Coil device

Abstract

To provide a coil device capable of reducing a loss of a magnetic material while securing desired inductance.SOLUTION: A coil device 1 includes: a core 10 that contains a magnetic material, and includes a mounting surface 15; and a conductive plate body 20 that includes a main body part 21 to be extended in a meander shape along the mounting surface 15 in an inner part of the core 10. The main body part 21 includes: at least one first folding part that is positioned to one end of a vibration direction of the main body part 21; and a plurality of second folding parts that is positioned to the other end of a vibration direction of the main body part 21. The number of at least one first folding parts is n(n≥1), and the number of second folding parts is n+1.SELECTED DRAWING: Figure 1A

Description

Technical Field

[0001] The present disclosure relates to a coil device that can be used, for example, as an inductor.

Background Art

[0002] For example, as shown in Patent Document 1, a coil device is known in which a part of a plate-shaped conductor (hereinafter, a conductive plate body) is disposed inside a core. The conductive plate body of Patent Document 1 is composed of a metal plate, a metal sheet, or a metal strip processed into a desired shape, and has a main body portion extending in an S shape inside the core. According to the coil device of Patent Document 1, by setting the shape of the main body portion to an S shape, the inductance value can be optimized.

[0003] By the way, when the shape of the main body portion is an S shape, a region (hereinafter, a dead space) where the magnetic flux of the conductive plate body hardly reaches (passes through) is likely to be formed inside the core. For example, in the coil device of Patent Document 1, it is considered that dead spaces are formed at the four corners of the core when viewed from a direction perpendicular to the mounting surface. Thus, when a dead space is formed in the core, the magnetic material disposed in the dead space hardly contributes to the inductance characteristics of the coil device. Therefore, the magnetic material constituting the core cannot be effectively utilized, and there arises a problem that loss of the magnetic material occurs.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The present disclosure provides a coil device capable of reducing the loss of a magnetic material while ensuring a desired inductance value.

Means for Solving the Problems

[0006] The coil device of the present disclosure includes a core containing a magnetic material and having a mounting surface, and, inside the core, a conductive plate body having a main body portion extending in a meandering shape along the mounting surface. The main body portion has at least one first folding portion located at one end in the deflection direction of the main body portion and a plurality of second folding portions located at the other end in the deflection direction of the main body portion. The number of at least one of the first folding portions is n (n≥1). The number of the plurality of second folding portions is n + 1.

[0007] In the coil device of the present disclosure, the number of at least one first folding portion is n (n≥1), and the number of the plurality of second folding portions is n + 1. Therefore, among the plurality of second folding portions, particularly the first second folding portion and the (n + 1)-th second folding portion are easily arranged at positions where a dead space of the core is likely to be formed (for example, when the core has a rectangular parallelepiped shape, at the corners of the core when viewed from a direction perpendicular to the mounting surface). As a result, the magnetic flux of the main body portion is likely to be evenly distributed inside the core, and the inductance characteristics of the coil device are improved. In addition, since it is difficult to form a dead space in the core, the magnetic material constituting the core can be effectively utilized, and the loss of the magnetic material can be reduced. Further, since the main body portion extends in a meandering shape, it is easy to secure the magnetic path length of the main body portion inside the core, and a desired inductance value can be easily obtained.

[0008] The main body portion protrudes toward one side in the deflection direction toward at least one of the first folding portions and protrudes toward the other side in the deflection direction toward the plurality of second folding portions, and the protruding direction of the main body portion toward one side in the deflection direction may be parallel to the protruding direction of the main body portion toward the other side in the deflection direction.

[0009] The core is perpendicular to the mounting surface and has a first side surface and a second side surface that face each other. The protruding directions of the main body portion to one side and the other side in the runout direction may be parallel to the direction in which the first side surface and the second side surface face each other.

[0010] The main body portion has a plurality of extending portions connected by at least one first folding portion and a plurality of second folding portions. The plurality of extending portions may be inclined with respect to the runout direction.

[0011] The conductive plate body has a first lead-out portion continuous with one end in the extending direction of the main body portion and a second lead-out portion continuous with the other end in the extending direction of the main body portion. The first lead-out portion has a first mounting portion disposed on the mounting surface, and the second lead-out portion may have a second mounting portion disposed on the mounting surface at a position different from the first mounting portion.

[0012] The core has a first side surface and a second side surface that are located on opposite sides of each other in the runout direction and extend in a direction perpendicular to the mounting surface. The first side surface is close to the plurality of second folding portions, and the second side surface is close to at least one first folding portion. The first mounting portion and the second mounting portion may extend on the mounting surface of the core from the second side surface toward the first side surface.

[0013] In the runout direction, the distance between the first folding portion and the outer edge of the core may be equal to the distance between the second folding portion and the outer edge of the core.

[0014] The main body portion may have a shape that is line-symmetric with respect to an axis parallel to the runout direction.

[0015] One end and the other end in the extending direction of the main body portion may be located on one side in the runout direction where the first folding portion is located.

[0016] The core has a first side surface and a second side surface that are located on opposite sides of each other in the deflection direction and extend in a direction perpendicular to the mounting surface. The first side surface is close to a plurality of the second folded portions, and the second side surface is close to at least one of the first folded portions. One end and the other end of the main body portion in the extending direction may be exposed from the core on the second side surface.

[0017] When viewed from a direction perpendicular to the mounting surface, one end of the main body portion in the extending direction is disposed at a first corner portion of the core, and the other end of the main body portion in the extending direction is disposed at a second corner portion of the core. In a direction perpendicular to the deflection direction, the first corner portion and the second corner portion may be located on opposite sides of each other.

[0018] The core has a first side surface and a second side surface that are located on opposite sides of each other in the deflection direction and extend in a direction perpendicular to the mounting surface. The first side surface is close to a plurality of the second folded portions, and the second side surface is close to at least one of the first folded portions. When viewed from a direction parallel to the mounting surface and perpendicular to the deflection direction, one end of the main body portion in the extending direction may pass through a region between at least one of the first folded portions and the second side surface.

[0019] The core may be a compacted powder body containing the magnetic material and resin.

[0020] When viewed from a direction perpendicular to the mounting surface, the main body portion may have an M shape.

Brief Description of the Drawings

[0021]

Figure 1A

Figure 1B

Figure 1C

Figure 1D

Figure 2

Figure 3

Figure 4A

Figure 4B

Figure 4C

Figure 4D

Figure 5

Mode for Carrying Out the Invention

[0022] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that the illustrated content is only schematically and exemplarily shown for the understanding of the present disclosure, and the appearance, dimensional ratios, etc. may be different from the actual object. Further, the present disclosure is not limited to the following embodiments.

