JP2785098B2 - Method for manufacturing thin-film magnetic head - Google Patents

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 used for writing / reading recording signals in a magnetic recording apparatus such as a magnetic disk drive, a flexible disk drive, a tape drive, a digital compact cassette and the like. More particularly, the present invention relates to a method for manufacturing an inductive thin film magnetic head that requires high dimensional accuracy at the tip of a magnetic pole.

[0002]

2. Description of the Related Art Conventionally, this kind of thin film magnetic head has
It is widely used to increase the recording density with the increase in capacity of a magnetic disk recording device, and is manufactured using a deposition technique such as electroplating or sputtering and a fine processing technique by photolithography. FIG. 7 shows an example of such a thin-film magnetic head for in-plane recording / reproducing. A lower magnetic film 2, a magnetic gap film 3 of alumina, and a lower insulating material of an organic resin material are formed on a substrate 1 of ceramic material. A layer 4, a conductor coil 5, an interlayer insulating layer 6, an upper insulating layer 7, an upper magnetic film 8, and an alumina protective film 9 are sequentially laminated. The lower magnetic film 2 and the upper magnetic film 8 form a rear gap 1 at the rear.
At the front end portion which is magnetically coupled at 0 and faces the magnetic recording medium, a pair of upper and lower magnetic poles 11 and 12 oppose each other with the magnetic gap film 4 interposed therebetween to form a magnetic circuit. Then, the write signal is converted into an inductive magnetic signal or the magnetic signal is converted into an electric signal by the conductor coil 5 spirally wound around the rear gap 10, so that the magnetic signal is transferred to the magnetic recording medium at the magnetic pole. Write information of
Perform reading.

In order to obtain a high reproduction output, it is necessary to increase the number of turns of the conductor coil. However, simply increasing the number of turns of the coil enlarges the upper and lower magnetic films and increases the length of the magnetic circuit from the tip of the magnetic pole to the coupling portion.
Electromagnetic conversion efficiency decreases. For this reason, by increasing the number of coil turns without excessively lengthening the magnetic circuit by forming the spiral conductor coil into a multilayer structure, a coil having two to four layers is usually used.

On the other hand, for high recording density and high speed, a thin track of a thin film magnetic head is required to be narrow. Since the track width is defined by the tip of the upper magnetic pole facing the recording medium, it is necessary to process the dimensions of the upper magnetic film, particularly the tip of the magnetic pole, with high precision.

Generally, the upper magnetic film is formed by electroplating using a photolithography technique as illustrated in FIG. After coating the plating base film 13 on the substrate 1 on which the lower magnetic film 2, the magnetic gap film 3, the insulating layers 4, 6, the conductor coil film 5, and the upper insulating layer 7 are laminated, a photoresist is applied to the surface by spin coating. I do. By arranging a photomask thereon, exposing and developing, a resist frame 14 for defining an upper magnetic film having a predetermined shape and dimensions is patterned. Next, for example, a NiFe film is electroplated using the resist frame 14 as a mask, and the resist frame, the unnecessary NiFe film and the plating base film are removed by etching, whereby a desired upper magnetic film is obtained. Therefore, in order to increase the dimensional accuracy of the upper magnetic pole, it is important to accurately pattern the resist frame.

[0006]

However, the conventional method of manufacturing a thin film magnetic head described above cannot sufficiently control the dimensional accuracy of the track width when processing the upper magnetic pole, as described below. There was a problem.

[0007] The thickness of the photoresist applied by spin coating is very difficult to control with high precision, and thus tends to vary depending on the position on the substrate. In particular, when trying to apply a thick photoresist, the rotation of the spin coat is reduced, so that the variation in the film thickness is further increased. The patterning of the photoresist is usually performed using an exposure device having a focus function. However, if the thickness variation is too large, it becomes difficult to adjust the focus, and the dimensional accuracy of the resist frame is reduced as a whole.

In the case of a thin film magnetic head having a multilayer coil as shown in FIGS. 7 and 8, an upper magnetic film 8 is formed.
In the structure shown in FIG.
Form upper magnetic pole 12 opposed to lower magnetic pole 11
Including the inclined portions formed by the insulating layers 4 and 6, between the tip portion, ie, the lowest portion, and the upper surface of the upper insulating layer 7.
A large step of about 0 μm is formed. For this reason,
The thickness of the photoresist applied from above is inevitably increased in the region B of the tip portion, and gradually decreased from the inclined portion toward the upper insulating layer 7, and particularly, the thickness of the photoresist applied from the upper insulating layer upper surface decreases. It becomes the thinnest at the corner A that transitions to the portion. Here, the forehead in the region B of the tip portion
If the thickness of the photoresist is too large, the dimensional accuracy of the resist frame is reduced as described above, and an upper magnetic pole having a desired size cannot be obtained, which may adversely affect the track width. Conversely, if the thickness of the tip portion is set so that a predetermined dimensional accuracy is obtained in the resist frame, the thickness of the upper insulating layer becomes too thin on the upper surface, and the height of the resist frame cannot be sufficiently obtained. . For this reason, when electroplating the upper magnetic film, the plating film is formed beyond the resist frame to cause overhang, which causes overetching in the subsequent etching process.

