KR920005490B1 - Magnetic ribbon and core - Google Patents

Abstract

Disclosed are a magnetic ribbon on at least one surface of which fine particles formed of nonmagnetic inorganic substance having insulating properties are attached and a magnetic core around which this magnetic ribbon is wound or on which it is laminated. The fine particles serve as a spacer to form a layer of air between adjacent layers of the magnetic ribbon.

Description

Magnetic ribbon and magnetic core

1 to 3 are graphs showing magnetic characteristics of the first embodiment of the present invention.

1 is a B-H characteristic diagram.

2 is a frequency characteristic diagram of iron loss.

3 is a frequency characteristic diagram of permeability.

4 to 6 are graphs showing magnetic characteristics of the second embodiment of the present invention.

4 is a B-H characteristic diagram.

5 is a frequency characteristic diagram of iron loss.

6 is a frequency characteristic diagram of permeability.

7 is a schematic diagram showing an apparatus for attaching fine powder.

8 is a view showing a manufacturing means of the magnetic core of the Troidal type.

9 is a graph showing differences in square ratios by interlayer insulation treatment of amorphous ribbons.

10 is a graph showing the difference of the excitation power by the interlayer insulation treatment of amorphous ribbon.

The present invention relates to a magnetic ribbon and a magnetic core formed by using the magnetic ribbon.

When the magnetic ribbon is wound or laminated to form a magnetic core, poor insulation between the ribbon layers results in eddy currents flowing between the ribbon layers and increases in total iron loss due to an increase in the loss of the eddy currents. This tendency is especially noticeable at high frequencies. Moreover, the frequency characteristic of permeability is bad, and it cannot be used suitably above 100 Hz.

Therefore, conventionally, in order to improve insulation between ribbon layers, an insulating layer made of a nonmagnetic material is provided between the ribbon layers, and as one means, a uniform insulating film is formed on the ribbon surface to solve the above problem.

However, when an amorphous magnetic ribbon is manufactured as a magnetic ribbon, it should be annealed at around 400 ° C. However, when such annealing is performed, the linear expansion coefficient of the insulating film is usually the amorphous ribbon because of the difference in the coefficient of linear expansion between the insulating film and the ribbon. Since the compressive stress is generated on the ribbon, the magnetic properties are deteriorated by the adverse effect of magnetostriction.

In addition, there is a problem that the insulating film that withstands annealing around 400 ° C is materially limited. When the insulating film is provided, when the magnetic core is formed, the filling rate (drop rate) of the magnetic body is lowered, resulting in the enlargement of the magnetic core.

Accordingly, an object of the present invention is to provide a magnetic ribbon and magnetic core having good magnetic properties by minimizing the reduction of the drop rate and securing insulation between the ribbons.

As a theoretical premise of the present invention, the present invention has been focused on the following points. That is, as described above, it is common to interpose an insulating film in the manufacture of the magnetic core by the magnetic ribbon, and among the skilled person, how to find an insulating material having good insulating performance is of greatest concern.

On the contrary, even if there is no such insulating film, if there is an air layer between the layers, it becomes an insulating layer, thereby preventing eddy currents and increasing the spot ratio as much as possible.

Thus, in order to secure such an air layer, the present invention provides a magnetic ribbon in which fine powder made of a nonmagnetic material and an insulating inorganic material is attached to at least one surface, and is wound or laminated to provide an iron core.

In the present invention, the above fine powder is attached to secure the air layer as the original purpose, but it is conceivable that the fine powder is uniformly and densely attached to at least one surface of the ribbon. In this case, the meaning of securing the air layer is eliminated, and since the fine molecular body acts as an insulating layer, the same effect as in the case of securing the air layer by fine powder is also obtained in this case. Therefore, the present invention is a broad concept including a case where the fine powder is roughly attached and a case where the fine powder is tightly attached.

In the present invention, the fine powder made of inorganic powder is attached to at least one surface to form a magnetic ribbon. When the magnetic ribbon is wound or laminated, the fine powder becomes a spacer and an air layer is formed between the layers of the ribbon.

