JPH07110920A - Magnetic recording/reproduction head - Google Patents

Abstract

PURPOSE:To obtain a magnetic recording/reproduction head which eliminates unstable reproducing operation by making a magnetoresistance effect element shorter than the depth of a gap in an in-gap type magnetic recording/ reproduction head having the magnetoresistance effect element. CONSTITUTION:A magnetic recording/reproduction head has a first magnetic pole 2 comprising the substrate made of a magnetic material, a thin film laminate coil 6 formed on the first magnetic pulse 2 together with a non-magnetic insulation film 4 and a second magnetic pole 8 connected magnetically to the first magnetic pole 2. The tip part of the magnetic pole 8 forms gaps 10 parallel in proximity to the first magnetic pole 2. A magnetoresistance effect element 12 is arranged between the gaps 10. The length in the depth of the gaps 10 of the magnetoresistance effect element 12 is made shorter than the depth thereof 10. Thus, in the recording operation, there is no slant component generated in a magnetic field to be applied to the magnetoresistance effect element 12 and a magnetic wall is hard to occur in the magnetoresistance effect element 12 thereby making possible the prevention of the reproducing operation from becoming unstable.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generally relates to a magnetic recording / reproducing head used in a magnetic disk device, and more particularly to a magnetic recording / reproducing head having a magnetoresistive effect element.

In recent years, a magnetic head utilizing a magnetoresistive effect in which electric resistance changes depending on the magnitude of a magnetic field is in a practical stage. A magnetic head utilizing the magnetoresistive effect is attracting attention as a reproducing head for a small-sized magnetic disk device because the output of the head does not depend on the moving speed of a recording medium due to its operating principle.

[0003]

2. Description of the Related Art Conventionally, a first magnetic pole made of a magnetic substrate, a thin-film laminated coil formed on the first magnetic pole together with a non-magnetic insulating film, and a first magnetic pole penetrating the central portion of the thin-film laminated coil. A magnetic recording head having a second magnetic pole magnetically coupled to is known.

A magnetic reproducing head having a magnetoresistive effect element and first and second shields arranged on both sides of the magnetoresistive effect element is also known. On the other hand, as a magnetic recording / reproducing head used for recording and reproducing, there has been proposed a magnetic recording / reproducing head in which the above-described magnetic recording head and magnetic reproducing head are integrated.

In the improved magnetic recording / reproducing head, one of the first and second magnetic poles is also used as one of the first and second shields in order to simplify the structure. .

In the further improved magnetic recording / reproducing head, the first and second magnetic poles are also used as the first and second shields in order to further simplify the structure.
That is, for example, the first and second shields are omitted, and the magnetoresistive effect element is arranged between the first and second magnetic poles.

In this so-called in-gap type head, since the magnetoresistive element used for reproduction is located in the gap between the first and second magnetic poles used for recording, the head is a magnetic disk. For example, when the recording medium is moved from the inside to the outside of the rotating recording medium, there is little reproduction loss due to the angle (yaw angle) formed by the head and the recording medium, and high-density recording becomes possible.

[0008]

However, in the in-gap type head, the magnetoresistive effect element is the first.
Further, since the magnetic field is in the gap between the second magnetic poles, the magnetic field at the time of recording is directly applied to the magnetoresistive effect element, and the magnetic domain structure of the element is changed to cause a problem that the reproducing operation becomes unstable.

Therefore, an object of the present invention is to provide an in-gap type magnetic recording / reproducing head in which the reproducing operation does not become unstable.

[0010]

According to the present invention, a first magnetic pole, a thin film laminated coil formed on the first magnetic pole together with a non-magnetic insulating film, and a central portion of the thin film laminated coil are penetrated. A second magnetic pole magnetically coupled to the first magnetic pole and a magnetoresistive effect element located between the first magnetic pole and the second magnetic pole are provided, and a tip portion of the second magnetic pole has the first magnetic pole. A gap for generating a recording magnetic field is formed in the vicinity of the first magnetic pole together with the tip of the first magnetic pole, and the tips of the first and second magnetic poles and the magnetoresistive effect element are located on substantially the same plane. The magnetoresistive effect element is provided with a magnetic recording / reproducing head (first configuration) having a length smaller than the depth of the gap.

