JPS6254810A - Thin film magnetic head - Google Patents

Abstract

PURPOSE:To form a thin film magnetic head with high reliability by providing an averaging means to a part of an upper magnetic layer or its vicinity so as to average the film quality of the protection film without losing the accuracy of the track width. CONSTITUTION:A through hole 6 is formed to a front and a rear part of an upper insulation layer 5 and taper etching spread upward is applied to the circumference of the through hole 6. The track width Tw of the magnetic gap is specified by a hole diameter of the front side through hole 6 formed to the upper insulation layer 5 and the gap length is specified by the film thickness of the lower insulation layer 3. Thus, even when the film thickness of the upper magnetic layer 8 is thick, the accuracy of the track width Tw is not deteriorated. Thus, the taper shape of the circumference of the upper magnetic layer 8 is selected to a shape preferable to the forming of a protection film 9, e.g., a slant taper angle of <=50 deg..

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a thin film magnetic head having a structure in which a conductive coil is provided between lower and upper magnetic layers constituting a magnetic circuit, and a protective film is further provided thereon.

[Background of the invention]

Various types of thin film magnetic heads have been known, one of which is the "IBM Disk St.
orage Technology j (198
As shown in pages 6 to 9 of ``February 2000'', a conductor coil and an upper magnetic layer covering a part of the conductor coil are formed on the lower magnetic layer by thin film formation technology. It has been proposed that the edge of the junction surface between the upper magnetic layer and the lower magnetic layer is used as a magnetic gap. This thing is
Due to its structure, the track width is defined by the width of the upper magnetic layer facing the recording medium, so from the perspective of increasing the precision of the track width, both parts of the upper magnetic layer have a nearly vertical shape, in other words, the upper The shape of the portion of the magnetic layer facing the recording medium was approximately rectangular.

In a thin-film magnetic head constructed in this way, a protective film is usually formed on the top for the purpose of ensuring reliability. As a result, the protective film in the vicinity becomes fragile. The weak parts of the protective film have inferior wear resistance compared to other parts, so especially when a magnetic head comes into contact with a recording medium, after a dent is formed in the weak part, the dent is There is a problem in that magnetic powder from the recording medium sticks to the disk, increasing spacing loss and deteriorating head characteristics.

[Purpose of the invention]

The ninth object of the present invention is to solve the problems of the prior art described above,
It is an object of the present invention to provide a highly reliable thin-film magnetic head in which the film quality of a protective film is made uniform without impairing the accuracy of track width.

[Neighborhood of invention]

Generally, when a thin film is formed on top of a step, it is known that the fragile film quality of the thin film can be improved by tapering the step. For example, according to experiments conducted by the present inventors,
When alumina (Altos) is formed as a protective film by vapor deposition, if the taper angle of the upper magnetic layer to the lower magnetic layer is 50 degrees or less, the protective film can be formed on the upper magnetic I- with uniform film quality. I know. Therefore, if both parts of the upper magnetic layer of a thin film magnetic head are patterned with a taper of 50 degrees or less, the above-mentioned problem of the film quality of the protective film can be solved. However, with this method alone, it becomes difficult to define the track width with a high degree of precision using the upper magnetic layer when the magnetic layer is thickened fc for the purpose of increasing the normal running life of the magnetic head.

In other words, from the point of view of increasing the accuracy of track width,
It is better for the taper angle of both edges of the upper magnetic layer to be steep and close to vertical. On the other hand, from the point of view of uniformity of the film quality of the protective film, the taper angle should be gentle (close to zero is better, and the taper angle should be close to zero). Regarding this, the two contradict each other.

As described above, the present invention achieves high accuracy of the track width and uniformity of the film quality of the protective film, which have been difficult to satisfy at the same time in the past, by providing a flattening means in a part of the upper magnetic layer or in the vicinity thereof. It was made possible by

As a specific example of flattening means, we focused on the insulating layer of a conductor coil whose thickness does not change even if the magnetic layer is completely thickened, and the track width is determined by the width of a through hole formed in the front gap of this insulating layer. A taper is formed at the periphery of the upper magnetic layer, the taper angle of which becomes smaller as it moves away from the magnetic gap, or a magnetic We adopted methods such as providing a magnetic layer that does not form a circuit.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to figures and planes.

