JP2007214425A - Powder magnetic core and inductor using it - Google Patents
Powder magnetic core and inductor using it Download PDFInfo
- Publication number
- JP2007214425A JP2007214425A JP2006033638A JP2006033638A JP2007214425A JP 2007214425 A JP2007214425 A JP 2007214425A JP 2006033638 A JP2006033638 A JP 2006033638A JP 2006033638 A JP2006033638 A JP 2006033638A JP 2007214425 A JP2007214425 A JP 2007214425A
- Authority
- JP
- Japan
- Prior art keywords
- powder
- soft magnetic
- inductor
- magnetic
- flat
- 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
本発明は圧粉磁心およびそれを用いたインダクタに関し、特に電源回路用に好適な圧粉磁心およびそれを用いたインダクタに関する。 The present invention relates to a dust core and an inductor using the same, and more particularly to a dust core suitable for a power supply circuit and an inductor using the same.
近年、ノートパソコンやＰＤＡ用などのＣＰＵの高性能化に伴った大電流化により、これら電源回路に用いられる素子の電力効率の改善要求が大きくなっている。 In recent years, the demand for improvement in the power efficiency of elements used in these power supply circuits has increased due to the increase in current accompanying the performance enhancement of CPUs for notebook personal computers and PDAs.
これらの大電流を要する電源回路にチョークコイルとして用いられるインダクタの磁心には、磁気飽和を起こさないための高い飽和磁束密度が必要とされるため、フェライト材料にくらべて飽和磁束密度が高い、軟磁性金属粉末とバインダーを混練した圧粉磁心が用いられている。 The inductor core used as a choke coil in these power supply circuits that require a large current requires a high saturation magnetic flux density to prevent magnetic saturation, so that the saturation magnetic flux density is higher than that of a ferrite material. A dust core in which magnetic metal powder and a binder are kneaded is used.
しかし、バインダーとの混練により製造される圧粉磁心は、バインダーによって粒子間距離が広げられることで透磁率が低下するため、高いインダクタンス素子の磁心として利用する場合には、巻き数を増やしたり、素子自体のサイズを大きくする必要があった。その結果、高いインダクタンスを得るために巻き数を増やした場合、導体の長さの増加により、素子の直流抵抗が増加し、銅損失が大きくなるという問題や、小型化が困難であるという問題がある。 However, the dust core produced by kneading with the binder has a reduced permeability because the interparticle distance is expanded by the binder, so when used as a magnetic core of a high inductance element, the number of turns can be increased, It was necessary to increase the size of the element itself. As a result, when the number of turns is increased in order to obtain a high inductance, there is a problem that the direct current resistance of the element increases due to an increase in the length of the conductor, resulting in a large copper loss and a problem that miniaturization is difficult. is there.
これに対し、特許文献１では扁平粉末を磁路方向に平行となるように配向させることによって、高透磁率を得る方法が提案されている。 On the other hand, Patent Document 1 proposes a method of obtaining high magnetic permeability by orienting flat powder so as to be parallel to the magnetic path direction.
しかしながら、球状粉を扁平化することにより粉末表面の比表面積が増加するため、バインダー混練時にバインダーが粉末表面に均一に被覆されず、絶縁性が低下することで、渦電流が増大し、結果的に初透磁率の周波数特性が低下するという問題があった。 However, since the specific surface area of the powder surface is increased by flattening the spherical powder, the binder is not uniformly coated on the powder surface when the binder is kneaded, and the insulation is reduced, resulting in an increase in eddy current. However, there is a problem that the frequency characteristics of the initial permeability are deteriorated.
また一般的にバインダーには熱硬化性樹脂が用いられるが、この場合扁平粉と樹脂バインダーとの混練物の成形体は、通常の球状粉と樹脂バインダーとの混練物の成形体とくらべて成形後のスプリングバックが大きく、成形体に占める磁性体の充填率が極めて上がりにくいという問題があった。 In general, a thermosetting resin is used as the binder. In this case, the molded product of the flat powder and the resin binder is molded in comparison with the molded product of the normal spherical powder and the resin binder. There was a problem that the subsequent spring back was large, and the filling rate of the magnetic material in the molded body was extremely difficult to increase.
本発明の課題は前記の問題を解決し、絶縁性が高く周波数特性が良好で、かつ磁性体の充填率が高く高透磁率な圧粉磁心と、それを用いた高電力効率なインダクタを提供することにある。 The object of the present invention is to solve the above problems, and provide a dust core having high insulation and good frequency characteristics, high magnetic material filling rate and high magnetic permeability, and a high power efficiency inductor using the same. There is to do.
本発明はＡｌまたはＣｒの少なくともいずれかを含む扁平粉末の表面に絶縁層を形成し、成形体を分割成形ののち接合することにより得られる初透磁率が高く周波数特性も良好な圧粉磁心を、全長が短く低直流抵抗な導体と組み合わせ、インダクタを作製することを検討した結果なされたものである。 The present invention provides a dust core having a high initial permeability and good frequency characteristics obtained by forming an insulating layer on the surface of a flat powder containing at least one of Al and Cr, and bonding the molded body after split molding. This is a result of studying the production of an inductor in combination with a conductor having a short overall length and a low DC resistance.