[0009] Therefore, the method of manufacturing the thin film magnetic head of the present invention has been made in view of the aforementioned problems, and an object, the upper magnetic film by electroplating using photolithography In forming the magnetic head , in particular, it is possible to control the dimension in the track width direction of the tip of the upper magnetic pole constituting the tip part with high precision, thereby achieving narrowing of the track, achieving high recording density and high speed. A method of manufacturing a thin-film magnetic head capable of preventing overhang of a plating film and eliminating the risk of over-etching, thereby improving yield and productivity and reducing manufacturing cost. Is to provide.

[0010]

According to the present invention, there is provided a method of manufacturing a thin-film magnetic head, comprising: a lower magnetic film having a lower magnetic pole; a magnetic gap film; A photoresist formed by patterning a photoresist on a substrate on which an insulating layer and a conductor coil film are laminated.
By electroplating using the dying frame as a mask
Thus, the upper portion opposing the lower magnetic pole via the magnetic gap film
Fabrication of thin-film magnetic head forming upper magnetic film with magnetic pole
In the manufacturing method, the first photo-coated on the substrate
Attempts to form the resist, at least its top pole
By patterning except for the part of the region that
A first resist frame portion is formed, and a first resist frame portion is formed thereon.
At least partially include the resist frame portion of
A second photoresist applied to the top pole
Pattern to include the portion of the area to be formed
To integrate with the first resist frame
To form a second resist frame portion.
A resist frame comprising first and second resist frame portions
From the step of forming the upper magnetic film using a frame.
The first photoresist is used for the second photoresist.
It is characterized by having a higher viscosity than dist . Claim
2. The method of manufacturing a thin-film magnetic head according to claim 2,
1, the first resist frame portion
Forming the first photoresist,
Is characterized by further heat treatment after patterning.
I do.

[0011]

Therefore, according to the method for manufacturing a thin film magnetic head of the first aspect , the first photoresist is made to have a high viscosity.
This makes the lamination of the insulating layer and the conductor coil film
Thick coating can be applied on the upper part of the step formed by
Therefore, this should be considered as the area where the upper magnetic film is to be formed.
Excluding the area where the upper pole is to be formed
Patterning according to the upper part of the step
Therefore, the first resist frame portion charges the upper magnetic film.
It is formed to a predetermined size and dimensional accuracy so as to have a height sufficient for electroplating . In addition, the second photo register
The strike is moved to the region where the upper magnetic pole is to be formed, ie, the step.
By patterning according to the lower part of
A second resist frame portion is formed with predetermined dimensions and dimensional accuracy , and the first resist frame portion is defined as a core.
As a result, predetermined dimensions and dimensional accuracy can be ensured as the entire final resist frame for electroplating the upper magnetic film. In addition to this
Instead, according to the method of manufacturing a thin-film magnetic head according to claim 2,
If the first resist frame is cured by heat treatment
Not only do they shrink, but they also have a rounded shape
The upper edge of the first resist frame portion,
The resist frame part of the core is applied as a core
Is filled with the second photoresist, so that the final
Thus, a resist frame with high dimensional accuracy can be obtained.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for manufacturing a thin-film magnetic head according to the present invention will be described below in detail with reference to FIGS.

Referring to FIG. 1A, an Al ₂ O ₃ —
On the ceramic substrate 1 made of TiC, a lower magnetic film 2 is patterned into a predetermined size and shape by sputtering or electroplating a permalloy alloy or the like by a known method, and a magnetic material such as alumina is formed thereon. Gap film 3, lower insulating layer 4, such as novolak resin, C
A conductor coil 5 having a four-layer structure made of u, an interlayer insulating layer 6 also made of novolak resin or the like, and an upper insulating layer 7 are laminated using a photolithography technique. A region where an upper magnetic pole facing the lower magnetic pole 11 at the front end of the lower magnetic film 2 with the magnetic gap film 3 interposed therebetween, that is, a front end portion 15 is formed on the substrate by the conductor coils 5 stacked in four layers.
If, between it than by laminating the rear of the upper insulating layer 7 portion, a large step is generated. By coating the entire substrate 1 on which the respective film layers are deposited, for example, with a permalloy alloy by sputtering or the like, the plating base film 13 is formed.
Is formed.

