JPH10112008A - Magnetic disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize high density, small size and fast access time by forming such a region in a joined part that the outer edge of a first joining face and the outer edge of a second joining face are directly joined without an insulating material interposed. SOLUTION: The outer edges 8, 9, 10 of the joining face of a first conductive layer 5 are exposed. Then a second conductive layer 7 such as copper having thin adhesive layers such as chromium on both surfaces is formed and etched through a mask 11 to obtain a direct joined structure between the whole joining face of the first conductive layer 5 and the whole joining face of the second conductive layer 7. By this method, a joined structure having no insulating material around the joined part of the first conductive layer 5 and the second conductive layer 7 can be obtd. and this joined part hardly causes peeling during heat treatment.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk drive, and more particularly to a magnetic disk drive having a thin-film magnetic head having a thin-film laminated structure.

[0002]

2. Description of the Related Art In recent years, a magnetic disk device having a thin film magnetic head having a structure in which a large number of conductors are wound around a limited area has been considered as a means for increasing the density and increasing the speed of a magnetic disk device. Have been. For example, a magnetic disk drive provided with a thin-film magnetic head in which an insulator layer and a conductor layer are stacked, which is disclosed in Japanese Patent Application Laid-Open No. 62-173607 (hereinafter referred to as a known technique), can be considered.

[0003]

The thin-film magnetic head of the prior art provided in the magnetic disk drive has a structure in which, as the thickness of the conductor layer increases, the width of the conductor coil decreases without increasing the resistance of the conductor. Therefore, the density and size of the magnetic head can be increased, and the density and speed of the magnetic disk drive can be increased. However, the known thin-film magnetic head has a problem that as the thickness of the conductor layer increases, peeling or disconnection occurs at the junction between the conductor layers during heat treatment such as thermal curing of a photoresist in a manufacturing process or annealing in a magnetic field. The thickness of the conductor layer cannot be increased, and the density of the magnetic disk drive increases,
This is an obstacle to high-speed access.

An object of the present invention is to make it possible to increase the density and reduce the size of a magnetic head, and to increase the density of a magnetic disk drive.
This is to achieve high-speed access.

[0005]

A thin-film magnetic head of the prior art provided in a magnetic disk drive is used at a joint between conductive layers at the time of heat treatment such as thermal curing of a photoresist or annealing in a magnetic field in a manufacturing process. When the cause of peeling or disconnection was intensively investigated, it was found that an insulator interposed at the outer edge of the bonding surface between the conductive layers was a main cause of peeling or disconnection. That is, since the thermal expansion coefficient of the insulator constituting the insulator layer is different from the thermal expansion coefficient of the conductor constituting the conductor layer, bonding between the conductor layers is caused by a difference in the amount of expansion between the insulator and the conductor during the heat treatment. It has been confirmed by analysis, experiment, and the like that the insulator interposed at the outer edge of the surface peels and breaks the joint, and that the phenomenon is more remarkable as the thickness of the conductor layer is larger.

[0006] An insulator interposed at the outer edge of the joint surface, which causes separation and disconnection of the joint, is necessary to prevent disconnection of the conductor layer in the joining step.

[0007] The junction between the prior art conductor layers is formed by the following steps.

Step 1. An insulator layer is formed over a conductor layer (hereinafter, referred to as a first conductor layer).

Step 2. By removing a part of the insulator layer, the central part of the bonding surface of the first conductor layer is exposed. (The insulator layer is left at the outer edge of the bonding surface of the first conductor layer.) A conductor layer (hereinafter, referred to as a second conductor layer) to be bonded to the first conductor layer is laminated on the insulator layer.

Step 4. Unnecessary portions of the second conductor layer are removed by etching to form a joint surface having substantially the same shape as the joint surface of the first conductor layer on the second conductor layer.

In the above step 2, the insulation layer is left at the outer edge of the bonding surface of the first conductor layer, thereby preventing disconnection due to overetching of the first conductor layer in step 4. .

According to this method, the thickness of the conductor layer cannot be increased, but this method is effective because it is effective in preventing disconnection of the first conductor layer.

