JP3300522B2 - Low loss oxide soft magnetic material - Google Patents
Low loss oxide soft magnetic materialInfo
- Publication number
- JP3300522B2 JP3300522B2 JP06126394A JP6126394A JP3300522B2 JP 3300522 B2 JP3300522 B2 JP 3300522B2 JP 06126394 A JP06126394 A JP 06126394A JP 6126394 A JP6126394 A JP 6126394A JP 3300522 B2 JP3300522 B2 JP 3300522B2
- Authority
- JP
- Japan
- Prior art keywords
- mol
- loss
- oxide
- moo
- low
- 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 - Fee Related
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
- H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
- H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
- H01F1/12—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials
- H01F1/34—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials non-metallic substances, e.g. ferrites
- H01F1/342—Oxides
- H01F1/344—Ferrites, e.g. having a cubic spinel structure (X2+O)(Y23+O3), e.g. magnetite Fe3O4
Landscapes
- Chemical & Material Sciences (AREA)
- Dispersion Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Compounds Of Iron (AREA)
- Magnetic Ceramics (AREA)
- Soft Magnetic Materials (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明は、低損失酸化物軟質磁性
材料、特に、高周波，高磁場下で用いられるスイッチン
グ電源用メイントランス，バックライトトランス，電源
用チョークコイル，TV用フライバックトランスなどの分
野で好適に用いられる高抵抗，低損失Ni-Zn 系フェライ
トに関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low-loss oxide soft magnetic material, in particular, a main transformer for a switching power supply, a backlight transformer, a choke coil for a power supply, a flyback transformer for a TV used under a high frequency and a high magnetic field. The present invention relates to a high-resistance, low-loss Ni-Zn ferrite suitably used in the field of (1).
【０００２】[0002]
【従来の技術】一般に、スイッチング電源は、100k〜20
0kHz帯域の変換周波数で使われるのが普通である。こう
したスイッチング電源に用いられるトランス材料として
は、従来、低損失Mn-Zn フェライトが用いられている
が、電子機器の小型軽量化に伴い、近年では、さらに高
い周波数帯域でもなお低損失特性を示す酸化物軟質磁性
材料に対する要求が高まっている。2. Description of the Related Art Generally, a switching power supply has a capacity of 100 k to 20 k.
It is usually used at the conversion frequency in the 0 kHz band. Conventionally, low-loss Mn-Zn ferrite has been used as a transformer material for such a switching power supply. There is an increasing demand for soft magnetic materials.
【０００３】さて、上記の用途に用いられる従来のMn-Z
n フェライトであっても、基本成分組成や微量添加物，
粉砕方法，焼成方法などを工夫することにより、１ＭHz
程度の周波数帯域までであれば、低損失で、かつ所望の
温度特性を示す材料が得られていた。しかしながら、従
来のMn-Zn フェライトでは、１ＭHz以上の高周波帯域で
も、高抵抗かつ低損失特性を示す材料を安定して得るこ
とは困難であった。Now, the conventional Mn-Z used for the above applications
n Even with ferrite, the basic component composition, trace additives,
By devising the pulverizing method and firing method, 1MHz
A material having low loss and exhibiting a desired temperature characteristic has been obtained up to a frequency band of the order. However, it has been difficult for conventional Mn-Zn ferrite to stably obtain a material exhibiting high resistance and low loss characteristics even in a high frequency band of 1 MHz or more.
【０００４】これに対し最近、上記Mn-Zn フェライトに
代わるものとして、Ni-Zn 系フェライトが注目されてい
る。それは、このNi-Zn 系フェライトが、１ＭHzを超え
るような高周波帯域においても、なお、磁気特性に優れ
かつ高抵抗を有するからである。ところが、このNi-Zn
系フェライトについては、ヒステリシス損失が大きいた
めに低損失材とすることが難しいという欠点があった。On the other hand, recently, as an alternative to the above-mentioned Mn-Zn ferrite, Ni-Zn ferrite has been attracting attention. This is because the Ni-Zn ferrite has excellent magnetic properties and high resistance even in a high frequency band exceeding 1 MHz. However, this Ni-Zn
The system ferrite has a disadvantage that it is difficult to use a low-loss material because of a large hysteresis loss.
【０００５】しかも、このNi-Zn 系フェライトは、電源
用トランスやバックライトトランス等の高磁場下で使用
されるべく開発された低損失Ni-Zn 系フェライトではな
い。例えば、特開平５−3112号公報および特開平５−21
222 号公報に提案されているMo含有Ni-Zn 系フェライト
などは、低磁場下での透磁率μi の温度特性、透磁率μ
i の制御に着目したものである。すなわち、これらの従
来技術は、高周波帯域の高磁場下で好適に用いられる低
損失Ni-Zn 系フェライトについての提案ではなかった。Moreover, the Ni-Zn ferrite is not a low-loss Ni-Zn ferrite developed to be used under a high magnetic field such as a power transformer or a backlight transformer. For example, JP-A-5-3112 and JP-A-5-21
The Mo-containing Ni-Zn ferrite proposed in Japanese Patent Publication No. 222 has temperature characteristics of permeability μ i under low magnetic field,
This focuses on the control of i . That is, these prior arts were not proposals for low-loss Ni-Zn-based ferrites suitably used under a high magnetic field in a high frequency band.
