JPH01259510A - Magnetic ribbon and magnetic core - Google Patents

Abstract

PURPOSE:To improve magnetic characteristics by minimizing the reduction of an occupation area rate to secure insulation among ribbon layers by allowing fine powder comprising a nonmagnetic insulating inorganic substance to adhere to at least one surface of a magnetic ribbon. CONSTITUTION:A magnetic ribbon is formed by allowing fine powder comprising a nonmagnetic, insulating inorganic substance to adhere to at least one surface thereof. The fine powder serves as a spacer to form air layers among ribbon layers. Antimony pentoxide is preferably available as the inorganic substance. Since the air layers are provided among the ribbon layers in such a manner to serve as insulating layers, an eddy current can be prevented from being produced and an occupation area rate can be increased to the utmost, to improve magnetic characteristics of the magnetic ribbon.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic ribbon and a magnetic core formed using the magnetic ribbon.

[Conventional technology]

When a magnetic core is formed by winding or laminating magnetic ribbons, if the insulation between the ribbon layers is poor, eddy currents flow between the ribbon layers, and the overall iron loss (magnetic loss) increases due to an increase in eddy current loss. This tendency is particularly noticeable in the case of high frequencies.And when the frequency characteristic of magnetic permeability is poor <100KHz
With the above conditions, no advantageous use can be expected.

Therefore, conventionally, in order to improve insulation between ribbon layers,
An attempt has been made to provide an insulating layer made of a non-magnetic material between the ribbon layers, and as a means of this, an insulating film like this is formed on the surface of the ribbon in an attempt to solve the above problem.

[Problem that the invention seeks to solve]

However, when producing an amorphous magnetic ribbon as a magnetic ribbon, annealing is performed at around 400°C, but when such annealing is performed, the difference in linear expansion coefficient between the insulating film and the ribbon, that is, the In most cases, the coefficient of linear expansion of the insulating film is larger than that of the amorphous ribbon, so compressive stress is generated in the ribbon, and the magnetic properties deteriorate due to the opposite effect of magnetostriction.

In addition, there is the problem that there are limited materials for an insulating film that can withstand annealing at around 400°C.Furthermore, when an insulating film is provided to form a magnetic core, the filling factor (space factor) of the magnetic material decreases.
decreases, resulting in an increase in the size of the magnetic core.

The present invention was made to solve these problems, and provides a magnetic ribbon and a magnetic core with good magnetic properties by minimizing the decrease in space factor and ensuring insulation between ribbon layers. This is a technical issue.

[Means for solving problems]

The present invention was made by first focusing on the following points as its theoretical premise.

That is, as mentioned earlier, when manufacturing a magnetic core using a magnetic ribbon, it is common to use an insulating film.
The greatest concern among those skilled in the art is how to find an insulating film material with good insulation performance.

However, from a different perspective, even if there is no such insulating film, if there is an air layer between the eyebrows, it will act as an insulating layer to prevent eddy currents and increase the space factor as much as possible.

Therefore, in the present invention, in order to secure such an air layer, fine powder made of a non-magnetic and insulating inorganic substance is attached to at least one surface to form a magnetic ribbon, and this is wound. Alternatively, they can be laminated to form a magnetic core.

In the present invention, the fine powder was attached as an initial purpose to ensure an air layer, but it is also conceivable that the fine powder was attached evenly and densely to at least one surface of the ribbon. In this case, there is no point in ensuring an air layer, and the fine powder itself acts as an insulating layer, but in this case as well, the same effect as when securing an air layer using fine powder can be obtained. Therefore, the present invention has a broad concept that includes both cases in which the fine powder is coarsely adhered and cases in which the fine powder is adhered densely.

[Effect]

Hereinafter, the effects of the present invention will be described, and further specific solutions will be explained.

In the present invention, a magnetic ribbon is made by attaching fine powder made of an inorganic substance to at least one surface, so when this magnetic ribbon is wound or laminated to form a magnetic core, the fine powder acts as a spacer between each layer of the ribbon. An air layer is formed.

On the other hand, when the fine powder is evenly and densely adhered to at least one surface of the ribbon, the fine powder itself acts as an insulating layer as described above.

