U.S. patent application number 12/401521 was filed with the patent office on 2009-08-13 for method and mechanism of pzt micro-actuator attachment for the hard disk driver arm.
This patent application is currently assigned to SAE MAGENTICS (H.K.) LTD.. Invention is credited to Masashi SHIRAISHI, Yi Ru XIE, Ming Gao YAO.
Application Number | 20090199380 12/401521 |
Document ID | / |
Family ID | 33426285 |
Filed Date | 2009-08-13 |
United States Patent
Application |
20090199380 |
Kind Code |
A1 |
YAO; Ming Gao ; et
al. |
August 13, 2009 |
METHOD AND MECHANISM OF PZT MICRO-ACTUATOR ATTACHMENT FOR THE HARD
DISK DRIVER ARM
Abstract
A fixture with a shaped molding may hold a first micro-actuator
part and a second micro-actuator part in place for coupling while
maintaining the structure of the first micro-actuator part. The
first micro-actuator part and the second micro-actuator part may be
a frame or a strip of piezoelectric material. A vacuum nozzle
system embedded in the fixture may hold the first micro-actuator
part in place. A mobile vacuum nozzle system may hold the second
micro-actuator in place and positions the second micro-actuator
part relative to the first micro-actuator part. A camera system may
monitor the process. A dispense may apply epoxy between the first
and second micro-actuator part. An ultraviolet source may provide
ultraviolet radiation for curing.
Inventors: |
YAO; Ming Gao; (Dongguan
City, CN) ; SHIRAISHI; Masashi; (Kowloon, HK)
; XIE; Yi Ru; (Dongguan City, CN) |
Correspondence
Address: |
KENYON & KENYON LLP
RIVERPARK TOWERS, SUITE 600, 333 W. SAN CARLOS ST.
SAN JOSE
CA
95110
US
|
Assignee: |
SAE MAGENTICS (H.K.) LTD.
Shatin
HK
|
Family ID: |
33426285 |
Appl. No.: |
12/401521 |
Filed: |
March 10, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11445083 |
Jun 1, 2006 |
7501737 |
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12401521 |
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|
10658985 |
Sep 10, 2003 |
7181825 |
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11445083 |
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Current U.S.
Class: |
29/25.35 |
Current CPC
Class: |
Y10T 29/53191 20150115;
Y10T 29/49799 20150115; H01L 41/313 20130101; Y10T 29/49032
20150115; Y10T 29/42 20150115; Y10T 29/53261 20150115; Y10T
29/49027 20150115; Y10T 29/53417 20150115; Y10T 29/5313 20150115;
Y10T 29/4913 20150115; G11B 5/5552 20130101; Y10T 29/4903 20150115;
Y10T 29/49025 20150115 |
Class at
Publication: |
29/25.35 |
International
Class: |
H04R 17/00 20060101
H04R017/00 |
Foreign Application Data
Date |
Code |
Application Number |
May 12, 2003 |
CN |
PCT/CN03/00340 |
Claims
1. A method, comprising: placing a first micro-actuator part in a
molding of a fixture; coupling a second micro-actuator part to the
first micro-actuator part; and using the fixture to maintain a
structure of the first micro-actuator part and the second
micro-actuator part.
2. The method of claim 1, further comprising holding the first
micro-actuator part in place with an embedded vacuum nozzle
system.
3. The method of claim 1, further comprising positioning the second
micro-actuator part relative to the first micro-actuator part for
coupling using a first mobile vacuum nozzle system.
4. The method of claim 1, wherein the first micro-actuator part is
a micro-actuator frame.
5. The method of claim 4, wherein the micro-actuator frame is
metal.
6. The method of claim 4, wherein the molding is a shaped
protrusion that matches the interior of the first micro-actuator
frame.
7. The method of claim 4, wherein the second micro-actuator part is
a first strip of piezoelectric material.
8. The method of claim 7, further comprising positioning a second
strip of piezoelectric material with a second mobile vacuum nozzle
system.
9. The method of claim 7, further comprising holding a second strip
of piezoelectric material with the first mobile vacuum nozzle
system.
10. The method of claim 1, wherein the molding is a shaped
indentation that matches the exterior of the first micro-actuator
part, the second micro-actuator part, and a third micro-actuator
part.
11. The method of claim 10, wherein the first micro-actuator part
is a first strip of piezoelectric material and the third
micro-actuator part is a second strip of piezoelectric
material.
