JP7568415B2 - Magnetic cores and coil parts - Google Patents

Description

The present invention relates to a magnetic core and a coil component including the magnetic core.

Patent Document 1 discloses a technology for forming a magnetic path with a core having a relatively high magnetic permeability (hereinafter, "high μ core") and a core having a relatively low magnetic permeability (hereinafter, "low μ core"). Specifically, the coil part of Patent Document 1 includes a core member and a coil wound around the core member. The coil winding axis extends in the vertical direction. The coil has an inner peripheral surface, an outer peripheral surface, and a first end face and a second end face that are continuous with the inner peripheral surface and the outer peripheral surface, respectively. The core member has a pressed powder core as the high μ core and a cast core as the low μ core. Here, the cast core is formed by dispersing magnetic powder in a hardened resin. The pressed powder core is located above a first straight line extending horizontally along the first end face of the coil and below a second straight line extending horizontally along the second end face of the coil in a predetermined cross section obtained by cutting the coil part along a plane including the coil winding axis and the magnetic path circulating inside the core member. Here, the horizontal direction is a direction perpendicular to the vertical direction. In the above-mentioned specific cross section, the cast core is located horizontally inside the inner surface of the coil or horizontally outside the outer surface of the coil, and is sandwiched between the powder cores in the vertical direction. In this way, by arranging high μ cores above and below the coil and low μ cores inside and outside the coil in the horizontal direction, the trajectory of the magnetic flux can be made closer to a rectangle, thereby significantly reducing AC copper loss around the corners of the coil.

Patent No. 6552332

For example, considering the magnetic path in the coil component of Patent Document 1, the high μ core requires a relatively high magnetic permeability in the horizontal direction, while the low μ core requires a relatively low magnetic permeability in the vertical direction. In other words, the high μ core does not need to have a relatively high magnetic permeability in the vertical direction, and the low μ core does not need to have a relatively low magnetic permeability in the horizontal direction. However, since the magnetic permeability in dust cores and cast cores is isotropic, there was a problem that when a dust core is used as a high μ core, the magnetic permeability in the vertical direction is unnecessarily high, and when a cast core is used as a low μ core, the magnetic permeability in the horizontal direction is unnecessarily low. Considering such a problem, if a suitable magnetic core with anisotropic magnetic permeability could be developed, it would be possible to eliminate the waste of magnetic permeability described above, and instead obtain other effects such as cost reduction.

Therefore, the present invention aims to provide a suitable magnetic core with anisotropic magnetic permeability and a coil component including the magnetic core.

The present invention provides a first magnetic core,
A magnetic core comprising a plurality of plate-shaped magnetic pieces and a binder that binds the plate-shaped magnetic pieces,
the plurality of plate-shaped magnetic pieces are oriented mainly along a predetermined plane,
Each of the plate-like magnetic pieces is made of a plurality of integrated magnetic powder grains, and each of the magnetic powder grains provides a magnetic core that is insulated coated.

In addition, the present invention provides a first magnetic core as the second magnetic core,
Each of the plate-like magnetic pieces provides a magnetic core which is a compressed body made of a plurality of magnetic powder particles.

In addition, the present invention provides a third magnetic core, which is the first or second magnetic core,
Each of the plate-like magnetic pieces provides a magnetic core having a ratio D/t of maximum length D to thickness t of 3 or more and 100 or less.

The present invention also provides a fourth magnetic core, which is the third magnetic core,
A magnetic core having a ratio D/t of 5 or more and 50 or less is provided.

In addition, the present invention provides a fifth magnetic core, which is any one of the first to fourth magnetic cores,
Each of the plate-like magnetic pieces has an area larger than a circle having a diameter of 1 mm, and a magnetic core having a maximum length D of 20 mm or less.

The present invention also provides a sixth magnetic core, which is the fifth magnetic core,
A magnetic core is provided having a maximum length D of 10 mm or less.

In addition, the present invention provides a seventh magnetic core, which is any one of the first to sixth magnetic cores,
The magnetic disk further includes a magnetic piece having a size smaller than that of the plate-shaped magnetic piece,
The magnetic pieces provide a magnetic core that is disposed between the plate-like magnetic pieces.

The present invention further provides a coil component comprising, as a first coil component, a core member including at least a portion of any one of the first to seventh magnetic cores, and a coil wound around the core member.

