JPH02260210A - Magnetic head - Google Patents

Abstract

PURPOSE:To suppress a shape effect and to decrease the waviness of reproduced output-frequency characteristics by forming chromium carbide between the surfaces of magnetic oxide material cores to face a gap and magnetic alloy material thin films. CONSTITUTION:The chromium carbide film 4 is formed between the surfaces 3 of the magnetic oxide material cores 1, 2 to face the gap and the magnetic alloy material thin films 5. The interdiffusion of oxygen, etc., between the magnetic alloy material thin films 5 and the magnetic oxide material cores 1, 2 is suppressed by the chromium carbide film 4. The deterioration in the soft magnetic characteristics of the magnetic oxide material cores 1, 2 and the magnetic alloy material thin films 5 is prevented near the boundary of the cores 1, 2 and the thin films 5. The action of the part where the soft magnetic characteristics are deteriorated as a gap at the time of reproduction is thereby prevented. The shape effect is prevented in this way and the waviness in the reproduced output-frequency characteristics is decreased. The quality of reproduction signal is thus improved.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides an MIC (M
The present invention relates to an etal in' Gap) type magnetic head.

[Conventional technology]

Conventionally, the MIC type has been developed which combines the advantages of oxide magnetic materials such as ferrite materials, which have high magnetic permeability and excellent wear resistance, and the advantages of alloy magnetic materials, which have high magnetic permeability and high saturation magnetic flux density. Magnetic heads are known. This magnetic head uses an oxide magnetic material for the core body and forms the vicinity of the gap using an alloy magnetic material.

In the manufacturing method of such a magnetic head, as shown in FIG.
As shown in a), an external winding groove 13 and a glass filling groove 14 are formed in one block 11 of the oxide magnetic material serving as the core.
and an internal winding groove 15, and as shown in FIG.
to form. After polishing the gap facing surfaces 16 and tape sliding surfaces 17 of each of the blocks 11 and 12 to a mirror finish, as shown in FIGS.
Grooves (track grooves) 18 for obtaining a predetermined gap track width are formed. Next, the gap facing surface 16
After removing the process-affected layer near the surface layer of block 11 by etching, as shown in FIGS.
- Alloy magnetic material thin film 1 having high magnetic permeability and high saturation magnetic flux density on each gap facing surface 16 in 12
9 is formed by a sputtering method or the like. Next, after forming a non-magnetic material such as SiO□ as a gap material with a thickness of about 0.3 μm on the gap forming portion on the alloy magnetic material thin film 19, as shown in FIG. 12 with each gap facing surface 16, 16
The glass 20 is placed in the cavity formed by the glass filling groove 14 and the internal winding groove 15, and heat welded. After forming a curved surface on the tape sliding surface 17 of the magnetic head block thus obtained, as shown in FIG.
By cutting along the virtual line b..., the same figure (j
), a magnetic head 22 (not yet wound) is obtained.

[Problem to be solved by the invention]

However, in the conventional magnetic head described above, the gap facing surface 16 of each of the flocs 11 and 12 made of oxide magnetic material is
Since the interface between the magnetic alloy material thin film 19 and the magnetic alloy material thin film 19 is parallel to the gap, as shown in FIG. 4, the waviness generated in the reproduced Kerr frequency characteristic is about 3 dB. This is due to the difference in magnetic properties between the oxide magnetic material and the alloy magnetic material, the reaction layer formed at the interface due to the diffusion of oxygen, etc., the incompletely removed portion of the altered layer, etc., which act as a pseudo gap. This is thought to be due to the so-called shape effect (contour effect). In FIG. 4, the relative speed between the magnetic recording medium and the magnetic head is 5.8 m/5ec0, and the magnetic recording medium used has a coercive force of 900 oersteds.

To solve this problem, the inventor of the present invention has already proposed a magnetic head in which chromium is interposed between an oxide magnetic material and an alloy magnetic material. As shown in FIGS. 5(a), 5(b), 5(c), and 5(d), this magnetic head undergoes the same manufacturing process as the magnetic head 22 described above (
After removing the damaged layer, a chromium (Cr) film 23 is formed on the gap facing surface 16 by sputtering or the like to a thickness of 10 to 200 mm, as shown in FIGS.
Form on top. Thereafter, an alloy magnetic material thin film 19 is formed on the chromium film 2 to a thickness of 2 to 6 μm by sputtering or the like.
3 and parallel to the gap. and,
A non-magnetic material such as StO□ is formed as a gap material at a gap forming portion of the alloy magnetic material thin film 19 to a thickness of about 0.3 μm. The subsequent manufacturing process is shown in Figures (h) and (i).
As shown in (j), processing similar to that of manufacturing the magnetic head described above is performed.

