Coil component

Abstract

Coil component (10) having the following features: a winding core part (11) with a central axis (CA); a first flange part (12) connected to a first end of the winding core part (11) in a direction along the central axis (CA); a second flange part (14) connected to a second end of the winding core part (11) located on an opposite side of the first end; a first terminal electrode (21) and a second terminal electrode (22) arranged on a surface of the first flange part (12); a third terminal electrode (23) and a fourth terminal electrode (24) arranged on a surface of the second flange part (14); a first wire (30) comprising a part extending in a spiral shape along a circumferential surface of the winding core part (11), the central axis (CA) serving as a rotation axis, the first wire (30) having a first end connected to the first terminal electrode (21) and a second end located on an opposite side of the first end connected to the third terminal electrode (23); and a second wire (40) comprising a part extending in a spiral shape outside the circumferential surface of the winding core part (11) in a radial direction centered on the central axis (CA), the central axis (CA) serving as a rotation axis, the second wire (40) having a first end connected to the second terminal electrode (22) and a second end located on an opposite side of the first end connected to the fourth terminal electrode (24), wherein the second wire (40) comprises an inner part (42) extending in a spiral shape continuously over a range of more than 360 degrees along the circumferential surface of the winding core part (11), and an outer part (41) extending in the radial direction in a spiral shape outside the inner part (42) and if, of the part of the first wire (30) wound around the winding core part (11), a first turn that is closest to the first end of the first wire (30) on a wire path of the first wire (30) is referred to as a first turn, and a last turn that is closest to the second end of the first wire (30) on the wire path of the first wire (30) is referred to as an M-th turn, wherein the outer part (41) consists of the part from the first turn to the (N-2)th turn and the inner part (42) consists of the part from the (N-1)th turn to the Nth turn of the second wire (40), and the (N-1)th turn and the Nth turn of the second wire (40) are arranged between the (M-1)th turn and the Mth turn of the first wire (30), wherein in the inner part, in a cross-section containing the central axis (CA), adjacent turns of the second wire (40) contact each other in a direction along the central axis (CA).

Description

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

[0002] A coil component disclosed in JP 2020-126976 A includes a winding core portion having a central axis and a first flange portion and a second flange portion. The winding core portion has a quadrangular columnar shape. The first flange portion is connected to a first end of the winding core portion. The second flange portion is connected to a second end of the winding core portion located on the opposite side of the first flange portion.

[0003] Furthermore, the coil component disclosed in JP 2020-126976 A has four terminal electrodes. A first terminal electrode and a second terminal electrode are arranged on a surface of the first flange part. A third terminal electrode and a fourth terminal electrode are arranged on a surface of the second flange part.

[0004] Furthermore, the coil component disclosed in JP 2020-126976 A includes a first wire and a second wire. A first end of the first wire is connected to the first terminal electrode. A second end of the first wire, located on the opposite side of the first wire from the first end, is connected to the third terminal electrode. A first end of the second wire is connected to the second terminal electrode. A second end of the second wire, located on the opposite side of the second wire from the first end, is connected to the fourth terminal electrode. The first wire and the second wire extend in a spiral shape outside the winding core in a radial direction centered on the central axis, with the central axis of the winding core as the rotation axis. Furthermore, most of the second wire is arranged outside the first wire in the radial direction.

[0005] In the coil component disclosed in JP 2020-126976 A, the second wire is arranged outside the first wire in the radial direction centered on the central axis. In other words, the second wire is farther away from the winding core portion than the first wire. Therefore, a leakage magnetic flux of the second wire is most likely to be larger than a leakage magnetic flux of the first wire. When the leakage magnetic flux of the second wire is large, the inductance value obtained by the second wire is smaller than the inductance value obtained by the first wire. As a result, the difference between the inductance value obtained by the first wire and the inductance value obtained by the second wire is increased.If the difference between the inductance values ​​obtained by the first wire and the second wire is large, it is possible that the characteristics of the coil component may be adversely affected.

[0006] DE 10 2013 114 352 A1, WO 2020 / 098 241 A1 and DE 10 2019 212 193 A1 each disclose a coil component.

[0007] The object of the present invention is to provide a coil component with improved characteristics.

[0008] The object is achieved by a coil component according to claim 1.

[0009] To solve this problem, one aspect of the present disclosure provides a coil component comprising: a winding core part having a central axis; a first flange part connected to a first end of the winding core part in a direction along the central axis; a second flange part connected to a second end of the winding core part located on an opposite side of the first end; a first terminal electrode and a second terminal electrode arranged on a surface of the first flange part; a third terminal electrode and a fourth terminal electrode arranged on a surface of the second flange part; a first wire including a part extending in a spiral shape along a circumferential surface of the winding core part, the central axis serving as a rotation axis, the first wire having a first end,which is connected to the first terminal electrode and a second end located on an opposite side of the first end connected to the third terminal electrode; and a second wire including a portion extending in a spiral shape outside the circumferential surface of the winding core portion in a radial direction centered on the central axis, the central axis serving as a rotation axis, the second wire having a first end connected to the second terminal electrode and a second end located on an opposite side of the first end connected to the fourth terminal electrode. The second wire includes an inner portion extending in a spiral shape continuously over a range of more than 360 degrees along the circumferential surface of the winding core portion, and an outer portion,which extends in a spiral shape outside the inner part in the radial direction. When, among the part of the first wire wound around the winding core part, a first turn located on a wire path of the first wire closest to the first end of the first wire is referred to as a first turn, and a last turn located on the wire path of the first wire closest to the second end of the first wire is referred to as the M-th turn, the outer part consists of the part from the first turn to the (N-2)th turn and the inner part consists of the part from the (N-1)th turn to the N-th turn of the second wire, and the (N-1)th turn and the N-th turn of the second wire are arranged between the (M-1)th turn and the M-th turn of the first wire, wherein in the inner part in a cross section including the central axis,adjacent turns of the second wire contact each other in a direction along the central axis.,

