Coil component

Abstract

When a second wire (60) is followed from a first wire end to a second wire end, a portion where the second wire shifts first from a second portion (P2) to a third portion (P3) is set as a specific portion. One turn from the specific portion toward the second wire end is defined as a specific turn (ST), and the turn of the second wire (60) including the specific portion is defined as an i-th turn (where i is an integer of 3 or more). The specific portion is wound at a valley between a (j-1)-th turn and a j-th turn of the second wire (60) (where j is an integer of 2 or more and less than i), and the specific turn (ST) has a crossing portion (CR) crossing the j-th turn of the second wire (60) from a second flange (31) side to a first flange (21) side in a direction along the central axis C.

Description

Coil parts

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

[0002] The coil component described in Patent Document 1 includes a winding core, a first flange, and a second flange. The winding core is rectangular prism-shaped. The first flange is connected to a first end of the winding core. The second flange is connected to a second end of the winding core. The coil component also includes four external electrodes, a first wire, and a second wire. Two of the four external electrodes are located on the surface of the first flange. The remaining two external electrodes are located on the surface of the second flange.

[0003] The first wire is wound directly around the winding core. A first end of the first wire is connected to the external electrode on the first flange. A second end of the first wire is connected to the external electrode on the second flange. The second wire is wound around the winding core from the outside of the first wire as a whole. A first end of the second wire is connected to the external electrode on the first flange. A second end of the second wire is connected to the external electrode on the second flange. The second wire is wound in the same direction as the first wire. Specifically, the second wire has a second portion wound around the first wire from the outside in a direction perpendicular to the central axis of the winding core, and a third portion wound around the second portion from the outside in a direction perpendicular to the central axis of the winding core.

[0004] U.S. Pat. No. 1,055,9415

[0005] In the coil component described in Patent Document 1, when the third portion is wound around the winding core, the third portion is pressed against the second portion. This pressing force can cause the second wire, which should belong to the third portion, to fall into the second portion. If the second wire is wound in a state different from the wire design, the coil component may not exhibit the designed characteristics.

[0006] In order to solve the above problems, the present disclosure provides a winding core, a first flange provided at a first end of the winding core in a direction along a central axis, a second flange provided at a second end of the winding core opposite to the first end, first and second external electrodes provided at the first flange, a third and fourth external electrode provided at the second flange, a first wire wound around the winding core, a first wire end connected to the first external electrode and a second wire end connected to the third external electrode, and a second wire wound around the winding core in the same direction as the first wire, a first wire end connected to the second external electrode and a second wire end connected to the fourth external electrode, wherein the number of turns of the first wire and the second wire increases by one for each full turn around the central axis from the first wire end toward the second wire end, and the first wire has a first portion wound continuously and directly around the winding core, The second wire has a second portion wound directly from the outside around the first portion in a direction perpendicular to the central axis, and a third portion wound directly from the outside around the second portion in a direction perpendicular to the central axis, and when the second wire is traced from the first wire end to the second wire end, the location where the second portion first switches to the third portion is defined as a specific portion, and one turn from the specific portion toward the second wire end is defined as a specific turn, and when the turn of the second wire that includes the specific portion is defined as the i-th turn (where i is an integer greater than or equal to 3), the specific turn includes a portion wound in the valley between the (j-1)-th turn and the j-th turn of the second wire (where j is an integer greater than or equal to 2 and less than i), and the specific turn is a coil component that has a crossing portion that crosses from the second flange side to the first flange side in a direction along the central axis for at least one turn of the second portion.

[0007] The present disclosure also provides a winding core, a first flange provided at a first end of the winding core in a direction along a central axis, a second flange provided at a second end of the winding core opposite to the first end, first and second external electrodes provided at the first flange, third and fourth external electrodes provided at the second flange, a first wire wound around the winding core, with a first wire end connected to the first external electrode and a second wire end connected to the third external electrode, and a second wire end wound around the winding core in the same direction as the first wire, with a first wire end connected to the second external electrode and a second wire end connected to the and a second wire connected to a fourth external electrode, wherein the number of turns of the first wire and the second wire increases by one for each full turn around the central axis from the first wire end toward the second wire end, the first wire has a first portion wound continuously and directly around the winding core, the second wire has a second portion wound directly from the outside around the first portion in a direction perpendicular to the central axis, and a third portion wound directly from the outside around the second portion in a direction perpendicular to the central axis, and the second wire is wound from the first wire end to the When tracing the second wire end, the first location where the second portion switches to the third portion is defined as a first specific location, the location one turn after the first specific location is defined as a second specific location, one turn from the first specific location toward the second wire end is defined as a first specific turn, one turn from the second specific location toward the second wire end is defined as a second specific turn, and the turn of the second wire including the first specific location is defined as the i-th turn (where i is an integer of 4 or more), the turn of the second wire including the second specific location is the (i+1)-th turn, and the first specific location is defined as the second wire is wound in a valley between the (j-1)th turn and the jth turn (where j is an integer equal to or greater than 2 and less than i-1), the second specific portion is wound in a valley between the (k-1)th turn and the kth turn (where k is an integer equal to or greater than 3 and less than i), the first specific turn has a first crossing portion that crosses from the second flange side to the first flange side in a direction along the central axis with respect to at least one turn of the second portion, and the second specific turn crosses a turn in the second portion other than the turn crossed by the first specific turn,The coil component has a second crossing portion that crosses from the second flange side to the first flange side in the direction along the central axis.

[0008] According to the above configuration, it is possible to prevent the second wire belonging to the third portion from being displaced toward the second portion.

[0009] Fig. 1 is a perspective view of a coil component according to a first embodiment. Fig. 2 is a schematic end view showing a portion of the coil component according to the first embodiment, the portion including the central axis and perpendicular to the left-right axis. Fig. 3 is a schematic end view showing a portion of a coil component according to a second embodiment, the portion including the central axis and perpendicular to the left-right axis. Fig. 4 is a schematic end view showing a portion of a coil component according to a third embodiment, the portion including the central axis and perpendicular to the left-right axis.

[0010] Hereinafter, an embodiment of a coil component will be described with reference to the drawings. Note that the drawings may show components enlarged to facilitate understanding. The dimensional ratios of the components may differ from those in the actual drawings or from those in other drawings.

[0011] First Embodiment <Overall Configuration> As shown in FIG. 1, a coil device 10 includes a drum core 10C and a planar core 10F.

[0012] The drum core 10C has a winding core 11, a first flange 21, and a second flange 31. The winding core 11 is in the shape of a quadrangular prism. That is, the winding core 11 has four side surfaces. The material of the winding core 11 is, for example, Ni-Zn ferrite.

[0013] The first flange 21 is provided at a first end in the direction along the central axis C of the winding core 11. Specifically, the first flange 21 is connected to the first end in the direction along the central axis C of the winding core 11. The second flange 31 is provided at a second end in the direction along the central axis C of the winding core 11. Specifically, the second flange 31 is connected to the second end in the direction along the central axis C of the winding core 11. The first flange 21 and the second flange 31 are made of the same material as the winding core 11. Furthermore, the first flange 21 and the second flange 31 are integrally molded with the winding core 11.

[0014] Here, an axis parallel to the central axis C is defined as the core axis X. A specific axis perpendicular to the core axis X is defined as the vertical axis Y. In the first embodiment, the vertical axis Y is a direction perpendicular to the mounting surface when the coil component 10 is mounted on a substrate. An axis perpendicular to both the core axis X and the vertical axis Y is defined as the left-right axis Z. One of the directions along the core axis X is defined as the positive direction X1, and the direction opposite to the positive direction X1 is defined as the negative direction X2. In the first embodiment, the positive direction X1 coincides with the direction from the winding core portion 11 toward the first flange portion 21. The negative direction X2 coincides with the direction from the winding core portion 11 toward the second flange portion 31. One of the directions along the vertical axis Y is defined as the upward direction Y1, and the direction opposite to the upward direction Y1 is defined as the downward direction Y2. One of the directions along the horizontal axis Z is defined as the rightward direction Z1, and the direction opposite to the rightward direction Z1 is defined as the leftward direction Z2. The upward direction Y1 and downward direction Y2 are used for convenience and do not specify the direction of gravity. Similarly, the rightward direction Z1 and leftward direction Z2 are used for convenience and do not limit the left and right directions from a particular viewpoint.

