JP2001067616A - Thin film magnetic head and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the precision of a track width and to obtain strong magnetic field intensity by dividing an upper magnetic head core into a first upper magnetic core and a second magnetic core which comes into contact with a lower magnetic core in the back part and the back contact part of the first upper magnetic core and forming the shape that the width of the back end part of the first upper magnetic core is wider than that of the tip end part of the same. SOLUTION: The difference in level consisting of a first insulated body 61 is formed after forming a lower magnetic core 3 and a magnetic gap film 4 on a substrate 14, and a first upper magnetic core 1 is formed in the position covering the difference in level. The first upper magnetic core 1 is provided with the same width as the width of a track in the tip end part and is provided with the width wider than the width of the track in the back end part. Next, a protective film 15 consisting of a non- magnetic film is formed in at least the area covering the first upper magnetic core 1, and the back part of the first upper magnetic core 1 is exposed by grinding it into flatness. Finally, the back part of the first upper magnetic core 1 and a second upper magnetic core 2 are formed after forming the insulated layer 62 covering a coil 5 excepting the coil 5 and the central part of the coil.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an inductive thin film magnetic head used for recording.

[0002]

2. Description of the Related Art As the recording density of a magnetic disk device increases, the coercive force of a magnetic recording medium increases, and the track width of an inductive thin-film magnetic head used for recording decreases. Further, as the coercive force of the magnetic recording medium is increased, the thickness of the inductive thin film magnetic head is increased in order to generate a magnetic flux sufficient for recording. That is, at present, at the tip of the inductive type thin film magnetic head, the film thickness is thicker than the track width, and its manufacture is more and more difficult.

In order to solve this problem, the upper magnetic core of the inductive type thin film magnetic head is divided into a front end and a rear end, and the front end of the upper magnetic core is formed on a low step so that a narrow track width can be precisely formed. The method of forming is disclosed in JP-A-2-247809.
No.

Further, an induction type thin film having a trench having a width narrower than the pole tip of the upper magnetic core in the pole tip region of the induction type thin film magnetic head, the width including a pole tip layer defining a track width. The structure of a magnetic head is described in JP-A-7-296328.

[0005]

SUMMARY OF THE INVENTION As mentioned above,
In the inductive type thin film magnetic head described in Japanese Patent No. 296328, the width of the pole tip of the upper magnetic core is wider than the pole tip layer that defines the track width. With this structure, the magnetic flux is kept large even at the tip of the upper magnetic core, and it is possible to produce a magnetic pole tip layer having a thin film thickness and a precise track width. However, since a large magnetic field leaks not only from the magnetic gap portion but also from the end of the pole tip of the upper magnetic core, the recording magnetic field is applied to the recording medium in a region wider than the desired track width during recording. There was a problem such as breaking the information to be done.

As one of means for solving this problem, in order to reduce the magnetic field leaking from the pole tip of the upper magnetic core, a magnetic core shape in which the pole tip surface of the upper magnetic core is disposed behind the air bearing surface is used. There is a way to do that. However, there is a problem that the head magnetic field greatly changes due to a change in the position of the pole tip surface of the upper magnetic core.

In the inductive type thin-film magnetic head described in Japanese Patent Application Laid-Open No. 2-247809, the upper magnetic core is divided into a front end and a rear end, and the rear end of the upper magnetic core is located at a position away from the medium facing surface. Since it is connected to the unit, there is no problem that adjacent information is destroyed. In the present invention, the tip and the rear of the upper magnetic core are connected via a contact hole formed in the protective film covering the tip of the upper magnetic core. At present, the recording frequency is increasing with the increase in the recording density of magnetic disk devices, especially with the increase in the linear recording density, and the inductive type thin film magnetic head including the magnetic path length is becoming smaller. And the magnetic field required for recording cannot be obtained.

