JP5382923B2 - Amorphous soft magnetic alloy powder, dust core and inductor - Google Patents

Description

  The present invention relates to an amorphous soft magnetic alloy powder having a low particle size and a high saturation magnetic flux density, a dust core and an inductor using the same.

  In recent years, various electronic devices have been reduced in size and advanced in function. As a result, inductors such as coils and transformers incorporated in these electronic devices have been required to be downsized and have inductance under a large current. Yes. In order to satisfy these requirements, it is necessary to simultaneously increase the saturation magnetic flux density of the magnetic core and to improve the loss characteristics in the high frequency range.

  The core material of inductor components used in high frequency ranges is generally soft ferrite, high silicon steel, soft magnetic metal powder (pure iron powder, Fe-Si-Cr powder, Fe-Si powder, permalloy powder, iron-based material) Amorphous powder).

  When soft ferrite is used, eddy current loss can be reduced due to its high specific resistance, but it has the disadvantage of low saturation magnetic flux density. Moreover, although high silicon steel is used as a high frequency magnetic core by laminating thin silicon plates that have been subjected to insulation treatment, it has been difficult to limit the shapes that can be processed.

  Soft magnetic metal powder is used as a powder magnetic core by compression molding a mixture of an insulating material such as resin. The dust core improves the loss characteristics by reducing the eddy current by coating the powder with an insulating resin or the like. Furthermore, since it has a high saturation magnetic flux density and a high degree of freedom in shape, dust cores using soft magnetic metal powder are actively used.

  It is known that when a dust core using soft magnetic metal powder is used in a high frequency range, the generation of eddy current can be further reduced by reducing the particle size. Therefore, carbonyl iron powder having an average particle size of about 3 μm to 10 μm is generally used as a soft magnetic metal powder having a low particle size that can be used in a high frequency range. However, while carbonyl iron powder has a low particle size and high saturation magnetic flux density, it is problematic that hysteresis loss increases due to magnetocrystalline anisotropy and magnetostriction because it is crystalline.

  Therefore, since it does not have a crystal structure of a specific orientation, there is no crystal magnetic anisotropy, hysteresis loss is small, and application of amorphous soft magnetic alloy powder having a high saturation magnetic flux density to a dust core has been promoted. Yes.

Amorphous soft magnetic alloy powder requires a high quenching rate of 10 ⁴ K / sec or more at the time of production, and the production is only by the water atomization method or the gas atomization method. The average particle size of the powder that can be produced by the conventional technique is 10 μm. The degree is the limit.

  On the other hand, in Patent Documents 1, 2, and 3, an average particle size of 0.1 by reacting an aqueous solution of a metal salt and an aqueous solution of a P-based reducing agent in the presence of a complexing agent, a pH adjusting agent, and a pH buffering agent. A method for producing spherical amorphous powders of 5 μm to 10 μm is disclosed. However, these manufacturing methods produce Co—Ni—P, Ni—P, and Co—P amorphous alloy powders, and their saturation magnetic flux density is much higher than that of Fe-based amorphous alloy powders. It is thought that it is very low.

Japanese Patent Laid-Open No. 10-317021 JP 2000-87120 A JP 2001-279306 A

  In order to increase the current and increase the efficiency of electronic components that have been demanded in recent years, it is necessary to reduce the deterioration of loss characteristics caused by the increase of eddy current loss in the high frequency region, especially in the powder magnetic core using soft magnetic alloy powder. There is.

  Accordingly, an object of the present invention is to provide an amorphous soft magnetic alloy powder having a particle size smaller than that of the conventional soft magnetic alloy powder, an amorphous structure, and a high saturation magnetic flux density (Bs). It is in.

  Another object of the present invention is to provide a dust core using the amorphous soft magnetic alloy powder and an inductor having a low loss in a high frequency range.

  The present inventors drop a reducing solution containing a B-based reducing agent while stirring a raw material solution containing an iron salt, a complexing agent, a pH adjusting agent, a dispersing agent and a P-based reducing agent. By the phase reduction method, it has been found that an amorphous soft magnetic alloy powder composed of at least Fe and B of Fe, B, and P, having a low particle size and a high saturation magnetic flux density (Bs) can be obtained. It came to be completed.