In addition, the present invention provides a first coil component as the second coil component,
The winding axis of the coil extends in a predetermined direction,
The core member surrounds at least a portion of the periphery of the coil,
The magnetic core provides a coil component that is disposed so that the predetermined plane is perpendicular to the predetermined direction.

Further, the present invention provides a third coil component as a second coil component,
The coil has an inner circumferential surface, an outer circumferential surface, and a first end surface and a second end surface that are continuous with the inner circumferential surface and the outer circumferential surface, respectively;
The core members include a first core member, a second core member, a third core member, and a fourth core member,
the first core member is located on the outer side in the predetermined direction of a first straight line extending in an orthogonal direction perpendicular to the predetermined direction along the first end face of the coil in a predetermined cross section of the coil part cut along a plane including a winding axis of the coil and a magnetic path circulating within the core member,
the second core member is located on the outer side in the predetermined direction of a second straight line extending in the perpendicular direction along the second end face of the coil, in the predetermined cross section;
the third core member is located inward in the orthogonal direction from the inner circumferential surface of the coil in the predetermined cross section, and is sandwiched between the first core member and the second core member in the predetermined direction,
the fourth core member is located outward in the orthogonal direction from the outer circumferential surface of the coil in the predetermined cross section, and is sandwiched between the first core member and the second core member in the predetermined direction,
At least one of the first core member, the second core member, the third core member, and the fourth core member provides a coil component made of the magnetic core.

Further, the present invention provides a fourth coil component, which is the third coil component,
The third core member and the fourth core member provide a coil component consisting of the magnetic core.

Further, the present invention provides a fifth coil component, which is the fourth coil component,
The first core member and the second core member provide a coil component comprising the magnetic core.

Further, the present invention provides a sixth coil component, which is the fourth coil component,
The first core member and the second core member provide a coil component made of dust cores.

Further, the present invention provides a seventh coil component, which is the third coil component,
the first core member and the second core member are made of the magnetic core,
The third core member and the fourth core member provide a coil component made of a cast core in which magnetic powder is dispersed in a hardened resin.

Furthermore, the present invention provides an eighth coil component, which is a first coil component,
The winding axis of the coil extends parallel to the predetermined plane,
The core member surrounds a portion of the periphery of the coil,
A magnetic path circulating within the core member provides a coil component that is aligned along the predetermined plane.

Since plate-shaped magnetic bodies (plate-shaped magnetic pieces) have shape magnetic anisotropy, it is easy to magnetize them in the direction along the plate surface, but it is difficult to magnetize them in the thickness direction. If such plate-shaped magnetic pieces are oriented along a specific plane to form a magnetic core, a magnetic core with high magnetic permeability in the specific plane and low magnetic permeability in a direction perpendicular to the specific plane can be obtained. Here, considering that a realistic magnetic core has a certain size in the direction perpendicular to the specific plane and the orientation process of the plate-shaped magnetic pieces, the plate-shaped magnetic pieces themselves must be somewhat large. Otherwise, appropriate orientation process cannot be performed. On the other hand, if the size of the plate-shaped magnetic pieces themselves becomes large, eddy current loss may occur when magnetic flux along the thickness direction of the plate-shaped magnetic pieces acts on the plate-shaped magnetic pieces.

The magnetic core of the present invention is formed by orienting the plate-shaped magnetic pieces, and as described above, has anisotropy in magnetic permeability. In addition, each plate-shaped magnetic piece is made by integrating a number of magnetic powder particles, each of which is insulated, by pressing or other methods. Therefore, even if the size of the plate-shaped magnetic pieces is made to be somewhat large, the generation of eddy currents can be suppressed. In other words, the plate-shaped magnetic pieces of the present invention are easy to orient and can suppress the generation of eddy current loss.

In addition, when a magnetic core is formed by orienting plate-shaped magnetic pieces of a certain size, many areas are formed where the plate-shaped magnetic pieces are spaced apart from each other, particularly in a specific in-plane direction. As a result, the total volume of the magnetic bodies that make up the magnetic core is significantly smaller than the volume of the magnetic core itself. In other words, the amount of magnetic body that makes up the magnetic core can be reduced, which allows for a reduction in the cost of the magnetic core in terms of materials.

