Coil component

Abstract

A coil component (100) comprises a drum core and a plate-shaped core (50). The drum core includes: a winding core part (11); a first flange part (20) connected to a first end of the winding core part (11); and a second flange part (30) connected to a second end of the winding core part (11). A wire W is wound around the winding core part (11) without the turns intersecting each other. The plate-shaped core (50) is connected to the surface of the first flange part (20) that faces in the first negative direction (X2) and the surface of the second flange part (30) that faces in the first negative direction (X2). The value obtained by dividing the flange thickness (D2) of the first flange part (20) by the winding core length (D1) of the first flange part (20) and the second flange part (30) is 0.18-0.4. On the surface of the winding core part (11) that faces to the first negative direction (X2) side, the proportion occupied by the wire W is 80% or more.

Description

Coil Component

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

[0002] The coil component of Patent Document 1 includes a core, a winding, and a case. The core includes a quadrangular prism-shaped winding portion and terminal portions connected to both ends of the winding portion. The winding is wound around the winding portion of the core. Further, the winding is wound over two layers. The case covers a part of the core and the winding.

[0003] Japanese Patent Laid-Open No. 2005-44858

[0004] A coil component as disclosed in Patent Document 1 generally has a characteristic that impedance reaches a maximum value at a specific alternating current frequency. Therefore, when it is intended to obtain high impedance over a wide alternating current frequency band, it is necessary to use a combination of a plurality of coil components having different characteristics. However, when mounting electronic components on a substrate or the like, space on the mounting surface is limited, so using an excessive number of coil components is not preferable. Therefore, a coil component capable of obtaining required impedance over a wide alternating current frequency band is desired.

[0005] A coil component that solves the above problem comprises a drum core containing a magnetic material, having a columnar winding core, a first flange connected to a first end in a direction parallel to the central axis of the winding core, and a second flange connected to a second end on the opposite side of the winding core from the first end; a plate-shaped core containing a magnetic material connected to the first and second flanges; and a wire wound around the winding core without the turns intersecting. When a specific axis perpendicular to the central axis is defined as the first axis, one of two directions parallel to the first axis is defined as the first positive direction, and the direction opposite to the first positive direction is defined as the first negative direction, the first and second flanges are located parallel to the first axis. The plate-shaped core protrudes outward from the winding core in the direction of the first flange, and is connected to the surface of the first flange facing the first negative direction and the surface of the second flange facing the first negative direction. The flange thickness is defined as the distance from the inner end surface of the first flange to the outer end surface of the first flange, and the winding core length is defined as the distance from the inner end surface of the first flange to the inner end surface of the second flange in a direction parallel to the central axis, on the first negative direction side of the winding core, where the value obtained by dividing the flange thickness by the winding core length is 0.18 or more and 0.4 or less. The proportion of the surface of the winding core facing the first negative direction that the wire occupies is 80% or more.

[0006] High impedance can be obtained over a wide AC frequency band.

[0007] Figure 1 is a perspective view of the coil component. Figure 2 is a cross-sectional view of the coil component. Figure 3 is a graph showing the impedance characteristics of the coil component.

[0008] <Embodiment of Coil Components> The first embodiment of the coil component is described below. Note that the drawings may be enlarged to facilitate understanding of the components. The dimensional ratios of the components may differ from those of the actual components or those shown in other drawings.

[0009] <Overall configuration of the coil component> As shown in Figure 1, the coil component 100 comprises a drum core 10 and a plate-shaped core 50.

[0010] The drum core 10 has a winding core portion 11, a first flange portion 20, and a second flange portion 30. The winding core portion 11 is roughly rectangular prism-shaped. The winding core portion 11 contains a magnetic material. Furthermore, the material of the winding core portion 11 is a non-conductive material. Specifically, the material of the winding core portion 11 is, for example, a mixture of an oxide material containing Ni, Cu, and Zn and a synthetic resin. Note that the oxide material containing Ni, Cu, and Zn is sometimes referred to as NiCuZn ferrite. An example of NiCuZn ferrite is a magnetic composition containing Fe, Ni, Cu, and Zn. Here, Fe, Ni, Cu, and Zn are used ２ O ３ Convert these to NiO, CuO, and ZnO, and set their total amount to 100 mol%. At this time, Fe is Fe ２ O ３ A material containing 46.70 mol% to 49.70 mol% of Cu converted to CuO, 4.00 mol% to 7.50 mol% of Cu converted to CuO, 7.00 mol% to 33.50 mol% of Zn converted to ZnO, with Ni as the remainder, can be used as a NiCuZn-based ferrite.

