Coil parts

Abstract

To provide a coil component which can prevent removal of electrode parts.SOLUTION: A coil component 1 comprises: an element body 2 which has a principal surface 2d serving as a mounting surface; a coil 3 disposed in the element body 2; and a first electrode part 6 and a second electrode part 7, spaced away from each other in a second direction D2, embedded in the element body 2 so as to be exposed from the principal surface 2d, and electrically connected to the coil 3. The first electrode part 6 has: a first surface 6a exposed from the principal surface; and a protruding part 6p which is disposed in the element body 2 in a manner being spaced away from the principal surface 2d. In the second direction D2, the protruding part 6p protrudes closer to the second electrode part 7 side than the first surface 6a.SELECTED DRAWING: Figure 3

Description

[Technical Field]

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

[0002] Patent Document 1 describes a laminated inductor including a laminate, a conductor pattern formed in a spiral shape within the laminate, and a pair of terminal electrodes formed at both ends of the mounting surface of the laminate, the pair of terminal electrodes being joined to a wiring pattern on a mounting board. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-206110 Summary of the Invention [Problem to be solved by the invention]

[0004] In the laminated inductor described in Patent Document 1, the mounting substrate may bend, and bending stress may be applied to the terminal electrodes, which may cause the terminal electrodes to peel off.

[0005] An object of the present disclosure is to provide a coil component that can suppress peeling of an electrode portion. [Means for solving the problem]

[0006] A coil component according to one aspect of the present disclosure comprises a base body having a main surface that serves as a mounting surface, a coil arranged within the base body, and first and second electrode portions that are spaced apart from each other in a first direction, embedded in the base body so as to be exposed from the main surface, and electrically connected to the coil, wherein the first electrode portion has a first surface exposed from the main surface and a protrusion that is arranged within the base body and spaced apart from the main surface, and the protrusion protrudes toward the second electrode portion in the first direction beyond the first surface.

[0007] In a coil component according to an aspect of the present disclosure, the first electrode portion has a protrusion disposed within the element body and spaced apart from the main surface. The protrusion functions as an anchor, thereby suppressing peeling of the first electrode portion.

[0008] The glass content of the first electrode portion may be 20% or less. In this case, because the first electrode portion has a lower glass content, it is more easily stretched than the element body and is less likely to break due to stress. Therefore, when a bending stress is applied to the first electrode portion, stress concentrates between the element body and the first electrode portion, generating shear stress. As a result, cracks are likely to occur in the element body starting from the area between the element body and the first electrode portion. The protruding portion of the first electrode portion disperses the shear stress caused by bending, thereby preventing cracks from occurring in the element body.

[0009] The first electrode portion may be a plated conductor. In this case, the first electrode portion is more elongated than the element body and less susceptible to fracture due to stress. Therefore, when a bending stress is applied to the first electrode portion, stress concentrates between the element body and the first electrode portion, generating shear stress. As a result, cracks are likely to occur in the element body, originating from the area between the element body and the first electrode portion. The protruding portion of the first electrode portion disperses the shear stress due to bending, thereby preventing cracks from occurring in the element body.

[0010] The first electrode portion has a second surface facing the first surface and bonded to the element body, and the surface roughness of the second surface may be greater than the surface roughness of the first surface. In this case, the bonded area between the element body and the first electrode portion is increased compared to a configuration in which the surface roughness of the second surface is small, thereby further suppressing peeling of the first electrode portion.

[0011] The element body may contain a plurality of soft magnetic metal particles. In this case, the first electrode portion is likely to have an uneven shape corresponding to the shape of the plurality of soft magnetic metal particles. This increases the bonding area between the element body and the first electrode portion, further suppressing peeling of the first electrode portion.

[0012] The length of the first electrode portion in the second direction orthogonal to the main surface may be 5% to 40% of the length of the element body in the second direction. In this case, by making it 5% or more, the bonding area between the element body and the first electrode portion increases, thereby further suppressing peeling of the first electrode portion. By making it 40% or less, the withstand voltage is increased with respect to the voltage generated between the first electrode portion and the second electrode portion during actual use. [Effects of the Invention]

[0013] According to one aspect of the present invention, it is possible to provide a coil component that can suppress peeling of an electrode portion. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a perspective view showing a coil component according to an embodiment. [Figure 2] FIG. 2 is an exploded perspective view of the coil component shown in FIG. [Figure 3] FIG. 3 is a cross-sectional view of the coil component shown in FIG. [Figure 4] FIG. 4 is a partially enlarged view of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same or corresponding elements are designated by the same reference numerals, and redundant description will be omitted.

[0016] As shown in FIG. 1, a coil component 1 according to the embodiment includes an element body 2 , a first external electrode 4 , and a second external electrode 5 .

