A dust core achieving both a high magnetic permeability and a high voltage resistance and a method of manufacturing the same are provided. The dust core is a dust core containing a powder of a soft magnetic composition. The powder of the soft magnetic composition includes at least an ellipsoidal powder having a flatness within a range from 3.0 to 6.0.

A composite magnetic body according to one aspect of the present invention includes a first metal magnetic particle covered with a first resin portion made of a first resin material and a second metal magnetic particle having a smaller particle size than the first metal magnetic particle, where the second metal magnetic particle is bound to the first metal magnetic particle via a second resin portion made of a second resin material, the second resin material having a softening point higher than the first resin material.

A magnetic shielding sheet is provided. The magnetic shielding sheet according to an embodiment of the present invention comprises: a plate-shaped magnetic sheet made of a magnetic material containing a metal component; and a cover member for covering the entire surface of the magnetic sheet so as to prevent the surface of the magnetic sheet from being exposed to the outside.

The present application relates to a composite material. The present application can provide a composite material having high magnetic permeability and also having excellent mechanical properties such as flexibility. The composite material may be used in various applications, and for example, may be used as an electromagnetic-wave shielding material and the like.

A magnetic material and an inductor capable of attaining both higher magnetic permeability and improved DC superposition characteristics. A composite magnetic material contains metal magnetic particles, in which the metal magnetic particles include first particles having a median diameter D.sub.50 of 1.3 m or more and 5.0 m or less (i.e., from 1.3 m to 5.0 m), and second particles having a median diameter D.sub.50 larger than the first particles. The first and second particles each include a core portion made of a metal magnetic material, and an insulating film provided on a surface of the core portion. The insulating film of the second particles has an average thickness of 40 nm or more and 100 nm or less (i.e., from 40 nm to 100 nm). The insulating film of the first particles has an average thickness smaller than that of the insulating film of the second particles.

Provided is a magnetic core in which metal magnetic particles occupy an area of 75% to 90% on a cross-section. The metal magnetic particles include first large particles having a crystalline metal material and having a Heywood diameter of 3 ?m or more on the cross-section of the magnetic core, and second large particles having a nanocrystal structure or an amorphous structure and having a Heywood diameter of 3 ?m or more, and an insulation coating of the first large particles is thicker than an insulation coating of the second large particles.

A magnetic core according to one embodiment of the present invention includes a material formed of iron (Fe)-silicon (Si)-boron (B), wherein a mass percentage of Fe in a first surface, which is an upper surface, is different from a mass percentage of Fe in a second surface which is a side surface, and a ratio of the mass percentage of Fe in the first surface to a difference between the mass percentage of Fe in the first surface and the mass percentage of Fe in the second surface is in the range of 6 to 21.

Wireless charging devices and wireless charging systems are provided. The wireless charging devices may include a receiving part coil and an electromagnetic-wave shielding sheet on the receiving part coil. The electromagnetic-wave shielding sheet may have a specific magnetic permeability of 100 or greater from 100 khz to 300 khz and may include a metal foam including a soft magnetic metal component.

A resin composition for forming a magnetic member of the present invention, which is used for compression molding, includes a thermosetting resin, magnetic particles, and non-magnetic particles having a lower specific gravity and a smaller cumulative 50% particle diameter D.sub.50 than the magnetic particles, in which the resin composition for forming a magnetic member is solid at 25? C.

A magnetic paste which comprises an epoxy resin (A) having an aromatic ring, an epoxy compound (B), a soft-magnetic powder (C), and a hardener (D), wherein the (A), (B), and (D) components have 25? C. viscosities which have relationships (A)>(B) and (A)>(D), and the content of the soft-magnetic powder (C) is 90-96 mass % of the whole magnetic paste. A mixture consisting only of the (A) to (D) components has a 25? C. viscosity, measured with a Brookfield viscometer with a no. 4 rotor at a rotation speed of 0.6 rpm, of 100-1,000 Pa.Math.s at five seconds after initiation of the measurement. This magnetic paste has flowability which can be poured into the mold but is inhibited from suffering the sedimentation of the magnetic particles, and gives a cured object in which up to the upper layer is filled with the soft-magnetic powder even after the thermal curing.