JP2018074072A - Coil component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coil component capable of suppressing magnetic saturation while having excellent DC superposition characteristics.SOLUTION: In a coil component 10 including a core part 2 having magnetic substance powder and a resin, an air-core coil part 41, a lead-out part lead out from the air-core part 41, and a terminal part, at least the whole of the air-core coil part 41 is embedded in the inside of the core part 2. When the maximum value of the shortest distance between an optional point on the outer periphery of a magnetic substance existing on the inner peripheral side of the air-core coil part 41 appearing on a cross section perpendicular to the direction of the winding axis of the air-core coil part 41 and a point on the outer periphery of a magnetic substance existing on the outer peripheral side of the air-core coil part 41 is set as Wmax, and the minimum value thereof is set as Wmin, Wmin/Wmax is not less than 0.90.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a coil component having an air-core coil and a core portion in which the air-core coil is embedded. In particular, the present invention relates to a coil component suitable for being mounted on a power system circuit.

  In recent years, with the downsizing and high performance of electronic devices, there is a demand for small and high performance coil components that can cope with higher frequencies and higher currents in power supply circuits such as DC / DC converters that drive these electronic devices. It is getting stronger.

  Conventionally, as a coil component that can achieve the above-described requirements, a coil-enclosed type in which an air-core coil wound with a wire is embedded in a powder magnetic core (core) obtained by press-molding a mixture of magnetic powder and resin Magnetic parts are known (see, for example, Patent Document 1).

  In order to obtain a small and high-performance coil component, it is important to suppress magnetic saturation during power supply driving because high inductance can be obtained and high inductance can be maintained up to a large current region. In order to achieve downsizing while suppressing magnetic saturation, it is necessary to effectively utilize the entire magnetic core by making the distribution of magnetic flux density generated in the magnetic core made of a magnetic material uniform. It becomes important. An example of the index representing the magnetic saturation characteristic is a DC superposition characteristic.

  Incidentally, as described in Patent Document 1, a coil-enclosed magnetic component usually has a configuration in which a cylindrical air-core coil is embedded inside a rectangular parallelepiped core. FIG. 8A shows the configuration. 8B is a view of the coil-enclosed magnetic component 100 as viewed from the winding axis direction of the air-core coil 40. The magnetic body (inside the core 20) disposed inside the air-core coil 40 is shown in FIG. While the outer peripheral shape of the core portion 21) is circular, the outer peripheral shape of the magnetic body (the outer leg portion 22 of the core 20) disposed outside the air-core coil has a quadrangular (square) configuration. .

Japanese Patent No. 3654251

  The present invention has been made in view of such a situation, and an object thereof is to provide a coil component that can suppress magnetic saturation and is excellent in DC superposition characteristics.

  As shown in FIG. 8B, the magnetic flux flowing from the core part 21 of the core 20 toward the outer leg part 22 of the core 20, that is, from the inside to the outside of the air core coil 40, Since the flow follows the shape, the direction is radial. On the other hand, in the outer leg portion 22 and in the vicinity of the corner portion formed away from the air-core coil (the portion surrounded by the dotted line in FIG. 8B), the generated magnetic flux density becomes extremely low, There is a problem that it is difficult to effectively use the entire core 20 made of a magnetic material.

  Therefore, the present inventors have heretofore been given no attention to the outer shape of the magnetic body positioned on the inner peripheral side of the air-core coil and the outer peripheral shape of the magnetic body positioned on the outer peripheral side of the air-core coil. Focusing on the influence on the magnetic characteristics, it has been found that by controlling these outer peripheral shapes, magnetic saturation is less likely to occur, and the present invention has been completed.

Aspects of the present invention include
[1] a core having magnetic powder and resin;
An air-core coil part, a lead-out part drawn from the air-core coil part, and a terminal part,
A coil component in which at least the entire air-core coil portion is embedded in the core portion,
In a cross-section of the coil component cut along a plane perpendicular to the winding axis direction of the air core coil portion, a point on the outer periphery of the magnetic body existing on the inner periphery side of the air core coil portion and the air core coil portion This is a coil component in which Wmin / Wmax is 0.90 or more when the maximum value of the shortest distance from a point on the outer periphery of the magnetic substance existing on the outer periphery side is Wmax and the minimum value is Wmin.

  The coil component having the above structure can make the distribution of the magnetic flux density in the core portion uniform, so that the DC superimposition characteristics of the coil component can be improved.

