Coil component

Abstract

To stably deposit external electrode plating at desired locations while maintaining the performance of a coil component.SOLUTION: A coil component according to an embodiment includes a magnetic base including metal magnetic particles and having, as outer surfaces, a first surface and a second surface facing each other, a third surface adjacent to both the first surface and the second surface, and a fourth surface adjacent to the first surface, the second surface, and the third surface, and having a first ridge portion extending between the third surface and the fourth surface, a conductor provided inside or on the surface of the magnetic base, an external electrode provided on the first surface of the magnetic base and electrically connected to the conductor, the external electrode having a plating layer, and a first insulating portion embedded in the magnetic base, with a portion exposed at a position closer to the first surface of the first ridge portion.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] In recent years, digital electronic devices have rapidly become smaller and more powerful, and electronic circuits and power supply circuits have become increasingly dense. This has led to an increase in the importance of high performance and high-density mounting of the coil components that make up these circuits. To miniaturize coil components while maintaining their performance, it is necessary to reduce the volume occupied by the external electrodes. To achieve this, sputtered films are used in some of the external electrodes to reduce their thickness, and the number of surfaces on which the external electrodes are provided is reduced from five to three, and then to just one.

[0003] Additionally, coil components using metallic magnetic materials are known to achieve both performance maintenance and miniaturization. Because metallic magnetic materials have improved magnetic saturation characteristics compared to ferrite magnetic materials, coil components using metallic magnetic materials are used in applications where direct current is applied. The improved magnetic saturation characteristics of coil components using metallic magnetic materials reduce the volume ratio of the magnetic material, enabling miniaturization.

[0004] On the other hand, metal magnetic materials have lower electrical resistance than ferrite magnetic materials. Therefore, when using metal magnetic particles on a magnetic substrate, there is a risk that the plating of the external electrodes may extend to unintended locations. To ensure stable plating in the intended locations, the magnetic substrate is subjected to an insulation treatment as necessary.

[0005] For example, Patent Document 1 proposes a technology in which an insulating layer is provided on the entire surface of the main body except for the locations of the external electrodes, so that the external electrodes are exposed only on the mounting surface. With the technology in Patent Document 1, the external electrodes are stably provided only in the desired locations. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 2023-106296 Summary of the Invention [Problem to be solved by the invention]

[0007] However, in the technology of Patent Document 1, the insulating layer is thickened to ensure insulation, so for coil components of the same size, the amount of magnetic material is reduced by the thickness of the insulating layer, resulting in a deterioration in magnetic properties. In view of the above circumstances, an object of the present invention is to provide a method for stably plating external electrodes at target locations while maintaining the performance of a coil component. [Means for solving the problem]

[0008] In order to solve the above problem, a coil component according to one embodiment of the present invention comprises: a magnetic base containing metal magnetic particles and having as outer surfaces a first surface and a second surface facing each other, a third surface adjacent to both the first surface and the second surface, and a fourth surface adjacent to the first surface, the second surface, and the third surface, and having a first ridge portion extending between the third surface and the fourth surface; a conductor provided inside or on the surface of the magnetic base; an external electrode provided on the first surface of the magnetic base and electrically connected to the conductor, the external electrode having a plating layer; and a first insulating portion embedded in the magnetic base, with a portion of the first insulating portion exposed near the first surface side of the first ridge portion.

[0009] In a coil component according to an aspect of the present invention, the first insulating portion is provided in plurality at intervals in the direction in which the first ridge portion extends. In the coil component according to one aspect of the present invention, the first ridge line portion of the magnetic base has a rounded surface.

[0010] In the coil component according to one aspect of the present invention, the first insulating portion extends in layers in a direction intersecting with the first ridge portion. According to a coil component of one embodiment of the present invention, the magnetic base has a second ridge portion extending between the first surface and at least one of the third surface and the fourth surface, which is an R-surface, and the first insulating portion is provided at a location adjacent to or overlapping the R-surface.

[0011] According to a coil component of one embodiment of the present invention, the external electrode is allowed to extend from the first surface to at least one of the third surface and the fourth surface, and the first insulating portion is provided at a location on at least one of the first ridge portion, the third surface, and the fourth surface that contacts the external electrode. In a coil component according to one aspect of the present invention, the first insulating portion is spaced apart from the conductor.

