Metal working – Method of mechanical manufacture – Electrical device making
Reexamination Certificate
2001-03-16
2003-06-03
Tugbang, A. Dexter (Department: 3729)
Metal working
Method of mechanical manufacture
Electrical device making
C029S603020, C029S603040, C029S426400, C360S244200, C360S245200, C360S245900, C360S264200
Reexamination Certificate
active
06571455
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method of manufacturing a head suspension for a disk drive incorporated in an information processing unit such as a personal computer.
2. Description of the Related Art
A hard disk drive (HDD) used for an information processing unit has magnetic or magneto-optical disks to write and read data and a carriage. The carriage is turned around a spindle by a positioning motor. The carriage is disclosed in, for example, U.S. Pat. No. 4,167,765. This carriage has arms, a head suspension attached to each arm, and a head attached to the suspension and having a slider.
When each disk in the HDD is rotated at high speed, the slider slightly floats above the disk and air bearings are formed between the disk and the slider.
FIG. 1
shows atypical suspension
101
of an HDD. The suspension
101
has a load beam
103
. The load beam
103
is fixed to a base plate
105
by, for example, laser welding. The base plate
105
is fitted to a carriage arm of the HDD.
The load beam
103
consists of a rigid part
107
of L
1
in length and a resilient part
109
of L
2
in length. A flexure
111
is fixed to the rigid part
107
by, for example, laser welding. An end of the flexure
111
has a tongue
113
to which a slider
115
is attached. The tongue
113
is pushed by a dimple
117
, which is formed at an end of the rigid part
107
. Although the dimple
117
is depicted with a solid line in
FIG. 1
, it is actually on the back of the tongue
113
.
The rigid part
107
is provided with positioning holes
121
and
125
, and the flexure
111
is provided with positioning holes
123
and
127
.
The holes
121
,
123
,
125
, and
127
are set on positioning pins of a jig to align the rigid part
107
and flexure
111
with each other, and the rigid part
107
and flexure
111
are fixed to each other by, for example, laser welding. The positioning and fixing of the flexure
111
to the rigid part
107
determine the vibration characteristics of the suspension
101
.
Disks of recent HDDs are designed to densely record data and revolve at high speed. It is required, therefore, to provide a suspension of improved vibration characteristics to carry out precision positioning of a head on an HDD disk surface, To meet the requirement, the suspension
101
must be compact. Namely, the distance A between the dimple
117
and a fitting center of the base plate
105
must be short. The distance A, however, must sufficiently be long to secure a proper distance between the holes
121
and
125
for correct positioning of the flexure
111
with respect to the rigid part
107
.
If the distance A is excessively shortened to improve vibration characteristics, the holes
121
and
125
will be too close to each other, thereby deteriorating positioning accuracy.
To solve this problem,
FIGS. 2A
to
2
C show a head suspension
101
A for a disk drive according to a prior art. This prior art forms a positioning hole
125
on the side of a base plate
105
. Even if the distance A (
FIG. 1
) between a dimple
117
and a fitting center of the base plate
105
is short, a sufficient distance is secured between positioning holes
121
(
123
) and
125
(
127
) for correct positioning of a flexure
111
to a rigid part
107
.
Formation of the suspension
101
A will be explained
FIG. 2A
is a plan view showing parts of the suspension
101
A before assembly, and
FIG. 2B
is a plan view showing the parts after assembly. In
FIG. 2A
, the flexure
111
is provided with the positioning holes
123
and
127
. The base plate
105
is fitted to a reinforcing plate
129
. The reinforcing plate
129
is solidly joined with the rigid part
107
of a load beam
103
through a bridge
131
, to form a semi-finished suspension
133
. The rigid part
107
is provided with the positioning bole
121
, and the reinforcing plate
129
with the positioning hole
125
.
A resilient material
135
is used to form a resilient part
109
of the load beam
103
. The resilient material
135
is placed over the rigid part
107
and reinforcing plate
129
and is fixed thereto by, for example, laser welding. Thereafter, the base plate
105
is fitted to the reinforcing plate
129
and is fixed thereto by, for example, laser welding
The semi-finished suspension
133
with the resilient material
135
and base plate
105
is set on a jig by passing pins of the jig through the holes
121
and
125
, and the flexure
111
is laid thereon by passing the jig pins passed through the holes
121
and
125
through the holes
123
and
127
respectively. This precisely positions the flexure
111
with respect to the rigid part
107
as shown in FIG.
2
B.
The distance between the holes
121
(
123
) and
125
(
127
) is appropriate for precision positioning between the rigid part
107
and the flexure
111
. Under this state, the flexure
111
is fixed to the rigid part
107
by, for example, laser welding.
Thereafter, the bridge
131
is cut off by, for example, a press, to complete the suspension
101
A of FIG.
2
C.
One problem of this prior art is to leave the peripheries of the holes
125
and
127
on the base plate
105
, to cause a horizontal imbalance on the base plate
105
. This imbalance deteriorates the vibration characteristics of the suspension
101
A.
SUMMARY OF TE INVENTION
An object of the present invention is to provide a method of manufacturing a bead suspension or a semi-finished suspension that is compact, secures a sufficient distance between positioning holes, and involves no base-plate imbalance.
In order to accomplish the object, a first aspect of the present invention provides a method of manufacturing a head suspension for a disk drive. The head suspension has a base plate to be supported by a carriage, a load beam including a rigid part resiliently supported by the base plate, to apply load onto a slider, and a flexure positioned and fitted to the load beam and having a read-write head. The method includes a first step of forming a semi-finished suspension having the base plate, the rigid part solidly joined with the base plate through a bridge, and a protrusion protruding from one of the base plate and rigid part and having a positioning bole to be aligned with a positioning hole formed through part of the flexure, a second step of fixing a resilient material to the base plate and rigid part of the semi-finished suspension so that the base plate may resiliently support the rigid part through the resilient material, a third step of aligning the positioning hole of the flexure with the positioning hole of the protrusion and fixing the flexure to the rigid part, and a fourth step of cutting off the positioning-hole-formed part of the flexure, the bridge, and the protrusion including the positioning hole.
The first aspect may form the positioning hole of the protrusion in the vicinity of the base plate, to secure a proper distance between the positioning hole and a positioning hole formed through the rigid part. This results in precisely positioning the flexure with respect to the rigid part and correctly fixing the flexure thereto. The first aspect cuts off the bridge, the protrusion having the positioning hole, and the positioning-hole-formed part of the flexure. As a result, the suspension manufactured from the semi-finished suspension has no positioning holes including their peripheries, to cause no horizontal imbalance and improve the vibration characteristics of the suspension. In addition, the suspension of the first aspect is compact to further improve the vibration characteristics thereof.
A second aspect of the present invention makes the bridge serve as the protrusion.
The second aspect forms the positioning hole to be aligned with the positioning hole of the flexure on the bridge that solidly joins the rigid part to the base plate. The second aspect provides the same effect as the first aspect.
A third aspect of the present invention forms, in the first step, the positioning hole through one of the protrusion and bridge in the vicinity
Kamisaku Takeshi
Takagi Yasuji
Kilpatrick & Stockton LLP
Sudo International Patent Office
Tugbang A. Dexter
LandOfFree
Method of manufacturing head suspension for disk drive, and... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method of manufacturing head suspension for disk drive, and..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of manufacturing head suspension for disk drive, and... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3148992