Coil component

Abstract

The invention provides a coil component capable of suppressing reduction of design freedom of a coil and further improving external impact resistance. The coil component is provided with a main body part including an insulating body, a coil, and a first conductor layer and a second conductor layer electrically connected to the coil, and the main body part has a substantially rectangular parallelepiped shape. A first ridge line portion between the top surface and one end surface; a second ridge line portion between one of the pair of side surfaces and one of the pair of end surfaces; and a third ridge line portion between the top surface and one of the pair of side surfaces. The first conductor layer is exposed to a part of the bottom surface of the main body part and at least a part of one of the pair of end surfaces, the second conductor layer is exposed to a part of the bottom surface of the main body part and at least a part of the other of the pair of end surfaces, and the first to third ridge line parts are each formed of a curved surface rounded so as to be curved in a convex shape. The curvature radius of the first ridge line portion is larger than the curvature radius of the second ridge line portion and the curvature radius of the third ridge line portion.

Description

Technical Field

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

[0002] Conventionally, as a coil component, for example, there is a laminated coil component described in Patent Document 1. The laminated coil component described in Patent Document 1 includes a coil disposed in an insulating base body. The coil is composed of, for example, a plurality of coil wiring layers laminated via insulating layers. These coil wiring layers are electrically connected by conduction conductors provided in the insulating layers.

[0003] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2018-26454

[0004] In a coil component, there is a case where, for example, a large load is applied during installation, and cracks, defects, etc. occur at the corners of the component. Therefore, a coil component with excellent external impact resistance is required. Patent Document 1, for example, discloses that a chamfered portion is provided at the corners of a substantially rectangular parallelepiped-shaped coil component. By providing the chamfered portion at the corners, it is difficult to generate cracks, defects, etc. near the corners during installation or the like.

[0005] However, according to the structure of Patent Document 1, there is still room for improvement in terms of maintaining a high degree of design freedom of the coil and suppressing the occurrence of cracks, defects, etc. at the corners. Summary of the Invention

[0006] Therefore, an object of the present invention is to solve the above problems and provide a coil component that can suppress a decrease in the design freedom of the coil and further improve the external impact resistance.

[0007] A coil component according to one aspect of the present invention includes a main body portion, and the main body portion includes:

[0008] An insulating base body;

[0009] A coil disposed inside the base body;

[0010] A first conductor layer electrically connected to one end side of the coil; and

[0011] A second conductor layer electrically connected to the other end side of the coil,

[0012] The main body portion is in a substantially rectangular parallelepiped shape, and the main body portion has:

[0013] A bottom surface for installation; a top surface located at a distance from the bottom surface in the height direction orthogonal to the bottom surface of the main body portion; a pair of end surfaces located at a distance from each other in a first direction orthogonal to the height direction; and a pair of side surfaces located at a distance from each other in a second direction orthogonal to the height direction and the first direction.

[0014] The first ridge portion is located between the top surface and one of the pair of end surfaces;

[0015] The second ridge portion is located between one of the pair of side surfaces and one of the pair of end surfaces; and

[0016] The third ridge portion is located between the top surface and one of the pair of side surfaces,

[0017] At least a part of the first conductor layer is exposed on a part of the bottom surface of the main body portion and at least a part of one of the pair of end surfaces,

[0018] At least a part of the second conductor layer is exposed on a part of the bottom surface of the main body portion and at least a part of the other of the pair of end surfaces,

[0019] The first ridge portion, the second ridge portion, and the third ridge portion are each formed by a curved surface that is rounded and bent into a convex shape,

[0020] The radius of curvature R1 of the first ridge portion is greater than the radius of curvature R2 of the second ridge portion and the radius of curvature R3 of the third ridge portion.

[0021] The coil component according to the present invention can suppress a decrease in the design freedom of the coil and further improve the resistance to external shocks. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic perspective view of a coil component according to an embodiment of the present invention.

[0023] Figure 2 is Figure 1 a schematic perspective view of the coil component.

[0024] Figure 3 is a schematic side view of the coil component viewed from the second direction Y Figure 1 of.

[0025] Figure 4 is Figure 1 a schematic top view of the coil component.

[0026] Figure 5 is a schematic end view of the coil component viewed from the first direction X Figure 1 of.

[0027] Figure 6 is a graph illustrating the relationship between the radius of curvature of the first ridge portion and the occurrence rate of top surface defects of the coil component.

[0028] Figure 7It is a schematic side view of the coil component of Modification 1 as viewed from the second direction Y.

[0029] Figure 8 is Figure 7 a schematic top view of the coil component.

[0030] Figure 9 is a schematic end view of Figure 7 the coil component as viewed from the first direction X.

[0031] Figure 10 is a schematic perspective view of the coil component of Modification 2.

[0032] Figure 11 is Figure 10 a schematic perspective view of the coil component shown.

[0033] Figure 12A is a schematic view for illustrating a method for measuring the radius of curvature, and is a schematic end view of the coil component as viewed from the first direction X.

[0034] Figure 12B is for showing the Figure 12A schematic perspective view of the sample for measuring the radius of curvature made of the coil component.

[0035] Figure 12C is an enlarged Figure 12B schematic enlarged side view of a part of the sample for measuring the radius of curvature.

[0036] Explanation of Reference Numerals

[0037] 1... main body portion, 10... green body, 11, 12... end faces, 13, 14... side faces, 15... bottom face, 16... top face, 20... coil, 21... coil wiring layer, 30... first external electrode, 31... first electrode layer, 32... first conductor layer, 40... second external electrode, 41... second electrode layer, 42... second conductor layer, a1... first ridge line portion, a2... second ridge line portion, a3... third ridge line portion, a4... fourth ridge line portion, R1 to R4... radius of curvature, 100, 101, 102... coil components. Detailed Description of the Invention

[0038] (Insight Underlying the Present Invention)

[0039] The inventors of the present invention conducted research to suppress a decrease in the design freedom of the coil and to improve the external impact resistance of the coil component, and as a result, found the following insights.

[0040] In conventional coil components, rounded corners (R portions) are typically formed at respective corners by barrel polishing (see Patent Document 1, etc.). In this case, since the multiple corners of the coil component are isotropically rounded, if the corners have the same shape and hardness, R portions with the same degree of curvature are generally formed.

[0041] As the rounding (radius of curvature) of the R portion increases, it becomes more difficult for cracks, defects, and fissures to occur at the corners. However, as the radius of curvature of the corners increases, the internal volume of the green body becomes smaller, and the area within the green body where a coil can be formed becomes smaller. As a result, for example, the number of turns of the coil (the number of layers in the case of a stacked coil), shape, dimensions, etc. are restricted, so there are cases where the design freedom of the coil is reduced. Consequently, there are cases where the desired electrical characteristics cannot be obtained.