[0012] A coil component according to one embodiment of the present invention further includes a second insulating portion that is partially exposed at a second ridge portion of the magnetic base extending between the first surface and at least one of the third surface and the fourth surface and is embedded in the magnetic base. [Effects of the Invention]

[0013] According to the present invention, it is possible to stably provide plating of external electrodes at target locations while maintaining the performance of the coil component. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a perspective view showing a coil component according to an embodiment of the present invention; [Figure 2] FIG. 2 is a perspective view showing the bottom side of the coil component shown in FIG. [Figure 3] FIG. 2 is a cross-sectional view of the coil component shown in FIG. [Figure 4] FIG. 2 is a top perspective view of the coil component shown in FIG. [Figure 5] 10 is a flowchart illustrating an example of a method for manufacturing a coil component. [Figure 6] FIG. 10 is a perspective view showing a modified example of a drum core mold. [Figure 7] FIG. 10 is a cross-sectional view showing a modified example of a drum core mold. [Figure 8] 10A and 10B are diagrams showing modified examples in which the number of external electrodes is different. [Figure 9] 10A and 10B are diagrams showing modified examples in which the shape of the insulating portion is different. [Figure 10] FIG. 10 is a diagram showing a modified example having a plurality of insulating portions. [Figure 11] FIG. 10 is a diagram showing a modified example having an R surface. [Figure 12] FIG. 2 is a partially enlarged view showing the R surface. [Figure 13] 10A and 10B are diagrams showing a modified example in which an insulating portion is in contact with an external electrode. [Figure 14] FIG. 10 is a diagram showing a modified example in which an insulating portion is also provided on the second ridge line. [Figure 15] FIG. 10 is a perspective view showing a modified example having external electrodes with two electrodes. [Figure 16] FIG. 10 is a cross-sectional view showing a modified example having external electrodes with two surfaces. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the present invention, and not all of the combinations of features described in the embodiments are necessarily essential to the configuration of the present invention. The configuration of the embodiments may be modified or changed as appropriate depending on the specifications of the device to which the present invention is applied and various conditions (such as usage conditions and usage environment).

[0016] The technical scope of the present invention is defined by the claims and is not limited by the individual embodiments described below. The drawings used in the following description may differ in scale and shape from the actual structure to make each configuration easier to understand. The correspondence between the drawings may also differ in some places to simplify the description. Components shown in previously described drawings may be referenced as appropriate in the description of subsequent drawings.

[0017] <One embodiment of the coil component> FIG. 1 is a perspective view showing a coil device 100 according to one embodiment of the present invention. The coil component 100 is mounted on a substrate 200. The substrate 200 is provided with, for example, two land portions 201. The coil component 100 has, for example, two external electrodes 12. The coil component 100 is mounted on the substrate 200 by joining each external electrode 12 and the land portion 201 with, for example, solder.

[0018] The circuit board 10 includes a coil component 100 and a substrate 200 on which the coil component 100 is mounted. The circuit board 10 is included in a variety of electronic devices. Examples of electronic devices that include the circuit board 10 include automotive electrical components, servers, board computers, and various other electronic devices.

[0019] In this specification, unless otherwise understood in the context, the directions will be described based on the "L axis" direction, the "W axis" direction, and the "H axis" direction in Figure 1, which will be referred to as the "length" direction, the "width" direction, and the "height" direction, respectively. The coil device 100 has, for example, a rectangular parallelepiped outer shape. That is, the coil device 100 has outer surfaces at both ends in the length direction L, both ends in the height direction H, and both ends in the width direction W.

[0020] The rectangular parallelepiped coil device 100 has sides with a length L dimension in the range of 1.0 to 4.5 mm, a width W dimension in the range of 0.5 to 3.2 mm, and a height H dimension in the range of 0.5 to 1.5 mm. The height H dimension is smaller than the length L dimension, and the height H dimension is smaller than the width W dimension.

[0021] The outer surfaces of the coil device 100 may be flat or curved. The eight corners and twelve ridges of the coil device 100 may be rounded. In this specification, even when the outer surface of the coil device 100 is partially curved or when the corners or ridges of the coil device 100 are rounded, such a shape may be referred to as a "rectangular parallelepiped shape." In other words, in this specification, when we refer to a "rectangular parallelepiped" or a "rectangular parallelepiped shape," it does not mean a "rectangular parallelepiped" in the strict mathematical sense.

