Coil component

Abstract

To provide a coil component having a plurality of coil elements, and to reduce variations in the DC resistance between the coil elements.SOLUTION: A magnetic coupling coil component 1 comprises: a substrate 10 having a first principal surface 10a and a second principal surface 10b; a first coil conductor 25 facing the first principal surface; and a second coil conductor 35 between the first coil conductor and the second principal surface. The first coil conductor has a first circulation part 25a, a first one end lead-out part 25b extending from one end of the first circulation part to the second surface, and a first other end lead-out part 25c extending from the other end of the first circulation part to the second surface. The second coil conductor has a second circulation part 35a, a second one end lead-out part 35b extending from one end of the second circulation part to the second surface, and a second other end lead-out part 35c extending from the other end of the second circulation part to the second surface. The first cross-sectional area indicating the cross-sectional area of the first one end lead-out part and the second cross-sectional area indicating the cross-sectional area of the first other end lead-out part, are both larger than the third cross-sectional area indicating the cross-sectional area of the second one end lead-out part and the fourth cross-sectional area indicating the cross-sectional area of the second other end lead-out part.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a coil assembly having a plurality of coil elements. [Background technology]

[0002] As one type of array-type coil component having a plurality of coil elements, a magnetically coupled coil component having two or more coil elements that are magnetically coupled to each other when in use is known. As described in JP 2016-131208 A, the magnetically coupled coil component has a base and two or more coil elements that are electrically insulated from each other within the base, and each of the two or more coil elements has a winding portion that extends along the circumferential direction around the coil axis. In the magnetically coupled coil component, two or more coil elements are arranged along the direction of the coil axis (in the vertical direction), and when in use, the two or more coil elements are magnetically coupled to each other. The magnetically coupled coil component is used in a circuit, for example, as a common mode choke coil, a transformer, or a coupled inductor.

[0003] In an array-type coil component, two or more coil elements may be arranged along the arrangement direction of the coil axis (in the horizontal direction). The coil elements included in the array-type coil component do not need to be magnetically coupled to each other. In an array-type coil component, a plurality of coils are packaged in one base body, thereby enabling high-density mounting of the plurality of coils. A conventional array-type coil component in which two or more coil elements are arranged in the horizontal direction is described in, for example, JP 2016-006830 A. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2016-131208 A [Patent Document 2] JP 2016-006830 A Summary of the Invention [Problem to be solved by the invention]

[0005] In an array-type coil component having a plurality of coil elements, it is desirable that the difference in DC resistance between the coil elements is small. Conventionally, the shape of the winding part and the number of turns of each coil element are made uniform to make the DC resistance of each coil element uniform.

[0006] In a coil component in which multiple coil elements are arranged vertically along the coil axis, the positions of both ends of the winding part of the coil elements (the winding start position and the winding end position) are different for each coil element, so the length of the lead-out part extending from both ends of the winding part to the mounting surface of the base is different for each coil element. Therefore, even if the shape and number of turns of the winding part are the same for multiple coil elements, the DC resistance of each coil element will differ due to the difference in the length of the lead-out part. Conventionally, since the number of turns of the winding part of each coil element is large (for example, in the examples shown in Patent Document 1 and Patent Document 2, it is 3 turns or more), the DC resistance of each coil element is greatly affected by the shape and number of turns of the winding part, and conversely, the difference in the length of the lead-out part does not have a large effect on the difference in the DC resistance of the coil elements. In other words, in a coil element with a large number of turns (for example, 3 turns or more), even if the length of the lead-out part differs between coil elements, the difference in the length of the lead-out part does not have a large effect on the difference in the DC resistance of each coil element.

[0007] However, as the number of turns in the winding portion decreases, the effect of differences in the length of the lead-out portion on the variation in the DC resistance of the coil elements increases. Up until now, there has been no sufficient study on suppressing the variation in the DC resistance of each coil element in a coil component having multiple coil elements with a small number of turns in the winding portion.

[0008] The object of the invention disclosed in this specification is to solve or alleviate at least a part of the above-mentioned problems. One of the more specific objects of the invention disclosed in this specification is to suppress the variation in DC resistance between coil elements in a coil component having a plurality of coil elements. One of the more specific objects of the present invention is to suppress the variation in DC resistance between coil elements in a coil component including a plurality of coil elements each having a winding part with a small number of turns (e.g., less than 2 turns).

[0009] Objects of the invention disclosed in this specification other than those mentioned above will become apparent by referring to the entire specification. The invention disclosed in this specification may solve the problems understood from the description of this specification instead of or in addition to the above problems. [Means for solving the problem]

[0010] A coil component according to one or more embodiments of the present invention includes a base body made of an insulating material and having a first surface and a second surface opposite to the first surface, a first coil conductor provided in the base body so as to face the first surface, and a second coil conductor provided in the base body between the first coil and the second surface. In one aspect, the first coil conductor has a first winding portion wound around a first coil axis, a first one-end lead portion extending from one end of the first winding portion to the second surface, and a first other-end lead portion extending from the other end of the first winding portion to the second surface. In one aspect, the second coil conductor has a second winding portion wound around the first coil axis, a second one-end lead portion extending from one end of the second winding portion to the second surface, and a second other-end lead portion extending from the other end of the second winding portion to the second surface. In one aspect, a first cross-sectional area indicating the cross-sectional area of ​​the first one-end drawn portion and a second cross-sectional area indicating the cross-sectional area of ​​the first other-end drawn portion are both larger than a third cross-sectional area indicating the cross-sectional area of ​​the second one-end drawn portion and a fourth cross-sectional area indicating the cross-sectional area of ​​the second other-end drawn portion. Effect of the Invention

[0011] According to one embodiment of the invention disclosed in this specification, in a coil component including a plurality of coil elements, it is possible to suppress the variation in DC resistance between the coil elements. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a perspective view illustrating a coil component according to a first embodiment. [Diagram 2] 2 is a cross-sectional view that illustrates a schematic cross section of the coil component of FIG. 1 taken along line II. [Figure 3a] 3 is a plan view showing a conductor pattern provided on the magnetic film 11a of FIG. 2. FIG. [Figure 3b] 3 is a plan view showing a conductor pattern provided on the magnetic film 11b of FIG. 2. FIG. [Figure 3c] 3 is a plan view showing a conductor pattern provided on the magnetic film 11c of FIG. 2. FIG. [Figure 3d] 3 is a plan view showing a conductor pattern provided on the magnetic film 11d of FIG. 2. FIG. [Figure 4] 2 is a transparent view of the magnetically coupled coil component of FIG. 1 as viewed from above. [Diagram 5] 2 is a perspective view of the magnetically coupled coil component of FIG. 1 as viewed from below. [Figure 6] FIG. 11 is a cross-sectional view showing a magnetically coupled coil component according to a second embodiment. [Figure 7] 7 is an enlarged cross-sectional view for explaining the drawing portion of FIG. 6. FIG. [Figure 8] FIG. 11 is a perspective view illustrating an array-type coil component according to a third embodiment. [Figure 9] FIG. 9 is a schematic cross-sectional view of the array-type coil component of FIG. 8. [Figure 10] FIG. 9 is a schematic cross-sectional view of the array-type coil component of FIG. 8. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Various embodiments of the present invention will be described below with reference to the drawings as appropriate. Note that components common to multiple drawings are given the same reference numerals throughout the multiple drawings. Please note that the drawings are not necessarily drawn to scale for the sake of convenience. The embodiments of the present invention described below do not limit the invention according to the claims. Elements described in the following embodiments are not necessarily essential to the solution of the invention.

[0014] 1. First embodiment The first embodiment relates to an array-type coil component having two coil elements. The array-type coil component of the first embodiment is a magnetically coupled coil component in which two coil elements are magnetically coupled to each other. The magnetically coupled coil component includes a plurality of coil elements that are magnetically coupled when in use.

[0015] 1-1 Basic structure of magnetically coupled coil components The basic structure of the magnetically coupled coil component 1 according to the first embodiment will be described with reference to Fig. 1. Fig. 1 is a perspective view of the magnetically coupled coil component 1 according to the first embodiment.

[0016] The magnetically coupled coil component 1 can be used as a choke coil for a DC-DC converter. The magnetically coupled coil component 1 can be applied to various magnetically coupled coil components such as transformers, coupled inductors, and others other than the choke coil for a DC-DC converter.

[0017] The magnetically coupled coil component 1 includes a plurality of coil elements that are magnetically coupled to each other when in use. In the illustrated example, the magnetically coupled coil component 1 includes two coil elements. More specifically, the magnetically coupled coil component 1 shown in FIG. 1 includes a base 10, a first coil element including a first coil conductor 25 provided on the base 10, and a second coil element including a second coil conductor 35 provided on the base 10. The magnetically coupled coil component 1 further includes a first external electrode 21 connected to one end of the first coil conductor 25, a second external electrode 22 connected to the other end of the first coil conductor 25, a third external electrode 23 connected to one end of the second coil conductor 35, and a fourth external electrode 24 connected to the other end of the second coil conductor 35. In the magnetically coupled coil component 1, the first coil element including the first coil conductor 25 and the second coil element including the second coil conductor 35 are magnetically coupled to each other.

[0018] The magnetically coupled coil component 1 can be mounted on a mounting board 2a. The mounting board 2a is provided with land portions 3a and 3b. The magnetically coupled coil component 1 is mounted on the mounting board 2a by joining the first external electrode 21, the second external electrode 22, the third external electrode 23, and the fourth external electrode 24 to the land portions 3a, 3b, 3c, and 3d, respectively. The circuit board 2 can include the magnetically coupled coil component 1 and a mounting board 2a on which the magnetically coupled coil component 1 is mounted. The circuit board 2 can be mounted on various electronic devices. Electronic devices on which the circuit board 2 can be mounted include smartphones, tablets, game consoles, automotive electrical equipment, servers, and various other electronic devices.

[0019] 1-2 Basic structure of the substrate 10 In one embodiment, the base 10 is made of an insulating material and has a rectangular parallelepiped shape. For example, the dimension (length dimension) of the magnetically coupled coil component 1 in the L-axis direction is in the range of 0.5 mm to 6.0 mm, the dimension (width dimension) in the W-axis direction is in the range of 0.3 mm to 4.5 mm, and the dimension (height dimension) in the T-axis direction is in the range of 0.3 mm to 4.5 mm. In one embodiment, the length dimension of the magnetically coupled coil component 1 may be greater than the width dimension. In this specification, the term "rectangular parallelepiped" or "rectangular parallelepiped shape" does not mean only "rectangular parallelepiped" in the mathematically strict sense. As described later, the corners and / or sides of the base 10 may be curved. The dimensions and shape of the base 10 are not limited to those explicitly stated in this specification.

