Coil component

Abstract

To provide a coil component in which an external electrode is hardly peeled off from a substrate.SOLUTION: The base body of the coil component 1 has a first surface 10a, a second surface 10c connected to the first surface, a third surface 10d facing the second surface in the L direction, a fourth surface connected to the first surface, and a fifth surface 10f facing the fourth surface in the W direction orthogonal to the L direction. The first external electrodes 21 are provided so as to be separated from the second surface in a first corner C1 including a first corner where the second surface and the fourth surface of the base body intersect and in a second corner A1 including a second corner where the second surface and the fifth surface of the base body intersect, while being in contact with the second surface in a region other than the first corner C2 and the second corner A2. The second external electrodes 22 are provided so as to be separated from the third surface at a third corner C3 including a third corner where the third surface and the fourth surface of the base body intersect and at a fourth corner A3 including a fourth corner where the third surface and the fifth surface of the base body intersect, while being in contact with the third surface in a region other than the third corner C4 and the fourth corner A4.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The disclosure herein relates primarily to coil components. [Background technology]

[0002] A coil component is a passive element used in electronic devices. For example, the coil component is used to remove noise from a power supply line or a signal line of a circuit. The coil component includes a base body made of a magnetic material, a coil conductor provided on the base body, and a pair of external electrodes connected to one end and the other end of the coil conductor.

[0003] In order to miniaturize the coil component, the external electrodes are sometimes attached to a single surface (mounting surface) of the surface of the base. For example, Japanese Patent Laid-Open Publication No. 2019-125606 (Patent Document 1) describes an inductor in which external electrodes are attached only to the mounting surface of the base. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-125606 Summary of the Invention [Problem to be solved by the invention]

[0005] External electrodes that are attached only to the mounting surface of the base are prone to peeling off from the base. Patent Document 1 describes that providing external electrodes at positions on the mounting surface of the base that are spaced apart from the side surfaces can prevent the external electrodes from peeling off from the base.

[0006] Positioning the external electrodes at a distance from the side surfaces on the mounting surface of the base has the positive effect of preventing the external electrodes from peeling off by making it difficult for the stress generated by an impact applied to the coil component to be transmitted to the external electrodes. However, it also has the negative effect of reducing the contact area between the external electrodes and the mounting surface of the base, thereby reducing the bonding strength between the external electrodes and the base, and promoting the peeling of the external electrodes to the same extent as the reduced bonding strength.

[0007] The inventions disclosed in this specification aim to solve or alleviate at least some of the problems in the prior art described above. One specific aim of the inventions disclosed in this specification is to provide a coil component in which external electrodes are less likely to peel off from the base. The inventions disclosed in this specification may also solve problems that are understood from sources other than those described in the "Problems to be Solved by the Invention" section. The various inventions disclosed in this specification may be collectively referred to as "the present invention." [Means for solving the problem]

[0008] A coil component according to one aspect of the present invention includes a base, a coil conductor provided inside the base, a first external electrode provided on a first surface of the base and connected to one end of the coil conductor, and a second external electrode provided on the first surface of the base at a distance from the first external electrode in a first direction and connected to the other end of the coil conductor. The base has a first surface, a second surface connected to the first surface, a third surface facing the second surface in the first direction and connected to the first surface, a fourth surface connected to the first surface, and a fifth surface facing the fourth surface in a second direction perpendicular to the first direction and connected to the first surface. When viewed from the normal direction of the first surface, the first external electrode is spaced from the second surface at a first corner including a first corner where the second surface of the base intersects with the fourth surface and at a second corner including a second corner where the second surface intersects with the fifth surface, but is in contact with the second surface in an area other than the first corner and the second corner. When viewed from the normal direction of the first surface, the second external electrode is spaced apart from the third surface at a third corner including a third corner where the third surface and the fourth surface of the base intersect and at a fourth corner including a fourth corner where the third surface and the fifth surface intersect, while being in contact with the third surface in an area other than the third corner and the fourth corner. [Effects of the Invention]

[0009] According to one aspect of the present invention, a coil component in which external electrodes are less likely to peel off from a base body can be obtained. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a perspective view schematically showing a coil component 1 according to one embodiment of the present invention. [Figure 2] FIG. 2 is a plan view of the coil device 1. [Figure 3] 2 is a cross-sectional view showing an enlarged portion of a cross section of the coil device 1 taken along line II. FIG. [Figure 4] 2 is a cross-sectional view showing an enlarged portion of the cross section of the coil device 1 taken along line II-II. FIG. [Figure 5] FIG. 10 is a plan view schematically showing a modified example of the coil device 1. [Figure 6]FIG. 1 is a plan view schematically showing a coil device 101 according to another embodiment of the present invention. [Figure 7] FIG. 10 is a plan view schematically showing a modified example of the coil device 101. [Figure 8a] 2 is a diagram schematically showing a plurality of magnetic sheets used in manufacturing the coil component 1. FIG. [Figure 8b] 1 is a plan view schematically showing a magnetic sheet 57 used in manufacturing the coil device 1. FIG. [Figure 9a] FIG. 2 is a schematic front view of a mother laminate 50 obtained by laminating magnetic sheets. [Figure 9b] FIG. 2 is a plan view of a mother laminate 50. DETAILED DESCRIPTION OF THE INVENTION

[0011] Various embodiments of the present invention will be described below with appropriate reference to the drawings. Components common to multiple drawings are designated by the same or similar reference numerals throughout the drawings. Please note that the drawings are not necessarily drawn to scale for the sake of convenience. The embodiments described below do not necessarily limit the invention according to the claims. Elements described in the following embodiments are not necessarily essential to the solution of the invention.