On the other hand, when fine powder is densely adhered to at least one surface of a ribbon, a fine particle body acts as an insulating layer as mentioned above.

Embodiments of the present invention will be described with reference to the accompanying drawings.

In the present invention, the magnetic ribbon is a thin magnetic band of a magnetic material, and the magnetic material is a ferromagnetic element such as Fe, Co, Ni, or an alloy of ferromagnetic elements, and a non-ferromagnetic element and a ferromagnetic material which are applied to improve properties. Alloy with an element, ferrite, a palloy, an amorphous alloy, etc. can be illustrated.

Amorphous metals include Fe-B, Fe-BC, Fe-B-Si, Fe-B-Si-C, Fe-B-Si-Cr, Fe-Co-B-Si, Fe-Ni-Mo-B, etc. Fe-based, Co-B, Co-Fe-Si-B, Co-Fe-Ni-Mo-B-Si, Co-Fe-Ni-B-Si, Co-Fe-Mn-B-Si, Co- Co type | system | group etc., such as Fe-Mn-Ni, Co-Mn-Ni-B-Si, Co-Fe-Mn-Ni-B, can be illustrated.

As the fine powder of the inorganic substance adhering to such magnetic ribbon, it is a condition that it is a nonmagnetic substance and has insulation. This is because if the fine powder is a magnetic substance and has conductivity, it will adversely affect the magnetic properties or the eddy current will easily flow.

Inorganic substances used in the present invention include: (1) a stable inorganic material in a natural state such as glass (sodium silicate), mica (alkali silicate alkali salt, pyrosilicate alkali salt), silicon carbide, calcium sulfate hemihydrate, potassium carbonate, barium sulfate, and the like. Material, (2) metal oxides such as aluminum oxide, boron oxide, magnesium oxide, silicon dioxide, dioxide, zinc oxide, konconium dioxide, antimony pentoxide, etc. ③ The materials and perovskites exemplified in the above ②. ), Ceramics formed from silicate glass, phosphate, titanate, niosha, tantalum, tungsten acid salt, or the like; Nitride such as aluminum nitride, oxidized and aluminum nitride sintered body, boron nitride, boron nitride magnesium, boron nitride composite, silicon nitride, silicon nitride lanthanum, sialon, carbides such as boron carbide, silicon carbide, aluminum carbide boron, titanium carbide, titanium diboride And ceramics formed by forming a single or composite ceramic material exemplified by borides such as calcium hexaboride and lint hexahexaborate. Of these, antimony pentaoxide is preferred.

As for the particle size of the fine powder of these inorganic materials, considering that the fine powder is uniformly attached to the ribbon to form an insulating layer, the particle size of the fine powder may be small, but making the size of the fine powder becomes difficult to manufacture. On the other hand, when too large, when the magnetic core is formed from the ribbon, the spacing between the ribbons becomes too large and the droplet rate of the magnetic body becomes small. For this reason, the particle size of the fine powder is preferably 10 μm to 2 μm.

The amount of adhesion of the fine powder is such that the fine powder per unit area (1 cm ² ) of the ribbon is 10 ⁻⁷ cm ² to 2 × 10 ^-4 cm ² , preferably 3 × 10 ^-6 cm ² to 10 ^-5 cm ² . It can be attached. When converted to a coating weight per unit area by weight of the derivative value has changed, but the 5 case of oxidation of antimony to ^{3.8 × 10 -7 g / cm 2} ~ 7.6 × 10 -4 g / cm 2, preferably in accordance with the specific gravity of the material of the fine The following are 1.1 × 10 ⁻⁵ g / cm ² to 3.8 × 10 ⁻⁵ g / cm ² .

The means for attaching fine powder is dispersed in a volatile organic solvent such as water or toluene, and the solution is applied to the ribbon surface and then forced or naturally dried to adhere the fine powder to the ribbon. The concentration of this solution determines the amount of adhesion to the ribbon. That is, in the case of antimony pentaoxide, it is good to disperse | distribute in the claude form at the ratio of 0.1-30 weight% with respect to toluene. Within this range, it is effective even if it is about 3% by weight, there is almost no drop in the drop rate, and magnetic properties are not deteriorated. It is preferable to determine the adhesion amount here that the thickness of the coating film of a solution is 10 micrometers or less here. Moreover, what is necessary is just to dry below 100 degreeC using a drying furnace depending on a solvent for evaporation of a solvent.

