TWI663610B - Inductive components and electrical and electronic equipment - Google Patents

Abstract

The present invention provides an inductive element capable of appropriately ensuring insulation withstand voltage even when the inductive element is miniaturized. The inductive element of the present invention includes a coil body wound with a conductive metal material covered with an insulating material, a pair of terminal plates extending from the coil body, and a magnetic core in which at least the coil body is embedded, And one end portion of each of the pair of terminal plates is located outside the magnetic core, and the inductance element further includes a pair of coating-type electrodes electrically connected to each of the pair of terminal plates and covering a portion of the surface of the magnetic core, The magnetic core contains magnetic powder. The cumulative particle size distribution of the magnetic powder on a volume basis is 10% cumulative particle diameter D10 is 1.8 μm or more and 3.0 μm or less, 50% cumulative particle diameter D50 is 4 μm or more and 5 μm or less, and 90% cumulative The particle diameter D90 is 7 μm or more and 10 μm or less.

Description

Inductive components and electrical and electronic equipment

The present invention relates to an inductive element having a coil embedded in a magnetic core and an electronic and electrical equipment provided with the inductive element.

Patent Document 1 describes an inductance element, which includes a coil body wound from a conductive metal material covered with an insulating material, a pair of terminal plates extending from the coil body, and At least one of the cores of the coil body is embedded therein, and one end of each of the pair of terminal plates is located outside the magnetic core, and the inductance element further includes a component electrically connected to each of the pair of terminal plates. A pair of coating electrodes, each of the pair of coating electrodes having a side coating portion provided on a portion of a side surface of the magnetic core with a direction along a winding axis of the coil body as an in-plane direction, The magnetic core is a collection of magnetic powders. The density of the magnetic powder in the first region in the magnetic core is lower than the density of the magnetic powder in the second region in the magnetic core. The first region contains a higher density than the coil body. A region further outside the outer side surface and a region on the outer peripheral side of the curved surface obtained by extending the outer side surface of the coil body in the direction of the winding axis of the coil body, the second area including the coil body The inner side surface closer to the inner area of the coil and causing the inner side surface of the extension member and the inner circumferential surface area of the obtained side of the direction of winding axis of the coil body.

[Prior technical literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2017-11042

As disclosed in Patent Document 1, an inductive element including a coil-enclosed powder magnetic core is often used as a component for driving a display portion of a mobile communication terminal such as a smart phone. For mobile communication terminals, requirements such as thinness and miniaturization continue to exist, and requirements for increasing the display section's capabilities such as increasing the maximum display brightness also continue to exist. Based on the existence of such requirements, the requirements for inductive components to meet miniaturization (including low backing) and insulation withstand voltage (to cope with high voltage driving voltage) are basically contradictory requirements.

The present invention is based on this situation, and an object thereof is to provide an inductive element capable of appropriately ensuring an insulation withstand voltage even when the inductive element is miniaturized. It is also an object of the present invention to provide an electronic and electrical machine equipped with the above-mentioned inductance element.

The present invention provided in order to solve the above-mentioned problems is, in one aspect, an inductance element characterized in that it includes a coil body wound from a conductive metal material covered with an insulating material, and extends from the coil body. A pair of terminal plates, and a magnetic core having at least the coil body embedded therein, and one end of each of the pair of terminal plates is located outside the magnetic core, and the inductance element is further provided with an electrical connection to the above Each of a pair of terminal plates and a pair of electrodes covering a part of the surface of the magnetic core, the magnetic core contains magnetic powder, and the cumulative particle size distribution of the magnetic powder on a volume basis is 10% and the cumulative particle diameter D10 is 1.8 μm or more And 3.0 μm or less, 50% cumulative particle diameter D50 is 4 μm or more and 5 μm or less, and 90% cumulative particle diameter D90 is 7 μm or more and 10 μm or less. By setting the particle size distribution of the magnetic powder contained in the powder core of the inductance element as described above, it is possible to appropriately maintain the magnetic characteristics of the inductance element and improve the insulation characteristics.

In the above-mentioned inductance element, there is a case where it is preferable to subtract the above-mentioned 10% accumulated particle diameter from the above-mentioned 90% accumulated particle diameter D90 from the viewpoint of more stably realizing appropriately maintaining the magnetic characteristics of the inductive element and improving the insulation characteristics. The difference obtained by the diameter D10 is 5 μm or more and 7 μm or less. In addition, in the above-mentioned inductance element, there is a case where the 50% cumulative particle diameter D50 and the 90% cumulative particle diameter are preferable from the viewpoint of more stably realizing appropriately maintaining the magnetic characteristics of the inductor element and improving the insulation characteristics. The product of the difference between the particle diameter D90 minus the 10% cumulative particle diameter D10 is 20 μm ² or more and 35 μm ² or less.

In the above-mentioned inductance element, the conductive metal material may be in a strip shape. In this case, the coil body is preferably a flat wound coil. In the case of flat winding, the potential difference between the conductive metal materials located adjacent to each other after winding in the coil body can be made between the conductive metal materials located adjacent to each other in the case of α winding, for example. The potential difference steadily decreases. Therefore, the degree of influence of the insulating property of the insulating material covering the conductive metal material on the insulating characteristics of the inductance element is low. Therefore, by appropriately managing the particle size distribution of the magnetic powder of the powder core as described above, the insulation characteristics of the inductance element can be stably improved.

