, the front panel 3 has an electromagnetic wave shielding layer 31 and an anti-reflection treatment layer 32 sequentially laminated on the surface of a transparent glass 30, and a near-infrared absorbing layer 33 laminated on the rear surface of the transparent glass 30. ing. An electromagnetic wave shield layer 31 is formed on the surface of the transparent glass 30 to shield (shield) electromagnetic waves to prevent adverse effects on surrounding electric and electronic devices and the human body. When the electromagnetic wave shield layer 31 is formed, For example, a method of forming an ink containing a conductive metal powder on a surface of the transparent glass 30 by a screen printing method is employed (see Patent Documents 1 and 2).
[0004]
[Patent Document 1]
JP-A-62-57297
[0005]
[Patent Document 2]
JP-A-9-283977
[0006]
[Problems to be solved by the invention]
As described above, the conventional electromagnetic wave shield simply forms a pattern on the transparent glass 30 using the ink containing the metal powder by the screen printing method. However, in this case, the transparent glass 30 is entirely fogged with the formation of the pattern. Therefore, there is a problem that important visibility required for the transparent glass 30 is impaired.
[0007]
The present invention has been made in view of the above, and an object of the present invention is to provide an electromagnetic wave shielding body which does not impair visibility and a method of manufacturing the same.
[0008]
[Means for Solving the Problems]
In the present invention, in order to achieve the above object, an electromagnetic wave shielding layer is formed on a transparent substrate, and the electromagnetic wave shielding layer is provided with a visibility holding layer formed on the transparent substrate and a conductive layer formed on the visibility holding layer. And layers.
A photosensitive visibility holding layer and a conductive layer are superposed on one surface of a transparent substrate, and these are patterned and exposed to form an intermediate to form an intermediate, and the intermediate is heat-treated to make the electromagnetic wave shielding layer conductive. It is characterized by doing so.
In forming the intermediate, it is preferable to expose the visibility maintaining layer from the other surface side of the transparent substrate.
[0009]
Further, in the present invention, in order to achieve the above object, a method for manufacturing an electromagnetic wave shielding,
A step of superposing and forming a photosensitive visibility holding layer and a conductive layer on one surface of a transparent substrate, a step of patternwise exposing and developing these to form an intermediate, and a step of heat-treating the intermediate to form an electromagnetic wave shielding layer. And making it conductive.
In forming the intermediate, it is preferable to expose the visibility maintaining layer from the other side of the transparent substrate.
Further, it is preferable that the visibility maintaining layer is formed of a black ink containing a resin composition curable by ultraviolet rays, and the conductive layer is formed of a conductive ink containing metal particles in a resin composition curable by ultraviolet rays.
[0010]
Here, as the transparent substrate in the claims, for example, an acrylic substrate or the like is used as long as the problem of distortion does not occur, in addition to the tempered glass. In addition to the electromagnetic wave shielding layer, a non-reflection treatment layer and a near-infrared absorbing layer for preventing malfunction of electronic equipment can be appropriately formed on this transparent substrate. The visibility maintaining layer is mainly made of black ink forming a black layer, but is not particularly limited as long as it absorbs light rays and can secure visibility. This visibility maintaining layer may or may not have conductivity or insulation. The PDP includes a DC type, an AC type, and a hybrid type, but is not limited thereto. The electromagnetic wave shield according to the present invention is used as a part of a front panel of a PDP, but is not limited thereto. For example, it can be applied to other devices such as FED.
[0011]
According to the present invention, a conductive layer is not provided directly on a transparent substrate, but a visibility maintaining layer that absorbs light is interposed between the transparent substrate and the conductive layer, and a conductive layer is indirectly provided on the transparent substrate. Therefore, fogging of the transparent substrate can be suppressed. Therefore, the visibility of the transparent substrate can be improved.