[0012] 1 First embodiment (coil component 1) 1-1 Basic structure of coil component 1 A coil component 1 according to a first embodiment of the present invention will be described with reference to Fig. 1 to Fig. 4. Fig. 1 is a perspective view schematically showing the coil component 1, Fig. 2 is a plan view of the coil component 1, Fig. 3 is a schematic cross-sectional view showing an enlarged portion of the cross section of the coil component 1 taken along line II, and Fig. 4 is a schematic cross-sectional view showing an enlarged portion of the cross section of the coil component 1 taken along line II-II.

[0013] For ease of explanation, each drawing may include an L axis, a W axis, and a T axis that are perpendicular to each other. In this specification, the dimensions, arrangement, shape, and other features of each component of the coil device 1 may be described based on the L axis, the W axis, and the T axis.

[0014] The coil component 1 is used in an electronic circuit, for example, to remove noise. The coil component 1 may be a power inductor incorporated in a power supply line, or an inductor used in a signal line.

[0015] The coil component 1 includes a base 10, a coil conductor 25 provided inside the base 10, a first external electrode 21 provided on the surface of the base 10, and a second external electrode 22 provided on the surface of the base 10 at a position spaced apart from the first external electrode 21. The first external electrode 21 is electrically connected to one end of the coil conductor 25, and the second external electrode 22 is electrically connected to the other end of the coil conductor 25.

[0016] 1-2 Base 10 First, the base 10 will be described. The base 10 is made of a magnetic material and has a rectangular parallelepiped shape. The base 10 has an upper surface 10a, a lower surface 10b, a first end surface 10c, a second end surface 10d, a first side surface 10e, and a second side surface 10f. The outer surface of the base 10 is defined by these six surfaces (10a to 10f). The upper surface 10a faces the lower surface 10b in the T-axis direction. The first end surface 10c faces the second end surface 10d in the L-axis direction. The first side surface 10e faces the second side surface 10f in the W-axis direction. The upper surface 10a is connected to the upper end of the first end surface 10c at an end in the L1 direction extending along the L-axis on the negative side of the L-axis, and is connected to the upper end of the second end surface 10d at an end in the L2 direction extending along the L-axis on the positive side of the L-axis. The upper surface 10a is connected to the upper end of the first side surface 10e at its end in the W1 direction, which extends along the W axis on the negative side of the W axis, and is connected to the upper end of the second side surface 10f at its end in the W2 direction, which extends along the W axis on the positive side of the W axis. The upper surface 10a is an example of the "first surface" described in the claims. The base 10 has a "rectangular parallelepiped shape," but the term "rectangular parallelepiped" does not necessarily mean "rectangular parallelepiped" in the strict mathematical sense. The corners and edges of the base 10 may be rounded.

[0017] The substrate 10 may contain a plurality of metal magnetic particles bonded together. The surfaces of the metal magnetic particles are coated with an insulating film. Therefore, the metal magnetic particles are insulated from each other. If the insulating film on the surface of the metal magnetic particles is damaged, the insulation resistance of the substrate 10 will decrease. For this reason, the substrate 10 may have an insulating film provided on its surface. In other words, the substrate 10 may have an insulating film (not shown). The insulating film may be provided on the upper surface 10a of the substrate 10 so as to cover areas where no external electrodes are provided. The insulating film is made of an insulating material with excellent insulating properties. The insulating film has a higher electrical resistivity than the substrate 10. Examples of insulating film materials include resin materials such as silicone resin, epoxy resin, and phenolic resin, glasses such as borosilicate glass, and metal oxides such as Al oxide.

[0018] 1-3 Coil conductor 25 Next, the coil conductor 25 will be described. The coil conductor 25 is made of a conductive material with excellent conductivity, such as Ag, Pd, Cu, Al, or an alloy thereof. The coil conductor 25 can have various shapes depending on the type of coil component 1. The coil conductor 25 is configured to have a shape that generates a desired inductance. For example, the coil conductor 25 has a spiral shape wound a predetermined number of turns around the coil axis. The coil conductor 25 may also have a linear shape.

[0019] 3, the coil conductor 25 has a first lead portion 25a and a second lead portion 25b. Both the first lead portion 25a and the second lead portion 25b are exposed to the outside of the base 10 from the upper surface 10a. The coil conductor 25 is connected to the first external electrode 21 at the first lead portion 25a, and is connected to the second external electrode 22 at the second lead portion 25b.

[0020] 1-4 First external electrode 21 and second external electrode 22 Next, the first external electrode 21 and the second external electrode 22 will be described. Both the first external electrode 21 and the second external electrode 22 are provided on the upper surface 10a of the base 10. In the illustrated embodiment, recesses having shapes corresponding to the first external electrode 21 and the second external electrode 22 are formed on the upper surface 10a of the base 10, and the first external electrode 21 and the second external electrode 22 are housed in these recesses. The first external electrode 21 is disposed so as to be spaced apart from the second external electrode 22 in the L-axis direction. As described above, one end of the coil conductor 25 is connected to the first external electrode 21, and the other end of the coil conductor 25 is connected to the second external electrode 22.

[0021] The configurations of the first external electrode 21 and the second external electrode 22 and their arrangement on the upper surface 10a will be described mainly with reference to Fig. 2. When viewed from the normal direction of the upper surface 10a (i.e., the T-axis direction), the first external electrode 21 is cut out at a portion facing a first corner C1 where the first end surface 10c and the first side surface 10e of the base 10 intersect and a portion facing a second corner C2 where the first end surface 10c and the second side surface 10f intersect. Therefore, the first external electrode 21 is spaced apart from the first end surface 10c and the first side surface 10e in a first corner region A1 including the first corner C1 and is spaced apart from the first end surface 10c and the second side surface 10f in a second corner region A2 including the second corner C2, while being disposed so as to contact the first end surface 10c in an intermediate region B1 interposed between the first corner region A1 and the second corner region A2 in the W-axis direction. That is, the first external electrode 21 does not extend to the end of the upper surface 10a in the L1 direction in the first corner region A1 and the second corner region A2, but extends to the end of the upper surface 10a in the L1 direction in an intermediate region B1 between the first corner region A1 and the second corner region A2. Therefore, the first external electrode 21 contacts the upper end of the first end surface 10c in the intermediate region B1 between the first corner region A1 and the second corner region A2 in the W-axis direction.