In the inductance element, the magnetic powder may include at least a part of an amorphous magnetic material. The amorphous magnetic material is harder than the crystalline magnetic material, and therefore, the shape of the magnetic powder is not easily changed as a step of forming a magnetic core from a magnetic powder, for example, by powder compacting. Therefore, if the magnetic powder used as a raw material component before the formation of the magnetic core is prepared in a manner having a particle size distribution as described above, the particle size distribution of the magnetic powder contained in the obtained magnetic core also roughly becomes the particle size distribution described above. . As described above, by including at least a portion of the magnetic powder with an amorphous magnetic material, an inductive element including a magnetic core including the magnetic powder having the above-mentioned particle size distribution can be easily obtained.

In the inductance element, the electrode may include a coating electrode. For example, a coating-type electrode formed by a step of applying a conductive paste is preferable because it is easy to manufacture. Electrode also It may have a laminated structure of a coating-type electrode and an electrode formed by other methods (for example, plating, sputtering, etc. may be cited as specific examples). Furthermore, if the recent strong demand for miniaturization of an inductance element is considered, there are also cases where the electrode is preferably an electrode including other methods as described above rather than a coated electrode.

As another aspect, the present invention provides an electronic and electrical machine in which the above-mentioned inductance element is mounted.

With the inductance element of the present invention, it is possible to appropriately maintain magnetic characteristics and improve insulation characteristics. Therefore, according to the present invention, it is possible to provide an inductive element capable of appropriately securing an insulation withstand voltage even when the inductive element is miniaturized. In addition, according to the present invention, there is also provided an electronic and electrical equipment in which the inductance element is mounted.

10‧‧‧ Coil Body

10P‧‧‧rolled body

20‧‧‧Terminal plate

25‧‧‧Terminal plate

30‧‧‧ core

31‧‧‧The first forming member

32‧‧‧ 2nd forming member

33‧‧‧Slit

34‧‧‧Slit

40‧‧‧ coated electrode

40a‧‧‧Side coating part

45‧‧‧ Coated electrode

45a‧‧‧Side coating part

50‧‧‧Press

51‧‧‧Mould body

52‧‧‧Mould

53‧‧‧Die

54‧‧‧cavity

100‧‧‧ Inductive element

100P‧‧‧Temporary assembly

101‧‧‧ the conductive strip closest to terminal board 20

102‧‧‧The conductive strip closest to the terminal board 25

BM‧‧‧Conductive tape

D10‧‧‧10% cumulative particle size

D50‧‧‧50% cumulative particle size

D90‧‧‧90% cumulative particle size

EP1‧‧‧ conductive path

EP2‧‧‧ conductive path

EP3‧‧‧ conductive path

G1‧‧‧Terminal plate 20 and conductive tape body 101

G2 ‧‧‧ between coated electrode 40 and conductive tape 101

HP1‧‧‧ Hollow

HP2‧‧‧ Hollow

P‧‧‧ Arrow

P1‧‧‧application point

P2‧‧‧ applied point

PR1‧‧‧Voltage application terminal

PR2‧‧‧voltage application terminal

X1‧‧‧ direction

X2‧‧‧ direction

Y1‧‧‧ direction

Y2‧‧‧ direction

Z1‧‧‧ direction

Z2‧‧‧ direction

FIG. 1 is a perspective view showing a part of the overall structure of an inductance element according to an embodiment of the present invention in a perspective perspective.

FIG. 2 is (a) a plan view showing a part of the entire structure of the inductance element shown in FIG. 1 in a perspective view, and (b) a cross-sectional view taken along A-A in FIG. 2 (a).

FIG. 3 is a diagram illustrating a conductive path formed in a magnetic core.

FIG. 4 is a perspective view showing the overall structure of a wound body used to form the inductance element shown in FIG. 1, and FIG. 4B is a perspective view of a molded member including magnetic powder used to form the inductance element shown in FIG. 1. A perspective view of one and (c) show a perspective view of the other of a molded member including magnetic powder for forming the inductance element shown in FIG. 1.

FIG. 5 is a cross-sectional view showing a process of manufacturing an inductance element using the component shown in FIG. 4.

FIG. 6 shows the accumulation of a measured volume basis for the magnetic powder used in the examples. A graph of the results from the particle size distribution.

FIG. 7 is a graph showing the relationship between the dielectric breakdown electric field and the 50% cumulative particle diameter D50 of the toroidal core of the embodiment.

FIG. 8 is a graph showing the relationship between the relative permeability μ and the 50% cumulative particle diameter D50 of the toroidal coil of the embodiment.

FIG. 9 is a graph showing the relationship between the insulation breakdown electric field of the toroidal core of the example and the difference obtained by subtracting the 10% cumulative particle diameter D10 from the 90% cumulative particle diameter D90.

FIG. 10 is a graph showing the relationship between the relative permeability μ of the toroidal coil of the example and the difference obtained by subtracting the 10% cumulative particle diameter D10 from the 90% cumulative particle diameter D90.

