JPH10308592A - Composite magnetic body and electromagnetic interference suppressing body - Google Patents
Composite magnetic body and electromagnetic interference suppressing bodyInfo
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- JPH10308592A JPH10308592A JP11716497A JP11716497A JPH10308592A JP H10308592 A JPH10308592 A JP H10308592A JP 11716497 A JP11716497 A JP 11716497A JP 11716497 A JP11716497 A JP 11716497A JP H10308592 A JPH10308592 A JP H10308592A
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- magnetic
- composite magnetic
- powder
- composite
- microwave band
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Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は，電磁干渉抑制体と
そのための複合磁性材料に関し，詳しくは，高周波領
域，特に，マイクロ波帯用電磁干渉抑制体とそれに用い
る複合磁性材料に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic interference suppressor and a composite magnetic material therefor, and more particularly to an electromagnetic interference suppressor for use in a high frequency region, particularly for a microwave band, and a composite magnetic material used therefor.
【０００２】[0002]
【従来の技術】近年，デジタル電子機器をはじめ高周波
を利用する電子機器類の普及が進み，中でも準マイクロ
波帯あるいはマイクロ波帯を使用する移動通信機器類の
普及がめざましい。このような，携帯電話に代表される
移動体通信機器では，小型化・軽量化の要求が顕著であ
り，電子部品の高密度実装化が最大の技術課題となって
いる。従って，過密に実装された電子部品類やプリント
配線あるいはモジュール間配線等が互いに極めて接近す
ることになり，更には，信号処理速度の高速化も図られ
ている為，静電結合及び／又は電磁結合による線間結合
の増大化や放射ノイズによる干渉などが生じ，機器の正
常な動作を妨げる事態が少なからず生じている。2. Description of the Related Art In recent years, electronic devices using high frequencies, such as digital electronic devices, have become widespread. In particular, mobile communication devices using a quasi-microwave band or a microwave band have been remarkably spread. In such mobile communication devices typified by mobile phones, there is a remarkable demand for miniaturization and weight reduction, and high-density mounting of electronic components is the greatest technical problem. Therefore, densely mounted electronic components, printed wiring or wiring between modules, etc., are extremely close to each other, and furthermore, the signal processing speed has been increased, so that electrostatic coupling and / or electromagnetic Coupling causes an increase in line-to-line coupling and interference due to radiated noise, etc., and there are not a few cases where normal operation of devices is hindered.
【０００３】このようないわゆる高周波電磁障害に対し
て従来は，主に導体シールドを施す事による対策がなさ
れてきた。Conventionally, countermeasures against such a so-called high-frequency electromagnetic interference have been made mainly by providing a conductor shield.
【０００４】[0004]
【発明が解決しようとする課題】しかしながら，導体シ
ールドは，空間とのインピーダンス不整合に起因する電
磁波の反射を利用する電磁障害対策である為に，遮蔽効
果は得られても不要輻射源からの反射による電磁結合が
助長される欠点がある。その欠点を解消するために，二
次的な電磁障害対策として，磁性体の磁気損失，即ち虚
数部透磁率μ''を利用した不要輻射の抑制が有効である
と考えられる。However, since the conductor shield is an electromagnetic interference countermeasure that utilizes the reflection of electromagnetic waves due to impedance mismatch with the space, even if the shielding effect is obtained, the shield from unnecessary radiation sources can be obtained. There is a disadvantage that electromagnetic coupling by reflection is promoted. In order to solve the drawback, it is considered effective to suppress the unnecessary radiation using the magnetic loss of the magnetic material, that is, the imaginary part permeability μ ″, as a secondary electromagnetic interference countermeasure.
