JP6385811B2 - Electronic components and equipment - Google Patents

Description

  The present invention relates to an electronic component including a part made of a molded body including a magnetic granular material and an electronic device on which the electronic component is mounted.

  Mobile electronic devices are rapidly replacing mobile phones with small-sized but multifunctional smartphones. In such a multifunctional portable electronic device, it is an urgent issue to increase the convenience for the user by extending the usable time by one charge. One solution to this problem is to increase the number of power supply circuits provided in an electronic device and control the operation of those circuits according to the operation of each device / unit connected to the circuit (in the specific example For example, when the display element is not used, the operation of the power supply circuit connected to the display element is stopped.) By reducing the power consumption of the electronic device. As the number of power supply circuits increases, a large number of inductance elements (for example, see Patent Document 1) for noise suppression, rectification, and smoothing are required. For these reasons, the number of inductance elements used in portable electronic devices tends to increase.

  However, since the size of the portable electronic device is naturally limited, it is required to reduce the size of the inductance element that has been used. Specifically, a core disposed between two terminals included in the inductance element is required to maintain insulation so as not to energize in the core. The distance between the two terminals (this specification) In this case, the inductance element may be downsized to such an extent that the distance between two terminals arranged opposite to each other is referred to as “distance between terminals”) is 4 mm or less.

JP 2006-13066 A

  The core of the inductance element is usually formed of a molded body containing magnetic powder particles (in the present specification, the portion formed of the molded body in the electronic component is also referred to as “molded body portion”). When the inductance element is reduced in size as described above, a molded body portion (core) is formed using an alloy-based magnetic particle having a high saturation magnetic flux density so that the inductance element has an appropriate DC superposition characteristic. However, it is desirable to increase the magnetic permeability of the molded body portion (core).

  Generally, the downsizing of the inductance element is realized by increasing the switching frequency of the switching power supply. To that end, it is necessary to reduce the core loss of the inductance element. Similarly, when the inductance element is operated at a high frequency, it is also desirable to increase the specific resistance of the molded body portion (core) of the inductance element that affects the core loss, thereby increasing the insulation of the molded body portion (core). . Furthermore, considering that the inductance element is mounted using a high-density mounting technique, it is necessary to maintain the strength of the molded body portion (core) to such an extent that it can be practically used.

  From the viewpoint of suppressing the decrease in insulation and strength of the molded body part (core), the insulation and binding properties between the powder particles arranged in the nearest position in the molded body constituting the molded body part (core) It is effective to increase the amount by increasing the amount of the binder. However, from this point of view, when the amount of the binder at the time of molding the raw material containing the granular material is increased, the core loss of the obtained molded body portion (core) or the permeability may be decreased.

  The above problem is not limited to the inductance element, and there is a concern that the same problem may occur with downsizing of other electronic parts having a portion formed of a molded body including magnetic powder particles.

  In view of the present situation, the present invention has a portion (molded body portion) made of a molded body containing magnetic particles and has a small size, and maintains the strength and insulation of the molded body portion. It is an object of the present invention to provide an electronic component having excellent magnetic properties.

One aspect of the present invention provided to solve the above-described problem is an electronic component having a powder core including magnetic particles and a binder component, and having an inter-terminal distance of 4 mm or less. The binder body component includes an Fe-based amorphous alloy powder, the binder component includes a binder of an organic material and a heated residue of the binder, and the dust core is measured in accordance with JIS Z2507: 2000. The compressed crushing strength is 8.9 N / mm ² or more and 33.6 N / mm ² or less, and the void parameter P1 defined by the following formula (i) in the dust core is 0.3 or more and 0.7 or less. with some, the powder particles having the magnetic contained in the dust core, the integrated value 50% by volume in the particle size distribution of the powder or granular material were measured using a laser diffraction scattering particle size distribution measuring apparatus Corresponding particle size (unit: μm) D ₅₀ is is not more 3μm or more 6μm or less, which is an electronic component characterized by having a particle size distribution represented by the following formula (ii).
P1 = Rv / (Rv + Rb) (i)
Here, Rv (unit: volume%) is the porosity after molding of the powder core, and Rb (unit: volume%) is occupied by the binder component after molding of the powder core. Volume ratio.
_{(D 90 -D 10) / D} 50 ≦ 1.3 (ii)
Here, D ₁₀ , D _50, and D ₉₀ are each a particle diameter (unit: 10% by volume) in the particle size distribution of the granular material measured using a laser diffraction / scattering particle size distribution measuring apparatus. μm) and a particle size (unit: μm) corresponding to an integrated value of 90% by volume.

When the void parameter P1 is in the above range, an appropriate amount of the binder component can be present in a region other than the region occupied by the magnetic particles in the molded body portion (the powder core) . Thus, it is possible to obtain an electronic component having excellent magnetic properties without significantly deteriorating the mechanical properties (strength) and insulation properties of the molded body portion.

The above-mentioned electronic component has a resistance value measured by applying a DC voltage of 15 V to a member made of the same material as the powder core including the magnetic powder and the distance between the measurement electrodes being 2 to 4 mm. It is preferable that the specific resistance calculated based on the above is 10 kΩ · m or more.

The electronic component may be an inductance element including the dust core .

The dust core of the electronic component preferably has a relative permeability of 20 or more at a frequency of 100 kHz.

The dust core of the electronic component may have a core loss measured under conditions of a frequency of 100 kHz and a maximum magnetic flux density of 100 mT, or may be 1500 kW / m ³ or less, or measured under a condition of a frequency of 100 kHz and a maximum magnetic flux density of 50 mT. The core loss may be 120 kW / m 3 or less.

The powder core of the electronic component is one in which the void parameter P1 is adjusted by changing the content of the binder with respect to the raw material when forming the raw material including the magnetic granular material and the binder. It may be. In this way, it is easy to adjust the air gap parameter P1.