FIG. 1A is a perspective view of the coil component according to the first embodiment of the present invention, and FIG. 1B is a perspective plan view of the coil component according to the first embodiment of the present invention. FIG. 2 is a cross-sectional view of the air core coil portion and the lead portion. FIG. 3A is a cross-sectional view of the coil component according to the first embodiment of the present invention, in which the coil component is cut along a plane perpendicular to the winding axis direction of the air-core coil portion. 4A is a diagram illustrating a configuration in which the corner portion of the outer leg portion is removed, and FIG. 4B is a diagram illustrating a configuration in which the corner portion of the center core portion is removed. (C) is a figure which shows the structure from which the corner | angular part of a center core part and an outer leg part is removed, and the shape after a corner | angular part is removed differs. FIG. 5A shows a configuration in which the shortest distance between a point on the outer periphery of the core portion and a point on the outer periphery of the outer leg portion is not constant because the sides constituting the outer periphery of the core portion are curved. FIG. 5 (b) shows that the shortest distance between a point on the outer periphery of the center core part and a point on the outer periphery of the outer leg part is due to the curved sides forming the outer periphery of the outer leg part. It is a figure which shows the structure which is not constant. FIG. 6A is a perspective view of the coil component according to the second embodiment of the present invention, and FIG. 6B is a perspective plan view of the coil component according to the second embodiment of the present invention. FIG. 7A is a perspective view of the coil component according to the third embodiment of the present invention, and FIG. 7B is a perspective plan view of the coil component according to the third embodiment of the present invention. FIG. 8A is a perspective view of a coil component according to the conventional example, and FIG. 8B is a perspective plan view of the coil component according to the conventional example.

Hereinafter, the present invention will be described in detail in the following order based on embodiments shown in the drawings.
1. Coil parts 1.1 First embodiment 1.2 Second embodiment 1.3 Third embodiment 2. Effect of the embodiment Modified example

(1. Coil parts)
As shown in FIGS. 1A and 1B, a coil component 10 according to the first embodiment includes a core part 2 as a compression molded body, and an air-core coil part 41 formed by winding a wire. The air core coil has a lead portion (not shown) drawn from the air core coil portion 41 and a terminal portion (not shown) electrically connected to the lead portion and provided on the outer periphery of the core portion 2. The entire part 41 is embedded in the core part 2. Therefore, in the actual coil component 10, the air core coil part 41 cannot be observed from the outside.

  As shown in FIGS. 1 (a) and (b), the outer shape of the core portion 2 is such that the square first main surface 2a and the second main surface 2b are four rectangular outer peripheral surfaces (first outer peripheral surface 2c). , The second outer peripheral surface 2d, the third outer peripheral surface 2e, and the fourth outer peripheral surface 2f).

  The core portion 2 is formed by compression molding or injection molding a granule containing a magnetic powder and a resin as a binder for binding the magnetic particles contained in the magnetic powder, and performing a heat treatment as necessary. . The material of the magnetic powder is not particularly limited as long as it exhibits predetermined magnetic properties. For example, Fe-Si (iron-silicon), Sendust (Fe-Si-Al; iron-silicon-aluminum), Examples include iron-based metal magnetic materials such as Fe-Si-Cr (iron-silicon-chromium), permalloy (Fe-Ni), and carbonyl iron. Moreover, ferrite such as Mn—Zn ferrite and Ni—Cu—Zn ferrite may be used.

  The resin as the binder is not particularly limited, and examples thereof include epoxy resins, phenol resins, acrylic resins, polyester resins, polyimides, polyamideimides, silicon resins, and combinations thereof.

  As shown in FIGS. 1A and 1B, the outer shape of the air-core coil portion 41 is a hollow square cylindrical shape, and the cross section of the air-core coil portion 41 as viewed from the winding axis direction of the air-core coil portion 41. Is a square ring.

  In the present embodiment, as shown in FIG. 2, the air core coil portion 41 is formed by winding the wire 4 a, and the lead portion 42 is drawn from the air core coil portion 41. The air-core coil portion 41 is embedded in the core portion 2 so that the winding axis O is perpendicular to both the main surfaces 2 a and 2 b of the core portion 2.