FIG. 1 is a front view of a thin film magnetic head according to an embodiment of the present invention viewed from the recording medium sliding surface side, FIG. 2 is a perspective view showing the state of the thin film magnetic head after the wafer process is completed, and FIG. FIG. 3 is a sectional view taken along line A--A in FIG. 2.

In these figures, 1 is a substrate, 2 is a lower magnetic layer forming a lower core formed on the substrate 1, and 3 is the lower magnetic layer 2.
The lower insulating layer 4 is formed on the lower insulating layer 3 and has one turn of conductor coil made of Aj, Cr-Cu-Cr, etc., and 5 is the lower insulating layer 3 formed on the lower insulating layer 3 so as to cover the conductor coil 4. The inner insulating layer 3.5, which is an upper insulating layer formed thereon, is made of 8i0, Sin, or the like. Through holes 6.7 are formed in the front and rear portions of this upper insulating layer 5, and the peripheral edges of both through holes 6.7 are tapered to widen upward. Further, an upper magnetic layer 8 serving as an upper core is formed on the upper insulating layer 5 so as to cover the conductor coil 4 across the conductor coil 4, and the upper magnetic layer 8 is connected to the lower insulating layer through a through hole 6 in the front part. The layer 3 is connected to the lower magnetic layer 2 via a through hole 7 at the rear portion. Both of the lower and upper magnetic layers 2.8 are made of permalloy, sendust, or the like, and the peripheral edge of the upper magnetic layer 80 is taper-etched with an upward taper. 9 is Sin.

The protective film 9 is a protective film made of Al2O, etc.
Although not shown in the figure, the conductor coil 4 is formed to cover the upper insulating layer 5 and the upper magnetic layer 8.

The above is IC! A film formation and photo-etching process similar to that of IJ construction is carried out, and after completion of the process, a preservation plate 10 is bonded to the protective film 9 to a predetermined gap depth shown by the line X-X in FIG. Polished. FIG. 1 shows the polished surface polished in this way, and as is clear from the figure, the track width T of the magnetic gap is shaped like IEt in the upper insulating layer 5, [in the front side through hole 6]. It is defined by the hole diameter, and the gap length is defined by the thickness of the lower insulating layer 3. Therefore, even if the thickness of the upper magnetic layer 8 becomes thicker, the accuracy of the track width Tw does not deteriorate. Therefore, the tapered shape of the peripheral portion of the upper magnetic layer 8 is changed to a shape preferable for forming the protective film 9, for example. 50
It is possible to create a gentle taper angle of less than 100 degrees.

Next, a method of patterning the upper magnetic M8 will be explained with reference to FIG.

First, as shown in FIG. 4(a), a photoresist film 80 is formed on the substrate 1 and becomes the uppermost magnetic layer.
1 to a predetermined thickness. Next, as shown in FIG. 4(b), this photoresist 11 is exposed and developed in the shape of the upper magnetic layer, and then a taber lla is attached to the pattern end of the photoresist 11 by heat treatment (FIG. 4(c) )
).

Thereafter, as shown in FIG. 4(d), the magnetic film 80p is tapered by ion etching to form an upper magnetic layer 8 having a desired taper angle α.

At this time, the taper angle α can be set to any desired angle by changing the incident angle of the ions (for example, Ar beam).
Considering the uniformity of the film quality of the protective film 9 that will be formed thereafter, it is appropriate that the angle is 50 degrees or less.

Finally, the photoresist 11 is removed, and a Taber-etched upper magnetic layer 8 is formed, as shown in FIG. 4(e).

In the method of patterning the upper magnetic layer described above,
Instead of the photoresist 11, it is also possible to use an organic resin that can be spin-coated. Further, by appropriately selecting the pattern end shape of the mask material and the ion etching conditions, the Taber shape can be set to various shapes as shown in FIG. That is, as shown in FIG. 5(a), the taper of the upper magnetic layer 8 is made into a two-stage structure, and the taper angle α of the side closer to the substrate 1 is made larger than the taper angle α of the side far away. As shown in FIG. 5(b), it is also possible to form both slave parts of the upper magnetic layer 8 into a rounded shape.
These shapes allow the film quality of the protective film 9 to be made more uniform.