When the surface of the electronic component after the molding of the dust core is observed using a secondary electron microscope with an acceleration voltage of 1.5 kV and an observation magnification of 3000, the determination rate of the powder in the observation image is 15 % Or more and 50% or less is preferable. The determination rate can be approximated as having a proportional relationship with the air gap parameter P1.

In the above electronic component, it is preferable that the air gap parameter P1 is not less than 0.32 and not more than 0.64.
By satisfying the relation of the above-mentioned formula (ii), hardly occurs the contact of the granular material each having a magnetic, easily improved insulating properties. From this viewpoint, it is preferable to satisfy the following formula (iii).
_{(D 90 -D 10) / D} 50 ≦ 1.0 (iii)
Here, D ₁₀ , D ₅₀ and D ₉₀ are as defined in the above formula (ii). It is preferred D ₅₀ is 5μm or more 6μm or less.

  Another embodiment of the present invention is an electronic device on which the above electronic component is mounted. As described above, even if the electronic component according to the present invention is small in size, the mechanical properties and insulation of the molded product portion are unlikely to deteriorate. For this reason, problems such as breakage are less likely to occur, and dielectric breakdown problems are less likely to occur. Therefore, even when the electronic device mounted with the electronic component according to the present invention is downsized, defects derived from the electronic component are not easily generated, and the operation stability is excellent.

  In the electronic component according to the above invention, since the void parameter P1 of the molded part is controlled to an appropriate range, the molded part is insulated even though the size of the electronic part is smaller than that of the conventional electronic component. In addition to excellent properties, it has excellent magnetic properties, and the crushing strength can be maintained sufficiently strong for practical use.

1 is a perspective view showing a part of the entire configuration of an inductance element according to an embodiment of the present invention. It is a partial front view which shows the state which mounted the inductance element shown in FIG. 1 on the mounting board | substrate. It is a graph which shows the relationship between specific resistance and the porosity based on the result of a present Example. It is a graph which shows the relationship between a relative magnetic permeability and a porosity based on the result of a present Example. It is a graph which shows the relationship between a core loss and a porosity based on the result of a present Example. It is a graph which shows the relationship between crushing strength and porosity based on the result of a present Example. It is a graph which shows the relationship between the relative value of a specific resistance, and the space | gap parameter P1 based on the result of a present Example. It is a graph which shows the relationship between the relative magnetic permeability based on the result of a present Example, and the air gap parameter P1. It is a graph which shows the relationship between the relative value of a core loss and the space | gap parameter P1 based on the result of a present Example. It is a graph which shows the relationship between the crushing strength and the space | gap parameter P1 based on the result of a present Example. It is a graph which shows the particle size distribution (integrated value) of the granular material (soft magnetic powder) which has the magnetism concerning a present Example. It is a graph which shows the relationship between the determination rate of the granular material which has magnetism (soft magnetic powder) based on the result of a present Example, and the space | gap parameter P1.

  Hereinafter, the embodiment of the present invention will be described by taking a case where the electronic component is the inductance element shown in FIGS. 1 and 2 as a specific example.

1. Inductance Element FIG. 1 is a perspective view showing a part of the entire configuration of an inductance element 1 according to an embodiment of the present invention. In FIG. 1, the lower surface (mounting surface) of the inductance element 1 is shown in an upward posture. FIG. 2 is a partial front view showing a state in which the inductance element 1 shown in FIG. 1 is mounted on the mounting substrate 10.

  The inductance element 1 shown in FIG. 1 includes a dust core 3, an air core coil 2 as a coil embedded in the dust core 3, and a pair of terminals electrically connected to the air core coil 2 by welding. Part 4.

  The air-core coil 2 is formed by spirally winding a conductive wire with an insulating coating. The air-core coil 2 includes a winding part 2a and lead-out end parts 2b and 2b drawn from the winding part 2a. The number of turns of the air-core coil 2 is appropriately set according to the required inductance.

  As shown in FIG. 1, 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 3a and are released toward the side surfaces 3b and 3c of the powder core 3. A part of the terminal portion 4 protruding from the side surfaces 3 b and 3 c of the dust 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 exposed on the outer surface of the dust core 3 and the connection end part 40 embedded in the dust core 3 and electrically connected to the lead-out ends 2b and 2b of the air-core coil 2. The powder 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 air-core coil 2. The first bent portion 42 a and the second bent portion 42 b are solder joint portions that are soldered to the mounting substrate 10. 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 2b of the air-core coil 2 are joined by resistance welding.

As shown in FIG. 2, the inductance element 1 is mounted on a mounting substrate 10.
A conductor pattern that is electrically connected to an external circuit is formed on the surface of the mounting substrate 10, and a pair of land portions 11 for mounting the inductance element 1 is formed by a part of the conductor pattern.

  As shown in FIG. 2, in the inductance element 1, the mounting surface 3 a is directed to the mounting substrate 10 side, and the first bent portion 42 a and the second bent portion 42 b that are exposed to the outside from the dust core 3 are mounted. The solder layer 12 is bonded to the land portion 11 of the substrate 10.

  In the soldering process, after the solder paste is applied to the land part 11 in the printing process, the inductance element 1 is mounted on the land part 11 so that the second bent part 42a faces, and the solder melts in the heating process. To do. As shown in FIGS. 1 and 2, the second bent portion 42 b faces the land portion 11 of the mounting substrate 10, and the first bent portion 42 a is exposed on the side surfaces 3 b and 3 c of the inductance element 1. The solder layer 12 is fixed to the land portion 11 and is sufficiently spread and fixed on the surfaces of both the second bent portion 42b and the first bent portion 42a which are solder joint portions.

  In the inductance element 1 shown in FIGS. 1 and 2, the portions corresponding to the terminals arranged opposite to each other are two first bent portions 42a. The distance between the terminals in the inductance element 1 shown in FIGS. 1 and 2 is the distance between the two first bent portions 42a. This corresponds to the distance between the side surface 3b and the side surface 3c of the powder core 3. That is, in the inductance element 1 shown in FIGS. 1 and 2, the distance between the terminals is determined by the shape of the dust core 3.