[0011] The first flange portion 20 is connected to the first end of the winding core portion 11 in a direction parallel to the central axis C. The second flange portion 30 is connected to the second end of the winding core portion 11 on the opposite side from the first end in a direction parallel to the central axis C. The material of the first flange portion 20 and the second flange portion 30 is the same as that of the winding core portion 11. Therefore, the first flange portion 20 and the second flange portion 30 contain magnetic material. Furthermore, the first flange portion 20 and the second flange portion 30 are integrally molded with the winding core portion 11.

[0012] Here, a specific axis perpendicular to the central axis C is defined as the first axis X. In this embodiment, when viewed in a direction parallel to the central axis C, the first axis X is parallel to two of the four sides of the winding core 11. The axis perpendicular to the central axis C and the first axis X is defined as the second axis Y. Furthermore, in this embodiment, the axis parallel to the central axis C is defined as the third axis Z. One of the directions parallel to the first axis X is defined as the first positive direction X1, and the direction opposite to the first positive direction X1 is defined as the first negative direction X2. Similarly, one of the directions parallel to the second axis Y is defined as the second positive direction Y1, and the direction opposite to the second positive direction Y1 is defined as the second negative direction Y2. Also, one of the directions parallel to the third axis Z is defined as the third positive direction Z1, and the direction opposite to the third positive direction Z1 is defined as the third negative direction Z2. In this embodiment, the direction from the core portion 11 toward the first flange portion 20 is defined as the third positive direction Z1, and the direction from the core portion 11 toward the second flange portion 30 is defined as the third negative direction Z2.

[0013] The first flange portion 20 protrudes outward from the winding core portion 11 in directions parallel to the first axis X and parallel to the second axis Y. Overall, the first flange portion 20 is a flattened rectangular prism shape with the smallest dimension in the direction parallel to the third axis Z. In the following description, the outer surface of the first flange portion 20 facing the third positive direction Z1 will be referred to as the outer end surface 20A. The outer surface of the first flange portion 20 facing the third negative direction Z2 will be referred to as the inner end surface 20B. Therefore, the inner end surface 20B is the surface to which the winding core portion 11 is connected. Incidentally, a so-called fillet-shaped portion may occur at the boundary between the inner end surface 20B and the outer surface of the winding core portion 11. In this case, the fillet portion will be considered part of the winding core portion 11. In other words, the inner end surface 20B is a planar portion.

[0014] The second flange portion 30 is symmetrical in the direction parallel to the third axis Z, with reference to a virtual plane that bisects the winding core portion 11 in a direction perpendicular to and parallel to the third axis Z. That is, the second flange portion 30 protrudes outward from the winding core portion 11 in the direction parallel to the first axis X and the direction parallel to the second axis Y. Overall, the second flange portion 30 is a flattened rectangular prism shape with the smallest dimension in the direction parallel to the third axis Z. In the following, the outer surface of the second flange portion 30 facing the third negative direction Z2 will be referred to as the outer end surface 30A. The outer surface of the second flange portion 30 facing the third positive direction Z1 will be referred to as the inner end surface 30B. Therefore, the inner end surface 30B is the surface to which the winding core portion 11 is connected. Furthermore, the inner end surface 30B of the second flange portion 30 faces the inner end surface 20B of the first flange portion 20 in a direction parallel to the third axis Z. Similar to the first flange portion 20, any fillet-shaped portion that may exist at the boundary between the inner end surface 30B of the second flange portion 30 and the outer surface of the core portion 11 is part of the core portion 11.

[0015] As shown in Figure 1, the plate-shaped core 50 is a rectangular plate. The plate-shaped core 50 has a flattened shape with the smallest dimension in the direction parallel to the first axis X. The long side of the plate-shaped core 50 is parallel to the third axis Z. The short side of the plate-shaped core 50 is parallel to the second axis Y. The plate-shaped core 50 is located on the first negative direction X2 side with respect to the drum core 10. The plate-shaped core 50 is connected to both the surface of the outer surface of the first flange 20 facing the first negative direction X2 side, and the surface of the outer surface of the second flange 30 facing the first negative direction X2 side. In other words, the plate-shaped core 50 spans the first flange 20 and the second flange 30. The material of the plate-shaped core 50 is the same as that of the drum core 10. That is, the plate-shaped core 50 contains a magnetic material. Also, the material of the plate-shaped core 50 is a non-conductive material.