  That is, according to the present invention, the average particle size is 0.1 μm or more and 5.0 μm or less composed of particles or fine particle aggregate particles having an average particle size of 0.01 μm or more and 1.0 μm or less. An amorphous soft magnetic alloy powder is obtained.

  According to the present invention, the composition of the above-mentioned amorphous soft magnetic alloy powder is 5 wt% ≦ B ≦ 10 wt%, 0 wt% ≦ P ≦ 5 wt%, with the balance being Fe. An amorphous soft magnetic alloy powder is obtained.

  In addition, according to the present invention, a powder magnetic core obtained by compression molding a mixture of the above-described amorphous soft magnetic alloy powder and a binder can be obtained. Further, according to the present invention, an inductor obtained by combining the dust core and the coil can be obtained.

  The amorphous soft magnetic alloy powder according to the present invention is a solution in which a reducing solution containing a B-based reducing agent is dropped while stirring a raw material solution containing an iron salt, a complexing agent, a pH adjusting agent, a dispersing agent and a P-based reducing agent. It is produced based on the liquid phase reduction method and has a smaller particle size than the metal powder obtained by the conventional water atomization method, and is composed of at least Fe and B among Fe, B and P, and has a high saturation magnetic flux density (Bs). An amorphous soft magnetic alloy powder having Furthermore, by using the obtained amorphous soft magnetic alloy powder for the powder magnetic core, the eddy current loss can be improved, and an inductor having a low loss especially in a high frequency region can be provided as compared with the prior art.

2 is a scanning electron micrograph of an amorphous soft magnetic alloy powder according to Example 1 of the present invention. It is the figure which showed the X-ray-diffraction pattern of the amorphous soft magnetic alloy powder by Example 1 and Comparative Example 1 of this invention. It is the figure which showed the Q value-frequency characteristic measured about the dust core for inductors produced with the amorphous soft magnetic alloy powder by Example 1, 2 of this invention, and the dust core by the comparative example 5.

  The production process of the amorphous soft magnetic alloy powder in the present invention is a raw material production that obtains a raw material liquid containing an iron salt, a complexing agent, a dispersant and a P-based reducing agent as a raw material, and a reducing liquid containing a B-based reducing agent. A pH adjusting step for adjusting the pH by adding a pH adjusting agent to the raw material solution, and a reducing step for obtaining an amorphous soft magnetic alloy powder by dropping the reducing solution while stirring the raw material solution. Composed of a combination.

  First, in the raw material manufacturing process, the iron salt, complexing agent, dispersing agent and P-based reducing agent as raw materials are weighed and put into a chemical resistant container such as a beaker together with distilled water, while stirring this. A raw material liquid is manufactured by dissolving. Furthermore, a B-type reducing agent is weighed, put into another chemical-resistant container together with distilled water, and dissolved with stirring to produce a reducing solution.

  Iron salts that can be used as raw materials include iron (II) chloride, iron (III) chloride, iron (III) nitrate, iron (II) sulfate, iron (III) sulfate, iron (II) acetate, iron oxalate ( II), ammonium iron (II) sulfate and the like, but are not limited to these as long as the same effect can be obtained.

  Complexing agents that can be used as raw materials include ammonium chloride, trisodium citrate, potassium citrate, citric acid, ammonium iron citrate, sodium acetate, ethylene glycol, ammonia water, hydrazine, etc., but the same effect However, the present invention is not limited to these.

  Examples of the dispersant that can be used as a raw material include polyvinyl pyrrolidone, but the dispersant is not limited thereto as long as the same effect can be obtained.

  Examples of the reducing agent that can be used as a raw material include sodium hypophosphite, hypophosphorous acid, ammonium hypophosphite, calcium hypophosphite, phosphorous acid and the like as P-based reducing agents. Examples of the B-based reducing agent include sodium borohydride, potassium borohydride, dimethylamine borane and the like. Furthermore, in addition to these substances, hydrazine can be used in combination with or replaced with a P-based reducing agent. These are not limited to these as long as the same effects can be obtained.

