JP2011014723A - Electromagnetic wave shield - Google Patents
Electromagnetic wave shield Download PDFInfo
- Publication number
- JP2011014723A JP2011014723A JP2009157719A JP2009157719A JP2011014723A JP 2011014723 A JP2011014723 A JP 2011014723A JP 2009157719 A JP2009157719 A JP 2009157719A JP 2009157719 A JP2009157719 A JP 2009157719A JP 2011014723 A JP2011014723 A JP 2011014723A
- Authority
- JP
- Japan
- Prior art keywords
- dielectric constant
- electromagnetic wave
- periodic structure
- wave shielding
- high dielectric
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 230000000737 periodic effect Effects 0.000 claims abstract description 60
- 230000005540 biological transmission Effects 0.000 claims abstract description 22
- AOWKSNWVBZGMTJ-UHFFFAOYSA-N calcium titanate Chemical compound [Ca+2].[O-][Ti]([O-])=O AOWKSNWVBZGMTJ-UHFFFAOYSA-N 0.000 claims description 8
- 229920003023 plastic Polymers 0.000 claims description 5
- 239000004033 plastic Substances 0.000 claims description 5
- 229910002113 barium titanate Inorganic materials 0.000 claims description 4
- JRPBQTZRNDNNOP-UHFFFAOYSA-N barium titanate Chemical compound [Ba+2].[Ba+2].[O-][Ti]([O-])([O-])[O-] JRPBQTZRNDNNOP-UHFFFAOYSA-N 0.000 claims description 4
- 239000005022 packaging material Substances 0.000 claims description 2
- 229910052751 metal Inorganic materials 0.000 abstract description 9
- 239000002184 metal Substances 0.000 abstract description 9
- 238000004519 manufacturing process Methods 0.000 abstract description 8
- 238000000411 transmission spectrum Methods 0.000 description 26
- 239000000463 material Substances 0.000 description 25
- 239000004038 photonic crystal Substances 0.000 description 24
- 229920005989 resin Polymers 0.000 description 23
- 239000011347 resin Substances 0.000 description 23
- -1 polyethylene terephthalate Polymers 0.000 description 12
- 238000010438 heat treatment Methods 0.000 description 11
- 238000000034 method Methods 0.000 description 11
- 239000003153 chemical reaction reagent Substances 0.000 description 10
- 230000000694 effects Effects 0.000 description 10
- 239000000126 substance Substances 0.000 description 10
- 238000005259 measurement Methods 0.000 description 9
- 238000004088 simulation Methods 0.000 description 8
- 239000005020 polyethylene terephthalate Substances 0.000 description 7
- 229920000139 polyethylene terephthalate Polymers 0.000 description 7
- 239000000843 powder Substances 0.000 description 7
- 229920003319 Araldite® Polymers 0.000 description 6
- VVQNEPGJFQJSBK-UHFFFAOYSA-N Methyl methacrylate Chemical compound COC(=O)C(C)=C VVQNEPGJFQJSBK-UHFFFAOYSA-N 0.000 description 6
- 241000209094 Oryza Species 0.000 description 6
- 235000007164 Oryza sativa Nutrition 0.000 description 6
- 239000004020 conductor Substances 0.000 description 6
- 238000012545 processing Methods 0.000 description 6
- 235000009566 rice Nutrition 0.000 description 6
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 6
- 229910001868 water Inorganic materials 0.000 description 6
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 5
- 229920006332 epoxy adhesive Polymers 0.000 description 5
- 238000000465 moulding Methods 0.000 description 5
- 230000003287 optical effect Effects 0.000 description 5
- 238000005245 sintering Methods 0.000 description 5
- PPBRXRYQALVLMV-UHFFFAOYSA-N Styrene Chemical compound C=CC1=CC=CC=C1 PPBRXRYQALVLMV-UHFFFAOYSA-N 0.000 description 4
- 239000008188 pellet Substances 0.000 description 4
- 239000002994 raw material Substances 0.000 description 4
- 239000000758 substrate Substances 0.000 description 4
- 239000004925 Acrylic resin Substances 0.000 description 3
- 229920000178 Acrylic resin Polymers 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 239000013078 crystal Substances 0.000 description 3
- 238000002847 impedance measurement Methods 0.000 description 3
- 239000010410 layer Substances 0.000 description 3
- 239000011159 matrix material Substances 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 239000000178 monomer Substances 0.000 description 3
- 230000008569 process Effects 0.000 description 3
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 description 3
- OZAIFHULBGXAKX-UHFFFAOYSA-N 2-(2-cyanopropan-2-yldiazenyl)-2-methylpropanenitrile Chemical compound N#CC(C)(C)N=NC(C)(C)C#N OZAIFHULBGXAKX-UHFFFAOYSA-N 0.000 description 2
- NLHHRLWOUZZQLW-UHFFFAOYSA-N Acrylonitrile Chemical compound C=CC#N NLHHRLWOUZZQLW-UHFFFAOYSA-N 0.000 description 2
- PAYRUJLWNCNPSJ-UHFFFAOYSA-N Aniline Chemical compound NC1=CC=CC=C1 PAYRUJLWNCNPSJ-UHFFFAOYSA-N 0.000 description 2
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 description 2
- BAPJBEWLBFYGME-UHFFFAOYSA-N Methyl acrylate Chemical compound COC(=O)C=C BAPJBEWLBFYGME-UHFFFAOYSA-N 0.000 description 2
- 239000004698 Polyethylene Substances 0.000 description 2
- 239000004743 Polypropylene Substances 0.000 description 2
- 230000000903 blocking effect Effects 0.000 description 2
- 239000006229 carbon black Substances 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 229920001971 elastomer Polymers 0.000 description 2
- 230000005672 electromagnetic field Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 230000001747 exhibiting effect Effects 0.000 description 2
- 238000000691 measurement method Methods 0.000 description 2
- 229920000609 methyl cellulose Polymers 0.000 description 2
- 239000001923 methylcellulose Substances 0.000 description 2
- 239000011022 opal Substances 0.000 description 2
- 239000000123 paper Substances 0.000 description 2
- 229920000573 polyethylene Polymers 0.000 description 2
- 229920001155 polypropylene Polymers 0.000 description 2
- BWHMMNNQKKPAPP-UHFFFAOYSA-L potassium carbonate Chemical compound [K+].[K+].[O-]C([O-])=O BWHMMNNQKKPAPP-UHFFFAOYSA-L 0.000 description 2
- LJCNRYVRMXRIQR-OLXYHTOASA-L potassium sodium L-tartrate Chemical compound [Na+].[K+].[O-]C(=O)[C@H](O)[C@@H](O)C([O-])=O LJCNRYVRMXRIQR-OLXYHTOASA-L 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- 239000002002 slurry Substances 0.000 description 2
- 235000011006 sodium potassium tartrate Nutrition 0.000 description 2
- 238000002834 transmittance Methods 0.000 description 2
- 229910000859 α-Fe Inorganic materials 0.000 description 2
- OEPOKWHJYJXUGD-UHFFFAOYSA-N 2-(3-phenylmethoxyphenyl)-1,3-thiazole-4-carbaldehyde Chemical compound O=CC1=CSC(C=2C=C(OCC=3C=CC=CC=3)C=CC=2)=N1 OEPOKWHJYJXUGD-UHFFFAOYSA-N 0.000 description 1
- 229920001342 Bakelite® Polymers 0.000 description 1
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 1
- 239000004278 EU approved seasoning Substances 0.000 description 1
- 239000004593 Epoxy Substances 0.000 description 1
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 1
- 239000005977 Ethylene Substances 0.000 description 1
- 240000008415 Lactuca sativa Species 0.000 description 1
- 229920000877 Melamine resin Polymers 0.000 description 1
- 239000004640 Melamine resin Substances 0.000 description 1
- 229920002319 Poly(methyl acrylate) Polymers 0.000 description 1
- 229930182556 Polyacetal Natural products 0.000 description 1
- 239000004721 Polyphenylene oxide Substances 0.000 description 1
- 239000004793 Polystyrene Substances 0.000 description 1
- 239000004372 Polyvinyl alcohol Substances 0.000 description 1
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- XTXRWKRVRITETP-UHFFFAOYSA-N Vinyl acetate Chemical compound CC(=O)OC=C XTXRWKRVRITETP-UHFFFAOYSA-N 0.000 description 1
- BZHJMEDXRYGGRV-UHFFFAOYSA-N Vinyl chloride Chemical compound ClC=C BZHJMEDXRYGGRV-UHFFFAOYSA-N 0.000 description 1
- 239000006096 absorbing agent Substances 0.000 description 1
- NIXOWILDQLNWCW-UHFFFAOYSA-N acrylic acid group Chemical group C(C=C)(=O)O NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 description 1
- 229920000122 acrylonitrile butadiene styrene Polymers 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 229920000180 alkyd Polymers 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 125000004103 aminoalkyl group Chemical group 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 239000004637 bakelite Substances 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 229920005549 butyl rubber Polymers 0.000 description 1
- 229910000019 calcium carbonate Inorganic materials 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 239000005018 casein Substances 0.000 description 1
- BECPQYXYKAMYBN-UHFFFAOYSA-N casein, tech. Chemical compound NCCCCC(C(O)=O)N=C(O)C(CC(O)=O)N=C(O)C(CCC(O)=N)N=C(O)C(CC(C)C)N=C(O)C(CCC(O)=O)N=C(O)C(CC(O)=O)N=C(O)C(CCC(O)=O)N=C(O)C(C(C)O)N=C(O)C(CCC(O)=N)N=C(O)C(CCC(O)=N)N=C(O)C(CCC(O)=N)N=C(O)C(CCC(O)=O)N=C(O)C(CCC(O)=O)N=C(O)C(COP(O)(O)=O)N=C(O)C(CCC(O)=N)N=C(O)C(N)CC1=CC=CC=C1 BECPQYXYKAMYBN-UHFFFAOYSA-N 0.000 description 1
- 235000021240 caseins Nutrition 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 229910010293 ceramic material Inorganic materials 0.000 description 1
- 239000000460 chlorine Substances 0.000 description 1
- 229910052801 chlorine Inorganic materials 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 235000011850 desserts Nutrition 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 239000010432 diamond Substances 0.000 description 1
- 229910003460 diamond Inorganic materials 0.000 description 1
- 239000003989 dielectric material Substances 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 229910052571 earthenware Inorganic materials 0.000 description 1
- 235000013399 edible fruits Nutrition 0.000 description 1
- 239000003822 epoxy resin Substances 0.000 description 1
- 125000000816 ethylene group Chemical group [H]C([H])([*:1])C([H])([H])[*:2] 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- 235000013305 food Nutrition 0.000 description 1
- 235000011194 food seasoning agent Nutrition 0.000 description 1
- DYDNPESBYVVLBO-UHFFFAOYSA-N formanilide Chemical compound O=CNC1=CC=CC=C1 DYDNPESBYVVLBO-UHFFFAOYSA-N 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 230000020169 heat generation Effects 0.000 description 1
- 239000004615 ingredient Substances 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 239000000113 methacrylic resin Substances 0.000 description 1
- 239000011259 mixed solution Substances 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 239000011087 paperboard Substances 0.000 description 1
- 238000000059 patterning Methods 0.000 description 1
- 238000005453 pelletization Methods 0.000 description 1
- 229910000889 permalloy Inorganic materials 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 239000005011 phenolic resin Substances 0.000 description 1
- 235000021110 pickles Nutrition 0.000 description 1
- 229920003229 poly(methyl methacrylate) Polymers 0.000 description 1
- 229920006122 polyamide resin Polymers 0.000 description 1
- 229920001748 polybutylene Polymers 0.000 description 1
- 239000004417 polycarbonate Substances 0.000 description 1
- 229920000515 polycarbonate Polymers 0.000 description 1
- 229920000647 polyepoxide Polymers 0.000 description 1
- 229920001225 polyester resin Polymers 0.000 description 1
- 239000004645 polyester resin Substances 0.000 description 1
- 229920000570 polyether Polymers 0.000 description 1
- 229920013716 polyethylene resin Polymers 0.000 description 1
- 239000004926 polymethyl methacrylate Substances 0.000 description 1
- 229920006324 polyoxymethylene Polymers 0.000 description 1
- 229920002223 polystyrene Polymers 0.000 description 1
- 239000004814 polyurethane Substances 0.000 description 1
- 229920002635 polyurethane Polymers 0.000 description 1
- 229920002451 polyvinyl alcohol Polymers 0.000 description 1
- 229910000027 potassium carbonate Inorganic materials 0.000 description 1
- 229940074439 potassium sodium tartrate Drugs 0.000 description 1
- 238000004080 punching Methods 0.000 description 1
- 235000012045 salad Nutrition 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000002356 single layer Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 239000004408 titanium dioxide Substances 0.000 description 1
- 229920006337 unsaturated polyester resin Polymers 0.000 description 1
- 235000013311 vegetables Nutrition 0.000 description 1
Landscapes
- Shielding Devices Or Components To Electric Or Magnetic Fields (AREA)
- Aerials With Secondary Devices (AREA)
Abstract
Description
本発明は、２次元フォトニック結晶構造による電磁波遮蔽体に関するものである。とりわけ電子レンジの電磁波（２．４５ＧＨｚ）を対象とした遮蔽体およびその製造方法、並びにその用途に関する。 The present invention relates to an electromagnetic wave shielding body having a two-dimensional photonic crystal structure. In particular, the present invention relates to a shield for electromagnetic waves (2.45 GHz) in a microwave oven, a method for manufacturing the same, and uses thereof.