[0017] The element body 2 has a substantially rectangular parallelepiped shape. The rectangular parallelepiped shape includes a rectangular parallelepiped shape with chamfered corners and ridges, and a rectangular parallelepiped shape with rounded corners and ridges. The element body 2 has, as its outer surfaces, a pair of end faces 2a, 2b facing each other, a pair of main faces 2c, 2d facing each other, and a pair of side faces 2e, 2f facing each other. The facing direction in which the pair of main faces 2c, 2d face each other is the first direction D1. The facing direction in which the pair of end faces 2a, 2b face each other is the second direction D2. The facing direction in which the pair of side faces 2e, 2f face each other is the third direction D3. In this embodiment, the first direction D1 is the height direction of the element body 2. The second direction D2 is the longitudinal direction of the element body 2 and is perpendicular to the first direction D1. The third direction D3 is the width direction of the element body 2 and is perpendicular to the first direction D1 and the second direction D2.

[0018] The pair of end faces 2a, 2b extend in a first direction D1 to connect the pair of principal faces 2c, 2d together. The pair of end faces 2a, 2b also extend in a third direction D3 (the direction of the short sides of the pair of principal faces 2c, 2d). The pair of end faces 2a, 2b are adjacent to the principal face 2d. The pair of side faces 2e, 2f extend in the first direction D1 to connect the pair of principal faces 2c, 2d together. The pair of side faces 2e, 2f also extend in a second direction D2 (the direction of the long sides of the pair of end faces 2a, 2b). The principal face 2d can be defined as a mounting surface that faces another electronic device (e.g., a circuit board or an electronic component) when the coil component 1 is mounted on the other electronic device. The coil component 1 is connected to the other electronic device by, for example, soldering.

[0019] As shown in FIG. 2, the element body 2 has a plurality of element layers 10a to 10p stacked in a first direction D1. The coil component 1 is a laminated coil component. The element layers 10a to 10p are stacked in this order in the first direction D1. In other words, the first direction D1 is the stacking direction. In an actual element body 2, the plurality of element layers 10a to 10p are integrated to the extent that the boundaries between the layers are not visible. Although FIG. 2 shows each of the element layers 10a to 10p as one layer, multiple element layers 10a and multiple element layers 10o are stacked. The main surface 2c is formed by the main surface of the element layer 10a located at the end of the stack. The main surface 2d is formed by the main surface of the element layer 10p.

[0020] The thickness of the element layers 10a-10p (length in the first direction D1) is, for example, 1 μm or more and 200 μm or less. While the element layers 10a-10p are shown as having the same thickness in Fig. 2, element layers 10b, 10d, 10f, 10h, 10j, 10l, and 10n, on which coil conductors 21-25, first connecting conductors 8, and second connecting conductors 9 (described later) are provided, are thicker than element layers 10c, 10e, 10g, 10i, 10k, 10m, and 10o, on which through-hole conductors 31-36 (described later) are provided. In this embodiment, the thicknesses of the element layers 10b, 10d, 10f, 10h, 10j, 10l, and 10n are the same, for example, 5 μm or more and 200 μm or less. In this embodiment, the thicknesses of the element layers 10c, 10e, 10g, 10i, 10k, 10m, and 10o are equal to one another, for example, not less than 1 μm and not more than 20 μm.

[0021] Each of the base layers 10a-10p includes a plurality of soft magnetic metal grains M (see FIG. 4). The soft magnetic metal grains M are made of a soft magnetic alloy (soft magnetic material). The soft magnetic alloy is, for example, an Fe-Si alloy. When the soft magnetic alloy is an Fe-Si alloy, it may contain P. The soft magnetic alloy may be, for example, an Fe-Ni-Si-M alloy. "M" includes one or more elements selected from Co, Cr, Mn, P, Ti, Zr, Hf, Nb, Ta, Mo, Mg, Ca, Sr, Ba, Zn, B, Al, and rare earth elements.

[0022] In the element layers 10a to 10p, the soft magnetic metal particles M are bonded to one another. The bond between the soft magnetic metal particles M is realized, for example, by bonding between oxide films formed on the surfaces of the soft magnetic metal particles M. In the element layers 10a to 10p, the soft magnetic metal particles M are electrically insulated from one another by the bonding between the oxide films. The thickness of the oxide film is, for example, not less than 5 nm and not more than 60 nm. The oxide film may be composed of one or more layers.

[0023] The element body 2 contains a resin. The resin is present among the soft magnetic metal particles M. The resin is a resin having electrical insulation properties (insulating resin). The insulating resin includes, for example, a silicone resin, a phenol resin, an acrylic resin, or an epoxy resin.