[0022] When viewed from the normal direction of the upper surface 10a, the second external electrode 22 is cut out at a portion facing a third corner C3 where the second end face 10d and the first side face 10e of the base 10 intersect and a portion facing a fourth corner C4 where the second end face 10d and the second side face 10f intersect. Therefore, the second external electrode 22 is spaced apart from the second end face 10d and the first side face 10e in a third corner region A3 including the third corner C3, and is spaced apart from the second end face 10d and the second side face 10f in a fourth corner region A4 including the fourth corner C4, while being in contact with the second end face 10d in an intermediate region B2 located between the third corner region A3 and the fourth corner region A4 in the W-axis direction. That is, the second external electrode 22 does not extend to the end of the upper surface 10a in the L2 direction in the third corner region A3 and the fourth corner region A4, but extends to the end of the upper surface 10a in the L2 direction in the intermediate region B2 between the third corner region A3 and the fourth corner region A4. Therefore, the second external electrode 22 contacts the upper end of the second end surface 10d in the intermediate region B2 between the third corner region A3 and the fourth corner region A4 in the W-axis direction.

[0023] In the illustrated embodiment, the first external electrode 21 and the second external electrode 22 are arranged so as to contact the first side surface 10e and the second side surface 10f as well. Specifically, the first external electrode 21 is arranged so as to contact the first side surface 10e in an intermediate region B3 that is located between the first corner region A1 and the third corner region A3 in the L-axis direction and adjacent to the first corner region A1. The first external electrode 21 is also arranged so as to contact the second side surface 10f in an intermediate region B4 that is located between the second corner region A2 and the fourth corner region A4 in the L-axis direction and adjacent to the second corner region A2. The second external electrode 22 is arranged so as to contact the first side surface 10e in an intermediate region B5 that is located between the first corner region A1 and the third corner region A3 in the L-axis direction and adjacent to the third corner region A3. The second external electrode 22 is also arranged so as to contact the second side surface 10f in an intermediate region B6 that is between the second corner region A2 and the fourth corner region A4 in the L-axis direction and adjacent to the fourth corner region A4.

[0024] When viewed from the normal direction of the upper surface 10a, the first corner region A1 has a rectangular or square shape with the first corner C1 as one of its vertices. Similarly, the second corner region A2 has a rectangular or square shape with the second corner C2 as one of its vertices, the third corner region A3 has a rectangular or square shape with the third corner C3 as one of its vertices, and the fourth corner region A4 has a rectangular or square shape with the fourth corner C4 as one of its vertices.

[0025] The first external electrode 21 is spaced apart from the first end face 10c and the first side face 10e in the first corner region A1, and is spaced apart from the first end face 10c and the second side face 10f in the second corner region A2. Therefore, when viewed from the normal direction of the top face 10a, the top face 10a of the base 10 is not covered by the first external electrode 21 in parts of the first corner region A1 and the second corner region A2, and is exposed from the notches in the first external electrode 21. The part of the top face 10a that is exposed from the first external electrode 21 in the first corner region A1 includes a flat surface F1 extending along the LW plane. As shown in FIG. 4, in the first corner region A1, the ridge connecting the top face 10a and the first end face 10c is rounded. Each of the ridges connecting the top surface 10a to the second end surface 10d, the first side surface 10e, or the second side surface 10f is also rounded. The flat surface F1 is located more inward of the top surface 10a than the rounded ridges between the top surface 10a and the first end surface 10c and the rounded ridges between the top surface 10a and the first side surface 10e. The area of ​​the top surface 10a exposed from the first external electrode 21 in the second corner region A2 includes a flat surface F2 extending along the LW plane. The flat surface F2 is located more inward of the top surface 10a than the rounded ridges between the top surface 10a and the first end surface 10c and the rounded ridges between the top surface 10a and the second side surface 10f.

[0026] The second external electrode 22 is spaced apart from the second end face 10d and the first side face 10e in the third corner region A3 and from the second end face 10d and the second side face 10f in the fourth corner region A4. Therefore, when viewed from the normal direction of the top face 10a, the top face 10a of the base 10 is not covered by the second external electrode 22 in parts of the third corner region A3 and the fourth corner region A4 and is exposed from the notches in the second external electrode 22. The part of the top face 10a that is exposed from the second external electrode 22 in the third corner region A3 includes a flat surface F3 extending along the LW plane. The flat surface F3 is located inside the top face 10a relative to the rounded ridge between the top face 10a and the second end face 10d and the rounded ridge between the top face 10a and the first side face 10e. The area of ​​the upper surface 10a that is exposed from the second external electrode 22 in the fourth corner region A4 includes a flat surface F4 that extends along the LW plane. The flat surface F4 is located more inward of the upper surface 10a than the rounded ridge between the upper surface 10a and the second end surface 10d and the rounded ridge between the upper surface 10a and the second side surface 10f.

[0027] When an insulating film is provided on the upper surface 10a of the base 10, the insulating film is exposed from the cutout portions of the first external electrode 21 and the second external electrode 22 in parts of the first corner region A1, the second corner region A2, the third corner region A3, and the fourth corner region A4.

