JPH0554339A - Composite magnetic head - Google Patents

Abstract

PURPOSE:To satisfy the reproduction output characteristic, frequency characteristic, and overwriting characteristic simultaneously. CONSTITUTION:First and second thin-film magnetic cores 1 and 2 constituting a recording magnetic gap in front of a face with a magnetic recording medium between front terminal parts are laminated. An MR magnetic sensing part 5 is arranged backward from the face in the magnetic gap and a head winding is arranged in the rear of it. In this composite magnetic head, DMR<Dind<=DR +3mum is satisfied when taking the depth of the recording magnetic gap as Dind and the depth of the reproduction magnetic gap as DMR.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite magnetic head suitable for recording / reproducing on / from a hard disk, for example.

[0002]

2. Description of the Related Art For example, a recording / reproducing head of a hard disk drive device comprises a recording head of an inductive head and a reproducing head of a magnetoresistive head (hereinafter referred to as an MR head) having excellent short wavelength sensitivity. It is generally a composite type. Such a composite type magnetic head is provided with, for example, an Al ₂ O ₃ —TiC called slider.
First, a recording magnetic gap is formed between a front end portion of a base made of, for example, facing a hard disk, that is, an ABS (air bearing surface) surface.
The thin film magnetic core and the second thin film magnetic core are laminated at a predetermined interval. Further, one end of the magnetoresistive effect sensing portion (hereinafter referred to as MR sensing portion) formed of at least the magnetoresistive effect thin film (hereinafter referred to as MR thin film) or one tip pole thereof in the magnetic gap is the ABS. Arranged to face the surface.

On the opposite side of the ABS surface, the M
The other electrode of the R magnetic sensing section is provided substantially parallel to the one electrode. Then, by energizing the MR magnetic sensitive portion, a magnetized state in a desired direction is given to the substantially central portion of the MR magnetic sensitive portion, and the linearity and high sensitivity with excellent magnetoresistance effect characteristics are provided. A bias conductor configured to operate in the characteristic region indicated by is provided so as to cross the MR magnetic sensing part via an insulating layer. Further, a spiral head winding is provided so as to surround a magnetic coupling portion which is a connection portion of the thin film magnetic core.

The composite type magnetic head formed in this way is a so-called shield type MR head in which the first thin film magnetic core and the second thin film magnetic core are magnetic shields.
The composite type head structure has an inductive head in which a head winding is wound on a magnetic path formed by the first thin film magnetic core and the second thin film magnetic core. Recording in this composite type magnetic head is performed by supplying a current from an AC power supply to a terminal portion drawn out from the head winding, and generating a magnetic flux based on the recording information from a magnetic gap g facing the ABS surface. On the other hand, for reproduction, a current is supplied from the DC power supply to the terminal portions of the front electrode and the rear electrode, which are laminated on the front and rear ends of the MR magnetic sensing portion, and a sense current is passed to the MR magnetic sensitive portion. A direct current is applied to the terminal portion of the bias conductor to give a magnetized state to the MR magnetic sensing section.

[0005]

In the composite magnetic head described above, the depth of the MR head is larger than that of the MR head. Therefore, the depth of the head is formed on the basis of the depth of the MR head. Therefore, when the depth of the inductive head is smaller than the depth of the MR head, the depth of the inductive head may become zero or less during depth processing. As a result, the facing distance between the front end portions of the first thin film magnetic core and the second thin film magnetic core forming the magnetic gap increases, and the recording efficiency decreases. On the other hand, if the depth of the inductive head is much larger than the depth of the MR head, the overwrite characteristic will be deteriorated this time.

As described above, in the composite type magnetic head, it is desirable to define the depths of the magnetic gaps of the MR head and the inductive head to the optimum values from the viewpoints of recording characteristics and reproducing characteristics.

Therefore, the present invention has been proposed in view of the above technical problems, and it is an object of the present invention to provide a composite magnetic head capable of simultaneously satisfying a reproduction output characteristic, a frequency characteristic, and an overwrite characteristic. To aim.

[0008]

In order to achieve the above-mentioned object, the present invention provides a first thin-film magnetic film that forms a recording magnetic gap between the front ends facing the surface facing the magnetic recording medium. A composite type in which a core and a second thin-film magnetic core are laminated, a magnetoresistive effect magnetic sensitive portion is arranged rearward from the contact surface in the magnetic gap, and a head winding is arranged rearward thereof. In the magnetic head, when the depth of the recording magnetic gap is D _Ind and the depth of the reproducing magnetic gap is D _MR , D _MR <D _Ind ≦ D _MR +3 μm.