[0016] As shown in Figure 1, the first external electrode 25 covers a portion of the outer surface of the first flange portion 20. Specifically, the first external electrode 25 covers the surface of the outer surface of the first flange portion 20 that faces the first positive direction X1. Furthermore, the first external electrode 25 covers the portion of the four surfaces of the first flange portion 20 that are adjacent to the surface facing the first positive direction X1, specifically the portion facing the first positive direction X1. In other words, the first external electrode 25 is a so-called five-sided electrode. Therefore, the first external electrode 25 covers a portion of the inner end surface 20B of the first flange portion 20.

[0017] The second external electrode 35 covers a portion of the outer surface of the second flange portion 30. Specifically, the second external electrode 35 covers the surface of the outer surface of the second flange portion 30 that faces the first positive direction X1. Furthermore, the second external electrode 35 covers the portion of the four surfaces of the second flange portion 30 that are adjacent to the surface facing the first positive direction X1, specifically the portion facing the first positive direction X1. In other words, the second external electrode 35 is a so-called five-sided electrode. Therefore, the second external electrode 35 covers a portion of the inner end surface 30B of the second flange portion 30.

[0018] As shown in Figure 1, the coil component 100 includes a wire W. Although not shown in the figure, the wire W consists of a copper wire and an insulating coating. The insulating coating covers the outer surface of the copper wire. The wire W has a substantially circular shape in cross-section perpendicular to the direction in which the wire W extends. The wire W is wound around the winding core 11. The first wire end of the wire W is joined to the first external electrode 25. The second wire end of the wire W is joined to the second external electrode 35.

[0019] As shown in Figure 2, the longitudinal dimension L, which is the distance from the edge of the coil component 100 closest to the third positive direction Z1 to the edge of the coil component 100 closest to the third negative direction Z2, in a direction parallel to the third axis Z, is 3 mm or more and 4 mm or less. In this embodiment, the longitudinal dimension L is approximately 3.3 mm. The edge of the coil component 100 closest to the third positive direction Z1 is the edge of the first external electrode 25 closest to the third positive direction Z1. The edge of the coil component 100 closest to the third negative direction Z2 is the edge of the second external electrode 35 closest to the third negative direction Z2.

[0020] <Shape of the First and Second Flange Sections> As shown in Figure 2, the portion of the first flange section 20 that is on the first negative direction X2 side of the end of the winding core section 11 is designated as the first portion 21. The portion of the first flange section 20 that is on the first positive direction X1 side of the end of the winding core section 11 that is on the first negative direction X2 side is designated as the second portion 22. In Figure 2, the position of the end of the winding core section 11 that is on the first negative direction X2 side is virtually shown as the first position P1 with a dashed line.

[0021] In the first portion 21 of the first flange 20, the outer end surface 20A and the inner end surface 20B extend parallel to each other. Also, in the first portion 21 of the first flange 20, the outer end surface 20A and the inner end surface 20B are perpendicular to the third axis Z. Therefore, when viewed in a direction parallel to the second axis Y, the outer end surface 20A and the inner end surface 20B of the first portion 21 extend parallel to the first axis X.

[0022] In the second portion 22 of the first flange 20, the outer end surface 20A and the inner end surface 20B extend parallel to each other. In the second portion 22 of the first flange 20, the outer end surface 20A and the inner end surface 20B are parallel to the second axis Y. On the other hand, in the second portion 22 of the first flange 20, the outer end surface 20A and the inner end surface 20B are inclined with respect to the first axis X. Specifically, when viewed in a direction parallel to the second axis Y, the outer end surface 20A and the inner end surface 20B of the second portion 22 are inclined in a direction away from the second flange 30 as they move toward the first positive direction X1, that is, toward the third positive direction Z1. In this embodiment, when viewed in a direction parallel to the second axis Y, the acute angle between the inner end surface 20B of the second portion 22 and a straight line parallel to the first axis X that intersects the inner end surface 20B is approximately 3 degrees.

[0023] As described above, the second portion 22 is the portion on the first positive direction X1 side of the first position P1. The entire outer end surface 20A and inner end surface 20B of the second portion 22 are inclined. Therefore, of the outer end surface 20A and inner end surface 20B of the first flange portion 20, the portion on the first positive direction X1 side of the winding core portion 11 is inclined so that it moves further away from the second flange portion 30 as it approaches the first positive direction X1. In Figure 2, the position of the end of the winding core portion 11 on the first positive direction X1 side is virtually shown as the second position P2 with a dashed line.

