JPH064816A - Magnetic head - Google Patents

Abstract

PURPOSE:To provide the magnetic head which can sufficiently suppress a pseudo output without degrading the head output. CONSTITUTION:This magnetic head is constituted by butting a pair of magnetic core half bodies 1, 11 consisting of ferromagnetic oxides against each other to constitute a main magnetic path, forming ferromagnetic metallic thin films 2 on the butt surfaces of at least one magnetic core half bodies and interposing a magnetic gap part 3 consisting of a nonmagnetic material between the ferromagnetic metallic thin films and the other magnetic core half body. The crystal bearings of the ferromagnetic oxides respectively constituting a pair of the magnetic core half bodies 1, 11 are set that the <110> direction of the one magnetic core half body 1 and the <110> direction of the other magnetic core half body 11 are approximately parallel respectively with a magnetic recording medium-facing surface 6 and that the angle theta formed by these two directions attains >=30 deg. and <=90 deg..

Description

Detailed Description of the Invention

[0001]

The present invention relates to a VTR (video tape recorder), DAT (digital audio tape recorder), FDD (floppy disk drive device), H
The present invention relates to a magnetic head installed in a magnetic recording / reproducing device such as a DD (hard disk drive device).

[0002]

2. Description of the Related Art In recent years, with the increase in recording density of such magnetic recording / reproducing apparatus, for example, as a recording medium of VTR, H
Metal tape with high c (coercive force) and S-VHS tape are about to be used.

On the other hand, as a magnetic head, a so-called metal head, in which a metal material having a high saturation magnetic flux density is arranged at least near the gap, is being adopted in response to the high coercive force of the magnetic medium.

FIGS. 5A, 5B and 5C show an example of the structure of a conventional metal head. In the metal head of FIG. 5 (a), a pair of ferromagnetic metal layers (22) and (23) are provided on both sides of the magnetic gap portion (3) to form a main core. It has a sandwich structure sandwiched by the non-magnetic substrates (53) and (54).

FIGS. 5 (b) and 5 (c) show a so-called MIG (metal-in-gap) head. On both sides of the magnetic gap portion (3), a pair of ferromagnetic metal thin films (spread only in the vicinity of the magnetic gap portion ( 24) and (25) are formed, and the main magnetic core is composed of a pair of magnetic core halves (12) and (13) made of an oxide magnetic material such as single crystal ferrite. Further, the gap width is regulated by the non-magnetic parts (5) and (51) such as glass.

Here, FIG. 5C shows a ferromagnetic metal thin film (24).
The boundary between (25) and the magnetic core halves (12) (13) is the gap forming surface.
FIG. 5B shows a parallel type MIG head substantially parallel to (82).
Shows an inclined MIG head in which the boundary surface is inclined with respect to the gap forming surface. The crystal orientation of the pair of magnetic core halves (12) and (13) shown in FIG.
2) is {110} and the gap forming surface (82) is set to be {100}.

On the other hand, in the parallel type MIG head shown in FIG. 6, the crystal orientation of the pair of magnetic core halves (12) and (13) is such that the main magnetic path constituting surface (72) is {211} and the gap forming surface is. (82) is set to be {111}.

In the conventional parallel type MIG head, as shown in FIG. 7, <110> of one magnetic core half body (12).
And the <110> direction of the other magnetic core half body (13) are parallel to each other in the surface (6) facing the magnetic recording medium.

[0009]

By the way, the sandwich type magnetic head and the tilted MIG head have a problem that the manufacturing process is complicated and the manufacturing cost is increased. On the other hand, the parallel MIG head has a relatively simple manufacturing process,
There is a problem that a so-called pseudo gap is formed at the interface between the ferromagnetic metal thin films (24) and (25) and the magnetic core of the oxide magnetic material, which adversely affects the head characteristics.

Therefore, various methods for reducing the pseudo output have been proposed (Japanese Patent Laid-Open No. 1-133204 (G11B5 / 127),
JP-A-2-98803 (G11B5 / 127)), in any of the methods, it is difficult to effectively suppress the pseudo output while maintaining the head output (recording / reproducing output) at a sufficient level. .

An object of the present invention is to provide a magnetic head capable of sufficiently suppressing the pseudo output without lowering the head output. Therefore, the inventor repeated an experiment in which the crystal orientations of the pair of magnetic core halves to form the main magnetic path were variously changed to compare the head performances, and as a result, the magnetic head having a specific crystal orientation had a good performance. The present invention has been completed and the present invention has been completed.

