JP2659989B2 - Magnetic head - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) The present invention relates to a magnetic head for recording and reproducing data on a magnetic recording medium.

(Prior Art) In recent years, a magnetic head (so-called metal head, metal in-gap head) in which a main core is formed using a metal magnetic material having a high saturation magnetic flux density has been developed so as to correspond to a metal tape.

In the above-described magnetic head, a main core is formed by using a metal magnetic material at a position where a pair of sub-cores formed of ferrite or the like oppose each other, and a magnetic gap is formed between these main cores.

The magnetic gap is formed by providing an insulating layer between the opposing main cores, and the gap material serving as the insulating layer is generally formed by a vacuum thin film forming method (for example, vacuum deposition or sputtering). An oxide film is used.

When the above-described magnetic head is configured, there is a process of bonding the above-described pair of sub-cores (in which the main core and the gap portion are formed) at a relatively high temperature using a glass material.

However, in the above-described conventional magnetic head, in the process of bonding a pair of cores, the elements (for example, oxygen, metal, etc.) constituting each part are formed at the interface between the oxide film forming the gap and the metal magnetic material forming the main core. Element), and oxygen in the oxide film may be mixed into the metal magnetic body serving as the main core, which may significantly degrade the magnetic characteristics of the main core. Further, the diffusion of oxygen in the oxide film forming the gap increases the gap length (effective gap = film thickness) of the gap. That is, the thickness is larger than the formed film thickness. This makes it difficult to obtain predetermined magnetic characteristics.

In addition, since the amount of diffusion of oxygen is determined by the bonding process (temperature time) of the two cores, the combination of the gap material, and the metal magnetic material, there is a problem that it is difficult to control the dimension of the effective gap.

(Problems to be Solved by the Invention) As described above, in the conventional magnetic head, in the head manufacturing process, the gap length of the gap portion that affects the characteristics of the magnetic head fluctuates, and it is difficult to obtain predetermined magnetic characteristics. In addition, there is a problem that it is difficult to control the dimension of the gap length.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-described problems, and an object of the present invention is to provide a magnetic head capable of easily controlling a dimension of a gap length and obtaining predetermined magnetic characteristics of the head.

[Constitution of the Invention] (Means for Solving the Problems) According to the present invention, a main core of a metal magnetic material is formed on each of opposing surfaces of a pair of sub-cores, and a magnetic gap is formed between these main cores. In the magnetic head on which the SiO ₂ film is formed, the main core has an opposing surface and a side surface opposing the SiO ₂ film, and the opposing surface of the main core selectively includes any one of IVa group elements. An oxide protective film is formed of a metal film of one element or an alloy film containing at least one of the elements.

(Operation) In the present invention, the surface between the main core and the oxide film is
Since an oxide protective film made of a metal film of any one of the IVa group elements or an alloy film containing at least one of the elements is formed, the dimension control of the gap length can be easily performed, and the head It is possible to obtain predetermined magnetic characteristics.

Note that, in the present invention, the oxidation protection film is not formed over the side surface of the main core, and the main core and the SiO ₂
Since it is selectively formed only on the surface between the films, there is no stress concentration and there is no distortion in the shape of the recording / reproducing track in the width direction, so that the magnetic characteristics during recording / reproducing are adversely affected. The dimensional control of the gap length can be achieved without the need.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a perspective view showing a magnetic head according to an embodiment of the present invention.

In the figure, reference numerals 1a and 1b denote a pair of sub-cores formed of, for example, ferrite. On the opposing surfaces of these sub-cores 1a and 1b, the main core is formed by a vacuum thin film technique using a metal magnetic material such as an Fe-Al-Si alloy.
2a and 2b are formed.

In addition, a Ti film, which is an oxidation protection film for protecting the oxidation of
3a and 3b are formed. Further, on opposite surfaces of the Ti films 3a and 3b, an SiO ₂ film 4a which is an oxide film serving as a gap portion is provided.
4b is provided.

The sub-cores 1a and 1b are abutted so that the SiO ₂ films 4a and 4b are in contact with each other, and both sides of the main cores 2a and 2b are joined by the glass 5. Reference numeral 6 denotes a through hole, and reference numeral 7 denotes a coil wound around the through hole 6.