However, as described above, it has been found that the insulator interposed at the outer edge of the bonding surface is a cause of separation and disconnection of the bonding surface and a cause that the thickness of the conductor layer cannot be increased. By removing the insulator interposed at the outer edge of the bonding surface, peeling and disconnection of the bonding surface can be prevented, and the thickness of the conductor layer can be increased.

The object of the present invention can be solved by the following configuration in a magnetic disk device having a magnetic disk for recording data and a magnetic head for recording and reproducing the data on and from the magnetic disk. . (1) The magnetic head has a laminated structure in which a conductor layer and an insulator layer are laminated, and a first conductor layer laminated on a surface of the conductor layer facing the substrate of the insulating layer; A second conductor layer laminated on the other surface of the insulating layer joins a first joint surface formed on the first conductor layer and a second joint surface formed on the second conductor layer. Are electrically connected to each other at the joined portion, and the outer edge of the first joining surface and the outer edge of the second joining surface are directly joined to each other without sandwiching an insulator in the joined portion. Have.

(2) The magnetic head has a laminated structure in which a conductor layer and an insulator layer are laminated, and a first conductor laminated on a surface of the conductor layer facing the substrate of the insulating layer. Layer, a second conductive layer laminated on the other surface of the insulating layer, a first bonding surface formed on the first conductive layer, and a second bonding surface formed on the second conductive layer And a first conductive layer near the first bonding surface has a region where the thickness is reduced.

(3) The magnetic head has a laminated structure in which a conductor layer and an insulator layer are laminated, and a first conductor laminated on a surface of the conductor layer facing the substrate of the insulating layer. Layer, a second conductive layer laminated on the other surface of the insulating layer, a first bonding surface formed on the first conductive layer, and a second bonding surface formed on the second conductive layer Are electrically joined to each other at a joining portion where the first conductor layer and the second conductor layer are joined at the joining portion.
It has a region joined by a different surface from the first joint surface and the second joint surface.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the mechanism of peeling / breaking in a junction structure between conductor layers of a conventional thin-film magnetic head used in a magnetic disk drive will be described with reference to FIG. In this drawing, a structure in which a base film 2, a gap material 3, a first insulator layer 4, a first conductor layer 5, a second insulator layer 6, and a second conductor layer 7 are laminated on a substrate 1 is shown. Figure 1
As shown in FIG. 9A, an insulator 34 is interposed at the outer edge of the joint surface between the first conductor layer 5 and the second conductor layer 7. In the case of a thin-film magnetic head, for example, copper is used as a conductor, and photoresist is used as an insulator, and the insulator tends to expand more than the conductor when subjected to heat treatment due to a large difference in thermal expansion coefficient between them. I do. As a result, as shown by the arrow in FIG. 19B, a stress is generated to push the joint part open, and peeling occurs at portions 35 and 36 in FIG. 19B. As shown in FIG. 19 (c), disconnection occurs. If no insulator is interposed around the joint, no stress is generated as indicated by the arrow in FIG. 19B, so that peeling and disconnection hardly occur.

According to the present invention, in a thin film laminated structure formed by laminating a conductor layer and an insulator layer, the outer edges of the joining surfaces of the first conductor layer and the second conductor layer are directly joined to each other. With the region, the stress induced by the thermal expansion of the insulator is reduced, and peeling and disconnection of the joint can be prevented. Note that breakage of the first conductor layer due to over-etching in the manufacturing process can be prevented by adjusting the thickness of the first conductor layer.

An embodiment of the present invention will be described below with reference to the drawings.

First, a bonding structure of a thin-film magnetic head for a magnetic disk drive according to a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a diagram showing a thin-film bonding structure between conductive layers of a thin-film magnetic head used in a magnetic disk drive. The entire bonding surface of the conductive layers is directly bonded. FIG.
And FIG. 3 is a process cross-sectional view for explaining a manufacturing process and a joint structure. 2 is a cross-sectional view taken along a plane ABC in FIG. 1, and FIG. 3 is a cross-sectional view taken along a plane DEF in FIG. As shown in FIG. 2 and FIG. 3, this structure comprises a substrate 1, a base film 2, a gap material 3, a first insulator layer 4, a first conductor layer 5, a second insulator layer 6, and a second conductor layer 7. Are stacked, but FIG. 1 shows only the first conductor layer 5 and the second conductor layer 7 in order to clarify the joint structure.