【０００５】ここで，不要輻射の吸収効率は，μ''＞
μ' なる周波数範囲において，μ''の大きさに見合って
高まることが知られている。従って，マイクロ波帯にて
大きな磁気損失を得るためには，実数部透磁率がＶＨＦ
帯（３０ＭＨｚ〜３００ＭＨｚ），準マイクロ波帯（３
００ＭＨｚ〜３ＧＨｚ），乃至はマイクロ波帯の低周波
側（３ＧＨｚ〜概ね１０ＧＨｚ）にて磁気共鳴により減
衰する特性を実現する必要がある。[0005] Here, the absorption efficiency of unnecessary radiation is μ ″>
It is known that in the frequency range of μ ′, it increases in proportion to the size of μ ″. Therefore, in order to obtain a large magnetic loss in the microwave band, the real part magnetic permeability is VHF.
Band (30 MHz to 300 MHz), quasi-microwave band (3
(00 MHz to 3 GHz) or a characteristic that attenuates due to magnetic resonance on the low frequency side (3 GHz to approximately 10 GHz) of the microwave band.
【０００６】そこで，本発明の一技術的課題は，ＶＨＦ
帯乃至マイクロ波帯に磁気共鳴が現れ，その結果，マイ
クロ波帯に大きな磁気損失を有する（即ち，虚数部透磁
率μ''が大きな）複合磁性体の提供することにある。Therefore, one technical problem of the present invention is that the VHF
An object of the present invention is to provide a composite magnetic material having magnetic resonance appearing in the band or the microwave band, and as a result, having a large magnetic loss in the microwave band (that is, having a large imaginary part permeability μ ″).
【０００７】また，本発明の他の技術的課題は，前記複
合磁性体を用いた電磁干渉抑制体を提供することにあ
る。Another technical object of the present invention is to provide an electromagnetic interference suppressor using the composite magnetic material.
【０００８】[0008]
【課題を解決するための手段】本発明によれば，保磁力
Ｈｃが１０〜３００ＯｅのＦｅ3 Ｏ4 （マグネタイト）
からなる磁性粉末と前記磁性粉末を結着する有機結合剤
とを備えた複合磁性体であって，ＶＨＦ帯乃至マイクロ
波帯において，磁気共鳴を有することを特徴とする複合
磁性体が得られる。According to the present invention, Fe 3 O 4 (magnetite) having a coercive force Hc of 10 to 300 Oe is provided.
A composite magnetic body comprising a magnetic powder comprising: and a magnetic binder for binding the magnetic powder, wherein the composite magnetic body has magnetic resonance in a VHF band or a microwave band.
【０００９】また，本発明によれば，前記複合磁性体に
おいて，前記磁性粉末粒子が球状又は八面体状の形状を
有することを特徴とする複合磁性体が得られる。According to the present invention, there is provided the composite magnetic material, wherein the magnetic powder particles have a spherical or octahedral shape.
【００１０】また，本発明によれば，前記複合磁性体に
おいて，前記磁性粉末粒子が形状磁気異方性を有するこ
とを特徴とする複合磁性体が得られる。Further, according to the present invention, in the composite magnetic body, the composite magnetic body is characterized in that the magnetic powder particles have a shape magnetic anisotropy.
【００１１】また，本発明によれば，前記複合磁性体に
おいて，前記磁性粉末粒子が針状の形状を有し，前記複
合磁性体中で配向もしくは配列されていることを特徴と
する複合磁性体が得られる。According to the present invention, in the composite magnetic body, the magnetic powder particles have a needle-like shape and are oriented or arranged in the composite magnetic body. Is obtained.
【００１２】さらに，本発明によれば，前記したいずれ
かの複合磁性体を任意の形状に加工してなり，マイクロ
波帯に磁気損失を有することを特徴とする電磁干渉抑制
体が得られる。Further, according to the present invention, there is provided an electromagnetic interference suppressor obtained by processing any of the above-described composite magnetic materials into an arbitrary shape and having a magnetic loss in a microwave band.
【００１３】[0013]
【発明の実施の形態】以下，本発明の実施の形態につい
て図面を参照して説明する。Embodiments of the present invention will be described below with reference to the drawings.