[0028] The dimension in the W-axis direction of each of the first corner region A1, the second corner region A2, the third corner region A3, and the fourth corner region A4 can be 1 / 10 or less of the dimension in the W-axis direction of the top surface 10a. Also, the dimension in the L-axis direction of each of the first corner region A1, the second corner region A2, the third corner region A3, and the fourth corner region A4 can be 1 / 10 or less of the dimension in the L-axis direction of the top surface 10a.

[0029] The first external electrode 21 and the second external electrode 22 may each have a base electrode layer and a plating layer covering the base electrode layer. The base electrode layer is formed, for example, by applying a paste-like conductive material to the upper surface 10a of the base 10 and then curing the applied conductive material. Examples of the conductive material for the base electrode layer include metal materials such as Cu, Ni, Ag, Pd, and Au, or alloy materials containing one or more of these metal materials. The plating layer is formed to cover the surface of the base electrode layer by, for example, electrolytic plating. The plating layer may have a two-layer structure. For example, the two-layer plating layer may have a first plating layer formed on the base electrode layer and a second plating layer formed on the first plating layer. The first plating layer may be, for example, a nickel plating layer, and the second plating layer may be, for example, a tin plating layer.

[0030] 1-5 Mechanism of delamination prevention Conventionally, it has been thought that when an external electrode provided on the mounting surface extends to the side or end face of the base, when an external impact is applied to the coil component, the portion of the interface between the base and the external electrode that is exposed from the side or end face of the base becomes the starting point of interfacial fracture, and a crack extends from this starting point of interfacial fracture along the interface, causing the external electrode to peel off from the base. Patent Document 1 explains that the external electrode provided on the mounting surface of the base is arranged so as to be separated from the side or end face of the base, and that this arrangement makes the external electrode less likely to peel off from the base.

[0031] However, when the entire external electrodes provided on the mounting surface of the base are positioned away from the side and end faces of the base, as in the inductor described in Patent Document 1, the contact area between the external electrodes and the base is reduced, and the bond strength between the external electrodes and the base is reduced accordingly. Therefore, the effect of preventing peeling by separating the external electrodes from the side and end faces of the base is somewhat negated by the reduced contact area.

[0032] In contrast, in the present invention, the arrangement of the first external electrode 21 and the second external electrode 22 on the upper surface 10a of the base 10 is such that the first external electrode 21 and the second external electrode 22 are spaced apart from the end faces and side faces of the base 10 in the first corner region A1, the second corner region A2, the third corner region A3, and the fourth corner region A4, which are close to the corners of the base 10 where stress is most concentrated when an impact is applied to the coil component 1, while the first external electrode 21 and the second external electrode 22 are extended to the ends of the upper surface 10a of the base 10 in regions other than the first corner region A1, the second corner region A2, the third corner region A3, and the fourth corner region A4.This minimizes the reduction in contact area while suppressing the occurrence of interfacial breakdown, thereby preventing the first external electrode 21 and the second external electrode 22 from peeling off from the upper surface 10a of the base 10.

[0033] According to a CAE (Computer Aided Engineering) analysis conducted by the present inventors, when an indenter is pressed into a coil component mounted on a substrate from the substrate side toward the coil component at a speed of 2 mm / sec, it was confirmed that the stress concentrated near the corners of the cubic-shaped coil component. In particular, when viewed from the normal direction of the top surface 10a, the stress in the regions corresponding to the first corner region A1, the second corner region A2, the third corner region A3, and the fourth corner region A4 (i.e., rectangular regions with each corner as a vertex, whose dimensions in the L-axis direction are 1 / 10 of the dimensions of the base in the L-axis direction and whose dimensions in the W-axis direction are 1 / 10 of the dimensions of the base in the W-axis direction) was approximately 2 to 3 times the stress acting on other regions. This stress distribution did not change significantly even when the dimensional ratio of the coil component or the indenter speed was changed. The analysis results showed that in cubic-shaped coil components, the corners of the base are likely to be the starting point of interfacial fracture, and that in areas of the ridges on the top surface of the base that connect to the end faces or side faces and are away from the corners (for example, intermediate areas B1 to B6 of coil component 1), interfacial fracture is significantly less likely to occur than near the corners.

[0034] In the present invention, by separating the first external electrode 21 and the second external electrode 22 from the end faces and side faces of the base 10 in the first corner region A1, the second corner region A2, the third corner region A3, and the fourth corner region A4, where stress is particularly concentrated when an external impact is applied to the coil component 1, it is possible to make it less likely that a starting point for interfacial failure will occur between the first external electrode 21 or the second external electrode 22 and the upper surface 10a of the base 10 due to stress generated by an external impact. Furthermore, by extending the first external electrode 21 and the second external electrode 22 to the edges of the upper surface 10a of the base 10 in regions other than the first corner region A1, the second corner region A2, the third corner region A3, and the fourth corner region A4 (i.e., the intermediate regions B1 to B6), it is possible to increase the contact area between each of the first external electrode 21 and the second external electrode 22 and the upper surface 10a of the base 10, compared to conventional coil components in which the entire external electrodes are arranged spaced apart from the side and end faces of the base. In this way, in the coil component 1, the reduction in the contact area between the first external electrode 21 and the second external electrode 22 and the upper surface 10a is minimized, and it is possible to suppress the occurrence of starting points for interfacial breakdown between the first external electrode 21 or the second external electrode 22 and the upper surface 10a of the base 10, so that the first external electrode 21 and the second external electrode 22 are less likely to peel off from the upper surface 10a of the base 10.

[0035] 1-6 Variations In the above-described embodiment, the shapes of the first external electrode 21 and the second external electrode 22 when viewed from the normal direction of the upper surface 10a are not limited to those shown in FIG. 2. Modified shapes of the first external electrode 21 and the second external electrode 22 in a plan view will be described with reference to FIG. 5. In FIG. 5, the shapes of the first external electrode 21 and the second external electrode 22 are modified compared to the embodiment shown in FIG. 2. Specifically, in the embodiment shown in FIG. 5, the first external electrode 21 has a curved portion 21a that curves convexly toward the first corner C1 and a curved portion 21b that curves convexly toward the second corner C2. Furthermore, the second external electrode 22 has a curved portion 22a that curves convexly toward the third corner C3 and a curved portion 22b that curves convexly toward the fourth corner C4.