  Subsequently, a pH adjusting step is performed in which the raw material liquid is adjusted to an optimum pH for the start of the reduction reaction by introducing a pH adjusting agent while stirring the produced raw material liquid in a chemical resistant container. Here, examples of the substance that can be used as the pH adjuster include sodium hydroxide and aqueous ammonia, but the substance is not limited to these as long as the same effect can be obtained.

  Subsequently, a reducing process is performed in which an amorphous soft magnetic alloy powder is produced by dropping a reducing solution adjusted in another chemical-resistant container while stirring the raw material solution after pH adjustment. In the reduction step, Fe ions existing in the raw material liquid are reduced by the action of the reducing liquid dropped on the raw material liquid, and at the same time, P and B are also reduced, thereby precipitating these elements, Fe, P, An amorphous soft magnetic alloy powder containing B is produced.

  Next, the above-mentioned amorphous soft magnetic alloy powder and a binder are mixed and compression-molded to produce a dust core, and further, this dust core is combined with a coil to produce an inductor. At this time, the content of the binder in the dust core is preferably 1% by weight or more from the viewpoint of ensuring insulation, and 5% by weight or less in order to avoid a significant decrease in saturation magnetic flux density and magnetic permeability. Further, a lubricant such as stearic acid may be appropriately added during compression molding.

  Here, a thermosetting resin is effective as a binder used by mixing with the amorphous soft magnetic alloy powder, and the type of the resin should be appropriately selected according to the use of the dust core and the required heat resistance. Can do. Examples of binders that can be suitably used include epoxy resins, phenol resins, silicone resins, polyamideimide resins, unsaturated polyester resins, diallyl phthalate resins, xylene resins, and the like, as long as they have similar effects. However, it is not limited to these.

[Example]
Examples of the present invention will be specifically described below. First, examples of the amorphous soft magnetic alloy powder of the present invention and the manufacturing method thereof will be described.

(Example 1)
Iron salt (II) chloride hydrate as an iron salt is 1.0 mol / l (mol / liter), and ammonium chloride and trisodium citrate hydrate as complexing agents are 1.5 mol / l and 0.8 mol / l, respectively. , Polyvinylpyrrolidone as a dispersant, 0.004 mol / l, sodium hypophosphite hydrate as a P-type reducing agent to a concentration of 1.5 mol / l, and 200 ml of distilled water in a glass container. I put it together. This was stirred at room temperature with a stirrer at a rotation speed of 160 rpm to 300 rpm for 60 to 120 minutes to prepare a raw material liquid.

  Next, sodium borohydride as a B-based reducing agent is weighed so as to have a concentration of 0.5 mol / l, and is poured together with 150 ml of distilled water into a glass container separate from the raw material liquid, and stirred at room temperature. A reducing solution was prepared by stirring for 5 to 10 minutes at a rotational speed of 160 to 300 rpm with a machine.

  Next, while stirring the prepared raw material liquid at room temperature with a stirrer at a rotation speed of 160 to 300 rpm, a 30% aqueous sodium hydroxide solution was added dropwise as a pH adjuster to adjust to pH = 10.

  Next, with respect to the raw material liquid stirred at a rotation speed of 160 to 300 rpm with a stirrer, a reducing solution was dropped at a dropping rate of 200 ml / hr using a dropping device. In addition, the same effect can be obtained by dropping while applying ultrasonic waves in an ultrasonic reaction tank. After completion of dropping, after confirming that the generation of bubbles from the surface of the raw material liquid has settled, the deposited powder is separated from the liquid, and the obtained powder is washed with water and alcohol, and then dried in an inert atmosphere. Thus, an amorphous soft magnetic alloy powder was obtained.

