JP2567221B2 - Thin film magnetic head and method of manufacturing the same - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin film magnetic head for a magnetic recording device and a manufacturing method thereof, and particularly to a thin film magnetic head for forming a highly accurate magnetic core shape and the same. It relates to a manufacturing method.

[Conventional technology]

FIG. 2 is a sectional view showing an example of a magnetic core portion of a conventional thin film magnetic head. In FIG. 2, reference numeral 21 is a substrate,
22 is a lower magnetic film, 23 is an upper magnetic film, 24 is a tip portion, 25 is a gear material, 26 is a conductor coil, and 27 is an organic resin film. A permalloy film 22 serving as a lower magnetic film is formed on the substrate 21, and constitutes a magnetic circuit together with a permalloy film 23 serving as an upper magnetic film formed later. Tip
In 24, a magnetic tape 25 is formed by interposing a gear material 25 made of an alumina film between the two permalloy films 22 and 23, and the magnetic material is written on the recording medium, for example, a magnetic disk by using the gear material. Read out. The principle is the same even when the medium is a magnetic tape.
A conductor coil 26 is provided between the permalloy films 22 and 23 so as to intersect the magnetic circuit, and the conductor coil is insulated by the permalloy films 22 and 23 and the organic resin film 27. The organic resin film 27 needs to have a thickness of about 10 μm or more in order to reduce the leakage magnetic flux between the permalloy films 22 and 23.

Now, as a patterning method of the permalloy film 23, a method of etching with a photosensitive resin film as a mask, a method of depositing permalloy on a portion without a photosensitive resin film by a selective plating method, and the like are considered. Even if the method is selected, it is necessary to pattern the photosensitive resin film in the place where there is a step of about 10 μm or more. On the other hand, in the thin film magnetic head, 1 μm is applied to the tip portion 24 of the permalloy film 23.
A pattern accuracy of m or less is required.

FIG. 3 shows, for example, as described in JP-A-60-37130, on a surface having the above-mentioned step,
It is a flowchart showing a process of patterning a photosensitive resin film typically. In FIG. 3, reference numeral 31 is a substrate, 33
Is a permalloy film, 34 is a step lower part, 37 is an organic resin film, 38 is a photosensitive resin film, and 39 is a photomask. FIG. 3A is a cross-sectional view of a pattern of an organic resin film 37 formed on a substrate 31 and a permalloy film 33 deposited thereon. When the photosensitive resin film 38 is applied and dried on this, the cross-sectional shape shown in FIG. 3B is obtained. Next, when exposure is performed using a contact mask aligner, the photosensitive resin film 38 adheres to the photomask 39 in the center of the pattern of the organic resin film 37, but the photosensitive resin film 38 separates from the photomask 39 in other portions. It is exposed in the state. The light used for exposure is close to parallel light, but when the light cannot be brought into close contact, it is in the same state as when it is out of focus, and the light distribution becomes broad. Even when the projection type mask aligner is used, the entire surface is out of focus because the surface of the photoresist film is uneven. Therefore, as shown in FIG. 3 (c), in the pattern of the photosensitive resin film 38 obtained after exposure and development, the resin film size is smaller than the photomask size in the lower part 34 of the step of the organic resin film 37. Change, and the variation becomes large. Therefore, as shown in FIG. 3 (d), even after the permalloy film 33 was patterned, the dimensional variation of the tip portion 34 became large, and a highly accurate shape of the tip portion of the magnetic film could not be obtained.

Therefore, for example, as shown in Japanese Patent Application No. 58-197695, a photosensitive resin film 38 is applied thickly to flatten the surface, and then the entire surface is exposed to etch the photosensitive resin to a predetermined film thickness. , A method of improving the close contact with the photomask has been proposed.

[Problems to be solved by the invention]

However, since it is difficult to control the etching film thickness by exposure, and the photosensitive resin film thickness during patterning is large and the dimensional accuracy tends to be poor, it has hardly been applied in practice.

An object of the present invention is to provide a magnetic film tip portion of a thin film magnetic head,
It is an object of the present invention to provide a thin film magnetic head for highly accurate patterning and a method for manufacturing the same.

