Inductor

Abstract

To provide an inductor capable of improving heat dissipation. [Solution] The inductor 1 comprises a magnetic core 10 made of a magnetic material, a pair of plate-shaped conductors, a first conductor 21 and a second conductor 22, and a heat sink 70 made of a plate-shaped metal disposed between the first conductor 21 and the second conductor 22. The first conductor 21 has a first internal conductor 31 provided inside the magnetic core 10 and a first external conductor 41 provided outside the magnetic core 10. The second conductor 22 has a second internal conductor 32 provided inside the magnetic core 10 and a second external conductor 42 provided outside the magnetic core 10. The heat sink 70 has an internal plate 71 provided inside the magnetic core 10 and an external plate 72 provided outside the magnetic core 10. The first internal conductor 31, the internal plate 71 and the second internal conductor 32 are laminated together.

Description

[[Technical Field]]

[0001] The present disclosure relates to an inductor. [[Background Art]]

[0002] In recent years, large-scale integrated circuits have been increasingly reduced in operating voltage, and the required current for elements has reached several tens of amperes. Accordingly, elements that are small and have a small thickness are demanded. As such an element, for example, an inductor including a pair of stacked plate-shaped conductors and a magnetic core surrounding the stacked portion of the conductors is known (see, for example, Patent Document 1). Patent Document 1 describes a magnetically coupled element including a first conductor and a second conductor each having a plate shape and stacked in an electrically insulated state, and a magnetic body disposed so as to surround the first conductor and the second conductor. [[Prior Art Literature]] [[Patent Literature]]

[0003] [[Patent Document 1]] Japanese Unexamined Patent Publication No. 2005-129590 [[Summary of Invention]] [[Problem to be Solved by the Invention]]

[0004] Incidentally, in recent years, due to an increase in information processing such as image processing and video processing, or an increase in the amount of communication data, the required current has increased, and the amount of heat generated by inductors has increased. Therefore, efficient heat dissipation of heat generated in the inductor is required.

[0005] The present disclosure provides an inductor capable of improving heat dissipation. [[Means for Solving the Problem]]

[0006] An inductor according to one aspect of the present disclosure comprises a magnetic core made of a magnetic material, a pair of plate-shaped conductors, a first conductor and a second conductor, and a plate-shaped heat sink made of metal disposed between the first conductor and the second conductor, wherein the first conductor has a first internal conductor provided inside the magnetic core and a first external conductor provided outside the magnetic core, the second conductor has a second internal conductor provided inside the magnetic core and a second external conductor provided outside the magnetic core, and the heat sink has an internal plate provided inside the magnetic core and an external plate provided outside the magnetic core, and the first internal conductor, the internal plate and the second internal conductor are laminated. [Effects of the Invention]

[0007] According to this disclosure, it is possible to provide an inductor that can improve heat dissipation. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a perspective view of an inductor according to an embodiment. [Figure 2] Figure 2 is a perspective view showing a pair of conductors, a pair of insulating layers, and a heat sink included in an inductor. [Figure 3] Figure 3 is an end view along the line III-III in Figure 2. [Figure 4] Figure 4 is a cross-sectional view along the line IV-IV in Figure 1. [Figure 5] Figure 5 is a perspective view showing the first conductor. [Figure 6] Figure 6 is a perspective view showing the second conductor. [Figure 7] Figure 7 is a perspective view showing the heat sink. [Figure 8] Figure 8 is a flowchart showing the method for manufacturing an inductor according to the embodiment. [Figure 9] Figure 9 is an end view showing the structure of the first conductor, heat sink, and second conductor of the inductor of the first modified example. [Figure 10]Figure 10 is an end view showing the structure of the first conductor, heat sink, and second conductor of the inductor of the second modified example. [Figure 11] Figure 11 is an end view showing the structure of the first conductor, heat sink, and second conductor of the inductor of the third modified example. [Figure 12] Figure 12 is a perspective view showing the structure of a pair of conductors, a pair of insulating layers, and a heat sink in an inductor of the fourth modified example. [Figure 13] Figure 13 is a cross-sectional view along the line XIII-XIII in Figure 12. [Figure 14] Figure 14 shows the simulation results for determining the maximum temperature in the magnetic core. [Figure 15] Figure 15 shows the simulation results for determining the dielectric strength and inductance values ​​of the inductor. [Modes for carrying out the invention]

[0009] Embodiments and modifications of this disclosure will be described in detail below with reference to the drawings. The embodiments and modifications described below are either comprehensive or specific examples. The numerical values, shapes, materials, components, arrangement positions of components, connection configurations, steps, and the order of steps shown in the following embodiments and modifications are examples only and are not intended to limit this disclosure. The various embodiments described herein can be combined with each other as long as they do not conflict. Furthermore, components in the following embodiments and modifications that are not described in an independent claim will be described as optional components.

[0010] Furthermore, in this specification, terms indicating relationships between elements such as perpendicular or parallel, terms indicating the shape of elements such as rectangular prisms, and numerical ranges are not expressions that represent only strict meanings, but rather expressions that include substantially equivalent ranges, such as differences of a few percent.

[0011] In addition, each drawing is a schematic diagram in which emphasis, omission, or ratio adjustment has been appropriately performed to illustrate the present disclosure. The drawings are not necessarily strictly illustrated, and may differ from actual shapes, positional relationships, and ratios. In each drawing, substantially identical components are denoted by the same reference numerals, and overlapping descriptions may be omitted or simplified.

[0012] In addition, each drawing shows an X-axis, a Y-axis, and a Z-axis, which represent three mutually orthogonal directions. These axes and the axial directions along these axes are used for description as necessary. It should be noted that the axes are provided for illustrative purposes only, and do not limit the direction and posture in which the inductor is used.

[0013] (Embodiment) [Configuration of Inductor] The configuration of the inductor 1 according to the embodiment will be described with reference to FIGS. 1 to 7.

[0014] FIG. 1 is a perspective view of the inductor 1 according to the embodiment. FIG. 2 is a perspective view showing a pair of conductors, a pair of insulating layers, and a heat dissipation plate 70 included in the inductor 1. FIG. 3 is an end view taken along line III-III in FIG. 2. FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 1. FIG. 5 is a perspective view showing the first conductor 21. FIG. 6 is a perspective view showing the second conductor 22. FIG. 7 is a perspective view showing the heat dissipation plate 70.

[0015] As shown in FIGS. 1 to 3, the inductor 1 is a transformer inductor including a magnetic core 10, a pair of plate-shaped conductors, and a heat dissipation plate 70. The magnetic core 10, the pair of conductors, and the heat dissipation plate 70 are integrally molded by pressing. The pair of conductors is constituted by a first conductor 21 and a second conductor 22. The first conductor 21, the heat dissipation plate 70, and the second conductor 22 are stacked in this order inside the magnetic core 10. In addition, the first conductor 21 and the second conductor 22 are insulated from each other. That is, the inductor 1 includes an insulating layer. In the present embodiment, the inductor 1 includes an insulating layer 81 and an insulating layer 82.

[0016] The following describes each component of inductor 1.