[0024] As shown in Figure 2, the portion of the second flange 30 that is on the first negative direction X2 side of the first position P1 is defined as the first portion 31. The portion of the second flange 30 that is on the first positive direction X1 side of the first position P1 is defined as the second portion 32. In this case, in the first portion 31 of the second flange 30, the outer end surface 30A and the inner end surface 30B extend parallel to each other. Also, in the first portion 31 of the second flange 30, the outer end surface 30A and the inner end surface 30B are perpendicular to the third axis Z. Therefore, when viewed in a direction parallel to the second axis Y, the outer end surface 30A and the inner end surface 30B of the first portion 31 extend parallel to the first axis X.

[0025] In the second portion 32 of the second flange 30, the outer end surface 30A and the inner end surface 30B extend parallel to each other. In the second portion 32 of the second flange 30, the outer end surface 30A and the inner end surface 30B are parallel to the second axis Y. On the other hand, in the second portion 32 of the second flange 30, the outer end surface 30A and the inner end surface 30B are inclined with respect to the first axis X. Specifically, when viewed in a direction parallel to the second axis Y, the outer end surface 30A and the inner end surface 30B of the second portion 32 are inclined in a direction away from the first flange 20 as they move toward the first positive direction X1, that is, toward the third negative direction Z2. In this embodiment, when viewed in a direction parallel to the second axis Y, the acute angle between the inner end surface 20B of the second portion 32 and the straight line parallel to the first axis X that intersects the inner end surface 30B is approximately 3 degrees.

[0026] The value obtained by dividing the flange thickness D2 of the first flange portion 20 by the winding core length D1 of the first flange portion 20 and the second flange portion 30 is between 0.18 and 0.4. In this embodiment, the value obtained by dividing the flange thickness D2 by the winding core length D1 is approximately 0.3. The flange thickness D3 of the second flange portion 30 is the same as the flange thickness D2 of the first flange portion 20. Therefore, the value obtained by dividing the flange thickness D3 by the winding core length D1 is approximately 0.3.

[0027] The flange thickness D2 is the distance from the inner end surface 20B of the first flange portion 20 to the outer end surface 20A of the first flange portion 20. More specifically, when viewed in a direction parallel to the second axis Y, the length of the line segment connecting any point on the inner end surface 20B of the first flange portion 20 to the outer end surface 20A with the shortest distance is the thickness of the first flange portion 20 at that point. This line segment is not necessarily parallel to the central axis C. The average value of the thickness of the first flange portion 20 at each point on the inner end surface 20B is the flange thickness D2. For example, a five-point average can be used for the average value here. In this embodiment, since the inner end surface 20B and the outer end surface 20A are parallel, the measured value of the first flange portion 20 at any point corresponds to the flange thickness D2. The same applies to the flange thickness D3 of the second flange portion 30.

[0028] The core length D1 is the distance in the direction parallel to the central axis C from the inner end surface 20B of the first flange portion 20 to the inner end surface 30B of the second flange portion 30, on the first negative direction X2 side of the end of the core portion 11 on the first negative direction X2 side. More specifically, the core length D1 is the average value of the distances in the direction parallel to the central axis C from the inner end surface 20B of the first flange portion 20 to the inner end surface 30B of the second flange portion 30 at each point on the first negative direction X2 side of the end of the core portion 11 on the first negative direction X2 side. Here, for example, a five-point average can be used for the average value. In this embodiment, since the inner end surface 20B of the first flange portion 20 and the inner end surface 30B of the second flange portion 30 are parallel to the end of the winding core portion 11 on the first negative direction X2 side, the measured distance between the two inner end surfaces at any point corresponds to the winding core length D1.

[0029] <Regarding the winding configuration of the wire> As shown in Figure 1, the first tip of the wire W is joined to the first external electrode 25. The wire W extends from the first external electrode 25 toward the ridge line on the first positive direction X1 and the second positive direction Y1 side of the winding core 11. When viewed facing the third negative direction Z2, the wire W is wound around the winding core 11 so as to advance counterclockwise toward the second flange 30. The wire W then extends toward the second external electrode 35 from the ridge line on the first negative direction X2 and the second negative direction Y2 side of the winding core 11 near the second flange 30. The second wire end of the wire W is joined to the second external electrode 35.