The above description has been about a thin film magnetic head equipped with a conductor coil 4 having one turn. Next, as shown in FIGS. I will explain about it. FIG. 6 is a perspective view of the thin film magnetic head showing the state after the completion of the process, and corresponds to FIG. 2 of the previous embodiment, and FIG.
This is a sectional view taken along the same line, and parts corresponding to FIGS. 2 and 3 are given the same amount.

In these figures, 40 is a conductor coil with multiple turns (4 turns in the example) formed on the lower insulating layer 3, and the upper insulating layer 5 formed on these conductor coils 40 is a conductor coil. It is flattened so that the unevenness of 40 is eliminated. Therefore, the upper magnetic layer 8 that is later formed to cover and traverse each conductor coil 40 does not have a step difference at the overlapped portion with the conductor coil 40.
The upper magnetic no. 8 can be patterned on the same substantially flat surface.

In the case of this embodiment as well, the recording medium sliding surface after polishing to the predetermined position indicated by the line X-X in FIG. 6 has the same form as that in FIG. 1, and the effect is also the same. Since the upper magnetic layer 8 can be turned on a substantially flat surface, the turning process is simpler than in the first embodiment, and the quality of the protective film 9 can be made more uniform. It becomes possible.

FIG. 8 is a front view of a thin film magnetic head according to still another embodiment of the present invention, viewed from the recording medium slide & J 1111 side, and parts corresponding to those in FIG. 1 are given the same reference numerals.

This embodiment differs from the above-mentioned two fc embodiments in that the upper magnetic layer 8 is planarized by devising the tapered shape of the upper magnetic layer 8.

That is, in FIG. 8, two-stage tapers are defined at both edges of the upper magnetic layer 8, and the track width Tw of the magnetic gap is defined by the width of the lower end of the upper magnetic layer 8. The length is determined by the thickness of the lower insulating layer 3. The taper shape of the upper magnetic layer 8 is a stepped shape in which the taper angle θ1 closer to the lower magnetic layer 2 is larger than the taper angle θ1 farther away. is 60-8
0 degree, U, is set to 50 degrees or less.

In the fc thin film magnetic head constructed in this way, the lower taper angle OI of the upper magnetic layer 8 that defines the tortoise width Tw is set to be larger than 50 degrees, so the film thickness of the upper magnetic layer 8 is Even if the track width Tw0) becomes thicker, the track width Tw0) will not decrease, and the upper taper angle θ2, which affects the quality of the protective film 90, is set to 50 degrees or less, ensuring uniform protection of the film quality. A membrane 9 is obtained.

Note that the upper magnetic layer 8 having such a stepped taper
The patterning method is basically the same as the process shown in FIG. 4, and the ion incident angles are set in two ways to obtain mutually different taper angles θ.

θ2 can be realized. Also, in this case, by appropriately selecting the pattern end shape of the ion etching mask material and the ion etching conditions, it is possible to smooth out the discontinuous part of the two-step taper angle and create a shape close to a radius. be.

9 to 11 show still other embodiments of the present invention, FIG. 9 is a perspective view of a thin film magnetic head, and FIG. 10 is a view of the thin film magnetic head from the recording medium sliding surface side. Front view,
FIG. 11 is a sectional view taken along the line CC in FIG.
Portions corresponding to those in FIGS. 3 to 3 are designated by the same reference numerals.