FIG. 11 is a graph showing the relationship between the product of the dielectric breakdown electric field and the difference between the 50% cumulative particle diameter D50 and the difference obtained by subtracting the 10% cumulative particle diameter D10 from the 90% cumulative particle diameter D90 in the toroidal magnetic core of the embodiment.

FIG. 12 is a graph showing the relationship between the product of the relative permeability μ and the 50% cumulative particle diameter D50 and the difference obtained by subtracting the 10% cumulative particle diameter D10 from the 90% cumulative particle diameter D90 of the toroidal coil of the embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view showing a part of the overall structure of an inductance element according to an embodiment of the present invention in a perspective perspective. FIG. 2 (a) is a plan view showing a part of the entire structure of the inductance element shown in FIG. 1 in perspective. Fig. 2 (b) is a sectional view taken along the line A-A of Fig. 2 (a).

An inductance element 100 according to an embodiment of the present invention has a structure in which a coil body 10 is embedded in a magnetic core 30 having a substantially cubic or rectangular parallelepiped shape and having a molded body including magnetic powder. The coil body 10, which is a flat-wound coil, is composed of a conductive metal material covered with an insulating material and has a cross section of A rectangular belt-shaped body, that is, a conductive belt body is formed by winding. The coil body 10 is a conductive tape body in which the plate surface of the conductive tape body is substantially perpendicular to the winding axis (direction along the Z1-Z2 direction) (that is, a surface along the XY plane) and determines the thickness direction of the coil body 10 The side end surface is oriented parallel to the winding axis, and is wound such that the plate surfaces of the conductive tape body overlap each other along the winding axis. Therefore, the upper and lower end faces (both end faces in the Z1-Z2 direction) of the coil body 10 have a direction along the winding axis of the coil of the coil body 10 as a normal line. As shown in FIG. 1 and FIG. 2, the coil body 10 is wound so that the conductive tape body has an oval shape. The plan view shape of the coil body 10 is not limited to an elliptical shape. The winding shape of the coil body 10 in plan view may also be a true circle, which can be appropriately selected by the industry. The cross-sectional shape of the coil body 10 is not limited. The cross-sectional shape of the coil body 10 may be circular. When the cross-sectional shape of the coil body 10 is rectangular, such as a rectangle, as described above, the occupancy rate of the coil body 10 can be increased, which is preferable.

The specific composition of the conductive metal material is not limited. Good conductors such as copper, copper alloy, aluminum, and aluminum alloy are preferred. The type of the insulating material covering the conductive metal material is not limited. Specific examples of the preferable material include a resin-based material such as enamel. In the case where the coil body 10 is a flat-wound coil, the insulating material located on the outer surface side is easily stretched. Therefore, it is preferable to use a material that does not easily fall in insulation even if such stretching is performed.

In a state where the coil body 10 has been wound into an oval shape, both ends of the conductive tape body constituting the coil body 10 protrude and are then folded back, so that a portion near the end of the conductive tape body constitutes the terminal plate 20, 25.

As shown in FIG. 1, one end portion of the conductive tape body constituting the coil body 10 is first bent at a right angle to the valley fold direction, then bent at a right angle to the peak fold direction, and then bent again at a right angle to the valley fold direction. The portion from the bent portion to the end of the conductive tape body constitutes the terminal plate 20. One end portion of the conductive band body constituting the coil body 10 is between the peak-fold portion and the second valley-fold portion, and protrudes from the inside of the magnetic core 30. The portion from the portion to the end of the conductive band body is located in the magnetic core 30 outside. By bending one of the ends of the conductive tape body constituting the coil body 10 as described above, the terminal plate 20 extending from the coil body 10 is positioned in a direction along the winding axis of the coil body 10 in the magnetic core 30. The surface of the wire (hereinafter, referred to as "upper surface of the magnetic core 30"), and one end portion of the terminal plate 20 is located outside the magnetic core 30.

The other end portion of the conductive tape body constituting the coil body 10 is first bent at a right angle in the direction of the peak fold, and then bent three times at a right angle in the direction of the valley fold. Forms a terminal plate 25. The other end portion of the conductive band body constituting the coil body 10 is protruded from the inside of the magnetic core 30 between the first valley fold portion and the second valley fold portion, and this portion reaches the end of the conductive band body. Partly outside the magnetic core 30. By bending one end portion of the conductive tape body constituting the coil body 10 as described above, the terminal plate 25 extending from the coil body 10 is located on the upper surface of the magnetic core 30, and one end portion of the terminal plate 25 is located on the magnetic core. 30 outside.

In the inductance element 100 shown in FIG. 1 or FIG. 2, the coil body 10 and the terminal plates 20 and 25 are made of the same member (conductive belt body), but the invention is not limited to this. A member may be separately joined to the end of the conductive tape body constituting the coil body 10, and the terminal plates 20 and 25 may be constituted by the member.

The pair of coated electrodes 40 and 45 are electrically connected to each of the terminal plates 20 and 25 on the upper surface of the magnetic core 30, and further have side coated portions 40 a and 45 a provided on one of the side surfaces of the magnetic core 30. As shown in FIG. 1, the coated electrodes 40 and 45 are also provided on the side of the core 30 and the side opposite to the side where the protruding portion of the core 30 in the conductive tape body constituting the coil body 10 is located. Part of it. Although not shown, a plating film containing metal elements such as nickel and tin may be provided on the coating electrodes 40 and 45 to improve the adhesion with the solder used when mounting the circuit board. Alternatively, instead of the coating electrodes 40 and 45, an electrode film may be formed on the magnetic core 30 by a method such as sputtering or plating.

