U.S. patent application number 15/281264 was filed with the patent office on 2018-04-05 for active fiber composite data storage device suspension.
This patent application is currently assigned to Seagate Technology LLC. The applicant listed for this patent is Seagate Technology LLC. Invention is credited to Vijay Kumar, Razman Zambri.
Application Number | 20180096701 15/281264 |
Document ID | / |
Family ID | 61758873 |
Filed Date | 2018-04-05 |
United States Patent
Application |
20180096701 |
Kind Code |
A1 |
Kumar; Vijay ; et
al. |
April 5, 2018 |
ACTIVE FIBER COMPOSITE DATA STORAGE DEVICE SUSPENSION
Abstract
A data storage device may employ a suspension that positions a
transducing head proximal a data storage medium. The suspension can
consist of an active fiber composite that spans a portion of a
loadbeam. The active fiber composite can be configured with at
least one active fiber contacting a supporting layer.
Inventors: |
Kumar; Vijay; (Edina,
MN) ; Zambri; Razman; (Eden Prairie, MN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Seagate Technology LLC |
Cupertino |
CA |
US |
|
|
Assignee: |
Seagate Technology LLC
|
Family ID: |
61758873 |
Appl. No.: |
15/281264 |
Filed: |
September 30, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G11B 5/5552 20130101;
G11B 5/4853 20130101; G11B 5/4833 20130101; G11B 5/483 20150901;
G11B 5/6058 20130101 |
International
Class: |
G11B 5/48 20060101
G11B005/48 |
Claims
1. An apparatus comprising a data storage device having a
suspension positioning a transducing head proximal a data storage
medium, the suspension comprising an active fiber composite
spanning a portion of a loadbeam, the active fiber composite
comprising a first active fiber contacting, and separated from a
second active fiber of the active fiber composite by, a
non-conductive supporting layer, the first active fiber and second
active fiber each separated from an electrode of the active fiber
composite by the supporting layer.
2. The apparatus of claim 1, wherein the non-conductive supporting
layer surrounds the first active fiber.
3. The apparatus of claim 1, wherein the active fiber composite
continuously contacts a top surface of the loadbeam, the top
surface opposite a bottom surface that contacts a gimbal, the
gimbal supporting the transducing head.
4. The apparatus of claim 1, wherein the first active fiber
comprises a piezoelectric transducer material.
5. (canceled)
6. The apparatus of claim 1, wherein the first active fiber has a
longitudinal axis aligned parallel with a longitudinal axis of the
active fiber composite.
7. The apparatus of claim 1, wherein the active fiber composite has
a greater thickness than the loadbeam.
8. The apparatus of claim 1, wherein the loadbeam is connected to a
baseplate via at least one microactuator.
9. An apparatus comprising a data storage device having a
suspension positioning a transducing head proximal a data storage
medium, the suspension comprising an active fiber composite
spanning a portion of a loadbeam, the active fiber composite
comprising a first and second active fibers suspended between a
first electrode and a second electrode, the first active fiber
separated from the second active fiber by contacting a supporting
layer, the first and second active fibers each separated from the
first and second electrodes by the supporting layer.
10. The apparatus of claim 9, wherein the first and second
electrodes are respectively positioned on separate surfaces of the
active fiber composite.
11. The apparatus of claim 9, wherein the first electrode is
separated from a third electrode on a common surface of the active
fiber composite.
12. The apparatus of claim 9, wherein the first and second
electrodes are electrically independent and connected to different
ports of a controller.
13. The apparatus of claim 9, wherein the first and second active
fibers are each electrically conductive and selectable.
14. The apparatus of claim 9, wherein the first electrode comprises
a positive lead and a negative lead.
15. The apparatus of claim 14, wherein the positive lead of the
first electrode comprises at least one positive finger separated
from at least one negative finger on a common surface of the active
fiber composite.
16. The apparatus of claim 9, wherein the active fiber composite
spans an aperture in the loadbeam.
