JP2018170304A - Dust core, method of producing the dust core, electrical/electronic component including the dust core, and electrical/electronic equipment including the electrical/electronic component mounted thereon - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dust core containing powder of a crystalline magnetic material such as carbonyl iron, which has excellent magnetic characteristics.SOLUTION: A dust core 1 contains powder of a crystalline magnetic material and powder of amorphous magnetic material. The dust core is characterized in that a first mixture ratio is 75 mass% or more and 95 mass% or less, the first mixture ratio being a mass ratio of the content of powder of the crystalline magnetic material with respect to the sum total of the content of powder of the crystalline magnetic material and the content of powder of the amorphous magnetic material.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a dust core, a method for producing the dust core, an electric / electronic component including the dust core, and an electric / electronic device on which the electric / electronic component is mounted.

  Powder cores used in boosters such as hybrid vehicles, reactors used in power generation and substation facilities, transformers and choke coils, etc. are compacted from a number of soft magnetic powders, and the resulting molded products are heat treated. Can be obtained.

  In Patent Document 1, a magnetic powder, a resin, a low-boiling solvent, and a high-boiling solvent are mixed to produce a slurry-like mixture; and the slurry-like mixture is heated to prepare the low-boiling-point solvent. A first drying step of evaporating to produce a paste-like mixture; a granulating step of pulverizing the paste-like mixture through a mesh to obtain particles; and heating the particles to the high-boiling solvent And a second drying step of obtaining magnetic particles by evaporating the material, and a method for producing the granulated product, and an inductor using the granulated product produced by the method for producing the granulated product are disclosed. Has been.

JP 2014-125655 A

  The above Patent Document 1 shows a specific example in which magnetic powder made of carbonyl iron powder (Carbonyl Iron Powder, hereinafter referred to as “CIP”) having a particle diameter of 3 to 5 μm is used. Yes. CIP is mainly used because it has high magnetic permeability and improves DC superposition characteristics.

  An object of the present invention is to provide a dust core containing a powder of a crystalline magnetic material such as CIP and having excellent magnetic properties. The present invention also provides a method for producing such a dust core, provides an electric / electronic component including such a dust core, and also provides an electric / electronic device mounted with such an electric / electronic component. Let it be an issue.

  As a result of studies by the present inventors in order to solve the above-mentioned problems, the dust core contains not only a crystalline magnetic material powder such as CIP but also a predetermined amount of amorphous magnetic material powder. New knowledge that it is possible to improve the magnetic properties.

  The present invention completed based on such knowledge is, in one aspect, a powder core containing a powder of a crystalline magnetic material and a powder of an amorphous magnetic material, the content of the powder of the crystalline magnetic material, The first mixing ratio, which is the mass ratio of the content of the crystalline magnetic material powder to the total content of the amorphous magnetic material powder, is 75% by mass to 95% by mass. It is a compacted core. When the dust core contains not only the crystalline magnetic material powder but also a predetermined amount of the amorphous magnetic material powder, the iron loss Pcv is likely to decrease.

  The first mixing ratio is preferably 80% by mass or more and 90% by mass or less because the magnetic properties of the dust core are more stably improved.

  In some cases, the crystalline magnetic material powder is preferably made of an insulating material.

  The crystalline magnetic material is Fe-Si-Cr alloy, Fe-Ni alloy, Fe-Co alloy, Fe-V alloy, Fe-Al alloy, Fe-Si alloy, Fe-Si-Al. One or two or more materials selected from the group consisting of a system alloy, carbonyl iron (CIP) and pure iron may be included. Among these, the crystalline magnetic material may be preferably made of carbonyl iron (CIP).

  The amorphous magnetic material includes one or more materials selected from the group consisting of Fe-Si-B alloys, Fe-PC-C alloys, and Co-Fe-Si-B alloys. You may go out. Among these, it may be preferable that the amorphous magnetic material is made of a Fe—PC alloy.

  In some cases, the median diameter D50 of the powder of the amorphous magnetic material is preferably 20 μm or less.

  The crystalline magnetic material powder and the amorphous magnetic material powder may contain a binding component that binds to another material contained in the powder core. In this case, the binding component preferably includes a component based on a resin material.

  In another aspect, the present invention provides a method for producing a powder core according to the present invention, wherein the binder component comprises the crystalline magnetic material powder, the amorphous magnetic material powder, and the resin material. A method for producing a dust core, comprising a molding step of obtaining a molded product by a molding process including pressure molding of a mixture including

  The compacted core obtained by the molding step may be the powder core. Or you may provide the heat processing process of obtaining the said powder core by the heat processing which heats the said molded product obtained by the said shaping | molding process.

  In another aspect, the present invention is an electric / electronic component comprising the dust core according to the present invention, a coil, and a connection terminal connected to each end of the coil, At least a part is an electric / electronic component arranged to be located in an induced magnetic field generated by the current when a current is passed through the coil via the connection terminal. Such an electric / electronic component can reduce iron loss based on the excellent characteristics of the powder core.

  According to another aspect of the present invention, there is provided an electrical / electronic device on which the electrical / electronic component according to the present invention is mounted, wherein the electrical / electronic component is connected to a substrate by the connection terminal. Electric / electronic equipment. Examples of such electrical / electronic devices include a power supply device including a power supply switching circuit, a voltage raising / lowering circuit, and a smoothing circuit, and a small portable communication device. Since the electrical / electronic device according to the present invention includes the electrical / electronic component according to the present invention, it is easy to cope with a large current and high speed.

  The dust core according to the above-described invention can have magnetic properties superior to those of a dust core including magnetic powder made of crystalline magnetic material powder. Moreover, according to this invention, the manufacturing method of said powder core, the electric / electronic component provided with said powder core, and the electric / electronic device by which this electric / electronic component was mounted are provided.

