JPH0783197B2 - Electromagnetic shield material - Google Patents
Electromagnetic shield materialInfo
- Publication number
- JPH0783197B2 JPH0783197B2 JP16420683A JP16420683A JPH0783197B2 JP H0783197 B2 JPH0783197 B2 JP H0783197B2 JP 16420683 A JP16420683 A JP 16420683A JP 16420683 A JP16420683 A JP 16420683A JP H0783197 B2 JPH0783197 B2 JP H0783197B2
- Authority
- JP
- Japan
- Prior art keywords
- ferrite
- vol
- electromagnetic shield
- conductive
- shield material
- 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.)
- Expired - Lifetime
Links
Description
【発明の詳細な説明】 （発明の技術分野） 本発明は、電子機器の筐体等に使用するのに好適な電磁
シールド材に関する。TECHNICAL FIELD OF THE INVENTION The present invention relates to an electromagnetic shield material suitable for use in a casing of electronic equipment.
（技術の背景） コンピュータ等の電子機器において、従来は放射ノイズ
を遮蔽する電磁シールド材として金属を用いてきた。し
かし、機器筺体等のプラスチック化に伴ない、亜鉛容射
あるいは導電性塗料により筐体等を構成する合成樹脂表
面に導電性皮膜を形成したものが採用されるようになっ
ているが、皮膜付着強度等の問題点がある。続いて、導
電性材料を樹脂と複合化することによって筐体等の用途
に適した電磁シールド材を形成することが試みられた。(Background of the Technology) In electronic devices such as computers, conventionally, metal has been used as an electromagnetic shield material that shields radiation noise. However, with the plasticization of equipment housings, etc., the one in which a conductive film is formed on the surface of synthetic resin that forms the housing etc. with zinc spray or conductive paint has been adopted, There are problems such as strength. Subsequently, an attempt was made to form an electromagnetic shield material suitable for applications such as a housing by compounding a conductive material with a resin.
以上のような従来の電磁シールド材は、入射電波の大部
分を反射することにより透過量を減衰して放射ノイズの
遮蔽を行なうものであるが、これでは入射波に対して反
射波はほとんど減衰せず、たとえばコンピュータの筐体
にそのような従来の電磁シールド材を使用した場合、内
部の放射ノイズエネルギーは蓄積され、そのコンピュー
タ自身に対して干渉を招いたりもしくは蓄積、増幅され
た放射ノイズがコネクタ、ケーブル等のシールドが充分
ではない部分から漏出する。The conventional electromagnetic shield material as described above attenuates the amount of transmission by reflecting most of the incident radio waves and shields radiation noise. However, if such a conventional electromagnetic shield material is used for a computer case, for example, the radiated noise energy inside is accumulated, causing interference to the computer itself, or radiated noise amplified and accumulated. It leaks from the part where the shield such as the connector and the cable is not enough.
このような問題点に対して、導電性の反射体によって反
射した放射ノイズを吸収し、放射エネルギーの蓄積を抑
制することが望まれている。For such a problem, it is desired to absorb the radiation noise reflected by the conductive reflector and suppress the accumulation of the radiant energy.
（発明の目的） 本発明は、上記の点に鑑み、加工性の良好な複合フェラ
イトの一面に抵抗体層を形成する構成とし、入射電波の
透過量を充分に少なくするとともに、反射波を複合フェ
ライト部分で吸収して放射ノイズエネルギーの蓄積防止
を図った電磁シールド材を提供しようとするものであ
る。(Object of the Invention) In view of the above points, the present invention has a structure in which a resistor layer is formed on one surface of a composite ferrite having good workability, to sufficiently reduce the amount of transmission of incident radio waves and to combine reflected waves. The present invention aims to provide an electromagnetic shield material that is absorbed by the ferrite part to prevent accumulation of radiated noise energy.
（発明の構成） 本発明の電磁シールド材の構成は、第１図の如く、磁性
層１と抵抗体層（導電性層）２の２層構造、もしくは必
要に応じて抵抗体層上に絶縁層を設けた３層構造であ
り、磁性層１は好ましくは電波の反射量−6dB以下とす
るために次のような条件を満たすように設定される。(Structure of the Invention) The structure of the electromagnetic shield material of the present invention is, as shown in FIG. 1, a two-layer structure of a magnetic layer 1 and a resistor layer (conductive layer) 2 or, if necessary, insulation on the resistor layer. The magnetic layer 1 has a three-layer structure in which layers are provided, and the magnetic layer 1 is preferably set so as to satisfy the following conditions in order to reduce the reflection amount of radio waves to −6 dB or less.