[0022] <Coil component structure> Fig. 2 is a perspective view showing the bottom side of the coil device 100 shown in Fig. 1, Fig. 3 is a cross-sectional view of the coil device 100, and Fig. 4 is a top perspective view of the coil device 100. Fig. 3 shows a cross section taken along line AA shown in Fig. 1. The following description will be made with reference to Figs. 1 to 4.

[0023] The coil device 100 has a magnetic base 11 , an external electrode 12 and an insulating portion 13 , and has a conductor 14 inside the magnetic base 11 . The magnetic base 11 has, for example, a hexahedral shape, such as a rectangular parallelepiped shape. That is, the magnetic base 11 has a bottom surface 101 at one end in the height direction H and a top surface 102 at the other end in the height direction H. The magnetic base 11 also has side surfaces 103 at both ends in the length direction L. Furthermore, the magnetic base 11 has a front surface 104 at one end in the width direction W and a rear surface 105 at the other end in the width direction W.

[0024] The bottom surface 101 corresponds to an example of the "first surface" of the present invention, and the top surface 102 corresponds to an example of the "second surface" of the present invention. One side surface 103 corresponds to an example of the "third surface" of the present invention, and the front surface 104 corresponds to an example of the "fourth surface" of the present invention. The other side surface 103 corresponds to an example of the "fifth surface" of the present invention, and the rear surface 105 corresponds to an example of the "sixth surface" of the present invention. The top surface 102 and the bottom surface 101 are positioned back to back. "Back to back" means that the surfaces face outward in opposite directions. The top surface 102 is adjacent to the side surface 103, the front surface 104, and the rear surface 105, and the bottom surface 101 is adjacent to the side surface 103, the front surface 104, and the rear surface 105. "Adjacent" means that there is no other surface between the surfaces, but rather a ridge line between them. In the example shown here, the adjacent surfaces are positioned so that they intersect at right angles.

[0025] The magnetic base 11 has four ridgelines extending in the height direction H, four ridgelines surrounding the bottom surface 101, and four ridgelines surrounding the top surface 102. The ridgeline extending between one side surface 103 and the front surface 104 is the first ridgeline 31. The ridgeline extending between the bottom surface 101 and the front surface 104 is the second ridgeline 32. The ridgeline extending between the top surface 102 and the front surface 104 is the third ridgeline 33. The ridgeline extending between one side surface 103 and the bottom surface 101 is the fourth ridgeline 34.

[0026] The magnetic substrate 11 in this embodiment is a magnetic body formed from a metal magnetic material and a binder. The binder bonds the metal magnetic materials together and has high insulating properties to prevent electrical conduction. The binder is used to bond the magnetic substrate 11 to a specific resistance of 10 6 For example, a binder with a specific resistance of 10 8 For the purpose of increasing the mechanical strength, resin, glass, or metal oxide can be selected as the binder. 5 A resistance of Ω / sq. or more may be used.

[0027] Since the metal magnetic material, whose main component is Fe, itself has low resistance, it is desirable to adjust the components and mixing ratio of the binder to match the metal magnetic material. 8 A material having a resistivity of Ωcm or more is selected, and in order to enhance the insulating properties, a resin is included as a binder, and glass or metal oxide can be selected as a component other than resin.

[0028] The magnetic substrate 11 has a very high internal resistivity, as well as a surface that also contains a binder. The metal magnetic material is metal magnetic particles containing one or more of Fe, Ni, and Co. In addition to the metal magnetic particles, the metal magnetic material may also contain ceramic magnetic particles of one or more of Mg, Mn, and Ni, or non-magnetic particles such as silica. The metal magnetic particles may contain one or more of Si, Cr, Al, B, and P in addition to Fe, Ni, and Co, or multiple types of metal magnetic particles may be combined.

[0029] The particle size of the metal magnetic material is 1 μm or more and 60 μm or less. Furthermore, when the metal magnetic material further contains other materials in addition to the metal magnetic particles, such as metal fine particles, metal oxides, or ceramic materials, the particle size of these other materials is on average 0.01 to 1 μm, which is smaller than that of the metal magnetic particles. When materials other than metal magnetic particles are contained, the purpose is to, for example, reduce voids or compensate for mechanical strength rather than to enhance magnetic function.

[0030] The magnetic substrate 11 has a filling rate of the metal magnetic material of 80 vol % or more and 88 vol % or less, with the remainder being other than the metal magnetic material, including an insulator or voids. The conductor 14 is made of a metal material with excellent conductivity. Examples of the metal material for the conductor 14 include one or more of Cu, Al, Ni, and Ag, or an alloy containing any of these metals. The conductor 14 may be a wound metal wire with an insulating film on its surface, or may be formed on the surface of a substrate, sheet, or the like by plating or printing.

