Coil component, method for manufacturing coil component, and electronic / electric device

Abstract

A coil component according to one embodiment of the present invention comprises: a coil section including an annular conductor section having a center axis along a first direction and having two electrical terminal sections; and a body section covering the annular conductor section with a first surface and a second surface disposed side by side in the first direction and containing magnetic particles and a binder. In the body section, a second material which forms a second region including the second surface, and a third material which forms a third region including a center region having an entire outer circumferential edge opposing an inner circumferential surface of the annular conductor section are different in at least one selected from the group consisting of: the composition of the magnetic particles; a shape distribution, which is a distribution related to shapes of the magnetic particles; the content of the magnetic particles; the composition of the binder; the content of the binder; and the composition and content of a third component when the third component other than the magnetic particles and the binder is included. This difference can add a new function to the body section. As a result, functionality of the body section increases and various characteristics of the coil component increase.

Description

Coil component, coil component manufacturing method, and electronic / electrical equipment

[0001] The present invention relates to a coil component, a method for manufacturing the same, and an electronic / electrical device in which the coil component is mounted.

[0002] Patent Document 1 discloses a power inductor comprising: a body containing magnetic powder and a polymer; at least one substrate provided inside the body and having at least one coil pattern formed on at least one surface thereof; and an insulating layer formed between the coil pattern and the body, wherein the body includes at least one region in which the particle size of the magnetic powder is distributed differently from the rest.

[0003] Patent Publication No. 2019-532519

[0004] In a coil component having a coil embedded in a main body, a magnetic circuit formed in the main body by energizing the coil travels along the central axis of the coil on the inner and outer circumferential sides of the coil, and across the central axis of the coil on the two bottom sides of the coil. Therefore, it may be preferable for the inner and bottom sides of the coil in the main body to have different magnetic properties. Furthermore, when the coil component is mounted on a substrate, the portion of the main body located on the bottom side of the coil may face the substrate or protrude from the substrate. Therefore, it may be preferable for the above portion to have different electrical and mechanical properties from the portion of the main body located on the inner circumferential side of the coil.

[0005] An object of the present invention is to provide a coil component with improved functionality of the main body, a method for manufacturing the coil component, and an electronic or electrical device incorporating the coil component.

[0006] In one aspect, the present invention provides a coil component including: a coil portion having an annular conductor portion with a central axis along a first direction and two electrical ends; and a main body portion covering the annular conductor portion with first and second faces aligned in the first direction and including a magnetic powder and a binder. The coil portion is exposed from the surface of the main body portion at a first end face connected to one of the two electrical ends of the annular conductor portion and a second end face connected to the other of the two electrical ends of the annular conductor portion. The main body portion includes a first region made of a first material and including the first face, a second region made of a second material and including the second face, and a third region made of a third material and located between the first face and the second face in the first direction. The third region includes a central region whose entire outer periphery faces the inner periphery of the annular conductor portion. The second material and the third material differ in one or more of the following: the composition of the magnetic powder; the shape distribution, which is the distribution of the shapes of the magnetic powder; the content of the magnetic powder; the composition of the binder; the content of the binder; and, if a third component other than the magnetic powder and the binder is contained, the composition and content of the third component.

[0007] In the coil component, the material of the third region including the central region can be made different from the material located near the intersecting plane, thereby imparting a new function to the main body and improving the performance of the main body.

[0008] In the coil component, the first material and the second material may be the same, and in this case, the region including the central region may have different properties from the other regions.

[0009] In the coil component described above, the first material and the second material may differ in one or more of the following: the composition of the magnetic powder, the shape distribution of the magnetic powder, the content of the magnetic powder, the composition of the binder, the content of the binder, and, if a third component other than the magnetic powder and the binder is contained, the composition and content of the third component. When the first region and the second region have different properties, an additional function is imparted to the main body portion, and the main body portion can be made more highly functional.

[0010] In the coil component described above, the first material and the third material may be the same. By making only the material located near the second surface different, the second region may have unique properties different from those of other regions.

[0011] In the coil component described above, the annular conductor may contact at least one of the first region and the second region at an end in the first direction. Since there is no third material between the annular conductor and the first region or the second region, it may be possible to more stably enjoy the benefits of providing the first region and the second region (such as positional stability of the coil within the main body and suppression of dielectric breakdown).

[0012] In the coil component described above, the third region may extend in the first direction so as to contact at least one of two ends of the annular conductor in the first direction. By having the third material extend between the annular conductor and the first region and / or between the annular conductor and the second region, it may be possible to more stably obtain the benefit of forming the third region from the third material (i.e., suppression of short circuits within the annular conductor due to local fracture of the insulating portion).

[0013] In the coil component described above, the second material may be harder than the third material. Since most of the second region is an area where no coil portion exists, making this region hard reduces defects due to damage or deformation of the main body. Furthermore, when the main body is formed by pressing a material containing magnetic powder and a hardenable material in a first direction, it becomes easier to control the position of the coil portion within the main body.

[0014] In the coil component, a second area ratio, which is an area ratio of the magnetic powder in a second cut surface obtained by cutting the second region along a surface orthogonal to the first direction, may be higher than a third area ratio, which is an area ratio of the magnetic powder in a third cut surface obtained by cutting the third region along a surface orthogonal to the first direction. In this case, the second region tends to be harder.

[0015] In the coil component described above, the second material may have higher insulating properties than the third material. When the second surface is a mounting surface, short circuits are less likely to occur on the mounting surface side. In particular, when bottom electrodes are provided, short circuits between bottom electrodes are less likely to occur. When the second surface is on the opposite side from the mounting surface, the second region is relatively susceptible to the effects of collisions, etc., but even if the exterior coating peels off due to a collision, dielectric breakdown is less likely to occur.

[0016] In the coil component, the resistivity of the second region may be greater than the resistivity of the third region, which makes it easier to achieve that the second material has higher insulating properties than the third material.

[0017] In the coil component described above, the magnetic powder contained in the second material may include a metal magnetic powder, and the relative permeability μ2 of the second region may be smaller than the relative permeability μ1 of the first region. One way to relatively increase the insulation of the second region is to increase the content of insulating material in the second material. In this case, the content of the metal magnetic powder is relatively reduced, and therefore the relative permeability μ2 of the second region is likely to be smaller than the relative permeability μ1 of the first region.

[0018] In the coil component described above, the length h2 of the second region in the first direction may be greater than the length h1 of the first region in the first direction. Even if the relative permeability μ2 of the second region is smaller than the relative permeability μ1 of the first region, as long as h2>h1, it is possible to prevent the magnetic reluctance of the second region from becoming excessively high.

[0019] In the above coil component, when the second region is cut along a plane orthogonal to the first direction to obtain a second cut surface, and the third region is cut along a plane orthogonal to the first direction to obtain a third cut surface, at least one of the following (A) or (B) may be satisfied: (A) a second area ratio that is the area ratio of the magnetic powder on the second cut surface is lower than a third area ratio that is the area ratio of the magnetic powder on the third cut surface; and (B) a second average equivalent circle diameter that is the average equivalent circle diameter of the magnetic powder on the second cut surface is larger than a third average equivalent circle diameter that is the average equivalent circle diameter of the magnetic powder on the third cut surface.

[0020] Regarding (A), by making the second area ratio smaller than the third area ratio, μ2<μ3 is easily realized. In this case, the area ratio of the binder is higher in the second region, so the insulating properties of the second region are likely to be higher.

[0021] Regarding (B), when the average equivalent circular diameter of the magnetic powder is relatively large, the filling rate tends to decrease. Therefore, by making the second average equivalent circular diameter greater than the third average equivalent circular diameter, μ2 < μ3 is easily achieved. In this case, the area ratio of the binder tends to be higher in the second region, and therefore the resistivity of the second region tends to be higher.

[0022] In the coil component described above, the second material may contain insulating inorganic particles as the third component. Many insulating inorganic particles have a higher dielectric strength than the binder, and this tendency is particularly pronounced when the binder is a polymer. By including inorganic particles as the third component of the second material, the possibility of dielectric breakdown occurring in the second region can be reduced.

[0023] In the coil component described above, the magnetic powder contained in the second material may include a metal magnetic powder having an insulating coating on its surface. When the magnetic powder is a metal magnetic powder, the magnetic powder forms a conductive path in the event of dielectric breakdown. Therefore, by having an insulating coating on the surface of the metal magnetic powder, it may be possible to reduce the possibility of dielectric breakdown occurring in the second region.

[0024] In the above coil component, the annular conductor portion may have an insulating portion on its surface, the magnetic powder contained in the third material may include metal magnetic powder, and when the second region is cut along a plane perpendicular to the first direction to obtain a second cut surface, and the third region is cut along a plane perpendicular to the first direction to obtain a third cut surface, at least one of the following (a) to (d) may be satisfied: (a) a third average equivalent circle diameter that is the average equivalent circle diameter of the magnetic powder at the third cut surface is smaller than a second average equivalent circle diameter that is the average equivalent circle diameter of the magnetic powder at the second cut surface, (b) a third median diameter that is the median diameter of the magnetic powder at the third cut surface is smaller than a second median diameter that is the median diameter of the magnetic powder at the second cut surface, and (c) a third maximum equivalent circle diameter that is the maximum equivalent circle diameter of the magnetic powder at the third cut surface is smaller than a second maximum equivalent circle diameter that is the maximum equivalent circle diameter of the magnetic powder at the second cut surface. (d) At least one of the second diameter distribution, which is the distribution of the equivalent circle diameters of the magnetic powder on the second cross section, and the third diameter distribution, which is the distribution of the equivalent circle diameters of the magnetic powder on the third cross section, has two or more peaks, and the third peak diameter, which is the maximum frequency equivalent circle diameter at the largest diameter peak among the peaks of the third diameter distribution, is smaller than the second peak diameter, which is the maximum frequency equivalent circle diameter at the largest diameter peak among the peaks of the second diameter distribution.

[0025] Regarding (a), since the third region is more likely to contain magnetic powder with a relatively small particle size, when forming the main body portion by pressing a material containing magnetic powder in a first direction, even if the insulating portion provided on the surface of the annular conductor portion is locally broken by the magnetic powder due to the pressing, a short circuit is less likely to occur within the annular conductor portion.

[0026] Regarding (b), since the third region is more likely to contain magnetic powder with a relatively small particle size, when forming the main body portion by pressing a material containing magnetic powder in a first direction, even if the insulating portion provided on the surface of the annular conductor portion is locally broken by the magnetic powder due to the pressing, a short circuit is less likely to occur within the annular conductor portion.

[0027] Regarding (c), since the third region is more likely to contain magnetic powder with a relatively small particle size, when forming the main body portion by pressing a material containing magnetic powder in a first direction, even if the insulating portion provided on the surface of the annular conductor portion is locally broken by the magnetic powder due to the pressing, a short circuit is less likely to occur within the annular conductor portion.

[0028] Regarding (d), since the third region is more likely to contain magnetic powder with a relatively small particle size, when forming the main body portion by pressing a material containing magnetic powder in a first direction, even if the insulating portion provided on the surface of the annular conductor portion is locally broken by the magnetic powder due to the pressing, a short circuit is less likely to occur within the annular conductor portion.

[0029] In the coil component described above, the annular conductor may have an insulating portion on its surface, the magnetic powder contained in the third material may include metal magnetic powder, and at least one of a second particle size distribution that is a volumetric particle size distribution of the magnetic powder contained in the second region and a third particle size distribution that is a volumetric particle size distribution of the magnetic powder contained in the third region may have two or more peaks. In this case, the third particle size that is the particle size with the highest frequency at the peak on the largest diameter side of the peaks in the third particle size distribution may be smaller than the second particle size that is the particle size with the highest frequency at the peak on the largest diameter side of the peaks in the second particle size distribution.

[0030] Since the third region is more likely to contain magnetic powder with relatively small particle diameters, when forming the main body portion by pressing a material containing magnetic powder in a first direction, even if the insulating portion provided on the surface of the annular conductor portion is locally broken by the magnetic powder due to the pressing, a short circuit is less likely to occur within the annular conductor portion.

[0031] In the coil component described above, the binder contained in the second region may contain a second polymer, and the binder contained in the third region may contain a third polymer. The physical properties of a polymer can be easily adjusted by adjusting the composition or polymerization of the monomer. Therefore, by including a polymer in the binder, it becomes easy to adjust the properties of the binder.

[0032] In the coil component, the weight-average molecular weight of the second polymer may be greater than the weight-average molecular weight of the third polymer. The second region containing the polymer with a relatively large molecular weight tends to have high strength and viscosity as a whole, and therefore may have excellent impact resistance.