[Means for solving problems]

Briefly describing the present invention, the first invention of the present invention relates to a thin film magnetic head, and in a thin film magnetic head formed by sequentially laminating a lower magnetic film, a magnetic gap film and an upper magnetic film on a substrate, Alternatively, with respect to the step formed on the underlying film on the substrate, a tip portion facing the magnetic disk of the lower magnetic film and the upper magnetic film is provided directly above the step, and the lower magnetic film is formed below the step. It is characterized by having a portion other than the tip portion.

A second invention of the present invention relates to a method for manufacturing a thin film magnetic head, which is a method for manufacturing a thin film magnetic head in which a lower magnetic film, a magnetic gap film and an upper magnetic film are sequentially laminated on a substrate, A step of forming a step on the base film on the substrate, a step of forming a lower magnetic film on the step, a tip portion of the lower magnetic film facing the magnetic disk is arranged immediately above the step, and A step of forming the lower magnetic film pattern so that a portion of the magnetic film other than the tip portion is located under the step, a step of forming a magnetic gap film on the lower magnetic film pattern, and an upper magnetic film formed thereon And a step of forming the upper magnetic film pattern so that at least a tip portion of the upper magnetic film facing the magnetic disk is disposed immediately above the step.

One of the methods for patterning a photosensitive resin film with the highest accuracy according to the present invention is to perform exposure using a contact type mask aligner while the photomask and the thin photosensitive resin film are in good contact with each other. It was made paying attention to that. The feature of the present invention is that a step is formed in advance on the substrate or the underlayer film of the magnetic film tip in order to bring the photomask and the thin photosensitive resin film into close contact at the time of patterning the magnetic film tip, which requires the most dimensional accuracy. The point is that the tip of the magnetic film is formed at the upper part of the step.

As a method for forming the step, there are a method of forming an underlying film on the substrate and then etching away unnecessary portions, and a method of etching or machining the substrate in advance to make the substrate itself uneven.

Although the step may be formed only at the tip of the magnetic film,
Depending on the suitability of the element formation process, steps including other parts may be formed. For example, by embedding the magnetic film part excluding the tip part in the concave part on the substrate, the original purpose is achieved. Is also good.

The step material is not particularly limited as long as a predetermined shape can be obtained, but it is preferable to use materials such as a substrate, an insulating film, and a protective film that form the thin film magnetic head.

In order to increase the recording density, the write bit length must be shortened. For this, a magnetic disk,
It is necessary to increase the coercive force of a recording medium such as a magnetic tape, but in order to write on this medium with a magnetic head, it is necessary to maximize the write magnetic field leaking from the magnetic gear at the tip of the head.

Fig. 6-1-1 shows a cross-sectional view of a conventional thin film magnetic head.
FIG. 6-1-2 shows a front view seen from the medium facing surface. Further, FIG. 6-2-1 shows a cross-sectional view of the thin film magnetic head of the present invention, and FIG. 6-2-2 shows a front view seen from the medium facing surface. In each figure, reference numeral 61 is a protective film, 62 is a lower magnetic film, and 63
Is an upper magnetic film, 68 is an upper magnetic film inclined portion, and 69 is a lower magnetic film inclined portion.

As shown in the respective front views, the cross-sectional area of the lower magnetic film 62 is larger than the cross-sectional area of the upper magnetic film 63 that determines the write track width (Tw). Therefore, in the conventional magnetic head, the sixth-
The magnitude of the write magnetic field was limited by the cross-sectional area of the upper magnetic film inclined portion 68 in FIG. However, according to the present invention, since the cross-sectional area of the lower magnetic film inclined portion 69 that limits the magnitude of the write magnetic field can be made larger than that of the irradiation, magnetic flux saturation in the magnetic film portion can be prevented and the write magnetic field can be increased. .

FIG. 7 is a graph showing the relationship between the write current (mA o-p, horizontal axis) flowing through the conductor coil of the magnetic head and the magnitude of the write magnetic field leaking from the magnetic gear (kA / m, vertical axis). . The solid line in the graph represents the conventional product, and the dotted line represents the product of the present invention. The spacing is 0.3 μm. By applying the present invention, the write magnetic field can be increased and a thin film magnetic head suitable for high density recording can be realized.