[0042] Therefore, in order to achieve both electrical characteristics and resistance to external shock, the inventors of the present application independently studied the radius of curvature of the corners of the coil component according to the positions of the corners of the coil component.

[0043] In a coil component, in addition to the corners on the mounting surface side, there are also corners (first ridge lines) between the end face and the top face where the external electrodes are located, corners (second ridge lines) between the side face and the end face, and corners (third ridge lines) between the top face and the side face. Among these, compared with the second and third ridge lines, the first ridge line is more likely to be subjected to external shock. For example, during installation, since the mounting nozzle adsorbs to the first ridge line between the end face and the top face where the external electrode is located, a large load is applied to the first ridge line. On the other hand, for the second and third ridge lines, if the radius of curvature is excessively increased, the impact on the design freedom of the coil increases. In addition, if the radius of curvature of the second ridge line is excessively increased, the external electrode located on the end face of the coil component will extend onto the second ridge line (the curved surface) and be visually confirmed from the side face. As a result, there is also a problem that it is judged as non-conforming during appearance screening and the yield rate decreases. Therefore, the position and size of the external electrode may be restricted.

[0044] Based on the above new insights, the inventors of the present application found that by making the radius of curvature R1 of the first ridge line larger than the radius of curvature R2 of the second ridge line and the radius of curvature R3 of the third ridge line, it is possible to suppress a reduction in the design freedom of the coil and the external electrode, and to suppress cracks and defects in the coil component, and completed the following invention.

[0045] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In addition, the present disclosure is not limited by this embodiment. Also, the same reference numerals are assigned to substantially the same components in the drawings. There are cases where the dimensions of the respective elements in the drawings are exaggerated for the purpose of illustration and are not necessarily to scale.

[0046] In addition, for the sake of convenience of explanation, the following assumes that terms indicating directions such as "upper", "lower", "right", "left", and "side" are used in the state during normal use, but this does not mean limiting the use state of the coil component of the present disclosure, etc.

[0047] In the drawings described below, the X-axis, Y-axis, and Z-axis orthogonal to each other are schematically shown for reference. The Z-axis is the axis corresponding to the height direction of the coil component when the surface on the mounting side of the coil component is used as the bottom surface.

[0048] "Embodiment"

[0049] (Outline of Coil Component)

[0050] Figure 1 It is a schematic perspective view showing an embodiment of the coil component. Figure 2 It is Figure 1 The perspective view of the coil component shown. Figure 3 It is from the second direction Y to observe Figure 1 The side view of the coil component. Figure 4 It is Figure 1 The top view of the coil component. Figure 5 It is from the first direction X to observe Figure 1 The end view of the coil component.

[0051] As Figure 1 and Figure 2 shown, the coil component 100 includes a main body portion 1, a first electrode layer 31, and a second electrode layer 41. The first electrode layer 31 and the second electrode layer 41 are disposed on the surface of the main body portion 1. The coil component 100 is electrically connected to the wiring of a circuit board (not shown) through the first electrode layer 31 and the second electrode layer 41.

[0052] The main body portion 1 has, for example, a substantially rectangular parallelepiped shape. "Substantially rectangular parallelepiped" includes a rectangular parallelepiped with rounded corners and / or ridge lines.

[0053] The main body portion 1 has a bottom surface 15 for mounting, a top surface 16 located at a distance from the bottom surface 15 in the height direction Z (hereinafter referred to as the "Z direction") of the main body portion 1, a pair of end faces 11, 12, and a pair of side faces 13, 14. The end faces 11, 12 are the faces located at a distance from each other in the first direction X orthogonal to the Z direction. The side faces 13, 14 are the faces located at a distance from each other in the second direction Y orthogonal to the height direction Z and the first direction X. In the illustrated example, the main body portion 1 is a rectangular parallelepiped that is long in the X direction. That is, the width of the side faces 13, 14 in the first direction X is greater than the width of the end faces 11, 12 in the second direction Y. The coil component 100 is mounted on a circuit board or the like such that the bottom surface 15 side faces the mounting surface.

[0054] As Figure 2 shown, the main body 1 includes an insulating green body 10, a coil 20 located inside the green body 10, a first conductor layer 32, and a second conductor layer 42.

[0055] The green body 10 has, for example, a structure formed by laminating a plurality of insulating layers. In Figure 2 the example shown, the lamination direction of the insulating layers is the direction (height direction Z) orthogonal to the bottom surface 15 and the top surface 16. In this specification, the so-called "orthogonal" only needs to be substantially orthogonal, and also includes a case of being substantially orthogonal in consideration of the range of actual deviations. In the illustrated example, the green body 10 is exposed at a part of the surface of the main body 1 (for example, a part where the first electrode layer 31 and the second electrode layer 41 are not disposed).

[0056] The green body 10 is formed using a photosensitive material (insulating paste) containing a filler and a glass material. The green body 10 may also be a fired product of such an insulating paste. The fired green body 10 may contain a glass component and a filler component. In addition, there is a case where a plurality of insulating layers are integrated by firing, and the boundaries of the insulating layers are not clear.

[0057] The coil 20 contains a conductive material such as Ag, Cu, Au, etc. The coil 20 can be formed of, for example, a conductive material and glass particles. The coil 20 is wound in a spiral shape along the lamination direction of the insulating layers. In Figure 2 the example shown, the axial direction L of the coil 20 is the direction orthogonal to the top surface 16. That is, the coil 20 is arranged to be wound along the height direction Z (longitudinally wound). The "axial direction L" refers to the direction parallel to the central axis of the spiral around which the coil 20 is wound.

[0058] The coil 20 has a plurality of coil wiring layers 21 arranged at a distance in the axial direction L and connection conductors (conductive conductors) disposed between two adjacent coil wiring layers 21. In this way, the plurality of coil wiring layers 21 are electrically connected in series to each other via a corresponding connection conductor, and constitute, for example, a spiral (HelicaL shape) coil 20.

[0059] The first conductor layer 32 and the second conductor layer 42 are formed of, for example, the same conductive material as the coil 20. The first conductor layer 32 and the second conductor layer 42 may be formed integrally with the coil 20 or may be formed of different materials from each other.

[0060] The first conductor layer 32 is electrically connected to one end side of the coil 20. The second conductor layer 42 is electrically connected to the other end side of the coil 20. The first conductor layer 32 and the first electrode layer 31 together constitute the first external electrode 30. The second conductor layer 42 and the second electrode layer 41 together constitute the second external electrode 40. In addition, in this example, each external electrode is composed of a conductor layer located inside the main body and an electrode layer disposed on the surface of the main body portion, but the external electrode only needs to include at least a conductor layer.