[0023] First Embodiment The coil device 1 shown in FIG. 1A is a surface mount type inductor and is mounted, for example, on a power supply circuit of an electronic device. The coil device 1 includes a core 10 and a conductive plate 20. The shape of the core 10 is not particularly limited, but in the example shown in FIG. 1A, it is substantially a hexahedron. The core 10 has a first side surface 11, a second side surface 12, a third side surface 13, a fourth side surface 14, a mounting surface 15, and a mounting opposing surface 16.

[0024] The ridge line between the first side surface 11 and the third side surface 13 is chamfered and curved when viewed from a direction perpendicular to the mounting surface 15. The ridge line between the first side surface 11 and the fourth side surface 14 is chamfered and curved when viewed from a direction perpendicular to the mounting surface 15. The ridge line between the second side surface 12 and the third side surface 13 is chamfered and curved when viewed from a direction perpendicular to the mounting surface 15. The ridge line between the second side surface 12 and the fourth side surface 14 is chamfered and curved when viewed from a direction perpendicular to the mounting surface 15. However, the chamfered portions of these ridge lines are not essential.

[0025] The first side surface 11 and the second side surface 12 have the same shape and face each other. The third side surface 13 and the fourth side surface 14 have the same shape and face each other. The mounting surface 15 and the mounting opposite surface 16 face each other.

[0026] In FIG. 1A etc., the X-axis is an axis along the direction in which the first side surface 11 and the second side surface 12 face each other. The Y-axis is an axis along the direction in which the third side surface 13 and the fourth side surface 14 face each other. The Z-axis is an axis along the direction in which the mounting surface 15 and the mounting opposite surface 16 face each other (the direction perpendicular to the mounting surface 15).

[0027] The X-axis, Y-axis, and Z-axis are perpendicular to each other. Hereinafter, for each of the X-axis, Y-axis, and Z-axis, the direction away from the center of the core 10 is defined as "outer side", and the direction approaching the center of the core 10 is defined as "inner side". Also, the positive direction side of the Z-axis is defined as "upper side", and the negative direction side of the Z-axis is defined as "lower side". However, the upper side in the Z-axis direction does not necessarily coincide with the upper side in the vertical direction. Also, the lower side in the Z-axis direction does not necessarily coincide with the lower side in the vertical direction.

[0028] The core 10 has a flat shape with a width in the Z-axis direction smaller than the width in the X-axis direction and the width in the Y-axis direction. The width of the core 10 in the X-axis direction is not particularly limited, but is, for example, 5.0 to 20.0 mm. The width of the core 10 in the Y-axis direction is not particularly limited, but is, for example, 5.0 to 20.0 mm. The width of the core 10 in the Z-axis direction (the thickness of the core 10) is not particularly limited, but is 0.3 to 5.0 mm.

[0029] The core 10 is made of a composite material containing a magnetic material and a resin. The core 10 is formed, for example, by powder pressing, injection molding, or machining. In this embodiment, the core 10 is a compacted body containing a magnetic material and a resin. The magnetic material constituting the core 10 is not particularly limited, and examples thereof include ferrites (such as Ni-Zn ferrites and Mn-Zn ferrites) or metal magnetic materials. The resin constituting the core 10 is not particularly limited, and examples thereof include epoxy resins and phenolic resins.

[0030] As shown in FIG. 1B, the core 10 has first recesses 17a and 17b and second recesses 18a and 18b. The first recesses 17a and 17b are formed in the mounting surface 15. The first recesses 17a and 17b are spaced apart along the Y-axis and extend parallel to each other along the X-axis. However, in this embodiment, the term "parallel" is not limited to strict parallelism, and a state where there is a deviation of several degrees (not particularly limited, for example, 3 degrees) or less from strict parallelism is also included in the concept of "parallel". Also, the term "perpendicular" is not limited to strict perpendicularity, and a state where there is a deviation of several degrees (not particularly limited, for example, 3 degrees) or less from strict perpendicularity is also included in the concept of "perpendicular".

[0031] The first recesses 17a and 17b extend from one end to the other end of the mounting surface 15 in the X-axis direction. The depth of the first recess 17a or 17b is smaller than the thickness of the conductive plate 20. The width of the first recess 17a or 17b in the Y-axis direction is larger than the width of the conductive plate 20 in the direction perpendicular to the extending direction thereof, and is not particularly limited, but is at least twice the width of the conductive plate 20 in the direction perpendicular to the extending direction thereof. The mounting portions 222 of the conductive plate 20 described later are disposed in the first recesses 17a and 17b.

[0032] The second recesses 18a and 18b are formed on the second side surface 12. The second recesses 18a and 18b are spaced apart along the Y-axis and extend parallel to each other along the Z-axis. The second recess 18a is continuous with the first recess 17a at the intersection of the second side surface 12 and the mounting surface 15. The second recess 18b is continuous with the first recess 17b at the intersection of the second side surface 12 and the mounting surface 15. The second recesses 18a and 18b extend from the intersection of the second side surface 12 and the mounting surface 15 toward the mounting opposing surface 16 by a predetermined length (which is shorter than the thickness of the core 10).

[0033] The depth of the second recess 18a may be the same as or different from the depth of the first recess 17a. The depth of the second recess 18b may be the same as or different from the depth of the first recess 17b. The side portions 221 of the conductive plate body 20, which will be described later, are disposed in the second recesses 18a and 18b.

[0034] A convex portion 19c is formed between the first recess 17a and the first recess 17b. The convex portion 19c extends from one end to the other end of the mounting surface 15 in the X-axis direction. A convex portion 19a is formed at one end of the mounting surface 15 in the Y-axis direction, and a convex portion 19b is formed at the other end of the mounting surface 15 in the Y-axis direction. The convex portions 19a and 19b extend from one end to the other end of the mounting surface 15 in the X-axis direction parallel to the convex portion 19c.

[0035] As shown in FIG. 1D, the core 10 has a first corner portion 10a, a second corner portion 10b, a third corner portion 10c, and a fourth corner portion 10d. The first corner portion 10a is formed by the second side surface 12 and the fourth side surface 14. The second corner portion 10b is formed by the second side surface 12 and the third side surface 13. The third corner portion 10c is formed by the first side surface 11 and the third side surface 13. The fourth corner portion 10d is formed by the first side surface 11 and the fourth side surface 14. The first corner portion 10a and the second corner portion 10b are located on opposite sides in the Y-axis direction. The third corner portion 10c and the fourth corner portion 10d are located on opposite sides in the Y-axis direction.