[0009]

In the composite magnetic head according to the present invention, since the depth of the recording magnetic gap of the inductive head is made larger than at least the depth of the reproducing magnetic gap of the MR head, the recording efficiency is not lowered.
Further, since the depth of the inductive head is made larger than the depth of the MR head to the extent that the overwrite characteristic is not deteriorated, the facing portions of the thin film magnetic cores facing each other become longer, and the frequency characteristic is improved.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments to which the present invention is applied will be described in detail below with reference to the drawings. Note that this embodiment is an example of a composite magnetic head in which a required bias magnetic field is applied to the MR magnetic sensing section by applying a direct current to the head winding during reproduction. In the composite magnetic head of the present embodiment, as shown in FIG. 1, the first thin film magnetic core 1 forming the recording magnetic gap g between the front end portions thereof.
And the second thin film magnetic core 2 is laminated on the base body 3 called a slider made of Al ₂ O ₃ —TiC or the like so as to face each other with a predetermined gap.

The first thin-film magnetic core 1 is provided directly on the substrate 3, and one end of the first thin-film magnetic core 1 is made to face an ABS surface 4 which is a contact surface with a magnetic recording medium such as a hard disk. Is provided so as to extend in a direction substantially orthogonal to. On the other hand, the second thin-film magnetic core 2 has its one end facing the ABS surface 4
The first thin film magnetic core 1 is provided so as to extend in a direction substantially orthogonal to the surface 4 and has a front end portion facing the ABS surface 4.
It is bent and formed so that the gap between and is narrowed. A magnetic gap g, which functions as a recording gap, faces the ABS surface 4 between the front end portions where the gap is narrowed. Further, the second thin film magnetic core 2 magnetically contacts the first thin film magnetic core 1 at the rear end to form a back gap and a closed magnetic path.

In this magnetic head, an MR magnetic sensitive portion 5 which is a magnetoresistive magnetic sensitive portion is provided rearward from the ABS 4 in the magnetic gap. MR
The magnetically sensitive portion 5 is formed, for example, as a rectangular pattern slightly narrower than the track width of the recording magnetic gap g, and is provided such that its longitudinal direction is orthogonal to the ABS surface 4. The MR magnetic sensing part 5 is arranged such that one end thereof faces the ABS surface 4 and the rear end edges of the MR thin film magnetic core 1 and the second thin film magnetic core 2 are substantially in the middle. It is said to be the position leading to. The MR
The magnetically sensitive portion 5 is provided on the first thin film magnetic core 1 through the first insulating layer 6a in order to insulate the first thin film magnetic core 1 provided on the base body 3 from each other. There is. Further, the MR magnetic sensing section 5 has a form in which a pair of MR thin films which are magnetostatically coupled via a non-magnetic insulating layer made of, for example, SiO ₂ are laminated in order to avoid the occurrence of Barkhausen noise. It is desirable to do.

A pair of electrodes 7a and 7b (hereinafter, referred to as ABS surface 4 side) for passing a sense current from a constant current source (not shown) are provided at the front end and the rear end of the MR magnetic sensing unit 5. The electrode 7a is referred to as a front end electrode 7a, and the electrode 7b provided at the rear end portion is referred to as a rear end electrode 7b).

The tip electrode 7a is formed, for example, as a wiring pattern having a substantially L shape in a plan view, and one end of the tip electrode 7a is laminated on the tip of the MR magnetic sensing section 5 and on the MR magnetic sensing section 5. One side edge of the pattern on the laminated side is the above A
It is exposed on the BS surface 4. In addition, the end of the wiring pattern drawn to the back side is a ground side terminal.

On the other hand, the rear end electrode 7b is the front end electrode 7a.
Similar to the above, it is formed as a substantially L-shaped wiring pattern in a plane, and is provided on the side opposite to the tip electrode 7a with the MR magnetic sensing part 5 interposed therebetween. The rear end electrode 7b is laminated on the rear end of the MR magnetic sensing part 5, and the end of the wiring pattern drawn to the back side serves as a terminal part on the current source side.

A spiral head is formed behind the rear electrode 7b so as to surround a magnetic coupling portion 8 which is a connection portion between the first thin film magnetic core 1 and the second thin film magnetic core 2. A winding 9 is provided. Head winding 9
Serves to supply a current according to the recording information to the magnetic path formed by the first thin film magnetic core 1 and the second thin film magnetic core 2 at the time of recording, and at the time of reproduction, has a desired direction to the MR magnetic sensing section 5. It functions as a bias conductor that gives the magnetization state of. This head winding 9 is connected to the electrode 7
a, 7b, MR magnetic sensing section 5, and second thin film magnetic core 2
The second insulating layer 6b and the third insulating layer 6b
Embedded by the insulating layer 6c. The ends of the wiring pattern drawn out from both ends of the head winding 9 serve as terminals for passing a current from the DC power supply or the AC power supply supplied to the head winding 9. In order to protect the composite magnetic head composed of the inductive head and the MR head configured as described above,
The protective film layer 10 is laminated on the thin film magnetic core 2 of FIG.

