JPH0721517A - Thin-film magnetic head - Google Patents

Abstract

PURPOSE:To improve the infiltration of an org. insulating resin and to sufficiently thicken an insulating film in the thin-film magnetic head having a magnetic circuit consisting of a magnetic film and a conductor coil film by eliminating the angular part on the upper edge of the magnetic film. CONSTITUTION:The angular part on the upper edge of a magnetic thin film 3 formed on an insulating film 2 on a substrate 1 is ground and rounded. Consequently, the infiltration of an org. insulating resin into the insulating film 5 on a gap 4 is improved, and the film 5 including the part corresponding to the upper end of the film 3 is sufficiently thickened. Meanwhile, a conductor coil film 8 forming a magnetic circuit with the film 5 is formed on the film 5. Since the film 5 is thickened in this way, the insulation between the magnetic film and the coil film is enhanced, and a thin-film magnetic head with the reliability improved by increasing the dielectric breakdown voltage is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a thin film magnetic head used in, for example, a magnetic disk device or other magnetic recording / reproducing device.

[0002]

2. Description of the Related Art Conventionally, a thin film magnetic head has been adopted in order to improve the recording density and the information transfer rate as the performance of a magnetic disk device is improved. Generally, a thin film magnetic head is manufactured by using a deposition technique such as electroplating or sputtering, and a fine processing technique by photolithography.

8 and 9 schematically show the structure of a conventionally known in-plane recording / reproducing thin film magnetic head. An insulating film 2 made of alumina or the like is deposited on a substrate 1 made of an Al ₂ O ₃ —TiC-based ceramic material or the like, and a lower magnetic film 3 forming a lower magnetic pole is formed thereon. A gap film 4 made of alumina or the like is formed on the lower magnetic film 3.
Is formed, and insulating films 5, 6, 7 made of an organic insulating resin material such as a novolac resin, spiral coil coils 8, 9 made of Cu, and an upper magnetic film 10 are sequentially laminated thereon. Further, a protective film 11 made of alumina or the like is formed on the upper magnetic film 10 by sputtering or the like. The thin film magnetic head element thus formed is cut out from the substrate and mounted on each slider to be used as a thin film magnetic head.

[0004]

According to the prior art, the insulating film is usually coated with, for example, a novolac resin, soft-baked, exposed with a photomask, developed, heat-treated and cured. It is formed. Since the novolac resin has fluidity due to heat and shrinks when baked, the first insulating film 5 is formed by the step between the lower magnetic film 3 and the substrate 1, as shown in FIG. The thickness near the edge of 3 becomes very thin. Figure 11
Is a diagram showing the relationship between the distance D between the upper end of the lower magnetic film 3 where the thickness of the insulating film 5 is thinnest and the conductor coil 8 and the withstand voltage of the insulating film, based on experimental results. . From this figure, it is easily understood that the withstand voltage drastically decreased when the distance D was 1 μm or less in this experiment. As described above, when the first conductor coil 8 formed on the first insulating film 5 and the lower magnetic film 3 are too close to each other at their edge portions, sufficient insulation is not maintained and the magnetic pole coils are not separated from each other. There is a problem that the insulation resistance and the dielectric breakdown voltage are lowered, and the recording / reproducing of information by the thin film head may not be normally performed.

Further, if the entire first insulating film 5 is formed thicker, the thickness of the first insulating film 5 near the peripheral edge of the lower magnetic film 3 can be sufficiently secured, but the leading end portion of the upper magnetic film 10 rises. Since the angle becomes extremely steep, the internal stress of the protective layer 11 formed thereon becomes large and cracks or the like may occur, which may reduce the reliability.

Therefore, the thin film magnetic head according to the first aspect of the invention is made in view of the above-mentioned problems of the prior art, and the purpose thereof is the edge of the magnetic film formed on the substrate. In the part, when the insulating film is formed, the organic insulating resin can be made to wrap around well and the film thickness can be made sufficiently thick. An object of the present invention is to provide a thin-film magnetic head which can be formed by a relatively simple method in which good insulation is ensured between the conductor coil film and the dielectric breakdown voltage, and reliability is improved.

In addition to the above, an object of the present invention is to provide a thin film magnetic head provided with a magnetic film which can be formed relatively easily by a mechanical method and can exhibit desired effects. To do.