[0020] The base 10 has a first main surface 10a, a second main surface 10b, a first end surface 10c, a second end surface 10d, a first side surface 10e, and a second side surface 10f. The first end surface 10c, the second end surface 10d, the first side surface 10e, and the second side surface 10f are all connected to the first main surface 10a and the second main surface 10b. The first end surface 10c connects the first side surface 10e and the second side surface 10f. The second end surface 10d also connects the first side surface 10e and the second side surface 10f. The first main surface 10a and the second main surface 10b form the surfaces at both ends of the base 10 in the height direction, the first end surface 10c and the second end surface 10d form the surfaces at both ends of the base 10 in the length direction, and the first side surface 10e and the second side surface 10f form the surfaces at both ends of the base 10 in the width direction. The first main surface 10a and the second main surface 10b face each other in the T-axis direction. The first end surface 10c and the second end surface 10d face each other in the L-axis direction. The first side surface 10e and the second side surface 10f face each other in the W-axis direction. As shown in FIG. 1, the first main surface 10a is located on the upper side of the base 10, and therefore the first main surface 10a may be referred to as the "upper surface." Similarly, the second main surface 10b may be referred to as the "lower surface" or "bottom surface."

[0021] In the illustrated embodiment, the second main surface 10b of the base 10 is provided with a first external electrode 21, a second external electrode 22, a third external electrode 23, and a fourth external electrode 24. When the magnetically coupled coil component 1 is mounted on a mounting board 2a, the second main surface 10b is disposed so as to face the mounting board 2a. For this reason, the second main surface 10b of the base 10 is sometimes called a "mounting surface." At least one of the first external electrode 21, the second external electrode 22, the third external electrode 23, and the fourth external electrode 24 may extend to a surface other than the lower surface 10b of the base 10. For example, the first external electrode 21 may extend so as to contact not only the lower surface 10b but also the first end surface 10c.

[0022] The upper surface 10a and the lower surface 10b are spaced apart by the height dimension of the base 10, the first end surface 10c and the second end surface 10d are spaced apart by the length dimension of the base 10, and the first side surface 10e and the second side surface 10f are spaced apart by the width dimension of the base 10. In this specification, unless otherwise understood in the context, the "length" direction, "width" direction, and "thickness" direction of the magnetically coupled coil component 1 are the L-axis direction, W-axis direction, and T-axis direction in FIG. 1, respectively.

[0023] The substrate 10 is made of an insulating material having excellent insulating properties. The substrate 10 may be made of a magnetic material. As the magnetic material for the substrate 10, a soft magnetic alloy material, a composite magnetic material in which magnetic particles are dispersed in a resin, a ferrite material, or any other known magnetic material can be used.

[0024] 1-3 Basic structure of coil conductor In the illustrated embodiment, the first coil conductor 25 is provided in the base 10 so as to face the upper surface 10a of the base 10. The second coil conductor 35 is provided in the base 10 so as to face the lower surface 10b of the base 10. Therefore, the first coil conductor 25 is disposed above the second coil conductor 35 (i.e., on the positive side in the T-axis direction). The second coil conductor 35 is interposed between the first coil conductor 25 and the lower surface 10b, but another coil conductor is not interposed between the first coil conductor 25 and the upper surface 10a. The first coil conductor 25 is interposed between the second coil conductor 35 and the upper surface 10a, but another coil conductor is not interposed between the second coil conductor 35 and the lower surface 10b. The first coil conductor 25 and the second coil conductor 35 are arranged along the T-axis direction. Since a portion of the insulating base 10 is interposed between the first coil conductor 25 and the second coil conductor 35, the first coil conductor 25 and the second coil conductor 35 are electrically insulated within the base 10.

[0025] The first coil conductor 25 has a first winding portion 25a, a first one-end drawn portion 25b connecting one end of the first winding portion 25a to the first external electrode 21, and a first other-end drawn portion 25c connecting the other end of the first winding portion 25a to the second external electrode 22. Similarly, the second coil conductor 35 has a second winding portion 35a, a second one-end drawn portion 35b connecting one end of the second winding portion 35a to the third external electrode 23, and a second other-end drawn portion 35c connecting the other end of the second winding portion 35a to the fourth external electrode 24.

[0026] The first winding portion 25a extends in a circumferential direction around the first coil axis Ax1 extending along the T-axis. Like the first winding portion 25a, the second winding portion 35a extends in a circumferential direction around the first coil axis Ax1. In the illustrated embodiment, the first coil axis Ax1 extends parallel to the T-axis. The first coil axis Ax1 does not have to be parallel to the T-axis. The first coil axis Ax1 intersects with the upper surface 10a and the lower surface 10b of the base 10. The first coil axis Ax1 extends in a direction perpendicular to the upper surface 10a, for example, passing through an intersection of diagonals of the first main surface 10a having a rectangular shape in a plan view. Details of the first winding portion 25a and the second winding portion 35a will be described later.

[0027] The first one-end drawn portion 25b extends downward along the T-axis from one end of the first winding portion 25a. One end of the first one-end drawn portion 25b is connected to one end of the first winding portion 25a. The other end of the first one-end drawn portion 25b is exposed outward from the base 10 through the lower surface 10b. The first one-end drawn portion 25b is connected to the first external electrode 21 at the other end exposed from the lower surface 10b.

[0028] The first other-end drawn portion 25c extends downward along the T-axis from the other end of the first winding portion 25a. One end of the first other-end drawn portion 25c is connected to the other end of the first winding portion 25a (the end opposite to the end to which the first one-end drawn portion 25b is connected). The other end of the first other-end drawn portion 25c is exposed to the outside of the base 10 from the lower surface 10b. The first other-end drawn portion 25c is connected to the second external electrode 22 at the other end exposed from the lower surface 10b.

[0029] The second one-end drawn portion 35b extends downward along the T-axis from one end of the second winding portion 35a. One end of the second one-end drawn portion 35b is connected to one end of the second winding portion 35a. The other end of the second one-end drawn portion 35b is exposed outside the base 10 from the lower surface 10b. The second one-end drawn portion 35b is connected to the third external electrode 23 at the other end exposed from the lower surface 10b.

[0030] The second other-end drawn portion 35c extends downward along the T-axis from the other end of the second winding portion 35a. One end of the second other-end drawn portion 35c is connected to the other end of the second winding portion 35a (the end opposite to the end to which the second one-end drawn portion 35b is connected). The other end of the second other-end drawn portion 35c is exposed to the outside of the base 10 from the lower surface 10b. The second other-end drawn portion 35c is connected to the fourth external electrode 24 at the other end exposed from the lower surface 10b.

[0031] The length in the T-axis direction of the first one-end drawn portion 25b and the length in the T-axis direction of the first other-end drawn portion 25c are both longer than the length in the T-axis direction of the second one-end drawn portion 35b and the length in the T-axis direction of the second other-end drawn portion 35c.

[0032] The first cross-sectional area indicating the cross-sectional area of ​​the first one-end drawn portion 25b and the second cross-sectional area indicating the cross-sectional area of ​​the first other-end drawn portion 25c are larger than the third cross-sectional area indicating the cross-sectional area of ​​the second one-end drawn portion 35b and the fourth cross-sectional area indicating the cross-sectional area of ​​the second other-end drawn portion 35c. The first cross-sectional area and the second cross-sectional area may be equal to each other. The third cross-sectional area and the fourth cross-sectional area may be equal to each other. The first cross-sectional area refers to the area of ​​a cross section obtained by cutting the first one-end drawn portion 25b in a plane parallel to the WL plane (in other words, a plane perpendicular to the T axis or a plane perpendicular to the first coil axis Ax1). The first one-end drawn portion 25b may be cut in a plane parallel to the WL plane at a plurality of different positions (for example, three positions or five positions) in the T axis direction to obtain each cross-sectional area, and the average of the cross-sectional areas of each cross section may be the first cross-sectional area. The second cross-sectional area, the third cross-sectional area, and the fourth cross-sectional area also have the same meaning as the first cross-sectional area. In other words, the second cross-sectional area refers to the area of ​​the cross section of the first one-end drawn portion 25b cut along a plane parallel to the WL plane, the third cross-sectional area refers to the area of ​​the cross section of the second one-end drawn portion 35b cut along a plane parallel to the WL plane, and the fourth cross-sectional area refers to the area of ​​the cross section of the second other-end drawn portion 35c cut along a plane parallel to the WL plane.

[0033] As described above, the first external electrode 21, the second external electrode 22, the third external electrode 23, and the fourth external electrode 24 are all provided on the lower surface 10b of the base body 10, and the first one-end drawn portion 25b, the first other-end drawn portion 25c, the second one-end drawn portion 35b, and the second other-end drawn portion 35c are each drawn to the lower surface 10b and connected to the corresponding external electrodes. In this manner, in the illustrated embodiment, the first coil conductor 25 is drawn from the lower surface 10b of the base body 10, so that the current path from the land portion 3a through the first external electrode 21 and the first coil conductor 25 to the land portion 3b via the second external electrode 22 can be shortened compared to an embodiment in which the first coil conductor 25 is drawn from a surface other than the lower surface 10b of the base body 10, and thus the DC resistance (Rdc) of the circuit element including the first coil conductor 25 can be reduced. Similarly, according to the illustrated embodiment, the second coil conductor 35 is pulled out from the lower surface 10b of the base 10, and therefore the current path from the land portion 3c through the third external electrode 23 and the second coil conductor 35 to the land portion 3d via the fourth external electrode 24 is shortened compared to an embodiment in which the second coil conductor 35 is pulled out from a surface other than the lower surface 10b of the base 10, thereby making it possible to reduce the DC resistance (Rdc) of the circuit element including the second coil conductor 35.

[0034] The surface of the first coil conductor 25 and the surface of the second coil conductor 35 may be covered with an insulating coating (not shown) made of an insulating material with excellent insulating properties. The insulating coating may be an oxide film formed on the surface of the first coil conductor 25 and the surface of the second coil conductor 35 during a heat treatment in the manufacturing process of the magnetically coupled coil component 1. The insulating coating may be a coating film made of a resin with excellent insulating properties, such as polyurethane, polyamideimide, polyimide, polyester, or polyester-imide.