[0015] The cross section of the winding core 11 perpendicular to the central axis C is rectangular. That is, the areas of at least two of the side surfaces of the winding core 11 are different. In the following description, as shown in FIG. 2 , of the four side surfaces of the winding core 11, the side surface with the largest area is referred to as the maximum surface 11A, and the side surface opposite to the maximum surface 11A is referred to as the opposing surface 11B. In this embodiment, of the four side surfaces of the winding core 11, the side surfaces with the largest areas are the upper and lower surfaces. In this embodiment, the maximum surface 11A is referred to as the upper surface of the winding core 11. The opposing surface 11B is referred to as the lower surface of the winding core 11.

[0016] In this disclosure, the term "upper surface" refers to a surface facing the upward direction Y1 in the direction along the vertical axis Y, and the term "lower surface" refers to a surface facing the downward direction Y2. The "upper surface" does not necessarily have to be orthogonal to the upward direction Y1. For example, the "upper surface of the coil component 10" refers to a surface that can be seen when the coil component 10 is viewed from the upward direction Y1 toward the downward direction Y2. The same applies to the lower surface.

[0017] 1 , the first flange 21 protrudes outward relative to the winding core 11 in directions along the vertical axis Y and the horizontal axis Z when viewed in a direction along the central axis C. The first flange 21 has a shape that is plane-symmetrical with respect to an imaginary plane that includes the central axis C and is perpendicular to the horizontal axis Z.

[0018] The first flange 21 has a main body 22 and a recess 23. The main body 22 is generally rectangular and has a thin thickness along the central axis C. When viewed in the negative direction X2, both edges of the main body 22 on the upper Y1 side and the lower Y2 side are parallel to the left-right axis Z. When viewed in the negative direction X2, both edges of the main body 22 on the left Z2 side and the right Z1 side are parallel to the up-down axis Y.

[0019] The recessed portion 23 is recessed downward in the Y2 direction from the upper surface of the main body portion 22. The dimension of the recessed portion 23 along the left-right axis Z decreases as it goes downward in the Y2 direction. The recessed portion 23 is located approximately in the center of the main body portion 22 along the left-right axis Z. The dimension of the recessed portion 23 along the central axis C is the same as the dimension of the main body portion 22 along the central axis C. In other words, a portion of the first flange portion 21 on the upward Y1 side has a bifurcated shape with the recessed portion 23 in between.

[0020] The second flange 31 and the first flange 21 have shapes that are plane-symmetrical with respect to an imaginary plane that passes through the center of the winding core 11 and is perpendicular to the central axis C. That is, when viewed from the direction along the central axis C, the second flange 31 protrudes outward from the winding core 11 in the directions along the vertical axis Y and the horizontal axis Z. The second flange 31 has a main body 32 and a recessed portion 33. The configurations of the main body 32 and the recessed portion 33 of the second flange 31 are similar to those of the main body 22 and the recessed portion 23 of the first flange 21. That is, the recessed portion 33 is recessed downward in the Y2 direction from the top surface of the main body 32.

[0021] The plate core 10F has a rectangular plate shape. The long sides of the plate core 10F are parallel to the central axis C. The short sides of the plate core 10F are parallel to the left-right axis Z. The plate core 10F is located on the downward direction Y2 side of the drum core 10C. The plate core 10F is connected to both the lower surface of the first flange portion 21 and the lower surface of the second flange portion 31. In other words, the plate core 10F is bridged between the first flange portion 21 and the second flange portion 31. The material of the plate core 10F is the same as the material of the drum core 10C.

[0022] The coil component 10 includes a first external electrode 41, a second external electrode 42, a third external electrode 43, and a fourth external electrode 44. The first external electrode 41 is provided on the first flange 21. That is, the first external electrode 41 is attached to the surface of the first flange 21. The first external electrode 41 is located on the surface of the first flange 21 on the upward Y1 side, and on the leftward Z2 side with respect to the recess 23.

[0023] The second external electrode 42 is provided on the first flange 21. That is, the second external electrode 42 is attached to the surface of the first flange 21. The second external electrode 42 is located on the surface of the first flange 21 on the upward Y1 side, and on the rightward Z1 side with respect to the recess 23.

[0024] The third external electrode 43 is provided on the second flange 31. That is, the third external electrode 43 is attached to the surface of the second flange 31. The third external electrode 43 is located on the surface of the second flange 31 on the upward Y1 side and on the leftward Z2 side with respect to the recess 33.

[0025] The fourth external electrode 44 is provided on the second flange 31. That is, the fourth external electrode 44 is attached to the surface of the second flange 31. The fourth external electrode 44 is located on the surface of the second flange 31 on the upward Y1 side, and on the rightward Z1 side with respect to the recess 33.

[0026] Although not shown, the first to fourth external electrodes 41 to 44 have a metal layer and a plating layer. The metal layer is, for example, a layer mainly composed of silver. The plating layer is made up of a plurality of layers, for example, a layer mainly composed of copper, a layer mainly composed of nickel, and a layer mainly composed of tin. In this embodiment, the surface of the coil component 10 on which the first to fourth external electrodes 41 to 44 are provided is the surface that faces the substrate when the coil component 10 is mounted on the substrate. Note that in FIG. 1, the first to fourth external electrodes 41 to 44 are shown by dashed dotted lines.

[0027] <Configuration of the First Wire and the Second Wire> As shown in Fig. 1 , the coil device 10 includes a first wire 50 and a second wire 60. The first wire 50 and the second wire 60 have portions wound around the winding core 11. Note that Fig. 1 simplifies the winding structure of the portions of the first wire 50 and the second wire 60 that are wound around the winding core 11, and illustrates each turn of each wire as if they were a cylindrical object integrated together.

[0028] Although not shown in the figures, the first wire 50 has a conductor and an insulating coating. The insulating coating covers the outer surface of the conductor. The first wire 50 has a substantially circular shape in a cross section perpendicular to the direction in which the first wire 50 extends. The first wire 50 has a first wire end 51 and a second wire end 52 opposite the first wire end 51. In each figure, the first wire 50 is colored with dots.

[0029] 1 , a first wire end 51 of the first wire 50 is connected to the first external electrode 41. A second wire end 52 of the first wire 50 is connected to the third external electrode 43. Here, when tracing the first wire 50 from the first wire end 51 to the second wire end 52, the point where the first wire 50 first comes into contact with the outer circumferential surface of the winding core 11 is defined as the 1.0 turn point of the first wire 50. In the first embodiment, the 1.0 turn point of the first wire 50 is located on a ridgeline on the rightward Z1 side and upward Y1 side of the winding core 11.

[0030] As shown in FIG. 2 , the number of turns of the first wire 50 increases by one each time the first wire 50 makes one revolution around the central axis C from the first wire end 51 to the second wire end 52. When viewed in the negative direction X2, the first wire 50 is wound around the winding core 11 so that the number of turns increases clockwise. Therefore, for example, when viewed in the negative direction X2, a point 36 degrees from the 1.0 turn point of the first wire 50 around the central axis C is the 1.1 turn point of the first wire 50. The first turn of the first wire 50 refers to the portion of the first wire 50 from the 1.0 turn point to just before the 2.0 turn point. The final turn of the first wire 50 refers to the turn that includes the last contact point of the first wire 50 with the outer circumferential surface of the winding core 11 when tracing the first wire 50 from the first wire end 51 to the second wire end 52. 2 to 4, any position within the range of the first turn is indicated as "1." The same applies to other numbers of turns. The number of turns shown in FIG. 2 does not have to match the number of turns counted from the start of winding during manufacturing.

[0031] As shown in Fig. 1, the second wire 60 has a similar configuration to the first wire 50. That is, the second wire 60 has a conductor and an insulating coating. The insulating coating covers the outer surface of the conductor. The second wire 60 has a substantially circular shape in a cross section perpendicular to the direction in which the second wire 60 extends. The second wire 60 has a first wire end 61 and a second wire end 62 opposite the first wire end 61.