[0036] Here, the first corner portion 10a is within a range within a predetermined length (not particularly limited, for example, a length corresponding to 1 / 3 or 1 / 4 of the width of the core 10 in the X-axis direction or Y-axis direction) from the intersection of the second side surface 12 and the fourth side surface 14 when viewed from a direction perpendicular to the mounting surface 15 (Z-axis direction). Also, the second corner portion 10b is within a range within a predetermined length (not particularly limited, for example, a length corresponding to 1 / 3 or 1 / 4 of the width of the core 10 in the X-axis direction or Y-axis direction) from the intersection of the second side surface 12 and the third side surface 13 when viewed from a direction perpendicular to the mounting surface 15 (Z-axis direction). Also, the third corner portion 10c is within a range within a predetermined length (not particularly limited, for example, a length corresponding to 1 / 3 or 1 / 4 of the width of the core 10 in the X-axis direction or Y-axis direction) from the intersection of the first side surface 11 and the third side surface 13 when viewed from a direction perpendicular to the mounting surface 15 (Z-axis direction). Also, the fourth corner portion 10d is within a range within a predetermined length (not particularly limited, for example, a length corresponding to 1 / 3 or 1 / 4 of the width of the core 10 in the X-axis direction or Y-axis direction) from the intersection of the first side surface 11 and the fourth side surface 14 when viewed from a direction perpendicular to the mounting surface 15 (Z-axis direction).

[0037] The conductive plate body 20 is formed of a plate-like conductor. The conductive plate body 20 is formed, for example, by machining (such as punching, bending, cutting, pressing, sheet metal working, casting, or forging) a metal plate (conductor plate), a metal sheet (conductor sheet), or a metal piece (conductor piece) into the shape shown in FIG. 2. The conductive plate body 20 has higher rigidity than a general wire (round wire, flat wire, etc.). The material constituting the conductive plate body 20 is not particularly limited, but is, for example, copper, a copper alloy, silver, or nickel.

[0038] A plating film is formed on at least a part of the conductive plate body 20. In the present embodiment, the plating film is formed on the entire conductive plate body 20, but the plating film may be formed only on a part of the conductive plate body 20 (for example, the mounting portion 222). By forming the plating film on the conductive plate body 20, the adhesion of the conductive bonding material (for example, solder or conductive adhesive) to the conductive plate body 20 is improved, and the mounting portion 222 can be easily connected to the mounting substrate by the conductive bonding material. The plating film may be a single layer or a multi-layer. The plating film is not particularly limited, but for example, it is Cu plating, Ni plating, Sn plating, Ni-Sn plating, Cu-Ni-Sn plating, Ni-Au plating or Au plating.

[0039] The conductive plate body 20 may be composed of a wire such as a flat wire. Further, the conductive plate body 20 may be an insulated coated wire in which a conductive core wire such as a flat wire is coated with an insulating coating (insulating coating layer). As the conductive plate body 20, for example, known windings such as AIW (polyamideimide copper wire), UEW (polyurethane copper wire), and PEW (polyester copper wire) can be adopted. The material constituting the wire is not particularly limited, but for example, it is copper, copper alloy, silver or nickel.

[0040] As shown in FIG. 1A, the conductive plate body 20 has a main body portion 21, a lead-out portion 22a, and a lead-out portion 22b. The width (lateral width) W1 in the direction orthogonal to the extending direction of the conductive plate body 20 is not particularly limited, but for example, it is 0.5 to 2.0 mm. The thickness of the conductive plate body 20 is not particularly limited, but for example, it is 0.05 to 0.5 mm.

[0041] The main body part 21 is embedded inside the core 10 and extends in a meandering (zigzag) shape along the mounting surface 15 inside the core 10. The main body part 21 extends from one side (the second side surface 12 side) to the other side (the first side surface 11 side) of the X-axis of the core 10 while swaying, and extends from one side (the fourth side surface 14 side) to the other side (the third side surface 13 side) in the Y-axis direction of the core 10. Hereinafter, the direction in which the main body part 21 sways is referred to as the swaying direction. In the present embodiment, the swaying direction is a direction parallel to the X-axis. However, as described above, "parallel" is not limited to strict parallelism only, and a state where it is deviated by several degrees (not particularly limited, for example, 3 degrees) or less with respect to strict parallelism is also included in the concept of "parallel".

[0042] As shown in FIG. 1D, when viewed from a direction perpendicular to the mounting surface 15 (that is, the Z-axis direction), the main body part 21 has a shape that is line-symmetric with respect to an axis (hereinafter, the symmetry axis) C1 parallel to the swaying direction (a direction parallel to the X-axis). However, when viewed from a direction perpendicular to the mounting surface 15, the main body part 21 may have a shape that is asymmetric with respect to the symmetry axis C1. The shape of the main body part 21 when viewed from a direction perpendicular to the mounting surface 15 is not particularly limited, but is an M-shaped.

[0043] As shown in FIG. 2, the main body part 21 includes a first extending part 211, a second extending part 212, a third extending part 213, a fourth extending part 214, a first turning part 215, a second turning part 216, and a third turning part 217.

[0044] The first extending part 211, the second extending part 212, the third extending part 213, and the fourth extending part 214 extend linearly so as to be inclined with respect to the symmetry axis C1. However, the first extending part 211, the second extending part 212, the third extending part 213, and the fourth extending part 214 may extend parallel to the symmetry axis C1. Further, the first extending part 211, the second extending part 212, the third extending part 213, and the fourth extending part 214 may be bent or curved.

[0045] The inclination angle θ1 of the first extending portion 211 with respect to the symmetry axis C1 is not particularly limited, but for example, 0° < θ1 ≤ 30 degrees. The same applies to the inclination angle θ2 of the second extending portion 212 with respect to the symmetry axis C1, the inclination angle θ3 of the third extending portion 213 with respect to the symmetry axis C1, and the inclination angle θ4 of the fourth extending portion 214 with respect to the symmetry axis C1. In the present embodiment, the values of θ1 to θ4 are equal to each other, but the values of θ1 to θ4 do not have to be equal to each other.

