JP2003317216A - Substrate and slider bar for thin-film magnetic head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a slider bar for a thin-film magnetic head capable of suppressing the occurrence of warping, and performing highly accurate patterning. <P>SOLUTION: This substrate 10 for thin-film magnetic head is provided with a plate-like nonmagnetic subtrate 1, alumina films 2 and 3 disposed on both surfaces of the substrate, and an element formation section 4 including a plurality of thin-film magnetic head elements formed on one alumina film of the substrate. The slider bar 20 for the thin-film magnetic head is provided with a strip-like nonmagnetic substrate 21, alumina films 22 and 23 disposed on two opposing surfaces of the substrate, and an element formation section 24 including a plurality of thin-film magnetic head elements 25 formed on one alumina film of the substrate. <P>COPYRIGHT: (C)2004,JPO

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 mounted on a hard disk drive or the like, a substrate for the thin film magnetic head, and a slider bar.

[0002]

2. Description of the Related Art In recent years, in magnetic recording devices, the demand for higher recording density has increased rapidly with the increase in the amount of information, and it is certain that this tendency will further increase in the future. Accordingly, the strip-shaped block (hereinafter referred to as “slider bar”) that constitutes the thin-film magnetic head has a very low flying height on the recording medium and is stable without changing due to the peripheral speed of the recording medium. It is required to have the above floating characteristics. In order to satisfy the demand, a technique for forming an air bearing surface with high precision in a slider bar for a thin film magnetic head is indispensable.

Regarding the above air bearing surface forming technology,
In conventional machining, even if linear machining is possible,
It was not possible to deal with the geometrical air bearing surface shape designed to improve the levitation characteristics. So now,
A method using a photolithography technique has been proposed as an alternative method to the machining. In this photolithography method, a mask material corresponding to the air bearing forming surface is formed, and the air bearing shape is formed by a dry etching process such as ion beam etching. Also, in terms of processing accuracy, since the air bearing surface shape and accuracy that cannot be achieved by machining can be secured,
The mask forming method and related techniques are essential techniques in the dry etching process. In this case, the number of thin-film magnetic head elements in one slider bar is limited to 40 to 60, and if processing is performed for each slider bar, the productivity will be significantly reduced. Processing.

Further, as a mask material for dry etching, there are a liquid photoresist generally used in a semiconductor process or a thin film magnetic head element forming process, and a dry film resist used in a wiring forming process of a printed board. Generally, dry etching using a patterned dry film resist as a mask material is mainly used.

Next, a process of manufacturing a slider bar for a thin film magnetic head using a conventional single-sided alumina film wafer will be described with reference to FIGS. This manufacturing process includes the following steps. (A) A disk-shaped AlTiC substrate 51 is prepared. (B) Film thickness of several tens of μm on one surface of the AlTiC substrate 51
The alumina film 52 is formed. (C) An element forming portion 54 including many thin film magnetic head elements is formed on the alumina film 52 (FIG. 5). The number of elements to be formed differs depending on the wafer size used. (D) The above-mentioned wafer is cut along the chain lines 61 and 62, and the stack 55 (several slider bars 60) having a predetermined size is cut.
Of the above) (FIGS. 6A and 6B). (E) After that, the slider bars 60 for thin film magnetic heads are obtained for each of them through the steps of grinding and polishing the cut surface (FIGS. 6B and 6C). (F) Surface 66 of the slider bar 60 facing the medium described above
After patterning the mask film, an air bearing surface based on a predetermined shape is formed by a method such as dry etching, as shown in FIG.

The conventional thin film magnetic head slider bar 60 is manufactured through the above steps. This slider bar 6
0 indicates an AlTiC substrate 71 as shown in FIG.
An alumina film 72 is formed on one surface of the above, and a plurality of thin film magnetic head elements 65 are formed on the alumina film 72. Usually, 40 to 60 thin film magnetic head elements 65 are formed on one slider bar 60 along the longitudinal direction.