[0010] According to the above configuration, the second wire has an inner part. The inner part is closer to the winding core part than the outer part. Therefore, a leakage magnetic flux of the inner part is smaller than a leakage magnetic flux of the outer part. Thus, a reduction in the inductance value obtained by the second wire can be suppressed. As a result, the inductance value obtained by the second wire can be made larger than the inductance value if the second wire consisted only of the outer part.

[0011] Furthermore, the inner part is located between the (M-1)th turn and the (M)th turn of the first wire. Therefore, the (M-1)th turn and the (M)th turn of the first wire, between which the inner part is located, are separated by a distance corresponding to the size of the inner part. Thus, the inductance value obtained by the first wire is smaller because the leakage magnet of the first wire is larger.

[0012] Thus, the difference between the inductance value obtained by the first wire and the inductance value obtained by the second wire can be reduced by making the inductance value obtained by the first wire smaller and making the inductance value obtained by the second wire larger.

[0013] According to the aspect of the present disclosure, it is possible to suppress an increase in the difference between an inductance value obtained by a first wire and an inductance value obtained by a second wire.

[0014] Preferred embodiments of the present invention are explained in more detail below with reference to the accompanying drawings. They show: Fig. 1 a perspective view of a coil component; Fig. 2 a plan view of the coil component; Fig. 3 is a partial sectional view of the coil component taken along line 3-3 in Fig. 2; Fig. 4 is a partial sectional view of a coil component of a comparative example; Fig. 5 is a graph showing mode conversion characteristics of a coil component of an example and a coil component of a comparative example; Fig. 6 is a partial sectional view of a coil component of a modification; Fig. 7 is a partial sectional view of a coil component of a modification; Fig. 8 is a partial sectional view of a coil component of a modification; Fig. 9 a partial sectional view of a coil component of a modification. Coil component of an embodiment

[0015] A coil component according to an embodiment will be described below. In the drawings, components may be shown in an enlarged manner to facilitate understanding. The dimensional relationships of the component elements may differ from the actual relationships or from the relationships in other drawings. Furthermore, hatching is used in the sectional views, but the hatching of some component elements may be omitted to facilitate understanding. Overall configuration

[0016] As it is in Fig. As shown in Figure 1, a coil component 10 includes a winding core portion 11. The winding core portion 11 has a quadrangular columnar shape. Therefore, the winding core portion 11 has a central axis CA and extends in a direction along the central axis CA. Furthermore, the winding core portion 11 has a circumferential surface 11F surrounding the central axis CA.

[0017] It should be noted that in the following description, an axis extending in a direction along the central axis CA is referred to as a first axis X. Further, an axis perpendicular to the first axis X is referred to as a second axis Y, and an axis perpendicular to the first axis X and the second axis Y is referred to as a third axis Z. In a cross section of the winding core part 11 perpendicular to the central axis CA, an axis extending parallel to a certain side of the four sides forming the quadrangular shape is referred to as the second axis Y, and an axis in a direction perpendicular to both the central axis CA and the second axis Y is referred to as the third axis Z. A direction along the first axis X is referred to as a first positive direction X1, and the other direction extending along the first axis X is referred to as a first negative direction X2.Furthermore, a direction along the second axis Y is referred to as a second positive direction Y1, and the other direction extending along the second axis Y is referred to as a second negative direction Y2. Furthermore, a direction along the third axis Z is referred to as a third positive direction Z1, and the other direction extending along the third axis Z is referred to as a third negative direction Z2.

[0018] The coil component 10 includes a first flange part 12 and a second flange part 14. The first flange part 12 is connected to a first end of the winding core part 11, the first end being the end on the side of the first positive direction X1. The first flange part 12 protrudes outward from the circumferential surface 11F of the winding core part 11 in a radial direction centered on the central axis CA.

[0019] A recessed portion 13 is recessed on an end surface of the first flange part 12 located on the third positive direction Z1 side. The recessed portion 13 is located in a central part of the first flange part 12 in a direction along the second axis Y. The recessed portion 13 is recessed over the entire area of ​​the first flange part 12 in a direction along the first axis X. Therefore, the end portions of the first flange part 12 in a direction along the second axis Y are shaped as if the first flange part 12 has been partially divided into two pieces, with the recessed portion 13 interposed therebetween.

[0020] The second flange part 14 is connected to a second end of the winding core part 11, the second end being the end on the first negative direction X2 side. The second flange part 14 is shaped to be symmetrical with the first flange part 12 in a direction along the first axis X, with the winding core part 11 interposed therebetween. In other words, a recessed portion 15, which is shaped to be symmetrical with the recessed portion 13 of the first flange part 12, is formed in an end surface of the second flange part 14 located on the third positive direction Z1 side.

[0021] The winding core part 11, the first flange part 12, and the second flange part 14 form a core 10C of the coil component 10. The material forming the core 10C is a non-conductive material. The material of the core 10C is, for example, aluminum oxide, a nickel-zinc ferrite, a resin, or a mixture of these materials.

