JPH06192837A - Hard cabon film applied amorphous magnetic alloy thin strip - Google Patents

Abstract

PURPOSE:To obtain a hard carbon film applied amorphous magnetic alloy thin strip excellent in insulating properties and heat radiation by coating the surface of an amorphous magnetic alloy with a hard carbon film having specified hardness. CONSTITUTION:The molten metal of transition metals such as iron, cobalt and nickel and a magnetic alloy contg. semimetals such as silicon, boron, carbon and phosphorus is rapidly solidified to obtain an amorphous magnetic alloy thin strip excellent in magnetic properties. The surface of this alloy is coated with a hard carbon film having 10 to 100mum thickness. This hard carbon film is formed preferably by an ion beam method using a Hall-type ion source, by which film forming can be executed with tight adhesion. Moreover, as for this hard carbon film, its heat radiability is high in about 1.0cm/S thermal diffusion constant, and its specific resistance is about 10<11> to 10<13>OMEGA.cm to reduce the loss of eddy current.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hard carbon film-coated amorphous magnetic alloy ribbon having insulation and heat dissipation properties.

[0002]

2. Description of the Related Art Amorphous magnetic alloy ribbons have excellent magnetic properties such as a small coercive force, a small magnetostriction, a large magnetic permeability even under a high frequency, and a high saturated magnetic flux density. Amorphous magnetic alloy ribbons are described in U.S. Pat. No. 3,862,6.
58, Japanese Patent Laid-Open No. 52-133826, Japanese Patent Laid-Open No. 53-53525, and the like.
It is manufactured by rapid solidification by the melt spin method. Then, after being processed into each shape such as a coil and a laminated plate and subjected to heat treatment, a high frequency transformer, an elastic wave filter,
It is used in applications such as choke coils and magnetic switches.

Amorphous magnetic alloy ribbons are used in the form of a coil or a plate when they are laminated.
In order to further improve the magnetic characteristics with the same shape,
It is necessary to electrically insulate each layer of the laminated amorphous magnetic alloy ribbons and to improve heat dissipation. Therefore, a resin film or a metal oxide is used as an insulating layer, but the insulating layer is deteriorated during annealing, the magnetic properties are deteriorated by giving extra internal stress to the metal ribbon, and the heat dissipation is deteriorated. There was a problem.

A hard carbon film is disclosed in JP-A-61-273263.
JP, JP-A-63-123802, JP-A-1-
Films can be formed by methods such as those disclosed in Japanese Patent No. 167211 and Japanese Patent Application Laid-Open No. 2-196095. In these methods, a metal containing iron as a main component is attached to the extent that peeling does not occur in normal handling. It is difficult to coat the hard carbon film by adhesion, and it is also difficult to form a hard carbon film that does not deteriorate in film quality and adhesion at the annealing temperature of the amorphous magnetic alloy ribbon of 300 to 560 ° C.

[0005]

SUMMARY OF THE INVENTION The present invention provides a hard carbon film-coated amorphous magnetic alloy ribbon which is excellent in insulation and heat dissipation.

[0006]

The gist of the present invention is that the thickness of the amorphous magnetic alloy is 10 nm or more and 100 nm or more.
A hard carbon film-coated amorphous magnetic alloy ribbon characterized by being coated with a hard carbon film having a thickness of μm or less. The amorphous magnetic alloy ribbon referred to in the present invention is as follows. U.S. Pat. No. 3,862,658, Japanese Patent Laid-Open No. 52-1338.
An amorphous alloy can be obtained by quenching and solidifying a melted alloy by the method disclosed in Japanese Patent Laid-Open No. 26, JP-A-53-53525, or the like. This amorphous alloy does not show diffraction lines by X-ray diffraction or electron beam diffraction, and has an atomic arrangement without long-range regularity.

The magnetic alloy composed of the above amorphous alloy has no magnetic anisotropy, unlike ordinary crystalline metals.
In particular, amorphous magnetic alloys of transition metals and semimetals have low coercive force, excellent soft magnetism, low magnetic loss, good workability such as thin plate processing, and easy manufacturing method. It has both excellent properties as a material and convenience in use. It is known that such amorphous magnetic alloys contain iron, cobalt, nickel as a transition metal component, and silicon, boron, carbon, phosphorus, etc. as a semi-metal component, and the composition is changed according to the use. Has been done.

In the present invention, in particular, an amorphous magnetic alloy ribbon is used as a magnetic core for generating a pulse-like electromagnetic field by rapidly reversing the magnetization with a large magnetic flux change width by a pulse-like alternating current. In applications, it was found that the use of a hard carbon film to insulate the laminated ribbons can improve the performance of the magnetic core without degrading the magnetic properties of the amorphous magnetic alloy itself. It is a thing. For example, comparing the thermal diffusion constants, about 0.03 cm ² / s for amorphous magnetic alloy and about 0.005 for heat resistant resin.
cm ² / s, and hard carbon is about 1.0 cm ² / s, so if an amorphous magnetic alloy ribbon coated with a hard carbon film is used for the magnetic core, the heat dissipation will be improved and the temperature rise of the magnetic core will occur. Can be suppressed. Further, the hard carbon film has a specific resistance of 10 ¹¹ to 10 ¹³ Ω.
Since it is about cm, eddy current loss can be reduced by using an amorphous magnetic alloy ribbon coated with a hard carbon film for the magnetic core.

Further, according to the present invention, even if the amorphous magnetic alloy ribbon mainly composed of iron used for the above-mentioned applications is changed in shape or annealed, the coated hard carbon film is not deteriorated. It exhibits excellent properties. What is referred to as a hard carbon film or a diamond-like carbon film in the present invention is as follows. The main constituent of the element is carbon, which has a hardness similar to that of natural diamond, is amorphous, and the electron beam diffraction pattern shows a halo pattern. The Raman spectrum shows a broad peak over the 1700 cm ^-1 of amorphous unique from 1100 cm ^-1. It is a uniform and smooth film in which no crystal grains are observed even when the hard carbon film is observed under a scanning electron microscope at a magnification of about 10,000 times. The hard carbon film is generally produced by a gas phase synthesis method using a hydrocarbon compound as a raw material, and contains 40 atom% or less of hydrogen according to Rutherford scattering analysis method using argon ions.
It is believed that hydrogen enters the dangling bond part of the carbon atom to stabilize the amorphous state and to provide a high hardness structure. It is speculated that the presence of an appropriate amount of hydrogen causes the hard carbon film to exhibit high hardness and thermal diffusion characteristics similar to those of natural diamond.If too much hydrogen is present in the hard carbon film, it becomes soft and becomes an organic film with a low thermal diffusivity. Become. Therefore, the hydrogen content was 35 atom% in the film when measured by Rutherford scattering analysis using argon ions.
Hereafter, it is preferably 20 to 30 atom%.

When the thickness of the hard carbon film coated on the amorphous magnetic alloy is less than 10 nm, pinholes are likely to occur, and when it is used for a laminated magnetic core which is the main application of the amorphous magnetic alloy, insulation between layers Can not be maintained and is inappropriate. If the thickness exceeds 100 μm, the internal stress becomes remarkable, and the magnetic characteristics of the amorphous magnetic alloy deteriorate, which is not suitable. Therefore, the thickness of the hard carbon film is set to 10 nm or more and 100 μm or less.

Plasma CVD is used as a method for forming a hard carbon film.
Method, sputtering method, combustion flame method, ion plating method, etc., the ion beam method using a Hall ion source for the amorphous magnetic alloy ribbon targeted by the present invention,
It is suitable because a practical hard carbon film with strong adhesion can be formed. It is not clear why the adhesion of the film becomes stronger than other methods, but according to the above ion beam method, a hard carbon film is formed by an ion beam with an appropriate energy distribution. Therefore, it is considered that a strong bond can be formed at the interface with the amorphous alloy substrate, and as a result, a hard carbon film having a strong adhesive force is formed.