即ち、本発明は、ＡｌおよびＣｒの少なくともいずれかを含みアスペクト比が２以上の扁平形状で表面に絶縁層を有するＦｅ-Ｓｉ系の軟磁性合金粉末が用いられ前記軟磁性合金粉末の扁平方向を加圧方向と垂直に配向させるようにバインダーと共に加圧成形された成形体が、複数個、前記加圧方向に重ねられ接合されたことを特徴とする圧粉磁心である。 That is, the present invention uses a Fe—Si based soft magnetic alloy powder having a flat shape having an aspect ratio of 2 or more and containing at least one of Al and Cr, and a flat direction of the soft magnetic alloy powder. A powder magnetic core, wherein a plurality of compacts molded together with a binder so as to be oriented perpendicularly to the pressurizing direction are stacked and joined in the pressurizing direction.
また本発明は、前記軟磁性合金粉末は、（１）８２〜８８重量％Ｆｅ - ８〜１０重量％Ｓｉ - ４〜８重量％Ａｌの組成の軟磁性合金、（２）７９〜９３重量％Ｆｅ - ５〜９重量％Ｓｉ - ２〜１２重量％Ｃｒの組成の軟磁性合金から選ばれるいずれか１種、または２種の混合物であることを特徴とする前記の圧粉磁心である。 According to the present invention, the soft magnetic alloy powder comprises (1) a soft magnetic alloy having a composition of 82 to 88 wt% Fe −8 to 10 wt% Si −4 to 8 wt% Al, and (2) 79 to 93 wt%. The powder magnetic core according to any one of the above, wherein the powder magnetic core is any one kind or a mixture of two kinds selected from soft magnetic alloys having a composition of Fe-5 to 9 wt% Si-2 to 12 wt% Cr.
また本発明は、前記絶縁層が大気中熱処理によって形成されるＡｌもしくはＣｒの不動態膜、またはリン酸を含む溶液による酸処理膜の、少なくともいずれかであることを特徴とする前記の圧粉磁心である。 Further, the present invention provides the above compacted powder, wherein the insulating layer is at least one of an Al or Cr passivated film formed by heat treatment in the atmosphere, or an acid-treated film using a solution containing phosphoric acid. It is a magnetic core.
また本発明は、前記軟磁性合金粉末の粉末充填率が７０％以上、初透磁率が４０以上、磁気共鳴周波数が１ＭＨｚ以上であることを特徴とする前記の圧粉磁心である。このように、粉末充填率を７０％以上とすることで、飽和磁束密度が高くなり大電流用のインダクタに適した圧粉磁心となる。また軟磁性合金粉末の扁平化により初透磁率を４０以上とすることで、インダクタを構成したとき、必要なインダクタンスを確保できる。さらに磁気共鳴周波数を１ＭＨｚ以上とすることで、高周波帯での透磁率を確保することができる。 The present invention is also the above-described dust core, wherein the soft magnetic alloy powder has a powder filling rate of 70% or more, an initial permeability of 40 or more, and a magnetic resonance frequency of 1 MHz or more. Thus, by setting the powder filling rate to 70% or more, the saturation magnetic flux density is increased, and a dust core suitable for an inductor for large current is obtained. Further, by setting the initial permeability to 40 or more by flattening the soft magnetic alloy powder, it is possible to secure necessary inductance when the inductor is configured. Furthermore, by setting the magnetic resonance frequency to 1 MHz or more, the magnetic permeability in the high frequency band can be ensured.
また本発明は、前記圧粉磁心の内部を通り、前記軟磁性合金粉末の扁平方向と垂直な方向に電流が流れるように導体を配置してなることを特徴とするインダクタである。 The present invention is also an inductor characterized in that a conductor is arranged so that a current flows in a direction perpendicular to the flat direction of the soft magnetic alloy powder through the inside of the powder magnetic core.
また本発明は、前記圧粉磁心が前記成形体を前記軟磁性合金粉末の扁平面に平行な面で接合してなることを特徴とする前記のインダクタである。 Further, the present invention is the inductor described above, wherein the dust core is formed by joining the compact with a plane parallel to the flat surface of the soft magnetic alloy powder.
また本発明は、前記圧粉磁心の初透磁率が４０以上、前記導体の直流抵抗が１ｍΩ以下であること特徴とする前記のインダクタである。このように圧粉磁心の初透磁率を４０以上とし、導体の直流抵抗を１ｍΩ以下とすることで小型で電力効率の高いインダクタを得る。 The present invention is the above inductor, wherein the dust core has an initial permeability of 40 or more and a DC resistance of the conductor is 1 mΩ or less. Thus, by setting the initial permeability of the dust core to 40 or more and the direct current resistance of the conductor to 1 mΩ or less, a small and highly power-efficient inductor is obtained.
また本発明は、前記導体が１本または２本であり、２本の場合には前記導体が電磁的に結合したことを特徴とする前記のインダクタである。 The present invention is the inductor described above, wherein the number of conductors is one or two, and in the case of two conductors, the conductors are electromagnetically coupled.
本発明の圧粉磁心は磁路方向に扁平粉末の扁平面を配向することにより、反磁界が低減されるため高い透磁率を示し、かつ粉末表面の絶縁層により渦電流を抑制するため、高周波での利用が可能となる。 The powder magnetic core of the present invention has a high magnetic permeability because the demagnetizing field is reduced by orienting the flat surface of the flat powder in the magnetic path direction, and the eddy current is suppressed by the insulating layer on the powder surface. It becomes possible to use at.