Next, as shown in FIG. 1B, a novolak resin-based positive photoresist 16 having a relatively high viscosity of, for example, about 200 to 500 cP is applied to the entire substrate 1 by spin coating. Thus, the thickness of the photoresist 16 on the upper insulating layer 7 can be made larger than before. The photoresist 16 is exposed by placing a photomask 17 thereon, developed using an ordinary developer, and washed with water. The photomask has an upper surface of the upper insulating layer 7 and an upper portion of the step, that is, an inclined portion between the upper insulating layer and the tip portion 15 so that good dimensional accuracy can be obtained regardless of the step. At 18, an exposure pattern is formed so as to leave the photoresist 16 at an upper position near the upper insulating layer.

The photoresist 16 is subjected to a heat treatment so as not to be deformed in the subsequent steps. In this embodiment, about 1 to about 140 ° C.
Bake for 2 hours. Thereby, as shown in FIGS. 1C and 2, the first frame portion 19 constituting the core portion of the resist frame for the final upper magnetic film, which will be described later,
Is obtained. The first frame portion 19 is patterned as described above, so that a final frame is formed as described later.
It is continuous from the leading end portion 15 when defining a resist frame
The lower end of the step, that is, at least the tip portion 15 at the lowest position of the step, while having a portion extending the inclined portion 18 downward from the upper insulating layer.
Are formed in the area excluding . As is well known, the novolak-based resin has fluidity and slightly shrinks when heated, so that the first frame portion 19 has an upper edge portion which is entirely rounded as shown in FIG. Or because the photoresist 16 is provided thicker than before as described above,
It is high enough to electroplate the top magnetic film.

Next, as shown in FIG. 4A, a novolak resin-based positive photoresist 20 having a relatively low viscosity of about 50 to 150 cP is applied to the entire substrate by spin coating. The spin coating is preferably performed at a relatively high speed so that the film thickness of the photoresist 20 becomes more uniform, and it is more convenient to set the rotation speed to 2000 rotations or more per minute. The photomask 2 is again placed above the substrate covered with the photoresist 20 in this manner.
1 is arranged, exposed and patterned. Unlike the photomask 17 of FIG. 1-B, the photomask 21 has an exposure pattern that matches the size and shape of the upper magnetic film to be formed. Therefore, by developing the photoresist 20 to remove the exposed portions and applying a heat treatment, as shown in FIG. 4A, the outer periphery of the final resist frame is added to the first frame portion 19 formed earlier. Are integrated with each other.

In the second exposure operation, the upper magnetic pole is
The focus and amount of exposure are appropriately adjusted so that desired good dimensional accuracy is obtained in the vicinity of the tip portion 15 which is the region to be formed . Therefore, in the vicinity of the upper insulating layer 7 where the first frame portion 19 has been previously formed, the exposure is not focused, and the photoresist 20 is applied only thinly, resulting in an overexposed state. However, the first frame portion 19 already heat-treated as described above is used.
Becomes a core, the rounded upper edge portion is also replenished by the second frame portion 22, and as shown in FIGS. 5 and 6, the first and second frame portions are integrated into a desired shape. A resist frame 23 for the upper magnetic film having dimensional accuracy and a sufficient height is obtained.

In this embodiment, when the second frame portion 22 is formed, the photoresist 20 is applied on the substrate so as to include the entire first frame portion 19 formed previously. However, in another embodiment, The coating can be performed so as to include only the portion near the distal end portion 15 of the first frame portion 19. Also in this case, the second frame portion 22 forms the desired resist frame 23 continuously and integrally with the first frame portion.

Using the resist frame 23 as a mask, a known soft magnetic material such as a permalloy alloy, for example, Ni
By electroplating the Fe film, an upper magnetic film 8 as shown in FIG. 7 is formed. According to the experimental results of the applicant of the present application, as shown in Table 1 below, the dimensional accuracy of the upper magnetic pole in the track width direction is greatly improved and the occurrence rate of overhang is significantly higher than that of the conventional method. To solve the problem of over-etching.

[0020]

[Table 1]

Although the present invention has been described with reference to the embodiments, it will be apparent to those skilled in the art that the present invention can be implemented by adding various modifications and alterations to the above embodiments within the technical scope thereof. Can be.

[0022]

Since the present invention is configured as described above, it has the following effects.