It is a perspective view which shows notionally the shape of the powder core which concerns on one Embodiment of this invention. It is a figure which shows notionally the spray dryer apparatus used in an example of the method of manufacturing granulated powder, and its operation | movement. It is a perspective view which shows notionally the shape of the toroidal core which is an electric / electronic component provided with the powder core which concerns on one Embodiment of this invention. It is a perspective view which shows a partial see-through | perspective view and shows the whole structure of the inductance element which is an electric / electronic component provided with the powder core which concerns on another one Embodiment of this invention. It is a partial front view which shows the state which mounted the inductance element shown in FIG. 4 on the mounting board | substrate. Median diameter D50 is a graph showing the dependence of the fitting result for the first mixing ratio of the amorphous magnetic constant k _h in the dust core containing powdered material of 5 [mu] m. Median diameter D50 is a graph showing the fitting result of dependence on a first mixing ratio of amorphous magnetic constant k _e in the dust core containing powdered material of 5 [mu] m. Median diameter D50 is a graph showing the dependence of the fitting result for the first mixing ratio of the amorphous magnetic constant k _h in the dust core containing powdered material of 8 [mu] m. Median diameter D50 is a graph showing the fitting result of dependence on a first mixing ratio of amorphous magnetic constant k _e in the dust core containing powdered material of 8 [mu] m. It is a graph which shows the fitting result of the dependence with respect to the 1st mixing ratio of the relative magnetic permeability (micro | micron | mu) 'in the powder core containing the powder of the amorphous magnetic material whose median diameter D50 is 5 micrometers. It is a graph which shows the fitting result of the dependence with respect to the 1st mixing ratio of Isat in the powder core containing the powder of the amorphous magnetic material whose median diameter D50 is 5 micrometers. For a dust core containing a powder of an amorphous magnetic material having a median diameter D50 of 5 μm and a first mixing ratio in the range of 50% by mass to 100% by mass, the iron loss ratio, initial permeability ratio and Isat ratio are It is the graph shown collectively.

Hereinafter, embodiments of the present invention will be described in detail.
1. 1. The dust core 1 according to one embodiment of the present invention shown in FIG. 1 is ring-shaped in appearance, and contains a powder of a crystalline magnetic material and a powder of an amorphous magnetic material. The powder core 1 according to the present embodiment is manufactured by a manufacturing method including a molding process including pressure molding of a mixture containing these powders. As a non-limiting example, the dust core 1 according to the present embodiment includes a crystalline magnetic material powder and an amorphous magnetic material powder as other materials (same type of material) contained in the dust core 1. Or it may be a dissimilar material). Hereinafter, these components will be described.

(1) Powder of crystalline magnetic material The crystalline magnetic material that gives the powder of crystalline magnetic material contained in the dust core 1 according to one embodiment of the present invention is crystalline (general X-ray diffraction) The specific type is not limited as long as the diffraction spectrum having a clear peak that can identify the material type is obtained by measurement) and is a ferromagnetic substance. Specific examples of crystalline magnetic materials include Fe-Si-Cr alloys, Fe-Ni alloys, Fe-Co alloys, Fe-V alloys, Fe-Al alloys, Fe-Si alloys, Fe-Si. -Al-based alloys, carbonyl iron (CIP) and pure iron. Said crystalline magnetic material may be comprised from one type of material, and may be comprised from multiple types of material. The crystalline magnetic material that gives the powder of the crystalline magnetic material is preferably one or more materials selected from the group consisting of the above materials, and among these, preferably contains CIP, More preferably, it consists of CIP.

  The shape of the powder of the crystalline magnetic material contained in the dust core 1 according to the embodiment of the present invention is not limited. The shape of the powder may be spherical or non-spherical. In the case of a non-spherical shape, it may have a shape anisotropy such as a scale shape, an oval sphere shape, a droplet shape, a needle shape, or an indefinite shape having no special shape anisotropy. Good. Examples of the amorphous powder include a case where a plurality of spherical powders are bonded in contact with each other, or are bonded so as to be partially embedded in other powders. Such an amorphous powder is easily observed in CIP.

  The shape of the powder may be a shape obtained at the stage of producing the powder, or may be a shape obtained by secondary processing of the produced powder. Examples of the former shape include a spherical shape, an oval shape, a droplet shape, and a needle shape, and examples of the latter shape include a scale shape.

  The particle size of the powder of the crystalline magnetic material contained in the powder core 1 according to the embodiment of the present invention is not limited. If this particle size is defined by the median diameter D50 (particle size when the volume cumulative value in the volume distribution of the soft magnetic powder measured by the laser diffraction scattering method is 50%), it is usually 1 μm to 20 μm. Scope. From the viewpoint of improving the handleability and the viewpoint of increasing the packing density of the crystalline magnetic material powder in the dust core, the median diameter D50 (also referred to as “first median diameter d1” in the present specification) of the crystalline magnetic material powder. .) Is preferably 1 μm or more and 15 μm or less, more preferably 1 μm or more and 10 μm or less, and particularly preferably 1 μm or more and 5 μm or less.

  At least a part of the crystalline magnetic material powder is preferably made of an insulating material, and the crystalline magnetic material powder is more preferably made of an insulating material. When insulation treatment is performed on the powder of the crystalline magnetic material, the insulation resistance of the dust core tends to be improved.

  The type of insulation treatment applied to the crystalline magnetic material powder is not limited. Examples include phosphoric acid treatment, phosphate treatment, oxidation treatment, and sol-gel method.

  The mass ratio of the content of the crystalline magnetic material powder to the sum of the content of the crystalline magnetic material powder and the content of the amorphous magnetic material powder (unit: mass%, in this specification, “first The mixing ratio ") is preferably 75% by mass or more and 95% by mass or less. When the first mixing ratio is within the above range, the iron loss Pcv tends to decrease. From the viewpoint of excellent balance with other magnetic properties such as magnetic permeability, the first mixing ratio is more preferably 78% by mass to 93% by mass, and further preferably 80% by mass to 90% by mass. .

