JP2006228824A - Inductor and its manufacturing method - Google Patents

Inductor and its manufacturing method Download PDF

Info

Publication number
JP2006228824A
JP2006228824A JP2005038111A JP2005038111A JP2006228824A JP 2006228824 A JP2006228824 A JP 2006228824A JP 2005038111 A JP2005038111 A JP 2005038111A JP 2005038111 A JP2005038111 A JP 2005038111A JP 2006228824 A JP2006228824 A JP 2006228824A
Authority
JP
Japan
Prior art keywords
powder
core
ferromagnetic metal
insulating
coil
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
Application number
JP2005038111A
Other languages
Japanese (ja)
Inventor
Masayoshi Ishii
政義 石井
Kazuyuki Okita
一幸 沖田
Hiroyuki Wada
浩之 和田
Hajime Daigaku
元 大學
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Tokyo Coil Engineering Co Ltd
Original Assignee
Tokyo Coil Engineering Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Tokyo Coil Engineering Co Ltd filed Critical Tokyo Coil Engineering Co Ltd
Priority to JP2005038111A priority Critical patent/JP2006228824A/en
Publication of JP2006228824A publication Critical patent/JP2006228824A/en
Pending legal-status Critical Current

Links

Images

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inductor which can be improved in insulation properties while being suppressed with a decline in inductance. <P>SOLUTION: Such an inductor is assumed, wherein a coil is embedded in a core consisting of a press-formed body of a ferromagnetic metal powder where the surface of ferromagnetic metal particles 6 is coated with an insulating material having a hardenability. The insulation layer which coats the surface of the ferromagnetic metal particles 6 consists of a plurality of insulation films 5a-5c, each formed of an insulating material hardened individually. By forming the insulation film from the insulation films 5a-5c hardened individually, a strong insulation film 5 can be obtained, and hence the insulation properties can be improved and a decline can be suppressed in inductance. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

本発明は、大電流や高周波でも好適に使用できるチョークコイルや他のコイル部品として用いられるインダクタに関する。   The present invention relates to a choke coil that can be suitably used even at high currents and high frequencies, and an inductor used as another coil component.

従来、絶縁材がコーティングされた強磁性金属粒子からなる強磁性金属粉末中にコイルを埋めた状態で、強磁性金属粉末をプレス成形により加圧して圧縮成形することで、加圧成形されたコア内にコイルを一体に埋設してなるインダクタが知られている(例えば特許文献1参照。)。   Conventionally, a core that has been press-molded by compressing and molding the ferromagnetic metal powder by press molding in a state where the coil is embedded in the ferromagnetic metal powder made of ferromagnetic metal particles coated with an insulating material. There is known an inductor in which a coil is integrally embedded therein (see, for example, Patent Document 1).

特許文献1のインダクタでは、強磁性金属粉末と絶縁材粉末とを混合した後、空気中において100〜300℃程度で20〜60分程度乾燥させることにより、強磁性金属粒子の表面が絶縁材でコーティングされた強磁性金属粉末を得ている。強磁性金属粉末に対する絶縁材粉末の混合量は1〜30体積%(wt%)である。絶縁材に樹脂絶縁材を用いる場合には、この樹脂絶縁材からなる絶縁層(絶縁被膜)は、前記乾燥の際に硬化される。この硬化は特許文献1のインダクタでは1回のみである。又、コイルが一体に埋設されたコア(コイル入りコア)には、樹脂絶縁材からなる絶縁層を熱硬化させてコアの機械的強度を向上するための熱処理が前記加圧成形後に施される。
特開2001−267160号公報〔請求項1、段落0002、0047〜0050、0059〜0067、0080〜0082、0085〜0087、図1(A)−(D)、図5(A)−(I)〕
In the inductor of Patent Document 1, after the ferromagnetic metal powder and the insulating material powder are mixed, the surface of the ferromagnetic metal particle is made of the insulating material by drying in air at about 100 to 300 ° C. for about 20 to 60 minutes. Coated ferromagnetic metal powder is obtained. The amount of the insulating material powder mixed with the ferromagnetic metal powder is 1 to 30% by volume (wt%). When a resin insulating material is used as the insulating material, the insulating layer (insulating film) made of the resin insulating material is cured during the drying. This curing is performed only once in the inductor of Patent Document 1. In addition, the core in which the coil is integrally embedded (coiled core) is subjected to a heat treatment after the pressure molding for thermosetting the insulating layer made of a resin insulating material to improve the mechanical strength of the core. .
JP-A-2001-267160 [Claim 1, paragraphs 0002, 0047-0050, 0059-0067, 0080-0082, 0085-0087, FIGS. 1 (A)-(D), FIGS. 5 (A)-(I) ]

例えば、パーソナルコンピュータやコンピュータゲーム機などの電子機器に、チョークコイルとして使用されるインダクタは、大電流でも好適に使用可能とする要求が強い。こうした用途には、強磁性金属粒子からなり飽和磁束密度が高い強磁性体粉末を原料としてコアを形成することが適している。   For example, an inductor used as a choke coil in an electronic device such as a personal computer or a computer game machine is strongly demanded to be suitably usable even with a large current. For such applications, it is suitable to form a core from a ferromagnetic powder made of ferromagnetic metal particles and having a high saturation magnetic flux density.

ところで、強磁性金属粉末は一般的に絶縁性が低いことが知られている。そこで、特許文献1のように強磁性金属粒子の表面を絶縁層でコーティングすることにより、この絶縁層でコアの電気抵抗を高めて渦電流損失を抑制できる。   Incidentally, it is known that the ferromagnetic metal powder generally has low insulation. Therefore, by coating the surface of the ferromagnetic metal particles with an insulating layer as in Patent Document 1, the insulating layer can increase the electrical resistance of the core and suppress eddy current loss.

しかし、特許文献1の技術はインダクタの絶縁性を高めるには適していない。すなわち、強磁性金属粉末と絶縁材粉末との混合により強磁性金属粒子の表面には1層だけ絶縁層が形成されるが、この絶縁層の厚みは0.3〜1.0μm程度であり、その強度は厚みに相応している。   However, the technique of Patent Document 1 is not suitable for increasing the insulation of the inductor. That is, only one insulating layer is formed on the surface of the ferromagnetic metal particles by mixing the ferromagnetic metal powder and the insulating material powder. The thickness of the insulating layer is about 0.3 to 1.0 μm, and its strength is It corresponds to the thickness.

又、混合された強磁性金属粉末はその金属粒子同士が結着して塊状となるため、これを解砕、つまり混合粉末に機械的な外力を加えて約500μm程度のコア成形粉末としている。このため、解砕の際に加えられる外力により絶縁層が部分的に破壊される。更に、次工程でのプレス成形の際に加えられるプレス圧力によっても、前記絶縁層は部分的に破壊される。その上、この後の熱処理工程では、絶縁層の軟化が起こるので、その際に強磁性金属粒子の応力が緩和されることを原因としても絶縁層が部分的に破壊される。   Further, since the mixed ferromagnetic metal powders are bonded together to form a lump, they are crushed, that is, a mechanical molding force is applied to the mixed powder to form a core molding powder of about 500 μm. For this reason, an insulating layer is partially destroyed by the external force applied in the case of crushing. Furthermore, the insulating layer is also partially broken by the press pressure applied during press molding in the next step. In addition, in the subsequent heat treatment step, the insulating layer is softened, so that the insulating layer is partially broken even if the stress of the ferromagnetic metal particles is relaxed.

こうした絶縁層の破壊により強磁性金属粒子間の絶縁性能は低下する。そのため、特許文献1に記載のインダクタの絶縁性は低く、その改善が求められている。   Due to the breakdown of the insulating layer, the insulating performance between the ferromagnetic metal particles is lowered. Therefore, the insulating property of the inductor described in Patent Document 1 is low, and there is a need for improvement.

又、特許文献1の技術で、絶縁材の使用量を増やして、強磁性金属粒子の表面をコーティングする絶縁層の厚くすれば、チョークコイル等インダクタの絶縁性を高めることが可能である。しかし、絶縁材の使用量を増やすほどインダクタのインダクタンス及び透磁率は低下するので、こうした対策は好ましくない。   Further, with the technique of Patent Document 1, if the amount of insulating material used is increased and the thickness of the insulating layer coating the surface of the ferromagnetic metal particles is increased, it is possible to improve the insulation of the inductor such as a choke coil. However, since the inductance and permeability of the inductor decrease as the amount of the insulating material used increases, such a countermeasure is not preferable.

本発明の目的は、インダクタンスの低下を抑制しつつ絶縁性を向上できるインダクタ及びその製造方法を提供することにある。   An object of the present invention is to provide an inductor that can improve insulation while suppressing a decrease in inductance, and a method for manufacturing the inductor.