However, even with the magnetic head in which the chromium film 23 is interposed between the blocks 11 and 12 made of oxide magnetic material and the alloy magnetic material thin film 19, as shown in FIG. A undulation of about 1 dB still remains in the frequency characteristics, and the performance cannot be said to be sufficient, and further improvement is desired. Note that the conditions in FIG. 6 are set similarly to the conditions in FIG. 4.

[Means to solve the problem]

In order to solve the above-mentioned problems, the magnetic head according to the present invention has an alloy magnetic material thin film having high magnetic permeability and high saturation magnetic flux density, which has a gap between the gap-opposed surface of the oxide magnetic material core having high magnetic permeability. The magnetic head is formed parallel to the oxide magnetic material core and is characterized in that chromium carbide is formed between the gap-opposed surface of the oxide magnetic material core and the alloy magnetic material thin film.

[For production]

According to the above configuration, mutual diffusion of oxygen and the like between the alloy magnetic material thin film and the oxide magnetic material core can be suppressed by the chromium carbide formed on the gap facing surface. Therefore, deterioration of the soft magnetic properties of the oxide magnetic material core and the alloy magnetic material thin film near the interface between the oxide magnetic material core and the alloy magnetic material thin film can be prevented, and the portion where the soft magnetic properties have deteriorated is left in the gap during playback. Therefore, the shape effect can be suppressed and the waviness in the reproduced output-frequency characteristic can be reduced.

〔Example〕

An embodiment of the present invention will be described below based on FIGS. 1 and 2.

In the magnetic head according to the present invention, as shown in FIG. 1(j), each of the gap-opposing surfaces 3 in the oxide magnetic material core 2 having high magnetic permeability has a predetermined width and a groove in the gap. Projections 3a, 3a having surfaces parallel to each other are formed. A chromium carbide film 4 with a thickness of 10 to 200 layers is formed on the gap opposing surfaces 3 and 3 including the protrusions 3a and 3a. is an alloy magnetic material thin film 5 having a thickness of 2 μm to 6 μm and having high magnetic permeability and high saturation magnetic flux density.
is formed. Then, between the oxide magnetic material cores 2 on which the chromium carbide film 4 and the alloy magnetic material thin film 5 are formed, a non-magnetic material such as Sing having a thickness of about 0.3 μm is used as a gap material between the protrusions 3a and 3a. The gap facing surfaces 3, 3 are butted against each other with a material interposed therebetween and fixed with molten glass 6.

In order to manufacture the above magnetic head, as shown in FIG. 3(a), one block 1' of the oxide magnetic material serving as the core is provided with an external winding groove 1'a and a glass filling groove 1'b. In addition to forming grooves 1'c for internal windings, as shown in FIG. Groove 2'
b. After polishing the gap facing surface 3 and tape sliding surface 7 of blocks 1' and 2' to a mirror finish, a predetermined gap track width is obtained, as shown in (C) and (d) of the figure. grooves (track grooves) 8... are formed. Next, after removing the process-affected layer near the surface of the gap facing surface 3 by etching, the chromium carbide film 4 is heated with nitrogen gas and acetylene gas, as shown in (e), (f), and (g) of the figure. It is formed on the gap facing surface 3 to a thickness of 10 to 200 layers by a reactive sputtering method using a mixed gas or the like. Alternatively, it is formed by sputtering using a chromium carbide target.

Here, if the thickness of the chromium carbide film 4 is thinner than 10,
Since the chromium carbide film 4 is discontinuous and formed in an island shape, the function of suppressing the shape effect is not exhibited.
Since the chromium carbide film 4 acts as a gap layer if it is thicker than a human body, the thickness of the chromium carbide film 4 is approximately 10 mm as described above.
Approximately 200 people are suitable. Note that the chromium carbide film 4
Within the thickness range of 10 to 200 people, the thinner the material, the more pronounced the shape effect suppression function becomes.

