Coil component

Abstract

The present application provides a coil component capable of suppressing migration of metal atoms constituting a coil conductor, which includes: a laminate (10) including a plurality of metal magnetic particles (31); and a coil conductor (25) disposed in the laminate (10) in contact with the laminate (10) and wound around a coil axis (A), the laminate (10) having an insulating portion (30) including a non-metal magnetic particle region (R2) defined by at least three metal magnetic particles (31) in a cross section of the laminate (10), in the insulating portion (30), the atomic proportion of Si is the highest among materials other than oxygen constituting the non-metal magnetic particle region (R2).

Description

Technical Field

[0001] The disclosure in this specification relates to a coil component. Background Technology

[0002] Existing coil components such as inductors typically include: a magnetic matrix made of a magnetic material; a coil conductor disposed within the magnetic matrix and wound around a coil axis; and external electrodes connected to the ends of the coil conductor. As a material for the magnetic matrix, metallic magnetic materials composed of metallic magnetic particles are known. Generally, metallic magnetic materials have a higher saturation magnetic flux density than ferrite materials, and are therefore suitable as materials for the magnetic matrix of coil components used to supply large current flows. For example, a coil component using such a metallic magnetic material is disclosed in Patent Document 1.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2018-121023 Summary of the Invention

[0006] The technical problem that the invention aims to solve

[0007] In magnetic matrices made of metallic magnetic materials, the saturation magnetic flux density is higher than that in magnetic matrices made of ferrite materials, but the insulation is reduced. Furthermore, due to heat treatment during the manufacturing process of the coil components, migration of metal atoms constituting the conductor occurs, and sometimes these metal atoms diffuse into the magnetic matrix. This migration of metal atoms from the coil conductor is a major cause of further reduction in the insulation of magnetic matrices made of metallic magnetic materials.

[0008] One object of the present invention is to provide a coil component capable of suppressing the migration of metal atoms constituting the coil conductor. Other objects of the present invention will be explained by way of the description in its entirety.

[0009] Technical solutions for solving technical problems

[0010] One embodiment of the coil component of the present invention includes: a substrate comprising a plurality of metallic magnetic particles; and a coil conductor disposed within the substrate in contact with the substrate. The substrate has an insulating portion comprising a non-metallic magnetic particle region defined by at least three metallic magnetic particles in a cross-section of the substrate. In the insulating portion, the atomic proportion of Si is highest among the materials other than oxygen constituting the non-metallic magnetic particle region. In one embodiment of the present invention, the coil conductor is wound around a coil axis.

[0011] In one embodiment of the present invention, the atomic proportion of Si in the material other than oxygen in the non-metallic magnetic particle region may be highest at the geometric center of the non-metallic magnetic particle region as observed from a cross-section along the coil axis. In another embodiment of the present invention, the atomic proportion of Si in the material other than oxygen in the non-metallic magnetic particle region may be highest at the geometric center of the non-metallic magnetic particle region in a cross-section obtained by cutting the substrate with a plane passing through the coil conductor.

[0012] In one embodiment of the present invention, the surface of each metallic magnetic particle may be covered by a Si-containing capping layer, and the composition of the capping layer material is different from the composition of the material of the non-metallic magnetic particle region at the geometric center.

[0013] In one embodiment of the present invention, the metallic magnetic particles may also be bonded to each other via a covering layer.

[0014] In one embodiment of the present invention, the atomic proportion of Si in the non-metallic magnetic particle region may be more than 50 at% and less than 95 at%.

[0015] In one embodiment of the present invention, the non-metallic magnetic particle region may also contain Fe, Cr and / or Al.

[0016] In one embodiment of the present invention, the metallic magnetic particles may also be an alloy containing Fe, Si, Cr or Al.

[0017] In one embodiment of the present invention, the coil conductor may include a first conductor pattern and a second conductor pattern that extend along a plane orthogonal to the coil axis and are spaced apart from each other in the direction of the coil axis, with an insulating portion disposed between the first conductor pattern and the second conductor pattern.

[0018] In one embodiment of the present invention, the coil component may also include an external electrode, which is disposed on the surface of the substrate and electrically connected to the coil conductor, and an insulating portion is disposed between the coil conductor and the external electrode.

[0019] In one embodiment of the present invention, the coil conductor may be disposed inside the insulating portion.

[0020] In one embodiment of the present invention, the entire substrate may be an insulating part.

[0021] In one embodiment of the present invention, the insulating portion may also be formed by heat treatment of a metal magnetic paste containing metal magnetic particles and silicone resin.

[0022] One embodiment of the present invention relates to a circuit board that includes any of the above-described electronic components. Another embodiment of the present invention relates to an electronic device that includes the above-described circuit board.

[0023] Invention Effects

[0024] According to the present invention, a coil component capable of suppressing the migration of metal atoms constituting a coil conductor is provided. Attached Figure Description

[0025] Figure 1 This is a perspective view of a coil component according to an embodiment of the present invention.

[0026] Figure 2 yes Figure 1 An exploded perspective view of the coil component.

[0027] Figure 3 It is a schematic representation of along Figure 1 A cross-sectional view of the coil component of line II.

[0028] Figure 4 It is a schematic representation Figure 3 An enlarged cross-sectional view of a portion of the insulation part.