[0033] The density of unreacted groups in the second polymer may be lower than the density of unreacted groups in the third polymer. The second region containing the polymer with a relatively low density of unreacted groups tends to have high strength and viscosity as a whole, and therefore may have excellent impact resistance.

[0034] In the coil component described above, when the second material contains a polymerization catalyst for forming the binder and the third material contains a polymerization catalyst for forming the binder, the content of the polymerization catalyst in the second material may be greater than the content of the polymerization catalyst in the third material. The second region containing the polymer with a relatively high content of the polymerization catalyst tends to have high strength and high viscosity as a whole, and therefore may have excellent impact resistance.

[0035] In the coil component, the hardness of the binder contained in the second region, as measured by a nanoindenter, may be smaller than the hardness of the binder contained in the third region, as measured by a nanoindenter. The second region, which contains a relatively hard binder, tends to have high strength and high viscosity overall, and therefore may have excellent impact resistance.

[0036] In another aspect, the present invention provides a method for manufacturing a coil component including a coil portion having an annular conductor portion with a central axis in a first direction and two electrical ends, and a main body portion including a magnetic powder and covering the annular conductor portion at a pair of intersecting surfaces aligned in the first direction. In this manufacturing method, a laminated structure is disposed in a mold cavity. The laminated structure includes the coil portion, a first member located on one side of the coil portion in the first direction and including a first magnetic powder and a first hardenable material, a second member located on the other side of the coil portion in the first direction and including a second magnetic powder and a second hardenable material, and a third member located between the first member and the second member and including a third magnetic powder and a third hardenable material. The method then includes increasing the pressure within the cavity to obtain a compact including the coil portion and the main body portion from the laminated structure. In the compact, a central region, the entire outer periphery of which faces the inner periphery of the annular conductor, is made of a material based on the third member.

[0037] In this way, by dividing the material constituting the main body into a plurality of parts and integrating them by molding, it becomes easy for the central region of the main body to have different properties from the other regions.

[0038] In the above-described method for manufacturing a coil component, the second member and the third member may differ in one or more selected from the group consisting of the composition of the second magnetic powder and the composition of the third magnetic powder, the particle size distribution of the second magnetic powder and the particle size distribution of the third magnetic powder, the content of the second magnetic powder in the second member and the content of the third magnetic powder in the third member, the composition of the second hardenable material and the composition of the third hardenable material, the content of the second hardenable material in the second member and the content of the third hardenable material in the third member, and, in a case where the second member contains a second additive component other than the second hardenable material and the second magnetic powder and the third member contains a third additive component other than the third hardenable material and the third magnetic powder, the composition of the second additive component and the composition of the third additive component.

[0039] In this specification, the term "curable material" includes a material that is cured and a material that causes curing (such as a polymerization initiator). The term "additive component" refers to a material that is not ferromagnetic and does not react with the curable material. Specific examples include a non-polymerizable material for softening a member and inorganic particles for improving insulation.

[0040] In the method for manufacturing a coil component described above, the first member and the third member may have the same composition. In this case, the first member and the third member may be integral with each other. This may improve productivity.

[0041] The method for manufacturing a coil component may include hardening the first hardenable material to the third hardenable material, wherein the first direction is along a vertical direction, the second member is located below the coil portion, and the second member is harder than the third member.

[0042] In the case where the second member is harder than the third member, at least one of the following (I) to (VI) may be satisfied. (I) For the laminated structure disposed in the cavity, the viscosity of the second curable material is higher than the viscosity of the third curable material. (II) For the laminated structure disposed in the cavity, the degree of polymerization of the second curable material is higher than the degree of polymerization of the third curable material. (III) For the laminated structure disposed in the cavity, the content of uncured material contained in the second curable material is lower than the content of uncured material contained in the third curable material. (IV) The second curable material and the third curable material contain a polymerization catalyst, and for the laminated structure disposed in the cavity, the content of the polymerization catalyst contained in the second curable material is higher than the content of the polymerization catalyst contained in the third curable material. (V) For the laminated structure disposed in the cavity, the volume ratio of the second magnetic powder contained in the second member is higher than the volume ratio of the third magnetic powder contained in the third member. (VI) When the gel time defined in JIS K5600-9-1:2006 is measured for the second curable material and the third curable material contained in the laminated structure placed in the cavity, the gel time of the second curable material is shorter than the gel time of the third curable material.

[0043] In the above-described method for manufacturing a coil component, the second member may have higher insulating properties than the third member.

[0044] In the above-mentioned method for manufacturing a coil component, the coil portion has an insulating portion covering a surface of the annular conductor portion, the third magnetic powder includes metal magnetic powder, and when the second member is cut in a plane perpendicular to the first direction to obtain a second member cut surface and the third member is cut to obtain a third member cut surface, at least one of the following (i) to (iv) may be satisfied. (i) A third member average equivalent circle diameter, which is the average equivalent circle diameter of the third magnetic powder at the cut surface of the third member, is smaller than a second member average equivalent circle diameter, which is the average equivalent circle diameter of the second magnetic powder at the cut surface of the second member; (ii) A third member median diameter, which is the median diameter of the third magnetic powder at the cut surface of the third member, is smaller than a second member median diameter, which is the median diameter of the second magnetic powder at the cut surface of the second member; and (iii) A third member maximum equivalent circle diameter, which is the maximum equivalent circle diameter of the third magnetic powder at the cut surface of the third member, is smaller than a second member maximum equivalent circle diameter, which is the maximum equivalent circle diameter of the magnetic powder at the cut surface of the second member. (iv) At least one of the second member diameter distribution, which is a distribution of the circle-equivalent diameters of the second magnetic powder at the cross section of the second member, and the third member diameter distribution, which is a distribution of the circle-equivalent diameters of the third magnetic powder at the cross section of the third member, has two or more peaks, and the third member peak diameter, which is the circle-equivalent diameter with the highest frequency at the peak on the largest diameter side among the peaks of the third member diameter distribution, is smaller than the second member peak diameter, which is the circle-equivalent diameter with the highest frequency at the peak on the largest diameter side among the peaks of the second member diameter distribution.

[0045] In another aspect, the present invention provides an electronic / electrical device incorporating the above-described coil component, wherein the coil component is connected to a substrate at terminals provided on exposed conductors located at two ends of the coil and exposed to the outside. Examples of such electronic / electrical devices include power supply units equipped with a power switching circuit, a voltage step-up circuit, a smoothing circuit, etc., and small portable communication devices. The electronic / electrical device according to the present invention includes the above-described coil component, and therefore has excellent overall characteristics as an inductance element.

[0046] According to the present invention, it is possible to impart new functions to the main body of a coil component, such as a function to prevent breakage during impact, a function to ensure insulation from external electrodes, a function to prevent short circuits within the coil portion, and a function to position the coil portion within the main body. By imparting these functions to the main body, high functionality is achieved, and a coil component is provided that has excellent electrical and other properties. When this coil component is mounted in an electronic or electrical device, the performance of the electronic or electrical device can be improved and the dimensions of the electronic or electrical device can be reduced. Furthermore, according to the present invention, an electronic or electrical device in which the coil component is mounted is provided. Furthermore, a method for manufacturing the above coil component is also provided.

[0047] 11A is an XZ cross-sectional view taken along line A-A' in FIG. 1; and FIG. 11B is an XZ cross-sectional view showing a state in which the coil component is mounted on a substrate. 11C is an XY cross-sectional view taken along line B-B' in FIG. 2; and FIG. 11D is an XZ cross-sectional view illustrating a modified example (part 1) of a coil component according to an embodiment of the present invention. 11E is an XZ cross-sectional view illustrating a modified example (part 2) of a coil component according to an embodiment of the present invention. 11F is an XZ cross-sectional view illustrating a different shape distribution of magnetic powder. 11G is an explanatory diagram (comparative example) of an example of the function of a main body portion of a coil component according to an embodiment of the present invention. 11H is an explanatory diagram (inventive example) of an example of the function of a main body portion of a coil component according to an embodiment of the present invention. 11H is an XZ cross-sectional view illustrating a different shape distribution of magnetic powder. 11H is an XZ cross-sectional view illustrating a modified example (part 4) of a coil component according to an embodiment of the present invention. 11G is an explanatory diagram (part 1) of an example of a manufacturing method for a coil component according to an embodiment of the present invention, which is an XY plan view of a coil array sheet. 11H is an XZ cross-sectional view taken along line C-C' in FIG. 11A; and FIG. 11F is an explanatory diagram (part 2) of an example of a manufacturing method for a coil component according to an embodiment of the present invention, which is an XZ cross-sectional view showing a state in which a coil array sheet and the like are arranged in a cavity of a mold. 16A , 16B, 16C, 16D, 16E, 16F, 16G, 16H, 16G, 16H, 16I, 16J, 16J, 16K ...

[0048] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0049] Fig. 1 is a perspective view conceptually showing the shape of a coil component according to an embodiment of the present invention. Fig. 2 is an XZ cross-sectional view taken along line AA' in Fig. 1. Fig. 3 is an XZ cross-sectional view showing the coil component mounted on a substrate. Fig. 4 is an XY cross-sectional view taken along line BB' in Fig. 2.

[0050] (Overall Configuration) A coil component 100 according to one embodiment of the present invention includes a coil portion 10 having a coil conductor portion 20 , a main body portion 30 , a first external electrode 41 , a second external electrode 42 , and exterior coatings 50 and 60 .

[0051] (Coil) As shown in FIGS. 2 to 4 , the coil portion 10 includes a coil conductor portion 20 having a spiral-shaped first spiral conductor portion 11 around a central axis O along a first direction (Z1-Z2 direction). The first spiral conductor portion 11 is an example of a part of an annular conductor portion. The spiral shape of the first spiral conductor portion 11 is a shape that moves away from the central axis O from an inner peripheral end portion 12, which is the inner peripheral end of a pair of ends of the first spiral conductor portion 11, toward an outer peripheral end portion 13, which is the outer peripheral end of the pair of ends of the first spiral conductor portion 11. In FIG. 4 , the first spiral conductor portion 11 has conductors arranged in a spiral shape that moves away from the central axis O in a clockwise direction from the inner peripheral end portion 12 toward the outer peripheral end portion 13, when viewed from the Z1 side in the Z1-Z2 direction. In this specification, the "spiral direction" of the spiral portion means the direction from the inner peripheral end portion to the outer peripheral end portion.

[0052] The conductor (conductive material) constituting the coil conductor portion 20 is not limited as long as it has appropriate conductivity. Specific examples of the conductor constituting the coil conductor portion 20 include metals such as copper, copper alloys, aluminum, and aluminum alloys. The coil conductor portion 20 can be manufactured using a film-forming technique such as plating. The coil portion 10 has an insulating coil insulation portion 80 on the surface of the coil conductor portion 20. This coil insulation portion 80 ensures insulation between adjacent conductors (between the surfaces of the conductors facing each other) in the coil conductor portion 20. Examples of materials constituting the coil insulation portion 80 include resin materials, but the material is not limited to a specific material and may be an inorganic material or a mixture of an organic material and an inorganic material. The coil insulation portion 80 is not provided at the ends of the two ends (the first lead-out end portion 14E and the second lead-out end portion 24E) of the coil conductor portion 20, and the coil portion 10 can be electrically connected to other components at these ends.

[0053] The coil insulating portion 80 may be thermoplastic, and specific examples thereof include thermoplastic resins containing paraxylylene-based polymers. Other examples of thermoplastic resins include polyethylene, polypropylene, polyamide, polyester, polyamideimide, polyimide, polysulfone, polycarbonate, liquid crystal polymer, polyvinylidene fluoride, and polytetrafluoroethylene. The coil insulating portion 80 as a whole is only required to be thermoplastic, and may contain, in addition to the above-mentioned thermoplastic resins, inorganic insulating particles, for example. Furthermore, examples of materials constituting the coil insulating portion 80 other than the above-mentioned thermoplastic resins include organic materials such as thermosetting resins and inorganic materials such as oxides.

