JPH103621A - Magneto-resistive effect/inductive composite type thin film magnetic head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress fluctuation in a reproducing output of an MR composite (magneto-resistive effect/inductive composite type thin film magnetic) head after recording. SOLUTION: This magnetic head 10 is constituted so that a magneto-resistive effect type (MR) magneto-sensitive element 90 is held between shield patterns 12 and 14 through electric insulating layers 86, 88, and holds a recording gap layer 94 and a conductive coil pattern 96 between the shield pattern 14 and a recording soft magnetic yoke pattern 92, and the shield pattern 12 is connected to the shield pattern 14 magnetically. Or, the shield pattern 12 and the shield pattern 14 are magnetically connected on a shield connection part 16 provided on the end part of a side opposite to the magneto-sensitive element 90.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetoresistive / inductive composite thin film magnetic head (hereinafter, referred to as "MR composite head") having both a reproducing head using the magnetoresistance effect and an inductive recording head. The present invention relates to an MR composite head in which Barkhausen noise, which lowers the reproduction output reliability, is reduced.

[0002]

2. Description of the Related Art The recent increase in the recording capacity of a magnetic disk drive has been remarkable. This increase in recording capacity
This is mainly due to the improvement in magnetic recording density. In general, as the magnetic recording density increases, the signal output reproduced by the magnetic head decreases. In order to improve this, a magnetoresistive read magnetic head, which replaces the conventional inductive read magnetic head, has come into practical use. To perform magnetic recording, an inductive magnetic head is provided adjacent to the magnetoresistive read magnetic head. A recording / reproducing head having such a structure is called an MR composite head.

FIG. 7 is a sectional view showing a conventional MR compound head. Hereinafter, description will be made based on this drawing.

[0004] The conventional MR composite head 80 comprises an electric insulating layer 8 between a shield pattern 82 and a shield pattern 84.
6,88, a magnetoresistive effect type magnetic sensing element (hereinafter referred to as "M
R magnetic sensing element ". ) 90, and a gap layer 94 and a conductor coil pattern 96 are sandwiched between a shield pattern 84 and a recording soft magnetic yoke pattern 92.

[0005]

In the reproducing operation of the MR composite head 80, a fluctuation in the reproduction output due to Barkhausen noise related to the magnetic domain hard structure of the MR magneto-sensitive element 90 is often observed. To solve this problem, Japanese Patent Application Laid-Open No. 63-96814 discloses a technique for controlling the direction of magnetic anisotropy of an MR magneto-sensitive element. However, when the recording head is arranged near the MR magneto-sensitive element as in the case of the MR composite head, control of the magnetic anisotropy of the MR magneto-sensitive element alone is not sufficient for controlling the fluctuation of the reproduction output. .

It is also known that a conventional MR compound head irregularly changes the reproduction output amplitude when recording and reproduction are repeated. When the reproduction output fluctuates irregularly, the data error of the magnetic disk device equipped with such an MR composite head increases. Depending on the degree of the fluctuation, a malfunction of the magnetic disk device may occur. It is understood that such a phenomenon is caused by Barkhausen noise caused by an irregular change in the magnetic domain structure such as an MR magnetic sensing element and a magnetic shield material which are constituent materials of the MR composite head.
As with the conventional inductive head, the MR composite head has a problem in that the output fluctuation is small only in the reproducing operation, and the reproducing output is likely to fluctuate in the recording operation.

[0007]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the fluctuation of the reproduction output after recording of an MR composite head and to improve the operation reliability of a magnetic disk device equipped with the MR composite head. .

[0008]

The inventor of the present invention has proposed a conventional MR.
As a result of repeated research on such problems of the composite head, the following has been clarified. In the conventional MR compound head, as shown in FIG. 7, the shield pattern 82 and the shield pattern 84 are not magnetically connected to each other.
The shield pattern 84 and the recording soft magnetic yoke pattern 92 are magnetically connected so as to interlink with the conductor coil pattern 96. In such a structure, when a recording current is applied to the conductor coil pattern 96, the gap layer 94
Except for the above, the recording soft magnetic yoke pattern 92 and the shield pattern 84, which form a substantially closed magnetic circuit, are strongly magnetized. On the other hand, the shield pattern 82 is hardly magnetized by the current magnetic field. Therefore, the strongly magnetized shield pattern 8
4 and the shield pattern 82 which is hardly magnetized, the MR magnetic sensing element 90 receives the leakage magnetic field from the shield pattern 84 strongly. That is, the conventional MR
The composite head 80 has a drawback in that an unnecessary magnetic field is applied to the MR magneto-sensitive element 90 every time a recording operation is performed, so that the stability of the MR magneto-sensitive element 90 is impaired and the stability of the subsequent reproducing operation is impaired. Was.