[0008]

In the inductive thin film magnetic head according to the present invention, the upper magnetic core is exposed to the medium facing surface in order to efficiently carry the magnetic flux to the tip of the upper magnetic core and realize a narrow track width. The first upper magnetic core is divided into a second upper magnetic core connected to the lower magnetic core at the rear and back contact portions of the first upper magnetic core. At this time, the first upper magnetic core has a shape in which the width of the rear end is wider than the width of the front end. In addition, at least an upper portion of the tip of the lower magnetic core in a region not covered by the first upper magnetic core is removed. Thereafter, a protective film is formed, and the protective film is flattened to expose at least the rear upper surface of the first upper magnetic core, so that the rear portion of the first upper magnetic core and the front end of the second upper magnetic core are exposed. To secure the connection area. The connection position is desirably the same as or behind the spread position of the first upper magnetic core. As a result, the magnetic flux sufficiently enters the first upper magnetic core, and the amount of the magnetic flux is limited in a portion where the first upper magnetic core is narrowed. Variations in the magnetic field due to variations in the connection position can be reduced.

When the saturation magnetic flux density of the magnetic recording medium increases and the magnetic field required for writing increases, magnetic saturation tends to occur at the tip of the magnetic core. In order to solve this problem, a material is used in which the saturation magnetic flux density at least in the vicinity of the gap between the first upper magnetic core and the lower magnetic core is higher than the saturation magnetic flux density of the second upper magnetic core and the lower magnetic core. Thus, magnetic saturation at the tip of the magnetic core can be avoided.

Further, a material having a high specific resistance or a magnetic film and a non-magnetic film are laminated in a portion having a larger volume than the first upper magnetic core, such as the second upper magnetic core and the lower magnetic core. By using a magnetic multi-layered film, it is possible to provide an inductive thin-film magnetic head having high high-frequency recording performance.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows one embodiment of a method for manufacturing an inductive thin film magnetic head according to the present invention. The inductive thin film magnetic head according to the present invention can be manufactured by the following steps. After forming the lower magnetic core 3 and the magnetic gap film 4 on the substrate 14,
A step made of the first insulating layer 61 is formed. Next, the first upper magnetic core 1 is formed at a position covering the step formed by the magnetic gap film 4 and the first insulating layer 61 (FIG. 1A). Here, the substrate 14 includes a reproducing head. As long as it has a means for detecting a magnetic field, there is no particular problem as a reproducing head,
For example, any of a magnetoresistive element, a spin valve element, a giant magnetoresistive element, and a tunnel magnetoresistive element may be used.

The first upper magnetic core 1 has a track width at the front end and a width wider than the track width at the rear end. Next, a focused ion beam (FIB) method,
The first upper magnetic core 1 and a suitable mask are used to process into a shape having a substantially track width by using an ion milling method or a reactive ion etching (RIE) method (FIG. 1).
b). In this embodiment, since a mask other than the first upper magnetic core 1 is not used in order to reduce the number of steps, the first insulating layer 6 is not used.
The portion not covered by the first upper magnetic core is also cut off. However, a region other than the medium facing surface of the magnetic head is masked, and the first upper magnetic core 1 and the magnetic gap film 4 in the region not covered with the mask and the upper end of the lower magnetic core 3 are removed. It doesn't matter.

Next, a protective film 15 made of a non-magnetic film is formed at least in a region covering the first upper magnetic core 1 (FIG. 1).
c).

Subsequently, the protection film 15 is flattened to expose at least the rear portion of the first upper magnetic core 1 (FIG. 1-d). The method of shaving the protective film may be mechanical polishing, but it is possible to use chemical mechanical polish (CM
P.) method is preferred.

Finally, after forming the coil 5 and the insulating layer 62 covering the coil 5 except for the center of the coil, the front end is connected to the rear of the first upper magnetic core 1 and the rear is connected to the rear of the lower magnetic core 3. A second upper magnetic core 2 is formed (FIG. 1-e).

FIG. 2 is a diagram showing a main part of an inductive thin film magnetic head according to the present invention. FIG. 2A is a cross-sectional view, and FIG.
FIG. 2C is a top view, and FIG. 2C is a view from the air bearing surface. The lower magnetic core 3 is connected to the lower magnetic core lower layer 31 and the saturation magnetic flux density (Bs).
And a lower magnetic core upper layer 32 higher than the lower magnetic core lower layer. The magnetic gap film 4 and the first insulating layer 61 are formed on at least the tip of the lower magnetic core 3, and the first upper magnetic core 1 is formed so as to cover the magnetic gap film 4 and the first insulating layer 61. I do. The tip portion of the lower magnetic core 3 is processed into a shape having a substantially track width by using the FIB method, the ion milling method using the first upper magnetic core 1, the first insulating layer 61, and an appropriate mask, or the RIE method. I do.