[0054] The coil insulating portion 80 preferably has excellent insulating properties. Specifically, the volume resistivity obtained by ASTM D257 is 1.0×10 14 In some cases, it is preferable that the volume resistivity is 1.0×10 Ωcm or more. 15 More preferably, it is 1.0×10 Ωcm or more. 16 The upper limit of the volume resistivity is not particularly limited. 20The dielectric constant may be Ωcm or less. Furthermore, it is preferable that the coil insulating portion 80 has excellent dielectric properties. Specifically, it may be preferable that the dielectric constant at 60 Hz obtained by ASTM D150 is 4.0 or less. This dielectric constant is more preferably 3.5 or less, and even more preferably 3.0 or less. The lower limit of this dielectric constant is not particularly limited. The dielectric constant may be 1.0 or more. The method for measuring the volume resistivity and dielectric constant of the coil insulating portion 80 is not limited as long as results equivalent to those obtained by ASTM D257 and D150 are expected. For example, a measurement sample is separately prepared by cutting a material corresponding to the coil insulating portion 80 to the dimensions required for measurement, and this measurement sample is used to identify the constituent materials through analytical techniques such as component analysis and FT-IR, and the characteristics of the material, such as volume resistivity, are evaluated.

[0055] As shown in Figures 2 to 4, the coil conductor portion 20 has a second spiral conductor portion 21 arranged alongside the first spiral conductor portion 11 in the first direction. The second spiral conductor portion 21 is another example of a part of an annular conductor portion. The second spiral conductor portion 21 has a spiral shape around a central axis O along the first direction (Z1-Z2 direction), in which the second spiral conductor portion 21 has a spiral shape that moves away from the central axis O from one end (inner peripheral end portion 22) that is the inner peripheral end of the second spiral conductor portion 21 to the other end (outer peripheral end portion 23) that is the outer peripheral end of the second spiral conductor portion 21. In the second spiral conductor portion 21, when viewed from the Z1 side in the Z1-Z2 direction, the conductor is arranged in a spiral shape that moves away from the central axis O in the opposite direction to the first spiral conductor portion 11 (counterclockwise in Figure 2).

[0056] The average value of the separation distance in the first direction (Z1-Z2 direction) between the first spiral conductor portion 11 and the second spiral conductor portion 21 is not particularly limited. The smaller this separation distance, the easier it is to reduce the height (dimension in the Z1-Z2 direction) of the coil component 100; however, if the separation distance is excessively small, the insulation between the first spiral conductor portion 11 and the second spiral conductor portion 21 is likely to deteriorate. From the viewpoint of achieving both a low profile (low height) of the coil component 100 and high insulation between the first spiral conductor portion 11 and the second spiral conductor portion 21, it may be preferable that the separation distance be 0.4 μm or more and 20 μm or less. In order to reduce variation in the separation distance and more reliably support the coil in the same plane during manufacturing, the separation distance is more preferably 1.0 μm or more, and even more preferably 5.0 μm or more.

[0057] The inner peripheral end 12 of the first spiral conductor portion 11 and the inner peripheral end 22 of the second spiral conductor portion 21 are electrically connected by a via portion VP. Starting from the connection portion to the via portion VP, the first spiral conductor portion 11 and the second spiral conductor portion 21 spiral in opposite directions. The via portion VP may be made of the same conductor as the coil conductor portion 20. In a specific example, the via portion VP is manufactured during the manufacturing process of the first spiral conductor portion 11 and the second spiral conductor portion 21. In this case, the via portion VP is integrated with the inner peripheral end 12 of the first spiral conductor portion 11 and the inner peripheral end 22 of the second spiral conductor portion 21. Therefore, in this embodiment, the annular conductor portion has the first spiral conductor portion 11, the second spiral conductor portion 21, and the via portion VP, and the outer peripheral ends 13 and 23 are the electrical ends of the two annular conductor portions.

[0058] The first lead 14 is connected to the outer peripheral end 13 of the first spiral conductor 11, and the second lead 24 is connected to the outer peripheral end 23 of the second spiral conductor 21. Therefore, the outer peripheral end 13 of the first spiral conductor 11 is substantially the interface with the first lead 14, and the outer peripheral end 23 of the second spiral conductor 21 is substantially the interface with the second lead 24. In a specific example, the first lead 14 and the second lead 24 are manufactured together in the process of manufacturing the first spiral conductor 11 and the second spiral conductor 21. In this case, the first lead 14 has a portion that is seamlessly integrated with the outer peripheral end 13 of the first spiral conductor 11, and the second lead 24 has a portion that is seamlessly integrated with the outer peripheral end 23 of the second spiral conductor 21.

[0059] That is, in this embodiment, the coil conductor portion 20 has a first spiral conductor portion 11, a first lead-out portion 14, a second spiral conductor portion 21, a second lead-out portion 24, and a via portion VP, which are manufactured so as to have integrated parts using a common manufacturing process.

[0060] (External Electrodes) As shown in FIG. 1 , the coil component 100 according to this embodiment has external electrodes provided on the outside of the main body 30 as terminals of the coil component 100. In other words, the external electrodes are provided on exposed conductor portions, which are portions of the coil portion 10 exposed to the outside. Specifically, the coil component 100 has a first external electrode 41 in contact with the first lead end 14E and a second external electrode 42 in contact with the second lead end 24E. The first external electrode 41 is continuous with a first lateral external electrode 41a located on the outer surface of the main body 30 and a first intersecting plane external electrode 41b located on the second surface 302 of the main body 30. The second external electrode 42 is continuous with a second lateral external electrode 42a located on the outer surface of the main body 30 and a second intersecting plane external electrode 42b located on the second surface 302 of the main body 30. When the first lateral external electrode 41a and the second lateral external electrode 42a are provided, solder S1 is located between the first board electrode E1 and the first lateral external electrode 41a, and between the first board electrode E1 and the first intersecting plane external electrode 41b, the solder S1 extending in the X1-X2 direction from a position on the board SB sufficiently distal to the first lateral external electrode 41a (on the X2 side in the X1-X2 direction) to a position facing the second surface 302. Similarly, solder S2 is located between the second board electrode E2 and the second lateral external electrode 42a, and between the second board electrode E2 and the second intersecting plane external electrode 42b, the solder S2 extending in the X1-X2 direction from a position on the board SB sufficiently distal to the second lateral external electrode 42a (on the X1 side in the X1-X2 direction) to a position facing the second surface 302.

[0061] The materials and configurations of the first external electrode 41 and the second external electrode 42 are not limited as long as they have appropriate conductivity. One non-limiting example of the first external electrode 41 and the second external electrode 42 is a layer having a Cu-plated / Ni-plated / Sn-plated structure from the side proximal to the surface of the main body 30. The first external electrode 41 and the second external electrode 42 may be formed as a coated electrode in which a conductive material such as silver is dispersed in a resin or the like. Alternatively, the first external electrode 41 and the second external electrode 42 may be a combination of a plated electrode and a coated electrode.

[0062] (Main Body) The main body 30 covers the first spiral conductor 11 and the second spiral conductor 21 with at least a pair of intersecting surfaces (first surface 301, second surface 302) aligned in a first direction (Z1-Z2 direction), and contains magnetic powder and a binder. In this embodiment, the main body 30 has four outer surfaces extending in the first direction (Z1-Z2 direction) between the pair of intersecting surfaces, and has a substantially rectangular parallelepiped shape. The main body 30 encompasses the portions of the coil 10 other than the outermost end surface of the first lead-out portion 14 (on the X2 side in the X1-X2 direction and on both sides in the Z1-Z2 direction) and the outermost end surfaces of the second lead-out portion 24 (on the X1 side in the X1-X2 direction and on both sides in the Z1-Z2 direction).

[0063] The coil portion 10 is exposed from the surface of the main body portion 30 at a first end face (first pull-out end 14E) connected to one of the two electrical ends of the annular conductor portion (outer peripheral end 13), and at a second end face (second pull-out end 24E) connected to the other of the two electrical ends of the annular conductor portion (outer peripheral end 23).

[0064] The main body 30 includes a first region 31 made of a first material and including a first surface 301, a second region 32 made of a second material and including a second surface 302, and a third region 33 made of a third material and located between the first surface 301 and the second surface 302 in the first direction. The third region 33 includes a central region CR whose entire outer edge faces the inner circumferential surface of the annular conductor (the first spiral conductor 11, the second spiral conductor 21, and the via portion VP). The length (thickness) of the central region CR in the first direction is appropriately set depending on the characteristics required of the central region CR, the shape of the inner circumferential side of the annular conductor, and the like. The thickness of the central region CR may be equal to the length of the annular conductor in the first direction (the thickness of the annular conductor), or may be half, or for example, one-quarter, of the thickness of the annular conductor. When the thickness of the central region CR is thinner than the thickness of the annular conductor portion, the central region CR may be positioned offset toward the first region 31, offset toward the second region 32, or positioned so as to be approximately equally spaced from the first region 31 and the second region 32.

[0065] In this embodiment, the second material and the third material differ in one or more of the following points [1] to [6]: [1] the composition of the magnetic powder; [2] the shape distribution, which is the distribution of the shapes of the magnetic powder; [3] the content of the magnetic powder; [4] the composition of the binder; [5] the content of the binder; and [6] the composition and content of a third component, which is a component other than the magnetic powder and the binder, if any.

[0066] By making the second material and the third material different in at least one of these, the main body 30 can be obtained in which the second region 32 and the third region 33 have different properties.

[0067] In the main body 30, the first material and the second material may be the same, and in this case, the third region 33 including the central region CR may have different characteristics from the other regions. For example, in the first region 31 and the second region 32, a magnetic circuit is formed in a direction intersecting the first direction when current is applied to the coil device 100. Therefore, by using the same material, a local increase in magnetic resistance may be suppressed. Furthermore, since the first region 31 includes the first surface 301 and the second region 32 includes the second surface 302, the hardness of the first region 31 and the second region 32 may make them less susceptible to external impacts.

[0068] In the main body 30, the first material and the second material may also differ in one or more of the characteristics selected from the group consisting of [1] to [6] above. Having different properties between the first region 31 and the second region 32 may impart additional functionality to the main body 30. For example, as shown in FIG. 3 , when the coil component 100 is mounted on the substrate SB, the first region 31 does not face the substrate SB. Therefore, the first material may be formed to be relatively hard to enhance resistance to external impacts. Meanwhile, the second region 32 faces the mounting surface, so the second material may be formed to have relatively high insulating properties.

[0069] The first material and the third material may be the same in the main body portion 30. By making only the second material located near the second surface 302 different from the other materials, the second region 32 may have unique properties different from the other regions, which may impart a new function to the main body portion 30 and make the main body portion 30 more highly functional.

[0070] The positional relationship between the boundary between the first region 31, the third region 33, and the second region 32 aligned in the first direction in the main body 30 and the end in the first direction of the portion of the coil section 10 where the annular conductor is located is not particularly limited. For example, the end in the first direction of the portion of the coil section 10 where the annular conductor is located may be in contact with at least one of the first region 31 and the second region 32. In FIG. 2 , the end (first end 101) on the Z1 side in the Z1-Z2 direction of the portion of the coil section 10 where the first spiral conductor 11 is located is in contact with the first region 31, and the end (second end 102) on the Z2 side in the Z1-Z2 direction of the portion of the coil section 10 where the second spiral conductor 21 is located is in contact with the second region 32. In this way, since there is no third material between the portion of the coil portion 10 where the annular conductor portion is located and the first region 31, or between the portion of the coil portion 10 where the annular conductor portion is located and the second region 32, it may be possible to more stably enjoy the benefits of providing the first region 31 and the second region 32 (such as positional stability of the coil portion 10 within the main body portion 30 and improved insulation).

[0071] FIG. 5 is an XZ cross-sectional view illustrating a modified example (part 1) of a coil component according to an embodiment of the present invention. As in the coil component 100A shown in FIG. 5, the third region 33 may extend in the first direction so as to contact at least one of two ends (first end 101, second end 102) in the first direction of the coil portion 10 at a portion where the annular conductor is located. In FIG. 5, the third region 33 extends on both sides in the first direction (the Z1 side and the Z2 side in the Z1-Z2 direction) and has a first extension portion 33E1 that contacts the first end 101 of the coil portion 10 and a second extension portion 33E2 that contacts the second end 102 of the coil portion 10. In this way, by extending the third material between the annular conductor portion and the first region 31 and / or between the annular conductor portion and the second region 32, it may be possible to more stably enjoy the benefits of constructing the third region 33 from the third material (such as suppressing short circuits within the coil portion 10 due to localized fracture of the insulating portion).

[0072] FIG. 6 is an XZ cross-sectional view illustrating a second modified example of a coil component according to an embodiment of the present invention. As in the coil component 100B shown in FIG. 6 , a first intermediate layer 341 made of a mixture of a first material and a third material may be present between the first region 31 and the third region 33. A second intermediate layer 342 made of a mixture of a second material and a third material may be present between the second region 32 and the third region 33. Depending on the manufacturing method, such intermediate layers may be unavoidably formed. The intermediate layers (first intermediate layer 341, second intermediate layer 342) may include a gradient region in which the composition changes in a direction including the first direction. By including such an intermediate layer, it may be possible to avoid effects based on changes in properties between regions, such as a local increase in magnetic resistance or a local decrease in mechanical properties.