2. Molded Body Part The inductance element 1 according to one embodiment of the present invention includes a part (molded body part) made of a molded body including a magnetic granular material. In the inductance element 1 shown in FIG. 1, the dust core 3 corresponds to a molded body portion.

The composition of the granular material having magnetism contained in the molded body portion (compact core 3) is not limited. A specific example of such a granular material is a soft magnetic powder containing a soft magnetic material. Specific examples of soft magnetic powders include soft magnetic alloy powders such as Fe-based amorphous alloy powders, Fe-Ni alloy powders, Fe-Si alloy powders, and pure iron powders (high purity iron powders); oxidation of ferrite and the like Examples thereof include soft magnetic powders. Fe-P-C-B- Si -based amorphous alloy which is a kind of Fe-based amorphous alloy, indicates that the composition is in the _{Fe 100-abcxyzt Ni a Sn b} Cr c P x C y B z Si t 0 at% ≦ a ≦ 10 at%, 0 at% ≦ b ≦ 3 at%, 0 at% ≦ c ≦ 6 at%, 3.0 at% ≦ x ≦ 10.8 at%, 2.0 at% ≦ y ≦ 9.8 at%, It is preferable that 0 at% ≦ z ≦ 8.0 at% and 0 at% ≦ t ≦ 5.0 at%.

  The magnetic granular material may be composed of only a magnetic material, or may be a mixture of a magnetic material and a material other than the material. A specific example of such a case is a granulated powder obtained by granulating a powder made of an alloy-based magnetic material using a resin-based material.

The particle size of the magnetic granular material is not limited. Basically, the smaller the particle size of the magnetic granular material, the higher the moldability. However, when the particle size is excessively small, the problem of agglomeration tends to become obvious, and chemicals such as oxidation Stability issues are likely to become apparent. Therefore, the magnetic granular material preferably has an average particle size of 1 μm or more and 100 μm or less, more preferably 2 μm or more and 50 μm or less, more preferably 3 μm or more and 25 μm or less, and more preferably 5 μm or more and 15 μm or less. It is particularly preferred. In the present specification, the “average particle diameter” of the granular material is a particle diameter (median) corresponding to an integrated value of 50% by volume in the particle size distribution of the granular material measured using a laser diffraction / scattering particle size distribution measuring apparatus. Diameter D ₅₀ ).

  The manufacturing method for forming the molded body portion (the powder core 3) is not limited. A raw material for forming a molded body part (a powder core 3) (in this specification, “raw material”, which is not specifically mentioned, means a raw material for forming a molded body part (a powder core 3)). In addition, the binder and components derived from the binder (in the present specification, these may be collectively referred to as “binder-based components”) are used to bind adjacent magnetic particles having magnetism. May be.

Specific examples of the binder include epoxy resin, silicone resin, silicone rubber, phenol resin, urea resin, melamine resin, liquid or powder resin such as PVA (polyvinyl alcohol), acrylic resin, organic material such as rubber; water glass (Na ₂ O—SiO ₂ ), oxide glass powder (Na ₂ O—B ₂ O ₃ —SiO ₂ , PbO—B ₂ O ₃ —SiO ₂ , PbO—BaO—SiO ₂ , Na ₂ O—B ₂ O _3- ZnO, CaO—BaO—SiO ₂ , Al ₂ O ₃ —B ₂ O ₃ —SiO ₂ , B ₂ O ₃ —SiO ₂ ), glassy substances (SiO ₂ , Al ₂ O ₃ , And inorganic materials such as ZrO ₂ , TiO _{2 and the} like as main components. The binder may be a mixture of an organic material and an inorganic material. The binder may be composed of one type of material or a mixture of a plurality of materials.

  In the case where the raw material contains a binder, the content is not limited. What is necessary is just to set suitably so that a molded object part (powder core 3) may have a desired characteristic.

  The raw material may contain zinc stearate, aluminum stearate, or the like as a lubricant for the purpose of adjusting the fluidity of magnetic particles. When the raw material contains a lubricant, the content is not limited. What is necessary is just to set suitably so that a molded object part (powder core 3) may have a desired characteristic.

3. Porosity In the molded part (compact core 3) of the electronic component (inductance element 1) according to one embodiment of the present invention, the porosity defined below is preferably 5% by volume or more and 30% by volume or less. There is a case.

  In this specification, the porosity (unit:%) is the percentage of the volume of the void defined as the portion where no solid substance is present in the molded body portion (compact core 3) with respect to the total volume of the molded body portion. means. The solid material constituting the molded body portion (the powder core 3) includes a magnetic granular material. When the raw material contains a component other than the magnetic granular material such as the binder, a binder component and the like are also included in the solid substance.

  The method for deriving the porosity is not limited. The porosity may be derived based on the composition of the molded body portion (the compact core 3) and the shape measurement result of the molded body. Or you may derive | lead-out the porosity based on the result of having observed the surface of the molded object part (compact core 3), a fracture surface, a cross section, etc.

  By adjusting the porosity to 5% by volume or more and 30% by volume or less, the insulation and magnetic properties of the molded body part (the dust core 3) of the electronic component (inductance element 1) according to an embodiment of the present invention are improved. It is not clear why it may be possible. When the porosity increases, magnetic properties such as magnetic permeability and core loss in the molded body portion (dust core 3) of the electronic component (inductance element 1) according to an embodiment of the present invention tend to be improved. Due to the high rate, internal stress generated in the granular material having magnetism in the molded body portion (specific examples include internal stress due to pressurization during molding and internal stress due to magnetostriction). There is a possibility that it is in a state where it is easily relaxed. Moreover, when the porosity becomes high, the tendency for the insulating property of the molded body portion (the powder core 3) to decrease is observed.