As shown in FIG. 2 (a), the coil body 10 is embedded inside the magnetic core 30. Since the coil body 10 series Since the coil is wound flat, the conductive tape body constituting the coil body 10 is wound around the winding axis in the direction Z1-Z2. Therefore, as shown in FIG. 2 (b), the potential difference between the conductive tape bodies adjacent in the Z1-Z2 direction in the coil body 10 is relatively small. Therefore, when the inductive element 100 is used, the possibility of insulation damage between the adjacent conductive tape bodies is low. Therefore, the insulating property of the insulating material covering the conductive metal material in the conductive tape body slightly affects the insulation characteristics of the inductance element 100.

On the other hand, as shown in FIG. 1, the terminal plate 20 of the two terminal plates 20 and 25 provided continuously with the coil body 10 is continuous with the end portion on the Z1 side in the Z1-Z2 direction of the coil body 10. Therefore, among the conductive strips constituting the coil body 10, the potential between the conductive strip 101 and the terminal plate 20 located at the end of the Z2 side in the Z1-Z2 direction and closest to the terminal plate 20 becomes larger than that of the other terminal plate. The potential between 25 and the conductive tape body 102 closest to the terminal plate 25. Therefore, in the inductive element 100, insulation breakdown easily occurs between the terminal plate 20 and the conductive tape body 101. In addition, since the terminal plate 20 and the coating electrode 40 are electrically connected, G2 between the coating electrode 40 and the conductive tape body 101 is also a portion prone to insulation breakdown. Therefore, the components constituting the magnetic core 30 have a dominant influence on the insulation characteristics of the inductance element 100.

The magnetic core 30 includes a portion of a molded body containing a magnetic powder and a magnetic powder. The volume-based cumulative particle size distribution obtained by measuring the magnetic powder contained in the magnetic core 30 by laser diffraction and scattering methods is based on the accumulation from the small particle diameter side, and the 10% cumulative particle diameter D10 is 1.8 μm or more and 3.0 μm or less, 50% cumulative particle diameter D50 is 4 μm or more and 5 μm or less, and 90% cumulative particle diameter D90 is 7 μm or more and 10 μm or less.

The magnetic powder contained in the magnetic core 30 does not include a powder having a single particle diameter, but has a specific particle size distribution because it includes a powder having a single particle diameter due to manufacturing reasons or availability. A magnetic core 30 containing a magnetic powder having the specific particle size distribution is generally Among the magnetic powders, relatively coarse particles or medium particles having a relatively large particle size are arranged adjacent to each other to constitute the outer shape of the magnetic core 30, and are used to fill a gap formed between the adjacent coarse particles or medium particles. Position fine magnetic powder.

Here, among several factors that affect the insulation characteristics of the inductive element 100, the insulation destruction electric field of the magnetic core 30 is based on improving the separation of two points in the magnetic core 30 (e.g., the magnetic core 30 has a ring shape) In this case, the voltage when a voltage is applied to each point on each bottom surface to cause insulation breakdown and a current flows between the two points is defined. When this insulation failure occurs, between two points to which a voltage is applied, a current flows in the conductive path having the lowest resistance.

FIG. 3 is a conceptual diagram for explaining a conductive path formed in the magnetic core 30. As shown in FIG. 3, the voltage application terminals PR1 and PR2 are brought into contact with each of two separated application points P1 and P2 of the magnetic core 30. At this time, the conductive path formed between the two application points P1 and P2 reaches the magnetic powder located at the other application point P2 through a plurality of magnetic powders by way of a rosary connection from the magnetic powder located at one application point P1. Way to form. The magnetic powder between two points P1 and P2 to which a voltage is applied has a specific particle size distribution as described above, so coarse or medium particles with a relatively large particle size are positioned adjacently and filled with Fine grains are positioned in the way of the coarse or medium grains. Therefore, as shown in FIG. 3, the conductive path formed between the two application points P1 and P2 can not only form the conductive path EP1 flowing in the coarse grain or medium grain constituting the outer shape, but also can form a coarse grain and Besides the medium grains, it also passes the conductive paths EP2 and EP3 of the fine grains.

The internal conductivity of the magnetic powder contained in the conductive path is relatively high. Therefore, the oxide film or the surface insulation coating on the surface of each of the adjacent magnetic powders in the conductive path is located between the adjacent magnetic powders. Non-conductive materials, such as binder components including organic components, dominate the resistance of the entire conductive path.

Therefore, among the conductive paths formed between two points to which a voltage is applied, In the conductive path EP1 flowing mainly in coarse or medium grains, the amount of magnetic powder constituting the conductive path is relatively small. Therefore, the amount of non-conductive substances located in the conductive path is relatively small, and the resistance value of the conductive path is easy. Go low. On the other hand, among the conductive paths formed between two points to which a voltage is applied, not only the coarse or medium grains constituting the outer shape but also the fine-grained conductive paths EP2 and EP3 constitute the magnetic powder constituting the conductive path. The number is relatively large. Therefore, the amount of non-conductive substances located in the conductive path is relatively increased, so that the resistance value of the conductive path is likely to be high.