[0061] In Figure 2 the example shown, the first conductor layer 32 is connected to, for example, the uppermost coil wiring layer 21 in the coil 20. The first conductor layer 32 extends from a part of the bottom surface 15 along at least a part of the end surface 11. When viewed in a side view from the side 13 side, the first conductor layer 32 can be formed in a substantially L shape. The first conductor layer 32 is exposed on the surface of the main body portion 1. Here, the first conductor layer 32 is exposed on a part of the bottom surface 15 and at least a part of the end surface 11 of the main body portion 1. The part of the first conductor layer 32 exposed on the bottom surface 15 is in the same plane as the part of the green body 10 (insulator) exposed on the bottom surface 15. In addition, the part of the first conductor layer 32 exposed on the end surface 11 is in the same plane as the part of the green body 10 exposed on the end surface 11.

[0062] The second conductor layer 42 is connected to, for example, the lowermost coil wiring layer 21 in the coil 20. The second conductor layer 42 extends from a part of the bottom surface 15 along at least a part of the end surface 12. When viewed in a side view from the side 14 side, the second conductor layer 42 can be formed in a substantially L shape. The second conductor layer 42 is exposed on the surface of the main body portion 1. Here, the second conductor layer 42 is exposed on a part of the bottom surface 15 and at least a part of the end surface 12 of the main body portion 1. The part of the second conductor layer 42 exposed on the bottom surface 15 is in the same plane as the part of the green body 10 exposed on the bottom surface 15. In addition, the part of the second conductor layer 42 exposed on the end surface 12 is in the same plane as the part of the insulating green body 10 exposed on the end surface 12.

[0063] The shape of the coil 20 is not limited to Figure 2 the example shown. In Figure 2 , when viewed from the axial direction L, the coil 20 is formed in a substantially oval shape, but the shape of the coil 20 viewed from the axial direction L is not limited to the oval shape, and it can also be a circular shape, an elliptical shape, a rectangular shape, other polygons, etc. In addition, the number of the coil wiring layers 21 constituting the coil 20 is not limited to the example shown. For example, in Figure 2 , the number of the coil wiring layers 21 can be further increased. In this case, the lowermost coil wiring layer 21 can also be located near the bottom surface 15.

[0064] The first electrode layer 31 and the second electrode layer 41 contain, for example, Ni and Sn. The first electrode layer 31 and the second electrode layer 41 may have a stacked structure including an Sn layer and a Ni layer located on the main body portion 1 side of the Sn layer. The Sn layer and the Ni layer may be plating layers.

[0065] The first electrode layer 31 is electrically connected to the first conductor layer 32. In Figure 2 the example shown, the first electrode layer 31 extends from a part of the bottom surface 15 of the main body portion 1 to at least a part of the end surface 11. The first electrode layer 31 is disposed on the part of the first conductor layer 32 that is exposed at the end surface 11 and the bottom surface 15. The first electrode layer 31 may also cover the exposed part of the first conductor layer 32. When viewed from the side 13 side in a side view, the first electrode layer 31 is formed in a substantially L shape.

[0066] The second electrode layer 41 is electrically connected to the second conductor layer 42. In Figure 2 the example shown, the second electrode layer 41 extends from a part of the bottom surface 15 of the main body portion 1 to at least a part of the end surface 12. The second electrode layer 41 is disposed on the part of the second conductor layer 42 that is exposed at the end surface 12 and the bottom surface 15. The second electrode layer 41 may also cover the exposed part of the second conductor layer 42. When viewed from the side 14 side in a side view, the second electrode layer 41 is formed in a substantially L shape.

[0067] (Radius of curvature at the ridge line portion of the main body portion)

[0068] Next, the radius of curvature of the corner portion (ridge line portion) in the coil component 100 will be described.

[0069] As Figures 1 to 5 shown, the coil component 100 has a plurality of ridge line portions respectively located between two adjacent faces. Each ridge line portion is a part connecting two adjacent faces. The plurality of ridge line portions include a first ridge line portion a1 to a fourth ridge line portion a4. The first ridge line portion a1 includes two ridge line portions between the top surface 16 and each of the end surfaces 11 and 12. The second ridge line portion a2 includes two ridge line portions between the side surface 13 and each of the end surfaces 11 and 12 and two ridge line portions between the side surface 14 and each of the end surfaces 11 and 12. The third ridge line portion a3 includes two ridge line portions between the top surface 16 and each of the side surfaces 13 and 14. The fourth ridge line portion a4 includes two ridge line portions between the bottom surface 15 and each of the end surfaces 11 and 12.

[0070] The first ridge line portion a1, the second ridge line portion a2, and the third ridge line portion a3 are formed of, for example, the insulating portion of the blank 10. At least a part of the fourth ridge line portion a4 is formed of the first conductor layer 32 or the second conductor layer 42.

[0071] The first ridge portion a1, the second ridge portion a2, and the third ridge portion a3 are each formed by a curved surface that is rounded and curved into a convex shape. The "curved surface" may be any surface having a substantially arc-shaped (curvature radius measurable) cross-section, and may also include minute irregularities and steps generated during processing such as barrel polishing and sandblasting. In Figures 1 to 5 In the example shown, the curvature radii R1 of the two first ridge portions a1 are configured to be substantially equal to each other. Similarly, the curvature radii R2 of the four second ridge portions a2 are configured to be substantially equal to each other, and the curvature radii R3 of the two third ridge portions a3 are configured to be substantially equal to each other.

[0072] The curvature radius R1 of the first ridge portion a1 is greater than the curvature radii R2 of the second ridge portion a2 and R3 of the third ridge portion a3 (R1 > R2 and R1 > R3). The curvature radius R1 is, for example, more than twice the curvature radii R2 and R3.

[0073] In addition, the curvature radius R2 of the second ridge portion a2 and the curvature radius R3 of the third ridge portion a3 are configured to be substantially the same (R2 = R3), for example.

[0074] The fourth ridge portion a4 is also formed by a curved surface that is rounded and curved into a convex shape. The curvature radius R4 of the fourth ridge portion a4 is less than the curvature radius R1 (R1 > R4). As Figures 1 to 5 shown, the curvature radius R4 may also be less than the curvature radii R2 and R3.

[0075] (Results of research experiments)

[0076] The present inventor investigated the influence of the curvature radii R1 to R3 on the generation of defects on the top surface, and thus will explain the results.