【０００６】[0006]
【発明が解決しようとする課題】以上説明したように、
従来のMn-Zn フェライトは、高周波帯域で高抵抗かつ低
損失特性を示すものではなく、一方従来のNi-Zn 系フェ
ライトは、高周波帯域で優れた磁気特性を有しかつ高抵
抗を示すが、低損失材とすることが難しいことに加え、
高周波，高磁場印加時には高磁気損失を招くという問題
があった。As described above,
Conventional Mn-Zn ferrites do not exhibit high resistance and low loss characteristics in the high frequency band, while conventional Ni-Zn ferrites have excellent magnetic characteristics and high resistance in the high frequency band, In addition to being difficult to use as a low-loss material,
There is a problem that high magnetic loss is caused when a high frequency and a high magnetic field are applied.
【０００７】本発明の主たる目的は、従来技術が抱える
上記問題を解消すること、即ち、高周波，高磁場下にお
いて、優れた磁気特性を示す低損失酸化物軟質磁性材料
を得ることにある。本発明の具体的な目的は、１ＭHz以
上の高周波帯域，0.1 Oe以上の高磁場下においても、高
抵抗で、かつ低損失特性を示すNi-Zn 系フェライトを提
案することにある。さらに本発明の他の具体的な目的
は、比抵抗≧106 Ωcm，コアロス値≦120mＷ／cm3 （１
MHz,20mT,100℃）を同時に実現できるNi-Zn 系フェライ
トを提案することにある。A main object of the present invention is to solve the above problems of the prior art, that is, to obtain a low-loss oxide soft magnetic material exhibiting excellent magnetic properties under a high frequency and a high magnetic field. A specific object of the present invention is to propose a Ni-Zn ferrite exhibiting high resistance and low loss characteristics even in a high frequency band of 1 MHz or more and a high magnetic field of 0.1 Oe or more. Still another specific object of the present invention is to provide a specific resistance ≧ 10 6 Ωcm and a core loss value ≦ 120 mW / cm 3 (1
It is an object of the present invention to propose a Ni-Zn ferrite capable of simultaneously realizing (MHz, 20mT, 100 ° C).
【０００８】[0008]
【課題を解決するための手段】上記目的実現のために鋭
意研究を重ねた結果、発明者らは、以下の内容を要旨構
成とする本発明を開発したのである。即ち、本発明は、 (1) Fe2O3:48〜51 mol％、ZnO ：25超〜34 mol％、NiO:
15〜27 mol％および残部不可避的不純物からなるもの
に、さらに、MoO3換算で 100〜10000ppmのMo酸化物を添
加してなる基本成分組成を有し、かつ、その焼結密度
が、理論密度の83〜97％であることを特徴とする低損失
酸化物軟質磁性材料である。Means for Solving the Problems As a result of intensive studies for realizing the above object, the present inventors have developed the present invention having the following contents as the gist. That is, the present invention is, (1) Fe 2 O 3 : 48~51 mol%, ZnO: 25 ultra ~34 mol%, NiO:
It has a basic component composition obtained by adding 100 to 10,000 ppm of Mo oxide in terms of MoO 3 to a material consisting of 15 to 27 mol% and the balance of unavoidable impurities, and the sintering density is the theoretical density. 83-97% of the low-loss oxide soft magnetic material.
【０００９】(2) 上記(1) に記載の低損失酸化物軟質磁
性材料の各成分組成は、下記の範囲にすることがより好
ましい。即ち、Fe2O3 については48.5〜50.0 mol％、Zn
O については27〜31 mol％、NiO については19〜24.5 m
ol％、Mo酸化物の添加量についてはMoO3換算で1000〜60
00ppm 、さらに好ましくはMoO3換算で2000〜5000ppmと
するのがよい。(2) More preferably, each component composition of the low-loss oxide soft magnetic material described in the above (1) is in the following range. That, 48.5 to 50.0 mol% for the Fe 2 O 3, Zn
27-31 mol% for O, 19-24.5 m for NiO
ol%, calculated as MoO 3 for the addition of Mo oxides 1000-60
The content is preferably 00 ppm, more preferably 2000 to 5000 ppm in terms of MoO 3 .
【００１０】(3) Fe2O3:48〜51 mol％、ZnO ：25超〜34
mol％、CuO:３ mol％未満、NiO:15〜27 mol％および残
部不可避的不純物からなるものに、さらに、MoO3換算で
100〜10000ppmのMo酸化物を添加してなる基本成分組成
を有し、かつ、その焼結密度が、理論密度の83〜97％で
あることを特徴とする低損失酸化物軟質磁性材料であ
る。(3) Fe 2 O 3 : 48 to 51 mol%, ZnO: more than 25 to 34
mol%, CuO: less than 3 mol%, NiO: those consisting of 15 to 27 mol%, and the balance inevitable impurities, further, calculated as MoO 3
It is a low-loss oxide soft magnetic material characterized by having a basic component composition obtained by adding 100 to 10,000 ppm of Mo oxide and having a sintered density of 83 to 97% of the theoretical density. .