従来から、電波吸収体や電磁波遮蔽体の原理としては、１．導電性物質で電磁波を反射させる、２．金属をアンテナとして作用させ電流に変換しアースに流す、３．導電性物質内部の電流に変換して抵抗で消費する、４．複素比透磁率の大きい材料で磁場を熱に変換させる、５．複素比誘電率の大きい材料を振動させ熱に変換する、等が知られており、具体的には、１．〜３．としては金属やカーボンブラックなどが、４．としてはフェライトやパーマロイなどが、５．としては水、アルミナや酸化チタンなどが用いられている。また、電磁波遮蔽効果を向上させるために、前記複数の原理を組み合わせたものが数多く提案されている。 Conventionally, the principle of a radio wave absorber or electromagnetic wave shield is as follows: 1. Reflect electromagnetic waves with a conductive material. 2. Metal acts as an antenna, converts it into current and flows it to ground. 3. It is converted into current inside the conductive material and consumed by resistance. 4. A magnetic field is converted into heat with a material having a large complex relative permeability. It is known that a material having a high complex dielectric constant is vibrated and converted into heat. ~ 3. As metal, carbon black, etc. As ferrite, permalloy, etc. For example, water, alumina, titanium oxide, or the like is used. In order to improve the electromagnetic wave shielding effect, many combinations of the plurality of principles have been proposed.
従来技術では，電磁波シールドとして周波数帯域を広範囲に遮蔽するための提案（特許文献１〜２）がある一方、通信の用途ではあるが特定波長を遮断させる（または通過する）ための提案（特許文献３）もなされている。また、透光性を確保するために透明導電体を塗布すること（特許文献４、５）や、不透明導電体をパターン化すること（特許文献６）も行われている。 In the prior art, there is a proposal (Patent Documents 1 and 2) for shielding a frequency band over a wide range as an electromagnetic wave shield, while a proposal for blocking (or passing) a specific wavelength is used for communication (Patent Document). 3) has also been made. Moreover, in order to ensure translucency, applying a transparent conductor (patent documents 4 and 5) and patterning an opaque conductor (patent document 6) are also performed.
一方、フォトニック結晶によって特定の波長の電磁波を閉じ込めたり遮断したりすることが知られている。フォトニック結晶とは、比誘電率（光領域においては屈折率）を周期的に変化させた周期構造体である。これらは電磁波に対する干渉作用を示し、特定の周波数領域の電磁波の通過を禁止する。すなわち、フォトニック結晶は特定の波長の電磁波や光を遮蔽することができる。この場合の禁止帯はフォトニックバンドギャップと呼ばれる。フォトニック結晶の嚆矢はヤブロノバイト（特許文献７および８）であり、その他ウッドパイル構造（特許文献９）、網目構造、ダイヤモンド構造（特許文献１０）、オパール構造及び逆オパール構造などが知られている。これらは何れも三次元周期を有する構造体であり、立体的な周期的構造が結晶にたとえられ、フォトニック結晶と呼ばれている。 On the other hand, it is known that an electromagnetic wave having a specific wavelength is confined or blocked by a photonic crystal. A photonic crystal is a periodic structure in which the relative dielectric constant (refractive index in the optical region) is periodically changed. These exhibit interference with electromagnetic waves and prohibit the passage of electromagnetic waves in a specific frequency range. That is, the photonic crystal can shield electromagnetic waves and light having a specific wavelength. The forbidden band in this case is called a photonic band gap. The arrowhead of the photonic crystal is Yablonovite (Patent Documents 7 and 8), and other woodpile structures (Patent Document 9), network structures, diamond structures (Patent Document 10), opal structures and inverse opal structures are known. . Each of these is a structure having a three-dimensional period, and a three-dimensional periodic structure is compared to a crystal and is called a photonic crystal.
しかしながら精緻な三次元周期構造体の製作は容易ではない。そこで、二次元周期構造を持つフォトニック結晶が注目されており、なかでもその作成の容易さからスラブ型二次元フォトニック結晶がよく利用されている。その代表例としては光導波路（特許文献１１）である。スラブ型二次元フォトニック結晶では、比誘電率あるいは屈折率の高い物質で板（スラブ）を作成し、所定の周期で開孔し、比誘電率あるいは屈折率の低い物質を空気としたものが一般的である。これら二次元フォトニック結晶は実際には厚みを有する立体物であるが、該厚み方向に比誘電率の周期的な変化は設けていない。比誘電率の周期的な変化は二次元面のみに設けているために、二次元フォトニック結晶と呼ばれている。 However, it is not easy to manufacture a precise three-dimensional periodic structure. Therefore, photonic crystals having a two-dimensional periodic structure are attracting attention, and among them, slab type two-dimensional photonic crystals are often used because of their ease of preparation. A typical example is an optical waveguide (Patent Document 11). In a slab type two-dimensional photonic crystal, a plate (slab) is made of a material having a high relative dielectric constant or refractive index, and a hole is formed at a predetermined cycle, and a material having a low relative dielectric constant or refractive index is air. It is common. These two-dimensional photonic crystals are actually three-dimensional objects having a thickness, but no periodic change in relative permittivity is provided in the thickness direction. Since the periodic change in the relative permittivity is provided only on the two-dimensional surface, it is called a two-dimensional photonic crystal.
これまで、これら公知のフォトニック結晶はマイクロ波領域より波長の短いミリ波や光を対象に研究されてきた。それは可視光領域で用いるフォトニック結晶の構造周期は波長の半分程度でも数百ｎｍ程度であり、光リソグラフィ法や光造形法、さらにはプレス加工技術を応用したナノインプリントなどの加工技術の発達によって微細構造を容易に作成することが可能になってきたためである。対象となる電磁波がマイクロ波領域では、その波長が１２ｃｍ程度となるために、比誘電率が１００以下の物質を使用する限り、フォトニック結晶の構造周期が波長の４分の１でも約３ｃｍ程度になり、周期構造物はどうしても
巨大化するという欠点を有していた。
Until now, these known photonic crystals have been studied for millimeter waves and light having wavelengths shorter than those in the microwave region. The photonic crystal used in the visible light region has a structural period of about several hundreds of nanometers even at half the wavelength, and is fine due to the development of processing techniques such as photolithographic methods, stereolithography, and nanoimprinting using press processing technology. This is because the structure can be easily created. Since the target electromagnetic wave has a wavelength of about 12 cm in the microwave region, as long as a material having a relative dielectric constant of 100 or less is used, even if the structural period of the photonic crystal is a quarter of the wavelength, it is about 3 cm. Therefore, the periodic structure has a drawback of enlarging.
本発明では、電子レンジの中で、加熱の為のマイクロ波を遮蔽し、被加熱材料の特定の位置が加熱されないようにすることができる電磁波遮蔽体の提供を試みた。
しかしながら、上記従来の電磁波遮蔽体を用いようとした場合にはさまざまな問題が生じる。
まず、金属やカーボンブラック等の導電性材料を使用する場合は、電子レンジの中で金属部分との間で放電が生じ大変危険である。また、フェライト等の磁性損失材料や水等の誘電損失材料を使用する場合は、被加熱材料自体の発熱は抑えられるものの、損失材料自体が発熱するために本用途には不向きである。
また、公知のフォトニック結晶を使用する場合には、周期構造物を大きくする必要があったため、局所的な電磁波の遮断には不向きである。
In the present invention, an attempt was made to provide an electromagnetic wave shielding body capable of shielding microwaves for heating in a microwave oven so that a specific position of a material to be heated is not heated.
However, various problems arise when trying to use the conventional electromagnetic shielding body.
First, when a conductive material such as metal or carbon black is used, a discharge occurs between the metal portion in the microwave oven, which is very dangerous. In addition, when a magnetic loss material such as ferrite or a dielectric loss material such as water is used, although the heat generation of the heated material itself can be suppressed, the loss material itself generates heat and is not suitable for this application.
In addition, when a known photonic crystal is used, it is necessary to enlarge the periodic structure, so that it is not suitable for blocking local electromagnetic waves.