[0022] The coil component 10 includes a top plate 16. The top plate 16 is connected to ends of the core 10C located on the third negative direction Z2 side. The top plate 16 has a rectangular plate-like shape. The top plate 16 is attached to the core 10C so that it extends between the end surface of the first flange part 12 on the third negative direction Z2 side and the end surface of the second flange part 14 on the third negative direction Z2 side. The top plate 16 is made of the same material as the core 10C and forms a closed magnetic path with the core 10C.

[0023] The coil component 10 includes a first terminal electrode 21, a second terminal electrode 22, a third terminal electrode 23, and a fourth terminal electrode 24. The first terminal electrode 21 is arranged on a surface of the first flange part 12. More specifically, the first terminal electrode 21 is arranged on the end surface of the first flange part 12 on the third positive direction Z1 side in a region that is further toward the second positive direction Y1 side than the recessed portion 13.

[0024] The second terminal electrode 22 is arranged on a surface of the first flange part 12. More specifically, the second terminal electrode 22 is arranged on the end surface of the first flange part 12 on the third positive direction Z1 side in a region located further toward the second negative direction Y2 side than the recessed portion 13.

[0025] The third terminal electrode 23 is arranged on a surface of the second flange part 14. More specifically, the third terminal electrode 23 is arranged on the end surface of the second flange part 14 on the third positive direction Z1 side in a region located further toward the second positive direction Y1 side than the recessed portion 15.

[0026] The fourth terminal electrode 24 is arranged on a surface of the second flange part 14. More specifically, the fourth terminal electrode 24 is arranged on the end surface of the second flange part 14 on the third positive direction Z1 side in a region located further toward the second negative direction Y2 side than the recessed portion 15. Note that, in the drawing, the first terminal electrode 21, the second terminal electrode 22, the third terminal electrode 23, and the fourth terminal electrode 24 are illustrated using two-dot chain lines.

[0027] The first to fourth terminal electrodes 21 to 24 each include a metal layer formed of silver and a plating layer formed of copper, nickel, or tin deposited on the surface of the metal layer. In this embodiment, the surface of the coil component 10 on which the first to fourth terminal electrodes 21 to 24 are provided is the surface facing a substrate when the coil component 10 is mounted on a substrate. First wire and second wire

[0028] The coil component 10 includes a first wire 30 and a second wire 40. A part of the first wire 30 extends in a spiral shape around the circumferential surface 11F of the winding core part 11, with the central axis CA as the rotation axis. As shown in Fig. As shown in Figure 3, the first wire 30 has a circular shape in a cross-section perpendicular to the direction in which the first wire 30 extends. The first wire 30 is made of a copper wire with a diameter of about 30 µm coated with an insulating film that is about 10 µm thick. In other words, the diameter of the first wire 30 is about 50 µm in a cross-section perpendicular to the direction in which the first wire 30 extends.

[0029] As it is in Fig. As shown in Figure 2, a first end of the first wire 30 is connected to the first terminal electrode 21. A portion of the first wire 30, including the first end of the first wire 30, extends from the first terminal electrode 21 to the land line that is closest to the second terminal electrode 22 among the four land lines of the winding core portion 11.

[0030] The first wire 30 is wound clockwise around the winding core part 11 when viewed in the first negative direction X2. A part of the first wire 30, including the second end of the first wire 30 on the opposite side of the first end in the extension direction of the first wire 30, extends from the land line farthest from the fourth terminal electrode 24 among the four land lines of the winding core part 11 to the third terminal electrode 23 near the second flange part 14 of the winding core part 11. The second end of the first wire 30 is connected to the third terminal electrode 23.

[0031] As it is in Fig. As shown in Figure 1, a portion of the second wire 40 extends in a spiral shape outside the circumferential surface 11F of the winding core portion 11 in a radial direction centered on the central axis CA, where the central axis CA is the rotation axis. The second wire 40 has the same cross-sectional shape and dimensions as the first wire 30.

[0032] As it is in Fig. As shown in Figure 2, a first end of the second wire 40 is connected to the second terminal electrode 22. A portion of the second wire 40, including the first end of the second wire 40, extends to the land line, among the four land lines of the winding core portion 11, that is farthest from the first terminal electrode 21.

[0033] The second wire 40 is wound clockwise around the winding core part 11 when viewed in the first negative direction X2. A part of the second wire 40, including the second end of the second wire 40 on the opposite side of the first end in the extension direction of the second wire 40, extends from the land line closest to the third terminal electrode 23 among the four land lines of the winding core part 11 to the fourth terminal electrode 24 near the second flange part 14 of the winding core part 11. The second end of the second wire 40 is connected to the fourth terminal electrode 24.

[0034] As it is in Fig. As shown in Figure 3, the portion of the first wire 30 extending in a spiral shape around the circumferential surface 11F of the winding core portion 11 is continuously wound over a range of more than 360 degrees, with the central axis CA acting as the rotation axis. When the first wire 30 is wound 360 degrees with the central axis CA as the rotation axis, the number of wound turns is "1." Then, each time the angle by which the first wire 30 is wound is increased by 360 degrees, the number of wound turns is increased by 1.

