JPH05266435A - Thin film magnetic head - Google Patents

Abstract

PURPOSE:To provide a thin film magnetic head with a simple structure which does not generate degradation of characteristics of an MR element due to metallic diffusion. CONSTITUTION:The head has a slider 1 and a read magnetic conversion element 2. The read magnetic conversion element 2 contains a first magnetic shield film 21, a second magnetic shield film 22 and a magnetoresistance effect element 23, and arranged by being placed opposite each other via a space and also constitute an electric circuit by being mutually connected electrically. The magnetoresistance effect element 23 is arranged between the first magnetic shield film 21 and the second magnetic shield film 22 and the magnetic field generated by an electric current flowing through an electric circuit which is made by both 21, 22 is impressed as a bias magnetic field Hb.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin film magnetic head, and more particularly to improvement of a thin film magnetic head using a magnetoresistive effect element (hereinafter referred to as MR element) as a read element.

[0002]

2. Description of the Related Art Conventionally, as a thin film magnetic head, a thin film magnetic head using an inductive thin film magnetic conversion element as a read / write element is best known. In a thin film magnetic head using an inductive thin film magnetic conversion element, it is necessary to increase the relative speed between the magnetic disk and the magnetic head or increase the number of coil turns in order to obtain a high read output. However, since the magnetic disk tends to be miniaturized, the increase in read output due to the increase in relative speed is not suitable for the actual situation. In addition, the read output due to the increase in the number of turns of the coil increases the inductance and the DC resistance of the coil, deteriorates the high frequency characteristics, and cannot be adapted to high speed reading. As a means for solving such a problem, a technique has been proposed in which the read element is composed of an MR element and the inductive type thin film magnetic conversion element is used only for writing. As a known technical document, for example, Japanese Patent Publication No. 5
9-35088 and Japanese Patent Publication No. 64-1846.

The read magnetic conversion element known in these publicly known documents includes a conductor film, an MR element, and a magnetic shield film. Two conductor films are provided, arranged side by side with an interval between each other, one end side being located on the medium facing surface side of the slider, and the other end side being guided rearward. The MR element is connected between the conductor films on one end side of the conductor films. The magnetic shield film includes a first magnetic shield film and a second magnetic shield film, which are arranged so as to sandwich the conductor film and the MR element from both sides in the vertical direction with a nonmagnetic electrically insulating film interposed therebetween. ..

A bias magnetic field is applied to the MR element in order to pass a sense current through the conductor film and to obtain a detection signal having a good linearity with respect to the input magnetic field. As a means for generating a bias magnetic field, a bias conductor film is directly formed on the MR element, and a shunt bias method in which a bias is applied by using a magnetic field generated by a current flowing through the bias conductor film, a thin film permanent magnet close to the MR element. A magnet bias method and the like in which a magnetic field generated by a thin film permanent magnet is used are known, and the shunt bias method is predominant.

In the read operation, M is passed through the conductor film.
A sense current is passed through the R element, and a change in the magnetic field of the magnetic disk is detected as a change in the electrical resistance value of the MR element. The magnetic shield film blocks the influence of the external magnetic field, particularly the influence of the magnetic field generated from the other magnetization reversal transition region, on the MR element during the read operation.

[0006]

However, when the shunt bias method is adopted, a bias conductor film having a minute thickness of about 0.1 to 0.2 μm is laminated on a magnetoresistive effect film such as permalloy constituting an MR element. Must be established. Therefore, the structure of the MR element portion becomes complicated.

Further, metal diffusion occurs between the bias conductor film and the MR element film, which causes problems such as deterioration of the characteristics of the MR element.

Therefore, an object of the present invention is to solve the above-mentioned problems, and to provide a thin film magnetic head having a simple structure and free from characteristic deterioration due to metal diffusion.

[0009]

To solve the above problems, the present invention is a thin film magnetic head having a slider and a read magnetic conversion element, wherein the read magnetic conversion element is a first magnetic element. A shield film, a second magnetic shield film, and an MR element are provided on the slider, and the first magnetic shield film and the second magnetic shield film are opposed to each other with a space therebetween. And the MR element is arranged between the first magnetic shield film and the second magnetic shield film to form an electric circuit. The magnetic field generated by the current flowing in the is applied as a bias magnetic field.