[0030] The wire W is wound around the core 11 without any turns intersecting each other. Here, "without turns intersecting" means that when viewed in a direction perpendicular to the third axis Z, the centerlines of the wire W do not intersect at any point. Therefore, when viewed in a direction perpendicular to the third axis Z, it is permissible for small portions of the outer circumference of the wire W to overlap, or for parts of the wire W to be separated from the outer surface of the core 11.

[0031] The wire W is wound around the core portion 11 over 26 turns. In this embodiment, the apparent number of wires W present on the surface of the core portion 11 facing the first negative direction X2 is defined as the number of turns of the wire W.

[0032] The proportion of the surface of the winding core 11 facing the first negative direction X2 that is occupied by the wire W is 80% or more. Hereinafter, this proportion will be referred to as the wire occupancy rate. In this embodiment, the wire occupancy rate is approximately 90%. The wire occupancy rate can be calculated by dividing the product of the diameter of the wire W and the number of turns of the wire W by the winding core length D1. Therefore, if there is a space between adjacent turns of the wire W, the area corresponding to that space is not included in the wire occupancy rate.

[0033] <Impedance Characteristics of Coil Components> As shown in Figure 3, the impedance of the wire W of the coil component 100 of the above embodiment was measured when various AC voltages were applied. The impedance of the coil component 100 reaches a maximum value when an AC voltage of approximately 120 MHz is applied. Furthermore, even when an AC voltage of 10 MHz was applied to the coil component 100, the impedance exceeded 700 Ω. That is, in the coil component 100, the impedance when an AC voltage of 10 MHz or more and 100 MHz or less is applied to the wire W is 700 Ω or more. In addition, when an AC voltage of 1 GHz was applied to the coil component 100, the impedance exceeded 750 Ω. Therefore, the impedance when an AC voltage of 100 MHz or more and 1 GHz or less is applied to the wire W is 750 Ω or more. Furthermore, when AC voltages of 2 GHz and 3 GHz were applied to the coil component 100, the impedance exceeded 250 Ω. Therefore, when an AC voltage of 2 GHz or more and 3 GHz or less is applied to wire W, the impedance is 250 Ω or more.

[0034] <Comparative Test> The impedance characteristics of the coil component 100 of the above embodiment were measured when the flange thickness D2 of the first flange portion 20, the flange thickness D3 of the second flange portion 30, and the number of turns were changed. In Tables 1 to 3, if "Low Frequency Z" is "G", it indicates that the impedance when a 10 MHz AC voltage is applied to the wire W is 700 Ω or more. If "Low Frequency Z" is "NG", it indicates that the impedance when a 10 MHz AC voltage is applied to the wire W is less than 700 Ω. Hereafter, if "Low Frequency Z" is "G", it will be expressed as having good impedance characteristics at low frequencies.

[0035] When "High Frequency Z" is "G", it indicates that the impedance when a 100 MHz AC voltage and a 1 GHz AC voltage are applied to wire W is 750 Ω or higher in both cases. In the following, when "High Frequency Z" is "G", it will be expressed as having good impedance characteristics at high frequencies.

[0036]

[0037] As shown in Table 1, in Examples 1-4 and Comparative Example 1, the core length D1 is 2.21 mm and the number of turns is 26. In Examples 1-4 and Comparative Example 1, the wire occupancy rate is 90%. On the other hand, in Examples 1-4 and Comparative Example 1, the flange thickness D2 of the first flange portion 20 and the flange thickness D3 of the second flange portion 30 are different. However, in all of the following examples, the flange thickness D2 of the first flange portion 20 and the flange thickness D3 of the second flange portion 30 are the same.

[0038] In Example 1, the flange thickness D2 is 0.402 mm. In this case, the value obtained by dividing the flange thickness D2 by the core length D1 is approximately 0.18. In Example 2, the flange thickness D2 is 0.520 mm. In this case, the value obtained by dividing the flange thickness D2 by the core length D1 is approximately 0.24. In Example 3, the flange thickness D2 is 0.603 mm. In this case, the value obtained by dividing the flange thickness D2 by the core length D1 is approximately 0.27. In Example 4, the flange thickness D2 is 0.804 mm. In this case, the value obtained by dividing the flange thickness D2 by the core length D1 is approximately 0.36. In Comparative Example 1, the flange thickness D2 is 0.201 mm. In this case, the value obtained by dividing the flange thickness D2 by the core length D1 is approximately 0.09.