[0012]

A magnetic head according to the present invention comprises a pair of magnetic core halves (1) (11) made of ferromagnetic oxide.
To form a main magnetic path, and a ferromagnetic metal thin film (2) is formed on the abutting surface of at least one of the magnetic core halves,
A magnetic head in which a magnetic gap portion (3) made of a non-magnetic material is interposed between the ferromagnetic metal thin film and the other magnetic core half body, the pair of magnetic core half bodies (1) (11) The crystal orientations of the ferromagnetic oxides that make up the
The <110> direction of (1) and the <1> of the other magnetic core half body (11)
The 10> directions are substantially parallel to the surface (6) facing the magnetic recording medium, and the angles formed by the two directions are set to 30 degrees or more and 90 degrees or less.

[0013]

It has been experimentally confirmed that the magnetic head according to the present invention can sufficiently suppress the pseudo output while maintaining the head output high as compared with the conventional magnetic head.

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings. The magnetic head according to the present invention, as shown in FIG.
A pair of magnetic core halves (1) and (11) made of Mn-Zn single crystal ferrite are abutted against each other to form a main magnetic core, and a film thickness of 6 μm made of sendust is formed on the abutting surfaces of both magnetic core halves.
The ferromagnetic metal thin films (2) and (21) are formed respectively. And, a magnetic gap part is formed between both ferromagnetic metal thin films (2) and (21).
(3) is interposed.

Non-magnetic parts (5) and (51) made of glass are provided on both sides of the magnetic gap part (3) to regulate the gap width. A coil winding window (4) is provided at the center of the main magnetic core.
Has been established.

The crystallographic orientation of the ferromagnetic oxide constituting the pair of magnetic core halves (1) and (11) is {21
1}, the gap forming surface (8) is {111}, and the recording medium facing surface (6) is {110}.

As shown in FIG. 2, the crystal orientations of the ferromagnetic oxides forming the pair of magnetic core halves (1) and (11) are the same as the <110> direction of one magnetic core half (1) and the other. Magnetic core half
The <110> direction of (11) is the magnetic recording medium facing surface (6).
It is parallel to the angle .theta., And the angle .theta. Between the two directions is set to be 30 degrees or more and 90 degrees or less, preferably about 70 degrees.

The experimental results obtained in the course of completing the present invention will be described below. Table 1 below shows the types of crystal orientations of the ferromagnetic oxide (Mn-Zn single crystal ferrite) that constitutes the magnetic core half body. The types and are the conventional magnetic head and the type is the magnetic head of the present invention. is there.

[0019]

[Table 1]

Table 2 below shows the common specifications of the seven magnetic heads used in the experiment. The expansion coefficient in the table is the average expansion coefficient (× 10 ^-7 / room temperature to 350 ° C.).
(° C.).

[0021]

[Table 2]

Table 3 below shows the experimental results for seven magnetic head prototypes. Since it is difficult to quantitatively measure the pseudo output, the undulation of the frequency characteristic curve was evaluated as a substitute characteristic. Incidentally, prototype No.
(7) is a magnetic head according to the invention disclosed in JP-A-1-133204.

[0023]

[Table 3]

Based on Table 3, based on the trial production Nos. (1), (3) and (5) of the ferrite material which is the conventional head, the trial productions No (2), (4) of the ferrite material which is the head of the present invention,
When the undulations of (6) are evaluated, the undulations of the heads of the present invention are reduced by 18%, 13%, and 15%, respectively, and all show good head characteristics.

Here, prototype Nos. (1) to (4) are magnetic heads having a track width of about 60 μm, and prototype Nos. (5),
(6) is a magnetic head with a track width of about 30 μm,
The head of the present invention has obtained good results regardless of the track width.

Further, it is considered that the fused glass generally used for joining two magnetic core halves has a great influence on the waviness of the frequency characteristic curve, but the experimental results in Table 3 show that the fused glass is A or Regardless of whether it is B,
The undulation is smaller in the head of the present invention using the ferrite material, and the output of the head of the present invention is about 2.3 dB higher than that of the conventional head when the recording / reproducing output is B glass. Furthermore, JP-A 1-1
The magnetic head of the present invention exhibits excellent characteristics even when compared with the prototype No. 7 according to the invention of Japanese Patent No. 33204.