According to the method of manufacturing a thin-film magnetic head according to the first aspect, first, by laminating a conductor coil, an insulating film and the like.
Despite the steps that occur on the substrate, as a final resist frame as a whole for electroplating the upper magnetic film,
Since a predetermined dimension and dimensional accuracy is ensured, using the same
An upper magnetic film formed Te is lower at the tip portion, that the step
In the upper magnetic pole formed in the region, a desired high dimensional accuracy, particularly a desired dimensional accuracy in the track width direction can be obtained, thereby further narrowing the track, achieving high recording density and high speed. Becomes possible. Furthermore, the final
Typical resist frame is the first resist frame part
Of the upper magnetic film to be formed above the step
By ensuring that the part is high enough,
There is a possibility that this may occur when the upper magnetic film is electroplated.
Since overhang can be reliably prevented and the problem of over-etching can be solved, the yield is greatly improved, the productivity is improved, and the manufacturing cost can be reduced. 3. The method of manufacturing a thin-film magnetic head according to claim 2,
For example, the core of the first resist frame portion is formed by heat treatment.
Function is further exhibited, and finally high enough
And a resist frame with high dimensional accuracy can be obtained.
It is possible to further narrow the track and improve the yield.
Wear.

[Brief description of the drawings]

FIG. 1 shows the first half of a step of forming an upper magnetic film by a method of manufacturing a thin-film magnetic head according to the present invention in the order of steps A;
FIG. 10 is a cross-sectional view consisting of FIGS.

FIG. 2 is a schematic perspective view showing a state of a substrate on which a core portion of a resist frame is formed.

FIG. 3 is a vertical sectional view taken along line III-III in FIG. 2;

FIG. 4 is a cross-sectional view including A and B showing the latter half of the step of forming an upper magnetic film by the method of the present invention in the order of steps.

FIG. 5 is a schematic perspective view showing a state of a substrate on which a resist frame has been completed.

6 is a vertical sectional view taken along line VI-VI of FIG.

FIG. 7 is a cross-sectional view showing a configuration of a conventional typical in-plane recording / reproducing thin film magnetic head.

FIG. 8 is a cross-sectional view showing a substrate on which a resist frame of an upper magnetic film is formed by a conventional method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Lower magnetic film 3 Magnetic gap film 4 Lower insulating layer 5 Conductor coil 6 Interlayer insulating layer 7 Upper insulating layer 8 Upper magnetic film 9 Protective film 10 Rear gap 11 Lower magnetic pole 12 Upper magnetic pole 13 Plating base film 14 Resist frame 15 Tip Part 16 Photoresist 17 Photomask 18 Inclined part 19 First frame part 20 Photoresist 21 Photomask 22 Second frame part 23 Resist frame

Continuing on the front page (72) Inventor Hiroaki Minami 2-15-17 Egawa, Shimamoto-cho, Mishima-gun, Osaka Prefecture Inside (72) Inventor Takao Hashiguchi 2-15-17, Egawa, Shimamoto-cho, Mishima-gun, Osaka Inside Readlight SMI Co., Ltd. (72) Tomohisa Umemoto 2-15-17 Egawa, Shimamoto-cho, Mishima-gun, Osaka Prefecture Inside 72-inch Readlight SMI Co., Ltd. -15-17 Inside Readlight SMI Co., Ltd. (72) Ronald A. Barr, Witzroad 111, Mountain View, 94040, California, U.S.A., USA (56) References JP-A-63-39110 (JP) JP-A-6-44526 (JP, A) JP-A-4-146508 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G11B 5/31

Claims (2)

(57) [Claims] 1. A substrate on which a lower magnetic film having a lower magnetic pole, a magnetic gap film, an insulating layer, and a conductor coil film are laminated,
By electroplating using a resist frame formed by patterning the photoresist as a mask,
A method of manufacturing a thin-film magnetic head for forming an upper magnetic film having an upper magnetic pole opposed to the lower magnetic pole via the magnetic gap film, wherein a first photoresist applied on the substrate is provided. At least a portion of the region where the upper magnetic pole is to be formed
Except, by patterning, the first resist frame portion is formed, thereon, a second photoresist coating the first resist frame portion so as to at least partially contain
And the portion of the region where the upper magnetic pole is to be formed
By patterning to include the first
Be integrated with the resist frame portion to form a second resist frame portion, by using a resist frame consisting of the first resist frame portion and the second resist frame portion, forming the upper magnetic layer made, the first photoresist, the second photoresist
A method for manufacturing a thin-film magnetic head, which has a higher viscosity than the above . (2) Forming the first resist frame portion
The first photoresist is patterned.
After annealing, further heat treatment
Item 3. A method for manufacturing a thin film magnetic head according to Item 1.