  Further, at least a pair of lead portions 42 that are both ends of the wire 4 a are drawn from the air core coil portion 41 to the outside of the core portion 2. The drawn wire 4a (drawing portion 42) is electrically connected to a pair of terminal portions provided on the outer peripheral surface of the core portion 2. In addition, a terminal part is not specifically limited, A well-known structure is applicable.

  The wire which comprises an air-core coil part and a drawer | drawing-out part is comprised by the conducting wire and the insulation coating layer which has coat | covered the outer periphery of the conducting wire as needed, for example. The conducting wire is made of, for example, Cu, Al, Fe, Ag, Au, phosphor bronze, or the like. The insulating coating layer is made of, for example, polyurethane, polyamideimide, polyimide, polyester, polyester-imide, polyester-nylon, or the like. The cross-sectional shape of the wire 4a is not particularly limited, and examples thereof include a circular shape and a rectangular shape.

  When a voltage is applied to the terminal portion, a current flows through the wire 4a, and a magnetic flux is generated so as to penetrate the hollow portion of the air-core coil portion 41, whereby the coil component exhibits predetermined magnetic characteristics.

  As described above, in the coil component shown in FIG. 8, the outer peripheral shape of the magnetic body located inside the air-core coil is circular, and the magnetic flux generated by the current flowing through the coil is radially outward from the inside of the air-core coil. Head for. Then, outside the air-core coil, the direction of the magnetic flux is along the outer peripheral surface of the air-core coil. Therefore, the magnetic flux generated at the corner indicated by the dotted line in FIG. 8 is small.

  Then, the magnetic flux density in the magnetic body located outside the air-core coil depends on the direction of magnetic flux generated in the magnetic body located inside the air-core coil, that is, the outer peripheral shape of the magnetic body located inside.

  Therefore, if the shape of the magnetic body located outside the air-core coil is brought close to the shape of the magnetic body located inside the air-core coil, variations in the magnetic flux density distribution between the inside and outside of the air-core coil can be suppressed. it can. In other words, even if the shape of the magnetic body positioned inside the air-core coil is brought closer to the shape of the magnetic body positioned outside the air-core coil, variation in the distribution of magnetic flux density can be suppressed similarly.

  Therefore, in the present embodiment, a cross-section in which the coil component is cut along a plane perpendicular to the winding axis O direction of the air-core coil portion in order to suppress variation in the distribution of magnetic flux density between the inside and the outside of the air-core coil portion. The variation in the shortest distance between the point on the outer periphery of the magnetic body located inside the air core coil portion and the point on the outer periphery of the magnetic body located outside the air core coil portion is within a predetermined range. The outer peripheral shape of the magnetic body positioned inside the air-core coil portion is made closer to the outer peripheral shape of the magnetic body positioned outside the air-core coil portion. Specifically, the maximum value of the shortest distance between the point on the outer periphery of the magnetic body existing inside the air-core coil unit and the point on the outer periphery of the magnetic body existing outside the air-core coil unit is Wmax, the minimum value Where Wmin / Wmax is 0.90 or more.

  When Wmin / Wmax is 1.00, that is, when the shortest distance is a constant value, the shape of the magnetic body positioned inside the air-core coil portion and the position outside the air-core coil portion are set. The shape of the magnetic body to be matched substantially coincides, and variation in the distribution of magnetic flux density can be effectively suppressed. Furthermore, if the shape of the magnetic body located inside the air-core coil portion does not match the shape of the magnetic body located outside the air-core coil portion, the shortest distance is not constant, but the minimum When the value (Wmin) and the maximum value (Wmax) satisfy the above relationship, variation in magnetic flux density distribution can be effectively suppressed as in the case where the shortest distance is constant.

  FIG. 3 shows a cross section of the coil component 10 cut along a plane perpendicular to the winding axis O direction of the air-core coil portion 41. In FIG. 3, when the magnetic body existing on the inner peripheral side of the air-core coil portion 41 is the central core portion 21 and the magnetic body existing on the outer peripheral side of the air-core coil portion 41 is the outer leg portion 22, The outer peripheral shape of the core portion 21 is square, which is equal to the inner peripheral shape of the air-core coil portion 41, and the outer peripheral shape of the outer leg portion 22 is also square, which is equal to the outer shape of the core portion 2.