本発明のインダクタは、硬化性の絶縁材で強磁性金属粒子の表面がコーティングされた強磁性金属粉末の加圧成形体からなるコア内にコイルを埋設したインダクタを前提とする。そして、前記目的を達成するために、請求項1の発明は、強磁性金属粒子の表面をコーティングした絶縁層を、硬化処理された絶縁材からなる複数層の絶縁被膜で形成している。   The inductor of the present invention is premised on an inductor in which a coil is embedded in a core made of a pressure-formed body of ferromagnetic metal powder coated with a surface of ferromagnetic metal particles with a curable insulating material. In order to achieve the above object, according to the first aspect of the present invention, the insulating layer coated on the surface of the ferromagnetic metal particles is formed of a plurality of insulating films made of a hardened insulating material.

この発明の好ましい形態では、前記コイルの径方向に位置するコア側面間の絶縁抵抗を1.0MΩ以上とできる。又、この発明の好ましい形態では、前記絶縁層の各部の厚みが0.6μm以上であるとよい。   In a preferred embodiment of the present invention, the insulation resistance between the core side surfaces located in the radial direction of the coil can be 1.0 MΩ or more. In a preferred embodiment of the present invention, the thickness of each part of the insulating layer is preferably 0.6 μm or more.

本発明のインダクタは、強磁性金属粒子がその表面をコーティングした複数層の絶縁被膜を有し、これらの被膜の夫々が硬化処理されているので、絶縁被膜が単層のものに比較して強磁性金属粒子表面の絶縁層(これは複数層の絶縁被膜からなる。)が強固でかつ外力に対して安定化する。これにより、絶縁被膜の耐圧性及び耐熱性が向上されて、絶縁被膜の形成後の解砕の際に加えられる外力、及びプレス成形の際に加えられるプレス圧力などの破損要因による絶縁層の破損が抑制される。したがって、強磁性金属粒子の絶縁性が向上されるとともに、この高い絶縁性を得るのに必要な絶縁材粉末の混合量が少量でよいことに伴いインダクタンスの低下を抑制できる。   The inductor of the present invention has a plurality of layers of insulating coatings whose surfaces are coated with ferromagnetic metal particles, and since each of these coatings is cured, the insulating coating is stronger than that of a single layer. The insulating layer on the surface of the magnetic metal particles (which consists of a plurality of insulating films) is strong and stabilized against external forces. As a result, the pressure resistance and heat resistance of the insulating film are improved, and the insulating layer is damaged due to external forces applied at the time of crushing after the insulating film is formed and damage factors such as press pressure applied at the time of press molding. Is suppressed. Therefore, the insulation of the ferromagnetic metal particles is improved, and a decrease in inductance can be suppressed due to the fact that the amount of the insulating material powder required to obtain this high insulation is small.

又、前記目的を達成するために、本発明のインダクタの製造方法は、強磁性金属粉末に硬化性の絶縁材粉末を混合してなる混合粉末を加熱して、前記混合により前記金属粉末の粒子の表面にコーティングされた前記絶縁材の被膜を硬化させる処理を複数回繰返してコア成形粉末を得る成形粉末形成工程と、成形型内にコイルを配置するとともにこのコイルが埋まるように前記コア成形粉末を前記成形型内に充填してから、この充填されたコア成形粉末を加圧して圧縮成形するプレス成形工程と、成形されたコイル入り圧粉コアを熱処理する熱処理工程と、を具備している。   In order to achieve the above object, the inductor manufacturing method of the present invention heats a mixed powder obtained by mixing a curable insulating material powder with a ferromagnetic metal powder, and the metal powder particles are mixed by the mixing. A molding powder forming step of obtaining a core molding powder by repeating the process of curing the coating of the insulating material coated on the surface of the core a plurality of times, and arranging the coil in the molding die and filling the coil so that the coil is buried And then pressing the filled core molding powder and compressing it, and a heat treatment step of heat-treating the molded coiled powder core. .

この発明方法では、成形粉末形成工程で、強磁性金属粉末と絶縁材粉末との混合粉末を加熱して、強磁性金属粒子表面の絶縁被膜を硬化させる処理を複数回実行するので、絶縁被膜が単層のものに比較して強磁性金属粒子表面の絶縁層(これは複数層の絶縁被膜からなる。)が強固でかつ外力及び熱に対して安定化する。このため、次のプレス成形工程に先立つ解砕時に混合粉末に加えられる外力、プレス成形工程で加えられるプレス圧、及びプレス成形工程後の熱処理工程で加えられる熱による絶縁層の軟化に拘わらず、絶縁層の破損が抑制される。したがって、絶縁性が向上されるとともに、この高い絶縁性を得るのに必要な絶縁材粉末の混合量が少量でよいことに伴いインダクタンスの低下が抑制されたインダクタを製造できる。   In the method of the present invention, since the mixed powder of the ferromagnetic metal powder and the insulating material powder is heated and the insulating coating on the surface of the ferromagnetic metal particles is cured a plurality of times in the molding powder forming step, the insulating coating is formed. Compared to a single layer, the insulating layer on the surface of the ferromagnetic metal particles (which consists of a plurality of insulating films) is strong and stabilized against external force and heat. Therefore, regardless of the external force applied to the mixed powder at the time of crushing prior to the next press molding process, the press pressure applied in the press molding process, and the softening of the insulating layer due to the heat applied in the heat treatment process after the press molding process, Damage to the insulating layer is suppressed. Therefore, it is possible to manufacture an inductor in which the insulation is improved and the decrease in inductance is suppressed due to the small amount of the insulating material powder required to obtain this high insulation.

又、本発明方法の好ましい形態では、前記成形粉末形成工程での前記強磁性金属粉末に対する前記絶縁材粉末のトータル混合量を1.0〜4.0wt%とするとよい。この発明では、強磁性金属粉末に対する絶縁材粉末のトータル混合量を1.0以上としたので、熱処理工程によって絶縁層がバインダーとして機能する際の強磁性金属粒子同士の接着性の低下が抑制されて、熱処理され後にコアにクラックが入ることを防止できる。又、強磁性金属粉末に対する絶縁材粉末のトータル混合量を4.0wt%以下としたので、熱処理工程でのコアが所定寸法以上に膨張して硬化することを防止できる。   In a preferred embodiment of the method of the present invention, the total amount of the insulating material powder mixed with the ferromagnetic metal powder in the molding powder forming step is preferably 1.0 to 4.0 wt%. In this invention, since the total mixing amount of the insulating material powder with respect to the ferromagnetic metal powder is 1.0 or more, a decrease in the adhesion between the ferromagnetic metal particles when the insulating layer functions as a binder by the heat treatment step is suppressed, It is possible to prevent the core from cracking after being heat-treated. Moreover, since the total amount of the insulating material powder to the ferromagnetic metal powder is 4.0 wt% or less, it is possible to prevent the core in the heat treatment process from expanding and curing to a predetermined dimension or more.

以上説明した本発明によれば、硬化処理された複数層の絶縁被膜からなる絶縁層を強磁性金属粒子の表面に設けることによって、インダクタンスの低下を抑制しつつ絶縁性を向上できるインダクタ及びその製造方法を提供できる。   According to the present invention described above, an inductor capable of improving insulation while suppressing a decrease in inductance by providing an insulating layer comprising a plurality of cured insulating films on the surface of the ferromagnetic metal particle, and its manufacture Can provide a method.

図1及び図2を参照して本発明の一実施形態を説明する。   An embodiment of the present invention will be described with reference to FIGS.

この一実施形態に係るインダクタは大電流が流れるチョークコイル1として使用されるもので、電子機器例えばテレビゲーム機などのコンピュータゲーム機やパーソナルコンピュータに搭載して好適に使用できる。このチョークコイル1は、図1(A)(B)(C)に示すように各面が互に直角に連続する六面体状をなして一体成形されたコア2と、このコア2に両端部を除いて埋設されたコイル3とを備えている。   The inductor according to this embodiment is used as the choke coil 1 through which a large current flows, and can be suitably used by being mounted on an electronic device such as a computer game machine such as a TV game machine or a personal computer. As shown in FIGS. 1 (A), (B), and (C), the choke coil 1 includes a core 2 that is integrally formed in a hexahedron shape in which each surface is continuous at a right angle to each other, and both ends of the core 2 are formed. It is provided with a coil 3 embedded except for the above.