[0046] As shown in FIG. 1D, the first extending portion 211 is located on the fourth side surface 14 side with respect to the symmetry axis C1. When viewed from the Z-axis direction, the first extending portion 211 is inclined with respect to the symmetry axis C1 so as to gradually separate from the fourth side surface 14 as it approaches the first side surface 11. Also, when viewed from the Z-axis direction, the first extending portion 211 is inclined with respect to the symmetry axis C1 so as to gradually approach the fourth side surface 14 as it approaches the second side surface 12. One end in the extending direction of the first extending portion 211 is located at the outer edge portion of the core 10 where the second side surface 12 is located and is continuous with the lead-out portion 22a (FIG. 1A). The other end in the extending direction of the first extending portion 211 is continuous with the first turning portion 215.

[0047] The second extending portion 212 is located on the fourth side surface 14 side with respect to the symmetry axis C1. When viewed from the Z-axis direction, the second extending portion 212 is inclined with respect to the symmetry axis C1 so as to gradually separate from the fourth side surface 14 as it approaches the second side surface 12. Also, when viewed from the Z-axis direction, the second extending portion 212 is inclined with respect to the symmetry axis C1 so as to gradually approach the fourth side surface 14 as it approaches the first side surface 11. One end in the extending direction of the second extending portion 212 is continuous with the first turning portion 215. The other end in the extending direction of the second extending portion 212 is continuous with the second turning portion 216.

[0048] The third extending portion 213 is located on the third side surface 13 side with respect to the symmetry axis C1. When viewed from the Z-axis direction, the third extending portion 213 is inclined with respect to the symmetry axis C1 such that it gradually moves away from the fourth side surface 14 as it approaches the first side surface 11. Also, when viewed from the Z-axis direction, the third extending portion 213 is inclined with respect to the symmetry axis C1 such that it gradually approaches the fourth side surface 14 as it approaches the second side surface 12. One end in the extending direction of the third extending portion 213 is continuous with the second turning portion 216. The other end in the extending direction of the third extending portion 213 is continuous with the third turning portion 217.

[0049] The fourth extending portion 214 is located on the third side surface 13 side with respect to the symmetry axis C1. When viewed from the Z-axis direction, the fourth extending portion 214 is inclined with respect to the symmetry axis C1 such that it gradually moves away from the fourth side surface 14 as it approaches the second side surface 12. Also, when viewed from the Z-axis direction, the fourth extending portion 214 is inclined with respect to the symmetry axis C1 such that it gradually approaches the fourth side surface 14 as it approaches the first side surface 11. One end in the extending direction of the fourth extending portion 214 is located at the outer edge portion of the core 10 where the second side surface 12 is located and is continuous with the lead-out portion 22b (FIG. 1A). The other end in the extending direction of the fourth extending portion 214 is continuous with the third turning portion 217.

[0050] The first extending portion 211 that constitutes one end portion 21a in the extending direction of the main body portion 21 and the fourth extending portion 214 that constitutes the other end portion 21b in the extending direction of the main body portion 21 are both drawn out to one side (the second side surface 12 side) in the deflection direction where the folding portion P2 is located. More specifically, the first extending portion 211 is drawn out toward the intersection portion (the first corner portion 10a) of the second side surface 12 and the fourth side surface 14. Also, the fourth extending portion 214 is drawn out toward the intersection portion (the second corner portion 10b) of the second side surface 12 and the third side surface 13. That is, when viewed from the direction perpendicular to the mounting surface 15, both the first extending portion 211 and the fourth extending portion 214 are drawn out toward the corner portion of the core 10. One end and the other end in the extending direction of the main body portion 21 are exposed from the core 10 at the second side surface 12.

[0051] When viewed from a direction perpendicular to the mounting surface 15, one end 21a in the extending direction of the main body portion 21 is disposed at the first corner portion 10a of the core 10. Further, the other end 21b in the extending direction of the main body portion 21 is disposed at the second corner portion 10b of the core 10.

[0052] Also, when viewed from a direction perpendicular to the deflection direction of the main body portion 21 (a direction parallel to the Y-axis), one end 21a in the extending direction of the main body portion 21 passes through a region between the folding portion P2 and the second side surface 12 along the deflection direction of the main body portion 21 (a direction parallel to the X-axis).

[0053] As shown in FIG. 2, the first turn portion 215, the second turn portion 216, and the third turn portion 217 linearly extend along a direction perpendicular to the deflection direction of the main body portion 21 (a direction perpendicular to the symmetry axis C1). However, the first turn portion 215, the second turn portion 216, and the third turn portion 217 may be inclined with respect to a direction perpendicular to the deflection direction of the main body portion 21 (a direction perpendicular to the symmetry axis C1). Further, the first turn portion 215, the second turn portion 216, and the third turn portion 217 may be bent or curved.

[0054] As shown in FIG. 1D, the first turn portion 215 connects the first extending portion 211 and the second extending portion 212. In the first turn portion 215, the deflection direction of the main body portion 21 is converted from one side (the first side surface 11 side) in the X-axis direction to the other side (the second side surface 12 side). In other words, the main body portion 21 is folded back from one side to the other side in the X-axis direction at the first turn portion 215. Thus, a first folding portion P1 of the main body portion 21 is formed at the position of the first turn portion 215.

[0055] The second turn portion 216 connects the second extending portion 212 and the third extending portion 213. In the second turn portion 216, the deflection direction of the main body portion 21 is converted from one side (the second side surface 12 side) in the X-axis direction to the other side (the first side surface 11 side). In other words, the main body portion 21 is folded back from one side to the other side in the X-axis direction at the second turn portion 216. Thus, a second folding portion P2 of the main body portion 21 is formed at the position of the second turn portion 216.

[0056] The third turning portion 217 connects the third extending portion 213 and the fourth extending portion 214. In the third turning portion 217, the deflection direction of the main body portion 21 is converted from one side (the first side surface 11 side) in the X-axis direction to the other side (the second side surface 12 side). In other words, the main body portion 21 is folded back from one side to the other side in the X-axis direction at the third turning portion 217. Thus, a third folding portion P3 of the main body portion 21 is formed at the position of the third turning portion 217.

[0057] The main body portion 21 has one folding portion P2 located at one end of the deflection direction of the main body portion 21, and two folding portions P1 and P3 located at the other end of the deflection direction of the main body portion 21. In the deflection direction (the direction parallel to the X-axis) of the main body portion 21, the folding portions P1 and P3 are located on the first side surface 11 side and are close to the first side surface 11. The folding portion P2 is located on the second side surface 12 side and is close to the second side surface 12.