(Examples 2 to 5, Comparative Examples 1 and 2)
Next, the concentration of sodium borohydride as the B-based reducing agent was set to 0.05 (Comparative Example 1), 0.10 (Example 2), 1.00 (Example 3), 1.50 (Example 4). ), 2.00 (Example 5), 3.00 (Comparative Example 2) The amount was changed to mol / l, and the other conditions were the same as in Example 1 described above, and the amorphous soft magnetic alloy powder was used. Got.

  Subsequently, for the obtained amorphous soft magnetic alloy powder, composition analysis using an ICP emission analyzer, measurement of particle diameter using a BET specific surface area meter, saturation magnetic flux density using a vibration sample magnetometer (VSM) Measurement of (Bs) and identification of the crystal structure using X-ray diffraction (XRD) were performed. Table 1 shows the composition, average particle diameter, saturation magnetic flux density (Bs), and crystal structure of the amorphous soft magnetic alloy powders obtained in Examples 1 to 5 and Comparative Examples 1 and 2.

  1 is a scanning electron microscope (SEM) photograph of the amorphous soft magnetic alloy powder of Example 1. FIG. As can be seen from FIG. 1, the amorphous soft magnetic alloy powder obtained in the present invention has two or more particles having a particle diameter of 0.01 μm or more and 1.0 μm or less, in which fine particle boundaries are clearly present on the particle surface. It is characterized by comprising particles formed from an aggregate of fine particles and single particles formed from only one particle.

  FIG. 2 shows X-ray diffraction results for the amorphous soft magnetic alloy powders of Example 1 and Comparative Example 1. Whether the crystal structure of the obtained powder was crystalline or amorphous was determined by an X-ray diffraction profile. Specifically, in the case of crystalline, a sharp peak derived from the crystal structure of the precipitated compound is generated, and in the case of amorphous, since there is no crystal structure, a sharp peak peculiar to crystalline is not seen. A broad peak occurs at 2θ = 45 ° and 80 °. Further, when crystalline and amorphous are mixed, an X-ray diffraction profile in which a sharp peak of crystal and an amorphous broad peak coexist is obtained.

  When looking at the X-ray diffraction profile shown in FIG. 2 on the basis of the above criteria, the X-ray diffraction profile of Example 1 shows only a broad peak peculiar to amorphous. It can be judged to be a phase. On the other hand, in the X-ray diffraction profile of Comparative Example 1, since the diffraction peak of crystalline (α-Fe) coexists in addition to the broad peak peculiar to amorphous, it is a mixed phase of amorphous and crystalline. It can be judged that there is.

  As shown in Table 1, the average particle size of the amorphous soft magnetic alloy powder of Comparative Example 1 having a B composition of 4.80% by weight is 0.05 μm, whereas the B composition is 5.10% by weight. The average particle size of the amorphous soft magnetic alloy powders of Examples 1 to 5 in the range of 0.1% to 10.18% by weight was in the range of 0.15 μm to 4.75 μm. On the other hand, the average particle size of the amorphous soft magnetic alloy powder of Comparative Example 2 having a B composition of 11.92% by weight was 6.00 μm.

  Further, the saturation magnetic flux density (Bs) of the amorphous soft magnetic alloy powders of Comparative Example 1, Example 1 to Example 5, and Comparative Example 2 in which the B composition is in the range of 4.80 wt% to 11.92 wt%. Was in the range from 1.20T to 1.60T.

  Further, the amorphous soft magnetic alloy powders of Examples 1 to 5 having a B composition in the range of 5.10 wt% to 10.18 wt% were amorphous. On the other hand, the crystal structure of the powder obtained from Comparative Example 1 where the B composition is 4.80% by weight and Comparative Example 2 where the B composition is 11.92% by weight was a mixed phase of crystalline (α-Fe) and amorphous. .

  From the above results, by adding dropwise a reducing solution in which the concentration of sodium borohydride, which is a B-based reducing agent, is adjusted so that the B composition is 5 wt% or more and 10 wt% or less, the average particle size is 0.1 μm or more and 5 An amorphous soft magnetic alloy powder that is in the range of 0.0 μm or less and is composed of only an amorphous phase can be obtained.