コイル3には、導電性金属線、例えば銅線、好ましくは図1に例示するように断面が長方形の平角銅線を好適に使用できる。コイル3は図示しないが外周を絶縁層で被覆されている。コイル3の両端部はコア2の互に平行な2つの側面の高さ方向中間部から外に突出している。これらの両端部は、コア2の前記側面に沿って折り曲げられるとともに、コア2の裏面に沿って折り曲げられている。コア2の裏面に沿ったコイル3の両端部は端子3aとして使用される。これらの端子3aの絶縁層は除去されている。端子3aは図示しない電子機器のプリント配線基板のプリント配線にリフロー半田付けされる。したがって、チョークコイル1は表面実装部品としてプリント基板に実装できる。   For the coil 3, a conductive metal wire, for example, a copper wire, preferably a rectangular copper wire having a rectangular cross section as illustrated in FIG. Although not shown, the coil 3 is coated with an insulating layer on the outer periphery. Both end portions of the coil 3 protrude outward from the intermediate portion in the height direction of two side surfaces of the core 2 parallel to each other. These both end portions are bent along the side surface of the core 2 and are bent along the back surface of the core 2. Both ends of the coil 3 along the back surface of the core 2 are used as terminals 3a. The insulating layer of these terminals 3a is removed. The terminal 3a is reflow soldered to a printed wiring of a printed wiring board of an electronic device (not shown). Therefore, the choke coil 1 can be mounted on a printed board as a surface mount component.

このチョークコイル1のコア2は図示しない加圧成形装置であるプレス機械の金型(成形型)を用いて加圧成形された圧粉体(加圧成形体)である。コイル3は、コア2の成形前に金型内に位置決めして配置され、コア2の加圧成形に伴って一体にコア2内に埋設されたものである。したがって、このチョークコイル1は一体成形型コイル部品と称することができる。   The core 2 of the choke coil 1 is a green compact (pressure-molded body) that is pressure-molded using a die (molding die) of a press machine that is a pressure molding apparatus (not shown). The coil 3 is positioned and arranged in the mold before the core 2 is molded, and is embedded in the core 2 integrally with the pressure molding of the core 2. Therefore, this choke coil 1 can be referred to as an integrally molded coil component.

コア2は、強磁性金属粉末からなるが、これを主成分としたものであってもよい。強磁性金属粉末は、図2(B)(C)又は図3(A)(B)に例示したように表面を被覆した絶縁層5を有した強磁性金属粒子6の集まりである。なお、図2(C)及び図3(B)はプレス成形を経て変形された強磁性金属粒子6を示している。   The core 2 is made of a ferromagnetic metal powder, but may be composed mainly of this. The ferromagnetic metal powder is a collection of ferromagnetic metal particles 6 having an insulating layer 5 having a surface coated as illustrated in FIGS. 2B, 2C, 3A, and 3B. 2C and 3B show the ferromagnetic metal particles 6 deformed through press molding.

絶縁層5は、強磁性金属粒子の表面をコーティングした複数層の絶縁被膜からなり、各絶縁被膜は例えば熱によって夫々硬化処理されている。図2(B)(C)は二層の絶縁被膜5a,5bで絶縁層5が形成された例を示し、図3(A)(B)は三層の絶縁被膜5a〜5cで絶縁層5が形成された例を示している。なお、図2(B)(C)及び図3(A)(B)中符号7は、隣接した絶縁被膜5a,5b間及び5b,5c間の境界を示している。この絶縁層5の厚みは最薄部でも0.6μm以上確保されている。   The insulating layer 5 is composed of a plurality of insulating coatings coated on the surface of the ferromagnetic metal particles, and each insulating coating is cured by, for example, heat. FIGS. 2B and 2C show an example in which the insulating layer 5 is formed of two layers of insulating coatings 5a and 5b, and FIGS. 3A and 3B show the insulating layer 5 of three layers of insulating coatings 5a to 5c. An example in which is formed is shown. 2 (C) and 3 (A) and 3 (B), reference numeral 7 indicates a boundary between adjacent insulating coatings 5a and 5b and between 5b and 5c. The insulating layer 5 has a thickness of 0.6 μm or more even at the thinnest part.

絶縁層5には、硬化性の絶縁材、好ましくはバインダーとしても機能する熱硬化性の無機材料又は有機材料を用いることができる。有機材料として、熱硬化性樹脂例えば水ガラス、シリコン樹脂、エポキシ樹脂などを挙げることができ、その内の少なくとも1種を選択してできる。   The insulating layer 5 can be made of a curable insulating material, preferably a thermosetting inorganic material or organic material that also functions as a binder. Examples of the organic material include thermosetting resins such as water glass, silicon resin, and epoxy resin, and at least one of them can be selected.

強磁性金属粒子6からなる強磁性金属粉末には、粉体硬度が低く、飽和磁束密度が高く、低ロス特性であるという特長を有した鉄系金属粒子を用いることができる。この種の材料として、例えばFe粉末、パーマロイ粉末、カルボニル鉄粉末、センダスト粉末などを挙げることができ、その内の少なくとも1種を選択してできる。   As the ferromagnetic metal powder composed of the ferromagnetic metal particles 6, iron-based metal particles having features such as low powder hardness, high saturation magnetic flux density, and low loss characteristics can be used. Examples of this type of material include Fe powder, permalloy powder, carbonyl iron powder, Sendust powder, and the like, and at least one of them can be selected.

前記チョークコイル1は、成形粉末形成工程と、プレス成形工程と、熱処理工程とを経て製造される。   The choke coil 1 is manufactured through a molding powder forming process, a press molding process, and a heat treatment process.

成形粉末工程では、強磁性金属粉末と熱硬化性の絶縁材粉末とを混合した後、この混合粉末を加熱することを複数回繰返してコア成形粉末を得る。強磁性金属粉末と硬化性の絶縁材粉末とが混合されることで、強磁性金属粒子6の表面に絶縁材がコーティングされて絶縁被膜が形成される。この混合粉末が加熱されることにより絶縁被膜が硬化される。   In the molding powder process, after mixing the ferromagnetic metal powder and the thermosetting insulating material powder, heating the mixed powder is repeated a plurality of times to obtain a core molding powder. By mixing the ferromagnetic metal powder and the curable insulating material powder, the surface of the ferromagnetic metal particle 6 is coated with the insulating material to form an insulating film. The insulating coating is cured by heating the mixed powder.

この絶縁被膜5aの硬化は、混合粉末を所定時間(20〜60分)の間所定温度(100〜300℃)の加熱雰囲気中に置くことでなされる。この場合、プロペラ式の攪拌機を用いて大気中雰囲気で混合される強磁性金属粉末と絶縁材粉末とを所定温度で所定時間攪拌することにより、絶縁被膜5aを硬化させることができる。又は、すでに混合して得た混合粉末を収めた耐熱性の容器を、高温槽を用いて大気中雰囲気で所定温度で所定時間加熱することより、絶縁被膜5aを硬化させることができる。   The insulating coating 5a is cured by placing the mixed powder in a heating atmosphere at a predetermined temperature (100 to 300 ° C.) for a predetermined time (20 to 60 minutes). In this case, the insulating coating 5a can be hardened by stirring the ferromagnetic metal powder and the insulating material powder, which are mixed in the atmosphere in the air using a propeller-type stirrer, at a predetermined temperature for a predetermined time. Alternatively, the insulating coating 5a can be cured by heating a heat-resistant container containing the mixed powder already obtained by mixing at a predetermined temperature in an air atmosphere for a predetermined time using a high temperature bath.

図2(A)に一層の絶縁被膜5aが強磁性金属粒子6の表面に形成された状態を示す。この絶縁被膜5aの厚みは0.3〜1.0μmである。   FIG. 2A shows a state in which a single insulating film 5 a is formed on the surface of the ferromagnetic metal particle 6. The insulating coating 5a has a thickness of 0.3 to 1.0 μm.

前者のように攪拌機を用いて絶縁被膜を熱硬化させると、混合粉末は1〜5mm程度の塊及びそれ以下の大きさとなる。又、後者のように高温槽を用いて絶縁被覆を熱硬化させると、混合粉末は略一塊の状態となる。このため、先に絶縁被膜が硬化処理された混合粉末塊は、2回目以降の絶縁被膜の形成に先立って解砕される。この解砕は、硬化処理された混合粉末塊を乳鉢などの解砕装置を用いて実施される。それにより、混合粉末塊は、粒径が約500μmの粉末状となる。   When the insulating film is heat-cured using a stirrer as in the former, the mixed powder becomes a lump of about 1 to 5 mm and a size smaller than that. In addition, when the insulating coating is thermally cured using a high-temperature tank as in the latter case, the mixed powder is in a substantially lump state. For this reason, the mixed powder lump in which the insulating coating has been hardened first is crushed prior to the formation of the second and subsequent insulating coatings. This crushing is performed by using a crushing apparatus such as a mortar for the mixed powder lump that has been subjected to the curing treatment. Thereby, the mixed powder lump becomes a powder having a particle size of about 500 μm.

