U.S. patent application number 13/469123 was filed with the patent office on 2012-08-30 for magnetic head suspension.
This patent application is currently assigned to Suncall Corporation. Invention is credited to Yasuo FUJIMOTO, Kenji MASHIMO, Satoru TAKASUGI.
Application Number | 20120218664 13/469123 |
Document ID | / |
Family ID | 39685592 |
Filed Date | 2012-08-30 |
United States Patent
Application |
20120218664 |
Kind Code |
A1 |
TAKASUGI; Satoru ; et
al. |
August 30, 2012 |
Magnetic Head Suspension
Abstract
The present invention provides a magnetic head suspension,
wherein a supporting portion such as an arm or base plate includes
a pair of supporting pieces extending from its opposite sides in
the widthwise direction to a tip-end side of the suspension, and a
concave portion which is defined by the pair of supporting pieces
and is opened toward the tip-end side of the suspension, there is
provided an elastically-deformable elastic plate which is connected
to the pair of supporting pieces at a first end and a second end in
the widthwise direction of the magnetic head suspension, the member
forming the load beam portion is connected to the elastic plate,
and the elastic plate forms the load bending portion.
Inventors: |
TAKASUGI; Satoru; (Kyoto-fu,
JP) ; FUJIMOTO; Yasuo; (Kyoto-fu, JP) ;
MASHIMO; Kenji; (Kyoto-fu, JP) |
Assignee: |
Suncall Corporation
Kyoto-fu
JP
|
Family ID: |
39685592 |
Appl. No.: |
13/469123 |
Filed: |
May 11, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
12028671 |
Feb 8, 2008 |
8203807 |
|
|
13469123 |
|
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Current U.S.
Class: |
360/234.3 ;
G9B/5.153; G9B/5.229 |
Current CPC
Class: |
G11B 5/4833
20130101 |
Class at
Publication: |
360/234.3 ;
G9B/5.229; G9B/5.153 |
International
Class: |
G11B 5/48 20060101
G11B005/48; G11B 5/60 20060101 G11B005/60 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 9, 2007 |
JP |
JP-2007-030369 |
Jul 17, 2007 |
JP |
JP-2007-185411 |
Claims
1. A magnetic head suspension comprising: a load bending portion
generating a load for pressing a magnetic head slider toward a disk
surface, wherein the load bending portion comprises an
elastically-deformable elastic plate; a load beam portion
transmitting the load to the magnetic head slider, wherein the load
beam portion is connected to the elastic plate; a supporting
portion supporting the load beam portion through the load bending
portion, wherein the supporting portion includes a pair of
supporting pieces extending from opposite sides of the supporting
portion in the widthwise direction to a tip-end side of the
suspension, and a concave portion which is defined by the pair of
supporting pieces and is opened toward the tip-end side of the
suspension; a flexure portion connected to the load beam portion
and supporting the magnetic head slider; and a restraint plate
connected to the supporting portion so as to be positioned on a
side of the load beam portion opposite from the elastic plate in a
direction orthogonal to the disk surface with the load beam portion
sandwiched between the restraint plate and the elastic plate,
wherein the elastic plate is connected to the pair of supporting
pieces at a first end and a second end in the widthwise direction
of the magnetic head suspension, wherein the elastic plate includes
first and second connected areas which are respectively connected
to the pair of supporting pieces, and a center area extending
between the first and second connected areas, and wherein the
center area includes a center connected portion to which the load
beam portion is connected, a first extending portion extending
between the center connected portion and the first connected area,
and a second extending portion extending between the center
connected portion and the second connected area, the second
extending portion being symmetrical with respect to the first
extending portion with a longitudinal center line of the magnetic
head suspension as a reference, wherein the restraint plate has one
or more protrusion portions which contact the load beam portion on
a load bending center line of the first and second extending
portions along the widthwise direction of the suspension, and
wherein the one or more protrusion portions are placed to be
symmetrical with the longitudinal center line as a reference.
2. The magnetic head suspension according to claim 1, wherein the
restraint plate has a single protrusion portion, and wherein the
single protrusion portion contacts the load beam portion over a
predetermined distance in the widthwise direction of the magnetic
head suspension.
3. A magnetic head suspension comprising: a load bending portion
generating a load for pressing a magnetic head slider toward a disk
surface, wherein the load bending portion comprises an
elastically-deformable elastic plate; a load beam portion
transmitting the load to the magnetic head slider, wherein the load
beam portion is connected to the elastic plate; a supporting
portion supporting the load beam portion through the load bending
portion, wherein the supporting portion includes a pair of
supporting pieces extending from opposite sides of the supporting
portion in the widthwise direction to a tip-end side of the
suspension, and a concave portion which is defined by the pair of
supporting pieces and is opened toward the tip-end side of the
suspension; a flexure portion connected to the load beam portion
and supporting the magnetic head slider; and a restraint plate
connected to the supporting portion so as to be positioned on a
side of the load beam portion opposite from the elastic plate in a
direction orthogonal to the disk surface with the load beam portion
sandwiched between the restraint plate and the elastic plate,
wherein the elastic plate is connected to the pair of supporting
pieces at a first end and a second end in the widthwise direction
of the magnetic head suspension, wherein the elastic plate includes
first and second connected areas which are respectively connected
to the pair of supporting pieces, and a center area extending
between the first and second connected areas, and wherein the
center area includes a center connected portion to which the load
beam portion is connected, a first extending portion extending
between the center connected portion and the first connected area,
and a second extending portion extending between the center
connected portion and the second connected area, the second
extending portion being symmetrical with respect to the first
extending portion with a longitudinal center line of the magnetic
head suspension as a reference, and wherein the restraint plate
includes a connected surface connected to the surface of the
supporting portion opposite from the disk surface, a coupling
surface folded in such a direction that the coupling surface angles
toward the disk surface from the connected surface, and a contact
surface which is folded from the free-end side of the coupled
surface and which is connected to the surface of the load beam
portion opposite from the disk surface in a surface-to-surface
manner, and wherein a border line between the coupling surface and
the contact surface is positioned on a load bending center line of
the first and second extending portions along the widthwise
direction of the suspension and is symmetrical with the
longitudinal center line as a reference.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a divisional application of U.S. patent
application Ser. No. 12/028,671, filed Feb. 8, 2008, the disclosure
of which is incorporated herein in its entirety be reference
thereto.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a suspension for supporting
a magnetic head slider for reading and/or writing data from and/to
a recording medium such as a hard disc device.
[0004] 2. Related Art
[0005] In recent years, data storage devices for reading and/or
writing data from and/to recording mediums through a magnetic head
slider have been widely used in mobile apparatuses such as
notebook-type personal computers and portable music players and,
along therewith, these data storage devices have been required to
have high impact resistance.
[0006] More specifically, when such a data storage device is
subjected to an external impulsive force with an acceleration equal
to or greater than a certain value in such a direction that the
magnetic head slider is separated from a disk surface, the magnetic
head slider jumps in such a direction that it separates from the
disk surface and, then, swings back from the jump to the disc
surface and impinges on the disk surface, thereby damaging the disk
surface. Accordingly, in order to increase the impact resistance of
the data storage device, there is a need for raising the value of
the acceleration (the critical acceleration) of an external
impulsive force which triggers jump of the magnetic head
slider.
[0007] For example, by increasing the load which presses the
magnetic head slider against the disk surface, it is possible to
raise the critical acceleration.
[0008] However, it is necessary to set the load to within a proper
range, in order to control the height of the magnetic head slider
above the disk surface. Accordingly, there is naturally a limit to
the method which increases the load for suppressing the jump of the
magnetic head slider.
[0009] As another structure for suppressing the jump of the
magnetic head slider, there is also known a structure in which the
mass of a load beam portion is reduced for reducing the inertial
force applied to the load beam portion when an impulsive force is
applied thereto, thus raising the critical acceleration.
[0010] However, when the thickness of the load beam portion is
reduced and/or a hole is formed in the load beam portion in order
to reduce the mass of the load beam portion, this will reduce the
rigidity of the load beam portion, thus inducing the problem of
degradation of the vibration characteristics and the
loading/unloading characteristics.
[0011] As still another structure for suppressing the jump of the
magnetic head slider, there has been proposed a structure in which
the load beam portion supported through a load bending portion by a
supporting portion such as an arm or a base plate is formed to have
an extending portion extending toward the base-end side of the
suspension (for example, JP-A. No. 9-082052, JP-A. No. 11-039808,
JP-A. No. 2004-348804, and JP-A. No. 2005-174506).
[0012] The conventional structure is configured so as to makes the
mass of the portion of the load beam portion which is closer to the
base-end side of the suspension than the load bending portion to be
as equal as possible to the mass of the portion thereof which is
closer to the tip-end side of the suspension than the load bending
portion. The structure is advantageous in suppressing the jump of
the magnetic head slider at a time when being subjected to an
external impulsive forced without degrading the rigidity of the
load beam portion.
[0013] However, in the magnetic head suspensions described in these
patent documents, the load beam portion is connected to the free
end portion of the load bending portion which is supported by the
supporting portion in a cantilever manner. With these structures,
the supporting point of the load beam portion (namely, the portion
of the load beam portion which is connected to the load bending
portion) may vary in the direction orthogonal to the disk surface
when an impulsive force is applied thereto.
[0014] Accordingly, the magnetic head suspensions described in
these patent documents can not sufficiently raise the critical
acceleration, although the problem of degradation of the rigidity
of the load beam portion does not occur.
SUMMARY OF THE INVENTION
[0015] The present invention is made in view of the conventional
techniques and aims to provide a magnetic head suspension capable
of preventing, as much as possible, the supporting point of a load
beam portion from varying in the direction orthogonal to a disk
surface when an impact is applied thereto, thus effectively raising
the critical acceleration of the impact which trigger the jump
action of the magnetic head slider.
[0016] The present invention provide, in order to achieve the aim,
a magnetic head suspension including a load bending portion
generating a load for pressing a magnetic head slider toward a disk
surface, a load beam portion transmitting the load to the magnetic
head slider, a supporting portion supporting the load beam portion
through the load bending portion, and a flexure portion connected
to the load beam portion and supporting the magnetic head slider,
wherein the supporting portion includes a pair of supporting pieces
extending from its opposite sides in the widthwise direction to a
tip-end side of the suspension, and a concave portion which is
defined by the pair of supporting pieces and is opened toward the
tip-end side of the suspension, there is provided an
elastically-deformable elastic plate which is connected to the pair
of supporting pieces at a first end and a second end in the
widthwise direction of the magnetic head suspension, the member
forming the load beam portion is connected to the elastic plate,
and the elastic plate forms the load bending portion.
[0017] According to the present invention, since the elastic plate,
which is supported at its first and second ends along the widthwise
direction of the suspension by the supporting portion in a
dual-supported manner, functions as the load bending portion, it is
possible to effectively prevent the supporting point of the load
beam portion (the point of the load beam portion which is connected
to the load bending portion) from varying in the direction
orthogonal to the disk surface when the external impulsive force is
applied thereto, thereby largely raising the critical acceleration
of the impulsive force which triggers the jump of the magnetic head
slider.
[0018] In one embodiment, the elastic plate is twisted such that a
tip end of a center area positioned between the first and second
ends comes close to the disk surface in a state where the first and
second ends are respectively connected to the pair of supporting
pieces to be bound.
