JPS6379211A - Magnetic substance-insulator multi-layer composite magnetic core - Google Patents

Abstract

PURPOSE:To obtain a high performance magnetic core corresponding to a high frequency with excellent corrosion-proof and wear resistance by laminating several layers of amorphous magnetic thin films and insulators or semiconductors having a film thickness three times or over that of the amorphous thin film directly alternately. CONSTITUTION:Very minute particles made of magnetic material are supplied to a high temperature flame of a jet inlet 2 formed to a nozzle 1 via a feed inlet 3 and molten. Simultaneously, a high pressure gas is led to the direction of arrow A via an inlet 4, the molten very minute particles are flown away and collided with the base 5 moving at a high speed and solidified quickly to form a coating film 6. Then minute particles made of an insulating material are collided with the film 6 to form the insulator film having a film thickness three times or over that of the film 6. The operation above is repeated to form plural layers, then the bonding stage or the like is not required and the high performance magnetic core corresponding to a high frequency is obtained with excellent corrosion proof and wear resistance.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a magnetic-insulator multilayer composite magnetic core widely used in magnetic heads of magnetic recording devices such as VTRs.

Conventional technology Multilayer composites such as those described above have conventionally been made by laminating thin films using an adhesive, which requires a time-consuming process to create the thin film and an adhesion process. Therefore, various problems have arisen in terms of durability and heat resistance. Furthermore, at present, the thickness of the atashi is even more limited, and 1
It is very difficult to get less than ooμm, 10 to 30
A .mu.m thick material is extremely expensive and impractical.

Therefore, one possible method for directly bonding thin films is to form multiple layers of a crystalline magnetic material and an insulating material and bond them together under high temperature and pressure. However, according to experiments conducted by the present inventors, it was found that the diffusion of elements between the two is intense, which not only changes the properties but also causes problems of oxidation in the case of metals. Since the crystallization temperature of an amorphous material is about 500° C. at the highest, such a method cannot be applied. Even thinner materials have hardly been tried due to these problems.

In addition, various methods have been proposed in the past to make the material amorphous by rapid cooling. For example, the Gunn method and the Pinneton-anvil method yield only small, irregularly shaped flakes. Although the roll method is much more suitable for mass production than these methods, it only yields tape-shaped products, and it is extremely difficult to control because tens of meters of tape-shaped amorphous material can be produced in an instant. Moreover, it is not possible to manufacture multi-layered products or composites.

Although there have been reports of laminated metal magnetic materials and insulating films, it is known that they have poor mechanical properties such as wear resistance and corrosion resistance, and are therefore inferior in reliability.

Problems to be Solved by the Invention A metallic magnetic material that has a high saturation magnetic flux density and has excellent recording and reproducing properties even for high coercive force tapes, etc. To provide a magnetic material-insulator multilayer composite magnetic core that has excellent properties, wear resistance, and reliability.

A means to solve the problem is to stack a plurality of layers by directly bonding amorphous magnetic films and insulating or semiconductor films alternately on a substrate,
In addition, an amorphous magnetic-insulator multilayer composite magnetic core is constructed, characterized in that the thickness ratio of the amorphous magnetic film to the insulator or semiconductor film is 3 or more.

Function: By alternately forming amorphous magnetic films on an insulator, a high-performance magnetic core capable of handling high frequencies can be obtained. Further, by using an amorphous magnetic material, corrosion resistance and abrasion resistance are improved, and therefore reliability is improved.

Furthermore, even if it crystallizes, it is as stable as an amorphous material because its composition is completely different from conventional magnetic materials (such as sendust and permalloy).

As will be clear from the following explanation, by stacking, high frequency support can be obtained, and since the volume fraction occupied by the amorphous magnetic material is large, its high saturation magnetic flux can be utilized as is.

EXAMPLE Hereinafter, an example of the present invention will be described based on the drawings. 1st
In the figure, 1 is a spray nozzle having a thermal spraying port 2, 3 is a supply port for fine particles communicating with the thermal spraying port 2 formed in the nozzle/L/1, and 4 is the spraying port 2 of the nozzle/I/1. A high-pressure gas inlet 5 formed at the rear is a base body disposed in front of the thermal spraying port 2, and moves at high speed in a direction perpendicular to the gas blowing direction (6).

In this configuration, first, the supply port 3 is connected to the high temperature mouth of the thermal spray port 2.
Microparticles made of magnetic material are supplied and melted through the inlet 4, and at the same time, high pressure gas is supplied through the inlet 4 as shown by the arrow (a).
This gas causes the dissolved microparticles to fly and collide with the substrate 6 which is moving at high speed in a direction perpendicular to the direction of arrow (A), and is rapidly solidified to form a film 6. Then, by the same operation as above, fine particles made of an insulating material are collided with the top of the film 6' and rapidly solidified to form the film 6, and this operation is repeated alternately to form a magnetic material. A multi-layered composite body consisting of a film and an insulating film is formed.

In the above embodiment, the fine particles are supplied into the spray nozzle 2 of the injection nozzle 1 through the supply port 3, but it is also possible to insert the rod-shaped body 7 into the spray nozzle 2 as shown by the solid line in FIG. Alternatively, the rod-shaped body 7 may be supplied in front of the thermal spraying port 2, as shown by the imaginary line in FIG.

Here, the speed at which the base body 5 is moved varies depending on the amount of microparticles and the amount of energy, but generally, it is sufficient to move at a speed of 3 oax/w or more. Furthermore, if the base body 5 is moved in a direction perpendicular to this at a rate of about o, tstytt/sec, a more desirable cooling state can be obtained.

It goes without saying that the same effect can be obtained even if the base body 6 is made cylindrical and rotated. Although the substrate 5 can be kept at a sufficiently low temperature (for example, 50 to 200° C.) by natural heat dissipation, the temperature may rise for a long time or when producing a very thick amorphous body. At this time, it is desirable to spray cooling gas or a cooling medium onto the front and back surfaces of the base 6 to promote heat dissipation.

Furthermore, microparticles made by melting the cooling gas or cooling medium are formed on the base 5.
It is desirable to accelerate cooling by blowing toward the area that is in contact with the gas and rapidly solidifies, and this also allows microparticles that have strayed from the gas flow to be blown away.

The thickness of the film applied in one operation is 6 to 50 mm, considering cooling etc.
The appropriate range is about μm, and it is also an easy range to handle. The distance between the thermal spraying port 2 and the base 5 is usually 50 to 300 mm.
fl is appropriate. It is possible to move closer or even further away, but considering flight speed, time, equipment conditions, etc., this would be a very difficult range to operate.

Therefore, the position of the surface where the film 6 is formed may change slightly, but in order to maintain a high level of film quality or obtain a film with a thickness of 5 to 10j11, it is necessary to change the position as the film thickness increases so that the conditions remain unchanged. It is desirable that the thermal spraying port 2 and the base body 5 be relatively spaced apart so that the position of the surface of the coating 6 with respect to the thermal spraying port 2 remains unchanged. Examples of methods for producing high-temperature light include oxygen-butane flame, acetylene flame, arc flame, and plasma flame.It is easy to send a high-pressure gun to this flame to blow away molten microparticles at high speed. Also, it is highly mass-producible. Plasma spraying is particularly excellent as a manufacturing method for the present invention. By such a method, a cooling rate of 103-b is usually obtained. Furthermore, according to the studies conducted by the present inventors, it is assumed that the molten flying particles are spherical or have a light color as shown in a and b of FIG. As shown in Figure C, it is stretched flat and tightly adheres to the base 5, which makes it extremely easy to cool and has a favorable effect on rapid cooling.

Further, the temperature of the substrate 6 is set to a temperature higher than the crystallization temperature, for example, e.
oot: If the substrate 6 is held at the above-mentioned level, the moving speed of the substrate 6 is reduced, or the thickness of the films formed at one time is made extremely thick, a crystallized film 6 can be obtained even with an amorphous material.

A film of an insulating material such as Al2O3, Sio2. It is easy to form a thin film with a thickness of 6 μm.The insulating layer does not have to be an oxide that can have a low resistance on the order of GΩ, as mentioned above, but it can be Even if the semiconductor material has a relatively low value on the order of MΩ・1 to Ω・1, it will have a low value of μΩ・
It has a much higher resistance than the conventional resistance, and functions well as an insulator. In this way, a multilayer composite was formed to serve as a magnetic core.

Next, the effect as a magnetic head core will be described.

First, MnZn or NiZn with a thickness of 0.15 to 2 ff
A metal magnetic thin film with a thickness of about 30 μm is formed on a substrate 6 of 7-elite, and a ferrite film is further formed on it with a thickness of about 10 μm.
0A! I added In. After polishing the ferrite at both ends to a total thickness of approximately 170 μm, cutting it to create a head shape as shown in Figure 4, forming a winding groove, and mirror-polishing the gap forming surface, the work is carried out. They were joined using solder at a temperature of about 230°C. In Fig. 4, 10 and 11 are ferrite, 1
2 is a magnetic alloy, and a gap 13 is located at the junction point thereof.