【００１１】(4) 上記(3) に記載の低損失酸化物軟質磁
性材料の各成分組成は、下記の範囲にすることがより好
ましい。即ち、Fe2O3 については48.5〜50.0 mol％、Zn
O については27〜31 mol％、CuO については２ mol％以
下、NiO については19〜24.5mol％、Mo酸化物の添加量
についてはMoO3換算で1000〜6000ppm 、さらに好ましく
はMoO3換算で2000〜5000ppm とするのがよい。(4) The composition of each component of the low-loss oxide soft magnetic material described in (3) above is more preferably in the following range. That, 48.5 to 50.0 mol% for the Fe 2 O 3, Zn
27 to 31 mol% for O, 2 mol% or less for CuO, 19~24.5mol% for NiO, calculated as MoO 3 for the addition of Mo oxide 1000～6000Ppm, more preferably calculated as MoO 3 2000 It is better to be 5000 ppm.
【００１２】(5) 上記(1) 〜(4) に記載の各酸化物軟質
磁性材料は、その比抵抗が106 Ωcm以上、１MHz,20mT,1
00℃でのコアロス値が120mＷ／cm3 以下であることを特
徴とする低損失酸化物軟質磁性材料である。(5) Each of the oxide soft magnetic materials described in the above (1) to (4) has a specific resistance of 10 6 Ωcm or more, 1 MHz, 20 mT, 1
The low-loss oxide soft magnetic material has a core loss value of 120 mW / cm 3 or less at 00 ° C.
【００１３】(6) 上記(1) 〜(5) に記載の各酸化物軟質
磁性材料は、その用途が、１ＭHz以上の高周波帯域，0.
1 Oe以上の高磁場下で使われるスイッチング電源用メイ
ントランス，バックライトトランス，電源用チョークコ
イル，TV用フライバックトランスなどの高周波対応低損
失磁性材料である。(6) Each of the oxide soft magnetic materials described in the above (1) to (5) is used for a high frequency band of 1 MHz or more, a high frequency band of 0.1 MHz or more.
High-frequency compatible low-loss magnetic materials such as main transformers for switching power supplies, backlight transformers, choke coils for power supplies, and flyback transformers for TVs used under high magnetic fields of 1 Oe or more.
【００１４】[0014]
【作用】ここで、本発明にかかる酸化物軟質磁性材料の
基本成分を構成するFe2O3 は、ヒステリス損失を支配す
る結晶磁気異方性定数ｋ1 と渦電流損失を支配する電気
抵抗を調整する役割を担い、その含有量は48〜51 mol
％、より好ましくは48.5〜50.0 mol％とする。この数値
に限定される理由は、Fe2O3 の含有量が48 mol％未満で
は、100 ℃でのヒステリシス損失を低減することができ
ず、一方、51 mol％超では、電気抵抗が急激に低下する
ために、渦電流損失が高くなるとともに、コアに直接巻
線できなくなるからである。Here, Fe 2 O 3 constituting a basic component of the oxide soft magnetic material according to the present invention has a crystal magnetic anisotropy constant k 1 which governs hysteresis loss and an electric resistance which governs eddy current loss. Plays a role in regulating, its content is 48-51 mol
%, More preferably 48.5 to 50.0 mol%. The reason for this limitation is that if the content of Fe 2 O 3 is less than 48 mol%, the hysteresis loss at 100 ° C. cannot be reduced, while if it exceeds 51 mol%, the electric resistance sharply increases. The reason for this is that the eddy current loss increases, and the core cannot be directly wound.
【００１５】本発明にかかる酸化物軟質磁性材料の基本
成分を構成するZnO は、上述のｋ1およびキュリー温度
Ｔc を調整する役割を担い、その含有量は25超〜34 mol
％、より好ましくは27〜31 mol％とする。この数値に限
定される理由は、ZnO の含有量が25 mol％以下では、残
留損失およびヒステリシス損失を低減することができ
ず、一方、34 mol％超では、キュリー点が低下するため
に、100 ℃での残留損失が著しく増大するからである。ZnO, which is a basic component of the oxide soft magnetic material according to the present invention, has a role of adjusting the above k 1 and Curie temperature Tc , and its content is more than 25 to 34 mol.
%, More preferably 27 to 31 mol%. The reason for the limitation to this value is that if the ZnO content is 25 mol% or less, the residual loss and hysteresis loss cannot be reduced, while if it exceeds 34 mol%, the Curie point is lowered. This is because the residual loss at ℃ is significantly increased.