Furthermore, in the magnetic core of the present invention, the magnetic permeability in the direction perpendicular to a specified plane is low. Therefore, when the magnetic core of the present invention is used in a location where a low μ core is required, it is not necessary to form a magnetic gap, etc. In other words, a magnetic core with a simple structure can be made, and manufacturing costs can be reduced.

FIG. 2 illustrates a magnetic core according to an embodiment of the present invention. 2 is a diagram showing a plate-shaped magnetic piece included in the magnetic core of FIG. 1 . 2A to 2C are diagrams for explaining a method of manufacturing the magnetic core of FIG. 1 . 1. FIG. 4 is another diagram for explaining the method of manufacturing the magnetic core of FIG. FIG. 13 is a diagram showing a magnetic core according to a modified example. 1 is a diagram showing a part of a predetermined cross section of a coil component according to a first embodiment of the present invention, in which a plate-shaped magnetic piece is omitted. 1 is a cross-sectional view showing a coil component according to a first embodiment. 1 is a diagram showing a configuration of a coil component according to a first embodiment, particularly a core, in which plate-shaped magnetic pieces are omitted. 1 is a diagram showing a coil component according to a second embodiment, in which the plate-shaped magnetic pieces are omitted. 1 is a diagram showing a coil component according to a third embodiment, in which the plate-shaped magnetic pieces are omitted. 10 is a diagram showing a coil component according to a fourth embodiment, in which the plate-shaped magnetic pieces are omitted. 11A and 11B are diagrams showing core members constituting a coil component according to a second embodiment of the present invention; 11A and 11B are diagrams illustrating a coil component according to a second embodiment;

Referring to FIG. 1, a magnetic core 1 according to an embodiment of the present invention comprises a plurality of plate-shaped magnetic pieces 2 and a binder 4 that binds the plate-shaped magnetic pieces 2. The plurality of plate-shaped magnetic pieces 2 are oriented mainly along a predetermined plane. In this embodiment, the predetermined plane is the XY plane. Each plate-shaped magnetic piece 2 is made of a plurality of integrated magnetic powder grains 3. Each magnetic powder grain 3 is coated with an insulating material. Examples of materials that can be used for the insulating coating include Si resin and phosphoric acid-based coatings.

Referring to FIG. 2, the plate-shaped magnetic piece 2 according to this embodiment is a compressed body made of a plurality of magnetic powder grains 3. That is, the plate-shaped magnetic piece 2 is formed by compressing and molding a plurality of magnetic powder grains 3. The magnetic powder grains 3 according to this embodiment are water-atomized powder. However, the present invention is not limited to this. For example, the magnetic powder grains 3 may be gas-atomized powder. There is no particular limitation on the material of the powder grains, and for example, pure iron, nanocrystals, sendust, Fe-Si alloy, amorphous alloy, etc. can be used. The compression molding according to this embodiment is performed using a roller compactor. However, the present invention is not limited to this. For example, the plate-shaped magnetic piece 2 may be formed by press molding.

The plate-shaped magnetic piece 2 in this embodiment is made by screening compression-molded plate-shaped magnetic pieces through a sieve with a specified mesh size.

Specifically, referring to FIG. 2, each of the plate-shaped magnetic pieces 2 according to this embodiment has a ratio D/t of the maximum length D to the thickness t of 3 or more and 100 or less. If the ratio is less than 3, it is difficult to orient the plate-shaped magnetic pieces 2, and if the ratio is more than 100, the strength of the plate-shaped magnetic pieces 2 decreases and they become deformed. Preferably, the ratio D/t is 5 or more and 50 or less in each plate-shaped magnetic piece 2. This is because when the lower limit of the ratio D/t is 5 or more, it is easier to orient the plate-shaped magnetic pieces 2 compared to when the ratio D/t is less than 5. Also, when the upper limit of the ratio D/t is 50 or less, the strength of the plate-shaped magnetic pieces 2 is higher and the plate-shaped magnetic pieces 2 are less likely to be damaged during orientation operations such as vibration, which will be described later, compared to when the ratio D/t is more than 50.

