Inductor and DC-DC converter

Abstract

The invention relates to an inductor and a DC-DC converter. The inductor includes: a coil conductor including a first conductor extending in a first direction, a second conductor extending in a second direction intersecting the first direction, and a connection conductor connecting one end portions of the first conductor and the second conductor to each other; a magnetic body having a corner portion disposed so as to face a connection conductor of the coil conductor; and a resin member disposed between the magnetic body and the first conductor of the coil conductor, at least one of the first conductor and the second conductor having a first recessed portion recessed from inside to outside at a position adjacent to the connection conductor. The dimension of the first recessed portion in a third direction intersecting the first and second directions is equal to or greater than the dimension in the third direction of a conductor having a shorter dimension in the third direction among the one conductor and the other conductor.

Description

Technical Field

[0001] The present disclosure relates to an inductor and a DC-DC converter. Background Art

[0002] Currently, as an inductor, an inductor described in Japanese Unexamined Patent Application Publication No. 2022-33703 is known. This inductor includes a coil conductor and a magnetic body serving as a magnetic core. The coil conductor has a bent portion. Summary of the Invention

[0003] Here, in an inductor, a resin member as an insulating member is sometimes disposed between the coil conductor and the magnetic body. In such a resin member, burrs sometimes formed that protrude from the end of the conductor of the coil conductor. Since the burrs of the resin member are interposed in the bent portion of the coil conductor, the positional relationship between the coil conductor and the magnetic body sometimes shifts. Due to the shift in the positional relationship between the coil conductor and the magnetic body, there is a problem that stable magnetic characteristics cannot be obtained.

[0004] Therefore, an object of the present disclosure is to provide an inductor and a DC-DC converter capable of obtaining stable magnetic characteristics.

[0005] The inductor according to one aspect of the present disclosure includes: a coil conductor including a first conductor extending in a first direction, a second conductor extending in a second direction intersecting the first direction, and a connecting conductor connecting one end of the first conductor and the second conductor to each other; a magnetic body having a corner portion, and the corner portion is configured to face the connecting conductor of the coil conductor; and a resin member disposed between the magnetic body and the first conductor of the coil conductor, at least one of the first conductor and the second conductor has a first recessed portion recessed from the inside to the outside at a position adjacent to the connecting conductor, and the size of the first recessed portion in a third direction intersecting the first and second directions is equal to or greater than the size of the shorter conductor in the third direction among one conductor and the other conductor.

[0006] The DC-DC converter according to one aspect of the present disclosure includes the above-described inductor.

[0007] According to one aspect of the present disclosure, an inductor and a DC-DC converter capable of obtaining stable magnetic characteristics can be provided. Brief Description of the Drawings

[0008] Figure 1 is a perspective view of the inductor of the present embodiment.

[0009] Figure 2 is a developed view of the inductor.

[0010] Figure 3 is showing the use of Figure 1Diagram of the circuit of the DC-DC converter of the inductor shown.

[0011] Figure 4 is a cross-sectional view along Figure 1 the IV-IV line.

[0012] Figure 5 is a cross-sectional view of the inductor showing a modified example.

[0013] Figure 6 is a cross-sectional view of the inductor showing a comparative example.

[0014] Figure 7 is a cross-sectional view of the inductor showing a comparative example.

[0015] Figure 8 is a cross-sectional view of the inductor showing a modified example.

[0016] Figure 9 (a) of is a cross-sectional view of the inductor showing a modified example, Figure 9 (b) of is a cross-sectional view of the inductor showing a comparative example.

[0017] Figure 10 is a cross-sectional view of the inductor showing a modified example.

[0018] Figure 11 is a cross-sectional view of the inductor showing a modified example.

[0019] Figure 12 is a cross-sectional view of the inductor showing a modified example.

[0020] Figure 13 is an exploded view of the inductor showing a modified example.

[0021] Figure 14 is a diagram of the circuit of the DC-DC converter showing a modified example.

[0022] Explanation of symbols:

[0023] 1…Inductor, 2A, 2B, 2C…Magnetic body (magnetic material), 3A, 3B…Coil conductor, 6A, 6B, 6C…Resin component, 11A, 11B…Conductor part (second conductor, third conductor), 12A, 12B…Conductor part (second conductor, third conductor), 13A, 13B…Connection part (fourth conductor), 14A, 14B…Terminal part (first conductor, fifth conductor), 15…Connection conductor, 16A, 16B…Terminal part (first conductor, fifth conductor), 21, 22…First recessed part, 23…Second recessed part, 30…Bending part (first conductor), 50…Burr (at least a part of the resin material), 60…Adhesive layer, 100, 500…DC-DC converter, 111…Conductor part (first conductor, second conductor), 112…Conductor part (second conductor), 113…Connection part (first conductor, second conductor). Detailed implementation mode

[0024] Hereinafter, some implementation modes of the present disclosure will be described in detail. However, the present disclosure is not limited to the following implementation modes.

[0025] First, with reference to Figure 1 and Figure 2 the schematic structure of the inductor 1 of this implementation mode will be described. Figure 1 is a perspective view of the inductor 1 of this implementation mode. Figure 2 is an exploded view of the inductor 1. In addition, in Figure 1 the state of mounting the inductor 1 on the substrate 101 is shown. The inductor 1 of this implementation mode is formed by laminating the magnetic bodies 2A, 2B, 2C and the coil conductors 3A, 3B in the X-axis direction. In this implementation mode, the X-axis direction, the Y-axis direction and the Z-axis direction are orthogonal to each other. In this implementation mode, the X-axis direction corresponds to the "first direction" in the claims, the Z-axis direction orthogonal to the X-axis direction corresponds to the "second direction" in the claims, and the Y-axis direction orthogonal to the X-axis direction and the Z-axis direction corresponds to the "third direction" in the claims.

[0026] As Figure 1 shown, the inductor 1 includes the magnetic body 2A, the magnetic body 2B, the magnetic body 2C, the coil conductor 3A, the coil conductor 3B, the resin material 5, the resin component 6A, the resin component 6B, and the resin component 6C. In addition, in order to easily understand the features, in Figure 1 the resin material 5 is represented by a phantom line. The inductor 1 can be used as the choke coil of the circuit of the DC-DC converter 100 shown in Figure 3 .

[0027] The magnetic bodies 2A and 2B are arranged in a state of being opposed to each other with a separation in the X-axis direction. The magnetic bodies 2B and 2C are arranged in a state of being opposed to each other with a separation in the X-axis direction. The magnetic bodies 2A, 2B, and 2C are arranged in order from the positive side of the X-axis direction. The magnetic bodies 2A, 2B, and 2C have a rectangular parallelepiped shape. The magnetic bodies 2A, 2B, and 2C have the same shape. The magnetic bodies 2A, 2B, and 2C can be composed of magnetic materials such as sintered cores of MnZn-based ferrites, NiZn-based ferrites, etc., and laminated cores formed by laminating soft magnetic metal plates. The magnetic permeability of the magnetic bodies 2A, 2B, and 2C can also be 1000 or more. In addition, the magnetic characteristics of the magnetic bodies 2A, 2B, and 2C can be substantially the same or different.