本発明は、特に電子レンジの中で、加熱の為のマイクロ波を遮蔽し、被加熱材料の特定の位置のみが加熱されないようにすることが可能な電磁波遮蔽体の提供を目的とするものであり、より具体的には、お弁当などを電子レンジで加熱する際、故意に温めたくない食材、例えばサラダ、生野菜、果物、デザート、漬け物、調味料等は加熱されないよう局所的に電磁波を遮断することができる電磁波遮蔽体の提供を目的とするものである。 An object of the present invention is to provide an electromagnetic wave shield capable of shielding a microwave for heating, particularly in a microwave oven, so that only a specific position of a material to be heated is not heated. Yes, more specifically, when heating a lunch box with a microwave oven, ingredients that you do not want to warm intentionally, such as salads, raw vegetables, fruits, desserts, pickles, seasonings, etc., are not locally heated. An object of the present invention is to provide an electromagnetic wave shielding body that can be blocked.
本発明者らは、電子レンジの中で、加熱の為のマイクロ波を遮蔽し、被加熱材料の特定の位置が加熱されないようにすることが可能な電磁波遮蔽体について鋭意検討した結果、比誘電率が１００を越える材料を用いて、製作が容易な二次元周期構造を形成することによって、電子レンジのマイクロ波（２．４５ＧＨｚ）を局所的に遮蔽することが可能であることを見出し、本発明を完成させるに至った。
すなわち本発明は、以下に示される二次元フォトニック結晶を有する電磁波遮蔽体、およびその製造方法を提供することにある。
As a result of intensive studies on an electromagnetic wave shielding body capable of shielding a microwave for heating in a microwave oven so that a specific position of a material to be heated is not heated, a specific dielectric It was found that microwaves (2.45 GHz) in a microwave oven can be locally shielded by forming a two-dimensional periodic structure that is easy to manufacture using a material with a rate exceeding 100. The invention has been completed.
That is, this invention is providing the electromagnetic wave shielding body which has the two-dimensional photonic crystal shown below, and its manufacturing method.
（１）比誘電率εＡが１００〜１００００である高誘電率部位Ａと、比誘電率εＢが１〜２０である低誘電率部位Ｂが二次元面内に０．５ｍｍ〜２５．０ｍｍの範囲の周期性をもって分布する二次元周期構造部Ｄを有する電磁波遮蔽体であって、該二次元面を１．４ＧＨｚ〜３．４ＧＨｚの電磁波が通過するとき、該周波数領域内の特定周波数に１０ｄＢ以上の透過減衰を示すことを特徴とする電磁波遮蔽体。
（２）前記高誘電率部位Ａがチタン酸カルシウムおよびチタン酸バリウムの少なくとも
一方を含有する上記（１）に記載の電磁波遮蔽体。
（３）前記低誘電率部位Ｂが空気またはプラスチックである上記（１）または（２）に記載の電磁波遮蔽体。
(1) A high dielectric constant portion A having a relative dielectric constant ε A of 100 to 10,000 and a low dielectric constant portion B having a relative dielectric constant ε B of 1 to 20 are 0.5 mm to 25.0 mm in a two-dimensional plane. An electromagnetic wave shielding body having a two-dimensional periodic structure portion D distributed with periodicity in a range of when a 1.4 GHz to 3.4 GHz electromagnetic wave passes through the two-dimensional surface, a specific frequency within the frequency region is obtained. An electromagnetic wave shield characterized by exhibiting transmission attenuation of 10 dB or more.
(2) The electromagnetic wave shielding body according to (1), wherein the high dielectric constant portion A contains at least one of calcium titanate and barium titanate.
(3) The electromagnetic wave shielding body according to (1) or (2), wherein the low dielectric constant portion B is air or plastic.
（４）２．４５ＧＨｚの電磁波における透過減衰が２０ｄＢ以上である上記（１）〜（３）のいずれかに記載の電磁波遮蔽体。
（５）二次元周期構造部Ｄが担持体Ｃ上に高誘電率部位Ａおよび低誘電率部位Ｂを交互に二次元配列した構造である上記（１）〜（４）のいずれかに記載の電磁波遮蔽体。
（６）二次元周期構造部Ｄが低誘電率部位Ｂの中に高誘電率部位Ａを二次元配列した構造である上記（１）〜（４）のいずれかに記載の電磁波遮蔽体。
（７）二次元周期構造部Ｄが高誘電率部位Ａの中に低誘電率部位Ｂとして開口部を二次元配列した構造である上記（１）〜（４）に記載の電磁波遮蔽体。
（８）上記（１）〜（７）に記載の電磁波遮蔽体を使用して製造した包装材料。
（９）上記（１）〜（７）に記載の電磁波遮蔽体を使用して製造した電波遮蔽体。
（１０）上記（１）〜（７）に記載の電磁波遮蔽体を使用して製造した帯域フィルター。
(4) The electromagnetic wave shielding body according to any one of (1) to (3), wherein a transmission attenuation in an electromagnetic wave of 2.45 GHz is 20 dB or more.
(5) The two-dimensional periodic structure portion D according to any one of (1) to (4), wherein the two-dimensional periodic structure portion D has a structure in which the high dielectric constant portions A and the low dielectric constant portions B are alternately two-dimensionally arranged on the carrier C. Electromagnetic wave shield.
(6) The electromagnetic wave shielding body according to any one of (1) to (4), wherein the two-dimensional periodic structure portion D has a structure in which the high dielectric constant portions A are two-dimensionally arranged in the low dielectric constant portions B.
(7) The electromagnetic wave shielding body according to (1) to (4), wherein the two-dimensional periodic structure portion D has a structure in which openings are two-dimensionally arranged as a low dielectric constant portion B in a high dielectric constant portion A.
(8) A packaging material manufactured using the electromagnetic wave shielding body according to (1) to (7) above.
(9) A radio wave shield manufactured using the electromagnetic wave shield described in (1) to (7) above.
(10) A band-pass filter manufactured using the electromagnetic wave shielding body according to (1) to (7) above.
本発明によれば、所望の波長の電磁波、特に電子レンジの加熱用マイクロ波を効率的に遮断可能な電磁波遮蔽体を提供することが可能である。本発明の高誘電率部位からなる２次元フォトニック結晶を有する電磁波遮蔽体を用いることによって、安全で局所的な電磁波の遮断を、余分な熱の発生もなく実施できる。また、本発明の高誘電率部位を二次元面に周期的に配置した二次元フォトニック結晶を有する電磁波遮蔽体は、三次元フォトニック結晶に比べ容易にかつ安価に提供することが可能である。 ADVANTAGE OF THE INVENTION According to this invention, it is possible to provide the electromagnetic wave shielding body which can interrupt | block efficiently the electromagnetic wave of a desired wavelength, especially the microwave for a microwave oven. By using the electromagnetic wave shielding body having a two-dimensional photonic crystal composed of a high dielectric constant part of the present invention, safe and local electromagnetic wave shielding can be carried out without generating extra heat. Further, the electromagnetic wave shielding body having the two-dimensional photonic crystal in which the high dielectric constant portions of the present invention are periodically arranged on the two-dimensional surface can be provided easily and inexpensively as compared with the three-dimensional photonic crystal. .
以下、本発明を詳細に説明する。
本明細書において下記高誘電率部位Ａおよび低誘電率部位Ｂのそれぞれの誘電率は比誘電率を示す。
［高誘電率部位Ａ］
本発明における高誘電率部位Ａとは、下記のインピーダンス測定法で測定される比誘電
率εＡが、１００〜１０，０００であることを特徴とするものである。同比誘電率εＡは１２０〜５，０００であることが好ましく、１４０〜１，０００であることがより好ましい。
インピーダンス測定法とは、電極間に充填層として固体試料を入れた状態と、充填層として空気を介在させた状態とでそれぞれインピーダンスを実測し、それらの値から正確な誘電率を求めるものである。
一般的に光領域においてフォトニックバンドギャップ効果を発現する物体をフォトニック結晶と称する。
電磁波の波長λは、ｋＣ／ｆで表される。ここで、ｋは定数、Ｃは電磁波の伝播する速さ、ｆは電磁波の周波数である。波長λの電磁波に対してフォトニックバンドギャップ効果を発現する周期構造体の周期ｄはλ／２ｎに比例する。ｎは周期構造体の単位構成要素の材質の光学的屈折率である。この屈折率ｎは材質の比誘電率εの平方根に比例するので、周期ｄはλ／２√εに比例する。光と同様にマイクロ波帯域においても、周期構造体が有する固有の比誘電率を選択するとともに周期を調整することにより、特定の波長に対応したフォトニックバンドギャップ効果を得ることが可能となる。この際、光領域における屈折率とマイクロ波領域における比誘電率が対応する。
Hereinafter, the present invention will be described in detail.
In the present specification, the dielectric constants of the high dielectric constant region A and the low dielectric constant region B described below indicate relative dielectric constants.
[High dielectric constant part A]
The high dielectric constant portion A in the present invention is characterized in that the relative dielectric constant ε A measured by the following impedance measurement method is 100 to 10,000. The relative dielectric constant ε A is preferably 120 to 5,000, more preferably 140 to 1,000.
The impedance measurement method is to measure the impedance in a state where a solid sample is inserted as a packed layer between electrodes and in a state where air is interposed as a packed layer, and to obtain an accurate dielectric constant from these values. .
In general, an object that exhibits a photonic band gap effect in an optical region is referred to as a photonic crystal.
The wavelength λ of the electromagnetic wave is expressed by kC / f. Here, k is a constant, C is the propagation speed of the electromagnetic wave, and f is the frequency of the electromagnetic wave. The period d of the periodic structure that exhibits the photonic band gap effect with respect to the electromagnetic wave having the wavelength λ is proportional to λ / 2n. n is the optical refractive index of the material of the unit component of the periodic structure. Since the refractive index n is proportional to the square root of the relative dielectric constant ε of the material, the period d is proportional to λ / 2√ε. Similar to light, also in the microwave band, a photonic band gap effect corresponding to a specific wavelength can be obtained by selecting a specific dielectric constant of the periodic structure and adjusting the period. At this time, the refractive index in the optical region corresponds to the relative dielectric constant in the microwave region.
