JP2000003810A - Dust core - Google Patents
Dust coreInfo
- Publication number
- JP2000003810A JP2000003810A JP18153898A JP18153898A JP2000003810A JP 2000003810 A JP2000003810 A JP 2000003810A JP 18153898 A JP18153898 A JP 18153898A JP 18153898 A JP18153898 A JP 18153898A JP 2000003810 A JP2000003810 A JP 2000003810A
- Authority
- JP
- Japan
- Prior art keywords
- powder
- flat
- crystal structure
- insulating
- dust core
- 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.)
- Pending
Links
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、チョークコイル等
に用いられる高性能な圧粉磁芯に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-performance dust core used for a choke coil or the like.
【０００２】[0002]
【従来の技術】高周波で用いられるチョークコイルとし
て、フェライト磁芯や圧粉磁芯が使用されている。これ
らの内、フェライト磁芯は、飽和磁束密度が小さいとい
う欠点を有している。これに対して、金属粉末を成形し
て作製される圧粉磁芯は、軟磁性フェライトに比べて高
い飽和磁束密度を持つため、直流重畳性に優れていると
いう長所を有している。2. Description of the Related Art Ferrite cores and dust cores are used as choke coils used at high frequencies. Among them, the ferrite core has a disadvantage that the saturation magnetic flux density is small. On the other hand, a dust core manufactured by molding a metal powder has an advantage of being superior in DC superimposition since it has a higher saturation magnetic flux density than soft magnetic ferrite.
【０００３】しかし、圧粉磁芯は、金属粉末を有機バイ
ンダー等と混合し圧縮成型して作製するため、透磁率が
低い、また透磁率の周波数特性が悪いという欠点を有す
る。However, since the dust core is prepared by mixing a metal powder with an organic binder or the like and compressing and molding the same, it has a drawback that the magnetic permeability is low and the frequency characteristic of the magnetic permeability is poor.
【０００４】一方、近年の電子機器の小型化要請に伴う
電子部品の小型化の要求に対し、圧粉磁芯の磁気特性に
対しても高特性化が強く望まれている。具体的な例とし
て、圧粉磁芯の小型化を達成しつつ、コイルのインダク
タンスは同等であるという要求に対し、その解決手段と
して、圧粉磁芯の透磁率の向上、周波数特性の改善及び
コアロスの改善が強く望まれている。On the other hand, in response to the demand for miniaturization of electronic components accompanying the recent demand for miniaturization of electronic equipment, it is strongly desired to improve the magnetic properties of the dust core. As a specific example, the demand for the coil to have the same inductance while achieving the miniaturization of the dust core is solved by improving the permeability of the dust core, improving the frequency characteristics, and the like. Improvement of core loss is strongly desired.
【０００５】一般に、圧粉磁芯の透磁率を向上させる方
法は大別して二点考えられ、原料である素材自体の透
磁率を上げる、充填率を上げる、という方法である。
従来透磁率を向上する方法は主として充填率の向上に主
点が置かれており、その手段として、例えば、成形圧
力を上げる、バインダー条件を種々変化させる、二
つ以上の異種形状、粒度、組成等の異なる粉末を配合さ
せる、等が検討されてきた。[0005] In general, there are roughly two methods for improving the magnetic permeability of a dust core. One method is to increase the magnetic permeability of the raw material itself, and the other is to increase the filling rate.
Conventionally, the method of improving the magnetic permeability mainly focuses on the improvement of the filling rate, for example, increasing the molding pressure, changing the binder conditions variously, two or more different shapes, particle size, composition It has been studied to mix powders different from each other.
