Dynamic magnetic information storage or retrieval – Head – Magnetoresistive reproducing head
Reexamination Certificate
2000-01-11
2002-02-19
Ometz, David L. (Department: 2652)
Dynamic magnetic information storage or retrieval
Head
Magnetoresistive reproducing head
C360S125330
Reexamination Certificate
active
06349021
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Present Invention
The present invention relates to a thin film magnetic head and, more particularly, to a combined-type thin film magnetic head in which a read magnetoresistive (MR) head having a magnetoresistive device and a write inductive head having a coil layer and a core layer are laminated.
2. Description of the Related Art
FIG. 5
is a perspective view of a conventional thin film magnetic head,
FIG. 6
is a sectional view taken along the line
6
—
6
of
FIG. 5
,
FIG. 7
is an enlarged front view observed from a direction indicated by an arrow
7
in
FIG. 6
, and
FIG. 8
is a schematic top plan view observed from a direction indicated by an arrow
8
in FIG.
6
. Furthermore,
FIG. 9
is a schematic top plan view illustrating a lead-out line pattern of the conventional thin film magnetic head, and
FIG. 10
is a top plan view illustrating an upper shield layer and a coil layer of the conventional thin film magnetic head.
A slider
1
of a thin film magnetic head mounted on a magnetic recording device such as a hard disk drive is composed of a ceramic material, e.g. a combination of alumina (Al
2
O
3
) and titanium carbide (TiC). The slider
1
has a read end surface
1
a
facing toward an upstream side of a moving direction of a disk surface of a magnetic recording medium, a trailing end surface
1
b
facing toward a downstream side, and a rail-shaped ABS surface
1
c
opposing a disk surface of the slider
1
as shown in FIG.
5
. The trailing end surface
1
b
is provided with a head device
2
and four bonding pads
3
for connection with an external circuit.
The head device
2
, which is formed of a thin film, is constituted by a combined-type thin film magnetic head wherein a read magnetoresistive magnetic head (hereinafter referred to as an “MR head”)
2
a
and a write inductive magnetic head (hereinafter referred to as an “inductive head”)
2
b
that is deposited on the MR head
2
a
as shown in FIG.
6
.
Referring to FIG.
6
and
FIG. 7
, the MR head
2
a
has a lower shield layer
2
a
1
formed of a Ni—Fe type alloy or a Permalloy, a lower gap layer
2
a
2
that is formed of a nonmagnetic material such as Al
2
O
3
and deposited on the lower shield layer
2
a
1
, a magnetoresistive (MR) device
2
a
3
provided in a central portion of an upper layer of the lower gap layer
2
a
2
, an electrode layer
2
a
4
formed from an upper surface of both ends of the MR device
2
a
3
through a surface of the lower gap layer
2
a
2
, an upper gap layer
2
a
5
that is provided on the MR device
2
a
3
and an upper layer of the electrode layer
2
a
4
and formed of a nonmagnetic material such as Al
2
O
3
, and an upper shield layer
2
a
6
′ that is formed on the upper layer of the upper gap layer
2
a
5
by plating and is formed of a magnetic material such as a Ni—Fe type alloy or Permalloy, all the layers being deposited on a trailing end surface
1
b
of the slider
1
. The MR device
2
a
3
shown in
FIG. 7
illustrates an anisotropic magnetoresistive (AMR) device that is formed of an SAL film Sa, a SHUNT film Sh, and an MR film M having magnetoresistive effect, the films being laminated in this order from the bottom. Furthermore, the electrode layer
2
a
4
shown in
FIG. 7
is comprised of a lower layer that is a hard bias layer H composed of CoPt, CoCrPt or the like, and an upper layer that is an electroconductive layer C composed of chrome (Cr), copper (Cu), or the like. The hard bias layer H applies a bias magnetic field, which is known as a longitudinal bias, to the MR film M in a direction parallel to the film surface thereof. In the MR head
2
a,
a reading magnetic gap length G
1
is decided by a distance between the MR film M and the lower shield layer
2
a
1
or the upper shield layer
2
a
6
′. A track width Tw is decided by a range wherein sense current flows between the two electrode layers
2
a
4
at both sides in the MR film M. A giant magnetoresistive (GMR) device may be used as the MR device
2
a
3
.
