Coil parts

Abstract

To provide a coil component having a structure capable of enhancing inductance.SOLUTION: A coil component 100 includes a core molded body 10, a first mounting terminal portion 51, a first current path 42, a second mounting terminal portion 55, a second current path 43, and a first return current path 31 and a second return current path 36 which are branched from a branch portion 44 which is an end portion 42b of the first current path 42 opposite to the first mounting terminal portion 51 side. The first return current path 31 has a first one end portion 32 at the branch portion 44, extends toward a first other end portion 33, and, is electrically connected, at the first other end portion 33, to a confluence portion 45 which is an end portion 43a on the first mounting terminal portion 51 side in the second current path 43. The second return current path 36 extends toward a second other end portion 38, and is electrically connected to the confluence portion 45 at the second other end portion 38.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a coil component. [Background technology]

[0002] An example of a coil component is described in Patent Document 1. The coil component of Patent Document 1 includes a core molding (referred to as a magnetic core in the document), a terminal portion, and a current path (referred to as a conductor portion in the document) connected to the terminal portion. The current path includes an insertion portion that is inserted into the magnetic core, and the insertion portion is configured to include a first portion and a second portion that is disposed on top of the first portion. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2020-198395 Summary of the Invention [Problem to be solved by the invention]

[0004] According to the investigations of the present inventors, the coil component of Patent Document 1 still has room for improvement in terms of increasing inductance.

[0005] The present invention has been made in view of the above-mentioned problems, and provides a coil component having a structure capable of improving inductance. [Means for solving the problem]

[0006] The present invention includes a core molded body formed of a magnetic material, a first mounting terminal portion; a first current path connected to the first mounting terminal portion; A second mounting terminal portion; a second current path connected to the second mounting terminal portion and extending in parallel to the first current path; a first return current path and a second return current path branching from a branch portion that is an end portion of the first current path opposite to the first mounting terminal portion; and the first return current path has a first end at the branch portion, extends from the first end toward a first other end located near an end of the first current path on the first mounting terminal portion side, and is electrically connected at the first other end to a junction portion that is an end of the second current path on the first mounting terminal portion side; The second return current path has a second end at the branch portion, extends from the second end toward a second other end located near the end of the first current path on the first mounting terminal portion side, and is electrically connected to the junction at the second other end. And, the first current path and the second current path are arranged side by side; the first return current path includes a first parallel extending portion extending in parallel to the first current path and the second current path in an arrangement direction of the first current path and the second current path, the second return current path includes a second parallel extending portion extending in parallel to the first current path and the second current path in the arrangement direction, a distance between the first current path and the second current path in the arrangement direction is a first distance; a second distance is a distance in the arrangement direction between the first parallel extension portion and one of the first current path and the second current path that is located closer to the first parallel extension portion, and When a distance in the arrangement direction between the second parallel extension portion and one of the first current path and the second current path that is located closer to the second parallel extension portion is defined as a third distance, Both the second distance and the third distance are greater than the first distance. A coil component is provided. [Effects of the Invention]

[0007] According to the present invention, a coil component having a structure capable of improving inductance is provided. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view of a coil component according to a first embodiment. [Figure 2] FIG. 2 is an exploded perspective view of the coil component according to the first embodiment. [Figure 3] FIG. 2 is a front view of the coil component according to the first embodiment. [Figure 4]FIG. 2 is a side view of the coil component according to the first embodiment. [Figure 5] 5(a) and 5(b) are plan views of the coil component according to the first embodiment, and in FIG. 5(b) the core molded body is not shown. [Figure 6] FIG. 6(a) is a cross-sectional view taken along the line AA shown in FIG. 5(a), and FIG. 6(b) is a partially enlarged view of part A shown in FIG. 6(a). [Figure 7] 7(a) is a cross-sectional view taken along line BB shown in FIG. 5(a), and FIG. 7(b) is a partially enlarged view of part A shown in FIG. 7(a). [Figure 8] FIG. 10 is a perspective view of a coil component according to a second embodiment. [Figure 9] 9(a) and 9(b) are plan views of the coil component according to the second embodiment, and in FIG. 9(b) the core molded body is not shown. [Figure 10] FIG. 10 is a side view of a coil component according to a second embodiment. [Figure 11] FIG. 10 is a perspective view of a coil component according to a third embodiment. [Figure 12] FIG. 10 is an exploded perspective view of a coil component according to a third embodiment. [Figure 13] 13(a) and 13(b) are plan views of the coil component according to the third embodiment, and in FIG. 13(b) the core molded body is not shown. [Figure 14] Figure 14(a) is a plan view of a first conductive member in the third embodiment, Figure 14(b) is a side view of the first conductive member in the third embodiment, Figure 14(c) is a plan view of a second conductive member in the third embodiment, and Figure 14(d) is a side view of the second conductive member in the third embodiment. [Figure 15] FIG. 10 is a perspective view of a coil component according to a fourth embodiment. [Figure 16] FIG. 10 is an exploded perspective view of a coil component according to a fourth embodiment. [Figure 17] FIG. 10 is a perspective view of a coil component according to a fifth embodiment. [Figure 18]18(a) and 18(b) are plan views of the coil component according to the fifth embodiment, and in FIG. 18(b) the core molded body is not shown. [Figure 19] FIG. 10 is a perspective view of a coil component according to a sixth embodiment. [Figure 20] 20(a) and 20(b) are plan views of the coil component according to the sixth embodiment, and in FIG. 20(b) the core molded body is not shown. [Figure 21] FIG. 10 is a side view of the coil component according to the sixth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described with reference to Figures 1 to 21. In all the drawings, similar components are denoted by the same reference numerals, and descriptions thereof will be omitted where appropriate.

[0010] [First embodiment] First, the first embodiment will be described with reference to FIGS. 1 to 7(b). As shown in any one of Figures 1 to 7(b), the coil device 100 of this embodiment has a core molding 10 (Figure 1, etc.) formed from a magnetic material, a first mounting terminal portion 51 (Figure 4, etc.), a first current path 42 (Figures 5(a) and 5(b), etc.) connected to the first mounting terminal portion 51, a second mounting terminal portion 55, a second current path 43 (Figures 5(a) and 5(b), etc.) connected to the second mounting terminal portion 55 (Figure 4, etc.) and extending in parallel to the first current path 42, and a first return current path 31 and a second return current path 36 (Figures 5(a) and 5(b), etc.) branching off from each other from a branch portion 44, which is an end portion 43b of the first current path 42 on the side opposite the first mounting terminal portion 51. 1, 5(a), 5(b), etc., the first return current path 31 has a first end portion 32 at the branch portion 44. The first return current path 31 extends from the first end portion 32 toward a first other end portion 33 located near an end portion 42a of the first current path 42 on the first mounting terminal 51 side. At the first other end portion 33, the first return current path 31 is electrically connected to a junction portion 45, which is an end portion 43a of the second current path 43 on the first mounting terminal 51 side. The second return current path 36 has a second end 37 at the branching portion 44. The second return current path 36 extends from the second end 37 toward a second other end 38 located near an end 42a of the first current path 42 on the first mounting terminal portion 51 side. The second return current path 36 is electrically connected to the junction 45 at the second other end 38. Note that "parallel" does not necessarily mean that the first current path 42 and the second current path 43 extend in directions that intersect with each other. In this case, for example, the angle formed between the first current path 42 and the second current path 43 is less than 45 degrees. Furthermore, the first current path 42 and the second current path 43 may be disposed on the same plane or may be in a twisted relationship. When the first current path 42 and the second current path 43 are in a twisted relationship, the maximum angle formed between the first current path 42 and the second current path 43 is less than 45 degrees when viewed from any direction.

[0011] According to the present embodiment, the coil device 100 includes a first return current path 31 and a second return current path 36 that are electrically connected to the first current path 42 and the second current path 43, respectively. The first return current path 31 branches off from an end 42b (branch portion 44) of the first current path 42 opposite the first mounting terminal 51 side, and is electrically connected to a junction 45 near an end 42a of the first current path 42 on the first mounting terminal 51 side (first other end portion 33). Similarly, the second return current path 36 branches off from an end 42b (branch portion 44) of the first current path 42 opposite the first mounting terminal 51 side, and is electrically connected to a junction 45 near an end 42a of the first current path 42 on the first mounting terminal 51 side (second other end portion 38). This allows the number of turns of the current paths of the coil device 100 to be more satisfactorily secured compared to a case in which the coil device 100 does not include the first return current path 31 and the second return current path 36. More specifically, a current applied from the first mounting terminal 51 flows through the first current path 42 toward the branching portion 44 (the side opposite to the first mounting terminal 51), and branches into the first return current path 31 and the second return current path 36 at the branching portion 44. The current branched into the first return current path 31 and the current branched into the second return current path 36 each flow toward the junction 45 (the side toward the first mounting terminal 51) and merge with each other at the junction 45. The merged currents flow through the second current path 43 toward an end 43b (the side toward the second mounting terminal 55) of the second current path 43 opposite to the side toward the first mounting terminal 51. That is, the coil component 100 is configured so that a current applied from the first mounting terminal 51 flows in a direction opposite to the first mounting terminal 51 side, then flows toward the first mounting terminal 51 side, and then flows again in a direction opposite to the first mounting terminal 51 side. This makes it possible to ensure a sufficient number of turns (for example, more than one turn) in the current path of the coil component 100, thereby improving the inductance of the coil component 100. Furthermore, the current applied to the first mounting terminal 51 flows in the first current path 42 from the first mounting terminal 51 side (end 42a side) toward the opposite side of the first mounting terminal 51 (end 42b side). Similarly, the current flowing into the second current path 43 from the junction 45 also flows from the first mounting terminal 51 side (end 43a side) toward the opposite side of the first mounting terminal 51 (end 43b side). In other words, the currents flowing in the first current path 42 and the second current path 43, which extend in parallel with each other, are in approximately the same direction. As a result, the magnetic flux loops of the first current path 42 and the second current path 43 enhance each other, and large magnetic flux loops are formed around the first current path 42 and the second current path 43. This further improves the inductance of the coil device 100. As described above, according to this embodiment, it is possible to realize the coil component 100 having a structure that can improve the inductance. Furthermore, since the number of turns of the current path of the coil component 100 can be ensured sufficiently without using any windings for the coil, the ease of manufacturing the coil component 100 can be improved.

[0012] In the following description, the up-down direction is referred to as the Z direction. The bottom (lower side) is the side on which the first mounting terminal portion 51 and the second mounting terminal portion 55 are arranged, i.e., the mounting surface side of the coil component 100. However, the positional relationships of the various parts (particularly the up-down positional relationships) during the manufacture and use of the coil component 100 are not limited to the positional relationships described in this specification. The first current path 42 extends in a direction perpendicular to the Z direction. The extension direction of the first current path 42 is referred to as the Y direction, and one side in the Y direction is referred to as the front (forward) and the other side is referred to as the rear (rear). Moreover, the direction perpendicular to both the Y direction and the Z direction is referred to as the X direction, and one side of the X direction is referred to as the left (leftward), and the other side is referred to as the right (rightward). These directions are indicated in each figure. Furthermore, in the Y direction, the center side of the first current path 42 is referred to as the inner side (inner side), and the side opposite the inner side is referred to as the outer side (outer side). Similarly, in the X direction, the center side of the first current path 42 is referred to as the inner side (inner side), and the side opposite the inner side is referred to as the outer side (outer side). Moreover, the direction perpendicular to the Z direction is referred to as horizontal (horizontal direction), and the direction along the Z direction is referred to as vertical (vertical direction). Furthermore, unless otherwise specified, the positional relationship of each part of the coil device 100 describes the positional relationship in a state where the parts of the coil device 100 are assembled together to form the coil device 100.