As described above, when insulation breakdown occurs, a current flows in the conductive path having the lowest resistance among the conductive paths formed between the two points P1 and P2 to which a voltage is applied. Therefore, among the three conductive paths EP1, EP2, and EP3 shown in FIG. 3, the conductive path for the current to flow when an insulation failure occurs is that the coarse particles or medium currents constituting the shape mainly flow and the amount of fine particles is small. Of conductive path EP1.

According to the above description, it is clear that among magnetic powders with a specific particle size distribution, coarse or medium grain magnetic powders have a greater impact on the susceptibility to insulation damage. Fine-grained magnetic powders easily cause insulation damage. The impact of sex is relatively low. That is, when there are many coarse-grained magnetic powders among the magnetic powders contained in the magnetic core 30, the resistance value of the conductive path is likely to be lowered, and as a result, the inductor 100 is liable to cause insulation breakdown.

In this way, from the viewpoint of improving the insulation characteristics, it is preferable that the magnetic powder with coarse grains is small. Therefore, the volume-based cumulative particle size of the magnetic powder included in the magnetic core 30 of the inductor element 100 according to an embodiment of the present invention The distribution system 90% cumulative particle diameter D90 is 10 μm or less. That is, those having a particle size exceeding 10 μm in the magnetic powder constituting the magnetic core 30 are as small as less than 10% on a volume basis. Thereby, the insulation characteristics of the inductive element 100 can be improved.

In addition, in the cumulative particle size distribution based on the volume basis of the magnetic powder, the cumulative particle size at 90% is D90. When it is 10 μm or less, the 50% cumulative particle size D50 in the cumulative particle size distribution of the volume basis of the magnetic powder is 5 μm or less, whereby the insulation destruction electric field of the magnetic core 30 can be particularly increased.

As described above, from the viewpoint of increasing the dielectric breakdown electric field of the magnetic core 30, the magnetic powder is preferably all fine particles. However, when the particle size distribution of the magnetic powder is excessively deviated to the fine particle side, the magnetic core 30 may be constituted. The ratio of non-magnetic materials such as the binder component in the materials tends to increase. An increase in the ratio of non-magnetic materials in the magnetic core 30 causes a decrease in magnetic characteristics such as relative permeability. Further, when the particle diameter of the magnetic powder is too small, disadvantages such as ease of acquisition and reduction in operability may occur.

Therefore, from the viewpoint of improving the insulation characteristics of the inductive element 100 and appropriately maintaining the magnetic characteristics, etc., the cumulative particle size distribution of the volume basis of the magnetic powder contained in the magnetic core 30 of the inductive element 100 is 10% of the cumulative particle diameter D10. It is 1.8 μm or more and 3.0 μm or less, the 50% cumulative particle diameter D50 is set to 4 μm or more and 5 μm or less, and the 90% cumulative particle size D90 is set to 7 μm or more and 10 μm or less. From the viewpoint of more stably realizing proper maintenance of the magnetic characteristics of the inductive element 100, the 10% cumulative particle diameter D10 is preferably 2.0 μm or more, and more preferably 2.3 μm or more. From the viewpoint of achieving a more stable improvement in the insulation characteristics of the inductive element 100, the 90% cumulative particle diameter D90 is preferably 9.0 μm or less, and more preferably 8.8 μm or less.

In the above, the difference obtained by subtracting the 10% cumulative particle diameter D10 from the 90% cumulative particle diameter D90 (D90-D10, hereinafter may also be described as “ΔD”) is more preferably 5 μm or more and 7 μm or less. When ΔD is 5 μm or more, the magnetic characteristics such as the relative permeability μ of the inductance element 100 can be improved more stably. When ΔD is 7 μm or less, the dielectric breakdown electric field of the magnetic core 30 is likely to increase more stably. Further, among the above, it is more preferable that D50 × ΔD, which is a value obtained by multiplying the 50% cumulative particle diameter D50 and ΔD, is 20 μm ² or more and 35 μm ² or less. When D50 × ΔD is 20 μm ² or more, the magnetic characteristics such as the relative permeability μ of the inductance element 100 can be improved more stably. When D50 × ΔD is 35 μm ² or less, the dielectric breakdown electric field of the magnetic core 30 is likely to increase more stably.

The composition and structure of the magnetic powder are not limited. From the viewpoint of improving the magnetic characteristics, there is a case where the magnetic powder is preferably an Fe-based alloy. The magnetic powder may be crystalline or amorphous, and may be so-called nanocrystalline containing fine crystals of about 20 nm or less. Specific examples of the Fe-based crystalline magnetic material include Fe-Si-Cr-based alloys, Fe-Ni-based alloys, Fe-Co-based alloys, Fe-V-based alloys, Fe-Al-based alloys, and Fe-Si-based alloys. Alloys, Fe-Si-Al based alloys, carbonyl iron and pure iron.