[0036] According to the embodiment shown in FIG. 5 , when viewed from the normal direction of the top surface 10 a, the first external electrode 21 has a shape without corners in the first corner region A1 and the second corner region A2. This reduces stress concentration in the regions of the first external electrode 21 located within the first corner region A1 and the second corner region A2 when an external impact is applied to the coil device 1. This makes the first corner region A1 and the second corner region A2 even less likely to become the starting point of interfacial fracture. This further reduces peeling of the first external electrode 21 from the base 10. Similarly, when an external impact is applied to the coil device 1, stress concentration in the regions of the second external electrode 22 located within the third corner region A3 and the fourth corner region A4 can be reduced. This reduces the third corner region A3 and the fourth corner region A4 even less likely to become the starting point of interfacial fracture. This further reduces peeling of the second external electrode 22 from the base 10.

[0037] 2 Second embodiment (coil component 101) Next, a coil component 101 according to a second embodiment will be described with reference to FIG. 6. FIG. 6 is a plan view of the coil component 101 according to the second embodiment. The coil component 101 differs from the coil component 1, which has two external electrodes, in that the coil component 101 has four external electrodes. The coil component 101 may include, for example, a magnetically coupled inductor (for example, a common mode choke coil). Descriptions of components of the coil component 101 that are the same as or similar to the components of the coil component 1 will be omitted as appropriate.

[0038] 6, the coil device 101 includes a first external electrode 121, a second external electrode 122, a third external electrode 123, and a fourth external electrode 124. The first external electrode 121 is disposed in a position facing the first corner C1. The second external electrode 122 is spaced apart from the first external electrode 121 in the L-axis direction and disposed in a position facing the third corner C3. The third external electrode 123 is spaced apart from the first external electrode 121 in the W-axis direction and disposed in a position facing the second corner C2. The fourth external electrode 124 is spaced apart from the second external electrode 122 in the W-axis direction and disposed in a position facing the fourth corner C4.

[0039] The coil component 101 includes two coil conductors (not shown) inside the base 10. The two coil conductors are, for example, a first coil conductor and a second coil conductor. The first coil conductor and the second coil conductor are electrically insulated from each other inside the base 10. The first external electrode 121 is connected to one end of the first coil conductor, and the second external electrode 122 is connected to the other end of the first coil conductor. The third external electrode 123 is connected to one end of a second coil conductor (not shown), and the fourth external electrode 124 is connected to the other end of the second coil conductor. The third external electrode 123 may be connected to the other end of the first coil conductor instead of the second external electrode 122. When the first external electrode 121 is connected to one end of the first coil conductor and the third external electrode is connected to the other end, the second external electrode 122 is connected to one end of the second coil conductor, and the fourth external electrode 124 is connected to the other end of the second coil conductor.

[0040] The arrangement of the first external electrode 121 to the fourth external electrode 124 on the upper surface 10a will be further described. When viewed from the normal direction of the upper surface 10a, the first external electrode 121 is arranged so as to be spaced apart from the first end surface 10c and the first side surface 10e in the first corner region A1, but to be in contact with the first end surface 10c in an intermediate region B11 that is between the first corner region A1 and the third corner region A3 and adjacent to the first corner region A1 in the W-axis direction, and to be in contact with the first side surface 10e in an intermediate region B12 that is between the first corner region A1 and the second corner region A2 and adjacent to the first corner region A1 in the L-axis direction.

[0041] When viewed from the normal direction of the top surface 10a, the second external electrode 122 is spaced apart from the second end face 10d and the first side face 10e in the second corner region A2, while contacting the second end face 10d in an intermediate region B21 located between the second corner region A2 and the fourth corner region A4 and adjacent to the second corner region A2 in the W-axis direction, and is arranged to contact the first side face 10e in an intermediate region B22 located between the first corner region A1 and the second corner region A2 and adjacent to the second corner region A2 in the L-axis direction.

[0042] When viewed from the normal direction of the top surface 10a, the third external electrode 123 is spaced apart from the first end face 10c and the second side face 10f in the third corner region A3, while being in contact with the first end face 10c in an intermediate region B31 located between the first corner region A1 and the third corner region A3 and adjacent to the third corner region A3 in the W-axis direction, and is also in contact with the second side face 10f in an intermediate region B32 located between the third corner region A3 and the fourth corner region A4 and adjacent to the third corner region A3 in the L-axis direction.

[0043] When viewed from the normal direction of the top surface 10a, the fourth external electrode 124 is spaced apart from the second end face 10d and the second side face 10f in the fourth corner region A4, while being in contact with the second end face 10d in an intermediate region B41 located between the second corner region A2 and the fourth corner region A4 and adjacent to the fourth corner region A4 in the W-axis direction, and is also arranged to be in contact with the second side face 10f in an intermediate region B42 located between the third corner region A3 and the fourth corner region A4 and adjacent to the fourth corner region A4 in the L-axis direction.

[0044] In the coil device 101, the first to fourth external electrodes 121 to 124 are arranged away from the end faces and side faces in the first corner region A1, second corner region A2, third corner region A3, and fourth corner region A4, where stress is most concentrated when an impact is applied to the coil device 101. This makes it difficult for interfacial breakdown to occur in the first to fourth external electrodes 121 to 124, where stress is most concentrated. Furthermore, the first to fourth external electrodes 121 to 124 are arranged in contact with the corresponding end faces and side faces in intermediate regions (intermediate regions B11, B12, ... B42) that are outside the first to fourth corner regions A1 to A4. This minimizes the reduction in contact area while suppressing the occurrence of interfacial breakdown. This suppresses peeling of the first to fourth external electrodes 121 to 124 from the upper surface 10a of the base 10.