[0073] (Mechanical Properties) The second material may be harder than the third material. Since most of the second region 32 is an area where the coil portion 10 is not present, making the second region 32 harder reduces the likelihood of defects due to damage or deformation of the main body portion 30. This provides the main body portion 30 with a new function of suppressing damage during impact. From this perspective, the first material may also be harder than the third material. Furthermore, as described below, when the main body portion 30 is formed by pressing a material containing a magnetic powder and a hardenable material in a first direction, it becomes easier to control the position of the coil portion 10 within the main body portion 30.

[0074] From the viewpoint of stably realizing that the second material is harder than the third material, it may be preferable that the second area ratio, which is the area ratio of the magnetic powder in the second cut surface obtained by cutting the second region 32 in a plane perpendicular to the first direction, is higher than the third area ratio, which is the area ratio of the magnetic powder in the third cut surface obtained by cutting the third region 33 in a plane perpendicular to the first direction.

[0075] FIG. 7 illustrates the different shape distributions of magnetic powder particles. The left image corresponds to an observation image of the third cross section, and the right image corresponds to an observation image of the second cross section. Within the dashed circle, the cross section of the magnetic powder is shown hatched, and the cross section of materials other than the magnetic powder (matrix), such as binders, is shown colorless. A specific example of a binder is a polymer, as described below, in which case the magnetic powder is harder than the matrix. Therefore, as shown in FIG. 7, when the second area ratio (right image) is higher than the third area ratio (left image), the second material is harder than the third material.

[0076] From the viewpoint of achieving both the hardness of the second region 32 and the appropriate maintenance of the magnetic and electrical properties of the coil component 100 by suppressing the effect of high magnetic resistance in the third region 33, it may be preferable that the difference between the second area ratio and the third area ratio be 1% or more and 5% or less based on the second area ratio.

[0077] (Magnetic Powder) Here, the magnetic powder will be described. The composition of the magnetic powder may be such that the magnetic substance of the magnetic powder is made of a conductive material or such that the magnetic substance of the magnetic powder is made of an insulating material.

[0078] A specific example of a conductive material is a metal material. When the magnetic powder is a metal magnetic powder, its crystallographic structure is not limited. This structure may include a crystalline phase or an amorphous phase. Here, a crystalline material is defined as a material consisting of a crystalline phase, an amorphous material as a material consisting of an amorphous phase, and a composite material as a material consisting of a crystalline phase and an amorphous material. A material contains a crystalline phase when the diffraction spectrum obtained by a general X-ray diffraction method includes a sharp diffraction peak that can identify the type of crystalline phase. Furthermore, a material contains an amorphous phase when the diffraction spectrum obtained by a general X-ray diffraction method includes a broad peak indicating an amorphous phase. A material also contains an amorphous phase when the DSC curve obtained by differential thermal analysis includes a peak indicating crystallization, i.e., heat generation associated with a phase change from an amorphous phase to a crystalline phase.

[0079] The material system of the magnetic body is not limited. Specific examples of crystalline materials include Fe—Si—Cr alloys, Fe—Ni alloys, Fe—Co alloys, Fe—V alloys, Fe—Al alloys, Fe—Si alloys, Fe—Si—Al alloys, pure iron, and Mn—Zn ferrite. Carbonyl iron powder is preferred as pure iron powder. Specific examples of amorphous materials include Fe—Si—B alloys, Fe—P—C alloys, and Co—Fe—Si—B alloys. Specific examples of composite materials include Fe—Zr alloys, Fe—Zr—B alloys, Fe—Nb—B alloys, Fe—Si—B—Nb—Cu alloys, and Fe—Si—B—P—Cu alloys. When the magnetic body contains Fe, the synergistic effect of improving magnetic properties is particularly large.

[0080] The chemical composition of the magnetic material is not limited. For example, an Fe—Si—Cr alloy may be composed of 1.0 to 10.0 mass% Si, 1.0 to 10.0 mass% Cr, and the balance consisting of Fe and impurities. Also, for example, an Fe—Ni alloy may be composed of 1.0 to 99.0 mass% Ni, and the balance consisting of Fe and impurities. Furthermore, for example, an Fe—P—C alloy may be composed of 1.0 to 13.0 atomic% P, 1.0 to 13.0 atomic% C, Fe, and impurities. This Fe—P—C alloy may contain one or more optional elements selected from the group consisting of Ni, Sn, Cr, B, and Si. In this case, for example, the amount of Ni may be 0 to 10.0 atomic %, the amount of Sn may be 0 to 3.0 atomic %, the amount of Cr may be 0 to 6.0 atomic %, the amount of B may be 0 to 9.0 atomic %, and the amount of Si may be 0 to 7.0 atomic %. The amount of Fe is preferably 65 atomic % or more. Furthermore, for example, the Fe-Si-B-Nb-Cu alloy may be composed of 1.0 to 16.0 atomic % Si, 1.0 to 15.0 atomic % B, 0.50 to 5.0 atomic % Nb, 0.50 to 5.0 atomic % Cu, and the balance consisting of Fe and impurities. In this case, the amount of Fe is preferably 65 atomic % or more.

[0081] A specific example of the magnetic powder made of insulating material is Ni--Zn ferrite.

[0082] The magnetic powder may be subjected to a surface insulating treatment. When the magnetic powder is subjected to a surface insulating treatment, the insulation resistance of the main body 30 is improved. The type of surface insulating treatment to be applied to the magnetic powder is not limited. Examples include phosphate treatment, phosphate salt treatment, and oxidation treatment. The magnetic powder may have an insulating coating on the surface of the magnetic particles. This insulating coating may contain at least one element selected from the group consisting of Si, P, and B, and O (oxygen).

[0083] The magnetic powder may be a mixture of a plurality of powder materials. The magnetic powder is preferably a ferromagnetic material, and more preferably a soft magnetic material.

[0084] The shape distribution, which is the distribution of the shapes of the magnetic powder, includes the shape of the magnetic powder itself (spherical, acicular, irregular, etc.) and the distribution of particle size. An example of the particle size range of the magnetic powder is 0.10 to 50.0 μm. Specific examples of particle size distribution include a volumetric particle size distribution obtained by performing particle size measurement on the magnetic powder using a laser diffraction / scattering method, and a distribution of the average circular equivalent diameter of the magnetic powder obtained by analyzing an image (secondary electron image) obtained by capturing an image of a cross section of the main body 30 with a scanning electron microscope.

[0085] (Insulating Properties) In the main body 30, the second material may have higher insulating properties than the third material. In this case, the main body 30 is provided with a new function of ensuring insulation from the external electrodes. When the second surface 302 is the mounting surface side (the side facing the substrate SB), short circuits are less likely to occur on the mounting surface side. In particular, when bottom electrodes such as the first intersecting plane external electrode 41b and the second intersecting plane external electrode 42b are provided, insulation between the bottom electrodes and the main body 30 is ensured, making it less likely that short circuits will occur between the bottom electrodes.

[0086] Although different from the configuration shown in the figures, when the second surface 302 is on the opposite side to the mounting surface, the second region 32 is relatively susceptible to the effects of a collision, etc., but even if the exterior coating 60 peels off due to a collision, dielectric breakdown is less likely to occur. From this perspective, the first material may also have higher insulating properties than the third material.

[0087] One way to make the insulating property of the second material higher than that of the third material is to make the resistivity of the second region 32 higher than that of the third region 33 .

[0088] When the magnetic powder contains metal magnetic powder, it may be preferable for the relative permeability μ2 of the second region 32 to be smaller than the relative permeability μ1 of the first region 31, from the viewpoint of reliably realizing that the second material has higher insulating properties than the third material. When the magnetic powder contains metal magnetic powder, contact between the magnetic powder particles inside the main body 30 increases the possibility of forming a conductive path that reduces the insulating properties. Therefore, one method for relatively improving the insulating properties of the second region 32 is to increase the content of insulating material in the second material. In this case, the content of metal magnetic powder is reduced, so the relative permeability μ2 of the second region 32 is likely to be smaller than the relative permeability μ1 of the first region 31.

[0089] In this case, in the main body 30, the length h2 in the first direction of the second region 32 may be greater than the length h1 in the first direction of the first region 31. Even if the relative permeability μ2 of the second region 32 is smaller than the relative permeability μ1 of the first region 31, as long as h2 > h1, it is possible to prevent the magnetic reluctance of the second region 32 from becoming excessively high.

[0090] When μ2<μ1 as described above, the following formula (1) may be satisfied. When the following formula (1) is satisfied, the magnetic resistance of the second region 32 is unlikely to become excessively high. Therefore, the deterioration of the magnetic characteristics of the coil device 100 is more reliably avoided. |μ1×h1−μ2×h2| / (μ1×h1)≦0.1 (1)

[0091] In order to more stably achieve an increase in the insulating properties of the second material compared to the insulating properties of the third material when the magnetic powder contains metal magnetic powder, when the second region 32 is cut in a plane (XY plane) perpendicular to the first direction to obtain a second cut surface, and the third region 33 is cut in a plane perpendicular to the first direction to obtain a third cut surface, at least one of the following (A) or (B) may be satisfied: (A) the second area ratio, which is the area ratio of the magnetic powder in the second cut surface, is lower than the third area ratio, which is the area ratio of the magnetic powder in the third cut surface; and (B) the second average equivalent circle diameter, which is the average equivalent circle diameter of the magnetic powder in the second cut surface, is larger than the third average equivalent circle diameter, which is the average equivalent circle diameter of the magnetic powder in the third cut surface.

[0092] Regarding (A), by making the second area ratio < the third area ratio, μ2 < μ3 is likely to be achieved. In this case, the area ratio of the binder is higher in the second region 32, so the insulation properties of the second region 32 are likely to be high. Using Figure 7 as an example, (A) is satisfied when the cross section shown in the left diagram, where the area ratio of the magnetic powder is relatively low, is the second cross section, and the cross section shown in the right diagram is the third cross section.

[0093] Regarding (B), when the average equivalent circular diameter of the magnetic powder is relatively large, the filling rate tends to decrease. Therefore, by making the second average equivalent circular diameter greater than the third average equivalent circular diameter, μ2 < μ3 is easily achieved. In this case, the area ratio of the binder tends to be higher in the second region 32, and therefore the resistivity of the second region 32 tends to be higher.

[0094] In order to more reliably increase the insulating properties of the second material compared to the insulating properties of the third material, the second material may contain insulating inorganic particles as a third component. Many insulating inorganic particles have a higher dielectric strength than the binder, and this tendency is particularly pronounced when the binder is a polymer. By including inorganic particles as a third component of the second material, the possibility of dielectric breakdown in the second region 32 can be reduced. The type of inorganic particles is not limited. Oxide inorganic particles such as silica, alumina, and zirconia may be preferred due to their availability.

[0095] From the viewpoint of more reliably realizing an increase in the insulating properties of the second material compared to the insulating properties of the third material, the magnetic powder contained in the second region 32 may include metal magnetic powder having an insulating coating on its surface. When the magnetic powder is metal magnetic powder, the magnetic powder forms a conductive path in the event of dielectric breakdown. Therefore, by having an insulating coating on the surface of the metal magnetic powder, it may be possible to reduce the possibility of dielectric breakdown occurring in the second region 32.

[0096] (Prevention of short circuits in the coil portion) Fig. 8A is an explanatory diagram (comparative example) of an example of the function of the main body of the coil component according to one embodiment of the present invention, Fig. 8B is an explanatory diagram (inventive example) of an example of the function of the main body of the coil component according to one embodiment of the present invention, and Fig. 8C is a diagram illustrating different shape distributions of the magnetic powder.

[0097] 8A, a coil insulating portion 80 is provided around the first spiral conductor portion 11 and the second spiral conductor portion 21 to prevent short circuits between turns of the same spiral conductor portion. In addition, an insulating interposer 90 is disposed between the first spiral conductor portion 11 and the second spiral conductor portion 21 as an insulating portion to prevent short circuits between turns of the first spiral conductor portion 11 and turns of the second spiral conductor portion 21 that are aligned with these turns in the first direction.