（１）磁性層は各種ゴム、各種樹脂等の高分子材料にフ
ェライト粒子を分散した複合フェライトである。(1) The magnetic layer is a composite ferrite in which ferrite particles are dispersed in a polymer material such as various rubbers and various resins.
（２）フェライトはMFe2O4のスピネル構造を持つ。ただ
しＭはFe,Ni,Co,Mn,Mg,Cu,Zn等の１種もしくは２種以上
の組み合わせからなる。(2) Ferrite has the spinel structure of MFe 2 O 4 . However, M is composed of one kind or a combination of two or more kinds of Fe, Ni, Co, Mn, Mg, Cu, Zn and the like.
（３）フェライトの粒子径は平均粒子径で1.0〜500μｍ
の範囲のものである。(3) The average particle size of ferrite is 1.0 to 500 μm.
It is in the range of.
（４）フェライトの複素比透磁率 ｒ＝μｒ′−ｊμｒ″）の虚数項μｒ″は2.0以上で
あること。(4) Complex relative permeability of ferrite r = μr′−jμr ″) The imaginary term μr ″ must be 2.0 or more.
（５）筐体としての使用を考慮し、厚さ5mm以下であ
る。(5) The thickness is 5 mm or less in consideration of use as a case.
（６）フェライトの体積混合比は40vol％〜65vol％であ
る。(6) The volume mixing ratio of ferrite is 40 vol% to 65 vol%.
また、抵抗体層２は好ましくは電波の透過量−30dB以下
とするために次のような条件を満たすように設定され
る。Further, the resistor layer 2 is preferably set so as to satisfy the following conditions in order to set the radio wave transmission amount to −30 dB or less.
（１）抵抗体層は、導電性繊維布、導電性複合材料にい
づれか１つからなる（完全反射体でなくてもよい）。(1) The resistor layer is made of either conductive fiber cloth or conductive composite material (not necessarily a perfect reflector).
（２）導電性繊維布は、たとえばアクリルやナイロン繊
維の表面層に硫化銅CuxS（ただしｘ＝１〜２）を形成し
た繊維を織って布としたもの［商品名：サンダーロン
SS−N:日本蚕毛染色（株）製］又は高分子繊維の表面に
NiあるいはCuを沈着した繊維を織って布としたもの（商
品名：メタックス：（株）高瀬染工場製）等がある。導
電性繊維布の面抵抗は10Ω／□以下であること。(2) The conductive fiber cloth is, for example, a cloth obtained by weaving fibers in which copper sulfide Cu x S (where x = 1 to 2) is formed on the surface layer of acrylic or nylon fiber [Product name: Sanderlon
SS-N: Nippon Silkworm Dye Co., Ltd.] or on the surface of polymer fiber
There is a cloth woven from fibers with Ni or Cu deposited (trade name: Metax: manufactured by Takase Dye Factory). The sheet resistance of the conductive fiber cloth shall be 10Ω / □ or less.
（３）導電性複合材料は、各種ゴム、各種樹脂等の高分
子材料にたとえばカーボンブラック（ケッチェンブラッ
クEC:ライオン・アクゾ（株）製）を分散したものであ
る。その厚さは0.3〜3mm、体積抵抗率は10Ω−cm以下で
あること。(3) The conductive composite material is, for example, carbon black (Ketjen Black EC: manufactured by Lion Akzo Co., Ltd.) dispersed in a polymer material such as various rubbers and various resins. Its thickness shall be 0.3 to 3 mm and its volume resistivity shall be 10 Ω-cm or less.
なお、フェライト粒子の体積混合比が40vol％未満であ
ると、電波の反射量の減衰特性が劣化するので好まし
く、フェライト粒子の体積混合比が65vol％を越えると
加工性が劣化するので好ましくない。また、導電性繊維
布の面抵抗が10Ω／□を越えたり、導電性複合材料の体
積抵抗率が10Ω−cmを越えると、電波の透過減衰量が劣
化するので好ましくない。If the volume mixing ratio of ferrite particles is less than 40 vol%, the attenuation characteristic of the reflection amount of radio waves is deteriorated, and if the volume mixing ratio of ferrite particles exceeds 65 vol%, the workability is deteriorated, which is not preferable. Further, if the sheet resistance of the conductive fiber cloth exceeds 10 Ω / □ or the volume resistivity of the conductive composite material exceeds 10 Ω-cm, the transmission attenuation of radio waves deteriorates, which is not preferable.
（発明の実施例） 以下、本発明の電磁シールド材を実施例により詳細に説
明する。(Examples of the Invention) Hereinafter, the electromagnetic shield material of the present invention will be described in detail with reference to Examples.