[0013] 1 and 2, in this embodiment, the core molding body 10 is formed, for example, in a substantially cubic shape. More specifically, the core molding body 10 has a front surface 12 facing forward, a back surface 13 facing backward, a pair of left and right side surfaces 14 facing left and right, respectively, an upper surface 15 facing upward, and a lower surface 16 facing downward. The core molded body 10 is formed, for example, in a shape that is symmetrical both left and right and front and rear. 4, for example, a pair of front and rear recesses 17 are formed on the lower surface 16. The pair of front and rear recesses 17 are slightly recessed upward from the lower surface 16. The bottom surface of each of the pair of front and rear recesses 17 is formed, for example, flat and arranged horizontally.

[0014] The core molding 10 is a composite magnetic body formed by, for example, compression molding a material containing a metal magnetic powder and a thermosetting resin, and the entire core molding 10 is integrally molded from this composite magnetic body. With this configuration, the core molded body 10 can have high magnetic permeability, and the inductance of the coil device 100 can be further improved.

[0015] 1, 2, 5(a) and 5(b), the coil device 100 includes, for example, a second conductive member 72 having a first mounting terminal portion 51 and a first current path 42, and a second conductive member 72 having a second mounting terminal portion 55 and a second current path 43. In other words, the first mounting terminal portion 51 and the first current path 42 are each formed by a portion of the first conductive member 71, and the second mounting terminal portion 55 and the second current path 43 are each formed by a portion of the second conductive member 72. This makes it possible to omit the steps of joining the first mounting terminal portion 51 and the first current path 42 to each other (for example, by resistance welding, laser welding, or the like) and joining the second mounting terminal portion 55 and the second current path 43 to each other (ditto) in the manufacturing process of the coil device 100. This further improves the ease of manufacturing the coil device 100.

[0016] 2 and 4, the first conductive member 71 has, in addition to the first mounting terminal portion 51 and the first current path 42, a first outer surface arrangement portion 46 interposed between the first mounting terminal portion 51 and the first current path 42. That is, the first mounting terminal portion 51 is connected to the first current path 42 (first portion 71a) via the first outer surface arrangement portion 46. Similarly, the second conductive member 72 has, in addition to the second mounting terminal portion 55 and the second current path 43, a second outer surface arrangement portion 47 interposed between the second mounting terminal portion 55 and the second current path 43. That is, the second mounting terminal portion 55 is connected to the second current path 43 (first portion 72a) via the second outer surface arrangement portion 47, for example.

[0017] In this embodiment, the first conductive member 71 and the second conductive member 72 are formed to have the same shape and dimensions, and are arranged in positions that are inverted relative to each other front to back and left to right. The first conductive member 71 has, for example, a first portion 71a formed in a flat plate shape extending in the front-rear direction, a vertical portion which is a plate-like portion connected to the first portion 71a and whose plate surface faces in the front-rear direction, and a horizontal portion which is a plate-like portion connected to the vertical portion and whose plate surface faces in the up-down direction. Similarly, the second conductive member 72 has, for example, a first portion 72a formed in a flat plate shape extending in the front-rear direction, a vertical portion, and a horizontal portion. In the present embodiment, for example, the first portion 71a of the first conductive member 71 constitutes the first current path 42, the vertical portion of the first conductive member 71 constitutes the first outer surface arrangement portion 46, and the horizontal portion of the first conductive member 71 constitutes the first mounting terminal portion 51. Similarly, for example, the first portion 72a of the second conductive member 72 constitutes the second current path 43, the vertical portion of the second conductive member 72 constitutes the second outer surface arrangement portion 47, and the horizontal portion of the second conductive member 72 constitutes the second mounting terminal portion 55.

[0018] The first current path 42 (first portion 71a) and the second current path 43 (first portion 72a) are set to have, for example, the same shape and the same dimensions. Each of the first current path 42 and the second current path 43 is formed in a substantially rectangular shape that is elongated in the front-rear direction in a plan view. The first current path 42 and the second current path 43 are formed flat and arranged horizontally. The first mounting terminal portion 51 and the second mounting terminal portion 55 are set to have, for example, the same shape and the same dimensions. Each of the first mounting terminal portion 51 and the second mounting terminal portion 55 is formed in a generally rectangular shape that is elongated in the left-right direction in a plan view. Each of the first mounting terminal portion 51 and the second mounting terminal portion 55 is formed flat and arranged horizontally. The first outer surface arrangement portion 46 and the second outer surface arrangement portion 47 are set to have, for example, the same shape and the same dimensions as each other. Each of the first outer surface arrangement portion 46 and the second outer surface arrangement portion 47 is formed flat and is arranged vertically. As shown in FIG. 3, the left-right width of the upper end of the second external surface arrangement portion 47 is set to be equal to the left-right width of the second current path 43, and the left-right width of the lower end of the second external surface arrangement portion 47 is set to be larger than the left-right width of the second current path 43. Therefore, the left-right width of the upper end of the second external surface arrangement portion 47 is smaller than the left-right width of the lower end of the second external surface arrangement portion 47. As shown in FIG. 3, the left-right width of the middle portion of the second external surface arrangement portion 47 in the vertical direction (the portion between the upper end and the lower end) widens downward in a one-sided tapered manner in front view. More specifically, the left edge of the middle portion of the second external surface arrangement portion 47 extends vertically, while the right edge of the middle portion is inclined downward and displaced to the right. Similarly, the left-right width dimension of the upper end of the first outer surface arrangement portion 46 is smaller than the left-right width dimension of the lower end of the first outer surface arrangement portion 46. The middle portion of the first outer surface arrangement portion 46 in the up-down direction (the portion between the upper end and the lower end) has a left-right width dimension that tapers downward in a single direction in a plan view. More specifically, the right edge of the middle portion of the first outer surface arrangement portion 46 extends vertically, while the left edge of the middle portion is inclined downward and displaced leftward. The first outer surface arrangement portion 46 and the second outer surface arrangement portion 47 face each other, and in particular, the lower end of the first outer surface arrangement portion 46 and the lower end of the second outer surface arrangement portion 47 face each other entirely.

[0019] 4 , the first mounting terminal portion 51 is disposed on the rear end side of the first current path 42. Therefore, the rear end portion of the first current path 42 constitutes an end portion 42a of the first current path 42 on the first mounting terminal portion 51 side, and the front end portion of the first current path 42 constitutes an end portion 42b (branch portion 44) of the first current path 42 opposite the first mounting terminal portion 51 side. Furthermore, as an example, the rear end portion of the second current path 43 constitutes an end portion 43a (junction portion 45) of the second current path 43 on the first mounting terminal portion 51 side, and the front end portion of the second current path 43 constitutes an end portion 43b of the second current path 43 opposite the first mounting terminal portion 51 side. More specifically, the upper edge of the first outer surface arrangement portion 46 is connected to, for example, the rear edge of the first current path 42 and extends downward from the rear edge. Meanwhile, the lower edge of the first outer surface arrangement portion 46 is connected to the rear edge of the first mounting terminal portion 51. Similarly, the upper edge of the second outer surface arrangement portion 47 is connected to, for example, the front edge of the second current path 43 and extends downward from the front edge. Meanwhile, the lower edge of the second outer surface arrangement portion 47 is connected to the front edge of the second mounting terminal portion 55. Furthermore, a boundary 46a between the first current path 42 and the first externally disposed portion 46 is curved in an arc shape (an arc shape that convexly extends upward toward the rear side) in a side view. Similarly, the second externally disposed portion 47 is connected to the front edge of the second current path 43 and extends downward from the front edge. Furthermore, a boundary 47a between the second current path 43 and the second externally disposed portion 47 is curved in an arc shape (an arc shape that convexly extends upward toward the rear side) in a side view.

[0020] In this embodiment, as an example, the left and right dimensions of the lower end of the first outer surface placement portion 46 and the lower end of the second outer surface placement portion 47 are set to dimensions slightly larger than the sum of the left and right width dimensions of the first current path 42 and the second current path 43. The left-right width of the lower end of the first outer surface arrangement portion 46 is set to, for example, the same width as the left-right width of the first mounting terminal portion 51. Similarly, the left-right width of the lower end of the second outer surface arrangement portion 47 is set to, for example, the same width as the left-right width of the second mounting terminal portion 55. This ensures a sufficient cross-sectional area for each of the first outer surface arrangement portion 46 and the second outer surface arrangement portion 47, thereby suppressing DC resistance in the first outer surface arrangement portion 46 and the second outer surface arrangement portion 47. Furthermore, the structural strength of the first outer surface arrangement portion 46 and the second outer surface arrangement portion 47 can be ensured sufficiently.

[0021] In this embodiment, each of the first conductive member 71 and the second conductive member 72 is made of a rectangular wire. This makes it possible to easily ensure that each of the first current path 42 and the second current path 43 has a sufficient cross-sectional area. Furthermore, by bending a rectangular wire, the first conductive member 71 having the first mounting terminal portion 51 and the first current path 42 can be easily formed. In the present embodiment, the first conductive member 71 having the first mounting terminal portion 51, the first outer surface arrangement portion 46, and the first current path 42 can be easily formed. Similarly, by bending a rectangular wire, the second conductive member 72 having the second mounting terminal portion 55 and the second current path 43 can be easily formed. In the present embodiment, the second conductive member 72 having the second mounting terminal portion 55, the second outer surface arrangement portion 47, and the second current path 43 can be easily formed. More specifically, the rectangular wire constituting the first conductive member 71 is bent (e.g., bent 90 degrees) at the boundary between the first mounting terminal portion 51 and the first outer surface arrangement portion 46, and is also bent (e.g., bent 90 degrees) at the boundary between the first current path 42 and the first outer surface arrangement portion 46. As a result, the first current path 42 is configured to be perpendicular to the first outer surface arrangement portion 46 and parallel to the first mounting terminal portion 51. Similarly, the rectangular wire constituting the second conductive member 72 is bent (e.g., bent 90 degrees) at the boundary between the second mounting terminal portion 55 and the second outer surface arrangement portion 47, and is also bent (e.g., bent 90 degrees) at the boundary between the second outer surface arrangement portion 47 and the second mounting terminal portion 55. As a result, the second current path 43 is configured to be perpendicular to the second outer surface arrangement portion 47 and parallel to the second mounting terminal portion 55.