  It is preferable that the porosity of the molded body part (compact core 3) of the electronic component (inductance element 1) according to an embodiment of the present invention is 10 volume% or more and 28 volume% or less, and 12 volume% or more and 27 volume%. % Or less, more preferably 15% by volume or more and 26% by volume or less. If the porosity is excessively high, the mechanical strength of the molded body portion (the powder core 3) may tend to decrease.

4). Air gap parameter P1
In this specification, the “gap parameter P1” is defined by the following equation (1). The void parameter P <b> 1 is a parameter indicating how much void portion is present in a region other than the region occupied by the magnetized powder in the molded product, that is, the molded product.
P1 = Rv / (Rv + Rb) (1)

  Here, Rv (unit: volume%) is the porosity (of the molded product) after the molding process in the molded body portion (compact core 3) of the electronic component (inductance element 1) according to an embodiment of the present invention. It is. Rb (unit: volume%) is occupied by the binder-based component (of the molded product) after molding of the molded body portion (the powder core 3) in the electronic component (inductance element 1) according to an embodiment of the present invention. Volume ratio (hereinafter, this volume ratio is also referred to as “binder content”). Even when a heat treatment that changes the composition of the binder component is performed on the molded body part (molded product) after the molding process, the binder content Rb in the state before the heat treatment is determined. It is possible to define the characteristics of the electronic component (inductance element 1) and the molded body portion (powder core 3) according to an embodiment of the present invention by the air gap parameter P1 calculated using the above. It should be noted that the molded body portion (compact core 3) of the electronic component (inductance element 1) according to one embodiment of the present invention may not be subjected to special heat treatment on the molded product after the molding process.

  The method for obtaining the binder content is not limited. In the case where the composition of the molded body portion (powder core 3) is clear, the binder content can be determined from information based on the composition and the measurement result of the volume. Even if the composition of the molded body part (powder core 3) is not clear, the binder component is removed from the molded body part (powder core 3) by means of heating or the like, and based on the mass change and the like at that time Thus, the binder content can be determined.

  In the electronic component (inductance element 1) according to an embodiment of the present invention, the air gap parameter P1 based on the above definition is 0.3 or more and 0.8 or less. When the air gap parameter P1 is 0.3 or more, it is possible to improve the magnetic characteristics and the insulating properties of the molded body portion (the dust core 3) of the electronic component (inductance element 1) according to the embodiment of the present invention. . The air gap parameter P1 is 0.45 or more from the viewpoint of more stably improving the magnetic characteristics and insulation of the molded body portion (the dust core 3) of the electronic component (inductance element 1) according to the embodiment of the present invention. May be preferred, may be more preferably 0.5 or more, may be more preferably 0.55 or more, and may be particularly preferably 0.6 or more. . When the air gap parameter P1 is 0.8 or less, it is possible to suppress a significant decrease in mechanical properties and insulating properties of a molded body portion (a dust core 3) of an electronic component (inductance element 1) according to an embodiment of the present invention. be able to. From the viewpoint of appropriately ensuring the mechanical properties (strength) of the molded body portion (the dust core 3) of the electronic component (inductance element 1) according to the embodiment of the present invention, the air gap parameter P1 is 0.75 or less. It may be preferable, and it may be preferable that it is 0.7 or less.

  It can be approximated that the void parameter P1 of the molded body portion (powder core 3) has a proportional relationship with the powder determination rate calculated based on the surface observation of the molded body portion (powder core 3). When the void parameter P1 is increased, the possibility that the binder component is present in a region other than the region occupied by the magnetic particles in the molded body portion (the powder core 3) is reduced. For this reason, when the granular material which has magnetism becomes easy to be exposed, and the surface of the molded body portion (the powder core 3) is observed, the possibility that the magnetic granular material is observed is high. Conceivable.

5. Magnetic Characteristics The electronic component according to one embodiment of the present invention may be an inductance element. When the electronic component according to an embodiment of the present invention is an inductance element (a specific example is the inductance element 1), the core included in the inductance element (a specific example is the dust core 3) has a frequency. The relative permeability at 100 kHz is preferably 20 or more. Moreover, it is preferable that the core loss measured on the conditions of a frequency of 100 kHz and a maximum magnetic flux density of 100 mT is 1500 kW / m ³ or less. Or it is preferable that the core loss measured on the conditions of 100 kHz and the maximum magnetic flux density of 50 mT is 120 kW / m ³ or less. Since the core has such magnetic characteristics, the electronic component according to the embodiment of the present invention can function effectively as an inductance element. From the viewpoint of enabling an electronic component according to an embodiment of the present invention to function more effectively as an inductance element, the core included in the inductance element has a relative permeability of 22 or more at a frequency of 100 MHz. Preferably, it is 25 or more. From the same point of view, the core included in the inductance element preferably has a core loss of 1500 kW / m ³ or less, particularly preferably 800 kW / m ³ or less, measured under conditions of a frequency of 100 kHz and a maximum magnetic flux density of 100 mT. . Alternatively, the core included in the inductance element preferably has a core loss measured under conditions of a frequency of 100 kHz and a maximum magnetic flux density of 50 mT of 100 kW / m ³ or less, particularly preferably 90 kW / m ³ or less.

6). Shape and Electrical Characteristics The electronic component according to one embodiment of the present invention has a distance between terminals of 4 mm or less. When the distance between the terminals becomes small in this way, the direct current resistance (insulation resistance) of the molded body portion located between the terminals tends to decrease. When this resistance value is lowered, the possibility of affecting the characteristics required for the electronic component increases. For example, when the electronic component is an inductance element, the direct current resistance (insulation resistance) of the molded body portion (core) decreases, so that it is difficult to perform functions required for the inductance element such as noise suppression, rectification, and smoothing. The possibility increases. However, in the electronic component (inductance element 1) according to an embodiment of the present invention, since the air gap parameter P1 of the molded body portion (core 3) is in the above range, its specific resistance is unlikely to decrease, and the molded body portion ( Excellent insulation of core 3). Therefore, the electronic component (inductance element 1) according to an embodiment of the present invention can appropriately perform the required function even when the size is small.

