JPH04102206A - Magnetic head - Google Patents

Abstract

PURPOSE:To improve reproducing and recording characteristic in low-pass and high-pass areas by guiding an axis of easy magnetization in the track width direction of soft magnetic metallic magnetic thin film provided with high saturation magnetic flux density Bs. CONSTITUTION:The soft magnetic metallic magnetic thin film provided with the high saturation magnetic flux density is adhered on the forming plane of a gap (g) between magnetic cores 1A and 1B. Firstly, magnetic anisotropy is eliminated from a magnetic head chip in which the magnetic cores 1A, 1B are formed by confronting an unifying in such way by applying heat annealing in rotary magnetic field centering an axis represented by chain line (a) in the center part of a chip located in the gap length direction (direction intersecting orthogonally to the gap forming plane of the magnetic cores 1A, 1B) of the head chip in a prescribed magnetic field. After that, the axis of easy magnetization is guided in the track width direction Tw by applying stationary magnetic field heat annealing in a state where an external magnetic field coincides with the track width direction Tw. A head coil 3 is wound across both magnetic cores 1A, 1B of the head chip.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic head, especially a so-called M It relates to a metal in gap (metal in gap) type magnetic head.

Summary of the Invention The present invention provides a magnetic head in which a soft magnetic metal film with a high saturation magnetic flux density is adhered to a magnetic gap forming surface, in which an axis of easy magnetization is induced in the metal magnetic film in the track width direction. Aim to improve recording and playback output characteristics.

[Conventional technology]

Magnetic materials used in magnetic heads are required to have high magnetic permeability. It is known that this high magnetic permeability can be obtained by forming a magnetic path in the direction of the hard magnetization axis at high frequencies of the MHz band or higher.

Therefore, controlling the magnitude and direction of the magnetic anisotropy of this magnetic material greatly influences the electromagnetic conversion characteristics of the magnetic head.

For example, JP-A-62-139114 (Document 1)
), in a thin film type magnetic head in which a magnetoresistive (MR) type magnetic head and an inductive type magnetic head are laminated on a substrate, the track width direction of both heads, that is,
The thin film yoke of the induction type magnetic head also has uniaxial anisotropy in the film surface direction, and the direction in which the magnetic flux passes in the film surface direction, which is almost orthogonal to this, is defined as the difficult magnetization axis direction, resulting in high magnetic permeability in the high frequency band. In this way, the recording efficiency of the head is improved.

Furthermore, in JP-A-63-304414 (Document 2), in a magnetic head using a Herad core having a multilayer structure in which ferromagnetic thin films and insulating thin films are alternately laminated, the direction of the axis of easy magnetization of the head core is defined as the track width. In order to improve the characteristics by paralleling the direction, the difficulty of making the track width direction the axis of easy magnetization due to the large demagnetizing field coefficient due to the shape is to be avoided. There is a description of compensation by tilting in the track width direction.

However, as shown in Figure 2, a pair of magnetic cores (IA
) and (IB) are opposed to each other, and a soft magnetic metal magnetic film (2) having a high saturation magnetic flux density Bs is formed on the surface where the magnetic gap g is formed between these front end surfaces, that is, on the front opposing end surfaces thereof. In the so-called MIG magnetic head, the direction of the magnetic path with respect to the soft magnetic metal magnetic film (2) is different from that of the thin film magnetic core in Documents 1 and 2 mentioned above. As shown in Publication No. 158606 (Document 3), by inducing uniaxial anisotropy in the gap depth direction, at least the magnetic permeability in the perpendicular direction to the soft magnetic metal magnetic film (2) can be improved. Proposals have been made for MIG-type magnetic heads that are capable of measuring magnetic fields.

However, it has been found that this type of magnetic head does not necessarily improve the frequency characteristics sufficiently in its recording and reproducing characteristics.

2. Problems to be Solved by the Invention The present invention provides a magnetic head of the above-mentioned MIG type which has stable recording and reproducing characteristics and excellent characteristics in the low and high frequencies.

Means for Solving Two Problems: In the present invention, as shown in an enlarged perspective view of the line in FIG. In a magnetic head formed by adhering a soft magnetic metal magnetic film (2) having a density Bs, an axis of easy magnetization is induced in the metal magnetic film (2) in the track radiation Tw direction.

[Effect]

According to the above-described configuration of the present invention, it has been confirmed that excellent recording and reproducing characteristics can be obtained in the low and high frequencies.

〔Example〕

Further, an example of the magnetic head according to the present invention will be explained in detail with reference to FIG.