Since a hard carbon film is conventionally an amorphous material, it is unstable in chemical energy, and when it is heated to a temperature higher than the film formation temperature, desorption of hydrogen and transformation into graphite proceed, It has been said that both the adhesive strength and insulating properties deteriorate. However, the hard carbon film formed by the ion beam method is
At the annealing temperature of the amorphous alloy ribbon of 360 to 560 ° C., neither the film quality nor the adhesive strength is deteriorated. Alternatively, a method of forming a hard carbon film after annealing the amorphous alloy ribbon may be adopted. In that case, other properties such as transparency, insulation, and hardness can be maximally imparted to the hard carbon film to be coated, rather than heat resistance.

Next, the structure of the hole accelerator used as the carbon ion source in the present invention will be described. FIG. 1 shows a schematic diagram of a stationary Hall accelerator ion source. In the figure, 1 is an anode, 2 is an intermediate electrode, and 3 is a cathode. By applying a potential difference of about 0 to 2000 V between electrodes corresponding to the axial direction of the acceleration region, gas is ionized and accelerated. The radial direction of the acceleration region is a portion surrounded by the coaxial cylindrical insulator 4. A magnetic field is applied to the acceleration region in the radial direction by the electromagnet 5 and the iron magnetic circuit 6. It is desirable that a magnetic field of about 10 ^-2 T can be applied in the radial direction of the magnetic circuit when a current of about 1 A is applied to the electromagnet. Therefore, the number of turns of the electromagnet is arbitrarily selected within the range that satisfies this condition. These magnetic circuits and cylindrical insulators are exposed to the plasma for a long time and are therefore forcedly cooled. A vacuum chamber 7 is connected to an exhaust system 9 through a conductance valve 8 and the inside of the system is 10 ⁻⁶ T.
A vacuum of the orr level can be used. 10 is a substrate, 1
1 is a substrate support. The substrate can be maintained at a predetermined temperature by the water cooling tube 12 or the heater 13. 1
Reference numeral 4 is a gas introduction tube to which a raw material gas for producing an ion beam is supplied. Such a hole accelerator ion source has the following operating characteristics, and the present invention effectively utilizes this characteristic.

Since no filament is used for ion generation, the reactive ion beam can be extracted. Therefore, as a pretreatment for coating, a gas capable of chemical etching, such as oxygen, chlorine, or fluorine, can be ionized and irradiated, and the effect of clarifying the substrate can be further enhanced. Ions are generated and accelerated in the same space.

It is possible to extract a high-current ion current without the limitation of space charge as in a conventional ion source. Since the ions are extracted with energy corresponding to the potential at the generation point in the acceleration region, the extracted ion beam has an energy distribution. By changing the strength and shape of the magnetic field in the acceleration region, the applied voltage and the gas pressure, the state of trapped electrons changes, and the characteristics of the discharge and the ion beam can be controlled.

A method of operating the apparatus will be described in detail with reference to the drawings. First, the vacuum chamber 7 and the ion source are set to 10 ^−6.
Use a Torr vacuum. An electric current is applied to the electromagnet of the magnetic circuit. When methane gas is caused to flow from the gas introduction pipe 14 to make the internal pressure of the ion source 10 ^-1 Torr or more and the application to the intermediate electrode is gradually increased, plasma is generated in the acceleration region at about 600V. After that, reduce the flow rate of methane gas and adjust the conductance valve to adjust the pressure in the ion source to 3.
Set to 5 × 10 ⁻³ Torr. At this time, if the discharge current between the ion source electrodes is maintained at about 1 A, the potential difference between the intermediate electrode and the cathode, that is, the discharge voltage becomes 900 to 1100V. At this time, the substrate may be grounded or 100 depending on the conditions.
A negative voltage of 0 V or less is applied. Under the above conditions, the deposition rate is 1 μm / h when the ion source-substrate distance is 200 mm.
Therefore, the operation may be performed for an arbitrary time depending on the ion source-substrate distance and the desired film thickness.