[0045] In the coil device 101, the shapes of the first external electrode 121 to the fourth external electrode 124 when viewed from the normal direction of the upper surface 10a are not limited to those shown in Fig. 6. Modified examples of the shapes that the first external electrodes 121 to the fourth external electrodes 124 can take in a plan view will be described with reference to Fig. 7. In the embodiment shown in Fig. 7, the first external electrode 121 has a curved portion 121a that curves convexly toward the first corner C1, the second external electrode 122 has a curved portion 122a that curves convexly toward the third corner C3, the third external electrode 123 has a curved portion 123a that curves convexly toward the second corner C2, and the fourth external electrode 124 has a curved portion 124a that curves convexly toward the fourth corner C4.

[0046] 7, when viewed from the normal direction of the upper surface 10a, the first to fourth external electrodes 121 to 124 have a shape without corners in the corresponding first corner region A1 to fourth corner region A4. Therefore, when an external impact is applied to the coil device 101, it is possible to mitigate the concentration of stress on the regions of the first to fourth external electrodes 121 to 124 that are inside the first to fourth corner regions A1 to A4. This makes it less likely that the first to fourth corner regions A1 to A4 will become the starting point of interfacial breakdown. This makes it less likely that the first to fourth external electrodes 121 to 124 will peel off from the base 10.

[0047] 3. Manufacturing method of coil component 1 Next, an example of a method for manufacturing the coil component 1 will be described with reference to FIGS. 8a, 8b, 9a, and 9b. In the following description, it is assumed that the coil component 1 is manufactured by a sheet lamination method. The coil component 1 may also be manufactured by a known method other than the sheet lamination method. For example, the coil component 1 may be manufactured by a lamination method such as a print lamination method, a thin film process method, or a slurry build method.

[0048] When manufacturing the coil component 1 by the sheet lamination method, first, a plurality of magnetic sheets are produced. The magnetic sheets are produced from a magnetic material paste obtained by kneading soft magnetic metal powder (raw material powder), which is the raw material for metal magnetic particles, with a binder resin and a solvent. The raw material powder contains, for example, Fe and an additive element. The additive element is, for example, one or more elements of Si, Cr, and Al. The binder resin for the magnetic material paste is, for example, an acrylic resin. The binder resin for the magnetic material paste may be a PVB resin, a phenol resin, a resin known as a binder resin other than those mentioned above, or a mixture thereof. The solvent is, for example, toluene.

[0049] To produce a magnetic sheet, a magnetic material paste is applied to the surface of a plastic base film by a doctor blade method or other common method. The magnetic material paste applied to the surface of this base film is dried to obtain a sheet-like compact. This sheet-like compact is then press-molded in a mold at a molding pressure of about 10 to 100 MPa to produce a magnetic sheet. Figure 8a shows a schematic diagram of magnetic sheets 51 to 57 produced as described above.

[0050] Next, a conductive paste is applied to some of the multiple magnetic sheets. In the example shown in FIG. 8a, the conductive paste is applied to magnetic sheets 51 to 54 of the magnetic sheets 51 to 57. The conductive paste is produced by kneading a conductive powder made of a conductive material with excellent conductivity, such as Ag, Pd, Cu, Al, or an alloy thereof, with a binder resin and a solvent. The binder resin for the conductive paste may be the same type of resin as the binder resin for the magnetic material paste. By applying the conductive paste to the magnetic sheets 51 to 54, unfired conductor patterns 61 to 64 are formed on the magnetic sheets 51 to 54. The conductive paste is applied to the magnetic sheets by, for example, a screen printing method.

[0051] Through holes (not shown) are formed in the magnetic sheets 51 to 53 and 56 to 57 in the stacking direction, and conductive paste is filled into these through holes. The conductive paste filled into the through holes becomes unsintered via conductors. The via conductors are arranged at positions that connect the conductive patterns formed on adjacent magnetic sheets. For example, the via conductor provided in the through hole formed in the magnetic sheet 51 is arranged so as to connect the conductive pattern 61 formed on the upper surface of the magnetic sheet 51 with the conductive pattern 62 formed on the upper surface of the magnetic sheet 52 adjacent to the magnetic sheet 51. The unsintered conductive patterns 61 to 64 and the unsintered via conductors become the coil conductor 25 after firing.

[0052] A conductor pattern 71 is formed on the magnetic material sheet 57, and the conductor pattern 71 will become the base electrode layer for the first external electrode 21 and the second external electrode 22 after firing. As shown in FIG. 8b, the conductor pattern 71 formed on the magnetic material sheet 57 has through holes 71a periodically provided in the W-axis direction and the L-axis direction. When the magnetic material sheet 57 on which the conductor pattern 71 is formed is viewed from above (i.e., when viewed from the perspective of FIG. 8b), the magnetic material sheet 57 is exposed through the through holes 71a. The conductor pattern 71 may be formed by applying the same conductive paste as that used for the conductor patterns 61 to 64 to the magnetic material sheet 57. The conductor pattern 71 may contain a conductive material different from that used for the conductor patterns 61 to 64.

[0053] Of the magnetic sheets 51 to 57, no conductive patterns are formed on the magnetic sheets 55 and 56. The magnetic sheets 55 and 56 serve as cover layers interposed between the lower surface 10b and the upper surface 10a of the base 10 and the conductive patterns 61 to 64 in the coil component 1. Through holes are formed in the magnetic sheet 56, and conductive paste filled in these through holes becomes the first lead portion 25a and the second lead portion 25b that lead the coil conductor 25 to the upper surface 10a of the base 10 after firing.