Further, according to the present invention, the first magnetic pole, the thin film laminated coil formed on the first magnetic pole together with the non-magnetic insulating film, and the first magnetic pole passing through the central portion of the thin film laminated coil,
Second magnetic pole magnetically coupled to the first magnetic pole, and a magnetoresistive effect element located between the first magnetic pole and the second magnetic pole, the tip of the second magnetic pole having the first magnetic pole. A gap for generating a recording magnetic field is formed in the vicinity of the first magnetic pole and the tip of the first magnetic pole, and the tips of the first and second magnetic poles and the magnetoresistive element are located on substantially the same plane. The resistance effect element has a length greater than the depth of the gap, and the second magnetic pole has a recording / reproducing head having an extension portion covering a portion of the magnetoresistance effect element located outside the gap. A second configuration) is provided.

[0012]

In the first and second configurations of the present invention, the gap between the tip of the second magnetic pole and the first magnetic pole is formed from the tips of the first and second magnetic poles. This is to increase the leakage magnetic field into the air and use this leakage magnetic field as the recording magnetic field.

In the first configuration of the present invention, since the magnetoresistive effect element is shorter than the depth of the gap, the magnetic field between the first and second magnetic poles is directly applied to the magnetoresistive effect element during recording. Even in this case, since the oblique component of the magnetic field is hardly generated, the magnetic domain structure of the magnetoresistive effect element is prevented from changing during reproduction, and the reproducing operation does not become unstable.

Further, in the second structure of the present invention, the magnetoresistive effect element is made longer than the depth of the gap, and the second magnetic pole has an extension portion covering a portion of the magnetoresistive effect element located outside the gap. Therefore, the reproduction operation is prevented from becoming unstable in the same manner as in the first configuration.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a sectional view of a conventional magnetic recording / reproducing head. This magnetic recording / reproducing head includes a first magnetic pole 2 made of a magnetic substrate, a thin film laminated coil 6 formed on the first magnetic pole 2 together with a non-magnetic insulating film 4, and a central portion of the thin film laminated coil 6. And a second magnetic pole 8 penetrating therethrough and magnetically coupled to the first magnetic pole 2.

The tip portion of the second magnetic pole 8 is close to the first magnetic pole 2 in parallel and is close to the gap 1 together with the tip portion of the first magnetic pole 2.
Forming 0. By forming the gap 10 as described above, the magnetic field is leaked into the air and the recording magnetic field RM is obtained.
Can be obtained.

A magnetoresistive effect element 12 is arranged between the tips of the first and second magnetic poles 2 and 8. The tip of the magnetoresistive effect element 12, the tips of the first and second magnetic poles 2 and 8, and the tip of the nonmagnetic insulating film 4 are located on substantially the same plane.

In the reproducing operation, the magnetoresistive effect element 1
A current is caused to flow in the direction perpendicular to the plane of FIG. 2 and the recording medium is moved in the vertical direction in the figure on a plane parallel to the plane, whereby a voltage drop in the magnetoresistive effect element 12 can be obtained as a reproduction output. it can.

In the conventional recording / reproducing head,
The length of the magnetoresistive effect element 12 in the gap depth direction is equal to the depth of the gap 10 (the first magnetic pole 2 in the second magnetic pole 8).
It is set shorter than the length of the part parallel to.

When the magnetoresistive effect element 12 is longer than the gap depth in this way, an oblique component with respect to the magnetoresistive effect element 12 is generated in the magnetic field generated between the first and second magnetic poles 2 and 8.

A phenomenon that occurs when an oblique magnetic field is applied to the magnetoresistive effect element will be described with reference to FIG. As shown in (A), when the magnetic field H is obliquely applied to the magnetoresistive effect element MRE, the domain wall MW is apt to occur in the magnetoresistive effect element MRE, and as a result, the magnetoresistive effect element MRE is reproduced by the reproducing head. When used as, the reproduction operation becomes unstable.

On the other hand, as shown in (B), when a perpendicular magnetic field H is applied to the magnetoresistive effect element MRE,
No magnetic domain wall is generated, and the magnetoresistive effect element MRE maintains a stable magnetic domain state. Therefore, when the magnetoresistive effect element MRE in which the stable magnetic domain state is maintained is used as the reproducing head, the reproducing operation does not become unstable. The present invention utilizes this phenomenon to provide a high-performance magnetic recording / reproducing head.