The specific operating method has been described above. The pressure inside the ion source for extracting the ion beam is 1
It can be arbitrarily selected in the range of 0 ^-5 Torr to 10 ^-1 Torr. Further, the flow rates of various gases change depending on the desired vacuum chamber pressure and the degree of opening of the conductance valve. The electromagnet current can also be selected according to the desired properties of the ion beam. Specifically, a stationary Hall accelerator ion source can form non-directional ions due to glow discharge and highly directional ion beam due to magnetron discharge according to the discharge characteristics and the physical quantity distribution in the acceleration region. For example, when the magnetic field is weak, non-directional ions due to glow discharge are mainly, and when the magnetic field is strong, ion beams with high directivity due to magnetron discharge are mainly. Ion beam energy due to magnetron discharge can be controlled by the discharge voltage, and ion energy due to glow discharge can be controlled by the voltage applied to the substrate. It is desirable to do.

During the coating of the hard carbon film, it is desirable to set the substrate potential so that the energy with which the ions collide with the substrate is about 800 eV. For example, the electromagnet current is 1.0 A, the ion source internal pressure is 3.5 × 10 ⁻³ Tor.
r, the discharge voltage of the ion source is 9 A when the discharge current is 1.0 A
It is in the range of 0 to 1100V. At this time, the energy of the ions that reach the substrate has a distribution centered on 500 eV, so the energy of the ions that strike the substrate is approximately 800
To obtain eV, -300V may be applied to the substrate.

As a comparison of hard carbon film forming methods,
Amorphous magnetic alloy using plate type DC plasma CVD equipment
Place the ribbon on the negative electrode side, pressure 3 Torr, gas ratio CH_Four
/ H ₂= 0.02, discharge voltage 350V, substrate temperature 300
A hard carbon film of 1 μm was prepared under the condition of ℃,
Good coating due to spontaneous peeling of the film within 4 hours
It did not become a sample.

As the raw material for obtaining the hard carbon film, methane has been exemplified above, but compounds containing various carbon atoms shown below can be used. Hydrogen-containing compounds Saturated hydrocarbons: methane, ethane, propane, butane, cyclohexane, etc. Unsaturated hydrocarbons: ethylene, propylene, butylene, acetylene, cyclohexene, etc. Aromatic hydrocarbons: benzene, toluene, xylene, etc. Alcohols: methanol, ethanol, Propanol, butanol, etc. Ethers: Dimethyl ether, methyl ethyl ether, etc. Containing ketone groups: Acetone, methyl ethyl ketone,
Diethyl ketone, acetophenone, etc. containing ketene groups: dimethyl ketene, phenyl ketene containing acetyl groups: acetic acid, acetic anhydride, acetophenone ester system: methyl acetate, ethyl acetate, isoamyl acetate containing aldehyde groups: formaldehyde, acetaldehyde, propione Aldehydes Nitrogen-containing compounds Amines: Methylamine, ethylamine, isopropylamine, dimethylamine, trimethylamine nitrile group-containing: acetonitrile, benzonitrile, acrylonitrile amide group-containing: acetamide nitro group compounds: nitroethane, nitromethane, nitrobenzene, nitropropane Oxygen-containing compound: carbon monoxide, carbon dioxide Peroxide: peracetic acid, t-butyl peroxide The above compounds are one kind or a mixture of two or more kinds. It can be used in.

[0021]

EXAMPLES Each raw material was weighed in the composition ratio shown in Table 1, melted in an argon gas atmosphere, and then rapidly cooled to prepare three types of mother alloys. Next, each mother alloy was rapidly cooled from 1300 ° C. at a cooling rate of 10 ⁶ ° C./s by a melt spin method,
A thin strip having a thickness of 20 μm and a width of 50 mm was prepared.

Next, using the stationary Hall accelerator ion source shown in FIG. 1, the distance between the ion source and the substrate is 200 mm.
Under the conditions shown in (3), three kinds of amorphous magnetic alloy ribbons were coated with a hard carbon film. As a result, the hard carbon film was coated not only on the ribbon portion having a width of 50 mm but also on the side edge portion of the ribbon having a width of about 20 μm. The physical properties and structure of the coated hard carbon film are as follows.