[0022] As described above, the first conductive member 71 and the second conductive member 72 are each formed of a rectangular wire. Therefore, the thickness of the first conductive member 71 is, for example, substantially uniform over the entire first conductive member 71. Similarly, the thickness of the second conductive member 72 is, for example, substantially uniform over the entire first conductive member 71. Furthermore, the first conductive member 71 and the second conductive member 72 are, for example, formed to have the same thickness. Therefore, the thickness dimension of the first current path 42 and the thickness dimension of the second current path 43 are substantially the same. However, the present invention is not limited to this example, and the thickness dimension of the first conductive member 71 and the thickness dimension of the second conductive member 72 may be different from each other. In other words, the thickness dimension of the first current path 42 and the thickness dimension of the second current path 43 may be different from each other.

[0023] In this embodiment, the first current path 42 and the second current path 43 are adjacent to each other with an insulating film interposed therebetween. This makes it possible to prevent the first current path 42 and the second current path 43 from being short-circuited even if the first current path 42 and the second current path 43 are disposed in close proximity to or in contact with each other. More specifically, for example, an insulating film is applied to the entire outer surface of the first conductive member 71 except for at least a portion of the branch portion 44 (end portion 42b of the first current path 42 opposite to the first mounting terminal portion 51). In other words, at least a portion of the portion of the first conductive member 71 that constitutes the branch portion 44 (end portion 42b) is a region where no insulating film is formed. Similarly, for example, an insulating film is applied to the entire outer surface of the second conductive member 72 except for at least a portion of the junction 45 (the end 43a of the second current path 43 on the first mounting terminal 51 side). In other words, at least a portion of the portion of the second conductive member 72 that constitutes the junction 45 (the end 43a) is an area where no insulating film is formed. In this embodiment, the entire upper surface of the end 42b of the first current path 42 is a region where no insulating film is formed, and the entire upper surface of the end 43a of the second current path 43 is a region where no insulating film is formed. In the present invention, it is sufficient that the insulating film is formed at least on each of the opposing surfaces of the first current path 42 and the second current path 43. Furthermore, as shown in Figures 6(b) and 7(b), the upper surfaces of the end 42b (branch portion 44) of the first current path 42 and the end 43a (confluence portion 45) of the second current path 43 are, for example, slightly raised locally upward.

[0024] As shown in FIGS. 1 and 2, the first return current path 31 and the second return current path 36 are formed by, for example, the second conductive member 72 and a conductive member different from the second conductive member 72. This allows each member to have a simple shape. Furthermore, the cross-sectional area of ​​each of the first return current path 31 and the second return current path 36, which are made of different conductive members, can be increased, thereby reducing the thickness of each of the first current path 42 (first conductive member 71) and the second current path 43 (second conductive member 72) and reducing the DC resistance of the current paths. This makes it easy to bend the first conductive member 71 and the second conductive member 72 (with a light force). This reduces the DC resistance of the current paths and improves the ease of manufacturing the coil device 100.

[0025] 2, 5(b), etc., in this embodiment, the coil device 100 includes, as another conductive member, a third conductive member 30 having a first return current path 31 and a second return current path 36. In other words, the first return current path 31 and the second return current path 36 are each formed by a portion of the third conductive member 30. As a result, the first return current path 31 and the second return current path 36 are configured from the same member, and therefore by assembling the third conductive member 30 to the first current path 42 and the second current path 43, the first return current path 31 and the second return current path 36 can be simultaneously assembled to the first current path 42 and the second current path 43. This improves the ease of manufacturing the coil device 100. The third conductive member 30 is, for example, a conductive ring member formed in a ring shape. This ensures that the structural strength of the third conductive member 30 is sufficient. 5(a) and 5(b), the ring conductive member (third conductive member 30) is formed, for example, in a substantially square shape with rounded corners in a plan view, and includes a pair of front and rear side portions and a pair of left and right side portions. The center of the third conductive member 30 forms a gap portion 30a. The pair of front and rear side portions extend, for example, in the left-right direction and are arranged parallel to each other. The pair of left and right side portions extend, for example, in the front-rear direction and are arranged parallel to each other. The planar shape of the conductive ring member is not particularly limited, and may be, for example, a polygonal shape other than a rectangular shape, a circular shape, an elliptical shape, or the like.

[0026] In this embodiment, the third conductive member 30, the first conductive member 71, and the second conductive member 72 are made of, for example, the same type of conductive material (e.g., copper, etc.). However, as described above, since the first conductive member 71 and the second conductive member 72 have insulating films formed thereon, the third conductive member 30 may or may not have an insulating film formed thereon. However, if the first conductive member 71 and the second conductive member 72 do not have insulating films formed thereon, the third conductive member 30 has an insulating film formed thereon. In this case, the insulating film is not formed in the portions of the third conductive member 30 corresponding to the branch portion 44 and the junction portion 45.

[0027] In the present embodiment, the thickness of the third conductive member 30 is, for example, substantially uniform throughout. Therefore, the first return current path 31 and the second return current path 36 are, for example, formed to have the same thickness. However, the present invention is not limited to this example, and the thickness of the third conductive member 30 may vary in its extension direction, and the thickness of the first return current path 31 and the thickness of the second return current path 36 may be different from each other. Furthermore, the thickness of the third conductive member 30 (the thickness of the first return current path 31 and the thickness of the second return current path 36) is set to be larger than the thickness of the first current path 42 and the thickness of the second current path 43. On the other hand, the width of the third conductive member 30 (the dimension in the horizontal direction and in a direction perpendicular to the extending direction) is set to be, for example, approximately equal to the left-right width of the first current path 42 and the left-right width of the second current path 43. This makes it possible to ensure a sufficient cross-sectional area for each of the first return current path 31 and the second return current path 36, thereby further reducing the DC resistance of the entire current path of the coil device 100. In other words, the inductance of the coil device 100 can be improved while reducing the DC resistance of the current path. However, for example, the cross-sectional area of ​​each of the first current path 42 and the second current path 43 may be larger than the cross-sectional area of ​​each of the first return current path 31 and the second return current path 36.

[0028] In this embodiment, the cross-sectional area of ​​the first return current path 31 is preferably 0.5 to 10 times, more preferably 0.5 to 3 times, the cross-sectional area of ​​the first current path 42, for example. The cross-sectional area of ​​the second return current path 36 is preferably, for example, 0.5 to 10 times the cross-sectional area of ​​the second current path 43, and more preferably 0.5 to 3 times.

[0029] In this embodiment, the core molded body 10 includes, for example, a first current path 42, a second current path 43, a first return current path 31, and a second return current path 36 therein. This makes it possible to suppress leakage magnetic flux from the coil device 100. 1, 3, 4, and 5(a), the first current path 42, the second current path 43, and the third conductive member 30 are each entirely embedded in the core molded body 10 (excluding the boundaries 46a and 47a). In other words, the core molded body 10 is integrally molded such that the first current path 42, the second current path 43, and the third conductive member 30 are entirely embedded in the core molded body 10. On the other hand, the first outer surface arrangement portion 46 , the second outer surface arrangement portion 47 , the first mounting terminal portion 51 and the second mounting terminal portion 55 are each arranged outside the core molded body 10 . More specifically, the inner surface (front surface) of the first outer surface arrangement portion 46 is disposed vertically, for example, along the front surface 12 of the core molding body 10. Similarly, the inner surface (rear surface) of the second outer surface arrangement portion 47 is disposed vertically, for example, along the back surface 13 of the core molding body 10. 4, the first mounting terminal portion 51 is disposed horizontally along the bottom surface of the rear recess 17 of the pair of front and rear recesses 17. In the vertical direction, the upper surface of the first mounting terminal portion 51 faces the bottom surface of the rear recess 17 and is in close proximity to or in contact (surface contact) with the bottom surface. Similarly, the second mounting terminal portion 55 is disposed horizontally along the bottom surface of the front recess 17 of the pair of front and rear recesses 17. In the vertical direction, the bottom surface of the front groove and the upper surface of the second mounting terminal portion 55 face each other and are in close proximity to or in contact (surface contact) with the bottom surface. The first mounting terminal portion 51 and the second mounting terminal portion 55 are disposed at substantially the same height position. The height positions of the lower surfaces of the first mounting terminal portion 51 and the second mounting terminal portion 55 are lower than the height position of the lower surface 16 of the core molded body 10. This makes it possible to suppress interference between the core molded body 10 and a substrate or the like (not shown) when the coil component 100 is mounted on the substrate or the like.

[0030] The first outer surface arrangement portion 46 and the second outer surface arrangement portion 47 may be adhesively fixed to the outer surface of the core molding body 10. More specifically, the inner surface of the first outer surface arrangement portion 46 may be adhesively fixed (surface-bonded) to the back surface 13 of the core molding body 10, and the inner surface of the second outer surface arrangement portion 47 may be adhesively fixed (surface-bonded) to the front surface 12 of the core molding body 10.

[0031] In this embodiment, as shown in Figures 5(a) and 5(b), the first current path 42 and the second current path 43 are arranged side by side, and the conductive ring member (third conductive member 30) is arranged on top of the first current path 42 and the second current path 43. This makes it possible to ensure a sufficient cross-sectional area of ​​the current path (the sum of the cross-sectional area of ​​the conductive ring member and the cross-sectional area of ​​the first current path 42) in the portion where the third conductive member 30 and the first current path 42 overlap and are electrically connected to each other. Similarly, it is possible to ensure a sufficient cross-sectional area of ​​the current path (the sum of the cross-sectional area of ​​the conductive ring member and the cross-sectional area of ​​the second current path 43) in the portion where the third conductive member 30 and the second current path 43 overlap and are electrically connected to each other. More specifically, the first current path 42 and the second current path 43 are disposed at approximately the same height. The upper surfaces of the first current path 42 and the second current path 43 are flush with each other, and the lower surfaces of the first current path 42 and the second current path 43 are flush with each other. As described above, the first current path 42 extends in the front-rear direction, and the second current path 43 also extends in the front-rear direction. That is, the first current path 42 and the second current path 43 extend in the same direction, and the first current path 42 and the second current path 43 extend parallel to each other. The first current path 42 and the second current path 43 are arranged horizontally, which is the left-right direction in this embodiment. As shown in FIGS. 5( a) and 5(b) , in this embodiment, the first current path 42 and the second current path 43 are arranged slightly spaced apart from each other in the left-right direction. However, as described above, since an insulating film is formed on the first conductive member 71 and the second conductive member 72, the first current path 42 and the second current path 43 may be disposed in contact with each other. The third conductive member 30 is disposed horizontally on the upper surface of the first current path 42 and the upper surface of the second current path 43, for example.

