Dynamic magnetic information storage or retrieval – Head – Core
Reexamination Certificate
2001-12-18
2004-02-03
Chen, Tianjie (Department: 2652)
Dynamic magnetic information storage or retrieval
Head
Core
C360S317000
Reexamination Certificate
active
06687084
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a perpendicular magnetic recording head for recording data on a recording medium, such as a disk having a hard surface, under application of a perpendicular magnetic field. More particularly, the present invention relates to a perpendicular magnetic recording head and a method of manufacturing the head, which can suppress the occurrence of fringing in a recording pattern, can form a main magnetic pole layer with high pattern accuracy and form a yoke surface having a large film thickness, and can improve the passing efficiency of magnetic flux.
2. Description of the Related Art
Conventionally, a perpendicular magnetic recording method is utilized in a device for recording magnetic data on a recording medium, such as a disk, with a high density.
FIG. 38
is a sectional view showing a general structure of a perpendicular magnetic recording head for use in the known perpendicular magnetic recording device.
As shown in
FIG. 38
, a perpendicular magnetic recording head H utilizing the perpendicular magnetic recording method is provided on a side end surface of a slider
1
moving or sliding in a floating relation over a recording medium. On a side end surface
1
a
of the slider
1
, for example, the perpendicular magnetic recording head H is disposed between a nonmagnetic film
2
and a nonmagnetic coating film
3
.
The perpendicular magnetic recording head H has an auxiliary magnetic pole layer
4
made of ferromagnetic materials, and a main magnetic pole layer
5
also made of ferromagnetic materials and formed above the auxiliary magnetic pole layer
4
with a space left between both the layers. An end surface
4
a
of the auxiliary magnetic pole layer
4
and an end surface
5
a
of the main magnetic pole layer
5
appear at an opposing surface Ha of the head positioned opposite to a recording medium M. The auxiliary magnetic pole layer
4
and the main magnetic pole layer
5
are magnetically coupled to each other in a magnetic coupling portion
6
located inward of the opposing surface Ha.
A nonmagnetic insulating layer
7
made of inorganic materials, such as Al
2
O
3
and SiO
2
, is positioned between the auxiliary magnetic pole layer
4
and the main magnetic pole layer
5
. In the opposing surface Ha, an end surface
7
a
of the nonmagnetic insulating layer
7
appears between the end surface
4
a
of the auxiliary magnetic pole layer
4
and the end surface
5
a
of the main magnetic pole layer
5
.
Then, a coil layer
8
made of conductive materials, e.g., Cu, is embedded in the nonmagnetic insulating layer
7
.
Also, as shown in
FIG. 38
, the end surface
5
a
of the main magnetic pole layer
5
has a thickness hw smaller than a thickness hr of the end surface
4
a
of the auxiliary magnetic pole layer
4
. A width size of the end surface
5
a
of the main magnetic pole layer
5
in the direction of track width (indicated by X in
FIG. 38
) defines a track width Tw that is much smaller than a width size of the end surface
4
a
of the auxiliary magnetic pole layer
4
in the direction of track width.
The recording medium M, on which magnetic data is to be recorded by the perpendicular magnetic recording head H, is moved in the Z-direction relative to the perpendicular magnetic recording head H. The recording medium M has a hard surface Ma on the outer surface side and a soft surface Mb on the inner side.
When a recording magnetic field is induced in both the auxiliary magnetic pole layer
4
and the main magnetic pole layer
5
upon energization of the coil layer
8
, a leaked recording magnetic field passes between the end surface
4
a
of the auxiliary magnetic pole layer
4
and the end surface
5
a
of the main magnetic pole layer
5
while perpendicularly penetrating the hard surface Ma of the recording medium M and propagating in the soft surface Mb. Since the end surface
5
a
of the main magnetic pole layer
5
has an area much smaller than that of the end surface
4
a
of the auxiliary magnetic pole layer
4
as described above, magnetic flux &PHgr; is concentrated on a portion of the recording medium opposing to the end surface
5
a
of the main magnetic pole layer
5
. Thus, magnetic data is recorded in a portion of the hard surface Ma opposing to the end surface
5
a
with the concentrated magnetic flux &PHgr;.
However, the conventional perpendicular magnetic recording head H, shown in
FIG. 38
, has the following problems.
(1) In the structure shown in
FIG. 38
, an upper surface of the nonmagnetic insulating layer
7
has a certain degree of roughness, and therefore the main magnetic pole layer
5
formed on the upper surface of the nonmagnetic insulating layer
7
has reduced pattern accuracy. On the other hand, it is particularly required not only to reduce the area of the end surface
5
a
of the main magnetic pole layer
5
, which appears at the opposing surface Ha, so that the leaked recording magnetic field is highly concentrated, but also to narrow the track width Tw defined by the end surface
5
a
for achieving a high recording density on the recording medium M.
Accordingly, the structure shown in
FIG. 38
causes a difficulty in forming the end surface
5
a
of the main magnetic pole layer
5
so as to provide a smaller track width Tw and hence a narrower track with high pattern accuracy. Thus, the conventional structure is not satisfactorily adaptable for a higher recording density.
(2) In order to introduce, to the opposing surface Ha, a magnetic field induced from the coil layer
8
, an inward area of the main magnetic pole layer
5
is required to have a larger cross-sectional area through which the magnetic flux is allowed to pass. In the structure shown in
FIG. 38
, however, the main magnetic pole layer
5
is formed to extend rearward in the height direction (indicated by Y in
FIG. 38
) with a substantially constant film thickness, and the film thickness of the main magnetic pole layer
5
cannot be increased in the inward area thereof. Hence, the magnetic field induced from the coil layer
8
cannot be effectively introduced to a fore end of the main magnetic pole layer
5
.
(3) Since the main magnetic pole layer
5
is formed as a single layer in the structure shown in
FIG. 38
, it is difficult to extremely reduce only the track width Tw defined by the end surface
5
a
of the main magnetic pole layer
5
. Stated otherwise, the main magnetic pole layer
5
is formed by forming a holed pattern on a resist layer and then applying a magnetic material to the holed pattern by, e.g., plating. Such a process has a difficulty in extremely reducing the width size of the holed pattern only in a portion where the end surface
5
a
is to be formed.
(4) When the slider
1
is moved between an outer periphery and an inner periphery of the recording medium M in the form of a disk, the end surface
5
a
of the main magnetic pole layer
5
is sometimes inclined and causes a skew angle with respect to the tangential direction of rotation of the recording medium M (i.e., the Z-direction in FIG.
38
). In the case of the end surface
5
a
of the main magnetic pole layer
5
being square or rectangular as shown in
FIG. 39
, if the end surface
5
a
of the main magnetic pole layer
5
has a skew angle with respect to the tangential direction of rotation of the recording medium (i.e., the Z-direction in FIG.
38
), a lateral side
5
b
of the main magnetic pole layer
5
provides an inclined leaked magnetic field within a track width Tw
1
, as indicated by a broken line, whereby fringing F occurs and off-track characteristics deteriorate.
SUMMARY OF THE INVENTION
With the view of overcoming the above-mentioned problems in the related art, it is an object of the present invention to provide a perpendicular magnetic recording head and a method of manufacturing the head, which can form an end surface of a main magnetic pole layer with higher pattern accuracy, and which is adaptable for a narrower track.
Another object of the present invention is to provide a perpendicu
Gochou Hideki
Kobayashi Kiyoshi
Sato Kiyoshi
Takahashi Toru
Watanabe Toshinori
Alps Electric Co. ,Ltd.
Brinks Hofer Gilson & Lione
Chen Tianjie
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