(Examples 1, 6 to 10, Comparative Example 3)
Next, the concentration of sodium hypophosphite hydrate as a P-based reducing agent was 0.00 (Example 6), 0.10 (Example 7), 0.50 (Example 8), 1.50. (Example 1), 2.00 (Example 9), 3.00 (Example 10), 4.00 (Comparative Example 3) The production was the same as Example 1 described above except that it was changed to mol / l. Work was performed under conditions to obtain amorphous soft magnetic alloy powder.

  Subsequently, for the obtained amorphous soft magnetic alloy powder, composition analysis using an ICP emission analyzer, measurement of particle diameter using a BET specific surface area meter, saturation magnetic flux density using a vibration sample magnetometer (VSM) Measurement of (Bs) and identification of the crystal structure using X-ray diffraction (XRD) were performed. Table 2 shows the composition, average particle diameter, saturation magnetic flux density (Bs), and crystal structure of the amorphous soft magnetic alloy powders obtained in Example 1, Examples 6 to 10 and Comparative Example 3.

  As shown in Table 2, the average particle sizes of the amorphous soft magnetic alloy powders of Example 1 and Examples 6 to 10 in which the P composition is in the range of 0.00 wt% to 4.73 wt% are The range was from 0.12 μm to 4.00 μm. On the other hand, the average particle diameter of the amorphous soft magnetic alloy powder of Comparative Example 3 having a P composition of 5.81% by weight was 5.80 μm.

  Further, the saturation magnetic flux density (Bs) of the amorphous soft magnetic alloy powders of Example 1, Examples 6 to 10 and Comparative Example 3 in which the P composition is in the range of 0.00 wt% to 5.81 wt%. Was in the range from 1.45T to 1.60T.

  In addition, the crystal structures of the amorphous soft magnetic alloy powders of Example 1 and Examples 6 to 10 in which the P composition was in the range of 0.00 wt% to 4.73 wt% were amorphous. On the other hand, the crystal structure of the powder obtained from Comparative Example 3 having a P composition of 5.81% by weight was a mixed phase of crystalline (α-Fe) and amorphous.

  From the above results, by preparing the raw material liquid by adjusting the concentration of sodium hypophosphite hydrate as the P-based reducing agent so that the P composition is 0 wt% or more and 5 wt% or less, the average particle size is An amorphous soft magnetic alloy powder having a range of 0.1 μm or more and 5.0 μm or less and composed only of an amorphous phase could be obtained.

(Example 1, Examples 11-17)
Next, the iron salt used as a raw material is iron (II) chloride hydrate, iron (III) chloride hydrate, iron nitrate (III) hydrate, iron sulfate (II) hydrate, iron sulfate (III ) Hydrate, iron (II) oxalate hydrate, iron (II) acetate, iron (II) ammonium sulfate one kind of iron salt, except for the same production conditions as in Example 1 above Work was performed to obtain amorphous soft magnetic alloy powder.

(Example 1, Examples 18-31)
Next, the complexing agent used is ammonium chloride, trisodium citrate hydrate, sodium acetate hydrate, citric acid hydrate, potassium citrate hydrate, ammonium iron citrate, ethylene glycol, hydrazine, ammonia A combination of two kinds of complexing agents selected from water was used, and the other processes were performed under the same production conditions as in Example 1 to obtain amorphous soft magnetic alloy powder.

(Example 1, Example 32)
Next, the pH adjuster to be used is either 30% sodium hydroxide or 30% ammonia water, and the other processes are performed under the same production conditions as in Example 1 to obtain an amorphous soft magnetic alloy powder. It was.

(Example 1, Examples 33 to 39, Comparative Example 4)
Next, as a reducing agent to be used, one P-based reducing agent selected from sodium hypophosphite hydrate, hypophosphorous acid, ammonium hypophosphite, calcium hypophosphite, phosphorous acid, and borohydride From a combination of one type B reducing agent selected from sodium, potassium borohydride, dimethylamine borane, or one type of reducing agent selected from the P type reducing agent and hydrazine, or from the above B type reducing agent A combination of one selected reducing agent and hydrazine was used, and the other processes were performed under the same production conditions as in Example 1 to obtain amorphous soft magnetic alloy powder.