したがって、2回目以降の絶縁被膜の形成は、前記解砕により得た粉末(言い換えれば硬化処理された絶縁被膜5aでコーティングされた強磁性金属粒子からなる強磁性金属粉末)と熱硬化性の絶縁材粉末とを混合した後、この混合粉末を加熱することでなされる。この場合の混合とそれに伴う加熱及び解砕は1回目と同じである。図2(B)に二層の絶縁被膜5a、5bからなる絶縁層5が強磁性金属粒子6の表面に形成された状態を示す。又、図3(A)に三層の絶縁被膜5a〜5cからなる絶縁層5が強磁性金属粒子6の表面に形成された状態を示す。絶縁被膜5b、5cの夫々の厚みは一層の絶縁被膜5aと同様に0.3〜1.0μmである。したがって、理論的には二層の絶縁被膜5a、5bで0.6〜2.0μmの絶縁層5の厚みを得られる。又、三層の絶縁被膜5a〜5cで0.9〜3.0μmの絶縁層5の厚みを得られるので、絶縁層5の厚みは最薄部でも略0.6μm以上を確保できる。このように絶縁層5を硬化処理された絶縁被膜を積層した構成としたことにより、相対的に内側の絶縁被膜が解砕やプレス圧力等によって部分的に損傷を受けることがあっても、相対的に外側の絶縁被膜によって前記部分的な損傷箇所を修復しつつ、絶縁層5の厚みを既述のように確保できるので、絶縁層5を強固にできる。   Therefore, the second and subsequent insulating coatings are formed by heat-curing insulation from the powder obtained by the crushing (in other words, ferromagnetic metal powder comprising ferromagnetic metal particles coated with the cured insulating coating 5a). After mixing the material powder, this mixed powder is heated. In this case, the mixing and the accompanying heating and crushing are the same as the first time. FIG. 2B shows a state in which the insulating layer 5 composed of two layers of insulating coatings 5 a and 5 b is formed on the surface of the ferromagnetic metal particle 6. FIG. 3A shows a state in which an insulating layer 5 composed of three layers of insulating coatings 5 a to 5 c is formed on the surface of the ferromagnetic metal particle 6. The thickness of each of the insulating coatings 5b and 5c is 0.3 to 1.0 [mu] m like the single insulating coating 5a. Therefore, theoretically, the thickness of the insulating layer 5 of 0.6 to 2.0 μm can be obtained with the two insulating coatings 5a and 5b. Moreover, since the thickness of the insulating layer 5 of 0.9 to 3.0 [mu] m can be obtained by the three layers of insulating coatings 5a to 5c, the thickness of the insulating layer 5 can be ensured to be approximately 0.6 [mu] m or more even at the thinnest part. As described above, the insulating layer 5 is configured by laminating the cured insulating coating, so that the relatively inner insulating coating may be partially damaged by crushing, pressing pressure, or the like. In particular, the thickness of the insulating layer 5 can be ensured as described above while the partially damaged portion is repaired by the outer insulating coating, so that the insulating layer 5 can be strengthened.

以上の硬化処理の繰り返しにおいて、混合される絶縁材粉末の量は各回同じであることが好ましいが同じでなくても良い。又、絶縁層5をなす絶縁材粉末の強磁性金属粉末に対するトータル混合量は、1.0〜4.0wtであることが好ましい。トータル混合量を1.0wt以上とすることは、コア2にクラックなどを生じる可能性が高くなることを防止する上で有効である。これに対して、トータル混合量を1.0wt未満とした場合には、後述の熱処理工程での加熱に伴う絶縁層5によるバインダーとしての機能が十分に発揮されず、強磁性金属粒子同士の接着性が不十分となる。又、トータル混合量を4.0wtとすることは、後述の熱処理工程での加熱に伴うコア2の硬化時に所定寸法以上にコア2が膨張することを防止する上で有効である。これに対して、トータル混合量が4.0wtを超える場合には、後述の熱処理工程でコア2が硬化する際に、このコア2が所定寸法以上に膨張し易くなる。   In the repetition of the above curing treatment, the amount of the insulating material powder to be mixed is preferably the same each time, but may not be the same. Moreover, it is preferable that the total mixing amount with respect to the ferromagnetic metal powder of the insulating material powder which comprises the insulating layer 5 is 1.0-4.0 wt. Setting the total mixing amount to 1.0 wt or more is effective in preventing an increase in the possibility of causing cracks in the core 2. On the other hand, when the total mixing amount is less than 1.0 wt, the function as a binder by the insulating layer 5 due to heating in the heat treatment step described later is not sufficiently exhibited, and the adhesion between the ferromagnetic metal particles Is insufficient. Further, setting the total mixing amount to 4.0 wt is effective in preventing the core 2 from expanding beyond a predetermined dimension when the core 2 is cured by heating in a heat treatment step described later. On the other hand, when the total mixing amount exceeds 4.0 wt, when the core 2 is cured in a heat treatment process described later, the core 2 is easily expanded to a predetermined dimension or more.

なお、以上成形粉末形成工程では、既述のように強磁性金属粉末と熱硬化性の絶縁材粉末とを混合し熱硬化処理した後、成形性を確保するための有機材料をさらに混合してもよい。   In the molding powder forming step, the ferromagnetic metal powder and the thermosetting insulating material powder are mixed and thermoset as described above, and then an organic material for ensuring moldability is further mixed. Also good.

以上説明した成形粉末形成工程では、所定回数の硬化処理後に、既述の解砕処理を施して、最終的に粒径が約500μmの粉末状からなるコア成形粉末を形成する。   In the molded powder forming step described above, after the predetermined number of curing processes, the above-described crushing process is performed to finally form a core molded powder having a particle size of about 500 μm.

次のプレス成形工程では、図示しないプレス装置の金型(成形型)内にコイル3を配置するとともに、このコイル3が埋まるように前記成形粉末形成工程で得たコア成形粉末を成形型内に充填してから、この充填されたコア成形粉末を加圧して圧縮成形する。これにより、コイル入り圧粉コアを成形できる。なお、このプレス成形工程での金型へのコア成形粉末の充填と加圧は、一回で実施することに限らず、2回に分けても良い。つまり、金型へのコア成形粉末を所定量充填してから、このコア成形粉末を加圧し圧縮成形して下部コアを形成し、この金型内の下部コア上にコイル3を載せた後に、金型内に更に所定量のコア成形粉末を充填し、次にこのコア成形粉末とともに下部コアを加圧することによって上部コアを成形し、これら上下コア間にコイル3を埋め込むことも可能である。   In the next press molding process, the coil 3 is arranged in a mold (molding die) of a not-shown pressing device, and the core molding powder obtained in the molding powder forming process is placed in the molding die so that the coil 3 is buried. After filling, the filled core molding powder is pressurized and compression molded. Thereby, the compact core with a coil can be fabricated. The filling and pressurization of the core molding powder into the mold in the press molding process are not limited to being performed once, and may be divided into two. That is, after a predetermined amount of core molding powder is filled into a mold, the core molding powder is pressurized and compression molded to form a lower core, and after the coil 3 is placed on the lower core in the mold, It is also possible to fill the mold with a predetermined amount of core molding powder and then press the lower core together with the core molding powder to mold the upper core and embed the coil 3 between the upper and lower cores.

次の熱処理工程では、プレス成形工程で成形されたコイル入りコアを熱処理する。この工程は、所定時間(20〜60分)の間所定温度(100〜300℃)の加熱雰囲気中にコイル入りコアを置くことでなされる。   In the next heat treatment step, the coiled core formed in the press forming step is heat treated. This step is performed by placing the coiled core in a heating atmosphere at a predetermined temperature (100 to 300 ° C.) for a predetermined time (20 to 60 minutes).

以上の手順で製造されたチョークコイル1では、少量の絶縁材粉末の使用でありながら、インダクタンスの低下を抑制しつつコイル3の径方向に位置するコア側面間の絶縁抵抗が1.0MΩ以上と高い絶縁性を確保できる(図4、図6、図7参照)。このことは以下の実施例1〜実施例3で確認できた。   In the choke coil 1 manufactured according to the above procedure, the insulation resistance between the core side surfaces located in the radial direction of the coil 3 is as high as 1.0 MΩ or more while suppressing a decrease in inductance while using a small amount of insulating powder. Insulation can be ensured (see FIGS. 4, 6, and 7). This could be confirmed in Examples 1 to 3 below.

絶縁抵抗の測定は、例えば図示しない絶縁抵抗計が有した一対のピンプローブを、図1(B)中コア側面2a,2bの縦横各中央となる位置に当てて(押し当て方向と位置を矢印で示す。)測定した。ピンプローブ間距離は10mm、使用したピンプローブの先端の面積は2.54mmである。又、インダクタンスの測定は、LCRメーターを用いてコイル3の両方の端子3a間で測定した。 Insulation resistance is measured by, for example, applying a pair of pin probes held by an insulation resistance meter (not shown) to the positions of the center sides 2a and 2b of the core side surfaces 2a and 2b in FIG. Measured.) The distance between the pin probes is 10 mm, and the area of the tip of the used pin probe is 2.54 mm 2 . The inductance was measured between both terminals 3a of the coil 3 using an LCR meter.