[0029] Figure 5 This is a schematic cross-sectional view of a coil component according to another embodiment of the present invention.

[0030] Figure 6 This is a schematic cross-sectional view of a coil component according to another embodiment of the present invention.

[0031] Figure 7 This is a schematic cross-sectional view of a coil component according to another embodiment of the present invention.

[0032] Figure 8 This is a schematic cross-sectional view of a coil component according to another embodiment of the present invention.

[0033] Figure 9 This is a perspective view of a coil component according to another embodiment of the present invention.

[0034] Figure 10 It is a schematic representation of along Figure 9 A cross-sectional view of the coil component of the II-II line.

[0035] Figure 11 It is a schematic representation Figure 10 A diagram showing an example of a deformed coil conductor.

[0036] Explanation of reference numerals in the attached figures

[0037] 1, 100, 200, 300, 400, 500... Coil components, 10... Laminated body (substrate), 21, 22... External electrodes, 25, 125... Coil conductors, 30... Insulation, 31... Metallic magnetic particles, 32... Covering layer, A... Coil axis, C11~C16... Conductor pattern, R1... Metallic magnetic particle area, R2... Non-metallic magnetic particle area. Detailed Implementation

[0038] Various embodiments of the present invention will now be described with appropriate reference to the accompanying drawings. Furthermore, common components in the multiple drawings are labeled with the same reference numerals in those drawings. It should be noted that, for ease of explanation, the drawings are not necessarily depicted at an exact scale.

[0039] Figure 1 This is a perspective view of the coil component 1 according to an embodiment of the present invention. Figure 2 yes Figure 1 An exploded perspective view of coil component 1. Figure 1 and Figure 2 In the diagram, a multilayer inductor, used as a passive component in various circuits, is shown as an example of coil component 1. The multilayer inductor is an example of a multilayer coil component to which the present invention can be applied. In addition to multilayer inductors, the present invention is also applicable to coil components manufactured by compression molding or thin-film molding, for example. The present invention can be applied to power inductors assembled into power lines and various other coil components.

[0040] The coil component 1 in the illustrated embodiment includes: a laminate (substrate) 10 containing a plurality of metallic magnetic particles; a coil conductor 25 disposed inside the laminate 10 and wound around a coil axis A; an external electrode 21 electrically connected to one end of the coil conductor 25; and an external electrode 22 electrically connected to the other end of the coil conductor 25. The laminate 10 is constructed by stacking layers of magnetic bodies formed of magnetic material. The coil conductor 25 has a plurality of conductor patterns C11 to C16. The plurality of conductor patterns C11 to C16 extend along a plane direction orthogonal to the coil axis A and are spaced apart from each other in the direction of the coil axis A. Each conductor pattern C11 to C16 is electrically connected to an adjacent conductor pattern via vias V1 to V5, described later. In this way, the coil conductor 25 is composed of conductor patterns C11 to C16 and vias V1 to V5. Conductor pattern C11 is electrically connected to the external electrode 21, and conductor C16 is electrically connected to the external electrode 22.

[0041] As shown in the figure, in one embodiment of the present invention, the laminate 10 is formed, for example, in a cuboid shape. The laminate 10 has a first main surface 10e, a second main surface 10f, a first end surface 10a, a second end surface 10c, a first side surface 10b, and a second side surface 10d. The laminate 10 is defined by these six surfaces on its outer surface. The first main surface 10e and the second main surface 10f are opposite to each other, the first end surface 10a and the second end surface 10c are opposite to each other, and the first side surface 10b and the second side surface 10d are opposite to each other. When the laminate 10 is formed into a cuboid shape, the first main surface 10e is parallel to the second main surface 10f, the first end surface 10a is parallel to the second end surface 10c, and the first side surface 10b is parallel to the second side surface 10d.

[0042] exist Figure 1 In the embodiment, the first main surface 10e is located on the upper side of the laminate 10; therefore, in this specification, the first main surface 10e is sometimes referred to as the "upper surface." Similarly, the second main surface 10f is sometimes referred to as the "lower surface." The coil component 1 is arranged with the second main surface 10f opposite to the circuit board (not shown); therefore, in this specification, the second main surface 10f is sometimes referred to as the "mounting surface." Furthermore, when referring to the vertical direction of the coil component 1, the term "mounting surface" is used... Figure 1 The vertical direction is used as the reference.

[0043] In this specification, unless otherwise understood in the context, the "length" direction, "width" direction, and "thickness" direction of coil component 1 are respectively set as Figure 1 The L-axis, W-axis, and T-axis are orthogonal to each other. The coil axis A extends along the T-axis. The direction of the surface extending, encompassing the W and L directions, is equivalent to a planar direction.

[0044] In one embodiment of the present invention, the coil component 1 is formed with a length dimension (dimension in the L-axis direction) of 0.2 to 6.0 mm, a width dimension (dimension in the W-axis direction) of 0.1 to 4.5 mm, and a thickness dimension (dimension in the T-axis direction) of 0.1 to 4.0 mm. These dimensions are merely examples, and the coil component 1 to which the present invention is applied can be of any size as long as it does not depart from the spirit of the present invention. In one embodiment, the coil component 1 is formed with a low height. For example, the coil component 1 is formed with its width dimension being larger than its thickness dimension.