[0031] The conductor 14 of this embodiment has a winding portion that is wound one or more times. FIGS. 3 and 4 show the winding portion of the conductor 14. The number of turns of the winding portion is, for example, 1.5 turns or more and 10.5 turns or less. The shape of the winding portion may be planar or spiral. The winding portion may have, for example, two turns facing each other on the upper and lower sides to form a single assembly. FIGS. 3 and 4 show an example of a so-called horizontally wound winding portion in which the conductor wire is wound along the bottom surface 101 and the top surface 102 of the magnetic base 11.

[0032] The conductor 14 has an extension portion (not shown) for electrical conduction with the outside. The extension portion connects the external electrode 12 to the conductor 14. Therefore, the external electrode 12 is electrically coupled to the conductor 14. The conductor 14 can be manufactured by any of the processes of winding, thin film, and lamination, and there are no particular limitations on the method.

[0033] The coil device 100 includes, as an example, two external electrodes 12. The external electrodes 12 shown in FIGS. 1 to 4 are of a type known as single-surface electrodes, and are provided, for example, on the bottom surface 101 of the magnetic base 11. The external electrodes 12 include a metal layer 21 having a thickness of, for example, 10 to 25 μm, and a plating layer 22 covering the metal layer 21 and having a thickness of, for example, 2 to 15 μm. The external electrodes 12 may include multiple metal layers 21, or may include a metal layer 21 that contains resin in part. The total thickness of the external electrodes 12 is, for example, 10 to 40 μm. The external electrodes 12 may include an underlayer between the metal layer 21 and the magnetic base 11.

[0034] The external electrode 12 is made up of one or both of a layer made of the same component as the conductor 14 and a layer made of a component having a higher resistance than the conductor 14. The external electrode 12 is also made up of one or both of a layer having the same filling rate as the conductor 14 and a layer having a lower filling rate than the conductor 14. The metal layer 21 is made of a metal material with excellent conductivity. Examples of metal materials that can be used include Cu and Ag, and alternatively, Ni, Pd, and Sn. The metal layer 21 is formed in a layered structure, with layers made primarily of each metal material or layers made partially of alloys overlapping each other.

[0035] The plating layer 22 is provided to increase the strength of soldering to the external electrode 12. For example, the plating layer 22 is made up of two layers, an upper layer and a lower layer, and the lower layer that contacts the metal layer 21 is made of, for example, Ni, and the upper layer that forms the surface of the external electrode 12 is made of, for example, Sn. The ridge lines 31, 32, 33, and 34 of the magnetic base 11 tend to have lower resistance and higher electric field strength than other parts. For this reason, when the plating layer 22 is formed on the bottom surface 101, the plating may extend along the first ridge line 31 and the second ridge line 32. In particular, if the plating extends to the first ridge line 31, it may affect adjacent electronic components and hinder high-density mounting.

[0036] The insulating portion 13 is embedded in the magnetic base 11 with a portion of it exposed at the first ridge line 31, and prevents the plating from spreading to the first ridge line 31. The insulating portion 13 is provided at a position closer to the bottom surface 101 on which the external electrode 12 is provided, in the direction along the first ridge line 31. In other words, the distance from the insulating portion 13 to the bottom surface 101 is shorter than the distance from the insulating portion 13 to the top surface 102. The insulating portion 13 divides the first ridge line 31 into the bottom surface 101 side and the top surface 102 at the above-mentioned position. The insulating portion 13 is provided at the first ridge line 31 on the same plane as the outer surface of the magnetic base 11 or recessed inward from the outer surface so as not to affect the outer dimensions of the coil device 100. The same applies when the insulating portion 13 extends to the side surface 103, the front surface 104, or the rear surface 105.

[0037] As an example, the insulating portion 13 spreads in layers in a direction intersecting with the first ridge line 31 extending in the height direction H. The insulating portion 13 may be provided in a continuous layer within the triangular range shown in Fig. 4, or may be provided in multiple separate layers within that range, or may be provided scattered within that range.