【０００６】[0006]
【発明が解決しようとする課題】しかし、上記の方法に
よる圧粉磁芯の透磁率の改善は既に検討がしつくされて
おり、例えば、成形圧力を上げる方法にしても、金型寿
命の低下等、製造コストの面からも無視できない状況に
ある。従って、現状の特性レベルからの大幅な改善は困
難な状況にあり、とても近年の機器の小型化に対応でき
るものではない。However, the improvement of the magnetic permeability of the dust core by the above-mentioned method has already been studied. For example, even if the molding pressure is increased, the life of the mold is reduced. The situation cannot be ignored in terms of manufacturing costs. Therefore, it is difficult to make a significant improvement from the current characteristic level, and it cannot cope with very recent downsizing of equipment.
【０００７】よって、本発明の課題は、高透磁率で、高
周波特性に優れ、しかも容易に製造できる圧粉磁芯を提
供することにある。Accordingly, an object of the present invention is to provide a dust core having high magnetic permeability, excellent high-frequency characteristics, and which can be easily manufactured.
【０００８】[0008]
【課題を解決するための手段】本発明者らは、前記課題
を達成するべく粉末形状と圧粉磁芯の透磁率の関係の検
討を重ねた結果、原料粉末のアスペクト比を高くするこ
とにより、圧粉磁芯の透磁率が格段に向上することがわ
かった。しかも、高アスペクト比の粉末で作製された磁
芯の高周波特性が、非常に優れていることを見出した。
さらに、調査を継続した結果、層状結晶構造を有する絶
縁性粉末を扁平状にし、混合することにより、高周波特
性が優れることを見出した。これは、絶縁性粉末が扁平
状のため、金属粉末間の接触面積を減少させることがで
き、これにより絶縁性が増し、抵抗が向上するためであ
る。Means for Solving the Problems The inventors of the present invention have repeatedly studied the relationship between the powder shape and the magnetic permeability of the dust core in order to achieve the above object, and as a result, have increased the aspect ratio of the raw material powder. It was found that the magnetic permeability of the dust core was significantly improved. In addition, they have found that the high frequency characteristics of a magnetic core made of a powder having a high aspect ratio are extremely excellent.
Furthermore, as a result of continuing the investigation, it was found that the high-frequency characteristics were excellent by flattening and mixing the insulating powder having a layered crystal structure. This is because, since the insulating powder is flat, the contact area between the metal powders can be reduced, thereby increasing the insulating property and improving the resistance.
【０００９】即ち、本発明は、Ｆｅ、Ｓｉ、Ａｌを主成
分とする扁平状の合金粉末と、層状結晶構造を有する扁
平状の絶縁性粉末と、有機結合剤とを混合した粉末を圧
縮成型してなる圧粉磁芯である。That is, the present invention provides a method of compression-molding a powder obtained by mixing a flat alloy powder mainly composed of Fe, Si and Al, a flat insulating powder having a layered crystal structure, and an organic binder. This is a dust core.
【００１０】また、本発明は、上記の圧粉磁芯におい
て、前記絶縁性粉末が０.１〜１０ｗｔ％混合されてい
る圧粉磁芯である。The present invention also provides a dust core as described above, wherein the insulating powder is mixed in an amount of 0.1 to 10 wt%.
【００１１】[0011]
【発明の実施の形態】出発原料は、溶解法によるインゴ
ットからの粉砕粉、アトマイズ粉等種々考えられるが、
組成の濃度分布が均一ならば、製法に制限はない。これ
ら粉末をボールミル、アトライター等で粉砕し、扁平化
させる。粉末のアスペクト比は５以上、厚みは５０μｍ
以下が適する。また、上記の合金粉末に混合する層状結
晶構造を有する絶縁性粉末も、ボールミル、アトライタ
ー等で粉砕し、扁平化させる。次に、上記の合金粉末
に、この絶縁性粉末を０.１〜１０ｗｔ％混合し圧縮成
型を行う。圧縮成型して得られた磁芯を図１に示す。図
１に示すように、層状結晶構造を有する絶縁性粉末２
が、扁平状の合金粉末１間に積層され、絶縁性粉末２が
合金粉末１の表面を絶縁しているのがわかる。この層状
結晶構造を有する絶縁性粉末は、例えば、黒鉛、二硫化
モリブデン、窒化ホウ素、モンモリロナイト、雲母等が
使用できる。絶縁性粉末の混合量を上記範囲に限定した
理由は、０.１ｗｔ％未満では、前述の作用を発揮でき
ず、１０ｗｔ％を越えた場合には、透磁率が低くなるた
めである。BEST MODE FOR CARRYING OUT THE INVENTION Various starting materials can be considered, such as pulverized powder from ingots and atomized powder by a dissolution method.