[0007]

In the manufacture of this slider bar for a thin film magnetic head, in order to improve productivity, as shown in FIG. 7A, a plurality of slider bars are arranged side by side to form a mask film as described above. Pattern. However, unlike a case where a flat wafer surface is a processing target such as a semiconductor process or a thin film magnetic head element forming process, the processing surface of each slider bar is often not flush.
That is, a strip-shaped thin-film magnetic head slider bar having a plurality of thin-film magnetic head elements is machined (cut, cut,
Since it is produced by grinding and polishing, shape error of tolerance (especially thickness variation) and warpage occur. Therefore, this shape error is an obstacle to simultaneously forming a uniform mask layer having a thickness of several μm on a plurality of slider bars.

Since the photomask undergoes processes such as photoresist formation, exposure and development, the curvature of the slider bar 60 affects the patterning accuracy. For example, as shown in FIGS. 7A and 7B, internal stress in the film or strain due to mechanical processing may be accumulated in the slider bar 60 to cause warpage d. In the case of exposure with a stepper or the like in photolithography, even if some fine adjustment can be performed, several heads to several tens of heads are exposed in a substantially linear manner at a time, so that each thin film magnetic head element 65 is exposed. In patterning, an error that depends on the warpage d occurs.

In the case of further improving the accuracy of the shape of the air bearing by the above-mentioned method, when patterning at the optimum position with the thin film magnetic head element as a reference, an error occurs depending on the degree of warp of the slider bar. The pattern shift must be eliminated. However, as the number of thin film magnetic head elements in one slider bar increases, patterning with accuracy on the order of microns becomes very difficult. Further, it is very difficult to realize a slider bar that does not warp with the existing wafer structure. Further, even if the jig is forced to correct the warp in the patterning formation process, the warp caused by the internal stress difference cannot be completely corrected.

Further, in order to increase the productivity by forming many thin film magnetic head elements with one slider bar,
It is necessary to lengthen the slider bar. On the other hand,
The amount of warp that occurs in the slider bar tends to depend on the length of the slider bar. Therefore, when the slider bar is lengthened, there is a relation that the generated warp increases.

SUMMARY OF THE INVENTION An object of the present invention is to provide a slider bar for a thin film magnetic head which can suppress warpage and can be patterned with high accuracy.

[0012]

A thin-film magnetic head substrate according to the present invention comprises a plate-shaped non-magnetic substrate and an alumina film provided on both surfaces of the substrate and having a thickness in the range of 10 to 100 μm. It is characterized by being provided.

A substrate for a thin film magnetic head according to the present invention comprises a plate-shaped non-magnetic substrate, alumina films provided on both surfaces of the substrate, and a plurality of substrates formed on one alumina film of the substrate. And an element forming portion including the thin film magnetic head element.

An AlTiC substrate, for example, can be used as the non-magnetic substrate constituting this thin film magnetic head substrate. Other non-magnetic substrates may be used. Also,
It is preferable that the alumina films provided on both surfaces of the non-magnetic substrate have almost the same film thickness. Of the alumina films on both surfaces, the alumina film on the surface on which the plurality of thin film magnetic head elements are formed has an effect as a shield layer. On the other hand, the alumina films on the opposite surfaces of the substrate have the effect of suppressing the warp in the thickness direction of the substrate in the manufacturing process of finishing the substrate into strip-shaped slider bars by machining. Further, the thickness of the alumina film is preferably in the range of 10 to 100 μm so that the effect of the shield layer is sufficiently obtained, while the thickness is not too thick. Furthermore, as a thin film magnetic head element,
For example, a magnetoresistive element can be used.

A slider bar for a thin film magnetic head according to the present invention comprises a strip-shaped non-magnetic substrate, an alumina film provided on two surfaces of the substrate facing each other, and an alumina film on one of the substrates. And an element forming portion including a plurality of thin film magnetic head elements formed.

A method of manufacturing a slider bar for a thin film magnetic head according to the present invention comprises a step of preparing a non-magnetic substrate, a step of forming an alumina film on both surfaces of the substrate, and an alumina film on one of the substrates. A step of forming a plurality of thin film magnetic head elements on the substrate, a step of cutting the substrate into a strip shape, and grinding / polishing the cut surface to form a mirror surface having a predetermined roughness. To do.