【００１４】図１は本発明の実施の形態による複合磁性
体の構造を模式的に示す断面図である。図１を参照する
と，複合磁性体１は，針状のＦｅ3 Ｏ4 （マグネタイ
ト）粒子からなる磁性粉末２を有機結着剤３の層の中に
分散し結着してなるものである。ここで，図中の符号４
は，取扱上で強度を必要とする場合，或いは電磁干渉抑
制体として高周波磁気損失特性の他にシールド特性を必
要とする場合に設けられる支持体で，機械的強度の改善
を目的とする場合には絶縁板でよいが，シールド特性を
必要とする場合には電気的特性を考慮して導電性の良い
材料を選択する必要がある。尚，後述する図３における
銅板も導電性の高いシールド材として使われている。FIG. 1 is a sectional view schematically showing a structure of a composite magnetic body according to an embodiment of the present invention. Referring to FIG. 1, a composite magnetic body 1 is formed by dispersing and binding a magnetic powder 2 composed of acicular Fe 3 O 4 (magnetite) particles in a layer of an organic binder 3. Here, reference numeral 4 in FIG.
This is a support provided when the strength is required in handling or when the electromagnetic interference suppressor needs shielding properties in addition to the high-frequency magnetic loss properties, and the purpose is to improve the mechanical strength. May be an insulating plate, but if shielding characteristics are required, it is necessary to select a material having good conductivity in consideration of the electrical characteristics. Note that a copper plate in FIG. 3 described later is also used as a highly conductive shielding material.
【００１５】磁性粉末２としては，保磁力Ｈｃが１０〜
３００ＯｅのＦｅ3 Ｏ4 （マグネタイト）を原料素材と
して用いる。このＦｅ3 Ｏ4 （マグネタイト）粉末は，
α−Ｆｅ2 Ｏ3 （ヘマタイト）粉末やγ−Ｆｅ2 Ｏ
3 （マグヘマイト）粉末を還元することにより直接微細
な寸法の粉末として得られる。複合磁性体１は，この磁
性粉末２を有機結着剤３で結着することによりを得るこ
とができる。The magnetic powder 2 has a coercive force Hc of 10 to 10.
300 Oe Fe 3 O 4 (magnetite) is used as a raw material. This Fe 3 O 4 (magnetite) powder
α-Fe 2 O 3 (hematite) powder or γ-Fe 2 O
3 By reducing (maghemite) powder, it can be obtained directly as a fine-sized powder. The composite magnetic body 1 can be obtained by binding the magnetic powder 2 with the organic binder 3.
【００１６】上記複合磁性体１において，より大きな虚
数部透磁率μ''を得るためには，磁性粉を針状ないし板
状にすることで形状異方性を付与し，その厚みを表皮深
さと同等以下にすると共に，反磁界係数Ｎｄをほぼ１に
近づけるために，針状ないし板状粉末のアスペクト比を
概ね１０以上とすると共に，磁性粉を複合磁性体中で配
向，配列させるとよい。ここで，表皮深さδは，次の数
１式により与えられる。In the composite magnetic body 1, in order to obtain a larger imaginary part magnetic permeability μ ″, the magnetic powder is made acicular or plate-like to give shape anisotropy, and its thickness is increased by the skin depth. In order to make the demagnetizing factor Nd close to 1, the aspect ratio of the acicular or plate-like powder should be approximately 10 or more, and the magnetic powder should be oriented and arranged in the composite magnetic material. . Here, the skin depth δ is given by the following equation (1).
【００１７】[0017]
【数１】 (Equation 1)
【００１８】上述の数１式において，ρは比抵抗，μは
透磁率，ｆは周波数を夫々表す。ここで，目的の周波数
によってその値が異なってくるが，粉末合成のしかたや
反応条件の設定を変えることで，所望の表皮深さとアス
ペクト比を有する磁性粉末を得ることが出来る。In the above equation 1, ρ represents specific resistance, μ represents magnetic permeability, and f represents frequency. Here, the value varies depending on the target frequency. By changing the method of powder synthesis and the setting of the reaction conditions, a magnetic powder having a desired skin depth and aspect ratio can be obtained.