[0035] Furthermore, of the part of the first wire 30 that extends in a spiral shape around the circumferential surface 11F of the winding core part 11, the region along the wire path of the first wire 30 from the end on the side connected to the first terminal electrode 21 to a point where the first wire 30 has been wound 360 degrees around the central axis CA is referred to as a first turn. Specifically, the region from the point where the first wire 30 first contacts the winding core part 11, starting from the side near the first end of the first wire 30, to the point where the first wire 30 has been wound 360 degrees around the central axis CA along the circumferential surface 11F of the winding core part 11 is referred to as the first turn.The number of turns of the first wire 30 wound around the winding core part 11 is a second turn, a third turn, and so on as the first wire 30 approaches the side near the third terminal electrode 23. The last turn, which is closest to the end along the wire path of the first wire 30 connected to the third terminal electrode 23, is referred to as the M-th turn. In this embodiment, the last turn of the first wire 30 refers to the last turn wound one full turn, counting from the first turn in the winding process of the first wire 30 around the winding core part 11. In short, in this embodiment, the first wire 30 is wound a total of M and a half turns around the winding core part 11.If there is a winding point where the first wire 30 does not extend a full turn after the Mth turn of the first wire 30, that turn number is omitted when specifying the turn number. In other words, the number of wound turns of the first wire 30 of this embodiment is M. Additionally, in this embodiment, "along the wire path of the first wire 30" means along a path followed by the first wire 30. In . Fig. 3, the first wire 30 is shown with an ellipse and number of turns.

[0036] Furthermore, of the part of the second wire 40 extending in a spiral shape outside the circumferential surface 11F of the winding core part 11 in the radial direction centered on the central axis CA, the range along the wire path of the second wire 40 from the end on the side connected to the second terminal electrode 22 to a point where the second wire 40 has been wound 360 degrees around the central axis CA is referred to as a first turn. The number of turns of the second wire 40 wound around the winding core part 11 is a second turn, a third turn, and so on as the second wire 40 approaches the side near the fourth terminal electrode 24. The last turn along the wire path of the second wire 40 closest to the end connected to the fourth terminal electrode 24 is referred to as the Nth turn.Furthermore, in this embodiment, the last turn of the second wire 40 refers to the last turn wound one full turn, counted from the first turn in the process of winding the second wire 40 around the winding core member 11. In short, in this embodiment, the second wire 40 is wound a total of N and a half turns around the winding core member 11. The method used to count the number of wound turns of the second wire 40 is the same as that used for the first wire 30. In other words, the number of wound turns of the second wire 40 is N. Furthermore, in this embodiment, "along the wire path of the second wire 40" means along a path followed by the second wire 40. In . Fig. 3, the second wire 40 is shown in white together with the number of turns.

[0037] In this embodiment, the number of wound turns N of the second wire 40 is equal to the number of wound turns M of the first wire 30. Furthermore, in this embodiment, the number of wound turns N of the second wire 40 and the number of wound turns M of the first wire 30 are each 5 or more.

[0038] The first turn of the first wire 30 extends in a spiral shape along the circumferential surface 11F of the winding core part 11 near the first flange part 12. The second turn of the first wire 30 extends adjacent to the edge of the first turn of the first wire 30 located on the first negative direction X2 side. Similarly, in the third to (M-1)th turns of the first wire 30, the first wire extends in a spiral shape along the circumferential surface 11F of the winding core part 11, so that a turn with a larger number of turns in the first negative direction X2 is arranged adjacent to the edge of the turn of the first wire 30 wound one turn earlier.

[0039] The first turn of the second wire 40 extends to a point outside the boundary between the first turn and the second turn of the first wire 30, which are adjacent to each other in a direction along the first axis X, in the radial direction centered on the central axis CA. Here, "turns adjacent to each other in a direction along the first axis X" refers to a specific turn, and a turn located one turn after that specific turn from the turns of the first wire 30 or the turns of the second wire 40.

[0040] In addition, the first turn of the second wire 40 extends along a boundary extending between turns of the first wire 30 that are adjacent to each other in a direction along the first axis X to contact the outer surfaces of the first turn and the second turn of the first wire 30.

[0041] The second turn of the second wire 40 extends at a point outside the boundary extending between the second turn and the third turn of the first wire 30, which are adjacent to each other in a direction along the first axis X, in the radial direction centered on the central axis CA. Furthermore, the second turn of the second wire 40 extends to contact the outer surfaces of the second turn and the third turn of the first wire 30 along this boundary. The second turn of the second wire 40 extends adjacent to the edge of the first turn of the second wire 40, which is on the side of the first negative direction X2.Similarly, in the third to (N-2)-th turns of the second wire 40, the second wire 40 extends in a spiral shape in contact with the outer surface of the first wire 30 so that a turn having a larger number of turns in the first negative direction X2 is arranged adjacent to the edge of the turn of the second wire 40 wound one turn earlier.

[0042] The (N-1)th turn of the second wire 40 extends adjacent to the edge of the (M-1)th turn of the first wire 30 located on the first negative direction X2 side. Then, the Nth turn of the second wire 40 extends adjacent to the edge of the (N-1)th turn of the second wire 40 located on the first negative direction X2 side. In other words, the (N-1)th turn and the Nth turn of the second wire 40 extend along the circumferential surface 11F of the winding core part 11. Therefore, the (N-1)th turn and the Nth turn of the second wire 40 are located closer to the inside in the radial direction centered on the central axis CA than the first to N-2th turns of the second wire 40.

[0043] Furthermore, the M-th turn of the first wire 30 extends adjacent to the edge of the N-th turn of the second wire 40, which is located on the side of the first negative direction X2. Therefore, the (N-1)-th turn and the N-th turn of the second wire 40 lie between the (M-1)-th turn and the M-th turn of the first wire 30. Outer part and inner part

[0044] The second wire 40 includes an outer part 41 and an inner part 42. In the second wire described above, the outer part 41 consists of the part from the first turn to the (N-2)th turn and the inner part 42 consists of the part from the (N-1)th turn to the Nth turn.