[0045] Figure 2 yes Figure 1 An exploded perspective view of coil component 1. Figure 2 For ease of illustration, external electrodes 21 and 22 are omitted. Figure 2As shown, the laminate 10 includes: a main body 20; an upper cover layer 18 disposed on the upper surface of the main body 20; and a lower cover layer 19 disposed on the lower surface of the main body 20. The main body 20 includes the laminated magnetic layers 11 to 16. Figure 2 The upper cover layer 18, magnetic body layer 11, magnetic body layer 12, magnetic body layer 13, magnetic body layer 14, magnetic body layer 15, magnetic body layer 16, magnetic body layer 17, and lower cover layer 19 are stacked sequentially from top to bottom.

[0046] The upper cover layer 18 comprises four magnetic layers 18a to 18d. In this upper cover layer 18, from... Figure 2 The magnetic layers 18a, 18b, 18c, and 18d are stacked sequentially above and below the surface.

[0047] The lower cover layer 19 comprises four magnetic layers 19a to 19d. In this lower cover layer 19, from... Figure 2 The magnetic layers 19a, 19b, 19c, and 19d are stacked sequentially from top to bottom.

[0048] The magnetic layers 11-16 constituting the main body 20, the magnetic layers 18a-18d constituting the upper cover layer 18, and the magnetic layers 19a-19d constituting the lower cover layer 19 contain metallic magnetic particles and an insulating resin material. The metallic magnetic particles applicable to this invention are materials that exhibit magnetism in their unoxidized metal portions, such as particles containing unoxidized metal particles or alloy particles. Magnetic particles applicable to this invention may, for example, contain at least one of Fe, Al, and Mn as an alloy component. Materials applicable to the magnetic particles of this invention may, for example, be alloy-based Fe-Si-Cr-Al, Fe-Si-Cr-Mn, Fe-Si-Al, Fe-Si-Mn, or Fe-Ni, amorphous Fe-Si-Cr-BC, or Fe-Si-B-Cr, Fe, or mixtures thereof. The resin material contained in each magnetic layer will be described later.

[0049] In addition to magnetic layers 11 to 16, 18a to 18d, and 19a to 19d, coil component 1 may include any number of magnetic layers as needed. A portion of magnetic layers 11 to 16, 18a to 18d, and 19a to 19d may be omitted appropriately.

[0050] Corresponding conductor patterns C11 to C16 are embedded in each of the magnetic layers 11 to 16. Before the magnetic layers 11 to 16 are stacked, the upper surfaces of the conductor patterns C11 to C16 are exposed from the upper surfaces of the magnetic layers 11 to 16. Each conductor pattern C11 to C16 is formed in a manner extending around the coil axis A. In the illustrated embodiment, the coil axis A extends in the T-axis direction, consistent with the stacking direction of the magnetic layers 11 to 16.

[0051] Through holes V1 to V5 are formed at predetermined positions in magnetic layers 11 to 15. Through holes V1 to V5 are formed by forming through holes in magnetic layers 11 to 15 in the T-axis direction at predetermined positions in magnetic layers 11 to 15, and embedding metal material in the through holes.

[0052] The conductor patterns C11 to C16 and the through holes V1 to V5 are formed in a manner that includes a metal with excellent conductivity, such as Ag, Pd, Cu, Al or alloys thereof.

[0053] In one embodiment, external electrode 21 is disposed on the first end face 10a of the laminate 10, and external electrode 22 is disposed on the second end face 10c of the laminate 10. As shown, external electrode 21 and external electrode 22 may also extend to the upper surface 10e, lower surface 10f, first side surface 10b, and second side surface 10d of the laminate 10. In this case, external electrode 21 is disposed such that it covers the entire first end face 10a of the laminate 10 and a portion of each of the upper surface 10e, lower surface 10f, first side surface 10b, and second side surface 10d, and external electrode 22 is disposed such that it covers the entire second end face 10c of the laminate 10 and a portion of each of the upper surface 10e, lower surface 10f, first side surface 10b, and second side surface 10d. The shapes of external electrode 21 and external electrode 22 are not particularly limited and can be appropriately changed. For example, external electrode 21 may be an L-shape covering a portion of each of the first end face 10a and lower surface 10f, or it may be a plate shape covering a portion of the lower surface 10f. Similarly, the external electrode 22 can also be an L-shaped object covering a portion of the second end face 10c and the lower surface 10f, or it can be a plate-shaped object covering a portion of the lower surface 10f.

[0054] Below, refer to Figure 3 and Figure 4 The laminate 10 of the coil component 1 will be described in more detail. Figure 3 It is a schematic representation of along Figure 1 A cross-sectional view of coil component 1 of line II. Figure 3 In the figure, the magnetic layers contained in the laminate 10 are partially omitted. Figure 4 It is a schematic representation Figure 3An enlarged cross-sectional view of a portion of the insulation part 30.