[0024] 3, a step is formed in part of the main surface 2d of the element body 2. Specifically, the end surface 2a side and the end surface 2b side of the main surface 2d are recessed closer to the main surface 2c than the central portion.

[0025] 1 and 3, the first external electrode 4 and the second external electrode 5 are arranged on the element body 2. The first external electrode 4 and the second external electrode 5 are arranged on the outer surface of the element body 2. The first external electrode 4 is arranged at one end of the element body 2 in the second direction D2. The second external electrode 5 is arranged at the other end of the element body 2 in the second direction D2. The first external electrode 4 and the second external electrode 5 are spaced apart from each other in the second direction D2.

[0026] The first external electrode 4 includes a first electrode portion 4a located on the end face 2a, a second electrode portion 4b located on the principal surface 2c, a third electrode portion 4c located on the principal surface 2d, a fourth electrode portion 4d located on the side face 2e, and a fifth electrode portion 4e located on the side face 2f. The first electrode portion 4a extends along the first direction D1 and the third direction D3 and has a rectangular shape when viewed from the second direction D2. The second electrode portion 4b extends along the second direction D2 and the third direction D3 and has a rectangular shape when viewed from the first direction D1. The third electrode portion 4c extends along the second direction D2 and the third direction D3 and has a rectangular shape when viewed from the first direction D1. The fourth electrode portion 4d extends along the first direction D1 and the second direction D2 and has a rectangular shape when viewed from the third direction D3. The fifth electrode portion 4e extends along the first direction D1 and the second direction D2 and has a rectangular shape when viewed from the third direction D3.

[0027] The first electrode portion 4a, the second electrode portion 4b, the third electrode portion 4c, the fourth electrode portion 4d, and the fifth electrode portion 4e are connected and electrically connected to each other at the ridge portions of the element body 2. The first external electrode 4 is formed on five surfaces: one end face 2a, a pair of main surfaces 2c and 2d, and a pair of side surfaces 2e and 2f. The first electrode portion 4a, the second electrode portion 4b, the third electrode portion 4c, the fourth electrode portion 4d, and the fifth electrode portion 4e are integrally formed.

[0028] The second external electrode 5 includes a first electrode portion 5a located on the end face 2b, a second electrode portion 5b located on the principal face 2c, a third electrode portion 5c located on the principal face 2d, a fourth electrode portion 5d located on the side face 2e, and a fifth electrode portion 5e located on the side face 2f. The first electrode portion 5a extends along the first direction D1 and the third direction D3 and has a rectangular shape when viewed from the second direction D2. The second electrode portion 5b extends along the second direction D2 and the third direction D3 and has a rectangular shape when viewed from the first direction D1. The third electrode portion 5c extends along the second direction D2 and the third direction D3 and has a rectangular shape when viewed from the first direction D1. The fourth electrode portion 5d extends along the first direction D1 and the second direction D2 and has a rectangular shape when viewed from the third direction D3. The fifth electrode portion 5e extends along the first direction D1 and the second direction D2 and has a rectangular shape when viewed from the third direction D3.

[0029] The first electrode portion 5a, the second electrode portion 5b, the third electrode portion 5c, the fourth electrode portion 5d, and the fifth electrode portion 5e are connected and electrically connected to each other at the ridge portions of the element body 2. The second external electrode 5 is formed on five surfaces: one end face 2b, a pair of main faces 2c and 2d, and a pair of side faces 2e and 2f. The first electrode portion 5a, the second electrode portion 5b, the third electrode portion 5c, the fourth electrode portion 5d, and the fifth electrode portion 5e are integrally formed.

[0030] The first external electrode 4 and the second external electrode 5 may be conductive resin layers. The conductive resin may be a mixture of a thermosetting resin with a conductive material and an organic solvent. The conductive material may be, for example, a conductive filler. The conductive filler may be metal powder. The metal powder may be, for example, Ag powder. The thermosetting resin may be, for example, a phenol resin or an epoxy resin.

[0031] As shown in FIGS. 2 and 3 , the coil component 1 further includes a first electrode portion 6 and a second electrode portion 7. The first electrode portion 6 and the second electrode portion 7 are spaced apart from each other in the second direction D2 and embedded in the element body 2 so as to be exposed from the main surface 2d. The first electrode portion 6 is provided so as to fill a step provided on the end face 2a side of the main surface 2d. The second electrode portion 7 is provided so as to fill a step provided on the end face 2b side of the main surface 2d. The first electrode portion 6 and the second electrode portion 7 are electrically connected to the coil 3 described below. The first electrode portion 6 is electrically connected to the first external electrode 4. The second electrode portion 7 is electrically connected to the second external electrode 5.