[0054] Next, the magnetic sheets 51 to 57 are stacked and then pressure-bonded together to obtain the mother laminate 50 shown in Figures 9a and 9b. During this pressure-bonding, the magnetic sheets are pressed in the stacking direction, so that the conductive pattern 71 is embedded inside the mother laminate 50. In the pressure-bonding step for producing the mother laminate 50, the stacked magnetic sheets 51 to 57 may be pressed with such a pressure that the upper surface of the conductive pattern 71 and the upper surface of the mother laminate 50 are flush with each other.

[0055] Next, the mother laminate 50 is cut along the cutting planes X1 and X2 shown in FIGS. 9a and 9b to produce singulated unsintered chip laminates. The cutting plane X1 is a plane that passes through the center of each of the through holes 71a formed in the conductive pattern 71 and extends parallel to the WT plane. The cutting plane X2 is a plane that passes through the center of each of the through holes 71a formed in the conductive pattern 71 and extends parallel to the LT plane. For example, a press blade or a rotary blade can be used to cut the mother laminate 50. The mother laminate 50 can be cut using a cutting machine such as a dicing machine or a laser processing machine.

[0056] Next, the mother laminate 50 is singulated to produce a chip laminate, which is then fired. By firing the chip laminate, the pressure-bonded magnetic sheets 51-57 become the base 10, the conductive patterns 61-64 and via conductors become the coil conductor 25, and the conductive pattern 71 becomes the base electrode layers of the first external electrode 21 and the second external electrode 22.

[0057] Next, a plating layer is formed on the base electrode layer to form the first external electrode 21 and the second external electrode 22. The plating layer is formed by, for example, electrolytic plating or electroless plating. The plating layer may include two or more plating layers. For example, a nickel plating layer may be formed on the base electrode layer, and a tin plating layer may be formed on this nickel plating layer.

[0058] In this manner, the coil component 1 is manufactured. In the manufacturing process of the coil component 1, the chip stack may be subjected to a polishing process such as barrel polishing. The polishing process rounds the corners and ridges of the base 10.

[0059] 4 Notes The dimensions, materials, and arrangements of each component described in the various embodiments above are not limited to those explicitly described in each embodiment, and each component can be modified to have any dimensions, materials, and arrangements that may fall within the scope of the present invention.

[0060] Components not explicitly described in this specification may be added to each of the above-described embodiments, and some of the components described in each embodiment may be omitted.

[0061] The designations "first," "second," "third," etc. in this specification are used to identify components and do not necessarily limit the number, order, or content thereof. Furthermore, numbers used to identify components are used in different contexts, and numbers used in one context do not necessarily indicate the same configuration in another context. Furthermore, this does not prevent a component identified by a certain number from also serving the function of a component identified by another number.

[0062] In this specification, when a certain component is referred to as "comprising" another component, it does not mean that other components are excluded, but that other components may be further included, unless it is inconsistent with the content of the present invention.

[0063] 5. Supplementary Notes The embodiments disclosed herein also include the following:

[0064] [Appendix 1] a base (10) having a first surface (10a), a second surface (10c) connected to the first surface, a third surface (10d) facing the second surface in a first direction (L) and connected to the first surface, a fourth surface (10e) connected to the first surface, and a fifth surface (10f) facing the fourth surface in a second direction (W) perpendicular to the first direction and connected to the first surface; a coil conductor (25) provided inside the base; a first external electrode (21) provided on the first surface of the base and connected to one end of the coil conductor; a second external electrode (22) provided on the first surface of the base body and spaced apart from the first external electrode in the first direction, and connected to the other end of the coil conductor; Equipped with the first external electrode is provided so as to be spaced from the second surface at a first corner (A1) including a first corner (C1) where the second surface and the fourth surface of the base intersect and at a second corner (A2) including a second corner (C2) where the second surface and the fifth surface intersect, when viewed from a normal direction of the first surface, while being in contact with the second surface in a region other than the first corner and the second corner, the second external electrode is provided so as to be spaced from the third surface at a third corner (A3) including a third corner (C3) where the third surface and the fourth surface of the base intersect and at a fourth corner (A4) including a fourth corner (C4) where the third surface and the fifth surface intersect, when viewed from the normal direction of the first surface, while being in contact with the third surface in an area other than the third corner and the fourth corner. Coil parts. [Appendix 2] the first external electrode is provided so as to be spaced from the fourth surface at the first corner portion when viewed from the normal direction of the first surface, and to be in contact with the fourth surface in a region other than the first corner portion. 10. The coil component according to claim 1. [Appendix 3] the first external electrode is provided so as to be spaced from the fifth surface at the second corner portion when viewed from the normal direction of the first surface, and to be in contact with the fifth surface in a region other than the second corner portion. 10. The coil component according to claim 1 or 2. [Appendix 4] At the first corner portion, a flat first flat portion that is a part of the first surface is interposed between the first external electrode and the second surface and between the first external electrode and the fourth surface. 4. The coil component according to claim 1, wherein the coil component is a coil having a diameter of 100 mm or less. [Appendix 5] the first external electrode has a curved portion (21a) that curves convexly toward the first corner portion when viewed from the normal direction of the first surface; 5. The coil component according to claim 1. [Appendix 6] further comprising an insulating film provided on the first surface of the base body; 6. The coil component according to claim 1, wherein the coil component is a coil element. [Appendix 7] the substrate includes a plurality of metal magnetic particles; 7. The coil component according to claim 1, wherein the coil component is a coil element. [Appendix 8] a base (10) having a first surface (10a), a second surface (10c) connected to the first surface, a third surface (10d) facing the second surface in a first direction (L) and connected to the first surface, a fourth surface (10e) connected to the first surface, and a fifth surface facing the fourth surface in a second direction (W) perpendicular to the first direction and connected to the first surface; a first coil conductor provided inside the base; a second coil conductor provided inside the base; a first external electrode (121) provided on the first surface of the base and connected to one end of the first coil conductor; a second external electrode (122) provided on the first surface of the base body and spaced apart from the first external electrode in the first direction, and connected to the other end of the first coil conductor; a third external electrode (123) provided on the first surface of the base body and spaced apart from the first external electrode (121) in the second direction and connected to one end of the second coil conductor; a fourth external electrode (124) provided on the first surface of the base body and spaced apart from the third external electrode in the first direction, and connected to the other end of the second coil conductor; Equipped with the first external electrode is provided so as to be spaced from the second surface at a first corner portion including a first corner (C1) where the second surface and the fourth surface of the base intersect, when viewed from a normal direction of the first surface, and to be in contact with the second surface in a region other than the first corner portion; the second external electrode is provided so as to be spaced from the third surface at a second corner portion including a third corner (C3) where the third surface and the fourth surface of the base intersect, when viewed from a normal direction of the first surface, and to be in contact with the third surface in a region other than the second corner portion; the third external electrode is provided so as to be spaced from the second surface at a third corner portion including a second corner (C2) where the second surface and the fifth surface of the base intersect, when viewed from the normal direction of the first surface, and to be in contact with the second surface in a region other than the third corner portion; the fourth external electrode is provided so as to be spaced from the third surface at a fourth corner portion including a fourth corner (C4) where the third surface and the fifth surface of the base intersect, when viewed from the normal direction of the first surface, and to be in contact with the third surface in a region other than the fourth corner portion. Coil parts. [Explanation of symbols]