[0028] The pair of coil conductors 3 (3A and 3B) included in the inductor 1 can be used for Figure 3 each choke coil of the circuit of the DC-DC converter 500 shown. The DC-DC converter 500 is a multiphase converter having a pair of conversion units each composed of a switching element SW1, SW2, choke coils 520A, 520B, diodes D1, D2, and these conversion units are connected in parallel. As the choke coils 520A, 520B of each conversion unit, the above-mentioned inductor 1 can be adopted. If the structure of the DC-DC converter 500 is described in more detail, the DC-DC converter 500 includes a pair of input terminals A1, A2, a pair of output terminals B1, B2, a switching element SW1 and a choke coil 520A connected in series in sequence between the input terminal A1 and the output terminal B1, a switching element SW2 and a choke coil 520B connected in series in sequence between the input terminal A1 and the output terminal B1, and a capacitor C1 connected between the output terminals B1, B2. The circuit composed of the switching element SW1 and the choke coil 520A and the circuit composed of the switching element SW2 and the choke coil 520B are connected in parallel between the input terminal A1 and the output terminal B1. The input terminal A2 and the output terminal B2 constitute a ground wire. A diode D2 is reversely connected between the connection point of the switching element SW1 and the choke coil 520A and the ground wire, and a diode D1 is reversely connected between the connection point of the switching element SW2 and the choke coil 520B and the ground wire. The switching elements SW1, SW2 are alternately turned on and off by a control circuit (not shown), thereby generating an output voltage obtained by stepping down the input voltage. By forming a pair of choke coils 520A, 520B in the DC-DC converter 500 from the pair of coil conductors 3A, 3B of the inductor 1, it is possible to reduce the number of components constituting the DC-DC converter 500.

[0029] As Figure 2As shown, the magnetic body 2A has main surfaces 2Aa and 2Ab, end surfaces 2Ac and 2Ad, and side surfaces 2Ae and 2Af. The main surfaces 2Aa and 2Ab are surfaces opposite to each other in the X-axis direction. The main surface 2Aa is disposed on the positive side of the X-axis direction, and the main surface 2Ab is disposed on the negative side of the X-axis direction. The end surfaces 2Ac and 2Ad are surfaces opposite to each other in the Y-axis direction. The end surface 2Ac is disposed on the positive side of the Y-axis direction, and the end surface 2Ad is disposed on the negative side of the Y-axis direction. The side surfaces 2Ae and 2Af are surfaces opposite to each other in the Z-axis direction. The side surface 2Ae is disposed on the positive side of the Z-axis direction, and the side surface 2Af is disposed on the negative side of the Z-axis direction.

[0030] The magnetic body 2B has main surfaces 2Ba and 2Bb, end surfaces 2Bc and 2Bd, and side surfaces 2Be and 2Bf. The magnetic body 2C has main surfaces 2Ca and 2Cb, end surfaces 2Cc and 2Cd, and side surfaces 2Ce and 2Cf. These surfaces have a structure with the same purpose as the main surfaces 2Aa and 2Ab, end surfaces 2Ac and 2Ad, and side surfaces 2Ae and 2Af of the magnetic body 2A.

[0031] The main surface 2Ab of the magnetic body 2A and the main surface 2Ba of the magnetic body 2B are arranged to face each other in a state of being separated from each other in the X-axis direction. The main surface 2Bb of the magnetic body 2B and the main surface 2Ca of the magnetic body 2C are arranged to face each other in a state of being separated from each other in the X-axis direction. Thus, the magnetic body 2A is arranged to clamp, in the X-axis direction, a portion (region 17A) located between the conductor portions 11A and 12A described later between itself and the magnetic body 2B. The magnetic body 2C is arranged to clamp, in the X-axis direction, a portion (region 17B) located between the conductor portions 11B and 12B described later between itself and the magnetic body 2B. In the present embodiment, when viewed from the X-axis direction, the end surfaces 2Ac and 2Ad, end surfaces 2Bc and 2Bd, and end surfaces 2Cc and 2Cd are arranged at the same position within the Y-Z plane in an overlapping manner. Therefore, the areas of the magnetic bodies 2A, 2B, and 2C when viewed from the X-axis direction can be the same. In addition, the thicknesses of the magnetic bodies 2A, 2B, and 2C in the X-axis direction can also be the same. That is, the magnetic bodies 2A, 2B, and 2C can have the same dimensions. In addition, in this specification, "the same position" includes a positional deviation within a range caused by manufacturing errors, etc., and "the same", "the same dimensions" include errors within a range caused by manufacturing deviations.

[0032] The coil conductor 3A includes a conductor portion 11A (second conductor), a conductor portion 12A (third conductor), a connecting portion 13A (fourth conductor), a terminal portion 14A (first conductor), and a terminal portion 16A (fifth conductor). The material of the coil conductor 3A is made of, for example, a metal selected from Cu, Ag, Au, Al, Ni, Sn, etc.

[0033] The conductor portions 11A and 12A extend in the Z-axis direction and are arranged between the magnetic bodies 2A and 2B in the X-axis direction. The conductor portion 11A is arranged on the positive side in the Y-axis direction, and the conductor portion 12A is arranged on the negative side in the Y-axis direction. The connecting portion 13A is a member that connects the conductor portion 11A and the conductor portion 12A. The connecting portion 13A is connected to the ends of the conductor portions 11A and 12A on the positive side in the Z-axis direction and extends in the Y-axis direction. The terminal portion 14A is provided at the end of the conductor portion 11A on the negative side in the Z-axis direction and extends in the positive side in the X-axis direction and the positive side in the Y-axis direction. The terminal portion 14A is formed by widening a part near the end of the conductor portion 11A on the negative side in the Z-axis direction toward the positive side in the Y direction and bending the widened portion toward the positive side in the X direction. The terminal portion 16A is provided at the end of the conductor portion 12A on the negative side in the Z-axis direction and extends in the positive side in the X-axis direction and the negative side in the Y-axis direction. The terminal portion 16A is formed by widening a part near the end of the conductor portion 12A on the negative side in the Z-axis direction toward the negative side in the Y direction and bending the widened portion toward the positive side in the X direction. The terminal portions 14A and 16A are joined to the electrode 102 (refer to Figure 1 ) of the substrate 101. Thus, the inductor 1 is mounted on the substrate 101. In addition, as long as the conductor portions 11A and 12A extend in the Z-axis direction, they may not be parallel to the Z-axis direction. Further, as long as the connecting portion 13A extends in the Y-axis direction, it may not be parallel to the Y-axis direction.

