Coil component

Abstract

To provide a coil component that causes an impedance peak to appear in a high frequency band and restrains a decrease in inductance.SOLUTION: A coil component ED1 includes an element body 1 including a pair of end faces 1a facing each other, and a coil 30 disposed within the element body 1. The coil 30 includes at least one coil conductor 31 and is disposed such that the coil axis is along a direction in which the pair of end faces 1a face each other. The element body 1 includes a pair of element body portions 3a, 3b including corresponding end faces 1a of the pair of end faces 1a, and an element body portion 3c located between the pair of element body portion 3a, 3b. The element body portion 3c includes a region 5a and a region 5b that are provided at different positions from each other in a first direction D1. The region 5b has a relative permeability and a relative dielectric constant that are smaller than those of the region 5a. At least one coil conductor 31 includes the coil conductor 31 disposed in the element body portion 3c.SELECTED DRAWING: Figure 3

Description

[Technical field]

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

[0002] A known coil component includes an element body and a coil disposed within the element body (see, for example, Patent Document 1). The element body includes a pair of end faces that face each other. The coil is disposed such that the coil axis is aligned in the direction in which the pair of end faces face each other. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 8-55726 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of one aspect of the present invention is to provide a coil component that causes an impedance peak to appear in a high frequency band and suppresses a decrease in inductance. [Means for solving the problem]

[0005] A coil component according to one aspect of the present invention comprises an element body including a pair of end faces facing each other, and a coil disposed within the element body. The coil includes at least one coil conductor and is disposed such that a coil axis is aligned in a direction in which the pair of end faces face each other. The element body includes a pair of first element body parts each including corresponding one of the pair of end faces, and a second element body part located between the pair of first element body parts. The second element body part includes a first region and a second region that are provided at different positions from each other in the above direction. The second region has a relative permeability and a relative dielectric constant that are respectively smaller than those of the first region. The at least one coil conductor includes a coil conductor disposed in the second element body part.

[0006] In the one aspect above, at least one coil conductor includes a coil conductor disposed in the second element part, and the second element part is reliably present at a position through which magnetic flux generated by the coil conductor passes. That is, the second element part affects the characteristics of the coil component, such as impedance and inductance. The second element part includes a first region and a second region, and the second region has a relative permeability and a relative dielectric constant that are respectively smaller than those of the first region. Since the second element part includes the second region, the one aspect above causes an impedance peak to appear in the high frequency band. Since the second element part also includes the first region, the one aspect above suppresses a decrease in inductance.

[0007] In the one aspect above, of three portions obtained by dividing the second body portion into three equal portions in a direction, a central portion may include the second region. In the configuration in which the central portion includes the second region, the second region that produces an impedance peak in the high frequency band is disposed in the central portion, thus ensuring that the impedance peak appears in the high frequency band.

[0008] In the above one embodiment, each of the three portions may include a first region and a second region. In the configuration in which each of the three portions includes a first region and a second region, the second region that causes an impedance peak to appear in the high frequency band is disposed in each of the three portions, so that this configuration more reliably causes an impedance peak to appear in the high frequency band.

[0009] In the one aspect, the second region may include a plurality of regions provided at different positions in the direction. In a configuration in which the second region includes the above-mentioned multiple regions, the multiple second regions that cause the impedance peak to appear in the high frequency band are arranged in the second body portion, and therefore this configuration more reliably causes the impedance peak to appear in the high frequency band.

[0010] In the one aspect, the plurality of regions may be provided symmetrically with respect to a central position of the length of the second body part in the direction. In the configuration in which the plurality of regions are symmetrically disposed about the central position, the plurality of second regions that cause an impedance peak to appear in a high frequency band are symmetrically disposed about the central position, thereby more reliably causing an impedance peak to appear in a high frequency band.

[0011] In the one aspect, the plurality of regions may be provided at approximately equal intervals in the direction. In the configuration in which the plurality of regions are provided at substantially equal intervals in the above direction, the plurality of second regions that cause the impedance peak to appear in the high frequency band are provided at substantially equal intervals, so that this configuration more reliably causes the impedance peak to appear in the high frequency band.

[0012] In the above aspect, the multiple regions may be provided so as to be biased toward one of the pair of first element body parts. In a configuration in which the multiple regions are biased toward one of a pair of first element parts, even if an element contained in the second region diffuses into the second element part, the element is unlikely to diffuse into the second element part closer to the other first element part. The first region provided in the second element part closer to the other first element part is unlikely to be affected by element diffusion. Therefore, this configuration reliably suppresses a decrease in inductance.

[0013] In the above aspect, the at least one coil conductor may include a plurality of coil conductors. The plurality of coil conductors may include a coil conductor disposed in the second region. In a configuration including a coil conductor in which a plurality of coil conductors are arranged in the second region, the plurality of coil conductors may be arranged in the second region. Thus, the appearance of an impedance peak in the high frequency band is realized by the plurality of coil conductors. As a result, the one aspect described above more reliably appears an impedance peak in the high frequency band.