(実施例1)
強磁性金属粉末にパーマロイ粉末を用いて、これにエポキシ樹脂からなる絶縁材粉末を、0.25wt%、0.5wt%、1.0wt%、1.5wt%、2.0wt%、2.5wt%混ぜた6種類の混合粉末を得て、これらの混合粉末を150℃で1時間硬化処理した。次に、この1回目の硬化処理がされた粉末を解砕してなる混合粉末に、さらにエポキシ樹脂からなる絶縁材粉末を、0.25wt%、0.5wt%、1.0wt%、1.5wt%、2.0wt%、2.5wt%混ぜた6種類の混合粉末を得て、これらの混合粉末を150℃で1時間硬化処理し、こうして2回目の硬化処理がされた粉末を解砕して、6種類のコア成形粉末を形成した。したがって、前記1回目と2回目の硬化処理が施された6種類のコア成形粉末の夫々に対する絶縁材粉末のトータル混合量は、0.5wt%、1.0wt%、2.0wt%、3.0wt%、4.0wt%、5.0wt%である。
Example 1
Permalloy powder is used for the ferromagnetic metal powder, and the insulating material powder made of epoxy resin is mixed with 0.25wt%, 0.5wt%, 1.0wt%, 1.5wt%, 2.0wt%, 2.5wt%. Mixed powders were obtained, and these mixed powders were cured at 150 ° C. for 1 hour. Next, an insulating material powder made of epoxy resin is further added to the mixed powder obtained by pulverizing the powder subjected to the first curing treatment, and 0.25 wt%, 0.5 wt%, 1.0 wt%, 1.5 wt%, 2.0 6 kinds of mixed powders mixed with wt% and 2.5wt% were obtained, and these mixed powders were cured at 150 ° C. for 1 hour. Thus, the second cured powder was crushed, A core molding powder was formed. Accordingly, the total mixed amount of the insulating material powder with respect to each of the six types of core molding powder subjected to the first and second curing treatments is 0.5 wt%, 1.0 wt%, 2.0 wt%, 3.0 wt%, 4.0 wt%, 5.0 wt%.

次に、プレス機械を用いて前記6種類のコア成形粉末毎のコイル入り圧粉コアを成形した。詳しくは、プレス機械は、図1(A)中の幅w及び奥行きdが夫々10mm、高さhが4mmのコア2を加圧成形できる金型(成形型)を備えるものであって、この金型内に巻数が3.5ターンの平角ワイヤー銅線からなるコイル3をセットするとともに、コア成形粉末を充填して、所定のプレス圧例えば3ton/cmでコイル入り圧粉コアを成形した。なお、6種類のコア成形粉末の成形は、各絶縁材粉末のトータル混合量に応じて充填率を合わせる条件で実施した。このプレス成形後、成形されたコイル入り圧粉コアの夫々に対して最後の硬化処理を例えば150℃で1時間の硬化処理を行った。 Next, the coiled powder core for each of the six types of core molding powders was molded using a press machine. Specifically, the press machine includes a mold (molding die) that can press-mold the core 2 having a width w and a depth d of 10 mm and a height h of 4 mm in FIG. A coil 3 made of a flat wire copper wire having a number of turns of 3.5 turns was set in the mold and filled with a core molding powder, and a dust core with a coil was molded at a predetermined press pressure, for example, 3 ton / cm 2 . In addition, the molding of the six types of core molding powder was performed under the condition of matching the filling rate according to the total mixed amount of each insulating material powder. After the press molding, the final curing process was performed at 150 ° C. for 1 hour, for example, on each of the molded cores with coil.

次に、以上の手順で製造された6種類の本発明サンプルの夫々について、電圧を25V印加した条件で、図1(B)中コア側面2a,2b間の絶縁抵抗と、コイル3の両方の端子3a間のインダクタンスとを夫々測定した。   Next, with respect to each of the six types of the present invention samples manufactured by the above procedure, both the insulation resistance between the core side surfaces 2a and 2b in FIG. The inductance between the terminals 3a was measured.

又、比較のためのサンプルを以下の手順で製造した。まず、強磁性金属粉末にパーマロイ粉末を用いて、これにエポキシ樹脂からなる絶縁材粉末を、0.5wt%、1.0wt%、2.0wt%、3.0wt%、4.0wt%、5.0wt%混ぜた6種類の混合粉末を得た。そして、この混合粉末に対する加熱処理を行わずに、次に前記プレス機械を用いて3ton/cmのプレス圧でコイル入り圧粉コアを得た後に、これらのコアを150℃で1時間硬化処理した。 Moreover, the sample for a comparison was manufactured in the following procedures. First, permalloy powder was used as the ferromagnetic metal powder, and this was mixed with 0.5 wt%, 1.0 wt%, 2.0 wt%, 3.0 wt%, 4.0 wt%, 5.0 wt% of insulating material powder made of epoxy resin. Different kinds of mixed powders were obtained. And without performing the heat processing with respect to this mixed powder, after obtaining the compacting core with a coil with the press pressure of 3 ton / cm < 2 > next using the said press machine, these cores were hardened at 150 degreeC for 1 hour. did.

この比較サンプルと、前記のように混合粉末を得る段階で2回熱硬化処理された本発明サンプルとについて、絶縁材粉末の混合量と測定された絶縁抵抗との関係を図4に示すとともに、絶縁材粉末の混合量と測定されたインダクタンスとの関係を図5に示す。なお、図4中縦軸の絶縁抵抗の値の対数目盛りである。   FIG. 4 shows the relationship between the mixed amount of the insulating material powder and the measured insulation resistance for this comparative sample and the present invention sample heat-treated twice in the stage of obtaining the mixed powder as described above, FIG. 5 shows the relationship between the mixing amount of the insulating material powder and the measured inductance. In addition, it is the logarithmic scale of the value of the insulation resistance of the vertical axis | shaft in FIG.

図4により、絶縁材粉末の混合量が同じであっても本発明サンプルの方が比較サンプルよりも高い絶縁抵抗を得られ、同じ絶縁抵抗であれば、絶縁材粉末の混合量が少なくてよいことが明らかとなった。ちなみに、絶縁抵抗が約0.5MΩでは、本発明での絶縁材混合量が0.5wt%であるのに対して比較例での絶縁材粉末の混合量は約2.7wtパーセントであり、絶縁材粉末の混合量を約2.2wt%削減できた。絶縁抵抗が約1.3MΩでは、本発明での絶縁材粉末の混合量が2.0wt%であるのに対して比較例での絶縁材粉末の混合量は約3.9wtパーセントであり、絶縁材粉末の混合量を約1.9wt%削減できた。絶縁抵抗が約11MΩでは、本発明での絶縁材粉末の混合量が3.5wt%であるのに対して比較例での絶縁材粉末の混合量は約5.0wtパーセントであり、絶縁材粉末の混合量を約1.5wt%削減できた。   According to FIG. 4, even if the mixing amount of the insulating material powder is the same, the sample of the present invention can obtain a higher insulation resistance than the comparative sample, and if the same insulating resistance, the mixing amount of the insulating material powder may be small. It became clear. By the way, when the insulation resistance is about 0.5 MΩ, the mixed amount of the insulating material in the comparative example is about 2.7 wt% while the mixed amount of the insulating material in the present invention is 0.5 wt%. The amount of mixing was reduced by about 2.2 wt%. When the insulation resistance is about 1.3 MΩ, the mixing amount of the insulating powder in the present invention is 2.0 wt%, whereas the mixing amount of the insulating powder in the comparative example is about 3.9 wt%. The amount of mixing was reduced by about 1.9 wt%. When the insulation resistance is about 11 MΩ, the mixing amount of the insulating material powder in the present invention is 3.5 wt%, whereas the mixing amount of the insulating material powder in the comparative example is about 5.0 wt%. The amount was reduced by about 1.5 wt%.

図5により、本発明サンプルでも比較サンプルでもインダクタンスは、絶縁材粉末の混合量が少ないほど高く、絶縁材粉末の混合量が多いほど低くなることが分かった。   From FIG. 5, it was found that the inductance is higher as the amount of the insulating material powder is smaller and lower as the amount of the insulating material powder is larger in both the inventive sample and the comparative sample.