In the composite magnetic head constructed as described above, the head winding 9 is used in place of the bias conductor, and a DC current is supplied to the head winding 9 to generate M.
Since the R magnetic field sensing portion 5 is configured to give a magnetized state in a desired direction, the number of terminals can be reduced and the layout area can be reduced to reduce the size of the head because the bias conductor is not needed. I can hope. Therefore, it is suitable for a magnetic head for a hard disk that is required to be downsized and have a large recording capacity.

In the composite magnetic head described above, the reproduction output Vp-p of the MR head depends on the depth of the MR head as shown in FIG. 3, and the output increases as the depth becomes smaller. ing. On the other hand, in the inductive head, when the depth becomes small as shown in FIG. 4, the tip portion of the second thin film magnetic core 2 is easily magnetically saturated, and the frequency characteristic D ₈₀ (the first reproduction output is 1
When it is set to 00%, it means the frequency at which the output becomes 80%. ) Is deteriorated. Further, in the inductive head, as shown in FIG. 5, the overwrite characteristic deteriorates as the depth increases.

From the above, in the present embodiment, the MR
In order to satisfy the reproduction output of the head and the frequency characteristic and the overwrite characteristic of the inductive head at the same time,
Depth D of magnetic gap for recording of inductive head
The depth D _MR of the reproducing magnetic gap between the _Ind and the MR head is defined as follows. That is, as shown in FIG. 2 which schematically shows the front end portion of the composite magnetic head, the depth D of the recording magnetic gap of the inductive head is set.
_Ind (the effective gap length L) is D _MR <D _Ind ≤ D _MR +3 μm with respect to the depth D _MR (the length of contact between the tip electrode 7a and the MR magnetic sensing part 5) of the reproducing magnetic gap of the MR head.
The relationship will be

The depth D _{Ind of the} inductive head is set to M
The depth D _{MR of the} R head is made larger in order to prevent deterioration of the frequency characteristics, and further, since the depth processing is performed with the depth D _{MR of the} MR head as a reference, the depth D _{Ind of the} inductive head is increased. Is to prevent it from becoming smaller than the depth D _{MR of the} MR head. The upper limit of the depth D _Ind of the inductive head is set to a value obtained by adding 3 μm to the depth D _{MR of the} MR head.
_This is because the overwrite characteristic deteriorates as _Ind increases. Thus, the depth D of the inductive head
By defining the depths D _MR of the _Ind and MR heads to be optimum values from the viewpoints of recording and reproduction, respectively, it is possible to simultaneously satisfy the reproduction output characteristic, the frequency characteristic and the overwrite characteristic.

In the above embodiment, the head winding is used in place of the bias conductor, and a direct current is supplied to the head winding to give the MR magnetic sensing section a magnetized state in a desired direction. However, the present invention can also be applied to a composite magnetic head having a structure in which a bias conductor is provided and a direct current is passed through the bias conductor to apply a bias to the MR magnetic sensing section.

[0022]

As is apparent from the above description, according to the composite type magnetic head of the present invention, the depth of the recording magnetic gap of the inductive head and the depth of the reproducing magnetic gap of the MR head are recorded and reproduced. Since it is specified from the viewpoint, the frequency characteristic and the overwrite characteristic at the time of recording can be improved, and at the same time, the reproduction output characteristic at the time of reproducing can be improved. Therefore, according to the present invention, it is possible to provide a composite type magnetic head which can satisfy both the recording characteristic and the reproducing characteristic at the same time.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a composite magnetic head to which the present invention is applied.

FIG. 2 is a schematic diagram schematically showing a front end portion of the composite magnetic head of FIG.

FIG. 3 is a characteristic diagram showing the relationship between the depth of the MR head and the reproduction output.

FIG. 4 is a characteristic diagram showing the relationship between the depth and frequency characteristics of the inductive head.

FIG. 5 is a characteristic diagram showing the relationship between the depth and the overwrite characteristic of the inductive head.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... 1st thin film magnetic core 2 ... 2nd thin film magnetic core 4 ... ABS surface 5 ... MR magnetic sensing part 7a ... Front end electrode 7b ... Rear end electrode

 ─────────────────────────────────────────────────── --Continued front page (72) Inventor Takuji Shibata 6-5-6 Kitashinagawa, Shinagawa-ku, Tokyo Sony Magne Products Co., Ltd.

Claims (1)

[Claims] 1. A first thin-film magnetic core and a second thin-film magnetic core, which form a recording magnetic gap and face a surface facing a magnetic recording medium, are stacked between front end portions, and the first thin-film magnetic core and the second thin-film magnetic core are stacked in the magnetic gap. In a composite type magnetic head in which a magnetoresistive effect magnetic sensitive portion is arranged from the contact surface toward the rear, and a head winding is arranged behind it, the depth of the recording magnetic gap is D _Ind , and the reproducing magnetic field is When the depth of the gap is D _MR , D _MR <D _Ind ≤ D _MR
A composite magnetic head having a size of +3 μm.