[0055] In one or more embodiments of the present invention, the laminate 10 has an insulating portion 30 in at least a portion thereof. Alternatively, the entire laminate 10 may also have an insulating portion 30. Figure 3 In the illustrated embodiment, the insulating portion 30 is provided in a manner that surrounds the coil conductor 25. That is, in the illustrated coil component 1, the coil conductor 25 is disposed inside the insulating portion 30. The coil conductor 125 is disposed within the laminate 10 in a manner that contacts the insulating portion 30. More specifically, in the illustrated embodiment, the magnetic layers 11 to 16 constituting the main body 20 (see reference 16) Figure 2 The magnetic body layer 18a of the upper cover layer 18 and the magnetic body layer 19a of the lower cover layer 19 are insulating parts 30.

[0056] Each magnetic layer of the laminate 10 is formed using a metallic magnetic paste containing metallic magnetic particles and an insulating resin material. However, in the magnetic layers 11-16, 18a, and 19a constituting the insulating portion 30, a metallic magnetic paste containing silicone resin is used as the resin material. The proportion of silicone resin in the metallic magnetic paste can be, for example, 5 vol% or more and 50 vol% or less. Examples of resin materials used as the metallic magnetic paste in the magnetic layers that do not constitute the insulating portion 30 (magnetic layers 18b-18d and 19b-19d in this embodiment) include polyvinyl butyral (PVB) resin, ethyl cellulose resin, polyvinyl alcohol resin, or acrylic resin. Furthermore, thermosetting resins with excellent insulating properties can also be used as the resin materials in the magnetic layers 18b-18d and 19b-19d that do not constitute the insulating portion 30. As thermosetting resins, epoxy resins, polyimide resins, polystyrene (PS) resins, high-density polyethylene (HDPE) resins, polyoxymethylene (POM) resins, polycarbonate (PC) resins, polyvinylidene fluoride (PVDF) resins, phenolic resins, polytetrafluoroethylene (PTFE) resins, or polybenzoxazole (PBO) resins can be used.

[0057] like Figure 4As shown, the insulating portion 30 includes: a metallic magnetic particle region R1 composed of a plurality of metallic magnetic particles 31; and a non-metallic particle region R2 defined by at least three metallic magnetic particles 31 in the cross-section of the laminate 10 along any direction. In the cross-section of the laminate 10, the three metallic magnetic particles 31 defining a non-metallic magnetic particle region R2 are in contact with each other. The non-metallic magnetic particle region R2 may also be defined by four or more metallic magnetic particles 31. In the non-metallic magnetic particle region R2, Si has the highest proportion among the materials other than oxygen constituting the non-metallic magnetic particle region R2. The non-metallic magnetic particle region R2 is filled with Si oxide. In addition to Si and oxygen, the non-metallic magnetic particle region R2 may also contain, for example, Fe and / or Cr. As an example, the proportion of Si in the materials other than oxygen in the non-metallic magnetic particle region R2 is 50 at% to 95 at% or less.

[0058] The proportion of Si in the nonmetallic magnetic particle region R2 is referenced to the geometric center C of the nonmetallic magnetic particle region R2 as observed from a cross-section along the coil axis A. That is, at the geometric center C of the nonmetallic magnetic particle region R2 as observed from a cross-section along the coil axis A, the atomic proportion of Si in materials other than oxygen is the highest. The Si proportion is determined using, for example, EDS (Energy Dispersive X-ray Spectroscopy) analysis.

[0059] The surface of each metallic magnetic particle 31 can also be covered by a capping layer 32. The capping layer 32 can be, for example, an oxide coating formed by oxidizing the surface of the metallic magnetic particles 31, a coating film containing Si, or a coating film containing elements other than Si. The oxide coating or coating film can also be an insulating film. The metallic magnetic particles 31 are bonded to each other via the capping layer 32. When a capping layer 32 is formed on the surface of the metallic magnetic particles 31, the capping layer 32 is part of the metallic magnetic particles 31 and is included in the metallic magnetic particle region R1. In this case, the material composition of the capping layer 32 can also be different from the material composition of the non-metallic magnetic particle region R2 at the geometric center C.

[0060] The following describes an example of the manufacturing method of coil component 1. First, an upper laminate, an intermediate laminate, and a lower laminate, which will become the upper cover layer 18, are formed. The upper laminate is formed by laminating multiple magnetic sheets that will become magnetic layers 18a to 18d. Similarly, the lower laminate is formed by laminating multiple magnetic sheets that will become magnetic layers 19a to 19d. The magnetic sheets are obtained, for example, by coating a metal magnetic paste onto the surface of a plastic base film, drying it, and then cutting the dried metal magnetic paste into a predetermined size. The metal magnetic paste is made, for example, by adding a solvent to a resin material containing metal magnetic particles. As the resin material used in the magnetic sheets that constitute the magnetic layers (magnetic layers 11 to 16, 18a, and 19a in the illustrated embodiment) of the insulating portion 30, silicone resin can be used. As the resin material used in the magnetic sheet that forms a magnetic layer that does not constitute the insulating part 30 (magnetic layers 18b-18d, 19b-19d in the illustrated embodiment), a resin material with excellent insulation properties such as polyvinyl butyral (PVB) resin or epoxy resin can be used.

