JPH08147627A - Thin-film magnetic head and its manufacture - Google Patents

Abstract

PURPOSE: To obtain a thin-film magnetic head whose dielectric breakdown strength can be enhanced and which can be miniaturized by a method wherein the insulating distance between a magnetic pole and a coil lead can be made sufficiently large without making a coil diameter large. CONSTITUTION: Spiral coil films 18a,..., 18c in an odd number of steps (three steps or higher) are formed between a lower-part magnetic pole 12 and an upper-part magnetic pole. A coil lead 66 is formed on the inner circumferential side of the coil film in the lowermost step, and a coil lead 68 is formed on the outer circumferential side of the coil film in the uppermost step. The coil lead 66 in the lower part is formed simultaneously when the lower-part magnetic pole is formed, and the coil lead 68 in the upper part is formed simultaneously when the upper-part magnetic pole is formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin film magnetic head having an odd number of spiral coil films (three or more stages),
More specifically, the present invention relates to a thin film magnetic head in which the coil film at the lowermost stage is provided on the inner peripheral side and the coil film at the uppermost stage is provided on the outer peripheral side, and a manufacturing method thereof.

[0002]

2. Description of the Related Art An ordinary thin film magnetic head for a hard disk has a structure in which a lower magnetic pole and an upper magnetic pole provided on a ceramic substrate are separated by a gap film and a coil is formed therebetween. In order to increase the number of turns of the coil, it is general that a spiral coil film is stacked in a plurality of stages (usually 2 to 3 stages) via an insulating layer. For example, when three spiral coil films are stacked, the lowermost coil film has a lower coil lead-out portion on the outer peripheral side, and the uppermost coil film has an upper coil lead-out portion on the inner peripheral side.

An example of a conventional thin film magnetic head is shown in FIGS. These show the state immediately before forming the upper magnetic pole, FIG. 6 is a vertical sectional view taken along the line Y ₁ -Y _{2 of} FIG. 7, and FIG. 7 is a plan view. On the ceramic substrate 10, the lower magnetic pole 1
2, gap film 14, lower insulating film 16, lowermost coil film 18a, intermediate insulating film 20a, intermediate coil film 18b, intermediate insulating film 20b, uppermost coil film 18c, upper insulating film 22.
Are formed in that order, and further, the plating underlayer 24 and the upper magnetic pole (not shown) are formed in this order. In this example, the spiral coil film is provided in three stages. The lower coil lead-out portion 26 continuous with the lowermost coil film 18a is provided at a position on the outer peripheral side of the lowermost coil film 18a. Top coil film 1
Although not shown, the upper coil lead-out portion continuous with 8c is provided with a coil connection hole 28 on the inner peripheral side of the uppermost coil film 18c and is connected through the connection hole 28.

The upper coil lead-out portion is formed at the same time when the upper magnetic pole is formed. As shown in FIG. 8, after the state shown in FIG. 6, a photoresist 30 is provided on the plating underlayer. Next, a mask 32 having a predetermined shape is placed and exposed, and the exposed portion is removed to form a resist pattern for forming a magnetic pole. Then, plating is performed with a material such as a nickel-iron alloy, and the upper magnetic pole and the upper coil lead-out portion are simultaneously formed in the portion where the plating underlayer is exposed.

[0005]

The provision of the upper coil lead-out portion on the inner peripheral side of the uppermost coil film 18c means that the upper coil lead-out portion is located near the magnetic pole coupling hole 34. To do. The mask 32 as shown in FIG.
Then, as shown in the enlarged view, light is diffusely reflected by the wall surface of the magnetic pole coupling hole 34 and the wall surface of the coil connection hole 28 (a ray of light is shown by reference numeral 36), and the photoresist 30 is exposed to the side surface more than necessary. To do. Therefore, when the exposed portion is removed to form the resist pattern for forming the magnetic pole, the actually obtained resist pattern 38 for forming the magnetic pole becomes thin as shown by the solid line in FIG. The broken line shows an ideal resist pattern.

Such a magnetic pole forming resist pattern 3
When the upper magnetic pole and the upper coil lead-out portion are formed by using 8 (the upper magnetic pole and the upper coil lead-out portion to be formed are shown by imaginary lines and denoted by reference numerals 40 and 42 respectively), both are originally Even though they are designed to be separated by the distance d _1, they are actually separated only by the distance d ₂ . That is, there is a problem that the gap between the upper magnetic pole 40 and the upper coil lead-out portion 42 becomes abnormally close, and the withstand voltage between the coil and the magnetic pole is lowered. In order to improve this, the coil diameter must be increased more than necessary in the prior art, which causes a drawback that the thin film magnetic head becomes large.