In addition, each plate-shaped magnetic piece 2 has an area larger than a circle with a diameter of 1 mm and a maximum length D of 20 mm or less. If the area is smaller than a circle with a diameter of 1 mm, it is difficult to orient the plate-shaped magnetic piece 2, and if the maximum length D is greater than 20 mm, the plate-shaped magnetic piece 2 is less likely to enter the gaps between other plate-shaped magnetic pieces 2. Preferably, the maximum length D of each plate-shaped magnetic piece 2 is 10 mm or less. This is because, when the maximum length D is 10 mm or less, the plate-shaped magnetic piece 2 is easier to orient, and each plate-shaped magnetic piece 2 is more likely to enter the gaps between other plate-shaped magnetic pieces 2 when oriented, compared to when the maximum length D is greater than 10 mm.

At this point, annealing may be performed to remove any distortion caused by compression molding. The annealing may be performed either before or after sorting using a sieve.

The plate-shaped magnetic pieces 2 selected in this manner are laid out and oriented in a case 60 as shown in Figures 3 and 4. Then, the epoxy resin that becomes the binder 4 is vacuum-impregnated to fill the gaps between the plate-shaped magnetic pieces 2, and the epoxy resin is hardened to obtain a magnetic core 1 consisting of the plate-shaped magnetic pieces 2 and the binder 4 shown in Figure 1. Here, the binder 4 may be a resin other than epoxy resin or other materials. In addition, the case 60 may not be used for the orientation treatment of the plate-shaped magnetic pieces 2. In addition, for the orientation treatment of the plate-shaped magnetic pieces 2, vibration may be applied to the case 60 before or after filling with resin, or a magnetic field may be applied to the plate-shaped magnetic pieces 2 in the case 60 after filling with resin. Furthermore, the method of filling the gaps between the plate-shaped magnetic pieces 2 with the material of the binder 4 may be a method other than vacuum impregnation, such as a casting method.

The magnetic core 1 thus formed has high magnetic permeability in a direction along a specified plane, but low magnetic permeability in a direction perpendicular to the specified plane, due to the shape anisotropy of the plate-shaped magnetic pieces 2. In FIG. 1, the magnetic permeability is high in a direction parallel to the XY plane, and low in the Z direction. In this way, according to this embodiment, it is possible to increase the magnetic permeability in the required direction while keeping the total amount of magnetic material used low. Furthermore, each plate-shaped magnetic piece 2 is an aggregate of insulating coated magnetic powder particles 3. Therefore, the generation of eddy currents is suppressed in the plate-shaped magnetic pieces 2.

Although the magnetic core 1 described above is composed of a plate-shaped magnetic piece 2 and a binder 4, the present invention is not limited to this. For example, the magnetic core 1A according to the modified example shown in FIG. 5 further includes, in addition to a plurality of plate-shaped magnetic pieces 2 and a binder 4, magnetic pieces 5 smaller in size than the plate-shaped magnetic pieces 2. As can be seen from FIG. 5, each magnetic piece 5 is arranged between the plate-shaped magnetic pieces 2. The other points are the same as the magnetic core 1A according to the embodiment shown in FIG. 1 described above. Each magnetic piece 5 may be made of one magnetic powder grain or may be made of multiple magnetic powder grains, as long as it is a magnetic body of a size that fits into the gap between the plate-shaped magnetic pieces 2. In the former case, for example, each magnetic piece 5 may be made of flattened atomized powder grains. In the latter case, each magnetic piece 5 may be made by compressing and molding multiple magnetic powder grains.

As shown in FIG. 6, the coil component 10 according to the first embodiment of the present invention includes a core member 20 including at least a portion of the magnetic core 1 as described above, and a coil 40 wound around the core member 20. Specifically, in the coil component 10 according to this embodiment, the winding axis 42 of the coil 40 extends in a predetermined direction. In this embodiment, the predetermined direction is the up-down direction or the Z direction. The core member 20 surrounds at least a portion of the periphery of the coil 40. FIG. 6 shows a portion of a predetermined cross section of the coil component 10 cut by a plane including the winding axis 42 of the coil 40 and the magnetic path 22 that circulates within the core member 20. The coil 40 shown in the figure is located within the core member 20 in the predetermined cross section, but the coil 40 does not have to be located within the core member 20 at any point other than the predetermined cross section.