実施例１ 平均粒径２μｍのMn−Zn−Feフェライトを60vol％、エ
ポキシ樹脂を40vol％の割合で混合した混合フェライト
Ｂで磁性層を構成し、面抵抗3.7Ω／□の導電性繊維（C
u沈着メタックス）を磁性層の片面に抵抗体層として複
合化（例えば磁性層と同時成型）した。この場合、複合
フェライトＢの材料定数は後述の表１の通りである。周
波数1000MHzのシールド特性は透過量−35dB、反射量は
−6dBとなった。Example 1 A magnetic layer was composed of mixed ferrite B in which 60 vol% of Mn-Zn-Fe ferrite having an average particle diameter of 2 μm and 40 vol% of epoxy resin were mixed to form a magnetic layer, and a conductive fiber (C
The u-deposited metax was compounded as a resistor layer on one side of the magnetic layer (for example, co-molded with the magnetic layer). In this case, the material constants of the composite ferrite B are as shown in Table 1 below. The shield characteristic at a frequency of 1000 MHz was -35 dB for transmission and -6 dB for reflection.
実施例２ 粒子径150μｍのMn−Zn−Feフェライトを60vol％、クロ
ロプレンゴム40vol％の割合で混合したフェライトＣで
磁性層を構成し、面抵抗3.7Ω／□の導電性繊維を磁性
層の片面に抵抗体層として複合化した。この場合、複合
フェライトＣの材料定数は後述の表１の通りである。Example 2 A magnetic layer was made of ferrite C in which Mn-Zn-Fe ferrite having a particle diameter of 150 μm was mixed at a ratio of 60 vol% and 40 vol% of chloroprene rubber. Was combined as a resistor layer. In this case, the material constants of the composite ferrite C are as shown in Table 1 below.
周波数1000MHzのシールド特性は透過量−35dB、反射量
は−8dBとなり、第２図実線で反射量の周波数特性を点
線で透過量の周波数特性を示す。The shield characteristic at a frequency of 1000 MHz is a transmission amount of −35 dB and a reflection amount of −8 dB. The solid line in FIG. 2 shows the reflection amount frequency characteristic and the dotted line shows the transmission amount frequency characteristic.
実施例３ 粒子径150μｍのMn−Zn−Feフェライトを60vol％、クロ
ロプレンゴム40vol％の割合で混合したフェライトＣで
磁性層を構成し、その片面にケッチェンブラック（体積
抵抗率0.6Ω−cmのもの）23vol％、クロロプレンゴム77
vol％の割合で混合した導電性複合材料を一体化した。
この場合、周波数1000MHzでのシールド特性は透過量−3
0dB、反射量は−8dBとなった。Example 3 A magnetic layer was constituted by ferrite C in which Mn-Zn-Fe ferrite having a particle diameter of 150 μm was mixed at a ratio of 60 vol% and 40 vol% of chloroprene rubber. 23 vol%, chloroprene rubber 77
The conductive composite materials mixed in a vol% ratio were integrated.
In this case, the shield characteristic at a frequency of 1000 MHz is the transmission amount −3.
The reflection amount was 0 dB and -8 dB.
ここで、εｒ′は複素比誘電率ｒの実数項、εｒ″は
同虚数項を示す。 Here, εr ′ is a real number term of the complex relative permittivity r, and εr ″ is the same imaginary number term.
以下の表２は、実施例1,2,3の1000MHzでの透過量と反射
量を比較して示したもので、参考のために、表１の複合
フェライトＡ（μｒ″が２より小さいもの）と面抵抗3.
7Ω／□の導電性繊維との組合せの場合を比較例として
示す。Table 2 below shows a comparison between the transmission amount and the reflection amount at 1000 MHz of Examples 1, 2, and 3. For reference, the composite ferrite A (μr ″ is less than 2 in Table 1) ) And sheet resistance 3.
The case of combination with 7Ω / □ conductive fiber is shown as a comparative example.
（発明の効果） 以上説明したように、本発明の電磁シールド材によれ
ば、次のような効果を上げることができる。 (Effects of the Invention) As described above, according to the electromagnetic shield material of the present invention, the following effects can be achieved.
（１）放射ノイズ等の入射電波を反射するだけでなく、
反射波を減衰させることができる。このため、機器筐体
として使用したとき、放射ノイズエネルギーが機器内に
蓄積されるのを防止することができる。(1) Not only reflects incident radio waves such as radiation noise, but also
The reflected wave can be attenuated. Therefore, when used as a device housing, it is possible to prevent radiated noise energy from being stored in the device.