以上のように同じ絶縁抵抗であれば、絶縁材混合量が本発明サンプルの方が比較サンプルより少量で済むことから、図5の結果により本発明サンプルの方が高いインダクタンスを得られる。すなわち、パーマロイ粉末にエポキシ樹脂の粉末を混ぜて混合粉末を形成する際、エポキシ樹脂を混ぜるたびに、このエポキシ樹脂からなる絶縁被膜を熱硬化処理して得たコア成形粉末を用いて製造されたチョークコイルの絶縁性及びインピーダンスは、少量のエポキシ樹脂の使用で夫々向上することができた。   As described above, if the insulation resistance is the same, the amount of the insulating material mixed in the sample of the present invention is smaller than that of the comparative sample. Therefore, the result of FIG. That is, when a mixed powder is formed by mixing an epoxy resin powder with a permalloy powder, each time an epoxy resin is mixed, it is manufactured using a core molding powder obtained by thermosetting an insulating coating made of this epoxy resin. The insulation and impedance of the choke coil could be improved by using a small amount of epoxy resin.

(実施例2)
実施例1と同様の手順で第1〜第5の本発明サンプルを製造して、その夫々について絶縁抵抗とインダクタンスを測定した。この場合第1の本発明サンプルの絶縁層は図2(A)に示すように熱硬化処理された一層の絶縁被膜のみからなる。第2の本発明サンプルの絶縁層は図2(B)(C)に示すように夫々熱硬化処理された二層の絶縁被膜からなる。第3の本発明サンプルの絶縁層は図3(A)(B)に示すように夫々熱硬化処理された三層の絶縁被膜からなる。第4の本発明サンプルの絶縁層は夫々熱硬化処理された四層の絶縁被膜からなる。第5の本発明サンプルの絶縁層は夫々熱硬化処理された互層の絶縁被膜からなる。
(Example 2)
First to fifth samples of the present invention were manufactured in the same procedure as in Example 1, and the insulation resistance and inductance were measured for each of the samples. In this case, the insulating layer of the first sample of the present invention consists of only one insulating film that has been heat-cured as shown in FIG. As shown in FIGS. 2B and 2C, the insulating layer of the second sample of the present invention consists of two layers of insulating coatings that are each thermoset. As shown in FIGS. 3 (A) and 3 (B), the insulating layer of the third sample of the present invention is composed of three layers of insulating coatings each heat-treated. The insulating layers of the fourth sample of the present invention are each composed of four layers of insulating coatings that have been thermoset. Each of the insulating layers of the fifth sample of the present invention is composed of an insulating coating of alternate layers that has been heat-cured.

この測定結果を図6に示す。なお、図6中縦軸の絶縁抵抗の値の対数目盛りである。   The measurement results are shown in FIG. In addition, it is the logarithmic scale of the value of the insulation resistance of the vertical axis | shaft in FIG.

図6によれば、硬化回数が増えてもインダクタンスにさほど大きな変化は見られず、又、硬化回数が増えるほど絶縁抵抗は高くなる傾向があり、特に、硬化回数が1回であるサンプルに対して硬化回数が2回以上のサンプルでは、絶縁抵抗が格段に高くなることが分かった。なお、以上の硬化回数に対するインダクタンス及び絶縁抵抗は、硬化回数が5回を超えて増えても同様である。そして、硬化回数が1回のサンプルの絶縁抵抗は、大電流や高周波が流れるチョークコイルとしては実用に適さないレベルであり、硬化回数が2回〜5回の本発明サンプルの絶縁抵抗は、大電流や高周波が流れるチョークコイルとしては実用に適するレベルであった。したがって、図6に示した測定結果から硬化回数は、2回以上、言い換えれば、強磁性金属粒子をコーティングした絶縁層が夫々硬化処理された2層以上の絶縁被膜からなるからなるコア成形粉末を用いると良いことが分かった。 According to FIG. 6, the inductance does not change so much even if the number of times of curing increases, and the insulation resistance tends to increase as the number of times of curing increases. Thus, it was found that the insulation resistance was remarkably increased in the sample having the number of times of curing of 2 times or more. The inductance and the insulation resistance with respect to the number of times of curing described above are the same even when the number of times of curing exceeds 5 times. The insulation resistance of the sample with a single curing frequency is not suitable for practical use as a choke coil through which a large current or high frequency flows, and the insulation resistance of the sample of the present invention with a curing frequency of 2 to 5 is large. As a choke coil through which current and high frequency flow, it was at a level suitable for practical use. Therefore, from the measurement results shown in FIG. 6, the number of times of curing is two times or more, in other words, a core molding powder consisting of two or more layers of insulating coatings each coated with ferromagnetic metal particles is cured. It turned out to be good to use.

(実施例3)
強磁性金属粉末にカルボニル鉄粉末を用いて、これにフェノール樹脂からなる絶縁材粉末を、0.25wt%、0.5wt%、1.0wt%、1.5wt%、2.0wt%、2.5wt%混ぜた6種類の混合粉末を得て、これらの混合粉末を120℃で1時間硬化処理した。次に、この1回目の硬化処理がされた粉末を解砕してなる混合粉末に、さらにフェノール樹脂からなる絶縁材粉末を、0.25wt%、0.5wt%、1.0wt%、1.5wt%、2.0wt%、2.5wt%混ぜた6種類の混合粉末を得て、これらの混合粉末を120℃で1時間硬化処理し、こうして2回目の硬化処理がされた粉末を解砕して、6種類のコア成形粉末を形成した。したがって、前記1回目と2回目の硬化処理が施された6種類のコア成形粉末の夫々に対する絶縁材粉末のトータル量は、0.5wt%、1.0wt%、2.0wt%、3.0wt%、4.0wt%、5.0wt%である。
(Example 3)
Six types of ferro-ferrous metal powder mixed with carbonyl iron powder and 0.25wt%, 0.5wt%, 1.0wt%, 1.5wt%, 2.0wt%, 2.5wt% insulating powder made of phenol resin The mixed powders were obtained, and these mixed powders were cured at 120 ° C. for 1 hour. Next, an insulating material powder made of a phenol resin is further added to the mixed powder obtained by pulverizing the powder subjected to the first curing treatment, and 0.25 wt%, 0.5 wt%, 1.0 wt%, 1.5 wt%, 2.0 6 kinds of mixed powders mixed with wt% and 2.5wt% were obtained, and these mixed powders were cured at 120 ° C for 1 hour, and thus the powder that had been cured for the second time was crushed, A core molding powder was formed. Accordingly, the total amount of the insulating material powder for each of the six types of core molding powders subjected to the first and second curing treatments is 0.5 wt%, 1.0 wt%, 2.0 wt%, 3.0 wt%, 4.0 wt%. %, 5.0 wt%.

次に、実施例1で説明したプレス機械を用い、その金型内に巻数が3.5ターンの平角ワイヤー銅線からなるコイル3をセットして、実施例1と同様に6種類のコア成形粉末毎のコイル入り圧粉コアを成形した。このプレス成形においても、各絶縁材粉末のトータル混合量に応じて充填率を合わせる条件で実施した。この後、プレス成形後、成形されたコイル入り圧粉コアの夫々に対して最後の硬化処理を例えば120℃で1時間の硬化処理を行った。   Next, using the press machine described in Example 1, the coil 3 made of a flat wire copper wire having a turn number of 3.5 turns is set in the die, and each of the six types of core molding powders is set as in Example 1. A green compact core with a coil was formed. This press molding was also performed under the condition of matching the filling rate according to the total amount of each insulating material powder. Then, after press molding, the final curing process was performed at 120 ° C. for 1 hour, for example, on each of the molded cores with coil.

そして、以上の手順で製造された6種類の本発明サンプルの夫々について、実施例1と同様に絶縁抵抗とインダクタンスとを測定した。   Then, the insulation resistance and the inductance were measured in the same manner as in Example 1 for each of the six types of the present invention samples manufactured by the above procedure.

又、比較のためのサンプルを以下の手順で製造した。まず、強磁性金属粉末にカルボニル鉄粉末を用いて、これにフェノール樹脂からなる絶縁材粉末を、0.5wt%、1.0wt%、2.0wt%、3.0wt%、4.0wt%、5.0wt%混ぜた6種類の混合粉末を得た。そして、この混合粉末に対する加熱処理を行わずに、次に、前記プレス機械を用いて3ton/cmのプレス圧でコイル入り圧粉コアを得た後に、これらのコアを更に120℃で1時間硬化処理した。 Moreover, the sample for a comparison was manufactured in the following procedures. First, carbonyl iron powder was used as the ferromagnetic metal powder, and this was mixed with 0.5 wt%, 1.0 wt%, 2.0 wt%, 3.0 wt%, 4.0 wt%, 5.0 wt% of the insulating material powder made of phenol resin. Six types of mixed powders were obtained. And without performing heat processing with respect to this mixed powder, next, after obtaining the compacting core with a coil with the press pressure of 3 ton / cm < 2 > using the said press machine, these cores were further further at 120 degreeC for 1 hour. Cured.