[0034] The coil conductor 3A has a side surface 3Aa on the positive side in the X-axis direction and a side surface 3Ab on the negative side in the X-axis direction. The side surface 3Aa is formed by arranging the side surfaces on the positive side in the X-axis direction of the conductor portions 11A and 12A and the connecting portion 13A on the same plane. The terminal portions 14A and 16A protrude more toward the positive side in the X-axis direction than the side surface 3Aa. The side surface 3Aa faces and contacts the main surface 2Ab of the magnetic body 2A in the X-axis direction. The side surface 3Ab is formed by arranging the side surfaces on the negative side in the X-axis direction of the conductor portions 11A and 12A and the connecting portion 13A on the same plane. The side surface 3Ab faces and contacts the main surface 2Ba of the magnetic body 2B in the X-axis direction. By arranging the magnetic bodies 2A, 2B, 2C and the coil conductors 3A, 3B in contact, particularly the positional relationship of the magnetic bodies 2A and 2B in the X-axis direction is stable. Therefore, the deviation of the inductance can be reduced. In addition, in this specification, "contact" includes not only the case where the magnetic bodies 2A and 2B are directly in contact with the coil conductor 3A but also the case of indirect contact via an insulating layer or an adhesive layer, etc. The same applies to the contact between the magnetic bodies 2B and 2C and the coil conductor 3B described later.

[0035] As Figure 2As shown, the coil conductor 3B includes a conductor portion 11B (second conductor), a conductor portion 12B (third conductor), a connecting portion 13B (fourth conductor), a terminal portion 14B (first conductor), and a terminal portion 16B (fifth conductor). The material of the coil conductor 3B may be the same as that of the coil conductor 3A.

[0036] The conductor portions 11B and 12B extend in the Z-axis direction and are arranged between the magnetic bodies 2B and 2C in the X-axis direction. The conductor portion 11B is arranged on the positive side in the Y-axis direction, and the conductor portion 12B is arranged on the negative side in the Y-axis direction. The connecting portion 13B is a component that connects the conductor portion 11B and the conductor portion 12B. The connecting portion 13B is connected to the ends of the conductor portions 11B and 12B on the positive side in the Z-axis direction and extends in the Y-axis direction. The terminal portion 14B is provided at the end of the conductor portion 11B on the negative side in the Z-axis direction and extends in the negative X-axis direction and the positive Y-axis direction. The terminal portion 14B is formed by widening a part near the end of the conductor portion 11B on the negative side in the Z-axis direction toward the positive Y-axis direction and bending the widened portion toward the negative X-axis direction. The terminal portion 16B is provided at the end of the conductor portion 12B on the negative side in the Z-axis direction and extends in the negative X-axis direction and the negative Y-axis direction. The terminal portion 16B is formed by widening a part near the end of the conductor portion 12B on the negative side in the Z-axis direction toward the negative Y-axis direction and bending the widened portion toward the negative X-axis direction. The terminal portions 14B and 16B are joined to the electrodes 102 of the substrate 101 (see Figure 1 ). Thus, the inductor 1 is mounted on the substrate 101. In addition, as long as the conductor portions 11B and 12B extend in the Z-axis direction, they may not be parallel to the Z-axis direction. Also, as long as the connecting portion 13B extends in the Y-axis direction, it may not be parallel to the Y-axis direction.

[0037] The coil conductor 3B has a side surface 3Ba on the positive side in the X-axis direction and a side surface 3Bb on the negative side in the X-axis direction. The side surface 3Ba is formed by arranging the side surfaces on the positive side in the X-axis direction of the conductor portions 11B, 12B, and the connecting portion 13B on the same plane. The side surface 3Ba faces and contacts the main surface 2Bb of the magnetic body 2B in the X-axis direction. The side surface 3Bb is formed by arranging the side surfaces on the negative side in the X-axis direction of the conductor portions 11B, 12B, and the connecting portion 13B on the same plane. The terminal portions 14B and 16B protrude more toward the negative side in the X-axis direction than the side surface 3Bb. The side surface 3Bb faces and contacts the main surface 2Ca of the magnetic body 2C in the X-axis direction.

[0038] The coil conductors 3A and 3B have a structure that is symmetric with respect to the ZY plane. Therefore, when viewed from the X-axis direction, they are formed in the same shape so as to overlap each other. In addition, "symmetric with respect to the plane" includes a positional deviation within a range caused by manufacturing errors or the like, and "the same shape" includes an error within a range caused by manufacturing deviations.

[0039] The resin member 6A is arranged to cover the side surface 2Af on the negative side in the Z-axis direction of the magnetic body 2A. The resin member 6B is arranged to cover the side surface 2Bf on the negative side in the Z-axis direction of the magnetic body 2B. The resin member 6C is arranged to cover the side surface 2Cf on the negative side in the Z-axis direction of the magnetic body 2C. The resin members 6A, 6B, and 6C are sheet-like members that cover substantially the entire surfaces of the side surfaces 2Af, 2Bf, and 2Cf. The material of the resin members 6A, 6B, and 6C is not particularly limited, and polyimide, polyamideimide, fluororesin, etc. can be used. As the resin members 6A, 6B, and 6C, for example, KAPTON (registered trademark) tape or the like can be used.

[0040] The side surfaces 2Af, 2Cf (the other surfaces) on the negative side in the Z-axis direction of the magnetic bodies 2A and 2C are placed on the upper surfaces 14a, 16a of the terminal portions 14A, 16A, 14B, and 16B via the resin members 6A and 6C. Thus, the resin member 6A is disposed between the magnetic body 2A and the terminal portions 14A and 16A. The resin member 6C is disposed between the magnetic body 2C and the terminal portions 14B and 16B. In the present embodiment, the side surface 2Bf on the negative side in the Z-axis direction of the magnetic body 2B is disposed at the same height as the side surfaces 2Af, 2Cf on the negative side in the Z-axis direction of the other magnetic bodies 2A and 2C. In addition, "the same height" includes an error within a range caused by manufacturing deviations.

[0041] Next, the resin material 5 will be described. The resin material 5 covers the assembly composed of the magnetic bodies 2A, 2B, 2C and the coil conductors 3A, 3B. The resin material 5 exposes at least the lower surfaces of the terminal portions 14A, 16A, 14B, 16B. Therefore, the resin material 5 covers at least the positive-side side surfaces 2Ae, 2Be, 2Ce of the magnetic bodies 2A, 2B, 2C in the Z-axis direction. The resin material 5 may contain magnetic powder. Specifically, as the material of the resin material 5, a thermosetting resin such as epoxy resin is used. When the resin material 5 contains magnetic powder, a mixture of soft magnetic metal powder and resin or the like can be used. As the soft magnetic metal powder, an iron-silicon alloy, permalloy, iron-silicon-aluminum alloy (Sendust), amorphous, nanocrystalline alloy or a mixture thereof can be used. In addition, when the resin material 5 contains magnetic powder, the magnetic permeability of the resin material 5 can be 5 or more, and can also be 20 or more. Furthermore, the magnetic permeability of the resin material 5 can be 100 or less, and can also be 50 or less. The resin material 5 can have a magnetic permeability lower than that of the magnetic bodies 2A, 2B, 2C. The resin material 5 is disposed in the regions 17A, 17B. That is, the resin material 5 is formed so as to cover the inner portions 11Aa, 11Ba, 12Aa, 12Ba, 13Aa, 13Ba.

