JP3089854B2 - Method for manufacturing thin-film magnetic head - Google Patents

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 including a step of forming a plurality of magnetic transducers on the surface of a wafer and then forming a protective film covering the magnetic transducers.

[0002]

2. Description of the Related Art When a floating type thin film magnetic head is manufactured, after a patterning step of aligning and forming a large number of thin film magnetic transducers on a wafer, as shown in FIG.
The protection film 31 is formed on the entire wafer 30 by sputtering or the like.

[0003]

However, when such a protective film 31 is formed on the wafer 30, FIG.
As shown in (B), the film stress warps the entire wafer. This warpage is caused by the central portion 30a of the wafer 30.
Is 2-3 μm on the protective film 31 side with respect to the peripheral portion 30b.
It is prominent to the extent.

[0004] The wafer thus distorted has a central portion 30 a because the upper portion of the protective film 31 is scraped off in a lead wire forming step performed thereafter, as shown in FIG.
And the peripheral portion 30b have different thicknesses. This leads to the generation of dimensional variations in the finally manufactured magnetic head, which is a serious problem.

Accordingly, the present invention provides a method of manufacturing a thin-film magnetic head capable of compensating for distortion of a wafer due to formation of a protective film.

[0006]

According to the present invention, there is provided a thin film magnetic method comprising the steps of forming a plurality of magnetic transducers on a surface of a wafer and then forming a protective film to cover the surface including the magnetic transducers. A method of manufacturing a head is provided, in which a back surface of a wafer is roughened during a thin film process after forming a protective film and before polishing the upper portion of the protective film .

It is preferable that the processing of the rough surface on the back surface of the wafer is a processing in which the center line average roughness Ra is a surface roughness of about 0.1 μm.

[0008]

When the back surface of the wafer is roughened to some extent during the thin film process and immediately after the formation of the protective film, the center portion 30a of the wafer is moved to its peripheral portion 3 by the formation of the protective film.
A stress that opposes the film stress protruding toward the film side with respect to 0b is generated, and the two are balanced to compensate for the warpage.

[0009]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a process diagram schematically illustrating a part of a manufacturing process of a floating type thin film magnetic head as one embodiment of the present invention, and FIG. 2 is a diagram showing a state of a wafer in the process. is there.

When manufacturing this kind of thin film magnetic head,
First, in S1 of FIG. 1, for example, Al ₂ O ₃ —TiC
A large number of thin film magnetic transducers are aligned and formed on the surface 20a side of the wafer 20 made of a ceramic material such as Actually, an electric insulating material such as Al ₂ O ₃ or SiO ₂ is sputtered on the surface 20 a of the wafer 20 to form a base film, and a thin film magnetic transducer is formed on the base film.

Next, in S2 of FIG. 1, a protective film 21 of about 35 μm is formed on the thin-film magnetic transducer and the wafer 20 by sputtering Al ₂ O ₃ or SiO ₂ or the like, as shown in FIG.
It is formed as shown in FIG.

Immediately after the formation of the protective film 21, in S3 of FIG. 1, the back surface 20b of the wafer 20 is wrapped to finish the surface roughness to about Ra ≒ 0.1 μm. By roughening the back surface in this way, a stress is generated, and this stress antagonizes the film stress by the protective film 21. As a result, FIG.
As shown in (B), the warpage of the wafer due to the formation of the protective film is compensated, and the wafer 20 is kept flat. In fact, G
By lapping with abrasive grains of C # 1000 for about 2 minutes, a surface roughness of Ra ≒ 0.1 μm is obtained. The surface roughness of the back surface of the wafer is variably set in accordance with the thickness of the protective film 21 so as to generate a stress that opposes the film stress.

Next, in S4 of FIG. 1, the protective film 21 is formed.
Is polished and lead wires are formed. As shown in FIG. 2C, according to the present invention, since the wafer has no warp,
The protection film 21 is uniformly removed.

In the next step S5, the wafer 20 is cut (full cut) so as to include several thin film magnetic transducers in row units to obtain a rod-shaped head block, and thereafter, groove processing is performed. Thereafter, each head block is further cut to obtain a head piece corresponding to each magnetic head.

After such a cutting is performed, S6 in FIG.
In this case, other processing such as polishing is performed, and the thin film magnetic head is manufactured by being separated from the processing jig.

In the above-described embodiment, the step of lapping the back surface 20b of the wafer 20 is performed immediately after the formation of the protective film 21. It is clear that this may be done.
However, if the back surface of the wafer is roughened before or during patterning, it is not preferable because a problem of contamination occurs.

The step of roughening the back surface 20b of the wafer 20 may be performed by various known methods other than lapping.

[0019]

As described above in detail, according to the present invention, after forming a plurality of magnetic transducers on the surface of a wafer,
A method for manufacturing a thin-film magnetic head including a step of forming a protective film so as to cover the surface including these magnetic transducers,
During the thin film process after the formation of the protective film and before the polishing treatment of the upper part of the protective film , the back surface of the wafer is processed into a rough surface so as to counteract the stress. As a result, uniformity of the thickness of the protective film can be ensured, and workability in the subsequent steps is greatly improved.

[Brief description of the drawings]

FIG. 1 is a process diagram schematically illustrating a part of a manufacturing process of a thin-film magnetic head as one embodiment of the present invention.

FIG. 2 is a view schematically showing a state of a wafer in a part of processes of the embodiment of FIG. 1;

FIG. 3 is a diagram schematically showing a state of a wafer in a partial process based on the prior art.

[Explanation of symbols]

 Reference Signs List 20 Wafer 20a Wafer front surface 20b Wafer back surface 21 Protective film

Claims (2)

(57) [Claims] 1. A method for manufacturing a thin film magnetic head, comprising: forming a plurality of magnetic transducers on a surface of a wafer, and then forming a protective film so as to cover the surface including the magnetic transducers, After the formation of the protective film, the polishing of the upper part of the protective film is performed.
A method of manufacturing a thin-film magnetic head, wherein a back surface of the wafer is roughened during a thin-film process before polishing . 2. The method of manufacturing a thin-film magnetic head according to claim 1, wherein said rough surface processing is performed to a surface roughness having a center line average roughness Ra of about 0.1 μm.