The object of the present invention is to solve the above-mentioned drawbacks of the prior art, and to make the insulation distance between the magnetic pole and the coil lead-out portion sufficiently large without increasing the coil diameter, thereby making the thin film magnetic head compact. It is to provide the technology that can.

[0008]

According to the present invention, in a thin film magnetic head in which an odd-numbered (three or more) spiral coil film is formed between a lower magnetic pole and an upper magnetic pole, the lowermost coil film is used. Is a thin film magnetic head having a coil lead-out portion on the inner peripheral side and having a coil lead-out portion on the outer peripheral side for the uppermost coil film.

Further, according to the present invention, the lower magnetic pole, the gap film, the lower insulating film, the lowermost coil film, the intermediate insulating film, the intermediate coil film, the intermediate insulating film, the uppermost coil film, the upper insulating film and the upper magnetic pole are formed on the substrate. In the method for manufacturing a thin film magnetic head in which each coil film has a spiral shape and is stacked in an odd number of stages, a lower coil lead-out portion is formed at a position on the inner circumference side of the coil at the same time when the lower magnetic pole is formed. A method of manufacturing a thin-film magnetic head in which an upper coil lead-out portion is formed at a position on the outer peripheral side of the coil at the same time when the upper magnetic pole is formed.

[0010]

The lower coil lead-out portion is located on the inner circumference side of the coil, but the portion above the head element is substantially flat when the lower magnetic pole is formed, and irregular reflection does not occur during resist exposure.
Therefore, the side wall of the resist pattern for forming the lower magnetic pole is formed substantially vertically. Therefore, the side surfaces of the lower magnetic pole and the lower coil lead-out portion are also vertical, the distance between them can be made as specified by the photomask, the insulation distance can be sufficiently secured, and the two do not approach or join. Since the upper coil lead-out portion is located on the outer circumferential side of the coil, even if diffused reflection occurs during resist exposure before forming the upper magnetic pole and the upper magnetic pole formation resist pattern is somewhat destroyed, the upper magnetic pole and the upper coil lead-out portion are not separated. The distance is large and there is no problem in terms of insulation.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a thin film magnetic head according to the present invention is shown in FIGS. These also show the state immediately before forming the upper magnetic pole and the upper coil lead-out portion.
X ₁ -X ₂ vertical sectional view, and FIG. 2 is a plan view. On the ceramic substrate 10, the lower magnetic pole 12 and the lower coil lead-out portion 66, the gap film 14, the lower insulating film 16, the lowermost coil film 18a, the intermediate insulating film 20a, the intermediate coil film 18b,
The intermediate insulating film 20b, the uppermost coil film 18c, and the upper insulating film 22 are formed in this order, and further the plating underlayer 24, the upper magnetic pole and the upper coil lead-out portion (both not shown) are formed. This example also has a configuration in which three spiral coil films are provided. The lower coil lead-out portion 66 that is continuous with the lowermost coil film 18a is provided at a position on the inner peripheral side of the lowermost coil film 18a. The upper coil lead-out portion 68 that is continuous with the uppermost coil film 18c is provided with a coil connection hole 70 on the outer peripheral side of the uppermost coil film 18c, and is connected through the connection hole 70.

The lower coil lead-out portion 66 is formed at the same time when the lower magnetic pole is formed. As shown in FIG. 3A, a photoresist 72 is applied on the ceramic substrate 10 and a mask 74 is placed thereon. Then, by exposing and removing the exposed portion, a lower magnetic pole forming resist pattern 76 as shown in FIG. 3B is obtained. Next, plating with a material such as nickel-iron alloy is performed to simultaneously form the lower magnetic pole 12 and the lower coil lead-out portion 66 as shown in FIG. 3C. Resist pattern 7 for lower magnetic pole formation
Since 6 is provided in a substantially flat portion on the ceramic substrate 10, diffuse reflection of light does not occur during exposure, and a vertical and beautiful side wall surface can be obtained. Therefore, as shown in FIG. 3C, the lower magnetic pole 12 and the lower coil lead-out portion 66 can be separated by a distance d ₃ that exactly corresponds to the mask.

The upper coil lead-out portion is formed at the same time when the upper magnetic pole is formed. As shown in FIG. 4, after the state shown in FIG. 1, a photoresist 78 is provided on the plating underlayer. Next, a mask 80 having a predetermined shape is placed and exposed, and the exposed portion is removed to form a resist pattern 82 for forming a magnetic pole.
(See FIG. 5). Then, plating is performed with a material such as a nickel-iron alloy, and the upper magnetic pole 84 and the upper coil lead-out portion 68 (each shown by a virtual line in FIG. 5) are simultaneously formed in the portion where the plating underlayer is exposed.