【００１９】上記複合磁性体１に用いる有機結着剤３と
しては，ポリエステル系樹脂，ポリエチレン系樹脂，ポ
リ塩化ビニル系樹脂，ポリビニルブチラール樹脂，ポリ
ウレタン樹脂，セルロース系樹脂，ＡＢＳ樹脂，ニトリ
ル−ブタジエン系ゴム，スチレン−ブタジエン系ゴム，
エポキシ樹脂，フェノール樹脂，アミド系樹脂，イミド
系樹脂，或いはそれらの共重合体を挙げることが出来
る。The organic binder 3 used in the composite magnetic body 1 includes polyester resin, polyethylene resin, polyvinyl chloride resin, polyvinyl butyral resin, polyurethane resin, cellulose resin, ABS resin, nitrile-butadiene resin. Rubber, styrene-butadiene rubber,
An epoxy resin, a phenol resin, an amide resin, an imide resin, or a copolymer thereof can be used.
【００２０】以上に述べたＦｅ3 Ｏ4 （マグネタイト）
からなる磁性粉末２と有機結着剤３とを混練・分散し複
合磁性体１を得る手段には，特に制限はなく，用いる結
着剤の性質や工程の容易さを基準に好ましい方法を選択
すればよい。The above-mentioned Fe 3 O 4 (magnetite)
The means for obtaining the composite magnetic material 1 by kneading and dispersing the magnetic powder 2 comprising the organic binder 3 and the organic binder 3 is not particularly limited, and a preferable method is selected based on the properties of the binder used and the ease of the process. do it.
【００２１】この混練・分散された磁性体混合物中の磁
性粒子を配向・配列させる手段としては，剪断応力によ
る方法と磁場配向による方法があり，いずれの方法を用
いても良い。As means for orienting and arranging the magnetic particles in the kneaded and dispersed magnetic substance mixture, there are a method based on shear stress and a method based on magnetic field orientation, and any method may be used.
【００２２】尚，本発明の実施の形態による複合磁性体
及びそれを用いた電磁干渉抑制体は，その構成要素から
判るように容易に可撓性を付与することが可能であり，
複雑な形状への対応や，厳しい耐振動，衝撃要求への対
応が可能である。It should be noted that the composite magnetic body and the electromagnetic interference suppressor using the same according to the embodiment of the present invention can easily be provided with flexibility as can be seen from the components thereof.
It can respond to complicated shapes and meet severe vibration and shock requirements.
【００２３】以下，本発明の実施の形態による複合磁性
体の製造の具体例について述べる。Hereinafter, a specific example of the production of the composite magnetic material according to the embodiment of the present invention will be described.
【００２４】まず，水熱合成法により，保磁力Ｈｃと粉
末形状の異なる各種のＦｅ3 Ｏ4 粉末を作成し，これら
を磁性粉末試料とした。。First, various Fe 3 O 4 powders having different coercive forces Hc and powder shapes were prepared by a hydrothermal synthesis method, and these were used as magnetic powder samples. .
【００２５】これらの各種粉末を用いて以下に述べる複
合磁性体試料を作製し，μ−ｆ特性を調べた。Using these various powders, composite magnetic material samples described below were prepared, and their μ-f characteristics were examined.
【００２６】μ−ｆ特性の測定には，トロイダル形状に
加工された複合磁性体試料を用いた。これを１ターンコ
イルを形成するテストフィクスチャに挿入し，インピー
ダンスを計測することにより，μ' 及びμ''を求めた。For the measurement of the μ-f characteristic, a composite magnetic material sample processed into a toroidal shape was used. This was inserted into a test fixture forming a one-turn coil, and μ ′ and μ ″ were determined by measuring the impedance.