After forming the chromium carbide film 4, an alloy magnetic material thin film 5 is formed on the chromium carbide film 4 by sputtering or the like to a thickness of 2 to 6 μm. Then, a non-magnetic material such as 5iOz is formed as a gap material to a thickness of about 0.3 μm at the gap forming portion on the alloy magnetic material thin film 5. Next, the same figure (
As shown in h), the above blocks 1' and 2' are pasted together with their respective gap facing surfaces 3 and 3 facing each other, and the glass filling grooves 1' b and 2' b and the internal winding groove 1' are formed. The molten glass 6 is placed in the hollow portions formed by c and is welded by heating. Then, after forming a curved surface on the tape sliding surface 7 of the thus obtained magnetic head block as shown in FIG. Same figure (j)
A magnetic head (not yet wound) is obtained as shown in FIG.

Therefore, a magnetic head can be obtained through a manufacturing process substantially similar to a conventional manufacturing process, mass productivity and uniformity of quality of the magnetic head can be maintained, and the price of the magnetic head can be reduced.

According to the above configuration, the chromium carbide film 4 formed on the gap facing surfaces 3 can suppress mutual diffusion of oxygen and the like between the alloy magnetic material thin film 5 and the oxide magnetic material core 2. Therefore, deterioration of the soft magnetic properties of the oxide magnetic material core 2 and the alloy magnetic material thin film 5 near the interface between the oxide magnetic material core 2 and the alloy magnetic material thin film 5 can be prevented, and the portions where the soft magnetic properties have deteriorated can be prevented. Since it no longer acts as a gap during reproduction, shape effects can be suppressed and waviness in reproduction output-frequency characteristics can be reduced.

FIG. 2 is a reproduction output-frequency characteristic diagram of a magnetic head obtained by forming a chromium carbide film 4 with a thickness of 50 μm by sputtering, and then forming a sendust alloy thin film with a thickness of 4 μm as the alloy magnetic material thin film 5. be. In this characteristic test, the relative speed between the magnetic head and the recording medium was 5
．． 8m/sec.

A recording medium with a coercive force of 900 oersted is used. As is clear from this figure, the waviness in the reproduced output-frequency characteristics is reduced to a range of 0.3 dB,
The quality of the reproduced signal could be significantly improved.

〔Effect of the invention〕

As described above, in the magnetic head according to the present invention, the alloy magnetic material thin film having high magnetic permeability and high saturation magnetic flux density is arranged parallel to the gap on the side of the gap-opposing surface of the oxide magnetic material core having high magnetic permeability. In the magnetic head thus formed, chromium carbide is formed between the gap-opposed surface of the oxide magnetic material core and the alloy magnetic material thin film.

Thereby, it is possible to suppress the so-called shape effect and reduce the waviness in the reproduced output-frequency characteristics, thereby achieving the effect that the quality of the reproduced signal can be significantly improved.

[Brief explanation of drawings]

1 and 2 show one embodiment of the present invention. FIGS. 1(a) to 1(f) and 1(h) to j) are perspective views showing each stage of the manufacturing process of a magnetic head, respectively;
Figure (g) is a sectional view of the main part in figure (f). FIG. 2 is a graph of reproduction output versus frequency characteristics in a magnetic head. 3 and 4 show conventional examples. 3(a) to 3(f) and 3(h) to 3(j) are perspective views showing each stage of the manufacturing process of the magnetic head, respectively;
Figure (g) is a sectional view of the main part in figure (f). FIG. 4 is a graph of reproduction output-frequency characteristics in the magnetic head. FIGS. 5 and 6 show other conventional examples. FIGS. 5(a) to 5(f) and (h) to j) are perspective views showing each stage of the manufacturing process of the magnetic head, respectively;
Figure (g) is a sectional view of the main part in figure (f). FIG. 6 is a graph of reproduction output-frequency characteristics in the magnetic head. 1 and 2 are oxide magnetic material cores, 1' and 2' are oxide magnetic material blocks, 3 is a gap facing surface, 4 is a chromium carbide film, 5 is an alloy magnetic material thin film, and 6 is molten glass. 2nd 5th MHz (MHz) 2nd (a) (C) (b) (d) (a) ]] (C) (b) (b) (d) ]6 Tomizu mouth dummy grain (MHz) Z (a) ] ] Fig. (C) Fig. (b) z Fig. (d) Tomizu ■ 4 sentences (MHz)

Claims (1)

[Claims] 1. A magnetic alloy magnetic material thin film having high magnetic permeability and high saturation magnetic flux density is formed parallel to the gap on the side of the gap-opposing surface of the oxide magnetic material core having high magnetic permeability. A magnetic head, characterized in that chromium carbide is formed between the gap-opposing surface of the oxide magnetic material core and the alloy magnetic material thin film.