Dynamic magnetic information storage or retrieval – Fluid bearing head support – Disk record
Reexamination Certificate
1999-06-08
2001-03-06
Klimowicz, William (Department: 2652)
Dynamic magnetic information storage or retrieval
Fluid bearing head support
Disk record
C360S236500
Reexamination Certificate
active
06198600
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a thin film magnetic head employed in a magnetic recording/reproduction apparatus such as a magnetic disk apparatus, and a manufacturing method thereof.
2. Discussion of Background
In order to assure high density recording in magnetic disk apparatuses, the recording track width of thin film magnetic heads has been reduced to 1.0 &mgr;m or less in recent years. One of the prior art methods to achieve such a small recording track width is to machine the air bearing surface (ABS) of the slider. Indented portions having a specific depth are obtained by polishing the surface of the slider facing opposite the medium, defining a pattern by removing the area that contains the end surface of the magnetic film through the Focused Ion Beam (FIB) etching technique or through photolithography, and machining the air bearing surface in conformance with the pattern thus defined by employing a means such as ion milling.
IEEE Transactions on Magnetics Vol. 27, No. 6, November 1991, for instance, discloses a reduced track width obtained by applying the FIB etching technique on the ABS of the slider, and IEEE Transactions on Magnetics Vol. 30, No. 6, November 1994 discloses a thin film magnetic head having a reduced track width obtained by machining the slider through photolithography.
During the machining processes described above, the end surface of the magnetic film constituting the pole tip becomes exposed within the indented portions. As a means for protecting this end surface from oxidation or corrosion, a single protective film is formed over the entire surface facing opposite the medium including the ABS and the indented portions. Normally, the protective film is constituted of diamond-like carbon (DLC).
However, since the protective film has a consistent thickness and is formed onto the ABS as well as inside the indented portions, this structure poses a problem in that in order to cover the entire end surface of the magnetic film exposed within the indented portions, it is necessary to use a rather thick protective film. This means that the protective film formed onto the air bearing surface is thick as well, causing spacing loss which in turn leads to deteriorated electromagnetic conversion characteristics.
The problem described above occurs whenever an area containing a pole tip is removed and thus, it is not limited to the process performed to achieve a reduction in the track width.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a thin film magnetic head in which the end surface of the magnetic film constituting a pole tip is reliably protected from oxidation, corrosion and the like while achieving a reduction in spacing loss.
It is a further object of the present invention to provide a suitable method for manufacturing the thin film magnetic head described above.
In order to achieve these objects, the thin film magnetic head according to the present invention comprises a slider, at least one inductive thin film magnetic transducer and a protective film. The slider having a base body surface facing opposite a medium, is provided with indented portions recessed from the surface facing opposite the medium.
The inductive thin film magnetic transducer has a pole tip of which the front end emerges at the base body surface and the indented portions.
The protective film covers the base body surface as well as the indented portions. The thickness of the protective film at the indented portions is larger than the thickness of the protective film at the base body surface.
As described above, in the thin film magnetic head according to the present invention, the inductive thin film magnetic transducer is provided with a pole tip whose front end emerges at the base body surface and the indented portions. By adopting this structure, electromagnetic conversion characteristics corresponding to the extent of the indentation of the pole tip imparted by the indented portions are realized. A typical objective to remove an area of the base body surface where a pole tip is situated, is to achieve a reduction in the track width. In this case, since the width of the pole tip in the direction of the tracks that intersects the direction in which the medium travels, is reduced by the formation of indented portions, a flying type thin film magnetic head having a track width that is reduced in correspondence to the extent of the indentation of the area where the pole tip is situated, is achieved.
The protective film is formed onto the base body surface. As a result, the front end of the magnetic film constituting the pole tip being exposed inside the indented portions is covered by the protective film so that the front end of the magnetic film is protected from oxidation and corrosion.
The film thickness of the protective film at the indented portions is set larger than the film thickness of the protective film at the base body surface. In other words, the film thickness of the protective film formed onto the base body surface is smaller than the film thickness of the protective film formed inside the indented portions. Thus, with the protective film covering the base body surface being thinner, the spacing loss can be reduced, while at the same time covering the front end of the magnetic film which constitutes the pole tip with the protective film.
REFERENCES:
patent: 5386400 (1995-01-01), Nakayama et al.
patent: 5617273 (1997-04-01), Carr et al.
patent: 5903969 (1999-05-01), Haga
patent: 5986851 (1999-11-01), Angelo et al.
patent: 6038101 (2000-03-01), Yoda et al.
patent: 6040965 (2000-03-01), Terunuma et al.
patent: 7-230615 (1995-08-01), None
Hisashi Takano, et al. “Submicron-trackwidth Inductive/MR Composite Head,” IEEE Transactions on Magnetics, vol. 27, No. 6, Nov. 1991, pp. 4678-4683.
K. Fukuda, et al. “Off-track Capability of a Pole Trimmed Thin Film Head,” IEEE Transactions on Magnetics, vol. 30, No. 6, Nov. 1994, pp. 3891-3893.
Kitao Mitsuhiro
Momoi Monjiro
Nakazawa Hiroki
Shibata Keiichi
Yamanaka Noboru
Klimowicz William
Oblon & Spivak, McClelland, Maier & Neustadt P.C.
TDK Corporation
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