The invention provides a powder magnetic core and a method for manufacturing a powder magnetic core through simple compression molding and capable of manufacturing a complicatedly shaped powder magnetic core with reliable high strength and insulating properties. A method for manufacturing a powder magnetic core with a metallic soft magnetic material powder includes: a first step including mixing a soft magnetic material powder and a binder; a second step including compression molding the mixture obtained after the first step; a third step including performing at least one of grinding and cutting on the compact obtained after the second step; and a fourth step including heat-treating the compact after the third step, wherein in the fourth step, the compact is heat-treated so that an oxide layer containing an element constituting the soft magnetic material powder is formed on the surface of the soft magnetic material powder.

The invention provides a powder magnetic core and a method for manufacturing a powder magnetic core through simple compression molding and capable of manufacturing a complicatedly shaped powder magnetic core with reliable high strength and insulating properties. A method for manufacturing a powder magnetic core with a metallic soft magnetic material powder includes: a first step including mixing a soft magnetic material powder and a binder; a second step including compression molding the mixture obtained after the first step; a third step including performing at least one of grinding and cutting on the compact obtained after the second step; and a fourth step including heat-treating the compact after the third step, wherein in the fourth step, the compact is heat-treated so that an oxide layer containing an element constituting the soft magnetic material powder is formed on the surface of the soft magnetic material powder.

A method for manufacturing a powder magnetic core, including a step of compacting a raw material powder to form a compact, a step of performing a first heat treatment on the compact to obtain a first heat-treated body, and a step of performing a second heat treatment on the first heat-treated body to obtain a second heat-treated body, wherein the raw material powder contains a soft magnetic powder and a lubricant that has a melting point Tm, the first heat treatment is performed in a temperature range from Tm to Tm+50° C. inclusive for a time longer than 10 minutes, and the second heat treatment is performed in a temperature range from 400° C. to 900° C. inclusive for a time of 3 minutes to 90 minutes inclusive, the temperature range of the second heat treatment being higher than the temperature range of the first heat treatment.

A method for manufacturing a powder magnetic core, including a step of compacting a raw material powder to form a compact, a step of performing a first heat treatment on the compact to obtain a first heat-treated body, and a step of performing a second heat treatment on the first heat-treated body to obtain a second heat-treated body, wherein the raw material powder contains a soft magnetic powder and a lubricant that has a melting point Tm, the first heat treatment is performed in a temperature range from Tm to Tm+50° C. inclusive for a time longer than 10 minutes, and the second heat treatment is performed in a temperature range from 400° C. to 900° C. inclusive for a time of 3 minutes to 90 minutes inclusive, the temperature range of the second heat treatment being higher than the temperature range of the first heat treatment.

The present application relates to an electromagnetic wave shielding film, which can provide an electromagnetic wave shielding film having excellent mechanical strength, flexibility, electrical insulation properties, bonding properties with other constituents, oxidation and high-temperature stability and the like, while having excellent electromagnetic shielding ability.

Provided is a soft magnetic powder that can produce a dust core having excellent magnetic properties. The soft magnetic powder has a chemical composition, excluding inevitable impurities, represented by a composition formula of Fe.sub.aSi.sub.bB.sub.cP.sub.dCu.sub.eM.sub.f, where the M is at least one element selected from the group consisting of Nb, Mo, Zr, Ta, W, Hf, Ti, V, Cr, Mn, C, Al, S, O, and N, 79 at %≤a≤84.5 at %, 0 at %≤b<6 at %, 0 at %<c≤10 at %, 4 at %<d≤11 at %, 0.2 at %≤e≤0.53 at %, 0 at %≤f≤4 at %, a+b+c+d+e+f=100 at %, a particle size is 1 mm or less, and a median of circularity of particles constituting the soft magnetic powder is 0.4 or more and 1.0 or less.

Provided is a soft magnetic powder that can produce a dust core having excellent magnetic properties. The soft magnetic powder has a chemical composition, excluding inevitable impurities, represented by a composition formula of Fe.sub.aSi.sub.bB.sub.cP.sub.dCu.sub.eM.sub.f, where the M is at least one element selected from the group consisting of Nb, Mo, Zr, Ta, W, Hf, Ti, V, Cr, Mn, C, Al, S, O, and N, 79 at %≤a≤84.5 at %, 0 at %≤b<6 at %, 0 at %<c≤10 at %, 4 at %<d≤11 at %, 0.2 at %≤e≤0.53 at %, 0 at %≤f≤4 at %, a+b+c+d+e+f=100 at %, a particle size is 1 mm or less, and a median of circularity of particles constituting the soft magnetic powder is 0.4 or more and 1.0 or less.

In an exemplary embodiment, a multilayer coil component includes: a substrate body; and a coil embedded in the substrate body and containing a wound conductor; wherein the substrate body has: magnetic layers containing multiple metal magnetic grains, provided around conductor layers that constitute parts of the wound conductor in a direction roughly orthogonal to the coil axis of the coil; and multiple high-hardness insulating grains harder than the multiple metal magnetic grains and smaller in average grain size than the multiple metal magnetic grains, provided between a pair of the conductor layers adjacent to each other in the direction of the coil axis and also between a pair of the magnetic layers adjacent to each other in the direction of the coil axis. The multilayer coil component can prevent shorting in the wound conductor while increasing the inductance.

In an exemplary embodiment, a multilayer coil component includes: a substrate body; and a coil embedded in the substrate body and containing a wound conductor; wherein the substrate body has: magnetic layers containing multiple metal magnetic grains, provided around conductor layers that constitute parts of the wound conductor in a direction roughly orthogonal to the coil axis of the coil; and multiple high-hardness insulating grains harder than the multiple metal magnetic grains and smaller in average grain size than the multiple metal magnetic grains, provided between a pair of the conductor layers adjacent to each other in the direction of the coil axis and also between a pair of the magnetic layers adjacent to each other in the direction of the coil axis. The multilayer coil component can prevent shorting in the wound conductor while increasing the inductance.

A composite magnetic body includes soft magnetic metal particles and non-magnetic ceramic particles each having a particle size (D50) smaller than that of the soft magnetic metal particles.