また、圧粉磁心を分割し成形した後に接合することにより、従来の扁平粉で作製した圧粉磁心に比べて高密度な圧粉磁心を得ることが出来る。そのように高密度の圧粉磁心を実用化することにより、高透磁率、高飽和磁束密度な圧粉磁心が実用化され、その結果インダクタの高性能化および小型化が可能となる。 In addition, a powder magnetic core having a higher density than that of a conventional powder magnetic core made of flat powder can be obtained by dividing the powder magnetic core and then bonding it. By putting such a high-density powder magnetic core into practical use, a powder magnetic core having a high magnetic permeability and a high saturation magnetic flux density can be put into practical use. As a result, it is possible to improve the performance and size of the inductor.
加えて、本発明のインダクタは、導体の直流抵抗が１ｍΩ以下と低いため、動作時における直流抵抗による銅損失が低く抑えられ、極めて高い電力効率を有するインダクタの提供が可能になる。 In addition, since the direct current resistance of the conductor is as low as 1 mΩ or less in the inductor of the present invention, copper loss due to the direct current resistance during operation can be kept low, and an inductor having extremely high power efficiency can be provided.
次に、具体的な例を挙げ、本発明の実施の形態について説明する。 Next, a specific example will be given to describe an embodiment of the present invention.
図１に本発明に係る成形体の斜視図を示す。図１において１は成形体、２は加圧方向、３は成形体断面を示す。 FIG. 1 shows a perspective view of a molded body according to the present invention. In FIG. 1, 1 is a molded body, 2 is a pressing direction, and 3 is a cross section of the molded body.
また、図２は成形体の原料となる軟磁性合金の扁平粉の走査電子顕微鏡像を示す。ここでは水アトマイズ法で作製した平均粒径２０μｍのＦｅ−Ｓｉ基合金を、ビーズミルを用いトルエン中、２時間で粉砕することにより扁平化した。 FIG. 2 shows a scanning electron microscope image of a flat powder of a soft magnetic alloy that is a raw material of the compact. Here, the Fe—Si base alloy having an average particle diameter of 20 μm produced by the water atomization method was flattened by pulverizing in toluene for 2 hours using a bead mill.
得られた図２の扁平粉末を、大気中６００℃で１時間熱処理することにより、粉末表面に絶縁層を形成した粉末を、熱硬化性樹脂５．０重量％と混練し、乾燥、擂潰し平均粒径２００μｍの造粒粉とした。 The obtained flat powder of FIG. 2 is heat-treated at 600 ° C. in the air for 1 hour, and the powder having an insulating layer formed on the powder surface is kneaded with 5.0% by weight of a thermosetting resin, dried and crushed. A granulated powder having an average particle size of 200 μm was obtained.
得られた造粒粉を金型中に充填し、加圧方向２より７００ＭＰａで加圧成形し、１５０℃で熱硬化させ成形体１を得た。 The obtained granulated powder was filled in a mold, pressure-molded at 700 MPa from the pressing direction 2, and thermoset at 150 ° C. to obtain a molded body 1.
図３に成形体断面３（図１参照）の実体顕微鏡像を示す。加圧方向に対して垂直方向に扁平粉末の長軸方向が配向していることがわかる。なお、ａおよびｂは図１で指示した断面内の位置に対応している、 FIG. 3 shows a stereoscopic microscope image of the cross section 3 (see FIG. 1) of the molded body. It can be seen that the major axis direction of the flat powder is oriented in a direction perpendicular to the pressing direction. Note that a and b correspond to the positions in the cross section indicated in FIG.
図４に、重量比率で表した、Ｆｅ−９．５％Ｓｉ−２．０％Ａｌ、Ｆｅ−９．５％Ｓｉ−４．０％Ａｌ、Ｆｅ−９．５％Ｓｉ−５．５％Ａｌ、およびＦｅ−９．５％Ｓｉ−８．０％ＡｌとＡｌ添加量を変化させた扁平粉を用いて作製した成形体の扁平粉の配向方向に測定した複素透磁率の実部μ’の周波数特性を示す。Ａｌ添加量が少ないＦｅ−９．５％Ｓｉ−２．０％Ａｌ組成の粉末を用いた成形体ではμ’が１００ｋＨｚ以上で減衰していく。これに対してＡｌ添加量が４．０％以上のＦｅ−９．５％Ｓｉ−４．０％Ａｌ、Ｆｅ−９．５％Ｓｉ−５．５％Ａｌ、およびＦｅ−９．５％Ｓｉ−８．０％Ａｌ組成の粉末を用いた成形体ではμ’が５０００ｋＨｚ以上で減衰しており、Ａｌ添加量が２．０％の粉末を用いて作製した成形体と比較して優れた周波数特性を有している。 In FIG. 4, expressed by weight ratio, Fe-9.5% Si-2.0% Al, Fe-9.5% Si-4.0% Al, Fe-9.5% Si-5.5% Real part μ ′ of the complex permeability measured in the orientation direction of the flat powder of the compact produced using Al and Fe-9.5% Si-8.0% Al and the flat powder in which the Al addition amount was changed The frequency characteristics of are shown. In a molded body using a powder of Fe-9.5% Si-2.0% Al composition with a small amount of Al added, μ ′ is attenuated at 100 kHz or more. In contrast, Fe-9.5% Si-4.0% Al, Fe-9.5% Si-5.5% Al, and Fe-9.5% Si with an Al addition amount of 4.0% or more. -In the molded body using the powder having the Al composition of 8.0%, μ 'is attenuated at 5000 kHz or more, and the frequency is superior to that of the molded body manufactured using the powder having the Al addition amount of 2.0%. It has characteristics.
