To obtain a magnetic core having an improved withstand voltage property while maintaining a high relative magnetic permeability, and the like. The magnetic core contains large particles observed as soft magnetic particles having a Heywood diameter of 5 μm or more and 25 μm or less and small particles observed as soft magnetic particles having a Heywood diameter of 0.5 μm or more and less than 5 μm in a cross section. C1<C2 is satisfied in which an average circularity of the small particles close to the large particles is C1 and an average circularity of all small particles observed in the cross section including small particles not close to the large particles is C2. The small particles close to the large particles are defined as small particles whose distance from centroids of the small particles to a surface of the large particles is 3 μm or less.

A dust core includes a compact containing a soft magnetic powder and also includes a cover coat for the compact. The cover coat contains a polyamideimide-modified epoxy resin. An electric/electronic component includes the dust core, a coil, and a connection terminal connected to each end portion of the coil. At least one portion of the dust core is placed so as to be located in an induced magnetic field generated by the current flowing in the coil through the connection terminal. An electric/electronic device includes the electric/electronic component.

A powder core includes a compact including a soft magnetic powder, and an outer coating of the compact. The outer coating contains polyethersulfone. An electric or electronic component including the powder core, and an electric or electronic device having the electric or electronic component mounted therein are also provided.

Provided are a magnetic resin composition including magnetic particles and an epoxy resin having an epoxy equivalent of 400 g/eq or more, in which a filling rate of the magnetic particles is 70% or more on an area basis; a cured product obtained by curing the magnetic resin composition; and an electronic component including the cured product.

A coil-type electronic component comprises an element including a magnetic element body and a coil conductor. A portion of the magnetic element body in between layers of the coil conductor adjacent to each other in an axis direction of the coil conductor includes first soft magnetic metal particles. A portion of the magnetic element body on an outer side along the axis includes second soft magnetic metal particles. The first soft magnetic metal particles have a saturation magnetization (Ms) higher than that of the second soft magnetic metal particles.

Provided is a method for manufacturing a high-density integrally-molded induct comprising the following steps: (1) winding an enameled wire coil to be spiral; (2) mechanically pressing first ferromagnetic powder into a magnetic core; (3) mounting the magnetic core into a. hollow cavity of the enameled wire coil; (4) mounting the enameled wire coil provided with the magnetic core into an injection mold; (5) uniformly mixing and stirring resin glue, a coupling agent and an accelerant, to obtain high-temperature resin glue; (6) uniformly stirring second ferromagnetic powder and the high-temperature resin glue, to obtain a magnetic composite material; (7) injecting the magnetic composite material into a mold cavity of the injection mold for molding, and solidifying the magnetic composite material to obtain an outer magnet; and (8) cooling and de-molding the outer magnet, to obtain a molded inductor. The inductor obtained using the above method is small in size, high in density, high in relative permeability, better in heat dissipation, and lone in service life. The inductor is simply manufactured using an integral molding method, thus reducing the production cost.

Disclosed herein is a composite magnetic sealing material includes a resin material and a filler blended in the resin material in a blended ratio of 30 vol. % or more to 85 vol. % or less. The filler includes a magnetic filler containing Fe and 32 wt. % or more and 39 wt. % or less of a metal material contained mainly of Ni, thereby a thermal expansion coefficient of the composite magnetic sealing material is 15 ppm/° C. or less.

A dust core includes a compact containing a soft magnetic powder and also includes a cover coat for the compact. The cover coat contains a polyamideimide-modified epoxy resin. An electric/electronic component includes the dust core, a coil, and a connection terminal connected to each end portion of the coil. At least one portion of the dust core is placed so as to be located in an induced magnetic field generated by the current flowing in the coil through the connection terminal. An electric/electronic device includes the electric/electronic component.

The present application relates to an internally embedded copper plate-type soft magnetic powder core inductor, a preparation method therefor, and a use thereof. The internally embedded copper plate-type soft magnetic powder core inductor comprises a copper plate, a surface of the copper plate is covered with a soft magnetic material, and an interfacing area of the soft magnetic material and the copper plate includes an insulating resin material. The internally embedded copper plate-type soft magnetic powder core inductor possesses high density, high magnetic core magnetic permeability, high inductance, high saturated magnetic flux density, low volume, and low magnetic flux leakage, if said powder core inductor is used to replace a ferrite inductor of a same inductance for a low voltage DC/DC converter circuit, the same or greater efficiency can be achieved, and inductor volume can be reduced by at least half; the withstand voltage of the internally embedded copper plate type soft magnetic powder core inductor can reach over 15V, and the preparation method for said inductor is simple, possessing high production efficiency and suitable for large-scale automated production.

There is provided a magnetic powder for high frequency use including, in percent by mass, 0.2 to 5.0% C and at least one selected from Group IV to VI elements, Mn, and Ni in a total of 0.1 to 30%, the balance being Fe or/and Co, inclusive 0% for Co), and incidental impurities, wherein the saturation magnetization exceeds 1.0 T and satisfies Expression (1): Co%/(Co%+Fe%)≤0.50. According to the magnetic powder, there is provided a metal magnetic powder having a saturation magnetization exceeding 1.0 T and also having a high FR of 200 MHz or more and a magnetic resin composition including the metal magnetic powder.