(2) Amorphous Magnetic Material Powder The amorphous magnetic material that provides the amorphous magnetic material powder contained in the dust core 1 according to an embodiment of the present invention is amorphous (generally As long as the X-ray diffraction measurement does not provide a diffraction spectrum with a clear peak that can identify the material type), and the material is a ferromagnetic material, particularly a soft magnetic material, the specific types are limited. Not. Specific examples of the amorphous magnetic material include an Fe-Si-B alloy, an Fe-PC-C alloy, and a Co-Fe-Si-B alloy. Said amorphous magnetic material may be comprised from one type of material, and may be comprised from multiple types of material. The magnetic material constituting the powder of the amorphous magnetic material is preferably one or more materials selected from the group consisting of the above materials, and among these, an Fe—PC alloy is used. It is preferable to contain it, and it is more preferable to consist of a Fe-PC system alloy.

Specific examples of the Fe-P-C-based alloy, composition _formula, shown in _{Fe 100 atomic% -a-b-c-x} -y-z-t Ni a Sn b Cr c P x C y B z Si t 0 atom% ≦ a ≦ 10 atom%, 0 atom% ≦ b ≦ 3 atom%, 0 atom% ≦ c ≦ 6 atom%, 6.8 atom% ≦ x ≦ 12.8 atom%, 2.2 atom Examples are Fe-based amorphous alloys in which% ≦ y ≦ 11.8 atomic%, 0 atomic% ≦ z ≦ 9.6 atomic%, and 0 atomic% ≦ t ≦ 7 atomic%. In the above composition formula, Ni, Sn, Cr, B, and Si are optional added elements.

  The addition amount a of Ni is preferably 0 atom% or more and 6 atom% or less, and more preferably 0 atom% or more and 4 atom% or less. The addition amount b of Sn is preferably 0 atom% or more and 2 atom% or less, and more preferably 1 atom% or more and 2 atom% or less. The addition amount c of Cr is preferably 0 atom% or more and 3 atom% or less, and more preferably 1 atom% or more and 2.5 atom% or less. In some cases, the addition amount x of P is preferably 8.8 atomic% or more. The addition amount y of C may be preferably 5.8 atomic% or more and 8.8 atomic% or less. The addition amount z of B is preferably 0 atom% or more and 9 atom% or less, and more preferably 0 atom% or more and 8 atom% or less. The addition amount t of Si is preferably 0 atom% or more and 6 atom% or less, and more preferably 0 atom% or more and 5.5 atom% or less.

  The shape of the powder of the amorphous magnetic material contained in the dust core 1 according to the embodiment of the present invention is not limited. Since the kind of the powder shape is the same as that of the crystalline magnetic material powder, the description thereof is omitted. In some cases, the amorphous magnetic material can be easily formed into a spherical shape or an elliptical spherical shape because of the manufacturing method. In general, since an amorphous magnetic material is harder than a crystalline magnetic material, it may be preferable to make the crystalline magnetic material non-spherical so that it is easily deformed during pressure molding.

  The shape of the powder of the amorphous magnetic material contained in the dust core 1 according to the embodiment of the present invention may be the shape obtained in the stage of producing the powder, or the produced powder is secondary The shape obtained by processing may be sufficient. Examples of the former shape include a sphere, an oval sphere, and a needle shape, and examples of the latter shape include a scale shape.

  The particle diameter of the powder of the amorphous magnetic material contained in the powder core 1 according to the embodiment of the present invention is not limited. If this particle diameter is defined by the median diameter D50, it may be preferable to be 20 μm or less. From the viewpoint of improving the handleability, the median diameter D50 (also referred to as “second median diameter d2” in this specification) of the powder of the amorphous magnetic material is preferably 1 μm or more, and preferably 2 μm or more. Is more preferable, and the thickness is particularly preferably 3 μm or more. From the viewpoint of increasing the packing density of the amorphous and crystalline magnetic material powder in the dust core 1, the median diameter D50 of the amorphous magnetic material powder is preferably 15 μm or less, and preferably 12 μm or less. It is more preferable that the thickness be 8 μm or less.

  The relationship between the first median diameter d1 and the second median diameter d2 is not limited. In general, since amorphous magnetic materials are harder than crystalline magnetic materials, voids formed when the first median diameter d1 is made relatively small and powders of amorphous magnetic materials are filled. In some cases, it is preferable that the crystalline magnetic material powder is easily filled. In this case, d1 / d2 is preferably 0.8 or less, and sometimes 0.5 or less.

(3) Binder Component The binder component includes a crystalline magnetic material powder and an amorphous magnetic material powder contained in the dust core 1 according to the present embodiment (in this specification, these powders are referred to as “magnetic The composition is not limited as long as it is a material that contributes to fixing. As a material constituting the binder component, an organic material such as a resin material and a thermal decomposition residue of the resin material (in this specification, these are collectively referred to as “components based on a resin material”), an inorganic material, and the like Is exemplified. Examples of the resin material include acrylic resin, silicone resin, epoxy resin, phenol resin, urea resin, and melamine resin. The binder component made of an inorganic material is exemplified by a glass-based material such as water glass. The binder component may be composed of one type of material or may be composed of a plurality of materials. The binder component may be a mixture of an organic material and an inorganic material.

  As the binding component, an insulating material is usually used. Thereby, it becomes possible to improve the insulation as the dust core 1.

2. Manufacturing method of powder core Although the manufacturing method of the powder core 1 which concerns on one embodiment of said this invention is not specifically limited, if the manufacturing method demonstrated below is employ | adopted, the powder core 1 will be manufactured more efficiently. Is realized.

  The manufacturing method of the powder core 1 which concerns on one Embodiment of this invention is equipped with the formation process demonstrated below, and may be further provided with the heat processing process.

(1) Molding step First, a mixture containing magnetic powder and a component that provides a binding component in the powder core 1 is prepared. The component that gives the binding component (also referred to as “binder component” in this specification) may be the binding component itself or may be a material different from the binding component. Specific examples of the latter include a case where the binder component is a resin material and the binder component is a thermal decomposition residue thereof.

  A molded product can be obtained by a molding process including pressure molding of the mixture. The pressurizing condition is not limited and is appropriately determined based on the composition of the binder component. For example, when the binder component is made of a thermosetting resin, it is preferable to heat the resin together with pressure to advance the resin curing reaction in the mold. On the other hand, in the case of compression molding, although the pressing force is high, heating is not a necessary condition and pressurization is performed for a short time.