  Assuming that the outer periphery of the center core portion 21 is A and the outer periphery of the outer leg portion 22 is B, the point A1 on the outer periphery A of the center core portion 21 is the shortest distance among the points on the outer periphery B of the outer leg portion 22. This point is point B1 (and B4) as shown in FIG. Similarly, at the point A2 on the outer periphery A of the core portion 21, the point that becomes the shortest distance is the point B2. Further, the distance W1 between the point A1 and the point B1 is equal to the distance W2 between the point A2 and the point B2, and W1 = W2 = W. That is, for any point on the outer periphery A of the core portion 21 shown in FIG. 3, the shortest distance from the point on the outer periphery B of the outer leg portion 22 is a constant value (W), and the coil component 10 shown in FIG. In this case, Wmin / Wmax is 1.00.

  Therefore, as described above, when Wmin / Wmax is 1.00, the shape of the core portion 21 and the shape of the outer leg portion 22 match, and the magnetic flux density in the core portion 21 and the outer leg portion are the same. The magnetic flux density of 22 can be brought close to. As a result, the distribution of the magnetic flux density in the core portion 2 can be made closer to uniform, and the magnetic saturation characteristics of the coil component can be improved.

  Regarding the distance between the point A1 on the outer periphery A of the core portion 21 and the point on the outer periphery B of the outer leg portion 22, consider not only the distance W1 to the point B1 but also the distance D to the point B3. Can do. However, the shortest distance between the point A1 and the points on the outer periphery B is the point B1 or the point B4, and there is no need to consider other points on the outer periphery B including the point B3.

  In other words, as long as the ratio between the minimum value and the maximum value of the shortest distance between the points constituting the corners of the outer leg portion 22 and the points on the outer periphery of the core portion 21 is within the above range, the points The shape of the corner portion of the outer leg portion 22 including B3 may not coincide with the shape of the corner portion of the corresponding core portion 21. Therefore, as long as Wmin / Wmax is within the above range, the corner portion of the outer leg portion 22 may have various shapes. Similarly, as long as the ratio between the minimum value and the maximum value of the shortest distance between the points constituting the corners of the center core portion 21 and the points on the outer periphery of the outer leg portion 22 is within the above range, the center core The shape of the corner of the portion 21 may have various shapes.

  For example, in FIG. 3, the outer periphery of the outer leg portion 22 has four corners. If such a corner exists, the coil component may be damaged due to chipping or the like. Therefore, as shown in FIG. 4A, for the purpose of preventing damage to the coil component, in the present embodiment, the corner portion of the outer leg portion 22 is preferably chamfered. The chamfered shape is not particularly limited, and may be, for example, an R chamfered shape or a C chamfered shape.

  The outer peripheral shape of the core portion 21 is defined by the inner peripheral shape of the air core coil portion 41. When the air core coil portion 41 has a hollow square cylindrical shape as shown in FIG. In consideration of the method and the like, usually, the wire is arranged so that the corner portion of the air-core coil portion 41 has a rounded shape. When such an air core coil portion 41 is arranged inside the core portion 2, the outer peripheral shape of the center core portion 21 follows the inner peripheral shape of the air core coil portion 41 as shown in FIG. The corner portion is removed.

  Further, the corner portions of the core portion 21 and the outer leg portion 22 are similarly removed, or the corner portions of the core portion 21 and the outer leg portion 22 as shown in FIG. Both are removed, but there may be a configuration in which the shape after removal is different. However, as described above, in the present invention, by setting Wmin / Wmax within the above range, variation in magnetic flux density distribution is suppressed and saturation magnetization is suppressed. Therefore, as long as such an effect is obtained, the case of various shapes such that the corners of the core 21 and the outer legs 22 are different is also included in the scope of the present invention.

  Furthermore, the configuration shown in FIG. 5 is a configuration in which the shortest distance between a point on the outer periphery of the core portion 21 and a point on the outer periphery of the outer leg portion 22 is not constant, but Wmin / Wmax is within the above range. If it exists, the above-described effects can be obtained, and it is included in the scope of the present invention.

  As shown in FIG. 5A, depending on the arrangement configuration of the air-core coil part, in the quadrangle formed by the outer periphery of the core part 21, the sides constituting the quadrangle may form a curve. In such a case, the shortest distance between the point on the outer periphery of the core portion 21 and the point on the outer periphery of the outer leg portion 22 is not constant. Here, when the shortest distance between an arbitrary point on the outer periphery A of the core portion 21 and a point on the outer periphery B of the outer leg portion 22 is W, as shown in FIG. The maximum value is Wmax and the minimum value is Wmin. In the coil component shown in FIG. 5 (a), if Wmin / Wmax is 0.90 or more, the above-described effects can be obtained, and the coil component is included in the scope of the present invention.