There is no limitation on the production method as long as the concentration distribution of the composition is uniform. These powders are pulverized with a ball mill, an attritor or the like to make them flat. The powder has an aspect ratio of 5 or more and a thickness of 50 μm
The following are suitable: Further, the insulating powder having a layered crystal structure mixed with the above alloy powder is also pulverized by a ball mill, an attritor, or the like, and flattened. Next, the insulating powder is mixed with the above alloy powder in an amount of 0.1 to 10% by weight and compression molding is performed. FIG. 1 shows a magnetic core obtained by compression molding. As shown in FIG. 1, insulating powder 2 having a layered crystal structure
Are laminated between the flat alloy powders 1 and the insulating powder 2 insulates the surface of the alloy powder 1. Examples of the insulating powder having the layered crystal structure include graphite, molybdenum disulfide, boron nitride, montmorillonite, and mica. The reason why the mixing amount of the insulating powder is limited to the above range is that if the content is less than 0.1 wt%, the above-mentioned effect cannot be exerted, and if it exceeds 10 wt%, the magnetic permeability becomes low.
【００１２】[0012]
【実施例】以下、本発明を実施例によって説明する。The present invention will be described below with reference to examples.
【００１３】（実施例１）アトマイズ法にて作製された
ＢａｌＦｅ−１０ｗｔ％Ｓｉ−５ｗｔ％Ａｌ合金粉末を
原料とし、ボールミルを使用して粉末の偏平化処理を行
った。本実施例では、アスペクト比が１５になるように
扁平化処理を行った。次に、絶縁性粉末として扁平化し
た窒化ホウ素を０〜１２ｗｔ％、上記の合金粉末に混合
し、結合剤としてこれら粉末にシリコーン樹脂を３ｗｔ
％混合し、外径２０ｍｍ、内径１０ｍｍの金型を用い、
室温で１０ｔｏｎ／ｃｍ2で成形し、トロイダル状の圧
粉磁芯を得た。(Example 1) A BalFe-10 wt% Si-5 wt% Al alloy powder produced by an atomizing method was used as a raw material and the powder was flattened using a ball mill. In this embodiment, the flattening process is performed so that the aspect ratio becomes 15. Next, 0 to 12 wt% of flattened boron nitride is mixed with the above alloy powder as an insulating powder, and 3 wt% of a silicone resin is added to these powders as a binder.
%, And using a mold having an outer diameter of 20 mm and an inner diameter of 10 mm,
It was molded at 10 ton / cm 2 at room temperature to obtain a toroidal dust core.
【００１４】次に、これらの圧粉磁芯を１７０℃で２時
間大気中で熱処理を行い、バインダー硬化を行った。次
に、酸化性雰囲気中である大気中で、７００℃、２時間
熱処理を行った。次に、これらの磁芯に対して巻線を
し、ＹＨＰ製インピーダンスアナライザー４１９４Ａを
用いて、１００ｋＨｚでのインダクタンスを測定後、透
磁率を計算で求めた。これらの結果を図２に示す。Next, these dust cores were heat-treated at 170 ° C. for 2 hours in the air to cure the binder. Next, heat treatment was performed at 700 ° C. for 2 hours in the air in an oxidizing atmosphere. Next, winding was performed on these magnetic cores, the inductance at 100 kHz was measured using a YHP impedance analyzer 4194A, and the magnetic permeability was determined by calculation. These results are shown in FIG.