  Hereinafter, the case where the mixture is granulated powder and compression molding will be described in some detail. Since the granulated powder is excellent in handleability, it is possible to improve the workability of the compression molding process in which the molding time is short and the productivity is excellent.

(1-1) Granulated powder Granulated powder contains magnetic powder and a binder component. The content of the binder component in the granulated powder is not particularly limited. When this content is too low, it becomes difficult for the binder component to hold the magnetic powder. In addition, when the content of the binder component is excessively low, in the powder core 1 obtained through the heat treatment step, the binder component composed of the thermal decomposition residue of the binder component causes a plurality of magnetic powders to be separated from each other. It becomes difficult to insulate. On the other hand, when the content of the binder component is excessively high, the content of the binder component contained in the powder core 1 obtained through the heat treatment step tends to be high. When the content of the binder component in the dust core 1 is increased, the magnetic properties of the dust core 1 are likely to be reduced. Therefore, the content of the binder component in the granulated powder is preferably set to an amount that is 0.5% by mass or more and 5.0% by mass or less with respect to the entire granulated powder. From the viewpoint of more stably reducing the possibility that the magnetic properties of the dust core 1 will decrease, the content of the binder component in the granulated powder is 1.0 mass% or more with respect to the entire granulated powder. The amount is preferably 5% by mass or less, and more preferably 1.2% by mass or more and 3.0% by mass or less.

  The granulated powder may contain materials other than the above magnetic powder and binder component. Examples of such materials include lubricants, silane coupling agents, and insulating fillers. In the case of containing a lubricant, the type is not particularly limited. It may be an organic lubricant or an inorganic lubricant. Specific examples of the organic lubricant include metal soaps such as zinc stearate and aluminum stearate. It is considered that such an organic lubricant is vaporized in the heat treatment step and hardly remains in the powder core 1.

  The manufacturing method of granulated powder is not specifically limited. The ingredients that give the granulated powder may be kneaded as they are, and the resulting kneaded product may be pulverized by a known method to obtain granulated powder, or a dispersion medium (water as an example) It is also possible to obtain a granulated powder by preparing a slurry to which is added, and drying and pulverizing the slurry. Screening and classification may be performed after pulverization to control the particle size distribution of the granulated powder.

As an example of a method for obtaining granulated powder from the above slurry, a method using a spray dryer can be mentioned. As shown in FIG. 2, a rotator 201 is provided in the spray dryer apparatus 200, and the slurry S is injected toward the rotor 201 from the upper part of the spray dryer apparatus 200. The rotor 201 rotates at a predetermined number of revolutions, and sprays the slurry S as droplets by centrifugal force in a chamber inside the spray dryer apparatus 200. Further, hot air is introduced into the chamber inside the spray dryer apparatus 200, whereby the dispersion medium (water) contained in the droplet-like slurry S is volatilized while maintaining the droplet shape. As a result, the granulated powder P is formed from the slurry S. The granulated powder P is collected from the lower part of the spray dryer apparatus 200. Each parameter such as the number of rotations of the rotor 201, the temperature of hot air introduced into the spray dryer apparatus 200, and the temperature at the bottom of the chamber may be set as appropriate. As specific examples of the setting ranges of these parameters, the rotation speed of the rotor 201 is 4000 to 6000 rpm, the hot air temperature introduced into the spray dryer apparatus 200 is 130 to 170 ° C., and the temperature at the bottom of the chamber is 80 to 90 ° C. . The atmosphere in the chamber and its pressure may be set as appropriate. As an example, the inside of the chamber is an air atmosphere, and the pressure is ₂ mmH ₂ O (about 0.02 kPa) as a differential pressure from the atmospheric pressure. You may further control the particle size distribution of the obtained granulated powder P by sieving.

(1-2) Pressing conditions The pressing conditions in compression molding are not particularly limited. What is necessary is just to set suitably in consideration of the composition of the granulated powder, the shape of the molded product obtained by the molding process, and the like. If the pressure applied when the granulated powder is compression-molded is excessively low, the mechanical strength of the molded product decreases. For this reason, it becomes easy to produce the problem that the handleability of a molded product falls and the mechanical strength of the powder core 1 obtained from the molded product falls. Moreover, the magnetic characteristics of the dust core 1 may deteriorate or the insulating properties may decrease. On the other hand, if the applied pressure during compression molding of the granulated powder is excessively high, it becomes difficult to create a molding die that can withstand the pressure. From the viewpoint of more stably reducing the possibility that the compression and pressurization process will adversely affect the mechanical properties and magnetic properties of the dust core 1 and facilitating mass production industrially, The applied pressure is preferably 0.3 GPa to 2 GPa, more preferably 0.5 GPa to 2 GPa, and particularly preferably 0.8 GPa to 2 GPa.

  In compression molding, pressurization may be performed while heating, or pressurization may be performed at room temperature.

(2) Heat treatment step The molded product obtained in the molding step may be the powder core 1 according to the present embodiment, or the molded product may be subjected to a heat treatment step and pressed as described below. A powder core 1 may be obtained.

  In the heat treatment process, the molded product obtained by the above molding process is heated to adjust the magnetic properties by correcting the distance between the magnetic powders and to relax the strain applied to the magnetic powder in the molding process. The powder core 1 is obtained by adjusting the magnetic characteristics.

  Since the purpose of the heat treatment step is to adjust the magnetic properties of the dust core 1 as described above, the heat treatment conditions such as the heat treatment temperature are set so that the magnetic properties of the dust core 1 are the best. As an example of a method for setting the heat treatment conditions, it is possible to change the heating temperature of the molded product and to make other conditions constant, such as the heating rate and the holding time at the heating temperature.

  The evaluation criteria for the magnetic properties of the dust core 1 when setting the heat treatment conditions are not particularly limited. The iron loss Pcv of the powder core 1 can be given as a specific example of the evaluation item. In this case, what is necessary is just to set the heating temperature of a molded product so that the iron loss Pcv of the powder core 1 may become the minimum. The measurement conditions of the iron loss Pcv are set as appropriate, and as an example, the conditions of a frequency of 100 kHz and a maximum magnetic flux density of 100 mT can be mentioned.