FIGS. 3 to 6 show the results of calculation of the magnetic field strength of the inductive thin film magnetic head according to the present invention by the integral element method. The shape of the magnetic head used for the calculation is as shown in FIG. 2, and the dimensions and physical properties of each part are as follows. The lower magnetic core 3 is composed of (40-60) Ni- (60-40) Fe of Bs = 1.6T on 80Ni-20Fe permalloy 2.5 μm of Bs = 1.0T.
Is set to 0.5 μm, and at the tip, the lower magnetic film upper layer 32 in a portion not covered by the first upper magnetic core 1 within the range of the gap depth 7 is removed. The gap depth 7 is
The distance is defined by the distance between the tip of the first insulating layer 61 and the air bearing surface. The gap depth 7 is 1.0 μm, and the thickness of the magnetic gap film is
It was 0.2 μm. Each of the first upper magnetic core 1 and the second upper magnetic core 2 was (40-60) Ni- (60-40) Fe, and the film thickness was 3.0 μm. The length of the pole tip 1 is 7.0 μm.
14 from the tip of the upper magnetic core 1
Is 2.0 μm, and the spread angle 12 of the first upper magnetic core 1 is 3 μm.
2 °. The spread angle 13 of the tip of the second upper magnetic core 2 was 45 °, and the distance from the air bearing surface to the tip of the second upper magnetic core 2 was 3.0 μm. Insulating layer 62 covering coil
Was set at 7.0 μm from the air bearing surface (coincident with the rear end of the first upper magnetic core 1). The angle 8 of the tip of the first insulating layer 61 formed on the magnetic gap film and the angle 9 of the tip of the insulating layer 62 covering the coil formed after forming the first upper magnetic core 1 are both 45. °. The thickness of the first insulating layer was 1.0 μm. The track width is 0.5 μm, the magnetomotive force is 0.35 AT, and the magnetic field is the maximum value of the component parallel to the floating surface calculated at a position 40 nm away from the head tip.

FIG. 3 is a diagram showing the relationship between the film thickness 10 of the first insulating layer 61 and the maximum magnetic field. White circles indicate the first upper magnetic core
When the spread angle 12 of 1 is 32 °, the black circles indicate the case where the spread angle is 0 °. Comparing the first upper magnetic core 1 with a divergence angle of 0 ° and 32 °, the first upper magnetic core 1 has a divergence angle of 32 °.
It can be seen that the magnetic field is increased by about 500 Oe. Also,
It can be seen that the change in the magnetic field is small when the thickness 10 of the first insulating layer 61 is in the range of 0 to 3 μm, and becomes maximum when the film thickness is 1 to 2 μm. As the thickness 10 of the insulating layer increases, the track width processing accuracy of the first upper magnetic core 1 deteriorates. Therefore, the thickness of the insulating layer is preferably smaller. Therefore, the film thickness 10 of the first insulating layer 61 is 0 to 2 μm
Is desirable.

FIG. 4 shows the spread angle 1 of the first upper magnetic core 1.
FIG. 4 is a diagram showing a relationship between 2 and a maximum magnetic field. Spread angle 12 is 0
In the case of °, the maximum magnetic field is about 5.5 kOe, but it becomes as large as about 5.9 kOe when the spread angle becomes 10 °, and when the spread angle 12 of the first upper magnetic core 1 is further increased, the maximum magnetic field becomes gentler. You can see that it increases. The optimum value of the maximum magnetic field is determined by various factors such as the coercive force and the recording density of the recording medium, and it is not always possible to say where the optimum value is, but if the spread angle 12 is 10 ° or more, the spread angle 12 is Even if it fluctuates in the process, the change of the maximum magnetic field is suppressed to a small value. Therefore, the spread angle 12 of the first upper magnetic core 1 is desirably 10 ° or more.