Another object of the present invention is to provide a thin film magnetic head provided with a magnetic film which can be formed by a relatively simple method and can exhibit desired effects.

Further, the invention according to claim 4 provides a thin film magnetic head having a magnetic film which can be formed relatively easily and in which the organic insulating resin for forming the insulating film is better wrapped around. The purpose is to

[0010]

The present invention is to achieve the above-mentioned object, and a thin film magnetic head according to claim 1 comprises a magnetic film and a conductor coil film formed on a substrate. And a conductor coil film is formed after an insulating film is formed on the magnetic film, the insulating film being formed on the magnetic film.

According to a second aspect of the thin-film magnetic head, in addition to the above-mentioned characteristic features of the first aspect, the upper edge of the magnetic film is formed to have rounded corners by polishing after the magnetic film is formed on the substrate. It is characterized by

A thin film magnetic head according to a third aspect of the invention is
It is characterized in that a step is formed at least partially on the upper edge of the magnetic film.

Furthermore, the thin-film magnetic head according to claim 4 is
It is characterized in that the peripheral portion of the magnetic film is at least partially inclined.

[0014]

Therefore, according to the thin-film magnetic head of the first aspect, in the portion of the magnetic film which has no corners from its upper edge, the organic insulating resin is prevented from wrapping around when the insulating film is formed thereon. Since this is improved, the insulating film can be formed sufficiently thick at the edge portion of the magnetic film without thickening the entire insulating film, and the insulating property between the magnetic pole coils is improved.

According to the thin film magnetic head of the second aspect,
In the portion where the corners of the upper edge of the magnetic film are rounded, the organic insulating resin can be better wrapped around and the insulating film can be formed to a sufficient film thickness.

According to the thin film magnetic head of the third aspect,
In the portion where the step is formed on the upper edge of the magnetic film, the thickness of the insulating film can be sufficiently secured.

According to the thin film magnetic head of the fourth aspect,
In the inclined portion of the peripheral edge of the magnetic film, it is possible to better wrap around the organic insulating resin and form an insulating film having a sufficient film thickness.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows a process of forming the conductor coil film 5 on the substrate 1 in the thin film magnetic head according to the first embodiment of the present invention. In Figure 1-A, Al
An insulating film 2 made of alumina or the like is deposited on a substrate 1 made of ₂ O ₃ —TiC by a usual method, and Ni—
A lower magnetic film 3 made of a soft magnetic material such as an Fe alloy or a cobalt alloy is patterned. This substrate 1 is shown in FIG.
As shown in -B, the surface on which the lower magnetic film 3 is formed faces downward, and is placed on the horizontally placed polishing sheet 12.
As the polishing sheet 12, for example, it is convenient to use a sheet-like polishing material having a particle size of about 1 to 4 μm. The polishing sheet 12 is fixed on a flexible base made of rubber.

Next, the substrate 1 which has been turned upside down is used as the polishing sheet 1.
The upper surface of the lower magnetic film 3 is lightly applied to the surface of the polishing sheet 2 and moved horizontally by about 10 to 100 mm. By polishing in this way, as shown in FIG. 1C, the corners of the upper edge of the lower magnetic film 3 are rounded off. At the same time, the entire upper surface of the lower magnetic film 3 is polished so that the film thickness becomes slightly thin. However, the lower magnetic film may be formed thicker in advance.

Then, as in the conventional case, after forming the gap layer 4 such as alumina on the lower magnetic film 3, an organic insulating resin material such as novolac resin is applied as shown in FIG. 1-D.
The organic insulating resin is soft-baked, exposed by applying a mask, developed, washed with water, and then heat-treated to form the insulating film 5. As described above, since the corners of the upper edge of the lower magnetic film 3 are rounded, the wraparound of the novolak resin is improved, and the edge portion of the lower magnetic film 3 is also prevented as shown in FIG. 1-E. The insulating film 5 having a sufficient film thickness can be obtained. Therefore, when the conductor coil 8 is formed on the insulating film 5, sufficient insulation with the lower magnetic film 3 is guaranteed.
Furthermore, the interlayer insulating films 6 and 7, the second conductor coil 9, and the upper magnetic film 10 are sequentially laminated on the conductor coil 8 by a usual method and the protective layer 11 is formed to form a thin film magnetic layer for in-plane recording / reproducing. The head is completed.