The provision of the upper coil lead-out portion 68 on the outer peripheral side of the uppermost coil film 18c means that the coil lead-out portion 68 is located far away from the magnetic pole coupling hole 34. When the mask 80 is placed and exposed as shown in FIG. 4, as shown in an enlarged view, light is emitted from the magnetic pole coupling hole 3.
Diffuse reflection (light rays are shown by reference numeral 36) on the wall surface of No. 4 and the wall surface of the coil connection hole 70, and the photoresist 78 is exposed to the side surface more than necessary. Therefore, when the exposed portion is removed to form the resist pattern for forming the magnetic pole, the side surface of the actually obtained resist pattern for forming the magnetic pole 82 is cut, as shown by the solid line in FIG. The broken line shows an ideal resist pattern.

Such a magnetic pole forming resist pattern 8
When the upper magnetic pole 84 and the upper coil lead-out portion 68 are formed using 2, the distance d ₄ between the two is far, and therefore even if the side surfaces are disturbed and slightly protruded, no problem occurs on the insulation. That is, a sufficiently large insulation distance d ₄ can be secured between the upper magnetic pole and the upper coil lead-out portion, and there is no problem if the breakdown voltage between the coil and the magnetic pole is lowered.

The concept of the present invention can be applied to the case where the coil film has only one step. However, in the case of one step, the magnetic pole coupling hole is shallow and the upper coil lead-out portion is provided on the inner circumference side of the coil.
The side surface of the resist pattern for forming the upper magnetic pole is not disturbed so much that the breakdown voltage is hardly reduced. Further, when the coil film has an even number of stages, there is no room to apply the present invention because the coil lead-out portion can be formed on the coil outer peripheral side in both the lower portion and the upper portion. The present invention can be applied to the case where the coil film has five or more stages, but it is not practical to make the number of stages so large that the structure and the process become complicated, and normally, the number of stages is three. Needless to say, the present invention can be applied to all types of thin film magnetic heads in which spiral coil films are arranged in odd stages.

[0017]

As described above, according to the present invention, the lower coil lead-out portion is provided on the inner peripheral side of the lowermost coil film, and the upper coil lead-out portion is provided on the outer peripheral side of the uppermost coil film. With this configuration, the insulation distance between the magnetic pole and the coil lead-out portion can be increased without increasing the coil diameter, which improves the withstand voltage. Then, the thin film magnetic head can be downsized to the extent that the coil diameter does not need to be increased (specifically, for example, about one coil width can be downsized).

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a state of a thin film magnetic head according to the present invention in the process of being manufactured.

FIG. 2 is a plan view thereof.

FIG. 3 is an explanatory diagram showing a process of forming a lower magnetic pole and a lower coil lead-out portion.

FIG. 4 is an explanatory view showing an exposure process of a resist pattern for forming an upper magnetic pole in the present invention.

FIG. 5 is a cross-sectional view of a resist pattern for forming an upper magnetic pole, which is obtained thereby.

FIG. 6 is a vertical cross-sectional view showing a state of a conventional thin film magnetic head during manufacturing.

FIG. 7 is a plan view thereof.

FIG. 8 is an explanatory view showing a conventional exposure process of a resist pattern for forming an upper magnetic pole.

FIG. 9 is a sectional view of a resist pattern for forming an upper magnetic pole, which is obtained thereby.

[Explanation of symbols]

 10 Ceramics Substrate 12 Lower Magnetic Pole 14 Gap Film 16 Lower Insulating Film 18a Lowermost Coil Film 18b Intermediate Coil Film 18c Uppermost Coil Film 20a, 20b Intermediate Insulating Film 22 Upper Insulating Film 24 Plating Underlayer 66 Lower Coil Leader 68 Upper Coil extraction part 72,78 Photoresist 74,80 Mask 84 Top pole

Claims (2)

[Claims] 1. In a thin-film magnetic head having an odd-numbered (three or more) spiral coil film formed between a lower magnetic pole and an upper magnetic pole, a coil lead-out portion is provided on the inner peripheral side of the lowermost coil film. And a coil lead-out portion on the outer peripheral side of the uppermost coil film. 2. A lower magnetic pole, a gap film, a lower insulating film, a lowermost coil film, an intermediate insulating film, an intermediate coil film, on a substrate.
An intermediate insulating film, an uppermost coil film, an upper insulating film, and an upper magnetic pole are sequentially formed, and each coil film has a spiral shape. A method of manufacturing a thin film magnetic head, characterized in that a lower coil lead-out portion is formed at a position on the inner circumference side of the coil, and an upper coil lead-out portion is formed at a position on the outer circumference side of the coil at the same time when the upper magnetic pole is formed.