本発明の遮蔽体のターゲットの一つである電子レンジのマイクロ波は波長が約１２ｃｍであるため、構造体の周期は実用上非常に大きくなりやすい。周期ｄはλ／２√εに比例するため、本発明に用いる構造体の周期を小さくするためには高誘電率部位の比誘電率が少なくとも１００以上である必要がある。高誘電率部位の比誘電率はできるだけ大きいことが望ましい。特定波長の電磁波の遮蔽にあたり、比誘電率は大きいほどその周期性を小さく設定することができ、局所的な遮蔽に有効であるが、比誘電率が１０，０００を超える材料は入手しにくい。
同時に、本発明に用いる高誘電率部位の誘電損率はできるだけ低いことが望ましい。それは電磁波を照射したときに電磁波遮蔽体自身が発熱することを防ぐためである。本発明の目的は、電子レンジで食品を加熱する際に本発明の電磁波遮蔽体を被覆した部分のみの加熱の抑制にあるので、電磁波遮蔽体自身が発熱することは本発明の目的に反する。同様な理由で、高磁性損失材料も使用することができない。金属等の導電性材料もまた内部抵抗によって発熱するため使用することができない。更に、金属は金属探知機で検知される欠点もあるので、弁当等出荷時の異物検知の観点から望ましくない。以上のことから、本発明で用いる高誘電率部位としては、チタン酸カルシウム、チタン酸バリウム、酒石酸カリウムナトリウム（ロッシェル塩）等が好ましい。
これらの高誘電率部位を構成する成分は、２種以上を混合して用いることもできる。混合物の比誘電率は、混合する成分の比誘電率と体積分率との積の総和として算出することができる。
Since the microwave of the microwave oven, which is one of the targets of the shield of the present invention, has a wavelength of about 12 cm, the period of the structure is likely to become very large in practice. Since the period d is proportional to λ / 2√ε, the relative dielectric constant of the high dielectric constant portion needs to be at least 100 or more in order to reduce the period of the structure used in the present invention. It is desirable that the relative dielectric constant of the high dielectric constant portion be as large as possible. In shielding electromagnetic waves of a specific wavelength, the larger the relative permittivity, the smaller the periodicity can be set, and this is effective for local shielding. However, it is difficult to obtain a material with a relative permittivity exceeding 10,000.
At the same time, it is desirable that the dielectric loss factor of the high dielectric constant portion used in the present invention be as low as possible. This is to prevent the electromagnetic shield itself from generating heat when it is irradiated with electromagnetic waves. The object of the present invention is to suppress the heating of only the portion coated with the electromagnetic wave shielding body of the present invention when the food is heated in the microwave oven, so that the electromagnetic wave shielding body itself generates heat is contrary to the object of the present invention. For the same reason, a high magnetic loss material cannot be used. Conductive materials such as metals cannot be used because they generate heat due to internal resistance. Further, since metal has a defect that it is detected by a metal detector, it is not desirable from the viewpoint of detecting foreign matter at the time of shipment such as a lunch box. From the above, as the high dielectric constant site used in the present invention, calcium titanate, barium titanate, potassium sodium tartrate (Rochelle salt) and the like are preferable.
These components constituting the high dielectric constant region can be used in combination of two or more. The relative dielectric constant of the mixture can be calculated as the sum of products of the relative dielectric constant and volume fraction of the components to be mixed.
［低誘電率部位Ｂ］
本発明における低誘電率部位Ｂとは、上記インピーダンス測定法で測定される比誘電率εＢが、１〜２０であることを特徴とするものである。該比誘電率εＢは１．２〜１０であることが好ましく、１．４〜５であることがより好ましい。
本発明に用いる低誘電率部位の比誘電率はできるだけ低いことが望ましい。一般にフォトニック結晶中において、電磁波のブラッグ回折が起こるときには、二種類の定在波が形成される。図３はその二種類の定在波を示している。定在波Ａは、波の振動が低誘電率領域で高いエネルギーを有し、定在波Ｂは、波の振動が高誘電率領域で高いエネルギーを有する。この２つの異なるモードにスプリットした定在波間のエネルギーを有する波は結晶中に存在できないので、バンドギャップが生じる。バンドギャップを広げたいのであれば、２つの定常波のエネルギー差を広げてやればよい。そのためには、２つの媒質で比誘電率のコントラストを強くすることが効果的である。以上のことから製造の容易さ等を鑑みて低誘電率部位Ｂとしては、空気、ガラス、陶器、プラスチック（樹脂）等から適宜選択
される。
低誘電率部位にプラスチックを用いれば、低誘電率部位をマトリクスとして高誘電率部位を一定周期に配置し包埋した二次元周期構造部を作成することができる。高誘電率の材料は人体等の有害な場合もあるので、樹脂で包埋した二次元周期構造部はこの有害性の問題も解決できる。該プラスチックとしては、アクリル系樹脂、アクリロニトリル系樹脂、アニリン樹脂、アニリンホルムアルデヒド樹脂、アミノアルキル樹脂、アルキッド樹脂、ＡＳ樹脂、ＡＢＳ樹脂、エチレン系樹脂、エポキシ系樹脂、塩化ビニル樹脂、塩化ビニリデン樹脂、塩素化ポリエーテル樹脂、カゼイン樹脂、ゴム、フッ化エチレン系樹脂、シリコン樹脂、酢酸ビニル樹脂、スチレン系樹脂、ＳＢＲ、スチロール樹脂、ポリアミド系樹脂、フェノール樹脂、ブチルゴム、不飽和ポリエステル系樹脂、ベークライト、ポリアセタール樹脂、ポリウレタン、ポリエステル系樹脂、ポリエチレン系樹脂、ポリエチレンテレフタレート、ポリカーボネート、ポリスチレン、ポリビニルアルコール、ポリブチレン系樹脂、ポリプロピレン、ポリメチルアクリレート、ポリメチルメタクリレート、メタクリル系樹脂、メラミン樹脂などが挙げられる。
[Low dielectric constant part B]
The low dielectric constant region B in the present invention is characterized in that the relative dielectric constant ε B measured by the impedance measurement method is 1 to 20. The relative dielectric constant ε B is preferably 1.2 to 10, and more preferably 1.4 to 5.
It is desirable that the relative dielectric constant of the low dielectric constant portion used in the present invention be as low as possible. In general, when Bragg diffraction of electromagnetic waves occurs in a photonic crystal, two types of standing waves are formed. FIG. 3 shows the two kinds of standing waves. The standing wave A has high energy in the low dielectric constant region, and the standing wave B has high energy in the high dielectric constant region. A wave having energy between the standing waves split into these two different modes cannot be present in the crystal, resulting in a band gap. If you want to widen the band gap, you can widen the energy difference between the two standing waves. For this purpose, it is effective to increase the contrast of the relative dielectric constant between the two media. In view of the above, the low dielectric constant portion B is appropriately selected from air, glass, earthenware, plastic (resin) and the like in view of ease of manufacture and the like.
If plastic is used for the low dielectric constant region, a two-dimensional periodic structure portion in which the low dielectric constant region is used as a matrix and the high dielectric constant region is arranged and embedded at a constant period can be created. Since a material with a high dielectric constant may be harmful to the human body or the like, the two-dimensional periodic structure part embedded with resin can solve this harmful problem. Examples of the plastic include acrylic resin, acrylonitrile resin, aniline resin, aniline formaldehyde resin, aminoalkyl resin, alkyd resin, AS resin, ABS resin, ethylene resin, epoxy resin, vinyl chloride resin, vinylidene chloride resin, chlorine Polyether resin, casein resin, rubber, fluorinated ethylene resin, silicon resin, vinyl acetate resin, styrene resin, SBR, styrene resin, polyamide resin, phenol resin, butyl rubber, unsaturated polyester resin, bakelite, polyacetal Resin, polyurethane, polyester resin, polyethylene resin, polyethylene terephthalate, polycarbonate, polystyrene, polyvinyl alcohol, polybutylene resin, polypropylene, polymethyl acrylate DOO, polymethyl methacrylate, methacrylic resin, and melamine resin.
[基本構造]
本発明における電磁波遮蔽体は、二次元面内に高誘電率部位と低誘電率部位を一定のピッチ（周期）で交互に配置した二次元周期構造部を有するものである。ここで「二次元」とは単に平面や平坦面に限定されるものではなく、例えば二次元面は若干の曲率があっても良く、波打っていても良く、凹凸があっても良い。該二次元面が１層構成である限り二次元周期構造体とみなしてよい。同一形状の二次元周期構造体をその形状を合致させるように重ね合わせて積層構造を形成した場合であっても、電磁波入射方向に有意な誘電率コントラストがない限り１層構成とみなしてよく、二次元周期構造体とみなされる。
[Basic structure]
The electromagnetic wave shielding body according to the present invention has a two-dimensional periodic structure portion in which high dielectric constant portions and low dielectric constant portions are alternately arranged at a constant pitch (period) in a two-dimensional plane. Here, the “two-dimensional” is not limited to a flat surface or a flat surface. For example, the two-dimensional surface may have a slight curvature, may be wavy, or have irregularities. As long as the two-dimensional surface has a single layer structure, it may be regarded as a two-dimensional periodic structure. Even when a two-dimensional periodic structure having the same shape is overlapped so as to match its shape to form a laminated structure, it may be regarded as a one-layer structure as long as there is no significant dielectric constant contrast in the electromagnetic wave incident direction. It is regarded as a two-dimensional periodic structure.
本発明において周期性とは、高誘電率部位と低誘電率部位を一定のピッチ（周期）で交互に配置した状態を指すものである。特定の周波数、たとえば２．４５ＧＨｚに透過減衰の谷を持ってくるには、高誘電率部位と低誘電率部位のそれぞれの比誘電率を適当な値に選択し、かつ高誘電率部位と低誘電率部位を最適な周期で配置することが必要となる。交互配置の様式はピッチが一定である場合、平行配置（格子状配置）、４５°千鳥配置、６０°千鳥配置、１２０°千鳥配置等のいずれでもよい。ピッチが乱れると、特許文献２に記載されている通り周波数依存性が低下するが、これらは使用目的に応じて使い分けることができる。例えば電子レンジで温める被加熱物が、部分的には加熱させずに、部分的には僅かに温めたい様な内容の場合は、二次元周期構造部はピッチを変更しながら高誘電率部位を配置するようなデザインもあり得る。 In the present invention, the term “periodicity” refers to a state in which high dielectric constant portions and low dielectric constant portions are alternately arranged at a constant pitch (period). In order to bring the transmission attenuation valley to a specific frequency, for example, 2.45 GHz, the relative dielectric constant of each of the high dielectric constant region and the low dielectric constant region is selected to an appropriate value, and the high dielectric constant region is low. It is necessary to arrange the dielectric constant portions at an optimum period. When the pitch is constant, the alternate arrangement may be any of parallel arrangement (lattice arrangement), 45 ° zigzag arrangement, 60 ° zigzag arrangement, 120 ° zigzag arrangement, and the like. When the pitch is disturbed, the frequency dependency is reduced as described in Patent Document 2, but these can be used properly according to the purpose of use. For example, if the object to be heated in a microwave oven has a content that does not partially heat but wants to warm slightly, the two-dimensional periodic structure part changes the pitch while changing the pitch. There can be a design to arrange.