Specific examples of the amorphous magnetic material include Fe-Si-B-based alloys, Fe-PC-based alloys, and Co-Fe-Si-B-based alloys. The amorphous magnetic material may include one material or a plurality of materials. The magnetic material constituting the powder of the amorphous magnetic material is preferably one or two or more materials selected from the group consisting of the above materials, and among these, it is more preferable to contain an Fe-PC-based alloy, more preferably It is made of Fe-PC based alloy. Specific examples of the Fe-PC alloy include a composition formula represented by Fe _{100 atomic% -abcxyzt} Ni _a sn _b Cr _c P _x C _y B _z Si _t and 0 atomic% ≦ a ≦ 10 atomic% and 0 atomic%. ≦ b ≦ 3 atom%, 0 atom% ≦ c ≦ 6 atom%, 6.8 atom% ≦ x ≦ 13 atom%, 2.2 atom% ≦ y ≦ 13 atom%, 0 atom% ≦ z ≦ 9 atom%, 0 atom% ≦ t ≦ 7 atomic% Fe-based amorphous alloy. In the above composition formula, Ni, Sn, Cr, B, and Si are arbitrary addition elements.

At least a part of the magnetic powder of the magnetic core 30 may include an amorphous magnetic material. The amorphous alloy is harder than the crystalline alloy, and therefore, the shape of the magnetic powder is unlikely to change during the step of forming the magnetic core 30 from the magnetic powder, for example, by powder compacting. Therefore, if the magnetic powder used as a raw material component before the magnetic core 30 is prepared in such a manner as to have a particle size distribution as described above, the particle size distribution of the magnetic powder contained in the obtained magnetic core 30 also becomes substantially as described above. Particle size distribution. As described above, by including at least a portion of the magnetic powder with an amorphous magnetic material, the inductive element 100 including the magnetic core 30 including the magnetic powder having the above-mentioned particle size distribution can be easily obtained.

The surface of the magnetic powder of the magnetic core 30 may be insulated. Examples of such a surface insulation treatment include phosphoric acid treatment, phosphate treatment, and oxidation treatment. It is also possible to apply a phosphoric acid-based glass material to the surface of a magnetic powder by a mechanical melting method. In this case, the magnetic powder is heated to a temperature equal to or higher than the glass transition temperature of the phosphoric acid-based glass material coated with the magnetic powder until it is formed into the magnetic core 30 or the inductive element 100, whereby the inductive element can be particularly improved. 100 insulation properties. Furthermore, at least a part of the coating of the phosphoric acid-based glass material heated to a temperature above the glass transition temperature as described above may be crystallized.

The manufacturing method of the inductance element 100 according to an embodiment of the present invention is not limited. If the manufacturing method described below is used, the inductance element 100 can be manufactured efficiently.

The manufacturing method of the inductive element 100 according to an embodiment of the present invention includes a forming process in which a direction along the winding axis of the coil body 10 (Z1-Z2 direction) is a pressing direction, and a forming process obtained by the forming process. A step of forming the coated electrodes 40 and 45 on the surface of the article. In a preferred example, the forming process includes an operation of integrating a plurality of forming members by press forming.

FIG. 4 (a) is a perspective view showing the overall configuration of the wound body 10P for forming the inductance element 100 shown in FIG. FIG. 4 (b) is a perspective view showing one of the forming members (the first forming member 31) including the magnetic powder for forming the inductance element 100. FIG. FIG. 4 (c) is a perspective view showing the other (second formed member 32) of a formed member including magnetic powder for forming the inductance element 100. FIG. 5 is a cross-sectional view showing a process of manufacturing the inductance element 100 using the wound body 10P and the first molded member 31 and the second molded member 32.

As shown in FIG. 4 (a), a conductive tape body BM is wound to prepare a wound body 10P. The shape of the wound body 10P shown in FIG. 4 (a) is different from that of the conductive tape body including the coil body 10 included in the inductance element 100. The plate surfaces of the portions of the terminal plates 20 and 25 are arranged in such a manner that the directions along the winding axis (Z1-Z2 direction) of the wound body 10P are in-plane directions.

The first forming member 31 shown in FIG. 4 (b) is a member constituting a part of the magnetic core 30 (the lower surface side of the magnetic core 30). The first forming member 31 has a hollow portion HP1 that can accommodate a part of the wound body 10P, and the wound body 10P is placed in the hollow portion HP1.

The second forming member 32 shown in FIG. 4 (c) is a member constituting another part of the magnetic core 30 (the upper surface side of the magnetic core 30). The second forming member 32 has a hollow portion HP2 capable of accommodating a part of the wound body 10P, and further includes slits 33 such that portions corresponding to the terminal plates 20 and 25 of the wound body 10P can be located outside the second forming member 32. 34. The second forming member 32 is placed on the first forming member 31 containing a part of the wound body 10P, and a part of the wound body 10P is housed in the hollow portion HP2, thereby obtaining a temporary assembly 100P of the inductance element 100. (Figure 5).

As shown in FIG. 5, the temporary assembly 100P is placed in a mold cavity 54 disposed between an upper mold 52 and a lower mold 53 in the mold body 51 of the press 50. Then, the upper mold 52 and the lower mold 53 are pressurized. The direction of pressing is as shown by the arrow P in FIG. 5 and is the direction in which the upper mold 52 and the lower mold 53 are close to each other.

