JPH0528436A - Magneto-resistance effect type head - Google Patents

Abstract

PURPOSE:To obtain stable reproduced output by forming a magneto-resistance effect element to a prescribed rectangular shape and exactly forming the width in the direction orthogonal with the current direction thereof to a design value. CONSTITUTION:The magneto-resistance effect element 1 and a bias layer 3 of a ferromagnetic material are laminated via a nonmagnetic metallic layer 2 held therebetween and a sensor current J is passed thereto through a conductor layer 4. A bias magnetic field is impressed to the effect element 1 by the magnetic field formed in the bias layer 3 by this current J. The effect element 1 is formed to the prescribed rectangular shape and the bias layer 3 is formed to project to the side of the surface facing a magnetic recording medium from the width h of the direction orthogonal with the current direction of the effect element 1. The bias layer 3 having the projecting part 3a exposed to the surface facing the magnetic recording medium is formed as the path for propagation of the signal magnetic fields from the magnetic recording medium.

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 used in a magnetic disk device or a magnetic tape device, and more particularly to a magnetoresistive head.

[0002]

2. Description of the Related Art In recent years, with the miniaturization and increase in capacity of magnetic disk devices, which are external storage devices of computer systems, there has been a demand for higher performance of thin-film magnetic heads used in magnetic disk devices. In order to satisfy this demand, attention has been paid to a magnetoresistive head which can obtain a high output without depending on the rotation speed of a magnetic disk.

FIG. 5 is an enlarged perspective view of a main portion of a conventional magnetoresistive head, and FIG. 6 is a side sectional view thereof.
8 is a rectangular magnetoresistive element made of a ferromagnetic material such as nickel iron (NiFe), 9 is a non-magnetic metal layer made of titanium (Ti), tungsten (W), molybdenum (Mo) or the like, and 10 is cobalt ( Co) type amorphous magnetic film or nickel / iron / rhodium (NiFeRh) magnetic film or iron nitride film (FeN)
Is a bias layer made of a ferromagnetic film, and these are sequentially laminated by a vacuum evaporation technique such as sputtering, and end portions thereof are formed on the surface 14 facing the magnetic disk.

The nonmagnetic metal layer 9 serves as a spacer provided between the magnetoresistive effect element 8 and the bias layer 10 in order to avoid magnetic exchange coupling. Reference numeral 11 is a lead conductor layer made of a gold (Au) film, 12 is a non-magnetic insulating layer, and 13a and 13b are magnetic shield layers made of a ferromagnetic material such as nickel iron (NiFe).

Magnetoresistive element 8 and bias layer 10
Is formed in a rectangular shape so that the easy axis of magnetization coincides with its longitudinal direction (y-axis direction). The lead conductor layer 11 is
The magnetoresistive effect element 8 is cut with a predetermined width (corresponding to the track width of the magnetic disk) in the longitudinal direction and joined to both ends of the magnetoresistive effect element 8.

The magnetoresistive effect element 8, the non-magnetic metal layer 9, the bias layer 10, and the lead conductor layer 11 are arranged between the two magnetic shield layers 13a and 13b (corresponding to a reproducing gap), but are non-magnetic. It is electrically insulated from the magnetic shield layers 13 a and 13 b via the insulating layer 12. These are sequentially laminated, for example, from the magnetic shield layer 13a side, and further, as shown in FIG. 6, the surface 14 facing the magnetic disk is formed by lapping from the dimension shown by the dotted line so that the current direction of the magnetoresistive element 8 is The magnetoresistive head is formed by processing so that the width (height) h in the orthogonal direction becomes a predetermined value.

As shown in FIG. 5, the sense current j flows to the magnetoresistive effect element 8, the nonmagnetic metal layer 9 and the bias layer 10 through the lead conductor layer 11, and the lead conductor layer 1
It flows into the signal detection region 8a of the rectangular magnetoresistive effect element 8 defined by 1. Further, the magnetic resistance is generated by two magnetic fields, that is, a magnetic field generated by a current flowing through the nonmagnetic metal layer 9 and a leakage magnetic field from the bias layer 10 magnetized by the magnetic field generated by the current flowing through the magnetoresistive element 8 and the nonmagnetic metal layer 9. The effect element 8 receives a bias magnetic field. As a result, the magnetoresistive head operates linearly with respect to the signal magnetic field from the magnetic disk directly under the head, converts it into a resistance change of the signal detection area 8a, and records it on the magnetic disk in the form of residual magnetization. Read the information.

[0008]

In such a conventional magnetoresistive head, the magnetoresistive element 8 is used.
The width (height) h in the direction orthogonal to the current direction is defined by lapping.
Although the value is as small as 5 μm, the lapping accuracy has a processing error of about ± 1 μm, and this error has a great influence in defining the width h of the magnetoresistive effect element 8. It was difficult to obtain the desired value. Therefore, the variation in the processing of the width h of the magnetoresistive effect element 8 causes the variation in the resistance value of the magnetoresistive effect element 8,
This causes a problem that the reproduction output varies greatly among the magnetoresistive heads.

According to the present invention, the lapping processing error of the surface of the magnetoresistive head facing the magnetic disk affects the prescribed width (height) h of the magnetoresistive element in the direction orthogonal to the current direction. It is an object of the present invention to provide a magnetoresistive effect type head capable of forming an accurate set width without variation of the resistance value of the magnetoresistive effect element.

[0010]

In order to solve the above-mentioned problems, the present invention comprises a magnetoresistive element 1 and a ferromagnetic material with a non-magnetic metal layer 2 sandwiched therebetween, as shown in FIG. 1 (a). A bias layer 3 is laminated, and a sense current J is flown through the conductor layer 4, and the sense current J causes the bias layer 3 to pass through.
In the magnetoresistive head in which a bias magnetic field is applied to the magnetoresistive effect element 1 by the magnetic field formed by the magnetoresistive effect element 1, the magnetoresistive effect element 1 is formed in a predetermined rectangular shape, and the bias layer 3 is formed.
Of the magnetoresistive effect element 1 is formed so as to protrude toward the surface facing the magnetic recording medium more than the width h in the direction orthogonal to the current direction, and the protruding portion 3 exposed on the surface facing the magnetic recording medium.
A bias layer 3 having a is formed as a propagation path of a signal magnetic field from a magnetic recording medium to provide a magnetoresistive head.

Further, as shown in FIG. 1B, the bias layer formed so as to protrude toward the surface facing the magnetic recording medium beyond the width h of the magnetoresistive effect element 1 in the direction orthogonal to the current direction. 3 is a magnetoresistive head in which only the portion of the protruding portion 3a of the magnetoresistive effect element 3 is close to the signal detection region 1a of the magnetoresistive effect element 1.

[0012]

According to the present invention, the magnetoresistive effect element 1 is formed into a predetermined rectangle by the photolithography technique, and
The width h in the direction orthogonal to the current direction is accurately formed to a design value, the bias layer 3 is formed so as to project toward the surface facing the magnetic recording medium, and the protruding facing surface is lapped to form the bias. Since the layer 3 is used as the propagation path of the signal magnetic field from the magnetic recording medium, the magnetoresistive effect element 1 itself is not lapped, and the magnetoresistive effect element 1 does not have a direction perpendicular to the current direction accurately defined by the photolithography technique. Since the width can be maintained, there is no variation in the resistance value of the magnetoresistive effect element 1, and there is no problem that the reproduction output varies greatly among the magnetoresistive effect heads.

[0013]

FIG. 2 is a perspective view showing the outline of an embodiment of the present invention, and FIG. 3 is a side sectional view of the main part thereof. In these figures, reference numeral 1 denotes a rectangular magnetoresistive element made of a ferromagnetic material such as nickel iron (NiFe), which is accurately formed in a rectangular shape by photolithography and has a width h in a direction orthogonal to the current direction. Accurately formed to the design value. 2 is titanium (Ti), tungsten (W), or molybdenum (Mo)
A non-magnetic metal layer 3 made of, for example, a cobalt (Co) -based amorphous magnetic film, or a bias layer made of a nickel, iron, rhodium (NiFeRh) magnetic film, or a ferromagnetic film such as an iron nitride film (FeN). The bias layer 3 is made larger than the width h of the magnetoresistive effect element 1 in the direction orthogonal to the current direction, and protrudes toward the surface facing the magnetic disk.

The magnetoresistive effect element 1, the non-magnetic metal layer 2 and the bias layer 3 have a laminated structure, and the non-magnetic metal layer 2 prevents the magnetoresistive effect element 1 and the bias layer 3 from magnetic exchange coupling. It acts as a spacer provided. 4 is gold
(Au) lead conductor layer, 5 is a non-magnetic insulating layer, 6
Reference numerals a and 6b are magnetic shield layers made of a ferromagnetic film such as NiFe.

Magnetoresistive element 1 and bias layer 3
Is formed in a rectangular shape so that the easy axis of magnetization coincides with its longitudinal direction (y-axis direction). The width h of the magnetoresistive effect element 1 in the direction orthogonal to the current direction is set to a desired designed value, but the width of the bias layer 3 is larger than the width h. The lead conductor layer 4 is the magnetoresistive effect element 1.
Is cut to a predetermined width in the longitudinal direction and is joined to both ends of the magnetoresistive effect element 1.

The magnetoresistive effect element 1, the nonmagnetic metal layer 2, the bias layer 3, and the lead conductor layer 4 are arranged between the two magnetic shield layers 6a and 6b (corresponding to the reproducing gap), but are nonmagnetic. Magnetic shield layer 6 through insulating layer 5
It is electrically insulated from a and 6b. These are sequentially laminated, for example, from the magnetic shield layer 6a side, and further, as shown in FIG. 3, the surface 7 facing the magnetic disk is lapped so that only the protruding portion 3a of the bias layer 3 is exposed, and the magnetic disk is formed. Bias layer 3 exposed on the surface opposite to
Forms a propagation path for a signal magnetic field from the magnetic disk to form a magnetoresistive head.

As shown in FIG. 2, the sense current j flows to the magnetoresistive effect element 1, the nonmagnetic metal layer 2 and the bias layer 3 through the lead conductor layer 4, and has a rectangular magnetoresistance defined by the lead conductor layer 4. Signal detection area 1 of effect element 1
flow to a. In addition, the magnetic field generated by the current flowing through the non-magnetic metal layer 2 and the magnetic field generated by the current flowing through the magnetoresistive element 1 and the non-magnetic metal layer 2 leaks from the bias layer 3 magnetized by two magnetic fields. The resistance effect element 1 receives a bias magnetic field. As a result, the magnetoresistive head operates linearly with respect to the signal magnetic field from the magnetic disk directly below the head, converts the resistance change of the signal detection area 1a into the information recorded in the magnetic disk in the form of residual magnetization. Read.

FIG. 4 is a perspective view showing the outline of another embodiment of the present invention, in which the magnetoresistive effect element 1 is projected toward the surface facing the magnetic disk more than the width h in the direction orthogonal to the current direction. The protruding portion 3a of the bias layer 3 formed as described above is formed only in the portion close to the signal detection region 1a of the magnetoresistive effect element 1, and the portion facing the other magnetic disk is retracted. In this case, there is an advantage of reducing side crosstalk from the recording track adjacent to the signal detection area 1a of the magnetoresistive effect element 1 of the magnetic disk. The magnetoresistive head of the present invention can also be applied to a magnetic tape.

[0019]

According to the magnetoresistive head of the present invention, the magnetoresistive element is formed into a predetermined rectangle by, for example, the photolithography technique, and the width in the direction orthogonal to the current direction is accurately formed to the designed value. Then, the bias layer is formed so as to project toward the surface facing the magnetic recording medium, and the protruding facing surface side is lapped so that the bias layer serves as the propagation path of the signal magnetic field from the magnetic recording medium. Since the magnetoresistive effect element itself can maintain the width in the direction orthogonal to the current direction accurately defined by the photolithography technology without being subjected to lapping processing, there is no variation in the resistance value of the magnetoresistive effect element. The problem that a large variation occurs in the reproduction output for each magnetoresistive head is eliminated, and a stable reproduction output can be obtained.

[Brief description of drawings]

FIG. 1 is a perspective view showing an outline of a magnetoresistive head of the present invention.

FIG. 2 is a perspective view schematically showing an embodiment of a magnetoresistive head of the present invention.

FIG. 3 is a side sectional view of a main part of the magnetoresistive head of the present invention.

FIG. 4 is a perspective view showing the outline of another embodiment of the magnetoresistive head of the present invention.

FIG. 5 is a perspective view showing an outline of a conventional magnetoresistive head.

FIG. 6 is a side sectional view of a main part of a conventional magnetoresistive head.

[Explanation of symbols]

1 Magnetoresistive element 1a Signal detection area 2 Non-magnetic metal layer 3 Bias layer 3a protrusion 4 Lead conductor layer 5 Non-magnetic insulating layer 6a, 6b Magnetic shield layer 7 Face to face magnetic disk 8 Magnetoresistive effect element 8a Signal detection area 9 Non-magnetic metal layer 10 Bias layer 11 Lead conductor layer 12 Non-magnetic insulating layer 13a, 13b Magnetic shield layer 14 Magnetic disk facing surface

Claims (2)

[Claims] 1. A magnetoresistive element (1) and a bias layer (3) made of a ferromagnetic material are laminated with a non-magnetic metal layer (2) sandwiched therebetween, and a sense current J is passed through the conductor layer (4). ,
In the magnetoresistive head in which a bias magnetic field is applied to the magnetoresistive effect element (1) by the magnetic field formed by the bias layer (3) by the sense current J, the magnetoresistive effect element (1) is formed into a predetermined rectangular shape. The bias layer (3) is formed so as to protrude toward the surface facing the magnetic recording medium more than the width h of the magnetoresistive effect element (1) in the direction orthogonal to the current direction. 2. A magnetoresistive head having a bias layer (3) having a protrusion (3a) exposed on the opposite surface thereof is formed as a propagation path of a signal magnetic field from a magnetic recording medium. 2. A protruding portion (3) of the bias layer (3) which is formed so as to protrude toward a surface facing a magnetic recording medium more than a width h of the magnetoresistive effect element (1) in a direction orthogonal to a current direction.
a) is the signal detection area (1) of the magnetoresistive effect element (1)
The magnetoresistive head according to claim 1, wherein only a portion close to (a) is provided.