[0042] Next, with reference to Figure 4 the structure near the negative-side side surface 2Cf of the magnetic body 2C in the Z-axis direction will be described in detail. Figure 4 is a cross-sectional view along the Figure 1 indicated line IV-IV. In addition, Figure 1 and Figure 2 are schematic structural diagrams. The thickness of the magnetic bodies 2A, 2B, 2C in the X-axis direction is depicted to be relatively thin, but the thickness in the X-axis direction can be increased as shown in Figure 4 .

[0043] At the portion shown in Figure 4 , the coil conductor 3B has a connection conductor 15. The connection conductor 15 is a part that connects one (negative side in the Z-axis direction) end 11a of the conductor portion 11B and one (positive side in the X-axis direction) end 14c of the terminal portion 14B. In the structure near the corner of the terminal portion 14B and the conductor portion 11B, there is a switching portion P1 that switches the outside (lower surface 14b side) of the terminal portion 14B from the state of extending in the X-axis direction to the Z-axis direction. In addition, there is a switching portion P2 that switches the outside (side surface 3Ba side) of the conductor portion 11B from the state of extending in the Z-axis direction to the X-axis direction. The connection conductor 15 is a part existing between these switching portions P1, P2. In Figure 4In this case, the surfaces 14a and 14b of the terminal portion 14B are depicted by a pair of chain double-dashed lines extending in the positive side of the X-axis direction, and the surfaces 3Ba and 3Bb of the conductor portion 11B are depicted by a pair of chain double-dashed lines extending in the negative side of the Z-axis direction. The region defined by these four-sided chain double-dashed lines is set as region E. The portion of the coil conductor 3B existing within region E corresponds to the connecting conductor 15. The outer side of the connecting conductor 15 has a curved shape 15a. The curved shape 15a depicts an arc that expands outward with a prescribed radius of curvature between the switching portions P1 and P2. Further, in the case where the surfaces of the conductor portion 11A and the terminal portion 14B are minute wavy surfaces or uneven surfaces, the chain double-dashed line extending in the positive side of the X-axis direction from the surface of the terminal portion 14B and the chain double-dashed line extending in the negative side of the Z-axis direction from the surface of the conductor portion 11A may also be regression lines (linear approximation).

[0044] The magnetic body 2C has a corner portion 25 between the main surface 2Ca on the positive side in the X-axis direction and the side surface 2Cf on the negative side in the Z-axis direction. As described above, the main surface 2Ca of the magnetic body 2C is in contact with the side surface 3Bb of the conductor portion 11B. The side surface 2Cf of the magnetic body 2C is in contact with the upper surface 14a of the terminal portion 14B via the resin member 6C. According to such a positional relationship, the corner portion 25 of the magnetic body 2C is arranged to face the connecting conductor 15 of the coil conductor 3B. The corner portion 25 of the magnetic body 2C and the connecting conductor 15 of the coil conductor 3B face each other in an inclined direction including a direction component in the X-axis direction and a direction component in the Z-axis direction.

[0045] The terminal portion 14B has a first recessed portion 21 that is recessed from the inside to the outside at a position adjacent to the connecting conductor 15. The first recessed portion 21 is recessed from the upper surface 14a, which is the inner surface of the terminal portion 14B, in the negative side of the Z-axis direction. The end portion 14c on the positive side in the X-axis direction is a position adjacent to the connecting conductor 15 on the negative side in the X-axis direction. Therefore, the terminal portion 14B has the first recessed portion 21 at least at the position of the end portion 14c. Further, the position adjacent to the connecting conductor 15 also includes a position slightly separated from the connecting conductor 15 (for example, within the range of manufacturing errors, etc.).

[0046] The conductor portion 11B has a first recessed portion 22 that is recessed from the inside to the outside at a position adjacent to the connecting conductor 15. The first recessed portion 22 is recessed from the side surface 3Bb, which is the inner surface of the conductor portion 11B, in the positive side of the X-axis direction. The end portion 11a on the negative side in the Z-axis direction is a position adjacent to the connecting conductor 15 on the positive side in the Z-axis direction. Therefore, the conductor portion 11B has the first recessed portion 22 at least at the position of the end portion 11a.

[0047] As described above, in the present embodiment, the terminal portion 14B and the conductor portion 11B each have first recessed portions 21 and 22 that are recessed from the inside to the outside at positions adjacent to the connection conductor 15. Further, in the present embodiment, the connection conductor 15 has a second recessed portion 23 that is recessed from the inside to the outside. The second recessed portion 23 is recessed from the position of the end portion 14c of the terminal portion 14B toward the positive side in the X-axis direction and is recessed from the position of the end portion 11a of the conductor portion 11B toward the negative side in the Z-axis direction. The second recessed portion 23 of the connection conductor 15 communicates with the first recessed portions 21 and 22. Further, in the following description, when referring to the "recessed portion 20", it means the recessed portion formed by combining the recessed portions 21, 22, and 23. In the present embodiment, the coil conductor 3B has a recessed portion 20 having an L-shaped cross section. The method of forming the recessed portion 20 is not particularly limited, and any known method for providing a recess with respect to the conductor may be used.

[0048] The resin member 6C sometimes has burrs 50 (a part of the resin member) formed during cutting or the like. The burrs 50 project from the main surface 2Ca of the magnetic body 2C toward the positive side in the X-axis direction. Such burrs 50 are received in the recessed portion 20 of the coil conductor 3B. In particular, the burrs 50 can be received in the first recessed portion 22 that is recessed toward the positive side in the X-axis direction without being bent. Further, the burrs 50 can be bent and received in the second recessed portion 23. Further, the burrs 50 can be bent (folded) and received in the first recessed portion 21 that is recessed toward the negative side in the Z-axis direction. Further, depending on the shape of the burrs 50, they can also be received in the plurality of recessed portions 21, 22, and 23. In addition, the shape of the burrs 50 may not be constant in the Y-axis direction, and depending on the portion in the Y-axis direction, the recessed portions 21, 22, and 23 in which they are received may also be different. The burrs 50 of the resin member 6B project from the main surface 2Bb of the magnetic body 2B toward the negative side in the X-axis direction. The burrs 50 of the resin member 6B are deformed in a bent shape 15a along the outer side of the connection conductor 15 and bent toward the negative side in the Z-axis direction.