[0045] As described above, the outer part 41, which consists of the part from the first turn to the (N-2)th turn of the second wire 40, extends in a spiral shape outside the inner part 42, which consists of the (N-1)th turn and the Nth turn of the second wire 40, in the radial direction centered on the central axis CA.

[0046] Furthermore, the inner part 42 is formed by two turns consisting of the (N-1)th turn and the Nth turn of the second wire 40. Therefore, the inner part 42 extends continuously along the circumferential surface 11F of the winding core part 11 in a spiral shape over a range of 720 degrees, which is larger than 360 degrees. Furthermore, in this embodiment, the number of wound turns N of the second wire 40 is 5 or more, and therefore, the number of wound turns of the inner part 42 is "2" and the number of wound turns of the outer part 41 is "3" or more. Therefore, the number of wound turns of the outer part 41 is greater than the number of wound turns of the inner part 42.

[0047] The Nth turn of the second wire 40 extends adjacent to the edge of the (N-1)th turn of the second wire 40 located on the side of the first negative direction X2. Therefore, in the inner part 42, turns of the second wire 40 adjacent to each other in a direction along the first axis X touch each other when viewed in a cross-section including the central axis CA.

[0048] In addition, the (N-1)th turn and the Nth turn of the second wire 40 are arranged between the (M-1)th turn and the Mth turn of the first wire 30. Therefore, the inner part 42 is arranged between turns of the first wire 30 that are adjacent to each other in a direction along the first axis X. Therefore, the inner part 42 is arranged between an Lth turn and an (L+1)th turn of the first wire 30, where L is an integer from 1 to M-1. Specifically, in this embodiment, L is M-1 among the integers from 1 to M-1. Comparison tests

[0049] First, a coil component 90 of a comparative example will be described. As shown in Fig. As shown in Figure 4, the coil component 90 of the comparative example differs from the coil component 10 of the above-described embodiment with respect to the M-th turn of the first wire 30 and the (N-1)th turn and the N-th turn of the second wire 40. More specifically, in the coil component 90 of the comparative example, the M-th turn of the first wire 30 extends adjacent to the edge of the (M-1)th turn of the first wire 30, which is located on the first negative direction X2 side. Therefore, the second wire 40 is not located between the (M-1)th turn and the M-th turn of the first wire 30.

[0050] In the coil component 90 of the comparative example, the (N-1)th turn of the second wire 40 extends adjacent to the edge of the (N-2)th turn of the second wire 40 located on the first negative direction X2 side. In addition, the N-th turn of the second wire 40 extends adjacent to the edge located on the first negative direction X2 side of the M-th turn of the first wire 30. Therefore, of the part of the second wire 40 extending in a spiral shape outside the circumferential surface 11F of the winding core part 11 in the radial direction centered on the central axis CA, the part from the first turn to the (N-1)-th turn forms the outer part 41. The N-th turn of the second wire 40 forms the inner part 42, which is located closer to the inside in the radial direction centered on the central axis CA than the outer part 41.However, in the inner part 42 of the coil component 90, adjacent turns of the second wire 40 do not touch each other and the inner part 42 of the coil component 90 is not arranged between adjacent turns of the first wire 30.

[0051] As it is in Fig. 5, values ​​of Sds21, which is a mode conversion characteristic, of the coil component 10 of the above-described embodiment and the coil component 90 of the comparative example were compared by conducting experiments. In Fig. 5, the horizontal axis represents the frequency and the vertical axis represents Sds21, which is a mode conversion characteristic. In Fig. 5, the solid line represents the characteristic of the coil component 10 of the above-described embodiment, and the one-dot chain line represents the characteristic of the coil component 90 of the comparative example. Thus, in the coil component 10 of the embodiment, Sds21 is reduced in a frequency range of 10 MHz and lower compared to the coil component 90 of the comparative example. How the embodiment works

[0052] According to the coil component 10 of the above-described embodiment, the second wire 40 includes the inner part 42. The inner part 42 extends continuously along the circumferential surface 11F of the winding core part 11 in a spiral shape over a range of more than 360 degrees, more specifically, over a range of 720 degrees. Furthermore, the inner part 42 is closer to the central axis CA than the outer part 41. Therefore, the leakage magnetic flux of the inner part 42 is smaller than the leakage magnetic flux of the outer part 41.

[0053] Furthermore, the inner part 42 is arranged between the L-th turn and the (L+1)-th turn of the first wire 30. Specifically, in this embodiment, the inner part 42 is arranged between the (M-1)-th turn and the M-th turn of the first wire 30. Therefore, the (M-1)-th turn and the M-th turn of the first wire 30, between which the inner part 42 is arranged, are separated by a distance corresponding to the size of the inner part 42. Therefore, a leakage magnetic flux of the first wire 30 is larger than the leakage magnetic flux would be if the (M-1)-th turn and the M-th turn were in contact with each other. Effects of the embodiment (1) According to the coil component 10 of the above-described embodiment, the second wire 40 includes the inner portion 42. Therefore, as in the above-described step, the leakage magnetic flux of the second wire 40 is smaller than the leakage magnetic flux would be if the second wire 40 did not include the inner portion 42. On the other hand, the leakage magnetic flux of the first wire 30 is larger than the leakage magnetic flux would be if the second wire 40 did not include the inner portion 42.