A thin film magnetic head according to the present invention comprises a non-magnetic substrate, an alumina film provided on two surfaces of the substrate facing each other, and a plurality of thin films formed on one alumina film of the substrate. And an element forming portion including the thin film magnetic head element.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION A substrate for a thin film magnetic head according to an embodiment of the present invention, a slider bar for a thin film magnetic head obtained from the substrate, and a method for manufacturing the same will be described below with reference to the accompanying drawings. The substantially same members are designated by the same reference numerals.

(First Embodiment) A thin film magnetic head substrate according to a first embodiment of the present invention will be described. First, as shown in FIG. 1, this thin film magnetic head substrate (wafer) is composed of a disk-shaped AlTiC substrate 1 on both surfaces of which alumina films 2 and 3 of about 30 μm having approximately the same thickness are formed. The disk-shaped AlTiC substrate 1 which is the base material has a diameter of 15.24c.
The size is m (φ6 inch). In addition, this AlTiC
The shape of the substrate 1 is not limited to the disc shape. Further, since the substrate 1 having the alumina films 2 and 3 on both surfaces has the alumina films having substantially the same film thickness on both surfaces, after the element forming portion 4 including the thin film magnetic head element is provided thereafter, it is machined into a strip shape. In the manufacturing process of finishing the slider bar 20, the warp of the substrate 1 in the thickness direction can be suppressed.

(Second Embodiment) A substrate 10 for a thin film magnetic head according to a second embodiment of the present invention will be described. First, the thin film magnetic head substrate (wafer) 10 is shown in FIG.
As shown in FIG. 1, a disk-shaped AlTiC substrate 1 having alumina films 2 and 3 of approximately 30 μm having substantially the same thickness formed on both sides, and a plurality of alumina films 2 formed on one alumina film 2 of the substrate 1. And an element forming portion 4 including a thin film magnetic head element.
AlTiC having alumina films 2 and 3 on both sides
The board 1 is the board according to the first embodiment. Also,
Since the substrate 1 having the alumina films 2 and 3 on both sides has the alumina films of substantially the same thickness on both sides, in the manufacturing process of finishing the strip-shaped slider bar 20 by machining thereafter, the substrate 1 in the thickness direction is formed. The warp can be suppressed.
It should be noted that, of the alumina films 2 and 3 formed on both sides of the substrate 1, the alumina film 2 on the surface on which the thin film magnetic head element is formed serves as a shield film for the base material AlTiC substrate 1, and the alumina film 3 on the opposite surface. Plays a role in correcting warpage caused by internal stress.

Next, a method of manufacturing the thin film magnetic head substrate 10 will be described. This manufacturing method includes the following steps. (A) A disk-shaped AlTiC substrate 1 is prepared. (B) Alumina films 2 and 3 each having a film thickness of about several tens of μm are formed on both surfaces of the AlTiC substrate 1 (FIG. 1B).
In this case, the film may be formed on one side or simultaneously on both sides. Further, the thicknesses of the alumina films 2 and 3 on both surfaces are made substantially the same. (C) An element forming portion 4 including a large number of thin film magnetic head elements is formed on one alumina film 2 of the substrate 1 (FIG. 2).
(B)). The number of elements to be formed differs depending on the wafer size used. Through the above steps, A having an alumina film on both sides
It is possible to fabricate a substrate 10 for a thin film magnetic head, which includes an lTiC substrate and an element forming portion including a plurality of thin film magnetic head elements.

(Third Embodiment) A slider bar for a thin film magnetic head according to a third embodiment of the present invention and a method of manufacturing the slider bar will be described. This thin film magnetic head slider bar 2
As shown in FIGS. 3B and 3C, 0 is an AlT having a strip shape and having alumina films 22 and 23 on both surfaces.
An iC substrate 21 and an element forming portion 24 including a plurality of thin film magnetic head elements 25 formed on one alumina film 2 of the substrate 21 are provided. The alumina films 22 and 23 have substantially the same film thickness, and the film thickness is preferably 10
˜100 μm. Thus, since the alumina films 22 and 23 having substantially the same thickness are formed on both surfaces, the substrate 2
It is possible to prevent 1 from curving and warping. Further, even if the length of the slider bar is lengthened, the occurrence of warpage can be suppressed.