[0019] In another embodiment, the pair of supporting pieces are
bended at bended positions between their base ends and tip ends in
such a manner that their tip ends come close to the disk surface.
The elastic plate is connected to the pair of supporting pieces at
portions closer to the tip ends than the bended positions.
[0020] Preferably, the elastic plate includes first and second
connected areas which are respectively connected to the pair of
supporting pieces, and a center area extending between the first
and second connected areas.
[0021] The center area includes a center connected portion to which
a member forming the load beam portion is connected, a first
extending portion extending between the center connected portion
and the first connected area, and a second extending portion
extending between the center connected portion and the second
connected area, the second extending portion being symmetrical with
respect to the first extending portion with a longitudinal center
line of the magnetic head suspension as a reference.
[0022] More preferably, the center connected portion has a width
greater than those of the first and second extending portions.
[0023] More preferably, the center connected portion is extended
toward both a tip-end side and a base-end side of the suspension
with the first and second extending portions as a reference.
[0024] Each of the first and second extending portions preferably
has, at both a tip-end side and a base-end side, outer curved
portions having a width gradually increased with decreasing
distance to the corresponding connected area, and inner curved
portions having a width gradually increased with decreasing
distance to the center connected portion.
[0025] The configuration makes it possible to stabilize the twist
action of the first and second extending portions.
[0026] The center connected portion of the elastic plate integrally
includes a tip-end-side flat-surface portion which is positioned on
a tip-end side of the suspension and which is connected to a member
forming the load beam portion at an attitude parallel to the member
forming the load beam portion, a center flat-surface portion which
is extended from the tip-end-side flat-surface portion toward the
base-end side of the suspension and which is inclined with respect
to the tip-end-side flat-surface portion such that it gradually
separates from the member forming the load beam portion with
increasing distance from the tip-end side toward the base-end side
and to which the first and second extending portions are connected,
and a base-end-side flat-surface portion which is extended toward
the base-end side of the suspension from the center flat-surface
portion through a bending portion and which is connected to the
member forming the load beam portion. The center flat-surface
portion is positioned within the same plane as the plane in which
there exist the first and second extending portions and the first
and second connected areas in a state before the magnetic head
suspension is mounted to a data storage device, and the first and
second extending portions are twisted to generate the load in a
state where the magnetic head suspension is operated after being
mounted to the data storage device.
[0027] The configuration makes it possible to obtain the load in a
state where the suspension is operated after being mounted to the
data storage device, without performing a twisting process on the
first and second extending portions before the suspension is
mounted to the data storage device.
[0028] In the above various configurations, the suspension
preferably further includes a restraint plate connected to the
supporting portion so as to be positioned on a side of a member
forming the load beam portion opposite from the elastic plate in a
direction orthogonal to the disk surface with the member forming
the load beam portion sandwiched between the restraint plate and
the elastic plate. The restraint plate has a single or plurality of
protrusion portion which contacts with the member forming the load
beam portion on a load bending center line of the first and second
extending portions along the widthwise direction of the suspension.
The single or plurality of protrusion portion is placed to be
symmetrical with the longitudinal center line as a reference.
[0029] The configuration makes it possible to more effectively
prevent the supporting point of the load beam portion from varying,
thereby more largely raising the critical acceleration of the
impulsive force which triggers the jump of the magnetic head
slider.
[0030] For example, the restraint plate may have the single
protrusion portion. The single protrusion portion is contacted with
the member forming the load beam portion over a predetermined
distance in the widthwise direction of the magnetic head
suspension.
[0031] The suspension may include, instead of the restraint plate
having the single protrusion portion, a restraint plate having a
connected surface connected to the surface of the supporting
portion opposite from the disk surface, a coupling surface folded
in such a direction that it comes close to the disk surface from
the connected surface, and a contact surface which is folded from
the free-end side of the coupled surface and which is connected to
the surface of the member forming the load beam portion opposite
from the disk surface in a surface-to-surface manner. A border line
between the coupling surface and the contact surface is positioned
on a load bending center line of the first and second extending
portions along the widthwise direction of the suspension and is
symmetrical with the longitudinal center line as a reference.
[0032] The configuration makes it possible to more effectively
prevent the supporting point of the load beam portion from varying,
thereby more largely raising the critical acceleration of the
impulsive force which triggers the jump of the magnetic head
slider.
[0033] In the above various configurations, a member forming the
load beam portion may preferably include a connected area to which
the elastic plate is connected, a tip-end area extending from the
connected area toward the tip-end side of the suspension, and a
base-end area extending from the connected area toward the base-end
side of the suspension.
[0034] More preferably, the member forming the load beam portion
may have flange portions which are provided at the opposite sides
thereof in the widthwise direction of, the suspension and which
extend so as to be across the elastic plate.
[0035] The flange portions preferably have heights gradually
decreased as they go from the base end to the tip end.
[0036] In the configuration where the load beam portion includes
the base-end area, the base-end area is preferably provided with a
balance mass member.
[0037] The configuration makes it possible to balance the mass of
the portion closer to the base-end side of the suspension than the
load bending center line with the mass of the portion closer to the
tip-end side of the suspension than the load bending center line
BL, thereby raising the critical acceleration of the impulsive
force which triggers the jump of the magnetic head slider.
[0038] When a longitudinal direction of the magnetic head
suspension between a center of gravity of an assembly formed by the
load beam portion, the flexure portion and the balance mass member,
and a load bending center line of the first and second extending
portions along the widthwise direction of the suspension is Lg, and
a length in the longitudinal direction of the suspension between
the load bending center line and the center of gravity of a tip-end
side portion of the assembly which is closer to the tip-end side of
the suspension than the load bending center line is La, the balance
mass member is preferably set to have a weight so that the length
Lg and the length La have a relationship of
0.ltoreq.Lg.ltoreq.0.3.times.La.
[0039] The configuration makes it possible to raise the critical
acceleration of the impulsive force which triggers the jump of the
magnetic head slider, in various conditions in which the magnetic
head suspension may be used.
[0040] More preferably, the magnetic head suspension according to
the present invention may further include a restriction plate
connected to the supporting portion so as to be positioned on a
side closer to the disk surface than the base-end side area of the
load beam portion.
[0041] The restriction plate is placed to overlap with at least a
portion of the balance mass member in a plan view.
[0042] According to the configuration, even if the balance mass
member jumps in such a direction that it is separate from the disk
surface when an external impulsive force is applied and then swings
back toward the disk surface, it is possible to effectively prevent
the balance mass member from impinging on the disk surface. It is
also possible to effectively prevent the balance mass member from
impinging on the disk surface even if an external impulsive force
is applied to the balance mass member in such a direction as to
cause the balance mass member to come close to the disk
surface.
[0043] Instead of or in addition to the provision of the
restriction plate, the balance mass member may include a connected
portion connected to the load beam portion and a base-end-side
bending portion positioned on a side closer to the base-end side of
the suspension than the connected portion, and the balance mass
member is configured so that its portion extending from the
base-end-side bending portion up to a base-end edge is gradually
separated from the disk surface with decreasing distance to the
base-end edge than the connected portion.
[0044] According to the configuration, even if the balance mass
member jumps in such a direction that it is separate from the disk
surface when an external impulsive force is applied and then swings
back toward the disk surface, it is possible to effectively prevent
the balance mass member from impinging on the disk surface. It is
also possible to effectively prevent the balance mass member from
impinging on the disk surface even if an external impulsive force
is applied to the balance mass member in such a direction as to
cause the balance mass member to come close to the disk
surface.
[0045] The balance mass member is preferably configured so that the
base-end-side bending portion has a thickness smaller than those of
the other areas of the balance mass member.
[0046] The magnetic head suspension may preferably include a signal
wiring member which has an insulation layer and a conductive layer
and which is integrally laminated on the flexure portion.
[0047] The signal wiring member includes a load-beam-portion side
area supported directly or indirectly by the load beam portion, a
supporting-portion side area supported directly or indirectly by
the supporting portion, and an aerial area extending in air between
the load-beam-portion side area and the supporting-portion side
area.
[0048] In one embodiment, the load-beam-portion side area and the
aerial area are symmetrical with the longitudinal center line of
the magnetic head suspension as a reference, and the aerial area
has at least one direction changing portion.
[0049] In another embodiment, the load-beam-portion side area and
the aerial area are symmetrical with the longitudinal center line
of the magnetic head suspension as a reference, and are placed to
substantially surround the balance mass member in a plan view.
[0050] In the above various configurations, the elastic plate may
be integrally formed with a member forming the flexure portion.
[0051] This configuration makes it possible to reduce the number of
fabricating processes, thereby reducing the cost.
[0052] More preferably, the first and second extending portions of
the elastic plate are provided with attenuation members which are
integrally laminated thereon and which are made of the same
materials as those of the insulation layer and the conductive
layer.
[0053] The configuration makes it possible to provide the
attenuation members without increasing the number of fabricating
processes.
[0054] The present invention also provides, in order to achieve the
aim, a magnetic head suspension including a load bending portion
generating a load for pressing a magnetic head slider toward a disk
surface, a load beam portion transmitting the load to the magnetic
head slider, a supporting portion supporting the load beam portion
through the load bending portion and including a concave portion
which is defined by a pair of supporting pieces extending from
opposite sides of the supporting portion in the widthwise direction
to a tip-end side of the suspension and which is opened toward the
tip-end side of the suspension, and a flexure portion connected to
the load beam portion and supporting the magnetic head slider.
[0055] The suspension further including an elastically-deformable
elastic plate having first and second ends in a widthwise direction
of the suspension respectively connected to the pair of supporting
pieces, and a balance mass member having a center portion which is
connected to the elastic plate, a tip-end portion which is
positioned on a tip-end side of the suspension than the center
portion and which is connected to a base-end portion of the load
beam portion, and a base-end portion which is positioned on a
base-end side of the suspension than the center portion.
[0056] The elastic plate includes first and second connected areas
which are respectively connected to the pair of supporting pieces,
and a center area extending between the first and second connected
areas.
[0057] The center area includes a center connected portion to which
the balance mass member is connected, a first extending portion
extending between the center connected portion and the first
connected area, and a second extending portion extending between
the center connected portion and the second connected area, so that
the elastic plate forms the load bending portion.
[0058] Each of the first and second extending portions preferably
has, at both a tip-end side and a base-end side, outer curved
portions having a width gradually increased with decreasing
distance to the corresponding connected area, and inner curved
portions having a width gradually increased with decreasing
distance to the center connected portion.
[0059] A member forming the load beam portion may integrally
include a flange area having a center flat-plate portion positioned
at the center in the widthwise direction of the suspension and a
pair of flange portions provided at the opposite sides of the
center flat-plate portion in the widthwise direction of the
suspension, an elastic-plate area forming the elastic plate, and a
flat-plate shaped coupling area which couples the center flat-plate
portion of the flange area to a tip-end edge of the center
connected portion of the elastic plate.
[0060] The configuration makes it possible to reduce the cost
thanks to reduction of the number of members and assembling
processes.
[0061] The tip-end portion of the balance mass member is preferably
connected to the center flat-plate portion of the load beam
portion, at a state where the tip-end portion of the balance mass
member is interposed between the pair of flange portions.
[0062] More preferably, the balance mass member may have a
tip-end-side bending portion at a portion corresponding to the
coupling area.
