JP2730447B2 - Thin film magnetic head and method of manufacturing the same - 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 and a method of manufacturing the same, and more specifically, a magnetic circuit is constituted by upper and lower cores and an intermediate core, and a non-magnetic layer And a method of manufacturing the same.

[0002]

2. Description of the Related Art A thin-film magnetic head in which layers constituting a magnetic circuit are formed flat by an upper core, a lower core, and an intermediate core is disclosed in JP-A-3-38308. FIG. 7A shows a cross section of a main part of one example. In the following description, for convenience, the medium facing surface side of the thin-film magnetic head is referred to as front, the opposite side is referred to as rear, the substrate side is referred to as lower, and the opposite side is referred to as upper.

[0003] An insulating film 12 is formed on a substrate 10, and a lower core 14 is formed on the insulating film 12. A front intermediate core 16 and a rear intermediate core 18 are formed on the lower core 14, respectively. A magnetic gap 2 made of an insulating film is provided between the lower core 14 and the front intermediate core 16.
0 is formed, and a coil 22 is formed so as to wind the rear intermediate core 18. An insulating film 24 is formed on the coil 22, and an insulating film 26 is further formed on the front intermediate core 16, the rear intermediate core 18, and the insulating film 24.
Are formed, and an upper core 28 is formed in the insulating film 26. The coil 22 is connected to the lead wire 30.

According to such a thin-film magnetic head, it is possible to favorably form a pattern of each part by a thin-film technique such as photolithography and to obtain excellent magnetic characteristics. There is a point. For example, in the case of a floating head for a magnetic disk, the life dimension L is generally set to about 1 μm, and it is assumed that the life dimension is shortened as shown in FIG. Then, since the thickness Δt of the front intermediate core 16 is reduced, a part of the magnetic pole is easily saturated.

[0005] In order to solve such problems,
There is a thin-film magnetic head disclosed in Japanese Patent Application No. 3-183791 filed by the present applicant. According to this, as shown in FIG. 2C, the nonmagnetic layer 3 for magnetically insulating between the lower core 14 and the front intermediate core 16 sandwiching the magnetic gap 20.
2 are formed. Thereby, the front intermediate core 1
6, it is possible to eliminate the partial magnetic flux saturation by preventing the thickness Δt from becoming thin, to reduce the leakage magnetic flux between the cores overlapping in a portion behind the position where the life dimension L = 0. The effect of improvement is obtained.

[0006]

In the thin-film magnetic head of FIG. 7C, as shown in the enlarged view of FIG. 7D, the upper surface of the non-magnetic layer 32 has the magnetic gap layer 20. Is located above the upper surface of. In other words, a step 34 having a certain size occurs between the magnetic gap layer 20 and the nonmagnetic layer 32.

As a matter of course, a magnetic film to be the front intermediate core 16 or the upper core 28 is formed on the magnetic gap layer 20 and the non-magnetic layer 32. There is a step 34 as shown. It is generally known that when a magnetic film is formed on a step, the magnetic characteristics of the magnetic film, such as an increase in coercive force (Hc), are significantly degraded, depending on the degree of inclination of the step. ing.

The portion where the step 34 occurs is a position where the life dimension L = 0 at the head end portion, and is an important portion where the magnetic flux is concentrated in the magnetic core. In particular, a floating thin film head used in a magnetic recording / reproducing device such as a fixed magnetic disk device for a computer generally has a life dimension of about 1 μm. For this reason, the deteriorated portion of the magnetic film becomes a portion for directly writing or reading a signal to or from the medium, and the adverse effect is more remarkable. As described above, when the magnetic characteristics of the magnetic core at the portion where the magnetic flux is concentrated are deteriorated, the characteristics of the magnetic head as a whole are also significantly reduced, which is a great obstacle particularly for high-density recording.

The present invention focuses on these points.
It is an object of the present invention to provide a thin-film magnetic head suitable for high-density recording and capable of obtaining good magnetic characteristics by preventing deterioration of characteristics of a magnetic core due to a step caused by formation of a non-magnetic layer, and a method of manufacturing the same. And

[0010]

In order to solve the problems of the above-mentioned conventional thin film magnetic head, the present invention provides a magnetic circuit comprising an upper core, a lower core, a front intermediate core, and a rear intermediate core. From the medium facing surface of the lower magnetic core of the magnetic cores sandwiching the gap layer.
In a thin-film magnetic head in which a nonmagnetic layer is formed at a position drawn by the depth of a gap, the nonmagnetic layer is embedded in a magnetic core so that the core surface becomes flat.

The method of manufacturing a thin-film magnetic head according to the present invention further comprises a step of forming a groove in the lower magnetic core, a step of embedding a non-magnetic layer in the groove, and a step of embedding the lower magnetic core after embedding. And flattening the surface.