[0038] The layered insulating portion 13 is desirable because it can be easily produced by lamination and its volume proportion is suppressed. The insulating portion 13 can stop the spread of plating even if its thickness is 5 μm or less. Insulating portion 13 is preferably provided at a position separated from conductor 14 to avoid a location through which magnetic flux generated by conductor 14 passes. As shown in Fig. 3, it is more preferable to provide insulating portion 13 at a position where it does not overlap conductor 14 when viewed in a direction along bottom surface 101, and it is even more preferable to provide insulating portion 13 at a position where it does not overlap conductor 14 when viewed in a direction perpendicular to bottom surface 101, as shown in Fig. 4. When viewed in a cross section intersecting with the first ridge line 31, the proportion of the insulating portion 13 is less than 10% of the area determined from the outer shape of the magnetic base 11. When viewed in a cross section parallel to the first ridge line 31, the proportion of the insulating portion 13 is less than 10% of the length of the first ridge line. In this way, the insulating portion 13 has little effect on the magnetic base 11 both on the surface and inside thereof, and does not cause a decrease in magnetic performance.

[0039] The resistivity of the insulating portion 13 is 10 times or more the resistivity of the magnetic base 11. For example, when the resistivity of the magnetic base 11 is 10 6 Ωcm, the insulating part 13 has a specific resistance of 10 7 The insulating portion 13 is provided to have a resistivity of Ωcm or more. Furthermore, the insulating portion 13 may have a resistivity 100 times or more that of the magnetic base 11. Since the insulating portion 13 has a higher resistivity than the magnetic base 11, the area where the insulating portion 13 is provided becomes smaller. In this way, a material with high resistivity is used for the insulating portion 13, and it may be a non-magnetic material. Specifically, resin, glass, metal oxide, etc. are used as the material for the insulating portion 13. The material for the insulating portion 13 is selected to match the binder of the magnetic base 11.

[0040] The resin may be a phenolic or epoxy thermosetting resin with a glass transition point of 150°C or higher. The glass may be a low-temperature fired LTCC material with a glass transition point of 750°C or lower. The metal oxide may be ceramic particles such as silica, alumina, or zirconia, or a composite material in which ceramic particles are bonded. Even when insulating portion 13 contains a magnetic material, the magnetic material is not continuously exposed on the surface of insulating portion 13. For example, the volume ratio of the magnetic material in insulating portion 13 is 10 vol % or less.

[0041] The insulating part 13 is formed of an insulating material having the same components as the binder of the magnetic base 11, or an insulating material having at least one of strength and hardness greater than that of the binder. For example, if the binder of the magnetic base 11 is a resin, the insulating material of the insulating part 13 may be an oxide. Also, for example, if the binder of the magnetic base 11 is an oxide, the insulating material of the insulating part 13 may be glass.

[0042] <Manufacturing method for coil components> FIG. 5 is a flowchart showing an example of a method for manufacturing a coil component. In step S101, a plurality of magnetic sheets made of a composite magnetic material containing the above-mentioned metal magnetic material and a binder are prepared, and a planar conductor pattern for forming the conductors 14 is created on the surface of the magnetic sheet by, for example, printing. The conductor pattern may be formed by a method other than printing, such as plating, vapor deposition, or paste transfer.

[0043] Also, on the surface of some of the magnetic sheets, an insulating layer having a shape as shown in FIG. 4 is formed in the areas that will become the insulating portions 13 by printing or transferring an insulating paste containing a glass material. To form connection conductors that interconnect the conductor patterns and lead conductors that connect the conductor patterns to the external electrodes 12, through holes are drilled in the magnetic sheet and filled with a conductive material. The through holes are drilled in positions that avoid the insulating layer. The connection conductors and lead conductors are formed by, for example, printing, filling, plating, vapor deposition, transfer, etc.

[0044] In step S102, the magnetic sheet and the magnetic sheet on which the conductor pattern, lead conductor, and insulating layer are formed are stacked and pressed together to obtain a laminate. This laminate corresponds to an assembly of multiple components. An electrode pattern corresponding to the metal layer 21 of the external electrode 12 is formed on the laminate by printing, plating, vapor deposition, transfer, etc.

[0045] In step S103, the laminate is cut into individual pieces to obtain molded bodies corresponding to the individual parts. In step S101, the insulating layer corresponding to the insulating portion 13 is formed in a pattern spanning multiple parts. Then, by cutting the laminate in step S103, the edge portions where the insulating layer has been cut are exposed on the cut surfaces and ridges of the individual molded bodies.