[0032] 1 , a first wire end 61 of the second wire 60 is connected to the second external electrode 42. A second wire end 62 of the second wire 60 is connected to the fourth external electrode 44. Here, when tracing the second wire 60 from the first wire end 61 to the second wire end 62, the first point whose angular position about the central axis C matches the angular position of the 1.0 turn point of the first wire 50 is defined as the 1.0 turn point of the second wire 60. That is, in the first embodiment, when viewed in a direction along the central axis C, the 1.0 turn point of the second wire 60 is located on a straight line connecting the ridge line on the rightward direction Z1 side and upward direction Y1 side of the winding core portion 11 and the central axis C.

[0033] 2 , the number of turns of the second wire 60 increases by one each time the second wire 60 makes one revolution around the central axis C from the first wire end 61 to the second wire end 62. When viewed in the negative direction X2, the second wire 60 is wound around the winding core 11 so that the winding progresses clockwise as the number of turns increases. In other words, the second wire 60 is wound around the winding core 11 in the same direction as the first wire 50. The number of turns of the second wire 60 is counted in the same way as the first wire 50.

[0034] With regard to the first wire 50 and the second wire 60, the portion that is directly wound around the winding core 11 is referred to as the first layer L1. Here, "directly wound" not only refers to a state in which the wire is in contact with the outer peripheral surface of the winding core 11, but also includes a state in which the wire is wound around the winding core 11 without any other wire between them, even if the wire is floating relative to the winding core 11.

[0035] Furthermore, with regard to the first wire 50 and the second wire 60, the portion wound from the outside in a direction perpendicular to the central axis C around the first layer L1 adjacent in the direction along the central axis C is referred to as the second layer L2.

[0036] Furthermore, with respect to the first wire 50 and the second wire 60, the portion wound from the outside in a direction perpendicular to the central axis C around the second layer L2 adjacent in the direction along the central axis C is referred to as a third layer L3.

[0037] <Regarding the Wire Winding Mode of the First Embodiment> As shown in Fig. 2 , all turns of the first wire 50 belong to the first layer L1. The first wire 50 is wound from the first turn to the eighth turn. The first wire 50 has a first portion P1. The first portion P1 is a portion of the first wire 50 that is continuously wound directly around the winding core 11. In this embodiment, the number of turns in the first portion P1 and the total number of turns of the first wire 50 are the same.

[0038] The first to eighth turns of the first wire 50 are wound in order such that the increasing number of turns leads to a position closer to the second flange 31 in the direction along the central axis C. Furthermore, the first to eighth turns of the first wire 50 are wound adjacent to each other in the direction along the central axis C. Here, "wound adjacent to each other" does not necessarily mean that the turns of adjacent wires are in contact with each other. Even if the turns of adjacent wires are not in contact with each other, they can be said to be adjacent as long as there is no other wire on the line connecting the centers of the adjacent wires when viewed in cross section.

[0039] The second wire 60 is wound from the first turn to the eighth turn. The second wire 60 has a second portion P2 and a third portion P3. In this embodiment, the number of turns including the second portion P2 and the third portion P3 is equal to the total number of turns of the second wire 60. Note that in Figure 2, the winding of the second wire 60 on the surface of the winding core 11 facing the right direction Z1 is simply illustrated by dashed lines.

[0040] The second portion P2 is a portion of the second wire 60 that is wound directly from the outside around the first portion P1 in a direction perpendicular to the central axis C. The second portion P2 can be roughly divided into a first half portion P2F and a second half portion P2L. In this embodiment, the first half portion P2F of the second portion P2 is a portion from the first turn of the second wire 60 to partway through the fifth turn. The fifth turn of the second wire 60 is located outside the fourth turn of the second wire 60 on the largest surface 11A of the winding core 11 in a direction perpendicular to the central axis C. In this way, the portion of the fifth turn up to the fourth turn belongs to the second portion P2.

[0041] The first turn of the second wire 60 is located in the valley between the first and second turns of the first wire 50. The second turn of the second wire 60 is located in the valley between the second and third turns of the first wire 50. The third turn of the second wire 60 is located in the valley between the third and fourth turns of the first wire 50. The fourth turn of the second wire 60 is located in the valley between the fourth and fifth turns of the first wire 50. The portion of the fifth turn of the second wire 60 that belongs to the second portion P2 is located in the valley between the fifth and sixth turns of the first wire 50.

[0042] The third portion P3 is a portion of the second wire 60 that is wound directly from the outside around the second portion P2 in a direction perpendicular to the central axis C. In this embodiment, the third portion P3 is a portion of the second wire 60 from the middle of the fifth turn to the middle of the sixth turn. In the sixth turn of the second wire 60, a portion of the second wire 60 that is located on the surface of the winding core 11 facing the right direction Z1 and on the opposing surface 11B is wound directly from the outside around the second portion P2 in a direction perpendicular to the central axis C. Therefore, this portion belongs to the third portion P3. On the other hand, a portion of the second wire 60 that is located on the surface of the winding core 11 facing the left direction Z2 and on the maximum surface 11A is wound directly from the outside around the first portion P1 in a direction perpendicular to the central axis C. Therefore, this portion belongs to the second portion P2.

[0043] Most of the portion of the fifth turn of the second wire 60 that belongs to the third portion P3 is located in the valley between the third and fourth turns of the second wire 60. Furthermore, most of the portion of the sixth turn of the second wire 60 that belongs to the third portion P3 is located in the valley between the third and fourth turns of the second wire 60.

[0044] The second half P2L of the second portion P2 is located closer to the second end 62 than the first half P2F of the second portion P2 when tracing the second wire 60 from the first end 61 to the second end 62. In this embodiment, the second half P2L of the second portion P2 is the portion of the second wire 60 from the middle of the sixth turn to the eighth turn.

[0045] The portion of the fifth turn of the second wire 60 that belongs to the second portion P2 is located between the valleys of the fifth and sixth turns of the first wire 50. The seventh turn of the second wire 60 is located between the valleys of the sixth and seventh turns of the first wire 50. The eighth turn of the second wire 60 is located between the valleys of the seventh and eighth turns of the first wire 50.

[0046] <Regarding the specific location and specific turn in the first embodiment> As shown in Fig. 2 , when tracing the second wire 60 from the first wire end 61 to the second wire end 62, the specific location is the location where the second portion P2 first switches to the third portion P3. In this embodiment, the specific location is located on the surface of the fifth turn of the second wire 60 facing the left direction Z2 of the winding core 11, that is, on the surface on the far side of the page relative to the winding core 11 in Fig. 2 . In other words, the turn of the second wire 60 that includes the specific location is the fifth turn. Furthermore, one turn from the specific location toward the second wire end 62 is defined as the specific turn ST. Therefore, the specific turn ST is the portion of the second wire 60 from the middle of the fifth turn to the middle of the sixth turn.

[0047] The specific turn ST includes a portion wound in the valley between the third and fourth turns of the second wire 60. In other words, when i is 5 and j is 4, the turn of the second wire 60 that includes the specific portion is the i-th turn. Furthermore, the specific turn ST is wound in the valley between the (j-1)th and j-th turns of the second wire 60. In this embodiment, the value of j is the same as the value of (i-1).

[0048] In other words, when M is 5, the specific turn ST is one turn that includes a portion of the Mth turn and a portion of the (M+1)th turn of the second wire 60. The portion of the Mth turn of the second wire 60 in the specific turn ST has a portion that is located in the valley between the (M-2)th turn of the second wire 60 and the (M-1)th turn of the second wire 60. The portion of the (M+1)th turn of the second wire 60 in the specific turn ST has a portion that is located in the valley between the (M-2)th turn of the second wire 60 and the (M-1)th turn of the second wire 60.

[0049] The specific turn ST has a crossing portion CR that crosses from the second flange 31 side to the first flange 21 side in the direction along the central axis C for at least one turn of the second portion P2. Specifically, the specific turn ST has a crossing portion CR that crosses from the second flange 31 side to the first flange 21 side in the direction along the central axis C for the fourth turn of the second wire 60. In other words, when j is 4, the specific turn ST has a crossing portion CR that crosses from the second flange 31 side to the first flange 21 side in the direction along the central axis C for the jth turn of the second wire 60. In this way, the specific turn ST of the second wire 60 is wound one turn back from the previous turn of the second wire 60. As shown in FIG. 2 , a part of the specific turn ST including the specific location may not be in contact with the fourth turn of the second wire 60 , but may be in contact with only the third turn of the second wire 60 .