In order to solve the above problems, an MR composite head according to the present invention provides a magnetoresistive effect type magnetic sensing element with an electric insulating layer interposed between a first shield pattern and a second shield pattern. And a recording gap layer and a conductor coil pattern are sandwiched between the second shield pattern and the recording soft magnetic yoke pattern. Further, the first shield pattern and the second shield pattern are magnetically connected.

[0010]

FIG. 1 is a sectional view showing a first embodiment of an MR compound head according to the present invention. Hereinafter, description will be made based on this drawing. However, the same parts as those in FIG.

In the MR composite head 10 according to the present invention, the MR magnetic sensing element 90 is sandwiched between the shield pattern 12 and the shield pattern 14 with the electric insulating layers 86 and 88 interposed therebetween. The recording gap layer 94 and the conductor coil pattern 96 are sandwiched between the yoke pattern 92 and the yoke pattern 92. And the shield pattern 12
And the shield pattern 14 are magnetically connected. The shield pattern 12 and the shield pattern 14 are magnetically connected by a shield connection part 16 provided at an end opposite to the MR magnetic sensing element 90.

When a recording current is applied to the conductor coil pattern 96, since the shield patterns 12, 14 are magnetically connected to each other via the shield connection portion 16, the magnetization state due to the current magnetic field is changed by the shield patterns 12, 14. It is almost the same. Accordingly, the leakage magnetic fields of the shield patterns 12 and 14 applied to the MR magneto-sensitive element 90 held between them cancel each other out and become small. That is, since the unnecessary magnetic field due to the recording operation is small, the MR magnetic sensing element 9
0 instability is not impaired, and the subsequent reproduction operation becomes stable.

In order to efficiently cancel the leakage magnetic field in the MR sensing element 90, it is desirable that the total magnetic flux generated from the shield pattern 12 and the total magnetic flux generated from the shield pattern 14 be as equal as possible. This total magnetic flux amount is generally represented by the product of the saturation magnetic flux density Br of the shield pattern material (soft magnetic material) and its cross-sectional area S. Since the width of the shield patterns 12 and 14 is sufficiently longer than the width of the MR magneto-sensitive element 90, equalizing the leakage magnetic field from the shield patterns 12 and 14 requires equalizing the total magnetic flux amount per unit length. Are equivalent. That is, the shield pattern 1
2 is equal to the product of the thickness of the shield pattern 14 and the saturation magnetic flux density Br, thereby reducing the unnecessary magnetic field applied to the MR magnetic sensing element 90. It is effective for

FIG. 2 is a sectional view showing a second embodiment of the MR compound head according to the present invention. Hereinafter, description will be made based on this drawing. However, the same parts as those in FIG.

The MR composite head 20 of the present embodiment differs from the MR composite head 10 of the first embodiment (FIG. 1) in the shield connection portions 22 of the shield patterns 12, 14. First, a spacer pattern 2 having a thickness equal to the total thickness of the electric insulating layers 86 and 88 is previously provided at the position of the shield connection portion 22.
4 is provided. The spacer pattern 24 is not particularly limited, whether it is a soft magnetic pattern or a non-magnetic pattern. Next, the shield pattern 12 is provided, and the electrical insulating layer 86, the MR magnetic sensing element 90,
The electric insulating layers 88 are stacked in this order, planarization is performed, and the levels of the upper surfaces of the electric insulating layers 88 and the shield pattern 12 are adjusted. Thereafter, a shield pattern 14, a gap layer 94, a conductor coil pattern 96, and a recording soft magnetic yoke pattern 92 are sequentially formed. By adopting such a configuration, the step of the recording soft magnetic yoke pattern 92 is reduced, so that there is an advantage that the connection of the shield pattern 14 is facilitated.

FIG. 3 is a sectional view showing a third embodiment of the MR compound head according to the present invention. Hereinafter, description will be made based on this drawing. However, the same parts as those in FIG.

In the MR composite head 30 of the present embodiment, the shield connection portions 32 and the spacer patterns 34 of the shield patterns 12 and 14 are combined with the MR composite head 20 of the second embodiment.
(FIG. 2). When the medium facing surface side of the shield connection part 32 protrudes right below the conductor coil pattern 96, the area of the shield connection part 32 is increased. By increasing the area of the shield connection part 32, the magnetization states of the shield patterns 12, 14 become more equal.

FIG. 4 is a sectional view showing a fourth embodiment of the MR compound head according to the present invention. Hereinafter, description will be made based on this drawing. However, the same parts as those in FIG.

In the MR composite head 40 of the present embodiment, the shield connection portions 42 and the spacer patterns 44 of the shield patterns 12 and 14 are combined with the MR composite head 30 of the third embodiment.
(FIG. 3). The medium connection surface side of the shield connection portion 42 is further positioned closer to the medium connection surface, and the area of the shield connection portion 42 is increased. In addition, shield connection part 4
2 entirely overlaps the conductor coil pattern 96.
For this reason, the current magnetic field from the conductor coil pattern 96 is more efficiently applied to the shield patterns 12, 14, and the uniformity of the magnetization state of each shield pattern 12, 14 is improved.