[0046] In step S104, the individual compacts are hardened by heat treatment, which may be performed at a temperature of 200°C or less, or may be performed by sintering at a temperature of 600°C or more, or 1100°C or more, depending on the raw materials used. In step S105, the hardened molded body is plated to form the plating layer 22 of the external electrode 12. The plating film is formed on the electrode pattern corresponding to the metal layer 21, and the extension of the plating along the ridges of the molded body is suppressed by the insulating layer exposed at the ridges of the molded body. Therefore, the plating film is stably formed in the desired locations corresponding to the plating layer 22. The coil component 100 is completed by the plating in step S105.

[0047] While Fig. 5 shows a lamination-type manufacturing method as an example of a manufacturing method for the coil component 100, the coil component 100 may also be manufactured by, for example, a powder compaction method. In a manufacturing method for the coil component 100 using the powder compaction method, an insulating member corresponding to the insulating portion 13 and a conductive member corresponding to the conductor 14 are prepared. Then, when a slurry containing a metal magnetic material and a bonding material is filled into a mold, the insulating member and the conductive member are positioned at desired positions within the mold. The materials within the mold are integrated by pressure, resulting in a compact in which the magnetic material, insulating member, and conductive member are bonded together.

[0048] The compact is subjected to, for example, surface polishing to expose the end faces of the insulating members and the ends of the conductor members. Then, the external electrodes 12 are formed to complete the coil component 100. Even in the case of the powder pressing method, the insulating members suppress the spread of the plating when the external electrodes 12 are plated, so the plating layer 22 is stably formed in the desired location.

[0049] Here, the "target location" refers to a location that is assumed in the design as the location of the plating layer 22 on the external electrode 12. In particular, it is desirable that the plating is contained within the plane of, for example, the bottom surface 101 where the external electrode 12 is provided, or that the plating does not extend beyond the plane. Next, it is desirable that the plating is contained within the design range within the plane of, for example, the bottom surface 101 where the external electrode 12 is provided, or that the plating does not extend beyond the design range.

[0050] <Modification> Modified examples of the coil component will be described. In the following, duplicated explanations of elements that are the same as elements that have already been explained will be omitted.

[0051] 6 and 7 are diagrams showing modified examples of the drum core type coil device 300. Fig. 6 is a perspective view showing the bottom side of the coil device 300, and Fig. 7 is a cross-sectional view taken along line BB in Fig. 6. Coil device 300 of the modified example includes a drum-core type magnetic base 310. Magnetic base 310 has two flanges 311 and a winding core 312 connecting flanges 311. Flanges 311 of magnetic base 310 have bottom surface 101, top surface 102, side surfaces 103, front surface 104, and rear surface 105, and flanges 311 also have first ridge line 31.

[0052] In coil device 300 of the modified example, conductor 14 is wound around the outer periphery of winding core 312, and conductor 14 is formed, for example, by winding a conductive wire around winding core 312. In the example shown in FIG. 7 , conductor 14 is wound vertically so as to wind around side surface 103. The coil device 300 of this modified example includes an exterior part 320 made of, for example, resin. The exterior part 320 covers the outer periphery of the conductor 14 to protect the conductor 14.

[0053] In the modified coil component 300, the insulating portion 13 is also provided at the first ridge line 31, so that the plating on the external electrode 12 is prevented from spreading, and the plating on the external electrode 12 is stably formed at the desired location.

[0054] FIG. 8 shows modified examples in which the number of external electrodes is different. A modified coil component 400 shown in Fig. 8 includes, for example, three pairs, or a total of six, external electrodes 12. In the coil component 400 shown in Fig. 8, insulating portions 13 are also provided at the first ridge lines 31, so that spreading of the plating on the external electrodes 12 is suppressed, and the plating on the external electrodes 12 is stably formed at the target locations.

[0055] FIG. 9 shows a modified example in which the insulating portion has a different shape. Fig. 9 shows a top perspective view corresponding to Fig. 4. In a modified coil device 500 shown in Fig. 9, insulating portion 13 extends along side surface 103 and is exposed at first ridge line 31 and other ridge lines. By extending insulating portion 13 in this manner, insulating portion 13 becomes larger, increasing its strength and facilitating manufacture.

[0056] FIG. 10 is a diagram showing a modified example having a plurality of insulating portions. FIG. 10 shows a cross-sectional view corresponding to FIG. A coil device 600 of a modified example shown in Fig. 10 has a plurality of insulating portions 13 at the location of the first ridge line 31. Each of the plurality of insulating portions 13 spreads in a layered manner in a direction intersecting with the first ridge line 31. The plurality of insulating portions 13 are also aligned in the direction in which the first ridge line 31 extends, and are spaced apart from one another in the direction in which the first ridge line 31 extends. By providing a plurality of insulating portions 13, the spread of the plating on the external electrode 12 is reliably prevented.