The molding conditions (pressurization, temperature during pressurization, pressurization time, etc.) of the temporary assembly 100P are appropriately set in accordance with the composition or shape of the molded members (the first molded member 31 and the second molded member 32). In the case of forming at normal temperature (non-heating), the magnetic core can be formed by pressing at a pressure of about 0.5 GPa to 2 GPa for several seconds (powder molding).

By performing pressure forming, the first forming member 31 and the second forming member 32 are integrated, and A magnetic core 30 including the coil body 10 is formed. In addition, during this press molding, the terminal plates 20 and 25 arranged so that the direction along the winding axis of the coil body 10 becomes the in-plane direction of the plate surface can be bent by 90 °, thereby enabling the terminal plate 20 and 25 to be bent on the core 30. Terminal plates 20 and 25 are arranged on the upper surface.

The first forming member 31 and the second forming member 32 may be formed by pre-forming. The materials constituting the first forming member 31 and the second forming member 32 are not limited as long as they include magnetic powder. It may contain a magnetic powder and may further contain an organic component. The organic component is preferably a binder component that binds magnetic powders to each other. The specific composition of the organic component as the binder component is not limited. The organic component may include a resin material, and examples of the resin material include silicone resin, epoxy resin, phenol resin, melamine resin, urea resin, acrylic resin, and olefin resin. The organic component may include a substance formed by subjecting the resin material described above to a heat treatment. The composition of the substance can be adjusted according to the composition of the resin material subjected to heat treatment, heat treatment conditions, and the like. The organic component is preferably capable of making the magnetic powders contained in the first molded member 31 and the second molded member 32 electrically independent from each other. The resin material related to the organic component may include one kind or plural kinds. For example, the resin material related to the organic component may be a mixture of a thermosetting resin such as a phenol resin and a thermoplastic resin such as an acrylic resin.

When the first molded member 31 and the second molded member 32 contain an organic component, the content of the organic component in each of the first molded member 31 and the second molded member 32 is not limited. When an organic component is a binder component, it is preferable to contain the quantity which can exhibit the function as a binder component suitably. In addition, it is preferable to set the content of the organic component in each of the first formed member 31 and the second formed member 32 in consideration of the following cases, that is, when the content of the organic component is too high, It is seen that the magnetic characteristics of the inductance element 100 including the magnetic core 30 including the first molded member 31 and the second molded member 32 tend to decrease.

Each of the first forming member 31 and the second forming member 32 may contain a magnetic powder and an organic system. Substances other than ingredients. Examples of the substance include insulating inorganic components such as glass and alumina; coupling agents such as a silane coupling agent for improving adhesion with magnetic powder and organic components; and the like. When the first formed member 31 and the second formed member 32 contain these substances, the content of these substances in each of the first formed member 31 and the second formed member 32 is not limited.

The magnetic core 30 may have an insulating layer on its surface and a portion near the surface if necessary. By having an insulating layer, the insulation properties of the magnetic core 30 can be improved. The material constituting the insulating layer is not limited. Specific examples of the material constituting the insulating layer include organic materials such as silicone resins, epoxy resins, butyraldehyde resins, and acrylic resins; inorganic materials such as oxides, nitrides, and carbides. .

The material constituting the coating electrodes 40 and 45 provided on the magnetic core 30 is not limited. From the viewpoint of excellent productivity, it is preferable to include a metallized layer formed of a conductive paste such as a silver paste, and a plating layer formed on the metallized layer. The material for forming the plating layer is not limited. Examples of the metal element contained in the material include copper, aluminum, zinc, nickel, iron, and tin. When the coated electrodes 40 and 45 are provided with a metallized layer and a plated layer, the coating amount of the conductive paste used to form the metallized layer may be exemplified by about 0.05 g / cm ² as the thickness of the plated layer. The range is, for example, about 5 to 10 μm. Furthermore, although the coated electrodes 40 and 45 are formed in the magnetic core 30 described above, copper, aluminum, zinc, nickel, iron, and tin can also be formed on the magnetic core 30 by plating or sputtering. The formed electrodes are directly formed on the magnetic core 30 instead of the coating electrodes 40 and 45.

Since the particle size distribution of the magnetic powder contained in the magnetic core 30 is appropriately controlled in the inductor element 100 according to an embodiment of the present invention, even when the inductor element 100 is particularly small, insulation damage is unlikely to occur. Therefore, even if the inductance element 100 according to an embodiment of the present invention is particularly small, it has excellent operation stability. Therefore, it is easy to miniaturize the electric and electronic equipment on which the inductance element 100 according to an embodiment of the present invention is mounted. In addition, it can be installed in the installation space of electrical and electronic equipment. Install multiple electronic parts. In this regard, the small size of the inductance element 100 enables miniaturization of a power switching circuit, a voltage step-up circuit, a smoothing circuit, a circuit that blocks high-frequency current, and the like. Therefore, it becomes easy to increase the power supply circuit of the electrical and electronic equipment. As a result, it is possible to perform more precise power supply control, and it is possible to suppress power consumption of electronic and electrical equipment.

The embodiments described above are described for easy understanding of the present invention, and are not described for limiting the present invention. Therefore, each element disclosed in the above embodiment means that it also includes all design changes or equivalents belonging to the technical scope of the present invention.