[0077] Figure 6 is an experimental result showing the relationship between the curvature radius R1 of the first ridge portion a1 and the generation rate of defects generated on the top surface 16 of the coil component 100. Here, the main body portion 1 has a rectangular parallelepiped shape (0.4 mm × 0.2 mm × 0.2 mm), and samples A to C having the curvature radii R1 to R4 of the main body portion 1 set as shown in Table 1 were used. By pressing a nozzle (front end shape: 0.3 mm × 0.15 mm) into the top surface side (near the first ridge portion) of each sample by 0.7 mm to apply a prescribed load, the generation rate of defects generated on the top surface was determined.

[0078] [Table 1]

[0079]

[0080] According to Figure 6From the results shown, even when the radius of curvature R2 to R4 is constant, if the radius of curvature R1 is increased, the generation of defects on the top surface can be suppressed. Therefore, it is confirmed that the strength of the top surface side can be improved without excessively increasing the radius of curvature R2 to R4.

[0081] In addition, in Figure 6 From the results shown, the larger the radius of curvature R1 is relative to the radius of curvature R2 to R4, the smaller the generation rate of defects. If the radius of curvature R1 is about twice the radius of curvature R2 to R4, no defects will occur on the top surface. It can be seen from this that by making the radius of curvature R1, for example, more than twice the radius of curvature R2 to R4, the generation of defects on the top surface can be more significantly suppressed.

[0082] (Effect)

[0083] The coil component 100 of the present embodiment includes a main body portion 1, and the main body portion 1 includes a coil 20. The main body portion 1 further includes a first conductor layer 32 and a second conductor layer 42. The first conductor layer 32 is exposed on a part of the bottom surface 15 and at least a part of the end surface 11 of the main body portion 1, and the second conductor layer 42 is exposed on a part of the bottom surface 15 and at least a part of the end surface 12 of the main body portion 1. The first ridge portion a1 between the top surface 16 in the main body portion 1 and one of the pair of end surfaces 11, 12, the second ridge portion a2 between one of the pair of side surfaces 13, 14 and one of the pair of end surfaces 11, 12, and the third ridge portion a3 between the top surface 16 and one of the pair of side surfaces 13, 14 are each formed by a curved surface, and the curved surface is a surface that is rounded and curved into a convex shape. The radius of curvature R1 of the first ridge portion a1 is greater than the radius of curvature R2 of the second ridge portion a2 and the radius of curvature R3 of the third ridge portion a3.

[0084] According to the above structure, by making the radius of curvature R1 of the first ridge portion a1, where a load is easily applied during installation or the like, greater than the radius of curvature R2, R3, the generation of breakage, defects, cracks, etc. of the main body portion 1 can be suppressed. In addition, by suppressing the radius of curvature R2, R3 to be smaller, a decrease in the internal volume of the main body portion 1 (the volume of the region where the coil 20 can be formed) can be suppressed. Therefore, a decrease in the design freedom of the coil 20 can be suppressed, and the impact resistance of the coil component 100 can be improved.

[0085] In addition, in this specification, the case where the radius of curvature of the ridge line portion has (satisfies) a specified size relationship includes not only the case where the radius of curvature of all the ridge line portions in the main body portion satisfies this size relationship, but also the case where the radius of curvature of a part of the ridge line portions satisfies this relationship. For example, as long as at least one first ridge line portion a1 has a radius of curvature larger than that of one second ridge line portion a2 and one third ridge line portion a3, the above effects can be obtained. However, by making the radius of curvature R1 of the two first ridge line portions a1 larger than the radii of curvature R2 and R3 of all the second ridge line portions a2 and third ridge line portions a3, the generation of breakage, defect, crack, etc. can be more effectively suppressed.

[0086] According to this embodiment, the radius of curvature R1 of the first ridge line portion a1 and the radius of curvature R2 of the second ridge line portion a2 satisfy R1 / R2≥2. Or, the radius of curvature R1 of the first ridge line portion a1 and the radius of curvature R3 of the third ridge line portion a3 satisfy R1 / R3≥2. With such a structure, it is possible to suppress the reduction of the design freedom of the coil 20 and more effectively suppress the generation of breakage, defect, etc. at the corner (first ridge line portion a1) of the coil member 100 (refer to Figure 6 ).

[0087] The radius of curvature R1 to the radius of curvature R3 may also be configured to satisfy R1 / R2≥2 and R1 / R3≥2. With such a structure, it is possible to maintain the design freedom of the coil 20 at a relatively high level and more effectively suppress the generation of breakage, defect, etc. at the corner (first ridge line portion a1) of the coil member 100 (refer to Figure 6 ).

[0088] According to this embodiment, the radius of curvature R2 of the second ridge line portion a2 and the radius of curvature R3 of the third ridge line portion a3 are configured to be the same (R2 = R3). With such a structure, the second ridge line portion a2 and the third ridge line portion a3 can be formed simultaneously by the same processing step (such as barrel processing). Therefore, the main body portion 1 can be manufactured more easily. In addition, as long as the radius of curvature R2 of the second ridge line portion a2 and the radius of curvature R3 of the third ridge line portion a3 are "the same" or "configured to be the same", it only needs to be designed to be the same, and considering the actual manufacturing deviation, it includes an error within ±5%.

[0089] According to this embodiment, the fourth ridge line portion a4 between the bottom surface 15 in the main body portion 1 and one of the pair of end surfaces 11, 12 is formed by a curved surface that is rounded and bent convexly. The radius of curvature R4 of the fourth ridge line portion a4 is, for example, smaller than the radius of curvature R1 of the first ridge line portion a1, the radius of curvature R2 of the second ridge line portion a2, and the radius of curvature R3 of the third ridge line portion a3. With such a structure, as described below, the generation of chip standing can be suppressed.

[0090] If the curvature radius R4 of the fourth ridge line portion a4 is excessively increased, during installation, solder wetting between the first external electrode 30 and the second external electrode 40 and the mounting surface on the bottom surface 15 of the coil component 100 is likely to become unbalanced. As a result, chip standing (tombstone phenomenon) where the coil component 100 is mounted obliquely is likely to occur. Therefore, by suppressing the curvature radius R4 of the fourth ridge line portion a4 to be smaller than the curvature radii R1 to R3, for example, the occurrence of chip standing can be suppressed. Further, in the illustrated example, since at least a part of the fourth ridge line portion a4 is covered by the first electrode layer 31 or the second electrode layer 41, breakage and defects caused by external impact are difficult to occur in the fourth ridge line portion a4. Therefore, even if the curvature radius R4 of the fourth ridge line portion a4 is made smaller than the other curvature radii R1 to R3, the external impact resistance of the coil component 100 can be ensured.