またＡｌ添加量が４．０％以上の粉末を用いて作製した成形体ではμ’減衰の直前に磁気共鳴によるピークが観察されており、μ’の減衰が磁気共鳴によるものと推察される。Ａｌ添加量２．０％の粉末を用いて作製した成形体はμ’の減衰直前に磁気共鳴のピークが見られず、渦電流による周波数の減衰と考えられる。 In addition, in a molded body produced using a powder having an Al addition amount of 4.0% or more, a peak due to magnetic resonance is observed immediately before μ ′ attenuation, and it is assumed that μ ′ attenuation is due to magnetic resonance. A molded body produced using powder with Al addition amount of 2.0% does not show a peak of magnetic resonance just before the attenuation of μ ′, and it is considered that the frequency is attenuated by eddy current.
図５に、重量比率で表した、Ｆｅ−６．５％Ｓｉ−１．０％Ｃｒ、Ｆｅ−６．５％Ｓｉ−２．０％Ｃｒ、Ｆｅ−６．５％Ｓｉ−６．０％Ｃｒ、およびＦｅ−６．５％Ｓｉ−１２．０％ＣｒとＣｒ添加量を変化させた扁平粉を用いて作製した成形体の扁平粉の配向方向に測定したμ’の周波数特性を示す。Ｃｒ添加量が少ないＦｅ−６．５％Ｓｉ−１．０％Ｃｒ組成の粉末を用いた成形体ではμ’が１０ｋＨｚ以上で減衰していく。これに対してＣｒ添加量が２．０％以上のＦｅ−６．５％Ｓｉ−２．０％Ｃｒ、Ｆｅ−６．５％Ｓｉ−６．０％Ｃｒ、およびＦｅ−６．５％Ｓｉ−１２．０％Ｃｒ組成の粉末を用いた成形体ではμ’が５０００ｋＨｚ以上で減衰しており、前述のＣｒ添加量が１．０％の粉末を用いて作製した成形体と比較して優れた周波数特性を有している。 In FIG. 5, Fe-6.5% Si-1.0% Cr, Fe-6.5% Si-2.0% Cr, Fe-6.5% Si-6.0% expressed by weight ratio. The frequency characteristics of μ ′ measured in the orientation direction of the flat powder of the compact produced using the flat powder in which Cr and Fe-6.5% Si-12.0% Cr and the added amount of Cr were changed are shown. In a compact using a powder of Fe-6.5% Si-1.0% Cr composition with a small amount of added Cr, μ ′ attenuates when the frequency is 10 kHz or more. In contrast, Fe-6.5% Si-2.0% Cr, Fe-6.5% Si-6.0% Cr, and Fe-6.5% Si with a Cr addition amount of 2.0% or more In the molded body using the powder of -12.0% Cr composition, μ ′ is attenuated at 5000 kHz or more, which is superior to the molded body manufactured using the powder having the Cr addition amount of 1.0%. It has a frequency characteristic.
またＣｒ添加量が２．０％以上の粉末を用いて作製した成形体ではμ’減衰の直前に磁気共鳴によるピークが観察されており、μ’の減衰が磁気共鳴によるものと推察される。Ｃｒ添加量１．０％の粉末を用いて作製した成形体はμ’の減衰直前に磁気共鳴のピークが見られず、渦電流による周波数の減衰と考えられる。 In addition, in a molded body produced using a powder having a Cr addition amount of 2.0% or more, a peak due to magnetic resonance is observed just before μ ′ attenuation, and it is assumed that μ ′ attenuation is due to magnetic resonance. A compact produced using a powder with 1.0% Cr addition does not show a magnetic resonance peak immediately before the attenuation of μ ′, and it is considered that the frequency is attenuated by an eddy current.
次に、これらのＡｌおよびＣｒ添加量と成形体の比抵抗の関係を図６に示す。Ａｌ添加量が４．０％以上、Ｃｒ添加量が２．０％以上で成形体の比抵抗が著しく増加していることがわかる。その結果ＡｌまたはＣｒ添加によるμ’の周波数特性の改善はＣｒおよびＡｌの添加により形成されたＡｌおよびＣｒの不動態膜が成形体の比抵抗を増加させたことによるものであることがわかる。 Next, the relationship between the added amounts of Al and Cr and the specific resistance of the molded body is shown in FIG. It can be seen that the specific resistance of the molded body is remarkably increased when the Al addition amount is 4.0% or more and the Cr addition amount is 2.0% or more. As a result, it can be seen that the improvement of the frequency characteristic of μ ′ due to the addition of Al or Cr is due to the fact that the Al and Cr passivating films formed by the addition of Cr and Al have increased the specific resistance of the compact.
