Abstract: A coil component including a core part and a coil part formed by winding a conductor in a coil form, in which the coil part is inside of the core part. The core part has a center pole part positioned in an area surrounded by an inner diameter of the coil part. The center pole part includes a first center pole part and a second center pole part each having different predetermined configurations, or the center pole part includes soft magnetic metal particles having predetermined deflection angles and aspect ratios.

Abstract: A method of manufacturing an inductor element includes preparing an insert member including a winding portion where a conductor is wound in a coil shape. A plurality of preliminary green compacts is obtained by conducting a preliminary compression molding of a granule containing a magnetic powder and a resin at a pressure of 2.5×102 to 1×103 MPa. The insert member and the plurality of preliminary green compacts are integrated so that a joint interface of the plurality of preliminary green compacts is formed intermittently.

Abstract: A soft magnetic alloy powder contains soft magnetic alloy particles. The soft magnetic alloy particles contain Fe and Si. The soft magnetic alloy particles each include crystal grains and crystal grain boundary between the crystal grains. At least one of the crystal grains has a Si segregation part.

Abstract: An inductor element includes a wire-winding portion and a core portion. In the wire-winding portion, a conductor is wound in a coil shape. The core portion surrounds the wire-winding portion and contains a magnetic powder and a resin. An inner-core central region is a region of the core portion within a distance from a winding axis center of the wire-winding portion toward an existing region of the wire-winding portion in an outward direction perpendicular to the winding axis center. A top-plate central region is a region of the core portion within a distance from the winding axis center toward a no-existing region of the wire-winding portion in the outward direction. S??S???2% is satisfied, where S? (%) and S? (%) are respectively an area ratio of the magnetic powder in the inner-core central region and the top-plate central region.

Abstract: An inductor element includes a wire-winding portion and a core portion. In the wire-winding portion, a conductor is wound in a coil shape. The core portion surrounds the wire-winding portion and contains a magnetic powder and a resin. The wire-winding portion includes an inner circumferential surface. A winding-wire inner circumferential neighboring region is a region of the core portion within a distance from the inner circumferential surface toward a winding axis of the wire-winding portion. An inner-core central region is a region of the core portion within a distance from the winding axis center toward an existing region of the wire-winding portion in an outward direction perpendicular to the winding axis center. S??S?1?5.0% is satisfied, where S?(%) and S?1(%) are respectively an area ratio of a magnetic powder in the inner-core central region and the winding-wire inner circumferential neighboring region.

Abstract: A method of manufacturing an inductor element includes preparing an insert member including a winding portion where a conductor is wound in a coil shape. A plurality of preliminary green compacts is obtained by conducting a preliminary compression molding of a granule containing a magnetic powder and a resin at a pressure of 2.5×102 to 1×103 MPa. The insert member and the plurality of preliminary green compacts are integrated so that a joint interface of the plurality of preliminary green compacts is formed intermittently.

Abstract: A method of manufacturing an inductor element includes preparing an insert member including a winding portion where a conductor is wound in a coil shape. A plurality of preliminary green compacts is obtained by conducting a preliminary compression molding of a granule containing a magnetic powder and a resin at a pressure of 2.5×102 to 1×103 MPa. The insert member and the plurality of preliminary green compacts are integrated so that a joint interface of the plurality of preliminary green compacts is formed intermittently.

Abstract: A coil device, in which an air-core coil of a cylindrical shape is buried in a core including a magnetic powder and a resin, showing, CV value of the below described cross sectional areas, SA1 to SA5, 0.55 or less, when an outer diameter of the air-core coil is “a1”, an inner diameter of the same is “a2”, and a distance between a surface of the core perpendicular to a direction of winding axis and an end of the air-core coil in the direction of winding axis is “h”, is provided. The coil device is superior in DC superimposing characteristic while suppressing the magnetic saturation.

Abstract: An inductor element includes a wire-winding portion and a core portion. In the wire-winding portion, a conductor is wound in a coil shape. The core portion surrounds the wire-winding portion and contains a magnetic powder and a resin. The wire-winding portion includes an inner circumferential surface. A winding-wire inner circumferential neighboring region is a region of the core portion within a distance from the inner circumferential surface toward a winding axis of the wire-winding portion. An inner-core central region is a region of the core portion within a distance from the winding axis center toward an existing region of the wire-winding portion in an outward direction perpendicular to the winding axis center. S??S?1?5.0% is satisfied, where S?(%) and S?1 (%) are respectively an area ratio of a magnetic powder in the inner-core central region and the winding-wire inner circumferential neighboring region.

Abstract: An inductor element includes a wire-winding portion and a core portion. In the wire-winding portion, a conductor is wound in a coil shape. The core portion surrounds the wire-winding portion and contains a magnetic powder and a resin. An inner-core central region is a region of the core portion within a distance from a winding axis center of the wire-winding portion toward an existing region of the wire-winding portion in an outward direction perpendicular to the winding axis center. A top-plate central region is a region of the core portion within a distance from the winding axis center toward a no-existing region of the wire-winding portion in the outward direction. S??S???2% is satisfied, where S? (%) and s? (%) are respectively an area ratio of the magnetic powder in the inner-core central region and the top-plate central region.

Abstract: A method of manufacturing an inductor element includes preparing an insert member including a winding portion where a conductor is wound in a coil shape. A plurality of preliminary green compacts is obtained by conducting a preliminary compression molding of a granule containing a magnetic powder and a resin at a pressure of 2.5×102 to 1×103 MPa. The insert member and the plurality of preliminary green compacts are integrated so that a joint interface of the plurality of preliminary green compacts is formed intermittently.