また、高誘電率部位が二次元面内に点在している構成であれば、該高誘電率部位を構成する物体の形状は、円柱、三角柱、三角錐、直方体、球、円錐台形、不定形のいずれでもよく、各々の形状が異なっていてもよい。即ち高誘電率部位の二次元面に並行方向での断面形状は円、楕円、多角形、不定形のいずれでもよく、各々の形状が異なっていてもよい。
高誘電率部位を二次元面に配列するにあたり、担持体Ｃを用いて、これの上に配置することが可能である。担持体Ｃとしては、ポリエチレンフィルム、ポリプロピレンフィルム、ポリエチレンテレフタレートフィルム、アクリル板、ポリエチレンテレフタレート板、紙、板紙、ポリエチレンラミネート紙等を用いることができる。
担持体Ｃの厚さは電磁波の波長に対して殆んど無視できる。例えば、厚さ６ｍｍ、比誘電率１．２の基板は実施例のマイクロ波透過スペクトル測定装置で透過強度の減衰がなく無視できるものである。基板の厚さに関しても、λ／２√εと比例関係にあるので、比誘電率が低いほど基板の厚さが厚くなる。
In addition, if the high dielectric constant region is scattered in a two-dimensional plane, the shape of the object constituting the high dielectric constant region can be a cylinder, triangular prism, triangular pyramid, rectangular parallelepiped, sphere, truncated cone, Any of the fixed shapes may be used, and each shape may be different. That is, the cross-sectional shape in the direction parallel to the two-dimensional surface of the high dielectric constant portion may be any of a circle, an ellipse, a polygon, and an indeterminate shape, and each shape may be different.
In order to arrange the high dielectric constant portions on the two-dimensional surface, it is possible to use the carrier C and arrange it on this. As the carrier C, a polyethylene film, a polypropylene film, a polyethylene terephthalate film, an acrylic plate, a polyethylene terephthalate plate, paper, paperboard, polyethylene laminated paper, or the like can be used.
The thickness of the carrier C is almost negligible with respect to the wavelength of the electromagnetic wave. For example, a substrate having a thickness of 6 mm and a relative dielectric constant of 1.2 is negligible with no attenuation of transmission intensity in the microwave transmission spectrum measuring apparatus of the embodiment. Since the thickness of the substrate is also proportional to λ / 2√ε, the lower the relative dielectric constant, the thicker the substrate.
上記構成の電磁波遮蔽体の製造方法は、上記高誘電率部位からなる物体を焼結・ペレッ
ト化したものを担持体Ｃの上に配列したものでもよく、さらに高誘電率部位間に樹脂を流し込んで包埋したものでもかまわない。
また上記構成は、上記高誘電率部位からなる板状体に二次元配列した開口部を設けたものでもよく、さらに同開口部に樹脂を流し込んで樹脂包埋したものでもかまわないし、或いは、低誘電性のセラミック材料板の中に高誘電率部位からなる材料を焼結したペレットを埋め込んで、外観上は低誘電体セラミック板となっていてもかまわない。
The method for producing an electromagnetic wave shielding body having the above-described structure may be obtained by sintering and pelletizing an object composed of the high dielectric constant portion on the carrier C, and pouring a resin between the high dielectric constant portions. It can be embedded in.
In addition, the above configuration may be one in which openings arranged in a two-dimensional array are provided in a plate-like body made of the high dielectric constant portion, and may be a resin embedded by pouring resin into the openings. The dielectric ceramic material plate may be a low dielectric ceramic plate in appearance by embedding pellets obtained by sintering a material having a high dielectric constant portion.
スラブ型電磁波遮蔽体については、上記高誘電率部位と低誘電率部位が反転したものと捉えることができるが、原理的には同じである。スラブの厚さは電磁波の波長に対して基本的に無視できるものであるが、比誘電率が高いほど基板の厚さを薄くできる。スラブにあける穴の形状も円筒形状、球状などいずれでもよく、テーパーがあってもかまわない。なお、スラブにあける穴のピッチが乱れると周波数依存性が低下することも前述の通りである。
スラブにあける穴は、高誘電率部位からなるスラブ１枚毎に開孔してもよいし、スラブを複数枚重ねて開孔してもよい
As for the slab type electromagnetic wave shielding body, it can be considered that the high dielectric constant part and the low dielectric constant part are inverted, but the principle is the same. The thickness of the slab is basically negligible with respect to the wavelength of the electromagnetic wave, but the thickness of the substrate can be reduced as the relative dielectric constant increases. The shape of the hole in the slab may be cylindrical or spherical, and may be tapered. In addition, as described above, the frequency dependency is lowered when the pitch of the holes in the slab is disturbed.
The hole in the slab may be opened for each slab composed of a high dielectric constant region, or a plurality of slabs may be stacked to be opened.
［透過減衰の測定方法］
本発明における電磁波遮蔽体による透過減衰の測定は、後述する実施例に記載の測定方法によって測定した。
本発明の電磁波遮蔽体は、その二次元面内を１．４ＧＨｚ〜３．４ＧＨｚの電磁波が通過するとき、該周波数領域内で１０ｄＢ以上の透過減衰を示すことを特徴とする。該周波数領域内で１２ｄＢ以上の透過減衰を示すことが好ましい。
特に本発明の電磁波遮蔽体は、その二次元面内を２．４５ＧＨｚの電磁波が通過するとき、同周波数における透過減衰が２０ｄＢ以上であることが好ましい。
[Measurement method of transmission attenuation]
The measurement of the transmission attenuation by the electromagnetic wave shielding body in the present invention was performed by the measurement method described in Examples described later.
The electromagnetic wave shielding body of the present invention is characterized by exhibiting a transmission attenuation of 10 dB or more in the frequency region when an electromagnetic wave of 1.4 GHz to 3.4 GHz passes through the two-dimensional plane. It is preferable that the transmission attenuation is 12 dB or more in the frequency domain.
In particular, the electromagnetic wave shielding body of the present invention preferably has a transmission attenuation of 20 dB or more at the same frequency when an electromagnetic wave of 2.45 GHz passes through the two-dimensional plane.
以下に実施例を挙げて本発明の特徴をさらに具体的に説明する。
以下の実施例に示す材料、使用量、割合、処理内容、処理手順等は、本発明の趣旨を逸脱しない限り適宜変更することができる。したがって、本発明の技術的な範囲は以下に示す具体例により何ら限定されるものではない。
The features of the present invention will be described more specifically with reference to the following examples.
The materials, amounts used, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the technical scope of the present invention is not limited by the specific examples shown below.
＜実施例１＞
［高誘電率部位Ａ１の作成］
（１）チタン酸カルシウム焼結原料の調製：
フラックス成分として炭酸カリウム（和光純薬(株)製、試薬）結晶２５ｇ、成形助剤としてメチルセルロース粉末（和光純薬(株)製、試薬）２５ｇを水１５００ｇに溶解し、これにアナターゼ型二酸化チタン粉末（和光純薬(株)製、試薬）６００ｇおよび炭酸カルシウム粉末（和光純薬(株)製、試薬）１０００ｇを加え、ニーダー（(株)井上製作所製、ＫＨ−１０−Ｆ）を用いて攪拌混合してスラリーを調製した。このスラリーを乾燥温度７５℃で8時間加熱乾燥し、チタン酸カルシウム焼結原料を得た。
（２）加圧成形：
得られたチタン酸カルシウム焼結原料を、真空土練機（(株)林田鉄工製、ＶＭ−０５）を用いて水を添加しながら混練し、湿式ラバープレス（油研工業（株）製、ＹＳＲＰ４−１０Ｗ）を用いて２００ＭＰａで３０秒間加圧して直径１０．５ｍｍ、高さ８．５ｍｍの円柱形状物に成形した。
（３）焼結処理：
得られた円柱形状の成形体を電気炉内で１２００℃、２時間焼結処理し、そのまま放冷し、高誘電率部位Ａ１を得た。得られた高誘電率部位Ａ１の直径は９．６ｍｍ、高さ８ｍｍ、密度４．０であった。
<Example 1>
[Creation of high dielectric constant part A1]
(1) Preparation of calcium titanate sintered raw material:
25 g of potassium carbonate (Wako Pure Chemical Industries, Ltd., reagent) crystals as a flux component and 25 g of methylcellulose powder (Wako Pure Chemicals, reagent) as a molding aid are dissolved in 1500 g of water, and this is anatase-type titanium dioxide. Add 600 g of powder (manufactured by Wako Pure Chemical Industries, Ltd., reagent) and 1000 g of calcium carbonate powder (manufactured by Wako Pure Chemical Industries, Ltd., reagent), and use a kneader (manufactured by Inoue Seisakusho, KH-10-F). A slurry was prepared by stirring and mixing. This slurry was heat-dried at a drying temperature of 75 ° C. for 8 hours to obtain a calcium titanate sintered raw material.
(2) Pressure molding:
The obtained calcium titanate sintered raw material was kneaded while adding water using a vacuum kneader (manufactured by Hayashida Tekko Co., Ltd., VM-05), and wet rubber press (manufactured by Yuken Kogyo Co., Ltd.) YSRP4-10W) was pressed at 200 MPa for 30 seconds to form a cylindrical product having a diameter of 10.5 mm and a height of 8.5 mm.
(3) Sintering process:
The obtained cylindrical shaped body was sintered in an electric furnace at 1200 ° C. for 2 hours and allowed to cool as it was to obtain a high dielectric constant region A1. The obtained high dielectric constant region A1 had a diameter of 9.6 mm, a height of 8 mm, and a density of 4.0.
［二次元周期構造部Ｄ１の作成］
担持体Ｃとしてポリエチレンテレフタレートフィルム（東レ(株)製、ルミラーＳ１０、厚さ７５μｍ）を用いて、担持体Ｃ上に１ｍｍの間隔をあけて高誘電率部位Ａ１を格子状に縦１０列×横５列に配置し、エポキシ系接着剤（ニチバン社製、アラルダイトＡＲ−Ｒ３０）で固定して二次元周期構造部Ｄ１を得た。この場合、低誘電率部位Ｂ１は空気である。
［マイクロ波透過スペクトル測定装置の製作］
断面形状が１０９．２２ｍｍ×５４．６１ｍｍの長方形である直線導波管（日本高周波(株)製）の両端に同軸導波管変換器（日本高周波(株)製）を取り付け、同軸ケーブルの一方をネットワークアナライザー（Ａｇｉｌｅｎｔ Ｔｅｃｈｎｏｌｏｇｉｅｓ社製、Ｅ８３６４Ｂ）の出力側に接続し、他方を同機器の入力側に接続し、直線導波管と同軸導波管変換器の接合面にサンプルシートを挟みこんで透過スペクトルが測定可能な装置を製作した。
[Create two-dimensional periodic structure D1]
A polyethylene terephthalate film (Lumirror S10, Toray Co., Ltd., 75 μm thick) is used as the carrier C, and the high dielectric constant portions A1 are arranged in a grid of 10 rows × 10 × The two-dimensional periodic structure part D1 was obtained by arranging in 5 rows and fixing with an epoxy adhesive (Araldite AR-R30, manufactured by Nichiban Co., Ltd.). In this case, the low dielectric constant part B1 is air.
[Production of microwave transmission spectrum measurement equipment]
A coaxial waveguide converter (manufactured by Nippon Radio Frequency Co., Ltd.) is attached to both ends of a straight waveguide (manufactured by Nippon Radio Frequency Co., Ltd.) having a rectangular cross section of 109.22 mm × 54.61 mm, and one end of the coaxial cable Is connected to the output side of the network analyzer (Agilent Technologies, E8364B), the other is connected to the input side of the equipment, and the sample sheet is sandwiched between the joint surface of the linear waveguide and coaxial waveguide converter A device capable of measuring the transmission spectrum was fabricated.