[0014] In the one aspect, the element may include a pair of external electrodes disposed on both ends of the element in the above direction and electrically connected to the coil. The element may include a side surface connecting the pair of end surfaces. Each of the pair of external electrodes may include an electrode portion located on the side surface. An edge of the electrode portion and the second region may be in contact with each other. The configuration in which the edge of the electrode portion and the second region are in contact with each other reduces stray capacitance formed between the coil and the external electrode, and therefore the above-mentioned one aspect more reliably produces an impedance peak in the high frequency band. Effect of the Invention

[0015] One aspect of the present invention provides a coil component that causes an impedance peak to appear in a high frequency band and suppresses a decrease in inductance. [Brief description of the drawings]

[0016] [Figure 1] FIG. 1 is a perspective view showing a coil component according to an embodiment. [Diagram 2] FIG. 2 is an exploded perspective view showing the coil and the connection portion. [Diagram 3] FIG. 3 is a diagram showing a cross-sectional configuration of the coil component according to the present embodiment. [Figure 4] FIG. 4 is a diagram showing a cross-sectional configuration of a coil component according to a first modified example of the present embodiment. [Diagram 5] FIG. 5 is a diagram showing a cross-sectional configuration of a coil component according to a second modified example of the present embodiment. [Figure 6] FIG. 6 is a diagram showing a cross-sectional configuration of a coil component according to a third modified example of the present embodiment. [Figure 7] FIG. 7 is a diagram showing a cross-sectional configuration of a coil component according to a fourth modified example of the present embodiment. [Figure 8] FIG. 8 is a diagram showing a cross-sectional configuration of a coil component according to a fifth modified example of the present embodiment. [Figure 9]FIG. 9 is a diagram showing a cross-sectional configuration of a coil component according to a sixth modified example of the present embodiment. [Figure 10] FIG. 10 is a diagram showing a cross-sectional configuration of a coil component according to a seventh modified example of the present embodiment. [Figure 11] FIG. 11 is a diagram showing a cross-sectional configuration of a coil component according to an eighth modified example of the present embodiment. [Figure 12] FIG. 12 is a diagram showing a cross-sectional configuration of a coil component according to a ninth modified example of the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In the description, the same elements or elements having the same functions will be denoted by the same reference numerals, and duplicated description will be omitted.

[0018] The configuration of the coil component ED1 according to this embodiment will be described with reference to Fig. 1 to Fig. 3. Fig. 1 is a perspective view showing the coil component according to this embodiment. Fig. 2 is an exploded perspective view showing a coil and a connection portion. Fig. 3 is a diagram showing a cross-sectional configuration of the coil component according to this embodiment. In Fig. 3, hatching showing a cross section is omitted. 1 to 3, the coil component ED1 includes an element body 1, a pair of external electrodes 10, and a coil 30. The pair of external electrodes 10 are disposed on surfaces of the element body 1. The coil 30 is disposed within the element body 1 and is electrically connected to the pair of external electrodes 10. The coil 30 is disposed such that its coil axis is aligned with a first direction D1.

[0019] The element body 1 has, for example, a rectangular parallelepiped shape. In this specification, the rectangular parallelepiped shape includes a rectangular parallelepiped shape with chamfered corners and ridges, or a rectangular parallelepiped shape with rounded corners and ridges. The element body 1 includes a pair of end faces 1a facing each other and four side faces 1c connecting the pair of end faces 1a. The surface of the element body 1 includes the pair of end faces 1a and the four side faces 1c. Each of the pair of end faces 1a and the four side faces 1c has a rectangular shape. In this specification, the rectangular shape includes, for example, a shape with each corner chamfered or a shape with each corner rounded.

[0020] A pair of end faces 1a face each other in a first direction D1. Of the four side faces 1c, a pair of side faces 1c face each other in a second direction D2. Another pair of side faces 1c face each other in a third direction D3. The four side faces 1c extend in the first direction D1 so as to connect the pair of end faces 1a. The first direction D1 intersects with the second direction D2 and also intersects with the third direction D3. The second direction D2 intersects with, for example, the third direction D3. In this embodiment, the first direction D1, the second direction D2, and the third direction D3 are perpendicular to each other. The length of the element body 1 in the first direction D1 is, for example, 0.4 to 1.6 mm. The length of the element body 1 in the second direction D2 is, for example, 0.2 to 1.0 mm. The length of the element body 1 in the third direction D3 is, for example, 0.2 to 0.8 mm. For example, the first direction D1 of the element body 1 is the long side direction.

[0021] A pair of external electrodes 10 are arranged on both ends of the element body 1. One external electrode 10 is arranged, for example, on one end face 1a. The other external electrode 10 is arranged, for example, on the other end face 1a. The pair of external electrodes 10 are spaced apart from each other in a first direction D1. Each of the pair of external electrodes 10 includes an electrode portion 10c located on four side faces 1c. Each of the electrode portions 10c is located on four side surfaces 1c. The electrode portions 10c include an edge 10e. One electrode portion 10c extends on the four side surfaces 1c, for example, from one end surface 1a to the edge 10e in a direction toward the other end surface 1a. The other electrode portion 10c extends on the four side surfaces 1c, for example, from the other end surface 1a to the edge 10e in a direction toward the one end surface 1a. The edge 10e is located on the four side surfaces 1c.

[0022] The external electrode 10 includes a conductive material. The conductive material includes, for example, Ag, Pd, Cu, or Al. The conductive material includes, for example, an Ag-Pd alloy, an Ag-Cu alloy, an Ag-Au alloy, or an Ag-Pt alloy. The external electrode 10 includes, for example, a Ni plating film, an Sn plating film, a Cu plating film, or an Au plating film. The external electrode 10 may have a multi-layer structure of these plating films, and may include a Ni plating film and an Sn plating film formed on the Ni plating film. The thickness of the portion of the external electrode 10 located on the end face 1a is, for example, 5 to 50 μm.