Example 1 A soft magnetic metal magnetic film made of, for example, a Co2r-based amorphous sputtered film and having a high saturation magnetic flux density Bs on the forming surface of the magnetic gap g of the main magnetic cores (IA) and (IB) made of Mn2n ferrite with high frequency characteristics. It has a structure in which it is coated with. In this way, the magnetic core (IA
) and (IB) are combined facing each other to form a magnetic herad tip, and this is applied in a required magnetic field, for example, 4 kOe, so that the gap length direction is orthogonal to the gap forming plane of the magnetic cores (IA) and (IB). First, magnetic anisotropy is eliminated by heating annealing in a rotating magnetic field, so-called RFA, by rotating the chip at 350° C. for 10 minutes around the axis indicated by the chain line a in FIG.

After that, static magnetic field heating annealing (so-called SFA) is carried out for 2 times with the external magnetic field aligned in the direction of the track width Tr.
This is carried out at 10° C. for 30 minutes to induce an axis of easy magnetization in the track width direction Tiv.

A head winding (3) is wound around both magnetic cores (IA) and (IB) of this head chip.

Comparative Example 1 A magnetic head was constructed using RFA and SFA in the same manner as in Example 1, but SFA was performed in the gap depth direction to induce an axis of easy magnetization in the gap depth direction.

The recording and reproducing output characteristics of each head according to Example 1 and Comparative Example 1 described above were measured. In this case, each magnetic head has a height of its magnetic cores (IA) and (IB), that is, a head chip height l of 9 mm, and a width W of 2.0 mm.
mm, the thickness t is 200 μm, the track width Tw is 85 μm, the gap length is 0.257 μm, the gap depth is 20 μm, and the thickness of the soft magnetic metal magnetic film (2) (thickness in the gap length direction). was set to 8 μm. The results of measuring the recording and reproducing output characteristics of the heads of Example 1 and Comparative Example 1 at each frequency with a metal thin film magnetic tape running at a running speed of 6.9 m/sec are shown below. Shown in 1. In this case, the characteristics of the annealing treatment performed only by RFA are O[
] B.

As is clear from this, the frequency characteristics of the magnetic head according to the present invention are improved in the low and high frequencies compared to the magnetic head of Comparative Example 1 in which the axis of easy magnetization was induced in the gap depth direction. .

The magnetic head according to the present invention is provided with a pair of magnetic blocks made of ferrite, for example, which form the magnetic cores (IA) and (IB) of a plurality of Herad chips, and these blocks are combined to face each other, and a plurality of heads are formed from this combined block. Chips can be cut and formed.

Each magnetic block has a winding groove (4) in advance on its opposing surface.
Further, a soft magnetic metal magnetic film (2) such as a CoXr-based amorphous film having a high saturation magnetic flux density Bs is deposited on the opposing surfaces of the two layers by sputtering, for example.

Each magnetic film (2) can be subjected to the above-mentioned RFA and SFA while being adhered to each block, or both blocks can be combined to form a combined block and then the above-mentioned RFA and SFA can be performed. Alternatively, the combined block may be cut to form each magnetic RAD tip, and then the above-mentioned RFA and SFA may be performed.

Further, in the example shown in FIG. 1, a notch (21) is formed on the outside of the wound so as to form a convex portion regulating the track width Tw at the center of the surface facing the magnetic recording medium. The shape is not limited to this, and various configurations can be used.

[Effect of Hathu]

As described above, according to the present invention, in the MIG type magnetic head, the axis of easy magnetization is induced particularly in the track width direction of the soft magnetic metal magnetic film (2) having a high saturation magnetic flux density Bs, thereby reducing the The playback/recording characteristics can be improved in the low and high ranges.

[Brief explanation of the drawing]

FIG. 1 is an enlarged perspective view of an example of a magnetic head according to the present invention, and FIG. 2 is a perspective view illustrating a conventional magnetic head. (IA) and (IB) are magnetic cores, (2) is a soft magnetic metal magnetic film, (3) is a head winding, and g is a magnetic gap. Sekiso 1 finish 4th place 4th Oni jJk Kiba 8th place
Month 1 = Yoru Ishizumi Ehet's - R's Liang Scream Nemiro Figure 1 Representative Rihito Matsu Kuma Hide Mori Figure 2

Claims (1)

[Claims] A magnetic head comprising a soft magnetic metal film with a high saturation magnetic flux density adhered to a magnetic gap forming surface of a magnetic core, wherein an axis of easy magnetization is induced in the metal magnetic film in the track width direction. A magnetic head characterized by comprising: