JPH03113817A - Thin film magnetic head and substrate therefor - Google Patents

Abstract

PURPOSE:To obtain the substrate for a thin-film magnetic head having an insulating film and free of warpage by forming an oxide insulating film on both principal planes of a ceramic substrate member. CONSTITUTION:The insulating film 3 is formed on both principal planes of the substrate member 2 to obtain the substrate 1 for a thin-film magnetic head. The member 2 is made of a ceramic material, and its thickness is preferably controlled to about 0.3-4.0 mm. Al2O3, Ta2O5, SiO2, etc., are appropriately used as the oxide insulating material for the film 3, and the thickness of the film 3 is preferably controlled to about 3-30mum. As a result, the warpage of the substrate 1 is prevented even if the member 2 is thinned.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a thin film magnetic head substrate and a thin film magnetic head.

<Prior Art> A floating type thin film magnetic head has been put into practical use as a new magnetic head. Thin-film magnetic heads (1) have excellent high-frequency characteristics and are capable of high-speed data transfer; (2) are capable of high-density recording; (3) are capable of miniaturizing the device; (4) - through bulk production. Cost reduction can be achieved.

It has various features such as these, and is expected to form the mainstream of magnetic heads in this field in the future.

Thin film magnetic heads are manufactured by performing a wafer process on a substrate, processing the wafer into sliders, and making chips into units.

In such a case, as shown in FIG. 4, a ceramic substrate member 2 having excellent wear resistance and slidability with the medium is usually used as the thin film magnetic head substrate l. The surface of the substrate member 2 is provided with improved electrical insulation.
In order to smooth the surface and prevent steps from occurring during polishing of the air bearing surface, A I2 z Os, 310
An insulating film 3 such as a is formed by a method such as sputtering.

However, when the insulating film 3 is formed on the surface of the substrate member 2, the compressive stress caused by the insulating film 3 causes the thin film magnetic head substrate 1 to warp as shown in the figure.

As a result, pattern deviations occur during thin film formation and patterning in the wafer process, and dimensional accuracy decreases, making it difficult to manufacture narrow track heads. Furthermore, as the diameter of the substrate increases, this effect becomes even greater. Moreover, the yield will also be low.

On the other hand, when using a thin film magnetic head, there is a demand for increasing the resonant frequency of a spring that supports the head, improving tracking characteristics between the disk and the head, and increasing access speed.

To this end, the slider may be made smaller in order to reduce the mass of the thin-film magnetic head.

In this case, since the slider floating surface becomes the cut end surface when chipping is performed, it is necessary to reduce the thickness of the thin film magnetic head substrate 1 in order to miniaturize the slider.

However, if the thickness of the substrate member is made thinner, the amount of warpage will further increase, making it completely difficult to form highly accurate fine patterns.

Here, Japanese Patent Publication No. 63-19308 discloses that after the surface of an insulating thin film deposited on a substrate is polished in a predetermined suspension by rotating it under pressure using a poly lasher, A method for manufacturing a substrate for a thin film magnetic head has been proposed in which a magnetic film is deposited on the insulating thin film.

According to this manufacturing method, it is said that processing distortions and the like on the surface of the insulating thin film can be removed, surface roughness can be eliminated, and a precise substrate plane can be obtained.

<Problems to be Solved by the Invention> However, in the manufacturing method described in Japanese Patent Publication No. 19308/1983, the warping of the thin film magnetic head substrate 2 caused by the compressive stress of the insulating film 3 is corrected, and the substrate 2 is The effect of returning it to a flat surface cannot be obtained.

An object of the present invention is to provide a substrate for a thin film magnetic head that has an insulating film and is free from warpage, and a thin film magnetic head that is excellent in mass production and has accurate dimensional accuracy.

Means for Solving the Problems> These objects are achieved by the following inventions (1) to (4).

(1) A thin film magnetic head substrate characterized by having oxide insulating films on both main surfaces of a ceramic substrate member.

(2) The thickness of the ceramic substrate member is 0.3 to 4
．． The thin film magnetic head substrate according to (1) above, which has a thickness of 0 mm.

(3) The thin film magnetic head substrate according to (1) or (2) above, wherein the oxide insulating film has a thickness of 3 to 30 mm.

(4) A thin film magnetic head characterized in that a slider member has an oxide insulating film on both end faces, and a thin film head element is formed on one of the insulating films.

Effect> In the thin film magnetic head substrate of the present invention, insulating films are formed on both main surfaces of the substrate member.

Therefore, the compressive stress of the insulating film is applied to both main surfaces of the substrate member, and warpage of the thin film magnetic head substrate can be prevented.