Further, if the visibility holding layer is exposed from the other surface side of the transparent substrate, the visibility holding layer is improved in corrosion resistance and the like, and the electromagnetic wave shield can be stably used for a long time.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a preferred embodiment of the present invention will be described with reference to the drawings. As shown in FIGS. A step of sequentially laminating and forming a layer 34 and a light-transmitting conductive layer 35, exposing and developing the black layer 34 and the conductive layer 35 through a mask 36, and forming a black layer from the rear side of the transparent glass 30. The method includes a step of exposing the layer 34 to form an intermediate 37, a step of heat-treating the intermediate 37 to form a conductive pattern on the electromagnetic wave shielding layer 31, and the like.
[0013]
The transparent glass 30 is made of, for example, a flat, substantially rectangular glass plate which is reinforced and has excellent heat resistance and translucency. As the transparent glass 30, for example, flat soda lime glass, low alkali glass, non-alkali glass, quartz glass or the like is used. The thickness of the transparent glass 30 is not particularly limited, but is preferably thinner from the viewpoint of ensuring visibility and light transmission. Specifically, it is formed to a thickness of 0.05 to 5 mm, preferably 1.5 to 3.0 mm from the viewpoints of visibility, light transmission, and mechanical strength.
[0014]
The black layer 34 is made of a black ink containing at least a resin composition curable by ultraviolet light, and includes a sensitizer, a polymerization inhibitor, a leveling agent, a dispersant, an antifoaming agent, a thickener, a precipitation inhibitor, and the like. It is added as needed and is formed on the entire surface of the transparent glass 30. The black layer 34 is prepared, for example, by appropriately blending a UV-curable resin composition, a black pigment, a metal oxide-based colorant, a predetermined solvent, and the like.
The conductive layer 35 is made of, for example, a resin composition curable by ultraviolet rays, a conductive imparting filler, in other words, a conductive ink containing metal particles, a sensitizer, a polymerization inhibitor, a leveling agent, a dispersant, a defoaming agent. , A thickener, a suspending agent, and the like are added as necessary, and are formed over the entire surface of the black layer 34.
[0015]
The ultraviolet-curable resin composition used for the black layer 34 and the conductive layer 35 may be any one that can be developed with water, an alkaline aqueous solution, a solvent, and the like. Among these, a resin that can be developed with an alkaline aqueous solution from the viewpoint of resolution and workability. Compositions are preferred. Such a resin composition is achieved by comprising an alkali-soluble resin, a crosslinkable monomer or oligomer having an unsaturated double bond, and a photopolymerization initiator.
[0016]
As a specific example of the alkali-soluble resin, an acrylic copolymer having an acidic group such as carboxylic acid and an ethylenically unsaturated group is most suitable. Examples of the component of the acidic group include acrylic acid, methacrylic acid, 2-methacryloyloxyethyl succinate, 2-acryloyloxyethyl succinate, 2-methacryloyloxyethyl phthalate, 2-acryloyloxyethyl phthalate, and the like.
[0017]
As the ethylenically unsaturated component, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, n-propyl acrylate, n-propyl methacrylate, isopropyl acrylate, isopropyl methacrylate, n-butyl acrylate, n-butyl methacrylate, sec-butyl acrylate , Sec-butyl methacrylate, isobutyl acrylate, isobutyl methacrylate, tert-butyl acrylate, tert-butyl methacrylate, allyl acrylate, allyl methacrylate, benzyl acrylate, benzyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate and the like.
As the alkali-soluble resin, various copolymers of the above components and other monomers can be used as long as the alkali developability is not impaired.