[0061] The intermediate laminate is formed by stacking multiple sheets containing conductor patterns, magnetic layers, and insulating materials. When manufacturing each sheet, first, a green sheet is formed on a base film. At this time, through-holes are formed through the green sheet along the stacking direction, creating through-holes. Next, a conductor pattern is formed on the green sheet using screen printing or the like. The metal material constituting the conductor pattern is thus embedded within the through-holes, forming through-holes. Then, a magnetic layer is printed in areas where no conductor pattern is formed. After sheets containing conductor patterns C11 to C16 are formed, the base film is removed, and sheets containing conductor pattern C16 are sequentially stacked down to sheets containing conductor pattern C11. Furthermore, since there are no other conductor patterns below conductor pattern C16, through-holes for forming through-holes are not required when manufacturing the sheet containing conductor pattern C16.

[0062] Next, an upper and lower laminate, sandwiching an intermediate laminate as described above, are hot-pressed together to obtain a main laminate. Then, the main laminate is monolithically cut to the desired size using a cutting device such as a dicing machine or laser processing machine, thereby obtaining a chip laminate equivalent to laminate 10. Next, the chip laminate is degreased and then heat-treated at a specified temperature. Through this heat treatment process, the silicone resin contained in the metallic magnetic paste is thermally decomposed into Si oxide, which fills the non-metallic magnetic particle region R2 of the insulating portion 30. Furthermore, if the metallic magnetic particles contain at least one of Al and Mn as alloying components, at least one of Al oxide and Mn oxide is generated during the heat treatment process, and this at least one of Al oxide and Mn oxide further fills the non-metallic magnetic particle region R2 of the insulating portion 30. In this way, at least one of Si oxide, Al oxide, and Mn oxide can also be mixed into the non-metallic magnetic particle region R2. Since the metallic magnetic particles contain at least one of Al and Mn, the porosity of the non-metallic magnetic particle region R2 can be reduced compared to the case where the metallic magnetic particles do not contain Al and Mn. Furthermore, since at least one of Al oxide and Mn oxide is present in the non-metallic magnetic particle region R2, adjacent metallic magnetic particles can be firmly bonded together, improving the mechanical strength of the substrate 10. Next, external electrodes 21 and 22 are formed by applying conductive paste to both ends of the heat-treated chip laminate. Through the above processes, the coil component 1 is obtained.

[0063] Below, refer to Figure 5 Another embodiment of the present invention will now be described. Figure 5 This indicates that the coil component of another embodiment of the present invention is used in conjunction with... Figure 3 A cross-sectional view obtained by cutting a section equivalent to the cross-section. For example... Figure 5 As shown, another embodiment of the coil component 100 of the present invention is similar to coil component 1, including: a laminate 10 containing a plurality of metallic magnetic particles; a coil conductor 25 disposed inside the laminate 10 and wound around a coil axis A; an external electrode 21 electrically connected to one end of the coil conductor 25; and an external electrode 22 electrically connected to the other end of the coil conductor 25. The coil component 100 differs from coil component 1 in that the insulating portion 30 of the laminate 10 is only disposed in the area between adjacent conductor patterns C11 to C16 in the direction of the coil axis A. The area between conductor patterns extends throughout the entire laminate 10 in a planar direction along the L-axis and W-axis directions.

[0064] Below, refer to Figure 6Another embodiment of the present invention will now be described. Figure 6 This indicates that the coil component of another embodiment of the present invention is used in conjunction with... Figure 3 A cross-sectional view obtained by cutting a section equivalent to the cross-section. For example... Figure 6 As shown, another embodiment of the coil component 200 of the present invention is similar to coil component 1, including: a laminate 10 containing a plurality of metallic magnetic particles; a coil conductor 25 disposed inside the laminate 10 and wound around a coil axis A; an external electrode 21 electrically connected to one end of the coil conductor 25; and an external electrode 22 electrically connected to the other end of the coil conductor 25. In the coil component 200, in the direction of the coil axis A, an insulating portion 30 is provided in the region between the conductor pattern C11 and the upper surface 10e of the laminate 10, and in the region between the conductor pattern C16 and the lower surface 10f of the laminate 10. That is, in the coil component 200, the upper cover layer 18 (magnetic layers 18a to 18d) and the lower cover layer 19 (magnetic layers 19a to 19d) correspond to the insulating portion 30.

[0065] Below, refer to Figure 7 Another embodiment of the present invention will now be described. Figure 7 This indicates that the coil component of another embodiment of the present invention is used in conjunction with... Figure 3 A cross-sectional view obtained by cutting a section equivalent to the cross-section. For example... Figure 7As shown, another embodiment of the coil component 300 of the present invention is similar to coil component 1, including: a laminate 10 containing a plurality of metallic magnetic particles; a coil conductor 25 disposed inside the laminate 10 and wound around a coil axis A; an external electrode 21 electrically connected to one end of the coil conductor 25; and an external electrode 22 electrically connected to the other end of the coil conductor 25. In coil component 300, the external electrodes 21 and 22 are only disposed on the lower surface 10f of the laminate 10. The coil conductor 25 further includes: a lead-out conductor 25A electrically connecting one end of the coil conductor 25 to the external electrode 21; and a lead-out conductor 25B electrically connecting the other end of the coil conductor 25 to the external electrode 22. More specifically, the lead-out conductor 25A is led out from the conductor pattern C11 along the direction of the coil axis A and connected to the external electrode 21. The lead-out conductor 25B is led out from the conductor pattern C16 along the direction of the coil axis A and connected to the external electrode 22. The insulating portion 30 of the coil component 300 is formed in such a way that it covers the entire coil conductor 25 (i.e., conductor patterns C11 to C16, through holes V1 to V5, and lead conductors 25A and 25B). Specifically, in the coil component 300, the magnetic layers 11 to 16 contained in the main body 20, the magnetic layer 18a contained in the upper cover layer 18, and the magnetic layers 19a to 19d contained in the lower cover layer 19 correspond to the insulating portion 30. Thus, the insulating portion 30 exists in the region where the conductor pattern C16, with the largest potential difference, faces the lead conductor 25A. Furthermore, although the potential difference is smaller than that between the conductor pattern C16 and the lead conductor 25A, the insulating portion 30 exists in the regions where the conductor patterns C12 to C15 and the through holes V1 to V5, with this potential difference, face the lead conductor 25A.