The first embodiment will be described along the manufacturing process. First, a base film 2 and a gap material 3 are formed on the substrate 1 by, for example, sputtering, and an insulator such as a photoresist is applied thereon, and then cured by heat treatment to form a first insulator layer 4 having a flat surface. To form A first conductor layer 5 made of copper or the like having a thin adhesive layer made of, for example, chromium on the lower surface is formed thereon and etched to perform the etching as shown in FIGS.
The state shown in FIG. Next, when a second insulator layer 6 made of a photoresist or the like is applied, FIGS. 2B and 3B
The state shown in FIG. After that, the second insulator layer 6 is exposed,
After development, heat curing is performed to obtain the state shown in FIGS. 2 (c) and 3 (c). In this case, conventionally, the first conductor layer 5
When the second conductor layer 7 is formed, an insulator such as a photoresist is left on the upper surfaces of the joining surface outer edges 8, 9, and 10 because the joining surface outer edges 8, 9, and 10 are not exposed. In this case, an insulator is interposed at the outer edge of the bonding surface. In the first embodiment, as shown in FIGS. 2C and 3C, the outer edges 8, 9, and 10 of the first conductive layer 5 are exposed. Thereafter, a second conductor layer 7 of copper or the like having a thin adhesive layer of, for example, chromium on the upper and lower surfaces is formed, and the mask 1 is formed.
When etching is performed with 1 attached, a structure is obtained in which the entire bonding surface of the first conductive layer 5 and the entire bonding surface of the second conductive layer 7 are directly bonded. This process is shown in FIGS. 2 (d), 2 (e) and 3
(D) and shown in FIG. In this way, a bonding structure in which an insulator does not intervene around the bonding portion between the first conductive layer 5 and the second conductive layer 7 can be obtained, and a structure that does not easily peel at the bonding portion during heat treatment can be obtained. Can be In this case, as shown in a portion 12 in FIG. 1, the first conductor layer 5 is over-etched and thinned, but by adjusting the thickness of the first conductor layer 5, film breakage can be prevented. .

FIG. 4 is also a thin-film joining structure diagram of the conductor layers of the thin-film magnetic head used in the magnetic disk drive, in which the entire joining surface of the conductor layers is directly joined. FIG. 1 is a three-dimensional view looking into the upper surface of the second conductive layer 7, whereas FIG. 4 is a three-dimensional view looking into the lower surface of the first conductive layer 5. FIG. 5 is a sectional view taken along plane GHI of FIG. This is because the width of the mask 11 is increased in the thin film junction structure shown in FIGS. 1 to 3, and the etching process shown in FIGS. 2D and 2E is performed as shown in FIGS. 5D and 5E. Obtained by substituting. The cross-sectional view taken along the plane JKL in FIG. 4 is the same as FIG. Also in this case, as shown in FIG. 2, the first conductor layer 5 is over-etched and thinned, but by adjusting the thickness of the first conductor layer 5, it is possible to prevent the film from being cut.

The structure of FIG. 4 has a larger bonding area than that of FIG. However, in the structure of FIG. 4, since the width of the first conductor layer 5 in the GH direction must be smaller than the width of the second conductor layer 7, stress concentrates on the step portion of the first conductor layer 5. Cheap. On the other hand, in the structure of FIG. 1, the width of the first conductor layer 5 in the AB direction is not limited as described above, so that the width of the step portion of the first conductor layer 5 in the AB direction is increased. Thereby, stress concentration at the step portion can be reduced.
Therefore, the structure of FIG. 1 is superior in reducing the stress concentration at the step.

Next, the bonding structure of the thin-film magnetic head for a magnetic disk drive according to a second embodiment of the present invention will be described with reference to FIGS.
This will be described with reference to FIG. These have a structure in which an insulator is interposed in a part of the outer peripheral portion of the joint surface between the first conductor layer 5 and the second conductor layer 7, but no insulator is interposed in the other part. . The portions 38 and 39 in FIG. 6 represent places where the insulator is interposed. FIG. 2 is a sectional view taken along the plane ABC in FIG.
This is exactly the same as (e). In this way, if there is at least one region where the joining surfaces are directly joined to the outer edge of the joining surface,
The peeling stress is reduced as compared with the joint structure in which an insulator is interposed on the entire outer edge of the joint surface.

FIG. 7 is a cross-sectional view taken along the plane RST in FIG. 8, and there is a region where the bonding surfaces are directly bonded to each other at the outer edge of the bonding surface, and an insulator is interposed over the entire outer edge of the bonding surface. The peeling stress is reduced as compared with the joint structure. The structure shown in FIG. 7 is excellent in that the first conductor layer 5 is not over-etched.

Also in the embodiment shown in FIG. 9, the first conductor layer 5 is not over-etched similarly to the structure of FIG. FIG. 10 is a cross-sectional view taken along plane R′S′T ′ in FIG. As shown in FIG. 10, also in this example, there is a region where the bonding surfaces are directly bonded to each other at the outer edge of the bonding surface as described above. Is reduced.

As a case where the first conductor layer 5 and the second conductor layer 7 are connected at an angle, for example, there is a joint structure as shown in FIG. FIG. 12 is a sectional view taken along plane XYZ in FIG. 11, and FIG. 13 is a sectional view taken along plane X′Y′Z ′ in FIG. As shown in these figures, also in this example, there is a region where the joining surfaces are directly joined to each other at the outer edge of the joining surface, and the peeling stress is reduced compared to the joining structure where the insulator is interposed on the entire outer edge of the joining surface. Is done.

Next, a thin-film magnetic head for a magnetic disk drive according to a third embodiment of the present invention will be described with reference to FIGS. The third embodiment is an inductive head having a three-layer structure including the first conductor layer 5, the second conductor layer 7, and the third conductor layer 14, but the present invention is not limited to this, and may be, for example, a magnetoresistive head. It is also applicable to effect (MR) heads.
FIG. 14 is a view of the substrate 1 as viewed from above, and FIG.
4 is a cross-sectional view cut by UV, and FIG. 16 is a cross-sectional view cut by VW in FIG. This embodiment will be described along the manufacturing process. First, a base film 2 is formed on a substrate 1.
, The first magnetic body 17 and the gap material 3 are formed by, for example, sputtering, and an insulator such as a photoresist is applied thereon, and then cured by heat treatment to form the first insulator layer 4 having a flat surface. I do. A first conductor layer 5 such as copper having a thin adhesive layer such as chromium on the lower surface is formed thereon,
Perform etching. Thereafter, a second insulator layer 6 made of a photoresist or the like is applied, exposed and developed, and then thermally cured. At this time, the portion to be the joint 19 between the first conductor layer 5 and the second conductor layer 7 is the same as that shown in FIGS. 2C and 3C. So that the outer edge of the bonding surface is exposed. Next, a second conductor layer 7 made of copper or the like having a thin adhesive layer made of, for example, chromium on the upper and lower surfaces is formed, and is etched. At this time, at the joint 19 between the first conductor layer 5 and the second conductor layer 7, FIG.
Etching is performed in the same manner as in FIGS. 2 (e), 3 (d) and 3 (e), and the third insulator layer 20 and the third conductor layer 1 are further etched.
4. The fourth insulator layer 21 is formed. The structure of the joint 15 between the second conductor layer 7 and the third conductor layer 14 is the same as that of the first conductor layer 5.
And the joint 19 of the second conductor layer 7. Next, the second magnetic body 18 is formed by sputtering or the like. In this case, the second magnetic body 18 is manufactured by the same manufacturing process as in FIG.
The junction 16 between the first conductor layer 14 and the third conductor layer 14 also has a structure in which no insulator is interposed.

A conductor such as copper and an insulator such as a photoresist, which constitute a thin-film magnetic head, have a large difference in thermal expansion coefficient. growing. Therefore, the present invention
Particularly when applied to a thin film magnetic head, the effect of improvement is great.

In the thin-film magnetic head of the above embodiment, the structure of the junction 19 between the first conductor layer 5 and the second conductor layer 7 and the junction 15 between the second conductor layer 7 and the third conductor layer 14 are as follows. , FIG.
Is used, but may be replaced with the structure shown in FIG. 4, FIG. 6, or FIG.

Another structure of the thin-film magnetic head according to the present invention is shown in FIG. 14 is different from FIG. 14 in that a joint 15 between the second conductor layer 7 and the third conductor layer 14 is formed.
However, it is located at a portion that is not covered by the second magnetic body 18 and has a structure in which complicated stress distribution is unlikely to occur. Therefore, there is an advantage that the magnetic characteristics of the second magnetic body 18 are kept stable.

When a magnetic head having a conventional joining structure is used, a stress for peeling off a joint between conductors is caused by thermal expansion of an insulator, and the stress is caused by a thick film constituting the magnetic head. Therefore, the film thickness cannot be increased so much. In the magnetic head having the bonding structure according to the present invention, such stress due to thermal expansion of the insulator is reduced, so that the thickness of the film constituting the magnetic head can be increased. Since the width of the conductor coil can be reduced by increasing the thickness of the conductor without increasing the resistance of the conductor, it can be said that this is suitable for increasing the density of the conductor coil.

Next, a magnetic disk drive according to a fourth embodiment of the present invention will be described with reference to FIG. This embodiment comprises a magnetic disk 24 as a magnetic recording medium, a thin-film magnetic head 22 according to the present invention, and actuator means for moving the magnetic head to a predetermined position on the magnetic disk, as in a normal magnetic disk device. And control means for controlling movement of the actuator means and transmission / reception of data read / written by the magnetic head 22.

The operation and the operation will be described below in more detail. A slider 23 supporting the magnetic head 22 is placed on a magnetic disk 24 supported by a rotating shaft 29,
When the magnetic disk 24 is rotated by the drive motor 30, the slider 23 flies above the magnetic disk 24. The slider 23 is attached to the arm 26 by a gimbal 25 having elasticity. By balancing the elastic force of the gimbal 25 and the air bearing force, a certain distance is maintained between the slider 23 and the magnetic disk 24.
The control device 33 includes a line 31, a line 32, a line 28
The control signal is transmitted or received through the controller to control the operation of the magnetic disk drive. The drive motor 30 is connected to a line 31
Through the control device 33. An actuator 27 such as a voice coil motor is controlled to move and position the slider 23 to a predetermined position on the magnetic disk 24 through a line 28. The data on the magnetic disk 24 read by the magnetic head 22 is converted into an electric signal and decoded through a line 32. Data to be written on the magnetic disk 24 is transmitted to the magnetic head 22 through the line 32 as an electric signal.

When a conventional thin-film magnetic head is used as the magnetic head of the magnetic disk drive, a stress for peeling off the junction between the conductors is caused by thermal expansion of the insulator, and the stress constitutes the magnetic head. Since the larger the film thickness, the larger the film thickness, the film thickness could not be made too large. When a thin-film magnetic head having the bonding structure of the present invention is used, such stress due to thermal expansion of the insulator is reduced, so that the thickness of the film constituting the magnetic head can be increased. By increasing the thickness of the conductor, the width of the conductor coil can be reduced without increasing the resistance of the conductor. This leads to the fact that the radius of the spiral coil can be reduced in the examples of FIGS. In consideration of the effect of reducing the amount of the insulator interposed at the outer edge of the joint, the pattern of the element can be reduced. As a result, the thickness of the slider 23 can be reduced.
By reducing the mass and size of the slider 23 in this manner, the slider 23 can access a predetermined position on the magnetic disk 24 at high speed. Further, the load on the gimbal 25 and the arm 26 can be reduced.

[0036]

According to the present invention, the density and size of the thin-film magnetic head can be increased, and the density of the magnetic disk device can be increased and the access speed can be increased.

[Brief description of the drawings]

FIG. 1 is a diagram showing a thin film bonding structure according to a first embodiment of the present invention.

FIG. 2 is a process sectional view of the thin film bonding structure of FIG.

FIG. 3 is a process sectional view of the thin film bonding structure of FIG. 1;

FIG. 4 is a diagram showing a thin film bonding structure according to a first embodiment of the present invention.

FIG. 5 is a process sectional view of the thin film bonding structure of FIG. 4;

FIG. 6 is a diagram showing a thin film junction structure according to a second embodiment of the present invention.

FIG. 7 is a diagram showing a thin film junction structure according to a second embodiment of the present invention.