[0054] Therefore, the inductance value obtained by the second wire 40 is increased because the leakage magnetic flux of the second wire 40 is less than the leakage magnetic flux would be if the second wire 40 did not have the inner part 42. On the other hand, the inductance value obtained by the first wire 30 is less than the inductance value would be if the second wire 40 did not have the inner part 42.

[0055] Therefore, the inductance value obtained by the first wire 30 is reduced, and the inductance value obtained by the second wire 40 is increased. Thus, the difference between the inductance value obtained by the first wire 30 and the inductance value obtained by the second wire 40 can be reduced. As a result, according to the coil component 10, Sds21, which is a mode conversion characteristic, can be reduced compared to a case where the second wire 40 does not have the inner part 42.

[0056] (2) According to the above-described embodiment, adjacent turns of the second wire 40 contact each other in the inner part 42. In other words, the inner part 42 has a position where adjacent turns contact each other in a direction along the central axis CA. Therefore, the generation of leakage magnetic flux can be suppressed at a position where adjacent turns contact each other, compared to a position where adjacent turns do not contact each other in the inner part 42. Therefore, according to the coil component 10 of the above-described embodiment, the generation of leakage magnetic flux can be further suppressed at the position where adjacent turns of the wire 40 contact each other in the inner part 42.

[0057] (3) According to the coil component 10 of the above-described embodiment, the inner part 42 is arranged between the (M-1)th and the Mth turns of the first wire 30. Therefore, in the process of manufacturing the coil component 10, it is sufficient that only the Mth turn, which is the last turn, is unwound from the (M-1)th turn when the first wire 30 is wound around the winding core part 11. Therefore, no substantial changes need to be made to the manufacturing equipment or the manufacturing process to arrange the inner part 42 between the (M-1)th turn and the Mth turn of the first wire 30.

[0058] (4) If the inner part 42 does not include the last turn and the inner part 42 is located somewhere in the middle of the winding of the second wire 40, it is necessary to wind the second wire 40 first as the outer part 41, then as the inner part 42, and then again as the outer part 41. Therefore, when winding the second wire 40, it may be necessary to change the winding method several times during the winding process.

[0059] Regarding this point, according to the coil component 10 of the above-described embodiment, the inner part 42 consists of the (N-1)th turn and the Nth turn of the second wire 40. In other words, the inner part 42 includes the Nth turn, which is the last turn. Therefore, when the second wire 40 is wound around the winding core part 11, it is sufficient that only the part including the last turn is wound as the inner part 42. Therefore, according to the above-described embodiment, after winding the second wire 40 as the inner part 42 in this way, there is no need to change the winding method to wind the second wire 40 as the outer part 41.

[0060] (5) According to the coil component 10 of the above-described embodiment, the number of wound turns of the first wire 30 is the same as the number of wound turns of the second wire 40. In this case, the inductance values ​​obtained by the wires cannot be adjusted using the number of wound turns. In this configuration, it is particularly desirable to provide the second wire 40 with the inner part 42 and reduce the difference between the inductance values ​​of the wires.

[0061] (6) Symmetry between the coil formed by the first wire 30 and the coil formed by the second wire 40 is easily achieved when the number of wound turns of the first wire 30 and the number of wound turns of the second wire 40 are equal. Furthermore, it is easy to match the inductance values ​​and the electrical resistance values ​​of the first wire 30 and the second wire 40.

[0062] (7) According to the coil component 10 of the above-described embodiment, the number of wound turns of the outer part 41 of the second wire 40 is greater than the number of wound turns of the inner part 42 of the second wire 40. When the number of wound turns of the outer part 40 is appropriately large, the inductance value obtained by the outer part 41 of the second wire 40 is smaller than the inductance value that would be obtained by a first wire 30 having the same number of wound turns as the outer part 41. In this configuration, it is particularly desirable to provide the second wire 40 with the inner part 42 in order to reduce the difference between the inductance values ​​of the wires. Coil components of other embodiments

[0063] The above-described embodiment may be modified as follows. The embodiments and the following modifications may be combined with each other, provided they are not technically incompatible.

[0064] The shape of the winding core part 11 in the above-described embodiment is not limited to the example given in the above-described embodiment. For example, the shape may be a cylindrical shape or a polygonal column shape, which is different from a square column shape.

[0065] In the embodiment described above, the upper plate 16 can be omitted.

[0066] In the embodiment described above, it is sufficient that the core 10C includes the winding core part 11, the first flange part 12, and the second flange part 14. For example, the recessed portion 13, 15 may be omitted. In this case, for example, it is sufficient that the first terminal electrode 21 and the second terminal electrode 22 are spaced apart from each other, and that the third terminal electrode 23 and the fourth terminal electrode 24 are spaced apart from each other.

[0067] In the above-described embodiment, the materials and shapes of the first to fourth terminal electrodes 21 to 24 are not limited to the examples in the above-described embodiment. For example, the material of the plating layers of the first to fourth terminal electrodes 21 to 24 may be tin, a nickel alloy, or the like. Furthermore, the first to fourth terminal electrodes 21 to 24 may not include plating layers, and the electrically conductive metal layers thereof may be exposed.

[0068] In the above-described embodiment, the cross-sectional shapes and dimensions of the first wire 30 and the second wire 40 are not limited to the examples given in the above-described embodiment. For example, the diameters of the copper wires and the thicknesses of the insulating films can be made larger than those described in the above-described embodiment.

[0069] The number of wound turns of the first wire 30 and the number of wound turns of the second wire 40 may differ.