Next, a method of manufacturing the slider bar 20 for the thin film magnetic head will be described. As shown in FIGS. 1 to 4, this manufacturing method includes the following steps. (A) A disk-shaped AlTiC substrate 1 is prepared. The shape of the substrate 1 is not limited to the disc shape. (B) Alumina films 2 and 3 each having a film thickness of about several tens of μm are formed on both surfaces of the AlTiC substrate 1 (FIG. 1B).
In this case, the film may be formed on one side or simultaneously on both sides. Further, the thicknesses of the alumina films 2 and 3 on both surfaces are made substantially the same. (C) An element forming portion 4 including a large number of thin film magnetic head elements 25 is formed on one alumina film 2 (FIG. 2).
(B)). Depending on the size of the wafer used, the device 25
The number of forming is different. The process up to this step is the same as the method for manufacturing the substrate for a thin film magnetic head according to the second embodiment. (D) The thin film magnetic head substrate 10 described above is replaced with a chain line 1
The thin film magnetic head slider bar 20 is obtained by cutting along the lines 1 and 12 (FIG. 3A) and grinding and polishing the cut surface (FIG. 3B). Here, for example, 200 slider bars 20 having a predetermined size are cut, both cut surfaces are ground, and further mirror-finished by polishing. (E) The obtained slider bar 20 has a sectional structure, for example, as shown in (c) of FIG. 3, in which alumina films 22 and 23 having substantially the same thickness are provided on both surfaces of an AlTiC substrate 21, and one of the alumina bars is formed. An element forming portion 24 including a plurality of thin film magnetic head elements 25 is formed on the film 22. Further, an air bearing surface 26 is formed on the element forming portion 24.
To form. (F) Next, a predetermined number of slider bars 20 are arranged in a certain direction, and a photolithography technique is used to pattern an air bearing surface 26 of a predetermined shape on the surface facing the medium, for example, a method such as dry etching. To form (FIG. 4). Through the above steps, the slider bar 20 for a thin film magnetic head can be manufactured. The amount of warpage due to the bending of the manufactured thin film magnetic head slider bar 20 was 0.5 μm or less, which was a good value. Accordingly, in the above steps, patterning by photolithography can be performed with high accuracy.

A thin film magnetic head can be manufactured using this slider bar for a thin film magnetic head. The obtained thin-film magnetic head comprises an AlTiC substrate which is a non-magnetic substrate, an alumina film provided on two surfaces of the substrate facing each other, and a plurality of thin-film magnetic heads formed on one alumina film of the substrate. And an element forming portion including a head element. As described above, since the nonmagnetic substrate has the alumina films of substantially the same thickness on both sides, it is possible to prevent the substrate from being curved and warped.

[0025]

As described above in detail, according to the thin-film magnetic head substrate of the present invention, since the non-magnetic substrate has the alumina film on both sides thereof, the strip-shaped substrate is machined by cutting, grinding, polishing or the like. When it is used as the slider bar, the warp generated by the internal stress of the alumina film can be corrected. As a result, the air bearing surface can be formed with high accuracy without misalignment in the photolithography method.

Further, according to the slider bar for a thin film magnetic head of the present invention, the strip-shaped non-magnetic substrate has alumina films on both sides thereof, and a plurality of thin film magnetic head elements are provided on one of the alumina films. The formed element forming portion is provided. Therefore, in order to improve the productivity, one slider bar can be lengthened to suppress the occurrence of warpage even when more thin film magnetic head elements are formed. Therefore, it is possible to enhance productivity and at the same time, patterning with high precision by photolithography. Further, even when the slider bar length is short, a further effect is exhibited.