  The atmosphere during the heat treatment is not particularly limited. In the case of an oxidizing atmosphere, the possibility of excessive thermal decomposition of the binder component and the possibility of progress of oxidation of the magnetic powder increases, so that an inert atmosphere such as nitrogen or argon, or a reducing property such as hydrogen Heat treatment is preferably performed in an atmosphere.

3. Electrical / Electronic Component An electrical / electronic component according to an embodiment of the present invention includes a dust core 1 according to an embodiment of the present invention, a coil, and a connection terminal connected to each end of the coil. . Here, at least a part of the dust core 1 is disposed so as to be located in an induced magnetic field generated by the current when a current is passed through the coil via the connection terminal.

  An example of such an electric / electronic component is the toroidal coil 10 shown in FIG. The toroidal coil 10 includes a coil 2 a formed by winding a coated conductive wire 2 around a ring-shaped dust core (toroidal core) 1. The portions (exposed end portions) 2b and 2c where the conductive wires are exposed at both ends of the covered conductive wire 2 constitute connection terminals. Ends 2d and 2e of the coil 2a can be defined in a portion of the coated conductive wire 2 located between the coil 2a and the exposed ends 2b and 2c. As described above, in the electrical / electronic component according to the present embodiment, the member constituting the coil and the member constituting the connection terminal may be constituted by one member.

  The electric / electronic component according to an embodiment of the present invention may include a dust core having a shape different from that of the dust core 1 according to the embodiment of the present invention. A specific example of such an electric / electronic component is an inductance element 20 shown in FIG. FIG. 4 is a perspective view showing a part of the entire configuration of the inductance element 20 according to the embodiment of the present invention. In FIG. 4, the lower surface (mounting surface) of the inductance element 20 is shown in an upward posture. FIG. 5 is a partial front view showing a state in which the inductance element 20 shown in FIG. 4 is mounted on the mounting substrate 100.

  The inductance element 20 shown in FIG. 4 includes a dust core 3, a coil 5 embedded in the dust core 3, and a pair of terminal portions 4 as connection terminals electrically connected to the coil 5 by welding. It is configured with.

  The coil 5 is formed by spirally winding a conductive wire with an insulating coating. The coil 5 includes a winding part 5a and lead-out end parts 5b and 5b drawn from the winding part 5a. The number of turns of the coil 5 is appropriately set according to the required inductance.

  As shown in FIG. 4, in the dust core 3, an accommodation recess 30 for accommodating a part of the terminal portion 4 is formed on the mounting surface 3 a for the mounting substrate. The storage recesses 30 are formed on both sides of the mounting surface 3 a and are formed to be released toward the side surfaces 3 b and 3 c of the powder core 3. Part of the terminal portion 4 protruding from the side surfaces 3 b and 3 c of the powder core 3 is bent toward the mounting surface 3 a and stored in the storage recess 30.

  The terminal portion 4 is formed of a thin plate-like Cu base material. The terminal part 4 is embedded in the dust core 3 and exposed to the connection end 40 electrically connected to the lead-out ends 5b, 5b of the coil 5, and the outer surface of the dust core 3. The dust core 3 includes a first bent portion 42a and a second bent portion 42b that are bent in order from the side surfaces 3b and 3c to the mounting surface 3a. The connection end 40 is a welded portion that is welded to the coil 5. The first bent portion 42 a and the second bent portion 42 b are solder joint portions that are soldered to the mounting substrate 100. The solder joint portion is a portion of the terminal portion 4 that is exposed from the dust core 3 and means a surface that faces at least the outside of the dust core 3.

  The connection end portion 40 of the terminal portion 4 and the extraction end portion 5b of the coil 5 are joined by resistance welding.

As shown in FIG. 5, the inductance element 20 is mounted on the mounting substrate 100.
A conductor pattern that is electrically connected to an external circuit is formed on the surface of the mounting substrate 100, and a pair of land portions 110 for mounting the inductance element 20 is formed by a part of the conductor pattern.

  As shown in FIG. 5, in the inductance element 20, the mounting surface 3a is directed to the mounting substrate 100 side, and the first bent portion 42a and the second bent portion 42b that are exposed to the outside from the dust core 3 are mounted. The solder layer 120 is bonded to the land portion 110 of the substrate 100.

  In the soldering process, after the solder paste is applied to the land part 110 in the printing process, the inductance element 20 is mounted so that the second bent part 42b faces the land part 110, and the solder melts in the heating process. To do. As shown in FIGS. 4 and 5, the second bent portion 42 b faces the land portion 110 of the mounting substrate 100, and the first bent portion 42 a is exposed on the side surfaces 3 b and 3 c of the inductance element 20. The solder layer 120 is fixed to the land portion 110 and is sufficiently spread and fixed to the surfaces of both the second bent portion 42b and the first bent portion 42a which are solder joint portions.

4). Electrical / Electronic Device An electrical / electronic device according to an embodiment of the present invention is mounted with an electrical / electronic component including the dust core according to the embodiment of the present invention. As such an electric / electronic device, a power supply device including a power switching circuit, a voltage raising / lowering circuit, a smoothing circuit, etc., through which a large current (for example, about 1 A or more in the case of a small inductor of several mm square) flows is exemplified. .

  When a large current is passed through a power supply device including a power supply switching circuit, a voltage raising / lowering circuit, a smoothing circuit, etc., if the iron loss Pcv of the dust core included in the electric / electronic component incorporated in the power supply device is high, the degree of heat generation And the reliability of the device is significantly reduced. For this reason, it is strongly required to reduce the iron loss Pcv of the dust core and increase the efficiency. The dust core used in the electrical / electronic component included in the electrical / electronic device according to the embodiment of the present invention has high iron loss Pcv, and thus has high efficiency, and a large current flows through the electrical / electronic device. Even so, the degree of heat generation is relatively low. For this reason, the electrical / electronic device according to an embodiment of the present invention is excellent in reliability.