  Further, as shown in FIG. 5B, in the quadrangle formed by the outer periphery of the outer leg portion 22, the above Wmin / Wmax is 0.90 or more even when the sides constituting the quadrangle may form a curve. If so, the above-described effects can be obtained, and it is included in the scope of the present invention.

  5A and 5B, the configuration in which the outer periphery of the core portion 21 and the outer periphery of the outer leg portion 22 are both convex toward the outside of the coil component has been described. Of course, the configuration in which the outer periphery of the core portion 21 and the outer periphery of the outer leg portion 22 are convex toward the center is the same as described above.

  Moreover, when it is set as the shape which removed the corner | angular part of the center core part 21 or the outer leg part 22, the distance D shown in FIG. 3 may become shorter than W1, and D may become the shortest distance. Even in this case, if Wmin / Wmax is 0.90 or more, the above-described effects can be obtained, and therefore, they are included in the scope of the present invention.

  The coil component according to the present embodiment includes, for example, a power circuit such as a DC / DC converter mounted on a personal computer or a portable electronic device, a choke coil in a power line mounted on a personal computer or a portable electronic device, etc. It is suitable as a coil component that requires high frequency and large current.

(1.2 Second Embodiment)
As shown in FIGS. 6 (a) and 6 (b), the coil component 10a according to the second embodiment includes a core part 21 in a cross section of the coil part by a plane perpendicular to the winding axis direction of the air core coil part. The outer peripheral shape and the outer peripheral shape of the outer leg portion 22 are the same as those of the coil component 10 of the first embodiment except that the outer peripheral shape is an octagonal shape. Also in the coil component 10a according to the present embodiment, the shortest distance between a point on the outer periphery of the core portion 21 and a point on the outer periphery of the outer leg portion 22 is constant (Wmin / Wmax = 1.00). The same effect as the coil component 10 according to the embodiment can be obtained. Also in this embodiment, if Wmin / Wmax is within the above range even if the shortest distance is not constant, the same effect as the coil component 10 according to the first embodiment can be obtained. Included within the scope of the invention.

(1.3 Third Embodiment)
As shown in FIGS. 7A and 7B, the coil component 10 b according to the third embodiment is configured so that the core part 21 has a cross-section of the coil part by a plane perpendicular to the winding axis direction of the air-core coil part. Except for the outer periphery shape and the outer periphery shape of the outer leg part 22 being circular, it is the same as that of the coil component 10 of 1st Embodiment, and the overlapping description is abbreviate | omitted. Also in the coil component 10b according to the present embodiment, the shortest distance between the point on the outer periphery of the core portion 21 and the point on the outer periphery of the outer leg portion 22 is constant (Wmin / Wmax = 1.00). The same effect as the coil component 10 according to the embodiment can be obtained. Also in this embodiment, even when the shortest distance is not constant, Wmin / Wmax is within the above range (for example, when one or both of the core portion 21 and the outer leg portion 22 are elliptical) ) Is included in the scope of the present invention because the same effect as the coil component 10 according to the first embodiment can be obtained.

(2. Effects of the embodiment)
In the above embodiment, from the viewpoint of the flow of magnetic flux, the point on the outer periphery of the core portion 21 and the outer periphery of the outer leg portion 22 in the cross section of the coil component by the plane perpendicular to the winding axis direction of the air core coil portion. Wmin / Wmax is 0.90 or more where the maximum value of the shortest distance to the point is Wmax and the minimum value is Wmin.

  By doing in this way, since the distribution of the magnetic flux density in the inside and outside of the air-core coil portion approaches uniformly, saturation magnetization is suppressed, and the DC superimposition characteristics of the coil component are improved.

  In addition, regarding the corners of the outer peripheral shape of the central core part and the outer peripheral shape of the outer leg part, even when these corner parts have various shapes, the case where Wmin / Wmax is within the above range is described above. An effect is obtained. Furthermore, even when the shortest distance between the point on the outer periphery of the core portion and the point on the outer periphery of the outer leg portion is not constant, the above-described effect can be obtained when Wmin / Wmax is within the above range.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to said embodiment at all, You may modify | change in various aspects within the scope of the present invention.