Abstract: A coil device, in which an air-core coil of a cylindrical shape is buried in a core including a magnetic powder and a resin, showing, CV value of the below described cross sectional areas, SA1 to SA5, 0.55 or less, when an outer diameter of the air-core coil is “a1”, an inner diameter of the same is “a2”, and a distance between a surface of the core perpendicular to a direction of winding axis and an end of the air-core coil in the direction of winding axis is “h”, is provided. The coil device is superior in DC superimposing characteristic while suppressing the magnetic saturation.

Abstract: A soft magnetic metal powder includes a plurality of soft magnetic metal particles composed of an Fe—Co based alloy. The Fe—Co based alloy includes 0.50 mass % or more and 8.00 mass % or less of Co and a remaining part composed of Fe and an inevitable impurity. A soft magnetic metal powder includes a plurality of soft magnetic metal particles composed of an Fe—Co based alloy. The Fe—Co based alloy includes 0.50 mass % or more and 8.00 mass % or less of Co, 0.01 mass % or more and 8.00 mass % or less of Si, and a remaining part composed of Fe and an inevitable impurity. The present invention can provide a soft magnetic metal powder or so having a favorable corrosion resistance.

Abstract: A Mn—Zn based ferrite having a main component comprised of 51 to 54 mol % of an iron oxide in Fe2O3 conversion, 14 to 21 mol % of a zinc oxide in ZnO conversion and the rest of a manganese oxide, wherein a content (? [ppm]) of cobalt oxide in a CoO conversion with respect to 100 wt % of the main component satisfies a relation formula below. Relation formula: Y1???Y2??(1) Note that Y1 and Y2 are expressed by the formulas below and CoO>0 [ppm]. Y1=(?0.13·B2+1.5·B?15.6A+850)/(0.0003·B+0.0098)?233??(2) Y2=(?0.40·B2+4.6·B?46.7A+2546)/(0.0003·B+0.0098)+1074??(3) The A and B in the above Y1 and Y2 are A=Fe2O3 (mol %) and B=ZnO (mol %).

Abstract: An Mn—Zn ferrite wherein 0 to 5000 ppm of a Co oxide in a Co3O4 conversion is contained in a basic component constituted by Fe2O3: 51.5 to 57.0 mol % and ZnO: 0 to 15 mol % (note that 0 is not included) wherein the rest is substantially constituted by MnO; and a value ? in a formula (1) below in said ferrite satisfies ??0.93. ?=((Fe2+?Mn3+?Co3+)×(4.29×A+1.91×B+2.19×C+2.01×D))/((A?B?C?D)×100)??formula (1). Note that in the formula (1), (Fe2+?Mn3+?Co3+): [wt %], A: Fe2O3 [mol %], B: MnO [mol %], C: ZnO [mol %] and D: CoO [mol %]. According to the present invention, a highly reliable Mn—Zn ferrite used as a magnetic core of a power supply transformer, etc. of a switching power supply, etc., having a small core loss in a wide temperature range, furthermore, exhibiting a little deterioration of core loss characteristics under a high temperature (in a high temperature storage test) and having excellent magnetic stability, a transformer magnetic core and a transformer can be provided.

Abstract: A transformer core having a high inductance, small inductance tolerance, and small harmonic distortion, in particular total harmonic distortion (THD), wherein a surface roughness of a gap forming surface (RaG) forming a gap for adjustment of the inductance is not more than 0.70 ?m, preferably not more than 0.45 ?m, a transformer using the same, and a method of production of a transformer core having the above properties polishing the gap forming surface forming the gap by a grinding wheel having polishing abrasives of a particle size of #400 to #8000, preferably #600 to #8000 (JIS-R6001).

Abstract: A Mn—Zn based ferrite having a main component comprised of 51 to 54 mol % of an iron oxide in Fe2O3 conversion, 14 to 21 mol % of a zinc oxide in ZnO conversion and the rest of a manganese oxide, wherein a content (&agr; [ppm]) of cobalt oxide in a CoO conversion with respect to 100 wt % of the main component satisfies a relation formula below.

Abstract: A ferrite core is provided. This ferrite core has high saturation flux density Bs at a high temperature of 100° C. or higher, and in particular, at around 150° C., and has excellent magnetic stability at a high temperature, experiencing reduced deterioration of magnetic properties, and in particular, reduced core loss at such high temperature (even by trading off some improvement in the level of the loss).

Abstract: An Mn—Zn ferrite wherein 0 to 5000 ppm of a Co oxide in a CO3O4 conversion is contained in a basic component constituted by Fe2O3: 51.5 to 57.0 mol % and ZnO: 0 to 15 mol % (note that 0 is not included) wherein the rest is substantially constituted by MnO; and a value &agr; in a formula (1) below in said ferrite satisfies &agr;≧0.93.

Abstract: The invention provides a manganese-zinc ferrite production process comprising a maximum temperature holding step for firing and a cooling step in a nitrogen atmosphere. The nitrogen atmosphere changeover temperature T in the cooling step is below 1,1500° C. and equal to or higher than 1,0000° C., and the cooling rate V1 conforms to the condition defined by: T≦(V1+1,450)/1.5  (1) Here T is the nitrogen atmosphere changeover temperature in ° C. and V1 is the cooling rate in ° C./hour from T down to 900° C.