[0032] The first electrode portion 6 and the second electrode portion 7 are arranged to sandwich the element body layer 10p in the second direction D2. The length L1 (thickness) of the first electrode portion 6 and the second electrode portion 7 in the first direction D1 is equal to the length (thickness) of the element body layer 10p in the first direction D1, and is, for example, 5 μm or more and 50 μm or less. The length L1 is 5% or more and 40% or less of the length L2 of the element body 2 in the first direction D1. The length L2 is, for example, 50 μm or more and 1600 μm or less. The length L2 may be, for example, 50 μm or more and 400 μm or less. The first electrode portion 6 and the second electrode portion 7 are, for example, a printing paste or a plated conductor. The first electrode portion 6 and the second electrode portion 7 contain a conductive material. The conductive material is, for example, Ag, Pd, Cu, Pt, or Ni. In the case of a printing paste, the conductive material may be, for example, Al. The glass content of the first electrode portion 6 and the second electrode portion 7 is 20% or less. The first electrode portion 6 and the second electrode portion 7 are less susceptible to breakage due to stress than the element body 2.

[0033] The first electrode portion 6 has a first surface 6a exposed from the element body 2, and a second surface 6b and a third surface 6c disposed within the element body 2 and joined to the element body 2. The first surface 6a is exposed from the main surface 2d. The length of the first surface 6a in the third direction D3 is equal to the length of the main surface 2d in the third direction D3. The first surface 6a has a rectangular shape when viewed from the first direction D1. The first surface 6a is flush with the main surface 2d and is connected flush with the main surface 2d. The first surface 6a is also connected flush with the end surface 2a, the side surface 2e, and the side surface 2f. The first surface 6a is covered by the third electrode portion 4c and is joined to the third electrode portion 4c. An end region of the first surface 6a, including an end 6a1 on the end surface 2b side, is exposed from the third electrode portion 4c.

[0034] The second surface 6b faces the first surface 6a in the first direction D1. The second surface 6b is provided substantially parallel to the main surface 2d. The second surface 6b has a rectangular shape when viewed from the first direction D1. Second side 6b The length of the second surface 6b in the third direction D3 is equal to the length of the main surface 2d in the third direction D3. When viewed from the first direction D1, the area of ​​the second surface 6b is larger than the area of ​​the first surface 6a. The length of the second surface 6b in the second direction D2 is longer than the length of the first surface 6a in the second direction D2.

[0035] The third surface 6c connects an end 6a1 of the first surface 6a on the end surface 2b side to an end 6b1 of the second surface 6b on the end surface 2b side. The end 6a1 is located closer to the end surface 2a than the end 6b1 in the second direction D2. The third surface 6c is an inclined surface that is inclined with respect to the first direction D1. When viewed from the third direction D3, the angle formed between the third surface 6c and the first surface 6a is an obtuse angle, and the angle formed between the third surface 6c and the second surface 6b is an acute angle. When viewed from the first direction D1, the entire third surface 6c overlaps with the second surface 6b.

[0036] The first electrode portion 6 is disposed within the element body 2 at a distance from the main surface 2d, and has a protrusion 6p that protrudes further toward the second electrode portion 7 than the first surface 6a in the second direction D2. The protrusion 6p is configured by an acute-angled ridge formed by the second surface 6b and the third surface 6c. When viewed from the third direction D3, the protrusion 6p has a tapered shape in which the length in the first direction D1 decreases toward the second electrode portion 7.

[0037] The second electrode portion 7 has a first surface 7a exposed from the element body 2, and a second surface 7b and a third surface 7c disposed within the element body 2 and joined to the element body 2. The first surface 7a is exposed from the main surface 2d. The length of the first surface 7a in the third direction D3 is equal to the length of the main surface 2d in the third direction D3. The first surface 7a has a rectangular shape when viewed from the first direction D1. The first surface 7a is flush with the main surface 2d and is connected flush with the main surface 2d. The first surface 7a is also connected flush with the end surface 2b, the side surface 2e, and the side surface 2f. The first surface 7a is covered by the third electrode portion 5c and is joined to the third electrode portion 5c. An end region of the first surface 7a, including an end 7a1 on the end surface 2a side, is exposed from the third electrode portion 5c.

[0038] The second surface 7b faces the first surface 7a in the first direction D1. The second surface 7b is provided substantially parallel to the main surface 2d. The second surface 7b has a rectangular shape when viewed from the first direction D1. Second side 7b The length of the second surface 7b in the third direction D3 is equal to the length of the main surface 2d in the third direction D3. When viewed from the first direction D1, the area of ​​the second surface 7b is larger than the area of ​​the first surface 7a. The length of the second surface 7b in the second direction D2 is longer than the length of the first surface 7a in the second direction D2.