[0066] Below, refer to Figure 8 Another embodiment of the present invention will now be described. Figure 8 This indicates that the coil component of another embodiment of the present invention is used in conjunction with... Figure 3 A cross-sectional view obtained by cutting a section equivalent to the cross-section. For example... Figure 8As shown, another embodiment of the coil component 400 of the present invention is similar to coil component 300, including: a laminate 10 containing a plurality of metallic magnetic particles; a coil conductor 25 disposed inside the laminate 10 and wound around a coil axis A; an external electrode 21 electrically connected to one end of the coil conductor 25; and an external electrode 22 electrically connected to the other end of the coil conductor 25. The external electrodes 21 and 22 of the coil component 400, like those of the coil component 300, are disposed only on the lower surface 10f of the laminate 10. The coil conductor 25 further includes: a lead-out conductor 25A electrically connecting one end of the coil conductor 25 to the external electrode 21; and a lead-out conductor 25B electrically connecting the other end of the coil conductor 25 to the external electrode 22. More specifically, the lead-out conductor 25A is led out from the conductor pattern C11 along the direction of the coil axis A and connected to the external electrode 21. The lead-out conductor 25B is led out from the conductor pattern C16 along the direction of the coil axis A and connected to the external electrode 22. In the coil component 400, an insulating portion 30 is provided in the region between the pattern C16 and the lower surface 10f of the laminate 10 in the direction of the coil axis A. That is, in the coil component 400, the lower cover layer 19 (magnetic layers 19a to 19d) corresponds to the insulating portion 30. Thus, an insulating portion 30 exists between the conductor pattern C16 with a large potential difference and the external electrode 21.

[0067] Below, refer to Figure 9 and Figure 10 Another embodiment of the present invention will now be described. Figure 9 A perspective view showing a coil component according to another embodiment of the present invention. (See diagram below.) Figure 9 As shown, in another embodiment of the present invention, the coil component 500 also includes a laminate 10, similar to the coil component 1. The coil component 500 further includes: a coil conductor 125 disposed inside the laminate 10; an external electrode 21 electrically connected to one end of the coil conductor 125; and an external electrode 22 electrically connected to the other end of the coil conductor 125.

[0068] The coil conductor 125 is arranged such that it is surrounded by the insulating portion 30 in the laminate 10. The coil conductor 125 is disposed within the laminate 10 in contact with the insulating portion 30. One end of the coil conductor 125 protrudes from the first end face 10c toward the outside of the magnetic substrate 10, and is connected to the external electrode 21 at this end. The other end of the coil conductor 125 protrudes from the second end face 10d toward the outside of the magnetic substrate 10, and is connected to the external electrode 22 at this other end. Thus, one end of the coil conductor 125 is connected to the external electrode 21, and the other end is connected to the external electrode 22.

[0069] When viewed from above (at a viewpoint from the T-axis), the coil conductor 125 extends linearly from the outer electrode 21 to the second outer electrode 22. That is, the coil conductor 125 does not have portions within the laminate 10 that are arranged opposite each other when viewed from above. In this specification, when the coil conductor 125 does not have portions within the laminate 10 that are opposite each other when viewed from above, the coil conductor 125 can extend linearly from the outer electrode 21 to the outer electrode 22. In the illustrated embodiment, the coil conductor 125 has a cuboid shape. The coil conductor 125 may have only one conductor pattern, or it may have multiple conductor patterns that are electrically insulated from each other within the laminate 10. When the coil conductor 125 has multiple conductor patterns, each conductor pattern has the same shape, and adjacent conductor patterns are separated from each other by a portion of the insulating portion 30 of the laminate 10.

[0070] exist Figure 9 and Figure 10 In the embodiment shown, the insulating part 30 is also as Figure 4 As shown, the insulating portion 30 comprises: a metallic magnetic particle region R1 composed of a plurality of metallic magnetic particles 31; and a non-metallic particle region R2 defined by at least three metallic magnetic particles 31 in a cross-section of the laminate 10 along any direction. In the non-metallic magnetic particle region R2, Si has the highest proportion among the materials other than oxygen constituting the non-metallic magnetic particle region R2. The proportion of Si in the non-metallic magnetic particle region R2 is based on the geometric center C of the non-metallic magnetic particle region R2 in a cross-section obtained by cutting through a plane passing through the coil conductor 125 (e.g., a plane passing through the coil conductor 125 and parallel to the LT plane). That is, at the geometric center C of the non-metallic magnetic particle region R2 in a cross-section obtained by cutting through a plane passing through the coil conductor 125, the atomic proportion of Si among the materials other than oxygen is the highest.