[0050] The crossing point CR is located on the surface facing the right direction Z1 of the side surface of the winding core 11. Therefore, the part of the specific turn ST closer to the first wire end 61 than the crossing point CR has a part located on the maximum surface 11A. Also, the part of the specific turn ST closer to the second wire end 62 than the crossing point CR has a part located on the opposing surface 11B.

[0051] <Effects of the First Embodiment> (1-1) In the first embodiment, the specific turn ST of the second wire 60 has a crossing portion CR, and is therefore wound so as to return toward the first flange 21 in the direction along the central axis C. As a result, in the first embodiment, the specific turn ST of the second wire 60 has a portion wound in the valley between the (j-1)th turn and the jth turn of the second portion P2, and a portion wound in the valley between the (j-2)th turn and the (j-1)th turn. That is, the specific turn ST is wound in a dispersed manner in the valleys of different turns. By winding the specific turn ST in this manner, the load from the specific turn ST is less likely to concentrate on the turn located in the negative direction X2, among the two adjacent turns of the second portion P2 located inside the specific turn ST. Therefore, the turn of the second portion P2 that the specific turn ST contacts is less likely to be displaced in the direction along the central axis C. As a result, the specific turn ST is less likely to fall into the second layer L2.

[0052] In particular, when the second wire 60 is wound from the first flange 21 side toward the second flange 31 side, at the timing of winding the specific turn ST, no other turns of the second wire 60 are present in the negative direction X2 relative to the fourth turn of the second wire 60. In this state, if a load acting in the negative direction X2 is concentrated on the fourth turn of the second wire 60, the fourth turn is likely to be misaligned in the negative direction X2. The configuration of the first embodiment particularly prevents such misalignment.

[0053] (1-2) Let us assume that the value of j is equal to the value of (i-2). In this case, the specific turn ST is wound back by at least two turns in the direction along the central axis C. Therefore, the length of the specific turn ST is sufficiently longer than the length of each of the other turns. If the wire length of the specific turn ST is too long, the coil component may not achieve the desired characteristics. In the first embodiment, the value of j is the same as the value of (i-1). This configuration makes it possible to reduce the wire length of the specific turn ST. Therefore, it is possible to reduce the changes in the characteristics of the coil component 10 caused by the length of the specific turn ST as described above.

[0054] (1-3) In the first embodiment, the portion of the specific turn ST closer to the first wire end 61 than the crossing point CR has a portion located on the maximum surface 11A. Furthermore, the portion of the specific turn ST closer to the second wire end 62 than the crossing point CR has a portion located on the opposing surface 11B. In other words, the specific turn ST has a portion located on the maximum surface 11A, between two adjacent turns of the second portion P2. Furthermore, the specific turn ST has a portion located on the opposing surface 11B, between two adjacent turns of the second portion P2. The crossing point CR is likely to be located on a surface sandwiched between the maximum surface 11A and the opposing surface 11B. This configuration makes the specific turn ST less likely to shift position, resulting in a stable winding shape.

[0055] Second Embodiment A second embodiment of the coil component will be described below. In the coil component of the second embodiment, the basic configurations of the drum core 10C, the planar core 10F, and the first wire 50, the winding manner of the first wire 50, the basic configuration of the second wire 60, and the configurations of the first external electrode 41 to the fourth external electrode 44 are the same as those of the first embodiment. The following describes the winding manner of the second wire 60, which is a configuration different from that of the first embodiment.

[0056] <Regarding the Wire Winding Mode of the Second Embodiment> As shown in Fig. 3 , the second wire 60 is wound from the first turn to the eighth turn. The second wire 60 has a second portion P2 and a third portion P3. In this embodiment, the number of turns including the second portion P2 and the third portion P3 is equal to the total number of turns of the second wire 60. In other words, when N is 4, the total number of turns of the second portion P2 and the third portion P3 of the second wire 60 is 2N. Note that in Fig. 3 , the winding mode of the second wire 60 on the surface of the winding core 11 facing the rightward direction Z1 is simply illustrated by dashed lines.

[0057] The second portion P2 is a portion of the second wire 60 that is wound directly from the outside around the first portion P1 in a direction perpendicular to the central axis C. The second portion P2 can be roughly divided into a first half portion P2F and a second half portion P2L. In this embodiment, the first half portion P2F of the second portion P2 is a portion from the first turn of the second wire 60 to partway through the fourth turn. The fourth turn of the second wire 60 is located outside the third turn of the second wire 60 on the largest surface 11A of the winding core 11 in a direction perpendicular to the central axis C. In this way, the portion of the fourth turn of the second wire 60 up to the point where it rides over the third turn of the second wire 60 belongs to the second portion P2.

[0058] The first turn of the second wire 60 is located in the valley between the first and second turns of the first wire 50. The second turn of the second wire 60 is located in the valley between the second and third turns of the first wire 50. The third turn of the second wire 60 is located in the valley between the third and fourth turns of the first wire 50. The part of the fourth turn of the second wire 60 that belongs to the second portion P2 is located in the valley between the fourth and fifth turns of the first wire 50.

[0059] The third portion P3 is a portion of the second wire 60 that is wound directly from the outside around the second portion P2 in a direction perpendicular to the central axis C. In this embodiment, the third portion P3 is a portion of the second wire 60 from the middle of the fourth turn to the middle of the fifth turn. In the fifth turn of the second wire 60, the portion of the second wire 60 that is located on the surface of the winding core 11 facing the right direction Z1 and on the opposing surface 11B is wound directly from the outside around the second portion P2 in a direction perpendicular to the central axis C. Therefore, this portion belongs to the third portion P3. On the other hand, the portion of the second wire 60 that is located on the surface of the winding core 11 facing the left direction Z2 and on the maximum surface 11A is wound directly from the outside around the first portion P1 in a direction perpendicular to the central axis C. Therefore, this portion belongs to the second portion P2.

[0060] Most of the portion of the fourth turn of the second wire 60 that belongs to the third portion P3 is located in the valley between the second and third turns of the second wire 60. Furthermore, most of the portion of the fifth turn of the second wire 60 that belongs to the third portion P3 is located in the valley between the second and third turns of the second wire 60.

[0061] The second half P2L of the second portion P2 is a portion of the second wire 60 that is wound directly from the outside around the first portion P1 in a direction perpendicular to the central axis C. Furthermore, when tracing the second wire 60 from the first wire end 61 to the second wire end 62, the second half P2L of the second portion P2 is located closer to the second wire end 62 than the first half P2F of the second portion P2. In this embodiment, the second half P2L of the second portion P2 is a portion of the second wire 60 from the middle of the fifth turn to the eighth turn.

[0062] The portion of the fifth turn of the second wire 60 that belongs to the second portion P2 is located between the valleys of the fourth and fifth turns of the first wire 50. The sixth turn of the second wire 60 is located between the valleys of the fifth and sixth turns of the first wire 50. The seventh turn of the second wire 60 is located between the valleys of the sixth and seventh turns of the first wire 50. The eighth turn of the second wire 60 is located between the valleys of the seventh and eighth turns of the first wire 50.

[0063] <Regarding the specific location and specific turn in the second embodiment> As shown in Fig. 3 , when tracing the second wire 60 from the first wire end 61 to the second wire end 62, the specific location is the location where the second portion P2 first switches to the third portion P3. In this embodiment, the specific location is located on the surface of the fourth turn of the second wire 60 facing the left direction Z2 of the winding core 11, that is, on the surface on the far side of the page relative to the winding core 11 in Fig. 2 . In other words, the turn of the second wire 60 that includes the specific location is the fourth turn. Furthermore, one turn from the specific location toward the second wire end 62 is defined as the specific turn ST. Therefore, the specific turn ST is the portion of the second wire 60 from the middle of the fourth turn to the middle of the fifth turn.