［マイクロ波透過スペクトルの測定］
上記で製作したマイクロ波透過スペクトル測定装置に、二次元周期構造部Ｄ１を挟み込み、１．４〜３．４ＧＨｚの範囲で透過スペクトルを測定したところ、２．２３ＧＨｚに−６０ｄＢ、２．５７ＧＨｚに−３２ｄＢの２つの谷を持ち、２．４２ＧＨｚに−１４．７ｄＢの極大値を持つ透過スペクトルが観測された。２．４５ＧＨｚでの透過強度は−１５．２ｄＢであった。
[Measurement of microwave transmission spectrum]
When the transmission spectrum was measured in the range of 1.4 to 3.4 GHz by sandwiching the two-dimensional periodic structure part D1 in the microwave transmission spectrum measuring device manufactured above, it was −60 dB at 2.23 GHz, −2.57 GHz— A transmission spectrum having two valleys of 32 dB and a maximum value of −14.7 dB at 2.42 GHz was observed. The transmission intensity at 2.45 GHz was -15.2 dB.
実施例１で得た電磁波遮蔽体の１．８〜３ＧＨｚの範囲における透過スペクトルを図４に示す。図４では電磁波遮蔽の程度を強調するために、縦軸を透過強度（ｄＢ）では無くこれを換算した透過率（％）としている。透過率Ｔ（％）と透過強度比Ｌ（ｄＢ）の関係は、下記式（１）で表される。
［数１］
Ｌ ＝ １０ｌｏｇ１０Ｔ／１００ ・・・ （１）
FIG. 4 shows a transmission spectrum of the electromagnetic wave shielding body obtained in Example 1 in the range of 1.8 to 3 GHz. In FIG. 4, in order to emphasize the degree of electromagnetic wave shielding, the vertical axis is not the transmission intensity (dB) but the transmittance (%) converted from this. The relationship between the transmittance T (%) and the transmission intensity ratio L (dB) is expressed by the following formula (1).
[Equation 1]
L = 10 log 10 T / 100 (1)
［ＴＬＭシミュレーション］
実施例１で得た電磁波遮蔽体の電磁波遮蔽効果を追確認するために、ＴＬＭ３次元電磁界解析ソフトウエア（商品名：ＣＳＴ ＭＩＣＲＯＳＴＲＩＰＥＳ、株式会社エーイーティー製）を用いて、ＴＬＭ（Ｔｒａｎｓｍｉｓｓｉｏｎ Ｌｉｎｅ Ｍａｔｒｉｘ：伝送線路行列）法によるシミュレーションを行った。
ＴＬＭ法とは、電磁界解析手法の一つで、空間の離散点間を１次元線路と仮定し、各格子点でホイヘンスの原理に基づく波動伝播（Ｍａｘｗｅｌｌ方程式）を計算により逐次的に解くものである。高誘電率部位Ａの比誘電率を１６６．５と仮定し、下記条件でシミュレーションモデルを作成したところ、得られた透過スペクトルは実測の透過スペクトルに対してよく近似するものであった。シミュレーションより得られた透過スペクトルを図５に示す。
[TLM simulation]
In order to further confirm the electromagnetic wave shielding effect of the electromagnetic wave shielding body obtained in Example 1, TLM (Transmission Line Matrix) was used using TLM three-dimensional electromagnetic field analysis software (trade name: CST MICROSTRIPES, manufactured by AET Co., Ltd.). : Transmission line matrix) simulation.
The TLM method is an electromagnetic field analysis method that assumes a one-dimensional line between discrete points in space, and solves wave propagation (Maxwell equation) based on Huygens's principle at each lattice point sequentially by calculation. It is. Assuming that the relative dielectric constant of the high dielectric constant region A is 166.5 and a simulation model was created under the following conditions, the obtained transmission spectrum closely approximated the actually measured transmission spectrum. The transmission spectrum obtained from the simulation is shown in FIG.
・ペレット直径：１０ｍｍ
・厚み：８ｍｍ
・ペレット間の距離：１ｍｍ
・ユニットセル：縦１０列×横５列配置
・寸法：１０９×５４×８ｍｍ
・高誘電率部位Ａの比誘電率：１６６．５
・低誘電率部位Ｂの比誘電率：１．０
また同シミュレーションからは、２．４５ＧＨｚのマイクロ波が、二次元周期構造部Ｄ１に隣接した部位においてその電場強度が２０％程度まで減衰しており、二次元周期構造部Ｄ１を殆ど透過しないという結果が得られた。結果の模式図を図６に示す。同図下部の
四角形がペレットを示している。
・ Pellet diameter: 10mm
・ Thickness: 8mm
・ Distance between pellets: 1 mm
-Unit cell: 10 rows x 5 rows-Dimensions: 109 x 54 x 8 mm
The relative dielectric constant of the high dielectric constant portion A: 166.5
The relative dielectric constant of the low dielectric constant region B: 1.0
Also, from the simulation, the result is that the 2.45 GHz microwave attenuates to about 20% in the portion adjacent to the two-dimensional periodic structure portion D1, and hardly transmits through the two-dimensional periodic structure portion D1. was gotten. A schematic diagram of the results is shown in FIG. The square at the bottom of the figure shows the pellet.
［マイクロ波遮蔽効果の測定］
あらかじめ冷蔵庫で保冷した米飯を縦１２０ｍｍ×横８０ｍｍ×深さ２０ｍｍの容器に入れ、米飯の上に実施例１の二次元周期構造部Ｄ１をかぶせ、５００Ｗ設定の家庭用電子レンジで１分間加熱した。その際の米飯の表面温度は赤外線カメラによって撮影した。結果を図７に示す。該図７中、左側が電磁波遮蔽体有りであり、右側が電磁波遮蔽体無しである。米飯の加熱前の表面温度は２０℃以下で、二次元周期構造部Ｄ１がない部分の加熱後の表面温度は６０℃に達していたのに対し、二次元周期構造部Ｄ１で保護された部分の加熱直後の表面温度は３０℃であった。また、二次元周期構造部Ｄ１を構成する高誘電率部位Ａ１の表面温度は３５℃であった。
[Measurement of microwave shielding effect]
The rice cooked in the refrigerator in advance is placed in a container 120 mm long x 80 mm wide x 20 mm deep, covered with the two-dimensional periodic structure D1 of Example 1 on the cooked rice, and heated in a household microwave oven set at 500W for 1 minute. . The surface temperature of the cooked rice was taken with an infrared camera. The results are shown in FIG. In FIG. 7, the left side has an electromagnetic wave shield and the right side has no electromagnetic wave shield. The surface temperature of the cooked rice before heating is 20 ° C. or less, and the surface temperature after heating of the portion without the two-dimensional periodic structure portion D1 reached 60 ° C., whereas the portion protected by the two-dimensional periodic structure portion D1 The surface temperature immediately after heating was 30 ° C. Further, the surface temperature of the high dielectric constant portion A1 constituting the two-dimensional periodic structure portion D1 was 35 ° C.
＜実施例２＞
［高誘電率部位Ａ２の作成］
（１）加工成形：
高誘電材料としてチタン酸バリウム粉末（和光純薬(株)製、試薬）５００ｇと成形助剤としてメチルセルロース粉末（和光純薬(株)製、試薬）２５ｇと水約１００ｇを真空混練押出成形機（三庄インダストリー(株)製、Ｖ−２０）に仕込み、直径５ｍｍのチューブ状に押し出した。押し出したチューブを５ｍｍの長さに切断し、７５℃で２時間乾燥して円柱形状の成形体を得た。
（２）焼結処理：
得られた円柱形の成形体を電気炉内で１２００℃で２時間の焼結処理し、そのまま放冷し高誘電率部位Ａ２を得た。高誘電率部位Ａ２の直径は４．６ｍｍ、高さ４．５ｍｍ、密度４．２であった。
<Example 2>
[Creation of high dielectric constant region A2]
(1) Processing molding:
500 g of barium titanate powder (manufactured by Wako Pure Chemical Industries, Ltd., reagent) as a high-dielectric material, 25 g of methylcellulose powder (manufactured by Wako Pure Chemical Industries, Ltd., reagent) as a molding aid, and about 100 g of water are vacuum kneaded and extruded ( The product was prepared in V-20) manufactured by Sanjo Industry Co., Ltd. and extruded into a tube shape having a diameter of 5 mm. The extruded tube was cut to a length of 5 mm and dried at 75 ° C. for 2 hours to obtain a cylindrical shaped body.
(2) Sintering process:
The obtained cylindrical shaped body was sintered in an electric furnace at 1200 ° C. for 2 hours and allowed to cool as it was to obtain a high dielectric constant region A2. The diameter of the high dielectric constant portion A2 was 4.6 mm, the height was 4.5 mm, and the density was 4.2.
［二次元周期構造部Ｄ２の作成］
実施例１と同様に担持体Ｃとしてポリエチレンテレフタレートフィルム（東レ(株)製、ルミラーＳ１０、厚さ７５μｍ）上に１ｍｍの間隔をあけて高誘電率部位Ａ２を格子状に縦１９列×横９列に配置し、エポキシ系接着剤（ニチバン社製、アラルダイトＡＲ−Ｒ３０）で固定して二次元周期構造部Ｄ２を得た。この場合、低誘電率部位Ｂ２は空気である。
[Create two-dimensional periodic structure D2]
In the same manner as in Example 1, as the support C, a polyethylene terephthalate film (manufactured by Toray Industries, Inc., Lumirror S10, thickness 75 μm) is spaced by 1 mm, and the high dielectric constant portions A2 are arranged in a lattice form in 19 rows × 9 rows. The two-dimensional periodic structure part D2 was obtained by arranging in a row and fixing with an epoxy adhesive (manufactured by Nichiban Co., Ltd., Araldite AR-R30). In this case, the low dielectric constant part B2 is air.
［マイクロ波透過スペクトルの測定］
実施例１と同様に二次元周期構造部Ｄ２の、１．４〜３．４ＧＨｚの範囲における透過スペクトルを測定したところ、３．１２ＧＨｚに−４０ｄＢ、３．３０ＧＨｚに−２５ｄＢの２つの谷を持ち、３．２３ＧＨｚに−４．６ｄＢの極大を持つ透過スペクトルが観測された。２．４５ＧＨｚでの透過強度は−２．５ｄＢであった。シミュレーションより高誘電率部位Ａ２の比誘電率は８８０と見積もられた。
[Measurement of microwave transmission spectrum]
When the transmission spectrum of the two-dimensional periodic structure portion D2 in the range of 1.4 to 3.4 GHz was measured in the same manner as in Example 1, it had two valleys of −40 dB at 3.12 GHz and −25 dB at 3.30 GHz. A transmission spectrum having a maximum of -4.6 dB at 3.23 GHz was observed. The transmission intensity at 2.45 GHz was -2.5 dB. From the simulation, the relative dielectric constant of the high dielectric constant region A2 was estimated to be 880.