[0098] However, when the magnetic powder MP3 contained in the third material constituting the third region 33 includes a metal magnetic powder, if the particle size of the magnetic powder MP3 is larger than the thickness of the interposer 90, there is a concern that the magnetic powder MP3 may be positioned so as to form a short-circuit path EP between the turn of the first spiral conductor portion 11 and the turn of the second spiral conductor portion 21, as shown in FIG. 8A. A similar short-circuit phenomenon may also occur between the first lead-out portion 14 and the turn of the second spiral conductor portion 21, or between the second lead-out portion 24 and the turn of the first spiral conductor portion 11. When a material containing the magnetic powder MP3 is placed around the coil portion 10 and pressurized to form the main body portion 30, the magnetic powder MP3 may come into contact with the conductor of the coil portion 10, partially destroying the insulating portion of the coil portion 10 (coil insulating portion 80, interposer 90), increasing the likelihood of the above-mentioned short-circuit phenomenon occurring.

[0099] Therefore, by making the shape distribution of the magnetic powder MP3 contained in the third material different from the shape distribution of the magnetic powder MP2 contained in the second material, a new function of suppressing short circuits in the coil portion 10 is imparted to the main body portion 30. In Fig. 8B, the magnetic powder MP3 contained in the third material is a metal magnetic powder having a smaller diameter than the magnetic powder MP2 contained in the second material and the magnetic powder MP1 contained in the first material. Therefore, even if the magnetic powder MP3 comes into contact with the conductor of the coil portion 10, partially destroying the insulating portion of the coil portion 10 (coil insulating portion 80, interposer 90), a short circuit is unlikely to occur.

[0100] The material constituting the interposer 90 is not limited as long as it has appropriate insulating properties. The interposer 90 has a volume resistivity of 1.0×10 obtained according to ASTM D257. 14 In some cases, it is preferable that the volume resistivity is 1.0×10 Ωcm or more. 15 More preferably, it is 1.0×10 Ωcm or more. 16 The upper limit of the volume resistivity is not particularly limited. 20 The dielectric constant may be Ωcm or less. Furthermore, it is preferable that the interposer 90 has excellent dielectric properties. Specifically, it may be preferable that the relative dielectric constant at 60 Hz obtained by ASTM D150 is 4.0 or less. This relative dielectric constant is more preferably 3.5 or less, and even more preferably 3.0 or less. The lower limit of this relative dielectric constant is not particularly limited. The relative dielectric constant may be 1.0 or more. To measure the volume resistivity and relative dielectric constant of the interposer 90, a separately prepared material corresponding to the interposer 90 is prepared and adjusted to the dimensions required for measurement. The material corresponding to the interposer 90 can be identified, as in the case of the coil insulating portion 80, through analytical techniques such as component analysis and FT-IR.

[0101] The material constituting the interposer 90 may be organic, inorganic, or a composite of organic and inorganic materials. When the interposer 90 is made of a composite material, the inorganic material may be in the form of particles dispersed in a matrix of organic material. Specific examples of organic materials include polyimide resin, polyethylene resin, polypropylene resin, polyamide resin, polyester resin, polyamideimide resin, polysulfone resin, polycarbonate resin, liquid crystal polymer resin, polyvinylidene fluoride resin, and polytetrafluoroethylene resin. Specific examples of inorganic materials, particularly composite materials, include inorganic materials such as oxides, carbides, nitrides, and inorganic salts. Examples of oxides include silica, alumina, and zirconia. Examples of carbides and nitrides include silicon carbide and boron nitride, respectively. Examples of inorganic salts include minerals such as wollastonite, kaolin, and mica. Among these, oxide-based materials such as oxides, silicates, and phosphates are preferred in terms of cost and insulating properties. For example, the inorganic material preferably contains at least one selected from the group consisting of silicon (Si), phosphorus (P), boron (B), and calcium (Ca).

[0102] From the viewpoint of more stably reducing the possibility of the above-mentioned short circuit phenomenon occurring, it may be preferable that, with regard to the shape distribution of the magnetic powder, when the second region is cut in a plane perpendicular to the first direction to obtain a second cut surface, and the third region is cut in a plane perpendicular to the first direction to obtain a third cut surface, the second cut surface and the third cut surface are compared to satisfy at least one of the following (a) to (d): (a) The third average equivalent circle diameter, which is the average equivalent circle diameter of magnetic powder MP3 at the third cut surface, is smaller than the second average equivalent circle diameter, which is the average equivalent circle diameter of magnetic powder MP2 at the second cut surface; (b) The third median diameter, which is the median diameter of magnetic powder MP3 at the third cut surface, is smaller than the second median diameter, which is the median diameter of magnetic powder MP2 at the second cut surface; and (c) The third maximum equivalent circle diameter, which is the maximum equivalent circle diameter of magnetic powder MP3 at the third cut surface, is smaller than the second maximum equivalent circle diameter, which is the maximum equivalent circle diameter of magnetic powder MP2 at the second cut surface. (d) At least one of the second diameter distribution, which is the distribution of the circular equivalent diameters of the magnetic powder MP2 on the second cross section, and the third diameter distribution, which is the distribution of the circular equivalent diameters of the magnetic powder MP3 on the third cross section, has two or more peaks, and the third peak diameter, which is the circular equivalent diameter with the highest frequency at the peak on the largest diameter side among the peaks of the third diameter distribution, is smaller than the second peak diameter, which is the circular equivalent diameter with the highest frequency at the peak on the largest diameter side among the peaks of the second diameter distribution.

[0103] Regarding (a), since the third region 33 is more likely to contain magnetic powder with a relatively small particle size, when the main body portion 30 is formed by applying pressure to a material containing magnetic powder MP3, even if the insulating portion (coil insulating portion 80, interposer 90) provided on the surface of the annular conductor portion (first spiral conductor portion 11, second spiral conductor portion 21, and via portion VP) is locally broken by the magnetic powder due to the application of pressure, a short circuit is less likely to occur within the annular conductor portion.

[0104] The difference between the second average equivalent circle diameter and the third average equivalent circle diameter may preferably be 1% or more and 5% or less based on the second average equivalent circle diameter. From the viewpoint of preventing short circuits within the annular conductor portion (the first spiral conductor portion 11, the second spiral conductor portion 21, and the via portion VP), a smaller third average equivalent circle diameter is preferable. However, since a smaller average equivalent circle diameter tends to increase the filling factor, if the third average equivalent circle diameter is excessively small, the filling factor of the second region 32 will be relatively low, and there is a concern that the magnetic resistance of the second region 32 will increase. By setting the third average equivalent circle diameter within the above range, it is possible to appropriately suppress short circuits within the annular conductor portion while preventing the magnetic resistance of the second region 32 from becoming too high.

[0105] Regarding (b), since the third region 33 is more likely to contain magnetic powder with a relatively small particle size, when the main body portion 30 is formed by applying pressure to a material containing magnetic powder MP3, even if the insulating portion provided on the surface of the annular conductor portion is locally broken by the magnetic powder due to the pressure, a short circuit is less likely to occur within the annular conductor portion.

[0106] The difference between the second median diameter and the third median diameter may be 1% or more and 5% or less based on the second median diameter. From the viewpoint of preventing short circuits within the annular conductor portion, a smaller third average circular equivalent diameter is preferable. However, since a smaller median diameter tends to increase the filling factor, if the third median diameter is excessively small, the filling factor of the second region 32 will be relatively low, and there is a concern that the magnetic resistance of the second region 32 will increase. If the third median diameter is within the above range, it is possible to appropriately suppress short circuits within the annular conductor portion while preventing the magnetic resistance of the second region 32 from becoming too high relatively.

[0107] Regarding (c), since the third region 33 is more likely to contain magnetic powder with a relatively small particle size, when the main body portion 30 is formed by applying pressure to a material containing magnetic powder MP3, even if the insulating portion provided on the surface of the annular conductor portion is locally broken by the magnetic powder MP3 due to the application of pressure, a short circuit is less likely to occur within the annular conductor portion.

[0108] The difference between the second maximum equivalent circle diameter and the third maximum equivalent circle diameter may preferably be 1% or more and 5% or less based on the second maximum equivalent circle diameter. From the viewpoint of preventing short circuits within the annular conductor portion, a smaller third maximum equivalent circle diameter is preferable. However, since a small maximum equivalent circle diameter may tend to increase the packing factor, if the third maximum equivalent circle diameter is excessively small, the packing factor of the second region 32 may be relatively low, and there may be a concern that the magnetic resistance of the second region 32 may increase. By setting the diameter within the above range, it is possible to appropriately suppress short circuits within the annular conductor portion while preventing the magnetic resistance of the second region 32 from becoming too high.

[0109] It may be preferable that the second maximum equivalent circle diameter is 12.0 μm or more and 50.0 μm or less, and the third maximum equivalent circle diameter is 2.0 μm or more and 10.0 μm or less. By setting the diameters within the above ranges, it is more likely that the effect of an increase in the magnetic resistance of the second region 32 can be suppressed while appropriately suppressing short circuits within the annular conductor portion.

[0110] Regarding (d), the third region 33 is more likely to contain magnetic powder with a relatively small particle size. Therefore, when forming the main body 30 by applying pressure to a material containing magnetic powder MP3, even if the insulating portion on the surface of the annular conductor is locally broken by the magnetic powder MP3 due to the application of pressure, a short circuit within the annular conductor is less likely to occur. Of the two distributions of equivalent circle diameters shown in Figure 8C, the distribution on the right has two peaks. Comparing the peaks on the largest diameter side of both distributions, the distribution on the right has a larger diameter. Therefore, of the two distributions of equivalent circle diameters shown in Figure 8C, the left side is an example of the third diameter distribution, and the right side is an example of the second diameter distribution.

[0111] It may be preferable that the difference between the second peak diameter and the third peak diameter be 1% or more and 5% or less based on the second peak diameter. From the viewpoint of preventing short circuits within the annular conductor portion, a smaller third peak diameter is preferable. However, since a smaller peak diameter tends to increase the filling factor, if the third peak diameter is excessively small, the filling factor of the second region 32 will be relatively low, and there is a concern that the magnetic resistance of the second region 32 will increase. If the third peak diameter is within the above range, it is possible to appropriately suppress short circuits within the annular conductor portion while preventing the magnetic resistance of the second region 32 from becoming too high relatively.

[0112] It may be preferable that the second diameter distribution has a larger number of peaks than the third diameter distribution. By including small-diameter magnetic powder in the second region 32, which contains relatively large-diameter magnetic powder, to the extent that it has a peak, it becomes easier to increase the packing density of the magnetic powder MP2, and the magnetic properties of the second region 32 tend to improve. Of the two distributions of equivalent-circle diameters shown in Figure 8C, the distribution on the right, which is an example of the second diameter distribution, has two peaks.

[0113] When the magnetic powder MP3 contains metal magnetic powder and the above-mentioned short circuit is a concern, from the viewpoint of more stably reducing the possibility of the short circuit phenomenon occurring, it may be preferable that at least one of the second particle size distribution, which is the volume particle size distribution of the magnetic powder contained in the second region 32, and the third particle size distribution, which is the volume particle size distribution of the magnetic powder contained in the third region 33, has two or more peaks, and that the third particle size, which is the particle size with the highest frequency at the peak on the largest diameter side among the peaks of the third particle size distribution, is smaller than the second particle size, which is the particle size with the highest frequency at the peak on the largest diameter side among the peaks of the second particle size distribution.

[0114] Since the third region 33 is more likely to contain magnetic powder with a relatively small particle size, when the main body 30 is formed by applying pressure to a material containing magnetic powder MP3, even if the insulating portion provided on the surface of the annular conductor portion is locally broken by the magnetic powder MP3 due to the pressure, a short circuit is less likely to occur within the annular conductor portion.

[0115] The difference between the second particle size and the third particle size may preferably be 1% or more and 5% or less based on the second particle size. From the viewpoint of preventing short circuits within the annular conductor portion, a smaller third particle size is preferable. However, since a small particle size as defined above may tend to increase the packing factor, if the third particle size is excessively small, the packing factor of the second region 32 may be relatively low, raising concerns about an increase in the magnetic resistance of the second region 32. Within the above range, it is possible to appropriately prevent short circuits within the annular conductor portion while preventing the magnetic resistance of the second region 32 from becoming too high.

[0116] It may be preferable that the second particle size distribution has a larger number of peaks than the third particle size distribution. By containing small-diameter magnetic powder to an extent that it has a peak in the second region 32 containing relatively large-diameter magnetic powder, it becomes easy to increase the filling rate of the magnetic powder MP2, and the magnetic properties of the second region 32 tend to be improved.