[0010]

The first magnetic shield film and the second magnetic shield film are arranged so as to face each other with a space therebetween, and the MR element is provided between the first magnetic shield film and the second magnetic shield film. Since the MR element is arranged, it is possible to block the MR element from being influenced by an external magnetic field, particularly, a magnetic field generated from another magnetization reversal transition region during the read operation.

The first magnetic shield film and the second magnetic shield film are electrically coupled to form an electric circuit.
In the MR element, the magnetic field generated by the current flowing in the electric circuit formed by the first and second magnetic shield films is applied as the bias magnetic field, so that the first magnetic shield film and the second magnetic shield film are used.
The magnetic shield film can also be used as a bias magnetic field generating means. The bias conductor film, which is essential in the conventional shut bias method, is unnecessary. Therefore, the structure is simplified and the characteristics of the MR element are not deteriorated due to metal diffusion.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a perspective view showing a model of a read magnetic conversion element constituting a thin film magnetic head according to the present invention, and FIG. 2 is a sectional view of the same. Reference numeral 1 is a slider, and 2 is a read magnetic conversion element. The slider 1 is made of a known ceramic structure, and the medium facing surface side is an air bearing surface 11 having a high degree of flatness. a indicates the traveling direction of the medium.

The read magnetic conversion element 2 includes a first magnetic shield film 21, a second magnetic shield film 22, and an MR.
The element 23 is included and is provided on the slider 1.
First magnetic shield film 21 and second magnetic shield film 2
2 are arranged to face each other with a space d therebetween and are electrically coupled to each other to form an electric circuit. Reference numeral 24 is a conductor film that electrically connects one ends of the first magnetic shield film 21 and the second magnetic shield film 22. The conductor film 24 is formed of, for example, a nonmagnetic metal film made of Au or the like. First
The other end of the magnetic shield film 21 is located on the side opposite to the direction in which the conductor film 24 is present, and is connected to the bias power source V via the current limiting resistor R.
Is grounded at the other end. This constitutes a bias circuit.

The MR element 23 includes the first magnetic shield film 2
The first magnetic shield film 22 and the first magnetic shield film 22.
The magnetic field generated by the current Ib flowing through the electric circuit formed by the magnetic shield film 21 and the second magnetic shield film 22 is applied as the bias magnetic field Hb. MR element 23
Is a thin film using a ferromagnetic thin film material such as Ni-Fe or Ni-Co, and is arranged between the conductor films 25-26. The conductor films 25 and 26 are arranged side by side substantially parallel to each other with a space therebetween, and the space located on the air bearing surface 11 side defines the track width.

In the read operation, the conductor films 21 and 22
Through the MR element 23, and at the same time, the bias current Ib is caused to flow in the electric circuit constituted by the first magnetic shield film 21, the second magnetic shield film 22 and the conductor film 24 to generate the bias magnetic field Hb. , The bias magnetic field Hb is applied to the MR element 23. Then, the change in the magnetic field of the magnetic disk (not shown) is reflected by the MR element 23.
It is detected as a change in the electric resistance value of.

Here, the first magnetic shield film 21 and the second magnetic shield film 22 are arranged so as to face each other with a space d therebetween, and the MR element 23 has the first magnetic shield film 2
Since the MR element 23 is arranged between the first magnetic shield film 22 and the second magnetic shield film 22, the MR element 23 is affected by an external magnetic field, particularly, a magnetic field generated from another magnetization reversal transition region during the read operation. Can be shut off.

Further, the first magnetic shield film 21 and the second magnetic shield film 21
Of the first magnetic shield film 2 and the MR element 23 are electrically coupled to each other to form an electric circuit.
The magnetic field generated by the current Ib flowing through the electric circuit formed by the first and second magnetic shield films 22 is the bias magnetic field H.
Since it is applied as b, the first magnetic shield film 21 and the second magnetic shield film 22 can also be used as the bias magnetic field generating means. The bias conductor film, which is essential in the conventional shut bias method, is unnecessary. Therefore, the structure is simplified and the characteristics of the MR element 23 are not deteriorated due to metal diffusion.