【００１５】図２より、絶縁性粉末を０.１〜１０ｗｔ
％混合したときに良好な特性が得られることがわかっ
た。As shown in FIG. 2, 0.1 to 10 wt.
%, It was found that good characteristics were obtained.
【００１６】（実施例２）実施例１と同様に、アトマイ
ズ法にて作製されたＢａｌＦｅ−１０ｗｔ％Ｓｉ−５ｗ
ｔ％Ａｌ合金粉末を原料とし、ボールミルを使用してア
スペクト比１５の扁平粉末を得た。次に、絶縁性粉末と
して扁平化した窒化ホウ素を５.０ｗｔ％、上記合金粉
末に混合し、結合剤としてこれら粉末にシリコーン樹脂
を３ｗｔ％混合し、外径２０ｍｍ、内径１０ｍｍの金型
を用い、室温で１０ｔｏｎ／ｃｍ2で成形し、トロイダ
ル状の圧粉磁芯を得た。(Example 2) As in Example 1, BalFe-10wt% Si-5w produced by the atomizing method
Using the t% Al alloy powder as a raw material, a flat powder having an aspect ratio of 15 was obtained using a ball mill. Next, 5.0 wt% of flattened boron nitride is mixed with the above alloy powder as an insulating powder, and 3 wt% of a silicone resin is mixed with these powders as a binder, and a mold having an outer diameter of 20 mm and an inner diameter of 10 mm is used. At room temperature at 10 ton / cm 2 to obtain a toroidal dust core.
【００１７】次に、これらの圧粉磁芯を実施例１と同様
に１７０℃で２時間大気中で熱処理を行い、バインダー
硬化を行った。次に、酸化性雰囲気中である大気中で、
７００℃、２時間熱処理を行った。次に、これらの磁芯
に対して巻線をし、ＹＨＰ製インピーダンスアナライザ
ー４１９４Ａを用いて、透磁率の周波数特性を測定し
た。Next, these dust cores were heat-treated in the air at 170 ° C. for 2 hours in the same manner as in Example 1 to cure the binder. Next, in an atmosphere that is in an oxidizing atmosphere,
Heat treatment was performed at 700 ° C. for 2 hours. Next, these magnetic cores were wound, and the frequency characteristics of the magnetic permeability were measured using a YHP impedance analyzer 4194A.
【００１８】比較例として、絶縁性粉末として層状結晶
構造ではないアルミナを５.０ｗｔ％混合して、同様に
トロイダル形状の圧粉磁芯を得、同様に測定した。これ
らの結果を図３に示す。As a comparative example, 5.0 wt% of alumina having no layered crystal structure was mixed as an insulating powder to obtain a dust core having a toroidal shape, and the same measurement was performed. These results are shown in FIG.
【００１９】図３より、絶縁性粉末が層状結晶構造を有
する窒化ホウ素で透磁率の周波数特性が良好で特に高周
波での高透磁率が得られることがわかる。FIG. 3 shows that the insulating powder is made of boron nitride having a layered crystal structure, whereby the frequency characteristics of the magnetic permeability are good, and a high magnetic permeability particularly at a high frequency can be obtained.
【００２０】[0020]
【発明の効果】以上説明したように、高透磁率で、高周
波特性に優れ、しかも容易に製造できる圧粉磁芯を提供
することができた。As described above, it is possible to provide a dust core having high magnetic permeability, excellent high-frequency characteristics, and which can be easily manufactured.
【図１】本発明のトロイダル状の圧粉磁芯の説明図。図
１（ａ）は、斜視図。図１（ｂ）は、図１（ａ）のＡ部
を拡大して模式的に示した図。FIG. 1 is an explanatory view of a toroidal dust core of the present invention. FIG. 1A is a perspective view. FIG. 1B is a diagram schematically showing an enlarged part A of FIG. 1A.