[0117] The above description compares the magnetic powder MP3 contained in the third region 33 with the magnetic powder MP2 contained in the second region 32. However, the magnetic powder MP1 contained in the first region 31 and the magnetic powder MP2 contained in the second region 32 may have a similar relationship. In this case, the shape distribution of the magnetic powder MP1 and the shape distribution of the magnetic powder MP2 may be equal or different. From the viewpoint of suppressing a local increase in magnetic resistance, it may be preferable that the shape distribution of the magnetic powder MP1 and the shape distribution of the magnetic powder MP2 are equal. When the second surface 302 is the mounting surface as in this embodiment, it may be preferable that the second region 32 has relatively high insulation properties or a relatively high hardness. From these viewpoints, it may be preferable that the shape distribution of the magnetic powder MP1 and the shape distribution of the magnetic powder MP2 are different.

[0118] (Binder) In the main body 30, the binder contained in the second region 32 may contain a second polymer, and the binder contained in the third region 33 may contain a third polymer. Since the physical properties of a polymer can be easily adjusted by adjusting the monomer composition and degree of polymerization, the binder containing a polymer makes it easy to adjust the binder's characteristics. Examples of polymers include acrylic resin, silicone resin, epoxy resin, phenolic resin, urea resin, melamine resin, and polyester resin. The binder may contain an inorganic material, for example, a glass-based material such as water glass.

[0119] The weight-average molecular weight of the second polymer may be greater than the weight-average molecular weight of the third polymer. The second region 32 containing the polymer with a relatively high molecular weight tends to have high strength and high viscosity overall. In this case, the difference between the weight-average molecular weight of the second polymer and the weight-average molecular weight of the third polymer may be 1% or more and 5% or less based on the weight-average molecular weight of the second polymer. The benefits of the high strength and high viscosity of the second region 32 can be stably enjoyed.

[0120] The density of unreacted groups in the second polymer may be lower than the density of unreacted groups in the third polymer. Examples of unreacted groups include active functional groups that are highly reactive with other functional groups, such as glycidyl groups, isocyanate groups, and carboxy groups, and functional groups having active hydrogen that react with such active functional groups (such as hydroxyl groups and amino groups). When the polymer is polymerized using a radical polymerization catalyst, ethylenically unsaturated bonds may also be unreacted groups.

[0121] The second region 32 containing the polymer with a relatively low density of unreacted groups tends to have high strength and high viscosity overall. In this case, the difference between the density of unreacted groups in the second polymer and the density of unreacted groups in the third polymer may be 1% or more and 5% or less based on the density of unreacted groups in the second polymer. This allows the benefits of high strength and high viscosity of the second region 32 to be stably enjoyed.

[0122] When the second material contains a polymerization catalyst for forming a binder and the third material contains a polymerization catalyst for forming a binder, the content of the polymerization catalyst in the second material may be greater than the content of the polymerization catalyst in the third material. The polymerization catalyst is appropriately selected depending on the monomer used to form the polymer. Examples of polymerization catalysts include urethane polymerization catalysts such as 2-(dimethylamino)ethanol, epoxy polymerization catalysts such as tetrabutylphosphonium bromide, and olefin polymerization catalysts such as metallocene compounds. The second region 32, which contains a polymer with a relatively high content of polymerization catalyst, tends to have high strength and viscosity overall. In this case, the difference between the content of the polymerization catalyst in the second material and the content of the polymerization catalyst in the third material may be 1% or more and 5% or less based on the content of the polymerization catalyst in the second material. The benefits of the high strength and high viscosity of the second region 32 can be consistently enjoyed.

[0123] The nanoindenter hardness of the binder contained in the second region 32 may be smaller than the nanoindenter hardness of the binder contained in the third region 33. The second region 32 containing a relatively hard binder tends to have high strength and high viscosity overall. In this case, the difference between the nanoindenter hardness of the second binder and the nanoindenter hardness of the third binder may be 1% or more and 5% or less, based on the nanoindenter hardness of the second binder. The benefits of the second region 32 being hard and highly viscous can be stably enjoyed.

[0124] The binder contained in the first region 31 may contain a first polymer. Specific examples of this polymer are the same as those of the second polymer and the third polymer. The binder contained in the first region 31 may contain an inorganic material. The first polymer may have the same composition as the second polymer or the third polymer, or may have a different composition from either of them.

[0125] 9 and 10 are XZ cross-sectional views illustrating a third and fourth modified example of the coil component according to an embodiment of the present invention.

[0126] The coil component 100C according to one of the modified examples of this embodiment shown in Figure 9 has a basic structure in common with the coil component 100, so only the differences in structure will be described, and the description of the common structure will be omitted.

[0127] In comparison with the coil component 100, the coil component 100C according to this example has a first connection conductor 15 extending from the first lead-out portion 14 toward the second surface 302 (the Z2 side in the Z1-Z2 direction), and a second connection conductor 25 extending from the second lead-out portion 24 toward the second surface 302 (the Z2 side in the Z1-Z2 direction). The first connection conductor 15 is exposed from the second surface 302 of the main body portion 30 at a first connection end portion 15E, and the second connection conductor 25 is exposed from the second surface 302 of the main body portion 30 at a second connection end portion 25E. The first connection end portion 15E is electrically connected to the first intersecting plane external electrode 41b as part of the first end face of the coil portion 10, and the second connection end portion 25E is electrically connected to the second intersecting plane external electrode 42b as part of the second end face of the coil portion 10. Therefore, the first external electrode 41 is electrically connected to the first lead-out end portion 14E and the first connection end portion 15E, and the second external electrode 42 is electrically connected to the second lead-out end portion 24E and the second connection end portion 25E, thereby stabilizing the electrical connection between the coil device 100 and the first board electrode E1 and the second board electrode E2.

[0128] The coil component 100D according to one of the modified examples of this embodiment shown in Figure 10 has a basic structure in common with the coil component 100C, so only the differences in structure will be described, and the description of the common structure will be omitted.

[0129] In the coil component 100D according to this example, the first external electrode 41 does not have a first lateral external electrode 41a but consists of a first intersecting plane external electrode 41b, and the second external electrode 42 does not have a second lateral external electrode 42a but consists of a second intersecting plane external electrode 42b. In the coil component 100C, an exterior coating 61 is located where the first lateral external electrode 41a is located, and an exterior coating 62 is located where the second lateral external electrode 42a is located. Therefore, in the coil component 100D, the first end face of the coil section 10 consists of the first connecting end 15E, the second end face of the coil section 10 consists of the second connecting end 25E, and the portions in electrical contact with the first board electrode E1 and the second board electrode E2 are located only on the mounting surface side (the Z2 side in the Z1-Z2 direction). Therefore, in the board SB on which the coil component 100D is mounted, the areas of the first board electrode E1 and the second board electrode E2 can be reduced, specifically, the extension portion of the first board electrode E1 on the X2 side in the X1-X2 direction can be shortened, and the extension portion of the second board electrode E2 on the X1 side in the X1-X2 direction can be shortened. In other words, by using the coil component 100D, it is possible to increase the packaging density of components mounted on the board SB.

[0130] (Method for Manufacturing Coil Component) The method for manufacturing the coil component according to this embodiment is not particularly limited. One non-limiting example of the manufacturing method is as follows.

[0131] FIG. 11A is an explanatory diagram (part 1) of an example of a manufacturing method for a coil component according to an embodiment of the present invention, and is an XY plan view of a coil array sheet. FIG. 11B is an XZ cross-sectional view taken along line CC' in FIG. 11A. FIG. 12 is an explanatory diagram (part 2) of an example of a manufacturing method for a coil component according to an embodiment of the present invention, and is an XZ cross-sectional view showing a state in which a coil array sheet and the like are placed in a cavity of a mold. FIG. 13 is an explanatory diagram (part 3) of an example of a manufacturing method for a coil component according to an embodiment of the present invention, and is an XZ cross-sectional view showing a state in which a molded body is formed after molding using a mold. FIG. 14 is an explanatory diagram (part 4) of an example of a manufacturing method for a coil component according to an embodiment of the present invention, and is an XZ cross-sectional view showing a state before cutting the molded body. FIG. 15 is an explanatory diagram (part 5) of an example of a manufacturing method for a coil component according to an embodiment of the present invention, and is an XZ cross-sectional view showing a state in which the molded body is cut to obtain coil chips.

[0132] First, as shown in the XY plan view of FIG. 11A and the XZ cross-sectional view of FIG. 11B, a coil array sheet 500 is formed in which a plurality of coil sections 10, each including a first spiral conductor section 11 and a second spiral conductor section 21 and a first lead section 14 and a second lead section 24, are connected to each other via a first linking conductor section 16 and a second linking conductor section 26. The manufacturing method is not limited, but a plating process can be used as described below. Specifically, first, a conductor layer (seed layer) is formed on both sides (the Z1 side and the Z2 side in the Z1-Z2 direction) of the surface of an insulating sheet substrate. Next, electroplating is performed to form a conductor, including the first spiral conductor section 11 and the second spiral conductor section 21, the first lead section 14 and the second lead section 24, and the first linking conductor section 16 and the second linking conductor section 26, on the conductor layer by plating deposits, as shown in FIG. 11B.

[0133] The method for forming the conductor is not limited. For example, a pattern of an insulating layer that is a negative pattern of the conductor may be formed on a conductor layer on an insulating sheet substrate, and an electroplating process may be performed in which an electric current is passed through the conductor layer, thereby depositing a plating deposit on the conductor layer exposed around the negative pattern, thereby forming a conductor having a desired shape. In this plating process, the plating deposit can be filled into the through-holes of the sheet substrate to form via portions VP.

[0134] Next, at least a portion of the exposed portion of the sheet substrate on which the conductor has been formed that is not covered by the conductor in the Z1-Z2 direction is removed. Specifically, the sheet substrate is removed so as to include the area of ​​the sheet substrate surrounded by the inner edges of the first spiral conductor portion 11 and the second spiral conductor portion 21 when viewed in the first direction (Z1-Z2 direction). As described above, when a negative pattern made of an insulating layer is used in the conductor formation step, the insulating layer is first removed, and then the conductor layer exposed in the Z1-Z2 direction due to the removal of the insulating layer is removed. In this way, a portion of the sheet substrate is exposed in the Z1-Z2 direction as an exposed portion, and a process of removing this exposed portion is performed.

[0135] The specific removal process for the sheet substrate is appropriately set depending on the constituent material of the sheet substrate. Removal processes are broadly classified into dry processes such as plasma etching and wet processes such as wet etching. A portion of the sheet substrate may be removed by the removal process, with the remainder remaining. For example, the sheet substrate may be made of a composite material having a matrix portion made of an organic material and an inorganic material dispersed in the matrix portion, and the removal process may remove the sheet substrate by removing the matrix portion made of the organic material.

[0136] Next, the coil insulating section 80 is formed so as to cover the exposed surface of the conductor, thereby forming the coil array sheet 500. Note that in the above manufacturing method, the portion of the insulating section of the coil array sheet 500 that is covered with the conductor on both sides in the Z1-Z2 direction is not made up of the coil insulating section 80 but of the remaining portion of the sheet base material, but is not shown in Figure 11B and is treated as the same as the coil insulating section 80.

[0137] The coil array sheet 500 obtained in this manner is placed in the cavity 70C of the mold 70. At this time, the first member 311 is positioned on one side in the first direction of the coil array sheet 500 including the coil portion 10, the second member 321 is positioned on the other side in the first direction of the coil array sheet 500 including the coil portion 10, and the third member 331 is positioned between the first member 311 and the second member 321. Specifically, as shown in FIG. 12 , the second member 321, a part 331A of the third member 331, the coil array sheet 500, another part 331B of the third member 331, and the first member 311 are arranged in this order from the lower mold 71 side (Z2 side in the Z1-Z2 direction) to the upper mold 72 side (Z1 side in the Z1-Z2 direction) of the mold 70. In this way, the laminated structure including the coil array sheet 500, the first member 311, the second member 321, and the third member 331 is placed in the cavity 70C of the mold 70.

[0138] The first member 311 contains a first magnetic powder and a first hardenable material, and after molding becomes a first material body 310 made of the first material that constitutes the first region 31. The second member 321 contains a second magnetic powder and a second hardenable material, and after molding becomes a second material body 320 made of the second material that constitutes the second region 32. The third member 331 contains a third magnetic powder and a third hardenable material, and after molding becomes a third material body 330 made of the third material that constitutes the third region 33 including the central region CR.