[0012]

According to the present invention, the nonmagnetic layer is formed so as to be embedded in the magnetic core, and the magnetic core after the embedding is flattened by polishing or the like. Therefore, good characteristics can be obtained even if a magnetic core is further formed on the magnetic core in which the non-magnetic layer is embedded.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a thin-film magnetic head and a method of manufacturing the same according to the present invention will be described below in detail with reference to the accompanying drawings. <First Embodiment> First, a first embodiment of the present invention will be described with reference to FIGS. FIG. 1A shows a cross section of a main part of the thin film magnetic head according to the first embodiment. As shown in FIG.
The non-magnetic layer is formed so as to be embedded in the core.

First, the manufacturing process of the thin-film magnetic head of this embodiment will be described in order with reference to FIGS. a. First, an insulating layer 52 and a lower core 54 are formed to a predetermined thickness on a substrate 50, and the surface is flattened (see FIG. 2A). This step is specifically shown in FIGS.
(D), or as shown in FIGS.

Starting from the first method, the substrate 50
A soft magnetic film 53 is formed thereon (see FIG. 4A), and this is used as a lower core 54 of a core-shaped pattern by etching or the like (see FIG. 4B). Next, an insulating film 51 is formed to a predetermined thickness on the main surface of the substrate 50 including the lower core 54 (see FIG. 4C), and the insulating film 51 deposited on the core pattern 54 is removed by polishing. The surface is flattened (see FIG. 4D). Thus, the insulating film 52 and the lower core 54 are obtained.

Next, a second method will be described. An insulating film 51 is formed on a substrate 50 (see FIG. 4).
(See (X)), and a core-shaped groove 55 is formed therein (see FIG. 4 (Y)). Then, a soft magnetic film 53 is formed on the main surface of the substrate 50 including the groove 55 (FIG. 4 (Z)).
The soft magnetic film 53 deposited on the insulating film 52 is removed by polishing to planarize the surface (see FIG. 4D). As a result, the soft magnetic film 53 remaining in the groove 55 is
4 is assumed.

Next, returning to FIG. 2, the front intermediate core 5 is formed on the insulating film 52 and the lower core 54 in the same manner as in FIG.
6, a rear intermediate core 58 and an insulating film 60 are formed (see FIG. 2B). Then, a groove 62 for embedding the non-magnetic layer is formed by etching on the boundary surface between the front intermediate core 56 and the insulating film 60 (see FIG. 2C). Further, a large number of grooves 64 for embedding the coil are formed in the insulating film 60 by etching (see FIG. 3D). Grooves 62, 64 formed as described above
Then, a metal material such as Cu is embedded, and the main surface is polished and removed so as to be flat.
8 (see FIG. 7E).

Next, a gap material 70 of an insulating material is formed to a predetermined thickness on the main surface of the substrate 50 except for the region where the rear intermediate core is formed (see FIG. 2F). In addition, the front intermediate core 72, the rear intermediate core 74, and the insulating film 76 are formed on the main surface in the same manner as in FIG. 2B (see FIG. 3G). And FIG.
The coil 78 of the second layer is formed in the same manner as in (D) and (E) (see FIG. 3H).

Next, the front intermediate core 72 and the rear intermediate core 7
The insulating film 80 is formed to a predetermined thickness in a portion excluding the formation region of No. 4 and the upper core 82 is formed in the same manner as in FIG.
Is formed (see FIG. 3I). Further, a lead wire 84 connected to the coil 78 is formed on the insulating film 80 (FIG. 3).
(J)). Then, a plurality of chips of each magnetic head element formed on the substrate are cut, and the medium facing surface is processed by a method such as polishing so as to have a predetermined gap depth (lifetime dimension). The thin film magnetic head of the first embodiment shown in FIG.

Next, the thin-film magnetic head according to this embodiment as described above will be considered. As shown in FIGS. 2C to 2E, the nonmagnetic layer 66 is embedded in the front intermediate core 56. And the other front intermediate core 72 is
It is formed on a flat surface as shown in FIGS. 2 (E) to 3 (J). As a result, the deterioration of the magnetic characteristics caused by the formation of the magnetic film on the step, particularly the deterioration of the characteristics at the tip portion of the magnetic core, is favorably prevented. As the material of the nonmagnetic layer 66, the same conductor as the material of the coil 68 is used. For this reason, the magnetic sealing effect between the front intermediate cores 56 and 72 sandwiching the magnetic gap 70 is increased, and the magnetic flux leakage can be reduced.

Further, the front end 66A of the non-magnetic layer 66 has a tapered shape that is inclined as shown in FIG. Thereby, it is possible to suppress the magnetic saturation of the core portion near the magnetic gap 70. For example, as shown in FIG.
If 6A is vertical, the core thickness Δt in the gap depth direction near the magnetic gap 70 becomes thin.
Therefore, the portion of the front intermediate core 56 between the medium facing surface and the front end 66A of the nonmagnetic layer 66 is likely to be magnetically saturated.