FIG. 5 is a sectional view showing a fifth embodiment of the MR composite head according to the present invention. Hereinafter, description will be made based on this drawing. However, the same parts as those in FIG.

In the MR composite head 50 of the present embodiment, the shield connection portions 52 of the shield patterns 12, 14 are different from those of the MR composite head 10 of the first embodiment (FIG. 1). The shield connection portion 52 is formed by removing the electrical insulating layers 86 and 88 more than in the case of the MR composite head 10 of the first embodiment. The effect is the same as that described in the fourth embodiment.

FIG. 6 is a sectional view showing a sixth embodiment of the MR compound head according to the present invention. Hereinafter, description will be made based on this drawing. However, the same parts as those in FIG.

In the MR composite head 60 of this embodiment, the stacking order is reversed, unlike the previous embodiments. Even if the stacking order is reversed, the shielding pattern 1
The effect that the unnecessary magnetic field applied to the MR sensing element 90 is reduced by magnetically connecting the second and the second with the shield connection portion 16 is the same as before.

[0024]

According to the MR composite head, the instability of the amplitude of the reproduction output after recording of the MR composite head can be improved. The reason is that an unnecessary magnetic field generated during a recording operation applied to the MR magneto-sensitive element can be reduced by connecting a shield pattern that holds the unnecessary magnetic field.

According to the MR composite head of the present invention, the shield connection portion for magnetically connecting the first shield pattern and the second shield pattern overlaps the conductor coil pattern, so that the area of the shield connection portion is increased. Can be increased, so that the magnetization state of each shield pattern can be made more equal. Therefore, the instability of the amplitude of the reproduction output after recording of the MR composite head can be further improved.

According to the MR compound head of the third aspect, the first
The distance from one end of the shield connection part for magnetically connecting the shield pattern to the second shield pattern to the medium facing surface is shorter than the distance from one end of the conductor coil pattern to the medium facing surface. Can be made larger, so that the magnetized state of each shield pattern can be further equalized. Therefore, the instability of the amplitude of the reproduction output after recording of the MR composite head can be further improved.

According to the MR compound head of the fourth aspect, the first
Since the product of the thickness of the shield pattern and its saturation magnetic flux density is substantially equal to the product of the thickness of the second shield pattern and its saturation magnetic flux density, the unnecessary magnetic field applied to the MR magneto-sensitive element is reduced. It can be reduced effectively. Therefore, the instability of the amplitude of the reproduction output after recording of the MR composite head can be further improved.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first embodiment of an MR composite head according to the present invention.

FIG. 2 is a sectional view showing a second embodiment of the MR composite head according to the present invention.

FIG. 3 is a sectional view showing a third embodiment of the MR compound head according to the present invention.

FIG. 4 is a sectional view showing a fourth embodiment of the MR compound head according to the present invention.

FIG. 5 is a sectional view showing a fifth embodiment of the MR composite head according to the present invention.

FIG. 6 is a sectional view showing a sixth embodiment of the MR compound head according to the present invention.

FIG. 7 is a sectional view showing a conventional MR compound head.

[Explanation of symbols]

 10, 20, 30, 40, 50, 60 MR composite head 12 (first) shield pattern 14 (second) shield pattern 16, 22, 32, 42, 52 shield connection part 86, 88 electric insulation layer 90 MR Magnetic sensing element 92 Soft magnetic yoke pattern for recording 94 Recording gap layer 96 Conductor coil pattern

Claims (4)

[Claims] 1. A magnetoresistive effect-type magnetic sensing element is sandwiched between a first shield pattern and a second shield pattern via an electrical insulating layer, and the second shield pattern and the soft magnetic yoke pattern for recording are interposed. A magnetoresistive / inductive combined type thin film magnetic head having a recording gap layer and a conductor coil pattern sandwiched therebetween, wherein the first shield pattern and the second shield pattern are magnetically connected. A characteristic magnetoresistive / inductive composite thin film magnetic head. 2. The combined magnetoresistive / inductive type according to claim 1, wherein a shield connection portion for magnetically connecting the first shield pattern and the second shield pattern overlaps the conductor coil pattern. Thin film magnetic head. 3. A distance from one end of a shield connection part for magnetically connecting the first shield pattern and the second shield pattern to a medium facing surface is from one end of the conductor coil pattern to the medium facing surface. 2. The combined magnetoresistive / inductive thin film magnetic head according to claim 1, wherein said head is shorter than the distance. 4. The product of the thickness of the first shield pattern and its saturation magnetic flux density is substantially equal to the product of the thickness of the second shield pattern and its saturation magnetic flux density.
A magnetoresistive / inductive composite thin-film magnetic head as described in the above.