[0049] Next, the dimensions of each part of the recessed portion 20 will be described. The length dimension of the first recessed portion 22 of the conductor portion 11B in the Z-axis direction can be larger than the thickness (dimension in the Z-axis direction) of the resin member 6C. In addition, the length dimension of the first recessed portion 22 of the conductor portion 11B in the Z-axis direction can be smaller than the radius of curvature of the curved shape 15a on the outer side of the connection conductor 15. Further, the length dimension of the first recessed portion 22 of the conductor portion 11B in the Z-axis direction can be smaller than half of the length dimension of the conductor portion 11B in the Z-axis direction. The depth (dimension in the X-axis direction) of the first recessed portion 22 of the conductor portion 11B can be smaller than half of the thickness dimension (dimension in the X-axis direction) of the conductor portion 11B. In addition, the depth (dimension in the X-axis direction) of the first recessed portion 22 of the conductor portion 11B can be larger than the length dimension (dimension in the X-axis direction) of the burr 50. Further, since the length dimension of the burr 50 is a value that can be predicted in the design stage, the depth of the first recessed portion 22 can be set based on this value.

[0050] The length dimension of the first recessed portion 21 of the terminal portion 14B in the X-axis direction can be larger than the thickness (dimension in the Z-axis direction) of the resin member 6C. In addition, the length dimension of the first recessed portion 21 of the terminal portion 14B in the X-axis direction can be smaller than the radius of curvature of the curved shape 15a on the outer side of the connection conductor 15. Further, the length dimension of the first recessed portion 21 of the terminal portion 14B in the X-axis direction can be smaller than half of the length dimension of the terminal portion 14B in the X-axis direction. The depth (dimension in the Z-axis direction) of the first recessed portion 21 of the terminal portion 14B can be smaller than half of the thickness dimension (dimension in the Z-axis direction) of the terminal portion 14B. Further, the depth of the first recessed portion 21 of the terminal portion 14B can be smaller than half of the thickness dimension of the terminal portion 14B in the Z-axis direction.

[0051] The dimension of the second recessed portion 23 of the connection conductor 15 in the Z-axis direction can be set to a dimension with the same purpose as the depth of the first recessed portion 21 of the terminal portion 14B in the Z-axis direction. The dimension of the second recessed portion 23 of the connection conductor 15 in the X-axis direction can be set to a dimension with the same purpose as the depth of the first recessed portion 22 of the conductor portion 11B in the X-axis direction. The radius of curvature of the inner side of the connection conductor 15 can be smaller than the thickness of the resin member 6C. In the present embodiment, since the connection conductor 15 has the second recessed portion 23, the corner R of the second recessed portion 23 is the radius of curvature of the inner side. In Figure 4 In the example shown, since the second recessed portion 23 does not have a corner R and is substantially a right angle, the radius of curvature of the inner side is smaller than the thickness of the resin member 6C.

[0052] The sizes of the first recesses 21 and 22 in the Y-axis direction (the third direction) are equal to or greater than the size of the shorter conductor in the Y-axis direction among the conductor portion 11B and the terminal portion 14B. In the present embodiment, the size of the conductor portion 11B in the Y-axis direction is shorter than the size of the terminal portion 14B in the Y-axis direction. Therefore, the sizes of the first recesses 21 and 22 in the Y-axis direction only need to be equal to or greater than the size of the shorter conductor portion 11B in the Y-axis direction. In the present embodiment, the first recess 21 may extend from one end portion 14d (refer to Figure 2 ) of the terminal portion 14B in the Y-axis direction (the third direction) to the other end portion 14e (refer to Figure 2 ). In this case, the size of the first recess 21 in the Y-axis direction is larger than the size of the shorter conductor portion 11B in the Y-axis direction. However, the size of the first recess 21 in the Y-axis direction may also be equal to the size of the shorter conductor portion 11B in the Y-axis direction. At this time, the first recess 21 may be formed in the region CE shown in Figure 2 . That is, the first recess 21 extends from the position corresponding to one end portion 11Ba (refer to Figure 2 ) of the conductor portion 11B in the Y-axis direction to the position corresponding to the other end portion 11Bb (refer to Figure 2 ). The first recess 22 may extend from one end portion 11Ba (refer to Figure 2 ) of the conductor portion 11B in the Y-axis direction to the other end portion 11Bb (refer to Figure 2 ).

[0053] The size of the connecting conductor 15 in the Y-axis direction is determined according to the size of the overlapping portion of the terminal portion 14B and the conductor portion 11B in the Y-axis direction. In the example shown in Figure 2 , the entire conductor portion 11B in the width direction is connected to the terminal portion 14B. Therefore, the second recess 23 of the connecting conductor 15 may extend from one end portion 11Ba (refer to Figure 2 ) of the conductor portion 11B in the Y-axis direction to the other end portion 11Bb (refer to Figure 2 ).

[0054] Here, the recess 20 is not limited to the structure shown in Figure 4 . At least one conductor of the terminal portion 14B and the conductor portion 11B only needs to have a first recess that is recessed from the inside to the outside at a position adjacent to the connecting conductor 15. For example, various structures shown in Figure 5 may be adopted. As shown in (a) of Figure 5 , the recess 20 may only have the first recess 22 of the conductor portion 11B. As shown in (b) of Figure 5 , the recess 20 may have the first recess 22 of the conductor portion 11B and the second recess 23 of the connecting conductor 15 that communicates with the first recess 22. AsFigure 5 As shown in (c) of FIG. Figure 5 As shown in (d) of FIG. Figure 5 As shown in (e) of FIG. Figure 5 In the manners shown in (a), (b), and (e) of FIG. Figure 5 the burr 50 can be received in the first recessed portion 22 recessed toward the positive side in the X-axis direction without being bent. In the manners shown in (c) and (d) of FIG.

[0055] In addition, as Figure 2 shown, the coil conductor 3B has a terminal portion 16B and a conductor portion 12B on the negative side in the Y-axis direction. The coil conductor 3B can have a recessed portion 20 with the same purpose near the connecting conductor that connects the terminal portion 16B and the conductor portion 12B. The magnetic body 2C is placed on the terminal portion 14B and the terminal portion 16B via the resin member 6C. At this time, the burr 50 (refer to Figure 4 ) of the resin member 6C provided on the magnetic body 2C is received in the recessed portion 20 of the terminal portion 14B and the conductor portion 11B, and the recessed portion 20 of the terminal portion 16B and the conductor portion 12B. In addition, the coil conductor 3A can have a recessed portion 20 with the same purpose near the connecting conductor that connects the terminal portion 14A and the conductor portion 11A, and have a recessed portion 20 with the same purpose near the connecting conductor that connects the terminal portion 16A and the conductor portion 12A. Figure 4 ) Figure 4 the same purpose near the connecting conductor that connects the terminal portion 16A and the conductor portion 12A. Figure 4 the same purpose.