[0018]
A crosslinkable monomer having an unsaturated double bond is a compound having at least one ethylenically unsaturated double bond, reacts with a radical generated from a photopolymerization initiator by light irradiation, and increases solubility in an alkali developing solution. Lower the pattern. Specifically, allyl acrylate, benzyl acrylate, butoxyethyl acrylate, butoxyethylene glycol acrylate, cyclohexyl acrylate, dicyclopentanyl acrylate, 2-ethylhexyl acrylate, glycerol acrylate, glycidyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl Acrylate, isobonyl acrylate, isooctyl acrylate, lauryl acrylate, 2-methoxy acrylate, methoxyethylene glycol acrylate, phenoxyethyl acrylate, stearyl acrylate, ethylene glycol diacrylate, diethylene glycol diacrylate, 1,4-butanediol diacrylate, 1, 5-pentanediol diacrylate 1,6-hexanediol diacrylate, 1,3-propanediol diacrylate, 1,4-cyclohexanediol diacrylate, 2,2-dimethylolpropane diacrylate, glycerol diacrylate, tripropylene glycol diacrylate, Glycerol triacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, ethylene oxide modified pentaerythritol tetraacrylate, propylene oxide modified pentaerythritol triacrylate, triethylene glycol diacrylate, polyoxypropyl trimethylolpropane triacrylate , Butylene glycol diacrylate, 1,2,4-butane Riol triacrylate, 2,2,4-trimethyl-1,3-pentanediol diacrylate, 1,10-decanediol dimethyl acrylate, pentaerythritol hexaacrylate and the above acrylate replaced with methacrylate, γ-methacryloxypropyl triacrylate Methoxysilane, 1-vinyl-2-pyrroline and the like can be mentioned. In addition, two or more kinds of the above-mentioned crosslinkable monomers may be combined.
[0019]
The photopolymerization initiator is not particularly limited as long as it can be used for a normal negative type photolithography. Specifically, benzophenone, methyl o-benzoylbenzoate, methyl 4-dimethylaminobenzoate, 4,4-bis (dimethylamine) benzophenone, 4,4-bis (diethylamine) benzophenone, α-aminoacetophenone, 4-dichlorobenzophenone, 4-benzoyl-4-methyldiphenyl ketone, dibenzyl ketone, 1-hydroxy-cyclohexyl-phenyl-ketone, fluoresone, 2,2-diethoxyacetophenone, 2,2-dimethoxy-1,2-diphenyl Ethane-1-one, 2-hydroxy-2-methyl-1 phenylpropan-1-one, pt-butyldichloroacetophenone, thioxanthone, 2-methylthioxanthone, 2-chlorothioxanthone, 2-isopropylthioxanthone, diethylthio Sandton, benzyl dimethyl ketal, benzyl-methoxyethyl acetal, benzoin, benzoin methyl ether, benzoin butyl ether, anthraquinone, 2-t-butylanthraquinone, 2-amylanthraquinone, β-chloroanthraquinone, anthrone, benzanthrone, dibenzosuberone, methylene Anthrone, 4-azitobenzalacetophenone, 2,6-bis (p-azidobenzylidene) cyclohexanone, 2,6-bis (p-azitobenzylidene) -4-methylcyclohexanone, 2-phenyl-1,2-butadione-2- (O-methoxycarbonyl) oxime, 1-phenyl-propanedione-2- (o-ethoxycarbonyl) oxime, 1-phenyl-3-ethoxy-propanetrione-2- (o-benzoy Oxime, Michler's ketone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, naphthalenesulfonyl chloride, quinoline sulfonyl chloride, N-phenylthioacdrine, 4,4-azobis Isobutyronitrile, diphenyl disulfide, benzothiazole sulfide, triphenylphosphine, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, camphorquinone, etc., but two or more kinds can be used in combination. is there.
[0020]
Examples of the metal particles include gold, silver, copper, nickel, palladium, and platinum having high conductivity. These may be used alone or in combination of two or more. Among these metal particles, silver particles are desirable from the viewpoint of availability, cost, conductivity, and oxidation resistance. The metal particles are desirably subjected to a surface treatment with various dispersants, so that secondary aggregation does not occur. As the dispersant, a dispersant having a property of decomposing or volatilizing in a heat treatment step is suitably used.