Here, the magnetic ribbon in the present invention is a thin ribbon of a magnetic material, and examples of the magnetic material include Fe and Co in transition metals.
Examples include single ferromagnetic elements such as Ni, alloys of ferromagnetic elements, alloys of non-ferromagnetic elements and ferromagnetic elements added to improve properties, ferrite, permalloy, amorphous alloys, etc. Amorphous metals include Fe-B, Fe-B-C, Fe-B-3i, Fe-B
-5i-C, Fe-B-8i-Cr, Fe-Co-B
-9t, Fe-based such as Fe-Ni-Mo-B, co-B,
Co-Fe-3i-B, Co-Fe-Ni-Mo
-B-8i, Co-Fe-N 1-B-8i, Co
-Fe-Mn-BrBX,i,Co-Fe-Mn-N
Examples include Co-based materials such as Co-Mn-N 1-B-8i and Co-Mn-N 1-B-8i.

The inorganic fine powder attached to such a magnetic ribbon must be non-magnetic and have insulating properties. This is because if the fine powder is magnetic and has electrical conductivity, it may adversely affect magnetic properties or cause eddy currents to easily flow.

In addition, the inorganic substances used in the present invention include ■slas (sodium silicate), mica (alkali aluminosilicate,
Alkaline phyllosilicate salts), silicon carbide, calcium sulfate hemihydrate, calcium carbonate, magnesium carbonate, calcium carbonate, barium sulfate, etc. Inorganic substances that are stable in their natural state, aluminum oxide, boron oxide, magnesium oxide, Metal oxides such as silicon dioxide, tin dioxide, zinc oxide, zirconium dioxide, antimony pentoxide,
■Materials exemplified in ■ above, others, perovskite,
Ceramics made of complex oxides such as silicate glass, phosphates, titanates, niobium, tantalum, and tungstates, aluminum nitride, aluminum oxynitride sintered bodies,
Boron nitride, boron magnesium nitride, boron nitride composite, silicon nitride, lanthanum silicon nitride, nitrides such as sialon, carbides such as boron carbide, silicon carbide, boron aluminum carbide, boron aluminum carbide, titanium carbide, diboride Examples include ceramics made of a single ceramic material or a composite of ceramic materials such as borides such as titanium, calcium hexaboride, and lanthanum hexaboride. Among these, antimony pentoxide is preferred.

Regarding the particle size of these inorganic fine powders, considering that the fine powder is evenly attached to the ribbon to form an insulating layer, the particle size of the fine powder may be small, but making it small is a factor that makes manufacturing difficult. Become. On the other hand, if it is too large, when the magnetic core is formed of ribbons, the width of the gap between the ribbons becomes too large and the space factor of the magnetic material becomes small. For these reasons, it is desirable that the particle size of the fine powder is 10 nm to 2 μm.

In addition, the amount of fine powder attached is 10-7 cm3 to 2X 10-'cm3, more preferably 3X10-'cm3 to 10-'cm3 per horizontal area (LC) of the ribbon. It is a good idea to do so. When this amount of adhesion is converted to the weight of fine powder per unit area, the value changes depending on the specific gravity of the material of the fine powder, but in the case of antimony pentoxide, 3.
8x 10-7g/cri ~7゜6X10-'g/c
rf, more preferably 1. lXl0-'g/cr♂~3
．． 8×10-'g/cr112.

The means for adhering the fine powder is to apply the fine powder to water or the surface of the ribbon and then forcefully or naturally dry it 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 pentoxide, it is preferable to disperse it in colloidal form at a ratio of 0.1 to 30% by weight with respect to toluene. 3% by weight within this range
It is effective even to a certain extent, with almost no decrease in space factor and no deterioration in magnetic properties. Here, the thickness of the solution coating film is 1
It is preferable that the thickness is 0 μm or less in determining the above-mentioned adhesion amount. Further, for evaporation of the solvent, it is preferable to use a drying oven and dry at 100° C. or lower depending on the solvent.