＜実施例３＞
［高誘電率部位Ａ３の作成］
（１）加工成形：
実施例1で作成したチタン酸カルシウム焼結原料を真空押出成形機（高浜工業(株)製、ＳＳＥ３３０）を用いて水を添加しながら混練し、ダイスから押し出し７ｍｍ厚の板状物を得た。得られた板状物にパンチングメタル（奥谷金網製作所(株)製、Ｎｏ．１０４２、開孔径６ｍｍ、ピッチ９ｍｍ、６０°千鳥配置）をかぶせて、けがき針で上記板状物をくりぬき、板状物に開孔を形成して室温で乾燥させた。
<Example 3>
[Creation of high dielectric constant part A3]
(1) Processing molding:
The calcium titanate sintered raw material prepared in Example 1 was kneaded while adding water using a vacuum extruder (manufactured by Takahama Kogyo Co., Ltd., SSE330), and extruded from a die to obtain a 7 mm thick plate-like product. . Punching metal (No. 1042, manufactured by Okutani Wire Net Manufacturing Co., Ltd., No. 1042, hole diameter 9 mm, pitch 9 mm, 60 ° staggered arrangement) is placed on the obtained plate-like material, and the plate-like material is hollowed out with a marking needle. Openings were formed in the product and dried at room temperature.
（２）焼結処理：
上記の開孔を成形した板状物を８００℃で２時間予備焼結した後、１１５０℃まで加熱
して２時間焼結させて厚さ６．１ｍｍ、開孔径５．３ｍｍ、配列周期７．９ｍｍ、密度３．９の高誘電率部位Ａ３を得た。
［二次元周期構造部Ｄ３の作成］
上記で得られた高誘電率部位Ａ３の２枚を穴の位置が一致するように重ねあわせ、両面テープを介して貼り合わせて二次元周期構造部Ｄ３を作成した。この場合、低誘電率部位Ｂ３は空気である。
(2) Sintering process:
The plate-shaped material formed with the above holes was pre-sintered at 800 ° C. for 2 hours, then heated to 1150 ° C. and sintered for 2 hours to obtain a thickness of 6.1 mm, a hole diameter of 5.3 mm, and an array period of 7. A high dielectric constant region A3 of 9 mm and a density of 3.9 was obtained.
[Create two-dimensional periodic structure D3]
Two pieces of the high dielectric constant portion A3 obtained above were overlapped so that the positions of the holes coincided, and bonded together via a double-sided tape to create a two-dimensional periodic structure portion D3. In this case, the low dielectric constant part B3 is air.
［マイクロ波透過スペクトルの測定］
上記二次元周期構造部Ｄ３の片面に、補強材としてポリエチレンテレフタレートフィルム（東レ(株)製、ルミラーＳ１０、厚さ７５μｍ）をエポキシ系接着剤（ニチバン社製、アラルダイトＡＲ−Ｒ３０）で貼り合わせ、マイクロ波透過スペクトル測定装置に二次元周期構造部Ｄ３を挟み込み、１．４〜３．４ＧＨｚの範囲で透過スペクトルを測定したところ、１．５３ＧＨｚに−３５ｄＢ、１．８７ＧＨｚに−２２ｄＢの２つの谷を持ち、１．７１ＧＨｚに−１２．３ｄＢの極大を持つ透過スペクトルが観測された。２．４５ＧＨｚでの透過強度は−６．４ｄＢであった。
[Measurement of microwave transmission spectrum]
A polyethylene terephthalate film (manufactured by Toray Industries Inc., Lumirror S10, thickness 75 μm) is bonded to one side of the two-dimensional periodic structure D3 with an epoxy adhesive (manufactured by Nichiban Co., Araldite AR-R30). The transmission spectrum was measured in the range of 1.4 to 3.4 GHz by sandwiching the two-dimensional periodic structure part D3 in the microwave transmission spectrum measuring apparatus, and two valleys of −35 dB at 1.53 GHz and −22 dB at 1.87 GHz were measured. A transmission spectrum having a maximum of −12.3 dB at 1.71 GHz was observed. The transmission intensity at 2.45 GHz was -6.4 dB.
＜実施例４＞
［高誘電率部位Ａ４の作成］
実施例１で作成した高誘電率部位Ａ１を用いた。
［低誘電率部位Ｂ４の作成］
アクリル酸メチル（和光純薬(株)製、試薬）１０ｇ、メタクリル酸メチル（和光純薬(株)製、試薬）７０ｇ、アクリロニトリル（和光純薬(株)製、試薬）２０ｇ、２，２−アゾビスイソブチロニトリル（和光純薬(株)製、試薬）０．０５ｇを混合し、低誘電率部位Ｂ４の材料となるＭＭＡ（メタクリル酸メチル）系モノマー混合液を調製した。
<Example 4>
[Creation of high dielectric constant region A4]
The high dielectric constant portion A1 prepared in Example 1 was used.
[Creation of low dielectric constant region B4]
Methyl acrylate (manufactured by Wako Pure Chemical Industries, Ltd., reagent) 10 g, methyl methacrylate (manufactured by Wako Pure Chemical Industries, Ltd., reagent) 70 g, acrylonitrile (manufactured by Wako Pure Chemical Industries, Ltd., reagent) 20 g, 2,2- 0.05 g of azobisisobutyronitrile (manufactured by Wako Pure Chemical Industries, Ltd., reagent) was mixed to prepare a MMA (methyl methacrylate) -based monomer mixed solution that becomes a material for the low dielectric constant region B4.
［二次元周期構造部Ｄ４の作成］
３ｍｍ厚のアクリル樹脂板を用いて内寸が長さ１０５ｍｍ×幅５０ｍｍ×高さ１０ｍｍの箱状容器を作成し、容器内に実施例1で得られた高誘電率部位Ａ１を１ｍｍの間隔をあ
けて格子状に縦９列×横４列に配置し、エポキシ系接着剤（ニチバン社製、アラルダイトＡＲ−Ｒ３０）で固定した。
次いで、作成した容器内に上記で調整したＭＭＡ系モノマー混合液を充填し、１２０ｍｍ×６０ｍｍ×厚さ３ｍｍのアクリル樹脂版を用いて容器内に空気が混入しないように塞ぎ、６０℃でＭＭＡ系モノマー混合液を重合させ、低誘電率部位Ｂ４がＭＭＡ系樹脂よりなり、高誘電率部位Ａ４と低誘電率部位Ｂ４が一体化した二次元周期構造部Ｄ４を作成した。従来公知の文献より低誘電率部位Ｂ４の比誘電率は約３．０と見積もられた。
［マイクロ波透過スペクトルの測定］
マイクロ波透過強度測定装置に二次元周期構造部Ｄ４を挟み込み、１．４〜３．４ＧＨｚの範囲で透過強度を測定したところ、２．４８ＧＨｚに−４３ｄＢ、２．６１ＧＨｚに−２８ｄＢの２つの谷を持ち、２．５５ＧＨｚに−８ｄＢの極大を持つ透過スペクトルが観測された。２．４５ＧＨｚでの透過強度は−３６ｄＢであった。
[Create two-dimensional periodic structure portion D4]
Using a 3 mm thick acrylic resin plate, a box-shaped container having an inner dimension of 105 mm long x 50 mm wide x 10 mm high is prepared, and the high dielectric constant part A1 obtained in Example 1 is placed in the container at an interval of 1 mm. It was opened and arranged in a lattice shape in 9 rows x 4 rows, and fixed with an epoxy adhesive (manufactured by Nichiban Co., Ltd., Araldite AR-R30).
Next, the prepared MMA monomer mixture liquid is filled in the prepared container, and the MMA system is sealed at 60 ° C. using an acrylic resin plate of 120 mm × 60 mm × thickness 3 mm so that air does not enter the container. The monomer mixture was polymerized to form a two-dimensional periodic structure portion D4 in which the low dielectric constant region B4 is made of MMA resin and the high dielectric constant region A4 and the low dielectric constant region B4 are integrated. From the conventionally known literature, the relative dielectric constant of the low dielectric constant region B4 was estimated to be about 3.0.
[Measurement of microwave transmission spectrum]
When the transmission intensity was measured in the range of 1.4 to 3.4 GHz by sandwiching the two-dimensional periodic structure part D4 in the microwave transmission intensity measuring device, two valleys of −43 dB at 2.48 GHz and −28 dB at 2.61 GHz were measured. And a transmission spectrum having a maximum of −8 dB at 2.55 GHz was observed. The transmission intensity at 2.45 GHz was −36 dB.
＜比較例１＞
［高誘電率部位Ａ５の作成］
高誘電率部位材料としてチタン酸カルシウム粉末を酸化チタン粉末に置き換えた以外は、実施例１と同様にして高誘電率部位Ａ５を得た。この高誘電率部位Ａ５の直径は９．７ｍｍ、高さ７．９ｍｍ、密度３．８であった。
なお、用いた酸化チタンの比誘電率は９５で本発明の範囲外であった。
［二次元周期構造部Ｄ５の作成］
実施例１の二次元周期構造部Ｄ１の作成と同様に、二次元周期構造部Ｄ５を作成した。しかしながら、実施例１と配列周期を合わせるため、０．９ｍｍ間隔で高誘電率部位Ａ５
を格子状に縦１０列×横５列に配置し、エポキシ系接着剤（ニチバン社製、アラルダイトＡＲ−Ｒ３０）で固定して二次元周期構造部Ｄ５を得た。
［マイクロ波透過スペクトルの測定］
実施例１と同様に、二次元周期構造部Ｄ５の１．４〜３．４ＧＨｚの範囲における透過スペクトルを測定したが、フォトニックバンドギャップに由来する明確な遮蔽効果は観察されなかった。
<Comparative Example 1>
[Creation of high dielectric constant region A5]
A high dielectric constant region A5 was obtained in the same manner as in Example 1 except that the calcium titanate powder was replaced with titanium oxide powder as the high dielectric constant region material. The high dielectric constant portion A5 had a diameter of 9.7 mm, a height of 7.9 mm, and a density of 3.8.
The titanium oxide used had a relative dielectric constant of 95, which was outside the scope of the present invention.
[Create two-dimensional periodic structure D5]
Similar to the creation of the two-dimensional periodic structure portion D1 of Example 1, a two-dimensional periodic structure portion D5 was created. However, in order to match the arrangement period with Example 1, the high dielectric constant regions A5 are spaced at 0.9 mm intervals.
Were arranged in a lattice form in 10 rows × 5 rows and fixed with an epoxy adhesive (manufactured by Nichiban Co., Ltd., Araldite AR-R30) to obtain a two-dimensional periodic structure part D5.