[0021]
The metal particles have an average particle size of 0.05 to 1 μm, preferably 0.07 to 0.8 μm, and a sphericity of 0.7 or more, preferably 0.8 or more, and are formed in a substantially spherical shape. You. This is because when the average particle size is less than 0.05 μm, it is necessary to increase the amount of addition to secure conductivity. Conversely, if it exceeds 1 μm, the light transmittance is adversely affected, and a fine pattern cannot be obtained. On the other hand, when the sphericity is less than 0.7, the light transmittance is deteriorated and it is difficult to form a fine pattern. In the measurement of the sphericity, the metal particles are dispersed in an appropriate dispersion medium, enlarged and observed with a microscope or the like, the major axis and minor axis of each particle are measured, and calculated by sphericity = minor axis / major axis. The average value of the items.
[0022]
The variation in the particle size of the metal particles is preferably 3σ or less of the average particle size. This is because if the particle size variation of the metal particles is too large, small metal particles enter between the large metal particles and it becomes difficult to obtain a good light transmittance.
[0023]
In the above, when manufacturing the electromagnetic wave shield body 38, first, a transparent glass 30 having a predetermined thickness is prepared (see FIG. 1), and a black layer 34 made of black ink is applied to the entire surface of the transparent glass 30. The conductive layer 35 is formed on the entire black layer 34 by coating and dried (see FIG. 2). In forming the conductive layer 35, for example, a screen printing method, a roll coater, a curtain coater, or the like can be used.
[0024]
After the black layer 34 and the conductive layer 35 are formed in a multilayer structure, a mask 36 having a predetermined pattern is disposed on the conductive layer 35, and the black layer 34 and the conductive layer 35 are partially exposed to light by an ultraviolet ray from an exposure apparatus. (See FIG. 3) to insolubilize with the developing solution, and develop the transparent glass 30 having a multilayer structure with a predetermined developing solution by a method such as spraying or dipping to form the black layer 34 and the conductive layer 35 into a predetermined pattern. The formed intermediate 37 is formed (see FIG. 4). In this developing operation, it is desirable to expose the black layer 34 from the back side of the transparent glass 30 to improve the corrosion resistance and the like.
[0025]
The exposure apparatus used for the above operation is not particularly limited, but is preferably of a type that performs a batch exposure by irradiating ultraviolet rays indicated by arrows in FIG. Further, the mask 36 may be opposed to the conductive layer 35 at an interval, but is preferably brought into close contact with the conductive layer 35 from the viewpoint of improving resolution. In the black layer 34 and the conductive layer 35, unnecessary regions that are not exposed during development are removed, and are patterned into a lattice, a stripe, a geometric pattern, or the like.
[0026]
Next, the intermediate body 37 is put into an oven or the like and heat-treated at a temperature of 200 to 600 ° C., and the heat treatment is maintained for a predetermined time and cooled to a predetermined temperature. Then, the intermediate body 37 is taken out of the oven, and then the intermediate body 37 is left for a predetermined time to make the electromagnetic wave shielding layer 31 completely conductive, whereby the electromagnetic wave shielding body 38 can be manufactured (see FIG. 5).
The line width of the pattern in the electromagnetic wave shielding layer 31 is preferably 2 to 40 μm. This is because if the line width is less than 2 μm, the electromagnetic wave shielding characteristics may be degraded and the pattern may be disconnected. Conversely, when the line width exceeds 40 μm, it is based on the reason that it is difficult to achieve both light transmission and shield characteristics.
[0027]
After the electromagnetic wave shielding body 38 is manufactured, the near-infrared absorbing layer 33 is adhered to the back surface of the transparent glass 30 with a transparent adhesive, and the antireflection treatment layer 32 is adhered to the electromagnetic wave shielding layer 31 with a transparent adhesive. Combine with a frame. Thus, the front panel 3 can be obtained.
Note that the antireflection treatment layer 32 can be omitted as appropriate if unnecessary.