[0056] In the coil conductor 3B, when the terminal portion 14B is regarded as the "first conductor" in the claims, the conductor portion 11B can be regarded as the "second conductor", the conductor portion 12B can be regarded as the "third conductor", the connecting portion 13B can be regarded as the "fourth conductor", and the terminal portion 16B can be regarded as the "fifth conductor". In the coil conductor 3B, when the terminal portion 16B is regarded as the "first conductor" in the claims, the conductor portion 12B can be regarded as the "second conductor", the conductor portion 11B can be regarded as the "third conductor", the connecting portion 13B can be regarded as the "fourth conductor", and the terminal portion 14B can be regarded as the "fifth conductor". In the coil conductor 3A, when the terminal portion 14A is regarded as the "first conductor" in the claims, the conductor portion 11A can be regarded as the "second conductor", the conductor portion 12A can be regarded as the "third conductor", the connecting portion 13A can be regarded as the "fourth conductor", and the terminal portion 16A can be regarded as the "fifth conductor". In the coil conductor 3A, when the terminal portion 16A is regarded as the "first conductor" in the claims, the conductor portion 12A can be regarded as the "second conductor", the conductor portion 11A can be regarded as the "third conductor", the connecting portion 13A can be regarded as the "fourth conductor", and the terminal portion 14A can be regarded as the "fifth conductor".

[0057] Next, the operations and effects of the inductor 1 and the DC-DC converter 100 of the present embodiment will be described. In addition, unless otherwise noted, regarding the inductor 1 of the present embodiment, refer to Figure 4 The operations and effects of the structure near the connecting conductor 15 that connects the terminal portion 14B and the conductor portion 11B will be described. However, the same operations and effects can also be obtained for the structures near the connecting conductors 15 in other portions.

[0058] In the inductor 1 of the present embodiment, the corner portion 25 of the magnetic body 2C is arranged to face the connecting conductor 15 of the coil conductor 3B. In addition, the inductor 1 includes a resin member 6C disposed between the magnetic body 2C and the terminal portion 14B of the coil conductor 3B. Therefore, the magnetic body 2C is disposed on the terminal portion 14B in a state of being insulated from the terminal portion 14B, and is disposed in a state of being positioned in the X-axis direction with respect to the conductor portion 11.

[0059] Here, refer to Figure 6 The inductor 200 of the comparative example will be described. Figure 6 The shown inductor 200 has a bent shape 55 formed by a corner R between the conductor portion 11B and the terminal portion 14B. In this case, as Figure 6 (a) of shows, if the side surface 2Cf of the magnetic body 2C is brought into contact with the upper surface 14a of the terminal portion 14B, the corner portion 25 of the magnetic body 2C and the bent shape 55 interfere with each other. As a result, a gap is formed between the magnetic body 2C and the side surface 3Bb of the conductor portion 11B. As Figure 6As shown in (b) thereof, if the magnetic body 2C is brought closer to the conductor portion 11B, the corner portion 25 rises to the bent shape 55. As Figure 6 As shown in (c) thereof, if the main surface 2Ca of the magnetic body 2C contacts the conductor portion 11, a gap is formed between the side surface 2Cf of the magnetic body 2C and the upper surface 14a of the terminal portion 14B.

[0060] Refer to Figure 7 The inductor 300 of other comparative examples will be described. For Figure 7 In the inductor 300 shown, no corner R is formed between the conductor portion 11B and the terminal portion 14B, and the side surface 3Bb stands up substantially perpendicularly from the upper surface 14a. In this case, as Figure 7 shown in (a), (b), and (c) thereof, the burr 50 of the resin member 6C is interposed between the main surface 2Ca of the magnetic body 2C and the side surface 3Bb of the conductor portion 11B, forming a gap. In this case, the distance between the main surface 2Ca of the magnetic body 2C and the side surface 3Bb of the conductor portion 11B varies depending on the size or the degree of collapse of the burr 50. The closer the magnetic body 2C and the conductor portion 11B are, the greater the inductance, and the farther the magnetic body 2C and the conductor portion 11B are, the smaller the inductance. Thus, in the inductors 200 and 300 of the comparative examples, there is a problem of unstable magnetic characteristics due to the positional deviation between the magnetic body 2C and the conductor portion 11B.

[0061] On the other hand, in the inductor 1 of the present embodiment, the terminal portion 14B and the conductor portion 11B have first recessed portions 21 and 22 that are recessed from the inside to the outside at positions adjacent to the connecting conductor 15. In addition, the size of the first recessed portions 21 and 22 in the Y-axis direction (the third direction) is equal to or greater than the size of the conductor (here, the conductor portion 11B) having the shorter size in the Y-axis direction among the conductor portion 11B and the terminal portion 14B. Therefore, even when the burr 50 is generated in the resin member 6C, the burr 50 can be accommodated in at least one of the first recessed portions 21 and 22. In this case, the main surface 2Ca of the magnetic body 2C can be stably brought into contact with the side surface 3Bb of the conductor portion 11B. Therefore, the positional deviation of the magnetic body 2C with respect to the conductor portion 11B can be suppressed. As a result, stable magnetic characteristics can be obtained. In addition, when the burr 50 is not generated in the resin member 6C, a part of the resin member 6C may not be accommodated in the first recessed portions 21 and 22.

[0062] At least a part (burr 50) of the resin member 6C can be accommodated in any one of the first recessed portions 21 and 22. In this case, as described above, the main surface 2Ca of the magnetic body 2C can be stably brought into contact with the side surface 3Bb of the conductor portion 11B. Therefore, the positional deviation of the magnetic body 2C with respect to the conductor portion 11B can be suppressed.

[0063] The terminal portion 14B (first conductor) and the conductor portion 11B (second conductor) can each have first recessed portions 21 and 22 that are recessed from the inside to the outside at positions adjacent to the connecting conductor 15. By having both the first recessed portions 21 and 22, regardless of the deformation mode of the burr 50, the burr 50 can be accommodated in either the first recessed portion 21 or the first recessed portion 22. In this way, it is easy to accommodate the burr 50.

[0064] It can be that the connecting conductor 15 has a second recessed portion 23 that is recessed from the inside to the outside, and the second recessed portion 23 of the connecting conductor 15 communicates with the first recessed portions 21 and 22 of at least one conductor. In this case, in a state where the recessed portion 20 that can accommodate the burr 50 is widened to suppress excessive deformation of the burr 50, the burr 50 can be accommodated in the recessed portion 20. Therefore, the positional deviation between the magnetic body 2C and the conductor portion 11B can be further suppressed, and more stable magnetic characteristics can be obtained.

[0065] The length dimension of the first recessed portion 22 of the conductor portion 11B in the Z-axis direction can be larger than the thickness of the resin member 6C. In this case, the reliability of the first recessed portion 22 to accommodate the burr 50 can be improved.