この比較サンプルと、前記のように混合粉末を得る段階で2回熱硬化処理された本発明サンプルとについて、絶縁材粉末の混合量と測定された絶縁抵抗との関係を図7に示すとともに、絶縁材粉末の混合量と測定されたインダクタンスとの関係を図8に示す。なお、図7中縦軸の絶縁抵抗の値の対数目盛りである。   FIG. 7 shows the relationship between the mixed amount of the insulating material powder and the measured insulation resistance for this comparative sample and the present invention sample heat-cured twice in the stage of obtaining the mixed powder as described above. FIG. 8 shows the relationship between the mixing amount of the insulating material powder and the measured inductance. In addition, it is the logarithmic scale of the value of the insulation resistance of the vertical axis | shaft in FIG.

これら図7と図8により、実施例1と同様に結果が得られた。つまり、カルボニル鉄粉末にフェノール樹脂の粉末を混ぜて混合粉末を形成する際、フェノール樹脂を混ぜるたびに、このフェノール樹脂からなる絶縁被膜を熱硬化処理して得たコア成形粉末を用いて製造されたチョークコイルの絶縁性及びインピーダンスは、少量のフェノール樹脂の使用で夫々向上することができた。   7 and 8, the results were obtained in the same manner as in Example 1. That is, when a mixed powder is formed by mixing a phenol resin powder with a carbonyl iron powder, each time the phenol resin is mixed, it is manufactured using a core molding powder obtained by heat-curing an insulating coating made of this phenol resin. The insulation and impedance of the choke coil could be improved by using a small amount of phenolic resin.

なお、本発明は、コイルと端子とが別々であって、これらが溶接などで接続されている構成のチョークコイルなどのインダクタにも適用できるとともに、コイルが平角銅線ではなく断面円形の導電性金属線である場合に、これを単層巻きではなく複層巻きとした構成のチョークコイルなどのインダクタにも適用できる。   The present invention can also be applied to an inductor such as a choke coil having a structure in which the coil and the terminal are separated and connected by welding or the like, and the coil is not a flat copper wire but has a circular cross-sectional conductivity. In the case of a metal wire, it can also be applied to an inductor such as a choke coil having a structure in which this is not a single layer winding but a multiple layer winding.

(A)は本発明の一実施形態に係るチョークコイルを例示する斜視図。(B)は図1(A)のチョークコイルを示す平面図。(C)は図1(A)のチョークコイルを示す断面図。FIG. 4A is a perspective view illustrating a choke coil according to an embodiment of the invention. (B) is a top view which shows the choke coil of FIG. 1 (A). (C) is sectional drawing which shows the choke coil of FIG. 1 (A). (A)は図1のチョークコイルのコアをなす強磁性金属粉末の粒子に一層の絶縁層が形成された状態を模式的に示す断面図。(B)は図1のチョークコイルのコアをなす強磁性金属粉末の粒子に二層の絶縁層が形成された状態を模式的に示す断面図。(C)は図2(B)の金属粒子がプレス成形によって変形した状態を模式的に示す断面図。(A) is sectional drawing which shows typically the state by which the insulating layer of one layer was formed in the particle | grains of the ferromagnetic metal powder which makes the core of the choke coil of FIG. (B) is sectional drawing which shows typically the state by which the two-layered insulating layer was formed in the particle | grains of the ferromagnetic metal powder which makes the core of the choke coil of FIG. (C) is sectional drawing which shows typically the state which the metal particle of FIG. 2 (B) deform | transformed by press molding. (A)は図1のチョークコイルのコアをなす強磁性金属粉末の粒子に三層の絶縁層が形成された状態を模式的に示す断面図。(B)は図3(A)の金属粒子がプレス成形によって変形した状態を模式的に示す断面図。(A) is sectional drawing which shows typically the state by which the three-layered insulating layer was formed in the particle | grains of the ferromagnetic metal powder which makes the core of the choke coil of FIG. (B) is sectional drawing which shows typically the state which the metal particle of FIG. 3 (A) deform | transformed by press molding. コアがパーマロイ粉末とエポキシ樹脂の混合粉末で成形された本発明に係るチョークコイルとその比較例の絶縁抵抗とエポキシ樹脂混合量との関係を示すグラフ。The graph which shows the relationship between the insulation resistance of the choke coil which concerns on this invention by which the core was shape | molded with the mixed powder of the permalloy powder, and the epoxy resin, and its comparative example, and the epoxy resin mixing amount. コアがパーマロイ粉末とエポキシ樹脂の混合粉末で成形された本発明に係るチョークコイルとその比較例のインダクタンスとエポキシ樹脂混合量との関係を示すグラフ。The graph which shows the relationship between the inductance of the choke coil which concerns on this invention by which the core was shape | molded with the mixed powder of the permalloy powder, and the epoxy resin, and its comparative example, and an epoxy resin mixing amount. コアがパーマロイ粉末とエポキシ樹脂の混合粉末で成形された本発明に係るチョークコイルの絶縁抵抗とインダクタンスとの関係を示すグラフ。The graph which shows the relationship between the insulation resistance and inductance of the choke coil which concerns on this invention by which the core was shape | molded with the mixed powder of the permalloy powder and the epoxy resin. コアがカルボニル鉄粉末とフェノール樹脂の混合粉末で成形された本発明に係るチョークコイルとその比較例の絶縁抵抗とフェノール樹脂混合量との関係を示すグラフ。The graph which shows the relationship between the insulation resistance of the choke coil which concerns on this invention by which the core was shape | molded with the mixed powder of the carbonyl iron powder, and the phenol resin, and its comparative example, and the phenol resin mixing amount. コアがパーマロイ粉末とエポキシ樹脂の混合粉末で成形された本発明に係るチョークコイルとその比較例のインダクタンスとフェノール樹脂混合量との関係を示すグラフ。The graph which shows the relationship between the choke coil based on this invention by which the core was shape | molded with the mixed powder of the permalloy powder and the epoxy resin, and the inductance of the comparative example, and the phenol resin mixing amount.

符号の説明Explanation of symbols

1…チョークコイル(インダクタ)、2…コア、3…コイル、5…絶縁層、5a〜5c…絶縁被膜、6…強磁性金属粒子、7…絶縁被膜間の境界   DESCRIPTION OF SYMBOLS 1 ... Choke coil (inductor), 2 ... Core, 3 ... Coil, 5 ... Insulating layer, 5a-5c ... Insulating coating, 6 ... Ferromagnetic metal particle, 7 ... Boundary between insulating coatings

Claims (5)

硬化性の絶縁材で強磁性金属粒子の表面がコーティングされた強磁性金属粉末の加圧成形体からなるコア内にコイルを埋設したインダクタにおいて、前記強磁性金属粒子の表面をコーティングした絶縁層を、夫々硬化処理された前記絶縁材からなる複数層の絶縁被膜で形成したインダクタ。   In an inductor in which a coil is embedded in a core made of a pressure-formed body of ferromagnetic metal powder coated with a surface of a ferromagnetic metal particle with a curable insulating material, an insulating layer coated with the surface of the ferromagnetic metal particle is provided. Inductors formed of a plurality of layers of insulating coatings made of the insulating material, each cured. 前記コイルの径方向に位置するコア側面間の絶縁抵抗が1.0MΩ以上である請求項1に記載のインダクタ。   The inductor according to claim 1, wherein an insulation resistance between core side surfaces located in a radial direction of the coil is 1.0 MΩ or more. 前記絶縁層の各部の厚みが0.6μm以上である請求項1又は2に記載のインダクタ。   The inductor according to claim 1 or 2, wherein a thickness of each part of the insulating layer is 0.6 µm or more. 強磁性金属粉末に熱硬化性の絶縁材粉末を混合してなる混合粉末を加熱して、前記混合により前記金属粉末の粒子の表面にコーティングされた前記絶縁材の被膜を硬化させる処理を複数回繰返してコア成形粉末を得る成形粉末形成工程と、
成形型内にコイルを配置するとともにこのコイルが埋まるように前記コア成形粉末を前記成形型内に充填してから、この充填されたコア成形粉末を加圧して圧縮成形するプレス成形工程と、
成形されたコイル入り圧粉コアを熱処理する熱処理工程と、
を具備したインダクタの製造方法。
Heating a mixed powder obtained by mixing a thermosetting insulating material powder with a ferromagnetic metal powder, and curing the coating film of the insulating material coated on the surface of the metal powder particles by the mixing a plurality of times. Molding powder forming step of repeatedly obtaining a core molding powder;
A press molding step of placing a coil in a molding die and filling the molding die with the core molding powder so as to fill the coil, and then pressurizing and compressing the filled core molding powder;
A heat treatment step for heat-treating the formed powdered core with coil;
An inductor manufacturing method comprising:
前記成形粉末形成工程での前記強磁性金属粉末に対する前記絶縁材粉末のトータル混合量を1.0〜4.0wt%とした請求項4に記載のインダクタの製造方法。   5. The method of manufacturing an inductor according to claim 4, wherein a total mixing amount of the insulating material powder with respect to the ferromagnetic metal powder in the molding powder forming step is 1.0 to 4.0 wt%.
JP2005038111A 2005-02-15 2005-02-15 Inductor and its manufacturing method Pending JP2006228824A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2005038111A JP2006228824A (en) 2005-02-15 2005-02-15 Inductor and its manufacturing method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2005038111A JP2006228824A (en) 2005-02-15 2005-02-15 Inductor and its manufacturing method