[0063] In the configuration, the coupling area preferably has a
width smaller than that of the base-end portion of the flange
area.
[0064] In the above various configurations, the balance mass member
preferably includes a base-end-side bending portion at the base-end
portion, and is configured so that its portion extending from the
base-end-side bending portion up to a base-end edge is gradually
separated from the disk surface with decreasing distance to the
base-end edge.
[0065] The balance mass member is preferably configured so that the
bending portion has a thickness smaller than those of the other
areas of the balance mass member.
[0066] In the above various configurations, the center connected
portion of the elastic plate preferably includes a tip-end-side
flat-surface portion which is positioned on a tip-end side of the
suspension and which is connected to the center portion of the
balance mass member at an attitude parallel to the center portion
of the balance mass member, a center flat-surface portion which is
extended from the tip-end-side flat-surface portion toward the
base-end side of the suspension and which is inclined with respect
to the tip-end-side flat-surface portion such that it gradually
separates from the center portion of the balance mass member with
increasing distance from the tip-end side toward the base-end side
and to which the first and second extending portions are connected,
and a base-end-side flat-surface portion which is extended toward
the base-end side of the suspension from the center flat-surface
portion through a bending portion and which is connected to the
center portion of the balance mass member at an attitude parallel
to the center portion of the balance mass member.
[0067] The center flat-surface portion is positioned within the
same plane as the plane in which there exist the first and second
extending portions and the first and second connected areas in a
state before the magnetic head suspension is mounted to a data
storage device, and the first and second extending portions are
twisted to generate the load in a state where the magnetic head
suspension is operated after being mounted to the data storage
device.
[0068] The configuration makes it possible to obtain the load in a
state where the suspension is operated after being mounted to the
data storage device, without performing a twisting process on the
first and second extending portions before the suspension is
mounted to the data storage device.
[0069] In the above various configurations, when a length in the
longitudinal direction of the magnetic head suspension between a
center of gravity of an assembly formed by the load beam portion,
the flexure portion and the balance mass member, and a load bending
center line of the first and second extending portions along the
widthwise direction of the suspension is Lg, and a length in the
longitudinal direction of the suspension between the load bending
center line and the center of gravity of a tip-end side portion of
the assembly which is closer to the tip-end side of the suspension
than the load bending center line is La, Lg and La is preferably
set to have a relationship of 0.ltoreq.Lg.ltoreq.0.3.times.La.
[0070] In the above various configuration, the pair of supporting
pieces preferably have base-end portions which are positioned on
the base-end side of the suspension, and tip-end portions which are
positioned on the tip-end side of the suspension than the base-end
portions and to which the elastic plate is connected, and the
base-end portions have widths greater than those of the tip-end
portions.
[0071] This configuration makes it possible to raise the resonance
frequency of the supporting portion 610 in the twisting mode,
thereby improving the positioning accuracy in moving the magnetic
head slider to a target track.
BRIEF DESCRIPTION OF THE DRAWINGS
[0072] The above, and other objects, features and advantages of the
present invention will become apparent from the detailed
description thereof in conjunction with the accompanying drawings
wherein.
[0073] FIGS. 1A and 1B are a top view and a bottom view of a
magnetic head suspension according to a first embodiment of the
present invention, respectively.
[0074] FIG. 2 is a perspective view of the magnetic head suspension
shown in FIGS. 1A and 1B.
[0075] FIG. 3 is a perspective view of a magnetic head suspension
modified from the suspension according to the first embodiment so
as to have a base plate as a supporting portion.
[0076] FIG. 4 is a top view of the supporting portion, of the
magnetic head suspension according to the first embodiment.
[0077] FIG. 5 is a bottom view of an elastic plate of the magnetic
head suspension according to the first embodiment.
[0078] FIGS. 6A and 6B are perspective views of the magnetic head
suspension according to the first embodiment in a state before it
is mounted to a data storage device and in a state where it
operated after being mounted to the date storage device,
respectively.
[0079] FIG. 7 is a bottom view of an exemplary modification of the
elastic plate of the magnetic head suspension according to the
first embodiment.
[0080] FIGS. 8A and 8B are perspective views of the elastic plate
shown in FIG. 7 in a state of being twisted and in a state of being
twisted back, respectively.
[0081] FIGS. 9A to 9C are a top view of a modified magnetic head
suspension having a different structure for generating the load by
the elastic plate, a side view of the same before it is mounted to
the data storage device, and a side view of the same in a state
where it is operated after being mounted to the data storage
device, respectively.
[0082] FIG. 10 is a partially-enlarged top view of the magnetic
head suspension according to the first embodiment.
[0083] FIGS. 11A to 11 D are a top view of a load beam portion of
the magnetic head suspension according to the first embodiment, a
side view thereof, a cross-sectional view taken along the line c-c
in FIG. 11A, and a cross-sectional view taken along the line d-d in
FIG. 11A, respectively.
[0084] FIGS. 12A and 12B are a top view of a bottom view of a
conventional magnetic head suspension having a load bending portion
supported in a cantilever manner, respectively.
[0085] FIG. 13 is a graph showing the results of analyses of the
critical acceleration on the basis of a finite-element method in an
example (example 1) of the magnetic head suspension according to
the first embodiment, an example (example 2) of a magnetic head
suspension modified from the first embodiment, and examples
(comparative example 1 and 2) of the conventional magnetic head
suspension, when impulsive waves having pulse widths of 1.00 msec,
1.50 msec and 2.00 msec are applied thereto.
[0086] FIG. 14 is a graph showing the results of the analyses, on
the basis of a finite-element method, for the critical acceleration
in the example 1, when the ratio K=Lg/La (center-of-gravity
position ratio) of the length Lg between the center of gravity
(entire gravity) of the assembly formed by the load beam portion,
the flexure portion and the balance mass member, and a load bending
center line of the elastic plate to the length La between the
center of gravity (tip-end side gravity) of the tip-end side
portion of the assembly which is closer to the tip-end side of the
suspension than the load bending center line and the load bending
center line is varied.
[0087] FIGS. 15A to 15C are a top view of a load beam portion
modified from the load beam portion of the magnetic head suspension
according to the first embodiment, a side view thereof, and a
cross-sectional view taken along the line c-c in FIG. 15A,
respectively.
[0088] FIG. 16 is a graph showing the results of the analyses, on
the basis of a finite-element method, on an example (example 3) of
the magnetic head suspension having the flange portions structured
such that their heights are gradually decreased as they go from the
base end to the tip end and an example (example 4) of the magnetic
head suspension having flange portions having substantially a
constant height, when impulsive waves having pulse widths of 1.00
msec, 1.50 msec and 2.00 msec are applied thereto.
[0089] FIGS. 17A and 17B are bottom views of an example and
alternative example of a modified magnetic head suspension which is
modified from the first embodiment so as to have a signal wiring
member integrally laminated on a flexure portion, respectively.
[0090] FIG. 18 is a partially-enlarged bottom view of the
alternative example of the modified magnetic head suspension in
which the signal wiring member integrally laminated on the flexure
portion.
[0091] FIGS. 19A to 19C are, respectively, a top view of a magnetic
head suspension according to a second embodiment of the present
invention, a bottom view thereof, and a cross-sectional view taken
along the line c-c in FIG. 19A.
[0092] FIG. 20 is a perspective view of the magnetic head
suspension according to the second embodiment.
[0093] FIG. 21 is a graph showing the results of analyses of the
critical accelerations in an example (the example 1) of the
magnetic head suspension according to the first embodiment and an
example (example 5) of the magnetic head suspension according to
the second embodiment, which are resulted from the application of
impulsive waves having pulse widths of 1.00 msec, 1.50 msec and
2.00 msec thereto, on the basis of a finite-element method.
[0094] FIGS. 22A and 22B are a top view of a magnetic head
suspension modified from the second embodiment and a
cross-sectional view taken along the line b-b in FIG. 22A,
respectively.
[0095] FIGS. 23A to 23C are a top view of a magnetic head
suspension modified from the second embodiment, a cross-sectional
view taken along the line b-b in FIG. 23A and a cross-sectional
view taken along the line c-c in FIG. 23A, respectively.
[0096] FIGS. 24A to 24C are a top view of a magnetic head
suspension according to a third embodiment of the present
invention, a bottom view thereof, and a cross-sectional view taken
along the line c-c in FIG. 24A, respectively.
[0097] FIGS. 25A and 25B are a top view and a bottom view of a
magnetic head suspension according to a fourth embodiment of the
present invention, respectively.
[0098] FIGS. 26A and 26B are partial side views of the magnetic
head suspension according to the fourth embodiment in a state
before it is mounted to a data storage device and in a state where
it is operated after being mounted to the data storage device,
respectively.
[0099] FIG. 27 is a perspective view of the magnetic head
suspension according to the fourth embodiment before being mounted
to the data storage device.
[0100] FIG. 28 is an exploded perspective view of the magnetic head
suspension according to the fourth embodiment before being mounted
to the data storage device.
[0101] FIGS. 29A and 29B are, respectively, a top view and a bottom
view of a balance mass member of the magnetic head suspension
according to the fourth embodiment.
[0102] FIG. 30A is a plan view of an elastic plate of the magnetic
head suspension according to the fourth embodiment.
[0103] FIG. 30B is a plan view of an exemplary modification of the
elastic plate.
[0104] FIGS. 31A and 31B are a top view and a bottom view of a
magnetic head suspension according to a fifth embodiment of the
present invention, respectively.
[0105] FIGS. 32A and 32B are partial side views of the magnetic
head suspension according to the fifth embodiment in a state before
it is mounted to a data storage device and in a state where it is
operated after being mounted to the data storage device,
respectively.
[0106] FIG. 33 is a perspective view shown from the disk-surface
side of the magnetic head suspension according to the fifth
embodiment in a state where it is operated after being mounted to
the data storage device.
[0107] FIG. 34 is a perspective view shown from the disk-surface
side of the elastic plate of the magnetic head suspension according
to the fifth embodiment.
[0108] FIGS. 35A and 35B are a top view and a bottom view of a
magnetic head suspension according to a sixth embodiment of the
present invention, respectively.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
First Embodiment
[0109] Hereinafter, one preferred embodiment of a magnetic head
suspension according to the present invention will be described,
with reference to the attached drawings.
[0110] FIGS. 1A and 1B illustrate a top view of a magnetic head
suspension 1A according to the present embodiment (a view
illustrating the side opposite from a disk surface) and a bottom
view of the same (a view illustrating the disk-surface side),
respectively.
[0111] Further, FIG. 2 illustrates a perspective view of the
magnetic head suspension 1A. In FIG. 1, the reference character 90
designates welding positions.
[0112] The magnetic head suspension 1A includes a load bending
portion 20 which generates a load for pressing a magnetic head
slider 100 against the disk surface, a load beam portion 30 which
transmits the load to the magnetic head slider 100, a supporting
portion 10 which supports the load beam portion 30 through the load
bending portion 20, and a flexure portion 40 which is connected to
the load beam portion 30 and supports the magnetic head slider
100.
[0113] The supporting portion 10 includes a main-body portion, a
pair of supporting pieces 11 extending toward the tip end from the
opposite sides of the main-body portion in the widthwise direction
of the suspension, and a concave portion 12 which is defined by the
pair of supporting pieces 11 so as to open to the tip-end side of
the suspension, as illustrated in FIG. 1 and FIG. 2.