  The embodiment described above is described for facilitating understanding of the present invention, and is not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

  EXAMPLES Hereinafter, although an Example etc. demonstrate this invention further more concretely, the scope of the present invention is not limited to these Examples etc.

Example 1
(1) Preparation of Fe-based amorphous alloy powder Using a water atomization method, weighed so as to have a composition of Fe _{71 atomic%} Ni _{6 atomic%} Cr _{2 atomic%} P _{11 atomic%} C _{8 atomic%} B _{2 atomic%} The amorphous magnetic material powder thus obtained was prepared as a magnetic powder. The first mixing ratio (the mass ratio of the content of the crystalline magnetic material powder to the total content of the crystalline magnetic material powder and the amorphous magnetic material powder) was 0% by mass. The particle size distribution of the obtained magnetic powder was measured by volume distribution using “Microtrack particle size distribution measuring device MT3300EX” manufactured by Nikkiso Co., Ltd. As a result, the median diameter D50, which is a particle diameter of 50% in the volume distribution, was 5 μm.

(2) Production of granulated powder 97.2 parts by mass of the above-mentioned amorphous magnetic material powder, 2.5 parts by mass of an insulating binder made of acrylic resin and phenol resin, and 0.3 mass of lubricant Were mixed with water as a solvent to obtain a slurry. The obtained slurry was dried and granulated using a spray dryer device to obtain a granulated powder having a median diameter D50 of 80 μm.

(3) Compression molding The obtained granulated powder is filled in a mold and press-molded at a surface pressure of 1.0 GPa to obtain a molded product having a ring shape with an outer diameter of 20 mm, an inner diameter of 12 mm and a thickness of 3 mm. It was.

(4) Heat treatment The obtained molded product was placed in a furnace in a nitrogen stream atmosphere, and the furnace temperature was heated from room temperature (23 ° C.) to 400 ° C. at a heating rate of 10 ° C./min. Was held for 1 hour, and then a heat treatment was performed to cool to room temperature in the furnace to obtain a toroidal core composed of a dust core.

(Examples 2 to 6)
When preparing the magnetic powder, the powder of the amorphous magnetic material used in Example 1 and the powder of the crystalline magnetic material made of carbonyl iron (CIP) subjected to insulation treatment (median diameter D50: 4.3 μm) ) And a toroidal core was produced in the same manner as in Example 1 except that the magnetic powder having the following first mixing ratio was used.
Example 2 5% by mass
Example 3 10% by mass
Example 4 15% by mass
Example 5 20% by mass
Example 6 30% by mass

(Example 7)
When the magnetic powder was prepared, instead of the amorphous magnetic material powder used in Example 1, all of the CIP subjected to insulation treatment used in Example 2 was used. A toroidal core was produced in the same manner as in Example 1 except that the first mixing ratio was 100% by mass.

(Example 8)
An amorphous magnetic material powder was prepared in the same manner as in the production method of Example 1 except that the median diameter D50 was 8 μm. Using this amorphous magnetic material powder, a toroidal core was produced in the same manner as in Example 1.

(Test Example 1) Measurement and Simulation of Iron Loss Pcv For the toroidal coils obtained by winding the coated copper wires on the toroidal cores produced in Examples 1 to 8 15 times on the primary side and 10 times on the secondary side, respectively, the BH analyzer (Iwasaki Tsushinki Co., Ltd. “SY-8217”), the frequency dependence of the iron loss Pcv (unit: kW / m ³ ) under the condition that the effective maximum magnetic flux density B _m is 15 mT (measurement frequency range: 100 kHz) ~ 3MHz) was measured.

As an example of a formula representing the frequency dependence of the iron loss Pcv, a formula shown in the following formula (1) is given.
_{Pcv = k h × f × B} m 1.6 + k e × f 2 × B m 2 (1)
Here, f is the frequency (unit: kHz), _{B m} is the effective maximum magnetic flux density (unit: mT) is, _{k h} and _{k e} is a constant, and the unit, the former (constant _{k h)} is kW / m ³ / kHz / (mT) ^1.6 or less, and the latter (constant k _e ) is kW / m ³ / (kHz) ² / (mT) ² .

Among the measurement results of the iron loss Pcv of the toroidal coil according Examples 1 to 7, frequency using the measurement results of 3MHz ranging from 1 MHz, to determine the two constants k _h and k _e for each Example. The results are shown in Table 1. In Table 1, it is omitted in units of constant k _h and constant k _e.

From the results shown in Table 1, for each of the two constants k _h and k _e in the dust core of the median diameter D50 contains a powder of amorphous magnetic material 5 [mu] m, it was determined the dependence on the first mixing ratio . As a result, as shown in FIG. 6, the dependence of the fitting result for the first mixing ratio of the constant k _h became formula given by the following formula (2). The correlation coefficient of the following formula (2) was 0.9980. On the other hand, as shown in FIG. 7, dependence of the fitting result for the first mixing ratio of the constant k _e became formula given by equation (3). The correlation coefficient of the following formula (3) was 0.9816. In the following formulas (2) and (3), x is the first mixing ratio (unit: mass%).
^{_{k h = 2.290 × 10 -7 x}} 2 + 4.737 × 10 -6 x-3.748 × 10 -5 (2)
k _e = 2.193 × 10 ⁻¹¹ x ² −6.411 × 10 ⁻¹⁰ x + 2.499 × 10 ⁻⁷ (3)

Based on the above formulas (2) and (3), the two constants k _h and k _e of the powder core containing the powder of the amorphous magnetic material having a median diameter D50 of 5 μm are used, and the first mixing ratio is 50 mass. % To 100% by mass. Then, from the two constants k _h and k _e thus obtained, a powder of an amorphous magnetic material having a median diameter D50 of 5 μm is contained, and the first mixing ratio is in the range of 50% by mass to 100% by mass. The core iron loss Pcv (frequency f: 2 MHz, effective maximum magnetic flux density B _m : 15 mT) was calculated. The results are shown in Table 2. In Table 2, the iron loss Pcv of the dust core when the first mixing ratio is 50% to 90% by mass is normalized with the iron loss Pcv of the dust core when the first mixing ratio is 100% by mass. The obtained value was shown as the iron loss ratio.