[0032] Here, as shown in Figure 5, as an example, in the third conductive member 30, the portion extending counterclockwise from the branching portion 44 to the junction 45 is the first return current path 31, and the portion extending clockwise from the branching portion 44 to the junction 45 is the second return current path 36. More specifically, as described above, in this embodiment, the upper surface of the end 42b (branch portion 44) of the first current path 42 is a region where no insulating film is formed, and the upper surface of the end 43a (confluence portion 45) of the second current path 43 is a region where no insulating film is formed. 6(a) to 7(b), a portion of the lower surface of the third conductive member 30 is in surface contact with each of the upper surface of the end 42b (branch portion 44) of the first current path 42 and the upper surface of the end 43a (junction 45) of the second current path 43. As a result, the third conductive member 30, and therefore each of the first return current path 31 and the second return current path 36, is electrically connected to the first current path 42 at the branch portion 44 and is electrically connected to the second current path 43 at the junction 45. In this embodiment, the third conductive member 30 and the first current path 42 may be joined to each other, for example, via a conductive bonding agent, or by resistance welding. Similarly, the third conductive member 30 and the second current path 43 may be joined to each other, for example, via a conductive bonding agent, or by resistance welding.

[0033] 4, 5(a), and 5(b), in this embodiment, the positions of the first conductive member 71 and the second conductive member 72 relative to the third conductive member 30 are set so that the branch portion 44 and the junction portion 45 are located at positions where the path lengths of the first return current path 31 and the second return current path 36 are the same. Also, as described above, the thickness of the third conductive member 30 is approximately uniform throughout the entire third conductive member 30. This results in a structure in which the first return current path 31 and the second return current path 36 have the same path length and cross-sectional area, so that the current applied to the first mounting terminal portion 51 passes through the first current path 42 and branches evenly into the first return current path 31 and the second return current path 36.

[0034] In this embodiment, in a plan view, as shown in Figures 5(a) and 5(b), for example, the central portion in the left-right direction of the third conductive member 30 is arranged so as to overlap with the first current path 42 and the second current path 43. More specifically, a portion of the center in the left-right direction of the front side edge of the third conductive member 30 is in surface contact with, for example, the upper surface of the end 42b (branch portion 44) of the first current path 42, and a portion of the center in the left-right direction of the rear side edge of the third conductive member 30 overlaps with, for example, the end 42a of the first current path 42. Furthermore, a portion of the center in the left-right direction of the rear side edge of the third conductive member 30 is in surface contact with, for example, the upper surface of the end 43a (junction portion 45) of the second current path 43, and a portion of the center in the left-right direction of the front side edge of the third conductive member 30 overlaps with, for example, the end 43b of the second current path 43. With this configuration, the magnetic flux loop can be evenly increased on both the right and left sides of the third conductive member 30 (both the right and left sides of the first current path 42 and the second current path 43), thereby further improving the inductance of the coil component 100. As shown in FIG. 4, the front end surface of the third conductive member 30 is arranged approximately flush with the front end surface of the end 42b of the first current path 42, and the rear end surface of the third conductive member 30 is arranged approximately flush with the rear end surface of the end 43a of the second current path 43. In the present embodiment, in the third conductive member 30 (ring conductive member), the portion on the right side of the branch portion 44 and the junction portion 45 constitutes the first return current path 31, and the portion on the left side constitutes the second return current path 36. In addition, in the third conductive member 30, for example, the portion overlapping with the branch portion 44 constitutes the first one end portion 32 and the second one end portion 37, and the portion overlapping with the junction portion 45 constitutes the first other end portion 33 and the second other end portion 38. However, the present invention is not limited to this example, and for example, in the third conductive member 30, the right-hand portion based on each of the branching portion 44 and the confluence portion 45 may constitute the second return current path 36, and the left-hand portion may constitute the first return current path 31.

[0035] 5(a) and 5(b), the first return current path 31 includes a first parallel extension portion 34 extending in parallel to the first current path 42 and the second current path 43. Similarly, the second return current path 36 includes a second parallel extension portion 39 extending in parallel to the first current path 42 and the second current path 43. This results in a structure in which the current flowing through each of the first parallel extension portion 34 and the second parallel extension portion 39 flows in the opposite direction to the current flowing through each of the first current path 42 and the second current path 43. Therefore, the magnetic flux loops generated around each of the first parallel extension portion 34 and the second parallel extension portion 39 and the magnetic flux loops generated around each of the first current path 42 and the second current path 43 can flow in directions that enhance each other's magnetic flux. Here, "parallel" does not necessarily mean parallel, and the first parallel extension portion 34 and the second parallel extension portion 39 may each extend in a direction intersecting the first current path 42 and the second current path 43. In this case, for example, the angle formed between the first parallel extension portion 34 and the second parallel extension portion 39 and the first current path 42 and the second current path 43 is less than 45 degrees. Furthermore, the first parallel extension portion 34 and the second parallel extension portion 39 and the first current path 42 and the second current path 43 may be arranged on the same plane or may be twisted relative to each other. When each of the first parallel extension portion 34 and the second parallel extension portion 39 and the first current path 42 and the second current path 43 are in a twisted relationship, the maximum angle formed by each of the first parallel extension portion 34 and the second parallel extension portion 39 and the first current path 42 and the second current path 43 is less than 45 degrees when viewed from any direction.

[0036] More specifically, as an example, the right side of the third conductive member 30 constitutes the first parallel extension portion 34, and the left side of the third conductive member 30 constitutes the second parallel extension portion 39. Therefore, each of the first parallel extension portion 34 and the second parallel extension portion 39 extends in the front-to-rear direction. The current flowing through each of the first current path 42 and the second current path 43 flows from rear to front (from the first mounting terminal 51 side to the opposite side from the first mounting terminal 51 side), while the current flowing through each of the first parallel extension portion 34 and the second parallel extension portion 39 flows from front to rear (from the opposite side from the first mounting terminal 51 side to the first mounting terminal 51 side). In addition, the left-right width dimension of the first parallel extension portion 34 is set to, for example, a dimension approximately equal to the left-right width dimension of the first current path 42, and the left-right width dimension of the second parallel extension portion 39 is set to a dimension approximately equal to the left-right width dimension of the first current path 42.

[0037] In this embodiment, a current applied from the first mounting terminal 51 flows through the first current path 42 toward the branch portion 44 (the side opposite to the first mounting terminal 51), and at the branch portion 44, branches into the first return current path 31 and the second return current path 36 via the upper surface of the end portion 42b. The current branching into the first return current path 31 passes through the first one end portion 32, the first parallel extending portion 34, and the first other end portion 33 in this order, and flows to the junction 45 via the upper surface of the end portion 42b. The current branching into the second return current path 36 passes through the second one end portion 37, the second return current path 36, and the second other end portion 38 in this order, and flows to the junction 45 via the upper surface of the end portion 43a. In this way, the current branching into the first return current path 31 and the current branching into the second return current path 36 merge with each other at the junction 45. The joined current passes through the second current path 43 and flows toward the end 43b (second mounting terminal 55 side) of the second current path 43 opposite to the first mounting terminal 51 side.

[0038] In this embodiment, the distance between the first current path 42 and the second current path 43 is defined as a first distance D1 (see FIG. 3), the distance between the first parallel extension portion 34 and either the first current path 42 or the second current path 43, whichever is closer to the first parallel extension portion 34, is defined as a second distance D2 (see FIG. 3), and the distance between the second parallel extension portion 39 and either the first current path 42 or the second current path 43, which is closer to the second parallel extension portion 39, is defined as a third distance D3 (see FIG. 3). Both the second distance D2 and the third distance D3 are greater than the first distance D1. This reduces the distance (first distance D1) between the first current path 42 and the second current path 43, thereby preventing the magnetic flux loops generated around the first current path 42 and the magnetic flux loops generated around the second current path 43 from canceling each other out. Furthermore, since both the second distance D2 and the third distance D3 can be ensured to be large, the magnetic flux loops generated around each of the first parallel extension portion 34 and the second parallel extension portion 39 and the magnetic flux loops generated around each of the first current path 42 and the second current path 43 can enhance each other's magnetic fluxes. Therefore, the inductance of the coil device 100 can be further improved. 3 , of the first current path 42 and the second current path 43, the first current path 42 is disposed on the right side, and the first parallel extension portion 34 is disposed on the right side of the first current path 42. Therefore, of the first current path 42 and the second current path 43, the one located closer to the first parallel extension portion 34 is the first current path 42. Therefore, the first current path 42 and the first parallel extension portion 34 are arranged in the left-right direction, and the second distance D2 is the separation distance between the first current path 42 and the first parallel extension portion 34 in the left-right direction. Furthermore, of the first current path 42 and the second current path 43, the second current path 43 is disposed on the left side, and the second return current path 36 is disposed on the left side of the second current path 43. Therefore, of the first current path 42 and the second current path 43, the one located closer to the second parallel extension portion 39 is the second current path 43. Therefore, the second current path 43 and the second parallel extension portion 39 are arranged in the left-right direction, and the third distance D3 is the separation distance between the second current path 43 and the second parallel extension portion 39 in the left-right direction.

[0039] The first distance D1 is preferably, for example, 20% to 200% of the dimension X shown in FIG. The second distance D2 is preferably, for example, 20% or more and 200% or less of the dimension X shown in FIG. The third distance D3 is preferably, for example, 20% to 200% of the dimension X shown in FIG.

[0040] Second Embodiment Next, a second embodiment will be described with reference to FIGS. The coil component 100 according to this embodiment differs from the coil component 100 according to the first embodiment in the points described below, but is otherwise configured similarly to the coil component 100 according to the first embodiment. Note that in Fig. 8, the core molded body 10 is indicated by a two-dot chain line for convenience.

[0041] In this embodiment, as shown in Figures 8, 9(a) and 9(b), the coil device 100 includes a second conductive member 72 and a third conductive member 30 having a first return current path 31 and a fourth conductive member 80 having a second return current path 36 as conductive members separate from the second conductive member 72. This configuration also improves the inductance.

[0042] 9(a) and 9(b), in plan view, the third conductive member 30 is formed, for example, in a substantially semi-annular shape that protrudes toward the right, and includes a pair of front and rear opposing portions and a connecting portion that interconnects the pair of front and rear opposing portions. The left end of the front opposing portion of the pair of front and rear opposing portions constitutes a first one end 32 of the first return current path 31, and the left end of the rear opposing portion of the pair of front and rear opposing portions constitutes a first other end 33 of the first return current path 31. The connecting portion of the third conductive member 30 constitutes a first parallel extending portion 34 of the first return current path 31. The pair of front and rear facing portions extend in the left-right direction and face each other in parallel. The first parallel extending portion 34 extends in the front-rear direction and is disposed horizontally. The left-right dimension of the rear opposing portion is set to be larger than the left-right dimension of the front opposing portion, for example, and the rear opposing portion (left end portion) protrudes further to the left than the tip end (left end portion) of the front opposing portion.

[0043] The fourth conductive member 80 is set to have, for example, the same shape and dimensions as the third conductive member 30, and is arranged in a front-to-back and left-to-right inverted orientation. Thus, like the third conductive member 30, the fourth conductive member 80 includes a pair of front and rear opposing portions and a connecting portion. The right end of the front opposing portion of the pair of front and rear opposing portions constitutes a second one end 37 of the second return current path 36, and the right end of the rear opposing portion of the pair of front and rear opposing portions constitutes a second other end 38 of the second return current path 36. The connecting portion of the fourth conductive member 80 constitutes a second parallel extending portion 39 of the second return current path 36. The left-right dimension of the front facing portion is set to be larger than the left-right dimension of the rear facing portion, for example, and the leading end (right end) of the front facing portion protrudes further right than the leading end (left end) of the rear facing portion.