[0114] In the present embodiment, as illustrated in FIG. 1 and FIG.
2, the supporting portion 10 is formed to be an arm. The supporting
portion 10 can be formed from a stainless-steel plate having a
thickness in the range of about 0.1 mm to 0.8 mm.
[0115] Further, as illustrated in FIG. 3, the supporting portion 10
can also be formed to be a base plate including a boss portion 15
to be connected to a tip end of an arm of an E block through swage
processing, instead of the arm.
[0116] The load beam portion 30 is a member for transmitting the
load generated from the load bending portion 20 to the magnetic
head slider 100 as described above and, therefore, is required to
have a predetermined rigidity.
[0117] Accordingly, the load beam portion 30 is preferably formed
from a member having a thickness greater than those of the load
bending portion 20 and the flexure portion 40. The load beam
portion 30 is formed from a stainless-steel plate having a
thickness in the range of about 0.02 mm to 0.1 mm.
[0118] The load beam portion 30 is provided, at its tip-end
portion, with a protrusion 31 which is a so-called dimple.
[0119] The protrusion 31 is protruded by, for example, about 0.05
mm to 0.1 mm, in such a direction that it comes close to the disk
surface. The protrusion 31 is contacted with a back surface (a
surface opposite from the disk surface) of a head mounting area 43
of the flexure portion 40, so that the load is transmitted to the
head mounting area 43 of the flexure portion 40 through the
protrusion 31.
[0120] Further, the detailed structure of the load beam portion 30
will be described later.
[0121] The flexure portion 40 is supported by the load beam portion
30 in a state where it supports the magnetic head slider 100.
[0122] More specifically, as illustrated in FIG. 1, the flexure
portion 40 includes a main-body area 41 bonded to the lower surface
of the load beam portion 30 (the surface thereof which faces to the
disk surface) through welding or the like, a pair of supporting
pieces 42 extending toward the tip-end side of the suspension from
the main-body area 41, and the head mounting area 43 supported by
the supporting pieces 42.
[0123] The head mounting area 43 supports the magnetic head slider
100 at its surface which faces to the disk surface.
[0124] As described above, the protrusion 31 is contacted with the
back surface of the head mounting area 43, which allows the head
mounting area 43 to sway flexibly in the direction of roll and in
the direction of pitch, with the protrusion 31 used as a
fulcrum.
[0125] The flexure portion 40 is formed from a member having lower
rigidity than that of the load beam portion 30, in order to allow
the head mounting area 43 to swing in the direction of roll and in
the direction of pitch. The flexure portion 40 is formed from a
stainless-steel plate having a thickness in the range of about
0.015 mm to 0.025 mm, for example.
[0126] In the present embodiment, the load bending portion 20 is
formed from an elastic plate 50 which is supported in a
dual-supported manner.
[0127] FIG. 4 illustrates a top view of the supporting portion 10
of the magnetic head suspension 1A according to the present
embodiment.
[0128] As illustrated in FIGS. 1 to 4, the supporting portion 10
includes the main-body portion, the pair of supporting pieces 11
extending toward the tip-end side of the suspension from the
opposite sides of the main-body portion in the widthwise direction
of the suspension, and the concave portion 12 which is defined by
the pair of supporting pieces 11 so as to open to the tip-end side
of the suspension.
[0129] Further, the magnetic head suspension 1A includes the
elastically-deformable elastic plate 50 which is connected to the
pair of supporting pieces 11 at first and second ends in the
widthwise direction of the magnetic head suspension, and the
elastic plate 50 supports the load beam portion 30 such that the
elastic plate 50 can form the load bending portion 20.
[0130] FIG. 5 illustrates a bottom view of the elastic plate
50.
[0131] As illustrated in FIG. 1, FIG. 2 and FIG. 5, the elastic
plate 50 extends in the widthwise direction of the magnetic head
suspension 1A in a state where it is supported at its opposite ends
by the pair of supporting pieces 11.
[0132] In the present embodiment, the elastic plate 50 is connected
to the bottom surfaces of the pair of supporting pieces 11 which
are faced to the disk surface and also supports the load beam
portion 30 at its upper surface opposite from the disk surface.
[0133] The elastic plate 50 includes first and second connected
areas 51a and 51b which are connected to the pair of supporting
pieces 11, respectively, and a center area 52 extending between the
first and second connected areas 51a and 51b, as illustrated in
FIG. 1 and FIG. 5.
[0134] The center area 52 includes a center connected portion 52c
to which the member forming the load beam portion 30 is connected,
a first extending portion 52a extending between the center
connected portion 52c and the first connected area 51a, and a
second extending portion 52b extending between the center connected
portion 52c and the second connected area 51b, wherein the first
extending portion 52a and the second extending portion 52b are
shaped to be symmetrical with the longitudinal center line CL of
the magnetic head suspension 1A as a reference.
[0135] The elastic plate 50 is twisted such that the tip end of the
center area 52 comes close to the disk surface in a state where the
first and second connected areas 51a and 51b are respectively
connected to the pair of supporting pieces 11 and, thus, the
elastic plate 50 is bound at its opposite ends, thereby generating
the load.
[0136] FIG. 6A and FIG. 6B illustrate a perspective view of the
magnetic head suspension 1A including the elastic plate 50 in a
state before the suspension 1A is mounted to a data storage device,
and a perspective view of the magnetic head suspension 1A in a
state where the magnetic head slider 100 is floated above the disk
surface due to the air pressure caused by the rotation of the disk
surface in the data storage device during the magnetic head
suspension 1A is operated after being mounted to the data storage
device.
[0137] Before the magnetic head suspension 1A is mounted to the
data storage device such as a hard disk device, the elastic plate
50 is twisted such that the tip end of the center area 52 of the
elastic plate 50 comes close to the disk surface, which causes the
load beam portion 30 to take an attitude inclined with respect to
the supporting portion 10 such that its tip end comes close to the
disk surface, as illustrated in FIG. 6A.
[0138] As illustrated in FIG. 6B, in a state where the magnetic
head suspension 1A operates to read and/or write data with the
magnetic head slider 100, the elastic plate 50 is twisted back due
to the air pressure caused by the rotation of the disk surface,
which causes the load beam portion 30 to be substantially parallel
to the disk surface, thereby causing the magnetic head slider 100
to float above the disk surface and to be maintained in a state
where it can read and/or write data from and/or to the disk
surface.
[0139] At this state, since the elastic plate 50 is twisted back
due to the air pressure, the elastic plate 50 possess elasticity in
such a direction that it presses the tip end of the load beam
portion 30 against the disk surface. This possessed elasticity
functions as the load for pressing the magnetic head slider 100
against the disk surface.
[0140] FIG. 7 is a bottom view of an exemplary modification 50B of
the elastic plate 50.
[0141] Preferably, as illustrated in FIG. 7, the elastic plate 50B
is formed such that the center connected portion 52c has a width
greater than that of the first and second extending portions 52a
and 52b.
[0142] With this structure, it is possible to easily perform the
process for twisting the elastic plate 50B, while easily securing
portions of the elastic plate 50B to which the load beam portion 30
is welded.
[0143] FIGS. 8A and 8B illustrate, respectively, a top perspective
view illustrating a state where the elastic plate 50B according to
the modification example is twisted (a state before the magnetic
head suspension 1A is mounted to the data storage device), and a
top perspective view illustrating a state where the elastic plate
50B has been twisted back (a state where the elastic plate 50B has
been twisted back due to the air pressure during the magnetic head
suspension 1A is operated after being mounted to the data storage
device).
[0144] More preferably, as illustrated in FIG. 7 and FIG. 8, the
center connected portion 52c is extended toward the tip-end side
and toward the base-end side of the suspension, such that the
center connected portion 52c is symmetrical with the load bending
center line BL of the first and second extending portions 52a and
52b extended in the widthwise direction of the magnetic head
suspension as a reference.
[0145] With this structure, it is possible to easily perform the
process for twisting the elastic plate 50B about the load bending
center line BL, while offering the aforementioned effects.
[0146] More preferably, as illustrated in FIG. 7 and FIG. 8, the
elastic plate 50B is formed such that the first and second
connected areas 51a and 51b have a width greater than that of the
first and second extending portions 52a and 52b.
[0147] With this structure, it is possible to easily perform the
process for twisting the elastic plate 50B, while securing portions
of the first and second connected areas 51a and 51b to which the
pair of supporting pieces 11 are welded.
[0148] Further, in the present embodiment, as previously described,
the processing for twisting the elastic plate 50, 50B is performed
before the magnetic head suspension 1A is mounted to the data
storage device and, further, the elastic plate 50, 50B is twisted
back through the air pressure in a state where the magnetic head
suspension 1A is operated, in order to generate the load. However,
instead of this structure, it is also possible to employ the
following structure.
[0149] FIG. 9 illustrates a magnetic head suspension 1B according
to a modified embodiment for causing the elastic plate 50, 50B to
generate the load. Further, FIGS. 9A to 9C illustrate,
respectively, a top view of the magnetic head suspension 1B
according to the modified embodiment, a side view of the same
before it is mounted to the data storage device, and a side view of
the same in a state where it is operated after being mounted to the
data storage device.
[0150] As illustrated in FIG. 9, in the magnetic head suspension 1B
according to the modified embodiment, the pair of supporting pieces
11 are bended at a bended position 11a between the base end and the
tip end in such a manner that their tip ends come close to the disk
surface, and the elastic plate 50 is connected to the pair of
supporting pieces 11 at a portion closer to the tip end than the
bended position 11a.
[0151] That is, before the magnetic head suspension 1B is mounted
to the data storage device, the load beam portion 30 takes an
attitude inclined such that it gradually comes close to the disk
surface with decreasing distance to the tip end, as illustrated in
FIG. 9B.
[0152] Further, in a state where the magnetic head suspension 1B is
operated after being mounted to the data storage device, the
elastic plate 50 is twisted through the air pressure such that the
load beam portion 30 is substantially parallel to the disk surface,
which causes the elastic plate 50 to generate the load (see FIG.
9C).
[0153] As described above, the magnetic head suspension 1A
according to the present embodiment and the magnetic head
suspension 1B according to the modified embodiment illustrated in
FIG. 9 are configured so that the elastic plate 50, 50B which is
supported at its opposite ends functions as the load bending
portion 20, thereby offering effects as follows.
[0154] That is, a conventional magnetic head suspension includes a
load bending portion formed to be a cantilever spring which is
supported at its base-end portion by a supporting portion such as
an arm and supports a load beam portion at its free end
portion.
[0155] With this conventional structure, when an external impulsive
force is applied thereto, this will largely vary the supporting
point of the load beam portion (namely, the point of the load beam
portion to which the load bending portion is connected), in the
direction orthogonal to the disk surface, Accordingly, even if the
weight of the load beam portion is reduced without involving the
reduction of the rigidity thereof and/or the masses of the tip-end
side and the base-end side of the load beam portion as the
supporting point of the load beam portion as a reference are
balanced, it is impossible to suppress sufficiently the jump of the
magnetic head slider in the direction orthogonal to the disk
surface.
[0156] On the contrary, the magnetic head suspension 1A according
to the present embodiment and the magnetic head suspension 1B
according to the modified embodiment are configured so that the
elastic plate 50, 50B supported at its opposite ends functions as
the load bending portion 20.
