Dynamic magnetic information storage or retrieval – Head mounting – Disk record
Reexamination Certificate
1999-12-14
2002-10-15
Miller, Brian E. (Department: 2652)
Dynamic magnetic information storage or retrieval
Head mounting
Disk record
C360S245300
Reexamination Certificate
active
06466413
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a magnetic head suspension for use in a rigid magnetic recording disk drive (hereinafter abbreviated to as HDD), and particularly to a wiring integrated suspension.
2. Discussion of the Background
A magnetic head suspension for HDD generally includes a flexure with a plate-shaped substrate that supports a magnetic head slider thereon, and a load beam that supports the said flexure in its lengthwise direction and includes a flexible portion that biases the slider flying on air by air pressures produced by rotation of a magnetic disk towards the disk surface.
There is a demand for supporting the magnetic head slider on the flexure, allowing the said slider to pitch and roll following the disk surface. To meet this demand, various flexures have been proposed. A most frequently used flexure among them is a so-called Watrous-type flexure, which is disclosed in the U.S. Pat. No. 4,167,765.
There is another demand in recent years for designing a magnetic head suspension having an arrangement that a part of wiring for connection between a magnetic head and an external signal member are integrally formed on the flexure to constitute a wiring structure, for the purpose of improving stability in attitude of a flying magnetic head slider, and reducing manufacturing steps of magnetic head sliders. This wiring structure generally includes a polyimide insulating layer laminated on the substrate of the flexure, a wiring conductor formed on the said polyimide insulating layer, and a polyimide protection layer covering the said wiring conductor.
FIGS. 15 and 16
illustrate a flexure
110
of the Watrous-type with an integrally formed wiring structure thereon, which is used for simultaneously achieving both demands as mentioned above. Specifically,
FIG. 15
is a perspective view of a distal end portion of the said flexure
110
, and
FIG. 16
is a rear side view of the distal end portion of the flexure
110
as viewed from the opposite side to a side, on which the slider is supported.
FIGS. 17 and 18
illustrate a suspension
100
with the flexure and a load beam
120
supporting the said flexure
110
. Specifically,
FIG. 17
is a side view of a distal end portion of the said suspension
100
, and
FIG. 18
is a view as viewed in the direction of the arrow E in FIG.
17
. In
FIG. 18
, a reference numeral
150
represents a magnetic head slider.
As illustrated in
FIGS. 15
to
18
, the flexure
110
of the Watrous-type includes a plate-shaped substrate that, in turn, includes a base portion
111
a
and a gimbal portion
111
b
distally extending from the said base portion
111
a.
The said gimbal portion
111
b
includes a pair of lateral arm portions
113
distally extending from the lateral side edges of the base portion
111
a
in such a manner as to be located in the same plane as that of the base portion, a connection portion
114
for connection between a pair of the lateral arm portions
113
at the distal ends of said lateral arm portions, and a slider-mounting portion
115
proximally extending from the substantial center of the connection portion
114
and located in a space between the lateral arm portions. The connection portion
114
has an offset bending portion
114
a
formed thereon that allows the slider-mounting portion
115
to be located in a second plane closer to the magnetic disk than a first plane, in which the base portion
111
a
and the lateral arm portions
113
are located.
The wiring structure
130
integrally formed on the flexure
110
includes a first plane portion
130
a
formed on the base portion of the flexure and the lateral arm portions, a second plane portion
130
b
formed on the slider-mounting portion, and an inclined portion
130
c
located between the first plane portion
130
a
and the second plane portion
130
b.
The said inclined portion
130
c
is a wire-bridging portion, under which no substrate support exists. Omitting the wiring structure on the connection portion
114
prevents the wiring structure from being damaged during forming of the offset bending portion
114
a
of the said connection portion
114
.
On the other hand, the load beam
120
is provided on the distal end thereof with a protuberance
121
that is adapted for abutting against the rear side of the slider-mounting portion
115
. With this arrangement, the slider-mounting portion
115
can pitch around a first axis parallel to the lengthwise direction of the suspension and roll around a second axis orthogonal to the said first axis and parallel to a slider mounting surface, with the protuberance
121
being a fulcrum, thereby allowing the slider mounted on the slider-mounting portion
115
to pitch and roll following the disk surface. The slider-mounting portion
115
is offset to the lateral arm portions
113
, so that the slider can be prevented from contacting the lateral arm portions
113
, even if the said slider is of such a dimension as to straddle over the lateral arm portions
113
.
Although the suspension of
FIGS. 17 and 18
produces the aforementioned effects, it is accompanied by the following disadvantages. That is, the suspension of the arrangement illustrated in
FIGS. 17 and 18
causes the inclined portion
130
c
to have stepped portion in order to be in conformity with the stepped configuration of the offset bending portion, This results in the formation of a bent part along the boundaries between the inclined portion and the first plane portion
30
a
or the second plane portion
130
b,
so that stress is concentrated into the bent part, thereby increasing the possibility of damaging the wiring structure.
FIGS. 19 and 20
illustrate a Watrous-type flexure
110
′ of a different example with the integrally formed wiring structure, in which corresponding or identical parts to those of the flexure
110
have been given the same reference characters to omit a detailed description thereof. The flexure
110
′ includes a pad stage
116
distally extending from the connection portion
114
. The said pad stage
116
forms thereon the second plane portion
130
b
of the wiring structure. As is the case with the flexure
110
, the entire region of the inclined portion
130
c
of the wiring structure is formed as the wire-bridging portion.
The flexure of
FIGS. 19 and 20
includes the inclined portions
130
c,
the total length of which is longer than the connection portion
114
, so that each of the said inclined portions has a gentle inclination as compared with the inclination in a corresponding offset bending portion
114
a.
Thus, the flexure
110
′ of this arrangement lowers stress concentration in the inclined portions
130
c
of the wiring structure as compared with the flexure
110
as illustrated in
FIGS. 15
to
18
.
However, according to the flexure
110
′ as illustrated in
FIGS. 19 and 20
, the entire region of each of the inclined portions
130
c
is formed as the wire-bridging portion with no support by the substrate, and the inclined portions
130
c
protrude sideways from the flexure substrate as viewed from above, so that any parts or matters are likely to contact the inclined portions of the wiring structure during assembly of the suspension or HDD, thereby increasing the possibility of damaging or deformation of the wiring structure. In addition, the wire-bridging portion which is not supported by the flexure substrate increases the possibility of causing the wiring structure to be vibrated by air pressures by rotation of the magnetic disk.
FIGS. 21
to
23
illustrate a flexure
110
″ of still a different example, which figures respectively illustrate a perspective view of a distal end portion of the said flexure, a rear view of the said flexure, and a view as viewed in the direction of F in
FIG. 22
, illustrating the state that the load beam
120
is joined to the flexure. The said flexure
110
″ includes a pair of reinforcing portions
117
, which extend in the lateral direction of the flexure from the pad stage
116
.
Miller Brian E.
Perkins Coie LLP
Suncall Corporation
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