  Subsequently, the obtained amorphous soft magnetic powder was subjected to composition analysis using an ICP emission analyzer, measurement of particle size using a BET specific surface area meter, vibration sample type magnetometer (VSM), as in Example 1. The saturation magnetic flux density (Bs) was measured using, and the crystal structure was identified using X-ray diffraction (XRD). Table 3 shows the evaluation results of the used iron salt and the obtained powder, Table 4 shows the combination of the complexing agent used and the evaluation result of the obtained powder, and Table 5 shows the combination of the pH adjusting agent used. Table 6 shows the evaluation results of the obtained powder and Table 6 shows the combination of reducing agents used and the evaluation result of the obtained powder. In addition, the density | concentration of each raw material in Example 11-39 and the comparative example 4 shall be the same as that of Example 1, Fe: 91.34 weight%, B: 7.86 weight%, P: 0.80 weight% A prototype was made so that Moreover, when the obtained amorphous soft magnetic alloy powder was subjected to ICP composition analysis, a result that almost reproduced the above composition was obtained in any powder.

  As shown in Table 3, as a result of trial manufacture by replacing only the iron salt to be used with the iron salt, the average grain size of the amorphous soft magnetic alloy powder obtained in Example 1 and Example 11 to Example 17 was obtained. The diameter was in the range of 0.8 μm to 1.5 μm.

  Moreover, as shown in Table 3, as a result of trial manufacture by replacing only the iron salt to be used with the iron salt, the amorphous soft magnetic alloy powders obtained in Example 1 and Example 11 to Example 17 were obtained. The crystal structure was all amorphous single phase.

  From the above results, the iron salt used as a raw material is iron (II) chloride hydrate, iron (III) chloride hydrate, iron nitrate (III) hydrate, iron sulfate (II) hydrate, iron sulfate (III) Hydrate, iron oxalate (II) hydrate, iron acetate (II), and iron (II) ammonium sulfate as one kind of iron salt, the average particle size is 0.1μm or more Amorphous soft magnetism in a range of 5.0 μm or less, P composition: 0% by weight to 5% by weight, B composition: 5% by weight to 10% by weight, and comprising only an amorphous phase Alloy powder could be obtained.

  It should be noted that even when two or more types of iron salts selected from the iron salts shown in Table 3 are used in combination, or when iron salts other than those described above are used, the same effect can be obtained. It is not something.

  As shown in Table 4, as a result of trial manufacture by replacing only the complexing agent to be used with two kinds of substances selected from the above complexing agents, powders obtained in Example 1 and Example 18 to Example 31 were obtained. The average particle size of was in the range of 0.8 μm to 2.3 μm.

  Further, as shown in Table 4, as a result of trial manufacture by replacing only the complexing agent to be used with two kinds of substances selected from the above complexing agents, the results obtained in Example 1 and Example 18 to Example 31 were obtained. The crystal structure of all the powders became an amorphous single phase.

  From the above results, the complexing agent used is ammonium chloride, trisodium citrate hydrate, sodium acetate hydrate, citric acid hydrate, potassium citrate hydrate, ammonium iron citrate, ethylene glycol, hydrazine, By using a combination of two complexing agents selected from aqueous ammonia, P composition: 0 wt% or more and 5 wt% or less, B composition: 5 It was possible to obtain amorphous soft magnetic alloy powder that was not less than 10% by weight and not more than 10% by weight and constituted only by an amorphous phase.

  In addition, combinations of the above complexing agents other than those shown in Table 4, combinations of three or more of the above complexing agents, and even when other complexing agents other than those described above are used, the same effects can be obtained. It is not limited to that.

  As shown in Table 5, as a result of trial manufacture by replacing only the pH adjuster to be used with the above pH adjuster, the average particle size of the powders obtained in Example 1 and Example 32 was 0.9 μm to 1. The range was 0 μm.