It is to be noted that partial magnetic flux saturation can be eliminated by preventing the front intermediate core from becoming thinner. Leakage magnetic flux between cores overlapping in a portion behind the position where the life dimension L = 0 is reduced. The improvement effect of providing the non-magnetic layer 66, which can be performed, can of course be obtained.

<Second Embodiment> Next, a second embodiment of the present invention will be described with reference to FIG. In the first embodiment, the same material as that of the coil 68 is used for the nonmagnetic layer 66. However, in the present embodiment, the nonmagnetic layer 90 is formed using a different material, for example, a nonmagnetic insulating material. Note that the same reference numerals are used for components similar to or corresponding to the first embodiment described above.

Up to the step shown in FIG.
This is the same as the embodiment. Then, a film of a nonmagnetic insulating material such as SiO ₂ is formed on the main surface of the substrate 50 including the groove 62, and unnecessary portions are polished and removed to form a flat surface (FIG. 5A). reference). Thus, the non-magnetic layer 9
After burying 0, a large number of grooves 92 for burying the coil are formed in the insulating film 60 by etching (see FIG. 5B). And these grooves 92
Then, a coil material such as Cu is embedded, and the main surface is polished and removed so as to be flat to form a coil 68 (see FIG. 5C). Thereafter, the process of FIG. 2F is continued.

According to the second embodiment, basically the same effects as those of the first embodiment can be obtained. However, since the use of different materials in a non-magnetic layer 9 0 and the coil 68, so that the increase 1 step than in the first embodiment. In other words,
As in the first embodiment, it is more convenient to embed and form the nonmagnetic layer 66 and the coil 68 at the same time using the same material because the process can be shortened.

<Other Embodiments> The present invention is not limited to the above-described embodiments, but includes, for example, the following. (1) In the embodiment shown in FIG. 6A, the nonmagnetic layer 100 is embedded in the lower core 54, and the magnetic gap 70 is formed between the lower core 54 and the front intermediate core 56.
In the embodiment shown in FIG. 6B, the non-magnetic layer 102 is embedded in the front intermediate core 72, and the magnetic gap 70 is formed between the front intermediate core 72 and the upper core 82.

The embodiment shown in FIG. 9C is the same as the first and second embodiments except that the nonmagnetic layer 104 is extended to the vicinity of the rear intermediate core 58. The embodiment shown in FIG. In the embodiment shown in FIG. 6A, the nonmagnetic layer 106 is extended to the vicinity of the rear intermediate core 58. As described above, the shape, embedded portion, thickness, material used, and the like of the nonmagnetic layer can be variously modified without departing from the gist thereof. (2) In the above embodiment, the coil is wound in two stages, but may be changed as needed as needed, such as one stage as in the conventional example of FIG. The shapes and dimensions of the other parts may be appropriately changed as needed as long as the same operation is achieved.

[0028]

As described above, according to the thin-film magnetic head and the method of manufacturing the same according to the present invention, since the non-magnetic layer is embedded in the magnetic core, the surface can be flattened. Even if a magnetic core is formed thereon, there is an effect that deterioration of characteristics can be prevented well and magnetic characteristics can be improved.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part showing a first embodiment of a thin film magnetic head according to the present invention.

FIG. 2 is an explanatory view showing a manufacturing process of the first embodiment.

FIG. 3 is an explanatory view showing a manufacturing process of the first embodiment.

FIG. 4 is an explanatory view showing in detail a part of the manufacturing process of the first embodiment.

FIG. 5 is an explanatory diagram showing main steps of a manufacturing process according to a second embodiment of the present invention.

FIG. 6 is a sectional view of a main part showing another embodiment of the present invention.

FIG. 7 is a sectional view of a main part showing a conventional thin film magnetic head.

[Explanation of symbols]

50: substrate, 52, 60, 76, 80: insulating film, 54:
Lower core, 56, 72 front intermediate core, 58, 74 rear intermediate core, 62, 64, 92 groove, 66, 90, 10
0, 102, 104, 106 ... non-magnetic layer, 68, 78 ...
Coil, 70: magnetic gap, 82: upper core, 84: lead wire, L: life dimension.

Claims (2)

(57) [Claims] 1. An upper core, a lower core, a front intermediate core, and a rear intermediate core, each layer of which constitutes a magnetic circuit is formed flat, and a medium of a lower magnetic core among magnetic cores sandwiching a gap layer is provided. Pulled in from the opposing surface by the gap depth
In a thin film magnetic head in which a non-magnetic layer is formed at a location ,
A thin-film magnetic head, wherein the non-magnetic layer is embedded in a magnetic core so that the surface of the core is flat. 2. The method of manufacturing a thin-film magnetic head according to claim 1, wherein a step of forming a groove in said lower magnetic core, a step of embedding a non-magnetic layer in said groove, and a step of embedding the lower magnetic core in said groove. Flattening the surface of the magnetic core.