[0064] The specific turn ST is wound in the valley between the second and third turns of the second wire 60. In other words, when i is 4 and j is 3, the turn of the second wire 60 that includes the specific location is the i-th turn. The specific turn ST is also wound in the valley between the (j-1)th and j-th turns of the second wire 60. In this embodiment, the value of j is the same as the value of (i-1).

[0065] In other words, when M is 4, the specific turn ST is one turn that includes a portion of the Mth turn and a portion of the (M+1)th turn of the second wire 60. The portion of the Mth turn of the second wire 60 in the specific turn ST has a portion that is located in the valley between the (M-2)th turn of the second wire 60 and the (M-1)th turn of the second wire 60. The portion of the (M+1)th turn of the second wire 60 in the specific turn ST has a portion that is located in the valley between the (M-2)th turn of the second wire 60 and the (M-1)th turn of the second wire 60.

[0066] As described above, the total number of turns in the second portion P2 and the third portion P3 of the second wire 60 is 2N. In the second embodiment, the value of N is the same as the value of i. That is, the number of turns in the second wire 60 that include the specific location is half the total number of turns in the second portion P2 and the third portion P3 of the second wire 60.

[0067] The specific turn ST has a crossing portion CR that crosses the third turn of the second wire 60 from the second flange 31 side to the first flange 21 side in the direction along the central axis C. In other words, when j is 3, the specific turn ST has a crossing portion CR that crosses the jth turn of the second wire 60 from the second flange 31 side to the first flange 21 side in the direction along the central axis C. In this way, the specific turn ST of the second wire 60 is wound back by one turn with respect to the previous turn of the second wire 60. Note that, as shown in FIG. 2 , a portion of the specific turn ST including the specific portion may not contact the third turn of the second wire 60, but may only contact the second turn of the second wire 60.

[0068] The specific turn ST has a crossing portion CR that crosses at least one turn of the second portion P2 from the second flange 31 side to the first flange 21 side in the direction along the central axis C. Specifically, the specific turn ST has a crossing portion CR that crosses the third turn of the second wire 60 from the second flange 31 side to the first flange 21 side in the direction along the central axis C. The crossing portion CR is located on a surface of the side surface of the winding core 11 that faces the rightward direction Z1. Therefore, a portion of the specific turn ST closer to the first wire end 61 than the crossing portion CR has a portion that is located on the maximum surface 11A. Furthermore, a portion of the specific turn ST closer to the second wire end 62 than the crossing portion CR has a portion that is located on the opposing surface 11B.

[0069] <Regarding stray capacitance in the second embodiment> In the following, it is assumed that the same positive voltage is applied to the first line end 51 of the first wire 50 and the first line end 61 of the second wire 60, and that a ground voltage is applied as a reference voltage to the second line end 52 of the first wire 50 and the second line end 62 of the second wire 60.

[0070] The greater the difference in the number of turns between the turns of the first wire 50 that contact the turns of the second wire 60, the greater the stray capacitance generated between adjacent turns of each wire. For example, as shown in FIG. 3 , the turns of the first wire 50 that contact the first turn of the second wire 60 are the first and second turns. In this case, there is no significant potential difference between the first turn of the second wire 60 and the first turn of the first wire 50. However, when comparing the potential of the first turn of the second wire 60 with the potential of the second turn of the first wire 50, the potential of the first turn of the second wire 60 is higher. Therefore, a stray capacitance corresponding to this potential difference is generated between the first turn of the second wire 60 and the second turn of the first wire 50.

[0071] Here, attention is focused on the range of the first half P2F of the second portion P2 of the second wire 60. When comparing the turns of the first wire 50 and the second wire 60 that contact each other in this range, the stray capacitance generated when the potential of the second wire 60 is one turn higher than the potential of the first wire 50 is defined as a negative unit capacitance A.

[0072] Also, attention is focused on the range of the latter half P2L of the second portion P2 of the second wire 60. When comparing the turns of the first wire 50 and the turns of the second wire 60 that contact each other in this range, the stray capacitance generated when the potential of the first wire 50 is one turn higher than the potential of the second wire 60 is defined as a positive unit capacitance B.

[0073] Focus on the potential drop of the specific turn ST of the second wire 60. Unlike the other turns, the specific turn ST of the second wire 60 is wound in a rewinding manner. Therefore, the wire length of the specific turn ST is longer than that of the other turns. As a result, the potential drop of the specific turn ST is greater than the potential drop of the other turns. Therefore, the absolute value of the stray capacitance for one turn generated between the second half P2L of the second portion P2 and the first wire 50 is greater than the absolute value of the stray capacitance for one turn generated between the first half P2F of the second portion P2 and the first wire 50. Therefore, the absolute value of the positive unit capacitance B is greater than the absolute value of the negative unit capacitance A. In the first embodiment, the coil device 10 has four negative unit capacitances A and three positive unit capacitances B. Furthermore, since the absolute value of the positive unit capacitance B is larger than the absolute value of the negative unit capacitance A, although the number of negative unit capacitances A and the number of positive unit capacitances B are different, the stray capacitance of the entire coil component 10 is close to zero.

[0074] <Effects of the Second Embodiment> In the second embodiment, in addition to the effects (1-1) to (1-3) of the first embodiment, the following effects can be further obtained.

[0075] (2-1) In the second embodiment, the total number of turns in the first wire 50 is 2N. Furthermore, the number of turns in the first portion P1 is equal to the total number of turns in the first wire 50. The total number of turns in the second wire 60 is 2N. Furthermore, the number of turns including the second portion P2 and the third portion P3 is equal to the total number of turns in the second wire 60. Furthermore, in the second embodiment, the value of N is the same as the value of i. With this configuration, as described above, the number of negative unit capacitances A is likely to be greater than the number of positive unit capacitances B. On the other hand, because the absolute value of the positive unit capacitance B is greater than the absolute value of the negative unit capacitance A, imbalance in stray capacitance is less likely to occur in the coil device 10 as a whole.

[0076] <Regarding the Third Embodiment> A coil component according to a third embodiment will be described below. In the coil component according to the third embodiment, the basic configurations of the drum core 10C, the planar core 10F, the first wire 50, the second wire 60, and the first to fourth external electrodes 41 to 44 are the same as those in the first embodiment. The following describes the winding manner of the first wire 50 and the winding manner of the second wire 60, which are different from those in the first embodiment.

[0077] <Regarding the Wire Winding Mode of the Third Embodiment> As shown in Fig. 4 , all turns of the first wire 50 belong to the first layer L1. The first wire 50 is wound from the first turn to the twelfth turn. The first wire 50 has a first portion P1. The first portion P1 is a portion of the first wire 50 that is continuously wound directly around the winding core 11. In this embodiment, the number of turns in the first portion P1 and the total number of turns of the first wire 50 are the same.

[0078] The first wire 50 is wound in order from the first turn to the twelfth turn such that the greater the number of turns, the closer the turns are to the second flange 31 in the direction along the central axis C. The first wire 50 is wound adjacent to the first turn to the twelfth turn in the direction along the central axis C.

[0079] The second wire 60 is wound from the first turn to the twelfth turn. The second wire 60 has a second portion P2 and a third portion P3. In this embodiment, the number of turns including the second portion P2 and the third portion P3 is equal to the total number of turns of the second wire 60. Note that in Figure 4, the winding of the second wire 60 on the surface of the winding core 11 facing the right direction Z1 is simply illustrated by dashed lines.

[0080] The second portion P2 is a portion of the second wire 60 that is wound directly from the outside around the first portion P1 in a direction perpendicular to the central axis C. The second portion P2 can be roughly divided into a first half portion P2F and a second half portion P2L. In this embodiment, the first half portion P2F of the second portion P2 is a portion from the first turn to partway through the sixth turn of the second wire 60. The sixth turn of the second wire 60 is located outside the fifth turn of the second wire 60 on the largest surface 11A of the winding core 11 in a direction perpendicular to the central axis C. In this way, the portion of the sixth turn of the second wire 60 up to the point where it rides over the fifth turn of the second wire 60 belongs to the second portion P2.