[0157] With this structure, when an external impulsive force is
applied thereto, it is possible to effectively prevent the
supporting point of the load beam portion 30 namely, the point of
the member forming the load beam portion 30 which is connected to
the elastic member 50, 50B) from varying in the direction
orthogonal to the disk surface, thus suppressing the jump of the
magnetic head slider 100 and largely raising the critical
acceleration of the impulsive force which triggers the jump of the
magnetic head slider 100.
[0158] Further, in the magnetic head suspension 1B according to the
modified embodiment illustrated in FIG. 9, it is possible to set
the value of the load, through the bending angle of the pair of
supporting pieces 11. This can offer the advantage of stably
controlling the load.
[0159] Further, the elastic plate 50, 50B is made of a member
capable of generating the load by its twisting action. That is, the
elastic plate 50, 50B is formed from a member having a thickness
smaller than that of the load beam portion 30 and can be preferably
formed from, for example, a stainless-steel plate having a
thickness in the range of about 0.02 mm to 0.1 mm.
[0160] FIG. 10 illustrates a partially-enlarged top view of the
magnetic head suspension 1A.
[0161] Preferably, the load beam portion 30 includes a base-end
area 30b extending from the elastic plate 50 toward the base end,
in addition to a tip-end area 30a which extends from the elastic
plate 50 toward the tip end and supports the flexure portion 40, as
illustrated in FIG. 10.
[0162] That is, the member forming the load beam portion 30
includes a connected area 30c connected to the elastic plate 50,
the tip-end area 30a extending from the connected area 30c toward
the tip-end side of the suspension, and the base-end area 30b
extending from the connected area 30c toward the base-end side of
the suspension.
[0163] The base-end area 30b provided in the load beam portion 30
makes it possible to balance the mass of the portion of the load
beam portion 30 closer to the base end of the suspension than the
load bending center line BL with the mass of the portion of the
load beam portion 30 closer to the tip-end side of the suspension
than the load bending center line BL.
[0164] FIG. 11 illustrates the load beam portion 30, wherein FIGS.
11A to 11D are a top view thereof, a side view thereof, a
cross-sectional view taken along the line c-c in FIG. 11A, and a
cross-sectional view taken along the line d-d in FIG. 11A,
respectively.
[0165] As illustrated in FIG. 10 and FIG. 11, the member forming
the load beam portion 30 has flange portions 35 extending at the
opposite sides thereof in the longitudinal direction of the
suspension so as to be across the elastic plate 50.
[0166] More preferably, the flange portions 35 are configured such
that their heights gradually decrease as it goes from the base end
to the tip end.
[0167] With this structure, it is possible to increase the mass of
the base-end area 30b of the load beam portion 30 with respect to
the mass of the tip-end area 30a while increasing the rigidity of
the load beam portion 30, which can effectively balance the mass of
the portion of the load beam 30 closer to the base-end side of the
suspension than the load bending center line BL with the mass of
the portion of the load beam portion 30 closer to the tip-end side
of the suspension than the load bending center line BL.
[0168] The magnetic head suspension 1A according to the present
embodiment includes a balance mass member 60 secured to the
base-end area 30b of the load beam portion 30, in addition to the
structure explained above, as illustrated in FIGS. 1, 2, 3, 9 and
10.
[0169] By providing the balance mass member 60, it is possible to
balance the mass of the portion of the load beam portion 30 closer
to the base-end side of the suspension than the elastic plate 50
with the mass of the portion of the load beam portion 30 closer to
the tip-end side of the suspension, while reducing the length of
the base-end area 30b as much as possible.
[0170] In the present embodiment, the base-end area 30b is
configured to position in the concave portion 12 in a plan
view.
[0171] Hereinafter, there will be described the results of analyses
of the critical acceleration (the acceleration of an impulsive
force which triggers the jump of the magnetic head slider 100) in
an example (hereinafter, referred to as an example 1) of the
magnetic head suspension 1A according to the present embodiment,
and the critical acceleration in an example (hereinafter, referred
to as a comparative example 1) of the conventional magnetic head
suspension illustrated in FIG. 12, on the basis of a finite-element
method.
[0172] The aforementioned analyses were performed under the
following condition.
[0173] In the example 1, the supporting portion 10, the load beam
portion 30, the elastic plate 50 forming the load bending portion
20 and the flexure portion 40 are all made of stainless-steel
plates (SUS304) having thicknesses of 0.4 mm, 0.025 mm, 0.02 mm and
0.02 mm, respectively.
[0174] In the example 1, a length La (see FIG. 10) in the
longitudinal direction of the magnetic head suspension between the
load bending center line BL and the center of gravity DG of the
tip-end side portion of the assembly constituted by the load beam
portion 30, the flexure portion 40 and the balance mass member 60
which is closer to the tip-end side of the suspension than the load
bending center line BL was set to 3.316 mm. Further, a length Lg
(see FIG. 10) in the longitudinal direction of the magnetic head
suspension between the center of gravity WG of the entire assembly
and the load bending center line BL was set to 0.25 mm. Further, a
length Lb (see FIG. 10) in the longitudinal direction of the
magnetic head suspension between the load bending center line BL
and the center of gravity PG of the base-end side portion of the
aforementioned assembly which is closer to the base-end side of the
suspension than the load bending center line BL was set to 1.54 mm.
It is preferable to make the position of the center of gravity of
the portion of the aforementioned assembly which is closer to the
base-end side of the suspension than the load bending center line
BL to be closer to the bending load center line BL as much as
possible, in order to prevent the reduction of the resonance
frequency of the magnetic head suspension 1A, particularly the
SWAY-mode frequency (the resonance-mode frequency at a time when
the magnetic head slider 100 is moved in the seek direction
parallel to the disk surface).
[0175] The comparative example 1 has an elastic plate 150 supported
in a cantilever manner by the supporting portion 10 as illustrated
in FIG. 12, instead of the elastic plate 50 supported at its
opposite ends by the supporting portion 10.
[0176] More specifically, the elastic plate 150 has a pair of
elastic pieces 151 supported at their base ends by the pair of
supporting pieces 11, and a coupling piece 152 coupling the free
end portions of the pair of elastic pieces 151 to each other,
wherein the load beam portion 30 is connected to the coupling piece
152.
[0177] In the comparative example 1 having the aforementioned
structure, the elastic pieces supported in a cantilever manner
functions as a load bending portion for generating the load for
pressing the magnetic head slider 100 against the disk surface.
[0178] The analysis on the comparative example 1 was performed
under the same condition as that for the example 1, except that the
thickness of the elastic plate 150 was set to 0.034 mm.
[0179] Analyses were performed for the critical accelerations of
the example 1 and the comparative example 1 when impulsive waves
(half-sine wave accelerations) having pulse widths of 1.00 msec,
1.50 msec and 2.00 msec were applied thereto, on the basis of a
finite-element method. FIG. 13 illustrates the results of the
analyses.
[0180] As illustrated in FIG. 13, the critical acceleration in the
example 1 is higher than that in the comparative example 1, for any
of the impulsive waves having the pulse widths.
[0181] More specifically, it is revealed that the critical
acceleration in the example 1 becomes higher as the pulse width of
the impulsive wave is increased, while the critical acceleration in
the comparative example 1 is substantially constant for any of the
pulse widths. The impulsive wave having a pulse width of 1.00 msec
corresponds to an impact on the data storage device when the data
storage device is fallen on a relatively-hard material such as a
concrete. The impulsive wave having a pulse width of 2.00 msec
corresponds to an impact on the data storage device when the data
storage device is fallen on a relatively-soft member such as a wood
desk, for example.
[0182] The same analyses were performed on an example (hereinafter,
referred to as an example 2) of the magnetic head suspension
provided by eliminating the balance mass member 60 from the example
1 and an example (hereinafter, referred to as a comparative example
2) of the magnetic head suspension provided by eliminating the
balance mass member 60 from the comparative example 1. The results
of these analyses are also illustrated in FIG. 13.
[0183] As is apparent from FIG. 13, the critical acceleration in
the example 2 is higher than that in the comparative example 2 for
any of the impulsive waves having the pulse widths, also in a
configuration having no balance mass member 60.
[0184] Further, analyses were performed, on the basis of a
finite-element method, for the critical acceleration in the example
1, when the ratio K=Lg/La (hereinafter, referred to as
center-of-gravity position ratio) of the length g between the
center of entire gravity WG and the load bending center line BL to
the length La between the center of tip-end side gravity DG and the
load bending center line BL was varied. FIG. 14 illustrates the
results of the analyses.
[0185] Please note that the range of K<0 means that the mass of
the balance mass member 60 is set such that the position of the
center of the gravity WG of the entire assembly is closer to the
base-end side of the suspension than the load bending center line
BL.
[0186] As is apparent from FIG. 14, in the range of K<0, the
critical acceleration for an applied impulsive wave having an
acceleration pulse width of 1.0 msec is suddenly decreased.
[0187] Further, as is apparent from FIG. 14, it is revealed that,
within the range of K.ltoreq.0.45, the example 1 has a critical
acceleration characteristic equal to or higher than that of the
comparative example 1 for all of the pulse widths.
[0188] Accordingly, it is preferable that the center-of-gravity
position ratio K falls in the range of 0.ltoreq.K.ltoreq.0.45.
[0189] Further, as is apparent from FIG. 14, within the range of
K.ltoreq.0.3, the critical acceleration in the example 1 is clearly
higher than that in the comparative example 1, for an impulsive
wave having a pulse width of 2.0 msec, that is in the case where
the data storage device fallen on a relatively-soft material such
as a wood desk.
[0190] Accordingly, it is preferable to set the mass of the balance
mass member 60 such that K falls within the range of
0.ltoreq.K.ltoreq.0.3, according to the condition under which the
data storage device utilizing the magnetic head suspension is
used.
[0191] Further, it is revealed that, within the range of
K.ltoreq.0.2, the critical acceleration in the example 1 is higher
than that in the comparative example 1, for all of the impulsive
waves having the puke waves.
[0192] Accordingly, it is more preferable to set the mass of the
balance mass member 60 such that K falls within the range of
0.ltoreq.K.ltoreq.0.2.
[0193] Further, analyses were performed, on the basis of a
finite-element method, on an example (hereinafter, referred to as
an example 3, see FIG. 11) of the magnetic head suspension 1A
having the flange portions 35 structured such that their heights
were gradually decreased as they went from the base end to the tip
end and an example (hereinafter, referred to as an example 4, see
FIG. 15) of the magnetic head suspension having flange portions 35
having substantially a constant height, when impulsive waves having
pulse widths of 1.00 msec, 1.50 msec and 2.00 msec were applied
thereto. FIG. 16 illustrates the results of the analyses.
[0194] In the example 3, the flange portions 35 are folded at an
angle of 75.degree. and also has a height of 0.345 mm at its
portion closest to the base end and has a height of 0.160 mm at its
portion closest to the tip end. On the other hand, in the example
4, the flange portions 35 are folded at the same angle as that of
the example 3 and also has a constant height of 0.180 mm from its
portion closest to the base end to its portion closest to the tip
end.