[0017] The magnetic core 10 is a compacted magnetic core formed from a mixture of magnetic material powder and a binder. The magnetic core 10 can be formed using any magnetic material. Ferrite may be used as the magnetic material, or other magnetic materials may be used. The metallic magnetic powder can be a particulate material having a predetermined elemental composition, such as Fe-Si-Al, Fe-Si, Fe-Si-Cr, or Fe-Si-Cr-B. The binder is a resin material such as a silicone resin, and the binder used is a material that can maintain a certain shape by insulating the particles of the metallic magnetic powder while binding the particles together.

[0018] The magnetic core 10 is formed into any shape by mold molding. In this embodiment, the magnetic core 10 has a rectangular parallelepiped shape. The size of the magnetic core 10 is not particularly limited, but for example, the dimension in the X-axis direction is 6 mm, the dimension in the Y-axis direction is 10 mm, and the dimension in the Z-axis direction is 5 mm.

[0019] As shown in Figure 1, the magnetic core 10 has a bottom surface 18, a top surface 19 located on the opposite side of the bottom surface 18, and four sides connecting the bottom surface 18 and the top surface 19. The four sides are composed of sides 11a, 11b, 11c, and 11d.

[0020] The base surface 18 is, for example, a surface having a flat portion. The base surface 18 and the top surface 19 are parallel to each other. The top surface 19 is located on the opposite side of the base surface 18 in the Z-axis direction. In other words, the base surface 18 and the top surface 19 are located on opposite sides of each other in the Z-axis direction. To put it another way, the base surface 18 and the top surface 19 are facing away from each other in the Z-axis direction. Also, the sides 11a and 11b are facing away from each other in the X-axis direction. Also, the sides 11c and 11d are facing away from each other in the Y-axis direction.

[0021] The bottom surface 18 and the top surface 19, and the sides 11a to 11d extend in directions that intersect each other, specifically in perpendicular directions. Also, the sides 11a and 11b, and the sides 11c and 11d extend in directions that intersect each other, specifically in perpendicular directions.

[0022] The bottom surface 18 is provided with four recesses 12a. The four recesses 12a are provided, for example, at each of the four corners of the bottom surface 18. The four recesses 12a are recessed from the bottom surface 18 toward the top surface 19. The ends of the first conductor 21 and the second conductor 22 are folded and housed in the four recesses 12a, for example.

[0023] Furthermore, in this embodiment, as shown in Figures 1 and 4, two recesses 12b are provided on the top surface 19. The two recesses 12b are recessed from the top surface 19 toward the bottom surface 18. Note that the recesses 12b are an example of the "first recess" of this disclosure.

[0024] Furthermore, in this embodiment, each of the side surfaces 11c and 11d is provided with one recess 12c. The recess 12c on side surface 11c is recessed from side surface 11c toward side surface 11d. The recess 12c on side surface 11c extends from approximately the center of side surface 11c toward the top surface 19. The recess 12c on side surface 11c is connected to one of the recesses 12b. Similarly, the recess 12c on side surface 11d is recessed from side surface 11d toward side surface 11c. The recess 12c on side surface 11d extends from approximately the center of side surface 11d toward the top surface 19. The recess 12c on side surface 11d is connected to the other recess 12b. Note that the recess 12c is an example of the "second recess" of this disclosure.

[0025] In this embodiment, as will be described later, a portion of the heat sink 70 is housed in the recesses 12b and 12c.

[0026] Each of the first conductor 21 and the second conductor 22 is formed from a conductive plate. The first conductor 21 and the second conductor 22 are composed of metallic materials selected from, for example, metals such as copper, aluminum, silver, and gold, alloys containing one or more of these metals, and materials consisting of metals or alloys and other substances. Specifically, in this embodiment, the first conductor 21 and the second conductor 22 are made of copper. In this embodiment, the first conductor 21 and the second conductor 22 have the same thickness. However, the thickness of the first conductor 21 may be greater than the thickness of the second conductor 22, or the thickness of the first conductor 21 may be less than the thickness of the second conductor 22. Also, in this embodiment, the first conductor 21 and the second conductor 22 have the same width. However, the width of the first conductor 21 may be greater than the width of the second conductor 22, or the width of the first conductor 21 may be less than the width of the second conductor 22.

[0027] As shown in Figures 2 and 5, the first conductor 21 has a shape that is rotationally symmetrical with respect to a center line L1 that passes through the center point P1 (see Figure 1) of the top surface 19 and is perpendicular to the top surface 19.

[0028] The first conductor 21 has a first internal conductor 31 provided inside the magnetic core 10 and two first external conductors 41 provided outside the magnetic core 10. The first internal conductor 31 and the two first external conductors 41 are formed by processing a single component made of the same material. In this embodiment, the first internal conductor 31 and the first external conductors 41 have the same and constant width. In this embodiment, width refers to the length in the direction perpendicular to the direction in which the object (here, the first internal conductor 31 and the first external conductors 41) extends and the thickness direction of the object.

[0029] The first internal conductor 31 is a portion embedded in the magnetic core 10. The first internal conductor 31 is positioned, for example, on the bottom surface 18 side of the second internal conductor 32, which will be described later. The first internal conductor 31 functions as the first coil of the inductor 1. The first internal conductor 31 is positioned parallel to the bottom surface 18 (or top surface 19). The first internal conductor 31 has a first laminated portion 311 that is laminated on the second conductor 22, and two first connecting portions 312 that are connected to the first laminated portion 311.

[0030] The first laminated portion 311 extends linearly along a direction perpendicular to the side surface 11c (or side surface 11d) of the magnetic core 10 (in the Y-axis direction). Two first connecting portions 312 are connected to the ends of the first laminated portion 311, respectively. One of the first connecting portions 312 extends toward the side surface 11a. This first connecting portion 312 connects the first laminated portion 311 to the first outer conductor 41 located on the side surface 11a. The other first connecting portion 312 extends toward the side surface 11b. This other first connecting portion 312 connects the first laminated portion 311 to the first outer conductor 41 located on the side surface 11b.

[0031] Each first outer conductor 41 has a first lead-out portion 51 and a first terminal portion 61.

[0032] The first terminal portion 61 is the part that connects to the circuit board (not shown) via a bonding member such as solder when the inductor 1 is mounted on the circuit board.

[0033] The first lead-out section 51 connects the first connection section 312 and the first terminal section 61 of the first internal conductor 31.

[0034] The first lead-out portion 51 is formed by bending it at a right angle to the first internal conductor 31. Specifically, the first lead-out portion 51 is bent toward the bottom surface 18 relative to the first internal conductor 31 and extends toward the bottom surface 18 along a direction perpendicular to the bottom surface 18, that is, along the side surface 11a or side surface 11b.

[0035] The first terminal portion 61 is connected to the end of the first extension portion 51 on the bottom surface 18 side. The first terminal portion 61 is formed by bending relative to the first extension portion 51. The first terminal portion 61 is bent so as to face the bottom surface 18, and at least a portion of it is housed in the recess 12a. The first terminal portion 61 protrudes outward from the bottom surface 18 (away from the bottom surface 18), for example, by 0.1 mm beyond the bottom surface 18.

[0036] In this embodiment, the insulating layer 81 is provided on the surface of the first conductor 21. The insulating layer 81 is formed of a resin material containing an inorganic filler such as silica or alumina, for example, a polyimide resin material. Alternatively, the insulating layer 81 may be an insulating coating formed by anodizing the surface of the first conductor 21.