More specifically, in a given cross section, the coil 40 has an inner peripheral surface 44, an outer peripheral surface 45, and a first end surface 46 and a second end surface 47 that are continuous with the inner peripheral surface 44 and the outer peripheral surface 45, respectively. In this embodiment, the first end surface 46 is the upper end surface, and the second end surface 47 is the lower end surface. The core member 20 has a first core member 24, a second core member 25, a third core member 26, and a fourth core member 27.

The first core member 24 is located outside in a predetermined direction from the first straight line 50 extending in the orthogonal direction along the first end face 46 of the coil 40 in a predetermined cross section. Here, the orthogonal direction is a direction perpendicular to the predetermined direction, and in this embodiment, it is the horizontal direction or the Y direction. That is, the first core member 24 is located outside in the Z direction from the first straight line 50 extending in the Y direction along the first end face 46 of the coil 40 in a predetermined cross section. The second core member 25 is located outside in a predetermined direction from the second straight line 52 extending in the orthogonal direction along the second end face 47 of the coil 40 in a predetermined cross section. The second core member 25 is located outside in the Z direction from the second straight line 52 extending in the Y direction along the second end face 47 of the coil 40 in a predetermined cross section. The third core member 26 is located inside in the orthogonal direction from the inner circumferential surface 44 of the coil 40 in a predetermined cross section, and is sandwiched between the first core member 24 and the second core member 25 in a predetermined direction. That is, in a given cross section, the third core member 26 is located inside the inner circumferential surface 44 of the coil 40 in the Y direction, and is sandwiched between the first core member 24 and the second core member 25 in the Z direction. In a given cross section, the fourth core member 27 is located outside the outer circumferential surface 45 of the coil 40 in the orthogonal direction, and is sandwiched between the first core member 24 and the second core member 25 in the given direction. That is, in a given cross section, the fourth core member 27 is located outside the outer circumferential surface 45 of the coil 40 in the Y direction, and is sandwiched between the first core member 24 and the second core member 25 in the Z direction.

At least one of the first core member 24, the second core member 25, the third core member 26, and the fourth core member 27 is made of the magnetic core 1 shown in FIG. 1, in which the magnetic core 1 is arranged so that a predetermined plane (i.e., an orientation plane) is perpendicular to a predetermined direction.

With reference to the description of Patent Document 1, if the first core member 24 and the second core member 25 have a high magnetic permeability in the Y direction and the third core member 26 and the fourth core member 27 have a low magnetic permeability in the Z direction, the trajectory of the magnetic flux can be made closer to a rectangle, thereby reducing AC copper loss. As described above, the magnetic core 1 has a high magnetic permeability along a predetermined plane due to the shape anisotropy of the plate-shaped magnetic piece 2, while having a low magnetic permeability in a direction perpendicular to the predetermined plane. Therefore, in the coil component 10 including the magnetic core 1 according to this embodiment, it is possible to reduce AC copper loss. In addition, since the magnetic powder grains 3 constituting the plate-shaped magnetic piece 2 are insulated, the generation of eddy currents is also suppressed. Furthermore, if the magnetic core 1 is arranged so that the predetermined plane (i.e., the orientation surface) is perpendicular to the predetermined direction in the third core member 26 and the fourth core member 27, it is not necessary to provide a magnetic gap. In other words, the structure is simplified, and manufacturing costs can be reduced.

Below, we will explain some examples of the coil component 10 according to the first embodiment, which have more specific configurations. The coil components according to the examples given below have a so-called pot core configuration.

Referring to Figures 7 and 8, the coil component 10A according to the first embodiment includes a core member 20A and a coil 40. The coil 40 is the same as the coil 40 according to the embodiment described above, so a description thereof will be omitted.

The core member 20A according to the first embodiment has a first core member 24A, a second core member 25A, a third core member 26A, and a fourth core member 27A that are integrally formed. Each of the first core member 24A, the second core member 25A, the third core member 26A, and the fourth core member 27A is made up of the magnetic core 1 shown in FIG. 1. That is, the core member 20A according to the first embodiment is entirely made up of the magnetic core 1 shown in FIG. 1. The orientation surface (i.e., the specified plane) of the plate-shaped magnetic piece 2 of the magnetic core 1 is mainly perpendicular to the extension direction (specified direction) of the winding shaft 42.