[0058] In the direction perpendicular to the deflection direction of the main body portion 21 (the direction parallel to the Y-axis), the folding portion P1 is located on the fourth side surface 14 side with respect to the symmetry axis C1. Also, in the direction perpendicular to the deflection direction of the main body portion 21 (the direction parallel to the Y-axis), the folding portion P3 is located on the third side surface 13 side with respect to the symmetry axis C1. The folding portion P2 is located at a position intersecting the symmetry axis C1. The folding portion P1 and the folding portion P3 are located on the same straight line along the Y-axis.

[0059] In this embodiment, one folding portion P2 is formed at one end of the deflection direction of the main body portion 21, but a plurality of folding portions may be formed. That is, the number of folding portions located at one end of the deflection direction of the main body portion 21 is at least one. Also, in this embodiment, two folding portions P1 and P2 are formed at the other end of the deflection direction of the main body portion 21, but three or more folding portions may be formed. That is, the number of folding portions located at the other end of the deflection direction of the main body portion 21 is a plurality.

[0060] In this embodiment, the following relationship holds. That is, when the number of folding portions located at one end in the deflection direction of the main body portion 21 is n (n ≥ 1), the number of folding portions located at the other end in the deflection direction of the main body portion 21 is n + 1. In the example shown in FIG. 1D, since n = 1, the number of folding portions (folding portion P2) located at one end in the deflection direction of the main body portion 21 is 1, and the number of folding portions (folding portions P1 and P3) located at the other end in the deflection direction of the main body portion 21 is 2. However, n ≥ 2 may also be possible.

[0061] The main body portion 21 protrudes toward one side (the second side surface 12 side) in the deflection direction toward the folding portion P2. Further, the main body portion 21 protrudes toward the other side (the first side surface 11 side) in the deflection direction toward the folding portions P1 and P3. In the folding portion P2, the protruding direction of the main body portion 21 toward one side in the deflection direction is parallel to the direction in which the first side surface 11 and the second side surface 12 face each other (that is, the X-axis direction). In the folding portions P1 and P3, the protruding direction of the main body portion 21 toward the other side in the deflection direction is parallel to the direction in which the first side surface 11 and the second side surface 12 face each other (that is, the X-axis direction). Therefore, the protruding direction of the main body portion 21 toward one side in the deflection direction in the folding portion P2 is parallel to the protruding direction of the main body portion 21 toward the other side in the deflection direction in the folding portions P1 and P3.

[0062] The deflection width W2 of the main body portion 21 (the width along the deflection direction of the main body portion 21 between the folding portion P1 and the folding portion P2) is not particularly limited, but for example, it is 1 / 3 or more or 1 / 2 or more of the width W3 of the core 10 in the X-axis direction. The deflection width of the main body portion 21 between the folding portion P1 and the folding portion P2 and the deflection width of the main body portion 21 between the folding portion P2 and the folding portion P3 are equal, but they may also be different.

[0063] In the swinging direction of the main body portion 21, the distance D1 between the folding portion P1 and the outer edge (the first side surface 11) of the core 10 is greater than the distance D2 between the folding portion P2 and the outer edge (the second side surface 12) of the core 10. However, D1 = D2 may also be possible, or D1 < D2 may also be possible. The distance D1 between the folding portion P1 and the outer edge of the core 10 is equal to the distance between the folding portion P3 and the outer edge of the core 10, but they may be different.

[0064] As shown in FIG. 2, the lead-out portion 22a is continuous with one end in the extending direction of the first extending portion 211. Also, the lead-out portion 22b is continuous with one end in the extending direction of the fourth extending portion 214. The lead-out portion 22a is bent in an L shape and has a side portion 221 and a mounting portion 222. Similarly, the lead-out portion 22b is bent in an L shape and has a side portion 221 and a mounting portion 222.

[0065] As shown in FIG. 1B, the side portion 221 is exposed outside the core 10 and is disposed on the second side surface 12. More specifically, the side portion 221 of the lead-out portion 22a is located between the first extending portion 211 and the mounting portion 222 of the lead-out portion 22a and is disposed in the second recess 18a. The side portion 221 of the lead-out portion 22b is located between the fourth extending portion 214 and the mounting portion 222 of the lead-out portion 22b and is disposed in the second recess 18b.

[0066] As shown in FIG. 3, the mounting portion 222 is exposed outside the core 10 and is disposed on the mounting surface 15. The mounting portion 222 extends parallel to the main body portion 21. The mounting portion 222 is a portion that is connected to a mounting substrate (not shown) by a conductive bonding material (such as solder or a conductive adhesive). As shown in FIG. 1B, the mounting portion 222 of the lead-out portion 22a and the mounting portion 222 of the lead-out portion 22b extend from the outer edge (the second side surface 12) of the core 10 toward the first side surface 11 side along the X axis. However, the extending direction of the mounting portion 222 may be inclined with respect to the X axis.

[0067] The mounting portion 222 of the lead-out portion 22a is disposed in the first concave portion 17a, and the mounting portion 222 of the lead-out portion 22b is disposed in the first concave portion 17b. In the example shown in FIG. 1C, since the depths of the first concave portions 17a and 17b are smaller than the thickness of the conductive plate body 20, a part of the mounting portion 222 protrudes below the mounting surface 15. However, the height position of the bottom surface of the mounting portion 222 may be equal to the height position of the mounting surface 15.

[0068] Next, a method for manufacturing the coil device 1 will be described. First, the conductive plate body 20 shown in FIG. 2 is prepared. The conductive plate body 20 is formed by processing a metal plate such as copper into the shape shown in FIG. 2. Next, the conductive plate body 20 is placed in a mold, and the mold is filled with a composite material of a magnetic material and a resin. Then, by compressing and curing the composite material, a compressed powder body of the core 10 having the main body portion 21 disposed therein is formed. Next, the lead-out portions 22a and 22b are bent as necessary. Then, as shown in FIG. 1B, the mounting portion 222 of the lead-out portion 22a and the mounting portion 222 of the lead-out portion 22b are disposed on the mounting surface 15 of the core 10. In this way, the coil device 1 can be manufactured.