FIG. 3 is a sectional view of a magnetic recording / reproducing head showing a first embodiment of the present invention. Portions substantially the same as those in FIG. 1 are designated by the same reference numerals. This embodiment is characterized in that the length of the magnetoresistive effect element 12 in the gap depth direction is set shorter than the depth of the gap 10. By doing so, since a diagonal component does not occur in the magnetic field applied to the magnetoresistive effect element 12 during the recording operation, a domain wall is less likely to be generated in the magnetoresistive effect element 12, and the reproducing operation is prevented from becoming unstable. .

By the way, in order to increase the recording magnetic field during the recording operation, if the distance between the first and second magnetic poles 2 and 8 in the gap is constant, it is effective to reduce the gap depth. Is. On the other hand, in order to increase the reproduction output during the reproducing operation, it is effective to increase the length of the magnetoresistive effect element 12 in the gap depth direction.

In the first embodiment shown in FIG. 3, since the length of the magnetoresistive element 12 in the gap depth direction is limited, the increase of the recording magnetic field or the reproduction output is limited. Examples in which this limitation is eliminated will be described below.

FIG. 4 is a sectional view of a magnetic recording / reproducing head showing a second embodiment of the present invention. In this embodiment, the length of the magnetoresistive effect element 12 in the gap depth direction is set to the gap 10.
It is characterized in that it is set longer than the depth of the second magnetic pole 8 and an extension portion 14 that integrally covers the portion of the second magnetic pole 8 located outside the gap of the magnetoresistive effect element 12 is provided.

Also in this embodiment, since the magnetic field is not obliquely applied to the magnetoresistive effect element 12 during the recording operation, it is possible to prevent the reproducing operation from becoming unstable.
Further, since the gap depth can be reduced, the recording magnetic field can be set large when the current flowing through the coil 6 is constant. Furthermore, since the length of the magnetoresistive effect element 12 in the gap depth direction can be set long, a large reproduction output can be obtained.

[0028]

As described above, according to the present invention,
As a result, it is possible to provide an in-gap type magnetic recording / reproducing head in which the reproducing operation is not unstable.

[Brief description of drawings]

FIG. 1 is a sectional view of a conventional magnetic recording / reproducing head.

FIG. 2 is an explanatory diagram of generation of domain walls.

FIG. 3 is a cross-sectional view of a magnetic recording / reproducing head showing a first embodiment of the present invention.

FIG. 4 is a sectional view of a magnetic recording / reproducing head showing a second embodiment of the present invention.

[Explanation of symbols]

 2 1st magnetic pole 4 Nonmagnetic insulating film 6 Laminated coil 8 2nd magnetic pole 10 Gap 12 Magnetoresistive element

Claims (2)

[Claims] 1. A first magnetic pole (2), a thin-film laminated coil (6) formed on the first magnetic pole (2) together with a non-magnetic insulating film (4), and the thin-film laminated coil (6). The first magnetic pole passing through the center of the
A second magnetic pole (8) magnetically coupled to (2), and a magnetoresistive effect element (12) located between the first magnetic pole (2) and the second magnetic pole (8), The tip of the second magnetic pole (8) is close to the first magnetic pole (2) and forms a gap (10) for generating a recording magnetic field together with the tip of the first magnetic pole (2). The first and second magnetic poles (2, 8) and the tips of the magnetoresistive effect element (12) are located on substantially the same plane, and the magnetoresistive effect element (12) is smaller than the depth of the gap (10). Magnetic recording / playback head with length. 2. A first magnetic pole (2), a thin film laminated coil (6) formed on the first magnetic pole (2) together with a non-magnetic insulating film (4), and the thin film laminated coil (6). The first magnetic pole passing through the center of the
A second magnetic pole (8) magnetically coupled to (2), and a magnetoresistive effect element (12) located between the first magnetic pole (2) and the second magnetic pole (8), The tip of the second magnetic pole (8) is close to the first magnetic pole (2) and forms a gap (10) for generating a recording magnetic field together with the tip of the first magnetic pole (2). The first and second magnetic poles (2, 8) and the tip of the magnetoresistive effect element (12) are located on substantially the same plane, and the magnetoresistive effect element (12) is larger than the depth of the gap (10). A read / write head having a length and the second magnetic pole (8) having an extension (14) covering a portion of the magnetoresistive effect element (12) located outside the gap (10). .