〔Example〕

Hereinafter, the present invention will be described more specifically with reference to Examples, but the present invention is not limited to these Examples.

Embodiment 1 An embodiment of the present invention will be described with reference to FIG. That is, FIG. 1 is a process diagram showing a process as one embodiment of the present invention. In FIG. 1, 11 is the substrate, 12 is the lower magnetic film, 13 is the upper magnetic film, 14 is the tip of the magnetic film, 15 is the gap material, 16 is the conductor coil, 17 is the organic insulating film, and 18 is the underlying step. To do. As shown in FIG. 1 (a), an Al ₂ O ₃ film 18 having a thickness of 10 μm is formed on the ceramic substrate 11, and then a predetermined pattern is formed by wet etching, as shown in FIG. 1 (b). The cross-sectional structure was obtained. Next, a permalloy film was formed as the lower magnetic film 12, and a magnetic core shape was formed by etching to obtain a cross-sectional structure shown in FIG. 1 (c). In the step of forming the photosensitive resin film pattern that will be the etching mask, the magnetic film tip portion 14, which requires precise dimensional accuracy, is above the base step 18, so that the photosensitive resin film can be formed thinly and at the time of exposure. The photomask and the surface of the photosensitive resin film were in close contact with each other, and highly precise patterning was possible. Further, the permalloy film 12 other than the tip portion is below the underlying step 18, and the patterning accuracy is poor, but the required dimensional accuracy of this portion is relatively gentle, and there was no problem.

Next, as shown in FIG. 1D, a gear material 15, a conductor coil 16 and an organic resin film 17 were formed. Organic resin film 17
The surface of the
Was formed so as to be flush with or slightly lower than the surface of. Then, a permalloy film to be the upper magnetic film 13 is formed, and a magnetic core shape is formed by etching.
A thin film magnetic head having a sectional structure shown in FIG.
In the process of forming the photosensitive resin film pattern that will be the etching mask, the resin film application surface is almost flat, so the photosensitive resin film can be thinly formed and the photomask and the photosensitive resin film surface are in good contact during exposure. As a result, highly precise patterning was achieved.

FIG. 4 shows the in-plane distribution of the dimensions of the magnetic film tip portion 14 when the element is formed on the substrate having a diameter of 76 mm. Figure 4-1 shows the conventional method, that is, the tip of the magnetic film below the step.
14 shows the result when 14 is patterned,
FIG. 2 shows the result of the method of the present invention, that is, the patterning of the magnetic film tip portion 14 on the step.
It has been found that the method of the present invention can reduce the dimensional variation and obtain a dimension value close to the photomask dimension.

Reference Example 1 A reference example of the present invention will be described with reference to FIG. That is, FIG. 5 is a process diagram showing a process as a reference example of the present invention. In FIG. 5, reference numeral 51 is a ceramic substrate, 52 is a lower magnetic film, 53 is an upper magnetic film, 54 is a tip of the magnetic film, 55 is a gear material, 56 is a conductor coil, 57 is an organic resin film, 58 is a groove,
59 means the tip of the organic resin film. After forming a groove 58 having a depth of 10 μm on the ceramic substrate 51 as shown in FIG. 5 (a), a permalloy film pattern as the lower magnetic film 52 is formed to obtain the structure shown in FIG. 5 (b). Obtained. Since the magnetic film tip portion 54, which requires precise dimensional accuracy, is located above the groove 58, the photosensitive resin film can be thinly formed, and at the time of exposure, the photomask and the surface of the photosensitive resin film are in close contact with each other, resulting in high accuracy. The patterning was completed.

Next, as shown in FIG. 5C, a gear material 55, a conductor coil 56, and an organic resin film 57 were formed. Organic resin film 57
The surface of was formed so as to be flush with or slightly lower than the surface of the gear material 55 formed on the substrate 51. Then, a permalloy pattern was formed as the upper magnetic film 53 to obtain a thin film magnetic head having a sectional structure shown in FIG. Since the upper part of Permalloy 53 is almost flat, the photosensitive resin film can be formed thinly, and the photomask and the surface of the photosensitive resin film are in close contact with each other at the time of exposure, and highly precise patterning can be performed.