[0065] 1. 101 Coil parts 10 Base 10a top surface 10c 1st end face 10d 2nd end face 10e First Side 10f 2nd side 25 Coil conductor 21, 121 1st external electrode 22, 122 2nd external electrode 123 Third external electrode 124 4th external electrode

Claims

1. a base body having a first surface, a second surface connected to the first surface, a third surface facing the second surface in a first direction and connected to the first surface, a fourth surface connected to the first surface, and a fifth surface facing the fourth surface in a second direction perpendicular to the first direction and connected to the first surface; a coil conductor provided inside the base; a first external electrode provided on the first surface of the base and connected to one end of the coil conductor; a second external electrode provided on the first surface of the base body and spaced apart from the first external electrode in the first direction, and connected to the other end of the coil conductor; Equipped with the first external electrode is provided so as to be spaced from the second surface at a first corner including a first corner where the second surface and the fourth surface of the base intersect and at a second corner including a second corner where the second surface and the fifth surface intersect, when viewed from a normal direction of the first surface, while being in contact with the second surface in a region other than the first corner and the second corner, the second external electrode is provided so as to be spaced from the third surface at a third corner including a third corner where the third surface and the fourth surface of the base intersect and at a fourth corner including a fourth corner where the third surface and the fifth surface intersect, when viewed from the normal direction of the first surface, while being in contact with the third surface in a region other than the third corner and the fourth corner. Coil parts.

2. the first external electrode is provided so as to be spaced from the fourth surface at the first corner portion when viewed from a normal direction of the first surface, and to be in contact with the fourth surface in a region other than the first corner portion; The coil component according to claim 1 .

3. the first external electrode is provided so as to be spaced from the fifth surface at the second corner portion when viewed from a normal direction of the first surface, and to be in contact with the fifth surface in a region other than the second corner portion; The coil component according to claim 1 .

4. At the first corner, a flat first flat portion that is a part of the first surface is interposed between the first external electrode and the second surface and between the first external electrode and the fourth surface. The coil component according to claim 1 .

5. the first external electrode has a curved portion that is curved convexly toward the first corner portion when viewed from a normal direction of the first surface; The coil component according to claim 1 .

6. further comprising an insulating film provided on the first surface of the base body; The coil component according to claim 1 .

7. the substrate includes a plurality of metal magnetic particles; The coil component according to claim 1 .

8. a base body having a first surface, a second surface connected to the first surface, a third surface facing the second surface in a first direction and connected to the first surface, a fourth surface connected to the first surface, and a fifth surface facing the fourth surface in a second direction perpendicular to the first direction and connected to the first surface; a first coil conductor provided inside the base; a second coil conductor provided inside the base; a first external electrode provided on the first surface of the base and connected to one end of the first coil conductor; a second external electrode provided on the first surface of the base body and spaced apart from the first external electrode in the first direction, and connected to the other end of the first coil conductor; a third external electrode provided on the first surface of the base body and spaced apart from the first external electrode in the second direction, and connected to one end of the second coil conductor; a fourth external electrode provided on the first surface of the base body and spaced apart from the third external electrode in the first direction, and connected to the other end of the second coil conductor; Equipped with the first external electrode is provided so as to be spaced from the second surface at a first corner portion including a first corner where the second surface and the fourth surface of the base intersect, when viewed from a normal direction of the first surface, and to be in contact with the second surface in a region other than the first corner portion; the second external electrode is provided so as to be spaced from the third surface at a second corner portion including a third corner where the third surface and the fourth surface of the base intersect, when viewed from a normal direction of the first surface, and to be in contact with the third surface in a region other than the second corner portion; the third external electrode is provided so as to be spaced from the second surface at a third corner portion including a second corner where the second surface and the fifth surface of the base intersect, when viewed from a normal direction of the first surface, and to be in contact with the second surface in a region other than the third corner portion; the fourth external electrode is provided so as to be spaced from the third surface at a fourth corner portion including a fourth corner where the third surface and the fifth surface of the base intersect, when viewed from the normal direction of the first surface, and to be in contact with the third surface in a region other than the fourth corner portion. Coil parts.

Images