[0070] In the above-described embodiment, the range over which the inner part 42 extends is preferably a range in which the inner part 42 extends at least continuously over more than 360 degrees along the circumferential surface 11F of the winding core part 11. In other words, in the above-described embodiment, the number of wound turns of the inner part 42 is not limited to the example given in the above-described embodiment, but is preferably greater than "1." When the inner part 42 extends continuously over a range of more than 360 degrees, the inner part 42 has turns that are at least partially adjacent to each other.

[0071] In the embodiment described above, in the inner part 42, turns that are adjacent to each other in a direction along the first axis X need not touch each other in a direction along the central axis CA.

[0072] In the embodiment described above, the inner part 42 extends in a spiral shape while being in constant contact with the circumferential surface 11F of the winding core part 11, but the inner part 42 may instead extend in a spiral shape with parts thereof separated from the circumferential surface 11F. For example, when the winding core part 11 is viewed in a direction along the central axis CA, the inner part 42 may contact the circumferential surface 11F near the four corners of the winding core part 11, and the inner part 42 may be separated from the circumferential surface 11F between these corners. Even if the inner part 42 intermittently contacts the circumferential surface 11F in this way, the inner part 42 can be said to extend along the circumferential surface 11F.

[0073] The number of wound turns of the inner part 42 may be greater than the example given in the embodiment described above. In the example given in Fig. 6, a second wire 140 of a coil component 110 includes an outer part 141 and an inner part 142. The outer part 141 is the part from the first turn to the (N-3)th turn of the second wire 140. In the outer part 141, each of the turns is separated from the adjacent turns in a direction in which the central axis CA extends. The inner part 142 is the part from the (N-2)th turn to the Nth turn of the second wire 140. Therefore, the number of wound turns of the inner part 142 is 3. In other words, in this modification, the inner part 142 extends continuously along the circumferential surface 11F of the winding core part 11 over a range of more than 720 degrees. In this case, the inductance value obtained by the second wire 140 can be made even larger than that of the coil component 10.

[0074] The number of wound turns of the inner part 42 may be greater than or equal to the number of wound turns of the outer part 41. The number of wound turns of the inner part 42 may be adjusted accordingly, along with the number of wound turns of the first wire 30, the number of wound turns of the second wire 40, or the diameter of the winding core part 11 centered on the central axis 10A.

[0075] In the embodiment described above, the inner part 42 does not need to include the Nth turn of the second wire 40. Even in this case, the inductance value obtained by the second wire 40 can be increased by the inner part 42.

[0076] In the embodiment described above, the inner part 42 may be arranged at a point that is not between the (M-1)th turn and the Mth turn of the first wire 30. For example, the inner part 42 may be arranged between the (M-2)th turn and the (M-1)th turn of the first wire 30. In other words, the inner part 42 may be arranged between the Lth turn and the (L+1)th turn of the first wire 30. In this case, too, the Lth turn and the (L+1)th turn of the first wire 30 are separated from each other because the inner part 42 is arranged between the Lth turn and the (L+1)th turn of the first wire 30. Thus, the difference between the inductance values ​​obtained by the two wires can be reduced by decreasing the inductance value obtained by the first wire 30 and increasing the inductance value obtained by the second wire 40.

[0077] In the embodiment described above, the second wire 40 may comprise, in addition to the inner part 42, a further part which is arranged closer to the inside than the outer part 41. In the embodiment shown in Fig. 7, a second wire 240 has an outer part 241, a first inner part 242, and a second inner part 243. The outer part 241 is the part from the second turn to the (N-2)th turn of the second wire 240. The first inner part 242 consists of the (N-1)th turn and the Nth turn of the second wire 240. The second inner part 243 consists of the first turn of the second wire 240. The first inner part 242 has the same configuration as the inner part 42 of the coil component 10 of the above-described embodiment. The second inner part 243 extends along the circumferential surface 11F of the winding core part 11 and is arranged between the first turn and the second turn of the first wire 30, which are adjacent turns of the first wire 30.In this case, a coil component 210 further includes the second inner part 243 in addition to the first inner part 242, and as a result, the inductance value obtained by the second wire 240 can be made larger than that of the coil component 10.

[0078] In addition, the Fig. 7, the second inner part 243 is the first turn of the second wire 40. Therefore, it is sufficient that only the first turn is wound differently from the outer part 241 to provide the second inner part 243 in the process of manufacturing the coil component 210.

[0079] Furthermore, the Fig. In the modification shown in Figure 7, the second inner part 243 extends continuously over a range of less than or equal to 360 degrees along the circumferential surface 11F of the winding core part 11. Therefore, the second inner part 243 can suppress the leakage magnetic flux by a smaller amount than the amount by which the leakage magnetic flux can be suppressed by the first inner part 242. Thus, it is easy to adjust the inductance value obtained by the second wire 40.

[0080] At the Fig. 7, the second inner part 243 need not consist of the first turn of the second wire 40. In the modification shown in Fig. 8, in a coil component 310, a second wire 340 has an outer portion 341, a first inner portion 342, and a second inner portion 343. The outer portion 341 is the portion from the first turn to the (N-3)th turn of the second wire 340. The first inner portion 342 consists of the (N-1)th turn and the Nth turn of the second wire 340. The second inner portion 343 consists of the (N-2)th turn. Also in this case, the (M-2)th turn and the (M-1)th turn of the first wire 340 are separated in a direction along the first axis X due to the presence of the second inner portion 343. Thus, the difference between the inductance values ​​can be adjusted by reducing the inductance value obtained by the first wire 30 by increasing the leakage magnetic flux of the first wire 30.