[0091] According to the present embodiment, the first conductor layer 32 is exposed at at least a part of the end face 11 and a part of the bottom surface 15, and forms at least a part of the fourth ridge line portion a4. Similarly, the second conductor layer 42 electrically connects the second electrode layer 41 and the other end side of the coil 20. The second conductor layer 42 is exposed at at least a part of the end face 12 and a part of the bottom surface 15, and forms at least a part of the fourth ridge line portion a4. According to such a structure, since at least a part of each fourth ridge line portion a4 is formed by the first conductor layer 32 or the second conductor layer 42 containing a relatively hard conductive material, the occurrence of breakage, defects, etc. on the fourth ridge line portion a4 can be suppressed. Further, by disposing the first electrode layer 31 or the second electrode layer 41 on the fourth ridge line portion a4, the fourth ridge line portion a4 can be protected from external impact.

[0092] In the coil component 100 of the present embodiment, the coil 20 has a plurality of coil wiring layers 21 stacked in the axial direction L. According to such a structure, by suppressing the curvature radii R2 and R3 to be relatively small, the design freedom regarding the shape, size, etc. of the coil wiring layer 21 can be improved.

[0093] <Modification Example 1>

[0094] The coil component of Modification Example 1 is different from the Figures 1 to 5 illustrated coil component 100 in that the curvature radius R2 and the curvature radius R3 are different from each other.

[0095] Figure 7 is a side view of the coil component of Modification Example 1 as viewed from the second direction Y. Figure 8 is Figure 7 a top view of the coil component. Figure 9 is an end view of the Figure 7 coil component as viewed from the first direction X.

[0096] In Figures 7 to 9In the coil component 101 shown, the radius of curvature R2 of the second ridge portion a2 is greater than the radius of curvature R3 of the third ridge portion a3 (R1>R2>R3).

[0097] According to such a structure, by reducing the radius of curvature R3, it is difficult to cause suction leakage when attracting with the mounting nozzle, and the occurrence of mounting defects can be suppressed.

[0098] Moreover, when the coil 20 is arranged to be wound longitudinally (the axial direction L is orthogonal to the top surface 16) ( Figure 2 ), as described below, it is more advantageous to set the respective radii of curvature as R2>R3.

[0099] When the longitudinally wound coil 20 is arranged inside the main body portion 1, if the radius of curvature R2 of the second ridge portion a2 is large, the area of the cross section parallel to the top surface 16 near the top surface 16 of the main body portion 1 becomes small. Therefore, for example, there may be a case where the inner diameter of the coil 20 (or the coil wiring layer 21) cannot be made sufficiently large, or the coil wiring layer 21 cannot be stacked near the top surface 16. In contrast, by suppressing the radius of curvature R3 to be smaller than the radius of curvature R2, the restrictions on the shape, size, or the number of stacked coil wiring layers 21 of the coil 20 (or the coil wiring layer 21) are reduced. Therefore, the design freedom of the longitudinally wound coil 20 can be improved. Therefore, the desired electrical characteristics of the coil component can be ensured, and the strength aspect of the coil component can be further improved.

[0100] In addition, the widths of the respective ridge portions a1~a3 (the width of the R portion) can be appropriately adjusted so that the respective ridge portions a1~a3 can have the desired radii of curvature R1~R3.

[0101] (Other coil components of Modification 1)

[0102] The radius of curvature R3 of the third ridge portion a3 may also be greater than the radius of curvature R2 of the second ridge portion a2 (R1>R3>R2).

[0103] According to such a structure, by increasing the radius of curvature R3 on the top surface 16 side, it is possible to easily relieve the external impact caused by the load applied to the top surface 16 side, and more effectively suppress defects generated on the top surface 16.

[0104] In addition, by suppressing the radius of curvature R2 to a relatively small extent, the width in the Y direction of the flat portions (unbent portions) on the end faces 11 and 12 increases, so that the entire first external electrode 30 and the second external electrode 40 can be arranged more reliably on the flat portions. Therefore, it is possible to suppress the first external electrode 30 (the first electrode layer 31 or the first conductor layer 32) and the second external electrode 40 (for example, the second electrode layer 41 or the second conductor layer 42) from extending onto the bent second ridge portion a2 and being visually recognized. Therefore, it is possible to suppress a decrease in the yield. In addition, the degrees of freedom in the size and position of the first external electrode 30 and the second external electrode 40 can be increased.

[0105] Moreover, in this modified example, the first electrode layer 31 is provided to cover the portions of the first conductor layer 32 exposed on the end face 11 and the bottom face 15 of the main body portion 1, and the second electrode layer 41 is provided to cover the portions of the second conductor layer 42 exposed on the end face 12 and the bottom face 15 of the main body portion 1. With such a structure, it is possible to suppress a decrease in the yield caused by the visual recognition of the electrode layers 31 and 41, and to suppress problems such as corrosion of the surfaces of the conductor layers 32 and 42 and solder corrosion of the conductor layers 32 and 42 during installation (soldering).

[0106] <Modified Example 2>

[0107] The coil component of Modified Example 2 is different from the Figures 1 to 5 shown coil component 100 in that the coil is arranged such that the axial direction L is orthogonal to a pair of side faces (here parallel to the top face) (wound laterally). In this specification, "parallel" only needs to be substantially parallel, and cases where it is approximately parallel are also included in consideration of the range of realistic deviations.

[0108] Figure 10 is a schematic perspective view of the coil component of Modified Example 2. Figure 11 is Figure 10 a schematic perspective view of the shown coil component.

[0109] As Figure 11 shown, in the coil component 102, the coil 20 has a plurality of coil wiring layers 21, and the plurality of coil wiring layers 21 are stacked in the direction from the side face 14 toward the side face 13. The stacking direction is parallel to the second direction Y. The axial direction L of the coil 20 is the same as the stacking direction and is parallel to the top face 16. The first conductor layer 32 and the second conductor layer 42 can be electrically connected to the ends of the coil 20 at a position lower than that of the longitudinally wound coil component. Therefore, in the Figure 10 and Figure 11 shown examples, the height in the Z direction of the first conductor layer 32 and the second conductor layer 42 and the height of the first electrode layer 31 and the second electrode layer 41 are lower than those in the Figure 1 and Figure 2The coil component 100 shown. In addition, the shape, arrangement, etc. of these electrodes are not particularly limited to the illustrated examples.

[0110] The radii of curvature R1 to R4 of the main body portion 1 of the coil component 102 are set, for example, to satisfy the same relationship (R1 > R2 = R3) as that of Figures 1 to 5 the coil component 100.