[0081] The first turn of the second wire 60 is located in the valley between the first and second turns of the first wire 50. The second turn of the second wire 60 is located in the valley between the second and third turns of the first wire 50. The third turn of the second wire 60 is located in the valley between the third and fourth turns of the first wire 50. The fourth turn of the second wire 60 is located in the valley between the fourth and fifth turns of the first wire 50. The fifth turn of the second wire 60 is located in the valley between the fifth and sixth turns of the first wire 50. A portion of the sixth turn of the second wire 60 belonging to the second portion P2 is located in the valley between the sixth and seventh turns of the first wire 50.

[0082] The third portion P3 is a portion of the second wire 60 that is wound directly from the outside around the second portion P2 in a direction perpendicular to the central axis C. In this embodiment, the third portion P3 is a portion of the second wire 60 from the middle of the sixth turn to the middle of the eighth turn. In the eighth turn of the second wire 60, the portion of the second wire 60 that is located on the surface of the winding core 11 facing the right direction Z1 and on the opposing surface 11B is wound directly from the outside around the second portion P2 in a direction perpendicular to the central axis C. Therefore, this portion belongs to the third portion P3. On the other hand, the portion of the second wire 60 that is located on the surface of the winding core 11 facing the left direction Z2 and on the maximum surface 11A is wound directly from the outside around the first portion P1 in a direction perpendicular to the central axis C. Therefore, this portion belongs to the second portion P2.

[0083] Most of the portion of the sixth turn of the second wire 60 that belongs to the third portion P3 is located in the valley between the third and fourth turns of the second wire 60. Furthermore, the seventh turn of the second wire 60 is located in the valley between the third and fourth turns of the second wire 60 on the opposing surface 11B. Furthermore, the seventh turn of the second wire 60 is located in the valley between the fourth and fifth turns of the second wire 60 on the maximum surface 11A. In other words, the seventh turn of the second wire 60 intersects with the fourth turn of the second wire 60. Most of the portion of the eighth turn of the second wire 60 that belongs to the third portion P3 is located in the valley between the fourth and fifth turns of the second wire 60.

[0084] The second half P2L of the second portion P2 is a portion of the second wire 60 that is wound directly from the outside around the first portion P1 in a direction perpendicular to the central axis C. Furthermore, when tracing the second wire 60 from the first wire end 61 to the second wire end 62, the second half P2L of the second portion P2 is located closer to the second wire end 62 than the first half P2F of the second portion P2. In this embodiment, the second half P2L of the second portion P2 is a portion of the second wire 60 from the middle of the eighth turn to the twelfth turn.

[0085] The portion of the eighth turn of the second wire 60 that belongs to the second portion P2 is located between the valleys of the sixth and seventh turns of the first wire 50. The ninth turn of the second wire 60 is located between the valleys of the seventh and eighth turns of the first wire 50. The tenth turn of the second wire 60 is located between the valleys of the eighth and ninth turns of the first wire 50. The eleventh turn of the second wire 60 is located between the valleys of the ninth and tenth turns of the first wire 50. The twelfth turn of the second wire 60 is located between the valleys of the tenth and eleventh turns of the first wire 50.

[0086] <Specific Location and Specific Turn in Third Embodiment> As shown in FIG. 4 , when tracing the second wire 60 from the first wire end 61 to the second wire end 62, the first location where the second portion P2 switches to the third portion P3 is defined as the first specific location. In this embodiment, the first specific location is located on the surface of the sixth turn of the second wire 60 facing the left direction Z2 of the winding core 11, that is, on the surface of the winding core 11 facing the back side of the page in FIG. 4 . In other words, the turn of the second wire 60 that includes the first specific location is the sixth turn. Furthermore, one turn from the first specific location toward the second wire end 62 is defined as the first specific turn ST1. Therefore, the first specific turn ST1 is a location from the middle of the sixth turn to the middle of the seventh turn of the second wire 60.

[0087] The first specific turn ST1 includes a portion wound in the valley between the third and fourth turns of the second wire 60. In other words, when i is 6 and j is 4, the turn of the second wire 60 that includes the first specific portion is the i-th turn. Furthermore, the first specific turn ST1 is wound in the valley between the (j-1)-th turn and the j-th turn of the second wire 60.

[0088] The first specific turn ST1 has a first crossing portion CR1 that crosses from the second flange 31 side to the first flange 21 side in the direction along the central axis C with respect to at least one turn of the second portion P2. Specifically, the first specific turn ST1 has a first crossing portion CR1 that crosses from the second flange 31 side to the first flange 21 side in the direction along the central axis C with respect to the fourth turn of the second wire 60. In other words, when j is 4, the first specific turn ST1 has a first crossing portion CR1 that crosses from the second flange 31 side to the first flange 21 side in the direction along the central axis C with respect to the jth turn of the second wire 60. In this way, the first specific turn ST1 is wound back one turn with respect to the previous turn of the second wire 60. As shown in Figure 4, the first specific turn ST1 including the first specific location may not be in contact with the fourth turn of the second wire 60, but may be in contact only with the third turn of the second wire 60.

[0089] The first crossing point CR1 is located on the surface facing the right direction Z1 of the side surface of the winding core portion 11. Therefore, a portion of the first specific turn ST1 closer to the first wire end 61 than the first crossing point CR1 has a portion located on the maximum surface 11A. Furthermore, a portion of the first specific turn ST1 closer to the second wire end 62 than the first crossing point CR1 has a portion located on the opposing surface 11B.

[0090] When tracing the second wire 60 from the first wire end 61 to the second wire end 62, the second specific location is a location one turn after the first specific location. In this embodiment, the second specific location is located on the seventh turn of the second wire 60, on a surface facing the left direction Z2 of the winding core 11, that is, on a surface on the far side of the page with respect to the winding core 11 in FIG. 4 . In other words, the turn of the second wire 60 that includes the second specific location is the seventh turn. Furthermore, one turn from the second specific location toward the second wire end 62 is referred to as the second specific turn ST2. Therefore, the second specific turn ST2 is a location from the middle of the seventh turn to the middle of the eighth turn of the second wire 60.

[0091] The second specific turn ST2 includes a portion wound in the valley between the fourth and fifth turns of the second wire 60. In other words, when i is 6 and k is 5, the turn of the second wire 60 that includes the second specific portion is the (i+1)th turn. Furthermore, the second specific turn ST2 is wound in the valley between the (k-1)th turn and the kth turn of the second wire 60.

[0092] The second specific turn ST2 has a second crossing portion CR2 that crosses from the second flange 31 side to the first flange 21 side in the direction along the central axis C for at least one turn of the second portion P2. Specifically, the second specific turn ST2 has a second crossing portion CR2 that crosses from the second flange 31 side to the first flange 21 side in the direction along the central axis C for the fifth turn of the second wire 60. In other words, when k is 5, the second specific turn ST2 has a second crossing portion CR2 that crosses from the second flange 31 side to the first flange 21 side in the direction along the central axis C for the kth turn of the second wire 60. In this way, the second specific turn ST2 is wound back by one turn. As shown in Figure 4, this may result in the second specific turn ST2 including the second specific location not being in contact with the fifth turn of the second wire 60, but only being in contact with the fourth turn of the second wire 60.

[0093] The second crossing point CR2 is located on a surface facing the right direction Z1 of the side surface of the winding core portion 11. Therefore, a portion of the second specific turn ST2 closer to the first wire end 61 than the second crossing point CR2 has a portion located on the maximum surface 11A. Furthermore, a portion of the second specific turn ST2 closer to the second wire end 62 than the second crossing point CR2 has a portion located on the opposing surface 11B.

[0094] Effects of the Third Embodiment (3-1) In the third embodiment, the first specific turn ST1 of the second wire 60 is wound so as to return toward the first flange 21 in the direction along the central axis C. That is, the first specific turn ST1 is wound in a dispersed manner in the valleys between different turns. By winding the first specific turn ST1 in this manner, the load from the first specific turn ST1 is less likely to be concentrated on the turn located in the negative direction X2, out of two adjacent turns of the second portion P2 located inside the first specific turn ST1. Therefore, the turn of the second portion P2 that comes into contact with the first specific turn ST1 is less likely to be displaced in the direction along the central axis C. As a result, the first specific turn ST1 is less likely to sink into the second layer L2. This is also true for the second specific turn ST2.