[0139] As mentioned above, in this specification, the term "curable material" includes both materials that are cured and materials that are cured (such as polymerization initiators). Specific examples include compounds containing active functional groups that are highly reactive with other functional groups, such as glycidyl groups, isocyanate groups, and carboxy groups, as well as compounds containing functional groups with active hydrogen (such as hydroxyl groups and amino groups) that react with such active functional groups. Crosslinking substances containing multivalent ions, such as magnesium and calcium, are also included in the curable material. When a curable material is polymerized using a radical polymerization catalyst, compounds with ethylenically unsaturated bonds can also be used as curable materials. Polymerization catalysts that initiate and continue the polymerization reaction of the above-mentioned polymerization-carrying substances are also included in the curable material. Examples of polymerization catalysts include urethane polymerization catalysts such as 2-(dimethylamino)ethanol, epoxy polymerization catalysts such as tetrabutylphosphonium bromide, and olefin polymerization catalysts such as metallocene compounds.

[0140] The second member 321 and the third member 331 differ in one or more points selected from the group consisting of the following [1] to [6]. [1] The composition of the second magnetic powder and the composition of the third magnetic powder; [2] The particle size distribution of the second magnetic powder and the particle size distribution of the third magnetic powder; [3] The content of the second magnetic powder in the second member 321 and the content of the third magnetic powder in the third member 331; [4] The composition of the second hardenable material and the composition of the third hardenable material; [5] The content of the second hardenable material in the second member 321 and the content of the third hardenable material in the third member 331; and [6] When the second member 321 contains a second additive component other than the second hardenable material and the second magnetic powder, and the third member 331 contains a third additive component other than the third hardenable material and the third magnetic powder, the composition of the second additive component and the composition of the third additive component.

[0141] This allows the second material formed from the second member 321 to be different from the third material formed from the third member 331, and allows the characteristics of the second region 32 to be different from the characteristics of the third region 33.

[0142] The laminated structure thus obtained is subjected to a molding process that includes increasing the pressure in the cavity, thereby forming the laminated structure into a coil portion 10 and a main body portion 30, as shown in Fig. 13. Specifically, a molded body 500A is obtained that includes a coil array sheet 500 including a plurality of coil portions 10 and a main body component 300 that provides the main body portion 30. The molding process for obtaining the molded body 500A from the laminated structure may involve heating in addition to pressurization. As will be described later, if the third curable material in the third member 331 is not cured to a sufficient degree, the curing may be completed by, for example, heating.

[0143] The first member 311 and the third member 331 may have the same composition, or the first member 311 and the third member 331 may be integral. When the first member 311 and the third member 331 are integral, the arrangement of the laminated structure in the cavity 70C of the mold 70 is facilitated. A specific example of an integral member is when the first member 311 and a part 331A of the third member 331 are integral. The second member 321 and the other part 331B of the third member 331 are made of different materials, but may be integrated by a preheating process or the like. In this case, the arrangement of the laminated structure in the cavity 70C of the mold 70 is also facilitated.

[0144] The molding process may include curing the first to third curable materials. By performing such a curing process, the first member 311 and the first material body 310 are made of different materials, the second member 321 and the second material body 320 are made of different materials, and the third member 331 and the third material body 330 are made of different materials. Therefore, the first member 311 to the third member 331 can be given unique functions in terms of molding process.

[0145] A specific example of such a unique function is the positioning function of the coil array sheet 500 within the mold during molding to form the molded body 500A. Specifically, as shown in FIG. 12 , when the first direction is aligned with the vertical direction (Z1-Z2 direction) and the second member 321 is positioned below the coil array sheet 500, the second member 321 is made harder than the third member 331. As a result, when a compressive force in the first direction is applied to the mold 70, the coil array sheet 500 is easily embedded within the relatively soft third member 331, particularly the portion 331A of the third member, but is difficult to embed within the relatively hard second member 321. As a result, during molding, the bottom of the coil array sheet 500 on the vertical lower side (Z2 side in the Z1-Z2 direction) is stabilized in contact with the upper end of the second member 321. This improves the positional accuracy in the vertical direction (first direction) of the coil array sheet 500 in the molded body 500A. Specifically, in the coil device 100, it becomes easy to set the distance between the end of the coil portion 10 on the Z2 side in the Z1-Z2 direction and the second surface 302 within an appropriate range.

[0146] Making the second member 321 harder than the third member 331 may be achieved by satisfying at least one of the following conditions (I) to (VI). (I) For the laminated structure disposed in the cavity, the viscosity of the second curable material is higher than the viscosity of the third curable material. (II) For the laminated structure disposed in the cavity, the degree of polymerization of the second curable material is higher than the degree of polymerization of the third curable material. (III) For the laminated structure disposed in the cavity, the content of uncured material contained in the second curable material is lower than the content of uncured material contained in the third curable material. (IV) The second curable material and the third curable material contain a polymerization catalyst, and for the laminated structure disposed in the cavity, the content of the polymerization catalyst contained in the second curable material is higher than the content of the polymerization catalyst contained in the third curable material. (V) For the laminated structure disposed in the cavity, the volume ratio of the second magnetic powder contained in the second member 321 is higher than the volume ratio of the third magnetic powder contained in the third member 331. (VI) When the gel time defined in JIS K5600-9-1:2006 is measured for the second curable material and the third curable material contained in the laminated structure placed in the cavity, the gel time of the second curable material is shorter than the gel time of the third curable material.

[0147] Just as the second member 321 is harder than the third member 331, the first member 311 may be harder than the third member 331. In this case, during the molding process, the end of the coil array sheet 500 on the upper vertical side (Z1 side in the Z1-Z2 direction) is stabilized in contact with the end of the second member 321 on the lower vertical side (Z2 side in the Z1-Z2 direction). This further improves the positional accuracy of the coil array sheet 500 in the molded body 500A in the vertical direction (first direction). Specifically, in the coil device 100, it becomes easy to set the distance between the end of the coil portion 10 on the Z1 side in the Z1-Z2 direction and the first surface 301 within an appropriate range.

[0148] The second member 321 may have higher insulating properties than the third member 331. In this case, the insulating properties of the second material formed from the second member 321 can be made higher than the insulating properties of the third material formed from the third member 331.

[0149] In the case where the coil portion 10 has an insulating portion (such as the coil insulating portion 80) covering the surface of the annular conductor portion, as in this embodiment, and the third magnetic powder contains metal magnetic powder, it may be preferable that when the second member 321 is cut to obtain a second member cut surface and the third member 331 is cut to obtain a third member cut surface, at least one of the following (i) to (iv) is satisfied. (i) The third member average equivalent circle diameter, which is the average equivalent circle diameter of the third magnetic powder at the cut surface of the third member, is smaller than the second member average equivalent circle diameter, which is the average equivalent circle diameter of the second magnetic powder at the cut surface of the second member; (ii) The third member median diameter, which is the median diameter of the third magnetic powder at the cut surface of the third member, is smaller than the second member median diameter, which is the median diameter of the second magnetic powder at the cut surface of the second member; and (iii) The third member maximum equivalent circle diameter, which is the maximum equivalent circle diameter of the third magnetic powder at the cut surface of the third member, is smaller than the second member maximum equivalent circle diameter, which is the maximum equivalent circle diameter of the magnetic powder at the cut surface of the second member. (iv) At least one of the second member diameter distribution, which is a distribution of the circle-equivalent diameters of the second magnetic powder at the cross section of the second member, and the third member diameter distribution, which is a distribution of the circle-equivalent diameters of the third magnetic powder at the cross section of the third member, has two or more peaks, and the third member peak diameter, which is the circle-equivalent diameter with the highest frequency at the peak on the largest diameter side among the peaks of the third member diameter distribution, is smaller than the second member peak diameter, which is the circle-equivalent diameter with the highest frequency at the peak on the largest diameter side among the peaks of the second member diameter distribution.

[0150] Once the molded body 500A has been formed in the cavity 70C of the mold 70, it is removed from the mold 70 and cut along dicing lines DL1 and DL2 shown in Fig. 14. This results in a coil chip 100Z having a main body portion 30 consisting of a first region 31, a second region 32, and a third region 33, and a coil portion 10. By forming exterior coatings 50 and 60 on this coil chip 100Z and then forming a first external electrode 41 and a second external electrode 42, the coil component 100 is obtained.

[0151] 16A to 18 are explanatory views (parts 1 to 3) of an example of a manufacturing method for a modified coil component according to an embodiment of the present invention. In the case where the first connection conductor 15 and the second connection conductor 25 are provided as in the coil components 100C and 100D described above, the coil component 10 may be configured to have the first connection conductor 15 and the second connection conductor 25 in the state of the coil array sheet 501, as shown in FIGS. 16A and 16B. In the coil array sheet 501, the second connection conductor 25 and the second linking conductor 26 are integrated, and are separated by cutting.

[0152] The molding process for the coil array sheet 501 is basically the same as that for the coil array sheet 500. In the example shown in Fig. 17, the portion of the coil array sheet 501 on the Z2 side in the Z1-Z2 direction, which includes the second connection conductor 25 and the second linking conductor 26, and the portion including the first connection conductor 15 (hereinafter, these portions will be referred to as "protruding portions"), are embedded in a part 331A of the third member and are in contact with the end of the second member 321 on the Z1 side in the Z1-Z2 direction. This arrangement can be achieved by making the second member 321 harder than the third member 331.

[0153] In this state, the molds are clamped to bring the lower mold 71 and the upper mold 72 close to each other, whereby the protruding portion is embedded inside the second member 321, and the first spiral conductor portion 11 and the second spiral conductor portion 21 of the coil portion 10 are embedded in the third member 331. Then, as in the case of the coil array sheet 500, hardening of each member progresses with the lower end (the end portion on the Z2 side in the Z1-Z2 direction) of the second spiral conductor portion 21 in contact with the upper end (the end portion on the Z1 side in the Z1-Z2 direction) of the second member 321, and a molded body 501A is obtained in which the coil array sheet 501 is embedded in the main body constituent member 300 including the first material body 310 made of the first material formed from the first member 311, the second material body 320 made of the second material formed from the second member 321, and the third material body 330 made of the third material formed from the third member 331. Thereafter, by carrying out the manufacturing method including cutting in the same manner as for molded body 500A, coil component 100C and coil component 100D can be obtained.

[0154] (Electronic / Electrical Device) An electronic / electrical device according to one embodiment of the present invention is an electronic / electrical device that incorporates coil components 100, 100A, 100B, 100C, and 100D according to one embodiment of the present invention, and coil components 100, 100A, 100B, 100C, and 100D are connected to a substrate SB via terminal portions (first external electrode 41 and second external electrode 42) provided on exposed conductor portions (e.g., first lead-out end 14E and second lead-out end 24E) that are located at two ends of coil portion 10 and exposed to the outside. Because the electronic / electrical device according to one embodiment of the present invention incorporates coil components 100, 100A, 100B, 100C, and 100D according to one embodiment of the present invention, it is easy to miniaturize the device. In particular, coil component 100D is easily adaptable to high-density packaging, and therefore devices including these components are particularly easy to miniaturize. Furthermore, even if a large current flows through the device or a high frequency is applied, the coil components 100, 100A, 100B, 100C, and 100D are less likely to suffer from deterioration in their characteristics or problems due to heat generation.

[0155] The above-described embodiments and examples are provided to facilitate understanding of the present invention and are not intended to limit the present invention. Therefore, the elements disclosed in the above embodiments are intended to encompass all design modifications and equivalents within the technical scope of the present invention. For example, in the above description, the second surface 302 of the main body 30 is positioned on the mounting surface side during use and on the lower side during manufacturing. However, this is not limited to this. For example, the first surface 301 of the main body 30 may be positioned on the lower side during manufacturing, and the second surface 302 may be positioned on the mounting surface side during use. In this case, by making the first member 311 harder than the third member 331, the positional stability of the coil portion 10 during molding can be improved. By making the first region 31 harder than the third region 33 during use, resistance to impacts such as collisions can be improved. By making the second region 32 more insulating than the third region 33, the possibility of a short circuit between the first substrate electrode E1 and the second substrate electrode E2 can be reduced. In addition, in the description of the manufacturing method of the coil devices 100 and 100D, the third member 331 is composed of two members and is arranged to sandwich the coil array sheet 500, but this is not limiting. The third member 331 may be composed of a single member and may be arranged above or below the coil array sheet 500.