[0039] The third surface 7c connects an end 7a1 of the first surface 7a on the end surface 2a side to an end 7b1 of the second surface 7b on the end surface 2a side. The end 7a1 is located closer to the end surface 2b than the end 7b1 in the second direction D2. The third surface 7c is an inclined surface that is inclined with respect to the first direction D1. When viewed from the third direction D3, the angle formed between the third surface 7c and the first surface 7a is an obtuse angle, and the angle formed between the third surface 7c and the second surface 7b is an acute angle. When viewed from the first direction D1, the entire third surface 7c overlaps with the second surface 7b.

[0040] The second electrode portion 7 is disposed within the element body 2 at a distance from the main surface 2d, and has a protrusion 7p that protrudes further toward the first electrode portion 6 than the first surface 7a in the second direction D2. The protrusion 7p is configured by an acute-angled ridge formed by the second surface 7b and the third surface 7c. When viewed from the third direction D3, the protrusion 7p has a tapered shape in which the length in the first direction D1 decreases toward the first electrode portion 6.

[0041] As shown in FIG. 4, the surface roughness (arithmetic mean roughness Ra) of the second surface 6b is greater than the surface roughness (arithmetic mean roughness Ra) of the first surface 6a. The surface roughness of the second surface 6b is 1.1 to 10 times the surface roughness of the first surface 6a. The second surface 6b is formed along the shape of the surface of the element body 2. The surface of the element body 2 has an uneven shape due to the plurality of soft magnetic metal particles M contained in the element body 2. The second surface 6b has a shape that reflects this uneven shape. The first surface 6a is a flat surface.

[0042] Although not shown in the figures, the first surface 7a and the second surface 7b of the second electrode portion 7 have the same shape as the first surface 6a and the second surface 6b of the first electrode portion 6. That is, the surface roughness (arithmetic mean roughness Ra) of the second surface 7b is also larger than the surface roughness (arithmetic mean roughness Ra) of the first surface 7a. The surface roughness of the second surface 7b is 1.1 to 10 times the surface roughness of the first surface 7a. As will be described later, when manufacturing the coil component 1, the conductor patterns that become the first electrode portion 6 and the second electrode portion 7 are pressed in the stacking direction when stacked together with green sheets that become the plurality of element layers 10a to 10p. As a result, uneven shapes corresponding to the shapes of the plurality of soft magnetic metal particles M are formed on the second surfaces 6b and 7b.

[0043] As shown in FIGS. 2 and 3, the coil device 1 further includes a coil 3, a first connecting conductor 8, and a second connecting conductor 9.

[0044] The coil 3 is disposed within the element body 2. The coil 3 is disposed at a distance from the outer surface of the element body 2. In this embodiment, the coil 3 is disposed at the center of the element body 2 in both the second direction D2 and the third direction D3. That is, the distance between the coil 3 and the end face 2a is equal to the distance between the coil 3 and the end face 2b. The distance between the coil 3 and the side face 2e is equal to the distance between the coil 3 and the side face 2f.

[0045] The coil 3 includes a plurality of coil conductors 21-25 electrically connected to each other and a plurality of through-hole conductors 31-36. The coil conductors 21-25 and the through-hole conductors 31-36, together with the first connecting conductor 8 and the second connecting conductor 9, are internal conductors arranged inside the coil 3. The internal conductors are, for example, printing paste or plated conductor. The internal conductors contain a conductive material. The conductive material is, for example, Ag, Pd, Cu, Al, or Ni. The internal conductors are, for example, made of the same material as each other. The internal conductors are, for example, made of the same material as the first electrode portion 6 and the second electrode portion 7.

[0046] The coil axis of the coil 3 is arranged along the first direction D1. The coil conductors 21 to 25 are arranged so that at least a portion of each of them overlaps with one another when viewed from the first direction D1. One end 21a of the coil conductor 21 constitutes one end 3a of the coil 3. The other end 21b of the coil conductor 21 is connected to one end 22a of the coil conductor 22 by a through-hole conductor 32. The other end 22b of the coil conductor 22 is connected to one end 23a of the coil conductor 23 by a through-hole conductor 33. The other end 23b of the coil conductor 23 is connected to one end 24a of the coil conductor 24 by a through-hole conductor 34. The other end 24b of the coil conductor 24 is connected to one end 25a of the coil conductor 25 by a through-hole conductor 35. The other end 25b of the coil conductor 25 constitutes the other end 3b of the coil 3.

[0047] Each of the ends 21a to 25a and 21b to 25b of the coil conductors 21 to 25 is formed in a circular shape when viewed from the first direction D1. When viewed from the first direction D1, the diameter of each of the ends 21a to 25a and 21b to 25b is larger than the line width of the coil conductors 21 to 25 (the line width of the portions of the coil conductors 21 to 25 other than the ends 21a to 25a and 21b to 25b). The enlarged ends 21a to 25a and 21b to 25b facilitate connection between the ends 21a to 25a and 21b to 25b and the through-hole conductors 31 to 36. The diameter of each of the ends 21a to 25a and 21b to 25b is equal to the diameter of the through-hole conductors 31 to 36.