To construct such a coil component 10A, for example, a method is used in which the coil 40 is placed inside a case (not shown) and then a mixture of the plate-shaped magnetic pieces 2 and the resin of the binder 4 is poured into the case. However, if the plate-shaped magnetic pieces 2 are large, the mixture may not flow easily. In that case, a method may be used in which, after the coil 40 is placed inside the case, the plate-shaped magnetic pieces 2 are further laid out and oriented inside the case, and then the resin, which is the material of the binder 4, is impregnated therewith.

Referring to FIG. 9, the coil part 10B according to the second embodiment includes a core member 20B and a coil 40. The coil 40 is the same as the coil 40 according to the first embodiment described above. On the other hand, the core member 20B has a first core member 24B, a second core member 25B, a third core member 26B, and a fourth core member 27B, which are formed separately. However, the material is the same as the core member 20A of the first embodiment in FIG. 7. In general, the larger the size of the plate-shaped magnetic piece 2, the easier it is to be oriented, but it is difficult to be oriented in a narrow space such as between the coil 40 and the case. Therefore, the shape of the magnetic core 1 hardened by a separate orientation process may be adjusted to form the first core member 24B, the second core member 25B, the third core member 26B, and the fourth core member 27B. In each of the first core member 24B, the second core member 25B, the third core member 26B, and the fourth core member 27B, the orientation surface of the plate-shaped magnetic piece 2 of the magnetic core 1 is primarily perpendicular to a predetermined direction.

Referring to FIG. 10, the coil part 10C according to the third embodiment includes a core member 20C and a coil 40. The coil 40 is the same as the coil according to the first embodiment described above. Meanwhile, the core member 20C has a first core member 24C, a second core member 25C, a third core member 26C, and a fourth core member 27C, which are formed separately. Here, the first core member 24C and the second core member 25C are so-called pressed powder cores. Meanwhile, the third core member 26C and the fourth core member 27C are made of the magnetic core 1 of FIG. 1. In the third core member 26C and the fourth core member 27C, the orientation surface of the plate-shaped magnetic piece 2 of the magnetic core 1 is mainly perpendicular to a predetermined direction. In this embodiment, the first core member 24C and the second core member 25C are pressed powder cores, but they may be made of, for example, laminated steel plates.

Referring to FIG. 11, the coil component 10D according to the fourth embodiment includes a core member 20D and a coil 40. The coil 40 is the same as the coil according to the first embodiment described above. Meanwhile, the core member 20D has a first core member 24D, a second core member 25D, a third core member 26D, and a fourth core member 27D, which are formed separately. Here, the first core member 24D and the second core member 25D are made of the magnetic core 1 of FIG. 1. Meanwhile, the third core member 26D and the fourth core member 27D are made of a cast core in which magnetic powder is dispersed in a hardened resin.

Referring to Figures 12 and 13, coil component 10E according to the second embodiment of the present invention includes a so-called EE core. More specifically, coil component 10E includes a core member 20E and a coil 40. Coil 40 is the same as the coil according to the first embodiment described above. Core member 20E includes a first core member 24E, a second core member 25E, a third core member 26E, and a fourth core member 27E that are integrated together. Unlike the first to fourth embodiments described above, core member 20E surrounds only a portion of the periphery of coil 40.

The first core member 24E, the second core member 25E, the third core member 26E, and the fourth core member 27E of this embodiment are all made of the magnetic core 1 of FIG. 1. That is, the core member 20E of this embodiment is made of the magnetic core 1 of FIG. 1. However, the relationship between the orientation direction of the plate-shaped magnetic pieces 2 of the magnetic core 1 and the magnetic path is different from that of the first embodiment described above. In this embodiment, the winding axis of the coil 40 is in the X direction. Also, the plate-shaped magnetic pieces 2 in the magnetic core 1 are oriented along the XY plane (a specified plane). That is, in this embodiment, the winding axis of the coil 40 extends parallel to the specified plane. Also, the magnetic path that circulates inside the core member 20E is along the specified plane. That is, the core member 20E made of the magnetic core 1 has a relatively high magnetic permeability along the magnetic path.

Although the present invention has been described above using various examples, the present invention is not limited to these. For example, in each of the coil components described above, the magnetic core 1A in FIG. 5 may be used instead of the magnetic core 1 in FIG. 1.