[0023] The coil 30 includes a plurality of coil conductors 31. The coil 30 may include at least one coil conductor 31. The coil conductors 31 are arranged so that at least a portion of each coil conductor 31 overlap each other when viewed from the first direction D1. For example, each coil conductor 31 has a shape in which a portion of a loop is interrupted. Each coil conductor 31 includes a pair of ends. Each coil conductor 31 extends along a circular track between the pair of ends. Among the plurality of coil conductors 31, adjacent coil conductors 31 are connected to each other at the ends of each coil conductor 31 via through-hole conductors 38. When viewed from the first direction D1, the above-mentioned adjacent coil conductors 31 overlap each other at the corresponding ends. The coil component ED1 includes a pair of connecting portions 33 arranged at both ends of the coil 30. The pair of connecting portions 33 electrically connect the coil 30 and the pair of external electrodes 10. In FIG. 1, the two-dot chain line typically indicates the contour of the outer shape of the coil 30 and the connecting portion 33.

[0024] As shown in FIG. 2, each of the pair of connecting portions 33 includes, for example, a plurality of conductors 33a and one conductor 33b. Among the plurality of conductors 33a, adjacent conductors 33a are connected to each other via a through-hole conductor 36. The through-hole conductor 36 electrically connects adjacent conductors 33a to each other, and the conductors 33a are not exposed, for example, at the end face 1a. When the conductor 33a is not exposed at the end face 1a, for example, the conductor 33a farthest from the coil 30 among the plurality of conductors 33a is connected to the external electrode 10 via a through-hole conductor 39. The through-hole conductor 39 is, for example, located between the conductor 33a farthest from the coil 30 and the external electrode 10, and electrically connects the conductor 33a farthest from the coil 30 to the external electrode 10. In this embodiment, the conductor 33a farthest from the coil 30 may be exposed at the end face 1a. When the conductor 33a is exposed at the end face 1a, the conductor 33a exposed at the end face 1a is directly connected to the external electrode 10, and each of the pair of connection portions 33 does not include a through-hole conductor 39. The coil component ED1 may include a configuration in which one of the pair of connection portions 33 includes a through-hole conductor 39, and the other of the pair of connection portions 33 does not include a through-hole conductor 39. In this configuration, one connection portion 33 is connected to the external electrode 10 at the through-hole conductor 39, and the other connection portion 33 is connected to the external electrode 10 at the conductor 33a exposed at the end face 1a.

[0025] The conductor 33b is located between the coil 30 and the conductor 33a that is closest to the coil 30 among the plurality of conductors 33a. The conductor 33b electrically connects the plurality of conductors 33a to the coil 30. The conductor 33b includes, for example, one end connected to the conductor 33a and the other end connected to the coil 30. One end of the conductor 33b is connected to the conductor 33a via the through-hole conductor 36. The other end of the conductor 33b is connected to the coil 30 via the through-hole conductor 37. Among the plurality of coil conductors 31 included in the coil 30, the coil conductor 31 that is closest to the end surface 1a is connected to the conductor 33b via the through-hole conductor 37. In FIG. 2, some of the plurality of conductors 33a and the through-hole conductors 36 are omitted from the illustration.

[0026] The coil 30 and the connection portion 33 include a conductive material. The conductive material includes, for example, Ag, Pd, Au, Cu, or Al. The conductive material includes, for example, an Ag-Pd alloy, an Ag-Cu alloy, an Ag-Au alloy, or an Ag-Pt alloy. The coil 30 and the connection portion 33 include, for example, the same conductive material as the external electrode 10. The coil 30 and the connection portion 33 may include a conductive material different from that of the external electrode 10.

[0027] The element body 1 includes a pair of element body parts 3a, 3b and an element body part 3c. The pair of element body parts 3a, 3b each include a corresponding end face 1a of a pair of end faces 1a. In this embodiment, the element body part 3a includes one end face 1a, and the element body part 3b includes the other end face 1a. The element body part 3c is located between the element body parts 3a and 3b in the first direction D1. In this embodiment, one connection part 33 is arranged on the element body part 3a. The other connection part 33 is arranged on the element body part 3b. The coil 30 is arranged on the element body part 3c. In FIG. 3, the through-hole conductors 36 are omitted from illustration. For example, when the element part 3a includes a first element part, the element part 3c includes a second element part. For example, when the element part 3b includes a first element part, the element part 3c includes a second element part.

[0028] The element body 1 includes, for example, a plurality of insulator layers having electrical insulation properties. In this embodiment, the element body 1 includes a plurality of insulator layers stacked in a first direction D1. The plurality of insulator layers are integrated to such an extent that the boundaries between them are not actually visible. Each of the plurality of insulator layers has, for example, a rectangular shape when viewed from the first direction D1. In this embodiment, the plurality of coil conductors 31 and the conductors 33a and 33b are each disposed between adjacent insulator layers among the plurality of insulator layers.

[0029] The boundaries between each of the element body parts 3a, 3b and the element body part 3c may be defined as follows. For example, a plane that is parallel to one end face 1a included in element portion 3a of the pair of end faces 1a and tangent to a surface of coil conductor 31 closest to the one end face 1a that faces the one end face 1a defines the boundary between element portion 3a and element portion 3c. For example, a plane that is parallel to the other end face 1a included in element portion 3b of the pair of end faces 1a and tangent to a surface of coil conductor 31 closest to the other end face 1a that faces the other end face 1a defines the boundary between element portion 3b and element portion 3c.