[0037] The insulating layer 81 is provided so as to cover at least the surface of the first laminated portion 311. In this embodiment, the insulating layer 81 also covers the surface of at least the portion of the first connection portion 312 that is connected to the first laminated portion 311. The insulating layer 81 is not provided on the first terminal portion 61. In this embodiment, the insulating layer 81 is not provided on the first outer conductor 41.

[0038] As shown in Figures 2 and 6, the second conductor 22 has a shape that is rotationally symmetrical with respect to a center line L1 that passes through the center point P1 (see Figure 1) of the top surface 19 and is perpendicular to the top surface 19.

[0039] The second conductor 22 has a second internal conductor 32 provided inside the magnetic core 10 and two second external conductors 42 provided outside the magnetic core 10. The second internal conductor 32 and the two second external conductors 42 are formed by processing a single component made of the same material. In this embodiment, the second internal conductor 32 and the second external conductors 42 have the same and constant width.

[0040] The second internal conductor 32 is a portion embedded in the magnetic core 10. The second internal conductor 32 is, for example, positioned on the top surface 19 side of the first internal conductor 31. The second internal conductor 32 functions as the second coil of the inductor 1. The second internal conductor 32 is positioned parallel to the bottom surface 18 (or top surface 19). The second internal conductor 32 has a second laminated portion 321 that is laminated on the first conductor 21, and two second connecting portions 322 that are connected to the second laminated portion 321.

[0041] The second laminated portion 321 extends linearly along a direction perpendicular to the side surface 11c (or side surface 11d) of the magnetic core 10 (in the Y-axis direction). Two second connecting portions 322 are connected to the ends of the second laminated portion 321, respectively. One second connecting portion 322 extends toward the side surface 11a. This second connecting portion 322 connects the second laminated portion 321 to the second outer conductor 42 located on the side surface 11a. The other second connecting portion 322 extends toward the side surface 11b. This second connecting portion 322 connects the second laminated portion 321 to the second outer conductor 42 located on the side surface 11b.

[0042] The width of the second internal conductor 32 is the same as the width of the first internal conductor 31. The first internal conductor 31 and the second internal conductor 32 overlap in at least a portion when viewed from a direction perpendicular to the bottom surface 18 (or top surface 19). Specifically, the first internal conductor 31 and the second internal conductor 32 face each other in at least a portion of the direction perpendicular to the bottom surface 18, via the heat sink 70. The distance between the first internal conductor 31 and the second internal conductor 32 is greater than or equal to the thickness of the heat sink 70, for example, 50 μm or more and 150 μm or less.

[0043] The distance between the second internal conductor 32 and the top surface 19 is, for example, the same as the distance between the first internal conductor 31 and the bottom surface 18, but it may be different.

[0044] Each second outer conductor 42 has a second lead-out portion 52 and a second terminal portion 62.

[0045] The second terminal portion 62 is the part that connects to the circuit board (not shown) via a bonding member such as solder when the inductor 1 is mounted on the circuit board.

[0046] The second lead-out section 52 connects the second connection section 322 and the second terminal section 62 of the second internal conductor 32.

[0047] The second lead portion 52 is formed by bending it relative to the second internal conductor 32. Specifically, the second lead portion 52 is bent toward the bottom surface 18 relative to the second internal conductor 32 and extends toward the bottom surface 18 along a direction perpendicular to the bottom surface 18, that is, along the side surface 11a or side surface 11b.

[0048] The second terminal portion 62 is connected to the bottom surface 18 side end of the second lead portion 52. The second terminal portion 62 is formed by bending relative to the second lead portion 52. The second terminal portion 62 is bent so as to face the bottom surface 18, and at least a portion of it is housed in the recess 12a. The second terminal portion 62 protrudes outward from the bottom surface 18, for example, by 0.1 mm.

[0049] In this embodiment, the insulating layer 82 is provided on the surface of the second conductor 22. The insulating layer 82 is formed of a resin material containing an inorganic filler such as silica or alumina, for example, a polyimide resin material. Alternatively, the insulating layer 82 may be an insulating coating formed by anodizing the surface of the second conductor 22.

[0050] The insulating layer 82 is provided so as to cover at least the surface of the second laminated portion 321. In this embodiment, the insulating layer 82 also covers the surface of at least the portion of the second connection portion 322 that is connected to the second laminated portion 321. The insulating layer 82 is not provided on the second terminal portion 62. In this embodiment, the insulating layer 82 is not provided on the second outer conductor 42.

[0051] As shown in Figures 2 and 7, the heat sink 70 is formed from a thermally conductive plate material. The heat sink 70 is made of a metallic material selected from, for example, metals such as copper, aluminum, silver, and gold, alloys containing one or more of these metals, and materials consisting of metals or alloys and other substances. The heat sink 70 may be made of a magnetic metal or a non-magnetic metal, but in this embodiment, the heat sink 70 is made of a non-magnetic metal so that the inductor 1 has a predetermined coupling coefficient (e.g., 0.4). Specifically, in this embodiment, the heat sink 70 is made of copper.

[0052] The heat sink 70 has a shape that is rotationally symmetrical with respect to the center line L1.

[0053] The heat sink 70 has an internal plate 71 provided inside the magnetic core 10 and two external plates 72 provided outside the magnetic core 10. The internal plate 71 and the two external plates 72 are formed by processing a single component made of the same material. At least a portion of the internal plate 71 and the external plates 72 (in this case, the side portion 721, which will be described later) has the same and constant width.

[0054] The internal plate 71 is a part embedded in the magnetic core 10. The internal plate 71 is positioned between the first internal conductor 31 and the second internal conductor 32. The internal plate 71 functions as a spacer to set the distance between the first internal conductor 31 and the second internal conductor 32 to a predetermined value. The internal plate 71 is positioned parallel to the bottom surface 18 (or top surface 19). The internal plate 71 has a laminated portion 711 that is laminated on the first conductor 21 and the second conductor 22, and two connecting portions 712 that are connected to the laminated portion 711.

[0055] The laminated portion 711 extends linearly along a direction perpendicular to the side surface 11c (or side surface 11d) of the magnetic core 10 (in the Y-axis direction). Two connecting portions 712 are connected to the ends of the laminated portion 711, respectively. In this embodiment, one connecting portion 712, the laminated portion 711, and the other connecting portion 712 extend in a straight line. One connecting portion 712 extends toward the side surface 11c. This connecting portion 712 connects the laminated portion 711 to the outer plate 72 located on the side surface 11c. The other connecting portion 712 extends toward the side surface 11d. This connecting portion 712 connects the laminated portion 711 to the outer plate 72 located on the side surface 11d.

[0056] The width of the laminated section 711 is the same as the width of the first laminated section 311 and the width of the second laminated section 321. The laminated section 711, the first laminated section 311, and the second laminated section 321 overlap in at least a portion when viewed from a direction perpendicular to the bottom surface 18 (or top surface 19). In other words, when viewed from a direction perpendicular to the bottom surface 18 (or top surface 19), at least a portion of the laminated section 711, at least a portion of the first laminated section 311, and at least a portion of the second laminated section 321 overlap. In this embodiment, the area where the internal plate 71 of the heat sink 70 and the first internal conductor 31 overlap is approximately the same as the area where the internal plate 71 and the second internal conductor 32 overlap.

[0057] Each external panel 72 has a side portion 721 and a top portion 722.

[0058] The top surface portion 722 is the part that is thermally connected to a heat sink (not shown), such as a metal plate, either directly or via thermal grease, when the heat sink is placed on the top surface 19 of the inductor 1.