[0195] As is apparent from FIG. 16, the example 3 having the flange
portions 35 formed such that their heights are gradually decreased
from the base end to the tip end exhibits a higher critical
acceleration than that of the example 4 having the flange portion
35 having the constant height, for all of the pulse widths.
[0196] Preferably, a signal wiring member 70 which is electrically
connected at a first end to the magnetic head slider 100 and also
is capable of outputting electrical signals to the outside at a
second end thereof can be laminated on the flexure portion 40, such
that the signal wiring member 70 is integral with the flexure
portion 40.
[0197] FIGS. 17A and 17B illustrate bottom views illustrating an
example 1C and an alternative example 1D of the magnetic head
suspension 1C having the signal wiring member 70 laminated on the
flexure portion 40 such that they are integral with each other.
[0198] More specifically, as illustrated in FIG. 17, the signal
wiring member 70 includes an insulation layer 71 laminated on the
member forming the flexure portion 40 and a conductive layer 72
laminated on the insulation layer 71 and, preferably, can further
include a protective layer (not illustrated) covering the
conductive layer.
[0199] In the structure including the signal wiring member 70
formed integrally with the flexure portion 40, the signal wiring
member 70 preferably includes a load-beam-portion side area 70a
supported directly or indirectly by the load beam portion 30
through the flexure portion 40, a supporting-portion side area 70b
supported directly or indirectly by the supporting portion 10, and
an aerial area 70c extending in air between the load-beam-portion
side area 70a and the supporting-portion side area 70b.
[0200] In the magnetic head suspension 1C illustrated in FIG. 17A,
the load-beam-portion side area 70a and the aerial area 70c are
symmetrical with the longitudinal center line CL of the magnetic
head suspension as a reference and, also, the aerial area 70c has
at least one direction changing portion 74.
[0201] In the magnetic head suspension 1D illustrated in FIG. 17B,
the load-beam-portion side area 70a and the aerial area 70c are
symmetrical with the longitudinal center line BL of the magnetic
head suspension as a reference and, also, are placed to
substantially surround the balance mass member 60 in a plan
view.
[0202] With the example 1C and the alternative example 1D, it is
possible to effectively prevent the signal wiring member from
interfering with the movement of the balance mass member 60 when
the impulsive wave was applied thereto.
[0203] Further, in the embodiment illustrated in FIG. 17A, the
direction changing portion 74 has a U-shape in a plan view, which
may induce vibrations of the U-shaped portion in a plan view due to
the air flows caused by the rotation of the disk. However, in the
embodiment illustrated in FIG. 17B, it is possible to prevent the
influence of the air flows caused by the rotation of the disk.
[0204] Further, the magnetic head assemblies 1C and 1D include an
elastic plate 50C configured to form both the load bending portion
20 and the flexure portion 40 as illustrated in FIGS. 17A and
17B.
[0205] That is, the elastic plate 50C is formed integrally with the
member forming the flexure 40.
[0206] With this structure, it is possible to reduce the number of
assembling processes and simplify the fabrication processes.
[0207] More preferably, as illustrated in FIG. 18, the first and
second extending portions 52a and 52b of the elastic plate 50C are
provided with attenuation members 75 including viscoelastic
members, which can stop the vibration of the elastic plate 50C as
rapidly as possible.
[0208] The attenuation members 75 are placed to be symmetrical with
the longitudinal center line as a reference. In the embodiment
illustrated in FIG. 18, there are provided a pair of attenuation
members 75 placed to be symmetrical to each other with the
longitudinal center line as a reference.
[0209] In the structure including the elastic plate 50C formed
integrally with the member forming the flexure portion 40 and also
including the signal wiring member 70 laminated on the flexure
portion 40 such that they are integral with each other, the
attenuation members 75 are preferably made of the same materials as
those of the insulation layer 71 and the conductive layer 72.
[0210] That is, it is preferable to laminate the attenuation
members 75 formed by the insulation layer 71 and the conductive
layer 72 on the first and second extending portions 52a and 52b, at
the same time as laminating the insulation layer 71 and the
conductive layer 72 on the flexure portion 40, which can form the
attenuation members 75 without increasing the number of fabrication
processes.
[0211] Further, the conductive layer 72 can be made of a metal such
as Cu, and the insulation layer 71 can be made of a resin such as
polyimide.
Second Embodiment
[0212] Hereinafter, there will be described another embodiment of
the magnetic head suspension according to the present invention
with reference to the attached drawings.
[0213] FIGS. 19A to 19C illustrate, respectively, a top view of a
magnetic head suspension 2A according to the second embodiment, a
bottom view of the same, and a cross-sectional view taken along the
line c-c in FIG. 19A.
[0214] Further, FIG. 20 illustrates a perspective view of the
magnetic head suspension 2A.
[0215] Further, in the drawings, the same components as those of
the first embodiment are designated by the same reference
characters and will not be described in detail.
[0216] As illustrated in FIG. 19 and FIG. 20, the magnetic head
suspension 2A includes a restraint plate 80 connected to the
supporting portion 10 and positioned on a side of the member
forming the load beam portion 30 opposite from the elastic plate 50
so that the member forming the load beam portion 30 is sandwiched
between the restraint plate 80 and the elastic plate 50 in the
direction orthogonal to the disk surface, in addition to the
structure of the magnetic head suspension 1A according to the first
embodiment.
[0217] The restraint plate 80 has a protrusion portion 81 which
contacts with the member forming the load beam portion 30 on the
load bending center line BL, as illustrated in FIGS. 19A and
19C.
[0218] In the present embodiment, as illustrated in FIG. 19, the
elastic plate 50 is connected to the lower surface of the
supporting portion 10 and, also, the member forming the load beam
portion 30 is connected to the upper surface of the elastic plate
50.
[0219] Accordingly, the restraint plate 80 is connected to the
upper surface of the supporting portion 10 such that the protrusion
portion 81 is protruded in the downward direction (the direction in
which it comes close to the disk surface).
[0220] The magnetic head suspension 2A including the restraint
plate 80 according to the second embodiment can effectively prevent
the supporting portion of the load beam portion 30 (namely, the
portion of the load beam portion 30 which is connected to the
elastic plate 50) from moving in the direction orthogonal to the
disk surface when an external impulsive force is applied thereto,
which can offer the advantage of raising the critical acceleration
of the impulsive force which triggers the jump of the magnetic head
slider 100, in addition to the advantages of the first
embodiment.
[0221] FIG. 21 illustrates the results of analyses of the critical
accelerations in an example (the example 1) of the magnetic head
suspension 1A according to the first embodiment illustrated in FIG.
1 and an example (hereinafter, referred to as an example 5) of the
magnetic head suspension 2A according to the second embodiment
illustrated in FIG. 19, which were resulted from the application of
impulsive waves (half-sine wave accelerations) having pulse widths
of 1.00 msec, 1.50 msec and 2.00 msec thereto, on the basis of a
finite-element method.
[0222] In the example 5, the restraint plate 80 was formed to have
a thickness of 0.045 mm, but the other conditions were the same as
those of the example 1.
[0223] As is apparent from FIG. 21, it is revealed that, when
impulsive waves having acceleration pulse widths of 1.5 msec and
2.0 msec are applied thereto, the critical acceleration in the
example 5 having the restraint plate 80 is higher by about 20 G/gf
to 90 G/gf than that in the example 1 having no restraint plate
80.
[0224] Further, in the present embodiment, as illustrated in FIG.
19, the restraint plate 80 has the single protrusion portion 81. In
this structure, the protruding portion 81 is brought into contact
with the load beam portion 30 at the intersection point between the
load bending center line BL and the longitudinal center line CL
(see FIG. 19A).
[0225] Instead of this structure, the restraint plate 80 can have a
plurality of protrusion portions 81. In the case where the
restraint plate 80 has a plurality of protrusion portions 81 as
described above, these plurality of protrusion portions 81 are
positioned along the load bending center line BL and are placed to
be symmetrical with the longitudinal center line CL as a
reference.
[0226] Also, the protrusion portion 81 can be configured to be
contacted with the load beam portion 30 in a line-to-line manner,
instead of being configured to be contacted with the load beam
portion 30 in a point-to-point manner, as illustrated in FIG.
19.
[0227] FIG. 22 illustrates an exemplary magnetic head suspension 2B
including a restraint plate 81B having a protrusion portion 81B
configured to be contacted with the load beam portion 30 in a
line-to-line manner. FIGS. 22A and 22B illustrate a top view of the
magnetic head suspension 2B and a cross-sectional view taken along
the line b-b in FIG. 22A, respectively.
[0228] As illustrated in FIG. 22, the restraint plate 80B has the
single protrusion portion 81B.
[0229] The single protrusion portion 81B is contacted with the load
beam portion 30 over a predetermined distance in the widthwise
direction of the magnetic head suspension, at a state where it is
placed along the load bending center line BL and is placed to be
symmetrical with the longitudinal center line CL as a
reference.
[0230] With this structure, similarly, it is possible to
effectively prevent the supporting point of the load beam portion
30 from varying in the direction orthogonal to the disk surface
when an impulsive force is applied thereto. Further, it is also
possible to increase the resonance frequency, particularly the
Torsion-mode frequency (the resonance frequency in a mode at which
the magnetic head slider 100 vibrates in the seek direction due to
the twist of the load beam portion 30).
[0231] Instead of the structures, it is also possible to provide a
restraint plate 80C structured to be contacted with the load beam
portion 30 in a surface-to-surface manner.
[0232] FIG. 23 illustrates a magnetic head suspension 2C including
the restraint plate 80C. FIGS. 23A to 23C are a top view of the
magnetic head suspension 2C, a cross-sectional view taken along the
line b-b in FIG. 23A and a cross-sectional view taken along the
line c-c in FIG. 23A.
[0233] The restraint plate 80C is connected to the supporting plate
10 and positioned on a side of the member forming the load beam
portion 30 opposite from the elastic plate 50 in the direction
orthogonal to the disk surface so that the member forming the load
beam portion 30 is sandwiched between the restraint plate 80C and
the elastic plate 50, similarly to the restraint plates 80, 80B in
FIGS. 19 and 22.
[0234] In the illustrated embodiment, the elastic plate 50 is
connected to the lower surface of the supporting portion 10 and,
also, the load beam portion 30 is connected to the upper surface of
the elastic plate 50. Accordingly, the restraint plate 80C is
connected to the upper surface of the supporting portion 10.
[0235] More specifically, as illustrated in FIG. 23, the restraint
plate 80C includes a connected surface 81 connected to the upper
surface (the surface opposite from the disk surface) of the
supporting portion 10, a coupling surface 82C folded in such a
direction that it comes close to the disk surface from the
connected surface 81C, and a contact surface 83C which is folded
from the free-end side of the coupled surface 82C and is connected
to the upper surface (the surface opposite from the disk surface)
of the member forming the load beam portion 30 in a
surface-to-surface manner.
[0236] A border line between the coupling surface 82C and the
contact surface 83C is positioned on the load bending center line
BL and also is symmetrical with the longitudinal center line CL as
a reference.
[0237] With this structure, it is also possible to effectively
prevent the supporting point of the load beam portion 30 from
varying in the direction orthogonal to the disk surface when an
impulsive force is applied thereto.
Third Embodiment
[0238] Hereinafter, still another embodiment of the magnetic head
suspension according to the present invention will be described,
with reference to the attached drawings.