[Measurement of microwave transmission spectrum]
Similarly to Example 1, the transmission spectrum of the two-dimensional periodic structure portion D5 in the range of 1.4 to 3.4 GHz was measured, but no clear shielding effect derived from the photonic band gap was observed.
＜比較例２＞
［二次元周期構造部Ｄ６の作成］
実施例１で得られた高誘電率部位Ａ１を用い、担持体Ｃとしてポリエチレンテレフタレートフィルム（東レ(株)製、ルミラーＳ１０、厚さ７５μｍ）を用い、担持体Ｃ上に高誘電率部位Ａ１と低誘電率部位（空気）の配列周期が遮蔽対象の電磁波（２．４５ＧＨｚ）の波長の４分の１を下回るように、１７．０ｍｍの間隔をあけて高誘電率部位Ａ１を格子状に縦４列×横２列に配置し、エポキシ系接着剤（ニチバン社製、アラルダイトＡＲ−Ｒ３０）で固定して二次元周期構造部Ｄ６を得た。
［マイクロ波透過スペクトルの測定］
実施例１と同様に、二次元周期構造部Ｄ６の１．４〜３．４ＧＨｚの範囲における透過スペクトルを測定したが、フォトニックバンドギャップに由来する明確な遮蔽効果は観察されなかった。
<Comparative Example 2>
[Create two-dimensional periodic structure D6]
Using the high dielectric constant part A1 obtained in Example 1, a polyethylene terephthalate film (Lumirror S10, manufactured by Toray Industries, Inc., thickness 75 μm) is used as the carrier C, and the high dielectric constant part A1 and the carrier C are The high dielectric constant portion A1 is vertically arranged in a grid pattern with an interval of 17.0 mm so that the arrangement period of the low dielectric constant portion (air) is less than a quarter of the wavelength of the electromagnetic wave to be shielded (2.45 GHz). Arranged in 4 rows × 2 rows and fixed with an epoxy-based adhesive (manufactured by Nichiban Co., Ltd., Araldite AR-R30) to obtain a two-dimensional periodic structure portion D6.
[Measurement of microwave transmission spectrum]
Similar to Example 1, the transmission spectrum in the range of 1.4 to 3.4 GHz of the two-dimensional periodic structure portion D6 was measured, but no clear shielding effect derived from the photonic band gap was observed.
各実施例および比較例で結果について下記の表１に示す。
本発明の電磁波遮蔽体により、所望の波長の電磁波、特に電子レンジの加熱用マイクロ波を効率的に遮断することが可能であり、該電磁波遮蔽体を用いる余分な熱の発生もなく、また、本発明の二次元フォトニック結晶を有する電磁波遮蔽体は、三次元フォトニック結晶に比べ容易にかつ安価に提供することができる。 With the electromagnetic wave shielding body of the present invention, it is possible to efficiently block an electromagnetic wave having a desired wavelength, particularly a microwave for heating in a microwave oven, without generation of extra heat using the electromagnetic wave shielding body, The electromagnetic wave shielding body having the two-dimensional photonic crystal of the present invention can be provided easily and inexpensively as compared with the three-dimensional photonic crystal.
Claims (10)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2009157719A JP5281504B2 (en) | 2009-07-02 | 2009-07-02 | EMI shield |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2009157719A JP5281504B2 (en) | 2009-07-02 | 2009-07-02 | EMI shield |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2011014723A true JP2011014723A (en) | 2011-01-20 |
| JP5281504B2 JP5281504B2 (en) | 2013-09-04 |
Family
ID=43593330
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2009157719A Active JP5281504B2 (en) | 2009-07-02 | 2009-07-02 | EMI shield |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP5281504B2 (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2014197838A (en) * | 2013-03-08 | 2014-10-16 | 国立大学法人大阪大学 | Photonic crystal slab electromagnetic wave absorber, high frequency metal wiring circuit, electronic component, transmitter, receiver, and proximity radio communication system |
| JP2020526151A (en) * | 2017-06-27 | 2020-08-27 | クアンチー インスティテュート オブ アドヴァンスト テクノロジーＫｕａｎｇ−Ｃｈｉ Ｉｎｓｔｉｔｕｔｅ Ｏｆ Ａｄｖａｎｃｅｄ Ｔｅｃｈｎｏｌｏｇｙ | Metamaterial and method for producing the same |
| WO2022181774A1 (en) * | 2021-02-25 | 2022-09-01 | 住友金属鉱山株式会社 | System equipped with electromagnetic wave absorber, and electromagnetic wave absorbing method using electromagnetic wave absorber |
| WO2022181772A1 (en) * | 2021-02-25 | 2022-09-01 | 住友金属鉱山株式会社 | Electromagnetic wave absorbent body, system comprising electromagnetic wave absorbent body, and electromagnetic wave absorption method using electromagnetic wave absorbent body |
| WO2023033011A1 (en) * | 2021-09-03 | 2023-03-09 | 日東電工株式会社 | Electromagnetic wave shield |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH09132279A (en) * | 1995-11-02 | 1997-05-20 | C I Kasei Co Ltd | Electromagnetic shielding container, electromagnetic shielding sheet, electromagnetic shielding bag, and lunch |
| JP2000307305A (en) * | 1999-04-26 | 2000-11-02 | Hitachi Ltd | High frequency communication equipment |
| JP2000341031A (en) * | 1999-05-28 | 2000-12-08 | Ion Kogaku Kenkyusho:Kk | Three-dimensional periodic structure and its manufacture |
| WO2001067540A1 (en) * | 2000-03-06 | 2001-09-13 | Fujitsu Limited | Shielding metal plate and circuit device comprising the same |
| WO2004086102A1 (en) * | 2003-03-26 | 2004-10-07 | Tdk Corporation | Two-dimensional photonic crystal, and waveguide and resonator using the same |
| WO2004113965A1 (en) * | 2003-06-19 | 2004-12-29 | Tdk Corporation | Process for producing photonic crystal and photonic crystal |
-
2009
- 2009-07-02 JP JP2009157719A patent/JP5281504B2/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH09132279A (en) * | 1995-11-02 | 1997-05-20 | C I Kasei Co Ltd | Electromagnetic shielding container, electromagnetic shielding sheet, electromagnetic shielding bag, and lunch |
| JP2000307305A (en) * | 1999-04-26 | 2000-11-02 | Hitachi Ltd | High frequency communication equipment |
| JP2000341031A (en) * | 1999-05-28 | 2000-12-08 | Ion Kogaku Kenkyusho:Kk | Three-dimensional periodic structure and its manufacture |
| WO2001067540A1 (en) * | 2000-03-06 | 2001-09-13 | Fujitsu Limited | Shielding metal plate and circuit device comprising the same |
| WO2004086102A1 (en) * | 2003-03-26 | 2004-10-07 | Tdk Corporation | Two-dimensional photonic crystal, and waveguide and resonator using the same |
| WO2004113965A1 (en) * | 2003-06-19 | 2004-12-29 | Tdk Corporation | Process for producing photonic crystal and photonic crystal |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2014197838A (en) * | 2013-03-08 | 2014-10-16 | 国立大学法人大阪大学 | Photonic crystal slab electromagnetic wave absorber, high frequency metal wiring circuit, electronic component, transmitter, receiver, and proximity radio communication system |
| JP2020526151A (en) * | 2017-06-27 | 2020-08-27 | クアンチー インスティテュート オブ アドヴァンスト テクノロジーＫｕａｎｇ−Ｃｈｉ Ｉｎｓｔｉｔｕｔｅ Ｏｆ Ａｄｖａｎｃｅｄ Ｔｅｃｈｎｏｌｏｇｙ | Metamaterial and method for producing the same |
| WO2022181774A1 (en) * | 2021-02-25 | 2022-09-01 | 住友金属鉱山株式会社 | System equipped with electromagnetic wave absorber, and electromagnetic wave absorbing method using electromagnetic wave absorber |
| WO2022181772A1 (en) * | 2021-02-25 | 2022-09-01 | 住友金属鉱山株式会社 | Electromagnetic wave absorbent body, system comprising electromagnetic wave absorbent body, and electromagnetic wave absorption method using electromagnetic wave absorbent body |
| WO2023033011A1 (en) * | 2021-09-03 | 2023-03-09 | 日東電工株式会社 | Electromagnetic wave shield |
Also Published As
| Publication number | Publication date |
|---|---|
| JP5281504B2 (en) | 2013-09-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5281504B2 (en) | EMI shield | |
| Zhang et al. | Robust photonic band gap from tunable scatterers | |
| Chaplain et al. | Delineating rainbow reflection and trapping with applications for energy harvesting | |
| JP4440213B2 (en) | Fractal structure, fractal structure aggregate and their uses | |
| CN105633588B (en) | A kind of adjustable Meta Materials resonance device of polarization insensitive guided mode resonance quality factor | |
| JP2012530945A (en) | Amorphous material with perfect photonic, electronic or phononic band gap | |
| CN104701595B (en) | A kind of Meta Materials resonance device | |
| US20130017348A1 (en) | Invisible enclosure | |
| Tasolamprou et al. | Flexible 3D printed conductive metamaterial units for electromagnetic applications in microwaves | |
| Xie et al. | Tunable double-band perfect absorbers via acoustic metasurfaces with nesting helical tracks | |
| Yang et al. | 3D/4D printed tunable electrical metamaterials with more sophisticated structures | |
| Christensen et al. | Negative refraction and backward waves in layered acoustic metamaterials | |
| Asad et al. | Single port bio-sensor design using metamaterial split ring resonator | |
| Arruda et al. | Electromagnetic energy within coated spheres containing dispersive metamaterials | |
| Liao et al. | Broadband controllable acoustic focusing and asymmetric focusing by acoustic metamaterials | |
| CN109799551B (en) | Fully-polarized and ultra-wideband electromagnetic wave angle selection transparent structure | |
| CN105576335B (en) | A kind of adjustable Meta Materials resonance device of guided mode resonance quality factor | |
| Dunklin et al. | Gold nanoparticle-polydimethylsiloxane films reflect light internally by optical diffraction and Mie scattering | |
| Di Gennaro et al. | Isotropic properties of the photonic band gap in quasicrystals with low-index contrast | |
| Della Villa et al. | A comparative study of representative categories of EBG dielectric quasi-crystals | |
| Pastuszczak et al. | Multilayer metamaterial absorbers inspired by perfectly matched layers | |
| Li et al. | Transparent and broadband switchable absorber/reflector based on structured water medium | |
| Tian et al. | Ultrasensitive displacement sensor based on tunable horn-shaped resonators | |
| Kao et al. | Calculated and measured transmittance of metallodielectric photonic crystals incorporating flat metal elements | |
| Abdullahi et al. | Use of Thermochromic Properties of VO2 for Reconfigurable Frequency Selection |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20120507 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20130422 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20130507 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20130524 |
|
| R150 | Certificate of patent or registration of utility model |
Free format text: JAPANESE INTERMEDIATE CODE: R150 Ref document number: 5281504 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |