JP2750722B2 - High permeability material - Google Patents

Description

The present invention relates to a high magnetic permeability material. More specifically, the present invention relates to a high-permeability material having good high-frequency characteristics and a high saturation magnetic flux density.

[Related Art] In recent years, there has been an increase in materials used in a high frequency region due to miniaturization of electronic devices and the like. Therefore, a high magnetic permeability material that operates in a higher frequency region has been demanded. As the high magnetic permeability material, there are a material using a ferromagnetic metal and a material using an oxide magnetic material.

[Problems to be Solved by the Invention] Since the ferromagnetic metal high permeability material has a small electric resistance, there is a problem that an eddy current loss is increased in a high frequency region and high frequency characteristics are deteriorated.

In addition, oxides such as ferrite are examples of magnetic materials having a small eddy current loss in a high frequency region, but they have a drawback that the saturation magnetic flux density is as small as 1/2 to 2/3 as compared with ferromagnetic metals.

SUMMARY OF THE INVENTION An object of the present invention is to solve the drawback of increasing the eddy current loss in the high-frequency region, which the prior art has, and to provide a high-permeability material having good high-frequency characteristics and a high saturation magnetic flux density. .

[Means for Solving the Problems] In order to achieve the above object, in the present invention, a polymer is deposited between the ferromagnetic metal particles by simultaneously depositing a ferromagnetic metal and a polymer by a vapor deposition method. The mixing ratio of the ferromagnetic metal and the polymer is in the range of 95 vol% to 60 vol% for the ferromagnetic metal and 5 vol% to 40 vol% for the polymer, so that the saturation magnetization becomes 800 G or more and the resistivity becomes higher. To provide a high magnetic permeability material characterized by being 180 μΩcm or more.

[Function] By simultaneous vapor deposition of a ferromagnetic metal and a polymer, a polymer is deposited between ferromagnetic metal particles, and a soft magnetic film having a large electric resistance can be obtained.

When co-evaporated, the ferromagnetic metal tends to have a column structure, and a polymer is deposited between the columns. Since the insulating polymer is deposited between the columns, the electric resistance is higher than that of the original ferromagnetic metal alone. Therefore, eddy current loss is reduced, and deterioration of magnetic permeability in a high frequency region is suppressed. As a result, the saturation magnetic flux density increases.

The high magnetic permeability material of the present invention can be manufactured by simultaneously depositing a ferromagnetic metal and a polymer on a substrate surface by a vapor deposition method. The “vapor deposition method” means a method of depositing a substance or compound to be deposited on a gas as a vapor or an ionized vapor in a gas or a vacuum space. This method includes vacuum deposition, ion plating, high-frequency ion plating, ion cluster beam, ion beam deposition, sputtering, and C
VD method and the like.

When the high magnetic permeability material of the present invention is manufactured by the vapor deposition method, it is preferable that the vapor deposition substrate is maintained at a temperature in the range of 80C to 220C. If the ferromagnetic metal and the polymer are simultaneously vapor-deposited while maintaining the deposition substrate at a temperature within this range, the polymer and metal carbide at the crystal grain boundaries of the ferromagnetic metal and the amorphous carbon or silicon-containing polymer may be formed. In this case, siliconized material, amorphous silicon, and the like are precipitated, these become an electrical insulating layer, and the resistivity is increased.

Ferromagnetic metals that can be used in the high magnetic permeability material of the present invention include, for example, simple substances such as Co, Fe, and Ni, alloys thereof, and alloys thereof with other elements. Such ferromagnetic metal alloys are well known to those skilled in the art.

Polymers that can be used to form the high permeability material of the present invention are linear or network polymers having from 10 to 1000, preferably from 30 to 500, more preferably from 70 to 200 carbon atoms. Specific examples include polyethylene, polyethylene terephthalate, polypropylene, polybutene, polystyrene, polytetrafluoroethylene, polybutadiene, polycarbonate, polyamide, polyimide, polyurethane, polyvinyl chloride, polyvinyl acetate, and silicon-based polymers.

The mixing ratio between the ferromagnetic metal and the polymer is generally at least 5 vol%, preferably at least 10 vol%, more preferably at least 12 vol% and at most 40 vol% of polymer. If the polymer is less than 5 vol%, the resistivity will be less than 180 μΩ-cm.
On the other hand, if the amount of the polymer exceeds 40 vol%, the separation of the ferromagnetic metal particles by the polymer becomes large, and not only the saturation magnetization becomes less than 800 G, but also the magnetic properties gradually become hard, which is not preferable.

The high-permeability material of the present invention can be formed as a film on a substrate, but can also be scraped off from the substrate to form a powder and mixed with a liquid or solid material such as a suitable vehicle or binder. . In this way, it is possible to produce molded articles of various shapes at desired times and places by any means such as coating, spraying or molding.

Accordingly, the novel high magnetic permeability material of the present invention can be formed on a fine substrate by a vapor deposition method, so that it can be used as a core material of a micro transformer or a high magnetic permeability material of a high-frequency inductor. In addition to a base layer of a magnetic recording medium such as a magnetic disk or the like, it can be used as a material for forming a core material of a magnetic head.

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples.

Examples 1 and 2 Using a vacuum deposition apparatus as shown in FIG. 1, a high magnetic permeability material was manufactured under the following conditions.

1. Ferromagnetic metal: iron 2. Polymer: polybutene (Example 1): polystyrene (Example 2) 3. Substrate: glass 4. Substrate temperature: 150 ° C. 5. Deposition rate: ferromagnetic metal 50Å / sec: polymer 10Å / sec A film having a thickness of 5 μm was formed on the substrate.

Examples 3 and 4 Using a high frequency sputtering apparatus as shown in FIG.
A high magnetic permeability material was produced under the following conditions.

1. Ferromagnetic metal: iron 2. Polymer: polybutene (Example 3): polystyrene (Example 4) 3. Substrate: glass 4. Substrate temperature: 150 ° C. 5. Ar pressure: 10 mTorr 6. Input power: 1.5 kW ( 13.56 MHz) A film having a thickness of 5 μm was formed on the substrate.

Comparative Example 1 Directional 3% SiFe is rolled to 10 μm and 750 ° C. in vacuum
For 1 hour to obtain a control.

Comparative Example 2 Using a vacuum deposition apparatus as shown in FIG.
(Sendust) film was prepared under the following conditions.

1. Ingot: FeAlSi alloy ingot 2. Substrate: glass 3. Substrate temperature: 300 ° C. 4. Evaporation rate: 50 ° / sec.

The magnetic properties (saturation magnetic flux density and coercive force), electrical resistivity and complex of each of the high magnetic permeability material of the present invention obtained in Examples 1 to 4 and the materials obtained in Comparative Examples 1 and 2 described above. The values of the real part μ ′ of the magnetic permeability at 0.1 MHz and 25 MHz are shown in Table 1 below. Magnetic properties are measured with a sample vibrating magnetometer, electrical resistivity is measured by a four-terminal method, and magnetic permeability is measured by pressing a ferrite core wound with a coil against each sample to create a magnetic circuit, using a vector impedance meter. It was measured.

As is evident from the results shown in Table 1, the high magnetic permeability material of the present invention has a high electric resistivity, so that the decrease in magnetic permeability in a high frequency region is small, and the high magnetic permeability is excellent in characteristics in a high frequency region. It is understood to be a material.

Further, since a high magnetic permeability material using an oxide magnetic material such as ferrite has a saturation magnetic flux density of 0.4 to 0.6 T, the high magnetic permeability material of the present invention is a high magnetic permeability material using an oxide magnetic material. The saturation magnetic flux density is larger than that of.

[Effects of the Invention] As described above, by using a magnetic material having a large electric resistivity in which a polymer is deposited between ferromagnetic metal particles, deterioration in a high frequency region and high permeability having a large saturation magnetic flux density are achieved. A magnetic susceptibility material is obtained.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an example of a vacuum evaporation apparatus used for producing the high magnetic permeability material of the present invention, and FIG. 2 is an example of a sputtering apparatus used for producing the high magnetic permeability material of the present invention. FIG.

Claims (1)

(57) [Claims] A ferromagnetic metal and a polymer are simultaneously deposited by a vapor deposition method to deposit a polymer between the ferromagnetic metal particles. 95vol% ~ 60vol%, polymer is
A material having a high magnetic permeability, wherein the material has a saturation magnetization of at least 800 G and a resistivity of at least 180 μΩcm.