[0071] The shape of the coil conductor 125 is not limited to the shape shown in the figure. The coil conductor 125 can also be as shown in the figure. Figure 11 As shown, it is constructed such that its two ends are exposed from the mounting surface 10b of the laminate 10. Figure 11 The coil conductor 125 shown includes: a first portion 125a1, one end of which protrudes from the mounting surface 10b and extends in the positive directions of the T-axis and L-axis; a second portion 125a2, one end of which protrudes from the mounting surface 10b and extends in the positive directions of the T-axis and L-axis; and a third portion 125a3 connecting the upper end of the first portion 125a1 to the upper end of the second portion 125a2. The lower end of the first portion 25a1 is connected to the external electrode 21, and the lower end of the second portion 25a2 is connected to the external electrode 22. In the illustrated embodiment, the third portion 25a3 extends parallel to the upper surface 10a.

[0072] In one or more embodiments of the present invention, the laminate 10 of the coil component has an insulating portion 30 comprising a non-metallic magnetic particle region R2 defined by at least three metallic magnetic particles 31, wherein Si has the highest atomic proportion among the materials constituting the non-metallic magnetic particle region R2 other than oxygen. In conventional coil components, the resin contained in the metallic magnetic paste decomposes into carbon dioxide and the like through thermal decomposition during the heat treatment of its manufacturing process, thus forming voids in the region defined by multiple metallic magnetic particles (i.e., the region corresponding to the non-metallic magnetic particle region R2). When such voids are formed, the metallic magnetic particles readily come into contact with oxygen, and the Fe, Si, Cr, etc. contained in the metallic magnetic particles are easily oxidized. As a result, the ionized substances contained in the metallic material of the coil conductor readily accept electrons, thus sometimes causing migration of metallic atoms in the coil conductor. In contrast, in the coil component 1 of one embodiment of the present invention, as described above, Si oxide is present in the non-metallic magnetic particle region R2. This is because when silicone resin is used as the resin in the metallic magnetic paste, and the silicone resin is thermally decomposed through heat treatment, the Si contained in the silicone resin remains even after thermal decomposition. The remaining Si oxidizes to become Si oxide. Since Si oxide exists in the non-metallic magnetic particle region R2, it is difficult to form voids through heat treatment, thus suppressing the oxidation of Fe, Si, Cr, etc., contained in the metallic magnetic particles. Therefore, the migration of metal atoms in the coil conductor 25 caused by heat treatment can be suppressed.

[0073] In one or more embodiments of the present invention, the migration of metal atoms in the coil conductor 25 may sometimes occur due to the movement of metal atoms in the non-metallic magnetic particle region R2 caused by the application of voltage to the coil conductor 25. In the insulation portion 30 of the coil component 1 according to one embodiment of the present invention, the formation of voids in the non-metallic magnetic particle region R2 is suppressed, so even after the coil component 1 is mounted to a substrate or the like, the migration of metal atoms in the coil conductor 25 caused by the application of voltage can be suppressed.

[0074] In one or more embodiments of the present invention, the coil conductor 25 is disposed inside the insulating portion 30. With this configuration, migration of the metallic material of the coil conductor 25 can be suppressed between the conductor patterns C11 to C16 of the coil conductor 25 and between the coil conductor 25 and the external electrodes 21 and 22. Therefore, the adverse condition of short circuits occurring inside the coil component 1 can be suppressed more reliably.

[0075] In one or more embodiments of the present invention, the insulating portion 30 is formed by heat-treating a metallic magnetic paste comprising metallic magnetic particles 31 and silicone resin. Compared to particulate Si oxide, silicone resin is more readily supplied to the gaps between the metallic magnetic particles 31, thus increasing the Si oxide filling rate in the non-metallic magnetic particle region R2. Therefore, the migration of metal atoms in the coil conductor 25 caused by heat treatment can be more effectively suppressed.

[0076] In one or more embodiments of the present invention, the coil conductor 25 may include conductor patterns C11 to C16 extending along a plane orthogonal to the coil axis A and spaced apart from each other in the direction of the coil axis A, with insulating portions 30 disposed between adjacent conductor patterns C11 to C16. With this configuration, migration of the metallic material of the coil conductor 25 between adjacent conductor patterns C11 to C16 can be suppressed.

[0077] In one or more embodiments of the present invention, the coil component may also include external electrodes 21 and 22 disposed on the surface of the laminate 10 and electrically connected to the coil conductor 25, with an insulating portion 30 disposed between the coil conductor 25 and the external electrodes 21 and 22. With this configuration, migration of the metallic material of the coil conductor 25 between the coil conductor 25 and the external electrodes 21 and 22 can be suppressed.