Further, in the thin film magnetic head, the organic resin film front end portion 59 must be accurately formed at a predetermined inclination angle due to the requirement of magnetic characteristics, but in the present embodiment, the groove 58 on the substrate is processed / formed. In doing so, it is easy to set the inclination angle to a predetermined value, and there is an advantage that an organic resin film having a highly accurate inclined surface can be formed.

〔The invention's effect〕

According to the present invention, since patterning can be performed in a state where the photomask and the thin photosensitive resin surface are in close contact with each other, a thin film magnetic head having a highly accurate magnetic film shape can be formed.

Further, according to the present invention, saturation of magnetic flux in the magnetic film portion can be prevented, the write magnetic field can be increased, and a thin film magnetic head suitable for high density recording can be realized.

[Brief description of drawings]

FIG. 1 is a process diagram showing a process as one embodiment of the present invention, FIG. 2 is a sectional view for explaining the structure of a conventional thin film magnetic head, and FIG. 3 is a manufacturing process of a conventional thin film magnetic head. 4-1 is a process diagram showing the conventional method, FIG. 4-2 is a graph showing each effect of the method of the present invention, FIG. 5 is a process diagram showing a process as a reference example of the present invention, 1 is a sectional view of a conventional thin film magnetic head, FIG. 6-1-2 is a front view seen from the medium facing surface, and FIG. 6-2-1 is a sectional view of the thin film magnetic head of the present invention. FIG. 6-2-2 is a front view seen from the medium facing surface, and FIG. 7 is a graph showing the relationship between the write current flowing through the conductor coil of the magnetic head and the magnitude of the write magnetic field leaking from the magnetic gear. 11 and 51: substrate, 12, 52 and 62: lower magnetic film, 13, 53 and
63: upper magnetic film, 14 and 54: tip of magnetic film, 15 and 55: gear material, 16 and 56: conductor coil, 17: organic insulating film, 18:
Base step, 57: Organic resin film, 61: Protective film

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masanobu Kazono 4026 Kujimachi, Hitachi, Ltd. Hitachi Ltd., Hitachi Research Laboratory (72) Shinji Narushige 4026 Kujicho, Hitachi Hitachi, Ltd. Hitachi, Ltd. In-lab (72) Inventor Osamu Hirai 2880 Kozu, Odawara City Odawara factory, Hitachi, Ltd. (56) Reference JP 57-113411 (JP, A) JP 60-113312 (JP, A) JP 55-93519 (JP, A) JP-A 61-153816 (JP, A)

Claims (3)

(57) [Claims] 1. A thin film magnetic head comprising a substrate, a lower magnetic film, a magnetic gap film, and an upper magnetic film, which are laminated in this order.
With respect to the step formed on the substrate or the base film on the substrate, there is a tip portion facing the magnetic disk of the lower magnetic film and the upper magnetic film immediately above the step, and below the step,
A thin-film magnetic head having a portion of the lower magnetic film other than the tip portion. 2. A method of manufacturing a thin film magnetic head in which a lower magnetic film, a magnetic gap film, and an upper magnetic film are sequentially laminated on a substrate, a step of forming a step on a substrate or a base film on the substrate, and a lower step on the step. A step of forming a magnetic film, so that a tip of the lower magnetic film facing the magnetic disk is arranged directly above the step, and a portion other than the tip of the lower magnetic film is arranged below the step. A step of forming the lower magnetic film pattern, a step of forming a magnetic gap film on the lower magnetic film pattern, a step of forming an upper magnetic film on the lower magnetic film pattern, and a tip portion of at least the upper magnetic film facing the magnetic disk. A method of manufacturing a thin film magnetic head, comprising a step of forming the upper magnetic film pattern so as to be arranged directly above a step. 3. The step of forming the lower magnetic film pattern and the upper magnetic film pattern forms a photosensitive resin pattern on the step and performs etching or plating using the pattern. 2. A method of manufacturing a thin film magnetic head according to claim 2.