[0111] <Example of Variation 3>

[0112] The coil component of Example of Variation 3 is a coil component having a horizontally wound coil. The coil component of Example of Variation 3 is different from the coil component 102 of Figure 10 and Figure 11 the Example of Variation 2 shown in that the radius of curvature R2 and the radius of curvature R3 are made different from each other.

[0113] In this example of variation, the radius of curvature R1 of the first ridge line portion a1 is greater than the radius of curvature R2 of the second ridge line portion a2 and the radius of curvature R3 of the third ridge line portion a3, and the radius of curvature R2 of the second ridge line portion a2 is greater than the radius of curvature R3 of the third ridge line portion a3 (R1 > R2 > R3).

[0114] When the coil 20 is arranged to be horizontally wound, as described below, it is more advantageous if the radii of curvature are set to R2 > R3.

[0115] When the horizontally wound coil 20 is arranged inside the main body portion 1, if the radius of curvature R3 is large, the cross-section (YZ cross-section) of the main body portion 1 parallel to the end face 11 becomes a shape in which the two corners on the top face 16 side are significantly missing. Therefore, there are cases where the inner diameter of the coil 20 cannot be increased sufficiently, or the coil wiring layers with a specified number of layers cannot be arranged. In contrast, according to this example of variation, by suppressing the radius of curvature R3 to a smaller extent, the design freedom of the horizontally wound coil 20 can be improved, and the inner diameter and the number of layers of the coil 20 can be increased. Therefore, the desired electrical characteristics of the coil component can be ensured, and the strength aspect of the coil component can be further improved.

[0116] (Other coil components of Example of Variation 3)

[0117] The radius of curvature R3 of the third ridge line portion a3 may also be greater than the radius of curvature R2 of the second ridge line portion a2 (R1 > R3 > R2).

[0118] According to such a structure, by increasing the radius of curvature R3 on the side of the top surface 16, it is easy to mitigate the external impact caused by the load applied to the side of the top surface 16, and it is possible to more effectively suppress defects and the like generated on the top surface 16. On the other hand, by suppressing the radius of curvature R2 to be smaller, it is possible to suppress the first electrode layer 31 disposed on the end surface 11 (or the first conductor layer 32 exposed on the end surface 11) and the second electrode layer 41 disposed on the end surface 12 (or the second conductor layer 42 exposed on the end surface 12) from extending onto the curved second ridge portion a2 and being visually recognized. Therefore, it is possible to suppress a reduction in the yield. In addition, it is possible to increase the degree of freedom in the size and position of the first external electrode 30 and the second external electrode 40.

[0119] <Manufacturing method of coil component>

[0120] For example, the coil components 100 to 102 can be manufactured by the following method.

[0121] · Step 1

[0122] First, an insulating paste mainly composed of borosilicate glass is repeatedly coated on a base material such as a carrier film by screen printing to form an insulating paste layer for the outer layer (that is, exposed on the surface of the main body portion).

[0123] · Step 2

[0124] Next, a photosensitive conductive paste mainly composed of Ag as a metal is coated on the insulating paste layer for the outer layer by screen printing to form a photosensitive conductive paste layer. Thereafter, through a photolithography process, a coil wiring layer and a conductor portion of a conductor layer serving as an external electrode are simultaneously formed from the photosensitive conductive paste layer.

[0125] · Step 3

[0126] A photosensitive insulating paste is coated by screen printing to cover the coil wiring layer and the external conductor layer to form an insulating paste layer. Thereafter, through a photolithography process, a via hole exposing a part of the coil wiring layer and an opening portion exposing the conductor portion are formed in the insulating paste layer.

[0127] · Step 4

[0128] For example, by screen printing, a photosensitive conductive paste is coated on the insulating paste layer, inside the opening of the insulating paste, and inside the via hole to form a photosensitive conductive paste layer. Thereafter, through a photolithography process, a connection conductor (conductive conductor) located inside the via hole and a conductor portion located inside the opening are formed from the photosensitive conductive paste layer.

[0129] By repeating Steps 3 and 4, a coil wiring layer is formed into a spiral coil connected via an insulating paste layer, and a conductor layer (the inner part of the external electrode) is formed by integrating the conductor portions of each layer. In addition, at least the lowermost layer and the uppermost layer of the coil wiring layer are patterned to be connected to the conductor portion. After that, as the uppermost layer, an outer layer insulating layer is formed by the same method as in Step 1, and a mother laminate is obtained.

[0130] · Step 5

[0131] For example, by cutting or the like, the obtained mother laminate is singulated into a plurality of unfired green laminate chips (cutting process). At this time, the conductor layer is exposed on the cut surface of the green laminate chip.

[0132] · Step 6

[0133] The unfired green laminate chips are fired under specified conditions to obtain laminate chips (fired products). Thus, the portion formed of the insulating paste becomes an insulating portion (green body) containing a glass component. The laminate chip is in a rectangular parallelepiped shape having a green body and coils and conductor layers buried in the green body, corresponding to Figure 2 the main body portion 1 shown.

[0134] · Step 7

[0135] Next, barrel processing (barrel polishing) is performed on the laminate chips. Since the conductor layer is harder than the insulating portion, the chamfering amount by barrel processing is reduced at the fourth ridge line portion a4 formed of the conductor layer. Therefore, in the laminate chips after barrel processing, the radius of curvature R4 of the fourth ridge line portion a4 is smaller than the radii of curvature R1 to R3 of the other ridge line portions a1 to a3 formed of the insulating portion. The radii of curvature R1 to R3 of the first ridge line portion a1 to the third ridge line portion a3 are substantially the same.

[0136] · Step 8

[0137] Next, the first ridge line portion a1 is processed so that the radius of curvature R1 of the first ridge line portion a1 is larger than the radius of curvature R2 of the second ridge line portion a2 and the radius of curvature R3 of the third ridge line portion a3. The processing method is not particularly limited, but for example, laser processing, sandblasting, etc. can be applied. In addition, the processing of the first ridge line portion a1 can also be performed before barrel processing (between Step 6 and Step 7) or before firing of the green laminate chips (between Step 5 and Step 6).

[0138] When making the radius of curvature R2 different from the radius of curvature R3, for example, further processing (laser processing, sandblasting, etc.) for increasing the radius of curvature can be performed on the second ridge line portion a2 or the third ridge line portion a3 before or after the processing of the first ridge line portion a1.

[0139] · Step 9

[0140] Next, electrode layers 31 and 41 are formed on the portions of the conductor layers 32 and 42 that are exposed on the surface of the stacked body chip (main body portion 1). The method for forming the electrode layers 31 and 41 is not particularly limited. For example, an electrode layer 31 and 41 including a Ni layer and a Sn layer can be formed by plating Ni to a thickness of 2 μm to 10 μm and then plating Sn to a thickness of 2 μm to 10 μm on the Ni plating layer. In this way, for example, a coil component 100 of 0.4 mm × 0.2 mm × 0.2 mm is manufactured.