【００１６】本発明にかかる酸化物軟質磁性材料の基本
成分を構成するNiO は、ｋ1 およびＴc を調整する役割
を担い、その含有量は15〜27 mol％、より好ましくは19
〜24.5 mol％とする。この数値に限定される理由は、Ni
O の含有量が15 mol％未満では、キュリー点が低下する
ために、100 ℃での残留損失が著しく増大するからであ
る。一方、27mol％超では、コアロス極小温度が100 ℃
より高くなり、100 ℃で低損失を得ることができなくな
るからである。NiO constituting the basic component of the soft oxide magnetic material according to the present invention has a role of adjusting k 1 and T c , and its content is 15 to 27 mol%, more preferably 19 mol%.
~ 24.5 mol%. The reason for limiting to this number is Ni
If the O 2 content is less than 15 mol%, the Curie point is lowered, so that the residual loss at 100 ° C. is significantly increased. On the other hand, if it exceeds 27 mol%, the minimum core loss temperature is 100 ° C.
This is because the temperature becomes higher and a low loss cannot be obtained at 100 ° C.
【００１７】本発明においては、焼成温度の低減（焼結
促進）と原料コストの削減をするために、上記NiO 成分
の一部をCuO 成分で置換してもよい。その置換量は、ｋ
1 およびＴc の変動幅を許容範囲内に抑え、かつMoO3添
加効果を十分に引き出すために、３ mol％未満、より好
ましくは２ mol％以下とする。NiO 成分のCuO 成分によ
る置換量を３ mol％未満とする理由は、３ mol％以上の
CuO で置換すると結晶粒内の結晶磁気異方性定数および
磁歪定数が大きく変化するからである。また、後述する
ように、MoO3添加による粒界応力緩和効果が得られなく
なり、高周波磁気損失が著しく劣化するからである。In the present invention, a part of the NiO component may be replaced with a CuO component in order to reduce the firing temperature (accelerate sintering) and reduce the raw material cost. The replacement amount is k
In order to keep the fluctuation range of 1 and Tc within an allowable range and sufficiently bring out the effect of adding MoO 3 , the content is set to less than 3 mol%, more preferably 2 mol% or less. The reason why the substitution amount of the NiO component by the CuO component is less than 3 mol%
This is because the substitution with CuO greatly changes the magnetocrystalline anisotropy constant and magnetostriction constant in the crystal grains. Further, as described later, the effect of relaxing grain boundary stress by adding MoO 3 cannot be obtained, and high-frequency magnetic loss is significantly deteriorated.
【００１８】本発明においては、低損失の酸化物軟質磁
性材料を得るために、上述したNi-Zn 系フェライトの基
本成分に加えてさらに、副成分としてMo酸化物を添加す
る。このMo酸化物は、MoO3換算で 100〜10000ppmを添加
し、より好ましくはMoO3換算で1000〜6000ppm 、さらに
好ましくはMoO3換算で2000〜5000ppm を添加する。この
理由は、Mo酸化物の含有量が10000ppmを超えると、結晶
粒の異常粒成長を起こしやすくなり、損失低減効果が得
られなくなるからである。また、100ppm未満では、顕著
な添加効果が得られないからである。In the present invention, in order to obtain a low-loss soft oxide magnetic material, Mo oxide is further added as a sub-component in addition to the above-mentioned basic component of the Ni-Zn ferrite. The Mo oxide is added in an amount of 100 to 10,000 ppm in terms of MoO 3 , more preferably 1000 to 6000 ppm in terms of MoO 3 , and still more preferably 2000 to 5000 ppm in terms of MoO 3 . The reason for this is that if the content of the Mo oxide exceeds 10,000 ppm, abnormal grain growth of crystal grains is likely to occur, and the loss reduction effect cannot be obtained. Also, if it is less than 100 ppm, a remarkable effect of addition cannot be obtained.
【００１９】次に、発明者らは、低損失材料を得るため
に、上記のMo酸化物を添加する意義について更に実験を
進めた。即ち、MoO3添加の有無による、 Ni-Zn系フェラ
イトのコアロスと焼結密度ρS ，多結晶粒径，粒界応力
との関係についても検討したのである。なお、この実験
に用いた Ni-Zn系フェライトの基本成分組成は、Fe2O3:
NiO:ZnO=49.5:20.5:30 mol％である。この実験結果によ
れば、コアロスと焼結密度ρS の関係については、図１
に示すように、MoO3を添加しない Ni-Zn系フェライトで
は、97％程度まではρS の増加に伴い実効的な磁性体占
有率増加を反映してコアロスが改善される。しかし、35
00ppm のMoO3を添加した Ni-Zn系フェライトでは、ρS
が高くなっても必ずしもコアロスは改善されないことが
わかった。また、多結晶粒径の依存性についても、上記
コアロスと焼結密度ρS の関係と同様の傾向が見られ
た。さらに、上記 Ni-Zn系フェライトの残留応力を３点
曲げ強度を測定して評価したところ、同じρS での圧縮
残留応力は、MoO3を添加した Ni-Zn系フェライトでより
低減されることを示唆する結果が得られた。また、破断
面をSEM 観察すると、無添加材では粒内破壊するが、Mo
O3を添加すると、粒界破壊することが判る。Next, the inventors conducted further experiments on the significance of adding the above-mentioned Mo oxide in order to obtain a low-loss material. That is, the relationship between the core loss of the Ni—Zn ferrite and the sintered density ρ S , the polycrystalline grain size, and the grain boundary stress depending on the presence or absence of MoO 3 was also examined. The basic component composition of the Ni-Zn ferrite used in this experiment was Fe 2 O 3 :
NiO: ZnO = 49.5: 20.5: 30 mol%. According to the experimental results, the relationship between the core loss and the sintered density ρ S is shown in FIG.
