Etching a substrate: processes – Forming or treating article containing magnetically...
Reexamination Certificate
2000-11-30
2003-09-30
Utech, Benjamin L. (Department: 1765)
Etching a substrate: processes
Forming or treating article containing magnetically...
C029S603070, C029S603180, C360S100100
Reexamination Certificate
active
06627094
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a method of manufacturing a thin film head, more precisely relates to a method of manufacturing a thin film head, which includes a pad capable of preventing the thin film head from sticking onto a recording medium.
In a contact-start-stop (CSS) type magnetic disk drive unit, magnetic heads contact surfaces of magnetic disks while rotation of the disks are stopped; the magnetic heads are floated above the surfaces of the disks by air streams, which are caused by rotation of the disks. Thus, floating patterns are formed in a disk-side face, which faces the surface of the disk, of each magnetic head. Further, pads, which is capable of reducing contact resistance between the disk and the head, are formed in the disk-side face.
The disk-side face of the conventional magnetic head is shown in FIG.
6
. The head
10
has the floating patterns
12
a
,
12
b
and
12
c
, shallow groove sections
14
a,
14
b
and
14
c
and a deep groove section
16
. The shallow groove sections
14
a,
14
b
and
14
c
and the deep groove section
16
act to generate negative pressure when the magnetic head
10
is floated, so that flatting level of the magnetic head
10
can be limited in a prescribed range. In the disk-side face, the floating patterns
12
a
,
12
b
and
12
c
are projected the most other than pads
18
a
,
18
b
,
18
c
and
18
d
; the floating patterns
12
a
,
12
b
and
12
c
are projected more than the shallow groove sections
14
a
,
14
b
and
14
c
; the deep groove section
16
is deeper than the shallow groove sections
14
a
,
14
b
and
14
c
. The pads
18
a
,
18
b
,
18
c
and
18
d
are provided in the shallow groove sections
14
a
,
14
b
and
14
c
, and their end faces are projected from surfaces of the floating patterns
12
a
,
12
b
and
12
c
.
FIG. 7
shows a state in which the magnetic head
10
is floating above a surface of a rotating disk
20
. The magnetic head
10
is held by a suspension
22
.
Each time the rotation of the disk is stopped, the pads contact the surface of the magnetic disk. Therefore, the pads must have enough durability because the pads contact the disk many times. To have enough durability, the contact resistance between the pads and the disk must be reduced, and the sticking of the head to the disk and the sticking of dust to the surface of the head must be prevented so as to reduce the contact resistance less than a prescribed value.
A conventional method of forming the pads is shown in
FIGS. 5A-5D
. Note that,
FIGS. 5A-5D
are sectional views taken along a line A—A in FIG.
6
.
In
FIG. 5A
, an adhesion layer
32
, a protection layer
34
, a stopper layer
36
and a pad layer
38
are piled, in this order, on a surface of a substrate
30
of a head slider, which has been finished by lapping machine. The adhesion layer
32
and the stopper layer
36
are silicon film layers; the protection layer
34
and the pad layer
38
are DLC (Diamond Like Carbon) film layers.
In
FIG. 5B
, the pad layer
38
has been etched, then the stopper layer
36
have been etched so as to form a pad
18
. In the etching step, the surface of the pad layer
38
is coated with resist
40
, and a resist pattern, which covers over a portion at which the pad
18
is formed, is formed by exposing and developing processes. Then etching is executed.
The pad layer
38
is dry-etched in oxygen gas, then the portion covered with the resist
40
is left and the pad
18
is formed. The stopper layer
36
is selectively etched with CF4 gas. By the etching step, the protection layer
34
other than the portion corresponding to the pad
18
is exposed.
In
FIG. 5C
, a floating pattern
12
and a shallow groove section
14
are formed. Resist
42
covers over the floating pattern
12
and the pad
18
. The protection layer
34
, which is the DLC layer, is dry-etched so as to form the floating pattern
12
, then the adhesive layer
32
and the substrate
30
are etched by ion milling so as to form the shallow groove section
14
. In this step, the surface of the substrate
30
is wholly etched.
In
FIG. 5D
, a deep groove section
16
is formed in the substrate
30
. To etch a portion corresponding the deep groove section
16
, the pad
18
, the floating pattern
12
and the shallow groove section
14
, other than the portion corresponding to the deep groove section
16
, are covered with resist
44
. The surface of the substrate
30
is etched, by ion milling or dry-etching, so as to form the deep groove section
16
in the surface of the substrate
30
.
In the conventional method in which the pad
18
is formed in the disk-side face of the head
10
, the stopper layer
36
is formed on the protection layer
34
so as not to etch the lower protection layer
34
when the pad layer
38
is etched.
Silicon invades into the protection layer
34
and a mixing layer is formed in the protection layer
34
when the silicon stopper layer
36
is formed on the protection layer
34
. Forming the mixing layer is unavoidable. The silicon in the protection layer
34
cannot be removed by etching and removing the stopper layer
36
, and it makes water-repellent property of the protection layer
34
lower. On the other hand, if the stopper layer
36
is etched for a long time so as to perfectly remove the silicon in the protection layer
34
, the protection layer
34
is damaged and has a porous structure. In this case, the protection layer
34
is apt to be corroded, and its corrosion-resisting property must be lowered.
SUMMARY OF THE INVENTION
The present invention was invented to solve the problems of the conventional method of forming the pads in the magnetic head.
An object of the present invention is to provide a method of manufacturing a thin film head, which includes a protection layer having enough corrosion-resisting property and water-repellent property, which is capable of keeping the magnetic head clean even if temperature and humidity are high, and which has enough durability and reliability.
To achieve the object, the method of manufacturing the thin film head, in which a pad, which contacts a disk, and a floating pattern are formed in a disk-side face, comprises the steps of: forming a adhesion layer on the disk-side face of a substrate, which is a main body of the thin film head; forming a protection layer on the adhesion layer; coating the protection layer with resist; patterning the resist so as to form a pad hole at a prescribed position, at which the pad is formed; forming a pad film on resist-coated faces including an inner face of the pad hole; and lifting off the resist so as to form the pad.
In the method, a diameter of the pad hole in the resist may be greater than that of the pad, and the pad, which has a prescribed shape, may be formed by etching the pad film after the resist is lifted off. By making the diameter of the pad hole greater than that of the pad, the pad can be precisely formed with predetermined thickness and shape.
In the method, a preferable relationship between a thickness “t” of the resist and a radius difference “L”, which is a difference between a radius of the pad hole and that of the pad, is L≧0.5t.
In the method, the pad film and the protection layer may be coated with another resist after the resist is lifted off, the another resist may be patterned so as to coat prescribed positions, at which the pad and the floating pattern are respectively formed, with the another resist, and the pad film, the protection layer and a surface of the substrate may be etched so as to form the pad and the floating pattern.
In the method, a water-repellent treatment may be executed on the disk-side face after forming the pad and the floating pattern. With this structure, the disk-side face can have higher water-repellent property, so that the disk-side face can be kept clean and the reliability of the head can be improved.
In the method, a base film may be formed as a base layer of the pad film so as to improve abrasion-resisting property of the pad. Hard film, e.g., silicon film, SiC film, is
Nakajima Hiroyuki
Watanuki Motoichi
Ahmed Shamim
Fujitsu Limited
Greer Burns & Crain Ltd.
Utech Benjamin L.
LandOfFree
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