[0030] The element body portion 3c includes a plurality of regions 5a and a plurality of regions 5b. In this embodiment, the element body portion 3c includes, for example, four regions 5a and four regions 5b. The four regions 5a and the four regions 5b are provided at different positions from each other in the first direction D1. The regions 5a and 5b are, for example, arranged alternately in the first direction D1. Each of the regions 5a and 5b includes an insulating layer. For example, when the region 5a includes a first region, the region 5b includes a second region.

[0031] The four regions 5b are arranged at intervals L1, L2, and L3 in the first direction D1, in the direction from the element body portion 3a to the element body portion 3b. That is, the two regions 5b closer to the element body portion 3a with respect to the central position CL1 are spaced apart by the interval L1. The two central regions 5b are spaced apart by the interval L2. The two regions 5b closer to the element body portion 3b with respect to the central position CL1 are spaced apart by the interval L3. In this embodiment, the intervals L1, L2, and L3 are approximately the same. The four regions 5b are provided at approximately equal intervals in the first direction D1. In this specification, the term "approximately equal intervals" may mean that the intervals are equal to each other and may also mean intervals that include slight differences or manufacturing errors within a preset range. For example, when each of the intervals L1, L2, and L3 falls within a range of ±20% of the average value of the intervals L1, L2, and L3, the regions 5b are considered to be provided at approximately equal intervals.

[0032] One edge 10e of the electrode portion 10c and the region 5b are in contact with each other, for example. In this embodiment, one edge 10e and the region 5b closest to the element body portion 3a are in contact with each other. The region 5b closest to the element body portion 3a is covered by one electrode portion 10c. The other edge 10e and the region 5b closest to the element body portion 3b are in contact with each other. The region 5b closest to the element body portion 3b is covered by the other electrode portion 10c. The two central regions 5b are not in contact with the edge 10e, for example. The two central regions 5b are exposed from the electrode portion 10c, for example.

[0033] In the element portion 3c, the insulator layer included in the region 5a includes a first material. The first material includes, for example, a ferrite material. The ferrite material included in the first material includes, for example, a Ni-Cu-Zn-based ferrite material, a Mg-Cu-Zn-based ferrite material, a Ni-Cu-Zn-Mg-based ferrite material, or a Ni-Cu-based ferrite material. The insulator layer included in the region 5b includes a second material. The second material includes, for example, a Ni-Cu-Zn-based ferrite material, a Mg-Cu-Zn-based ferrite material, a Ni-Cu-Zn-Mg-based ferrite material, a Ni-Cu-based ferrite material, a Cu-Zn-based ferrite material, a glass-based material, a forsterite material, a willemite material, an alumina material, a cordierite material, a steatite material, a mullite material, or a mixture of these materials. The second material refers to a material having a relative permeability and a relative dielectric constant smaller than those of the first material. Therefore, the second material may include a magnetic material as long as it has a relative permeability and a relative dielectric constant smaller than those of the first material. The insulator layers disposed on the element portions 3a and 3b include, for example, the first material. The first material has a relative magnetic permeability of, for example, 2 to 1500. The second material contained in region 5b has a relative magnetic permeability of, for example, 1 to 10. In this embodiment, the second material contained in region 5b has a relative magnetic permeability of, for example, 1. The first material has a relative dielectric constant of, for example, 8 to 20. The second material contained in region 5b has a relative dielectric constant of, for example, 3 to 15.

[0034] In this embodiment, the region 5b has a relative permeability and a relative dielectric constant that are smaller than those of the region 5a, respectively. That is, the relative permeability of the region 5b is smaller than that of the region 5a, and the relative dielectric constant of the region 5b is smaller than that of the region 5a.

[0035] The element body portion 3c includes three portions, 7a, 7b, and 7c. The portions 7a, 7b, and 7c are arranged in the first direction D1, for example, in the order of the portions 7a, 7b, and 7c. The portion 7b is located in the middle of the portions 7a, 7b, and 7c. The portion 7a is located near the element body portion 3a. The portion 7c is located near the element body portion 3b. The portions 7a, 7b, and 7c divide the element body portion 3c into three equal parts in the first direction D1, for example.

[0036] In this specification, the term "divided into three equal parts" may refer to division into three equal parts including slight differences or manufacturing errors within a preset range. For example, if the length of each of the parts 7a, 7b, and 7c in the first direction D1 falls within a range of ±20% of the average length of the parts 7a, 7b, and 7c in the first direction D1, each of the parts 7a, 7b, and 7c is considered to be a division of the body part 3c into three equal parts in the first direction D1.

[0037] Each of the portions 7a, 7b, and 7c includes, for example, a region 5a and a region 5b. In this embodiment, the portion 7a includes one region 5a and two regions 5b. The portion 7b includes two regions 5a and two regions 5b. The portion 7c includes two regions 5a and one region 5b. The portions 7a and 7b adjacent to each other include one region 5a and one region 5b located at the boundary between the portions 7a and 7b in an overlapping manner. The portions 7b and 7c adjacent to each other include one region 5a and one region 5b located at the boundary between the portions 7b and 7c in an overlapping manner. In each of the multiple regions 5b, three insulator layers including the second material are stacked continuously with no region 5a sandwiched between them.

[0038] A coil component ED2 according to a first modified example of this embodiment will be described with reference to Fig. 4. Fig. 4 is a diagram showing a cross-sectional configuration of the coil component according to the first modified example of this embodiment. In Fig. 4, hatching indicating a cross section and illustration of the through-hole conductors 36 are omitted. The configuration of the coil component ED2 is the same as that of the coil component ED1, except for the arrangement of the regions 5a and 5b.