FIG. 8 is a cross-sectional view of the thin film bonding structure of FIG.

FIG. 9 is a diagram showing a thin film junction structure according to a second embodiment of the present invention.

FIG. 10 is a cross-sectional view of the thin film bonding structure of FIG.

FIG. 11 is a diagram showing a thin film bonding structure according to a second embodiment of the present invention.

FIG. 12 is a cross-sectional view of the thin film bonding structure of FIG.

FIG. 13 is a cross-sectional view of the thin film bonding structure of FIG.

FIG. 14 is a structural diagram of a thin-film magnetic head according to a third embodiment of the present invention.

FIG. 15 is a sectional view of the thin-film magnetic head of FIG. 14;

FIG. 16 is a sectional view of the thin-film magnetic head of FIG.

FIG. 17 is a structural diagram of a thin-film magnetic head according to a fourth embodiment of the present invention.

FIG. 18 is a configuration diagram of a magnetic disk drive according to a fifth embodiment of the present invention.

FIG. 19 is an explanatory view of a bonding part peeling mechanism of a conventional thin film bonding structure.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Substrate, 2 ... Under film, 3 ... Gap material, 4 ... First insulator layer, 5 ... First conductor layer, 6 ... Second insulator layer, 7 ... Second conductor layer, 8, 9, Reference numeral 10: outer peripheral portion of the bonding surface of the first conductive layer, 11: mask, 14: third conductive layer, 17: first magnetic body, 18: second magnetic body, 20: third insulating layer, 21 ...
Fourth insulator layer, 22: magnetic head, 23: slider, 2
4: magnetic disk, 25: gimbal, 26: arm, 2
7 ... actuator, 29 ... rotary axis, 30 ... drive motor, 33 ... control device, 37 ... protective film.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Naoto Saito 502, Kandachicho, Tsuchiura-shi, Ibaraki Pref.Mechanical Research Laboratory, Hitachi, Ltd. Within Storage System Division (72) Inventor Kiyonori Shiraki 2880 Kozu, Odawara-shi, Kanagawa Prefecture Storage System Division, Hitachi, Ltd.

Claims (3)

[Claims] 1. A magnetic disk for recording data,
In a magnetic disk drive provided with a magnetic head for recording and reproducing the data on and from the magnetic disk, the magnetic head has a laminated structure in which a conductive layer and an insulating layer are stacked, and the insulating layer among the conductive layers A first conductor layer laminated on a surface of the layer facing the substrate, and a first bonding surface formed on the first conductor layer with a second conductor layer laminated on the other surface of the insulating layer And a second bonding surface formed on the second conductor layer, and are electrically connected to each other at a bonding portion, and an outer edge of the first bonding surface and the second bonding surface at the bonding portion. A magnetic disk drive having an area directly joined to an outer edge of the magnetic disk without interposing an insulator. 2. A magnetic disk for recording data,
In a magnetic disk drive provided with a magnetic head for recording and reproducing the data on and from the magnetic disk, the magnetic head has a laminated structure in which a conductive layer and an insulating layer are stacked, and the insulating layer among the conductive layers A first conductor layer laminated on a surface of the layer facing the substrate, and a first bonding surface formed on the first conductor layer with a second conductor layer laminated on the other surface of the insulating layer And the second joint surface formed on the second conductor layer is electrically joined to each other at a joint portion, and the thickness of the first conductor layer near the first joint surface is reduced. A magnetic disk drive characterized in that the magnetic disk drive has a region where the magnetic disk drive operates. 3. A magnetic disk for recording data,
In a magnetic disk drive provided with a magnetic head for recording and reproducing the data on and from the magnetic disk, the magnetic head has a laminated structure in which a conductive layer and an insulating layer are stacked, and the insulating layer among the conductive layers A first conductor layer laminated on a surface of the layer facing the substrate, and a first bonding surface formed on the first conductor layer with a second conductor layer laminated on the other surface of the insulating layer And a second joint surface formed on the second conductor layer, and are electrically joined to each other at a joint portion, and further, the first conductor layer and the second conductor at the joint portion. A magnetic disk drive, wherein the layer has a region joined by a surface different from the first joint surface and the second joint surface.