FIG. 2 shows a second embodiment of the present invention. In the second embodiment, the step 13 is formed in the peripheral portion of the lower magnetic film 3 except for the tip portion forming the magnetic pole.
Is provided in the area through which FIG. 3 shows a process of forming the lower magnetic film 3 having the step 13. Similar to the first embodiment, on the substrate 1,
A lower magnetic film 3 is formed by patterning on an insulating film 2 made of alumina or the like (FIG. 3-A). First, the substrate 1 including the lower magnetic film 3 is formed by using the photolithography technique.
Photoresist is applied on the above, exposed by applying a predetermined mask, developed, washed with water, and then heat-treated to form a resist layer 14 on the lower magnetic film 3 as shown in FIG. 3B.

The resist layer 14 is formed so as to expose the peripheral portion of the upper surface of the lower magnetic film 3 where the step 13 is provided. Next, the lower magnetic film 3 is subjected to chemical etching to partially remove the exposed peripheral portion to a certain depth. As a result, the step 13 is obtained as shown in FIG. In another embodiment, the exposed portion can be removed by performing ion milling perpendicularly to the lower magnetic film 3, and the step 13 can be similarly generated. Then, the gap film 4, the insulating film 5, and the first conductor coil 8 are formed on the lower magnetic film 3 by using a usual method. As shown in FIG. 3D, since the peripheral portion of the lower magnetic film has no corners, the thickness of the insulating film 5 can be sufficiently secured. The step 13 has a thickness T of the lower magnetic film 3.
In this case, if the depth is set to about 1/3 to 1 / 2T and the width is set to 1 μm or less, it is convenient in terms of processing accuracy and action and effect.

FIG. 4 shows a third embodiment of the present invention which is a modification of the second embodiment. In this embodiment, the lower magnetic film 3 includes a first layer 15 formed on the substrate 1,
The second layer 16 is stacked on the second layer 16. A step 17 is formed around the lower magnetic film 3 including the tip portion. First, as shown in FIG. 5A, a first photolithography technique is used to form a first film on a substrate 1 having an insulating film 2.
The layer 15 is formed to be thinner than usual and has a predetermined planar shape of the lower magnetic film. Similarly, the second layer 16 is placed on the first layer 15,
As shown in FIG. 4, the lower magnetic film 3 is formed excluding the tip portion and the peripheral portion. Thereby, as in the second embodiment,
It is possible to form a thin film magnetic head that secures insulation with the conductor coil 8 even in the peripheral portion of the lower magnetic film 3. Also in this case, it is preferable to set the width of the step 17 to 1 μm or less and the depth to 3 μm or less from the viewpoint of processing accuracy and action and effect.

FIG. 6 shows a fourth embodiment of the present invention. In this embodiment, as shown in FIG. 6-A, the peripheral portion of the lower magnetic film 3 is inclined at an angle θ, for example 45 °, with respect to the upper surface thereof. After forming the gap film 4 on the lower magnetic film in the same manner as the conventional method, the organic insulating film 5 of novolac resin is formed. As shown in FIG. 6-B, the insulating film 5 has a film thickness enough to secure sufficient insulation even with the peripheral portion of the lower magnetic film and the conductor coil 8 formed on the lower magnetic film. can get.

The lower magnetic film 3 is formed by using, for example, the ion milling described in connection with FIG. 3-B in the second embodiment. In the second embodiment, ion milling was performed perpendicularly to the lower magnetic film 3, but in the present embodiment, the peripheral edge of the lower magnetic film 3 on which the resist layer 14 is formed so that the peripheral portion is similarly exposed is formed. On the other hand, ion milling is performed at the angle θ. As a result, the corners of the edge portion of the lower magnetic film 3 are obliquely removed as shown in FIG. 6-A.

The lower magnetic film 3 of the fourth embodiment is shown in FIG.
Can be formed by a process as shown in FIG.
After depositing the insulating film 2 on the substrate 1, a frame resist 18 that defines the dimensions of the lower magnetic film 3 is formed by using, for example, an image reverse method of photolithography.
The reverse taper shape as shown in A is formed. Next, the lower magnetic film 3 is formed by electroplating (FIG. 7-B). Then, when the frame resist 18 is removed, the lower magnetic film 3 whose peripheral portion is inclined at, for example, 45 ° is obtained as shown in FIG. 7-C.

