A ferrite core includes a ferrite sintered body in which integrally formed are a winding core portion, extending in a lengthwise direction, and flange portions provided at both ends in the lengthwise direction of the winding core portion and projecting from the winding core portion in at least a height direction orthogonal to the lengthwise direction. Pores are present inside the winding core portion and the flange portions, and an abundance ratio of the pores in the winding core portion is equal to or more than about 0.05% and equal to or less than about 1.00% (i.e., from about 0.05% to about 1.00%).

The invention concerns a magnetic core device (1) to be used in a power converter (100), comprising at least one fixation leg (7), and a body (51) comprising a magnetic core (3). The at least one fixation leg (7) extends from the body (51), and is configured to firmly fixate the magnetic core device (1) to a target component (110) such as a housing (110) of the power converter (100). The at least one fixation leg (7) and the body (51) are integrally formed as one-piece.

In an embodiment, a coil component 10 has a drum core 20 housed in a through hole 32 of a ring core 30, and two types of securing parts are provided in a gap G between an outer circumference of one flange part 24 of the drum core 20 and an inner circumference of the through hole 32. Terminal electrodes 50A, 50B connecting to ends 46A, 46B pulled out from a winding wire 40 wound around the drum core 20 are assembled to the ring core 30. Second securing parts 60A, 60B are arranged to opposite to each other with respect to a center C of the flange part 24, and first securing parts 62A, 62B are provided to cover an outer side of the second securing parts 60A, 60B. A hardness of the second securing part is higher than that of the first securing part.

An inductor (100) includes a pair of magnetic members (cores (10, 20)), a main body having coils (71, 72), and a sheet-formed fixation member (60), wherein the fixation member (60) is bound across the cores (10, 20) and the main body, to thereby fix the cores (10, 20) which configure a closed magnetic path, and to thereby fix at least one of the cores (10, 20) to the main body.

A ferrite core includes a ferrite sintered body in which integrally formed are a winding core portion, extending in a lengthwise direction, and flange portions provided at both ends in the lengthwise direction of the winding core portion and projecting from the winding core portion in at least a height direction orthogonal to the lengthwise direction. Pores are present inside the winding core portion and the flange portions, and an abundance ratio of the pores in the winding core portion is equal to or more than about 0.05% and equal to or less than about 1.00% (i.e., from about 0.05% to about 1.00%).

A noise filter including a conductor and an annular core. The conductor has a wound portion. The annular core is formed of a magnetic material and passes through the wound portion. The annular core is formed of a pair of split cores that are assembled together with joining surfaces on both ends to be joined to each other. At least one of a recess portion and a projection portion that engage with each other is formed on the joining surfaces of the split cores which are joined to each other.

A coil component includes a body, a coil disposed in the body, an external electrode disposed on one surface of the body and including at least one recess, and a via electrode disposed in the body and connecting the coil to the external electrode.

In an embodiment, a coil component 10 has a drum core 20 housed in a through hole 32 of a ring core 30, and two types of securing parts are provided in a gap G between an outer circumference of one flange part 24 of the drum core 20 and an inner circumference of the through hole 32. Terminal electrodes 50A, 50B connecting to ends 46A, 46B pulled out from a winding wire 40 wound around the drum core 20 are assembled to the ring core 30. Second securing parts 60A, 60B are arranged to opposite to each other with respect to a center C of the flange part 24, and first securing parts 62A, 62B are provided to cover an outer side of the second securing parts 60A, 60B. A hardness of the second securing part is higher than that of the first securing part.

A noise filter including a conductor and an annular core. The conductor has a wound portion. The annular core is formed of a magnetic material and passes through the wound portion. The annular core is formed of a pair of split cores that are assembled together with joining surfaces on both ends to be joined to each other. At least one of a recess portion and a projection portion that engage with each other is formed on the joining surfaces of the split cores which are joined to each other.

A coil component according to the present invention includes: a magnetic core made of a mixture of a powdery magnetic material and a binding agent and obtained by press forming the mixture; a coil element embedded in the magnetic core and having an end portion protruding from the magnetic core; and a holding member configured to hold the end portion of the coil element. The holding member has a first slit and a second slit which faces the first slit. The end portion of the coil element and the holding member are welded together in an area between the first slit and the second slit.