[0035] 1-4 Specific explanation of magnetically coupled coil component 1 Next, the magnetically coupled coil component 1 will be further described with reference to Fig. 2. Fig. 2 shows a cross-sectional view of the magnetically coupled coil component 1 taken along line II parallel to the W axis. Fig. 2 depicts a portion of the first coil conductor 25 and the second coil conductor 35 through the base 10. Fig. 2 shows a cross-section of the magnetically coupled coil component 1 taken along a plane that passes through the first coil axis Ax1 and is parallel to the WT plane.

[0036] 1-4-1 Description of the base 10 As shown in FIG. 2, the base 10 is divided into a main body 11, an upper cover 12 disposed above the main body 11, and a lower cover 13 disposed below the main body 11. The upper surface of the main body 11 is in contact with the lower surface of the upper cover 12. The lower surface of the main body 11 is in contact with the upper surface of the lower cover 13. A first winding portion 25a and a second winding portion 35a are disposed inside the main body 11. The upper cover 12 does not include any of the members constituting the first coil conductor 25. The lower cover 13 does not include the first winding portion 25a and the second winding portion 35a, but includes a first one-end drawn portion 25b, a first other-end drawn portion 25c, a second one-end drawn portion 35b, and a part of the second other-end drawn portion 35c.

[0037] In one embodiment, the base 10 is a laminate in which a plurality of magnetic films are laminated. As described later, the main body 11 may be a laminate in which a magnetic film having a conductor pattern corresponding to the first winding portion 25a formed on its surface and a magnetic film having a conductor pattern corresponding to the second winding portion 35a formed on its surface are laminated. The upper cover 12 may be a laminate in which a plurality of magnetic films are laminated. The lower cover 13 may be a laminate in which a plurality of magnetic films are laminated. The magnetic film constituting the lower cover 13 has through holes formed therein for passing through the first one-end drawn portion 25b, the first other-end drawn portion 25c, the second one-end drawn portion 35b, and the second other-end drawn portion 35c, respectively.

[0038] The thickness (dimension in the T-axis direction) of the main body 11 can be changed depending on the number and film thickness of the magnetic films that make up the main body 11. For example, the thickness of the main body 11 can be increased by increasing the number of magnetic films that make up the main body 11. Also, the thickness of the main body 11 can be increased by increasing the thickness of each of the magnetic films that make up the main body 11. Similarly, the thickness of each of the upper cover part 12 and the lower cover part 13 can be adjusted by changing the number of magnetic films that make up the upper cover part 12 and the lower cover part 13, respectively, and / or the film thickness of each magnetic film.

[0039] In the embodiment shown in FIG. 2, the main body 11 is a laminated body formed by stacking magnetic films 11a, 11b, 11c, and 11d. However, the boundaries between the magnetic films 11a to 11d may not be visible even when the cross section of the base 110 is observed by SEM. The main body 11 may include magnetic films other than the magnetic films 11a to 11d. Conductive patterns constituting a part of the first coil conductor 25 and the second coil conductor 35 are formed on the upper surfaces of the magnetic films 11a to 11d. In addition, through holes penetrating each magnetic film in the T-axis direction are formed at predetermined positions of the magnetic films 11a to 11d, and via conductors are embedded in the through holes. Each of the conductor patterns and via conductors of the magnetic coupling coil component 1 is formed by printing a conductive paste made of a metal or alloy with excellent conductivity on a magnetic sheet, which is a precursor of the magnetic films 11a to 11d, by screen printing, and heating the conductive paste printed on the magnetic sheet. The conductive paste may be made of Ag, Pd, Cu, Al, or an alloy thereof. The conductive pattern and via conductors of the magnetically coupled coil component 1 may be made of a material other than those mentioned above. The conductive pattern and via conductors of the magnetically coupled coil component 1 may be made by, for example, a sputtering method, an inkjet method, or any other known method.

[0040] 1-4-2 Coil conductor structure 3a to 3d, the first coil conductor 25 and the second coil conductor 35 will now be further described.

[0041] As shown in FIG. 3a, the first upper conductor pattern 25a1 is formed on the upper surface of the magnetic film 11a. The first upper conductor pattern 25a1 extends in the circumferential direction around the first coil axis Ax1 by a number of turns less than one turn in a plane (LW plane) perpendicular to the first coil axis Ax1. The number of turns of the conductor pattern extending in the circumferential direction around the first coil axis Ax1 indicates the proportion of the area in which the conductor pattern is formed in the circumferential direction around the first coil axis Ax1. The number of turns of a given conductor pattern can be expressed using the central angle of the area in which the conductor pattern extends around the first coil axis Ax1. For example, in FIG. 3a, the first upper conductor pattern 25a1 extends in the circumferential direction around the first coil axis Ax1 within a range of a central angle α1, so the number of turns of the first upper conductor pattern 25a1 can be expressed as (α1 / 360) turns. For example, if α1 is 150°, the number of turns of the first upper conductor pattern 25a1 is approximately 0.42 turns.

[0042] A through hole penetrating the magnetic film 11a in the T-axis direction is provided in a region of the magnetic film 11a overlapping with one end of the first upper conductor pattern 25a1, and a via conductor constituting a part of the first one-end drawn-out portion 25b is embedded in this through hole. Also, a through hole penetrating the magnetic film 11a in the T-axis direction is provided in a region of the magnetic film 11a overlapping with the other end of the first upper conductor pattern 25a1, and a via conductor serving as the via conductor V1 is embedded in this through hole.

[0043] As shown in Fig. 3b, a first lower conductor pattern 25a2 is formed on the upper surface of the magnetic film 11b. The first lower conductor pattern 25a2 extends for approximately one turn in the circumferential direction around the first coil axis Ax1 in a plane (LW plane) perpendicular to the first coil axis Ax1. One end of the first lower conductor pattern 25a2 is connected to a via conductor V1. A through hole penetrating the magnetic film 11b in the T-axis direction is provided in a region of the magnetic film 11b overlapping with the other end of the first lower conductor pattern 25a2, and a via conductor constituting a part of the first other end drawn portion 25c is embedded in the through hole.

[0044] In this manner, the first upper conductor pattern 25a1 and the first lower conductor pattern 25a2 are connected by the via conductor V1. The first upper conductor pattern 25a1, the via conductor V1, and the first lower conductor pattern 25a2 connected in this manner constitute the first winding portion 25a of the first coil conductor 25. Since the first upper conductor pattern 25a1 is wound around the first coil axis Ax1 by approximately 0.42 turns and the first lower conductor pattern 25a2 is wound around the first coil axis Ax1 by approximately 1 turn, the first winding portion 25a is wound around the first coil axis Ax1 by approximately 1.42 turns.

[0045] In one embodiment, the number of turns of the first winding part 25a is greater than 1 and less than 2. The number of turns of the first winding part 25a may be 1.5 or less. For example, when the magnetically coupled coil component 1 is used in a high-frequency circuit, the first coil conductor 25 is required to have a small inductance value. To achieve this small inductance value, the number of turns of the first winding part 25a is set to less than 2.

[0046] As shown in Fig. 3c, a second upper conductor pattern 35a1 is formed on the upper surface of the magnetic film 11c. The second upper conductor pattern 35a1 extends for approximately one turn in the circumferential direction around the first coil axis Ax1 in a plane (LW plane) perpendicular to the first coil axis Ax1. In the illustrated embodiment, the second upper conductor pattern 35a1 may have a shape symmetrical to the first lower conductor pattern 25a2 with respect to a straight line passing through the coil axis and extending along the L axis.

[0047] A through hole penetrating the magnetic film 11c in the T-axis direction is provided in a region of the magnetic film 11c overlapping one end of the second upper conductor pattern 35a1, and a via conductor constituting a part of the second one-end drawn-out portion 35b is embedded in this through hole. A through hole penetrating the magnetic film 11c in the T-axis direction is provided in a region of the magnetic film 11c overlapping the other end of the second upper conductor pattern 35a1, and a via conductor V2 is embedded in this through hole. Furthermore, a through hole penetrating the magnetic film 11c in the T-axis direction is provided in the lower right corner of the magnetic film 11c, and a via conductor constituting a part of the first other-end drawn-out portion 25c is embedded in this through hole.

[0048] As shown in Fig. 3d, a second lower conductor pattern 35a2 is formed on the upper surface of the magnetic film 11d. The second lower conductor pattern 35a2 extends about 0.42 turns in the circumferential direction around the first coil axis Ax1 in a plane (LW plane) perpendicular to the first coil axis Ax1. The second lower conductor pattern 35a2 may have a shape symmetrical to the first upper conductor pattern 25a1 with respect to a straight line passing through the coil axis and extending along the L axis.

[0049] Each of the magnetic films 11a to 11d has a plate shape extending along the LW plane. The first coil axis Ax1 extends in a direction perpendicular to each of the magnetic films 11a to 11d.

[0050] One end of the second lower conductor pattern 35a2 is connected to the via conductor V2. A through hole penetrating the magnetic film 11d in the T-axis direction is provided in a region of the magnetic film 11d that overlaps with the other end of the second lower conductor pattern 35a2, and a via conductor constituting a part of the second other end drawn portion 35c is embedded in this through hole. Furthermore, a through hole penetrating the magnetic film 11c in the T-axis direction is provided in each of the lower right corner and the upper left corner of the magnetic film 11d, and a via conductor constituting a part of the first other end drawn portion 25c is embedded in this through hole formed in the lower right corner. Furthermore, a via conductor constituting a part of the second one end drawn portion 35b is embedded in the through hole formed in the upper left corner.

[0051] In this manner, the second upper conductor pattern 35a1 and the second lower conductor pattern 35a2 are connected by the via conductor V2. The second upper conductor pattern 35a1, the via conductor V2, and the second lower conductor pattern 35a2 connected in this manner constitute the second winding portion 35a of the second coil conductor 35. Since the second upper conductor pattern 35a1 is wound around the first coil axis Ax1 by approximately one turn and the second lower conductor pattern 35a2 is wound around the first coil axis Ax1 by approximately 0.42 turns, the second winding portion 35a is wound around the first coil axis Ax1 by approximately 1.42 turns.

[0052] In one embodiment, the number of turns of the first winding part 25a and the second winding part 35a is greater than 1 turn and less than 2 turns. The number of turns of the first winding part 25a and the second winding part 35a may be 1.5 turns or less. For example, when the magnetically coupled coil component 1 is used in a high-frequency circuit, the first coil conductor 25 and the second coil conductor 35 are required to have a small inductance value. To achieve this small inductance value, the number of turns of the first winding part 25a and the second winding part 35a is less than 2.