[0059] The side portion 721 connects the connection portion 712 of the internal plate 71 to the top portion 722. The side portion 721 is formed by bending relative to the internal plate 71. Specifically, the side portion 721 is bent toward the top surface 19 relative to the internal plate 71 and extends toward the top surface 19 along a direction perpendicular to the top surface 19, that is, along the side portion 11c or side portion 11d.

[0060] In this embodiment, the side portion 721 is housed in a recess 12c (see Figure 4) provided on the side portions 11c and 11d. The side portion 721 may also protrude from the recess 12c in the Y-axis direction, but in this embodiment, it does not protrude from the recess 12c. Specifically, the side portion 721 is positioned flush with the side portion 11c or the side portion 11d.

[0061] The top surface portion 722 is connected to the end of the side surface portion 721 on the top surface 19 side. The top surface portion 722 is formed by bending relative to the side surface portion 721. Specifically, the top surface portion 722 is bent inward toward the top surface 19 relative to the side surface portion 721 and extends along the top surface 19.

[0062] In this embodiment, the top surface portion 722 is housed in a recess 12b (see Figure 4) provided in the top surface 19. While the top surface portion 722 may protrude from the recess 12b in the Z-axis direction, in this embodiment it does not protrude from the recess 12b. Specifically, the top surface portion 722 is positioned flush with the top surface 19.

[0063] The positions of the two top surfaces 722 on the top surface 19 are not particularly limited, but for example, they are located at the corners of the top surface 19 that face each other, with the center point P1 (see Figure 1) in between. This prevents the two top surfaces 722 from being placed too close to each other. In other words, it prevents high-temperature components from being placed close together. This prevents a decrease in heat dissipation.

[0064] The width W722 (length in the Y-axis direction) of the top surface 722 is greater than the width W721 (length in the X-axis direction) of the side surface 721 and the width W71 (length in the X-axis direction) of the internal plate 71. The widths W721 of the side surface 721 and the internal plate 71 are the same size and constant. The widths W721 of the side surface 721 and the internal plate 71 are the same size as the widths of the first conductor 21 and the second conductor 22.

[0065] Furthermore, the width W722 of the top surface 722 is greater than the width W31 of the first internal conductor 31 (see Figure 5) and the width W32 of the second internal conductor 32 (see Figure 6).

[0066] In this embodiment, as described above, the inductor 1 includes a heat sink 70 made of a plate-shaped metal that is placed between the first conductor 21 and the second conductor 22, and the heat sink 70 has an internal plate 71 provided inside the magnetic core 10 and an external plate 72 provided outside the magnetic core 10.

[0067] This allows the heat generated in the first conductor 21 and the second conductor 22 to be transferred to the outer plate 72 of the heat sink 70 via the inner plate 71. As a result, heat can be dissipated from the outer plate 72 to other components such as a heat sink. Therefore, the heat dissipation performance of the inductor 1 can be improved.

[0068] Furthermore, in this embodiment, as described above, the outer plate 72 has a top surface portion 722 that is positioned on the top surface 19.

[0069] This allows the heat generated in the first conductor 21 and the second conductor 22 to be easily dissipated to the heat sink located on the top surface via the top surface portion 722. Therefore, the heat dissipation performance of the inductor 1 can be easily improved.

[0070] Furthermore, in this embodiment, as described above, the top surface 19 is provided with a recess 12b on which the top surface portion 722 is arranged.

[0071] This prevents the top surface 722 from protruding from the top surface 19 of the magnetic core 10 on the opposite side from the bottom surface 18, thereby preventing the inductor 1 from becoming larger in the thickness direction. Furthermore, by making the top surface 722 and the top surface 19 nearly flush, heat can be easily transferred to the heat sink from both the top surface 722 and the top surface 19 while suppressing a decrease in the volume of the magnetic core 10.

[0072] Furthermore, in this embodiment, as described above, the outer plate 72 has a top surface portion 722 and a side surface portion 721 connected to the top surface portion 722.

[0073] This allows the heat generated in the first conductor 21 and the second conductor 22 to be transferred to the top surface 722 via the side surface 721 located on the outside of the magnetic core 10. As a result, heat can be dissipated from the side surface 721 into, for example, the air, thereby further improving the heat dissipation performance of the inductor 1.

[0074] Furthermore, in this embodiment, as described above, recesses 12c on which the side portion 721 is arranged are provided on the side surfaces 11a to 11d (here, side surfaces 11c and 11d).

[0075] This prevents the side portion 721 from protruding outward from the sides 11a to 11d (in this case, sides 11c and 11d) of the magnetic core 10, thus preventing the inductor 1 from becoming larger, for example, in the Y-axis direction. Furthermore, by making the side portion 721 and the sides 11a to 11d (in this case, sides 11c and 11d) substantially flush, it is possible to suppress the reduction in the volume of the magnetic core 10 even when a recess 12c is provided.

[0076] Furthermore, in this embodiment, as described above, the heat sink 70 is made of a non-magnetic metal.

[0077] This makes it easy to prevent the coupling coefficient from becoming larger than the desired value (e.g., 0.4).

[0078] Furthermore, in this embodiment, as described above, when viewed from a direction perpendicular to the bottom surface 18, at least a portion of the first internal conductor 31, at least a portion of the internal plate 71, and at least a portion of the second internal conductor 32 overlap.

[0079] This allows the heat generated in the first conductor 21 and the second conductor 22 to be easily transferred from at least a portion of the first internal conductor 31 and at least a portion of the second internal conductor 32 to at least a portion of the internal plate 71.

[0080] Furthermore, in this embodiment, as described above, the width W722 of the top surface portion 722 is greater than the width W31 of the first internal conductor 31 and the width W32 of the second internal conductor 32.

[0081] This makes it easy to secure a contact area between the top surface 722 and the heat sink, thereby easily improving the heat dissipation of the inductor 1.

[0082] [Inductor manufacturing method] A method for manufacturing the inductor 1 according to the embodiment will now be described. Figure 8 is a flowchart showing the method for manufacturing the inductor 1 according to the embodiment.

[0083] As shown in Figure 8, the method for manufacturing the inductor 1 includes a conductor formation step S110, an insulating layer formation step S120, a heat sink formation step S130, a magnetic core formation step S140, and a bending step S150.

[0084] First, in the conductive material formation step S110, a first conductive material 21 is formed by punching a metal plate into a predetermined shape. Similarly, a second conductive material 22 is formed by punching another metal plate into a predetermined shape.

[0085] Next, in the insulating layer formation step S120, an insulating layer is formed on the surface of the first conductor 21, and then the insulating layer on the surface between the first outer conductor 41 and a part of the first connection part 312 is removed to form an insulating layer 81. Similarly, an insulating layer is formed on the surface of the second conductor 22, and then the insulating layer on the surface between the second outer conductor 42 and a part of the second connection part 322 is removed to form an insulating layer 82. The insulating layers are formed by, for example, coating or immersion. Alternatively, the insulating layers may be formed by applying anodizing treatment to the surface of the conductor. The insulating layers are removed by, for example, laser processing.

[0086] Next, in the heat sink forming process S130, the heat sink 70 is formed by punching out a metal plate into a predetermined shape.

[0087] Next, in the magnetic core forming process S140, the magnetic core 10 is press-molded together with the first conductor 21, the heat sink 70, and the second conductor 22. Specifically, the first conductor 21, which has an insulating layer 81, the heat sink 70, and the second conductor 22, which has an insulating layer 82, are stacked in this order. Then, a portion of the first conductor 21, a portion of the heat sink 70, and a portion of the second conductor 22 are enclosed in a mold, and a mixture containing magnetic material powder and a binder is injected into the mold to form the magnetic core 10. The portion of the first conductor 21 embedded in the magnetic core 10 becomes the first internal conductor 31, and the portion of the first conductor 21 not embedded in the magnetic core 10 becomes the first external conductor 41. Also, the portion of the second conductor 22 embedded in the magnetic core 10 becomes the second internal conductor 32, and the portion of the second conductor 22 not embedded in the magnetic core 10 becomes the second external conductor 42. Furthermore, the portion of the heat sink 70 embedded in the magnetic core 10 becomes the internal plate 71, and the portion of the heat sink 70 not embedded in the magnetic core 10 becomes the external plate 72.

[0088] Next, in the bending process S150, the two first lead portions 51 of the first outer conductor 41 of the first conductor 21 are bent, and the two first terminal portions 61 are also bent. In addition, the two second lead portions 52 of the second outer conductor 42 of the second conductor 22 are bent, and the two second terminal portions 62 are also bent. Furthermore, the two side portions 721 of the outer plate 72 of the heat sink 70 are bent, and the two top portions 722 are also bent. At this time, the two side portions 721 are housed in the recess 12c, and the two top portions 722 are housed in the recess 12b.

[0089] The inductor 1 is manufactured through the processes shown in Figure 8.

[0090] In this embodiment, an example is shown in which the heat sink formation step S130 is performed after the conductor formation step S110 and the insulating layer formation step S120, but this disclosure is not limited to this. For example, the heat sink formation step S130 may be performed before the conductor formation step S110. Alternatively, the heat sink formation step S130 may be performed in parallel with the conductor formation step S110 or the insulating layer formation step S120.

[0091] Furthermore, in this embodiment, an example is shown in which an insulating layer is provided on the surface of the conductor before the magnetic core forming step S140, and then a portion of the insulating layer is removed to form insulating layers 81 and 82, but the disclosure is not limited thereto. For example, insulating layers 81 and 82 may be formed by providing an insulating layer on the surface of the conductor before the magnetic core forming step S140, and then removing the portion of the insulating layer that is exposed from the magnetic core 10 after the magnetic core forming step S140. Alternatively, insulating layers 81 and 82 may be formed by removing the portion of the insulating layer that is exposed from the magnetic core 10 after the bending step S150. In this case, only the insulating layer on the outward-facing surfaces of the first terminal portion 61 and the second terminal portion 62 (the surfaces opposite to the surface facing the magnetic core 10) may be removed by polishing or the like.

[0092] [First variation] Next, a first modified example of the inductor 1 according to the above embodiment will be described with reference to Figure 9. Figure 9 is an end view showing the structure of the first conductor 21, the heat sink 70, and the second conductor 22 of the inductor 1 of the first modified example.

[0093] As shown in Figure 9, in the first modified example, unlike the above embodiment, the first conductor 21 is not provided with an insulating layer 81. Also, the second conductor 22 is not provided with an insulating layer 82. And the heat sink 70 is provided with an insulating layer 83.

[0094] Specifically, in the first modified example, the insulating layer 83 is provided on the surface of the heat sink 70. The insulating layer 83 is provided so as to cover at least the surface of the laminated portion 711 of the inner plate 71. The material and thickness of the insulating layer 83 are the same as those of the insulating layer 81 or insulating layer 82.

[0095] The method for forming the insulating layer 83 is the same as the method for forming the insulating layers 81 and 82. Specifically, after forming an insulating layer on the surface of the heat sink 70, the insulating layer 83 is formed by, for example, removing the insulating layer on the surface of the outer plate 72.

[0096] Other configurations and manufacturing methods of the first modified example are the same as those of the embodiments described above.

[0097] In the first modified example, as described above, an insulating layer 83 is provided in the portion of the inner plate 71 located between the first inner conductor 31 and the second inner conductor 32.

[0098] This makes it possible, for example, to improve the voltage withstand characteristics of inductor 1 or to increase the inductance value of inductor 1.

[0099] In the first modified example, as described above, the first conductor 21 and the second conductor 22 are not provided with insulating layers 81 and 82, so the inductance value of the inductor 1 can be increased.

[0100] Other effects of the first modification are the same as those of the embodiment described above.

[0101] [Second variation] Next, a second modified example of the inductor 1 according to the above embodiment will be described with reference to Figure 10. Figure 10 is an end view showing the structure of the first conductor 21, the heat sink 70, and the second conductor 22 of the inductor 1 of the second modified example.

[0102] As shown in Figure 10, in the second modified example, unlike the above embodiment, insulating layers are provided on all of the first conductor 21, the second conductor 22, and the heat sink 70. Specifically, the first conductor 21 is provided with an insulating layer 81. The second conductor 22 is provided with an insulating layer 82. The heat sink 70 is provided with an insulating layer 83.

[0103] The other configurations and manufacturing methods of the second modified example are the same as those of the embodiments described above.

[0104] In the second modified example, as described above, insulating layers 81, 82, and 83 are provided on the first conductor 21, the second conductor 22, and the heat sink 70, respectively, thereby improving the dielectric strength characteristics of the inductor 1.

[0105] The other effects of the second modification are the same as those of the first modification described above.

[0106] [Third variation] Next, a third modified example of the inductor 1 according to the above embodiment will be described with reference to Figure 11. Figure 11 is an end view showing the structure of the first conductor 21, the heat sink 70, and the second conductor 22 of the inductor 1 of the third modified example.

[0107] As shown in Figure 11, in the third modified example, unlike the embodiments described above, an insulating layer is provided on only one of the first conductor 21 and the second conductor 22. Here, we will describe an example in which the first conductor 21 does not have an insulating layer 81, and the second conductor 22 has an insulating layer 82. Note that the insulating layer 81 and the insulating layer 82 are examples of the "second insulating layer" in this disclosure.

[0108] In the third modified example, an insulating layer 83 is provided on the surface of the heat sink 70. However, in the third modified example, the insulating layer 83 is provided on the portion of the heat sink 70 facing the first conductor 21, but not on the portion of the heat sink 70 facing the second conductor 22. Note that the insulating layer 83 is an example of the "first insulating layer" of this disclosure.

[0109] Specifically, the heat sink 70 has a first opposing surface 70a facing the first conductor 21, a second opposing surface 70b facing the second conductor 22, and two side surfaces 70c connecting the first opposing surface 70a and the second opposing surface 70b. The insulating layer 83 is provided on at least the first opposing surface 70a. In the third modified example, the insulating layer 83 is also provided on the side surfaces 70c. On the other hand, the insulating layer 83 is not provided on the second opposing surface 70b.

[0110] The insulating layer 83 is formed, for example, by spraying a mist of insulating resin onto the surface of the heat sink 70. Alternatively, as in the above embodiments, the insulating layer 83 may be formed by first forming an insulating layer on the surface of the heat sink 70 and then removing a predetermined area.

[0111] The other configurations and manufacturing methods of the third modified example are the same as those of the embodiments described above.

[0112] In the third modified example, as described above, insulating layers 81 and 82 (in this case, insulating layer 81) are not provided on the surface of at least one of the first internal conductor 31 and the second internal conductor 32 (in this case, the first internal conductor 31), and insulating layer 83 is provided on the portion of the internal plate 71 that faces the surface where insulating layers 81 and 82 are not provided (in this case, the first opposing surface 70a).

[0113] This makes it easy to ensure the dielectric strength of the inductor 1 even when insulating layers 81 and / or 82 are not provided. Furthermore, since insulating layers 81 and 82 are not provided on at least one of the first internal conductor 31 and the second internal conductor 32, at least one of the magnetic paths of the magnetic flux circulating around the first internal conductor 31 when the first conductor 21 is energized, and the magnetic paths of the magnetic flux circulating around the second internal conductor 32 when the second conductor 22 is energized can be shortened. As a result, the inductance value of the inductor 1 can be increased.

[0114] The other effects of the third modification are the same as those of the first modification described above.

[0115] [Fourth variation] Next, a fourth modification of the inductor 1 according to the above embodiment will be described with reference to Figure 12. Figure 12 is a perspective view showing the structure of a pair of conductors, a pair of insulating layers, and a heat sink 70 of the inductor 1 of the fourth modification. Figure 13 is a cross-sectional view along the line XIII-XIII in Figure 12.

[0116] As shown in Figures 12 and 13, in the fourth modified example, unlike the embodiments described above, the area where the inner plate 71 of the heat sink 70 and the first inner conductor 31 overlap is larger than the area where the inner plate 71 and the second inner conductor 32 overlap.

[0117] Specifically, the internal plate 71 has, for example, a laminated portion 711 and two connecting portions 712, as well as two extension portions 713. The extension portions 713 extend from the laminated portion 711 and / or the connecting portions 712 along the first connecting portion 312. The extension portions 713 face the first connecting portion 312 of the first internal conductor 31, but do not face the second connecting portion 322 of the second internal conductor 32. In other words, the extension portions 713 and the first connecting portion 312 overlap, while the extension portions 713 and the second connecting portion 322 do not overlap.

[0118] Furthermore, in the fourth modified example, the width W713 (length in the Y-axis direction) of the extension portion 713 is greater than the width W312 (length in the Y-axis direction) of the first connecting portion 312. Note that the width W713 of the extension portion 713 may be the same as or smaller than the width W312 of the first connecting portion 312.

[0119] As described above, the first internal conductor 31 functions as a first coil, and the second internal conductor 32 functions as a second coil. Therefore, a larger current flows through the first internal conductor 31 than through the second internal conductor 32. Consequently, the amount of heat generated in the first internal conductor 31 tends to be greater than that generated in the second internal conductor 32. Therefore, by providing an extension portion 713 on the internal plate 71 and increasing the overlapping area between the internal plate 71 and the first internal conductor 31, heat dissipation can be further improved.

[0120] Furthermore, since a larger current flows through the first internal conductor 31 than through the second internal conductor 32, it is preferable that the resistance of the first internal conductor 31 is smaller than the resistance of the second internal conductor 32. For example, the width of the first internal conductor 31 may be larger than the width of the second internal conductor 32. Also, for example, the thickness of the first internal conductor 31 may be larger than the thickness of the second internal conductor 32.

[0121] The other configurations and manufacturing methods of the fourth modified example are the same as those of the embodiments described above.

[0122] In the fourth modified example, as described above, the area where the internal plate 71 and the first internal conductor 31 overlap when viewed from a direction perpendicular to the bottom surface 18 is larger than the area where the internal plate 71 and the second internal conductor 32 overlap.

[0123] This allows more of the heat generated in the first conductor 31 to be transferred to the heat sink 70. As a result, the heat dissipation performance of the inductor 1 can be further improved.

[0124] Furthermore, in the fourth modified example, as described above, the resistance value of the first internal conductor 31 is smaller than the resistance value of the second internal conductor 32.

[0125] This makes it possible to suppress the heat generated in the first internal conductor 31, which is used as the first coil.

[0126] [Simulation 1] Next, we will describe the simulations performed to confirm the effects of the above embodiments. These simulations were performed for Example 1, which corresponds to the above embodiment, Example 2, which corresponds to the fourth modified example, and a comparative example.

[0127] In Example 1, the dimensions of the magnetic core 10 in the X, Y, and Z directions were set to 6 mm, 10 mm, and 5 mm, respectively. The first conductor 21 and the second conductor 22 were made of copper with a thickness of 0.3 mm. The insulating layers 81 and 82 were made of polyamide-imide with a thickness of 10 μm. The heat sink 70 was made of copper with a thickness of 100 μm. A model was used in which a heat sink made of an aluminum plate of a predetermined size was placed on the top surface 19 of the inductor 1. The other structures of Example 1 were the same as in the above embodiment.

[0128] In Example 2, two extensions 713 were provided on the internal plate 71. The other structural features of Example 2 were the same as those of Example 1.

[0129] In the comparative example, the inductor 1 was not provided with a heat sink 70. Instead, a spacer (not shown) of the same shape and size as the laminated portion 711 of the heat sink 70 was provided between the first laminated portion 311 and the second laminated portion 321. The material of this spacer was polyamide-imide, the same as that of the insulating layer 81 and insulating layer 82. The other structural features of the comparative example were the same as those of Example 1.

[0130] Then, simulations were performed for Example 1, Example 2, and the Comparative Example. Specifically, the maximum temperature in the magnetic core 10 was determined when a predetermined voltage was applied to the first conductor 21 and current was passed through the first conductor 21. The results are shown in Figure 14.

[0131] As shown in Figure 14, in Example 1, the maximum temperature of the magnetic core 10 was 139.0°C. In Example 2, the maximum temperature of the magnetic core 10 was 137.4°C. In the comparative example, the maximum temperature of the magnetic core 10 was 144.5°C. In other words, it was found that the heat dissipation of the inductor 1 was improved in Examples 1 and 2 compared to the comparative example.

[0132] This is thought to be due to the following reasons. In the comparative example, the heat generated in the first conductor 21 and the second conductor 22 is transferred to the heat sink via the magnetic core 10, making it difficult to improve heat dissipation. On the other hand, in Example 1, the heat generated in the first conductor 21 and the second conductor 22 is mainly transferred to the heat sink via the heat sink plate 70, which is thought to have improved the heat dissipation of the inductor 1. Furthermore, in Example 2, by providing an extension portion 713 on the heat sink plate 70, more heat generated in the first conductor 31 is transferred to the heat sink plate 70. As a result, more heat is transferred to the heat sink, which is thought to have further improved the heat dissipation of the inductor 1.

[0133] [Simulation 2] Next, we will describe the simulations conducted to confirm the effects of the first, second, and third modified examples. These simulations were performed for Example 1, which corresponds to the above embodiment; Example 3, which corresponds to the first modified example; Example 4, which corresponds to the second modified example; and Example 5, which corresponds to the third modified example.

[0134] Example 1 is the same as the model described above. Note that it is not necessary to place a heatsink on the top surface 19 of the inductor 1.

[0135] In Example 3, the first conductor 21 and the second conductor 22 were not provided with insulating layers 81 and 82, and an insulating layer 83 was provided on the heat sink 70. The insulating layer 83 was made of polyamide-imide and had a thickness of 10 μm. The other structural features of Example 3 were the same as those of Example 1.