Magnetic ribbons, especially amorphous ribbons, may be annealed for 0.5 to 5 hours at a temperature of 300 to 500 ° C. in an inert gas atmosphere such as nitrogen to remove strain as necessary. This annealing may be performed after winding or laminating the ribbons to the magnetic core, or may be performed as it is. In particular, when the annealing is performed at a temperature of 10 to 15 ° C. higher than the Curie point, a good high frequency characteristic is obtained. The annealing may be performed in a magnetic field or in a magnetic field.

In the case of annealing the wound or laminated amorphous magnetic core, the linear expansion does not affect the magnetic core because the fine powder between the ribbons is powdered. Rather, it serves to absorb the stress accompanying the shrinkage of the amorphous ribbon.

Based on the above, the method of manufacturing the magnetic core by this invention is demonstrated.

First, a magnetic ribbon and a fine powder solution are prepared, and a fine powder solution is applied to at least one surface of the magnetic ribbon by various coating methods and the solvent is dried. The obtained differentially attached magnetic ribbon is wound while applying tension to obtain a Troydal magnetic core. Finally, strain removal and annealing are performed as necessary.

Moreover, as for the tension added when winding, 0.05-2 kg is preferable.

On the other hand, in the case of manufacturing a laminated magnetic core, a ribbon with fine powder is cut into a predetermined shape and laminated to form a magnetic core, but annealing performed as necessary may be performed before lamination, or after laminating to form a magnetic core.

An embodiment of the present invention will be described below.

Amorphous ribbon 1a made by Allied corp using the apparatus shown in FIG. When transferring 2605S-2 (Fe78-B13-Si9, 10mm side) into colloidal solution of antimony pentaoxide (2), take it out and put it in a pair of bar corners (3) to drop the excess solution and warm air dryer (4). ), And the fine ribbon with a fine powder was wound up while blowing by warm air. The colloidal solution (2) of antimony pentaoxide was prepared by dispersing 3% by weight of antimony pentaoxide to 97% by weight of toluene as a solvent.

Subsequently, as shown in FIG. 8, the differential bonding ribbon 1b was transferred through the roller 5 and wound while applying tension at the final end to form an amorphous magnetic core 6. In addition, plural magnetic cores of the same dimension were formed, and each was annealed at 435 ° C. for 2 hours under nitrogen atmosphere. The B-H characteristic, the frequency characteristic of iron loss, and the frequency characteristic of permeability were measured about the magnetic core thus obtained. The B-H characteristics were measured for two cases where a magnetic field of 10 ernst (Oe) was applied and a magnetic field of 1 ernst (Oe) was applied.

Moreover, the colloidal solution which disperse | distributed 30 weight% of antimony pentaoxides with respect to 70 weight% of toluene was apply | coated, and the same measurement was performed.

In general, in order to improve the insulation between the ribbon layers in order to improve the magnetic properties (iron loss characteristics, frequency characteristics of magnetic permeability), it is conceivable to form an insulating film made of an alcohol or the like between the layers.

Advantages In the case of using silicon steel as a magnetic ribbon, it is known that the effect of the insulating film on the magnetic core properties is small, and a unique improvement can be expected due to the tension of the insulating film.

When the amorphous alloy is used as the magnetic ribbon and an insulating film is formed between the ribbon layers, the present inventors found that the magnetic properties such as the square ratio and the excitation power are greatly influenced by the stress from the insulating film. It became.

FIG. 9 shows the change of the square ratio (%) with respect to the annealing temperature in the amorphous ribbon (2605S-2: Fe28-B13-S19) manufactured by Aride, where 0 is the case where no insulating layer is formed. Is the same as in Example, and the case of forming an insulating differential layer of anti-pentoxide is shown, and □ represents the characteristic change in the case of forming an insulating coating made of alcohol.