  Further, as shown in Table 5, as a result of trial manufacture by replacing only the pH adjuster to be used with the above pH adjuster, the crystal structures of the powders obtained in Example 1 and Example 32 were all amorphous. Became a phase.

  From the above results, when the pH adjuster to be used is a pH adjuster selected from sodium hydroxide and aqueous ammonia, the average particle size is in the range of 0.1 μm to 5.0 μm, P composition: 0 wt% or more An amorphous soft magnetic alloy powder having 5% by weight or less, B composition: 5% by weight or more and 10% by weight or less and composed only of an amorphous phase could be obtained.

  Further, even when two or more combinations of pH adjusting agents shown in Table 5 or other pH adjusting agents are used, the same effects are not limited thereto.

    As shown in Table 6, as a result of trial manufacture by replacing only the reducing agent to be used with two kinds of substances selected from the above reducing agents, the average of the powders obtained in Example 1, Example 33 to Example 39 The particle size ranged from 0.8 μm to 1.5 μm.

  Further, as shown in Table 6, as a result of trial manufacture by replacing only the reducing agent to be used with two kinds of substances selected from the above reducing agents, the powders obtained in Example 1, Example 33 to Example 39 were obtained. The crystal structure of all became an amorphous single phase.

  On the other hand, in the case of Comparative Example 4 in which the reducing agent used was a combination of sodium hypophosphite and hydrazine, a powder having an average particle size of 0.5 μm was obtained, but B was included in any reducing agent. Therefore, the B composition of the obtained powder did not satisfy 5% by weight or more and 10% by weight or less, and the crystal structure was a mixed phase of crystalline and amorphous.

  From the above results, one reducing agent selected from sodium hypophosphite hydrate, hypophosphorous acid, ammonium hypophosphite, calcium hypophosphite and phosphorous acid as a reducing agent to be used and borohydride By using a combination of one type B reducing agent selected from sodium, potassium borohydride, and dimethylamine borane, or a combination of one type of reducing agent selected from the aforementioned B type reducing agent and hydrazine, the average particle size In the range of 0.1 μm to 5.0 μm in diameter, P composition: 0% to 5% by weight, B composition: 5% to 10% by weight, and composed only of an amorphous phase An amorphous soft magnetic alloy powder could be obtained.

  In addition, even when two or more combinations of reducing agents shown in Table 6 or other reducing agents are used, the same is not limited thereto as long as the same effect is obtained.

  Subsequently, examples of the powder magnetic cores for inductors produced by mixing the amorphous soft magnetic alloy powders obtained in Examples 1 and 2 of the present invention with a binder made of a thermosetting resin and compression molding them. explain.

After adding and mixing a phenol resin so that it may become a ratio of 3.0 weight% with a resin component with respect to the amorphous soft magnetic alloy powder produced in the above-mentioned Example 1, 2, the mixture was made into a metal mold. Filled and compression molded at a pressure of 10 ton / cm ² to produce a ring-shaped dust core having an outer diameter of 13 mm, an inner diameter of 8 mm, and a height of 5 mm, followed by resin curing heat treatment, and a dust core for inductors Got.

(Comparative Example 5)
As Comparative Example 5, a phenol resin was added and mixed so that the proportion of the resin component was 3.0% by weight with respect to carbonyl iron powder (average particle size = 6 μm), and then the mixture was filled in a mold. Surface pressure: By compression molding at a pressure of 10 ton / cm ² , a ring-shaped dust core having an outer shape of 13 mm, an inner diameter of 8 mm, and a height of 5 mm was manufactured, and resin curing heat treatment was performed to obtain a dust core for inductors. .

  Next, a 10-turn winding was made using a copper wire for the dust core for inductor made of the amorphous soft magnetic alloy powder of Examples 1 and 2 and the dust core for inductor of Comparative Example 5 respectively. About what gave, Q value in the frequency range of 1 kHz or more and 40 MHz or less was measured using the impedance analyzer, and the measurement result was shown in FIG.

