Nec Tokin Corporation

Nec Tokin Corporaton

Tamiko Ambo

Teruhiko Fujiwara

Toru Ito

Masayoshi Ishii

Haruki Hoshi

Keita Isogai

Hatsuo Matsumoto

Teruhiko c/o Nec Tokin Corp Fujiwara

Hatsuo c/o Nec Tokin Corp Matsumoto

Haruki c/o Nec Tokin Corp Hoshi

Toru c/o Nec Tokin Corp Ito

Keita c/o Nec Tokin Corp Isogai

Masayoshi c/o Nec Tokin Corp Ishii

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 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.

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

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 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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Tokyo, Japan

Tamiko Ambo