By the way, magnetic ribbons, especially amorphous ribbons, are heated at a temperature of 0.5 to 5 ℃ in an inert gas atmosphere such as nitrogen at a temperature of 300 to 500 ° C.
Time annealing is recommended. This annealing may be performed after the ribbon is wound or laminated to form a magnetic core, or may be performed in the ribbon state, particularly at a temperature 10 to 50°C higher than the Curie point. When annealing with , good properties at high frequencies can be obtained. Note that annealing may be performed in a magnetic field or without a magnetic field.

When annealing a wound or laminated amorphous magnetic core, since the fine powder between the ribbons is powder, linear expansion does not affect the magnetic core, but rather absorbs the stress caused by the contraction of the amorphous ribbon. It has this effect.

Based on the above, a method for manufacturing a magnetic core according to the present invention will be described.

First, a magnetic ribbon and a solution of fine powder are prepared, and the 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 magnetic ribbon with one layer of fine powder is wound under tension to obtain a toroidal magnetic core. I
& After that, annealing is performed to remove strain if necessary.9 Note that the tension applied during winding is preferably 0.05 to 2 kg.

On the other hand, in the case of manufacturing a laminated magnetic core, the ribbons with slight shading are cut into a predetermined shape and laminated to form the magnetic core. However, annealing may be performed as necessary during the lamination process, or even after lamination. This may be done after forming the magnetic core.

〔Example〕

The present invention will be explained in detail below.

In the apparatus shown in Fig. 7, amorphous ribbon (LA), 2605S-2 (Fe7aB13 S
i6.10mm width) was immersed in a colloidal solution of antimony pentoxide (2) in a progressive manner, and when pulled up, it was sandwiched between a pair of bar coaters (3) to remove excess solution, and heated with hot air in a hot air dryer (4). While drying, remove the ribbon with fine powder (1b
) was wound up.

The colloidal solution (2) of antimony pentoxide uses toluene as a solvent, and 3% by weight of antimony pentoxide is dispersed in 97% by weight of toluene.

Next, as shown in FIG. 8, the ribbon with fine powder (1b)
was sequentially fed through rollers (5) and wound at the final stage while applying tension to form an amorphous magnetic core (6). Then, a plurality of magnetic cores having the same dimensions were formed, and each core was annealed at 435° C. for 2 hours under a nitrogen cloud.

The B-H characteristics, iron loss frequency characteristics, and magnetic permeability frequency characteristics of each of the obtained magnetic cores were measured. The B-11 characteristics were measured in two cases: when a magnetic field of 10 oersted (Oe) was applied and when a magnetic field of 1 oersted (Oe) was applied.

Further, a colloidal solution in which 30% by weight of antimony pentoxide was dispersed in 70% by weight of toluene was applied, and the same measurements were performed. The details of each example are as follows.

■Example 1 (3% by weight solution) (a) Magnetic core; 1-1 fidal core wound with the above magnetic ribbon; inner diameter = 23. OOmrn Outer diameter = 37.00mm Height = 10.00mm Mass -42, OOg Material density = 7.18g/rn3 Body Ff4 = 5.850X10-6 (m') Effective cross-sectional area = 6.207X10-' (rrt2 ) Average magnetic path length = 9.425X10-2 (m) Space factor = 88.67% (
Ratio of the ribbon to the total volume) Tension when winding the magnetic ribbon = 0.8 kg (b) Coated colloid solution; Organic solvent = toluene 100% by weight Fine powder - antimony pentoxide 3% by weight ('c) Results *B-H Characteristics: *Frequency characteristics of iron loss shown in Figure 1; Number of turns of the primary winding wound around the core shown in Figure 2 is 5. Number of turns of the secondary winding is 1.
It is 0.

*Frequency characteristics of magnetic permeability; The number of turns of the primary winding wound around the core shown in Figure 3 is 10. Measured magnetic field = 5 mOe Measured current = 2.65173 mA ■Example 2 (30w 1% solution) (a) Magnetic core 1-loidal core wound with the above magnetic ribbon Inner diameter 23.00 mm Outer diameter = 37.00 mm Height = 10.00 mm Mass = 25.57 g Density of material = 7,18 g,/m' Volume = 3
．． 61 x 10-60-6 (effective cross-sectional area = 3.77
9X10-' (m2) average magnetic path length = 9.425xlO-
2 (m) Space factor = 53.98% Tension at the same time as magnetic ribbon winding - 0.8 kg (b) Coated colloid solution; Organic solvent = toluene 70% by weight Fine powder - antimony pentoxide 30% by weight (c) Results * B-H characteristics; shown in Fig. 4 *Frequency characteristics of iron loss; Fig. 5 The number of turns of the primary winding wound around the core is 5. The number of turns of the secondary winding is 1
It is 0.

