Sumitomo Electric Industries, Limited

Koji Mimura

Toru Maeda

Yasushi Mochida

Kazuyuki Maeda

Haruhisa Toyoda

Takao Nishioka

Hirokazu Kugai

Naoto Igarashi

Kazuhiro Hirose

A soft magnetic material includes a plurality of composite magnetic particles () each including a metal magnetic particle () and an insulation coating () covering the surface of the metal magnetic particle (), wherein the insulation coating () contains Si (silicon), and 80% or more of Si contained in the insulation coating constitutes a silsesquioxane skeleton. Therefore, it is possible to effectively decrease a hysteresis loss while suppressing an increase in eddy-current loss.

Soft magnetic material, powder magnetic core, method for manufacturing soft magnetic material, and method for manufacturing powder magnetic core

The object of the present invention is to provide a powder core and method for making the same that is equipped with insulative coating having superior heat resistance, with the coating making it possible to adequately restrict the flow of eddy currents between particles. The powder core is equipped with a plurality of compound magnetic particles bonded to each other. Each of said plurality of composite magnetic particles includes: a metal magnetic particle; an insulative lower layer coatingsurrounding a surfaceof said metal magnetic particle; an upper layer coatingsurrounding said lower layer coatingand containing silicon; and dispersed particlescontaining a metal oxide compound and disposed in said lower layer coatingand/or said upper layer coating. A mean particle diameter R of the dispersed particlesmeets the condition 10 nm&#x3c;R&#x2266;2 T, where the average thickness of the coating combining the lower layer coatingand the upper layer coatingis T.

Dust core with specific relationship between particle diameter and coating thickness, and method for producing same

A soft magnetic material includes a plurality of composite magnetic particles () having metallic magnetic particles () that are composed of pure iron, and an insulation film () that surrounds the surface of the metallic magnetic particles (), wherein the manganese content of the metallic magnetic particles () is 0.013 mass % or less, and is more preferably 0.008 mass % or less. Hysteresis loss can thereby be effectively reduced.

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Itami, Japan

Koji Mimura