[0069] As shown in FIG. 1D, in the coil device 1 of the present embodiment, the number of at least one folded-back portion (first folded-back portion) located at one end in the deflection direction of the main body portion 21 is n (n≥1, and n = 1 in the present embodiment). Also, the number of a plurality of folded-back portions (second folded-back portions) located at the other end in the deflection direction of the main body portion 21 is n + 1 (in the present embodiment, n = 1). Therefore, it becomes easy to arrange the folded-back portion P1 and the folded-back portion P3 at positions where the dead space of the core 10 is likely to be formed (for example, the third corner portion 10c and the fourth corner portion 10d of the core 10 when viewed from a direction perpendicular to the mounting surface 15). As a result, the magnetic flux of the main body portion 21 is likely to be evenly distributed inside the core 10, and the inductance characteristics of the coil device 1 are improved. Also, since it becomes difficult to form a dead space in the core 10, the magnetic material constituting the core 10 can be effectively utilized, and the loss of the magnetic material can be reduced. Further, since the main body portion 21 extends in a meandering shape, it becomes easy to secure the magnetic path length of the main body portion 21 inside the core 10, and a desired inductance value can be easily obtained.

[0070] Also, the main body portion 21 protrudes toward one side in the deflection direction toward the folded-back portion P2 and protrudes toward the other side in the deflection direction toward the folded-back portions P1 and P3, and the protruding direction of the main body portion 21 toward one side in the deflection direction is parallel to the protruding direction of the main body portion 21 toward the other side in the deflection direction. Therefore, the n (n = 1 in the present embodiment) folded-back portions P2 located at one end in the deflection direction of the main body portion 21 and the n + 1 (n = 1 in the present embodiment) folded-back portions P1 and P3 located at the other end in the deflection direction of the main body portion 21 can be regularly arranged alternately inside the core 10. As a result, it becomes difficult to form a dead space in the core 10, the inductance characteristics of the coil device 1 are improved, and the loss of the magnetic material can be reduced.

[0071] Further, the core 10 is perpendicular to the mounting surface 15 and has a first side surface 11 and a second side surface 12 that face each other. The protruding directions of the main body portion 21 to one side and the other side in the deflection direction are parallel to the direction in which the first side surface 11 and the second side surface 12 face each other (i.e., the X-axis direction). Therefore, it is easy to arrange the first folding portion P1 and the n + 1 (in this embodiment, n = 1) -th folding portion P3 located at the other end in the deflection direction of the main body portion 21 at positions where the dead space of the core 10 is likely to be formed (for example, the third corner portion 10c and the fourth corner portion 10d of the core 10 when viewed from the direction perpendicular to the mounting surface 15). Therefore, the inductance characteristics of the coil device 1 can be improved, and the loss of the magnetic material can be reduced.

[0072] Further, the main body portion 21 has first to fourth extending portions 211 to 214 connected by a folding portion P2 located at one end in the deflection direction of the main body portion 21 and folding portions P1 and P3 located at the other end in the deflection direction of the main body portion 21. Also, the first to fourth extending portions 211 to 214 are inclined with respect to the deflection direction. Therefore, according to the inclination angle of the first to fourth extending portions 211 to 214 with respect to the deflection direction, the arrangement area of the first to fourth extending portions 211 to 214 in the core 10 can be expanded. As a result, it becomes difficult for a dead space to be formed in the core 10, the inductance characteristics of the coil device 1 can be improved, and the loss of the magnetic material can be reduced.

[0073] Also, as shown in FIGS. 1A and 1B, the conductive plate body 20 has a lead - out portion 22a continuous with one end in the extending direction of the main body portion 21 and a lead - out portion 22b continuous with the other end in the extending direction of the main body portion 21. The lead - out portion 22a has a mounting portion 222 disposed on the mounting surface 15. The lead - out portion 22b also has a mounting portion 222 disposed on the mounting surface 15 at a position different from the mounting portion 222 of the lead - out portion 22a. By disposing the mounting portions 222 of each of the lead - out portion 22a and the lead - out portion 22b on the mounting surface 15, the size of the coil device 1 can be reduced in the direction parallel to the mounting surface 15.

[0074] Further, the core 10 has a first side surface 11 and a second side surface 12 that are located on opposite sides of each other in the deflection direction and extend in a direction perpendicular to the mounting surface 15. The first side surface 11 is close to the second folding portions P1 and P3, and the second side surface 12 is close to the folding portion P1. The mounting portions 222 of the lead-out portion 22a and the lead-out portion 22b extend on the mounting surface 15 from the second side surface 12 toward the first side surface 11. Therefore, it is easy to ensure the length of the mounting portion 222, and the mounting strength of the coil device 1 can be increased. In the example shown in FIG. 1B, the length of the mounting portion 222 along the X-axis is 80% or more of the width of the core 10 in the X-axis direction. However, the length of the mounting portion 222 along the X-axis is not particularly limited, and it may be 50% or more of the width of the core 10 in the X-axis direction.

[0075] Also, as shown in FIG. 1D, in the deflection direction (the direction parallel to the X-axis) of the main body portion 21, the distance D2 between the folding portion P2 located at one end of the deflection direction of the main body portion 21 and the outer edge (the second side surface 12) of the core 10 is equal to the distance D1 between the folding portion P1 located at the other end of the deflection direction of the main body portion 21 and the outer edge (the first side surface 11) of the core 10. Therefore, on one side (the side where the folding portion P2 is located) or the other side (the side where the folding portion P1 is located) of the deflection direction of the main body portion 21, it is difficult to form a dead space in the core 10. Therefore, the inductance characteristics of the coil device 1 can be improved, and the loss of the magnetic material can be reduced.

[0076] Further, the main body portion 21 has a shape that is line-symmetric with respect to an axis parallel to the deflection direction. Therefore, in the plane parallel to the mounting surface 15, the symmetry of the main body portion 21 is improved with respect to the central axis of the main body portion 21 (however, it is an axis extending in the direction parallel to the deflection direction and is the symmetry axis C1 shown in FIG. 1D). By arranging such a main body portion 21 inside the core 10, it is difficult to form a dead space in the core 10, the inductance characteristics of the coil device 1 can be improved, and the loss of the magnetic material can be reduced.

[0077] Also, one end and the other end in the extending direction of the main body portion 21 are located on one side (the second side surface 12 side) in the swaying direction where the folding portion P2 (the folding portion located at one end in the swaying direction of the main body portion 21) is located. Therefore, it becomes easier to draw out one end and the other end in the extending direction of the main body portion 21 to positions where a dead space of the core is likely to be formed (for example, the first corner portion 10a and the second corner portion 10b of the core 10). As a result, the inductance characteristics of the coil device 1 can be improved and the loss of the magnetic material can be reduced.