[0057] FIG. 11 is a diagram showing a modified example having a rounded surface. 11, the ridges of the magnetic base 11 are rounded. That is, the magnetic base 11 has four ridges extending in the height direction H, four ridges surrounding the bottom surface 101, and four ridges surrounding the top surface 102. However, the magnetic base 11 may have some ridges that are not rounded. The ridge portion extending between one side surface 103 and the front surface 104 is the first ridge portion 710. The ridge portion extending between the bottom surface 101 and the front surface 104 is the second ridge portion 720. The ridge portion extending between the top surface 102 and the front surface 104 is the third ridge portion 730. The ridge portion extending between one side surface 103 and the bottom surface 101 is the fourth ridge portion 740.

[0058] The radius of curvature of the rounded surfaces of the ridge portions 710, 720, 730, and 740 is, for example, 20 μm or more and 100 μm or less. By rounding the ridge portions 710, 720, 730, and 740, chipping of the corners of the magnetic base 11 is suppressed, and spreading of the plating due to current concentration on the sharp ridges is also suppressed.

[0059] 11 includes insulating portion 13 at first ridge portion 710, and a portion of insulating portion 13 is exposed at first ridge portion 710. The presence of insulating portion 13, coupled with the fact that first ridge portion 710 has an R-surface, strongly suppresses the spread of plating along first ridge portion 710.

[0060] 11, the insulating portion 13 is provided at a location on the rounded surface adjacent to the second ridge portion 720. This prevents the plating of the external electrode 12 from extending beyond the rounded surface of the second ridge portion 720 toward the first ridge portion 710. The insulating portion 13 is exposed on the ridge line where there is no rounded surface, or is exposed within the range of the ridge line portion of the rounded surface, thereby suppressing the spread of the plating, and these are collectively referred to as "exposed on the ridge line portion." Here, the range of the ridge line portion will be explained.

[0061] FIG. 12 is a partial enlarged view showing the R surface. The range of the ridge line portions is common to the ridge line portions 710, 720, 730, and 740 of the magnetic base 11, and FIG. 12 shows the second ridge line portion 720 as a representative of the ridge line portions 710, 720, 730, and 740.

[0062] The range of ridge portion 720 is the range of an R surface with a radius of curvature R1. The radius of curvature R1 is calculated from the distance D1 between ridge portion 720 and an imaginary ridge line 721, where the extensions of bottom surface 101 and side surface 103 intersect, by R1 = (√2 + 1)D1. A boundary 722 of the range of ridge portion 720 is located at a distance of radius of curvature R1 from imaginary ridge line 721.

[0063] 11 may be provided, for example, at a location that contacts the boundary 722 of the second ridge line portion 720, or may be provided at a location that straddles the boundary 722. In either case, the insulating portion 13 is adjacent to the rounded surface of the second ridge line portion 720.

[0064] FIG. 13 is a diagram showing a modified example in which the insulating portion is in contact with the external electrode. 13, magnetic base 11 also has ridge portions 710, 720, 730, and 740 on the R-plane. Insulating portion 13 is provided at the end of first ridge portion 710 in contact with external electrode 12. From another perspective, insulating portion 13 is provided at a location overlapping with second ridge portion 720 on the R-plane.

[0065] By providing the insulating portion 13 at the location in contact with the external electrode 12, the spread of plating on the external electrode 12 is further suppressed.

[0066] FIG. 14 is a diagram showing a modified example in which an insulating portion is also provided on the second edge line. 1 to 4, the coil device 900 of the modified example shown in Fig. 14 includes a first insulating portion 13 at the location of the first ridge line 31. Furthermore, the coil device 900 shown in Fig. 14 includes a second insulating portion 910 at the location of the second ridge line 32. That is, the second insulating portion 910 is embedded in the magnetic base 11 with a portion of the second insulating portion 910 exposed at the location of the second ridge line 32. By providing the second insulating portion 910, the plating of the external electrodes 12 is prevented from spreading along the second ridge lines 32, and the external electrodes 12 are prevented from coming close to or coming into contact with each other.