[0053] In one embodiment, the length of the first winding portion 25a is equal to the length of the second winding portion 35a. The length of the first winding portion 25a is expressed by the sum of the length of the first upper conductor pattern 25a1, the length of the via conductor V1, and the length of the first lower conductor pattern 25a2, and the length of the second winding portion 35a is expressed by the sum of the length of the second upper conductor pattern 35a1, the length of the via conductor V2, and the length of the second lower conductor pattern 35a2. Note that, since the influence of the via conductor V1 on the inductance of the first winding portion 25a and the influence of the via conductor V2 on the inductance of the second winding portion 35a are both slight, when considering the influence of the length of the first winding portion 25a and the length of the second winding portion 35a on the inductance, the length of the via conductor V1 and the length of the via conductor V2 can be ignored.

[0054] As shown in the illustrated example, the first winding part 25a having less than two turns is obtained by joining the conductor patterns formed over two layers with a via conductor. Similarly, the second winding part 35a having less than two turns is obtained by joining the conductor patterns formed over two layers with a via conductor. Thus, the first winding part 25a can be obtained by stacking two magnetic films, and the second winding part 35a can be obtained by stacking another two magnetic films. On the other hand, when the number of turns is two or more, it is necessary to connect the conductor patterns formed on each of the three or more magnetic films with a via conductor. Thus, by making the number of turns of the first winding part 25a and the second winding part 35a less than two, the number of magnetic films constituting each of the first winding part 25a and the second winding part 35a can be two, so that the height dimension of the magnetically coupled coil component 1 can be made smaller than that of the first winding part 25a and the second winding part 35a having two or more turns.

[0055] As can be seen from FIG. 3b to FIG. 3d, not only the magnetic film 11a but also each of the magnetic films 11b to 11d has a through hole for embedding the via conductor constituting the first one-end drawn portion 25b, and the via conductor is embedded in the through hole. Although not shown, each of the magnetic films constituting the lower cover part 13 also has a through hole for embedding the via conductor constituting the first one-end drawn portion 25b, and the via conductor is embedded in the through hole. Since the via conductors embedded in the through holes are formed at the same position in a plan view, the via conductors adjacent in the T-axis direction are electrically connected to each other. In this way, the first one-end drawn portion 25b is formed by joining the via conductors embedded in the through holes formed in the magnetic films 11a to 11d and each of the magnetic films constituting the lower cover part 13. Similar to the first one-end lead portion 25b, the first other-end lead portion 25c, the second one-end lead portion 35b, and the second other-end lead portion 35c are also formed by joining via conductors embedded in a magnetic film.

[0056] The thickness dimension of the first upper conductor pattern 25a1, the first lower conductor pattern 25a2, the second upper conductor pattern 35a1, and the second lower conductor pattern 35a2 may be equal to each other. The thickness dimension of each conductor pattern indicates the thickness of the conductor pattern in the direction along the first coil axis Ax1 (T-axis direction).

[0057] Next, the shapes of the first coil conductor 25 and the second coil conductor 35 will be further described with reference to Fig. 4 and Fig. 5. Fig. 4 shows a perspective view of the magnetically coupled coil component 1 seen through the base 10 from the positive side of the T axis. Fig. 5 shows a perspective view of the magnetically coupled coil component 1 seen through the base 10 from the negative side of the T axis.

[0058] As shown in FIG. 4 and FIG. 5, when the magnetically coupled coil component 1 is viewed from the T-axis direction, a part of the first winding part 25a extends along an elliptical closed loop orbit CL1. Since the first one-end lead portion 25b and the first other-end lead portion 25c are provided near the upper right and lower right corners of the base body 10 in a plan view, a part of the first winding part 25a departs from the closed loop orbit CL1 and extends toward the first one-end lead portion 25b and the first other-end lead portion 25c. The shape of the closed loop orbit CL1 is not limited to an elliptical shape. The shape of the closed loop orbit CL1 may be an oval, a circle, a rectangle, a polygon, or a shape other than these in a plan view. Like the first winding part 25a, a part of the second winding part 35a extends along an elliptical closed loop orbit CL2. The description of the first winding part 25a in this paragraph also applies to the second winding part 35a.

[0059] In the illustrated embodiment, the width dimension W11 of the first winding portion 25a is equal to the width dimension W12 of the second winding portion 35a. The width dimension W11 of the first winding portion 25a is the dimension of the first winding portion 25a in a direction perpendicular to the closed loop trajectory CL1. Similarly, the width dimension W12 of the second winding portion 35a is the dimension of the second winding portion 35a in a direction perpendicular to the closed loop trajectory CL2. In the illustrated embodiment, the width dimension W11 of the first winding portion 25a is equal to the width dimension W12 of the second winding portion 35a.

[0060] Since the length (number of turns) and cross-sectional area of ​​the first winding portion 25a in a cross section perpendicular to the closed loop orbit CL1 are equal to the length (number of turns) and cross-sectional area of ​​the second winding portion 35a in a cross section perpendicular to the closed loop orbit CL2, respectively, the DC resistance in the first winding portion 25a is equal to the DC resistance in the second winding portion 35a.

[0061] 1-4-3 Comparison with conventional magnetically coupled coil components In conventional magnetically coupled coil components having a set of coil conductors arranged along a coil axis within a base, the winding portions of the set of coil conductors are often designed to extend the same number of turns along the same shaped orbital path so that the DC resistance in each winding portion is uniform, and to have the same cross-sectional shape.

[0062] In the magnetically coupled coil component 1, since the first winding portion 25a and the second winding portion 35a each have less than two turns, the first one-end lead-out portion 25b and the first other-end lead-out portion 25c have a large effect on the DC resistance of the first coil conductor 25, and the second one-end lead-out portion 35b and the second other-end lead-out portion 35c have a large effect on the DC resistance of the second coil conductor 35. Therefore, in order to uniform the DC resistance of the first coil conductor 25 and the DC resistance of the second coil conductor 35, it is necessary not only to uniform the DC resistance of the first winding portion 25a and the DC resistance of the second winding portion 35a, but also to design the first coil conductor 25 and the second coil conductor 35 taking into account the difference between the influence of the first one-end lead-out portion 25b and the first other-end lead-out portion 25c on the DC resistance of the first coil conductor 25 and the influence of the second one-end lead-out portion 35b and the second other-end lead-out portion 35c on the DC resistance of the second coil conductor 35.

[0063] In this regard, in the magnetically coupled coil component 1, the first coil conductor 25 is positioned higher in the T-axis direction than the second coil conductor 35, and therefore the lengths of the first one-end drawn-out portion 25b and the first other-end drawn-out portion 25c, which are drawn out to the lower surface 10b, are longer than the lengths of the second one-end drawn-out portion 35b and the second other-end drawn-out portion 35c, which are also drawn out to the lower surface 10b. In the magnetically coupled coil component 1 of the first embodiment, the first cross-sectional area indicating the cross-sectional area of ​​the first one-end drawn portion 25b and the second cross-sectional area indicating the cross-sectional area of ​​the first other-end drawn portion 25c are larger than the third cross-sectional area indicating the cross-sectional area of ​​the second one-end drawn portion 35b and the fourth cross-sectional area indicating the cross-sectional area of ​​the second other-end drawn portion 35c. Therefore, the total DC resistance in the first one-end drawn portion 25b and the first other-end drawn portion 25c can be made close to the total DC resistance in the second one-end drawn portion 35b and the second other-end drawn portion 35c.

[0064] As described above, in the magnetically coupled coil component 1 of the first embodiment, even if the first winding portion 25a and the second winding portion 35a, both of which have less than two turns, have the same shape and cross-sectional area, by making the first cross-sectional area indicating the cross-sectional area of ​​the first one-end drawn portion 25b and the second cross-sectional area indicating the cross-sectional area of ​​the first other-end drawn portion 25c larger than the third cross-sectional area indicating the cross-sectional area of ​​the second one-end drawn portion 35b and the fourth cross-sectional area indicating the cross-sectional area of ​​the second other-end drawn portion 35c, the DC resistance of the first coil conductor 25 and the DC resistance of the second coil conductor 35 can be made uniform.

[0065] If the shape of the first winding part 25a is made different from that of the second winding part 35a, the magnetic path of the interlinking magnetic flux becomes longer, which may reduce the inductance of the magnetically coupled coil component 1. According to the first embodiment, the first winding part 25a and the second winding part 35a have shapes symmetrical to each other, so that the DC resistance of the first coil conductor 25 and the DC resistance of the second coil conductor 35 can be made uniform without reducing the inductance of the magnetically coupled coil component 1.

[0066] Furthermore, in the magnetically coupled coil component 1, not only is the difference in DC resistance between the coil conductors reduced, but the shape of the first winding portion 25a and the shape of the second winding portion 35a are made equal to each other, thereby suppressing a decrease in inductance of the magnetically coupled coil component 1.

[0067] The difference between the DC resistance of the first coil conductor 25 and the DC resistance of the second coil conductor 35 is preferably 10% or less of the DC resistance of the first coil conductor 25. When the difference between the DC resistance of the first coil conductor 25 and the DC resistance of the second coil conductor 35 is 10% or less, it can be determined that the DC resistance of the first coil conductor 25 and the DC resistance of the second coil conductor 35 are equal or uniform. The difference between the DC resistance of the first coil conductor 25 and the DC resistance of the second coil conductor 35 is preferably 5% or less.

[0068] 1-4-4 Manufacturing method Next, a description will be given of an example of a method for manufacturing the magnetically coupled coil component 1. The magnetically coupled coil component 1 can be manufactured by, for example, a sheet lamination method. In the following, a description will be given of an example of a method for manufacturing the magnetically coupled coil component 1 by the sheet lamination method.

[0069] First, a magnetic sheet is prepared as a precursor of each of the magnetic films (including the magnetic films 11a to 11d) constituting the substrate 10. The magnetic sheet is prepared, for example, by kneading soft magnetic metal powder with resin to prepare a slurry, applying this slurry to the surface of a plastic base film by a doctor blade method or another common method, drying it, and cutting the dried slurry to a predetermined size.