【００２７】（試料１）以下の表１の配合からなる磁性
体ペーストを調合し，これをドクターブレード法により
製膜し，熱プレスを施した後に８５℃にて２４時間キュ
アリングを行い試料１を得た。(Sample 1) A magnetic paste having the composition shown in Table 1 below was prepared, formed into a film by the doctor blade method, subjected to hot pressing, and then cured at 85 ° C. for 24 hours to obtain Sample 1. I got
【００２８】[0028]
【表１】 [Table 1]
【００２９】（試料２）以下の表２の配合からなる磁性
体ペーストを調合し，これをドクターブレード法により
製膜し，熱プレスを施した後に８５℃にて２４時間キュ
アリングを行い試料２を得た。(Sample 2) A magnetic paste having the composition shown in Table 2 below was prepared, formed into a film by a doctor blade method, subjected to hot pressing, and then cured at 85 ° C. for 24 hours to obtain a sample 2 I got
【００３０】[0030]
【表２】 [Table 2]
【００３１】（試料３）以下の表３の配合からなる磁性
体ペーストを調合し，これをドクターブレード法により
製膜し，熱プレスを施した後に８５℃にて２４時間キュ
アリングを行い試料３を得た。(Sample 3) A magnetic paste having the composition shown in Table 3 below was prepared, formed into a film by the doctor blade method, subjected to hot pressing, and then cured at 85 ° C. for 24 hours to obtain Sample 3. I got
【００３２】尚，得られた試料３を走査型電子顕微鏡を
用いて解析したところ，粒子配列方向は試料膜面内の長
手方向であった。When the obtained sample 3 was analyzed using a scanning electron microscope, the particle arrangement direction was the longitudinal direction in the sample film plane.
【００３３】[0033]
【表３】 [Table 3]
【００３４】上記の試料１〜３について測定された磁気
共鳴周波数ｆｒおよび周波数２ＧＨｚのときの虚数部透
磁率μ''を下記表４に示す。Table 4 shows the magnetic resonance frequency fr and the imaginary part magnetic permeability μ ″ at a frequency of 2 GHz measured for the above-mentioned samples 1 to 3.
【００３５】[0035]
【表４】 [Table 4]
【００３６】また，図２は，試料１のμ−ｆ特性を示す
もので，他の試料についても表１に示すｆｒの大きさか
ら判るように，高周波数領域に磁気共鳴が認められた。FIG. 2 shows the μ-f characteristic of the sample 1. As can be seen from the magnitude of fr shown in Table 1, magnetic resonance was observed in the high frequency region of the other samples.
【００３７】前記表１および図２からわかるように，本
発明によれば，マイクロ波帯で磁気損失の高い複合磁性
材料が得られる。As can be seen from Table 1 and FIG. 2, according to the present invention, a composite magnetic material having a high magnetic loss in a microwave band can be obtained.
【００３８】又，上記試料を用いて，その電磁干渉抑制
効果を図３のような評価系を用いて測定した。Further, the effect of suppressing electromagnetic interference was measured using the above-mentioned sample using an evaluation system as shown in FIG.
【００３９】ここで，厚さが２ｍｍで一辺の長さが２０
ｃｍの複合磁性体１０の裏に銅板１１を裏打ちして電磁
干渉抑制体試料を作成した。この試料に対し，電磁界波
源用発信器１２からループ径１ｍｍの送信用微小ループ
アンテナ１３を介して，電磁波を放射し，電磁干渉抑制
体試料からの反射波を同じ寸法形状の受信用微小ループ
アンテナ１４で受信して，反射波の強度ネットワークア
ナライザ（電磁界強度測定器）１５で測定した。Here, the thickness is 2 mm and the length of one side is 20
A copper plate 11 was backed on the back of the composite magnetic body 10 cm to prepare an electromagnetic interference suppressor sample. An electromagnetic wave is radiated from the electromagnetic wave source oscillator 12 through the transmitting minute loop antenna 13 having a loop diameter of 1 mm to the sample, and the reflected wave from the electromagnetic interference suppressing body sample is received by the receiving minute loop having the same size and shape. The signal was received by the antenna 14 and the intensity of the reflected wave was measured by a network analyzer (electromagnetic field intensity measuring device) 15.
【００４０】その結果を表面抵抗と共に下記表５に示
す。The results are shown in Table 5 below together with the surface resistance.