17. A method comprising: positioning a transducing head proximal a
data storage medium with a suspension of a data storage device, the
suspension comprising an active fiber composite spanning a portion
of a loadbeam, the active fiber composite comprising a first active
fiber and a second active fiber, the first active fiber physically
separated from the second active fiber, each active fiber
contacting a non-conductive supporting layer, each active fiber
separated from an electrode of the active fiber composite by the
supporting layer; activating at least one electrode of the active
fiber composite to manipulate a position of the transducing head
relative to the data storage medium; and sensing a position of the
suspension with the active fiber composite while the at least one
electrode is activated.
18. The method of claim 17, wherein the transducing head is
manipulated to decrease an air bearing size between the transducing
head and the data storage medium.
19. The method of claim 17, wherein the transducing head is
manipulated to rotate the loadbeam and move the transducing head
from a first track of the data storage medium to a different second
track of the data storage medium.
20. The method of claim 17, wherein motion of the transducing head
is sensed by a controller via signals received from the active
fiber composite.
Description
SUMMARY
[0001] A data storage device, in some embodiments, has a data
storage device with a suspension that positions a transducing head
proximal a data storage medium. The suspension consists of an
active fiber composite that spans a portion of a loadbeam and is
configured with at least one active fiber contacting a supporting
layer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0002] FIG. 1 is a block representation of an example data storage
system arranged in accordance with various embodiments.
[0003] FIGS. 2A and 2B respectively show portions of an example
head-gimbal assembly capable of being used in the data storage
system of FIG. 1.
[0004] FIG. 3 depicts a line representation of a portion of an
example active fiber composite that may be employed in the data
storage system of FIG. 1.
[0005] FIGS. 4A-4C respectively are side view line representations
of example active fiber composites constructed and operated in
accordance with various embodiments.
[0006] FIG. 5 conveys a top view line representation of a portion
of an example head-gimbal assembly capable of being utilized in the
data storage system of FIG. 1.
[0007] FIG. 6 provides a flowchart for an example active fiber
control routine performed in accordance with various
embodiments.
DETAILED DESCRIPTION
[0008] In data storage devices with rotating media, such as hard
disk drives and hybrid drives that employ rotating and solid-state
memories, a suspension enables data reading and writing operations.
Various embodiments are generally directed to a data storage system
that employs a suspension configured with an active fiber composite
that improve the material properties of the suspension. The use of
one or more active fiber composites provides cost benefits and
additional data sensing capabilities that are unavailable with
conventional data storage suspensions.
[0009] FIG. 1 is a block representation of an example data storage
system 100 in which embodiments of the present disclosure can be
employed. The data storage system 100 can employ one or more data
storage devices that each have a controller 102, such as a
microcontroller, microprocessor, or application specific integrated
circuit (ASIC), and a local memory module 104. The controller 102
can be a fixed or programmable processor based control circuit that
provides top level communication and control functions as the
device interfaces with one or more remote host devices 106 via a
wired and/or wireless network 108. Data from a local or remote host
device is transferred for storage into the memory 104, which can
take a variety of volatile and/or non-volatile configurations, such
as hard disk drive (HDD), hybrid, and solid-state non-volatile
memories
[0010] Various embodiments arrange at least one magnetic rotatable
data storage medium 110 into a HDD where the medium 110 is rotated
at a predetermined speed by a spindle motor 112 at a constant high
velocity about a central axis 114. A plurality of concentric data
tracks, such as track 116, are defined on the various disk
recording surfaces and accessed by a corresponding transducing head
118 that is positioned over a selected tack by a rotary
micro-actuator assembly 120 that pivots about a central actuator
axis 122 in response to a voice coil motor 124. In other HDD
designs, the controller 102 and micro-actuator 120 can be
dual-stage, or more generally multi-stage. For example, a primary
stage can be a voice-coil motor actuated servo system that actuates
the entire head-stack assembly in which the head-gimbal assembly
resides while a second stage could be a micro-actuator system that
has a wider and larger maximum frequency response. Such multi-stage
micro-actuation systems afford increased servo bandwidth and
improved tracking performance resulting in increased recording
areal density.
[0011] Controlled application of current to the voice coil motor
124 induces controlled rotation of the micro-actuator 120 about
axis 122 and radial movement of the head(s) 118 across the disk
surfaces. A preamplifier/driver circuit (preamp) may operably be
connected between the controller 102 and the transducing head 118
to enable data transfers between a host device and the disks 110.