[0028]
According to the above, the conductive layer 35 is not formed directly on the transparent glass 30, but the achromatic black layer 34 that absorbs light is interposed between the transparent glass 30 and the conductive layer 35. Is not cloudy as a whole. Therefore, the visibility required for the transparent glass 30 can be significantly improved. In addition, since the black layer 34 is exposed from the rear surface side of the transparent glass 30 to cure the boundary surface between the transparent glass 30 and the black layer 34, the corrosion resistance and the like are improved, and it can be used stably for a long time. Furthermore, since the black layer 34 and the conductive layer 35 are each made photosensitive and a normal photolithography method is used, it is possible to form a pattern with higher precision as compared with a screen printing method, a relief printing method, or the like. And cost reduction can be greatly expected.
[0029]
【Example】
Hereinafter, examples of the method for manufacturing an electromagnetic wave shield according to the present invention will be described together with comparative examples.
The electromagnetic wave shields of Examples 1, 2, and 3 and Comparative Examples 1, 2, and 3 were respectively manufactured, and the shielding effect, light transmission, and visibility of each electromagnetic wave shield were tested, and the results are summarized in Table 1. .
[0030]
Example 1
First, a transparent glass having a thickness of 2.5 mm is prepared, a black layer made of black ink is applied to the entire surface of the transparent glass, formed and dried, and a conductive layer made of conductive ink is stacked on the entire black layer. The coating was formed and dried. Soda-lime glass was used as the transparent glass. The black ink was prepared by preparing the resin components, black pigment, and methoxybutyl acetate as a solvent shown in Table 1. The compounding ratio of the black pigment in Table 1 is a weight compounding ratio with respect to the resin material. The thickness of the black layer after coating and drying was 1 μm.
[0031]
The conductive layer was manufactured by preparing the resin components, conductive fillers, and methoxybutyl acetate as a solvent described in Table 1. The mixing ratio of the conductivity-imparting filler in Table 1 is a weight mixing ratio with respect to the resin material. The thickness of the conductive layer after coating and drying was set to 10 μm.
[0032]
Each UV resin of the black layer and the conductive layer described in Table 1 is an alkali-soluble resin of a styrene-maleic anhydride copolymer system, polyethylene glycol dimethacrylate as a crosslinkable monomer, and bis (2,4) as a photopolymerization initiator. (6,6-Trimethylbenzoyl) -phenylphosphine oxide and 1-hydroxy-cyclohexyl-phenyl-ketone, each containing 5 parts by weight of a photopolymerization initiator based on 100 parts by weight of alkali-soluble resin and crosslinking monomer in total It is.
[0033]
Next, a mask is placed on the conductive layer composed of a silver layer, and the black layer and the conductive layer are partially exposed to light with an exposure device to make them insoluble in a developing solution. The transparent glass having a multi-layer structure was immersed in a developing solution consisting of: and developed to form an intermediate in which a black layer and a conductive layer were formed in a predetermined pattern.
The mask was a negative type in which a predetermined pattern was transparent. As the exposure apparatus, a parallel light exposure apparatus using a Fresnel lens equipped with a 3 kW metal halide lamp was used, and the exposure amount of ultraviolet light was 800 mJ / cm. ² Set to. The black layer and the conductive layer had a bias of 15 ° and were formed in a lattice-shaped pattern having the width and pitch shown in Table 1.
[0034]
Next, the intermediate was put into a programmable oven or the like, heated from room temperature at a heating rate of 10 ° C./min, heat-treated at 320 ° C. shown in Table 1, and maintained at this temperature for 60 minutes. Then, when the intermediate was cooled to 180 ° C. at a cooling rate of 10 ° C./min, the intermediate was taken out, and then the intermediate was allowed to cool to room temperature to produce an electromagnetic shield having an electromagnetic shield layer made conductive.
The pattern width of the electromagnetic wave shielding layer after the heat treatment was set to 15 μm, and the pattern pitch was set to 0.25 mm. Table 1 shows materials, configurations, pattern forming methods, and manufacturing conditions of this example.
[0035]
Example 2
The thickness of the black layer after coating and drying was set to 2 μm, the thickness of the conductive layer after coating and drying was set to 7 μm, and the pattern width of the electromagnetic wave shielding layer after heat treatment was set to 18 μm. The intermediate was heat-treated at 300 ° C. Table 1 shows materials, configurations, pattern forming methods, and manufacturing conditions of this example.