[0078] In one or more embodiments of the present invention, the metallic magnetic particles 31 may also comprise Al. With this configuration, the covering layer 32 of the metallic magnetic particles 31 can easily become thicker, thus reducing the gap between the non-metallic magnetic particle regions R2 defined by the metallic magnetic particles 31. Consequently, the path for the metal elements used to form the coil conductor 25 to move due to ionization is narrowed, making it easier to suppress the migration of metal elements.

[0079] In one or more embodiments of the present invention, the metallic magnetic particles 31 may also contain Cr. Cr inhibits the oxidation of Fe contained in the metallic magnetic particles 31, and therefore, the ionization of the metal elements in the coil conductor 25 accompanying the oxidation of Fe can be suppressed. Therefore, the migration of the metal material in the coil conductor 25 can be suppressed.

[0080] The dimensions, materials, and configurations of the constituent elements described in the various embodiments above are not limited to those explicitly stated in each embodiment. These constituent elements can be modified to have any dimensions, materials, and configurations that are within the scope of this invention. Furthermore, constituent elements not explicitly stated in this specification can be added to the above embodiments, and some constituent elements described in each embodiment can be omitted.

[0081] For example, in the above embodiments, various examples are given for the location of the insulating portion 30, but as long as the insulating portion 30 is provided in at least a portion of the laminate 10, the location of the insulating portion 30 is not limited to the above embodiments.

Claims

1. A coil component, characterized in that, include: A matrix containing multiple metallic magnetic particles; and A coil conductor, disposed within the substrate in contact with the substrate, and wound around the coil axis. The substrate has an insulating portion, which includes a non-metallic magnetic particle region defined by at least three of the metallic magnetic particles in a cross-section of the substrate. In the insulating portion, Si has the highest atomic proportion among the materials other than oxygen that constitute the non-metallic magnetic particle region. The surface of each of the aforementioned metallic magnetic particles is covered by a Si-containing coating, which is an oxide film containing oxides of the elements contained in the metallic magnetic particles. The metallic magnetic particles are bonded to each other through the coating. The composition of the material of the covering layer is different from that of the material of the non-metallic magnetic particle region at the geometric center of the non-metallic magnetic particle region in the cross section along the axis of the coil.

2. The coil component as described in claim 1, characterized in that: At the geometric center, the proportion of Si atoms is highest in the material other than oxygen that constitutes the region of the non-metallic magnetic particles.

3. The coil component as described in claim 1 or 2, characterized in that: The coil conductor includes a first conductor pattern and a second conductor pattern that extend along a plane orthogonal to the coil axis and are spaced apart from each other in the direction of the coil axis. The insulating portion of the substrate is disposed between the first conductor pattern and the second conductor pattern.

4. A coil component, characterized in that, include: A matrix containing multiple metallic magnetic particles; A coil conductor is disposed within the substrate in such a manner that it contacts the substrate. The substrate has an insulating portion, which includes a non-metallic magnetic particle region defined by at least three of the metallic magnetic particles in a cross-section of the substrate. In the insulating portion, Si has the highest atomic proportion among the materials other than oxygen that constitute the non-metallic magnetic particle region. The surface of each of the aforementioned metallic magnetic particles is covered by a Si-containing coating, which is an oxide film containing oxides of the elements contained in the metallic magnetic particles. The metallic magnetic particles are bonded to each other through the coating. The composition of the material of the covering layer is different from that of the material of the non-metallic magnetic particle region at the geometric center of the non-metallic magnetic particle region in the cross section along the axis of the coil.

5. The coil component as described in claim 4, characterized in that: At the geometric center, the proportion of Si atoms is highest in the material other than oxygen that constitutes the region of the non-metallic magnetic particles.

6. The coil component as claimed in any one of claims 1, 2, 4, and 5, characterized in that: The atomic proportion of Si in the non-metallic magnetic particle region is more than 50 at% and less than 95 at%.

7. The coil component as claimed in any one of claims 1, 2, 4, and 5, characterized in that: The non-metallic magnetic particle region contains Fe, Cr and / or Al.

8. The coil component as described in claim 7, characterized in that: The metallic magnetic particles are alloys containing Fe, Si, Cr, or Al.

9. The coil component as claimed in any one of claims 1, 2, 4 and 5, characterized in that: The non-metallic magnetic particle region contains at least one of Al and Mn.

10. The coil component as claimed in any one of claims 1, 2, 4, and 5, characterized in that: The metallic magnetic particles contain at least one of Al and Mn.

11. The coil component as claimed in any one of claims 1, 2, 4 and 5, characterized in that: It also includes an external electrode, which is disposed on the surface of the substrate and electrically connected to the coil conductor. The insulating portion is disposed between the coil conductor and the external electrode.

12. The coil component as claimed in any one of claims 1, 2, 4 and 5, characterized in that: The coil conductor is disposed inside the insulation portion.

13. The coil component as claimed in any one of claims 1, 2, 4 and 5, characterized in that: The entire substrate is the insulating part.

14. The coil component as claimed in any one of claims 1, 2, 4 and 5, characterized in that: The insulating portion is formed by heat-treating a metallic magnetic paste containing the metallic magnetic particles and silicone resin.

15. A circuit board, characterized in that: It includes the coil component according to any one of claims 1 to 14.

16. An electronic component, characterized in that: It includes the circuit board as described in claim 15.

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