[0239] FIGS. 24A to 24C illustrate a top view of the magnetic head
suspension 3A according to the third embodiment, a bottom view of
the same, and a cross-sectional view taken along the line c-c in
FIG. 24A.
[0240] Further, in the drawings, the same components as those of
the first and second embodiments are designated by the same
reference characters and will not be described in detail.
[0241] As illustrated in FIG. 24, the magnetic head suspension 3A
includes a restriction plate 90 connected to the supporting portion
10 such that it is positioned on a side closer to the disk surface
than the base-end side area of the load beam 30, in addition to the
structure of the magnetic head suspension 1A according to the first
embodiment.
[0242] The restriction plate 90 is placed to overlap with at least
a portion of the balance mass member 60 in a plan view.
[0243] By providing the restriction plate 90, it is possible to
effectively prevent the balance mass member 90, which has been
jumped in such a direction that it separates from the disk surface
when an impact is applied the suspension, from swinging back toward
the disk surface and impinging on the disk surface. Further, even
if an external impulsive force is applied to the balance mass
member 60 in such a direction as to cause the balance mass member
60 to come close to the disk surface, it is possible to effectively
prevent the balance mass member from impinging on the disk
surface.
[0244] As illustrated in FIG. 24C, the restriction plate 90 is
connected to the supporting portion 10 such that there is a
predetermined interval (for example, 0.1 mm to 0.2 mm) between the
restriction plate 90 and the balance mass member 60, at a normal
state where no impact is applied thereto.
[0245] More specifically, the restriction plate 90 includes a first
and second connected areas 91a and 91b connected to the lower
surfaces of the pair of supporting pieces 11, and a cover area 91c
extending between the first and second connected areas 91a and 91b
such that it overlaps with at least a portion of the balance mass
member 60 in a plan view.
[0246] Further, the cover area 91c is positioned more proximally to
the disk surface than the plane in which there exists the lower
surface of the supporting portion 10, such that there is the
predetermined interval between the cover area 91c and the lower
surface of the balance mass member 60.
[0247] The restriction plate 90 can be preferably formed from a
stainless-steel plate with a thickness in the range of about 0.02
mm to 0.1 mm, for example.
[0248] While, in the present embodiment, there has been described a
case where the restriction plate 90 is provided in the magnetic
head suspension 1A according to the first embodiment, the
restriction plate 90 can also be provided in the magnetic head
suspension 2A according to the second embodiment, as a matter of
cause.
Fourth Embodiment
[0249] Hereinafter, still another embodiment of the magnetic head
suspension according to the present invention will be described,
with reference to the attached drawings.
[0250] FIGS. 25A and 25B illustrate a top view and a bottom view of
the magnetic head suspension 4A according to the present
embodiment, respectively.
[0251] Further, FIG. 26 illustrates a partial side view of the
magnetic head suspension 4A.
[0252] FIGS. 26A and 26B illustrate the magnetic head suspension 4A
in a state before it is mounted to a data storage device and in a
state where it is operated after being mounted to the data storage
device, respectively.
[0253] Further, FIG. 27 and FIG. 28 illustrate, respectively, a
perspective view and an exploded perspective view illustrating,
from above, in a state before it is mounted to the data storage
device.
[0254] Further, in the drawings, the same components as those of
the first to third embodiments are designated by the same reference
characters and will not be described in detail.
[0255] As illustrated in FIGS. 25 to 28, the magnetic head
suspension 4A according to the present embodiment includes a
balance mass member 460, a load beam portion 430 and an elastic
plate 450, instead of the balance mass member 60, the load beam
portion 30 and the elastic plate 50 in the magnetic head suspension
1A according to the first embodiment.
[0256] FIGS. 29A and 29B illustrate, respectively, a top view and a
bottom view of the balance mass member 460.
[0257] As illustrated in FIGS. 25 to 29, the balance mass member
460 includes a tip end portion 461 connected to the base-end
portion of the load beam portion 430, a base-end portion 463
extending toward the base-end side of the suspension within the
concave portion 12 beyond the elastic plate 450, and a center
portion 462 positioned between the tip end portion 461 and the
base-end portion 463 and connected to the elastic plate 450.
[0258] That is, as illustrated in FIG. 29, the balance mass member
460 includes the center portion 462 connected to the elastic plate
450, the tip end portion 461 which is extended toward the tip-end
side of the suspension from the center portion 462 and is connected
to the load beam portion 430, and the base-end portion 463
extending from the center portion 462 toward the base-end side of
the suspension, in the longitudinal direction of the magnetic head
suspension 4A.
[0259] Preferably, as illustrated in FIG. 29, the balance mass
member 460 is configured such that its base-end portion 463 has a
base-end-side bending portion 463a and its portion extending from
the base-end-side bending portion 463a up to the base-end edge is
gradually separated from the disk surface with decreasing distance
to the base end.
[0260] With this structure, when an impact is applied thereto, it
is possible to effectively prevent the balance mass member 460
jumped in such a direction that it separates from the disk surface
from impinging on the disk surface during swaying back toward the
disk surface. Further, even if an external impulsive force is
applied to the balance mass member 460 in such a direction that it
comes close to the disk surface, it is possible to effectively
prevent the balance mass member 460 from impinging on the disk
surface.
[0261] At the base-end-side bending portion 463a, for example, a
groove with a depth equal to 1/2 to 3/4 of the thickness of the
balance mass member can be formed in the widthwise direction, as
illustrated in FIG. 29. By forming this groove, it is possible to
easily perform the processing for bending the balance mass member
460 at the base-end-side bending portion 463a.
[0262] The groove can be formed, with preferable controllability,
by etching the portion of the balance mass member 460 corresponding
to the base-end-side bending portion 463a from a single side
thereof.
[0263] Similarly to the first embodiment, it is preferable that
there is the relationship of 0.ltoreq.Lg.ltoreq.0.45.times.. La,
more preferably 0.ltoreq.Lg.ltoreq.0.3.times.La and, more
preferably 0.ltoreq.Lg.ltoreq.0.2.times.La in the magnetic head
suspension 4A including the balance mass member 460, wherein Lg is
the length in the longitudinal direction of the magnetic head
suspension between the center of gravity WG of the assembly
constituted by the load beam portion 430, the flexure portion 40
and the balance mass member 460 and the load bending center line BL
of the first and second extending portions 52a and 52b along the
widthwise direction of the magnetic head suspension and, also, La
is the length in the longitudinal direction of the magnetic head
suspension between the load bending center line BL and the center
of gravity DG of the portion of the aforementioned assembly which
is closer to the tip end than the load bending center line BL.
[0264] FIG. 30A illustrates a plan view of the elastic plate
450.
[0265] The elastic plate 450 has a first and second connected areas
51a and 51b which are connected to the pair of supporting pieces
11, and a center area 52 extending between the first and second
connected areas 51a and 51b as illustrated in FIG. 30A, similarly
to in the first embodiment.
[0266] The center area 52 has a center connected portion 52c which
is positioned at the center in the widthwise direction of the
magnetic head suspension 4A, a first extending portion 52a
extending between the center connected portion 52c and the first
connected area 51a, and a second extending portion 52b extending
between the center connected portion 52c and the second connected
area 51b.
[0267] The first and second extending portion 52a and 52b are
shaped to be symmetrical to each other with the longitudinal center
line CL of the magnetic head suspension 4A as a reference,
similarly to in the embodiments.
[0268] Further, the first and second extending portions 52a and 52b
are shaped to be symmetrical with the load bending center line BL
as a reference.
[0269] In the present embodiment, the elastic plate 450 is
connected to the balance mass member 460, as described above. More
specifically, the center connected portion 52c is connected to the
center portion 462 of the balance mass member 460.
[0270] The first and second extending portions 52a and 52b are
twisted such that the tip end side of the load beam portion 430
comes close to the disk surface in a state before the magnetic head
suspension 4A according to the present embodiment is mounted to a
data storage device (see FIG. 26A) and, further, the first and
second extending portions 52a and 52b are twisted back in a state
where the magnetic head suspension 4A is operated after being
mounted to the data storage device (see FIG. 26B), similarly to the
magnetic head suspension 1A.
[0271] In the magnetic head suspension 4A with the aforementioned
structure, the elastic plate 450 supported at its opposite ends
functions as the load bending portion 20, similarly to in
aforementioned respective embodiments.
[0272] Accordingly, when an external impulsive force is applied
thereto, it is possible to effectively prevent the supporting point
of the load beam portion 430 (namely, the portion of the load beam
portion 430 which is connected to the elastic member 450) from
varying in the direction orthogonal to the disk surface, thus
suppressing the jump of the magnetic head slider 100 and largely
raising the acceleration limit of the impulsive force which
triggers the jump of the magnetic head slider 100.
[0273] Preferably, as illustrated in FIG. 30A, each of the first
and second extending portions 52a and 52b has outer curved portions
455 having a width gradually increased with decreasing distance to
the corresponding connected area 51a, 51b, and inner curved
portions 456 having a width gradually increased with decreasing
distance to the center connected portion 52c, at its tip-end side
and base-end side.
[0274] This structure allows the first and second extending
portions 52a and 52b to perform the twist action in a stable
manner, thus reducing the variation of the spring constant of the
elastic plate 450, in comparison with the structure having the
rectangular-shaped first and second extending portions 52a and 52b
(see FIG. 30B).
[0275] In the present embodiment, as illustrated in FIG. 30A, the
outer curved portions 455 and the inner curved portions 456 are
both formed to have an arc shape.
[0276] In this structure, preferably, the radius R of the outer
curved portions 455 and the inner curved portions 456 is set to
within the range of 1/4.times.W to 1/3.times.W, assuming that the
width between the opposite end portions of the first and second
extending portions 52a and 52b is W.
[0277] Instead of this structure, the outer curved portions 455 and
the inner curved portions 456 of the respective extending portions
52a and 52b at their tip-end side and/or base-end side are formed
to have a single elliptical shape.
[0278] In the present embodiment, the load beam portion 430 is
positioned more proximally to the tip-end side of the suspension
than the elastic plate 450. That is, the load beam portion 430 has
a base-end portion terminated at a position closer to the tip-end
side of the suspension than the elastic plate 450.
[0279] In this structure, preferably, the load beam portion 430 and
the elastic plate 450 are integrally formed from a single member as
illustrated in FIG. 28.
[0280] This structure can reduce the number of members and the
number of assembling processes, thereby reducing the cost, and also
can improve the assembling accuracy.
[0281] More specifically, as illustrated in FIG. 28, the member
forming the load beam portion 430 includes a flange area 430a
having a center flat-plate portion 431 positioned at the center in
the widthwise direction of the suspension and a pair of flange
portions 435 provided at the opposite sides of the center
flat-plate portion 431 in the widthwise direction, an elastic-plate
area 430c forming the elastic plate 450, and a flat-plate shaped
coupling area 430b which couples the center flat-plate portion 431
of the flange area 430a to the tip-end edge of the center connected
portion 52c of the elastic plate 450, wherein these portions are
integrally formed.
[0282] By coupling the flange area 430a and the elastic-plate
forming area 430c to each other through the flat-plate shaped
coupling area 430b as described above, it is possible to easily
form the load beam portion 430 having the flange portion 430 and
the elastic plate 450 from a single member.
[0283] The coupling area 430b is formed to have a flat-plate shape
as described above and therefore has rigidity lower than that of
the flange area 430a.