[0044] As shown in Figures 8 and 10, the third conductive member 30 having the first return current path 31 is arranged, for example, below each of the first current path 42 and the second current path 43, and the fourth conductive member 80 having the second return current path 36 is arranged, for example, above each of the first current path 42 and the second current path 43. More specifically, in this embodiment, the entire upper surface and the entire lower surface of the end 42b (branch portion 44) of the first current path 42 are regions where no insulating film is formed. 9(a), 9(b), and 10, for example, the upper surface of the first end 32 of the first return current path 31 is in surface contact with the lower surface of the end 42b of the first current path 42, and the lower surface of the second end 37 of the second return current path 36 is in surface contact with the upper surface of the end 42b. As a result, the first return current path 31 and the second return current path 36 are each electrically connected to the branch portion 44, and are also electrically connected to each other via the branch portion 44. Similarly, in this embodiment, the upper and lower surfaces of the end 43a (junction 45) of the second current path 43 are regions where no insulating film is formed. 9(a), 9(b), and 10, for example, the upper surface of the first other end 33 of the first return current path 31 is in surface contact with the lower surface of the end 43a of the second current path 43, and the lower surface of the second other end 38 of the second return current path 36 is in surface contact with the upper surface of the end 43a. As a result, the first return current path 31 and the second return current path 36 are each electrically connected to the junction 45, and are also electrically connected to each other via the junction 45.

[0045] Third Embodiment Next, a third embodiment will be described with reference to FIGS. 11 to 14(d). The coil component 100 of this embodiment differs from the coil component 100 of the first embodiment described above in the points described below, but is otherwise configured in the same way as the coil component 100 of the first embodiment described above.

[0046] In this embodiment, the coil device 100 further includes a third return current path 91 and a fourth return current path 96 branching off from the branch portion 44 . The third return current path 91 has a third end portion 92 at the branch portion 44. The third return current path 91 extends from the third end portion 92 toward a third other end portion 93 located near the end portion 43b of the first current path 42 on the first mounting terminal portion 51 side, and is electrically connected to the junction portion 45 at the third other end portion 93. Similarly, the fourth return current path 96 has a fourth end portion 97 at the branch portion 44. The fourth return current path 96 extends from the fourth end portion 97 toward a fourth other end portion 98 located near the end portion 43b of the first current path 42 on the first mounting terminal portion 51 side, and is electrically connected to the junction portion 45 at the fourth other end portion 98. Even with this configuration, the number of turns of the current path of the coil device 100 can be ensured to be sufficient, and the inductance of the coil device 100 can be further improved.

[0047] In this embodiment, the coil device 100 does not include the third conductive member 30. Instead, the first conductive member 71 further includes a first return current path 31 and a second return current path 36 in addition to the first current path 42, the first outer surface arrangement portion 46, and the first mounting terminal portion 51. In other words, the first current path 42, the first outer surface arrangement portion 46, the first mounting terminal portion 51, the first return current path 31, and the second return current path 36 are integrally molded with one another. This allows the number of members constituting the coil device 100 to be reduced, thereby improving ease of manufacturing the coil device 100.

[0048] In this embodiment, the first conductive member 71 is made of a copper plate, and the first current path 42, the first outer surface arrangement portion 46, and the first mounting terminal portion 51 are formed by bending the copper plate. Also, as shown in Figures 14(a) and 14(b), the first conductive member 71 has, for example, in addition to a first portion 71a constituting the first current path 42, a second portion 71b constituting the first return current path 31 and a third portion 71c constituting the second return current path 36. The second portion 71b and the third portion 71c are formed, for example, in bilaterally symmetrical shapes. More specifically, in a plan view, the second portion 71b is formed, for example, in a substantially semi-annular shape that is convex toward the left, and the third portion 71c is formed, for example, in a substantially semi-annular shape that is convex toward the right. Each of the second part 71b and the third part 71c includes, for example, a pair of front and rear opposing portions extending in the left-right direction, and a connecting portion that connects the pair of front and rear opposing portions and extends in the front-to-rear direction.

[0049] 14(a), as an example, the left end of the facing portion on the front side of the second portion 71b constitutes the first one end 32 of the first return current path 31, the left end of the facing portion on the rear side of the second portion 71b constitutes the first other end 33 of the first return current path 31, and the connecting portion of the second portion 71b constitutes the first parallel extension 34 of the first return current path 31. Similarly, as an example, the right end of the facing portion on the front side of the third portion 71c constitutes the second one end 37 of the second return current path 36, the right end of the facing portion on the rear side of the third portion 71c constitutes the second other end 38 of the second return current path 36, and the connecting portion of the third portion 71c constitutes the second parallel extension 39 of the second return current path 36. The first one end 32 (the facing portion on the front side of the second portion 71b) of the first return current path 31 is directly connected to the right end of the end 42b (branch portion 44) of the first current path 42, and the second one end 37 (the facing portion on the front side of the third portion 71c) of the second return current path 36 is directly connected to the left end of the end 42b. On the other hand, the first other end 33 (the facing portion on the rear side of the second portion 72b) of the first return current path 31 is slightly spaced apart from the right end of the end 42a of the first current path 42 on the first mounting terminal portion 51 side, and the second other end 38 (the facing portion on the rear side of the third portion 72c) of the second return current path 36 is slightly spaced apart from the left end of the end 42a. 14(b), the first current path 42 (first portion 71a), the first return current path 31 (second portion 71b), and the second return current path 36 (third portion 71c) are disposed at substantially the same height. The first current path 42, the first return current path 31, and the second return current path 36 are set to have substantially the same thickness.

[0050] Similarly, in this embodiment, the second conductive member 72 further includes a third return current path 91 and a fourth return current path 96, in addition to the second current path 43, the second outer surface arrangement portion 47, and the second mounting terminal portion 55. In other words, the second current path 43, the second outer surface arrangement portion 47, the second mounting terminal portion 55, the third return current path 91, and the fourth return current path 96 are integrally formed with one another. Similarly to the first conductive member 71, the second conductive member 72 is made of, for example, a copper plate, and the second current path 43, the second outer surface arrangement portion 47, and the second mounting terminal portion 55 are formed by bending the copper plate. As shown in Figures 14(c) and 14(d), the second conductive member 72 is set to, for example, the same shape and dimensions as the first conductive member 71, and is arranged in a posture that is inverted front to back and left to right. More specifically, the second conductive member 72 has, for example, a first portion 72a constituting the second current path 43, a second portion 72b constituting the third return current path 91, and a third portion 72c constituting the fourth return current path 96. Similarly to the second portion 71b and the third portion 71c of the first conductive member 71, each of the second portion 72b and the third portion 72c includes a pair of front and rear opposing portions extending in the left-right direction and a connecting portion connecting the pair of front and rear opposing portions and extending in the front-rear direction. As an example, the left end of the facing portion on the front side of the second portion 72b constitutes a third one end portion 92 of a third return current path 91, the left end of the facing portion on the rear side of the second portion 72b constitutes a third other end portion 93 of the third return current path 91, and the connecting portion of the second portion 72b constitutes a third parallel extension portion 94 of the third return current path 91. Similarly, as an example, the right end of the facing portion on the front side of the third portion 72c constitutes a fourth one end portion 97 of a fourth return current path 96, the right end of the facing portion on the rear side of the third portion 72c constitutes a fourth other end portion 98 of the fourth return current path 96, and the connecting portion of the third portion 72c constitutes a fourth parallel extension portion 99 of the fourth return current path 96. A third other end 93 (a portion facing the rear of the second portion 72b) of the third return current path 91 is directly connected to the right end of the end 43a (junction 45) of the second current path 43 on the first mounting terminal 51 side, and a fourth other end 98 (a portion facing the rear of the third portion 72c) of the fourth return current path 96 is directly connected to the left end of the end 43a. On the other hand, a third one end 92 (a portion facing the front of the second portion 72b) of the third return current path 91 is slightly spaced apart from the right end of the end 43b of the second current path 43 opposite the first mounting terminal 51 side, and a fourth one end 97 (a portion facing the front of the third portion 72c) of the fourth return current path 96 is slightly spaced apart from the right end of the end 43b. 14(d), the second current path 43, the third return current path 91, and the fourth return current path 96 are disposed at substantially the same height. In addition, the second current path 43, the third return current path 91, and the fourth return current path 96 are set to have substantially the same thickness. In addition, in this embodiment, the left and right width dimensions of the first current path 42 (first portion 71a) are set to dimensions equivalent to the left and right width dimensions of the first external surface arrangement portion 46 and the first mounting terminal portion 51, and the left and right width dimensions of the second current path 43 (first portion 72a) are set to dimensions equivalent to the left and right width dimensions of the second external surface arrangement portion 47 and the second mounting terminal portion 55.

[0051] Here, the third return current path 91 includes, for example, a third parallel extension portion 94 that extends in parallel to the first current path 42 and the second current path 43. Similarly, the fourth return current path 96 includes, for example, a fourth parallel extension portion 99 that extends in parallel to the first current path 42 and the second current path 43 . This allows the magnetic flux loops generated around each of the third parallel extension portion 94 and the fourth parallel extension portion 99 and the magnetic flux loops generated around each of the first current path 42 and the second current path 43 to flow in directions that enhance each other's magnetic flux. 13(a) and 13(b), the third parallel extending portion 94 is formed, for example, by the connecting portion of the second portion 72b of the second conductive member 72, and the fourth parallel extending portion 99 is formed, for example, by the connecting portion of the third portion 72c of the second conductive member 72. Therefore, the third parallel extending portion 94 and the fourth parallel extending portion 99 each extend in the front-rear direction and are arranged parallel to each other. Here, "parallel" does not necessarily mean parallel, and the third parallel extension portion 94 and the fourth parallel extension portion 99 may extend in a direction intersecting the first current path 42 and the second current path 43. In this case, for example, the angle formed between the third parallel extension portion 94 and the fourth parallel extension portion 99 and the first current path 42 and the second current path 43 is less than 45 degrees. Furthermore, the third parallel extension portion 94 and the fourth parallel extension portion 99 and the first current path 42 and the second current path 43 may be disposed on the same plane or may be twisted. When the third parallel extension portion 94 and the fourth parallel extension portion 99 and the first current path 42 and the second current path 43 are twisted, the maximum angle formed between the third parallel extension portion 94 and the fourth parallel extension portion 99 and the first current path 42 and the second current path 43 is less than 45 degrees when viewed from any direction.