FIG. 5 is a diagram showing the relationship between the connection position of the first upper magnetic core 1 and the second upper magnetic core 2 and the maximum magnetic field. FIG. 5A is a diagram showing the relationship between the distance between the air bearing surface and the tip of the second upper magnetic core and the maximum magnetic field. It can be seen that the center magnetic field does not change much even if the tip of the second upper magnetic core moves 1 μm forward or backward from the center value (= 2 μm). FIG.
(b) is a diagram showing the relationship between the distance between the air bearing surface and the tip of the insulating film covering the coil and the maximum magnetic field. Insulating film covering the coil
It can be seen that the maximum magnetic field changes little when the tip of 62 moves behind the center value (= 7 μm), but decreases when moving forward. This is the first upper magnetic core 1
The rear portion of the first upper magnetic core 1 and the second upper portion are wide because the front end portion of the insulating film 62 covering the coil comes out before the rear end portion of the first upper magnetic core 1. It is considered that this is because the contact area of the tip of the magnetic core 2 is greatly reduced.

In the present invention, the first upper magnetic core 1 and the first
After the formation of the protective film covering the upper magnetic core, the protective film is removed by flattening to expose the upper part of the rear part of the first upper magnetic core. It is difficult to terminate the processing due to the process. Then, when the relationship between the cut amount of the first upper magnetic core 1 by the flattening process and the maximum magnetic field was examined, the result shown in FIG. 6 was obtained. The maximum magnetic field does not decrease so much until the cut amount is 2 μm. For example, when the target of the cut amount is 1 μm and the variation in the process is ± 0.5 μm, there is almost no decrease in the maximum magnetic field.

FIG. 7 shows the digging depth of the tip of the lower magnetic core.
FIG. 4 is a diagram showing a relationship between 11 and a recording magnetic field. FIG. 7 (a) shows the relationship between the digging depth 11 at the tip of the lower magnetic core and the maximum magnetic field, and FIG. 7 (b) shows the relationship between the digging depth 11 at the tip of the lower magnetic core and the erase width due to the recording magnetic field. FIG. The erase width was calculated with the coercive force of the medium being 3.4 kOe. The white circles indicate that the lower magnetic core has a thickness of 2.5μm and thickness of 80Ni-20Fe permalloy.
In the case of 0.5 μm (40-60) Ni− (60-40) Fe, black circles indicate that the lower magnetic core is 80Ni-20Fe permalloy with a thickness of 2.75 μm and (40-60) Ni− with a thickness of 0.25 μm. (60 to 40) Fe. FIG. 7A shows that the larger the thickness of the high Bs film on the lower magnetic core, the larger the maximum magnetic field, but the difference is small. FIG. 7B shows that the depth of the excavation at the tip of the lower magnetic core can be made sufficiently small as long as it is 0.2 μm or more, which is the same as the thickness of the magnetic gap.

With the increase in recording density of magnetic disk drives,
Not only the track width has been narrowed, but also the linear recording density has been improved, so that the recording frequency of the inductive thin film magnetic head has been improved. When the recording frequency increases, the magnetic field strength of the head decreases due to eddy current loss. Eddy current loss depends on the cross-sectional area and specific resistance of the magnetic core of the inductive thin film magnetic head. Since the first upper magnetic core 1 is small, it can be considered that there is almost no eddy current loss. 1st upper magnetic core 1, 2nd
In order to reduce the eddy current loss of the upper magnetic core 2 and the lower magnetic core 3, a magnetic film having a large specific resistance is used, or a magnetic film and an insulating film are used as a magnetic core material so that the eddy current hardly flows. It is sufficient to use a magnetic multilayer film composed of the above laminated films.

FIG. 8 is a diagram showing a magnetic disk drive of one embodiment using an inductive thin film magnetic head according to the present invention.
1 shows an outline in which an inductive thin film magnetic head according to the present invention is applied to a magnetic disk device as a magnetic recording device. However, it is possible to mount the inductive thin film magnetic head of the present invention also on a magnetic recording device such as a magnetic tape device.

The illustrated magnetic disk drive comprises a magnetic disk 1110 as a magnetic recording medium formed on a disk for recording data in a recording area called a concentric track, and a magnetic transducer. A magnetic head 1118 according to the present invention for performing reading and writing, actuator means for moving the magnetic head 1118 to a predetermined position on a magnetic disk 1110 supporting the magnetic head 1118, transmission / reception and actuator means for data read and written by the magnetic head 1118 And control means for controlling movement of the robot.