  The distance between terminals of the electronic component (inductance element 1) according to an embodiment of the present invention may be 3 mm or less, or 2 mm or less. The lower limit of the distance between terminals of the electronic component (inductance element 1) according to the embodiment of the present invention is not limited. The distance between the terminals is preferably 100 μm or more, more preferably 500 μm or more, and particularly preferably 1 mm or more.

  In this specification, the specific resistance of the molded body part is a resistance value measured by applying a DC voltage of 15 V to a member made of the same material as the molded body part with a distance between measurement electrodes of 2 to 4 mm. A value calculated based on the unit (unit: kΩ · m or MΩ · m). Since an electronic component is normally driven at about several volts to 10 volts, about 15 volts is appropriate as an applied voltage for evaluating insulation.

  The specific resistance of the molded part (powder core 3) of the electronic component (inductance element 1) according to one embodiment of the present invention is preferably 10 kΩ · m or more, more preferably 15 kΩ · m or more. 20 kΩ · m or more is particularly preferable.

The specific resistance of the molded part (powder core 3) of the electronic component (inductance element 1) according to an embodiment of the present invention is the particle size distribution of the magnetic granular material included in the molded part (powder core 3). Can be changed by adjusting. For example, when it has the particle size distribution shown by following formula (2), a specific resistance can be raised. It is considered that the smaller the P2 expressed by the following formula (2), the narrower the distribution range of the particle diameter with respect to the average particle diameter, and the lower the degree of contact between the magnetic granular materials.
_{P2 = (D 90 -D 10)} / D 50 ≦ 2.0 (2)

Here, D ₁₀ , D _50, and D ₉₀ are particles corresponding to an integrated value (cumulative frequency) of 10 vol% in the particle size distribution of the granular material measured using a laser diffraction / scattering particle size distribution measuring device, respectively. The diameter (unit: μm), the particle size corresponding to an integrated value of 50% by volume (unit: μm, that is, the average particle size) and the particle size corresponding to an integrated value of 90% by volume (unit: μm).

  From the viewpoint of increasing the specific resistance, P2 represented by the above formula (2) is preferably 1.7 or less, more preferably 1.5 or less, and particularly preferably 1.3 or less. As P2 decreases, the specific resistance may increase significantly. Specifically, it may be about 1 GΩ · m or more.

7). Control Method of Mechanical Properties The control method of the porosity and the void parameter P1 of the molded body portion (the dust core 3) of the electronic component (inductance element 1) according to an embodiment of the present invention is not limited. The porosity and the void parameter P1 can be controlled by changing the manufacturing process of the molded body portion (the dust core 3).

  Hereinafter, as a specific example, the molded body portion (compact core 3) is manufactured by a manufacturing method including a step of pressure-molding a raw material including a magnetic granular material and a binder. A method for controlling the porosity and the void parameter P1 of the powder core 3) through the manufacturing process will be described.

  As one of the above control methods, there is a method of changing the composition of the binder contained in the raw material or the content of the binder in the raw material. By changing these, the content and properties of the binder component of the molded body obtained from the raw material are affected, and the porosity and the void parameter P1 of the molded body portion (the dust core 3) can be changed. it can. According to this method, it is possible to reduce the porosity and the void parameter P1 by increasing the binder content in the raw material. However, specific numerical values of the porosity and the void parameter P1 and the degree of change thereof vary depending on the type of binder and other factors.

  As another one of the above control methods, after the raw material is pressure-molded, it is subjected to a removal treatment for removing a component based on the binder, that is, a part of the binder-based component, to thereby form a molded body portion (a powder core 3 ) Is changed. According to this method, when the porosity is increased, the content of the binder component in the molded body portion (compact core 3) is relatively reduced, and the void parameter P1 is increased.

  Examples of the removal treatment include heat treatment, dissolution treatment, and decomposition treatment by irradiation with energy rays.

  When the removal treatment is performed by heat treatment, the thermophysical properties of the binder (specific examples include thermoplastic properties, thermosetting properties, composite properties obtained by mixing materials having these properties), and the like. It is preferable to appropriately set the relationship between the heating temperature and the decomposition temperature of the binder. The heat treatment conditions (heating temperature, heating time, etc.) are not limited as long as the binder component can be removed. For the purpose of relieving the stress of the magnetic granular material contained in the molded product obtained by pressure-molding the raw material, the molded product is subjected to a heat treatment to form a molded body part (compact core 3). In order to improve the production efficiency, it is preferable to perform the heat treatment, which is a kind of the above-described removal treatment. In the case where the removal treatment is performed by heat treatment, the binder component contained in the molded body portion (compact core 3) may include a heated residue of the binder.

  As a specific example in the case of performing the removal treatment by the dissolution treatment, the molded product may be brought into contact with a liquid capable of dissolving the binder component. Examples of the contact method include dipping and spraying.

  As a specific example in the case of performing the removal process by the decomposition process by irradiation with energy rays, it is exemplified that the molded product is irradiated with microwaves, ultraviolet rays, X-rays, electron beams, lasers, and the like. Infrared irradiation may provide substantially the same effect as the above heat treatment.

  As another one of the above control methods, there is a method of changing the porosity and the void parameter P1 of the molded body part (the dust core 3) by changing the manufacturing conditions of the molded body constituting the molded body part. It is done. Specifically, pressure forming conditions (pressing pressure, pressing time, etc.), and heating conditions (heating temperature, heating time, etc.) can be changed when heat treatment is further performed.

  In controlling the porosity and the void parameter P1 of the molded body portion (powder core 3), the above method may be used alone, or a plurality of methods (including methods other than the above methods) may be combined. Also good.

