Tdk Corporation

Katsushi Yasuhara

Yasuhide Yamashita

Chiomi Sato

Masahiko Watanabe

Kenya Takagawa

Yuji Sezai

Hiroyuki Ono

Takashi Ito

Syota Goto

Ryoma Nakazawa

Shoji Inoue

Yusuke Taniguchi

Osamu Takeda

Shigetoshi Ishida

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.

Soft magnetic alloy powder, dust core, and coil component

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&#xd7;10to 1&#xd7;10MPa. 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.

Method of manufacturing of an inductor element

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&#x3b1;&#x2212;S&#x3b2;&#x2265;&#x2212;2% is satisfied, where S&#x3b1; (%) and S&#x3b2; (%) are respectively an area ratio of the magnetic powder in the inner-core central region and the top-plate central region.

Inductor element

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&#x3b1;&#x2212;S&#x3b2;1&#x2265;5.0% is satisfied, where S&#x3b1;(%) and S&#x3b2;1(%) are respectively an area ratio of a magnetic powder in the inner-core central region and the winding-wire inner circumferential neighboring region.

Inductor element and method of manufacturing the same

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, SAto SA, 0.55 or less, when an outer diameter of the air-core coil is 'a', an inner diameter of the same is 'a', 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 &#x201c;h&#x201d;, is provided. The coil device is superior in DC superimposing characteristic while suppressing the magnetic saturation.

Coil device

A Mn&#x2014;Zn based ferrite having a main component comprised of 51 to 54 mol % of an iron oxide in FeOconversion, 14 to 21 mol % of a zinc oxide in ZnO conversion and the rest of a manganese oxide, wherein a content (&#x3b1; [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&#x2266;&#x3b1;&#x2266;Y2&#x2003;&#x2003;(1) Note that Y1 and Y2 are expressed by the formulas below and CoO&#x3e;0 [ppm].1=(&#x2212;0.13&#xb7;+1.5&#xb7;&#x2212;15.6+850)/(0.0003&#xb7;+0.0098)&#x2212;233&#x2003;&#x2003;(2)2=(&#x2212;0.40&#xb7;+4.6&#xb7;&#x2212;46.7+2546)/(0.0003&#xb7;+0.0098)+1074&#x2003;&#x2003;(3) The A and B in the above Y1 and Y2 are A=FeO(mol %) and B=ZnO (mol %).

Mn-Zn based ferrite, magnetic core for transformer and transformer

An Mn&#x2014;Zn ferrite wherein 0 to 5000 ppm of a Co oxide in a CoOconversion is contained in a basic component constituted by FeO: 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 &#x3b1; in a formula (1) below in said ferrite satisfies &#x3b1;&#x2267;0.93.&#x3b1;=((Fe&#x2212;Mn&#x2212;Co)&#xd7;(4.291.912.192.01))/(()&#xd7;100)&#x2003;&#x2003;formula (1).Note that in the formula (1), (Fe&#x2212;Mn&#x2212;Co): [wt %], A: FeO[mol %], B: MnO [mol %], C: ZnO [mol %] and D: CoO [mol %]. According to the present invention, a highly reliable Mn&#x2014;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.

Mn-Zn ferrite, transformer magnetic core and transformer

Ferrite core and its production method

Mn-Zn ferrite production process, Mn-Zn ferrite, and ferrite core for power supplies

MnZn ferrite comprises a main component comprising iron oxide 52.5 to 54.0 mol % in terms of Fe2O3, zinc oxide 7.7 to 10.8 mol % in terms of ZnO, and manganese oxide of the remaining, and sub-components of silicon oxide 60 to 140 ppm in terms of SiO and calcium oxide 350 to 700 ppm in terms of CaO, and further contains nickel oxide 4500 ppm or lower (not including 0) in terms of NiO.

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Tokyo, Japan

Katsushi Yasuhara