また比較として、重量比率で表して、Ｆｅ−９．５％Ｓｉ−５．５％Ａｌ、およびＦｅ−６．５％Ｓｉ−６．０％Ｃｒ粉末をビーズミルで扁平化したのち、大気中の熱処理を行わずに造粒した未熱処理粉末で作製した成形体のμ’の周波数特性を熱処理粉末で作製した成形体のμ’と共に図７に示した。５．５％Ａｌ添加および６．０％Ｃｒ添加のどちらにおいても、未熱処理粉末を用いて作製した成形体にくらべて、熱処理粉末を用いて作製した成形体の方が良好な周波数特性を示した。これは大気中熱処理によって粉末中のＡｌまたはＣｒが酸化物からなる不動態膜を粉末表面に形成し、絶縁性を改善するためと考えられる。以上よりＡｌを４．０％以上またはＣｒを２．０％以上含む軟磁性合金粉末に対して、熱処理により絶縁層を形成した粉末を用いて作製する成形体が、優れた周波数特性を持つことが明らかである。またＡｌとＣｒを共に含有させてもよい。 For comparison, the Fe-9.5% Si-5.5% Al and Fe-6.5% Si-6.0% Cr powders were flattened with a bead mill and expressed in the weight ratio. FIG. 7 shows the frequency characteristics of μ ′ of the molded body made of the unheated powder granulated without heat treatment, together with μ ′ of the molded body made of the heat treated powder. In both 5.5% Al addition and 6.0% Cr addition, the molded body produced using the heat treated powder shows better frequency characteristics than the molded body produced using the unheat treated powder. It was. This is presumably because a passive film made of oxide of Al or Cr in the powder is formed on the surface of the powder by heat treatment in the atmosphere to improve insulation. From the above, compacts made from powders with an insulating layer formed by heat treatment of soft magnetic alloy powder containing Al 4.0% or more or Cr 2.0% or more have excellent frequency characteristics. Is clear. Moreover, you may contain both Al and Cr.
図８にビーズミルによる粉砕時間を変化させることによって、アスペクト比１〜５０と扁平化度を変化させた種々のＦｅ−Ｓｉ−Ａｌ扁平粉末に対し、熱硬化性樹脂からなるバインダー量を変化させることによって、成形体内の磁性粉末の充填率を変化させた場合の、初透磁率μiの関係を示した。扁平化を行う前のアスペクト比１（球状）粉末を用いて作製した成形体のμiは２５〜３０であるが、ビーズミル粉砕によりアスペクト比２まで弱扁平化した扁平粉末を用いて作製した成形体ではμiは３８〜４２と大きく増加している。さらに扁平化を進めることによりμiは著しく増加していく。以上により扁平粉のアスペクト比は２以上であれば、透磁率の向上に十分な効果を発現できることが確認された。 In FIG. 8, by changing the grinding time by the bead mill, the amount of binder made of thermosetting resin is changed with respect to various Fe—Si—Al flat powders having different aspect ratios of 1 to 50 and flatness. Shows the relationship of the initial permeability μi when the filling rate of the magnetic powder in the molded body is changed. Although the μi of the molded body prepared using the aspect ratio 1 (spherical) powder before flattening is 25 to 30, the molded body manufactured using the flat powder weakly flattened to an aspect ratio of 2 by bead milling. Then, μi is greatly increased to 38-42. Furthermore, μi increases remarkably by further flattening. From the above, it was confirmed that if the aspect ratio of the flat powder is 2 or more, a sufficient effect for improving the magnetic permeability can be exhibited.
ただし、扁平化が進むにつれてスプリングバックの影響が大きくなり、成形体充填率が減少するため、透磁率と飽和磁束度を考慮して、所望の特性を満たすアスペクト比の扁平粉を用いて成形体を作製することが必要となる。 However, as flattening progresses, the effect of springback increases, and the compact filling ratio decreases. Therefore, the compact using a flat powder with an aspect ratio that satisfies the desired characteristics in consideration of the magnetic permeability and saturation magnetic flux. It is necessary to produce.
そこで、種々のアスペクト比の粉末を用いて高さ３ｍｍ、６ｍｍ、１２ｍｍと異なる高さで成形し１５０℃で硬化した成形体の成形後およびキュア後の磁性粉末充填率を図９に示す。アスペクト比が大きくなるにつれてキュア時のスプリングバックによる膨張によって成形体に占める磁性粉末充填率が大きく低下する。しかし、成形体の高さを低くすることにより、成形後のスプリングバックが大幅に減少する。その理由を図面に基づいて説明する。図１０は高さが異なる成形体内部での磁性粉末充填率の分布を示し、図１０（ａ）は成形高さが大の場合、図１０（ｂ）は成形高さが小の場合を示す。同図のように、成形体高さが小さい方が、成形体内部まで成形圧力が伝達し、充填率の高く緻密な成形体が得られるからである。 Therefore, FIG. 9 shows the magnetic powder filling rate after molding and curing of a molded body molded at a height different from 3 mm, 6 mm, and 12 mm using various aspect ratio powders and cured at 150 ° C. As the aspect ratio increases, the magnetic powder filling ratio in the molded body greatly decreases due to expansion by springback during curing. However, by reducing the height of the molded body, the spring back after molding is greatly reduced. The reason will be described with reference to the drawings. FIG. 10 shows the distribution of the magnetic powder filling rate inside the compacts having different heights, FIG. 10 (a) shows the case where the molding height is large, and FIG. 10 (b) shows the case where the molding height is small. . This is because, as shown in the figure, when the molded body height is smaller, the molding pressure is transmitted to the inside of the molded body, and a dense molded body having a high filling rate can be obtained.