[Example]

Hereinafter, the present invention will be specifically described as soon as possible through examples and the like, but the scope of the present invention is not limited to these examples and the like.

(Example 1)

The same type of magnetic powder as that contained in the magnetic core of the inductive element according to one embodiment of the present invention is used to make the toroidal magnetic core. The shape and manufacturing conditions of the toroidal core are as follows.

(shape)

Type 1: outer diameter 20mm x inner diameter 12.7mm x thickness 3.0mm

Type 2: outer diameter 9mmm x inner diameter 5mm x thickness 1.0mm

(Magnetic powder)

All of the magnetic powders are Fe-P-C-based amorphous alloy materials and are coated with phosphoric acid-based glass by a mechanical melting method. The cumulative particle size distribution of the volume basis of the magnetic powder of each example was measured using a "Microtrac particle size distribution measuring device MT3300EX" manufactured by Nikkiso Co., Ltd. The 10% cumulative particle size D10, 50% cumulative particle size D50, and 90% cumulative particle size D90 in these cumulative particle size distributions are described in Table 1. In addition, ΔD (D90-D10) and D50 × ΔD calculated based on the obtained particle size distribution are also shown in Table 1. Fig. 6 shows the results of the fifth and tenth embodiments. Cumulative particle size distribution of the magnetic powder used.

(Forming)

Temperature: normal temperature (25 ℃)

Pressure: 0.6 ~ 1.2GPa

(Heat treatment)

The highest temperature reached: 350 ~ 500 ℃

Heating time: 0.1 ~ 1 hour

Using the bottom surface of the obtained toroidal core as the application point, the "PROGRAMABLE HF AC TESTER MOEDL 11802" manufactured by Chroma was used to measure the insulation withstand voltage (unit: V), and the obtained insulation withstand voltage was divided by the toroidal The thickness (mm) of the core was used to calculate the dielectric breakdown electric field (V / mm). The calculation results are shown in Table 1.

In addition, an impedance analyzer ("4192A" manufactured by HP Corporation) was used for a toroidal coil obtained by winding a coated copper wire five times on a toroidal core of type 2. The relative permeability μ was measured at 100 kHz. The measurement results are shown in Table 1.

As shown in Table 1 and Figures 7 and 8 prepared based on the results of Table 1, when the 50% cumulative particle diameter D50 is confirmed to be 4 μm or more, the relative permeability μ is steadily 20 or more and 5 μm. In the following cases, the dielectric breakdown electric field stably becomes 100 V / mm or more. In this case, as shown in Table 1, the 10% cumulative particle diameter D10 satisfies 1.8 μm to 3.0 μm, and the 90% cumulative particle diameter D90 satisfies 7 μm to 10 μm.

In addition, as shown in Table 1 and FIGS. 9 and 10 prepared based on the results of Table 1, when ΔD is confirmed to be 5 μm or more, the relative permeability μ is more stable to 20 or more and 7 μm or less. In this case, the dielectric breakdown electric field becomes more stable at 100 V / mm or more. Furthermore, as shown in Table 1 and Figs. 11 and 12 prepared based on the results of Table 1, it can be confirmed that when D50 × ΔD is 20 μm ² or more, the relative permeability μ becomes more stable at 20 or more. In the case of 35 μm ² or less, the dielectric breakdown electric field becomes more stable at 100 V / mm or more. In addition, as shown in Table 1 and FIGS. 8, 10, and 12, the shape (especially the thickness) of the toroidal core has a slight effect on the electric field of insulation breakdown.

[Industrial availability]

An inductive element provided with a magnetoresistance effect element according to an embodiment of the present invention can be preferably used as a constituent element of a power circuit of a display section in a portable electronic device such as a smart phone or a notebook computer.

Claims (6)

An inductance element is characterized in that it has a coil body wound by a conductive metal material covered with an insulating material, a pair of terminal plates extending from the coil body, and at least the coil is embedded in the coil body. A magnetic core, and one end of each of the pair of terminal plates is located outside the magnetic core, the inductive element further includes an electrical connection to each of the pair of terminal plates and a surface of the magnetic core. A pair of electrodes that are partially covered, the magnetic core contains magnetic powder, and the cumulative particle size distribution of the magnetic powder on a volume basis is 10% cumulative particle diameter D10 is 1.8 μm or more and 3.0 μm or less, and 50% cumulative particle diameter D50 is 4 μm or more and 5 μm or less, and the 90% cumulative particle diameter D90 is 7 μm or more and 10 μm or less. The difference obtained by subtracting the 10% cumulative particle diameter D10 from the 90% cumulative particle diameter D90 is 5 μm or more and 7 μm or less. For example, the inductance element of claim 1, wherein the product of the difference between the 50% cumulative particle diameter D50 and the 90% cumulative particle diameter D90 minus the 10% cumulative particle diameter D10 is 20 μm ² or more and 35 μm ² or less. The inductor element according to claim 1, wherein the conductive metal material is in a strip shape and the coil body is a flat wound coil. The inductive element of claim 1, wherein at least a part of the magnetic powder includes an amorphous magnetic material. The inductive element according to claim 1, wherein the electrode includes a coating electrode. An electric and electronic equipment, which is equipped with an inductive element as claimed in claim 1.