[0070] Next, through holes are formed in the T-axis direction in each magnetic sheet, which is a precursor of the magnetic films 11a to 11d, at predetermined positions in each magnetic sheet. Next, a conductive paste is printed on the upper surface of each magnetic sheet, which is a precursor of the magnetic films 11a to 11d, by screen printing to form an unfired conductor pattern on the magnetic sheet, and the conductive paste is embedded in the through holes formed in each magnetic sheet. The unfired conductor pattern formed on the magnetic sheet, which is a precursor of the magnetic film 11a, becomes the first upper conductor pattern 25a1 after heating, and the unfired conductor pattern formed on the magnetic sheet, which is a precursor of the magnetic film 11b, becomes the first lower conductor pattern 25a2 after heating. In addition, the unfired conductor pattern formed on the magnetic sheet, which is a precursor of the magnetic film 11c, becomes the second upper conductor pattern 35a1 after heating, and the unfired conductor pattern formed on the magnetic sheet, which is a precursor of the magnetic film 11d, becomes the second lower conductor pattern 35a2 after heating. The conductive paste filled in the through holes formed in each magnetic sheet becomes the first one-end drawn portion 25b, the first other-end drawn portion 25c, the second one-end drawn portion 35b, and the second other-end drawn portion 35c after heating. The through holes into which the first one-end drawn portion 25b and the first other-end drawn portion 25c are filled are formed in each magnetic sheet so as to have a larger diameter than the through holes into which the second one-end drawn portion 35b and the second other-end drawn portion 35c are filled. Each conductor pattern can be formed by various known methods other than the screen printing method.

[0071] The magnetic sheet serving as the precursor of the magnetic film 11a may be a single magnetic sheet or a laminated sheet formed by stacking multiple magnetic sheets. Similarly, the magnetic sheet serving as the precursor of each of the magnetic films 11b-11d may be a single magnetic sheet or a laminated sheet formed by stacking multiple magnetic sheets. By adjusting the number of magnetic sheets constituting the magnetic films 11a-11d, the thickness of each of the magnetic films 11a-11d can be adjusted.

[0072] Next, the magnetic sheets which are precursors of the magnetic films 11a to 11d, the magnetic sheets which are precursors of the upper cover portion 12, and the magnetic sheets which are precursors of the lower cover portion 13 are stacked to obtain a laminate. In this laminate, the number of magnetic sheets included in the precursor of the upper cover portion 12 is made greater than the number of magnetic sheets included in the precursor of the lower cover portion 13, so that the first distance T1 can be made greater than the second distance T2 in the magnetically coupled coil component 1 which is the finished product. The stacked magnetic sheets may be thermocompressed by a press machine. Next, the main laminate is divided into pieces of a desired size using a cutting machine such as a dicing machine or a laser processing machine to obtain a chip laminate. The ends of the chip laminate may be polished by barrel polishing or the like as necessary.

[0073] Next, the chip stack is degreased, and the degreased chip stack is heat-treated to obtain the base 10. This heat treatment forms an oxide layer on the surface of each of the soft magnetic metal powder particles contained in the magnetic sheet, and adjacent soft magnetic metal powder particles are bonded to each other via the oxide layer. The heat treatment of the chip stack is performed, for example, at a heating temperature of 600°C to 800°C for a heating time of 20 minutes to 120 minutes.

[0074] Next, a conductive paste is applied to the lower surface 10b of the base 10 to form the first external electrode 21, the second external electrode 22, the third external electrode 23, and the fourth external electrode 24. The first external electrode 21, the second external electrode 22, the third external electrode 23, and the fourth external electrode 24 may include a plating layer. This plating layer may be two or more layers. The two plating layers may include a Ni plating layer and a Sn plating layer provided on the outside of the Ni plating layer.

[0075] In this manner, the magnetically coupled coil component 1 is obtained. The magnetically coupled coil component 1 may be produced by a compression molding method, a thin film process method, a slurry build method, or any other known method.

[0076] Some of the steps included in the above manufacturing method may be omitted as appropriate. In the manufacturing method of the magnetically coupled coil component 1, steps not explicitly described in this specification may be performed as necessary. Some of the steps included in the manufacturing method of the magnetically coupled coil component 1 may be performed in a different order as needed, as long as this does not deviate from the spirit of the present invention. Some of the steps included in the manufacturing method of the magnetically coupled coil component 1 may be performed simultaneously or in parallel, if possible.

[0077] 2. Second embodiment (modification of magnetically coupled coil component 1) Next, a modified example of the magnetically coupled coil component 1 will be described with reference to Fig. 6 and Fig. 7. Fig. 6 shows a cross section along the WT plane of the magnetically coupled coil component 1 according to this embodiment, and Fig. 7 shows an enlarged view of the first one-end drawn portion 25b of the magnetically coupled coil component 1 in Fig. 6. In Fig. 6, the coil conductor is drawn through the base.

[0078] The first one-end drawn portion 25b in the magnetically coupled coil component 1 according to the second embodiment has a small diameter portion and a large diameter portion having a cross-sectional area larger than the small diameter portion. For example, the first one-end drawn portion 25b shown in FIG. 6 and FIG. 7 has a first small diameter portion 25b1, a large diameter portion 25b2, and a second small diameter portion 25b3. The large diameter portion 25b2 has a cross-sectional area larger than the first small diameter portion 25b1 and the second small diameter portion 25b3. In this embodiment, when the cross-sectional area or cross-sectional shape of the first one-end drawn portion 25b is described, it means the area or shape of a cross section obtained by cutting the first one-end drawn portion 25b on a plane along the WL plane. Similarly, when the cross-sectional area or cross-sectional shape of the first other-end drawn portion 25c, the second one-end drawn portion 35b, and the second other-end drawn portion 35c is described, it means the area or shape of a cross section cut on a plane along the WL plane.

[0079] The cross-sectional areas of the first small diameter portion 25b1 and the second small diameter portion 25b3 are both equal to or larger than the cross-sectional areas of the second one-end lead portion 35b and the second other-end lead portion 35c.

[0080] As described above, in the magnetically coupled coil component 1 according to the second embodiment, the first cross-sectional area indicating the cross-sectional area of ​​the first one-end drawn portion 25b and the second cross-sectional area indicating the cross-sectional area of ​​the first other-end drawn portion 25c are made larger than the third cross-sectional area indicating the cross-sectional area of ​​the second one-end drawn portion 35b and the fourth cross-sectional area indicating the cross-sectional area of ​​the second other-end drawn portion 35c, thereby making the DC resistance of the first coil conductor 25 and the DC resistance of the second coil conductor 35 uniform.

[0081] In the illustrated embodiment, the cross sections of the first small diameter portion 25b1 and the second small diameter portion 25b3 have a circular shape with a radius d1, and the cross section of the large diameter portion 25b2 has a circular shape with a radius d2 larger than the radius d1. In the illustrated embodiment, it is assumed that the cross-sectional area of ​​the first small diameter portion 25b1 and the cross-sectional area of ​​the second small diameter portion 25b3 are equal, but the cross-sectional area of ​​the second small diameter portion 25b3 may be different from the cross-sectional area of ​​the first small diameter portion 25b1. The cross sections of the first small diameter portion 25b1, the large diameter portion 25b2, and the second small diameter portion 25b3 may have a shape other than a circle. For example, the cross-sectional shape of the first small diameter portion 25b1, the large diameter portion 25b2, and the second small diameter portion 25b3 may be a triangle, a rectangle, or a polygon other than these, an ellipse, or an oval, other than a circle. The cross-sectional shapes of the first small diameter portion 25b1, the large diameter portion 25b2, and the second small diameter portion 25b3 may be the same or different from each other. For example, the cross sections of the first small diameter portion 25b1 and the second small diameter portion 25b3 may be circular, and the cross section of the large diameter portion 25b2 may be rectangular. The cross-sectional shapes of the first small diameter portion 25b1, the large diameter portion 25b2, and the second small diameter portion 25b3 may be appropriately selected.

[0082] As shown in FIG. 7, the central axis Cx2 of the large diameter portion 25b2 is disposed closer to the first coil axis Ax1 than the central axis Cx1 of the first small diameter portion 25b1 and the second small diameter portion 25b3. In the illustrated embodiment, it is assumed that the first small diameter portion 25b1 and the second small diameter portion 25b3 have a common central axis Cx1. The central axis Cx1 of the first small diameter portion 25b1 is an axis that passes through the geometric center of the cross section of the first small diameter portion 25b1 and extends parallel to the T axis. The central axis Cx2 of the large diameter portion 25b2 is an axis that passes through the geometric center of the cross section of the large diameter portion 25b2 and extends parallel to the T axis. By configuring and arranging the large diameter portion 25b2 so that the central axis Cx2 of the large diameter portion 25b2 is located closer to the first coil axis Ax1 than the central axis Cx1 of the first small diameter portion 25b1 and the second small diameter portion 25b3, it is possible to prevent the gap between the large diameter portion 25b2 and the surface of the base 10 from narrowing. In addition, the gap between the large diameter portion 25b2 and the first side surface 10e of the base 10 may be made closer to or equal to the gap between the first small diameter portion 25b1 and the first side surface 10e of the base 10. By preventing the gap between the large diameter portion 25b2 and the surface of the base 10 from narrowing, it is possible to prevent a short circuit from occurring between the large diameter portion 25b2 and a conductor outside the magnetically coupled coil component 1 (for example, a conductor portion of another electronic component).

[0083] The large diameter portion 25b2 may be disposed at a position shifted from the second upper conductor pattern 35a1 and the second lower conductor pattern 35a2 of the second winding portion 35a in the T-axis direction. In the example shown in Fig. 6, the large diameter portion 25b2 is disposed at a position on the negative side in the T-axis direction from the second upper conductor pattern 35a1 and the second lower conductor pattern 35a2 of the second winding portion 35a. By disposing the large diameter portion 25b2 at a position shifted from the second upper conductor pattern 35a1 and the second lower conductor pattern 35a2 of the second winding portion 35a in the T-axis direction, a space can be secured between the large diameter portion 25b2 of the first coil conductor 25 and the second winding portion 35a of the second coil conductor 35, so that electrical insulation between the large diameter portion 25b2 and the second winding portion 35a can be easily secured.

[0084] In the second embodiment, the first other-end drawn portion 25c, although not shown, may have a small diameter portion and a large diameter portion having a cross-sectional area larger than that of the small diameter portion, similar to the first one-end drawn portion 25b. The first other-end drawn portion 25c may be formed in a cylindrical shape having a constant or approximately constant radius along the T-axis direction, similar to the first embodiment. The description of the first one-end drawn portion 25b in the second embodiment also applies to the first other-end drawn portion 25c.

[0085] 3. Third embodiment The third embodiment relates to an array-type coil component in which a plurality of coil elements are arranged in the horizontal direction (W-axis direction). Hereinafter, an array-type coil component 100 according to the third embodiment will be described with reference to Figs. 8 to 10.