The following conclusions can be drawn from the above experimental results. That is, a magnetic head in which a ferromagnetic metal thin film (2) (21) is formed on the gap forming surface of at least one of the pair of magnetic core halves (1) (11) made of single crystal ferrite. In the recording medium facing surface (6) and the <110> direction of the magnetic core material (single crystal ferrite) are substantially parallel to each other, and one magnetic core half ( The angle θ formed by the <110> direction of 1) and the <110> direction of the other magnetic core half body (11) has a value of around 70 degrees, so that the magnetic core half bodies (1) and (11) By determining the crystal orientation, excellent effects can be obtained in terms of suppressing pseudo output and maintaining recording / reproducing output.

The angle θ is determined by the recording medium facing surface (6),
It can be changed to an optimum value in the range of 30 to 90 degrees depending on the crystal orientation of the main magnetic path constituting surface (7) or the gap forming surface (8).

The effect of the present invention is that two magnetic core halves are used.
(1) (11) It is thought that this is due to the superposition of the respective effects, and the same effect can be obtained even when the crystal orientations of the two magnetic core halves (1) and (11) are different from each other. .

For example, as shown in FIG. 3, one magnetic core half body
The crystal orientation of (1) is the same as that of the above embodiment, and the crystal orientation of the other magnetic core half body (11) is {2 when the main magnetic path constituting surface (71) is {2.
10}, the gap forming surface (81) is set to {521}, and the recording medium facing surface (6) is set to {211}, the same effect can be obtained.

Further, in the above embodiment, the ferromagnetic metal thin film is used.
(2) Although sendust is used as the material in (21), the same effect can be obtained when other ferromagnetic metal materials are used.

Furthermore, the shape of the ferromagnetic metal thin films (2) and (21) on the recording medium facing surface (6) can be variously changed as shown in FIGS. 4 (a) (b) (c). Needless to say, the effects of the present invention can be obtained in this case as well.

The above description of the embodiments is for explaining the present invention, and should not be construed as limiting the invention described in the claims or limiting the scope. The configuration of each part of the present invention is not limited to the above-mentioned embodiment, and it goes without saying that various modifications can be made within the technical scope described in the claims. For example, the present invention is effective not only in a magnetic head for a VTR, but also in an HDD head in which the recording medium does not directly contact the recording medium facing surface and an FDD head.

[Brief description of drawings]

FIG. 1 is a perspective view showing a crystal orientation in a magnetic head of the present invention.

FIG. 2 is a plan view of the magnetic head.

FIG. 3 is a perspective view showing another embodiment.

FIG. 4 is a plan view showing still another embodiment.

FIG. 5 is a perspective view showing a conventional magnetic head.

FIG. 6 is a perspective view showing a crystal orientation in a conventional magnetic head.

FIG. 7 is a plan view of the magnetic head.

[Explanation of symbols]

 (1) Magnetic core half body (11) Magnetic core half body (2) Ferromagnetic metal thin film (21) Ferromagnetic metal thin film (3) Magnetic gap part (6) Recording medium facing surface (7) Main magnetic path constituent surface ( 8) Gap forming surface

Claims (3)

[Claims] 1. A main magnetic path is formed by abutting a pair of magnetic core halves (1) (11) made of ferromagnetic oxide, and a ferromagnetic metal thin film (2) is provided on the abutting surface of at least one magnetic core half. ) Is formed, and a magnetic gap portion (3) made of a non-magnetic material is interposed between the ferromagnetic metal thin film and the other magnetic core half body, a pair of magnetic core half bodies (1) (1
The crystal orientations of the ferromagnetic oxides that compose each of 1) are the <110> direction of one magnetic core half (1) and the other magnetic core half
The <110> direction in (11) is the surface facing the magnetic recording medium.
A magnetic head which is substantially parallel to (6) and is set such that an angle formed in both directions is 30 degrees or more and 90 degrees or less. 2. The crystal orientation of the ferromagnetic oxide forming the pair of magnetic core halves (1) and (11) is such that the main magnetic path forming surface (7) is substantially {2.
11. The magnetic head according to claim 1, wherein the gap forming surface (8) is substantially {111} and the recording medium facing surface (6) is substantially {110}. 3. The angle between the <110> direction of one magnetic core half body (1) and the <110> direction of the other magnetic core half body (11) is about 70 degrees. Magnetic head.