[0052] In the present embodiment, similarly to the first and second embodiments, the thickness of each of the first conductive member 71 and the second conductive member 72 is, for example, substantially uniform throughout and is equal to one another. Therefore, the first current path 42, the second current path 43, and the first return current path 31 to the fourth return current path 96 are set to have equal thicknesses. 14(a), the left-right width dimension of the first current path 42 is set to be larger than, for example, the width dimension (dimension in the horizontal direction and perpendicular to the extension direction) of the first return current path 31 and the width dimension (ditto) of the second return current path 36. Similarly, as shown in FIG. 14(b), the left-right width dimension of the second current path 43 is set to be larger than, for example, the width dimension (dimension in the horizontal direction and perpendicular to the extension direction) of the third return current path 91 and the width dimension (ditto) of the fourth return current path 96. This allows the DC resistance of the current path of the coil device 100 to be reduced. In addition, in the present embodiment, as an example, the left-right width dimension of each of the first return current path 31 to the fourth return current path 96 is set to about half the left-right width dimension of each of the first current path 42 and the second current path 43. In other words, since there are four return current paths, each having a cross-sectional area that is about half the cross-sectional area of ​​each of the first current path 42 and the second current path 43, the overall cross-sectional area of ​​the return current paths can be double the cross-sectional area of ​​each of the first current path 42 and the second current path 43. Therefore, the DC resistance in the current paths of the coil device 100 can be further reduced.

[0053] As shown in FIGS. 11 and 12, in this embodiment, the first conductive member 71 and the second conductive member 72 are stacked one on top of the other. More specifically, the second current path 43 is disposed, for example, overlapping the first current path 42. Therefore, in the present embodiment, the first current path 42 and the second current path 43 are arranged in the vertical direction. Furthermore, the third return current path 91 is disposed overlapping the first return current path 31, and the fourth return current path 96 is disposed overlapping the second return current path 36. Here, the entire upper surface 32a of the left end of the first end portion 32 and the entire upper surface 37a of the right end of the second end portion 37 are regions where no insulating film is formed. Also, the entire lower surface 92a of the right end of the third end portion 92 and the entire lower surface 97a of the left end of the fourth end portion 97 are regions where no insulating film is formed. The upper surface 32a of the right end of the first end portion 32 is in surface contact with the lower surface 92a of the right end of the third end portion 92, and the upper surface 37a of the left end of the second end portion 37 is in surface contact with the lower surface 97a of the left end of the fourth end portion 97. Similarly, the entire upper surface 33a of the right end of the first other end 33 and the entire upper surface 38a of the left end of the second other end 38 are each an area where no insulating film is formed. Furthermore, the entire lower surface 93a of the right end of the third other end 93 and the entire lower surface 98a of the left end of the fourth other end 98 are each an area where no insulating film is formed. The upper surface 33a of the right end of the first other end 33 is in surface contact with the lower surface 93a of the right end of the third other end 93, and the upper surface 38a of the left end of the second other end 38 is in surface contact with the lower surface 98a of the left end of the fourth other end 98. As a result, near the branching point 44 and near the confluence point 45, the first return current path 31 and the third return current path 91 (and thus the fourth return current path 96) are electrically connected to each other, and the second return current path 36 and the fourth return current path 96 (and thus the third return current path 91) are electrically connected to each other. In this embodiment, the first conductive member 71 and the second conductive member 72 may be joined together, for example, via a conductive bonding agent, or by resistance welding.

[0054] In the present embodiment, a portion of the current that flows from the first mounting terminal portion 51 through the first current path 42 and into the branch portion 44 branches into the first return current path 31 and the third return current path 91 via the upper surface 33a of the first other end portion 33 and the lower surface 93a of the third other end portion 93. The current that branches into the first return current path 31 and the current that branches into the third return current path 91 flow toward the junction portion 45 via the upper surface 33a of the first other end portion 33 and the lower surface 93a of the third other end portion 93, and merges at the junction portion 45. Similarly, the rest of the current that flows from the first mounting terminal 51 through the first current path 42 and into the branch portion 44 branches into the second return current path 36 and the fourth return current path 96 via the upper surface 37a of the second end portion 37 and the lower surface 97a of the fourth end portion 97, respectively. The current that branches into the second return current path 36 and the current that branches into the fourth return current path 96 flow toward the junction 45 via the upper surface 38a of the second other end portion 38 and the lower surface 98a of the fourth other end portion 98, and merge at the junction 45. The current that flows into the junction 45 then passes through the second current path 43 and the second outer surface arrangement portion 47, in this order, and flows to the second mounting terminal 55.

[0055] Here, the distance between the first current path 42 and the second current path 43 is the first distance, the distance between the first current path 42 or the second current path 43 that is located closer to the third parallel extension portion 94 and the third parallel extension portion 94 is the fourth distance, and the distance between the first current path 42 or the second current path 43 that is located closer to the fourth parallel extension portion 99 and the fourth parallel extension portion 99 is the fifth distance. In the present embodiment, as shown in FIGS. 13(a) and 13(b), both the fourth distance and the fifth distance are greater than the first distance. This makes it possible to ensure that both the fourth distance and the fifth distance are large, so that the magnetic flux loops generated around each of the third parallel extension portion 94 and the fourth parallel extension portion 99 and the magnetic flux loops generated around each of the first current path 42 and the second current path 43 can mutually enhance their magnetic fluxes, thereby further improving the inductance of the coil device 100.

[0056] More specifically, in this embodiment, the first current path 42 and the second current path 43 are arranged in the vertical direction, and the first current path 42 and the second current path 43 are entirely overlapped with each other. Therefore, the distance (first distance) between the first current path 42 and the second current path 43 is substantially equal to zero. This more reliably prevents the magnetic flux loop generated around the first current path 42 and the magnetic flux loop generated around the second current path 43 from being oriented in directions that cancel each other out. Furthermore, in the present embodiment, of the first current path 42 and the second current path 43, the first current path 42 is disposed on the right side, and the third parallel extension portion 94 is disposed on the right side of the first current path 42. Therefore, of the first current path 42 and the second current path 43, the one located closer to the third parallel extension portion 94 is the first current path 42. Therefore, the first current path 42 and the third parallel extension portion 94 are arranged in the left-right direction, and the third distance is the separation distance between the first current path 42 and the third parallel extension portion 94 in the left-right direction. Furthermore, of the first current path 42 and the second current path 43, the second current path 43 is disposed on the left side, and the second return current path 36 is disposed on the left side of the second current path 43. Therefore, of the first current path 42 and the second current path 43, the one located closer to the fourth parallel extension portion 99 is the second current path 43. Therefore, the arrangement direction of the second current path 43 and the fourth parallel extension portion 99 is the left-right direction, and the fourth distance is the separation distance between the second current path 43 and the fourth parallel extension portion 99 in the left-right direction.

[0057] Furthermore, as shown in FIGS. 13(a) and 13(b), in this embodiment, the entire first return current path 31 and the entire third return current path 91 overlap each other. More specifically, the entire first parallel extension portion 34 and the entire third parallel extension portion 94 overlap each other. As described above, the first parallel extension portion 34 and the third parallel extension portion 94 each extend in the front-rear direction. That is, the extension direction of the first parallel extension portion 34 and the extension direction of the third parallel extension portion 94 are the same, and the first parallel extension portion 34 and the third parallel extension portion 94 extend parallel to each other. The first parallel extension portion 34 and the third parallel extension portion 94 are arranged in the up-down direction, and the distance between the first parallel extension portion 34 and the third parallel extension portion 94 is, for example, substantially equal to zero. The current flowing through the first parallel extension portion 34 and the current flowing through the third parallel extension portion 94 are configured to flow in the same direction. This results in a large magnetic flux loop being formed around the first return current path 31 and the third return current path 91. Similarly, the entire second return current path 36 and the entire fourth return current path 96 overlap each other. More specifically, the second parallel extension portion 39 and the fourth parallel extension portion 99 extend parallel to each other, the second parallel extension portion 39 and the fourth parallel extension portion 99 are arranged in the vertical direction, and the distance between the second parallel extension portion 39 and the fourth parallel extension portion 99 is, for example, substantially equal to zero. The current flowing through the second parallel extension portion 39 and the current flowing through the fourth parallel extension portion 99 are configured to flow in the same direction. As a result, a large magnetic flux loop is formed around the second parallel extension portion 39 and the fourth parallel extension portion 99. In this way, the inductance of the coil device 100 can also be improved according to this embodiment.

[0058] In this embodiment, the combination of the first return current path 31 and the second return current path 36, and the combination of the third return current path 91 and the fourth return current path 96 are not limited to the above examples. For example, any two of the second portion 71b and the third portion 71c of the first conductive member 71 and the second portion 72b and the third portion 72c of the second conductive member 72 can be the first return current path 31 and the second return current path 36. Any remaining two of the second portion 71b to the third portion 72c can be the third return current path 91 and the fourth return current path 96. Furthermore, in the above, an example has been described in which the coil device 100 has four return current paths, namely, the first return current path 31 to the third return current path 91, but the present invention is not limited to this example, and the number of return current paths provided in the coil device 100 may be, for example, two or three.

[0059] [Fourth embodiment] Next, a fourth embodiment will be described with reference to FIGS. The coil component 100 according to this embodiment differs from the coil components 100 according to the first to third embodiments in the points described below, but is otherwise configured in the same manner as the coil components 100 according to the first to third embodiments.

[0060] In this embodiment, the core molded body 10 includes a first molded body 11 and a second molded body 21 combined with each other. As shown in Figures 15 and 16, a first current path 42, a second current path 43, a first return current path 31, and a second return current path 36 are arranged between the first molded body 11 and the second molded body 21. According to this configuration, the core molded body 10 is divided into two parts, which can improve the structural strength of the individual core molded bodies (the first molded body 11 and the second molded body 21). Therefore, even if ferrite or a metallic magnetic material is used as the material for the core molded body 10, the structural strength of the individual core molded bodies (the first molded body 11 and the second molded body 21) can be sufficiently ensured. Therefore, the manufacturing cost of the coil component 100 can be reduced. Furthermore, the ease of manufacturing the coil component 100 can be improved.

[0061] More specifically, as shown in FIG. 16, the core molding body 10 is formed by, for example, stacking and assembling two upper and lower components, namely, a lower first molding body 11 and an upper second molding body 21. The first molded body 11 is formed in the shape of a flat rectangular parallelepiped whose top-to-bottom dimension is smaller than both its left-to-right and front-to-rear dimensions. The first molded body 11 has a front surface 12 facing forward, a back surface 13 facing backward, a pair of left and right side surfaces 14 facing left and right, respectively, an upper surface 15 facing upward, and a lower surface 16 facing downward. The second molded body 21 is formed in a flat plate shape with its plate surface facing the up-down direction, and is formed in a substantially rectangular shape in a plan view. The second molded body 21 has a front end surface 22 facing forward, a rear end surface 23 facing rearward, a pair of left and right side end surfaces 24 facing left and right, respectively, a top surface 25 facing upward, and a bottom surface 26 facing downward.

[0062] The first compact 11 and the second compact 21 are each integrally molded from a magnetic material such as ferrite, for example. However, the first compact 11 and the second compact 21 may each be made from a metallic magnetic material, for example. In this embodiment, the left-right width dimension of the first molded body 11 is slightly smaller than the left-right width dimension of the second molded body 21, and the front-rear width dimension of the first molded body 11 is slightly smaller than the front-rear width dimension of the second molded body 21. In addition, the up-down dimension of the first molded body 11 is, for example, larger than the up-down dimension of the second molded body 21.