[0048] Coil conductor 21 is provided on element layer 10d. Coil conductor 22 is provided on element layer 10f. Coil conductor 23 is provided on element layer 10h. Coil conductor 24 is provided on element layer 10j. Coil conductor 25 is provided on element layer 10l. Each of coil conductors 21 to 25 is provided to penetrate corresponding element layer 10d, 10f, 10h, 10j, 10l in its thickness direction (first direction D1). Coil conductor 21 is arranged closest to main surface 2c among coil conductors 21 to 25. Coil conductor 25 is arranged closest to main surface 2d among coil conductors 21 to 25.

[0049] In this embodiment, the lengths in the first direction D1 of the multiple coil conductors 21 to 25 are equal to each other. The lengths in the first direction D1 of the multiple coil conductors 21 to 25 are equal to the thicknesses of the corresponding element layers 10d, 10f, 10h, 10j, and 10l.

[0050] The through-hole conductor 31 is provided in the element body layer 10c. The through-hole conductor 32 is provided in the element body layer 10e. The through-hole conductor 33 is provided in the element body layer 10g. The through-hole conductor 34 is provided in the element body layer 10i. The through-hole conductor 35 is provided in the element body layer 10k. The through-hole conductor 36 is provided in the element body layer 10m. Each of the through-hole conductors 31 to 36 is provided to penetrate the corresponding element body layer 10c, 10e, 10g, 10i, 10k, and 10m in its thickness direction (first direction D1).

[0051] In this embodiment, the lengths in the first direction D1 of the through-hole conductors 31 to 36 are equal to each other, and the lengths in the first direction D1 of the through-hole conductors 31 to 36 are equal to the thicknesses of the corresponding element layers 10c, 10e, 10g, 10i, 10k, and 10m.

[0052] The first connecting conductor 8 connects one end 3a of the coil 3 and the first electrode portion 4a of the first external electrode 4. The coil conductor 21 including the end 3a has the same potential as the first external electrode 4. The first connecting conductor 8 extends in the second direction D2. The first connecting conductor 8 has a first end 8a and a second end 8b. The first end 8a is exposed from the end face 2a and is connected to the first electrode portion 4a.

[0053] The second end 8b is connected to one end 3a of the coil 3 by a through-hole conductor 31. The second end 8b is formed in a circular shape when viewed from the first direction D1. When viewed from the first direction D1, the diameter of the second end 8b is larger than the line width of the first connecting conductor 8 other than the two end portions 8a, 8b. By enlarging the second end 8b in this manner, it becomes easier to connect the second end 8b to the through-hole conductor 31.

[0054] The second connecting conductor 9 connects the other end 3b of the coil 3 and the first electrode portion 5a of the second external electrode 5. The coil conductor 25 including the end 3b has the same potential as the second external electrode 5. The second connecting conductor 9 extends in the second direction D2. The second connecting conductor 9 has a first end 9a and a second end 9b. The first end 9a is exposed from the end face 2b and is connected to the first electrode portion 5a.

[0055] The second end 9b is connected to the other end 3b of the coil 3 by a through-hole conductor 36. The second end 9b is formed in a circular shape when viewed from the first direction D1. When viewed from the first direction D1, the diameter of the second end 9b is larger than the line width of the portion of the second connecting conductor 9 other than the two end portions 9a, 9b. By enlarging the second end 9b in this manner, it becomes easier to connect the second end 9b to the through-hole conductor 36.

[0056] Next, a method for manufacturing the coil device 1 will be described.

[0057] A slurry is prepared by mixing soft magnetic metal particles M, an insulating resin, a solvent, etc. The prepared slurry is applied to a substrate (e.g., a PET film) by, for example, screen printing or doctor blade, to form green sheets that will become the plurality of element layers 10a on the substrate. Green sheets that will become the plurality of element layers 10o are also formed on the substrate in the same manner.

[0058] A conductor pattern that will become the first connecting conductors 8 is formed on the substrate by screen printing or plating. Next, a slurry is applied to the substrate by, for example, screen printing so as to fill in the periphery of the conductor pattern. In this way, green sheets that will become the multiple element layers 10b are formed on the substrate. After the corresponding conductor patterns are formed on the substrate, the green sheets that will become the multiple element layers 10c to 10n, 10p are also formed so as to fill in the periphery of the conductor patterns.

