JPS5817522A - Magnetic head and its manufacture - Google Patents

Abstract

PURPOSE:To obtain a head which has high wear resistance and provides superior short-wavelength recording and reproduction, by forming a gap-butting surface of a thin film of a metallic magnetic material, and making a medium contacting part other than the gap formation part of a wear-resistive ceramic. CONSTITUTION:A magnetic head consists of a back core part 1 made of Mn-Zn ferrite, a metallic thin film magnetic material 2, a spacer 3 for gap formation, a sliding surface 4 made of a wear-resistive ceramic, and a window 5 for winding. The metallic thin film is formed by thin-film forming techinique such as sputtering and vapor deposition, or by plasma melt-spraying techinique. The head sliding surface never wears because it is protected by the wear-resistive ceramic. The gap part uses a metallic material with high saturated magnetic flux density, so a head magnetic field is never saturated.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic spatula Y for recording and reproducing data while in contact with a magnetic recording medium such as a magnetic tape or a magnetic disk, and a method for manufacturing the same. A recording/reproducing magnetic head (hereinafter simply referred to as a magnetic head will refer to this type of magnetic head) is:
Because it is placed and reproduced in close contact with the medium, there is less space 7 gloss and excellent short wavelength characteristics at high frequencies.
The problem with magnetic recording media is that the sliding surface of the magnetic head wears out. As a result of efforts to develop magnetic materials with excellent wear resistance, for example, sendust has been developed as a metallic magnetic material, and ferrite has been developed as an inorganic magnetic material.◇However, both sendust and ferrite are magnetic Currently, magnetic recording is required to have higher recording density, larger capacity, and higher speed, and as a result, as the recording industry moves to the United States, magnetic recording media are required to have advantages and disadvantages. He-1000 (
01)) have been developed and are being adopted. Correspondingly, it is necessary to increase the magnetic field of the magnetic head and the magnetic head, and the magnetic head material is also required to have a high magnetic flux density. Sendust has a saturation magnetic flux density of approximately 10.0
00 (G), but it is inferior to ferrite in terms of wear resistance, and the material itself is extremely brittle and hard, making it difficult to form precise head cores and iazzos by processing from ingots. On the other hand, 7 with excellent wear resistance
Elite has the advantage of having good high-frequency characteristics due to its high electrical resistance, and is relatively compact in precision head processing, but its saturation magnetic flux density is 5.000 to 6,000 (G), about half that of stem dust. However, as a magnetic source for high coercive force magnetic recording media, it has the disadvantage of insufficient magnetic flux density.

The magnetic head of the present invention takes advantage of the advantages of these two materials: metal magnetic material with poor wear resistance but high saturation magnetic flux density, and ferrite material with low saturation magnetic flux density but excellent high frequency characteristics, and also with short wavelength. This is a highly wear-resistant magnetic head with excellent recording and reproducing performance. In other words, the sliding surface of the magnetic head is protected by wear-resistant ceramics, eliminating the problem of wear, and the gap is made of a metallic material with high saturation magnetic flux density, which eliminates the problem of wear that occurs in conventional ferrite magnetic heads. The saturation phenomenon of the head magnetic field does not occur, and this gap part is made of A? Tutter 9 vapor deposition.

Since the metal thin film is processed using thin film forming techniques such as plating and etching, it is easy to perform fine precision processing and form narrow tracks and narrow gaps. Furthermore, the thickness of the metal magnetic material in the gap ranges from several 1000× to several μm.
By reducing the magnetic pole length of the magnetic head, the four-shaped effect can be used.
It is possible to increase the reproduction output in the high frequency region. In addition, the wear-resistant ceramics that protect the sliding surface of the magnetic head can be arbitrarily controlled in the range from several micrometers to several tens of micrometers by using plasma spraying technology, making mass production very easy. As described above, the magnetic head and its manufacturing method of the present invention have many advantages and are excellent as a short wavelength recording magnetic head.

The structure of the magnetic head of the present invention having such characteristics is that the gap abutting surface is made of a thin film of metallic magnetic material, and the part other than the gap forming part that comes into contact with the magnetic recording medium is made of wear-resistant ceramic. Furthermore, Mn-Zn
- A magnetic head characterized in that the pack core is formed by bonding ferrite with the above-mentioned metal magnetic thin film, and at least one type of wear-resistant ceramic selected from oxides, nitrides, and carbides. This magnetic head is characterized by using ceramics including the above. The inventors conducted a more in-depth experimental study to find out which inorganic compounds are better among oxides, nitrides, and carbides. Ceramics containing at least one type of nitride as a composition are used as wear-resistant ceramics, or ceramics containing at least one of silicon nitride, titanium nitride, and boron nitride as a nitride. Alternatively, it has been found that ceramics containing at least one of silicon carbide, titanium carbide, and zirconium carbide as a carbide are superior to wear-resistant ceramics.

An example of the magnetic head of the present invention will be described with reference to the drawings.

In the drawing, 1 is a pack core made of Mn-Zn ferrite, 2 is a metal thin film magnetic material, and 3 is a gear forming step (
4 is a sliding surface made of wear-resistant ceramics, and 5 is a winding window. One of the features of the present invention is that by using thin film formation technology, it is easy to form very precise gaps. Currently, in home video tape recorders, the accuracy of the gap width is less than ±0.03 μm, which is said to be the limit for precision machining compared to bulk, and it is extremely difficult to increase the precision any further. seems difficult. However, the magnetic head of the present invention has
As can be seen from the figure, the metal thin film magnetic material and the gear gear forming spacer are prepared by coating, vapor deposition, plating,
Because it is formed using techniques such as etching, the film thickness can be controlled in units of several tens of times, so the finishing accuracy of the gap width can be ±0.001 μm, less than one-tenth of the conventional level, making it extremely precise. It became possible to form a gap.

Furthermore, in the magnetic head of the present invention, the distance between the metal thin film, the gear-forming spacer, and the metal thin film corresponds to the magnetic pole length, and since this is a submicron length, the shape effect of the magnetic head ( Contour effect) provides excellent high frequency characteristics.

In order to solve the problem of wear on the sliding surface of the magnetic head, the inventors of the present invention took into consideration the structure of the magnetic head of the present invention, and as a result of investigating various compounds, they decided to coat the sliding surface with wear-resistant ceramics. As a result, the amount of wear is comparable to that of conventional ferrite (
When using non-magnetic Ferray I, we obtained excellent results with a magnetic flux of less than or equal to 10%. Among these, as wear-resistant ceramics, oxides, nitrides, and carbides have better hardness, corrosion resistance, wear resistance, and chemical and thermal stability than other inorganic compounds.

It has been found that ceramics containing at least one of these materials are excellent in machinability, etc., and are good for improving the wear resistance of magnetic and magnetic materials. Among substances, nitrides, and carbides, oxides include nonmagnetic ferrite, aluminum oxide, and titanium oxide, nitrides include silicon nitride, titanium nitride, and boron nitride, and carbides include silicon carbide and titanium carbide. , carbide/zolconium,
It has been found that among these compounds, one is excellent as a wear-resistant ceramic for the sliding surface structure of the magnetic head of the present invention. Therefore, in the present invention, a ceramic containing at least one type of the above-mentioned ceramics as a composition is used as a wear-resistant ceramic. Therefore, when processing the sliding surface of the magnetic head, it is difficult to process using general processing methods. Therefore, after examining various processing methods, the inventors found that forming a bond using the Gradama thermal spraying method was the optimal processing method. I found out that it is a law. In plasma spraying, the adhesion to the Mn-Zn-ferrite substrate is extremely strong, and the film formation speed is fast (several μm).
/min), a uniform and homogeneous film can be easily formed, and the film can also be very hard. This is a desirable characteristic of the wear-resistant ceramic used in the present invention.

In addition, the advantages of using thin film formation technology (Snow-Archid 9 vapor deposition, plating, etching) in the manufacturing method of bonding a metal thin film magnetic material with Mn-Zn-ferrite have been mentioned many times before. , will not be repeated here.

As described above, the magnetic head of the present invention has many structural features.
It has special magnetic properties and manufacturing characteristics.

Examples will be described below.

Example-1 Mn-Zn-ferrite single crystal (Mn025 Molty Z
(21
1) After polishing and mirror-finishing the surface, apply argon, sulphate, and ivy.