As a result, it can be seen that, when the insulating film is formed on the amorphous ribbon, the value of the square ratio decreases to 1/2 or less as compared with the case where the insulating layer is not formed. On the other hand, in the case of an insulating differential layer, it turns out that the fall of a square ratio is suppressed.

In addition, as shown in FIG. 10, the excitation power characteristic also shows a large increase when the insulating film is formed on the amorphous ribbon, but close to the characteristic when the insulating layer is not provided in the case of the insulating differential layer. .

In this regard, it has been found that, in the case of using an amorphous alloy as the magnetic material, it is particularly effective to equip the fine powder with an insulating differential layer as an insulating layer. Detailed conditions of each embodiment are as follows.

① Example 1 (3 wt% solution)

(a) Magnetic core: Troydal core wound the above magnetic ribbon.

Inner diameter = 23.00mm

Outer Diameter = 37.00mm

Height = 10.00mm

Mass = 42.00 g

Density of material = 7.18 g / m ²

Volume = 5.850 × 10 ^-6 (m ² )

Effective cross section = 6.207 × 10 ^-5 (m ² )

Average growth length = 9.425 × 10 ^-2 (m ² )

Drop rate = 88.67% (ratio of ribbon to total)

Tension when winding magnetic ribbon = 0.8 kg

(b) Colloidal solution applied:

Organic solvent = 97% by weight of toluene

Fine powder = 5% antimony oxide

(c) results

* B-H characteristics: shown in FIG.

* Frequency characteristics of iron loss: shown in FIG. The number of turns of the primary winding wound on the core is 5 and the number of turns of the secondary winding is 10.

* Frequency characteristic of permeability: It is shown in FIG. The number of turns of the primary winding wound on the core is 10.

Measuring field = 5 mOe

Measuring Current = 2.65173mA

② Example 2 (30 wt% solution)

(a) Magnetic core: Troydal core wound the above magnetic ribbon.

Inner diameter = 23.00mm

Outer Diameter = 37.00mm

Height = 10.00mm

Mass = 25.57 g

Density of material = 7.18 g / m ²

Volume = 3.561 × 10 ^-6 (m ² )

Effective cross section = 3.779 × 10 ^-5 (m ² )

Average growth length = 9.425 × 10 ^-2 (m ² )

Drip rate = 53.98%

Tension when winding magnetic ribbon = 0.8 kg

(b) Colloidal solution applied:

Organic solvent = toluene 70% by weight

Fine powder = 30% by weight of antimony oxide

(c) results

* B-H characteristics: shown in FIG.

* Frequency characteristics of iron loss: shown in FIG. The number of turns of the primary winding wound on the core is 5 and the number of turns of the secondary winding is 10.

* Frequency characteristic of permeability: It is shown in FIG. The number of turns of the primary winding wound on the core is 10.

Measuring field = 5 mOe

Measured current = 2.65173AmA

In the above results, the magnetic core of the embodiment is that the hysteresis is closer to the linear and is generally low for iron loss, and in particular, the rise in the high frequency part can be reduced to a lower level. An almost constant permeability was obtained up to 200 KHZ.

As described above, in the present invention, the above-described configuration can improve the magnetic characteristics, particularly at frequencies of 10 KHZ or more, and make the droplet ratio as large as possible, contributing to the miniaturization of the magnetic core.

Claims (6)

A magnetic ribbon characterized by adhering fine powder made of a nonmagnetic material and an insulating inorganic substance to at least one surface. The magnetic ribbon of claim 1, wherein the magnetic ribbon is made of amorphous metal. The magnetic ribbon according to claim 1 or 2, wherein the inorganic material is a metal oxide and the fine powder has a size of 10 nm to 2 m. The magnetic ribbon according to claim 1 or 2, wherein the magnetic ribbon is annealed in an inert gas atmosphere at a temperature of 300 to 500 ° C. for 0.5 to 5 hours. A magnetic core formed by winding or laminating the magnetic ribbon according to any one of claims 1 to 4. A magnetic core obtained by winding or stacking the magnetic ribbon according to any one of claims 1 to 3, followed by annealing for 0.5 to 5 hours at a temperature of 300 to 500 ° C. in an inert gas atmosphere.

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