During a data write operation, a data writer 126 of the transducing
head 118 forms of a sequence of magnetic flux transitions in a
recording layer of the associated disc 110. During a subsequent
read operation, a data reader 130 is aligned with a corresponding
track 116 on which the data to be retrieved is resident.
[0012] As shown, the transducing head 118 can be supported by a
loadbeam 132 portion of the micro-actuator 120, which acts to
suspend and separate the data writer 128 and reader 130 above the
data storage medium 110 by an air bearing 134. It is noted that the
transducing head 118 and loadbeam 132 can be collectively referred
to as a head-gimbal assembly and may comprise any number of
components, such as a dimple, slider, and flex circuit, that
provide sophisticated suspension and actuation with respect to the
underlying data storage medium 110. FIGS. 2A and 2B respectively
illustrate top and side view line representations of portions of an
example head-gimbal assembly 140 that may be utilized in the data
storage system 100 of FIG. 1.
[0013] In the top view of FIG. 2A, a baseplate 142 is attached to a
loadbeam 144. It is contemplated that the loadbeam 144 continuously
extends from the baseplate 142 to a slider region 146 where a data
reader 148 and writer 150 are resident, as shown in FIG. 2B. In
some embodiments, an active fiber composite 152 spans a gap 154 in
the loadbeam 144, as represented between segmented lines, while
other embodiments place the active fiber composite 152 atop the
loadbeam 144. The active fiber composite 152 can consist of at
least pair of interdigitized electrodes 156 that are physically
separated, but can be selectively be activated, and sensed, to
activate and monitor the physical configuration of at least a
portion of the active fiber composite 152.
[0014] The active fiber composite 152 may be complemented by one or
more microactuators 158 that may be any material and/or mechanism
for moving the loadbeam 144. The size and position of the active
fiber composite 152 can be customized so that a flex circuit 160
and gimbal 162 can be incorporated into the head-gimbal assembly
140 without adding weight or changing the center of gravity of the
loadbeam 144, when compared to a continuous metal loadbeam
alone.
[0015] FIG. 2B shows how the baseplate can have a thickness 164,
such as 150 .mu.m, while the loadbeam 144 has a smaller thickness
166, such as 30 .mu.M, and the active fiber composite 152 has a
greater thickness 168, such as 200-300 .mu.m. When the active fiber
composite 152 spans an aperture, gap, or void 154 in the loadbeam
144 with a zero thickness, there will areas of overlap between the
composite 152 and loadbeam 144 to allow for adhesion, such as via
laser welding, fastener(s), or an adhesive. To clarify, the active
fiber composite 152 may provide the only physical connection
between two, otherwise separate loadbeam portions, may span a lack
of loadbeam material, or may continuously rest atop the loadbeam
144.
[0016] It is noted that the loadbeam 144, portions of the gimbal
160, and the baseplate 142 may individually be constructed as a
single sheet of material, such as formed or stamped stainless
steel. Such configuration can be imprecise, particularly in high
data density HDD where data tracks are potentially more narrow and
closer together. By replacing some, or all, of the loadbeam 144
with the active fiber composite 152, the actuation sensitivity and
resolution of the head-gimbal assembly 140 can be optimized for
high data density data storage environments.
[0017] FIG. 3 is a cross-sectional line representation of a portion
of an active fiber composite 170 that can be used for portions of
at least loadbeam, baseplate, and gimbal of a head-gimbal assembly
in accordance with various embodiments. The active fiber composite
170 has at least one active fiber 172 that can be any electrically
selectable material, such as perovskite that exhibits piezoelectric
effects (PZT). A non-conductive material 174, such as epoxy,
supports each active fiber 172. The supporting material 174 and
active fiber(s) 172 can respectively be arranged with any
cross-sectional shape and size, such as rectangular, square,
circular, semi-circular, and rhomboid, to allow at least one pair
of electrodes to be positioned to selectively engage the active
fiber(s) 172 to induce and/or sense a physical configuration of the
active fiber composite 170.
[0018] In the non-limiting embodiment of FIG. 3, the supporting
material 174 has a rectangular shape on which a first 176 and
second 178 pair of electrodes are printed. Each electrode pair 176
and 178 consists of leads 180 having different magnetic polarities,
which induces, and senses, movement of the supporting material 174.