Next, a manufacturing process of the above-described magnetic head will be described.

First, as shown in FIG. 2 (a), a ferrite substrate 11 which is a plate-shaped sub-core having a size of 5 mm × 5 mm × 1.5 mm and formed with a predetermined concave groove 11a is placed on the ferrite substrate 11 as shown in FIG. As shown in (1), the Fe—Al—Si alloy film 12 is formed to a thickness of about 5 μm by a vacuum thin film forming method. Next, a Ti metal film 13 serving as an oxidation protection film is formed on the Fe-Al-Si alloy film 12 to a thickness of about 300 mm. Further, an SiO ₂ film 14 as a gap material for forming a gap portion is formed on the Ti metal film 13 to a thickness of about 1200 mm.

Thereafter, as shown in FIG. 2 (c), the two ferrite substrate 11 in the state of FIG. 2 (b), respectively SiO ₂ film 14,
Butt so that the fourteen surfaces are joined, and ferrite substrate 1
The bonding glass 15 is arranged in the through hole formed by the concave grooves 11a formed in the grooves 1 and 11, and the ferrite substrates 11 are bonded by performing a heat treatment at about 500 ° C. for 1 hour. . Thereafter, a through-hole 6 is formed in a portion of the glass 15 filled in a predetermined through-hole, cut at a broken line portion shown in FIG. A magnetic head is obtained.

The output of the magnetic head was measured, and the effective gap determined from the output was about 3400 °.

Next, a magnetic head having the same structure as above was manufactured by changing the conditions of heat treatment (600 ° C. for 1 hour, 500 ° C.
Min) In both cases, the required effective gap is approximately
3400 3.

Therefore, in this embodiment, the surface between the Fe—Al—Si alloy film 12 serving as the main cores 2a and 2b and the SiO ₂ film 14 serving as an oxide film is formed of one of the IVa group elements. Since the Ti film 13, which is an oxide protective film made of a metal film or an alloy film containing at least one of the elements, is formed, the dimension of the gap length can be easily controlled, and the predetermined magnetic characteristics of the head can be improved. It is possible to obtain.

By the way, as in the manufacture of the conventional magnetic head, Fe-Al
-Si alloy layer respectively formed directly SiO ₂ film having a thickness of 1500Å on, when the optical measurement of the gap portion formed by these SiO ₂ film is bonded is a magnetic head of 3000 Å, by the glass Heat treatment conditions in the bonding process
The treatment was performed in three ways: 500 ° C. for 30 minutes, 500 ° C. for 1 hour, and 600 ° C. for 1 hour, and the effective gap of each magnetic head subjected to each of these treatments was about 3400 °, about 3500 °, and about 4000 ° respectively. Met. In addition, each of these values and each value in the above-described embodiment are shown in the following table.

[Effects of the Invention] As described above, in the magnetic head of the present invention, any one of the IVa group elements may
Since the oxide protective film made of a metal film of one element or an alloy film containing at least one element is formed, it is possible to easily control the dimension of the gap length and obtain a predetermined magnetic characteristic of the head. it can.

In addition, since the oxide protective film was selectively formed on the surface between the main core and the SiO ₂ film, there was no stress concentration, and the
No distortion occurs in the shape of the reproduction track in the width direction.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a magnetic head according to an embodiment of the present invention, and FIGS. 2 (a), (b) and (c) are perspective views each for explaining a manufacturing process of the magnetic head of FIG. It is. 1a, 1b …… Sub core, 2a, 2b …… Main core, 3a, 3b…
... Ti film, 4a, 4b ... SiO ₂ film.

Claims (1)

(57) [Claims] 1. A magnetic head in which a main core of a metal magnetic material is formed on each of opposing surfaces of a pair of sub-cores, and an SiO ₂ film for forming a magnetic gap is formed between these main cores. The main core has an opposing surface and a side surface opposing an SiO ₂ film, and the opposing surface of the main core is selectively provided with a metal film of at least one of Group IVa elements, or at least one of them. A magnetic head, wherein an oxidation protection film made of an alloy film containing two of the above elements is formed.