As shown in (1), in the case of Ni-Zn ferrite to which MoO 3 is not added, the core loss is improved up to about 97%, reflecting an effective increase in the magnetic material occupancy with an increase in ρ S. But 35
For Ni-Zn ferrite to which 00 ppm MoO 3 is added, ρ S
It has been found that the core loss is not always improved even if the value becomes higher. In addition, the same tendency as the relationship between the core loss and the sintering density ρ S was observed in the dependence of the polycrystalline grain size. Furthermore, when the residual stress of the above Ni-Zn ferrite was evaluated by measuring the three-point bending strength, it was found that the compressive residual stress at the same ρ S was further reduced by the Ni-Zn ferrite to which MoO 3 was added. Was obtained. When the fracture surface was observed by SEM, intra-granular fracture occurred with the additive-free material.
It can be seen that when O 3 is added, grain boundary fracture occurs.
【００２０】以上の実験事実から、発明者らは、MoO3添
加によって低損失化する過程について以下の判断をする
に到った。例えば、コアロスの改善機構としては、酸化
物軟質磁性材料の焼成温度域に沸点をもつMoO3を添加す
ることにより、焼成中にMoO3の一部が粒界から蒸発し、
粒界に残留する圧縮応力が緩和され、その結果、ヒステ
リシス損失および残留損失が低減される。なぜなら、Mo
O3は、低沸点酸化物（単体での沸点；1260℃）であり、
酸化物軟質磁性材料の焼成温度域で一部粒界から昇華す
ることで粒界応力を緩和し、粒界に残留する圧縮応力に
起因する磁気損失劣化を抑制することができるからであ
る。このことは、1200℃程度で約３時間焼成した後の、
MoO3のコア内残存率が60〜90％であることが、元素分析
の結果から確認されたことからも明らかである。このよ
うにコアロスが改善され低損失化するのである。なお、
CuO, Bi2O3, V2O5のような Ni-Zn系フェライトの焼結温
度を低下させる成分（いわゆる焼結促進成分）がMoO3と
共に多量に存在すると、焼成後のMoO3のコア内残存率が
90〜100 ％となり、粒界応力緩和効果が得られず、逆に
コアロス改善効果は制限されることがわかった。From the above experimental facts, the inventors have come to the following judgment on the process of reducing the loss by adding MoO 3 . For example, as a mechanism for improving core loss, by adding MoO 3 having a boiling point to the firing temperature range of the oxide soft magnetic material, part of MoO 3 evaporates from grain boundaries during firing,
The compressive stress remaining at the grain boundaries is reduced, and as a result, hysteresis loss and residual loss are reduced. Because Mo
O 3 is a low-boiling oxide (boiling point alone: 1260 ° C.)
This is because, by partially sublimating from the grain boundary in the firing temperature range of the oxide soft magnetic material, the grain boundary stress can be relaxed, and magnetic loss deterioration due to the compressive stress remaining at the grain boundary can be suppressed. This means that after firing at about 1200 ° C for about 3 hours,
It is clear from the result of elemental analysis that the residual ratio of MoO 3 in the core was 60 to 90%. Thus, the core loss is improved and the loss is reduced. In addition,
CuO, Bi 2 O 3, V 2 when the Ni-Zn-based component to lower the sintering temperature of the ferrite, such as O 5 (so-called sinter-promoting component) a large amount of present with MoO 3, the core of MoO 3 after firing Of the remaining
It was found that the effect of relaxing the grain boundary stress was not obtained, and the effect of improving the core loss was limited.
【００２１】次に、本発明においては、上述したMoO3添
加による損失改善効果をより効果的に引き出すために、
磁性材料の焼結密度ρS を、理論密度の83〜97％、より
好ましくは85〜95％、更に好ましくは88〜93とする。こ
の数値に限定される理由は、前記焼結密度ρS が83％未
満では、実効的な磁性体占有率が低いためにコアロスを
低減させることができず、一方、97％を超える高密度と
すると、粒界の残留圧縮応力が高くなるためにコアロス
を低減させることができなくなるからである。Next, in the present invention, in order to more effectively bring out the above-described loss improvement effect by adding MoO 3 ,
The sintered density ρ S of the magnetic material is set to 83 to 97% of the theoretical density, more preferably 85 to 95%, and still more preferably 88 to 93. The reason for being limited to this value is that when the sintering density ρ S is less than 83%, the core loss cannot be reduced due to the low effective magnetic material occupancy, while the high density exceeding 97% Then, the core loss cannot be reduced because the residual compressive stress at the grain boundary increases.
【００２２】以上説明したような構成になる本発明の酸
化物軟質磁性材料によれば、高周波，高磁場印加下でも
高抵抗でかつ低損失特性を示す Ni-Zn系フェライトを得
ることができる。より具体的には、比抵抗≧106 Ωcm，
コアロス値≦120mＷ／cm3 （１MHz,20mT,100℃）を同時
に実現できる Ni-Zn系フェライトを得ることができる。
ここで、コアロス値の測定条件を１MHz,20mT,100℃とす
る理由は、本発明の用途であるスイッチング電源用メイ
ントランスの高周波での代表的使用条件だからである。
従って、本発明の酸化物軟質磁性材料は、高周波，高磁
場印加下でも高抵抗でかつ低損失特性を示すので、１Ｍ
Hz以上の高周波帯域，0.1 Oe以上の高磁場下で使われる
スイッチング電源用メイントランス，バックライトトラ
ンス，電源用チョークコイル，TV用フライバックトラン
スなどの用途として好適である。According to the soft magnetic oxide material of the present invention having the above-described structure, a Ni-Zn ferrite exhibiting high resistance and low loss characteristics even under high frequency and high magnetic field application can be obtained. More specifically, specific resistance ≧ 10 6 Ωcm,
It is possible to obtain a Ni-Zn ferrite capable of simultaneously realizing a core loss value ≦ 120 mW / cm 3 (1 MHz, 20 mT, 100 ° C.).
The reason why the measurement conditions of the core loss value are set to 1 MHz, 20 mT, and 100 ° C. is that the core transformer for a switching power supply, which is an application of the present invention, is a typical use condition at a high frequency.
Therefore, the oxide soft magnetic material of the present invention has high resistance and low loss characteristics even under the application of high frequency and high magnetic field.
It is suitable for applications such as main transformers for switching power supplies, backlight transformers, choke coils for power supplies, and flyback transformers for TVs, which are used in a high frequency band of Hz or more and a high magnetic field of 0.1 Oe or more.
【００２３】[0023]
（実施例１）表１に示す成分組成比となるように、主要
酸化物原料であるFe2O3, ZnO, NiO,CuOを秤量し、湿式
混合し、850 ℃で３時間仮焼して Ni-Zn系フェライト仮
焼粉を得た。次に、上記仮焼粉にMoO3を3000ppm 添加し
た後、湿式粉砕し、乾燥後、バインダーとしてＰＶＡを
添加して造粒し、その後、成形圧力１ton/cm2 で成形し
て外径36mm, 内径24mm, 高さ８mmのトロイダル形状の成
形体を得た。そして、得られた成形体を、大気中，100
0,1050,1100,1150,1200℃で３時間焼成してMo含有 Ni-Z
n系フェライトコアを得た。(Example 1) Fe 2 O 3 , ZnO, NiO, and CuO, which are main oxide raw materials, were weighed, wet-mixed, and calcined at 850 ° C. for 3 hours so that the component composition ratios shown in Table 1 were obtained. Ni-Zn ferrite calcined powder was obtained. Next, after adding 3000 ppm of MoO 3 to the calcined powder, wet pulverizing, drying, adding PVA as a binder and granulating, and then molding at a molding pressure of 1 ton / cm 2 to form an outer diameter of 36 mm, A toroidal shaped body having an inner diameter of 24 mm and a height of 8 mm was obtained. Then, the obtained molded body is placed in the atmosphere for 100 hours.
Mo-containing Ni-Z fired at 0,1050,1100,1150,1200 ℃ for 3 hours
An n-based ferrite core was obtained.
【００２４】このようにして得られたコアのうち、焼結
密度ρS 85〜90％のMo含有 Ni-Zn系フェライトコアにつ
いて、コアロスを１MHz,20mT,100℃の条件下で、比抵抗
を室温，10Ｖ印加の条件下で測定した。比較例として、
本発明の範囲外の組成を用いて同様の方法でコアを作製
し、コアロスおよび比抵抗を測定した。その結果を表１
に示す。この表に示された結果から明らかなように、本
発明の成分組成範囲内で低損失になることがわかる。Among the cores thus obtained, the specific resistance of the Mo-containing Ni-Zn ferrite core having a sintering density ρ s of 85 to 90% under the conditions of a core loss of 1 MHz, 20 mT and 100 ° C. The measurement was performed under the conditions of room temperature and 10 V applied. As a comparative example,
A core was prepared in the same manner using a composition outside the range of the present invention, and the core loss and the specific resistance were measured. Table 1 shows the results.
Shown in As is clear from the results shown in this table, it can be seen that the loss is low within the component composition range of the present invention.