In contrast to a microactuator, such as element 156 of FIG. 2A, the
active fiber composite 170 utilizes the active fiber(s) 172 to
simultaneously sense the physical configuration of the supporting
material 174 while the electrode pairs 176 and 178 are activated to
induce physical deformation of the supporting material 174. As
such, the active fiber composite can be used for very sensitive
active damping and vibration suppression that is not possible with
microactuators that lack the combination of electrodes and active
fibers.
[0019] It is noted that the respective electrode pairs 176 and 178
are positioned on opposite surfaces of the supporting material 174.
The position and patterning of the respective leads 180 can be
optimized in combination with the configuration of the active
fiber(s) 172 to utilize the d.sub.33 piezoelectric coefficient of
the active fiber(s) 172. The ability to customize the configuration
of the electrode pairs 176 and 178 with respect to the active
fiber(s) 172 can provide an improved microactuator with increased
sensitivity and resolution compared to when a PZT material is
imprinted with electrodes.
[0020] FIGS. 4A, 4B, and 4C respectively display cross-sectional
line representations of different active fiber composites 190, 200,
and 210 that can individually, and collectively, be employed in a
head-gimbal assembly in accordance with assorted embodiments. The
active fiber composite 190 of FIG. 4A shows how an active fiber 192
is oriented along a longitudinal axis of the support material 194
with a magnetic pole direction shown by arrow 196. Electrode leads
198 are organized as an electrode pair positioned on opposite
surfaces with a portion of the leads 198 being carrying a positive
polarity, as illustrated by an arrow coming out of the page along
the X axis, and another portion of the leads 198 carrying a
negative polarity, as illustrated by an arrow going into the page
along the X axis.
[0021] With the leads 198 being placed on separate surfaces of the
support material 194 and opposite sides of the active fiber 192,
the active fiber composite 190 can be characterized as a
double-sided composite. The respective electrode leads 198 may be
shorted by using electrical patterns on the side of the support
material 194, which can electrically isolate the leads 198 from
other electrical traces of a gimbal assembly. In FIG. 4B, the
active fiber composite 200 has electrode leads 198 patterned on a
single side of the support material 194 with the active fiber 192
oriented and poled in the same manner as composite 190.
[0022] The active fiber composite 210 of FIG. 4C shows how the
active fiber 192 is oriented with the longitudinal axis parallel to
the Y axis, but is magnetically poled parallel to the Z axis, which
is also the thickness direction of the support material 194. While
interdigitized electrode leads 198 may be utilized in the active
fiber composite 210, some embodiments pattern opposite top 212 and
bottom 214 surfaces of the support material 194 as single electrode
layers 216 that continuously extend to contact a majority of the
surface area of the top 212 or bottom 214 surfaces. It is
contemplated that the respective electrode layers can be
selectively activated with either positive or negative polarity to
engage with the active fiber 192.
[0023] A first electrode layer may be connected to the loadbeam of
a head-gimbal assembly via a conductive adhesive that may be used
for an interconnect while the opposite electrode layer is directly
connected to an electrical ground. The opposite polarities of the
respective electrode layers and/or leads 198 can provide rotary
motion of the support material 194 about the X, Y, or Z axes
depending on the orientation of the electrodes.
[0024] FIG. 5 depicts a top view line representation of an example
head-gimbal assembly 220 portion of a data storage system
configured in accordance with various embodiments so that an active
fiber composite 222 replaces a portion of a loadbeam 224. The
active fiber composite 222 provides the only physical
interconnection between a mount 226 and gimbal 228 portions of the
loadbeam 224. The mount 226 and gimbal 228 portions may be rigid,
flexible, or semi-rigid to allow the active fiber composite 222 to
concurrently induce a selected physical position of the gimbal 230
while sensing and sending the physical configuration of the
composite 222 to a host, such as controller 102 of FIG. 1.
[0025] As shown, the active fiber composite 222 has first 232 and
second 234 electrode regions that each have a pair of electrode
leads polarized in opposite directions. The respective electrode
regions 232 and 234 have different sizes and positions that can be
complemented by one or more electrode layers, or electrode pairs,
on the opposite bottom side of the active fiber composite 222.