[0036]
Example 3
The same as in Example 1, except that the thickness of the black layer after coating and drying is 3 μm, the thickness of the conductive layer after coating and drying is 5 μm, and the pattern width of the electromagnetic wave shielding layer after heat treatment is 20 μm. The pattern pitch was set to 0.3 mm. The intermediate was heat-treated at 280 ° C. Table 1 shows materials, configurations, pattern forming methods, and manufacturing conditions of this example.
[0037]
Comparative Example 1
The basic manufacturing method is based on Example 1, but each resin component of the black layer and the conductive layer is not a UV resin but a thermoplastic resin, and a styrene-ethylene-butylene-styrene copolymer resin is used as the thermoplastic resin. Using. Also, instead of employing UV exposure, a black layer made of black ink is partially screen-printed and dried on the entire surface of the transparent glass, and a conductive layer made of conductive ink is partially formed on the entire black layer. Screen printed and dried. Table 1 shows materials, configurations, pattern forming methods, and manufacturing conditions of this comparative example.
[0038]
Comparative Example 2
The black ink was omitted, and the entire surface of the transparent glass was directly coated with a conductive layer made of a conductive ink containing a UV resin, dried, and then exposed to UV. Table 1 shows materials, configurations, pattern forming methods, manufacturing conditions, and evaluation results of this comparative example.
Comparative Example 3
The black ink was omitted, and a conductive layer made of a conductive ink containing a thermoplastic resin was screen-printed and dried on the entire surface of the transparent glass. The pattern width of the electromagnetic wave shielding layer was set to 50 μm, and the pattern pitch was set to 0.3 mm. Table 1 shows materials, configurations, pattern forming methods, and manufacturing conditions of this comparative example.
[0039]
Shield effect test
Each electromagnetic wave shielding body was cut into 20 × 20 cm in length and width, and the attenuation rate (dB) of the electromagnetic wave in the frequency range of 0.1 MHz to 1 GHz was measured by the Advantest method, and the shielding effect of each electromagnetic wave shielding body at the above frequency was evaluated. Table 1 shows the results of evaluating the attenuation rate (dB) of electromagnetic waves at a frequency of 200 MHz according to the following evaluation criteria as an index of the shielding effect.
〔Evaluation criteria〕
XX: 0 to 10 dB
×: 10 to 20 dB
Δ: 20 to 40 dB
○: 40 to 50 dB
◎: Over 50 dB
[0040]
Light transmission test
The spectral transmittance of visible light (wavelength: 400 to 700 nm) of each electromagnetic wave shield was measured, and the transmittance of each electromagnetic wave shield was evaluated according to the following evaluation criteria using the lowest value as an index.
〔Evaluation criteria〕
XX: 0-40%
×: 40 to 50%
Δ: 50 to 60%
○: 60 to 70%
◎: More than 70%
[0041]
Visibility test
The electromagnetic wave shielding layer of each electromagnetic wave shielding body was set inside, and the electromagnetic wave shielding layer was placed at the front of the display screen of the PDP with an interval of 5 mm, and the visibility of the display screen was evaluated according to the following evaluation criteria.
〔Evaluation criteria〕
×: unevenness or mesh was confirmed over the entire surface
Δ: Slight unevenness or mesh confirmed
: No unevenness or mesh was observed at all, and the contrast was sufficiently high to obtain a good image.
◎: No unevenness or mesh was confirmed at all, and the contrast was extremely high, and an extremely good image was obtained.
[0042]
[Table 1]

[0043]
Test results
With respect to the electromagnetic wave shielding bodies of Examples 1, 2, and 3, very good shielding effects, translucency, and visibility were confirmed.
On the other hand, with respect to the electromagnetic wave shielding body of Comparative Example 1, the black layer and the conductive layer were screen-printed. However, it was very difficult to superimpose the black layer and the conductive layer, resulting in misalignment, Light transmittance and visibility could not be obtained.