12. The method of claim 10, wherein the second micro-actuator part
is a micro-actuator frame.
13. The method of claim 12, wherein the micro-actuator frame is
metal.
14. The method of claim 1, further comprising maintaining the
structure of multiple frames simultaneously with multiple
moldings.
15. The method of claim 1, further comprising observing the fixture
with a camera system.
16. The method of claim 1, further comprising applying an adhesive
between the first micro-actuator part and the second micro-actuator
part.
17. The method of claim 16, further comprising curing the adhesive
is cured with ultraviolet radiation.
18. A fixture, comprising: a molding to hold a first micro-actuator
part to be coupled to a second micro-actuator part and shaped to
maintain a structure of the first micro-actuator part and the
second micro-actuator part.
19. The fixture of claim 18, further comprising an embedded vacuum
nozzle system to hold the first micro-actuator part in place.
20. The fixture of claim 18, wherein a first mobile vacuum nozzle
system positions the second micro-actuator part relative to the
first micro-actuator part for coupling.
21. The fixture of claim 18, wherein the first micro-actuator part
is a micro-actuator frame.
22. The fixture of claim 21, wherein the micro-actuator frame is
metal.
23. The fixture of claim 21, wherein the molding is a shaped
protrusion that matches the interior of the micro-actuator
frame.
24. The fixture of claim 21, wherein the second micro-actuator part
is a first strip of piezoelectric material.
25. The fixture of claim 24, wherein a second strip of
piezoelectric material is positioned with a second mobile vacuum
nozzle system.
26. The fixture of claim 24, wherein the first mobile vacuum nozzle
system holds a second strip of piezoelectric material.
27. The fixture of claim 18, wherein the molding is a shaped
indentation that matches the exterior of the first micro-actuator
part, the second micro-actuator part, and a third micro-actuator
part.
28. The fixture of claim 27, wherein the first micro-actuator part
is a first strip of piezoelectric material and the third
micro-actuator part is a second strip of piezoelectric
material.
29. The fixture of claim 27, wherein the second micro-actuator part
is a micro-actuator frame.
30. The fixture of claim 29, wherein the micro-actuator frame is
metal.
31. The fixture of claim 18, further comprising multiple moldings
capable of maintaining the structure of multiple frames
simultaneously.
32. The fixture of claim 18, wherein a camera system observes the
fixture.
33. The fixture of claim 18, wherein an adhesive applicator applies
an adhesive between the first micro-actuator part and the second
micro-actuator part.
34. The fixture of claim 33, wherein the adhesive is cured with
ultraviolet radiation.
35. A system, comprising: an embedded vacuum nozzle system to hold
a first micro-actuator part to be coupled to a second
micro-actuator part; a first mobile vacuum nozzle system positions
the second micro-actuator part relative to the first micro-actuator
part for coupling; and a molding shaped to maintain a structure of
the first micro-actuator part and the second micro-actuator
part.
36. The system of claim 35, wherein the molding is a shaped
protrusion that matches the interior of the first micro-actuator
part.
37. The system of claim 35, wherein the first micro-actuator part
is a micro-actuator frame.
38. The system of claim 37, wherein the micro-actuator frame is
metal.
39. The system of claim 37, wherein the second micro-actuator part
is a first strip of piezoelectric material.
40. The system of claim 39, further comprising a second mobile
vacuum nozzle system to position a second strip of piezoelectric
material.
41. The system of claim 39, wherein the first mobile vacuum nozzle
system holds a second strip of piezoelectric material.
42. The system of claim 35, wherein the molding is a shaped
indentation that matches the exterior of the first micro-actuator
part, the second micro-actuator part, and a third micro-actuator
part.
43. The system of claim 42, wherein the first micro-actuator part
is a first strip of piezoelectric material and the third
micro-actuator part is a second strip of piezoelectric
material.
44. The system of claim 43, wherein the second micro-actuator part
is a micro-actuator frame.
45. The system of claim 44, wherein the micro-actuator frame is
metal.
46. The system of claim 35, further comprising multiple moldings
capable of maintaining the structure of multiple frames
simultaneously.
47. The system of claim 35, further comprising a camera system to
observe the fixture.
48. The system of claim 35, further comprising an adhesive
applicator to apply an adhesive between the first micro-actuator
part and the second micro-actuator part.
49. The system of claim 48, wherein curing the adhesive is cured
with ultraviolet radiation.