[0136] In Example 4, insulating layers 81, 82, and 83 were provided on the first conductor 21, the second conductor 22, and the heat sink 70, respectively. The other structures of Example 4 were the same as those of Example 1.

[0137] In Example 5, the first conductor 21 was not provided with an insulating layer 81, the second conductor 22 was provided with an insulating layer 82, and the heat sink 70 was provided with an insulating layer 83. However, the insulating layer 83 was provided on the first opposing surface 70a and the side surface 70c, but not on the second opposing surface 70b. The other structures of Example 5 were the same as those of Example 1.

[0138] Then, simulations were performed for Example 1 and Examples 3 to 5. Specifically, the withstand voltage and inductance value (also called L value) of inductor 1 were determined. The results are shown in Figure 15.

[0139] As shown in Figure 15, the withstand voltages of Example 1, Example 3 to Example 5 were approximately 2kV, 0.2kV, 4kV, and 2kV, respectively. This shows that all of Examples 1, 3 to Example 5 have sufficient withstand voltage characteristics. Furthermore, Example 4 was found to have improved withstand voltage characteristics compared to Example 1.

[0140] This is thought to be due to the following reason: In Example 4, in addition to providing insulating layers 81 and 82 on the first conductor 21 and the second conductor 22, an insulating layer 83 is also provided on the heat sink 70, which is thought to have improved the dielectric strength of the inductor 1.

[0141] Furthermore, the inductance values ​​for Example 1 and Examples 3-5 were "small," "large," "small," and "medium," respectively. This revealed that Examples 3 and 5 had larger inductance values ​​compared to Examples 1 and 4. Note that "small," "medium," and "large" are relative evaluation values, not absolute evaluation values.

[0142] This is thought to be due to the following reasons. In Example 5, an insulating layer 81 is not provided on the surface of the first conductor 21. Therefore, compared to the case where an insulating layer 81 is provided, the magnetic path of the magnetic flux circulating around the first internal conductor 31 when current is passed through the first conductor 21 becomes shorter. Consequently, it is thought that the inductance value of the inductor 1 became larger. Also, in Example 3, an insulating layer 81 is not provided on the surface of the first conductor 21, and an insulating layer 82 is not provided on the surface of the second conductor 22. Therefore, compared to the case where both insulating layers 81 and 82 are provided, the magnetic path of the magnetic flux circulating around the first internal conductor 31 when current is passed through the first conductor 21 becomes shorter, and the magnetic path of the magnetic flux circulating around the second internal conductor 32 when current is passed through the second conductor 22 becomes shorter. Consequently, it is thought that the inductance value of the inductor 1 became even larger.

[0143] (summary) The following is an example of the inductor 1 according to the above embodiment.

[0144] The inductor 1 of Example 1 comprises a magnetic core 10 made of a magnetic material, a pair of plate-shaped conductors, a first conductor 21 and a second conductor 22, and a heat sink 70 made of a plate-shaped metal disposed between the first conductor 21 and the second conductor 22. The first conductor 21 has a first internal conductor 31 provided inside the magnetic core 10 and a first external conductor 41 provided outside the magnetic core 10. The second conductor 22 has a second internal conductor 32 provided inside the magnetic core 10 and a second external conductor 42 provided outside the magnetic core 10. The heat sink 70 has an internal plate 71 provided inside the magnetic core 10 and an external plate 72 provided outside the magnetic core 10. The first internal conductor 31, the internal plate 71, and the second internal conductor 32 are stacked.

[0145] With this configuration, the heat generated in the first conductor 21 and the second conductor 22 can be transferred to the outer plate 72 of the heat sink 70 via the inner plate 71. This allows heat to be dissipated from the outer plate 72 to other components such as a heat sink. Therefore, the heat dissipation performance of the inductor 1 can be improved.

[0146] The inductor 1 in Example 2 is the inductor described in Example 1, wherein the magnetic core 10 has a bottom surface 18, a top surface 19 located on the opposite side of the bottom surface 18, and sides 11a to 11d connecting the bottom surface 18 and the top surface 19, and the outer plate 72 has a top surface portion 722 that is positioned on the top surface 19.

[0147] Generally, the heat sink is placed on the top surface 19 of the inductor 1. Therefore, as described above, by having a top surface portion 722 on which the outer plate 72 is placed on the top surface 19, the heat generated in the first conductor 21 and the second conductor 22 can be easily dissipated to the heat sink via the top surface portion 722. Thus, the heat dissipation performance of the inductor 1 can be easily improved.

[0148] Inductor 1 in Example 3 is the inductor described in Example 2, and the top surface 19 is provided with a recess 12b on which the top surface portion 722 is arranged.

[0149] This configuration prevents the top surface 722 from protruding from the top surface 19 of the magnetic core 10 on the opposite side from the bottom surface 18, thereby preventing the inductor 1 from becoming larger in the thickness direction. Furthermore, by making the top surface 722 and the top surface 19 nearly flush, heat can be easily transferred to the heat sink from both the top surface 722 and the top surface 19 while suppressing a reduction in the volume of the magnetic core 10.

[0150] The inductor 1 in Example 4 is the inductor described in Example 2 or 3, wherein the outer plate 72 has a top surface portion 722 and side portions 721 that are connected to the inner plate 71 on the side surfaces 11a to 11d and extend to the top surface 19 and connect to the top surface portion 722.

[0151] With this configuration, the heat generated in the first conductor 21 and the second conductor 22 can be transferred to the top surface 722 via the side surface 721 located on the outside of the magnetic core 10. This allows the heat to be dissipated from the side surface 721 into, for example, the air, thereby further improving the heat dissipation performance of the inductor 1.

[0152] The inductor 1 in Example 5 is the inductor described in Example 4, and the sides 11a to 11d are provided with recesses 12c on which the side portion 721 is arranged.

[0153] This configuration prevents the side portion 721 from protruding outward from the side portions 11a to 11d of the magnetic core 10, thereby preventing the inductor 1 from increasing in the direction intersecting the thickness direction. Furthermore, if the side portion 721 and the side portions 11a to 11d are made nearly flush, the reduction in the volume of the magnetic core 10 can be suppressed.

[0154] Inductor 1 in Example 6 is an inductor described in any of Examples 1 to 5, and the heat sink 70 is made of a non-magnetic metal.

[0155] This configuration makes it easy to prevent the coupling coefficient from becoming larger than the desired value.

[0156] Inductor 1 in Example 7 is an inductor described in any of Examples 1 to 6, wherein the magnetic core 10 has a bottom surface 18, a top surface 19 located on the opposite side of the bottom surface 18, and sides 11a to 11d connecting the bottom surface 18 and the top surface 19, and when viewed from a direction perpendicular to the bottom surface 18, at least a part of the first internal conductor 31, at least a part of the internal plate 71, and at least a part of the second internal conductor 32 overlap.

[0157] With this configuration, the heat generated in the first conductor 21 and the second conductor 22 can be easily transferred from at least a portion of the first internal conductor 31 and at least a portion of the second internal conductor 32 to at least a portion of the internal plate 71.