*Frequency characteristics of magnetic permeability; The number of turns of the primary winding wound around the core shown in Fig. 6 is 10. Measured magnetic field = 5 mOe Measured magnetic field = 5 moe. Measured current = 2.65173 mA. , the hysteresis is closer to linearity, and the iron loss is also lower overall, especially in the high frequency range, the increase can be suppressed to a low level.

Almost constant magnetic permeability was obtained up to 200 kHz.

〔Effect of the invention〕

In the present invention, since the above structure is adopted, particularly.

Can improve magnetic properties at frequencies above 10 kHz,
Furthermore, the space factor can be increased as much as possible, contributing to miniaturization of the magnetic core.

[Brief explanation of the drawing]

Figures 1 to 3 are graphs showing the magnetic characteristics of the first embodiment of the present invention. Figure 1 is the B-H characteristic, Figure 2 is the frequency characteristic of iron loss, and Figure 3 is the transparent This is the frequency characteristic of magnetic property. Fourth
0 to 6 are graphs showing the magnetic characteristics of the second embodiment of the present invention. FIG. 4 is the B-H characteristic, FIG. 5 is the frequency characteristic of iron loss, and FIG. 6 is the magnetic permeability characteristic. It is a frequency characteristic. Further, FIG. 7 is a schematic diagram showing a fine powder adhesion processing device, and FIG. 8 is a diagram showing a means for manufacturing a toroidal magnetic core. 1a: Magnetic ribbon (untreated), 1b: Magnetic ribbon with fine powder, 2: Colloidal solution of fine powder, 3: Bar coater, 4: Warm air dryer, 5: Roller. 6. Magnetic core. Patent Applicant: Mitsui Petrochemical Industries, Ltd. Figure 1 Figure 2 Opening Reed Income LHz] Figure 3 [Hz] Figure 7 Yoshi, Commissioner of the Patent Office 1) Written by Mr. Shibori 1, Indication of the case 1988 Patent Application No. 88694 2, Title of the invention Magnetic ribbon and magnetic core 3, Relationship with the amended person case Patent applicant Address: 3-2-5 Kasumigaseki, Chiyoda-ku, Tokyo Name (5118) Mitsui Petrochemical Industries Co., Ltd. Representative: Shogo Takebayashi 4, Agent: 3rd floor 6, Floriculture Building, 3-10 Kanda Jimbocho, Chiyoda-ku, Tokyo 101; Contents of the amendment (1) rCo-Fe-Mn-13rI3iJ on page 6, line 10 of the specification is replaced by rCo
-Fe-Mn-B-SiJ. (2) Co-based materials such as rco-Mn-Ni-B-Si can be exemplified on page 6, line 11 of the specification. " is rCo-Mn-Ni-B-St, Go-Fe-Mn
Co-based materials such as -N i -B can be exemplified. ” he corrected.

Claims (6)

[Claims] (1) A magnetic ribbon characterized by having fine powder made of a non-magnetic and insulating inorganic substance adhered to at least one surface. (2) The magnetic ribbon according to claim 1, which is made of an amorphous metal. (3) The inorganic substance is a metal oxide, and the diameter of the fine powder is 10
The magnetic ribbon according to claim 1 or 2, which has a diameter of nm to 2 μm. (4) 300-500℃ in an inert gas atmosphere
Claim 1 annealed for 0.5 to 5 hours at a temperature of
The magnetic ribbon according to any one of Items 1 to 3. (5) A magnetic core formed by winding or laminating the magnetic ribbon according to any one of claims 1 to 4. (6) After winding or laminating the magnetic ribbon according to any one of claims 1 to 3, the magnetic ribbon is heated at a temperature of 0.5 to 5
Magnetic core obtained by time annealing.