[0039] The body portion 3c includes 24 regions 5a and 24 regions 5b. The 24 regions 5b are provided at different positions in the first direction D1. Each of the portions 7a, 7b, and 7c includes eight regions 5a and eight regions 5b. In the first modified example, the 24 regions 5b are arranged at approximately equal intervals in the first direction D1. For example, one insulator layer included in the region 5b and one insulator layer included in the region 5a are alternately laminated. One edge 10e and the three regions 5b close to the element portion 3a are in contact with each other. The other edge 10e and the two regions 5b close to the element portion 3b are in contact with each other. For example, the regions 5b other than the above five regions 5b are not in contact with the edge 10e and are exposed from the electrode portion 10c.

[0040] A coil component ED3 according to a second modified example of this embodiment will be described with reference to Fig. 5. Fig. 5 is a diagram showing a cross-sectional configuration of the coil component according to the second modified example of this embodiment. In Fig. 5, hatching indicating a cross section and illustration of the through-hole conductors 36 are omitted. The configuration of the coil component ED3 is the same as that of the coil component ED1, except for the arrangement of the regions 5a and 5b.

[0041] The body portion 3c includes three regions 5a and three regions 5b. The three regions 5b are provided at different positions in the first direction D1. The portion 7a includes two regions 5a and two regions 5b. The portion 7b includes two regions 5a and one region 5b. The portion 7c includes one region 5a and does not include a region 5b.

[0042] In the second modified example, each of the three regions 5b is provided so as to be biased toward the element body portion 3a. The three regions 5b are provided near the element body portion 3a with respect to the central position CL1. The three regions 5b are arranged at intervals L1, L2 from each other in the first direction D1, in the direction from the element body portion 3a to the element body portion 3b. For example, the intervals L1, L2 are approximately the same. The three regions 5b are provided at approximately equal intervals in the first direction D1. In each of the three regions 5b, three insulator layers containing the second material are stacked continuously with no region 5a in between.

[0043] One edge 10e and region 5b closest to element portion 3a are in contact with each other. The other edge 10e and region 5b are not in contact with each other. The two regions 5b closest to element portion 3b are not in contact with edge 10e and are exposed from electrode portion 10c.

[0044] A coil component ED4 according to a third modified example of this embodiment will be described with reference to Fig. 6. Fig. 6 is a diagram showing a cross-sectional configuration of the coil component according to the third modified example of this embodiment. In Fig. 6, hatching indicating a cross section and illustration of the through-hole conductor 36 are omitted. The configuration of the coil component ED4 is the same as that of the coil component ED1, except for the arrangement of the regions 5a and 5b.

[0045] The body portion 3c includes five regions 5a and four regions 5b. The four regions 5b are provided at different positions in the first direction D1. In the third modified example, the four regions 5b are provided symmetrically with respect to a central position CL1. Of the four regions 5b, the distances between the two central regions 5b and the central position CL1 are substantially the same. Of the four regions 5b, the distances between the two end regions 5b and the central position CL1 are substantially the same. Of the four regions 5b, the central position CL1 is located between the two central regions 5b.

[0046] In the example shown in Fig. 6, the portions 7a and 7c include one region 5a and no region 5b. The portion 7b includes five regions 5a and four regions 5b. In a third variant, each of the portions 7a and 7c may include a region 5b. For example, each of the portions 7a and 7c may include two regions 5a and one region 5b, and the portion 7b may include three regions 5a and two regions 5b. For example, each of the portions 7a and 7c may include three regions 5a and two regions 5b, and the portion 7b may include one region 5a and no region 5b.

[0047] The four regions 5b are arranged at intervals L1, L2, and L3 in the first direction D1, that is, in the direction from the element portion 3a to the element portion 3b. In the third modified example, the intervals L1, L2, and L3 are approximately the same. The four regions 5b are provided at approximately equal intervals in the first direction D1.

[0048] In each of the four regions 5b, one insulator layer containing the second material is laminated continuously with each other. The edge 10e and the region 5b are not in contact with each other. The four regions 5b are not in contact with the edge 10e and are exposed from the electrode portion 10c.

[0049] A coil component ED5 according to a fourth modified example of this embodiment will be described with reference to Fig. 7. Fig. 7 is a diagram showing a cross-sectional configuration of the coil component according to the fourth modified example of this embodiment. In Fig. 7, hatching indicating a cross section and illustration of the through-hole conductor 36 are omitted. The configuration of the coil component ED5 is the same as that of the coil component ED1, except for the arrangement of the regions 5a and 5b.

[0050] The body portion 3c includes four regions 5a and five regions 5b. The five regions 5b are provided at different positions in the first direction D1. The portion 7a includes two regions 5a and two regions 5b. The portion 7b includes three regions 5a and two regions 5b. The portion 7c includes two regions 5a and one region 5b.

[0051] In the fourth modified example, the five regions 5b are not provided symmetrically with respect to the central position CL1. The five regions 5b are arranged at intervals L1, L2, L3, and L4 in the first direction D1, that is, in the direction from the element body portion 3a to the element body portion 3b. In the fourth modified example, the intervals L1, L2, L3, and L4 are different from one another. For example, the interval L4 is the largest, followed by the interval L2. The interval L3 is next largest, and the interval L1 is the smallest. In each of the five regions 5b, three insulator layers containing the second material are stacked consecutively one after the other without any region 5a in between.