【００４１】[0041]
【表５】 [Table 5]
【００４２】ここで，表面抵抗はＡＳＴＭ−Ｄ−２５７
法による測定値である。電磁干渉抑制効果の値は，銅板
を基準（０ｄＢ）としたときの信号減衰量である。Here, the surface resistance is ASTM-D-257.
It is a measured value by the method. The value of the electromagnetic interference suppression effect is the signal attenuation when the copper plate is set as a reference (0 dB).
【００４３】前記表２により以下に述べる効果が明白で
ある。The following effects are apparent from Table 2 above.
【００４４】即ち，本発明の複合磁性体によれば，表面
抵抗の値が１０7 〜１０8 Ωとなっており，導体やバル
クの金属磁性体等にみられるようなインピーダンス不整
合による電磁波の表面反射を抑制出来る。That is, according to the composite magnetic material of the present invention, the value of the surface resistance is 10 7 to 10 8 Ω, and the electromagnetic wave due to the impedance mismatch as seen in a conductor, a bulk metal magnetic material, or the like. Surface reflection can be suppressed.
【００４５】更に，本発明の複合磁性体は，マイクロ波
帯で良好な電磁干渉抑制効果を有することが理解出来
る。Further, it can be understood that the composite magnetic material of the present invention has a good effect of suppressing electromagnetic interference in the microwave band.
【００４６】[0046]
【発明の効果】以上述べたように，本発明によれば，Ｆ
ｅ3 Ｏ4 （マグネタイト）からなる磁性粉末が有機結着
剤で結着されてなり，マイクロ波帯で高い磁気損失を有
し，従ってマイクロ波帯の電磁波を抑制できる複合磁性
体が提供できる。As described above, according to the present invention, F
It is possible to provide a composite magnetic material in which a magnetic powder made of e 3 O 4 (magnetite) is bound with an organic binder, has high magnetic loss in a microwave band, and can suppress electromagnetic waves in the microwave band.
【００４７】また，本発明によれば，前記複合磁性体を
用いてマイクロ波帯で有効な薄厚の電磁干渉抑制体を提
供することが出来る。Further, according to the present invention, it is possible to provide a thin electromagnetic interference suppressor which is effective in a microwave band by using the composite magnetic material.
【図１】本発明の実施の形態による複合磁性体の構造を
模式的に示す断面を図である。FIG. 1 is a cross-sectional view schematically showing a structure of a composite magnetic body according to an embodiment of the present invention.
【図２】本発明の実施の形態による複合磁性体の試料１
のμ−ｆ特性を示す図である。FIG. 2 shows a sample 1 of a composite magnetic material according to the embodiment of the present invention.
FIG. 4 is a diagram showing the μ-f characteristic of FIG.
【図３】本発明の実施の形態による複合磁性体試料を用
いた電磁干渉抑制体の特性評価に用いた評価系を示す概
略図である。FIG. 3 is a schematic diagram showing an evaluation system used for evaluating characteristics of an electromagnetic interference suppressor using a composite magnetic material sample according to an embodiment of the present invention.
１ 複合磁性体 ２ 磁性粉末（針状Ｆｅ3 Ｏ4 （マグネタイト）
磁性体粒子） ３ 有機結着剤 ４ 支持体 １０ 複合磁性体 １１ 銅板 １２ 電磁界波源用発信器 １３ 送信用微小ループアンテナ １４ 受信用微小ループアンテナ １５ 電磁界強度測定器1 composite magnetic body 2 magnetic powder (needle-like Fe 3 O 4 (magnetite)
Magnetic Particles) 3 Organic Binder 4 Support 10 Composite Magnetic Material 11 Copper Plate 12 Transmitter for Electromagnetic Wave Source 13 Micro Loop Antenna for Transmission 14 Micro Loop Antenna for Reception 15 Electromagnetic Field Strength Measuring Instrument
Claims (5)
Ｏ4 （マグネタイト）からなる磁性粉末と前記磁性粉末
を結着する有機結合剤とを備えた複合磁性体であって，
ＶＨＦ帯乃至マイクロ波帯において，磁気共鳴を有する
ことを特徴とする複合磁性体。1. An Fe 3 having a coercive force Hc of 10 to 300 Oe.