[0066] The depth of the first recessed portion 21 of the terminal portion 14B can be smaller than half of the thickness dimension of the terminal portion 14B. Additionally, the depth of the first recessed portion 22 of the conductor portion 11B can be smaller than half of the thickness dimension of the conductor portion 11B. In this case, by suppressing the reduction of the conductor volume of the coil conductor 3B, an increase in resistance can be suppressed.

[0067] The curvature radius of the inner side of the connecting conductor 15 can be smaller than the thickness of the resin member 6C. In this case, interference between the corner R on the inner peripheral side of the connecting conductor 15 and the burr 50 can be suppressed. Therefore, the magnetic body 2C can be arranged close to the conductor portion 11B, and thus stable and high magnetic characteristics can be obtained.

[0068] It can be that the outer side of the connecting conductor 15 has a curved shape 15a, and the length dimension of the first recessed portion 22 of the conductor portion 11B in the Z-axis direction is smaller than the curvature radius of the curved shape 15a of the connecting conductor 15. In this case, by suppressing the reduction of the conductor volume of the coil conductor 3B, an increase in resistance can be suppressed.

[0069] It can be that the outer side of the connecting conductor 15 has a curved shape 15a, and the length dimension of the first recessed portion 21 of the terminal portion 14B in the X-axis direction is smaller than the curvature radius of the curved shape 15a of the connecting conductor 15. In this case, by suppressing the reduction of the conductor volume of the coil conductor 3B, an increase in resistance can be suppressed.

[0070] It is possible that the coil conductor 3B includes a conductor portion 12B (third conductor) extending in the Z-axis direction, a connecting portion 13B (fourth conductor) that connects the other end 11b of the conductor portion 11B and one end of the conductor portion 12B, and a terminal portion 16B (fifth conductor) that is connected to the other end of the conductor portion 12B and extends in the X-axis direction. The magnetic body 2C is placed on the terminal portions 14B and 16B via the resin member 6. In this way, by supporting the magnetic body 2C with the terminal portions 14B and 16B on both sides in the Y-axis direction, the positional relationship between the magnetic body 2C and the coil conductor 3B can be fixed, and stable magnetic characteristics can be obtained.

[0071] The DC-DC converter 100 of the present embodiment includes the above-described inductor.

[0072] According to this DC-DC converter 100, since the deviation of the inductance of the inductor 1 is small, a DC-DC converter 100 with a small deviation in the output waveform can be obtained. In addition, since the adhesion between the resin and the magnetic body is high, a DC-DC converter 100 with high long-term reliability can be obtained.

[0073] The present disclosure is not limited to the above-described embodiment.

[0074] For example, the inductor 1 shown in Figure 8 may also be adopted. In the inductor 1 shown in Figure 8 , the conductor portion 11B and the magnetic body 2C can be adhered via the adhesive layer 60. In this case, the adhesive layer 60 is interposed between the main surface 2Ca of the magnetic body 2C and the side surface 3Bb of the conductor portion 11B. Therefore, by adjusting the thickness of the adhesive layer 60, the positional deviation between the magnetic body 2C and the conductor portion 11B can be suppressed. For example, as shown in (b) of Figure 9 , even when the adhesive layer 60 is provided, when the recessed portion 20 is not formed, the bent shape 55 and the burr 50 at the corner sometimes interfere. In contrast, according to the structure shown in Figure 8 , the burr 50 can be accommodated in the recessed portion 20.

[0075] Here, as shown in (a) of Figure 9 , inside the recessed portion 20, the connecting conductor 15 can have a bent shape 15b on the inner side. At this time, the radius of curvature of the bent shape 15b on the inner side of the connecting conductor 15 can be smaller than the thickness of the adhesive layer 60. In this case, the interference between the burr 50 accommodated in the recessed portion 20 and the bent shape 15b of the connecting conductor 15 can be suppressed. Therefore, since the magnetic body 2C can be arranged close to the conductor portion 11B, stable and high magnetic characteristics can be obtained.

[0076] The shape of the coil conductor is not limited to the shape adopted in the above-described embodiment, and can be appropriately changed within the scope not departing from the gist of the present disclosure.

[0077] For example, a coil conductor 3B as shown in Figure 10 can be adopted. Figure 10 In the coil conductor 3B shown, the positive-side portion of the conductor portion 11B (and the conductor portion 12B) in the Z-axis direction and the portion of the connecting portion 13B are bent portions 30. The bent portion 30 is shaped to extend toward the negative side in the X-axis direction. In this way, the shape of the coil conductor can also be appropriately changed.

[0078] In addition, the position where the recessed portion 20 is formed can also be appropriately changed as the shape of the coil conductor changes. For example, a coil conductor 130 as shown in Figure 11 can be adopted. The coil conductor 130 has a pair of conductor portions 111, 112 that stand up from the substrate 101 toward the positive side in the Z-axis direction, and a connecting portion 113 that extends in the Y-axis direction so as to connect the upper ends of the conductor portions 111, 112 to each other. The magnetic body 120 is arranged to be inserted into the inner peripheral portion of the coil conductor 130 in the X-axis direction. The magnetic body 120 contacts the connecting portion 113 and contacts the conductor portion 111 via the resin member 6. In this case, the recessed portion 20 can be formed at the bent portion between the conductor portion 111 and the connecting portion 113. In this case, the conductor portion 111 corresponds to the "first conductor" in the claims, and the connecting portion 113 corresponds to the "second conductor" in the claims.

[0079] In addition, a structure as shown in Figure 12 (a) can be adopted. In Figure 12 (a), with respect to the coil conductor 130 shown in Figure 11 , the magnetic body 120 contacts the connecting portion 113 via the resin member 6. The recessed portion 20 can be formed at the bent portion between the conductor portion 111 and the connecting portion 113. In addition, the recessed portion 20 can be formed at the bent portion between the conductor portion 112 and the connecting portion 113. In this case, the connecting portion 113 corresponds to the "first conductor" in the claims, and the conductor portions 111, 112 correspond to the "second conductor" in the claims.

[0080] In addition, a structure as shown in Figure 12 (b) can be adopted. The coil conductor 203 has a structure in which the terminal portions 14B, 16B are removed from the coil conductor 3B shown in Figure 10 . In addition, the magnetic body 2C contacts the bent portion 30 via the resin member 6. In this case, the recessed portion 20 is formed between the bent portion 30 and the conductor portion 11B. In this case, the bent portion 30 corresponds to the "first conductor" in the claims, and the conductor portion 11B corresponds to the "second conductor" in the claims.