[0095] In particular, when the second wire 60 is wound from the first flange 21 side toward the second flange 31 side, at the timing of winding the second specific turn ST2, no other turns of the second wire 60 are present in the negative direction X2 relative to the fifth turn of the second wire 60. In this state, if a load acting in the negative direction X2 concentrates on the fifth turn of the second wire 60, the fifth turn is likely to be misaligned in the negative direction X2. The configuration of the third embodiment particularly prevents such misalignment.

[0096] <Modifications> The first, second, and third embodiments can be modified and implemented as follows: The first, second, and third embodiments described above and the following modifications can be combined and implemented within a range that does not cause technical contradictions.

[0097] In the first and second embodiments, the configuration of the coil component 10 is not limited to the above configuration. For example, the coil component 10 does not need to include the planar core 10F. Furthermore, the shape of the planar core 10F is not limited to a rectangular plate. For example, the planar core 10F may be an elliptical plate.

[0098] In the first, second, and third embodiments, the shape of the winding core 11 is not limited to the examples of the above embodiments. That is, the winding core 11 is not limited to a quadrangular prism in which at least two of the side surfaces of the winding core 11 have different areas. For example, the shape of the winding core 11 may be a quadrangular prism with a square cross section, a cylindrical shape, or a polygonal prism shape other than a quadrangular prism.

[0099] In the first, second, and third embodiments, the maximum surface 11A of the winding core portion 11 is not limited to the upper surface. In the first, second, and third embodiments, the material of the drum core 10C and the planar core 10F is not limited to the examples of the above embodiments. For example, the material of the drum core 10C and the planar core 10F is not limited to Ni-Zn ferrite, but may be Mn-Zn ferrite, etc. Furthermore, the material of the drum core 10C and the planar core 10F may be ferrite, alumina, synthetic resin, a mixture thereof, etc.

[0100] In the first, second, and third embodiments, the configuration of the drum core 10C is not limited to the examples of the above embodiments. For example, the first flange 21 may not have the recess 23. In this case, it is sufficient that the first external electrode 41 and the second external electrode 42 are spaced apart from each other. The same applies to the second flange 31.

[0101] In the first, second, and third embodiments, the material and shape of the first to fourth external electrodes 41 to 44 are not limited to the examples in each embodiment. For example, the plating layer of the first to fourth external electrodes 41 to 44 may be a single conductive layer. Alternatively, the first to fourth external electrodes 41 to 44 may not have a plating layer, and a conductive metal layer may be exposed. Alternatively, the first to fourth external electrodes 41 to 44 may be formed from a plate-shaped metal material.

[0102] In the first, second, and third embodiments, the cross-sectional shapes of the first wire 50 and the second wire 60 are not limited to those of the above embodiments. For example, the cross-sectional shapes of the first wire 50 and the second wire 60 may be elliptical, rectangular, or the like.

[0103] In the first, second, and third embodiments, the total number of turns in the first wire 50 and the second wire 60 is not limited to the examples in the above embodiments. That is, in the first embodiment, the total number of turns in the first wire 50 is not limited to 2N. Furthermore, the total number of turns in the second wire 60 is not limited to 2N. For example, the first wire 50 may have turns that do not belong to the first portion P1. That is, the number of turns including the first portion P1 may not match the total number of turns in the first wire 50. Furthermore, the second wire 60 may have turns that do not belong to either the second portion P2 or the third portion P3. That is, the number of turns including the second portion P2 and the third portion P3 may not match the total number of turns in the second wire 60.

[0104] In the first embodiment, the specific point may or may not be in contact with the fourth turn of the second wire 60. In the second embodiment, the specific point may or may not be in contact with the third turn of the second wire 60. In the third embodiment, the first specific point may or may not be in contact with the fourth turn of the second wire 60. The second specific point may or may not be in contact with the fifth turn of the second wire 60.

[0105] In the second embodiment, when the total number of turns in the first wire 50 is 2N and the total number of turns in the second wire 60 is 2N, the turn of the second wire 60 that includes the specific location does not have to be the Nth turn. That is, the value of N and the value of i may be different.

[0106] In the first and second embodiments, the specific number of turns of the second wire 60 including the specific location and the specific number of turns of the second wire 60 around which the specific location is wound are not limited to the examples of the above embodiments. When i is an integer of 3 or greater, the turn of the second wire 60 including the specific location may be the i-th turn. Furthermore, when j is an integer of 2 or greater and less than i, the specific location may be wound in the valley between the (j-1)th turn and the j-th turn of the second wire 60. Furthermore, in the first embodiment, the value of j may be a value different from (i-1).

[0107] In the first embodiment, the specific turn ST of the second wire 60 may cross two or more turns of the second portion P2. That is, the specific turn ST may be unwound by two or more turns. This also applies to the second and third embodiments.

[0108] In the first and second embodiments, the portion of the specific turn ST closer to the first wire end 61 than the crossing point CR may not have a portion located on the largest surface 11A. Also, the portion of the specific turn ST closer to the second wire end 62 than the crossing point CR may not have a portion located on the opposing surface 11B. This also applies to the third embodiment.

[0109] In the first embodiment, the specific number of turns of the second wire 60 around which the specific turn ST is wound is not limited to the example of the above embodiment. For example, when M is an integer greater than or equal to 3, the specific turn ST is one turn that includes a portion of the Mth turn of the second wire 60 and a portion of the (M+1)th turn. Furthermore, it is assumed that a portion of the Mth turn of the second wire 60 in the specific turn ST has a portion located in a valley between the (M-2)th turn of the second wire 60 and the (M-1)th turn of the second wire 60. In this case, a portion of the (M+1)th turn of the second wire 60 in the specific turn ST may be located in a position different from the valley between the (M-2)th turn of the second wire 60 and the (M-1)th turn of the second wire 60. This also applies to the second embodiment.

[0110] In the third embodiment, the specific number of turns of the second wire 60 including the first specific location and the specific number of turns of the second wire 60 around which the first specific location is wound are not limited to the examples of the above embodiment. When i is an integer equal to or greater than 4, the turn of the second wire 60 including the first specific location may be the i-th turn. When j is an integer equal to or greater than 2 and less than i-1, the first specific location may be wound in the valley between the (j-1)th turn and the jth turn of the second wire 60. The same applies to the second specific location. The turn of the second wire 60 including the second specific location may be the (i+1)th turn. When k is an integer equal to or greater than 3 and less than i, the second specific location may be wound in the valley between the (k-1)th turn and the kth turn of the second wire 60.

[0111] <Supplementary Notes> The technical ideas that can be understood from the above-described embodiment and modifications will be described. [1] A winding core, a first flange provided at a first end of the winding core in a direction along the central axis, a second flange provided at a second end of the winding core opposite to the first end, first and second external electrodes provided at the first flange, a third and fourth external electrode provided at the second flange, a first wire wound around the winding core, a first wire end connected to the first external electrode and a second wire end connected to the third external electrode, and a second wire wound around the winding core in the same direction as the first wire, a first wire end connected to the second external electrode and a second wire end connected to the fourth external electrode, wherein the number of turns of the first wire and the second wire increases by one for each full turn around the central axis from the first wire end toward the second wire end, and the first wire has a first portion wound continuously and directly around the winding core, and the second wire is a second portion wound directly from the outside around the first portion in a direction perpendicular to the central axis, and a third portion wound directly from the outside around the second portion in a direction perpendicular to the central axis, wherein when tracing the second wire from the first wire end to the second wire end, a point where the second portion first switches to the third portion is defined as a specific portion, one turn from the specific portion toward the second wire end is defined as a specific turn, and when a turn of the second wire that includes the specific portion is defined as the i-th turn (where i is an integer of 3 or greater), the specific turn includes a portion wound in a valley between the (j-1)-th turn and the j-th turn of the second wire (where j is an integer of 2 or greater and less than i), and the specific turn has a crossing portion that crosses from the second flange side to the first flange side in a direction along the central axis for at least one turn of the second portion.

[0112] [2] A coil component according to [1], wherein, when N is an integer greater than or equal to 3, the total number of turns in the first wire is 2N, the total number of turns in the second wire is 2N, the number of turns in the first portion is equal to the total number of turns in the first wire, the number of turns including the second portion and the third portion is equal to the total number of turns in the second wire, and the value of N is the same as the value of i.