図１１にこれらの成形体の、扁平粉の配向方向に測定した初透磁率を示す。アスペクト比が低い状態ではスプリングバックの影響が少ないため、成形後およびキュア後で成形体の初透磁率は大差ないが、アスペクト比が５０の粉末で作製した成形体では、各々の成形体が薄いほど透磁率の減少が少ない。これは前述のスプリングバックの低減効果により磁性体充填率が高く、反磁界が少ない成形体が実現されるためである。 FIG. 11 shows the initial permeability of these compacts measured in the orientation direction of the flat powder. Since the influence of springback is small when the aspect ratio is low, the initial permeability of the molded body after molding and after curing is not much different, but in the molded body made of powder with an aspect ratio of 50, each molded body is thin. The smaller the decrease in permeability. This is because a compact with a high magnetic material filling rate and a small demagnetizing field is realized by the effect of reducing the spring back described above.
次に、種々の高さで作製した前述の成形体１をエポキシ樹脂で接着することにより、図１２に斜視図で示すように接合した圧粉磁心を作製した。接着後の圧粉磁心は高さ１２ｍｍの一定とした。表１に、各々の成形体の高さ、接合した個数、圧粉磁心の密度および初透磁率を示した。 Next, the above-described molded body 1 produced at various heights was bonded with an epoxy resin, so that dust cores joined as shown in a perspective view in FIG. 12 were produced. The dust core after bonding was kept constant at a height of 12 mm. Table 1 shows the height of each molded body, the number of bonded bodies, the density of the dust core, and the initial permeability.
前述のように成形体高さを削減することにより磁性粉末充填率は増加するため、接着後の圧粉磁心の密度も増加し、これに従って初透磁率も増加する。以上により本発明によって、従来の扁平粉を用いた圧粉磁心より優れた圧粉磁心の提供が可能となった。 Since the magnetic powder filling rate is increased by reducing the height of the molded body as described above, the density of the dust core after bonding is also increased, and the initial permeability is accordingly increased. As described above, according to the present invention, it is possible to provide a powder magnetic core superior to a powder magnetic core using a conventional flat powder.
次に、前述の成形体を接合した圧粉磁心で図１３に斜視図で示す直線構造型インダクタを構成した。図中、１は成形体、４は圧粉磁心、５は平角銅線、６はインダクタである。挿入した平角銅線５は厚み０．５ｍｍ、幅２ｍｍで、表面をポリアミドイミド被覆された直線構造平角銅線であり、圧粉磁心とはエポキシ樹脂で接合した。 Next, a linear structure type inductor shown in a perspective view in FIG. In the figure, 1 is a compact, 4 is a dust core, 5 is a flat copper wire, and 6 is an inductor. The inserted rectangular copper wire 5 is a straight rectangular copper wire having a thickness of 0.5 mm and a width of 2 mm and coated on the surface with a polyamideimide, and was bonded to the dust core with an epoxy resin.
比較例として球状のＦｅ−Ｓｉ−Ａｌ粉末と巻き線構造の平角導体を用いて、図１４に斜視図で示す巻き線構造型インダクタを作製した。図中、７は巻き線状平角銅線、８は圧粉磁心、９はインダクタである。巻き線状平角銅線は巻き数３．５ターンで前述と同様な平角銅線を用い作製した。 As a comparative example, a wound structure type inductor shown in a perspective view in FIG. 14 was fabricated using a spherical Fe—Si—Al powder and a rectangular conductor having a wound structure. In the figure, 7 is a wound flat rectangular copper wire, 8 is a dust core, and 9 is an inductor. The wound flat rectangular copper wire was manufactured using the same rectangular copper wire as described above with the number of turns of 3.5 turns.
作製した２つのインダクタのインダクタンスＬ（μＨ）、直流比抵抗Ｒdc（ｍΩ）および種々の電流値における銅損失Ｐcu（ｍＷ）の値を表２に示す。 Table 2 shows the values of the inductance L (μH), the DC specific resistance Rdc (mΩ), and the copper loss Pcu (mW) at various current values.
どちらのインダクタも０．５６μＨとＬ値は同等であるが、Ｒdc値は本発明の直線構造型が０．４２ｍΩと極めて低い値を示す。銅損失Ｐcuの値もＲdcに比例するため、極めて優れたインダクタが実用化できたといえる。 Both inductors have the same L value of 0.56 μH, but the Rdc value of the linear structure type of the present invention is as low as 0.42 mΩ. Since the value of the copper loss Pcu is also proportional to Rdc, it can be said that an extremely excellent inductor has been put into practical use.