[0039] In Examples 1 to 4 described above, the impedance characteristics were good at both low and high frequencies. On the other hand, in Comparative Example 1, the impedance characteristics were not good at low frequencies. From these findings, it was found that under the condition of a wire occupancy rate of 90%, if the value obtained by dividing the flange thickness D2 by the winding core length D1 is at least 0.18, then the impedance characteristics are good at both low and high frequencies.

[0040]

[0041] As shown in Table 2, in Examples 5-7 and Comparative Example 2, the core length D1 is 2.21 mm and the number of turns is 23. In Examples 5-7 and Comparative Example 2, the wire occupancy rate is 80%. On the other hand, in Examples 5-7 and Comparative Example 2, the flange thickness D2 of the first flange portion 20 and the flange thickness D3 of the second flange portion 30 are different. In all of the following examples, the flange thickness D2 of the first flange portion 20 and the flange thickness D3 of the second flange portion 30 are the same.

[0042] In Example 5, the flange thickness D2 is 0.402 mm. At this time, the value obtained by dividing the flange thickness D2 by the core length D1 is approximately 0.18. In Example 6, the flange thickness D2 is 0.603 mm. At this time, the value obtained by dividing the flange thickness D2 by the core length D1 is approximately 0.27. In Example 7, the flange thickness D2 is 0.804 mm. At this time, the value obtained by dividing the flange thickness D2 by the core length D1 is approximately 0.36. In Comparative Example 2, the flange thickness D2 is 0.201 mm. At this time, the value obtained by dividing the flange thickness D2 by the core length D1 is approximately 0.09.

[0043] In the case of Examples 5 to 7 described above, the impedance characteristics at low frequencies were favorable, and the impedance characteristics at high frequencies were also favorable. On the other hand, in the case of Comparative Example 2, the impedance characteristics at low frequencies were not favorable. From these results, it was found that under the condition that the wire occupation rate is 80%, if the value obtained by dividing the flange thickness D2 by the core length D1 is at least 0.18 or more, the impedance characteristics are favorable in both low frequency and high frequency cases.

[0044]

[0045] As shown in Table 3, in Comparative Examples 3 to 6, the core length D1 is 2.21 mm and the number of turns is 20 turns in all cases. In Comparative Examples 3 to 6, the wire occupation rate is 70% in all cases. On the other hand, in Comparative Examples 3 to 6, the flange thickness D2 of the first flange portion 20 and the flange thickness D3 of the second flange portion 30 are different from each other. Note that in any of the following examples, the flange thickness D2 of the first flange portion 20 and the flange thickness D3 of the second flange portion 30 are the same.

[0046] In Comparative Example 3, the flange thickness D2 is 0.201 mm. At this time, the value obtained by dividing the flange thickness D2 by the core length D1 is approximately 0.09. In Comparative Example 4, the flange thickness D2 is 0.402 mm. At this time, the value obtained by dividing the flange thickness D2 by the core length D1 is approximately 0.18. In Comparative Example 5, the flange thickness D2 is 0.603 mm. At this time, the value obtained by dividing the flange thickness D2 by the core length D1 is approximately 0.27. In Comparative Example 6, the flange thickness D2 is 0.804 mm. At this time, the value obtained by dividing the flange thickness D2 by the core length D1 is approximately 0.36.

[0047] In the above comparative examples 3 to 6, the impedance characteristics at low frequencies were not good in any of them. From these results and the comparison results of Example 1, Example 5, and Comparative Example 4, which differed only in wire occupancy, it was found that a wire occupancy of 80% or more is preferable in order to obtain favorable impedance characteristics at low frequencies.

[0048] In addition to the above, although not shown in the figures, a similar impedance characteristic test was performed on a coil component in which the wire W was wound over two layers using the same drum core 10 and plate core 50 as in Example 2, such that some turns of the wire W overlapped with other turns. Specifically, the wire W was wound around the winding core 11 so that 4 of the 26 turns of the wire W overlapped with other turns. In this case, the impedance characteristics at high frequencies were not good.

[0049] Furthermore, under the condition that the core length D1 is 2.21, if the value obtained by dividing the flange thickness D2 by the core length D1 exceeds 0.4, the longitudinal dimension L of the coil component 100 will exceed 4 mm. Therefore, if the longitudinal dimension L of the coil component 100 is required to be 4 mm or less, it is undesirable for the value obtained by dividing the flange thickness D2 by the core length D1 to exceed 0.4.