（２）磁性層を高分子材料にフェライト粒子を混合した
フェライトで構成し、抵抗体層を導電性繊維布又は導電
性複合材料で構成しているので、任意の形状に成型する
ことが容易であり、軽量でかつ耐久性にも優れている。(2) Since the magnetic layer is made of ferrite in which ferrite particles are mixed with a polymer material, and the resistor layer is made of conductive fiber cloth or conductive composite material, it is easy to mold it into an arbitrary shape. Yes, it is lightweight and has excellent durability.
第１図は本発明の電磁シールド材の構造を示す断面図、
第２図は実施例２の場合の反射量及び透過量の周波数特
性を示すグラフである。 １……磁性層、２……抵抗体層。FIG. 1 is a sectional view showing the structure of an electromagnetic shield material of the present invention,
FIG. 2 is a graph showing frequency characteristics of reflection amount and transmission amount in the case of the second embodiment. 1 ... Magnetic layer, 2 ... Resistor layer.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 三沢 宣貴 東京都中央区日本橋一丁目13番１号 テイ ーデイーケイ株式会社内 (56)参考文献 特開 昭54−60504（ＪＰ，Ａ) 特開 昭47−26952（ＪＰ，Ａ) ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Nobutaka Misawa 1-13-1, Nihonbashi, Chuo-ku, Tokyo TDK Corporation (56) References JP-A-54-60504 (JP, A) JP-A-SHO 47-26952 (JP, A)
Claims (1)
40vol％〜65vol％の割合で混合した複素比透磁率の虚数
項（μｒ″）が２以上である複数フェライトの一面に、
面抵抗が10Ω／□以下の導電性繊維布又は体積抵抗率が
10Ω−cm以下の導電性複合材料からなる抵抗体層を複合
化又は一体化したことを特徴とする電磁シールド材。1. A volume mixing ratio of ferrite particles to a polymer material.
On one surface of a plurality of ferrites having an imaginary number term (μr ″) of complex relative permeability of 2 or more mixed in a ratio of 40 vol% to 65 vol%,
Conductive fiber cloth with surface resistance of 10Ω / □ or less or volume resistivity
An electromagnetic shield material, characterized in that a resistor layer made of a conductive composite material of 10 Ω-cm or less is compounded or integrated.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16420683A JPH0783197B2 (en) | 1983-09-08 | 1983-09-08 | Electromagnetic shield material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16420683A JPH0783197B2 (en) | 1983-09-08 | 1983-09-08 | Electromagnetic shield material |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6057700A JPS6057700A (en) | 1985-04-03 |
| JPH0783197B2 true JPH0783197B2 (en) | 1995-09-06 |
Family
ID=15788679
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP16420683A Expired - Lifetime JPH0783197B2 (en) | 1983-09-08 | 1983-09-08 | Electromagnetic shield material |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0783197B2 (en) |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH03114295A (en) * | 1989-09-27 | 1991-05-15 | Yoshio Niioka | Radio wave absorber |
| JPH0685472B2 (en) * | 1989-11-08 | 1994-10-26 | 鹿島建設株式会社 | Radio wave absorber |
| JP2666560B2 (en) * | 1990-10-29 | 1997-10-22 | ティーディーケイ株式会社 | Radio wave absorber |
| JP2591322B2 (en) * | 1990-10-29 | 1997-03-19 | ティーディーケイ株式会社 | Radio wave absorber |
| JP3097343B2 (en) * | 1992-08-04 | 2000-10-10 | ティーディーケイ株式会社 | Thin radio wave absorber |
| JP2951487B2 (en) * | 1992-09-11 | 1999-09-20 | ユニデン株式会社 | Electromagnetic wave shielding method |
| JP2002217585A (en) * | 2001-01-15 | 2002-08-02 | Kitagawa Ind Co Ltd | Electromagnetic wave suppression member, and method for suppressing electromagnetic wave |
| JP2003110278A (en) * | 2001-10-01 | 2003-04-11 | Tdk Corp | Radio wave absorber and radio wave absorbing sheet, and their manufacturing method |
| JP5140249B2 (en) * | 2006-06-01 | 2013-02-06 | 株式会社シンセイ | Manufacturing method for shield case of electronic equipment |
| JP2010147218A (en) * | 2008-12-18 | 2010-07-01 | Panasonic Corp | Ferrite composite sheet and method of manufacturing the same, and communication device for mobile terminal using the same |
-
1983
- 1983-09-08 JP JP16420683A patent/JPH0783197B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6057700A (en) | 1985-04-03 |
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