[0086] FIG. 8 shows a perspective view of the array coil component 100 according to the second embodiment, FIG. 9 shows a top view of the array coil component 100, and FIG. 10 shows a schematic cross-sectional view of the array coil component 100. In FIG. 9, each coil conductor is illustrated through the base 110. As shown in these figures, the array coil component 100 includes three magnetically coupled coils 101, 201, and 301. The multiple coil elements included in the array coil component 100 may be magnetically coupled coil components as shown in the figures, or may be other coil components. The number of coil elements included in the array coil component 100 is not limited to three, and may be two, or may be four or more.

[0087] The array-type coil component 100 includes a base 110, and the coil conductors constituting the magnetically coupled coils 101, 201, and 301 are provided on the base 110. The base 110 is made of an insulating material, like the base 10, and electrically insulates the coil conductors constituting the magnetically coupled coils 101, 201, and 301 from each other.

[0088] The base 110 has an upper surface 110a, a lower surface 110b, a first end surface 110c, a second end surface 110d, a first side surface 110e, and a second side surface 110f. The base 110 is configured similarly to the base 10, except that the dimension in the W-axis direction is larger in order to accommodate the coil conductors constituting the three magnetically coupled coils. The above description of the base 10 also applies to the base 110 as much as possible. For example, similar to the base 10, the upper surface 110a and the lower surface 110b of the base 110 form the surfaces of both ends of the base 110 in the T-axis direction, the first end surface 110c and the second end surface 110d form the surfaces of both ends of the base 110 in the L-axis direction, and the first side surface 110e and the second side surface 110f form the surfaces of both ends of the base 110 in the W-axis direction. For ease of explanation, FIG. 9 illustrates an X1 axis that extends parallel to the W axis from the positive side to the negative side along the W axis.

[0089] In the illustrated embodiment, the magnetically coupled coils 101, 201, and 301 are arranged along the X1 axis direction parallel to the W axis direction. That is, in the array-type coil component 100, the magnetically coupled coil 301, the magnetically coupled coil 101, and the magnetically coupled coil 201 are arranged in this order along the X1 axis direction. The magnetically coupled coil 201 is arranged at a position spaced apart from the magnetically coupled coil 101 in the X1 axis direction. Similarly, the magnetically coupled coil 101 is arranged at a position spaced apart from the magnetically coupled coil 301 in the X1 axis direction.

[0090] In the illustrated embodiment, the magnetically coupled coil 101 of the array-type coil component 100 includes a first coil conductor 125 and a second coil conductor 135. The first coil conductor 125 is disposed to face the upper surface 110a of the base 110, and the second coil conductor 135 is disposed to face the lower surface 110b of the base 110. Although not illustrated, two external electrodes (a first external electrode and a second external electrode) connected to both ends of the first coil conductor 125 of the magnetically coupled coil 101 and two external electrodes (a third external electrode and a fourth external electrode) connected to both ends of the second coil conductor 135 are provided on the lower surface 110b of the base 110.

[0091] In the illustrated embodiment, the first coil conductor 125 has a first winding portion 125a extending in a circumferential direction around the first coil axis Ax1, a first one-end drawn portion 125b connecting one end of the first winding portion 125a to a first external electrode (not shown), and a first other-end drawn portion 125c connecting the other end of the first winding portion 125a to a second external electrode (not shown). The first winding portion 125a has a first upper conductor pattern 125a1, a first lower conductor pattern 125a2, and a via conductor (not shown) connecting the first upper conductor pattern 125a1 and the first lower conductor pattern 125a2. The second coil conductor 135 has a second winding portion 135a extending in the circumferential direction around the first coil axis Ax1, a second one-end drawn portion 135b connecting one end of the second winding portion 135a to a third external electrode (not shown), and a second other-end drawn portion 135c connecting the other end of the second winding portion 135a to a fourth external electrode (not shown). The second winding portion 135a has a second upper conductor pattern 135a1, a second lower conductor pattern 135a2, and a via conductor (not shown) connecting the second upper conductor pattern 135a1 and the second lower conductor pattern 135a2. The first winding portion 125a of the first coil conductor 125 extends in the circumferential direction around the first coil axis Ax1 for a number of turns that is greater than one turn and less than two turns.

[0092] A first cross-sectional area indicating the cross-sectional area of ​​the first one-end drawn portion 125b and a second cross-sectional area indicating the cross-sectional area of ​​the first other-end drawn portion 125c are larger than a third cross-sectional area indicating the cross-sectional area of ​​the second one-end drawn portion 135b and a fourth cross-sectional area indicating the cross-sectional area of ​​the second other-end drawn portion 135c.

[0093] In a plan view (when viewed from the direction of the T-axis), the first coil conductor 125 has the same shape as the first coil conductor 25 of embodiment 1. Specifically, the first winding portion 125a, the first one-end drawn portion 125b, and the first other-end drawn portion 125c have the same shapes as the first winding portion 25a, the first one-end drawn portion 25b, and the first other-end drawn portion 25c, respectively.

[0094] The second coil conductor 135 has a second winding portion 135a, a second one-end drawn portion 135b connecting one end of the second winding portion 135a to the third external electrode, and a second other-end drawn portion 135c connecting the other end of the second winding portion 135a to the second external electrode. The second winding portion 135a extends in the circumferential direction around the first coil axis Ax1 by a number of turns greater than one turn and less than two turns. The second coil conductor 135 may have the same shape as the second coil conductor 35 of the first embodiment in a plan view (from a viewpoint seen from the T-axis direction). Specifically, the second winding portion 135a, the second one-end drawn portion 135b, and the second other-end drawn portion 135c may have the same shapes as the second winding portion 35a, the second one-end drawn portion 35b, and the second other-end drawn portion 35c, respectively.

[0095] In the illustrated embodiment, the magnetically coupled coil 201 of the array-type coil component 100 includes a third coil conductor 225 and a fourth coil conductor 235. In the T-axis direction, the third coil conductor 225 faces the upper surface 110a of the base 110, and the fourth coil conductor 235 faces the lower surface 110b of the base 110. In the W-axis direction, the third coil conductor 225 is provided between the first coil conductor 125 and the first side surface 110e of the base 110, and the fourth coil conductor 235 is provided between the second coil conductor 135 and the first side surface 110e. Although not illustrated, two external electrodes (a fifth external electrode and a sixth external electrode) connected to both ends of the third coil conductor 225 of the magnetically coupled coil 201 and two external electrodes (a seventh external electrode and an eighth external electrode) connected to both ends of the fourth coil conductor 235 are provided on the lower surface 110b of the base 110.

[0096] In the illustrated embodiment, the third coil conductor 225 has a third winding portion 225a extending in the circumferential direction around the second coil axis Ax2, a third one-end lead portion 225b connecting one end of the third winding portion 225a to a fifth external electrode (not shown), and a third other-end lead portion 225c connecting the other end of the third winding portion 225a to a sixth external electrode (not shown). The third winding portion 225a has a third upper conductor pattern 225a1, a third lower conductor pattern 225a2, and a via conductor (not shown) connecting the third upper conductor pattern 225a1 and the third lower conductor pattern 225a2. The third winding portion 225a extends in the circumferential direction around the second coil axis Ax2 for a number of turns that is greater than one turn and less than two turns. The fourth coil conductor 235 has a fourth winding portion 235a extending in the circumferential direction around the second coil axis Ax2, a fourth one-end drawn portion 235b connecting one end of the fourth winding portion 235a to a seventh external electrode (not shown), and a fourth other-end drawn portion 235c connecting the other end of the fourth winding portion 235a to an eighth external electrode (not shown). The fourth winding portion 235a has a fourth upper conductor pattern 235a1, a fourth lower conductor pattern 235a2, and a via conductor (not shown) connecting the fourth upper conductor pattern 235a1 and the fourth lower conductor pattern 235a2. The fourth winding portion 235a extends in the circumferential direction around the second coil axis Ax2 for a number of turns that is greater than one turn and less than two turns.

[0097] The third coil conductor 225 has the same shape in a plan view (when viewed from the direction of the T-axis) as the first coil conductor 125. Specifically, the third winding portion 225a, the third one-end lead portion 225b, and the third other-end lead portion 225c have the same shapes as the first winding portion 125a, the first one-end lead portion 125b, and the first other-end lead portion 125c, respectively.

[0098] The third one-end drawn portion 225b extends along the T-axis from one end of the third winding portion 225a to the lower surface 10b of the base 110, and the third other-end drawn portion 225c extends along the T-axis from the other end of the third winding portion 225a to the lower surface 10b of the base 110. A fifth cross-sectional area indicating the cross-sectional area of ​​the third one-end drawn portion 225b and a sixth cross-sectional area indicating the cross-sectional area of ​​the third other-end drawn portion 225c are larger than a seventh cross-sectional area indicating the cross-sectional area of ​​the fourth one-end drawn portion 235b and an eighth cross-sectional area indicating the cross-sectional area of ​​the fourth other-end drawn portion 235c.

[0099] The fourth coil conductor 235 has the same shape as the second coil conductor 135 in a plan view. Specifically, a fourth winding portion 235a, a fourth one-end lead portion 235b, and a fourth other-end lead portion 235c of the fourth coil conductor 235 have the same shapes as the second winding portion 35a, the second one-end lead portion 35b, and the second other-end lead portion 35c of the second coil conductor 135, respectively.

[0100] In the illustrated embodiment, the magnetically coupled coil 301 of the array-type coil component 100 includes a fifth coil conductor 325 and a sixth coil conductor 335. In the T-axis direction, the fifth coil conductor 325 is disposed to face the upper surface 110a of the base 110, and the sixth coil conductor 335 is disposed to face the lower surface 110b of the base 110. In the W-axis direction, the fifth coil conductor 325 is provided between the first coil conductor 125 and the second side surface 110f of the base 110, and the sixth coil conductor 335 is provided between the second coil conductor 135 and the second side surface 110f. Although not shown in the figure, two external electrodes (ninth external electrode and tenth external electrode) connected to both ends of the fifth coil conductor 325 of the magnetically coupled coil 301 and two external electrodes (eleventh external electrode and twelfth external electrode) connected to both ends of the sixth coil conductor 335 are provided on the lower surface 110b of the base 110.