[0078] Also, the core 10 has a first side surface 11 and a second side surface 12 that are located on opposite sides in the swaying direction and extend in a direction perpendicular to the mounting surface 15. And the first side surface 11 is close to the folding portions P1 and P3, and the second side surface 12 is close to the folding portion P2. And one end and the other end in the extending direction of the main body portion 21 are exposed from the core 10 on the second side surface 12. In this case, since one end and the other end in the extending direction of the main body portion 21 are arranged in the vicinity of the second side surface 12, it becomes difficult to form a dead space in the core 10. As a result, the inductance characteristics of the coil device 1 can be improved and the loss of the magnetic material can be reduced.

[0079] Also, when viewed from a direction perpendicular to the mounting surface 15, one end portion 21a in the extending direction of the main body portion 21 is arranged at the first corner portion 10a of the core 10, and the other end portion 21b in the extending direction of the main body portion 21 is arranged at the second corner portion 10b of the core 10. And in the direction perpendicular to the swaying direction (the direction parallel to the Y axis), the first corner portion 10a and the second corner portion 10b are located on opposite sides of each other. Therefore, it becomes easier to draw out one end portion 21a and the other end portion 21b in the extending direction of the main body portion 21 to positions where a dead space of the core 10 is likely to be formed (for example, the first corner portion 10a and the second corner portion 10b of the core 10). Thereby, the inductance characteristics of the coil device 1 can be improved and the loss of the magnetic material can be reduced.

[0080] Further, when viewed from a direction parallel to the mounting surface 15 and perpendicular to the deflection direction (a direction parallel to the Y-axis), one end portion 21a in the extending direction of the main body portion 21 passes through the region between the folding portion P2 and the second side surface 12. In this case, since one end portion 21a in the extending direction of the main body portion 21 is disposed in the region between the folding portion P2 and the second side surface 12, it is difficult to form a dead space in the core 10. As a result, the inductance characteristics of the coil device 1 are improved, and the loss of the magnetic material can be reduced.

[0081] Further, the core 10 is a compacted powder including a magnetic material and a resin. Therefore, the inductance characteristics of the coil device 1 are improved, and it becomes easier to miniaturize the coil device 1.

[0082] Further, when viewed from a direction perpendicular to the mounting surface 15, the main body portion 21 has an M shape. Therefore, it becomes easier to dispose the two folding portions P1 and P3 at positions where a dead space of the core 10 is likely to be formed (for example, the third corner portion 10c and the fourth corner portion 10d of the core 10). As a result, the inductance characteristics of the coil device 1 are improved, and the loss of the magnetic material can be reduced.

[0083] Second Embodiment The coil device 1A of the second embodiment shown in FIG. 4A has the same configuration as the coil device 1 of the first embodiment, except for the following points. The same reference numerals are given to the portions overlapping with the coil device 1 of the first embodiment, and the detailed description thereof is omitted.

[0084] As shown in FIG. 4A, the coil device 1A includes a core 10A and a conductive plate body 20A. As shown in FIGS. 4A and 4B, the core 10A has first recesses 17aA and 17bA and second recesses 18aA and 18bA. The first recess 17aA is formed on one side in the Y-axis direction of the mounting surface 15, and the first recess 17bA is formed on the other side in the Y-axis direction of the mounting surface 15. The width in the X-axis direction of the first recess 17aA or 17bA is not particularly limited, but is 1 / 2 or more of the width of the core 10A in the X-axis direction.

[0085] The second recess 18aA is formed on the fourth side surface 14 and is continuous with the first recess 17aA. The second recess 18aA extends along the Z-axis with a predetermined length (however, a length smaller than the thickness of the core 10A) so as to be orthogonal to the first recess 17aA. The width of the second recess 18aA in the X-axis direction is the same as the width of the first recess 17aA in the X-axis direction, but it may be different.

[0086] The second recess 18bA is formed on the third side surface 13 and is continuous with the first recess 17bA. The second recess 18bA extends along the Z-axis with a predetermined length (however, a length smaller than the thickness of the core 10A) so as to be orthogonal to the first recess 17bA. The width of the second recess 18bA in the X-axis direction is the same as the width of the first recess 17bA in the X-axis direction, but it may be different.

[0087] As shown in FIG. 4C, the side portion 221 of the lead-out portion 22a is disposed in the second recess 18aA, and the mounting portion 222 of the lead-out portion 22a is disposed in the first recess 17aA. The side portion 221 passes through the second recess 18aA without contacting the second recess 18aA, but it may contact the second recess 18aA.

[0088] The side portion 221 of the lead-out portion 22b is disposed in the second recess 18bA, and the mounting portion 222 of the lead-out portion 22b is disposed in the first recess 17bA. The side portion 221 passes through the second recess 18bA without contacting the second recess 18bA, but it may contact the second recess 18bA.

[0089] As shown in FIG. 5, the conductive plate body 20A has a main body portion 21A. The main body portion 21A has a fifth extending portion 218 and a sixth extending portion 219. The fifth extending portion 218 is continuous with one end in the extending direction of the first extending portion 211 and linearly extends along a direction perpendicular to the deflection direction of the main body portion 21A (that is, a direction parallel to the Y-axis). The sixth extending portion 219 is continuous with one end in the extending direction of the fourth extending portion 214 and linearly extends along a direction perpendicular to the deflection direction of the main body portion 21A (that is, a direction parallel to the Y-axis).

[0090] As shown in FIG. 4D, the fifth extending portion 218 is located at the central portion of the core 10A in the X-axis direction and extends to one side (the fourth side surface 14 side) of the core 10 in the Y-axis direction. The first extending portion 211 extends obliquely with respect to the symmetry axis C1 from one end in the extending direction of the first turning portion 215 to one end in the extending direction of the fifth extending portion 218 so as to connect the first turning portion 215 and the fifth extending portion 218. The first extending portion 211 extends from the first turning portion 215 to the central portion of the core 10A in the X-axis direction.

[0091] Further, the sixth extending portion 219 is located at the central portion of the core 10A in the X-axis direction and extends to the other side (the third side surface 13 side) of the core 10A in the Y-axis direction. The fourth extending portion 214 extends obliquely with respect to the symmetry axis C1 from one end in the extending direction of the third turning portion 217 to one end in the extending direction of the sixth extending portion 219 so as to connect the third turning portion 217 and the sixth extending portion 219. The fourth extending portion 214 extends from the third turning portion 217 to the central portion of the core 10A in the X-axis direction.