[0141] <Method for Measuring Curvature Radius>

[0142] The curvature radius of each ridge line portion can be measured, for example, by the following method. Here, although the method for measuring the curvature radius R1 is described as an example, the same method can be applied to the other curvature radii R2 to R4.

[0143] Figures 12A to 12C They are schematic views illustrating the method for measuring the curvature radius. Figure 12A It is an end view of the coil component 100 observed from the first direction X. Figure 12B It represents Figure 12A A perspective view of a sample for measuring the curvature radius made of the coil component 100. Figure 12C It is an enlarged side view of a part of the sample for measuring the curvature radius that magnifies Figure 12B That part.

[0144] First, as shown in Figure 12A and Figure 12B , the coil component is processed to expose a surface 130 parallel to the side surfaces 13 and 14 to produce a sample for measuring the curvature radius. For example, it can be ground from the side surface 13 side along the second direction Y until the thickness of the coil component 100 in the second direction Y becomes approximately 1 / 2. Next, as shown in Figure 12C , the curvature radius of one or both of the two upper corners of the rectangular surface 130 is measured. For example, the vicinity of the corner of the surface 130 is photographed by a shape analysis laser microscope ("VK-X1000" manufactured by KEYENCE), and the obtained image is analyzed using a multi-analysis application program. Here, using a radius measurement tool, the curvature radius R1 of the corner is measured based on the above image.

[0145] Furthermore, the present invention is not limited to the above-described embodiments, and design changes can be made without departing from the gist of the present invention. For example, the shape, arrangement, number (number of stacked layers), material, etc. of the coil wiring layer, connection conductor, and external electrode in the coil component are also not limited to Figures 1 to 11 the example shown in Figure 2, Figure 8 In the examples shown, etc., the coil 20 is formed by laminating and winding a plurality of coil wiring layers with a winding number of less than one turn, but the winding number of the coil wiring layer can also be one turn or more. That is to say, each coil wiring layer can also be in a planar spiral shape. Also, the coil may not have a laminated structure. In addition, the structure of the external electrodes is not limited to the illustrated examples. The first conductor layer and the second conductor layer only need to be arranged so as to be exposed at at least a part of the end face and a part of the bottom face of the main body portion, and may not have the L-shaped configuration shown in the figure. Similarly, the first electrode layer and the second electrode layer only need to be respectively arranged on the surface of the main body portion and be electrically connected to the first conductor layer and the second conductor layer, and may not have the L-shaped configuration shown in the figure. For example, the first electrode layer and the second electrode layer may also only cover a part of the corresponding conductor layer. Also, each external electrode only needs to have a conductor layer located inside the main body portion, and may not have an electrode layer (such as a plating layer) on the surface of the main body portion.

[0146] The above description can also be expressed as follows.

[0147] The coil component of the first mode includes a main body portion, which includes:

[0148] An insulating green body;

[0149] A coil disposed inside the above green body;

[0150] A first conductor layer electrically connected to one end side of the above coil; and

[0151] A second conductor layer electrically connected to the other end side of the above coil,

[0152] The above main body portion is in a substantially rectangular parallelepiped shape, and the above main body portion has:

[0153] A bottom surface for mounting; a top surface located at a distance from the above bottom surface in the height direction orthogonal to the above bottom surface of the above main body portion; a pair of end faces located at a distance from each other in a first direction orthogonal to the above height direction; a pair of side faces located at a distance from each other in a second direction orthogonal to the above height direction and the above first direction;

[0154] A first ridge line portion located between the above top surface and one of the above pair of end faces;

[0155] A second ridge line portion located between one of the above pair of side faces and one of the above pair of end faces; and

[0156] A third ridge line portion located between the above top surface and one of the above pair of side faces,

[0157] The above-mentioned first conductor layer is exposed at least partially on a part of the bottom surface of the above-mentioned main body portion and at least partially on one of the pair of end surfaces.

[0158] The above-mentioned second conductor layer is exposed at least partially on a part of the bottom surface of the above-mentioned main body portion and at least partially on the other of the pair of end surfaces.

[0159] The above-mentioned first ridge line portion, the above-mentioned second ridge line portion, and the above-mentioned third ridge line portion are respectively formed by curved surfaces that are rounded and bent into convex shapes.

[0160] The radius of curvature R1 of the above-mentioned first ridge line portion is greater than the radius of curvature R2 of the above-mentioned second ridge line portion and the radius of curvature R3 of the above-mentioned third ridge line portion.

[0161] The coil component of the second mode is within the coil component of the first mode.

[0162] The radius of curvature R1 of the above-mentioned first ridge line portion and the radius of curvature R2 of the above-mentioned second ridge line portion satisfy R1 / R2≥2.

[0163] The coil component of the third mode is within the coil component of the first mode.

[0164] The radius of curvature R1 of the above-mentioned first ridge line portion and the radius of curvature R3 of the above-mentioned third ridge line portion satisfy R1 / R3≥2.

[0165] The coil component of the fourth mode is within the coil component of the first mode.

[0166] The radius of curvature R1 of the above-mentioned first ridge line portion, the radius of curvature R2 of the above-mentioned second ridge line portion, and the radius of curvature R3 of the above-mentioned third ridge line portion satisfy R1 / R2≥2 and R1 / R3≥2.

[0167] The coil component of the fifth mode is within the coil component described in any one of the first mode to the fourth mode.

[0168] The radius of curvature R2 of the above-mentioned second ridge line portion and the radius of curvature R3 of the above-mentioned third ridge line portion are configured to be the same.

[0169] The coil component of the sixth mode is within the coil component described in any one of the first mode to the fourth mode.

[0170] The radius of curvature R3 of the above-mentioned third ridge line portion is greater than the radius of curvature R2 of the above-mentioned second ridge line portion.

[0171] The coil component of the seventh mode is within the coil component of the sixth mode.

[0172] A first electrode layer that covers the part of the above-mentioned first conductor layer exposed on one end surface and the bottom surface of the above-mentioned main body portion; and

[0173] The second electrode layer covers the portions of the second conductor layer that are exposed on the other end face and the bottom face of the main body portion.

[0174] The coil component of the eighth mode is among the coil components described in any one of the first mode to the fourth mode.

[0175] The radius of curvature R2 of the second ridge line portion is greater than the radius of curvature R3 of the third ridge line portion.

[0176] The coil component of the ninth mode is among the coil components described in any one of the first mode to the eighth mode.