The present invention is not limited to the above embodiment, and can be carried out by making various modifications and changes within the technical scope thereof. For example, the present invention can be similarly applied to a perpendicular recording / reproducing thin film magnetic head. Further, the shape, size, and range of the peripheral edge of the lower magnetic film having no corners can be appropriately set to the shape, size, etc. other than those in the above-described embodiment according to requirements. Also, as will be apparent to those skilled in the art, various methods other than the above can be used to eliminate the corners from the peripheral edge of the lower magnetic film.

[0029]

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

According to the thin film magnetic head of the first aspect,
By eliminating the corners from the upper edge of the magnetic film, the wraparound of the organic insulating resin is improved, and it is possible to secure a sufficient film thickness at the edge portion of the magnetic film without thickening the entire insulating film. It is possible to secure the insulation between the conductor coil and the lower magnetic film without increasing cracks in the protective layer, increase the breakdown voltage, and improve the reliability.

Further, according to the thin film magnetic head of the second aspect, the corners of the upper edge of the magnetic film are mechanically rounded by a relatively simple polishing process, so that the organic insulating resin can be better wrapped around. Sufficient and easy insulation between the conductor coil and the magnetic film can be ensured.

Further, according to the thin film magnetic head of the third aspect, it is possible to easily form the magnetic film having the stepped portion at the peripheral portion thereof, whereby the insulating film at the edge portion of the magnetic film is formed. Since the thickness is sufficiently ensured, the insulation between the conductor coil and the magnetic film can be easily ensured.

According to the thin film magnetic head of the fourth aspect,
The inclination of the peripheral edge of the magnetic film improves the wraparound of the organic insulating resin, so the film thickness of the insulating film is sufficiently secured even in the peripheral part of the magnetic film, and the insulation between the conductor coil and the magnetic film is more sufficient. It can be secured easily and easily.

[Brief description of drawings]

1A to 1E are cross-sectional views showing a process of forming a lower magnetic film of a thin film magnetic head according to a first embodiment of the present invention.

FIG. 2 is a plan view showing a lower magnetic film of a thin film magnetic head according to a second embodiment of the present invention.

3A to 3D are sectional views taken along line III-III of FIG. 2 showing the process of forming the lower magnetic film of the second embodiment.

FIG. 4 is a plan view showing a lower magnetic film of a thin film magnetic head according to a third embodiment of the present invention.

5 is a cross-sectional view taken along line VV of FIG. 4 showing the process of forming the lower magnetic film of the third embodiment, which is composed of FIGS.

6A to 6B are views showing a process of forming a lower magnetic film of a thin film magnetic head according to a fourth embodiment of the present invention, which includes FIGS.

7A to 7C are cross-sectional views showing another process of forming the lower magnetic film of the fourth embodiment, which is shown in FIGS.

FIG. 8 is a schematic perspective view showing the structure of a conventional thin film magnetic head.

9 is a longitudinal sectional view of the thin film magnetic head shown in FIG.

10 is a cross-sectional view taken along line XX of FIG.

FIG. 11 is a diagram showing the relationship between the distance D between the upper end of the lower magnetic film and the conductor coil and the withstand voltage of the insulating film.

[Explanation of symbols]

 1 substrate 2 insulating film 3 lower magnetic film 4 gap film 5, 6, 7 insulating film 8, 9 conductor coil 10 upper magnetic film 11 protective layer 12 polishing sheet 13 step 14 resist layer 15 first layer 16 second layer 17 step 18 Frame resist

Claims (4)

[Claims] 1. A thin-film magnetic head having a magnetic circuit comprising a magnetic film formed on a substrate and a conductor coil film formed on the substrate via an insulating film, wherein the magnetic film is A thin-film magnetic head, characterized in that at least a part of the upper edge is removed. 2. The thin-film magnetic head according to claim 1, wherein the upper edge of the magnetic film has rounded corners by polishing the magnetic film after the magnetic film is formed on the substrate. 3. The thin film magnetic head according to claim 1, wherein a step is formed at least partially on the upper edge of the magnetic film. 4. The thin film magnetic head according to claim 1, wherein a peripheral portion of the magnetic film is at least partially inclined.