Among the measurement results of the iron loss Pcv of the toroidal coil according to Example 8, two constants k _h and k _e were obtained using the measurement results in the frequency range of 1 MHz to 3 MHz. The results are shown in Table 3.

The results of the two constants k _h and k _{e according} to Example 8 shown in Table 3 were close to the results of the two constants k _h and k _{e according} to Example 1 shown in Table 1. Accordingly, Example 8, using the results of constant k _h and constant k _e in Examples 2 6 and Example 7, in the dust core of the median diameter D50 contains a powder of amorphous magnetic material of 8μm The dependence on the first mixing ratio was determined for each of the two constants k _h and k _e . As a result, as shown in FIG. 8, dependence of the fitting result for the first mixing ratio of the constant k _h became formula given by the following equation (4). The correlation coefficient of the following formula (4) was 0.9980. On the other hand, as shown in FIG. 9, the dependence of the fitting result for the first mixing ratio of the constant k _e became formula given by equation (5). The correlation coefficient of the following formula (5) was 0.9843. In the following formulas (4) and (5), x is the first mixing ratio (unit: mass%).
^{_{k h = 2.290 × 10 -7 x}} 2 + 4.737 × 10 -6 x-3.748 × 10 -5 (4)
k _e = 2.032 × 10 ⁻¹¹ x ² −4.509 × 10 ⁻¹⁰ x + 2.468 × 10 ⁻⁷ (5)

Based on the above formulas (4) and (5), two constants k _h and k _e of the powder core containing the powder of the amorphous magnetic material having a median diameter D50 of 8 μm are used, and the first mixing ratio is 50 mass. % To 100% by mass. Then, thus two constants k _h and k _e obtained, a powder of median diameter D50 of containing a powder of amorphous magnetic material of 8 [mu] m, the first mixture ratio is in the range of 50 wt% of 100 wt% The core iron loss Pcv (frequency f: 2 MHz, effective maximum magnetic flux density B _m : 15 mT) was calculated. Table 4 shows the results and the iron loss ratio obtained in the same manner as in Table 2.

(Test Example 2) Measurement of magnetic permeability For a toroidal coil obtained by winding a coated copper wire 40 times on the primary side and 10 times on the secondary side respectively on the toroidal core produced in Examples 1 to 8, an impedance analyzer (HP Corporation) was obtained. Using the product “4192A”), the initial permeability μ ′ was measured under the condition of 100 kHz. The results are shown in Table 5. In the column of D50 in Table 5, the median diameter D50 of the powder of the amorphous magnetic material contained in the dust core is shown.

From the results shown in Table 5, the dependency of the initial permeability μ ′ on the first mixing ratio in a dust core containing powder of an amorphous magnetic material having a median diameter D50 of 5 μm was determined. As a result, as shown in FIG. 10, the fitting result of the dependence of the initial permeability μ ′ on the first mixing ratio is an expression shown by the following expression (6). The correlation coefficient of the following formula (6) was 0.9934. In addition, in following formula (6), x is a 1st mixing ratio (unit: mass%).
μ ′ = − 7.44 × 10 ⁻⁴ x ² + 1.529 × 10 ⁻¹ x + 2.859 × 10 ¹ (6)

  Based on the above formula (6), the initial permeability μ of the dust core containing a powder of an amorphous magnetic material having a median diameter D50 of 5 μm and a first mixing ratio in the range of 50% by mass to 100% by mass. 'Calculated. The results are shown in Table 6. Table 6 shows the initial permeability μ ′ of the dust core when the first mixing ratio is 50 mass% to 90 mass%, and the initial permeability μ of the dust core when the first mixing ratio is 100 mass%. The value normalized by 'is shown as the initial permeability ratio.

  Assuming that the dependence of the initial permeability μ ′ on the first mixing ratio in a dust core containing powder of an amorphous magnetic material with a median diameter D50 of 8 μm is represented by a linear line, Examples 8 and 7 From the measurement results of the initial permeability μ ′, the initial permeability in the powder mixture core containing the powder of the amorphous magnetic material having a median diameter D50 of 8 μm is in the range of 50% by mass to 100% by mass. μ ′ was calculated. Table 7 shows the results and the initial permeability ratio obtained in the same manner as in Table 5.

(Test Example 3) Measurement of DC superposition characteristics Using the toroidal coil formed from the toroidal core produced in Examples 1 to 8, a DC current was superimposed on the toroidal coil in accordance with JIS C2560-2. From the applied current value Isat (unit: A) when the ratio (ΔL / L ₀ ) of the change amount ΔL of the inductance L to the value L ₀ of the inductance L before application of the superimposed current (initial) is 30%, DC The superposition characteristics were evaluated. The results are shown in Table 8. The column D50 in Table 8 shows the median diameter D50 of the amorphous magnetic material powder contained in the dust core.

From the results shown in Table 8, the dependency of Isat on the first mixing ratio in a powder core containing powder of an amorphous magnetic material having a median diameter D50 of 5 μm was determined. As a result, as shown in FIG. 11, the fitting result of the dependence on the first mixing ratio of Isat was expressed by the following formula (7). The correlation coefficient of the following formula (7) was 0.9954. In addition, in following formula (7), x is a 1st mixing ratio (unit: mass%).
Isat = 6.602 × 10 ⁻² x + 1.149 × 10 ¹ (7)

  Based on the above formula (7), the Isat of the powder core containing the powder of the amorphous magnetic material having a median diameter D50 of 5 μm and the first mixing ratio in the range of 50% by mass to 100% by mass was calculated. . The results are shown in Table 9. Table 9 shows the Isat of the dust core when the first mixing ratio is 50% to 90% by mass, and the value Isat normalized by the Isat of the dust core when the first mixing ratio is 100% by mass. Shown as a ratio.

