Murata Manufacturing Co., Ltd.

Hideaki Ooi

Takuya Ishida

Mitsuru Odahara

Mikito Sugiyama

Koichi Ida

Hiroaki Takashima

Naotaka Hata

Kuniaki Watanabe

Takao Kawachi

Keiichi Ishida

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 Dof 1.3 μm or more and 5.0 μm or less (i.e., from 1.3 μm to 5.0 μm), and second particles having a median diameter Dlarger 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.

Composite magnetic material and inductor using the same

A coil component that can maintain a high magnetic permeability and improve a DC superposition characteristic, and a method for producing a magnetic powder-containing resin material used to provide such a coil component. A coil component according includes an element body including a coil conductor and a magnetic portion. The coil conductor is formed of a wound conductor wire. The magnetic portion containing metal magnetic material grains covered with an insulating coating, a resin, and insulator grains. The coil component further includes an external electrode electrically connected to an extended portion of the coil conductor and disposed on a surface of the element body. The insulator grains have a relative permeability lower than a relative permeability of the metal magnetic material grains, and the insulator grains and the insulating coating are a compound whose main component is the same.

Coil component and method for producing magnetic powder-containing resin material used therefor

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 Dof 1.3 &#x3bc;m or more and 5.0 &#x3bc;m or less (i.e., from 1.3 &#x3bc;m to 5.0 &#x3bc;m), and second particles having a median diameter Dlarger 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.

A coil component includes a body, a coil conductor embedded in the body, and outer electrodes disposed on the outside of the body. The body includes a first magnetic layer containing a substantially spherical metallic magnetic material and second and third layers containing a substantially flat metallic magnetic material. At least the wound section of the coil conductor is between the second and third magnetic layers in the direction along the axis of the coil conductor. In the direction perpendicular to the axis, the second and third magnetic layers have a width equal to or larger than the outer diameter of the wound section of the coil component. The substantially flat metallic magnetic material is oriented so that the flat plane thereof is perpendicular to the axis of the coil conductor. The first magnetic layer extends between the second and third magnetic layers and the outer electrodes.

Coil component

An inductor includes a coil including a winding portion and a lead-out portion, a body constituted by a magnetic member and enclosing the coil, a protection layer disposed on a surface of the body, and an outer electrode. The body has a bottom surface, a top surface, two end surfaces, two side surfaces, and first and second R-chamfered sections. The outer electrode includes first and second electrode regions. The first electrode region is located on the bottom surface and is electrically connected to the lead-out portion. The second electrode region is located on the protection layer on each end surface. The radius of curvature of the first R-chamfered section in a cross section perpendicular to the bottom surface and the end surfaces is smaller than that of the second R-chamfered section in a cross section perpendicular to the end surfaces and the side surfaces.

Inductor

An inductor includes a coil including a winding portion and an lead-out portion, a body constituted by a magnetic member and enclosing the coil, a protection layer disposed on a surface of the body, and an outer electrode. The body has a bottom surface, a top surface, two end surfaces, two side surfaces, and first and second R-chamfered sections. The outer electrode includes first and second electrode regions. The first electrode region is located on the bottom surface and is electrically connected to the lead-out portion. The second electrode region is located on the protection layer on each end surface. The number of conductive particles in the first electrode region intersecting with a unit length of a straight line perpendicular to the bottom surface is greater than that in the second electrode region intersecting with a unit length of a straight line perpendicular to the end surface.

An inductor includes a coil including a winding portion and a lead-out portion, a body constituted by a magnetic member and enclosing the coil, a protection layer disposed on a surface of the body, and an outer electrode. The body has a bottom surface, a top surface, two end surfaces, two side surfaces, and first and second R-chamfered sections. The outer electrode includes first and second electrode regions. The first electrode region is located on the bottom surface and is electrically connected to the lead-out portion. The second electrode region is located on the protection layer on each end surface. The surface roughness of part of the bottom surface where the first electrode region is disposed is greater than that of the protection layer on each of the end surfaces where the second electrode region is disposed.

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Nagaokakyo, Japan

Hideaki Ooi