Publications (1)

Publication Number Publication Date
JP2006228824A true JP2006228824A (en) 2006-08-31

Family

ID=36989948

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2005038111A Pending JP2006228824A (en) 2005-02-15 2005-02-15 Inductor and its manufacturing method

Country Status (1)

Country Link
JP (1) JP2006228824A (en)

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7563428B2 (en) 1999-06-02 2009-07-21 The Board Of Regents Of The University Of Oklahoma Method of making carbon nanotubes
JP2009253030A (en) * 2008-04-07 2009-10-29 Toyota Central R&D Labs Inc Powder for magnetic core, dust core, and manufacturing method of them
JP2010183057A (en) * 2009-01-07 2010-08-19 Sumitomo Electric Ind Ltd Production process for soft magnetic material, soft magnetic material, and powder magnetic core
JP2011087682A (en) * 2009-10-21 2011-05-06 Fujishoji Co Ltd Game machine
JP2015216316A (en) * 2014-05-13 2015-12-03 Necトーキン株式会社 Coil component
JP2019102529A (en) * 2017-11-29 2019-06-24 Tdk株式会社 Method for manufacturing inductor element
US10893609B2 (en) 2012-09-11 2021-01-12 Ferric Inc. Integrated circuit with laminated magnetic core inductor including a ferromagnetic alloy
US11058001B2 (en) 2012-09-11 2021-07-06 Ferric Inc. Integrated circuit with laminated magnetic core inductor and magnetic flux closure layer
US11064610B2 (en) 2012-09-11 2021-07-13 Ferric Inc. Laminated magnetic core inductor with insulating and interface layers
US11116081B2 (en) 2012-09-11 2021-09-07 Ferric Inc. Laminated magnetic core inductor with magnetic flux closure path parallel to easy axes of magnetization of magnetic layers
US11197374B2 (en) 2012-09-11 2021-12-07 Ferric Inc. Integrated switched inductor power converter having first and second powertrain phases
US11302469B2 (en) * 2014-06-23 2022-04-12 Ferric Inc. Method for fabricating inductors with deposition-induced magnetically-anisotropic cores
JP7375469B2 (en) 2019-10-30 2023-11-08 セイコーエプソン株式会社 Insulator-coated magnetic alloy powder particles, powder magnetic cores, and coil parts

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001267160A (en) * 2000-01-12 2001-09-28 Tdk Corp Coil sealing dust core and method for manufacturing the same
JP2002280224A (en) * 2001-01-05 2002-09-27 Humanelecs Co Ltd Amorphous alloy powder core and nanocrystal alloy powder core, and their manufacturing method
JP2004031883A (en) * 2002-05-09 2004-01-29 Murata Mfg Co Ltd Coil component and manufacturing method thereof
JP2004363466A (en) * 2003-06-06 2004-12-24 Toko Inc Complex magnetic material and method for manufacturing inductor using the same

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001267160A (en) * 2000-01-12 2001-09-28 Tdk Corp Coil sealing dust core and method for manufacturing the same
JP2002280224A (en) * 2001-01-05 2002-09-27 Humanelecs Co Ltd Amorphous alloy powder core and nanocrystal alloy powder core, and their manufacturing method
JP2004031883A (en) * 2002-05-09 2004-01-29 Murata Mfg Co Ltd Coil component and manufacturing method thereof
JP2004363466A (en) * 2003-06-06 2004-12-24 Toko Inc Complex magnetic material and method for manufacturing inductor using the same

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7563428B2 (en) 1999-06-02 2009-07-21 The Board Of Regents Of The University Of Oklahoma Method of making carbon nanotubes
JP2009253030A (en) * 2008-04-07 2009-10-29 Toyota Central R&D Labs Inc Powder for magnetic core, dust core, and manufacturing method of them
JP2010183057A (en) * 2009-01-07 2010-08-19 Sumitomo Electric Ind Ltd Production process for soft magnetic material, soft magnetic material, and powder magnetic core
JP2010183056A (en) * 2009-01-07 2010-08-19 Sumitomo Electric Ind Ltd Method for producing soft magnetic material, soft magnetic material, and powder magnetic core
JP2011087682A (en) * 2009-10-21 2011-05-06 Fujishoji Co Ltd Game machine
US11058001B2 (en) 2012-09-11 2021-07-06 Ferric Inc. Integrated circuit with laminated magnetic core inductor and magnetic flux closure layer
US10893609B2 (en) 2012-09-11 2021-01-12 Ferric Inc. Integrated circuit with laminated magnetic core inductor including a ferromagnetic alloy
US11064610B2 (en) 2012-09-11 2021-07-13 Ferric Inc. Laminated magnetic core inductor with insulating and interface layers
US11116081B2 (en) 2012-09-11 2021-09-07 Ferric Inc. Laminated magnetic core inductor with magnetic flux closure path parallel to easy axes of magnetization of magnetic layers
US11197374B2 (en) 2012-09-11 2021-12-07 Ferric Inc. Integrated switched inductor power converter having first and second powertrain phases
US11903130B2 (en) 2012-09-11 2024-02-13 Ferric Inc. Method of manufacturing laminated magnetic core inductor with insulating and interface layers
JP2015216316A (en) * 2014-05-13 2015-12-03 Necトーキン株式会社 Coil component
US11302469B2 (en) * 2014-06-23 2022-04-12 Ferric Inc. Method for fabricating inductors with deposition-induced magnetically-anisotropic cores
JP2019102529A (en) * 2017-11-29 2019-06-24 Tdk株式会社 Method for manufacturing inductor element
JP7027843B2 (en) 2017-11-29 2022-03-02 Tdk株式会社 Manufacturing method of inductor element
JP7375469B2 (en) 2019-10-30 2023-11-08 セイコーエプソン株式会社 Insulator-coated magnetic alloy powder particles, powder magnetic cores, and coil parts

Similar Documents

Publication Publication Date Title
JP2006228824A (en) Inductor and its manufacturing method
TW556234B (en) Coil component and method for manufacturing the same
US6791445B2 (en) Coil-embedded dust core and method for manufacturing the same
JP6508878B2 (en) Soft magnetic molding
KR100433200B1 (en) Composite magnetic material, magnetic elements and method of manufacturing the same
US6882261B2 (en) Coil-embedded dust core and method for manufacturing the same, and coil and method for manufacturing the same
JP7426191B2 (en) Magnetic substrate containing soft magnetic metal particles and electronic components containing the magnetic substrate
JP2001267160A (en) Coil sealing dust core and method for manufacturing the same
CN108806920B (en) Inductance element
KR20140061036A (en) Multilayered power inductor and method for preparing the same
JP6506658B2 (en) Dust core, electronic / electrical component comprising the dust core, and electronic / electrical device on which the electronic / electrical component is mounted
CN106816262B (en) coil device
JP2014082382A (en) Magnetic powder, inductor element, and method for manufacturing inductor element
CN106816261A (en) Coil device
JP2010010426A (en) Inductor and method of manufacturing the same
JP7424845B2 (en) Coil parts, circuit boards and electronic equipment
JP2006228825A (en) Inductor and its manufacturing method
CN108806921B (en) Inductance element
JP2006019706A (en) Coil-encapsulated dust core manufacturing method and coil encapsulated dust core
CN112652446A (en) Coil component and method for manufacturing same
JP2018022916A (en) Electronic component and electronic device
JP6456729B2 (en) Inductor element and manufacturing method thereof
JP2007254814A (en) Fe-Ni-BASED SOFT MAGNETIC ALLOY POWDER, GREEN COMPACT, AND COIL-SEALED DUST CORE
KR101872601B1 (en) Magnetic powder and inductor comprising the same
JP6955382B2 (en) Laminated coil

Legal Events

Date Code Title Description
A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20070629

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20070911

A02 Decision of refusal

Free format text: JAPANESE INTERMEDIATE CODE: A02

Effective date: 20080122