[0052] In the fourth modification, one edge 10e and the region 5b closest to the element body portion 3a are in contact with each other. The other edge 10e and the region 5b closest to the element body portion 3b are in contact with each other. For example, the three regions 5b located third to fifth from the element body portion 3a are not in contact with the edge 10e and are exposed from the electrode portion 10c.

[0053] A coil component ED6 according to a fifth modified example of this embodiment will be described with reference to Fig. 8. Fig. 8 is a diagram showing a cross-sectional configuration of a coil component according to a fifth modified example of this embodiment. In Fig. 8, hatching indicating a cross section and illustration of the through-hole conductors 36 are omitted. The configuration of the coil component ED6 is the same as that of the coil component ED1, except for the arrangement of the regions 5a and 5b.

[0054] The body portion 3c includes five regions 5a and four regions 5b. The four regions 5b are provided at different positions in the first direction D1. The portion 7a includes two regions 5a and two regions 5b. The portion 7b includes two regions 5a and two regions 5b. The portion 7c includes two regions 5a and one region 5b.

[0055] In the fifth modified example, the four regions 5b are not provided symmetrically with respect to the central position CL1. The four regions 5b are provided so as to be biased toward the element body portion 3a. In each of the four regions 5b, four insulator layers containing the second material are continuously stacked one after the other without a region 5a in between. The four regions 5b are arranged at intervals L1, L2, and L3 in the first direction D1, in the direction from the element body portion 3a toward the element body portion 3b. For example, the intervals L1, L2, and L3 are approximately the same as each other. The four regions 5b are provided at approximately equal intervals in the first direction D1.

[0056] One edge 10e and a part of region 5b closest to element body portion 3a are in contact with each other. A part of region 5b closest to element body portion 3a is covered by electrode portion 10c. One edge 10e and the other part of region 5b closest to element body portion 3a are not in contact with each other. The other part of region 5b closest to element body portion 3a is not covered by one electrode portion 10c. The other edge 10e and region 5b are not in contact with each other. The three regions 5b closest to element body portion 3b are not in contact with edge 10e and are exposed from electrode portion 10c.

[0057] A coil component ED7 according to a sixth modified example of this embodiment will be described with reference to Fig. 9. Fig. 9 is a diagram showing a cross-sectional configuration of a coil component according to the sixth modified example of this embodiment. In Fig. 9, hatching indicating a cross section and illustration of the through-hole conductors 36 are omitted. The configuration of the coil component ED7 is the same as that of the coil component ED1, except for the arrangement of the regions 5a and 5b.

[0058] The body portion 3c includes two regions 5a and two regions 5b. The two regions 5b are provided at different positions in the first direction D1. The portion 7a includes one region 5a and one region 5b. The portion 7b includes two regions 5a and one region 5b. The portion 7c includes one region 5a and does not include a region 5b.

[0059] In the sixth modified example, the two regions 5b are not provided symmetrically with respect to the center position CL1. The two regions 5b are provided so as to be biased toward the element body portion 3a. In each of the two regions 5b, three insulator layers containing the second material are stacked successively with no region 5a in between.

[0060] One edge 10e and region 5b close to element portion 3a are in contact with each other. Region 5b close to element portion 3a is covered by one electrode portion 10c. Region 5b close to element portion 3b is not in contact with edge 10e and is exposed from electrode portion 10c.

[0061] A coil component ED8 according to a seventh modified example of this embodiment will be described with reference to Fig. 10. Fig. 10 is a diagram showing a cross-sectional configuration of a coil component according to a seventh modified example of this embodiment. In Fig. 10, hatching indicating a cross section and illustration of a through-hole conductor 36 are omitted. The configuration of the coil component ED8 is the same as that of the coil component ED1, except for the arrangement of the regions 5a and 5b.

[0062] The body portion 3c includes two regions 5a and two regions 5b. The two regions 5b are provided at different positions in the first direction D1. The portion 7a includes two regions 5a and two regions 5b. The portions 7b and 7c include one region 5a and do not include a region 5b.

[0063] In the seventh modification, the two regions 5b are not provided symmetrically with respect to the center position CL1. The two regions 5b are provided so as to be biased toward the element body portion 3a. In each of the two regions 5b, two insulator layers containing the second material are laminated successively to each other without the region 5a in between.

[0064] One edge 10e and a part of the region 5b located second from the element body portion 3a are in contact with each other. One edge 10e and a part of the region 5b located second from the element body portion 3a are in contact with each other. The region 5b located second from the element body portion 3a and a part of the region 5b located second from the element body portion 3a are covered by one electrode portion 10c. One edge 10e and the other part of the region 5b located second from the element body portion 3a are not in contact with each other. The other part of the region 5b located second from the element body portion 3a is exposed from one electrode portion 10c. The other edge 10e is not in contact with any of the regions 5b. The other edge 10e does not cover any of the regions 5b.

[0065] A coil component ED9 according to an eighth modified example of this embodiment will be described with reference to Fig. 11. Fig. 11 is a diagram showing a cross-sectional configuration of the coil component according to the eighth modified example of this embodiment. In Fig. 11, hatching indicating a cross section and illustration of the through-hole conductors 36 are omitted. The configuration of the coil component ED9 is the same as that of the coil component ED1, except for the arrangement of the regions 5a and 5b.