8). Electronic Component An electronic device according to an embodiment of the present invention is one in which an electronic component (inductance element 1) according to an embodiment of the present invention is mounted. Since the electronic component (inductance element 1) according to an embodiment of the present invention is small in size, the molded product portion is manufactured because the mechanical properties and insulating properties of the molded product portion (powder core 3) are unlikely to deteriorate. At the time of manufacture as an electronic component, when mounted on an electronic device, and when used as an electronic device, problems such as breakage are less likely to occur, and problems of dielectric breakdown are less likely to occur. Therefore, since the electronic device mounted with the electronic component according to the present invention is mounted with a small-sized electronic component, the electronic device can be reduced in size and weight. In addition, even when the size and weight are reduced in this way, defects derived from electronic components are unlikely to occur and the operational stability is excellent.

  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, the present invention will be described more specifically with reference to examples. However, the scope of the present invention is not limited to these examples.
Example 1
(Example 1-1)
Using a water atomization method, non-obtained obtained by weighing to a composition of Fe _{74.43 at%} Cr _{1.96 at%} P _{9.04 at%} C _{2.16 at%} B _{7.54 at%} Si _{4.87 at%} A crystalline soft magnetic powder was prepared as a soft magnetic powder. The particle size distribution of the obtained soft magnetic powder was measured by volume distribution using “Microtrack particle size distribution measuring device MT3300EX” manufactured by Nikkiso Co., Ltd. As a result, the average particle diameter (D ₅₀ ) was 10.6 μm.

  100 parts by mass of the above soft magnetic powder, 2 parts by mass of a binder containing a resin-based material including a novolac epoxy resin, and 0.3 parts by mass of a lubricant composed of zinc stearate are mixed in water as a solvent, A slurry as a raw material was obtained.

  The obtained slurry was pulverized after drying, and fine powder of 300 μm or less and coarse powder of 850 μm or more were removed using a sieve having an opening of 300 μm and a sieve of 850 μm to obtain granulated powder.

  The granulated powder obtained by the above method is filled in a mold, and pressure-molded under conditions of pressing at a mold temperature of 150 ° C. and a surface pressure of 25 MPa for 35 minutes. By holding for a time, a molded product was obtained.

  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 372 ° C. at a rate of temperature increase of 40 ° C./min. Then, heat treatment was performed to cool to room temperature in the furnace. Thus, an annular core having an outer diameter of 20 mm, an inner diameter of 12 mm, and a thickness of 4 mm was obtained.

(Examples 1-2 to 1-5)
Although it is the manufacturing method similar to Example 1-1, by implementing the manufacturing method which changed the compounding quantity of the binder into the following * BR> 謔 in the slurry preparation of Example 1-1, it is shown in Table 1. As shown, a core having a different porosity and void parameter P1 from the core produced in Example 1-1 was produced.
Example 1-2: 3 parts by mass Example 1-3: 4 parts by mass Example 1-4: 5 parts by mass Example 1-5: 6 parts by mass

In addition, about the core manufactured in the Example, porosity Rv (unit:%), the volume V of the core obtained from the core shape measurement, the density ρ1 and the mass m1 of the soft magnetic powder, and the density ρ2 of the binder component It calculated based on the following formula using mass ρ2.
Rv = {1- (m1 / ρ1 + m2 / ρ2) / V} × 100
In the above calculation, it was assumed that the entire amount of the lubricant was volatilized during the heat treatment.
For the core produced in Example 1, the volume content Rb (unit:%) of the binder component was calculated based on the following formula, in the same manner as the porosity Rv.
Rb = (m2 / ρ2) / V × 100
Using the volume ratio Rb and the void ratio Rv occupied by the binder component, the void parameter P1 was calculated based on the following formula.
P1 = Rv / (Rv + Rb)
The space | gap parameter P1 has shown the ratio for which a space | gap part accounts in the area | regions other than the area | region which a soft magnetic powder occupies in the core which is a molded object part after a shaping | molding process.

Example 2
(Example 2-1)
100 parts by mass of soft magnetic powder prepared in the same manner as in Example 1, 2 parts by mass of a binder containing a resin-based material including an acrylic resin that is a thermoplastic resin and a phenolic resin that is a thermosetting resin, and stearic acid 0.3 parts by mass of a lubricant composed of zinc was mixed with water as a solvent to obtain a slurry as a raw material for the core.

  The obtained slurry was pulverized after drying, and fine powder of 300 μm or less and coarse powder of 850 μm or more were removed using a sieve having an opening of 300 μm and a sieve of 850 μm to obtain granulated powder.

  The granulated powder obtained by the above method was filled in a mold and pressure-molded under the conditions of a mold temperature of 23 ° C. and a surface pressure of 1.5 GPa to obtain a molded product.

  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 372 ° C. at a rate of temperature increase of 40 ° C./min. Then, heat treatment was performed to cool to room temperature in the furnace. Thus, an annular core having an outer diameter of 20 mm, an inner diameter of 12 mm, and a thickness of 2 mm was obtained. The obtained core contained a heated residue of the binder as a binder component.

(Examples 2-2 to 2-13)
Although it was the same manufacturing method as Example 2-1, at least one of changing the binder content in the slurry as a raw material, changing the composition of the binder, and changing the molding surface pressure was performed. By implementing the manufacturing method, as shown in Table 2, a core having a porosity different from that of the core manufactured in Example 2-1 was manufactured.
The changes of the manufacturing conditions in each example are summarized below.

Examples 2-2 to 2-4: The binder content in Example 2-1 was changed.
Examples 2-5 to 2-7: The binder composition was changed for each of Examples 2-2 to 2-4.
Example 2-8: The molding surface pressure of Example 2-1 was changed.
Examples 2-9 and 2-10: The binder content of Example 2-8 was changed.
Examples 2-11 to 2-15: The binder composition was changed for each of Examples 2-8 (Example 2-14 had the same conditions as Example 2-8).
Examples 2-16 to 2-19: The thermoplastic resin species contained in the binder was changed for each of Examples 2-12 to 2-15.
Example 2-20: The binder was changed to a binder made of a thermoplastic resin of the type used in Examples 2-16 to 2-19.

(Example 3-1)
Although it is the same as that of Example 1, 100 mass parts of soft magnetic powder which consists of an amorphous soft magnetic powder prepared so that an average particle diameter may be set to 5-6 micrometers, 70 mass% of acrylic resins which are thermoplastic resins And 2 parts by mass of a binder containing a resin material containing 30% by mass of a phenolic resin which is a thermosetting resin, and 0.3 parts by mass of a lubricant composed of zinc stearate are mixed in water as a solvent to obtain a core. As a raw material, a slurry was obtained.

  The obtained slurry was pulverized after drying, and fine powder of 300 μm or less and coarse powder of 850 μm or more were removed using a sieve having an opening of 300 μm and a sieve of 850 μm to obtain granulated powder.

  The granulated powder obtained by the above method was filled in a mold, and pressure-molded under conditions where the mold temperature was 23 ° C. and the surface pressure was 1 GPa to obtain a molded product. In this example, the void parameter P1 of the molded product (core before heat treatment) was calculated as the molded body portion after the molding process.

  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 372 ° C. at a temperature rising rate of 40 ° C./min, and at this temperature for 17 minutes. Then, heat treatment was performed to cool to room temperature in the furnace. Thus, an annular core having an outer diameter of 20 mm, an inner diameter of 12.7 mm, and a thickness of 3 mm was obtained. The resulting binder component of the core contained a heated residue of the binder.

(Examples 3-2 to 3-5)
Although it is the manufacturing method similar to Example 3-1, the core manufactured in Example 3-1 is shown in Table 3 by implementing the manufacturing method which changes the binder content in the slurry as a raw material. Produced cores having different porosity and void parameter P1.

(Test Example 1) Derivation of Specific Resistance Based on the resistance value measured by applying a DC voltage of 15 V in the thickness direction (2 to 4 mm) of the core manufactured according to the example, the specific resistance (unit: kΩ · m or MΩ · m) was calculated. The calculation results are shown in Tables 1 to 3. Moreover, the relationship between the specific resistance obtained from Table 1 and the porosity is shown in FIG. Regarding Examples 1 and 3, the relationship between the relative value (relative value of specific resistance) obtained by normalizing the value of the other specific resistance of the example with the maximum specific resistance value obtained in each example and the air gap parameter P1 Is shown in FIG.

(Test Example 2) Measurement of magnetic properties The core manufactured according to the example was measured for relative permeability (unit: dimensionless) at a frequency of 100 kHz using an impedance analyzer ("4192A" manufactured by HP), and BH analyzer. (Core loss (unit: kW / m ³ ) was measured under the conditions of a frequency of 100 kHz and a maximum magnetic flux density of 100 mT (Examples 1 and 2) or 50 mT (Example 3) using “SY-8217” manufactured by Iwasaki Tsushinki Co., Ltd. did. These measurement results are shown in Tables 1 to 3. FIG. 4 shows the relationship between the relative magnetic permeability and the porosity obtained from the measurement results in Table 1, and FIG. 5 shows the relationship between the core loss and the porosity obtained from the measurement results in Table 1. FIG. 8 shows the relationship between the relative magnetic permeability obtained from the measurement results of Table 1 and Table 3 and the air gap parameter P1. Regarding Examples 1 and 3, the relationship between the relative value (core loss relative value) obtained by normalizing the other core loss values of the example according to the maximum value of the core loss obtained in each example and the air gap parameter P1 is shown in FIG. Shown in

(Test Example 3) Measurement of crushing strength The core produced in Examples 1 and 3 was measured by a test method based on JIS Z2507: 2000, and crushing strength (unit: N / mm ² ) was obtained. Table 1 shows the obtained crushing strength. FIG. 6 shows the relationship between the crushing strength shown in Table 1 and the porosity. FIG. 10 shows the relationship between the crushing strength shown in Tables 1 and 3 and the void parameter P1.

(Test Example 4) Particle size distribution of soft magnetic powder Soft magnetic powder made of amorphous soft magnetic powder produced by the same production method as amorphous soft magnetic powder used in Example 1 and soft magnetic powder used in Example 3 About each of magnetic powder, the particle size distribution was measured by volume distribution using "Microtrack particle size distribution measuring apparatus MT3300EX" by Nikkiso Co., Ltd. FIG. 11 shows the relationship between the cumulative frequency (integrated value) of the particle diameters of the soft magnetic powder according to each example and the particle diameter. Table 10 shows D ₁₀ , D ₅₀ and D ₉₀ obtained from these measurements, and P2 calculated based on the above formula (2).

(Test Example 5) Observation of core surface and measurement of powder judgment rate For the core manufactured in Examples 1 and 3, the surface in the state after molding (the state before heat treatment in Example 3) was determined as secondary electrons. Using a microscope, the acceleration voltage was 1.5 kV, and the magnification was 3000 times. Image processing software ("XG Vision Editor (4.2.0041)" manufactured by Keyence Corporation) that obtains the powder area ratio in the image as a judgment rate (unit:%) by detecting the contour of the powder is obtained. The automatic analysis mode was applied to the observed images. When the relationship between the obtained result (judgment rate) and the void parameter P1 was plotted, it was possible to approximate it with a proportional relationship, and the proportionality coefficient was 54 (FIG. 12).

The following knowledge was obtained from Example 1.
-It is possible to control the electrical properties, magnetic properties and mechanical properties of the core by changing the porosity (Table 1 and FIGS. 3 to 6).
-By setting the porosity to 30% or less, the specific resistance of the core can be 10 kΩ · m or more (Table 1 and FIG. 3).
-By setting the porosity to 5% or more, the relative permeability of the core can be set to 20 or more (Table 1 and FIG. 4).
When the air gap parameter P1 is reduced, that is, when the proportion of the air gap portion in the region other than the soft magnetic powder of the core is reduced, the crushing strength is increased and the specific resistance is improved, but the core loss and the relative magnetic permeability are deteriorated. In order to adjust these in a balanced manner, it is effective to adjust the air gap parameter P1.