【００２５】[0025]
【表１】 [Table 1]
【００２６】（実施例２）Fe2O3=49.5 mol％, ZnO=28.0
mol％, NiO=21.5 mol％, CuO=1.0mol％となるように、
主要酸化物原料を秤量し、湿式混合し、850 ℃で３時間
仮焼して Ni-Zn系フェライト仮焼粉を得た。次に、上記
仮焼粉に、表２に示す量;0〜15000ppm（外枠量）のMoO3
を添加したのち湿式粉砕し、次いで乾燥後、バインダー
としてＰＶＡを添加して造粒し、その後、成形圧力１to
n/cm2 で成形して外径36mm, 内径24mm, 高さ８mmのトロ
イダル形状の成形体を得た。そして、得られた成形体
を、大気中， 950〜1150℃の温度で３時間焼成してMo含
有 Ni-Zn系フェライトコアを得た。Example 2 Fe 2 O 3 = 49.5 mol%, ZnO = 28.0
mol%, NiO = 21.5 mol%, CuO = 1.0 mol%
The main oxide raw materials were weighed, wet-mixed, and calcined at 850 ° C. for 3 hours to obtain a calcined Ni-Zn ferrite powder. Next, in the calcined powder, the amount shown in Table 2; 0 to 15000 ppm (outer frame amount) of MoO 3
, Wet pulverization, then drying, adding PVA as a binder to granulate, and then forming at a pressure of 1 to
By molding at n / cm 2 , a toroidal molded body having an outer diameter of 36 mm, an inner diameter of 24 mm, and a height of 8 mm was obtained. The obtained compact was fired in the air at a temperature of 950 to 1150 ° C. for 3 hours to obtain a Mo-containing Ni—Zn ferrite core.
【００２７】このようにして得られたMo含有 Ni-Zn系フ
ェライトコアについて、コアロスを１MHz,20mT,100℃の
条件下で、比抵抗を室温，10Ｖ印加の条件下で測定し
た。その結果を表２に示す。この表に示された結果から
明らかなように、コアロスの低減効果は、MoO3添加量が
100〜10000ppmの範囲で得られ、特に1000〜6000ppm の
範囲で顕著であることがわかる。なお、表２に記載のコ
アは全て、ρS ＝90〜95％，比抵抗≧108 Ωcmの範囲に
あった。With respect to the Mo-containing Ni-Zn ferrite core thus obtained, the core loss was measured under the conditions of 1 MHz, 20 mT, and 100 ° C., and the specific resistance was measured under the conditions of room temperature and 10 V applied. Table 2 shows the results. As apparent from the results this has been shown in the table, the core loss reduction effect of, MoO 3 amount of addition
It can be seen that it is obtained in the range of 100 to 10,000 ppm, and particularly remarkable in the range of 1000 to 6000 ppm. In addition, all the cores described in Table 2 were in the range of ρ s = 90 to 95% and the specific resistance ≧ 10 8 Ωcm.
【００２８】[0028]
【表２】 [Table 2]
【００２９】（実施例３）Fe2O3=49.0 mol％, ZnO=30.0
mol％, NiO=20.5 mol％, CuO=0.5mol％となるように、
主要酸化物原料を秤量し、湿式混合し、875 ℃で３時間
仮焼して Ni-Zn系フェライト仮焼粉を得た。次に、上記
仮焼粉に、3500ppm のMoO3を添加したのち湿式粉砕し、
次いで乾燥後、バインダーとしてＰＶＡを添加して造粒
し、その後、成形圧力１ton/cm2 で成形して外径36mm,
内径24mm, 高さ８mmのトロイダル形状の成形体を得た。
そして、得られた成形体を、大気中， 1050 ℃の温度で
１〜20時間焼成してρS 80〜98％のMo含有 Ni-Zn系フェ
ライトコアを得た。Example 3 Fe 2 O 3 = 49.0 mol%, ZnO = 30.0
mol%, NiO = 20.5 mol%, CuO = 0.5 mol%
The main oxide raw materials were weighed, wet-mixed, and calcined at 875 ° C. for 3 hours to obtain a calcined Ni-Zn ferrite powder. Next, 3500 ppm of MoO 3 was added to the calcined powder, followed by wet pulverization,
Next, after drying, PVA was added as a binder and granulated, and then molded at a molding pressure of 1 ton / cm 2 to form an outer diameter of 36 mm.
A toroidal shaped body having an inner diameter of 24 mm and a height of 8 mm was obtained.
Then, the resulting molded body in air to obtain a Mo-containing Ni-Zn ferrite core was calcined 20 hours at a temperature of 1050 ℃ ρ S 80~98%.