[0066] The element portion 3c includes two regions 5a and one region 5b. The portions 7a and 7c include one region 5a but do not include region 5b. The portion 7b includes two regions 5a and one region 5b. In one region 5b, three insulator layers including the second material are stacked continuously with no region 5a in between. One region 5b is not in contact with the edge 10e and is exposed from the electrode portion 10c.

[0067] A coil component ED10 according to a ninth modified example of this embodiment will be described with reference to Fig. 12. Fig. 12 is a diagram showing a cross-sectional configuration of a coil component according to the ninth modified example of this embodiment. In Fig. 12, hatching indicating a cross section and illustration of the through-hole conductors 36 are omitted. The configuration of the coil component ED10 is the same as that of the coil component ED1, except for the size of the element portions 3a, 3b, and 3c, the configuration of the coil 30, and the arrangement of the regions 5a and 5b.

[0068] Each of the body parts 3a, 3b is longer in the first direction D1 than the body parts 3a, 3b according to this embodiment. The number of coil conductors 31 included in the coil 30 according to the ninth modified example is smaller than the number of coil conductors 31 included in the coil 30 according to this embodiment. The body part 3c includes two regions 5a and one region 5b. In the ninth modified example, the parts 7a, 7b, 7c each include one region 5a but do not include region 5b. The one region 5b is not in contact with the edge 10e and is exposed from the electrode part 10c.

[0069] As described above, in the coil components ED1 to ED10, at least one coil conductor 31 includes a coil conductor 31 arranged in the element body portion 3c, and the element body portion 3c is certainly present at a position where the magnetic flux generated by the coil conductor 31 passes. That is, the element body portion 3c affects the characteristics of the coil component, such as impedance and inductance. The element body portion 3c includes a region 5a and a region 5b, and the region 5b has a relative permeability and a relative dielectric constant that are respectively smaller than those of the region 5a. Since the element body portion 3c includes the region 5b, the coil components ED1 to ED10 cause an impedance peak to appear in a high frequency band. Since the element body portion 3c also includes the region 5a, the coil components ED1 to ED10 suppress a decrease in inductance. The coil components ED1 to ED10 achieve high impedance in a high frequency band, for example, from 700 MHz to 3 GHz.

[0070] In the coil components ED1 to ED7, ED9, and ED10, the element portion 3b is divided into three equal parts 7a, 7b, and 7c in the first direction D1, and the central part 7b includes the region 5b. In the coil parts ED1 to ED7, ED9, and ED10, the region 5b that causes an impedance peak to appear in a high frequency band is arranged in the portion 7b. Therefore, the coil parts ED1 to ED7, ED9, and ED10 reliably cause an impedance peak to appear in a high frequency band.

[0071] In the coil parts ED1, ED2, ED5, and ED6, each of the three portions 7a, 7b, and 7c includes a region 5a and a region 5b. In the coil parts ED1, ED2, ED5, and ED6, the region 5b that produces an impedance peak in the high frequency band is disposed in each of the three parts 7a, 7b, and 7c, respectively. Therefore, the coil parts ED1, ED2, ED5, and ED6 more reliably produce an impedance peak in the high frequency band.

[0072] In the coil components ED1 to ED8, the region 5b includes a plurality of regions 5b provided at different positions in the first direction D1. In the coil parts ED1 to ED8, a plurality of regions 5b that cause impedance peaks to appear in the high frequency band are arranged in the element portion 3c. Therefore, the coil parts ED1 to ED8 more reliably cause impedance peaks to appear in the high frequency band.

[0073] In the coil component ED4, the multiple regions 5b are provided symmetrically with respect to the central position CL1 of the element portion 3c. In the coil part ED4, a plurality of regions 5b that cause an impedance peak to appear in a high frequency band are provided symmetrically with respect to the central position CL1. Therefore, the coil part ED4 more reliably causes an impedance peak to appear in a high frequency band.

[0074] In the coil components ED1 to ED4, ED6, the multiple regions 5b are provided at approximately equal intervals in the first direction D1. In the coil parts ED1 to ED4, ED6, a plurality of regions 5b that cause impedance peaks to appear in the high frequency band are provided at substantially equal intervals, and therefore, the coil parts ED1 to ED4 more reliably cause impedance peaks to appear in the high frequency band.

[0075] In the coil components ED3, ED7, and ED8, the multiple regions 5b are provided so as to be biased toward one element portion 3a of the pair of element portions 3a, 3b. In the coil components ED3, ED7, and ED8, even if an element contained in region 5b diffuses into element portion 3c, the element is unlikely to diffuse into element portion 3c that is closer to element portion 3b. Region 5a provided in element portion 3c that is closer to element portion 3b is unlikely to be affected by element diffusion. Therefore, coil components ED3, ED7, and ED8 reliably suppress a decrease in inductance. In the coil components ED4 and ED9, the portion 7b includes the region 5a, and the portions 7a and 7c do not include the region 5b. Even if an element contained in the region 5b diffuses into the element portion 3c, the element is unlikely to diffuse into the element portion 3c close to the element portions 3a and 3b. The element portion 3c close to the element portions 3a and 3b is unlikely to be affected by element diffusion. Therefore, the coil components ED4 and ED9 reliably suppress a decrease in inductance.

[0076] In the coil components ED1 to ED10, at least one coil conductor 31 includes a plurality of coil conductors 31. The plurality of coil conductors 31 includes the coil conductor 31 disposed in the region 5b. In the coil parts ED1 to ED10, the multiple coil conductors 31 can be arranged in the region 5b. Therefore, the occurrence of an impedance peak in the high frequency band is realized by the multiple coil conductors 31. As a result, the coil parts ED1 to ED10 more reliably cause the impedance peak to occur in the high frequency band.