[0177] The main body portion further has a fourth ridge line portion. The fourth ridge line portion is located between the bottom face and one of the pair of end faces. The fourth ridge line portion is formed by a curved surface that is rounded and curved into a convex shape.

[0178] The radius of curvature R4 of the fourth ridge line portion is less than the radius of curvature R1 of the first ridge line portion, the radius of curvature R2 of the second ridge line portion, and the radius of curvature R3 of the third ridge line portion.

[0179] The coil component of the tenth mode is among the coil components of the ninth mode.

[0180] At least a part of the fourth ridge line portion between the one end face of the pair of end faces and the bottom face is constituted by the first conductor layer.

[0181] At least a part of the fourth ridge line portion between the other end face of the pair of end faces and the bottom face is constituted by the second conductor layer.

[0182] The coil component of the eleventh mode is among the coil components described in any one of the first mode to the tenth mode.

[0183] The coil has a plurality of coil wiring layers and conductive conductors. Among them, the plurality of coil wiring layers are stacked in the axial direction of the coil, and the conductive conductors electrically connect two adjacent coil wiring layers in the axial direction to each other.

[0184] The coil component of the twelfth mode is among the coil components described in any one of the first mode to the fourth mode.

[0185] The coil has a plurality of coil wiring layers and conductive conductors. Among them, the plurality of coil wiring layers are stacked in the axial direction of the coil, and the conductive conductors electrically connect two adjacent coil wiring layers in the axial direction to each other. The axial direction is orthogonal to the top face.

[0186] The radius of curvature R3 of the third ridge line portion is greater than the radius of curvature R2 of the second ridge line portion.

[0187] The coil component of the thirteenth mode is any one of the coil components of the first mode to the fourth mode.

[0188] The coil has a plurality of coil wiring layers and conduction conductors. Among them, the plurality of coil wiring layers are stacked in the axial direction of the coil, the conduction conductors electrically connect two adjacent coil wiring layers in the axial direction, and the axial direction is orthogonal to the pair of side surfaces.

[0189] The radius of curvature R2 of the second ridge line portion is greater than the radius of curvature R3 of the third ridge line portion.

[0190] Since the coil component of the present invention has high insulation between the coil wiring layers, it can be used, for example, as a coil for impedance matching (matching coil) of a high-frequency circuit, and can be used in electronic devices such as personal computers, DVD players, digital cameras, TVs, mobile phones, automotive electronics, medical / industrial instruments, etc. The coil component of the present invention can also be suitably applied to tuning circuits, filter circuits, rectifier smoothing circuits, etc.

Claims

1. A coil component includes a main body portion, and the main body portion includes: An insulating blank; A coil disposed inside the blank; A first conductor layer electrically connected to one end side of the coil; and A second conductor layer electrically connected to the other end side of the coil, The main body portion is in a substantially rectangular parallelepiped shape, and the main body portion has: A bottom surface for mounting; a top surface located at a distance from the bottom surface in a height direction orthogonal to the bottom surface of the main body portion; a pair of end surfaces located at a distance from each other in a first direction orthogonal to the height direction; a pair of side surfaces located at a distance from each other in a second direction orthogonal to the height direction and the first direction; A first ridge portion located between the top surface and one of the pair of end surfaces; A second ridge portion located between one of the pair of side surfaces and one of the pair of end surfaces; and A third ridge portion located between the top surface and one of the pair of side surfaces, The first conductor layer is exposed on at least a part of a part of the bottom surface of the main body portion and one of the pair of end surfaces, The second conductor layer is exposed on at least a part of a part of the bottom surface of the main body portion and the other of the pair of end surfaces, The first ridge portion, the second ridge portion, and the third ridge portion are each formed by a curved surface that is rounded and curved into a convex shape, The radius of curvature (R1) of the first ridge portion is greater than the radius of curvature (R2) of the second ridge portion and the radius of curvature (R3) of the third ridge portion.

2. The coil component according to claim 1, wherein The radius of curvature (R1) of the first ridge portion and the radius of curvature (R2) of the second ridge portion satisfy R1 / R2≥2.

3. The coil component according to claim 1, wherein The radius of curvature (R1) of the first ridge portion and the radius of curvature (R3) of the third ridge portion satisfy R1 / R3≥2.

4. The coil component according to claim 1, wherein The radius of curvature (R1) of the first ridge portion, the radius of curvature (R2) of the second ridge portion, and the radius of curvature (R3) of the third ridge portion satisfy R1 / R2≥2 and R1 / R3≥2.

5. The coil component according to any one of claims 1 to 4, wherein It is configured that the radius of curvature (R2) of the second ridge portion is the same as the radius of curvature (R3) of the third ridge portion.

6. The coil component according to any one of claims 1 to 4, wherein The radius of curvature (R3) of the third ridge portion is greater than the radius of curvature (R2) of the second ridge portion.

7. The coil component according to claim 6, wherein, It further includes: A first electrode layer covering the portions of the first conductor layer exposed on one end surface and the bottom surface of the main body portion; and A second electrode layer covering the portions of the second conductor layer exposed on the other end surface and the bottom surface of the main body portion.

8. The coil component according to any one of claims 1 to 4, wherein The radius of curvature (R2) of the second ridge portion is greater than the radius of curvature (R3) of the third ridge portion.

9. The coil component according to any one of claims 1 to 8, wherein, the main body portion further has a fourth ridge line portion located between the bottom surface and one of the pair of end surfaces, and the fourth ridge line portion is formed by a curved surface that is rounded and curved into a convex shape, the radius of curvature (R4) of the fourth ridge line portion is smaller than the radius of curvature (R1) of the first ridge line portion, the radius of curvature (R2) of the second ridge line portion, and the radius of curvature (R3) of the third ridge line portion.

10. The coil component according to claim 9, wherein, at least a part of the fourth ridge line portion between the one end surface and the bottom surface is constituted by the first conductor layer, at least a part of the fourth ridge line portion between the other end surface and the bottom surface is constituted by the second conductor layer.

11. The coil component according to any one of claims 1 to 10, wherein, the coil has a plurality of coil wiring layers and conduction conductors, wherein the plurality of coil wiring layers are stacked in the axial direction of the coil, and the conduction conductors electrically connect two adjacent coil wiring layers in the axial direction to each other.

12. The coil component according to claim 11, wherein, the axial direction is orthogonal to the top surface, the radius of curvature (R3) of the third ridge line portion is larger than the radius of curvature (R2) of the second ridge line portion.

13. The coil component according to claim 11, wherein, the axial direction is orthogonal to the pair of side surfaces, the radius of curvature (R2) of the second ridge line portion is larger than the radius of curvature (R3) of the third ridge line portion.

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