Dust Core and Method for Producing Same
First Claim
1. A powder core comprising:
- a plurality of composite magnetic particles bonded to each other;
wherein;
each of said plurality of composite magnetic particles includes;
a metal magnetic particle;
an insulative lower layer coating surrounding a surface of said metal magnetic particle;
an upper layer coating surrounding said lower layer coating and containing silicon; and
dispersed particles containing a metal oxide compound and disposed in said upper layer coating and/or said lower layer coating; and
a mean particle diameter R of said dispersed particles meets a condition 10 nm<
R≦
2 T, where T is an average thickness of a coating formed from said lower layer coating and said upper layer coating.
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Accused Products
Abstract
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 10; an insulative lower layer coating 20 surrounding a surface 10a of said metal magnetic particle 10; an upper layer coating 30 surrounding said lower layer coating 20 and containing silicon; and dispersed particles 50 containing a metal oxide compound and disposed in said lower layer coating 20 and/or said upper layer coating 30. A mean particle diameter R of the dispersed particles 50 meets the condition 10 nm<R≦2 T, where the average thickness of the coating combining the lower layer coating 20 and the upper layer coating 30 is T.
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Citations
6 Claims
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1. A powder core comprising:
- a plurality of composite magnetic particles bonded to each other;
wherein;
each of said plurality of composite magnetic particles includes;
a metal magnetic particle;
an insulative lower layer coating surrounding a surface of said metal magnetic particle;
an upper layer coating surrounding said lower layer coating and containing silicon; and
dispersed particles containing a metal oxide compound and disposed in said upper layer coating and/or said lower layer coating; anda mean particle diameter R of said dispersed particles meets a condition 10 nm<
R≦
2 T, where T is an average thickness of a coating formed from said lower layer coating and said upper layer coating. - View Dependent Claims (2, 3, 4, 5, 6)
- a plurality of composite magnetic particles bonded to each other;
Specification