[0113] [3] The coil component according to [1] or [2], wherein the value of j is the same as (i-1). [4] The coil component according to any one of [1] to [3], wherein the winding core portion is a quadrangular prism having four side surfaces, at least two of which have different areas, and when the side surface having the largest area among the four side surfaces of the winding core portion is defined as a maximum surface and the side surface opposite to the maximum surface is defined as an opposing surface, a portion of the specific turn closer to the first wire end than the crossing location has a location located on the maximum surface, and a portion of the specific turn closer to the second wire end than the crossing location has a location located on the opposing surface.

[0114] [5] The specific turn is one turn including a portion of the Mth turn of the second wire and a portion of the (M+1)th turn (where M is an integer of 3 or more), and the portion of the Mth turn of the second wire in the specific turn has a portion located in a valley between the (M-2)th turn of the second wire and the (M-1)th turn of the second wire, and the portion of the (M+1)th turn of the second wire in the specific turn has a portion located in a valley between the (M-2)th turn of the second wire and the (M-1)th turn of the second wire. A coil component according to any one of [1] to [4].

[0115] [6] A winding core, a first flange provided at a first end of the winding core in a direction along the central axis, a second flange provided at a second end of the winding core opposite to the first end, a first external electrode and a second external electrode provided at the first flange, a third external electrode and a fourth external electrode provided at the second flange, a first wire wound around the winding core and having a first wire end connected to the first external electrode and a second wire end connected to the third external electrode, and a second wire end wound around the winding core in the same direction as the first wire and having a first wire end connected to the second external electrode and a second wire end connected to the fourth external electrode. and a second wire connected to an electrode, wherein the number of turns of the first wire and the second wire increases by one for each full turn around the central axis from the first wire end toward the second wire end, the first wire has a first portion wound continuously and directly around the winding core, the second wire has a second portion wound directly from the outside around the first portion in a direction perpendicular to the central axis, and a third portion wound directly from the outside around the second portion in a direction perpendicular to the central axis, and the second wire is wound from the first wire end to the second wire When tracing the wire end, a location where the second portion first switches to the third portion is defined as a first specific location, a location one turn after the first specific location is defined as a second specific location, one turn from the first specific location toward the second wire end is defined as a first specific turn, one turn from the second specific location toward the second wire end is defined as a second specific turn, and the turn of the second wire including the first specific location is defined as the i-th turn (where i is an integer of 4 or more), the turn of the second wire including the second specific location is the (i+1)-th turn, and the first specific location is defined as the second wire is wound in a valley between the (j-1)th turn and the jth turn (where j is an integer not less than 2 and not more than i-1), the second specific portion is wound in a valley between the (k-1)th turn and the kth turn (where k is an integer not less than 3 and not more than i), the first specific turn has a first crossing portion that crosses from the second flange side to the first flange side in a direction along the central axis with respect to at least one turn of the second portion, and the second specific turn crosses a turn in the second portion other than the turn crossed by the first specific turn,A coil component having a second crossing portion that crosses from the second flange side to the first flange side in the direction along the central axis.

[0116] C...Central axis CR...Crossing point P1...First portion P2...Second portion P3...Third portion ST...Specific turn 10...Coil component 10C...Drum core 11...Winding core portion 11A...Maximum surface 11B...Opposite surface 21...First flange portion 31...Second flange portion 41...First external electrode 42...Second external electrode 43...Third external electrode 44...Fourth external electrode 50...First wire 60...Second wire

Claims

1. A winding core; a first flange provided at a first end of the winding core in a direction along the central axis; a second flange provided at a second end of the winding core opposite the first end; first and second external electrodes provided at the first flange; a third and fourth external electrode provided at the second flange; a first wire wound around the winding core, a first wire end connected to the first external electrode and a second wire end connected to the third external electrode; and a second wire wound around the winding core in the same direction as the first wire, a first wire end connected to the second external electrode and a second wire end connected to the fourth external electrode, wherein the number of turns of the first wire and the second wire increases by one for each full revolution around the central axis from the first wire end toward the second wire end, and the first wire has a first portion wound continuously and directly around the winding core, the second wire has a second portion wound directly from the outside around the first portion in a direction perpendicular to the central axis, and a third portion wound directly from the outside around the second portion in a direction perpendicular to the central axis; when tracing the second wire from the first wire end to the second wire end, a location where the second portion first switches to the third portion is defined as a specific location, one turn from the specific location toward the second wire end is defined as a specific turn, and the turn of the second wire that includes the specific location is defined as the i-th turn (where i is an integer of 3 or greater), the specific turn includes a location wound in a valley between the (j-1)-th turn and the j-th turn of the second wire (where j is an integer of 2 or greater and less than i), and the specific turn has a crossing portion that crosses from the second flange side to the first flange side in a direction along the central axis for at least one turn of the second portion.

2. A coil component as described in claim 1, wherein, when N is an integer greater than or equal to 3, the total number of turns in the first wire is 2N, the total number of turns in the second wire is 2N, the number of turns in the first portion is equal to the total number of turns in the first wire, the number of turns including the second portion and the third portion is equal to the total number of turns in the second wire, and the value of N is the same as the value of i.

3. A coil component according to claim 1 or 2, wherein the value of j is the same as (i-1).

4. The coil component according to any one of claims 1 to 3, wherein the winding core is a quadrangular prism having four side surfaces, at least two of which have different areas, and when the side surface with the largest area of ​​the four side surfaces of the winding core is defined as the largest surface and the side surface opposite to the largest surface is defined as the opposing surface, a portion of the specific turn closer to the first wire end than the crossing point has a location located on the largest surface, and a portion of the specific turn closer to the second wire end than the crossing point has a location located on the opposing surface.

5. A coil component according to any one of claims 1 to 4, wherein the specific turn is one turn including a portion of the Mth turn and a portion of the (M+1)th turn (where M is an integer of 3 or greater) of the second wire, wherein the portion of the Mth turn of the second wire in the specific turn has a portion located in a valley between the (M-2)th turn of the second wire and the (M-1)th turn of the second wire, and wherein the portion of the (M+1)th turn of the second wire in the specific turn has a portion located in a valley between the (M-2)th turn of the second wire and the (M-1)th turn of the second wire.

6. A winding core; a first flange provided at a first end of the winding core in a direction along the central axis; a second flange provided at a second end of the winding core opposite the first end; first and second external electrodes provided at the first flange; a third and fourth external electrode provided at the second flange; a first wire wound around the winding core, a first wire end connected to the first external electrode and a second wire end connected to the third external electrode; and a second wire wound around the winding core in the same direction as the first wire, a first wire end connected to the second external electrode and a second wire end connected to the fourth external electrode, wherein the number of turns of the first wire and the second wire increases by one for each full revolution around the central axis from the first wire end toward the second wire end, and the first wire has a first portion wound continuously and directly around the winding core, the second wire has a second portion wound directly from the outside around the first portion in a direction perpendicular to the central axis, and a third portion wound directly from the outside around the second portion in a direction perpendicular to the central axis; when tracing the second wire from the first wire end to the second wire end, a first specific portion is a location where the second portion first switches to the third portion; a second specific portion is a location one turn after the first specific portion; one turn from the first specific portion toward the second wire end is a first specific turn; and one turn from the second specific portion toward the second wire end is a second specific turn; when the turn of the second wire including the first specific portion is the i-th turn (where i is an integer greater than or equal to 4), the turn of the second wire including the second specific portion is the (i+1)-th turn; the first specific portion is wound in a valley between the (j-1)th turn and the jth turn of the second wire (where j is an integer greater than or equal to 2 and less than i-1), the second specific portion is wound in a valley between the (k-1)th turn and the kth turn of the second wire (where k is an integer greater than or equal to 3 and less than i), and the first specific turn has a first crossing portion that crosses from the second flange side to the first flange side in a direction along the central axis with respect to at least one turn of the second portion,The second specific turn is a coil component having a second crossing portion that crosses a turn other than the turn that the first specific turn crosses in the second portion, from the second flange side to the first flange side in a direction along the central axis.

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