In these figures, a lower magnetic layer 2 is placed on a non-magnetic substrate 1.
Further, a conductor coil/I/4 is laminated thereon, insulated from each other by upper and lower insulating layers 3 and 5, and an upper magnetic layer 8 is formed on these insulating layers 3 and 5. The lower magnetic layer 2 and the upper magnetic layer 8 are connected at the rear part to form a magnetic circuit, but at the front part, they face each other with the lower insulating layer 3 in between, forming a magnetic gap. The track width Tw of the magnetic gap is defined by the width of the upper magnetic layer 8 formed on the sliding surface of the recording medium.
The gap length is defined by the thickness of the lower insulating layer 3. Further, a magnetic material pattern 12 is formed around and close to the upper magnetic layer 8. This magnetic material pattern 1
2 is made of the same material as the upper magnetic layer 8, and is formed on the insulating layers 3 and 5 at the same time as the upper magnetic layer 8, but is separated from the upper magnetic layer 8 at a predetermined distance to form a magnetic circuit. Not formed. Furthermore, a relatively thin first protective film 9 is formed to cover the entire upper magnetic layer 8 and magnetic pattern 12.
' is formed, and in order to flatten the recess 9a generated between the upper magnetic layer 8 and the magnetic pattern 12 when forming the first protective film 9', a second protective film is partially formed including the recess 9a. A film 9'' is formed by a mask vapor deposition method or the like. Note that these protective films 9' and 9'' are not shown in FIG.

In the thin film magnetic head configured in this way, the top of the substrate 1 is flattened by the magnetic material pattern 12;
It is possible to make the film JX of the protective film 9'19'' formed thereafter uniform.Also, it is possible to make the film JX of the protective film 9'19'' formed after that uniform. The other parts have a thin film structure with only the first protective film 9'.
It is possible to reduce cracks, peeling, etc. due to internal stress of the tracheal membrane.

[Effects of the Invention] As explained above, according to the present invention, the upper magnetic layer can be flattened without impairing the track width sheath of the magnetic gap, and therefore the upper magnetic layer formed on the upper fA magnetic noodle can be flattened. It becomes possible to make the quality of the protective film uniform, and it is possible to provide a highly reliable thin film magnetic head.

[Brief explanation of drawings]

FIG. 1 is a front view of a thin film magnetic head according to an embodiment of the present invention viewed from the recording medium drawing/moving surface side, FIG. 3 is a cross-sectional view taken along line A-A in FIG. 2, FIG. 4 is an explanatory diagram showing the patterning process of the upper magnetic layer provided in the thin-film magnetic head, and FIGS. 5(a) and 5(b) are A front view illustrating another Taber shape of the upper magnetic layer, FIG.
FIG. 7 is a cross-sectional view taken along line t3-B in FIG. 6, and FIG. 8 is a thin-film magnetic head according to still another embodiment of the present invention. All recording media printing
FIG. 9 is a perspective view of a thin film magnetic head according to still another embodiment of the present invention, and FIG. 10 is a front view of the thin film magnetic head from the recording medium sliding surface side. , FIG. 11 is a sectional view taken along line C-C1W in FIG. 9. 1...Substrate, 2...Lower magnetic j-13
...Lower insulating layer, 4.40... Conductor coil, 5... Upper insulating layer, 6.7...
Through hole, 8...Top magnetic layer. 9, 9', 9"...Protective film, 10...
・・Protective plate, 12 ・・・Maternal body pattern (magnetic 7
m). Agent Patent Attorney Takeshi Miribe (and 1 other person) 1 figure, 2 figures, 3 figures, 4 figures (σ)

Claims (4)

[Claims] (1) In a thin film magnetic head in which a conductive coil is provided between a lower magnetic layer formed on a substrate and an upper magnetic layer forming a magnetic circuit together with the lower magnetic layer, with an insulating layer interposed therebetween, the upper A thin film magnetic head characterized in that a flattening means for flattening the upper magnetic layer is provided at or near a part of the magnetic layer. (2) In claim (1), the upper magnetic layer is provided to cover through holes formed in the front and rear portions of the insulating layer, and each of the upper magnetic layer and the through hole is 1. A thin film magnetic head, wherein the flattening means is constituted by a taper provided on a peripheral edge of the head. (3) In claim (1), the flattening means is constituted by a taper provided at the peripheral edge of the upper magnetic layer, and the taper angle of the taper moves away from the magnetic gap surface. A thin film magnetic head characterized in that it is set to be smaller in size. (4) In claim (1), the flattening means is constituted by a magnetic layer made of the same material as the upper magnetic layer, and the magnetic layer has a magnetic circuit around the upper magnetic layer. A thin film magnetic head characterized in that the thin film magnetic heads are provided in close proximity to each other so as not to form.