[0092] In the deflection direction of the main body portion 21A, the distance D1 between the folding portion P1 and the outer edge (the first side surface 11) of the core 10 is equal to the distance D2 between the folding portion P2 and the outer edge (the second side surface 12) of the core 10. However, D1 > D2 may also be possible, or D1 < D2 may also be possible. The distance D1 between the folding portion P1 and the outer edge of the core 10 is equal to the distance between the folding portion P3 and the outer edge of the core 10, but they may be different.

[0093] Also in this embodiment, the same effects as those of the first embodiment can be obtained. In addition, in this embodiment, compared with the first embodiment, the length in the extending direction of the main body portion 21A (particularly, the first extending portion 211 and the fourth extending portion 214) is short. Thus, by adjusting the length in the extending direction of the main body portion 21A, the inductance value of the coil device 1A can be adjusted to a desired value.

[0094] Note that the present disclosure is not limited to the above-described embodiments, and various modifications can be made within the scope of the present disclosure.

[0095] In the above embodiment, although the application example of the present disclosure to the inductor has been described, the present disclosure may be applied to other coil devices.

[0096] As shown in FIG. 1D, the protruding direction of the main body portion 21 to one side in the swinging direction of the main body portion 21 was parallel to the protruding direction of the main body portion 21 to the other side in the swinging direction, but it may not be parallel. Further, the protruding direction of the main body portion 21 to one side in the swinging direction was parallel to the direction in which the first side surface 11 and the second side surface 12 face each other (that is, the X-axis direction), but it may not be parallel.

[0097] As shown in FIG. 1B, the mounting portions 222 of the lead-out portion 22a and the lead-out portion 22b were both arranged on the mounting surface 15, but they may be arranged on the first side surface 11, the second side surface 12, the third side surface 13, or the fourth side surface 14.

Explanation of Reference Numerals

[0098] 1, 1A... Coil device 10, 10A... Core 10a to 10d... First corner portion to fourth corner portion 11... First side surface 12... Second side surface 13... Third side surface 14... Fourth side surface 15... Mounting surface 16... Mounting opposing surface 17a, 17b, 17aA, 17bA... First recess 18a, 18b, 18aA, 18bA... Second recess 19a, 19b, 19c... Protrusion 20, 20A... Conductive plate body 21, 21A... Main body portion 21a, 21b... End portion 211... First extending portion 212... Second extending portion 213... Third extending portion 214... Fourth extending portion 215... First turn portion 216... Second turn portion 217... Third turn portion 218... Fifth extending portion 219…Sixth extended portion 22a, 22b…Lead-out portion 221…Side portion 222…Mounting portion P1, P2, P3…Folding-back portion

Claims

1. A core including a magnetic material and having a mounting surface, and a conductive plate body having a main body portion extending in a meandering shape along the mounting surface inside the core. The main body portion has at least one first folding portion located at one end in the deflection direction of the main body portion and a plurality of second folding portions located at the other end in the deflection direction of the main body portion. The number of at least one of the first folding portions is n (n≥1). A coil device in which the number of the plurality of second folding portions is n + 1.

2. The main body portion protrudes toward one side in the deflection direction toward at least one of the first folding portions and protrudes toward the other side in the deflection direction toward the plurality of second folding portions. The protruding direction of the main body portion toward one side in the deflection direction is parallel to the protruding direction of the main body portion toward the other side in the deflection direction. The coil device according to claim 1.

3. The core is perpendicular to the mounting surface and has a first side surface and a second side surface facing each other. The protruding directions of the main body portion toward one side and the other side in the deflection direction are parallel to the direction in which the first side surface and the second side surface face each other. The coil device according to claim 2.

4. The main body portion has a plurality of extending portions connected by at least one of the first folding portions and the plurality of second folding portions. The plurality of extending portions are inclined with respect to the deflection direction. The coil device according to claim 1 or 2.

5. The conductive plate body has a first lead-out portion continuous with one end in the extending direction of the main body portion and a second lead-out portion continuous with the other end in the extending direction of the main body portion. The first lead-out portion has a first mounting portion disposed on the mounting surface. The second lead-out portion has a second mounting portion disposed on the mounting surface at a position different from the first mounting portion. The coil device according to claim 1 or 2.

6. The core has a first side surface and a second side surface located on opposite sides in the deflection direction and extending in a direction perpendicular to the mounting surface. The first side surface is close to the plurality of second folding portions. The second side surface is close to at least one of the first folding portions. The first mounting portion and the second mounting portion extend on the mounting surface of the core from the second side surface toward the first side surface. The coil device according to claim 5.

7. The coil device according to claim 1 or 2, wherein, in the deflection direction, the distance between the first folded-back portion and the outer edge of the core is equal to the distance between the second folded-back portion and the outer edge of the core.

8. The coil device according to claim 1 or 2, wherein the main body portion has a shape that is line-symmetric with respect to an axis parallel to the deflection direction.

9. The coil device according to claim 1 or 2, wherein one end and the other end in the extending direction of the main body portion are located on one side in the deflection direction where the first folded-back portion is located.

10. The core has a first side surface and a second side surface that are located on opposite sides in the deflection direction and extend in a direction perpendicular to the mounting surface. The first side surface is close to a plurality of the second folded-back portions. The second side surface is close to at least one of the first folded-back portions. The coil device according to claim 9, wherein one end and the other end in the extending direction of the main body portion are exposed from the core on the second side surface.

11. When viewed from a direction perpendicular to the mounting surface, one end in the extending direction of the main body portion is disposed at a first corner portion of the core, and the other end in the extending direction of the main body portion is disposed at a second corner portion of the core. The coil device according to claim 1 or 2, wherein in a direction perpendicular to the deflection direction, the first corner portion and the second corner portion are located on opposite sides of each other.

12. The core has a first side surface and a second side surface that are located on opposite sides in the deflection direction and extend in a direction perpendicular to the mounting surface. The first side surface is close to a plurality of the second folded-back portions. The second side surface is close to at least one of the first folded-back portions. The coil device according to claim 1 or 2, wherein the mounting surface is parallel, and when viewed from a direction perpendicular to the deflection direction, one end in the extending direction of the main body portion passes through a region between at least one of the first folded-back portions and the second side surface.

13. The coil device according to claim 1 or 2, wherein the core is a compacted powder body containing the magnetic material and resin.

14. The coil device according to claim 1 or 2, wherein when viewed from a direction perpendicular to the mounting surface, the main body portion has an M shape.

Images