[0081] At the Fig. 7, the second inner part 243 may extend continuously over a range of more than 360 degrees along the circumferential surface 11F of the winding core part 11. In the modification shown in Fig. 9, in a coil component 410, a second wire 440 has a first outer part 441, a second outer part 442, a first inner part 443, and a second inner part 444. The outer part 441 is the part from the first turn to the (N-5)th turn of the second wire 440. The second outer part 442 is the (N-2)th turn of the second wire 440. The first inner part 443 consists of the (N-1)th turn and the Nth turn of the second wire 440. The second inner part 444 consists of the (N-4)th turn and the (N-3)th turn of the second wire 440. Thus, the coil component 10 of the embodiment described above can be provided with a plurality of inner parts 42. In the case of the embodiment shown in Fig. 9, the inductance value obtained by the second wire 440 can be made larger than in the case where there is no second inner part 444.

[0082] At the Fig. 7, the second inner part 243 does not need to be positioned between the first turn and the second turn of the first wire 30. It is sufficient that the second inner part 243 is positioned between a K-th turn and a (K+1)-th turn of the first wire 30, where k is an integer from 1 to M-1. Since the second inner part 243 is provided separately from the first inner part 242, K is a different integer than L. For example, in the modification shown in Fig. 8 shown modification K 1 and L is M-1. In addition, for example, in the Fig. 9 shown modification K M-4 and L is N-1.

[0083] In the above-described embodiment, the outer part 41 and the inner part 42 were mainly described as being located at positions arranged on a surface of the circumferential surface 11F oriented in the third positive direction Z1. It is sufficient that the positional relationship between the outer part 41 and the inner part 42 in a direction along the first axis X is satisfied in any cross section including the central axis CA. Therefore, the same configuration does not need to be used for all surfaces constituting the circumferential surface 11F. For example, on the surface oriented from the circumferential surface 11F in the third negative direction Z2, the (M-1)th turn of the first wire 30 may extend at a point outside the (N-1)th turn of the second wire 40 in the radial direction centered on the central axis CA.

Claims

[1] Coil component (10) having the following features: a winding core part (11) with a central axis (CA); a first flange part (12) connected to a first end of the winding core part (11) in a direction along the central axis (CA); a second flange part (14) connected to a second end of the winding core part (11) located on an opposite side of the first end; a first terminal electrode (21) and a second terminal electrode (22) arranged on a surface of the first flange part (12); a third terminal electrode (23) and a fourth terminal electrode (24) arranged on a surface of the second flange part (14); a first wire (30) comprising a part extending in a spiral shape along a circumferential surface of the winding core part (11), the central axis (CA) serving as a rotation axis, the first wire (30) having a first end connected to the first terminal electrode (21) and a second end located on an opposite side of the first end connected to the third terminal electrode (23); and a second wire (40) comprising a part extending in a spiral shape outside the circumferential surface of the winding core part (11) in a radial direction centered on the central axis (CA), the central axis (CA) serving as a rotation axis, the second wire (40) having a first end connected to the second terminal electrode (22) and a second end located on an opposite side of the first end connected to the fourth terminal electrode (24), wherein the second wire (40) comprises an inner part (42) extending in a spiral shape continuously over a range of more than 360 degrees along the circumferential surface of the winding core part (11), and an outer part (41) extending in the radial direction in a spiral shape outside the inner part (42) and if, of the part of the first wire (30) wound around the winding core part (11), a first turn that is closest to the first end of the first wire (30) on a wire path of the first wire (30) is referred to as a first turn, and a last turn that is closest to the second end of the first wire (30) on the wire path of the first wire (30) is referred to as an M-th turn, wherein the outer part (41) consists of the part from the first turn to the (N-2)th turn and the inner part (42) consists of the part from the (N-1)th turn to the Nth turn of the second wire (40), and the (N-1)th turn and the Nth turn of the second wire (40) are arranged between the (M-1)th turn and the Mth turn of the first wire (30), wherein in the inner part, in a cross-section containing the central axis (CA), adjacent turns of the second wire (40) contact each other in a direction along the central axis (CA). [2] The coil component (10) according to claim 1, wherein, of the part of the second wire (40) wound around the winding core part (11), a first turn that is closest to the first end of the second wire (40) on a wire path of the second wire (40) is referred to as a first turn, and a last turn that is closest to the second end of the second wire (40) on the wire path of the second wire (40) is referred to as an N-th turn. [3] Coil component (10) according to one of claims 1 or 2, wherein the number of wound turns of the first wire (30) is the same as the number of wound turns of the second wire (40). [4] Coil component (10) according to one of claims 1 to 3, wherein the number of wound turns of the outer part is greater than the number of wound turns of the inner part (42). [5] Coil component (10) according to one of claims 1 to 4, wherein the inner part (42) extends continuously over a range of more than 720 degrees along the circumferential surface of the winding core part (11). [6] Coil component (10) according to one of claims 1 to 5, wherein the inner part (42) consists of a first inner part (142) and L is an integer from 1 to M-1, if K is an integer different from L, the second wire (40) comprises a second inner part (243) extending along the circumferential surface of the winding core part (11) and arranged between a K-th turn and a (K-1)-th turn of the first wire (30). [7] The coil component (10) according to claim 6, wherein the second inner portion (243) extends over a range of less than or equal to 360 degrees along the circumferential surface of the winding core portion (11). [8] Coil component (10) according to claim 6, wherein the second inner part (243) extends continuously over a range of more than 360 degrees along the circumferential surface of the winding core part (11).

Images