[0026] By independently positioning and electrically connecting
electrodes in combination with tuning the position and pole
orientation of the active fiber(s), any desired motion can be
induced and sensed by the active fiber composite 222. For example,
if a reaction force in a downtrack direction (X axis) is desired,
the baseplate 236 can be constructed, partially or wholly, of an
active fiber composite material with a PZT material active fiber
oriented such that it is parallel to the longitudinal direction of
the suspension (Y axis) to induce a d.sub.31 mode response from the
active fiber(s) that can be used for sensing force and position of
the active fiber composite as well as the position of the gimbal
230. Similarly, if transverse force is to be induced and/or sensed,
the active fiber of an active fiber composite is oriented parallel
to an offtrack direction (Y axis).
[0027] Since the direction of the active fiber(s) of an active
fiber composite are set during fabrication, active fibers can be
proactively oriented in different, orthogonal directions in the
support material to allow for movement inducement and sensing in
downtrack and offtrack directions. In some embodiments, the active
fiber(s) of an active fiber composite is used for sensing loadbeam
224 and gimbal 230 motion, which can be utilized for active damping
by tuning the input signal to the active fiber(s) and/or the
composite electrodes.
[0028] It is noted that the multiple electrode regions 232 and 234
can be characterized as a multizone configuration that enables
multi-mode control. That is, by using independent electrode
patterning for the respective regions 232 and 234, the response and
sensing of from the different zones of the support material can be
captured independently. With a multizone electrode configuration,
the various electrodes can be connected independently, such as with
extra pin-outs, or can be connected in series so that the response
from each electrode can be isolated by a local and/or remote
controller during post-processing of active fiber composite
signals.
[0029] FIG. 6 provides an example active fiber control routine 250
that may be carried out by a head-gimbal assembly configured in
accordance with various embodiments described in FIGS. 1-5. The
routine 250 begins by constructing a head-gimbal assembly in step
252 with at least one active fiber composite having at least two
electrodes. Each active fiber composite will have one or more
active fiber(s) surrounded by a non-conductive support
material.
[0030] Step 252 tunes the orientation of the active fiber(s),
number of electrodes, position of the electrodes, and position of
the active fiber composite to induce customized gimbal movement in
step 254 and suspension position sensing in step 256 by activating
at least one electrode and active fiber in step 258. The concurrent
execution of steps 254 and 256 is not required and the respective
steps can be performed independently, if desired. The activation of
a single electrode or electrode pair may be complemented by
actuation or sensing from one or more additional electrodes.
[0031] Decision 260 evaluates and determines if a supplemental
electrode, or electrode pair, is to be activated. If multi-mode
activation is chosen from decision 260, step 262 proceeds to
activate at least one secondary electrode, which may be physically
separate from the electrode(s) activated in step 258. At the
conclusion of step 262, or in the event no additional electrodes
are to be activated, step 264 then utilizes the concurrent active
fiber composite induced movement and position sensing to actively
control vibration and dampen gimbal movement, which can optimize
the performance of the head-gimbal assembly. The various steps and
decision of routine 250 are not required or limiting and additional
aspects can be added just as existing aspects can be changed or
removed.
[0032] Through the various embodiments of the present disclosure,
an active fiber composite can supplement or replace portions of a
head-gimbal assembly to allow simultaneous inducement of movement
and sensing of position. The replacement of portions of a
baseplate, loadbeam, or both with one or more active fiber
composites improves the material properties and behavior of a data
storage device suspension while maintaining similar mass and
stiffness as suspensions constructed with rigid materials, like
stainless steel. The ability to supplement an active fiber
composite with a microactuator and/or a secondary active fiber
composite provides multi-mode suspension actuation that can
increase the sensitivity and precision in positioning a data
transducer over a data track and data bit.
[0033] It is to be understood that even though numerous
characteristics and configurations of various embodiments of the
present disclosure have been set forth in the foregoing
description, together with details of the structure and function of
various embodiments, this detailed description is illustrative
only, and changes may be made in detail, especially in matters of
structure and arrangements of parts within the principles of the
present disclosure to the full extent indicated by the broad
general meaning of the terms in which the appended claims are
expressed. For example, the particular elements may vary depending
on the particular application without departing from the spirit and
scope of the present technology.
* * * * *