[0156] 100, 100A, 100B, 100C, 100D: Coil component 10: Coil portion 11: First spiral conductor portion 12, 22: Inner peripheral end portion 13, 23: Outer peripheral end portion 14: First lead-out portion 14E: First lead-out end portion 15: First connecting conductor portion 15E: First connecting end portion 16: First linking conductor portion 20: Coil conductor portion 21: Second spiral conductor portion 24: Second lead-out portion 24E: Second lead-out end portion 25: Second connecting conductor portion 25E: Second connecting end portion 26: Second linking conductor portion 30: Main body portion 31: First region 32: Second region 33: Third region 33E1: First extension portion 33E2: Second extension portion 41: First external electrode 41a: First lateral external electrode 41b: First intersecting plane external electrode 42: Second external electrode 42a: Second lateral external electrode 42b: Second intersecting plane external electrode 50, 60, 61, 62: Exterior coating 70: Mold 70C: Cavity 71: Lower mold 72: Upper mold 80: Coil insulating portion 90: Interposer 100Z: Coil chip 101: First end portion 102: Second end portion 300: Main body portion constituent member 301: First surface 302: Second surface 310: First material body 311: First member 320: Second material body 321: Second member 330: Third material body 331: Third member 331A: Part of the third member 331B: Another part of the third member 341: First intermediate layer 342: Second intermediate layer 500, 501: Coil array sheet 500A, 501A: Molded body CR: Central region DL1, DL2: Dicing line E1: First board electrode E2: Second board electrode EP: Short circuit path MP1, MP2, MP3: Magnetic powder O: Central axis S1, S2: Solder SB: Board VP: Via portion

Claims

1. A coil portion having an annular conductor portion having a central axis along a first direction and two electrical ends; and a main body portion covering the annular conductor portion with a first face and a second face aligned in the first direction, the main body portion including a magnetic powder and a binder, wherein the coil portion is exposed from a surface of the main body portion at a first end face connected to one of the two electrical ends of the annular conductor portion and a second end face connected to the other of the two electrical ends of the annular conductor portion, the main body portion including: a first region made of a first material and including the first face; a second region made of a second material and including the second face; and a third region made of a third material and located between the first face and the second face in the first direction, the third region including a central region whose entire outer circumferential edge faces an inner circumferential surface of the annular conductor portion, the second material and the third material being determined by: a composition of the magnetic powder; a shape distribution which is a distribution relating to the shape of the magnetic powder; a content of the magnetic powder; A coil component characterized in that the two components are different in at least one selected from the group consisting of the composition of the binder, the content of the binder, and, when a third component other than the magnetic powder and the binder is contained, the composition and the content of the third component.

2. The coil component according to claim 1, wherein the first material and the second material are equal.

3. A coil component as described in claim 1, wherein the first material and the second material differ in one or more selected from the group consisting of: the composition of the magnetic powder, the shape distribution of the magnetic powder, the amount of the magnetic powder, the composition of the binder, the amount of the binder, and, if a third component other than the magnetic powder and the binder is contained, the composition and the amount of the third component.

4. The coil component according to claim 1, wherein the first material and the third material are equal.

5. A coil component according to claim 1, wherein the annular conductor portion is in contact with at least one of the first region and the second region at an end in the first direction.

6. A coil component as described in claim 1, wherein the third region extends in the first direction so as to contact at least one of two ends of the annular conductor portion in the first direction.

7. The coil component according to claim 1, wherein the second material is harder than the third material.

8. A coil component as described in claim 7, wherein a second area ratio, which is the area ratio of the magnetic powder in a second cut surface obtained by cutting the second region with a surface perpendicular to the first direction, is higher than a third area ratio, which is the area ratio of the magnetic powder in a third cut surface obtained by cutting the third region with a surface perpendicular to the first direction.

9. The coil component according to claim 1, wherein the second material has higher insulating properties than the third material.

10. The coil component according to claim 9, wherein the resistivity of the second region is greater than the resistivity of the third region.

11. A coil component as described in claim 9, wherein the magnetic powder contained in the second material includes metal magnetic powder, and the relative permeability μ2 of the second region is smaller than the relative permeability μ1 of the first region.

12. The coil component according to claim 11, wherein the length h2 of the second region in the first direction is greater than the length h1 of the first region in the first direction.

13. A coil component as described in claim 9, which satisfies at least one of the following when the second region is cut with a plane perpendicular to the first direction to obtain a second cut surface, and the third region is cut with a plane perpendicular to the first direction to obtain a third cut surface: (A) a second area ratio that is an area ratio of the magnetic powder on the second cut surface is lower than a third area ratio that is an area ratio of the magnetic powder on the third cut surface; and (B) a second average equivalent circle diameter that is an average equivalent circle diameter of the magnetic powder on the second cut surface is larger than a third average equivalent circle diameter that is an average equivalent circle diameter of the magnetic powder on the third cut surface.

14. The coil component according to claim 9, wherein the second material contains insulating inorganic particles as the third component.

15. A coil component as described in claim 9, wherein the magnetic powder contained in the second material includes metallic magnetic powder having an insulating coating on its surface.

16. The annular conductor portion has an insulating portion on its surface, the magnetic powder contained in the third material includes a metal magnetic powder, and when the second region is cut in a plane perpendicular to the first direction to obtain a second cut surface, and the third region is cut in a plane perpendicular to the first direction to obtain a third cut surface, (a) a third average equivalent circle diameter which is an average equivalent circle diameter of the magnetic powder at the third cut surface is smaller than a second average equivalent circle diameter which is an average equivalent circle diameter of the magnetic powder at the second cut surface, (b) a third median diameter which is a median diameter of the magnetic powder at the third cut surface is smaller than a second median diameter which is a median diameter of the magnetic powder at the second cut surface, and (c) a third maximum equivalent circle diameter which is a maximum equivalent circle diameter of the magnetic powder at the third cut surface is smaller than a second maximum equivalent circle diameter which is a maximum equivalent circle diameter of the magnetic powder at the second cut surface, (d) at least one of a second diameter distribution which is a distribution of circular equivalent diameters of the magnetic powder on the second cut surface and a third diameter distribution which is a distribution of circular equivalent diameters of the magnetic powder on the third cut surface has two or more peaks, and a third peak diameter which is a circular equivalent diameter with a maximum frequency at the peak on the largest diameter side among the peaks in the third diameter distribution is smaller than a second peak diameter which is a circular equivalent diameter with a maximum frequency at the peak on the largest diameter side among the peaks in the second diameter distribution.

17. A coil component as described in claim 1, wherein the annular conductor portion has an insulating portion on its surface, the magnetic powder contained in the third material includes metal magnetic powder, at least one of a second particle size distribution which is a volumetric particle size distribution of the magnetic powder contained in the second region and a third particle size distribution which is a volumetric particle size distribution of the magnetic powder contained in the third region has two or more peaks, and a third particle size which is the particle size with the greatest frequency at the peak on the largest diameter side among the peaks of the third particle size distribution is smaller than a second particle size which is the particle size with the greatest frequency at the peak on the largest diameter side among the peaks of the second particle size distribution.

18. The coil component according to claim 1, wherein the binder contained in the second region contains a second polymer, and the binder contained in the third region contains a third polymer.

19. The coil component according to claim 18, wherein the weight average molecular weight of the second polymer is greater than the weight average molecular weight of the third polymer.

20. The coil component according to claim 18, wherein the density of unreacted groups in the second polymer is lower than the density of unreacted groups in the third polymer.

21. The coil component according to claim 18, wherein the second material contains a polymerization catalyst for forming the binder, the third material contains a polymerization catalyst for forming the binder, and a content of the polymerization catalyst in the second material is greater than a content of the polymerization catalyst in the third material.

22. The coil component according to claim 18, wherein the hardness of the binder included in the second region measured by a nanoindenter is less than the hardness of the binder included in the third region measured by a nanoindenter.

23. A method for manufacturing a coil component comprising: a coil portion having an annular conductor portion having a central axis in a first direction and two electrical ends; and a main body portion including a magnetic powder, covering the annular conductor portion at a pair of intersecting surfaces aligned in the first direction, the main body portion including a magnetic powder, the method comprising: arranging, in a cavity of a mold, a laminated structure including the coil portion, a first member located on one side of the coil portion in the first direction, the first member including a first magnetic powder and a first hardenable material, a second member located on the other side of the coil portion in the first direction, the second member including a second magnetic powder and a second hardenable material, and a third member located between the first member and the second member, the third member including a third magnetic powder and a third hardenable material, and increasing the pressure in the cavity, thereby obtaining a molded body including the coil portion and the main body portion from the laminated structure, the method comprising: increasing the pressure in the cavity; and a central region of the molded body, the central region having an outer circumferential edge facing the inner circumferential surface of the annular conductor portion, the central region being made of a material based on the third member.

24. The method for manufacturing a coil component according to claim 23, wherein the second member and the third member differ in one or more selected from the group consisting of: a composition of the second magnetic powder and a composition of the third magnetic powder; a particle size distribution of the second magnetic powder and a particle size distribution of the third magnetic powder; a content of the second magnetic powder in the second member and a content of the third magnetic powder in the third member; a composition of the second hardenable material and a composition of the third hardenable material; a content of the second hardenable material in the second member and a content of the third hardenable material in the third member; and, in a case where the second member contains a second additive component other than the second hardenable material and the second magnetic powder and the third member contains a third additive component other than the third hardenable material and the third magnetic powder, a composition of the second additive component and a composition of the third additive component.

25. The method of manufacturing a coil component according to claim 23, wherein the first member and the third member have the same composition.

26. The method for manufacturing a coil component according to claim 25, wherein the first member and the third member are integral.

27. The method of claim 23, further comprising curing said third hardenable material from said first hardenable material.

28. A method for manufacturing a coil component as described in claim 27, wherein the first direction is along a vertical direction, the second member is located below the coil portion, and the second member is harder than the third member.

29. (I) for the laminated structure disposed in the cavity, the viscosity of the second curable material is higher than the viscosity of the third curable material; (II) for the laminated structure disposed in the cavity, the degree of polymerization of the second curable material is higher than the degree of polymerization of the third curable material; (III) for the laminated structure disposed in the cavity, the content of uncured material contained in the second curable material is lower than the content of uncured material contained in the third curable material; (IV) the second curable material and the third curable material contain a polymerization catalyst, and for the laminated structure disposed in the cavity, the content of the polymerization catalyst contained in the second curable material is higher than the content of the polymerization catalyst contained in the third curable material; (V) for the laminated structure disposed in the cavity, the volume ratio of the second magnetic powder contained in the second member is higher than the volume ratio of the third magnetic powder contained in the third member; (VI) when a gel time defined in JIS K5600-9-1:2006 is measured for the second hardenable material and the third hardenable material contained in the laminated structure disposed in the cavity, the gel time of the second hardenable material is shorter than the gel time of the third hardenable material.

30. A method for manufacturing a coil component as set forth in claim 23, wherein the second member has higher insulating properties than the third member.

31. The coil portion has an insulating portion covering a surface of the annular conductor portion, the third magnetic powder includes metal magnetic powder, and when the second member is cut in a plane perpendicular to the first direction to obtain a second member cut surface, and the third member is cut to obtain a third member cut surface, (i) a third member average equivalent circle diameter that is the average equivalent circle diameter of the third magnetic powder at the third member cut surface is smaller than a second member average equivalent circle diameter that is the average equivalent circle diameter of the second magnetic powder at the second member cut surface, and (ii) a third member median diameter that is the median diameter of the third magnetic powder at the third member cut surface is smaller than a second member median diameter that is the median diameter of the second magnetic powder at the second member cut surface, and 24. The method for manufacturing a coil component according to claim 23, wherein at least one of the following is satisfied: (iii) a third member maximum equivalent circle diameter, which is a maximum equivalent circle diameter of the third magnetic powder at the cut surface of the third member, is smaller than a second member maximum equivalent circle diameter, which is a maximum equivalent circle diameter of the magnetic powder at the cut surface of the second member; and (iv) at least one of a second member diameter distribution, which is a distribution of equivalent circle diameters of the second magnetic powder at the cut surface of the second member, and a third member diameter distribution, which is a distribution of equivalent circle diameters of the third magnetic powder at the cut surface of the third member, has two or more peaks, and a third member peak diameter, which is a maximum frequency equivalent circle diameter at the largest diameter peak among the peaks in the third member diameter distribution, is smaller than a second member peak diameter, which is a maximum frequency equivalent circle diameter at the largest diameter peak among the peaks in the second member diameter distribution.

32. An electronic or electrical device incorporating the coil component described in claim 1, wherein the coil component is connected to a substrate via terminal portions provided on exposed conductor portions located at each of the two ends of the coil portion and exposed to the outside.