Nec Tokin Corporation

Nec Tokin Corporaton

Toru Ito

Teruhiko Fujiwara

Masayoshi Ishii

Haruki Hoshi

Keita Isogai

Tamiko Ambo

Hatsuo Matsumoto

Kazuyuki Okita

Toshiya Sato

Masahiro Kondo

Tadakuni Sato

Hisao Nishino

Mizuho Sato

Gen Daigaku

Ryutaro Isoda

Takao Yamada

In order to provide an inductance part having excellent DC superposition characteristic and core-loss, a magnetically biasing magnet, which is disposed in a magnetic gap of a magnetic core, is a bond magnet comprising magnetic powder and plastic resin with the content of the resin being 20% or more on the base of volumetric ratio and which has a specific resistance of 0.1&#x3a9;&#xb7;cm or more. The magnetic powder used is rare-earth magnetic powder having an intrinsic coercive force of 5 kOe or more, Curie point of 300&#xb0; C. or more, and an average particle size of 2.0&#x2013;50 &#x3bc;m. A magnetically biasing magnet used in an inductance part that is treated by the reflow soldering method has a resin content of 30% or more and the magnetic powder used therein is Sm&#x2014;Co magnetic powder having an intrinsic coercive force of 10 kOe or more, Curie point of 500&#xb0; C. or more, and an average particle size of 2.5&#x2013;50 &#x3bc;m. A thin magnet having a thickness of 500 &#x3bc;m or less can be realized for a small-sized inductance part.

Magnetically biasing bond magnet for improving DC superposition characteristics of magnetic coil

An inductor component according to the present invention includes a magnetic core including at least one magnetic gap having a gap length of about 50 to 10,000 &#x3bc;m in a magnetic path, a magnet for magnetic bias arranged in the neighborhood of the magnetic gap in order to supply magnetic bias from both sides of the magnetic gap, and a coil having at least one turn applied to the magnetic core. The aforementioned magnet for magnetic bias is a bonded magnet containing a resin and a magnet powder dispersed in the resin and having a resistivity of 1 &#x3a9;&#xb7;cm or more. The magnet powder includes a rare-earth magnet powder having an intrinsic coercive force of 5 KOe or more, a Curie point of 300&#xb0; C. or more, the maximum particle diameter of 150 &#x3bc;m or less, and an average particle diameter of 2.0 to 50 &#x3bc;m m and coated with inorganic glass, and the rare-earth magnet powder is selected from the group consisting of a Sm&#x2014;Co magnet powder, Nd&#x2014;Fe&#x2014;B magnet powder, and Sm&#x2014;Fe&#x2014;N magnet powder.

Magnetic core including magnet for magnetic bias and inductor component using the same

In order to provide an inductance part having excellent DC superposition characteristic and core-loss, a magnetically biasing magnet, which is disposed in a magnetic gap of a magnetic core, is a bond magnet comprising magnetic powder and plastic resin with the content of the resin being 20% or more on the base of volumetric ratio and which has a specific resistance of 0.1&#x3a9;&#x2022;cm or more. The magnetic powder used is rare-earth magnetic powder having an intrinsic coercive force of 5 kOe or more, Curie point of 300&#xb0; C. or more, and an average particle size of 2.0-50 &#x3bc;m. A magnetically biasing magnet used in an inductance part that is treated by the reflow soldering method has a resin content of 30% or more and the magnetic powder used therein is Sm&#x2014;Co magnetic powder having an intrinsic coercive force of 10 kOe or more, Curie point of 500&#xb0; C. or more, and an average particle size of 2.5-50 &#x3bc;m. A thin magnet having a thickness of 500 &#x3bc;m or less can be realized for a small-sized inductance part.

An inductance component includes a magnetic core ( ) forming a magnetic circuit having a magnetic gap, an exciting coil ( ) wound around the magnetic core, and a permanent magnet ( ) disposed in the magnetic gap. The permanent magnet is greater in sectional area than the magnetic core.

Inductance component comprising a permanent magnet greater in sectional area than a magnetic path and disposed in a magnetic gap

An inductance component comprises a magnetic core having at least one magnetic gap, means for generating a direct-current biased magnetic field produced by mounting a permanent magnet in the vicinity of a generally closed magnetic circuit which passes through the magnetic gap in the magnetic core or on the outside thereof, and a coil wound around the magnetic core, wherein the permanent magnet is mounted near the magnetic gap at one or more legs of the magnetic core which sandwich the magnetic gap.

Inductance component having a permanent magnet in the vicinity of a magnetic gap

An inductor component according to the present invention includes a magnetic core including at least one magnetic gap having a gap length of about 50 to 10,000 &mgr;m in a magnetic path, a magnet for magnetic bias arranged in the neighborhood of the magnetic gap in order to supply magnetic bias from both sides of the magnetic gap, and a coil having at least one turn applied to the magnetic core. The aforementioned magnet for magnetic bias is a bonded magnet containing a resin and a magnet powder dispersed in the resin and having a resistivity of 1 &OHgr;&middot;cm or more. The magnet powder includes a rare-earth magnet powder having an intrinsic coercive force of 5 KOe or more, a Curie point of 300&deg; C. or more, the maximum particle diameter of 150 &mgr;m or less, and an average particle diameter of 2.0 to 50 &mgr;m and coated with inorganic glass, and the rare-earth magnet powder is selected from the group consisting of a Sm&mdash;Co magnet powder, Nd&mdash;Fe&mdash;B magnet powder, and Sm&mdash;Fe&mdash;N magnet powder.