[0101] In the illustrated embodiment, the fifth coil conductor 325 has a fifth winding portion 325a extending in the circumferential direction around the third coil axis Ax1, a fifth one-end lead portion 325b connecting one end of the fifth winding portion 325a to a ninth external electrode (not shown), and a fifth other-end lead portion 325c connecting the other end of the fifth winding portion 325a to a tenth external electrode (not shown). The fifth winding portion 325a has a fifth upper conductor pattern 325a1, a fifth lower conductor pattern 325a2, and a via conductor (not shown) connecting the fifth upper conductor pattern 325a1 and the fifth lower conductor pattern 325a2. The fifth winding portion 325a extends in the circumferential direction around the second coil axis Ax2 for a number of turns that is greater than one turn and less than two turns. The sixth coil conductor 335 has a sixth winding portion 335a extending in the circumferential direction around the third coil axis Ax3, a sixth one-end lead portion 335b connecting one end of the sixth winding portion 335a to an eleventh external electrode (not shown), and a sixth other-end lead portion 335c connecting the other end of the sixth winding portion 335a to a twelfth external electrode (not shown). The sixth winding portion 335a has a sixth upper conductor pattern 335a1, a sixth lower conductor pattern 335a2, and a via conductor (not shown) connecting the sixth upper conductor pattern 335a1 and the sixth lower conductor pattern 335a2. The sixth winding portion 335a extends in the circumferential direction around the second coil axis Ax2 for a number of turns that is greater than one turn and less than two turns.

[0102] The fifth coil conductor 325 has the same shape as the first coil conductor 125 in a plan view. Specifically, a fifth winding portion 325a, a fifth one-end lead portion 325b, and a fifth other-end lead portion 325c of the fifth coil conductor 325 have the same shapes as the first winding portion 125a, the first one-end lead portion 125b, and the first other-end lead portion 125c of the first coil conductor 125, respectively.

[0103] The sixth one-end drawn portion 335b extends along the T-axis from one end of the sixth winding portion 335a to the lower surface 10b of the base 110, and the sixth other-end drawn portion 335c extends along the T-axis from the other end of the sixth winding portion 335a to the lower surface 10b of the base 110. A ninth cross-sectional area indicating the cross-sectional area of ​​the fifth one-end drawn portion 325b and a tenth cross-sectional area indicating the cross-sectional area of ​​the fifth other-end drawn portion 325c are larger than an eleventh cross-sectional area indicating the cross-sectional area of ​​the sixth one-end drawn portion 335b and a twelfth cross-sectional area indicating the cross-sectional area of ​​the sixth other-end drawn portion 335c.

[0104] In the array-type coil component 100, the first cross-sectional area indicating the cross-sectional area of ​​the first one-end drawn portion 125b and the second cross-sectional area indicating the cross-sectional area of ​​the first other-end drawn portion 125c are larger than the third cross-sectional area indicating the cross-sectional area of ​​the second one-end drawn portion 135b and the fourth cross-sectional area indicating the cross-sectional area of ​​the second other-end drawn portion 135c. Therefore, the total DC resistance in the first one-end drawn portion 125b and the first other-end drawn portion 125c can be made equal to the total DC resistance in the second one-end drawn portion 135b and the second other-end drawn portion 135c, thereby making the DC resistance of the first coil conductor 125 and the DC resistance of the second coil conductor 135 uniform. Furthermore, the fifth cross-sectional area indicating the cross-sectional area of ​​the third one-end drawn portion 225b and the sixth cross-sectional area indicating the cross-sectional area of ​​the third other-end drawn portion 225c are larger than the seventh cross-sectional area indicating the cross-sectional area of ​​the fourth one-end drawn portion 235b and the eighth cross-sectional area indicating the cross-sectional area of ​​the fourth other-end drawn portion 235c. Therefore, the total DC resistance in the third one-end drawn portion 225b and the third other-end drawn portion 225c can be made equal to the total DC resistance in the fourth one-end drawn portion 235b and the fourth other-end drawn portion 235c, thereby making the DC resistance of the third coil conductor 225 and the DC resistance of the fourth coil conductor 235 uniform. Furthermore, the ninth cross-sectional area indicating the cross-sectional area of ​​the fifth one-end drawn portion 325b and the tenth cross-sectional area indicating the cross-sectional area of ​​the fifth other-end drawn portion 325c are larger than the eleventh cross-sectional area indicating the cross-sectional area of ​​the sixth one-end drawn portion 335b and the twelfth cross-sectional area indicating the cross-sectional area of ​​the sixth other-end drawn portion 335c. Therefore, the total DC resistance in the fifth one-end drawn portion 325b and the fifth other-end drawn portion 325c can be made equal to the total DC resistance in the sixth one-end drawn portion 335b and the sixth other-end drawn portion 335c, thereby making the DC resistance of the fifth coil conductor 325 and the DC resistance of the sixth coil conductor 335 uniform.

[0105] The difference between the DC resistance of the first coil conductor 125 and the DC resistance of the second coil conductor 135 is preferably 10% or less of the DC resistance of the first coil conductor 125. The difference between the DC resistance of the first coil conductor 125 and the DC resistance of the third coil conductor 225 is preferably 10% or less of the DC resistance of the first coil conductor 125. The difference between the DC resistance of the first coil conductor 125 and the DC resistance of the fifth coil conductor 325 is preferably 10% or less of the DC resistance of the first coil conductor 125. The difference between the DC resistance of the third coil conductor 225 and the DC resistance of the fourth coil conductor 235 is preferably 10% or less of the DC resistance of the third coil conductor 225. The difference between the DC resistance of the fifth coil conductor 325 and the DC resistance of the sixth coil conductor 335 is preferably 10% or less of the DC resistance of the fifth coil conductor 325. When comparing the DC resistance of two coil conductors adjacent to each other in the T-axis direction or the W-axis direction among the first coil conductor 125 to the sixth coil conductor 335, if the difference in the DC resistance of the two coil conductors being compared is 10% or less of the DC resistance of a reference coil conductor among the two coil conductors, it can be determined that the DC resistances of the compared coil conductors are equal or uniform. Any of the two coil conductors being compared may be the reference coil conductor. When comparing the DC resistance of two coil conductors adjacent to each other in the T-axis direction or the W-axis direction among the first coil conductor 125 to the sixth coil conductor 335, it is preferable that the difference in the DC resistance of the two coil conductors being compared is 5% or less of the DC resistance of a reference coil conductor among the two coil conductors.

[0106] As described above, in the array type coil component 100, the difference in DC resistance between the coil conductors arranged in the T-axis direction can be reduced, and the difference in DC resistance between the coil conductors arranged in the W-axis direction can be reduced. Therefore, the DC resistance of each coil conductor included in the array type coil component 100 can be made uniform. In addition, the array type coil component 100 has the same effect as the magnetically coupled coil component 1 of the first embodiment. For example, in the array type coil component 100, not only the difference in DC resistance between each coil conductor is reduced, but also the shape of the winding part of each coil conductor constituting each magnetically coupled coil (magnetically coupled coils 101 to 301) is made equal to each other, thereby suppressing a decrease in inductance of each magnetically coupled coil component 1.

[0107] At least one of the first one-end drawn portion 125b, the first other-end drawn portion 125c, the third one-end drawn portion 225b, the third other-end drawn portion 225c, the fifth one-end drawn portion 325b, and the fifth other-end drawn portion 325c may have a small diameter portion and a large diameter portion having a cross-sectional area larger than the cross-sectional area of ​​the small diameter portion, similar to the first one-end drawn portion 25b described in the second embodiment. In this case, the central axis of the large diameter portion is disposed closer to the coil axis than the central axis of the small diameter portion. For example, when the first one-end drawn portion 125b includes a small diameter portion and a large diameter portion having a cross-sectional area larger than the small diameter portion, the central axis of the large diameter portion is disposed closer to the first coil axis Ax1 than the central axis of the small diameter portion. This makes it possible to increase the distance between the large diameter portion of the first one-end drawn portion 125b and the third coil conductor 225 facing the first one-end drawn portion 125b, compared to when the central axis of the large diameter portion and the central axis of the small diameter portion are arranged on the same axis. This improves the insulation between the first one-end drawn portion 125b and the third coil conductor 225. Even when a small diameter portion and a large diameter portion are formed in the drawn portion of another coil conductor, the insulation between adjacent coil conductors can be improved by arranging the central axis of the large diameter portion closer to the coil axis of the coil conductor than the central axis of the small diameter portion.

[0108] As described above, the first winding portion 125a, the second winding portion 135a, the third winding portion 225a, the fourth winding portion a, the fifth winding portion 325a, and the sixth winding portion 335a each have less than two turns, so that the DC resistance of the first coil conductor 125, the second coil conductor 135, the third coil conductor 225, the fourth coil conductor 235, the fifth coil conductor 325, and the sixth coil conductor 335 can be small, for example, less than 100 mΩ, and the inductance of the first coil conductor 125, the second coil conductor 135, the third coil conductor 225, the fourth coil conductor 235, the fifth coil conductor 325, and the sixth coil conductor 335 can be small, for example, less than 100 nH. According to the embodiment described in the present application, even if the DC resistance of each coil conductor is small, for example, less than 100 mΩ, the difference in DC resistance between each coil conductor can be small. Furthermore, according to the embodiments described in the present application, even if the inductance of each coil conductor is small, for example, less than 100 nH, the difference in DC resistance between each coil conductor can be made small. For example, even if the inductance of each coil conductor is less than 100 nH and the DC resistance of each coil conductor is less than 100 mΩ, the difference in DC resistance between each coil conductor can be made 10% or less and the difference in inductance can be made 20% or less.

[0109] Since the winding parts of the coil conductors in the array-type coil component 100 can have the same shape, it is possible to make the inductance of each coil conductor uniform. In the array-type coil component 100, a plurality of coil elements having such uniform inductance are packaged as one component, so that a plurality of coil elements for the same purpose can be mounted in a small mounting area.

[0110] In the array-type coil component 100, the difference in inductance between the coil elements is reduced without reducing the inner diameter of the winding part of each coil element, and thus the decrease in magnetic saturation is suppressed. Therefore, even if the base 110 is made of a metallic magnetic material, the array-type coil component 100 can be used in a circuit using a high DC current without decreasing the DC resistance.

[0111] The array-type coil component 100 can be fabricated by a sheet lamination method, a compression molding method, a thin film process method, a slurry build method, or other known methods.

[0112] According to each of the above embodiments, in the array type coil component 100, by making the shape of the first winding portion 25a equal to the shape of the second winding portion 35a, it is possible to reduce the difference in DC resistance between each coil conductor while suppressing a decrease in inductance.