  The Q value handled in the present invention represents the sharpness of resonance, which is a characteristic of the inductor, and the higher the value, the smaller the loss.

  As shown in FIG. 3, in the case of the inductor dust core made of the amorphous soft magnetic alloy powder of Example 1, the Q value is almost equal to the Q value of Comparative Example 5 in the frequency range below 100 kHz. However, in the frequency range of 100 kHz or more, it was significantly larger than the Q value of Comparative Example 5. Further, the peak of the Q value moved to a higher frequency side, and the maximum value of the Q value also increased.

  As shown in FIG. 3, in the case of the dust core for inductor made of the amorphous soft magnetic alloy powder of Example 2, the Q value is almost equal to the Q value of Comparative Example 5 in a frequency range of less than 100 kHz. However, in the frequency range of 100 kHz or more, it was significantly larger than the Q value of Comparative Example 5. Further, the peak of the Q value moved to a higher frequency side, and the maximum value of the Q value also increased.

  Further, as shown in FIG. 3, the Q value of the powder magnetic core for the inductor produced from the amorphous soft magnetic alloy powder of Example 2 is the same as that for the inductor produced from the amorphous soft magnetic alloy powder of Example 1. Compared with the Q value of the dust core, it is slightly smaller in the frequency range below 5 MHz, but it is almost the same when the frequency exceeds 5 MHz, and the Q value is completely above 20 MHz.

  From the above results, by using the amorphous soft magnetic alloy powder produced according to the manufacturing method of the present invention, the Q value is large and the loss is low in a high frequency range as compared with the conventional dust core for inductors using carbonyl iron powder. A dust core for inductors was obtained.

  Therefore, as described above, according to the method for producing the amorphous soft magnetic alloy powder of the present invention, the amorphous soft magnetic alloy having a smaller particle size and higher saturation magnetic flux density (Bs) than the carbonyl iron powder of the prior art. A powder could be produced.

  Also, the powder for inductor produced by using the carbonyl iron powder produced by the prior art by producing the powder magnetic core for inductor of the present invention by mixing the amorphous soft magnetic alloy powder of the present invention and the binder. It was possible to manufacture a dust core for inductors with lower loss at a higher frequency than the magnetic core.

  The embodiment of the present invention has been described above with reference to the drawings. However, the present invention is not limited to this embodiment, and the present invention can be applied even if there are changes in members and configurations without departing from the spirit of the present invention. include. That is, it goes without saying that the present invention also includes various modifications and corrections that can naturally be made by those skilled in the art.

  The amorphous soft magnetic alloy powder obtained by the present invention has a smaller particle size compared to the soft magnetic powder obtained by the prior art, and the powder is composed of fine particles or fine particle aggregate particles and is high. Since it has a saturation magnetic flux density (Bs), it has excellent soft magnetic characteristics in a high frequency range.

  Therefore, the amorphous soft magnetic alloy powder obtained by the present invention is suitable for use as an inductor for power supply components of electronic equipment, which is required to cope with large current and high frequency.

Claims (4)

An amorphous soft magnetic alloy powder comprising particles formed from an aggregate of two or more fine particles having a particle size of 0.01 μm or more and 1.0 μm or less and single particles formed of only one particle. And
Ri Der average particle diameter of the total produced powder is 0.1μm or more 5.0μm or less,
An amorphous soft magnetic alloy powder characterized in that 5% by weight ≦ B ≦ 10% by weight, 0.06% by weight ≦ P ≦ 5% by weight, and the balance is Fe . The amorphous soft magnetic alloy powder according to claim 1, wherein the reducing liquid containing the B-based reducing agent is stirred while the raw material liquid containing the iron salt, complexing agent, pH adjusting agent, dispersing agent and P-based reducing agent is stirred. Amorphous soft magnetic alloy powder produced by dropping A powder magnetic core obtained by mixing the amorphous soft magnetic alloy powder according to claim 1 or 2 with a binder and compression molding. An inductor formed by combining the dust core according to claim 3 and a coil.