[0284] To cope with this point, in the present embodiment, as
illustrated in FIG. 27, the tip-end portion 461 of the balance mass
member 460 is connected to the center flat-plate portion 431, at a
state where the tip-end portion 461 of the balance mass member 460
is interposed between the pair of flange portions 435.
[0285] That is, in the present embodiment, the balance mass member
460 also functions as a reinforcing member which reinforces the
rigidity of the coupling area 430b.
[0286] Further, since the flange area 430a and the elastic-plate
area 430c are coupled to each other through the flat-plate shaped
coupling area 430b and, also, the tip-end portion 461 of the
balance mass member 460 is connected to the center flat-plate
portion 431 with the tip-end portion 461 interposed between the
pair of flange portions 435, it is possible to easily perform the
process for bending the magnetic head suspension 4A at the coupling
area 430b, thereby facilitating the operations for adjusting the
position of the center line of the twisting mode of the magnetic
head suspension 4A with respect to the apex of the dimple 31.
[0287] That is, even in the event of the occurrence of vibrations
of the magnetic head suspension 4A in a twisting mode, when the
center line of the vibrations in the twisting mode passes through
the apex of the dimple 31, it is possible to effectively prevent
the deviation of the position of the magnetic head slider 100 due
to the vibrations in the aforementioned twisting mode.
[0288] The positioning of the center line of the twisting mode can
be performed by applying a bending process to the load beam portion
430 and the balance mass member 460 at a position closer to the
tip-end side of the suspension than the load bending portion
20.
[0289] To cope with this point, in the present embodiment, the
flange area 430a and the elastic-plate area 430c are coupled to
each other through the flat-plate shaped coupling area 430b, as
described above. This enables performing the process for bending
the magnetic head suspension 4A at the coupling area 430b which
does not have the flange portion 435, thereby enabling the bending
process with higher accuracy.
[0290] More preferably, as illustrated in FIG. 28, the coupling
area 430b is formed to have a width smaller than that of the
base-end portion of the flange area 430a.
[0291] With this structure, it is possible to perform more easily
the aforementioned bending process on the coupling area 430b.
[0292] More preferably, as illustrated in FIG. 29, the balance mass
member 460 has a tip-end-side bending portion 461a at the portion
of the tip-end portion 461 which corresponds to the coupling area
430b.
[0293] The tip-end-side bending portion 461a is structured to have
a thickness smaller than those of the other areas.
[0294] With this structure, it is possible to easily perform the
bending process on the balance mass member 460 and the load beam
portion 430 at the coupling area 430b, at a state where the balance
mass member 460 is connected to the load beam portion 430.
[0295] The tip-end-side bending portion 461a can be formed to be a
groove having a depth equal to 1/2 to 3/4 of the thickness of the
aforementioned balance mass member along the widthwise direction,
for example, as illustrated in FIG. 29.
[0296] The groove can be formed, with preferable controllability,
by etching the portion of the balance mass member 460 corresponding
to the tip-end-side bending portion 461a from a single side
thereof.
Fifth Embodiment
[0297] Hereinafter, still another embodiment of the magnetic head
suspension according to the present invention will be described,
with reference to the attached drawings.
[0298] FIGS. 31A and 31B illustrate a top view and a bottom view of
the magnetic head suspension 5A according to the present
embodiment, respectively.
[0299] Further, FIG. 32 illustrates a partial side view of the
magnetic head suspension 5A.
[0300] FIGS. 32A and 32B illustrate the magnetic head suspension 5A
in a state before it is mounted to a data storage device and in a
state where it is operated after being mounted to the data storage
device.
[0301] Further, FIG. 33 illustrates a perspective view illustrating
the magnetic head suspension 5A in a state where it is operated
after being mounted to the data storage device, from the
disk-surface side.
[0302] Further, in the drawings, the same components as those of
the first to fourth embodiment are designated by the same reference
characters and will not be described in detail.
[0303] The magnetic head suspension 5A according to the present
embodiment includes an elastic plate 550, instead of the elastic
plate 450 in the magnetic head suspension 4A according to the
fourth embodiment.
[0304] FIG. 34 illustrates a perspective view illustrating the
elastic plate 550, from the disk-surface side.
[0305] The elastic plate 550 includes the first and second
connected areas which are connected to the pair of supporting
pieces 11, and a center area 52 extending between the first and
second connected areas 51a and 51b. The center area 52 includes the
center connected portion 52c which is connected to the balance mass
member 460, the first extending portion 52a extending between the
center connected portion 52c and the first connected area 51a, and
the second extending portion 52b extending between the center
connected portion 52c and the second connected area 51b.
[0306] The elastic plate 550 is different from the elastic plates
50 and 450 according to the respective embodiments, in that the
center connected portion 52c has the following structures.
[0307] That is, in the present embodiment, as illustrated in FIG.
34, the center connected portion 52c includes a tip-end-side
flat-surface portion 551 which is positioned on a tip-end side and
is connected to the center portion 462 of the balance mass member
460 at an attitude parallel to the center portion 462, a center
flat-surface portion 552 which is extended from the tip-end-side
flat-surface portion 551 toward the base-end side of the suspension
and which is inclined with respect to the tip-end-side flat-surface
portion 551 such that it gradually separates from the center
portion 462 of the balance mass member 460 with increasing distance
from the tip-end side toward the base-end side and to which the
first and second extending portions 52a and 52b are connected, and
a base-end-side flat-surface portion 553 which is extended toward
the base-end side of the suspension from the center flat-surface
portion 552 with a bending portion 554 interposed therebetween and
is connected to the center portion 462 of the balance mass member
460 at an attitude parallel to the center portion 462.
[0308] The elastic plate 550 is structured such that, in a state
before the magnetic head suspension 5A is mounted to a data storage
device, the center flat-surface portion 552 is positioned within
the same plane as the plane in which there exist the first and
second extending portions 52a and 52b and the first and second
connected areas 51a and 51b and, in a state where the magnetic head
suspension 5A is operated after being mounted to the data storage
device, the first and second extending portions 52a and 52b are
twisted, thus generating the load.
[0309] With the magnetic head suspension 5A including the elastic
plate 550 having the aforementioned structure, it is possible to
generate the load in a state where it is operated after being
mounted to the data storage device, without performing a process
for twisting the elastic plate 550 before it is mounted to the data
storage device. This can reduce the number of processes, thus
reducing the cost, and also enables stably controlling the
load.
[0310] That is, in the magnetic head suspension 4A according to the
fourth embodiment, before it is mounted to a data storage device,
the elastic plate 450 is subjected to a twisting process such that
the tip-end side of the load beam portion 430 comes close to the
disk surface and, also, in a state where it is operated, the
elastic plate 450 is twisted back due to the air pressure, thereby
generating the load.
[0311] On the contrary, in the magnetic head suspension 5A
according to the present embodiment, in a state before it is
mounted to a data storage device, the load beam 30 is inclined with
respect to the supporting portion 10 by an angle corresponding to
the angle of the inclination of the center flat-surface portion 552
with respect to the tip-end-side flat-surface portion 551 such that
the tip-end side of the load beam portion 30 comes close to the
disk surface, while the elastic plate 550 is not twisted, and,
also, in a state where it is operated after being mounted to the
data storage device, the tip-end side of the load beam portion 30
is pushed upwardly by the air pressure, which causes the first and
second extending portions 52a and 52b to be twisted, thereby
generating the load.
[0312] This can eliminate the process for twisting the elastic
plate 550 and also can stabilize the load, in comparison with the
structures in which the elastic plate is twisted back to generate
the load.
[0313] Although, in the present embodiment, the elastic plate 550
is formed as a member separated from the load beam portion 30, the
elastic plate 550 and the load beam portion 30 can be integrally
formed from a single member, as in the fourth embodiment.
[0314] Further, although, in the present embodiment, there has been
exemplified the structure which provides the elastic plate 550 in
the magnetic head suspension 4A according to the fourth embodiment,
the elastic plate 550 can also be applied to the magnetic head
suspension 1A according to the first embodiment, as a matter of
cause.
[0315] In the case where the elastic plate 550 is applied to the
magnetic head suspension 1A according to the first embodiment, the
tip-end-side flat-surface portion 551 is connected to the member
forming the load beam portion 30 at an attitude parallel thereto,
the center flat-surface portion 552 is inclined with respect to the
tip-end-side flat-surface portion 551 such that it gradually
separates from the member forming the load beam portion 30 with
increasing distance from the tip-end side toward the base-end side,
and the base-end-side flat-surface portion 553 is extended from the
center flat-surface portion 552 toward the base-end side of the
suspension through the bending portion 554 and is connected to the
member forming the load beam portion 30.
Sixth Embodiment
[0316] Hereinafter, still another embodiment of the magnetic head
suspension according to the present invention will be described,
with reference to the attached drawings.
[0317] FIGS. 35A and 35B illustrate a top view and a bottom view of
the magnetic head suspension 6A according to the embodiment,
respectively.
[0318] Further, in the drawings, the same components as those of
the first to fifth embodiments are designated by the same reference
characters and will not be described in detail.
[0319] In the respective embodiments explained above, the pair of
supporting pieces 11 have a constant width over the entire area in
the longitudinal direction from the base-end side to the tip-end
side.
[0320] On the contrary, as illustrated in FIG. 35, the magnetic
head suspension 6A according to the present embodiment includes a
pair of supporting pieces 611 having base-end portions 611a and
tip-end portions 611b to which the elastic plate 50 is connected,
wherein the base-end portions 611a have widths greater than those
of the tip-end portions 611b.
[0321] That is, the magnetic head suspension 6A includes a
supporting portion 610, instead of the supporting portion 10 in the
magnetic head suspension 1A according to the first embodiment.
[0322] The supporting portion 610 includes the pair of supporting
pieces 611 extending from its opposite sides in the widthwise
direction of the magnetic head suspension 6A toward the tip-end
side of the suspension, and a concave portion 12 which is defined
by the pair of supporting pieces 611 to be opened toward the
tip-end side of the suspension, as illustrated in FIG. 35.
[0323] Further, the pair of supporting pieces 611 includes the
base-end portions 611a positioned on the base-end side of the
suspension, and the tip-end portions 611b which are positioned more
proximally to the tip-end side of the suspension than the base-end
portion 611a and to which the elastic plate 50 is connected,
wherein the base-end portions 611a have widths greater than those
of the tip-end portions 611b.
[0324] With the magnetic head suspension 6A having the
aforementioned structure, it is possible to raise the resonance
frequency of the supporting portion 610 in the twisting mode, out
of the vibration modes which can occur in the magnetic head
suspension, thus improving the positioning accuracy in moving the
magnetic head slider 100 to a desired track.
[0325] Further, although, in the present embodiment, there has been
exemplified the structure which provides the pair of supporting
pieces 611 in the magnetic head suspension 1A according to the
first embodiment, the pair of supporting pieces 611 can also be
applied to the magnetic head suspensions 2A to 5A according to the
other embodiments, as a matter of cause.
[0326] This specification is by no means intended to restrict the
present invention to the preferred embodiment and the modified
embodiment set forth therein. Various modifications to the
suspension for supporting the magnetic head slider may be made by
those skilled in the art without departing from the spirit and
scope of the present invention as defined in the appended
claims.
* * * * *