[0067] 15 and 16 are diagrams showing modified examples having external electrodes with two surfaces, Fig. 15 is a perspective view showing the bottom side of the coil component, and Fig. 16 is a cross-sectional view showing a cross section taken along line CC in Fig. 15. 15 and 16 includes an external electrode 1010 of a type called a two-surface electrode. That is, the external electrode 1010 straddles two surfaces, the bottom surface 101 and the side surface 103, and has a bottom surface portion 1011 located on the bottom surface 101 and a side surface portion 1012 located on the side surface 103. Alternatively, the external electrode 1010 may span three surfaces, the bottom surface 101, the side surface 103, and the front surface 104, and have a bottom surface portion 1011 located on the bottom surface 101, a side surface portion 1012 located on the side surface 103, and a front surface portion 1013 located on the front surface 104. The first insulating portion 13 is in contact with a part of the external electrode 1010 at least on the first ridge line, the side surface 103, or the front surface 104.

[0068] 15 and 16 includes a plurality of insulating portions 13 at the first ridge line 31. In the case of an external electrode 1010 that is a two-surface electrode having side portions 1012, suppression of plating extension along the first ridge line 31 is strongly required, and therefore the plurality of insulating portions 13 strongly suppresses plating extension.

[0069] 15 and 16, at least one of the insulating portions 13 arranged along the first ridge line 31 is provided in contact with the external electrode 1010. In Fig. 16, the shape of the side surface portion 1012 of the external electrode 1010 in a cross section passing through the center of the side surface 103 is shown by a solid line, and the shape of the end portion near the first ridge line 31, away from the cross section, is shown by a dotted line. In other words, the end portion of the side surface portion 1012 protrudes toward the upper surface 102, and the insulating portion 13 is in contact with the end portion of the side surface portion 1012. Since the first insulating portion 13 is provided in contact with the external electrode 1010, the spread of the plating on the external electrode 1010 is stopped in the vicinity of the external electrode 1010. Therefore, the plating is also stably formed at the desired location on the side surface portion 1012 located on the side surface 103. [Explanation of symbols]

[0070] 10 Circuit Board 11 Magnetic substrate 12 External electrode 13 First insulating section 14 Conductors 21 Metal layer 22 plating layer 31, 32, 33, 34 Ridgeline 100, 300, 400, 500, 600, 700, 800, 900, 1000 Coil parts 101 bottom 102 Top surface 103 Side 104 Front 105 Rear 200 boards 201 Land Club 310 Magnetic substrate 311 flange 312 Core 320 Exterior part 710, 720, 730, 740 Ridge line part 721 Virtual Ridge 722 Boundary 910 Second insulation section 1010 External electrode with two electrodes 1011 Bottom part 1012 Side part 1013 Front part

Claims

1. a magnetic substrate containing metal magnetic particles, the magnetic substrate having as outer surfaces a first surface and a second surface facing each other, a third surface adjacent to both the first surface and the second surface, and a fourth surface adjacent to the first surface, the second surface, and the third surface, and the magnetic substrate having a first ridge portion extending between the third surface and the fourth surface; a conductor provided inside or on the surface of the magnetic substrate; an external electrode provided on a first surface of the magnetic substrate and electrically connected to the conductor, the external electrode having a plating layer; a first insulating portion that is partially exposed at a location of the first ridge line portion closer to the first surface and is embedded in the magnetic base; A coil component comprising:

2. The coil component according to claim 1 , wherein a plurality of the first insulating portions are provided at intervals in the direction in which the first ridge portion extends.

3. The coil component according to claim 1 , wherein the first ridge portion of the magnetic substrate has a rounded surface.

4. The coil component according to claim 1 , wherein the first insulating portion extends in a layered manner in a direction intersecting with the first ridge portion.

5. a second ridge portion of the magnetic substrate extending between the first surface and at least one of the third surface and the fourth surface is an R-surface, The coil component according to claim 1 , wherein the first insulating portion is provided at a location adjacent to or overlapping with the rounded surface.

6. the external electrode is allowed to extend from the first surface to at least one of the third surface and the fourth surface; The coil component according to claim 1 , wherein the first insulating portion is provided at a location on at least one of the first ridge portion, the third surface, and the fourth surface that is in contact with the external electrode.

7. The coil component according to claim 1 , wherein the first insulating portion is spaced apart from the conductor.

8. 2. The coil component according to claim 1, further comprising a second insulating portion embedded in the magnetic base and partially exposed at a second ridge portion of the magnetic base extending between the first surface and at least one of the third surface and the fourth surface.

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