Therefore, it is possible to prevent pattern misalignment, decrease in dimensional accuracy, etc. in the wafer process when manufacturing a thin film magnetic head.

Therefore, it is possible to obtain a thin film magnetic head having accurate dimensions and excellent mass productivity.

<Specific structure of the invention> Hereinafter, the specific configuration of the present invention will be explained in detail.

As shown in FIG. 1, a thin film magnetic head substrate 1 of the present invention is obtained by forming an insulating film 3 on both main surfaces of a substrate member 2. As shown in FIG.

The substrate member 2 is made of ceramic material.

As the ceramic material used in the present invention, any conventionally known ceramic material can be used, such as Aj2. Os
Ceramics containing -Tie as a main component, ceramics containing ZrOi as a main component, ceramics containing SiC as a main component, or ceramics containing Alx as a main component are suitable. These also contain Mg as an additive.

Y, Z r Os, T i Os, etc. may be contained.

The thickness of the substrate member 2 is preferably about 0.3 to 4.0 mm.

If it is less than the above range, it will be difficult to function as a slider when manufacturing a thin film magnetic head, and if it exceeds the above range, the mass will increase and it will be difficult to obtain a sufficient access speed.

Note that the present invention is particularly effective when the thickness of the substrate member 2 is set to 3.0 mm or less, since warpage of the substrate 1 can be prevented even if the thickness of the thin-film magnetic head substrate 1 is reduced.

The insulating film 3 used in the present invention is made of an oxide insulating material.

As the oxide insulating material for the insulating film 3, any conventionally known oxide insulating material can be used, such as AA*Os, Ta, etc.
g Os , S i Os, etc. are preferred.

The thickness of the insulating film 3 is preferably about 3 to 30 mm.

If it is less than the above range, the effect as an insulating film will be insufficient,
If it exceeds the above range, the film forming time will be long (and the cost will be high).

The insulating film 3 is formed on both main surfaces of the substrate member 2, and prevents the substrate 1 from warping by applying equal compressive stress to both main surfaces.

In this case, it is preferable that the thicknesses of the insulating films 3.3 are the same, but the effects of the present invention can be achieved even if the difference in thickness between the two insulating films is within 50%.

Note that there is no restriction on the order in which the insulating films 3.3 are formed.

For example, a sputtering method is suitable for forming the insulating film 3.

Next, a thin film magnetic head of the present invention manufactured using the above-mentioned thin film magnetic head substrate 1 will be explained.

2 and 3 show preferred embodiments of the thin film magnetic head of the present invention.

The thin film magnetic head 5 shown in FIGS. 2 and 3 is constructed by forming a thin film head element 4 on a slider 10. As shown in FIG.

The thin film head element 4 is attached to a slider 10 as shown in the figure.
On top, a lower magnetic pole layer 41, a gap layer 42, an insulating layer 43,
A coil layer 44, an insulating layer 45, an upper magnetic pole layer 46, and a protective layer 47 are sequentially formed.

In the present invention, the aforementioned thin film magnetic head substrate 1 is used for the slider 10.

That is, the slider 10 is obtained by forming an oxide insulating film 3 on both end surfaces of a slider member 20 made of ceramics.

Therefore, warping of the slider 10 can be prevented, and a thin film magnetic head 5 with good dimensional accuracy can be obtained.

In this case, the thickness of the slider member 20 (slider member 20
(distance between both end faces) is 0.3 to 4.0 as described above.
It is preferable that it is about mm.

Further, the film thickness of the oxide insulating film 3 is 3 to 30 mm as described above.
It is preferable that it is about IJm.

By setting it within the above range, the mass of the thin film magnetic head 5 can be set within a predetermined value, and sufficient access speed etc. can be obtained.

Note that the insulating film 3 on the back side of the wafer, that is, on the side opposite to the element forming surface, does not necessarily need to be formed over the entire surface, and may be in the shape of a strip, for example. Further, it may be removed by polishing before processing the slider.

Any conventionally known material can be used for the lower and upper magnetic pole layers 41, 46, such as permalloy, sendust, CO-based amorphous magnetic alloy, and the like.

The magnetic poles are usually provided as a lower magnetic pole layer 41 and an upper magnetic pole layer 46 as shown, and a gap layer 42 is formed between the lower magnetic pole layer 41 and the upper magnetic pole layer 46.

The gap layer 42 may be made of various known materials such as Al25Os and 5ins.

The patterns, film thicknesses, etc. of the pole layers 41, 46 and the gap layer 42 may be any known ones.

The material of the coil layer 44 is not particularly limited, and a commonly used metal such as A2 or Cu may be used.

There are no restrictions on the winding pattern or winding density of the coil, and known patterns may be appropriately selected and used.

Further, the coil layer 44 may be formed using a sputtering method, a plating method, or the like.

In the illustrated example, the coil layer 44 is a so-called spiral type, and is spirally arranged between the upper and lower magnetic pole layers 41 and 46.
An insulating layer 43.45 is provided between 1.46 and 43.46.

Any conventionally known material can be used for the insulating layers 43, 45. For example, when a thin film is formed by sputtering, 5iO1, A2203, etc. can be used.

Further, a protective layer 47 is provided on the top pole layer 46 .

As the material of the protective layer 47, any conventionally known material can be used, and for example, Al, AOS, etc. can be used.

The manufacturing process of such a thin film magnetic head is usually performed by forming a thin film and forming a pattern.

As described above, conventionally known techniques such as sputtering or plating may be used to form the thin films of each layer.

Pattern formation of each layer of the thin film magnetic head can be performed by selective etching or selective deposition, which are conventionally known techniques.

Etching can be performed by wet etching or dry etching.

<Example> Hereinafter, the present invention will be explained in further detail by giving specific examples of the present invention.

Example 1 As shown in FIG. 1, AQ*O* insulating films 3 were formed on both main surfaces of an Aρgos TiC substrate member 2 to produce thin film magnetic head substrate sample No. 1.

The substrate member 2 is disk-shaped and has a diameter The length was 76.2 mm and the thickness was 2.8 mm.

The insulating film 3 was simultaneously formed on both main surfaces of the substrate member 2 by sputtering, and the film thickness was set to 10-.

Further, as shown in FIG. 4, the insulating film 3 was formed only on one main surface of the substrate member 2, and the other conditions were as follows.
A comparative sample identical to o.1 was also produced.

In addition, in the comparison sample, the thickness of the substrate member 2 was 2.8 mm, and sample No. 2.4.0 m
Sample No. 3 was obtained with m.

For each sample, the radius of curvature r of the substrate was determined in order to confirm the amount of warpage of the substrate.

The results are shown in Table 1.

table 1 [ml 1 (present invention) 2 (comparison) 3 (comparison) 3630 38 84 Table 1 clearly shows the effects of the present invention.

In Table 1, for sample No. 1, theoretically the amount of warpage should be 0, that is, the radius of curvature should be infinite, but due to variations in the sputtering conditions on the front and back surfaces, the stress changes and a slight It is thought that warping occurred.

<Effects of the Invention> In the thin film magnetic head substrate of the present invention, insulating films are formed on both main surfaces of the substrate member.

Therefore, the compressive stress of the insulating film can be applied almost equally to both main surfaces of the substrate member.

Therefore, even if the thickness of the substrate member is reduced, it is possible to prevent the thin film magnetic head substrate from warping.

Furthermore, if a thin film magnetic head is manufactured using the above substrate,
Dimensional deviations in the wafer process can be prevented, and cutting and the like can be performed accurately and easily when turning the wafer into chips. Therefore, it is possible to obtain a thin film magnetic head with excellent mass productivity and high dimensional accuracy.

Furthermore, since the slider of the thin film magnetic head can be made smaller, the resonant frequency of the spring supporting the head can be increased, the tracking characteristics between the disk and the head can be improved, and the access speed can be increased.

[Brief explanation of drawings]

FIG. 1 is a partial cross-sectional view showing an example of the thin film magnetic head substrate of the present invention. FIG. 2 is a perspective view showing an example of the thin film magnetic head of the present invention. FIG. 3 is a partial sectional view showing an example of the thin film magnetic head of the present invention. FIG. 4 is a partial sectional view showing a conventional thin film magnetic head substrate. Explanation of symbols 1 Thin film magnetic spatula 2 Substrate member 3 Insulating film 4 Thin film head element 41 Lower magnetic pole layer 42 Gap layer 43, 45 Insulating layer 44...Coil layer 46...Substrate for upper magnetic pole layer 47...Protective layer 5...Thin film magnetic head 10...Slider 20...Slider member Applicant: TDC Co., Ltd. Agent People Patent Attorney Ishii Kankan Patent Attorney
Increase 1) Tatsuya 1 G, 2 FIG, 3 1G, 4

Claims (4)

[Claims] (1) A thin film magnetic head substrate characterized by having oxide insulating films on both main surfaces of a ceramic substrate member. (2) The thickness of the ceramic substrate member is 0.3 to 4
．． 2. The thin film magnetic head substrate according to claim 1, which has a thickness of 0 mm. (3) The thin film magnetic head substrate according to claim 1 or 2, wherein the oxide insulating film has a thickness of 3 to 30 μm. (4) A thin film magnetic head characterized in that a slider member has an oxide insulating film on both end faces, and a thin film head element is formed on one of the insulating films.