From Example 2, the following knowledge was obtained.
-It is possible to control the electrical and magnetic properties of the core by changing the various factors in the manufacturing process and adjusting the porosity (Table 2).

From Examples 1 and 3, the following findings were obtained.
-It is possible to control the electrical characteristics, magnetic characteristics and mechanical characteristics of the core by changing the air gap parameter P1 (Table 3 and FIGS. 7 to 10).
-By setting the air gap parameter P1 to 0.3 or more, the relative permeability of the core can be set to 20 or more (Table 3 and FIG. 8).
-By setting the void parameter P1 to 0.8 or less, more preferably 0.75 or less, the crushing strength of the core can be 7 MPa or more. More preferably, the crushing strength of the core can be made 15 MPa or more by setting the void parameter P1 to 0.7 or less. (Table 3 and FIG. 10).
By setting the void parameter P1 to 0.3 or more, it is possible to reduce the specific resistance and the core loss, and the void parameter P1 is 0.45 or more, preferably 0.5 or more, more preferably 0.55. As described above, more preferably, if it is set to 0.6 or more, the specific resistance and the core loss can be more stably reduced (Table 3 and FIGS. 7 and 9). The threshold value as to whether or not the specific resistance and core loss in the void parameter P1 are reduced may be influenced by the composition of the binder component contained in the core.

The following findings were also obtained.
-The value of specific resistance can be changed by changing the particle size distribution of the soft magnetic powder (Table 1, Table 3, Table 4, and FIG. 11). Specifically, the value of the specific resistance can be remarkably increased by using soft magnetic powder having a relatively narrow particle size distribution width.
-The determination rate of the powder obtained by observing the surface of the core after the molding process and detecting the contour of the powder is proportional to the void parameter P1 (FIG. 12). Therefore, if the determination rate of the powder is in the range of 15% to 50% based on the favorable range of the air gap parameter P1 of 0.3 to 0.8, the electrical characteristics, the magnetic characteristics, and the mechanical characteristics. It is possible to obtain an excellent core.

  The electronic component of the present invention is suitable as an inductance element used in a power supply circuit of a mobile phone, a smartphone, a notebook computer, or the like.

1 Inductance element 2 Air-core coil (coil)
3 Powder core 4 Terminal part 10 Mounting substrate 12 Solder layer 40 Connection end (welded part)
42a First bend (solder joint)
42b Second bend (solder joint)

Claims (12)

An electronic component comprising a powder core including magnetic particles and a binder component, and having an inter-terminal distance of 4 mm or less,
The magnetic granular material includes Fe-based amorphous alloy powder,
The binder component comprises an organic material binder and a heated residue of the binder,
The dust core has a crushing strength measured according to JIS Z2507: 2000 of 8.9 N / mm ² or more and 33.6 N / mm ² or less,
In the powder core, the air gap parameter P1 defined by the following formula (1) is 0.3 or more and 0.7 or less, and the powdered magnetic material contained in the powder core is laser diffraction scattered. D ₅₀ which is a particle size (unit: μm) corresponding to an integrated value of 50% by volume in the particle size distribution of the granular material measured using an equation particle size distribution measuring device is 3 μm or more and 6 μm or less. An electronic component having a particle size distribution represented by 2) .
P1 = Rv / (Rv + Rb) (1)
Here, Rv (unit: volume%) is the porosity after molding of the powder core, and Rb (unit: volume%) is occupied by the binder component after molding of the powder core. Volume ratio.
_{(D 90 -D 10) / D} 50 ≦ 1.3 (2)
Here, D ₁₀ and D ₉₀ are respectively a particle size (unit: μm) corresponding to an integrated value of 10% by volume in the particle size distribution of the granular material measured using a laser diffraction / scattering particle size distribution measuring device. The particle size (unit: μm) corresponding to an integrated value of 90% by volume.   A specific resistance calculated based on a resistance value measured by applying a direct current voltage of 15 V to a member made of the same material as the dust core, with a distance between measurement electrodes of 2 to 4 mm, is 10 kΩ · m or more. The electronic component according to claim 1, wherein   The electronic component according to claim 1, wherein the electronic component is an inductance element including the dust core.   The electronic component according to claim 3, wherein the dust core has a relative permeability of 20 or more at a frequency of 100 kHz. 5. The electronic component according to claim 3, wherein the dust core has a core loss measured under conditions of a frequency of 100 kHz and a maximum magnetic flux density of 100 mT of 1500 kW / m ³ or less. 5. The electronic component according to claim 3, wherein the dust core has a core loss of 120 kW / m ³ or less measured under conditions of a frequency of 100 kHz and a maximum magnetic flux density of 50 mT.   In forming the raw material including the magnetic powder and the binder, the powder core is obtained by adjusting the void parameter P1 by changing the content of the binder with respect to the raw material. Item 7. The electronic component according to any one of Items 1 to 6.   When the surface of the compacted core after molding is observed with a secondary electron microscope at an accelerating voltage of 1.5 kV and an observation magnification of 3000 times, the determination rate of the powder in the observed image is 15% or more and 50%. The electronic component according to claim 1, which is the following.   The electronic component according to any one of claims 1 to 8, wherein the air gap parameter P1 is not less than 0.32 and not more than 0.64.   The electronic component as described in any one of Claim 1 to 9 which satisfy | fills following formula (3).
    (D ₉₀ -D ₁₀ ) / D ₅₀ ≦ 1.0 (3)
  Where D ₁₀ , D ₅₀ And D ₉₀ Is as defined in claim 1.   D ₅₀ The electronic component according to any one of claims 1 to 10, wherein is 5 μm or more and 6 μm or less. The electronic device which mounted the electronic component as described in any one of Claim 1 to 11 .