FIG. 3 is a sectional view showing a specific structural example of the thin film magnetic head according to the present invention. In the figure, the same reference numerals as those in FIGS. 1 and 2 denote the same components. Reference numeral 3 is a magnetic conversion element for writing.

The slider 1 has an electric insulating film 12 made of alumina or the like on a base portion 10 which is a ceramic structure. The read magnetic conversion element 2 is the MR element 23.
Are embedded inside the electric insulating film 12 in layers. The second magnetic shield film 22 is provided between the base portion 10 of the slider 1 and the insulating film 12, and is made of a magnetic film such as permalloy. The first magnetic shield film 21 also serves as the lower magnetic film 31 of the write magnetic conversion element 3 as described later.

The writing element 33 has a lower magnetic film 31, an upper magnetic film 32, a coil film 33, a gap film 34 made of alumina or the like, an insulating film 35 made of an organic resin such as novolac resin, and a protective film 36. Then, it is laminated on the insulating film 12. Lower magnetic film 31 and upper magnetic film 32
Of the pole portions P1 and P2 facing each other across the gap film 34 having a very small thickness.
Write in. The yoke portions of the lower magnetic film 31 and the upper magnetic film 32 are connected to each other so as to complete a magnetic circuit in the back gap portion on the side opposite to the pole portions P1 and P2. On the insulating film 35,
The coil film 33 is formed so as to spirally surround the coupling portion of the yoke portion. Although the drawing shows the in-plane recording / reproducing magnetic head, it may be a perpendicular magnetic recording / reproducing magnetic head or the like.

The lower magnetic film 31 is also used as the first magnetic shield film 21 of the read magnetic conversion element 2.

[0022]

As described above, the present invention is a thin film magnetic head having a slider and a read magnetic conversion element, wherein the read magnetic conversion element includes a first magnetic shield film and a second magnetic shield film. Magnetic shield film and an MR element are provided on the slider, and the first magnetic shield film and the second magnetic shield film are arranged facing each other with a space therebetween and are electrically coupled together. The MR element is arranged between the first magnetic shield film and the second magnetic shield film, and the MR element is arranged between the first magnetic shield film and the second magnetic shield film.
Since the magnetic field generated by the current flowing in the electric circuit constituted by the magnetic shield film is applied as the bias magnetic field, the first magnetic shield film and the second magnetic shield film are also used as the bias magnetic field generating means, and the conventional shut-off device is used. The bias conductor film, which was essential in the bias method, can be omitted,
It is possible to provide a thin film magnetic head which has a simple structure and does not cause deterioration of the characteristics of the MR element due to metal diffusion.

[Brief description of drawings]

FIG. 1 is a modeled perspective view showing a read magnetic conversion element portion constituting a thin-film magnetic head according to the present invention.

FIG. 2 is a cross-sectional view showing a model of a magnetic conversion element for reading which constitutes a thin film magnetic head according to the present invention.

FIG. 3 is a sectional view showing a specific example of a thin film magnetic head according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 slider 2 magnetic read element for reading 21 first magnetic shield film 22 second magnetic shield film 23 MR element 24, 25 magnetic shield film 3 magnetic read element for writing

Claims (1)

[Claims] 1. A thin-film magnetic head having a slider and a read magnetic conversion element, wherein the read magnetic conversion element includes a first magnetic shield film, a second magnetic shield film, and a magnetoresistive effect. An element and is provided on the slider, and the first magnetic shield film and the second magnetic shield film are arranged to face each other with a space therebetween, and are electrically coupled to each other. An electric circuit is configured, and the magnetoresistive effect element is disposed between the first magnetic shield film and the second magnetic shield film, and a magnetic field generated by a current flowing in the electric circuit serves as a bias magnetic field. Applied thin film magnetic head.