次に、これらのインダクタをチョークコイルとして実装した降圧型ＤＣ−ＤＣコンバーターを作製し、その電力効率を測定し図１５に示した。低電流側で両者の間の電力効率はほぼ変わらないが、１０Ａ以上の大電流領域で、本発明の直線構造型のインダクタが従来型の巻き線構造型インダクタにくらべて優れた電力効率を示している。これは本発明のインダクタのＲdcが極めて低いことから、大電流領域における銅損失を大幅に低減することが可能なためである。以上の本発明により、電力効率を大幅に改善するインダクタの提供が可能となった。 Next, a step-down DC-DC converter in which these inductors are mounted as choke coils was manufactured, and the power efficiency thereof was measured and shown in FIG. Although the power efficiency between the two is almost the same on the low current side, the linear structure type inductor of the present invention shows superior power efficiency compared to the conventional wound structure type inductor in a large current region of 10 A or more. ing. This is because the Rdc of the inductor of the present invention is extremely low, and thus it is possible to significantly reduce the copper loss in the large current region. The present invention as described above makes it possible to provide an inductor that greatly improves power efficiency.
また本発明は、図１６に斜視図で示すように、平角銅線１１ａ，１１ｂのような導体を２本設置し、各々の導体が圧粉磁心を介し結合係数１以下で電磁的に結合して動作する４端子インダクタ構造をとることも可能である。 Further, in the present invention, as shown in a perspective view in FIG. 16, two conductors such as flat copper wires 11a and 11b are installed, and each conductor is electromagnetically coupled through a dust core with a coupling coefficient of 1 or less. It is also possible to adopt a four-terminal inductor structure that operates in the same manner.
なお、上記実施の形態では大気中熱処理により軟磁性粉末の粒子表面に絶縁層を形成する例を示したが、リン酸処理などによって、すなわちリン酸を含む溶液による酸処理膜などで絶縁層を形成しても同様の効果が得られることを別途確認した。 In the above embodiment, an example in which an insulating layer is formed on the surface of the soft magnetic powder particles by heat treatment in the atmosphere has been shown. It was separately confirmed that the same effect can be obtained even if formed.
１ 成形体
２ 加圧方向
３ 成形体断面
４，８，１０ 圧粉磁心
５，１１ａ，１１ｂ 平角銅線
６，９ インダクタ
７ 巻き線状平角銅線
１２ ４端子インダクタ
DESCRIPTION OF SYMBOLS 1 Forming body 2 Pressing direction 3 Forming body cross section 4, 8, 10 Powder magnetic core 5, 11a, 11b Flat copper wire 6, 9 Inductor 7 Winding flat copper wire 12 4-terminal inductor
Claims (8)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2006033638A JP2007214425A (en) | 2006-02-10 | 2006-02-10 | Powder magnetic core and inductor using it |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2006033638A JP2007214425A (en) | 2006-02-10 | 2006-02-10 | Powder magnetic core and inductor using it |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2007214425A true JP2007214425A (en) | 2007-08-23 |
Family
ID=38492577
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2006033638A Pending JP2007214425A (en) | 2006-02-10 | 2006-02-10 | Powder magnetic core and inductor using it |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2007214425A (en) |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2009075110A1 (en) * | 2007-12-12 | 2009-06-18 | Panasonic Corporation | Inductance part and method for manufacturing the same |
| JP2010263042A (en) * | 2009-05-01 | 2010-11-18 | Canon Electronics Inc | Dust core, and method of manufacturing the same |
| JP2013026356A (en) * | 2011-07-19 | 2013-02-04 | Taiyo Yuden Co Ltd | Magnetic material and coil component using the same |
| JP2013045926A (en) * | 2011-08-25 | 2013-03-04 | Taiyo Yuden Co Ltd | Electrode formation method of electronic component |
| JP2013045927A (en) * | 2011-08-25 | 2013-03-04 | Taiyo Yuden Co Ltd | Electronic component and manufacturing method therefor |
| JP2013077618A (en) * | 2011-09-29 | 2013-04-25 | Taiyo Yuden Co Ltd | Soft magnetic alloy assembly and electronic component using the same |
| KR101640469B1 (en) * | 2016-06-27 | 2016-07-18 | (주)대한특수금속 | Method for manufacturing single-pole only usable magnet |
| JP2017017366A (en) * | 2016-10-27 | 2017-01-19 | 太陽誘電株式会社 | Electronic component |
| JP2020061530A (en) * | 2018-10-12 | 2020-04-16 | 株式会社トーキン | Magnetic component and manufacturing method thereof |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH06267723A (en) * | 1993-03-16 | 1994-09-22 | Tdk Corp | Composite soft magnetic material |
| JPH1197228A (en) * | 1997-09-19 | 1999-04-09 | Tokin Corp | Dust core and its manufacture |
| JPH11204359A (en) * | 1998-01-14 | 1999-07-30 | Tokin Corp | Method and device for manufacturing dust core |
| JP2001332411A (en) * | 2000-05-19 | 2001-11-30 | Daido Steel Co Ltd | Composite magnetic material |
| JP2003209010A (en) * | 2001-11-07 | 2003-07-25 | Mate Co Ltd | Soft magnetic resin composition, its manufacturing method and molded body |
| JP2004270016A (en) * | 2003-03-12 | 2004-09-30 | Sanyo Special Steel Co Ltd | Powder for dust core |
| JP2005310864A (en) * | 2004-04-19 | 2005-11-04 | Matsushita Electric Ind Co Ltd | Coil component |
-
2006
- 2006-02-10 JP JP2006033638A patent/JP2007214425A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH06267723A (en) * | 1993-03-16 | 1994-09-22 | Tdk Corp | Composite soft magnetic material |
| JPH1197228A (en) * | 1997-09-19 | 1999-04-09 | Tokin Corp | Dust core and its manufacture |
| JPH11204359A (en) * | 1998-01-14 | 1999-07-30 | Tokin Corp | Method and device for manufacturing dust core |
| JP2001332411A (en) * | 2000-05-19 | 2001-11-30 | Daido Steel Co Ltd | Composite magnetic material |
| JP2003209010A (en) * | 2001-11-07 | 2003-07-25 | Mate Co Ltd | Soft magnetic resin composition, its manufacturing method and molded body |
| JP2004270016A (en) * | 2003-03-12 | 2004-09-30 | Sanyo Special Steel Co Ltd | Powder for dust core |
| JP2005310864A (en) * | 2004-04-19 | 2005-11-04 | Matsushita Electric Ind Co Ltd | Coil component |
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2009075110A1 (en) * | 2007-12-12 | 2009-06-18 | Panasonic Corporation | Inductance part and method for manufacturing the same |
| US8339227B2 (en) | 2007-12-12 | 2012-12-25 | Panasonic Corporation | Inductance part and method for manufacturing the same |
| JP2010263042A (en) * | 2009-05-01 | 2010-11-18 | Canon Electronics Inc | Dust core, and method of manufacturing the same |
| JP2013026356A (en) * | 2011-07-19 | 2013-02-04 | Taiyo Yuden Co Ltd | Magnetic material and coil component using the same |
| JP2013045926A (en) * | 2011-08-25 | 2013-03-04 | Taiyo Yuden Co Ltd | Electrode formation method of electronic component |
| JP2013045927A (en) * | 2011-08-25 | 2013-03-04 | Taiyo Yuden Co Ltd | Electronic component and manufacturing method therefor |
| JP2013077618A (en) * | 2011-09-29 | 2013-04-25 | Taiyo Yuden Co Ltd | Soft magnetic alloy assembly and electronic component using the same |
| KR101640469B1 (en) * | 2016-06-27 | 2016-07-18 | (주)대한특수금속 | Method for manufacturing single-pole only usable magnet |
| WO2018004222A1 (en) * | 2016-06-27 | 2018-01-04 | (주)대한특수금속 | Method for manufacturing magnet having only one available pole |
| US11141788B2 (en) | 2016-06-27 | 2021-10-12 | Dae Han Special Metal Ind Co., Ltd. | Method for manufacturing single-pole only usable magnet |
| JP2017017366A (en) * | 2016-10-27 | 2017-01-19 | 太陽誘電株式会社 | Electronic component |
| JP2020061530A (en) * | 2018-10-12 | 2020-04-16 | 株式会社トーキン | Magnetic component and manufacturing method thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| TW492020B (en) | Composite magnetic body, and magnetic element and method of manufacturing the same | |
| JP4308864B2 (en) | Soft magnetic alloy powder, green compact and inductance element | |
| JP6277426B2 (en) | Composite magnetic body and method for producing the same | |
| JP2007214425A (en) | Powder magnetic core and inductor using it | |
| TW557457B (en) | Compressed magnetic core with built-in coil and manufacturing method thereof | |
| JP5974803B2 (en) | Soft magnetic alloy powder, green compact, dust core and magnetic element | |
| JP2003229311A (en) | Coil-enclosed powder magnetic core, method of manufacturing the same, and coil and method of manufacturing the coil | |
| JP2010118486A (en) | Inductor and method of manufacturing the same | |
| JP2008270368A (en) | Dust core and method of manufacturing the same | |
| JP2007134381A (en) | Composite magnetic material, dust core using the same, and magnetic element | |
| JP2008288370A (en) | Surface mounting inductor, and manufacturing method thereof | |
| CN107658090A (en) | Soft magnetic metal compressed-core and the reactor for possessing soft magnetic metal compressed-core | |
| JP2010272604A (en) | Soft magnetic powder and dust core using the same, and inductor and method of manufacturing the same | |
| JP2006032907A (en) | High-frequency core and inductance component using the same | |
| JP2002313632A (en) | Magnetic element and its manufacturing method | |
| JP2008192897A (en) | Dust core and reactor | |
| JP2007134591A (en) | Composite magnetic material, dust core using the same and magnetic element | |
| CN111834075B (en) | Alloy powder composition, molded body, method for producing same, and inductor | |
| JPH11176680A (en) | Manufacture of core | |
| JP2007123376A (en) | Compound magnetic substance and magnetic device using same, and method of manufacturing same | |
| JP2008060506A (en) | Inductor and method of manufacturing the same | |
| JP2005136164A (en) | Coil component and electronic device using it | |
| JP2008147324A (en) | Inductance element | |
| WO2011121947A1 (en) | Complex magnetic material, coil-embedded type magnetic element using the same, and manufacturing method thereof | |
| JP4701531B2 (en) | Dust core |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20081001 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20100113 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20100120 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20100318 |
|
| A02 | Decision of refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A02 Effective date: 20101222 |