There is a metal magnetic material with a high saturation magnetic flux density of 8000G or more in the gap part, and the back core is assisted with ferrite 10 or 11, so it not only has the advantage of high core efficiency but also has the advantage of high bonding as mentioned above. There is a point that it is easy. This head has a coercive force of 10,000 G, which is difficult to apply because the saturation magnetic flux density is as low as 5,000 G, especially like ferrite. Magnetic tapes with coercive force as high as
It was effective for inputting signals with high frequencies up to 5 MHz for R). In addition, the metal magnetic material mentioned above is layered with a thickness of 30 μm.
Instead, it is better to use a two-part method in which a thinner film of approximately 16 μm is applied, an insulating layer of AIO, 5LO2, or ferrite is applied thinner (for example, 3 μm), and an even thinner magnetic metal layer is applied with a thickness of approximately 15 μm. Needless to say, it has good magnetic properties at high frequencies.

The magnetic core includes a metal magnetic layer 1 as shown in FIG.
It can also be obtained by directly bonding 5 and insulating layers 16 alternately to form a laminated layer 9 by the method described above, or by processing a hollow core 17. At this time, it is desirable to use ferrite as the insulating layer 16 because the saturation magnetic flux density of the magnetic core increases by the amount of the insulator. The laminated ferrite layers may have inferior properties if left as is, so inert gas (
For example, it is desirable to recrystallize by heating to about 106 tons in N2 gas). Furthermore, when manufacturing a magnetic core as shown in FIG. 6, for example, a female mold is made, and the coating 6 is laminated on the bottom of the female mold, and at the same time, the bottom part is gradually retreated so that it is constantly If the position where the film 6 is formed is kept substantially constant, a magnetic core as shown in FIG. 5 can be directly manufactured. In addition, because the precision of the contact surface with the mold is somewhat poor, 1
It is desirable that the product be subjected to a grinding process of approximately 0.0 to 300 Am. Needless to say, grinding is unnecessary for applications with poor precision.

The amorphous material to be applied to the present invention may be anything that can be melted in a high-temperature flame and turned into amorphous by cooling at a rate of 1000° C./sec or more, which is commonly said to be the case, and can be applied to a wide range of materials. Applicable. In addition, the generally well-known Nupagu (a method of rapidly cooling ions, elements, etc. that are in gaseous motion corresponding to a high temperature state and forming a thin film on a substrate)
You can also do this by

Next, specific examples will be described. This is not intended to limit the scope of the invention.

Example 1 In FIG. 1, (F eo , sN
1 o, 1CO0, 1) O-77Bo, 14Si0
．． An alloy powder having an average particle size of 65 μm obtained by totomizing the molten metal No. 09 was used. With a plasma output of 35V and 700A, using Ar as the plasma gas, the above raw material was heated at about 5H7
Thermal spraying was carried out in b. At this time, it was estimated that the molten particles were flying at speeds faster than the speed of sound. The base body 6 is an Al plate with a thickness of 3 mm and placed 110 ff from the thermal spray nozzle 2), and its surface is cooled by two cooling gas flows. The base body 5 is vertically ts
o tx/sec, moving at a speed of 11/sec from side to side, and the spraying surface was 250 x 150 m. After thermal spraying, the obtained thermal spray coating 6 has a thickness of 0.1 ff and a thickness of 250 to 150 cm!
It was a rectangular plate of R, and as a result of X-ray diffraction, it was found to be an amorphous body with few obvious diffraction peaks. In the cylindrical bond test method, it shows an adhesive strength of about 3504/cd.
No peeling was observed even during normal cutting.

Example 2 As raw material powder (Fe□, 1N1 o, 1Coo
, s ) 0.75 Bo , 1sS lo ,
The molten metal of No. 1 was atomized to obtain an alloy powder with an average particle size of 40 Am. This was carried out under the same conditions as in Example 1, with a diameter of 160 mm.
Thermal spraying was performed on a rotating cylindrical substrate at 11 IM, 90 r, p, m. The direction of thermal spraying was set to approximately coincide with the central axis of the cylinder. X-ray diffraction of a cylindrical sample sprayed to a thickness of 0.2 silk revealed that it was amorphous. The adhesive strength was about 310#/c shoulder. Furthermore, on top of this, “0.36” 0.64Fe204 with an average particle size of 3oμm
A fine powder of 100 ml was thermally sprayed to form a coating 6 with a thickness of about 13 μm, and an amorphous coating 6 with a thickness of about 0.15 m was repeatedly sprayed thereon.

The adhesive strength was approximately 29o#/crri.

Example 3 In the same manner as in Example 2, an amorphous film with a thickness of about 30 μm,
A total of 10 layers of ferrite films having a thickness of about 9 μm were alternately sprayed. Its adhesive strength was approximately 3 e oH/c4.

After removing the substrate by grinding and extracting the toroid by ultrasonic processing, it was annealed at 350°C for 2 hours, and the magnetic flux density and magnetic permeability were measured.
z was 13000.3MH2 and 400. It is conventional to use only metal of the same thickness! l) 3MHz
The magnetic permeability was too small to be measured.

Example 4 (Co0.95''0.05)O-75BO,15S
A molten metal of iO,1 was atomized to obtain an alloy powder with an average particle size of 6 μm. This powder was treated under the same conditions as in Example 1.

, 6Zn0.3Fe2.1o4 substrate (thickness o, 9ff
) (see Figure 2). Film thickness is approximately 150μm
Met. As a result of X-ray diffraction, this film was confirmed to be completely amorphous. Furthermore, on top of this, the same ferrite is crushed to a particle size of about 45 μm, and then 100 μm
Sprayed. Next, both sides were ground and finished flat to a thickness of about 180 μm, winding grooves were provided, and after annealing in pure N2 at 950°C for 30 minutes, the gap was joined with low melting glass at 450°C. The gear tooth width was adjusted to 32 μm by grinding both sides, and the gap depth was adjusted to 40 μm and the gap length was 0.4 μm. When we tested a wooden head and a conventional MnZn ferrite head with the same shape using a tape from a magnetic recording/reproducing device (VTR), we found that the coercive force was 4500. There was almost no difference in conventional tapes, but for metal tapes with a coercive force of 10,000°, the self-recording and reproducing characteristics at 5MHz were better in the case of the present invention. Compared to conventional products,
It was about 4dB better. Furthermore, the magnetic head of the present invention exhibits wear resistance comparable to that of ferrite. For example, examples of the present invention, permalloy made in the same shape, and Sendust.

As a result of a wear resistance test of ferrite magnetic heads at the same time, each was 16μm 175Ar after 100 hours.
n, 35 μm, and 10 Jm. Regarding the corrosion resistance against 1% NaC4 solution, rusting was observed in Kana 9 for Permalloy and Sendust, whereas almost no rusting was observed in the amounts used in the present invention.

As described in the above embodiments, the film thickness ratio of the amorphous magnetic film and the insulating or semiconductor film sandwiched therebetween is approximately 15 ttrn/3ttm, 0.
1BH/13μm.

30 Am/9 .mu.m, which is about 5,115.3 times higher, and it can be said that the above-mentioned characteristics including mass productivity are maintained if the ratio is at least 3 times.

Effects of the Invention The magnetic material-insulator multilayer composite magnetic core of the present invention does not require a process of forming a thin film or an adhesion process, and has various characteristics such as excellent durability and heat resistance. It is ideal for magnetic heads and magnetic cores. Further, according to the present invention, the magnetic flux density as a composite is high, there is no decrease in magnetic permeability due to the skin effect in a high frequency range, and the effective track width when used as a magnetic head is increased. Furthermore, according to the present invention, significant improvements in corrosion resistance, abrasion resistance, and reliability as a result have been observed. In addition, it has good recording and reproducing characteristics for tapes with high coercive force, making it very useful as a magnetic core for future high-density recording.

[Brief explanation of the drawing]

FIG. 1 is a schematic vertical cross-sectional view showing one embodiment of the present invention, FIG. 2 is a schematic vertical cross-sectional view of main parts showing another embodiment of the present invention, and FIG.
Figures a, b, and c are explanatory diagrams explaining the flight state and collision state of microparticles, and Figure 4 a, b. C is a front view, side view, and plan view of the magnetic head, and FIG. 5 is a perspective view of the magnetic core. 1...Injection nozzle, 2...Thermal spray port, 3
..... Supply port for microparticles, 4 .... High pressure gas introduction port, 6 ..... Substrate, e ..... Film,
7...rod-shaped body, to, 11...ferrite, 12...magnetic alloy, 15...metal magnetic material, 16...insulation Layer, 17...
Hollow core. Name of agent: Patent attorney Toshio Nakao and 1 other person 2nd
Figure 4 Figure 5 (C-n

Claims (2)

[Claims] (1) A plurality of layers are formed by directly bonding an amorphous magnetic film and an insulator or semiconductor film on a substrate, and the film thickness of the amorphous magnetic film relative to the insulator or semiconductor film is A magnetic material-insulator multilayer composite magnetic core characterized in that the ratio of the magnetic material and the insulating material is 3 or more. (2) A patent characterized in that multiple layers of an amorphous magnetic film and an insulating or semiconductor film are laminated on a substrate, and then crystallized by heating to a temperature higher than the crystallization temperature of the amorphous magnetic film. A magnetic material-insulator multilayer composite magnetic core according to claim 1.