[0044]
With respect to the electromagnetic wave shield of Comparative Example 2, although a sufficient shielding effect and translucency could be obtained, the conductive layer was entirely cloudy due to the silver color, and sufficient visibility could not be confirmed. For this reason, it did not reach a practicable quality level.
Further, with respect to the electromagnetic wave shielding body of Comparative Example 3, a shielding effect and a light-transmitting property without practical problems could be obtained, but the conductive layer was entirely clouded due to the silver color, and sufficient visibility could not be obtained. Was. For this reason, it did not reach a practicable quality level.
[0045]
【The invention's effect】
As described above, according to the present invention, a photosensitive visibility holding layer is formed on a transparent substrate, and a photosensitive conductive layer is formed over the visibility holding layer, so that visibility and the like are not impaired. This has the effect.
[Brief description of the drawings]
FIG. 1 is a schematic explanatory view showing a transparent glass in an embodiment of a method for manufacturing an electromagnetic wave shield according to the present invention.
FIG. 2 is a schematic explanatory view showing a state in which a black layer is applied to the entire surface of a transparent glass and dried, and a conductive layer is applied on the entire black layer in the embodiment of the method for manufacturing an electromagnetic wave shield according to the present invention. It is.
FIG. 3 is a schematic explanatory view showing a state in which a mask is set on the conductive layer and the black layer and the conductive layer are exposed to ultraviolet rays in the embodiment of the method for manufacturing an electromagnetic wave shield according to the present invention.
FIG. 4 is a schematic explanatory view showing an intermediate in which a black layer and a conductive layer are formed in a predetermined pattern in the embodiment of the method for manufacturing an electromagnetic wave shield according to the present invention.
FIG. 5 is a schematic explanatory view showing an electromagnetic wave shield in which an electromagnetic wave shield layer is completely made conductive in an embodiment of the electromagnetic wave shield according to the present invention and a method of manufacturing the same.
FIG. 6 is an overall perspective explanatory view showing a plasma display.
FIG. 7 is an explanatory diagram showing a front panel of the plasma display.
[Explanation of symbols]
1 Plasma display panel (PDP)
2 Panel body
3 Front panel
30 Transparent glass (transparent substrate)
31 Electromagnetic wave shield layer
34 black layer (visibility maintaining layer)
35 conductive layer
36 Mask
37 intermediate
38 Electromagnetic wave shield

Claims (5)

Forming an electromagnetic wave shielding layer on a transparent substrate, the electromagnetic wave shielding layer, a visibility holding layer formed on the transparent substrate, an electromagnetic wave shielding body comprising a conductive layer formed on the visibility holding layer,
A photosensitive visibility holding layer and a conductive layer are superposed on one surface of a transparent substrate, and these are patterned and exposed to form an intermediate to form an intermediate, and the intermediate is heat-treated to make the electromagnetic wave shielding layer conductive. An electromagnetic shielding body characterized in that: The electromagnetic wave shield according to claim 1, wherein the visibility holding layer is exposed from the other surface side of the transparent substrate when the intermediate is formed. A method of manufacturing an electromagnetic wave shielding body for shielding electromagnetic waves,
A step of superposing and forming a photosensitive visibility holding layer and a conductive layer on one surface of a transparent substrate, a step of patternwise exposing and developing these to form an intermediate, and a step of heat-treating the intermediate to form an electromagnetic wave shielding layer. A method for producing an electromagnetic wave shielding body, comprising: 4. The method for manufacturing an electromagnetic wave shield according to claim 3, wherein the visibility maintaining layer is exposed from the other surface side of the transparent substrate when forming the intermediate. 4. The visibility maintaining layer is formed by a black ink containing a resin composition curable by ultraviolet rays, and the conductive layer is formed by a conductive ink containing metal particles in a resin composition curable by ultraviolet rays. 5. The method for manufacturing an electromagnetic wave shield according to item 4.

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