Etch Schiff, "L-Flumina" was plasma sprayed. The alumina had a purity of 99.99% and an average particle diameter of 50 μm, and the plasma output was 30 kV, 50'OA, and Ar was used as the plasma gas. 0 on the surface
, an alumina layer with a thickness of 1.5 cm was formed. Next, the (111) plane perpendicular to the (211) plane on which the alumina layer was formed was polished and polished to a mirror finish, and then thoroughly washed with argon, solute, and tar.
．． After etching, add sendust to 0.3ttm±0.00
A film was formed using a 1 μm O precision 11i using a magnetron Suno 9 tube method with an output of 200 W and 1.7 kV. The above process was carried out in the same manner on a ferrite core having a winding window on the (111) plane to form alumina on the (211) plane and a sendust thin film on the (111) plane. Next, sealing glass with a low softening point (600-700°C) was placed on top of the flat (111) Sendust thin film using a high-frequency snokutter to a thickness of 13 μm ± 0.01 μm.
With this core, we form a film with a precision of ' (11
1) Cores having winding windows on their faces were crimped to each other with their (111) faces joined together in an electric furnace (750°C for 1 hour).

The head core made in this way was mechanically sliced to form a magnetic head, and a wear resistance test was performed.The amount of wear was approximately 1/1 that of the (211) plane of single crystal Mn-Zn-ferrite. It was 3 or less, and no gap collapse occurred. Also, metal tape (coercive force He~1000
As a result of investigating the performance of a magnetic head using (Oe)), it was found that there was no distortion like in a ferrite head with insufficient saturation magnetic flux density during self-recording and playback, and the playback output was several dB higher than that of a ferrite head. .

Example-2 Similar to Example-1, silicon nitride fine particles (average particle diameter 100 μm) were used instead of alumina at 35 kV, 7
With a power of 00 A, plasma spraying will produce A as f-lasma.
(using r gas), a film with a thickness of approximately 0.12 m is coated with ferrite (1
10) The (211) plane perpendicular to this is coated with a Sendust film (0.5 μm thick), and a flat core and a windowed core are formed in the same manner as in Example-1. and (
211) The glass surfaces were fused together and made magnetic.

As a result of the wear resistance test, the amount of wear was approximately 1/2 that of the (110) plane of single crystal Mn-Zn-7 elite, which was excellent, and there was no gap collapse or force.

[Brief explanation of drawings]

The drawing shows an example of the magnetic head of the present invention. 1: Mn-Zn-ferrite, 2: Metal thin film magnetic material,
3: Gah! Forming spacer, 4: Wear-resistant ceramics, 5: Winding window 0 128- Glance 23≧21

Claims (7)

[Claims] (1) In a magnetic head that records and plays while in contact with a magnetic recording medium, the gap abutting surface is made of a thin film of metallic magnetic material, and the parts other than the gap forming part that come into contact with the magnetic recording medium are made of wear-resistant material. 1. A magnetic head comprising a pack core made of magnetic ceramics, and further comprising a Mn--Zn ferrite bonded to the aforementioned metal magnetic thin film to form a pack core. (2) The magnetic head according to claim (1), characterized in that a ceramic containing at least one type of oxide, nitride, and carbide is used as the wear-resistant ceramic. . (3) The magnetic head according to claim (2), wherein the oxide is a ceramic containing at least one of non-magnetic ferrite, aluminum oxide, and titanium oxide. (4) The magnetic head according to claim (2), wherein the nitride is a ceramic containing at least one of silicon nitride, titanium nitride, and boron nitride. (5) A head using ceramics containing at least one of silicon carbide, titanium carbide, and zirconium carbide as a carbide. (6) The gap abutting surfaces are made of a thin film of metallic magnetic material, the parts other than the gear and gap forming parts that come into contact with the magnetic recording medium are made of wear-resistant ceramics, and the thin film of metallic magnetic material is made of Mn. -Zn ferrite head core,
A method for manufacturing a magnet, which is characterized by forming a bond using a thin film forming technique (sumi-9, evaporation, etching, etching). (7) The gear and pushbutting surfaces are made of a thin film of metallic magnetic material, and the parts other than the gap forming part that come into contact with the magnetic recording medium are made of wear-resistant ceramics. A method for manufacturing a magnetic head, characterized in that a bond is formed by plasma welding on a Zn7 elite core.