[0063] As shown in FIG. 16, a groove 18a is formed on the surface of the first compact 11 facing the second compact 21. More specifically, the upper surface 15 of the first molded body 11 is provided with a groove portion 18a recessed downward, the front surface 12 is provided with a recess 19b recessed inward (rearward), the back surface 13 is provided with a recess 19b recessed inward (rearward), and the lower surface 16 is provided with a second groove portion 18b recessed upward. The groove 18a is formed from the front end to the rear end of the upper surface 15 of the first molded body 11. The groove 18a extends linearly in the front-to-rear direction and is recessed downward. The groove 18a is formed to a uniform depth overall, and the bottom surface of the groove 18a is generally flat and horizontal. The second groove portion 18b is formed, for example, from the front end to the rear end of the lower surface 16 of the first molded body 11. The second groove portion 18b extends linearly in the front-rear direction and is recessed upward. The groove portion 18a and the second groove portion 18b are disposed at positions equivalent to each other in the left-right direction. More specifically, as an example, the groove portion 18a is disposed at the center of the upper surface 15 of the first molded body 11 in the left-right direction, and the second groove portion 18b is disposed at the center of the lower surface 16 of the first molded body 11 in the left-right direction. The depth (dimension in the front-to-rear direction) of each recess 19a, 19b is uniform overall. Therefore, the bottom surface of the front recess 19a is a vertical plane that is perpendicular to the Y direction and faces forward, and the bottom surface of the rear recess 19b is a vertical plane that is perpendicular to the Y direction and faces backward. The front recess 19a is formed from the front edge of the groove 18a to the front edge of the second groove 18b. Similarly, the rear recess 19b is formed from the rear edge of the groove 18a to the rear edge of the second groove 18b. Each of the recesses 19a and 19b is formed in a substantially rectangular shape when viewed from the front (or rear).

[0064] As shown in FIG. 16, a convex portion 28 that convexly faces the first compact 11 side is formed on the surface of the second compact 21 facing the first compact 11 side. More specifically, the protrusions 28 protrude downward from the lower surface 26 of the second molded body 21. The protrusions 28 are formed, for example, in a generally rectangular shape with rounded corners in a plan view. The lower surface of the protrusions 28, the bottom surface of the grooves 18a, are generally flat and horizontal. The protrusion 28 is set to have a size, for example, slightly smaller than the second molded body 21, and is disposed in the center of the lower surface 26 of the second molded body 21. The vertical dimension of the protrusion 28 is set to be smaller than the vertical dimension of the second molded body 21, for example.

[0065] In this embodiment, the first conductive member 71 and the second conductive member 72 are set to have the same shape and dimensions as those in the first and second embodiments, respectively. The first conductive member 71 has a first current path 42 (first portion 72a), a first outer surface arrangement portion 46, and a first mounting terminal portion 51. Similarly, the second conductive member 72 has a second current path 43 (first portion 72a), a second outer surface arrangement portion 47, and a second mounting terminal portion 55. The third conductive member 30 is, for example, a conductive ring member, similar to the first embodiment. Therefore, the third conductive member 30 (conductive ring member) has a pair of front and rear side portions, a pair of left and right side portions, and a gap portion 30a.

[0066] In this embodiment, the first current path 42 and the second current path 43 are arranged in the groove portion 18a. More specifically, the first portion 71a (first current path 42) of the first conductive member 71 and the first portion 72a (second current path 43) of the second conductive member 72 are housed in the groove portion 18a and are arranged horizontally along the bottom surface of the groove portion 18a. The first outer surface portion 46 of the first conductive member 71 is disposed vertically along the bottom surface of the front recess 19b, and preferably the entire first outer surface portion 46 is housed in the front recess 19b. The first mounting terminal portion 51 of the first conductive member 71 is disposed horizontally along the bottom surface of the second groove portion 18b. The second outer surface portion 47 of the second conductive member 72 is disposed vertically along the bottom surface 31a of the rear recess 19b, and preferably the entire second outer surface portion 47 is housed in the rear recess 19b. The second mounting terminal portion 55 of the second conductive member 72 is disposed horizontally along the bottom surface of the second groove portion 18b.

[0067] In the present embodiment, the left-right width dimension of the groove portion 18a is set to, for example, approximately equal to or slightly larger than the sum of the left-right width dimensions of the first current path 42 and the second current path 43. Similarly, the left-right width dimension of the second groove portion 18b is set to, for example, approximately equal to or slightly larger than the sum of the left-right width dimensions of the first current path 42 and the second current path 43. The left-right width of each of the recesses 19a, 19b is set to be, for example, approximately equal to or larger than the left-right width of each of the first outer surface arrangement portion 46 and the second outer surface arrangement portion 47.

[0068] Furthermore, in this embodiment, as shown in FIG. 15, a protrusion 28 is inserted into a gap 30a in the center of the conductive ring member (third conductive member 30). This allows the second molded body 21 and the third conductive member 30 to be easily assembled together. More specifically, in a plan view, the outer shape of the protrusion 28 is set to, for example, substantially the same shape and dimensions as the outer shape of the gap 30a of the conductive ring member (the inner shape of the conductive ring member). Therefore, the protrusion 28 fits well into the conductive ring member. Furthermore, the lower surface of the protrusion 28 is in surface contact with, for example, the upper surface 15 of the first molded body 11.

[0069] As shown in Figures 15 and 16, the first molded body 11 and the second molded body 21 are fixed to each other, for example, with the first current path 42, the second current path 43, and the third conductive member 30 (conductive ring member) sandwiched between them. The method for fixing the first molded body 11 and the second molded body 21 to each other is not particularly limited, and for example, they may be fixed (surface-bonded) by interposing either or both of an adhesive tape (not shown) and an adhesive (not shown) between the surface of the first molded body 11 facing the second molded body 21 and the surface of the second molded body 21 facing the first molded body 11, or they may be fixed by wrapping a fixing tape (not shown) around the outer periphery of each of the first molded body 11 and the second molded body 21.

[0070] Although the embodiments have been described above with reference to the drawings, these are merely examples of the present invention and include various modifications and improvements as long as the object of the present invention is achieved.

[0071] For example, although the above describes an example in which the first mounting terminal portion 51 and the first current path 42 are each formed by a part of a single member (first conductive member 71), the present invention is not limited to this example, and the first mounting terminal portion 51 may be formed by a member separate from the first current path 42 and may be indirectly or directly electrically (and mechanically) connected to the first current path 42. Similarly, the above describes an example in which the second mounting terminal portion 55 and the second current path 43 are each formed by a part of a single member (second conductive member 72), but the present invention is not limited to this example, and the second mounting terminal portion 55 may be formed by a member separate from the second current path 43 and may be indirectly or directly electrically (and mechanically) connected to the second current path 43.

[0072] Furthermore, in the above, an example has been described in which current flows from the first mounting terminal portion 51 through the first current path 42 and the second current path 43 to the second mounting terminal portion 55, but the present invention is not limited to this example, and for example, the current may be applied to the second mounting terminal portion 55 and configured to flow toward the first mounting terminal portion 51.

[0073] In addition, in the fourth embodiment, an example was described in which the groove portion 18a accommodating the first current path 42 and the second current path 43 is selectively formed in the first molded body 11 out of the first molded body 11 and the second molded body 21, but the groove portion 18a may be formed on the lower surface 26 of the second molded body 21, or may be formed on both the upper surface 15 of the first molded body 11 and the lower surface 26 of the second molded body 21.

[0074] Furthermore, for example, in the above description, an example has been described in which the coil device 100 has both the first return current path 31 and the second return current path 36, but the present invention is not limited to this example, and as shown in Figures 17 to 21, the number of return current flow paths provided in the coil device 100 may be one. That is, the present invention may be a coil component having a core molding 10 formed from a magnetic material, a first mounting terminal portion 51, a first current path 42 connected to the first mounting terminal portion 51, a second mounting terminal portion 55, a second current path 43 connected to the second mounting terminal portion 55 and extending in parallel to the first current path 42, and a return current path 110 connecting an end portion 42b of the first current path 42 opposite the first mounting terminal portion 51 side and an end portion 43a of the second current path 43 on the first mounting terminal portion side. Even with this configuration, it is possible to realize the coil component 100 having a structure that can improve inductance. In this case, the return current path 110 includes a parallel extension portion 112 extending in parallel to the first current path 42 and the second current path 43, and if the distance between the first current path 42 and the second current path 43 is defined as a first distance, and the distance between the first current path 42 or the second current path 43, whichever is located closer to the parallel extension portion 112, and the parallel extension portion 112 is defined as a second distance, it is preferable that the second distance is greater than the first distance. By doing so, on the other hand, it is possible to ensure a larger second distance, and therefore the magnetic flux loop generated around the parallel extending portion 112 and the magnetic flux loops generated around each of the first current path 42 and the second current path 43 can mutually enhance their magnetic fluxes, thereby further improving the inductance of the coil device 100.

[0075] 17, 18(a), and 18(b), when the coil device 100 has one return current flow path, the third conductive member 30 is formed, for example, in a semi-annular shape in a plan view. As an example, the third conductive member 30 is disposed horizontally, and one end of the approximately semi-annular third conductive member 30 is disposed on the upper surface of the end 42b (branch portion 44) of the first current path 42, and the other end of the third conductive member 30 is disposed on the upper surface of the end 43a (junction 45) of the second current path 43. Alternatively, as shown in FIGS. 19 to 21 , the third conductive member 30 is formed, for example, in a substantially semi-annular shape in a side view. As an example, the third conductive member 30 is disposed vertically. In this case, as shown in FIG. 21 , the first current path 42 is bent, for example, so that the end 42 b (branch portion 44) stands upright, and the second current path 43 is bent, for example, so that the end 43 a (junction portion 45) stands upright. One end of the substantially semi-annular third conductive member 30 is in surface contact with the front surface of the end 42 a of the first current path 42, and the other end of the third conductive member 30 is in surface contact with the rear surface of the end 43 a of the second current path 43. Furthermore, as shown in FIGS. 20( a) and 20(b), the third conductive member 30 is inclined, for example, to the right from the branch portion 44 toward the junction 45 in a plan view.