Further, by connecting a plurality of magnetic disk devices, it is possible to form a disk array device having a large storage capacity.

[0027]

According to the present invention, it is possible to provide an inductive thin film magnetic head having good track width accuracy and strong magnetic field strength.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a method of manufacturing an inductive thin film magnetic head according to the present invention.

FIG. 2 is a diagram showing a main part of an inductive thin film magnetic head according to the present invention.

FIG. 3 is a diagram showing the relationship between the first insulating layer thickness and the maximum magnetic field of the inductive thin film magnetic head according to the present invention.

FIG. 4 is a diagram showing the relationship between the spread angle of the first upper magnetic core and the maximum magnetic field of the inductive thin film magnetic head according to the present invention.

FIG. 5 is a diagram showing a relationship between a connection position of a first upper magnetic core 1 and a second upper magnetic core 2 and a maximum magnetic field of the inductive thin film magnetic head according to the present invention.

FIG. 6 is a diagram illustrating a relationship between a cut amount of the first upper magnetic core and a maximum magnetic field by flattening a protective film of the first upper magnetic core.

FIG. 7 is a diagram showing the relationship between the depth of excavation at the tip of the lower magnetic core of the inductive thin film magnetic head according to the present invention, the maximum magnetic field, and the erase width.

FIG. 8 is a diagram showing a magnetic disk drive using an inductive thin film magnetic head according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... 1st upper magnetic core, 2 ... 2nd upper magnetic core, 3
... lower magnetic core, 31: lower magnetic core lower layer, 32: lower magnetic core upper layer, 4: magnetic gap, 5: coil, 6: insulator, 61: first insulator, 62: insulation covering the coil Body, 7
... gap depth, 8 ... tip angle of the first insulator, 9
... the angle of the tip of the insulator covering the coil, 10 ... the thickness of the first insulator, 11 ... the digging depth at the top tip of the lower magnetic core, 12 ... the spread angle of the first upper magnetic core, 13…
Spread angle of second upper magnetic core, 14 ... substrate, 15 ... first
Protective film for upper magnetic core, 1110 ... Magnetic disk, 1112 ...
Rotating shaft, 1114 motor, 1116 slider, 1118 magnetic head, 1120 gimbal, 1122 arm, 1124 actuator, 1126 control means, 1128 transmission line, 1130
Transmission line.

Continued on the front page (72) Inventor Tomohiro Okada 1-280 Higashi Koikekubo, Kokubunji-shi, Tokyo Inside the Hitachi, Ltd. Central Research Laboratory (72) Inventor Tetsuo Ito 1-280 Higashi Koikekubo, Kokubunji-shi, Tokyo Inside the Central Research Laboratory, Hitachi, Ltd. (72) Inventor Kazue Kudo 1-280 Higashi Koikekubo, Kokubunji-shi, Tokyo Inside the Hitachi, Ltd.Central Research Laboratories (72) Inventor Nobuo Yoshida 1-280 Higashi Koikebo-ku, Kokubunji-shi, Tokyo F-term in the Central Research Laboratory, Hitachi, Ltd. 5D033 BA01 BA07 BA08 BA13 CA01 CA05 DA01 DA02 DA07

Claims (15)