[0050] <Effects of the Embodiment> The above embodiment provides the following effects. (1) In the above embodiment, the wire W is wound around the winding core 11 without the turns crossing each other. With this winding method of the wire W, the potential difference between adjacent turns in the wire W is less likely to become large. As a result, a decrease in impedance can be suppressed, especially in the high frequency band. On the other hand, in the above embodiment, the wire occupancy rate is 80% or more. In other words, the number of turns of the wire W is large relative to the winding core length D1. With such a large number of turns, a decrease in impedance can be suppressed, especially in the low frequency band. Furthermore, in the above embodiment, the value obtained by dividing the flange thickness D2 by the winding core length D1 is 0.18 or more and 0.4 or less. Assuming that the winding core length D1 is constant, within this ratio range, a wide magnetic path from each flange to the plate-shaped core 50 can be secured without excessively increasing the longitudinal dimension L of the coil component 100. As a result, impedance can be improved in both the low frequency band and the high frequency band. As a result, the coil component 100 of this embodiment can obtain the necessary impedance over a wide AC frequency band.

[0051] (2) In the above embodiment, when an AC voltage of 10 MHz or more and 100 MHz or less is applied to the wire W, the impedance of the coil component 100 is 700 Ω or more. Also, when an AC voltage of 100 MHz or more and 1 GHz or less is applied to the wire W, the impedance of the coil component 100 is 750 Ω or more. Furthermore, when an AC voltage of 2 GHz or more and 3 GHz or less is applied to the wire W, the impedance of the coil component 100 is 250 Ω or more.

[0052] For example, a coil component 100 may be placed on wiring in a Power Over Coax (PoC) system, where signals and power are transmitted through the same wiring. In this case, depending on the processing circuit mounted on the PoC wiring, the coil component 100 may be required to have a high impedance in each of the above frequency bands. In this respect, the coil component 100 of this embodiment is suitable as a component on wiring in a PoC system because, as described above, it can exhibit a high impedance over a wide frequency band.

[0053] (3) In the above embodiment, the longitudinal dimension L of the coil component 100 is 3 mm or more and 4 mm or less. This dimension is within the range used for this type of coil component 100. Therefore, the coil component 100 in the above embodiment exhibits high impedance without being excessively large in size.

[0054] (4) When manufacturing the coil component 100 as described above, the wire W is wound around the winding core 11. When the wire occupancy rate is increased as in the above embodiment, the wire W is wound close to the first flange 20. In the coil component 100 of the above embodiment, the first external electrode 25 covers a part of the inner end surface 20B of the first flange 20. Therefore, when winding the wire W close to the first flange 20, there is a possibility that the wire W may come into contact with the first external electrode 25.

[0055] In this regard, in the above embodiment, the outer end surface 20A and the inner end surface 20B of the second portion 22 of the first flange portion 20 are inclined such that they move away from the second flange portion 30 as they move toward the first positive direction X1. Therefore, when winding the wire W onto the winding core portion 11, the wire W is less likely to come into contact with the first external electrode 25. Although the effect on the first flange portion 20 has been described, the same effect is obtained on the second flange portion 30 as well.

[0056] <Examples of Modifications> The above embodiment can be implemented with the following modifications. The above embodiment and the following examples of modifications can be combined with each other to the extent that they do not contradict each other technically. The examples of modifications illustrated below for the first flange portion 20 can also be applied to the second flange portion 30.

[0057] In the above embodiment, the shape of the first flange portion 20 can be changed as appropriate. For example, the entire outer end surface 20A and inner end surface 20B of the second portion 22 of the first flange portion 20 may be planar in shape perpendicular to the third axis Z. That is, the outer end surface 20A and inner end surface 20B of the second portion 22 may be flush with the outer end surface 20A and inner end surface 20B of the first portion 21.

[0058] In the above embodiment, the core portion 11 does not have to be substantially rectangular prism-shaped. For example, the core portion 11 may be cylindrical. If the core portion 11 is cylindrical, the surface of the core portion 11 facing the first negative direction X2 refers to the area that can be seen when viewing the core portion 11 facing the first positive direction X1.