【図２】実施例１の圧粉磁芯における絶縁性粉末の混合
量と透磁率μの関係を示した図。FIG. 2 is a diagram showing the relationship between the mixing amount of insulating powder and the magnetic permeability μ in the dust core of Example 1.
【図３】実施例２と比較例の透磁率μ’の周波数特性を
示した図。FIG. 3 is a diagram showing frequency characteristics of magnetic permeability μ ′ of Example 2 and Comparative Example.
１ 合金粉末 ２ 絶縁性粉末 1 alloy powder 2 insulating powder
Claims (2)
の合金粉末と、層状結晶構造を有する扁平状の絶縁性粉
末と、有機結合剤とを混合した粉末を圧縮成型してなる
ことを特徴とする圧粉磁芯。1. A compression-molded powder obtained by mixing a flat alloy powder mainly composed of Fe, Si, and Al, a flat insulating powder having a layered crystal structure, and an organic binder. A dust core characterized by the following.
絶縁性粉末が０.１〜１０ｗｔ％混合されていることを
特徴とする圧粉磁芯。2. The dust core according to claim 1, wherein the insulating powder is mixed in an amount of 0.1 to 10% by weight.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18153898A JP2000003810A (en) | 1998-06-12 | 1998-06-12 | Dust core |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18153898A JP2000003810A (en) | 1998-06-12 | 1998-06-12 | Dust core |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2000003810A true JP2000003810A (en) | 2000-01-07 |
Family
ID=16102537
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP18153898A Pending JP2000003810A (en) | 1998-06-12 | 1998-06-12 | Dust core |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2000003810A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2009128427A1 (en) * | 2008-04-15 | 2009-10-22 | 東邦亜鉛株式会社 | Method for producing composite magnetic material and composite magnetic material |
| US7998361B2 (en) | 2004-03-31 | 2011-08-16 | Sumitomo Electric Industries, Ltd. | Soft magnetic material and powder magnetic core |
| JP5384711B1 (en) * | 2012-10-05 | 2014-01-08 | Ｎｅｃトーキン株式会社 | Magnetic flat powder, method for producing the same, and magnetic sheet |
| JP2014116573A (en) * | 2012-02-06 | 2014-06-26 | Ntn Corp | Magnetic core powder and powder magnetic core |
| CN112349470A (en) * | 2020-11-05 | 2021-02-09 | 成都银河磁体股份有限公司 | Injection molding magnet material, injection molding magnet and preparation method thereof |
-
1998
- 1998-06-12 JP JP18153898A patent/JP2000003810A/en active Pending
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7998361B2 (en) | 2004-03-31 | 2011-08-16 | Sumitomo Electric Industries, Ltd. | Soft magnetic material and powder magnetic core |
| WO2009128427A1 (en) * | 2008-04-15 | 2009-10-22 | 東邦亜鉛株式会社 | Method for producing composite magnetic material and composite magnetic material |
| US20110024671A1 (en) * | 2008-04-15 | 2011-02-03 | Toho Zinc Co., Ltd. | Method of producing composite magnetic material and composite magnetic material |
| JP5358562B2 (en) * | 2008-04-15 | 2013-12-04 | 東邦亜鉛株式会社 | Method for producing composite magnetic material and composite magnetic material |
| JP2014116573A (en) * | 2012-02-06 | 2014-06-26 | Ntn Corp | Magnetic core powder and powder magnetic core |
| US9773596B2 (en) | 2012-02-06 | 2017-09-26 | Ntn Corporation | Powder for magnetic core and powder magnetic core |
| JP5384711B1 (en) * | 2012-10-05 | 2014-01-08 | Ｎｅｃトーキン株式会社 | Magnetic flat powder, method for producing the same, and magnetic sheet |
| CN112349470A (en) * | 2020-11-05 | 2021-02-09 | 成都银河磁体股份有限公司 | Injection molding magnet material, injection molding magnet and preparation method thereof |
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