[0059] Next, the green sheets that will become the multiple element layers 10a-10p are transferred and stacked in this order, each with its conductor pattern. The green sheets are pressed in the stacking direction to form a laminate. The green sheet laminate is then fired to form a laminate substrate. The laminate substrate is then cut into chips of a predetermined size using a cutting machine equipped with a rotary blade, forming individual laminates. Next, the corners and ridges of the laminate are chamfered by barrel polishing.

[0060] The laminate is then immersed in a resin liquid to impregnate the laminate with the resin, thereby forming the element body 2. Next, resin electrode layers that will become the first external electrode 4 and the second external electrode 5 are formed on both ends of the element body 2 by, for example, a dipping method. In this way, the coil component 1 is formed.

[0061] As described above, the coil component 1 has the first electrode portion 6 and the second electrode portion 7 that are exposed from the main surface 2d, which is the mounting surface. The first electrode portion 6 and the second electrode portion 7 each have protrusions 6p and 7p that are disposed within the element body 2 and spaced apart from the main surface 2d. The protrusions 6p and 7p function as anchors, thereby preventing the first electrode portion 6 and the second electrode portion 7 from peeling off or falling off from the element body 2.

[0062] The coil component 1 is mounted on another electronic device by joining the first electrode portion 6 and the second electrode portion 7 together with the first external electrode 4 and the second external electrode 5 to mounting electrodes of the other electronic device, for example, by soldering. If the other electronic device bends while the coil component 1 is mounted on the other electronic device, bending stress is applied to the first electrode portion 6 and the second electrode portion 7. The glass content of the first electrode portion 6 and the second electrode portion 7 is 20% or less. Because the glass content of the first electrode portion 6 and the second electrode portion 7 is low, they are more easily stretched than the element body 2 and are less likely to be broken by stress. Therefore, when bending stress is applied to the first electrode portion 6 and the second electrode portion 7, stress is concentrated between the first electrode portion 6 and the second electrode portion 7 and the element body 2, generating shear stresses F1 and F2, as shown in FIG. 3 .

[0063] If the interface between the first electrode portion 6 and the element body 2 extends in the same direction as the shear stress F1, cracks are likely to occur in the element body 2 starting from the interface. The third surface 6c of the first electrode portion 6 extends in a direction substantially perpendicular to the shear stress F1. Therefore, the interface between the third surface 6c and the element body 2 is less likely to be the starting point of cracks in the element body 2. Furthermore, the protrusion 6p disperses the shear stress F1, thereby suppressing the occurrence of cracks in the element body 2. Therefore, the cracks are less likely to affect the internal conductors.

[0064] If the interface between the second electrode portion 7 and the element body 2 extends in the same direction as the shear stress F2, cracks are likely to occur in the element body 2 starting from the interface. The third surface 7c of the second electrode portion 7 extends in a direction approximately perpendicular to the shear stress F2. Therefore, the interface between the third surface 7c and the element body 2 is less likely to be the starting point of cracks in the element body 2. Furthermore, the protrusion 7p disperses the shear stress F2, thereby suppressing the occurrence of cracks in the element body 2. Therefore, the cracks are less likely to affect the internal conductors.

[0065] When the first electrode portion 6 and the second electrode portion 7 are plated conductors, the first electrode portion 6 and the second electrode portion 7 are more elongated than the element body 2 and are less likely to be broken by stress. Therefore, when a bending stress is applied to the first electrode portion 6 and the second electrode portion 7, stress is concentrated between the element body 2 and each of the first electrode portion 6 and the second electrode portion 7, causing shear stress. As a result, cracks are likely to occur in the element body 2, originating from between the element body 2 and each of the first electrode portion 6 and the second electrode portion 7. Even in this case, the protrusions 6p and 7p distribute the shear stresses F1 and F2 caused by bending, thereby preventing cracks from occurring in the element body 2.

[0066] In the first electrode unit 6, the surface roughness of the second surface 6b is greater than the surface roughness of the first surface 6a. Compared to a configuration in which the surface roughness of the second surface 6b is smaller, the bonding area between the element body 2 and the first electrode unit 6 is increased, further suppressing peeling of the first electrode unit 6. In the second electrode unit 7, the surface roughness of the second surface 7b is greater than the surface roughness of the first surface 7a. Compared to a configuration in which the surface roughness of the second surface 7b is smaller, the bonding area between the element body 2 and the second electrode unit 7 is increased, further suppressing peeling of the second electrode unit 7.

[0067] The element body 2 contains a plurality of soft magnetic metal particles M. Therefore, the second surface 6b of the first electrode portion 6 and the second surface 7b of the second electrode portion 7 are likely to have an uneven shape corresponding to the shape of the plurality of soft magnetic metal particles M. This increases the bonding area between the element body 2 and the first electrode portion 6, further suppressing peeling of the first electrode portion 6. Since the bonding area between the element body 2 and the second electrode portion 7 is increased, further suppressing peeling of the second electrode portion 7.