[0076] The present embodiment encompasses the following technical ideas. (1) a core molded body formed of a magnetic material; a first mounting terminal portion; a first current path connected to the first mounting terminal portion; A second mounting terminal portion; a second current path connected to the second mounting terminal portion and extending in parallel to the first current path; a first return current path and a second return current path branching from a branch portion that is an end portion of the first current path opposite to the first mounting terminal portion; and the first return current path has a first end at the branch portion, extends from the first end toward a first other end located near an end of the first current path on the first mounting terminal portion side, and is electrically connected at the first other end to a junction portion that is an end of the second current path on the first mounting terminal portion side; The second return current path has a second end at the branch portion, extends from the second end toward a second other end located near the end of the first current path on the first mounting terminal portion side, and is a coil component electrically connected to the junction at the second other end. (2) the first return current path includes a first parallel extension portion extending in parallel with the first current path and the second current path; the second return current path includes a second parallel extension portion extending in parallel to the first current path and the second current path; a distance between the first current path and the second current path is defined as a first distance; a distance between the first parallel extension portion and one of the first current path and the second current path that is located closer to the first parallel extension portion is defined as a second distance; When the distance between the second parallel extension portion and one of the first current path and the second current path that is located closer to the second parallel extension portion is defined as a third distance, The coil component according to (1), wherein both the second distance and the third distance are greater than the first distance. (3) The coil component according to (1) or (2), wherein the first current path and the second current path are adjacent to each other via an insulating film. (4) a first conductive member having the first mounting terminal portion and the first current path; a second conductive member having the second mounting terminal portion and the second current path; The coil component according to any one of (1) to (3), comprising: (5) The coil component according to (4), wherein the first return current path and the second return current path are formed by conductive members different from the first conductive member and the second conductive member. (6) The coil component according to (5), further comprising a third conductive member having the first return current path and the second return current path as the other conductive member. (7) The coil component according to (6), wherein the third conductive member is a conductive ring member formed in a ring shape. (8) the first current path and the second current path are arranged side by side; The coil component according to (7), wherein the conductive ring member is disposed on top of the first current path and the second current path. (9) The coil component according to (5), wherein the other conductive members include a third conductive member having the first return current path and a fourth conductive member having the second return current path. (10) The coil component according to any one of (4) to (9), wherein each of the first conductive member and the second conductive member is made of a rectangular wire. (11) The power supply further includes a third return current path and a fourth return current path branching from the branch portion, the third return current path has a third one end at the branch portion, extends from the third one end toward a third other end located near an end of the first current path on the first mounting terminal portion side, and is electrically connected to the junction portion at the third other end; The coil component according to any one of (1) to (4), wherein the fourth return current path has a fourth end at the branch portion, extends from the fourth end toward a fourth other end located near an end of the first current path on the first mounting terminal portion side, and is electrically connected to the junction at the fourth other end. (12) The third return current path includes a third parallel extension portion extending in parallel with the first current path and the second current path, the fourth return current path includes a fourth parallel extension portion extending in parallel with the first current path and the second current path; a distance between the first current path and the second current path is defined as a first distance; a distance between the third parallel extension portion and one of the first current path and the second current path that is located closer to the third parallel extension portion is defined as a fourth distance; When the distance between the fourth parallel extension portion and one of the first current path and the second current path that is located closer to the fourth parallel extension portion is defined as a fifth distance, The coil component according to (11), wherein both the fourth distance and the fifth distance are greater than the first distance. (13) The core compact is a composite magnetic body formed by compression molding a material containing a metal magnetic powder and a thermosetting resin, The coil component according to any one of (1) to (12), including the first current path, the second current path, the first return current path, and the second return current path. (14) The core molded body includes a first molded body and a second molded body combined with each other, A coil component according to any one of (1) to (12), wherein the first current path, the second current path, the first return current path, and the second return current path are arranged between the first molded body and the second molded body. (15) The core molded body includes a first molded body and a second molded body combined with each other, the first current path, the second current path, the first return current path, and the second return current path are disposed between the first molded body and the second molded body; a convex portion that is convex toward the first molded body is formed on a surface of the second molded body facing the first molded body, The coil component according to (7) or (8), wherein the protrusion is inserted into a gap in the center of the conductive ring member. (16) A coil component according to (14) or (15), wherein a groove is formed on the surface of the first compact facing the second compact, and the first current path and the second current path are arranged in the groove. <1> a core molded body formed of a magnetic material; a first mounting terminal portion; a first current path connected to the first mounting terminal portion; A second mounting terminal portion; a second current path connected to the second mounting terminal portion and extending in parallel to the first current path; a return current path that interconnects an end of the first current path opposite to the first mounting terminal portion and an end of the second current path on the first mounting terminal portion side; A coil component having: <2> the return current path includes a parallel extension portion extending in parallel with the first current path and the second current path, a distance between the first current path and the second current path is defined as a first distance; When the distance between the parallel extension portion and one of the first current path and the second current path that is located closer to the parallel extension portion is defined as a second distance, The second distance is greater than the first distance. <1> The coil component according to claim 1. [Explanation of symbols]

[0077] 10 Core molding 11 First core molding 12 Front 13 Back 14 Side 15 Top side 16 Bottom side 17 Recess 18a Groove 18b 2nd groove 19a, 19b recessed portion 21 Second core molding 22 Front 23 Back 24 Side 25 Top 26 Bottom side 28 Convex part 30 third conductive member 31 First return current path 32 First end 33 First other end 34 1st parallel extension part 36 Second return current path 37 Second one end 38 Second other end 39 Second parallel extension part 42 First current path 42a, 42b end 43 Second current path 43a, 42b end 44 Branch 45 Junction 46 1st outer surface arrangement part 47 Second outer surface arrangement part 51 First mounting terminal part 55 Second mounting terminal part 71 first conductive member 71a Part 1 71b Part 2 71c Part 3 72 second conductive member 72a Part 1 72b Part 2 72c Part 3 80 fourth conductive member 91 Third return current path 92 Third one end 93 Third other end 94 Third parallel extension part 96 4th return current path 97 4th one end 98 4th other end 99 4th parallel extension part 100 Coil parts

Claims

1. a core molded body formed of a magnetic material; a first mounting terminal portion; a first current path connected to the first mounting terminal portion; a second mounting terminal portion; a second current path connected to the second mounting terminal portion and extending in parallel to the first current path; a first return current path and a second return current path branching from a branch portion that is an end of the first current path on the opposite side from the first mounting terminal portion; and the first return current path has a first end at the branch portion, extends from the first end toward a first other end located near an end of the first current path on the first mounting terminal portion side, and is electrically connected at the first other end to a junction portion that is an end of the second current path on the first mounting terminal portion side; the second return current path has a second one end at the branch portion, extends from the second one end toward a second other end located near an end of the first current path on the first mounting terminal portion side, and is electrically connected to the junction portion at the second other end; the first current path and the second current path are arranged side by side; the first return current path includes a first parallel extending portion extending in parallel to the first current path and the second current path in an arrangement direction of the first current path and the second current path, the second return current path includes a second parallel extending portion extending in parallel to the first current path and the second current path in the arrangement direction; a separation distance between the first current path and the second current path in the arrangement direction is defined as a first distance; a second distance is a distance in the arrangement direction between the first parallel extension portion and one of the first current path and the second current path that is located closer to the first parallel extension portion, and When a distance in the arrangement direction between the second parallel extension portion and one of the first current path and the second current path that is located closer to the second parallel extension portion is defined as a third distance, The coil component, wherein both the second distance and the third distance are greater than the first distance.

2. The coil component according to claim 1 , wherein the first current path and the second current path are adjacent to each other with an insulating film interposed therebetween.

3. a first conductive member having the first mounting terminal portion and the first current path; a second conductive member having the second mounting terminal portion and the second current path; The coil component according to claim 1 or 2, comprising:

4. A core molded body formed of a magnetic material; a first mounting terminal portion; a first current path connected to the first mounting terminal portion; a second mounting terminal portion; a second current path connected to the second mounting terminal portion and extending in parallel to the first current path; a first return current path and a second return current path branching from a branch portion that is an end of the first current path on the opposite side from the first mounting terminal portion; a first conductive member having the first mounting terminal portion and the first current path; a second conductive member having the second mounting terminal portion and the second current path; and the first return current path has a first end at the branch portion, extends from the first end toward a first other end located near an end of the first current path on the first mounting terminal portion side, and is electrically connected at the first other end to a junction portion that is an end of the second current path on the first mounting terminal portion side; the second return current path has a second one end at the branch portion, extends from the second one end toward a second other end located near an end of the first current path on the first mounting terminal portion side, and is electrically connected to the junction portion at the second other end; The first return current path and the second return current path are formed by conductive members different from the first conductive member and the second conductive member.

5. The coil component according to claim 4 , further comprising, as the other conductive member, a third conductive member having the first return current path and the second return current path.

6. The coil component according to claim 5 , wherein the third conductive member is a conductive ring member formed in a ring shape.

7. the first current path and the second current path are arranged side by side; The coil component according to claim 6 , wherein the conductive ring member is disposed over the first current path and the second current path.

8. The coil component according to claim 4 , wherein the other conductive members include a third conductive member having the first return current path and a fourth conductive member having the second return current path.

9. The coil component according to claim 3 , wherein each of the first conductive member and the second conductive member is made of a rectangular wire.

10. A core molded body formed of a magnetic material; a first mounting terminal portion; a first current path connected to the first mounting terminal portion; a second mounting terminal portion; a second current path connected to the second mounting terminal portion and extending in parallel to the first current path; a first return current path and a second return current path branching from a branch portion that is an end of the first current path on the opposite side from the first mounting terminal portion; and the first return current path has a first end at the branch portion, extends from the first end toward a first other end located near an end of the first current path on the first mounting terminal portion side, and is electrically connected at the first other end to a junction portion that is an end of the second current path on the first mounting terminal portion side; the second return current path has a second one end at the branch portion, extends from the second one end toward a second other end located near an end of the first current path on the first mounting terminal portion side, and is electrically connected to the junction portion at the second other end; a third return current path and a fourth return current path branching from the branch portion; the third return current path has a third one end at the branch portion, extends from the third one end toward a third other end located near an end of the first current path on the first mounting terminal portion side, and is electrically connected to the junction portion at the third other end; The fourth return current path has a fourth end at the branch portion, extends from the fourth end toward a fourth other end located near the end of the first current path on the first mounting terminal portion side, and is a coil component that is electrically connected to the junction at the fourth other end.

11. the third return current path includes a third parallel extension portion extending in parallel with the first current path and the second current path; the fourth return current path includes a fourth parallel extension portion extending in parallel with the first current path and the second current path; a distance between the first current path and the second current path is defined as a first distance; a distance between the third parallel extension portion and one of the first current path and the second current path, which is located closer to the third parallel extension portion, is defined as a fourth distance; When the distance between the fourth parallel extension portion and one of the first current path and the second current path that is located closer to the fourth parallel extension portion is defined as a fifth distance, The coil component according to claim 10 , wherein both the fourth distance and the fifth distance are greater than the first distance.

12. the core compact is a composite magnetic body formed by compression molding a material containing a metal magnetic powder and a thermosetting resin, The coil component according to claim 1 , comprising the first current path, the second current path, the first return current path, and the second return current path.

13. The core molded body includes a first molded body and a second molded body combined with each other, A coil component according to any one of claims 1 to 11, wherein the first current path, the second current path, the first return current path, and the second return current path are arranged between the first molded body and the second molded body.

14. The core molded body includes a first molded body and a second molded body combined with each other, the first current path, the second current path, the first return current path, and the second return current path are disposed between the first molded body and the second molded body; a convex portion that is convex toward the first molded body is formed on a surface of the second molded body facing the first molded body, 8. The coil component according to claim 6, wherein the protrusion is inserted into a gap in the center of the conductive ring member.

15. The coil component according to claim 13 or 14, wherein a groove portion is formed on the surface of the first compact facing the second compact, and the first current path and the second current path are arranged in the groove portion.

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