Referring now to FIG.
6
and
FIG. 8
, the inductive head
2
b
includes a lower core layer
2
b
1
′ serving also as the upper shield layer
2
a
6
′ of the MR head
2
a
, a nonmagnetic material layer
2
b
2
that is provided above the lower core layer
2
b
1
′ and forms a write magnetic gap G, a coil insulating layers
2
b
3
and
2
b
3
′ that are deposited on the nonmagnetic material layer
2
b
2
and composed of an organic resin material or the like, flat spiral coil layers
2
b
4
that are buried in the coil insulating layers
2
b
3
and
2
b
3
′ and composed of a low-resistance electroconductive material such as Cu, and an upper core layer
2
b
5
that has one end thereof in contact with the nonmagnetic material layer
2
b
2
adjacent to the ABS surface
1
c
and the other end thereof connected to the lower core layer
2
b
1
′, and is composed of a magnetic material such as a Ni—Fe, type alloy or Permalloy.
Referring now to FIG.
8
and
FIG. 9
, two connecting terminals
10
a
and
10
b
that are formed simultaneously and located away from the lower core layer
2
b
1
′ are formed at both sides of the lower core layer
2
b
1
′ and connected to the two electrode layers
2
a
4
that are connected to both ends of the MR device
2
a
3
. Furthermore, four lead-out lines
4
a,
4
b,
4
c,
and
4
d
formed of a low-resistance electroconductive material such as copper (Cu) are provided on the coil insulating layer
2
b
3
by being plated thereon at the same time when the coil layers
2
b
4
are formed. Two lead-out lines
4
a
and
4
b
respectively have connection ends
4
a
1
and
4
b
1
that oppose both sides of the lower core layer
2
b
1
′ and are conductively connected to the two connecting terminals
10
a
and
10
b,
respectively, via contact holes (not shown) provided in the upper gap layer
2
a
5
. The lead-out line
4
c,
is integrally formed continuously from an outermost circumferential end of the coil layers
2
b
4
. The lead-out line
4
d
has a connecting end
4
d
1
at a side of the lower core layer
2
b
1
′ and is connected to a central end N of the coil layers
2
b
4
via a contact hole (not shown) provided in the coil insulating layer
2
b
3
by a lead layer
5
provided on the coil insulating layer
2
b
3
by plating at the same time when the upper core layer
2
b
5
is formed.
The other ends of the individual lead-out lines
4
a,
4
b,
4
c,
and
4
d
are provided with bump connections
4
a
2
,
4
b
2
,
4
c
1
, and
4
d
2
, and bumps (not shown) formed of a Ni—Fe type alloy or Permalloy, or the like are provided thereon. A protective layer
6
formed of Al
2
O
3
or the like is provided on the entire trailing end surface
1
b
of the slider
1
, covering the upper layers, including the upper core layer
2
b
5
, the lead-out lines
4
a,
4
b,
4
c,
and
4
d
and the bumps (not shown), etc. Four bonding pads
3
composed of gold are formed by plating on the upper layers of the four bumps (not shown) that have been partly exposed by polishing the trailing end surface
1
b,
as shown in FIG.
5
and FIG.
9
. Thus, the four bonding pads
3
and the head device
2
are electrically connected to make up the conventional thin film magnetic head.
With an increasing capacity of a magnetic recording device such as a hard disk drive, the slider
1
of a thin film magnetic head is becoming smaller, leading to a necessity for an effective disposition of the bonding pads
3
and the head device
2
in a limited space of the trailing end surface
1
b.
Regarding the head device
2
, a size of the coil layers
2
b
4
is a decisive factor in determining a size or area of the trailing end surface
1
b.
In order to place the head device
2
in the limited space, the coil layers
2
b
4
are formed to have an almost circular shape as shown in
FIG. 9
or an elliptic shape which is slightly compressed laterally or in a track width direction, while it is longer in a vertical direction orthogonal to the track width direction or height dir
Altman, III Franklin D.
Ometz David L.
LandOfFree
Thin film magnetic head does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Thin film magnetic head, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Thin film magnetic head will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2965745