[Claims] 1. A lower magnetic core formed on a substrate, an upper magnetic core coupled to the lower magnetic core by a back contact at a rear end, and a coil disposed around the upper magnetic core and the lower magnetic core. An inductive thin-film magnetic head having an insulating layer formed between a coil, an upper magnetic core and a lower magnetic core, wherein the upper magnetic core has a first upper magnetic core exposed to the medium facing surface and The first upper magnetic core is connected to the rear end of the upper magnetic core, and the rear has a second upper magnetic core connected to the lower magnetic core at the back contact portion, and the rear end is wider than the front end of the first upper magnetic core. An inductive thin-film magnetic head, characterized in that: 2. The distance between the rear portion of the first upper magnetic core and the lower magnetic core is 0 to 2 μm greater than the thickness of the magnetic gap film.
2. The inductive thin film magnetic head according to claim 1, wherein m is larger than m. 3. The inductive thin film according to claim 1, wherein the first upper magnetic core comprises a front end having a track width and a rear end having a spread angle of 10 to 90 degrees. Magnetic head. 4. A method according to claim 1, wherein a saturation magnetic flux density of at least an upper end portion of the lower magnetic core and the first upper magnetic core is larger than a saturation magnetic flux density of at least one of the second upper magnetic core and the lower magnetic core. Claim 1,
4. The inductive thin film magnetic head according to claim 2. 5. The induction according to claim 1, wherein at least an upper end portion of the lower magnetic core and a saturation magnetic flux density of the first upper magnetic core are 1.3T or more. Type thin film magnetic head. 6. A method according to claim 1, wherein a portion of the upper end portion of the lower magnetic core that is not covered by the first upper magnetic core is removed by at least a thickness of the magnetic gap film. 6. The inductive thin film magnetic head according to claim 4. 7. The magnetic recording medium according to claim 1, wherein the specific resistance of at least one of the second upper magnetic core and the lower magnetic core is larger than the specific resistance of the first upper magnetic core.
7. The inductive thin film magnetic head according to 3, 4, 5, or 6. 8. The apparatus according to claim 1, wherein at least one of the second upper magnetic core and the lower magnetic core has a specific resistance of 45 μΩ · cm or more. 4. The inductive thin film magnetic head according to claim 1. 9. The method according to claim 1, wherein at least one of the second upper magnetic core and the lower magnetic core is a magnetic multilayer film formed by laminating a magnetic film and an insulating film. 9. The inductive thin film magnetic head according to any one of claims 4, 5, 6, 7, and 8. 10. A step of forming a lower magnetic core on a substrate, a step of forming an insulating layer including a magnetic gap portion made of a non-magnetic material on the lower magnetic core, and a step of forming an insulating layer including the magnetic gap portion on the lower magnetic core. Forming a first upper magnetic core made of a magnetic material, and using the first upper magnetic core as a mask to remove a magnetic gap in at least a region including a medium facing surface of a magnetic head and an upper part of a lower magnetic core tip. Performing a step of forming a protective film made of a non-magnetic material; a step of exposing at least a rear portion of the first upper magnetic core by flattening the protective film; Forming a conductor coil for inducing a magnetic field on the surface facing the medium between the first upper magnetic core and the lower magnetic core, and between the conductor coil and between the conductor coil and the first upper magnetic core And guidance Forming an insulating layer that insulates between the body coil and the second upper magnetic core; and forming a second upper magnetic core that is connected to a rear portion of the first upper magnetic core. A method for manufacturing an inductive thin film magnetic head. 11. A step of forming a lower magnetic core on a substrate, a step of forming an insulating layer including a magnetic gap portion made of a nonmagnetic material on the lower magnetic core, and a step of forming an insulating layer including the magnetic gap portion on the lower magnetic core. Forming a first upper magnetic core made of a magnetic material, covering the first upper magnetic core with a mask material except at least a region including the medium facing surface, and forming at least the mask material and the first magnetic core. Removing the magnetic gap in the region not covered by the upper magnetic core and the upper portion of the lower magnetic core tip, forming a protective film made of a non-magnetic material, and flattening the protective film. Exposing at least a rear portion of the first upper magnetic core; and forming a conductor coil that induces a magnetic field on a surface of the protective film facing the medium between the first upper magnetic core and the lower magnetic core. form Forming an insulating layer that insulates between the conductor coils, between the conductor coil and the first upper magnetic core, and between the conductor coil and the second upper magnetic core; Forming a second upper magnetic core connected to the rear portion of the upper magnetic core. 12. As a method of flattening the protective film,
12. The method for manufacturing an inductive thin film magnetic head according to claim 10, wherein a chemical mechanical polishing method is used. 13. An inductive thin-film magnetic head manufactured by the method according to claim 10, 11, 12, and having the features according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9. . 14. A magnetic recording / reproducing apparatus comprising a magnetic recording medium, a motor for driving the magnetic recording medium and a magnetic head for recording / reproducing on / from the magnetic recording medium, wherein the recording head is used as a recording head. A magnetic recording / reproducing apparatus comprising at least one inductive thin-film magnetic head according to any one of Claims 7, 8, 9, and 13. 15. The inductive type according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, or 13 as a recording head in a magnetic disk array device having a plurality of magnetic disk devices connected. A magnetic disk array device comprising at least one thin film magnetic head.