[0081] In the above-described embodiments, the inductor has a plurality of coil conductors, but the number of coil conductors is not particularly limited, and an inductor having one coil conductor may be provided. For example, Figure 13 the inductor 1 shown includes one coil conductor 3A and magnetic bodies 2A and 2B. Such one coil conductor 3A can be used for Figure 14 the DC-DC converter 100 shown. As Figure 14 shown, the DC-DC converter 100 includes: a pair of input terminals for inputting a DC input voltage, a pair of output terminals, a switching element 105 and a choke coil 106 connected in series to the high potential side of the pair of input terminals, a diode 103 connected between the connection point of the switching element 105 and the choke coil 106 and the low potential side of the pair of input terminals, and a capacitor 104 connected between the pair of output terminals. The DC-DC converter 100 operates as a step-down converter that steps down the input DC voltage by switching the conduction and disconnection of the switching element 105 based on a control signal from a control circuit (not shown). In addition, the DC-DC converter 100 may be a multi-phase converter having a plurality of conversion units composed of the switching element 105, the choke coil 106, and the diode 103, and these conversion units are connected in parallel. As the choke coil 106 of each conversion unit, the above-described inductor 1 can be employed.

[0082] [Mode 1]

[0083] An inductor, wherein

[0084] it includes:

[0085] a coil conductor including a first conductor extending in a first direction, a second conductor extending in a second direction intersecting the first direction, and a connection conductor connecting one end of the first conductor and the second conductor to each other;

[0086] a magnetic body having a corner portion, and the corner portion is configured to face the connection conductor of the coil conductor; and

[0087] a resin member disposed between the magnetic body and the first conductor of the coil conductor,

[0088] at least one of the first conductor and the second conductor has a first recessed portion recessed from the inside to the outside at a position adjacent to the connection conductor,

[0089] the size of the first recessed portion in a third direction intersecting the first and second directions is equal to or greater than the size of the shorter conductor of the one conductor and the other conductor in the third direction.

[0090] [Mode 2]

[0091] The inductor according to Mode 1, wherein

[0092] At least a part of the resin member is received in the first recess.

[0093] [Mode 3]

[0094] The inductor according to Mode 1 or 2, wherein

[0095] The first conductor and the second conductor each have the first recess that is recessed from the inside to the outside at a position adjacent to the connection conductor.

[0096] [Mode 4]

[0097] The inductor according to any one of Modes 1 to 3, wherein

[0098] The connection conductor has a second recess that is recessed from the inside to the outside,

[0099] The second recess of the connection conductor communicates with the first recess of the at least one conductor.

[0100] [Mode 5]

[0101] The inductor according to any one of Modes 1 to 4, wherein

[0102] The length dimension in the second direction of the first recess of the second conductor is larger than the thickness of the resin member.

[0103] [Mode 6]

[0104] The inductor according to any one of Modes 1 to 5, wherein

[0105] The depth of the first recess of the at least one conductor is smaller than half of the thickness dimension of the conductor.

[0106] [Mode 7]

[0107] The inductor according to any one of Modes 1 to 6, wherein

[0108] The second conductor and the magnetic body are bonded together via an adhesive layer,

[0109] The radius of curvature of the inner side of the connection conductor is smaller than the thickness of the adhesive layer.

[0110] [Mode 8]

[0111] The inductor according to any one of Modes 1 to 7, wherein

[0112] The radius of curvature of the inner side of the connection conductor is smaller than the thickness of the resin member.

[0113] [Mode 9]

[0114] The inductor according to any one of Modes 1 to 8, wherein,

[0115] The outer side of the connection conductor has a curved shape,

[0116] The length dimension of the first recess of the second conductor in the second direction is smaller than the radius of curvature of the curved shape of the connection conductor.

[0117] [Mode 10]

[0118] The inductor according to any one of Modes 1 to 9, wherein,

[0119] The outer side of the connection conductor has a curved shape,

[0120] The length dimension of the first recess of the first conductor in the first direction is smaller than the radius of curvature of the curved shape of the connection conductor.

[0121] [Mode 11]

[0122] The inductor according to any one of Modes 1 to 10, wherein,

[0123] The coil conductor includes:

[0124] A third conductor extending in the second direction;

[0125] A fourth conductor connecting the other end of the second conductor and one end of the third conductor; and

[0126] A fifth conductor connected to the other end of the third conductor and extending in the first direction,

[0127] The magnetic body is placed on the first conductor and the fifth conductor via the resin member.

[0128] [Mode 12]

[0129] A DC-DC converter, wherein,

[0130] It includes the inductor according to any one of Modes 1 to 11.

Claims

1. An inductor, wherein: have: a coil conductor including a first conductor extending in a first direction, a second conductor extending in a second direction intersecting the first direction, and a connecting conductor connecting one end portions of the first conductor and the second conductor to each other; a magnetic body having a corner portion, wherein the corner portion is arranged to be opposite to the connection conductor of the coil conductor; as well as a resin member disposed between the magnetic body and the first conductor of the coil conductor, At least one of the first conductor and the second conductor has a first recessed portion recessed from the inside to the outside at a position adjacent to the connection conductor. A dimension of the first recessed portion in a third direction intersecting the first and second directions is equal to or larger than a dimension of the conductor in the third direction that is shorter than the other conductor.

2. The inductor according to claim 1, wherein At least a portion of the resin member is accommodated in the first recessed portion.

3. The inductor according to claim 1, wherein: The first conductor and the second conductor each have the first recessed portion recessed from the inside to the outside at a position adjacent to the connection conductor.

4. The inductor according to claim 1, wherein: The connecting conductor has a second recessed portion recessed from the inside to the outside, The second recessed portion of the connecting conductor communicates with the first recessed portion of the at least one conductor.

5. The inductor according to claim 1, wherein A length dimension of the first recessed portion of the second conductor in the second direction is greater than a thickness of the resin member.

6. The inductor according to claim 1, wherein The depth of the first recessed portion of the at least one conductor is less than half of the thickness dimension of the conductor.

7. The inductor according to claim 1, wherein: The second conductor and the magnetic body are closely bonded via an adhesive layer. The inner curvature radius of the connection conductor is smaller than the thickness of the adhesive layer.

8. The inductor according to claim 1, wherein The curvature radius of the inner side of the connecting conductor is smaller than the thickness of the resin member.

9. The inductor according to claim 1, wherein: The outer side of the connecting conductor has a bent shape, A length dimension of the first recessed portion of the second conductor in the second direction is smaller than a radius of curvature of the bent shape of the connection conductor.

10. The inductor according to claim 1, wherein The outer side of the connecting conductor has a bent shape, A length dimension of the first recessed portion of the first conductor in the first direction is smaller than a radius of curvature of the bent shape of the connection conductor.

11. The inductor according to claim 1, wherein The coil conductor comprises: a third conductor extending along the second direction; a fourth conductor connecting the other end of the second conductor and one end of the third conductor; and a fifth conductor connected to the other end of the third conductor and extending along the first direction, The magnetic body is placed on the first conductor and the fifth conductor via the resin member.

12. A DC-DC converter, wherein: An inductor according to any one of claims 1 to 11 is provided.

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