REFERENCE SIGNS LIST 1, 1A magnetic core 2 plate-shaped magnetic piece 3 magnetic powder grain 4 binder 5 magnetic piece 10, 10A, 10B, 10C, 10D, 10E coil component 20, 20A, 20b, 20C, 20D, 20E core member 22 magnetic path 24, 24A, 24B, 24C, 24D, 24E first core member 25, 25A, 25B, 25C, 25D, 25E second core member 26, 26A, 26B, 26C, 26D, 26E third core member 27, 27A, 27B, 27C, 27D, 27E fourth core member 40 coil 42 winding shaft 44 inner peripheral surface 45 outer peripheral surface 46 first end surface 47 second end surface 50 first straight line 52 Second straight line 60 case

Claims (15)

A magnetic core comprising a plurality of plate-shaped magnetic pieces and a binder that binds the plate-shaped magnetic pieces,
the plurality of plate-shaped magnetic pieces are oriented mainly along a predetermined plane,
Each of the plate-shaped magnetic pieces is an aggregate of a plurality of integrated magnetic powder particles, and each of the magnetic powder particles is an insulating coated magnetic core. 2. The magnetic core according to claim 1,
Each of the plate-like magnetic pieces is a magnetic core which is a compressed body made of a plurality of magnetic powder particles. 3. The magnetic core according to claim 1,
Each of the plate-like magnetic pieces is a magnetic core having a ratio D/t of maximum length D to thickness t of 3 or more and 100 or less. 4. The magnetic core according to claim 3,
A magnetic core having a ratio D/t of 5 or more and 50 or less. A magnetic core according to any one of claims 1 to 4,
A magnetic core in which each of the plate-like magnetic pieces has an area larger than a circle having a diameter of 1 mm and a maximum length D of 20 mm or less. 6. The magnetic core according to claim 5,
A magnetic core having a maximum length D of 10 mm or less. A magnetic core according to any one of claims 1 to 6,
The magnetic disk further includes a magnetic piece having a size smaller than that of the plate-shaped magnetic piece,
The magnetic pieces are magnetic cores arranged between the plate-shaped magnetic pieces. A coil component comprising a core member at least partially including the magnetic core according to any one of claims 1 to 7, and a coil wound around the core member. The coil component according to claim 8,
The winding axis of the coil extends in a predetermined direction,
The core member surrounds at least a portion of the periphery of the coil,
The magnetic core is a coil component that is disposed so that the predetermined plane is perpendicular to the predetermined direction. The coil component according to claim 9,
The coil has an inner circumferential surface, an outer circumferential surface, and a first end surface and a second end surface that are continuous with the inner circumferential surface and the outer circumferential surface, respectively;
The core members include a first core member, a second core member, a third core member, and a fourth core member,
the first core member is located on the outer side in the predetermined direction of a first straight line extending in an orthogonal direction perpendicular to the predetermined direction along the first end face of the coil in a predetermined cross section of the coil part cut along a plane including a winding axis of the coil and a magnetic path circulating within the core member,
the second core member is located, in the predetermined cross section, on the outer side of a second straight line extending in the perpendicular direction along the second end face of the coil,
the third core member is located inward in the orthogonal direction from the inner circumferential surface of the coil in the predetermined cross section, and is sandwiched between the first core member and the second core member in the predetermined direction,
the fourth core member is located outward in the orthogonal direction from the outer circumferential surface of the coil in the predetermined cross section, and is sandwiched between the first core member and the second core member in the predetermined direction,
At least one of the first core member, the second core member, the third core member, and the fourth core member is a coil component formed of the magnetic core. The coil component according to claim 10,
The third core member and the fourth core member are coil components formed of the magnetic core. The coil component according to claim 11,
The first core member and the second core member are coil components formed of the magnetic core. The coil component according to claim 11,
The first core member and the second core member are coil components formed of dust cores. The coil component according to claim 10,
the first core member and the second core member are made of the magnetic core,
The third core member and the fourth core member are coil components each made of a cast core in which magnetic powder is dispersed in hardened resin. The coil component according to claim 8,
The winding axis of the coil extends parallel to the predetermined plane,
The core member surrounds a portion of the periphery of the coil,
A coil component in which a magnetic path circulating within the core member is aligned along the predetermined plane.

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