【００３０】このようにして得られたMo含有 Ni-Zn系フ
ェライトコアについて、コアロスを１MHz,20mT,100℃の
条件下で、比抵抗を室温，10Ｖ印加の条件下で測定し
た。その結果を図１に示す。この図に示された結果から
明らかなように、ρS ＝83〜97％の範囲でのみ低損失特
性が得られることがわかった。なお、図に記載のコアは
全て、比抵抗≧106 Ωcmの範囲にあった。With respect to the thus obtained Mo-containing Ni—Zn ferrite core, the core loss was measured under the conditions of 1 MHz, 20 mT, and 100 ° C., and the specific resistance was measured under the conditions of room temperature and 10 V applied. The result is shown in FIG. As is clear from the results shown in this figure, it was found that low loss characteristics were obtained only in the range of ρ s = 83 to 97%. All the cores shown in the figure were in the range of specific resistance ≧ 10 6 Ωcm.
【００３１】なお、上述した各実施例では、MoO3の添加
は粉砕前に行ったが、仮焼温度が1000℃以下の温度範囲
であれば他の成分とともに仮焼前に入れても同様の効果
が得られる。In each of the above-described embodiments, the addition of MoO 3 was performed before the pulverization. However, if the calcination temperature is within a temperature range of 1000 ° C. or less, the same applies even if it is added before the calcination together with other components. The effect is obtained.
【００３２】[0032]
【発明の効果】以上説明したように本発明の酸化物軟質
磁性材料によれば、１ＭHz以上の高周波帯域，0.1 Oe以
上の高磁場下でも、比抵抗≧106 Ωcmで、かつ低損失特
性を示す Ni-Zn系フェライトを得ることができる。した
がって、本発明の酸化物軟質磁性材料は、特に、１ＭＨ
ｚ以上の高周波帯域，0.1 Oe以上の高磁場下で使用され
るスイッチング電源用トランスのような用途に対し優れ
た特性を発揮する。As described above, according to the oxide soft magnetic material of the present invention, even in a high frequency band of 1 MHz or more and a high magnetic field of 0.1 Oe or more, the specific resistance ≧ 10 6 Ωcm and the low loss characteristics are obtained. The following Ni-Zn ferrite can be obtained. Therefore, the oxide soft magnetic material of the present invention is particularly suitable for 1 MH
It exhibits excellent characteristics for applications such as switching power supply transformers used in high frequency bands of z or higher and high magnetic fields of 0.1 Oe or higher.
【図１】コアロスの相対焼結密度依存性に関し、MoO3添
加とMoO3無添加について比較したグラフである。FIG. 1 is a graph showing the dependency of core loss on relative sintering density when MoO 3 is added and MoO 3 is not added.
───────────────────────────────────────────────────── フロントページの続き (58)調査した分野(Int.Cl.7，ＤＢ名) H01F 1/12 - 1/375 ──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. 7 , DB name) H01F 1/12-1/375
Claims (3)
％、NiO:15〜27 mol％および残部不可避的不純物からな
るものに、さらに、MoO3換算で 100〜10000ppm のMo酸
化物を添加してなる基本成分組成を有し、かつ、その焼
結密度が、理論密度の83〜97％であることを特徴とする
低損失酸化物軟質磁性材料。(1) Fe 2 O 3 : 48 to 51 mol%, ZnO: more than 25 to 34 mol%
%, NiO: 15~27 mol% and that the balance incidental impurities, and further has a basic component composition obtained by adding Mo oxides 100~10000ppm calculated as MoO 3, and sintered density thereof A low-loss oxide soft magnetic material characterized by having a density of 83 to 97% of the theoretical density.
％、CuO:３ mol％未満、NiO:15〜27 mol％および残部不
可避的不純物からなるものに、さらに、MoO3換算で 100
〜10000ppmのMo酸化物を添加してなる基本成分組成を有
し、かつ、その焼結密度が、理論密度の83〜97％である
ことを特徴とする低損失酸化物軟質磁性材料。2. Fe 2 O 3 : 48 to 51 mol%, ZnO: more than 25 to 34 mol%
%, CuO: less than 3 mol%, NiO: those consisting of 15 to 27 mol%, and the balance inevitable impurities, in addition, MoO 3 terms 100
A low-loss soft oxide magnetic material characterized by having a basic component composition obtained by adding up to 10,000 ppm of Mo oxide and having a sintering density of 83 to 97% of a theoretical density.
質磁性材料であって、この材料の比抵抗が106 Ωcm以
上、１MHz,20mT,100℃でのコアロス値が120mＷ／cm3 以
下であることを特徴とする低損失酸化物軟質磁性材料。3. The soft magnetic oxide material according to claim 1, wherein the material has a specific resistance of 10 6 Ωcm or more and a core loss value of 120 mW / cm 3 at 1 MHz, 20 mT, and 100 ° C. A low-loss oxide soft magnetic material characterized by the following.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP06126394A JP3300522B2 (en) | 1994-03-30 | 1994-03-30 | Low loss oxide soft magnetic material |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP06126394A JP3300522B2 (en) | 1994-03-30 | 1994-03-30 | Low loss oxide soft magnetic material |
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| Publication Number | Publication Date |
|---|---|
| JPH07272917A JPH07272917A (en) | 1995-10-20 |
| JP3300522B2 true JP3300522B2 (en) | 2002-07-08 |
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