[Brief description of drawings]

1A is a plan view of a thin film magnetic head substrate according to a first embodiment of the present invention, and FIG. 1B is a front view of FIG.

2A is a plan view of a thin-film magnetic head substrate according to a second embodiment of the present invention, and FIG. 2B is a front view of FIG.

3A is a plan view showing a cutting step in a method of manufacturing a slider bar for a thin film magnetic head according to a third embodiment of the present invention, and FIG. 3B is a cutting step performed in the cutting step of FIG. It is a perspective view showing a plurality of slider bars are
(C) is an enlarged sectional view of a portion A of one slider bar in (b).

FIG. 4 is a perspective view showing formation of an air bearing surface in a method of manufacturing a slider bar for a thin film magnetic head according to a third embodiment of the present invention.

5A is a plan view of a conventional thin film magnetic head substrate, and FIG. 5B is a front view of FIG.

FIG. 6A is a plan view showing a cutting process of a slider bar for a thin film magnetic head of a conventional example, and FIG. 6B is a schematic view showing that the cut stack is composed of a plurality of slider bars. And (c) is an enlarged cross-sectional view of portion B of (b).

FIG. 7A is a plan view showing a step of patterning and dry-etching a plurality of slider bars so as to be in contact with each other in the thickness direction in a manufacturing process of a slider bar for a thin film magnetic head; FIG. 7A is a perspective view showing a curved state of one slider bar in (a).

[Explanation of symbols]

1 AlTiC substrate 2,3 alumina film 4 Element formation part 10 Substrate (wafer) for thin film magnetic head 11, 12 cutting line 20 slider bar 21 AlTiC substrate 22, 23 Alumina film 24 Element formation part 25 Thin film magnetic head element 26 Air bearing surface 51 AlTiC substrate 52 Alumina film 54 Thin film magnetic head element 55 stack 60 slider bar 61, 62 cutting line 64 element formation part 65 Thin film magnetic head element 66 Medium facing surface (air bearing surface) 71 AlTiC substrate 72 Alumina film d Warp

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Sadayoshi Ito             1 Juden Matsushita, 1-8 Koshinmachi, Takamatsu City, Kagawa Prefecture             Child Industry Co., Ltd. (72) Inventor Ryuichi Nakagami             1 Juden Matsushita, 1-8 Koshinmachi, Takamatsu City, Kagawa Prefecture             Child Industry Co., Ltd. (72) Inventor Kozo Tagashi             1 Juden Matsushita, 1-8 Koshinmachi, Takamatsu City, Kagawa Prefecture             Child Industry Co., Ltd. F-term (reference) 5D033 BA51 DA02 DA31                 5D042 NA02 PA08 RA04

Claims (6)

[Claims] 1. A substrate for a thin film magnetic head, comprising a plate-shaped non-magnetic substrate, and an alumina film provided on both surfaces of the substrate and having a film thickness in the range of 10 to 100 μm. 2. An element formation including a plate-shaped non-magnetic substrate, alumina films provided on both surfaces of the substrate, and a plurality of thin film magnetic head elements formed on one alumina film of the substrate. And a substrate for a thin-film magnetic head. 3. The thin-film magnetic head substrate according to claim 2, wherein the alumina film has a film thickness in the range of 10 to 100 μm. 4. A strip-shaped non-magnetic substrate, an alumina film provided on two surfaces of the substrate facing each other, and a plurality of thin film magnetic heads formed on one alumina film of the substrate. A slider bar for a thin film magnetic head, comprising: an element forming portion including an element. 5. A step of preparing a non-magnetic substrate, a step of forming an alumina film on both surfaces of the substrate, and a step of forming a plurality of thin film magnetic head elements on one alumina film of the substrate. A step of cutting the substrate into a strip shape, grinding and polishing the cut surface to form a mirror surface having a predetermined roughness, and manufacturing a slider bar for a thin film magnetic head. 6. A non-magnetic substrate, an alumina film provided on two surfaces of the substrate facing each other, and a plurality of thin film magnetic head elements formed on one alumina film of the substrate. A thin-film magnetic head comprising an element forming portion.