[0068] The length L1 of the first electrode portion 6 and the second electrode portion 7 is between 5% and 40% of the length L2 of the element body 2. By making it 5% or more, the bonding area between the element body 2 and each of the first electrode portion 6 and the second electrode portion 7 increases, further suppressing peeling of the first electrode portion 6 and the second electrode portion 7. By making it 40% or less, the withstand voltage is increased with respect to the voltage generated between the first electrode portion 6 and the second electrode portion 7 during actual use.

[0069] Although the embodiments of the present invention have been described above, the present invention is not necessarily limited to the above-described embodiments, and various modifications are possible without departing from the spirit of the present invention.

[0070] At least one of the first electrode portion 6 and the second electrode portion 7 may have the protrusions 6p, 7p. The protrusions 6p, 7p may have a shape that functions as an anchor and is not limited to the shape of the above embodiment. For example, the protrusions 6p, 7p may have a shape that has a constant length in the first direction D1 instead of a tapered shape.

[0071] The first electrode portion 6 is in contact with each of the end face 2a, the side face 2e, and the side face 2f when viewed from the first direction D1, but may be spaced apart from each of the end face 2a, the side face 2e, and the side face 2f. The second electrode portion 7 is in contact with each of the end face 2b, the side face 2e, and the side face 2f when viewed from the first direction D1, but may be spaced apart from each of the end face 2b, the side face 2e, and the side face 2f.

[0072] The element body 2 does not necessarily need to be composed of soft magnetic metal particles M, and may be composed of ferrite (for example, Ni-Cu-Zn ferrite, Ni-Cu-Zn-Mg ferrite, or Cu-Zn ferrite), a dielectric material, etc. The coil conductors 21 to 25, the through-hole conductors 31 to 36, the first connecting conductor 8, the second connecting conductor 9, the first electrode portion 6, and the second electrode portion 7 may be sintered metal conductors.

[0073] The second end 8b of the first connecting conductor 8, the second end 9b of the second connecting conductor 9, and the ends 21a to 25a, 21b to 25b of the coil conductors 21 to 25 are enlarged when viewed from the first direction D1, but they do not have to be enlarged.

[0074] The first connecting conductor 8 is disposed on a different magnetic layer from the coil conductor 21, but may be disposed on the same magnetic layer. In this case, the first connecting conductor 8 and the coil conductor 21 are directly connected to each other so as to be continuous within the same magnetic layer, without the through-hole conductor 31 interposed therebetween. The second connecting conductor 9 is disposed on a different magnetic layer from the coil conductor 25, but may be disposed on the same magnetic layer. In this case, the second connecting conductor 9 and the coil conductor 25 are directly connected to each other so as to be continuous within the same magnetic layer, without the through-hole conductor 36 interposed therebetween.

[0075] The first external electrode 4 may not include the second electrode portion 4b, and the second external electrode 5 may not include the second electrode portion 5b.

[0076] The first connecting conductor 8 is exposed at the end face 2a and the second connecting conductor 9 is exposed at the end face 2b, but the first connecting conductor 8 and the second connecting conductor 9 may also be exposed at the main face 2d. [Explanation of symbols]

[0077] 1...coil component, 2...element body, 2d...main surface, 3...coil, 6...first electrode portion, 6a...first surface, 6b...second surface, 6p...protrusion, 7...second electrode portion, 7a...first surface, 7b...second surface, 7p...protrusion, M...soft magnetic metal particle.

Claims

1. an element body having a main surface serving as a mounting surface; a coil disposed within the element body; a first electrode portion and a second electrode portion that are spaced apart from each other in a first direction, are embedded in the element body so as to be exposed from the main surface, and are electrically connected to the coil; an external electrode disposed on the element body; Equipped with the first electrode portion has a first surface exposed from the main surface and a protrusion disposed within the element body and spaced apart from the main surface, the protruding portion protrudes toward the second electrode portion further than the first surface in the first direction, The first surface has a region covered by the external electrode and a region exposed from the external electrode. Coil parts.

2. The glass content of the first electrode portion is 20% or less. The coil component according to claim 1 .

3. The first electrode portion is a plated conductor. The coil component according to claim 1 or 2.

4. the first electrode portion has a second surface that faces the first surface and is joined to the element body, the surface roughness of the second surface is greater than the surface roughness of the first surface; The coil component according to any one of claims 1 to 3.

5. The element body includes a plurality of soft magnetic metal particles. The coil component according to any one of claims 1 to 4.

6. a length of the first electrode portion in a second direction orthogonal to the main surface is 5% to 40% of a length of the element body in the second direction; The coil component according to any one of claims 1 to 5.

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