Film thickness: 1.2 μm 10 gf weighted Vic
kers hardness: 5000 kgf / mm ^{2 In the} adhesion test using cellophane tape, no defect was found in each sample. Film adhesion by the test method ^{scratching: 20 × 10 7 N / m} 2 Raman spectrum: shows a broad peak from 1100 cm ^-1 over the 1700 cm ^-1.

Hydrogen content: 30 atom% Specific resistance: 1 × 10 ¹¹ Ωcm Electron diffraction image: halo pattern with no clear diffraction line Magnetic properties of amorphous magnetic alloy ribbon before and after coating with hard carbon film It became like 1.

[0025]

[Table 1]

[0026]

[Table 2]

Next, the above three kinds of amorphous carbon alloy thin ribbons coated with a hard carbon film were annealed in an argon atmosphere under the annealing conditions shown in Table 3 for 1 hour. As a result, the physical properties and structure of the hard carbon film were as follows. Film thickness: 1.2 μm 10 gf weighted Vickers hardness: 4500 kgf / mm ^{2 In the} adhesion test using cellophane tape, no defect was found in each sample.

The scratch adhesion of the membrane according to Test ^{Method: 20 × 10 7 N / m} 2 Raman spectrum: shows a broad peak from 1100 cm ^-1 over the 1700 cm ^-1. Hydrogen content: 28 atom% Electron diffraction image: Halo pattern with no visible diffraction line Measurement of various magnetic and thermal properties of a hard carbon film-coated amorphous magnetic alloy ribbon produced by a stationary hole accelerator ion source Tables 3 and 4 (continued from Table 3) show the results of comparison with the magnetic characteristics of the amorphous magnetic alloy ribbons not coated with the hard carbon film. From this result, the hard carbon film can be used as a heat-conductive insulating layer that can withstand the annealing temperature without changing the magnetic properties such as the squareness ratio, magnetic permeability, and core loss of the amorphous magnetic alloy ribbon. It became clear that it could be done.

[0029]

[Table 3]

[0030]

[Table 4]

[0031]

The hard carbon film-coated amorphous magnetic alloy ribbon according to the present invention can be used to manufacture a magnetic core having excellent heat dissipation and high-frequency magnetic characteristics, and a transformer, elastic wave filter, and choke coil having excellent high-frequency characteristics. , Magnetic switch can be manufactured.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a stationary Hall accelerator ion source used in the present invention.

FIG. 2 is an enlarged view of a main part of the stationary Hall accelerator ion source of FIG.

[Explanation of symbols]

 1 Anode 2 Intermediate Electrode 3 Cathode 4 Coaxial Cylindrical Insulator 5 Electromagnet 6 Magnetic Circuit 7 Vacuum Chamber 8 Conductance Valve 9 Exhaust System 10 Substrate 11 Substrate Support 12 Water Cooling Pipe 13 Heater 14 Gas Inlet Pipe

 ─────────────────────────────────────────────────── ─── Continuation of the front page (71) Applicant 591107090 Toshiyuki Governor, Gokasho official land in Uji City, Kyoto Prefecture 554 (72) Inventor Morihiro Okada 1618 Ida, Nakahara-ku, Kawasaki-shi, Kanagawa Nippon Steel 1st Technical Research Institute Co., Ltd. (72) Inventor Kiyoshi Yoshikawa 25 Kinugasa Somon-cho, Kita-ku, Kyoto-shi, Kyoto (72) Inventor Yasushi Yamamoto Gokasho-Kenchi, Kyoto Prefecture ) Inventor, Toshiyuki, Gokasho official land, Uji City, Kyoto Prefecture Kyoto University Staff Housing 554

Claims (1)

[Claims] 1. A hard carbon film-coated amorphous magnetic alloy ribbon, characterized in that the surface of an amorphous magnetic alloy is coated with a hard carbon film having a thickness of 10 nm or more and 100 μm or less.