A composite magnetic material comprising a magnetic powder made of O 4 (magnetite) and an organic binder binding the magnetic powder,
A composite magnetic material having magnetic resonance in a VHF band or a microwave band.
記磁性粉末粒子が球状又は八面体状の形状を有すること
を特徴とする複合磁性体。2. The composite magnetic body according to claim 1, wherein said magnetic powder particles have a spherical or octahedral shape.
記磁性粉末粒子が形状磁気異方性を有することを特徴と
する複合磁性体。3. The composite magnetic body according to claim 1, wherein said magnetic powder particles have shape magnetic anisotropy.
記磁性粉末粒子が針状の形状を有し，前記複合磁性体中
で配向もしくは配列されていることを特徴とする複合磁
性体。4. The composite magnetic body according to claim 3, wherein said magnetic powder particles have a needle-like shape and are oriented or arranged in said composite magnetic body.
記載の複合磁性体を任意の形状に加工してなり，マイク
ロ波帯に磁気損失を有することを特徴とする電磁干渉抑
制体。5. An electromagnetic interference suppressor obtained by processing the composite magnetic body according to claim 1 into an arbitrary shape and having a magnetic loss in a microwave band. .
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11716497A JPH10308592A (en) | 1997-05-07 | 1997-05-07 | Composite magnetic body and electromagnetic interference suppressing body |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11716497A JPH10308592A (en) | 1997-05-07 | 1997-05-07 | Composite magnetic body and electromagnetic interference suppressing body |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH10308592A true JPH10308592A (en) | 1998-11-17 |
Family
ID=14705043
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP11716497A Withdrawn JPH10308592A (en) | 1997-05-07 | 1997-05-07 | Composite magnetic body and electromagnetic interference suppressing body |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH10308592A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002271468A (en) * | 2001-03-09 | 2002-09-20 | Nec Tokin Corp | Electromagnetic wave protective device and portable communication apparatus fixed with that device |
| JP2002280208A (en) * | 2001-03-22 | 2002-09-27 | Mitsubishi Cable Ind Ltd | Wave absorber |
| JP2008103691A (en) * | 2006-09-05 | 2008-05-01 | Matsushita Electric Ind Co Ltd | Magnetic substance striped array sheet, rfid magnetic sheet, electromagnetic shield sheet, and manufacturing methods for them |
| RU2713365C1 (en) * | 2019-04-01 | 2020-02-04 | Федеральное государственное бюджетное образовательное учреждение высшего образования "Кубанский государственный технологический университет" (ФГБОУ ВО "КубГТУ") | Method of producing composite material |
-
1997
- 1997-05-07 JP JP11716497A patent/JPH10308592A/en not_active Withdrawn
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002271468A (en) * | 2001-03-09 | 2002-09-20 | Nec Tokin Corp | Electromagnetic wave protective device and portable communication apparatus fixed with that device |
| JP4598975B2 (en) * | 2001-03-09 | 2010-12-15 | Ｎｅｃトーキン株式会社 | Portable communication equipment with an electromagnetic wave protection device |
| JP2002280208A (en) * | 2001-03-22 | 2002-09-27 | Mitsubishi Cable Ind Ltd | Wave absorber |
| JP2008103691A (en) * | 2006-09-05 | 2008-05-01 | Matsushita Electric Ind Co Ltd | Magnetic substance striped array sheet, rfid magnetic sheet, electromagnetic shield sheet, and manufacturing methods for them |
| RU2713365C1 (en) * | 2019-04-01 | 2020-02-04 | Федеральное государственное бюджетное образовательное учреждение высшего образования "Кубанский государственный технологический университет" (ФГБОУ ВО "КубГТУ") | Method of producing composite material |
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| A761 | Written withdrawal of application |
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