[0077] The coil components ED1 to ED3, ED5 to ED8 each include a pair of external electrodes 10 that are disposed at both ends of the element body 1 in the first direction D1 and are electrically connected to the coil 30. The element body 1 includes a side surface 1c connecting a pair of end faces 1a. One external electrode 10 includes an electrode portion 10c located on the side surface 1c. An edge 10e of one electrode portion 10c and the region 5b are in contact with each other. Each of the other external electrodes 10 includes the other electrode portion 10c located on the side surface 1c. An edge 10e of the other electrode portion 10c and the region 5b are in contact with each other. The coil components ED1 to ED3 and ED5 to ED8 reduce the stray capacitance formed between the coil 30 and the external electrode 10. Therefore, the coil components ED1 to ED3 and ED5 to ED8 more reliably cause an impedance peak to appear in the high frequency band.

[0078] The above describes the embodiments and modifications of the present invention, but the present invention is not necessarily limited to the above-described embodiments and modifications, and various modifications are possible without departing from the spirit of the present invention.

[0079] In the coil device ED1, among the three portions 7a, 7b, and 7c, only the portions 7b and 7c located at both ends may include the region 5b. As described above, the configuration in which the portion 7b located in the center includes the region 5b reliably produces an impedance peak in the high frequency band.

[0080] As will be understood from the above description of the embodiments and modifications, this specification includes disclosure of the following aspects. (Appendix 1) an element body including a pair of end faces facing each other; A coil disposed within the element body, The coil includes at least one coil conductor and is disposed such that a coil axis is aligned in a direction in which the pair of end faces face each other, the element body includes a pair of first element body parts each including corresponding one of the pair of end surfaces, and a second element body part located between the pair of first element body parts, the second body portion includes a first region and a second region provided at different positions in the direction, The second region has a relative permeability and a relative dielectric constant smaller than those of the first region, The at least one coil conductor includes a coil conductor disposed in the second body portion. (Appendix 2) 2. The coil component described in claim 1, wherein the second body part is divided into three equal parts in the direction, and a central part of the three parts includes the second region. (Appendix 3) 3. The coil component of claim 2, wherein each of the three portions includes the first region and the second region. (Appendix 4) 4. The coil component according to claim 1, wherein the second region includes a plurality of regions provided at different positions in the direction. (Appendix 5) The coil component according to claim 4, wherein the plurality of regions are provided symmetrically with respect to a central position of the length of the second body portion in the direction. (Appendix 6) 6. The coil component according to claim 4, wherein the plurality of regions are provided at approximately equal intervals in the direction. (Appendix 7) The coil component according to claim 4, wherein the plurality of regions are provided so as to be biased toward one of the pair of first element parts. (Appendix 8) the at least one coil conductor includes a plurality of coil conductors; 8. The coil component according to claim 1, wherein the plurality of coil conductors includes the coil conductor disposed in the second region. (Appendix 9) a pair of external electrodes disposed on both ends of the element body in the direction and electrically connected to the coil; the element body includes a side surface connecting the pair of end surfaces, Each of the pair of external electrodes includes an electrode portion located on the side surface, 9. The coil component according to claim 1, wherein an edge of the electrode portion and the second region are in contact with each other. [Explanation of symbols]

[0081] 1... body, 1a... end face, 1c... side face, 3a... body part, 3b... body part, 3c... body part, 5a... region, 5b... region, 7a... part, 7b... part, 7c... part, 10... external electrode, 10c... electrode part, 10e... edge, 30... coil, 31... coil conductor, CL1... central position, ED1... coil component, D1... first direction.

Claims

1. an element body including a pair of end faces facing each other; A coil disposed within the element body, The coil includes at least one coil conductor and is disposed such that a coil axis is aligned in a direction in which the pair of end faces face each other, the element body includes a pair of first element body parts each including corresponding one of the pair of end surfaces, and a second element body part located between the pair of first element body parts, the second body portion includes a first region and a second region provided at different positions in the direction, The second region has a relative permeability and a relative dielectric constant smaller than those of the first region, The at least one coil conductor includes a coil conductor disposed in the second body portion.

2. The coil component according to claim 1 , wherein a central portion of three portions obtained by dividing the second body portion into three equal portions in the direction includes the second region.

3. The coil component according to claim 2 , wherein each of the three portions includes the first region and the second region.

4. The coil component according to claim 1 , wherein the second region includes a plurality of regions provided at different positions in the direction.

5. The coil component according to claim 4 , wherein the plurality of regions are provided symmetrically with respect to a center position of the length of the second element part in the direction.

6. The coil component according to claim 4 , wherein the plurality of regions are provided at substantially equal intervals in the direction.

7. The coil component according to claim 4 , wherein the plurality of regions are provided so as to be biased toward one of the pair of first element parts.

8. the at least one coil conductor includes a plurality of coil conductors; The coil component according to claim 1 , wherein the plurality of coil conductors includes the coil conductor disposed in the second region.

9. a pair of external electrodes disposed on both ends of the element body in the direction and electrically connected to the coil; the element body includes a side surface connecting the pair of end surfaces, Each of the pair of external electrodes includes an electrode portion located on the side surface, The coil component according to claim 1 , wherein an edge of the electrode portion and the second region are in contact with each other.

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