[0059] - In the above embodiment, the shape and dimensions of the plate-shaped core 50 are not limited. The plate-shaped core 50 only needs to be connected to at least the first flange portion 20 and the second flange portion 30. - In the above embodiment, the materials of the drum core 10 and the plate-shaped core 50 can be changed as appropriate. The materials of the drum core 10 and the plate-shaped core 50 only need to be magnetic materials. Examples of magnetic materials include various ferrites and permalloys. In addition, elements such as Ni, Mo, Cu, Cr, Ti, and Nb may be added to these materials as needed, or various synthetic resins may be mixed in.

[0060] - The number of turns of wire W can be changed as appropriate. Considering the diameter of wire W, the length of the winding core D1, etc., the number of turns of wire W should be changed as appropriate so that the wire occupancy rate is 80% or more. - The longitudinal dimension L of the coil component 100 may be less than 3 mm or more than 4 mm.

[0061] - In the second portion 22 of the first flange portion 20, the angle of inclination of the outer end surface 20A and the inner end surface 20B is not limited to the example of the above embodiment. If the angle is 1 degree or more, the outer end surface 20A and the inner end surface 20B can be considered to be inclined beyond the manufacturing tolerance.

[0062] - In the second portion 22 of the first flange portion 20, if the outer end surface 20A and the inner end surface 20B are inclined in a direction that moves away from the first flange portion 20 as it moves toward the first positive direction X1, at least on the first positive direction X1 side from the second position P2, then the same effect as in (4) of the above embodiment can be obtained.

[0063] The coil component 100 may have an impedance of less than 700Ω when an AC voltage of 10MHz to 100MHz is applied to the wire W. Furthermore, the coil component 100 may have an impedance of less than 750Ω when an AC voltage of 100MHz to 1GHz is applied to the wire W. Additionally, the coil component 100 may have an impedance of less than 250Ω when an AC voltage of 2GHz to 3GHz is applied to the wire W. Generally, as the size of the coil component 100 decreases, the impedance in each frequency band also decreases. Even in this case, according to the above embodiment, a large impedance can be achieved over a wide frequency band relative to its size.

[0064] 100... Coil component 10... Drum core 11... Winding core 20... First flange 30... Second flange 50... Plate core W... Wire D1... Winding core length D2... Flange thickness

Claims

1. A drum core containing a magnetic material, having a columnar winding core, a first flange connected to a first end in a direction parallel to the central axis of the winding core, and a second flange connected to a second end on the opposite side of the winding core; a plate-shaped core containing a magnetic material, connected to the first and second flanges; and a wire wound around the winding core without turns intersecting, wherein a specific axis perpendicular to the central axis is defined as the first axis, one of two directions parallel to the first axis is defined as the first positive direction, and the direction opposite to the first positive direction is defined as the first negative direction, the first and second flanges protrude outward from the winding core in a direction parallel to the first axis, and the plate-shaped core is connected to the surface of the first flange facing the first negative direction and the surface of the second flange facing the first negative direction. A coil component in which, when the distance from the inner end face of the first flange to the outer end face of the first flange is defined as the flange thickness, and the distance from the inner end face of the first flange to the inner end face of the second flange in a direction parallel to the central axis, on the first negative direction side of the winding core portion, is defined as the winding core length, the value obtained by dividing the flange thickness by the winding core length is 0.18 or more and 0.4 or less, and the proportion of the surface of the winding core portion facing the first negative direction is 80% or more.

2. The coil component according to claim 1, wherein the impedance when an AC voltage of 10 MHz or more and 100 MHz or less is applied to the wire is 700 Ω or more.

3. The coil component according to claim 1 or 2, wherein the impedance when an AC voltage of 100 MHz or more and 1 GHz or less is applied to the wire is 750 Ω or more.

4. The coil component according to any one of claims 1 to 3, wherein the impedance when an AC voltage of 2 GHz or more and 3 GHz or less is applied to the wire is 250 Ω or more.

5. The coil component according to any one of claims 1 to 4, wherein the dimension from one end to the other in a direction parallel to the central axis is 3 mm or more and 4 mm or less.

6. The coil component according to any one of claims 1 to 5, comprising an external electrode covering a part of the inner end surface of the first flange, wherein the wire end is joined to the external electrode, and when viewed in a direction perpendicular to both the central axis and the first axis, the portion of the outer end surface and the inner end surface of the first flange that is closer to the first positive direction than the end of the winding core is inclined to move away from the second flange as it moves toward the first positive direction.

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