(3. Modified examples)
In the above-described embodiment, the air-core coil portion is configured by winding a wire a plurality of times, but may be configured by a single ring-shaped conductor.

(Experimental example 1)
EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to a following example.

  A metal magnetic material powder mainly composed of iron as a magnetic powder and an epoxy resin as a resin were mixed and granulated into granules. Subsequently, a hollow square cylindrical or circular air core coil produced using an insulating film copper wire, and granules obtained by granulation are put into a mold having a predetermined shape, Pressure molding was performed with pressure to obtain a molded body in which an air-core coil was embedded. These samples were heat-treated under a predetermined temperature condition to obtain the coil parts according to Examples 1 to 6 and the coil parts according to Comparative Examples 1 to 3 in which the shape of the formed body was reflected as it was. Note that the coil components according to Examples 3 to 6 and the coil components according to Comparative Examples 2 and 3 were produced by appropriately adjusting the conditions of the curves of the sides constituting the outer periphery of the core portion and the outer leg portion.

  Note that the dimensions of the coil components according to Examples 1 to 6 and the coil components according to Comparative Examples 1 to 3 are both a square shape with a side of approximately 3 mm, a height of 1 mm, and Wmin / Wmax. The values were those shown in Table 1. In the coil component according to the first embodiment, the outer peripheral shape of the center core portion and the outer leg portion is the shape shown in FIG. 3, and in the coil component according to the second embodiment, the corner portion of the outer leg portion has an R chamfer (R = 0.5 mm) and the shape shown in FIG. In the coil component according to Comparative Example 1, the outer peripheral shapes of the core portion and the outer leg portion were the shapes shown in FIG. In the coil parts according to Examples 3 to 6 and the coil parts according to Comparative Examples 2 and 3, the outer peripheral shapes of the core part and the outer leg part were the shapes shown in FIG. 5 (a) or (b).

  The initial inductance value and the saturation characteristic at the time of DC superimposition of the inductance value were evaluated for the obtained coil component sample. The inductance value was measured using an LCR meter (Agilent Technology 4284A) and a direct current using a DC bias power source (Agilent Technology 42841A).

  The initial inductance value was an inductance value when no DC current was applied, and the saturation characteristics when the inductance value was superimposed on DC were the inductance values when 1.5 A and 3.0 A DC currents were applied.

  The larger the initial inductance value, the better the performance as a coil component. The larger the inductance value when DC is superimposed, the higher the inductance value can be maintained up to a large current range, indicating the magnetic saturation characteristics. It shows that the direct current superposition characteristics are excellent. The results are shown in Table 1.

  From Table 1, it was confirmed that Examples 1 and 2 had a value of Wmin / Wmax of 1.00, and both the initial inductance value and the saturation characteristic at the time of direct current superimposition of the inductance value were good. On the other hand, since the value of Wmin / Wmax is very small in Comparative Example 1, it is confirmed that the saturation characteristics at the time of direct current superimposition of the initial inductance value and the inductance value are very inferior to those of Examples 1 and 2. did it.

  Even when the value of Wmin / Wmax is smaller than 1.00, when it is within the scope of the present invention (Examples 3 to 6), good characteristics comparable to those of Examples 1 and 2 are obtained. It was confirmed that On the other hand, in Comparative Examples 2 and 3, since the value of Wmin / Wmax was outside the range of the present invention, it was confirmed that the initial inductance value and the saturation characteristic at the time of direct current superimposition of the inductance value were inferior.

DESCRIPTION OF SYMBOLS 10, 10a, 10b, 10c ... Coil components 2 ... Core part 21 ... Core part 22 ... Outer leg part 4a ... Wire 41 ... Air core coil part 42 ... Lead-out part

Claims (1)

A core having magnetic powder and resin;
An air-core coil part, a lead-out part drawn from the air-core coil part, and a terminal part,
A coil component in which at least the entire air-core coil portion is embedded in the core portion,
An arbitrary point on the outer periphery of the magnetic body existing on the inner peripheral side of the air-core coil portion and the air-core coil in a cross section obtained by cutting the coil component along a plane perpendicular to the winding axis direction of the air-core coil portion A coil component in which Wmin / Wmax is 0.90 or more, where Wmax is the maximum value of the shortest distance from a point on the outer periphery of the magnetic body existing on the outer periphery side of the part, and Wmin is the minimum value.

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