[0158] Inductor 1 in Example 8 is an inductor described in any of Examples 1 to 7, wherein the magnetic core 10 has a bottom surface 18, a top surface 19 located on the opposite side of the bottom surface 18, and sides 11a to 11d connecting the bottom surface 18 and the top surface 19, and the area where the internal plate 71 and the first internal conductor 31 overlap when viewed from a direction perpendicular to the bottom surface 18 is larger than the area where the internal plate 71 and the second internal conductor 32 overlap.

[0159] This configuration allows more heat generated in the first conductor 31 to be transferred to the heat sink 70. As a result, the heat dissipation performance of the inductor 1 can be further improved.

[0160] Inductor 1 in Example 9 is the inductor described in Example 8, wherein the resistance of the first internal conductor 31 is smaller than the resistance of the second internal conductor 32.

[0161] For example, when the first internal conductor 31 is used as the first coil and the second internal conductor 32 is used as the second coil, the resistance of the first internal conductor 31 may be made smaller than the resistance of the second internal conductor 32 in order to suppress the heat generated in the first internal conductor 31. In other words, when the resistance of the first internal conductor 31 is smaller than the resistance of the second internal conductor 32, the first internal conductor 31 is generally used as the first coil. Therefore, by making the overlapping area of ​​the internal plate 71 and the first internal conductor 31 larger than the overlapping area of ​​the internal plate 71 and the second internal conductor 32, more of the heat generated in the first internal conductor 31, which is used as the first coil, can be transferred to the heat sink 70.

[0162] Inductor 1 in Example 10 is an inductor described in any of Examples 1 to 9, wherein an insulating layer 83 is provided in the portion of the internal plate 71 located between the first internal conductor 31 and the second internal conductor 32.

[0163] This configuration allows, for example, to improve the voltage withstand characteristics of inductor 1 or to increase the inductance value of inductor 1.

[0164] Inductor 1 in Example 11 is the inductor described in Example 10, wherein at least one surface of the first internal conductor 31 and the second internal conductor 32 is not provided with insulating layers 81 and 82, and insulating layer 83 is provided on the portion of the internal plate 71 that faces the surface not provided with insulating layers 81 and 82.

[0165] With this configuration, the dielectric strength characteristics of the inductor 1 can be easily ensured even if insulating layers 81 and / or 82 are not provided. Furthermore, since insulating layers 81 and 82 are not provided on at least one of the first internal conductor 31 and the second internal conductor 32, at least one of the distance between the first internal conductor 31 and the magnetic core 10, and the distance between the second internal conductor 32 and the magnetic core 10 can be reduced. As a result, the inductance value of the inductor 1 can be increased.

[0166] Inductor 1 in Example 12 is an inductor described in any of Examples 2 to 5, wherein the width W722 of the top surface portion 722 is greater than the width W31 of the first internal conductor 31 and the width W32 of the second internal conductor 32.

[0167] With this configuration, the contact area between the top surface 722 and the heat sink can be easily secured, thus easily improving the heat dissipation performance of the inductor 1.

[0168] (Other embodiments, etc.) The embodiments and modifications of the inductors, etc., described above have been explained, but the disclosure is not limited to the embodiments and modifications described above. Without departing from the spirit of the disclosure, various modifications that a person skilled in the art could conceive of the embodiments and modifications, as well as other forms constructed by combining some of the components of the embodiments and modifications, are also included in the scope of the disclosure.

[0169] For example, electrical products or circuits using the above-described inductor are also included in this disclosure. Examples of electrical products include power supply devices equipped with the above-described inductor, and various devices equipped with said power supply devices.

[0170] Furthermore, although the above embodiments show examples in which the magnetic core 10 is provided with recesses 12b and 12c, this disclosure is not limited thereto. For example, the magnetic core 10 does not have to be provided with recesses 12b and / or 12c. In other words, the surface of the heat sink 70 and the surface of the magnetic core 10 do not have to be flush.

[0171] Furthermore, while the above embodiments show an example in which the heat sink 70 is formed to be exposed to the outside of the magnetic core 10 from the side surfaces 11c and 11d of the magnetic core 10 and extends to the top surface 19, this disclosure is not limited to this. For example, the heat sink 70 may extend inside the magnetic core 10 to the top surface 19 of the magnetic core 10 and be exposed to the outside of the magnetic core 10 from the top surface 19. Also, for example, the outer plate 72 of the heat sink 70 does not have to be placed on the top surface 19. [Industrial applicability]

[0172] This disclosure can be applied, for example, to an inductor having a pair of conductors. [Explanation of Symbols]

[0173] 1 Inductor 10 magnetic core 11a~11d Side 12b Recess (First recess) 12c recess (second recess) 18. Base 19 Top surface 21 First Conductor 22 Second Conductor 31 First Inner Conductor 32 Second Inner Conductor 41 First outer conductor 42 Second outer conductor 70 Heat sink 71 Internal plate 72 Exterior panel 81, 82 Insulating layer (second insulating layer) 83. Insulating layer (first insulating layer) 721 Side part 722 Top section Widths W31, W32, W722

Claims

1. A magnetic core made of magnetic material, A pair of plate-shaped conductors, a first conductor and a second conductor, A heat sink made of a plate-shaped metal is placed between the first conductor and the second conductor, Equipped with, The first conductor comprises a first internal conductor provided inside the magnetic core and a first external conductor provided outside the magnetic core. The second conductor comprises a second internal conductor provided inside the magnetic core and a second external conductor provided outside the magnetic core. The heat sink has an internal plate provided inside the magnetic core and an external plate provided outside the magnetic core. The first internal conductor, the internal plate, and the second internal conductor are laminated. Inductor.

2. The magnetic core has a bottom surface, a top surface located on the opposite side of the bottom surface, and a side surface connecting the bottom surface and the top surface. The aforementioned external plate has a top surface portion that is positioned on the top surface, The inductor according to claim 1.

3. The top surface is provided with a first recess on which the top surface portion is arranged. The inductor according to claim 2.

4. The outer plate has a top surface portion and a side portion that is connected to the inner plate on the side surface and extends to the top surface and connects to the top surface portion. The inductor according to claim 2.

5. The aforementioned side surface is provided with a second recess in which the aforementioned side surface portion is arranged. The inductor according to claim 4.

6. The heat sink is made of a non-magnetic metal. The inductor according to claim 1.

7. The magnetic core has a bottom surface, a top surface located on the opposite side of the bottom surface, and a side surface connecting the bottom surface and the top surface. When viewed from a direction perpendicular to the bottom surface, at least a portion of the first internal conductor, at least a portion of the internal plate, and at least a portion of the second internal conductor overlap. The inductor according to claim 1.

8. The magnetic core has a bottom surface, a top surface located on the opposite side of the bottom surface, and a side surface connecting the bottom surface and the top surface. When viewed from a direction perpendicular to the bottom surface, the area where the inner plate and the first inner conductor overlap is larger than the area where the inner plate and the second inner conductor overlap. The inductor according to claim 1.

9. The resistance of the first internal conductor is smaller than the resistance of the second internal conductor. The inductor according to claim 8.

10. A first insulating layer is provided in the portion of the inner plate located between the first inner conductor and the second inner conductor. The inductor according to claim 1.

11. The second insulating layer is not provided on at least one surface of the first internal conductor and the second internal conductor. The first insulating layer is provided on the portion of the internal plate that faces the surface where the second insulating layer is not provided. The inductor according to claim 10.

12. The width of the top surface is greater than the width of the first internal conductor and the width of the second internal conductor. The inductor according to claim 2.

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