  Measurement of Isat of Examples 8 and 7 assuming that the dependence of Isat on the first mixing ratio in a powder core containing powder of amorphous magnetic material having a median diameter D50 of 8 μm is represented by a linear line From the results, Isat was calculated for a dust core containing a powder of an amorphous magnetic material having a median diameter D50 of 8 μm and a first mixing ratio in the range of 50 mass% to 100 mass%. Table 10 shows the results and Isat ratios obtained in the same manner as in Table 9.

  FIG. 12 shows an iron loss ratio and an initial permeability ratio for a dust core containing a powder of an amorphous magnetic material having a median diameter D50 of 5 μm and a first mixing ratio in the range of 50% by mass to 100% by mass. And Isat ratio are collectively shown in one graph. As shown in FIG. 12, in contrast to the powder core (Example 7) in which the magnetic powder is made of CIP, when the magnetic powder contained in the powder core includes an amorphous magnetic material powder, Although all of the loss ratio, the initial permeability ratio, and the Isat ratio are reduced, it has been confirmed that the iron loss ratio is greatly reduced as compared with the other two ratios. This result shows that by mixing magnetic powder made of amorphous magnetic material powder into a powder core made of CIP, the iron loss can be greatly reduced while reducing the initial permeability and Isat. It shows that it is possible. As is clear from FIG. 12, the iron loss Pcv decreases more significantly as the ratio of the magnetic powder made of the amorphous magnetic material powder mixed in the dust core increases.

In order to confirm the relationship between the degree of decrease in the iron loss Pcv and the degree of decrease in other magnetic characteristics, evaluation was performed using the following formula (8) and the following formula (9).
R1 _i = (1-C _i ) / (1-P _i ) (8)
R2 _i = (1-C _i ) / (1-I _i ) (9)

Here, C _i is the iron loss ratio when the first mixing ratio is i mass%, and P _i is the initial permeability ratio when the first mixing ratio is i mass%. Therefore, R1 _i is an index indicating how much the iron loss Pcv has decreased with reference to the amount of decrease in the initial permeability μ ′ when the first mixing ratio is i mass%. I _i is the Isat ratio when the first mixing ratio is i mass%. Therefore, R2 _i is an index indicating how much the iron loss Pcv is reduced based on the decrease amount of Isat when the first mixing ratio is i mass%. Table 11 shows the calculation results.

  From Table 11, the larger the first mixing ratio, that is, by reducing the degree of mixing the magnetic powder made of amorphous magnetic material powder into the powder core made of CIP, the magnetic powder becomes more effective (others It is understood that the iron loss Pcv can be reduced (with less influence on the magnetic properties).

  The electric / electronic component using the dust core of the present invention can be suitably used as a booster circuit for a hybrid vehicle or the like, a reactor, a transformer, a choke coil, or the like used for power generation or substation facilities.

1 ... Compact core (toroidal core)
DESCRIPTION OF SYMBOLS 10 ... Toroidal coil 2 ... Coated conductive wire 2a ... Coils 2b, 2c ... Exposed end part 2d, 2e ... End part 20 of coil 2a ... Inductance element 3 ... Powder core 3a ... Mounting surface 3b, 3c of powder core 3 ... Side surface 4 of dust core 3 ... Terminal portion 5 ... Coil 5a ... Winding portion 5b of coil 5 ... Pull-out end 30 of coil 5 ... Storage recess 40 ... Connection end 42a ... First bent portion 42b ... Second bent portion DESCRIPTION OF SYMBOLS 100 ... Mounting board 110 ... Land part 120 ... Solder layer 200 ... Spray dryer apparatus 201 ... Rotor S ... Slurry P ... Granulated powder

Claims (15)

A powder core containing a powder of crystalline magnetic material and a powder of amorphous magnetic material,
The first mixing ratio, which is a mass ratio of the content of the crystalline magnetic material powder to the sum of the content of the crystalline magnetic material powder and the content of the amorphous magnetic material powder, is 75% by mass. A dust core characterized by being 95% by mass or less.   The powder core according to claim 1, wherein the first mixing ratio is 80 mass% or more and 90 mass% or less.   The powder core according to claim 1 or 2, wherein the powder of the crystalline magnetic material is made of an insulating material.   The crystalline magnetic material is Fe-Si-Cr alloy, Fe-Ni alloy, Fe-Co alloy, Fe-V alloy, Fe-Al alloy, Fe-Si alloy, Fe-Si-Al. The dust core according to any one of claims 1 to 3, comprising one or more materials selected from the group consisting of a system alloy, carbonyl iron and pure iron.   The powder core according to claim 4, wherein the crystalline magnetic material is made of carbonyl iron.   The amorphous magnetic material includes one or more materials selected from the group consisting of Fe-Si-B alloys, Fe-PC-C alloys, and Co-Fe-Si-B alloys. The powder core according to any one of claims 1 to 5.   The dust core according to claim 6, wherein the amorphous magnetic material is made of an Fe—P—C alloy.   The powder core according to any one of claims 1 to 7, wherein a median diameter D50 of the powder of the amorphous magnetic material is 20 µm or less.   9. The composition according to claim 1, further comprising: a binder component that binds the powder of the crystalline magnetic material and the powder of the amorphous magnetic material to another material contained in the powder core. The dust core according to one item.   The powder core according to claim 9, wherein the binding component includes a component based on a resin material.   11. The method for producing a dust core according to claim 10, comprising pressure molding of a mixture comprising the crystalline magnetic material powder and the amorphous magnetic material powder and a binder component comprising the resin material. A method for producing a powder core, comprising a molding step of obtaining a molded product by a molding process.   The manufacturing method according to claim 11, wherein the molded product obtained by the molding step is the powder core.   The manufacturing method of Claim 11 provided with the heat processing process which obtains the said powder core by the heat processing which heats the said molded product obtained by the said shaping | molding process.   An electric / electronic component comprising a dust core, a coil, and a connection terminal connected to each end of the coil according to any one of claims 1 to 10, wherein at least a part of the dust core is An electric / electronic component arranged so as to be located in an induced magnetic field generated by the current when a current is passed through the coil via the connection terminal.   15. An electric / electronic device in which the electric / electronic component according to claim 14 is mounted, wherein the electric / electronic component is connected to a substrate by the connection terminal.