[0113] 4 Notes The dimensions, materials, and arrangements of each component described in the various embodiments above are not limited to those explicitly described in each embodiment, and each component can be modified to have any dimensions, materials, and arrangements that can be included in the scope of the present invention. For example, the first coil conductor 25 and the second coil conductor 35 may each be a planar coil extending more than one turn and less than two turns around the first coil axis Ax1. The first coil conductor 125 to the sixth coil conductor 335 provided in the array type coil component 100 may also each be a planar coil extending more than one turn and less than two turns around each coil axis.

[0114] Components not explicitly described in this specification may be added to each of the above-described embodiments, and some of the components described in each embodiment may be omitted.

[0115] The designations "first," "second," "third," and the like in this specification are given to identify components, and do not necessarily limit the number, order, or content. Furthermore, numbers for identifying components are used in different contexts, and a number used in one context does not necessarily indicate the same configuration in another context. Furthermore, a component identified by a certain number does not prevent the component from also having the function of a component identified by another number.

[0116] 5. Supplementary Notes The embodiments disclosed herein also include the following. [Appendix 1] a base made of an insulating material and having a first surface and a second surface opposite to the first surface; a first coil conductor provided within the base so as to face the first surface; a second coil conductor provided within the base between the first coil conductor and the second surface; Equipped with the first coil conductor has a first winding portion wound around a first coil axis, a first one-end drawn-out portion extending from one end of the first winding portion to the second surface, and a first other-end drawn-out portion extending from the other end of the first winding portion to the second surface, the second coil conductor has a second winding portion wound around the first coil axis, a second one-end drawn-out portion extending from one end of the second winding portion to the second surface, and a second other-end drawn-out portion extending from the other end of the second winding portion to the second surface, a first cross-sectional area indicating a cross-sectional area of ​​the first one-end drawn portion and a second cross-sectional area indicating a cross-sectional area of ​​the first other-end drawn portion are both larger than a third cross-sectional area indicating a cross-sectional area of ​​the second one-end drawn portion and a fourth cross-sectional area indicating a cross-sectional area of ​​the second other-end drawn portion; Coil parts. [Appendix 2] The first one-end lead portion has a small diameter portion having a cross-sectional area equal to or greater than the third cross-sectional area and the fourth cross-sectional area, and a large diameter portion having a cross-sectional area larger than the small diameter portion. 2. A coil component as described in appended claim 1. [Appendix 3] the first cross-sectional area is equal to the second cross-sectional area; the third cross-sectional area is equal to the fourth cross-sectional area; 3. The coil component according to claim 1 or 2. [Appendix 4] a difference between a first DC resistance indicating a DC resistance of the first coil conductor and a second DC resistance indicating a DC resistance of the second coil conductor is 5% or less of the first DC resistance; 4. The coil component according to claim 1 , [Appendix 5] the first winding portion extends around the first coil axis by more than one turn but less than two turns, The second winding portion extends around the first coil axis by more than one turn and less than two turns. 5. The coil component according to claim 1 , [Appendix 6] The length of the first turn is equal to the length of the second turn. 6. The coil component according to claim 1 , [Appendix 7] the base has a third surface connecting the first surface and the second surface, and a fourth surface opposing the third surface; a third coil conductor provided within the base between the first coil conductor and the third surface so as to face the first surface; a fourth coil conductor provided within the base between the third coil conductor and the second surface; Further equipped with the third coil conductor has a third winding portion wound around a second coil axis, a third one-end drawn-out portion extending from one end of the third winding portion to the second surface, and a third other-end drawn-out portion extending from the other end of the third winding portion to the second surface, the fourth coil conductor has a fourth winding portion wound around the second coil axis, a fourth one-end drawn-out portion extending from one end of the fourth winding portion to the second surface, and a fourth other-end drawn-out portion extending from the other end of the fourth winding portion to the second surface, a fifth cross-sectional area indicating a cross-sectional area of ​​the third one-end drawn portion and a sixth cross-sectional area indicating a cross-sectional area of ​​the third other-end drawn portion are both larger than a seventh cross-sectional area indicating a cross-sectional area of ​​the fourth one-end drawn portion and an eighth cross-sectional area indicating a cross-sectional area of ​​the fourth other-end drawn portion; 7. The coil component according to claim 1 , [Appendix 8] The first coil conductor is the first one-end lead portion has a small diameter portion having a cross-sectional area larger than the third cross-sectional area and the fourth cross-sectional area, and a large diameter portion having a cross-sectional area larger than the small diameter portion, The central axis of the large diameter portion is disposed closer to the first coil axis than the central axis of the small diameter portion. 8. The coil component according to claim 7. [Appendix 9] a fifth coil conductor provided within the base between the first coil conductor and the fourth surface so as to face the first surface; a sixth coil conductor provided within the base between the fifth coil conductor and the second surface; Further equipped with the fifth coil conductor has a fifth winding portion wound around a third coil axis, a fifth one-end drawn-out portion extending from one end of the fifth winding portion to the second surface, and a fifth other-end drawn-out portion extending from the other end of the fifth winding portion to the second surface, the sixth coil conductor has a sixth winding portion wound around the third coil axis, a sixth one-end drawn-out portion extending from one end of the sixth winding portion to the second surface, and a sixth other-end drawn-out portion extending from the other end of the sixth winding portion to the second surface, a ninth cross-sectional area indicating a cross-sectional area of ​​the fifth one-end drawn portion and a tenth cross-sectional area indicating a cross-sectional area of ​​the fifth other-end drawn portion are both larger than an eleventh cross-sectional area indicating a cross-sectional area of ​​the sixth one-end drawn portion and a twelfth cross-sectional area indicating a cross-sectional area of ​​the sixth other-end drawn portion; 9. The coil component according to claim 7 or 8. [Explanation of symbols]

[0117] 1, 101, 201, 301 Magnetically coupled coil parts 100 Array type coil parts 10, 110 base 21 1st external electrode 22 2nd external electrode 23 Third external electrode 24 4th external electrode 25, 125 First coil conductor 35, 135 Second coil conductor 225 Third coil conductor 235 4th coil conductor 325 5th coil conductor 335 6th coil conductor

Claims

1. a base made of an insulating material and having a first surface and a second surface opposite to the first surface; a first coil conductor provided within the base body so as to face the first surface; a second coil conductor provided within the base between the first coil conductor and the second surface; Equipped with the first coil conductor has a first winding portion wound around a first coil axis, a first one-end drawn-out portion extending from one end of the first winding portion to the second surface, and a first other-end drawn-out portion extending from the other end of the first winding portion to the second surface, the second coil conductor has a second winding portion wound around the first coil axis, a second one-end drawn-out portion extending from one end of the second winding portion to the second surface, and a second other-end drawn-out portion extending from the other end of the second winding portion to the second surface, a first cross-sectional area indicating a cross-sectional area of ​​the first one-end drawn portion and a second cross-sectional area indicating a cross-sectional area of ​​the first other-end drawn portion are both larger than a third cross-sectional area indicating a cross-sectional area of ​​the second one-end drawn portion and a fourth cross-sectional area indicating a cross-sectional area of ​​the second other-end drawn portion; Coil parts.

2. The first one-end lead portion has a small diameter portion having a cross-sectional area equal to or greater than the third cross-sectional area and the fourth cross-sectional area, and a large diameter portion having a cross-sectional area larger than the small diameter portion. The coil component according to claim 1 .

3. the first cross-sectional area is equal to the second cross-sectional area; the third cross-sectional area is equal to the fourth cross-sectional area; The coil component according to claim 1 .

4. a difference between a first DC resistance indicating a DC resistance of the first coil conductor and a second DC resistance indicating a DC resistance of the second coil conductor is 10% or less of the first DC resistance; The coil component according to claim 1 .

5. the first winding portion extends around the first coil axis by more than one turn and less than two turns, The second winding portion extends around the first coil axis by more than one turn and less than two turns. The coil component according to claim 1 .

6. The length of the first turn is equal to the length of the second turn. The coil component according to claim 1 .

7. the base has a third surface connecting the first surface and the second surface, and a fourth surface opposing the third surface; a third coil conductor provided within the base between the first coil conductor and the third surface so as to face the first surface; a fourth coil conductor provided within the base between the third coil conductor and the second surface; Further equipped with the third coil conductor has a third winding portion wound around a second coil axis, a third one-end drawn-out portion extending from one end of the third winding portion to the second surface, and a third other-end drawn-out portion extending from the other end of the third winding portion to the second surface, the fourth coil conductor has a fourth winding portion wound around the second coil axis, a fourth one-end drawn-out portion extending from one end of the fourth winding portion to the second surface, and a fourth other-end drawn-out portion extending from the other end of the fourth winding portion to the second surface, a fifth cross-sectional area indicating a cross-sectional area of ​​the third one-end drawn portion and a sixth cross-sectional area indicating a cross-sectional area of ​​the third other-end drawn portion are both larger than a seventh cross-sectional area indicating a cross-sectional area of ​​the fourth one-end drawn portion and an eighth cross-sectional area indicating a cross-sectional area of ​​the fourth other-end drawn portion; The coil component according to claim 1 .

8. The first coil conductor is the first one-end lead portion has a small diameter portion having a cross-sectional area larger than the third cross-sectional area and the fourth cross-sectional area, and a large diameter portion having a cross-sectional area larger than the small diameter portion, The central axis of the large diameter portion is disposed closer to the first coil axis than the central axis of the small diameter portion. The coil component according to claim 7.

9. a fifth coil conductor provided within the base between the first coil conductor and the fourth surface so as to face the first surface; a sixth coil conductor provided within the base body between the fifth coil conductor and the second surface; Further equipped with the fifth coil conductor has a fifth winding portion wound around a third coil axis, a fifth one-end drawn-out portion extending from one end of the fifth winding portion to the second surface, and a fifth other-end drawn-out portion extending from the other end of the fifth winding portion to the second surface, the sixth coil conductor has a sixth winding portion wound around the third coil axis, a sixth one-end drawn-out portion extending from one end of the sixth winding portion to the second surface, and a sixth other-end drawn-out portion extending from the other end of the sixth winding portion to the second surface, a ninth cross-sectional area indicating a cross-sectional area of ​​the fifth one-end drawn portion and a tenth cross-sectional area indicating a cross-sectional area of ​​the fifth other-end drawn portion are both larger than an eleventh cross-sectional area indicating a cross-sectional area of ​​the sixth one-end drawn portion and a twelfth cross-sectional area indicating a cross-sectional area of ​​the sixth other-end drawn portion; The coil component according to claim 7.

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