An inductor component is provided which includes a magnetic core having at least one gap, an excitation coil disposed on the magnetic core so as to form a magnetic path on the magnetic core, at least one permanent magnet disposed near the at least one gap, and at least one first soft magnetic material piece disposed between the at least one permanent magnet and the magnetic core, wherein the first soft magnetic material piece is formed of a soft magnetic material which has a smaller permeability and less eddy current loss than the magnetic core.

Inductor component having a permanent magnet in the vicinity of magnetic gap

A low-profile magnetic core capable of reducing the thickness of an inductor component is provided. The magnetic core includes at least one gap in a magnetic path, and a permanent magnet is inserted in the gap. The magnetic core has an alternating current magnetic permeability at 20 kHz of 45 or more in a magnetic field of 120 Oe under application of direct current, and has a core loss characteristic of 100 kW/m or less under the conditions of 20 kHz and the maximum magnetic flux density of 0.1 T. An inductor component is produced by applying at least one turn of coil to the aforementioned magnetic core.

Magnetic core including bias magnet and inductor component using the same

An inductor component contains a drum magnetic core made of a magnetic material having a structure including integrated flanges at both ends of a columnar material, a coil wound around the columnar material in the drum magnetic core and placed between the flanges, and a permanent magnet placed in the neighborhood of the drum magnetic core with the coil wound around. This inductor component contains a sleeve core fitted to the outside of the drum magnetic core. The permanent magnet is placed in at least one gap in a closed magnetic circuit formed with the drum magnetic core and the sleeve core in order to apply a direct-current magnetic field in the direction opposite to the direction of a magnetic field generated by a magnetomotive force due to the coil.

Inductor component containing permanent magnet for magnetic bias and method of manufacturing the same

Disposed in a magnetic gap of a magnetic core, a magnetically biasing permanent magnet is a bond magnet comprising rare-earth magnetic powder and a binder resin. The rare-earth magnetic powder has an intrinsic coercive force of 5 kOe or more, a Curie temperature of 300&deg; C. or more, and an average particle size of 2.0-50 &mgr;m. The rare-earth magnetic power has a surface coated with a metallic layer containing an oxidation-resistant metal. In order to enable a surface-mount to reflow, the rare-earth magnetic powder may have the intrinsic coercive force of 10 kOe or more, the Curie temperature of 500&deg; C. and the average particle size of 2.5-50 &mgr;m. In addition, to prevent specific resistance from degrading, the metallic layer desirably may be coated with a glass layer consisting of low-melting glass having a softening point less than a melting point of the oxidation-resistant metal.

Magnetic core comprising a bond magnet including magnetic powder whose particle's surface is coated with oxidation-resistant metal

A magnetic core has an open magnetic path and includes a magnetic body forming the open magnetic path and having a soft magnetic property, and a permanent magnet at least at one end of the magnetic path of the magnetic body. A coil assembly includes the magnetic core having the open magnetic path. The magnetic core includes the magnetic body forming the open magnetic path and having the soft magnetic property. The coil assembly also includes the permanent magnet at least at one end of the magnetic path of the magnetic body, and at least one coil having at least one turn wound around the magnetic core. A power supply circuit includes the coil assembly. The coil assembly includes the magnetic core having the open magnetic path. The magnetic core includes the magnetic body forming the open magnetic path and having the soft magnetic property. The coil assembly further includes the permanent magnet at least at one end of the magnetic path of the magnetic body and at least one coil having at least one turn wound around the magnetic core. In the power supply circuit, a magnetic field is generated in response to an exciting current that flows through the coil of the coil assembly when an input voltage is applied, and is also applied to the magnetic body having the soft magnetic property. The magnetic field is opposite in direction to a magnetic field which is applied to the magnetic body having the soft magnetic property by the permanent magnet.

Magnetic core, coil assembly and power supply circuit using the same

A magnetic core having excellent DC superposition characteristics and core-loss characteristics is provided. The magnetic core comprises a magnetically biasing magnet disposed in a magnetic gap thereof to provide a magnetic bias from opposite ends of the magnetic gap to the core. The said magnetically biasing magnet comprises a bond magnet which comprises rare-earth magnetic powder and a binder resin. The rare-earth magnetic powder has an intrinsic coercive force of 5 kOe or more, a Curie temperature Tc of 300&deg; C. or more, specific resistance of 0.1 &OHgr;&middot;cm or more, residual magnetization Br of 1000 to 4000 G and coercive force bHc of a B-H curve of 0.9 kOe or more.

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Miyagi, Japan

Toru Ito