Description
BACKGROUND INFORMATION
[0001] The present invention relates to magnetic hard disk drives.
More specifically, the present invention relates to a method of
assembling micro-actuators.
[0002] In the art today, different methods are utilized to improve
recording density of hard disk drives. FIG. 1 provides an
illustration of a typical disk drive. The typical disk drive has a
head gimbal assembly (HGA) configured to read from and write to a
magnetic hard disk 101. The HGA and the magnetic hard disk 101 are
mounted to the base 102 of a main board 103. The disk 101 is
rotated relative to the base 102 by a spindle motor 104. The HGA
typically includes an actuator arm 105 and a load beam 106. The HGA
supports and positions a magnetic read/write slider 107 above the
magnetic hard disk 101. The HGA is rotated relative to the base 102
along the axis of a bearing assembly 108 by a voice coil motor 109.
A relay flexible printed circuit 110 connects a board unit 111 to
the magnetic read/write slider 107.
[0003] FIGS. 2a-d provide an illustration of two embodiments of a
piezoelectric micro-actuator. FIG. 2a illustrates a micro-actuator
with a U-shaped ceramic frame configuration 201. The frame 201 may
be Zirconia. The frame 201 may have two arms 202 opposite a base
203. A slider 204 may be held by the two arms 202 at the end
opposite the base 203. A strip of piezoelectric material 205 may be
attached to each arm 202. FIG. 2b illustrates the micro-actuator as
attached to an actuator suspension 206. The micro-actuator may be
coupled to a suspension tongue 207. Traces 208, coupled along the
suspension 206, apply a voltage to the strips of piezoelectric
material 205. These voltages may cause the strips 205 to contract
and expand, moving the placement of the slider 204.
[0004] FIG. 2c illustrates an alternate version of the
micro-actuator. In this embodiment, a metallic frame 209 has a base
210 with two arms 211 perpendicular to the plane of the base 210. A
slider support 212 may hold the slider between the two arms 211. A
strip of piezoelectric material 213 is coupled to each arm 211. The
micro-actuator may then be attached to the head suspension 206 in
the same manner as the ceramic micro-actuator, as shown in FIG.
2d.
[0005] One embodiment of a method of manufacturing the metallic
frame 209 is shown in FIGS. 3a-d. The frame 209 may be stainless
steel, such as SUS304. As shown in FIG. 3a, the two arms 211 of the
metallic frame 209 may be formed using vertical forming by machine
or laser. A hole 301 may be formed on the slider support 212 to
facilitate the slider 204 mounting. The support connections 302 and
the base connections 303 may be narrowed to improve resonance. The
two strips of piezoelectric material 213 may each have at least one
contact pad 304 attached that allows the strips 213 to be
electrically coupled to a control circuit. As shown in FIG. 3b, the
strips 213 may be coupled to the arms 211 of the metallic frame
209. As shown in FIG. 3c, the slider 204 may be coupled to the
slider support 212. The slider 204 may be coupled using epoxy or
some other kind of adhesive. The epoxy may be cured using the hole
301 in the slider support 212. As shown in FIG. 3d, the
micro-actuator may then be attached to the suspension tongue
207.
[0006] FIGS. 4a-b provides an illustration in a pair of charts of
the effect of adhesive thickness on stroke and resonance. FIG. 4a
compares the stroke in micrometers to the adhesive thickness in
millimeters. In this example, stroke pertains to the amount of
deflection of the slider caused by the micro-actuator. FIG. 4b
compares the resonance frequency of the micro-actuator in kilohertz
to the adhesive thickness in millimeters. Due to the small size of
the micro-actuators and the fragile nature of the piezoelectric
material, stress fractures and distortions remain problems.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 provides an illustration of a typical disk drive.
[0008] FIGS. 2a-d provide an illustration of two embodiments of a
piezoelectric micro-actuator.
[0009] FIGS. 3a-d provide an illustration of one embodiment of a
method of manufacturing the metallic frame.
[0010] FIGS. 4a-b provide an illustration in a pair of charts of
the effect of adhesive thickness on stroke and resonance.
[0011] FIGS. 5a-e provide an illustration of one embodiment of a
method for attaching the strips of piezoelectric material to the
metallic frame.
[0012] FIG. 6 provides an illustration in a flowchart of one
embodiment of a method for using the fixture
[0013] FIGS. 7a-e provide an illustration of an alternate
embodiment of a method for attaching the strips of piezoelectric
material to multiple metallic frames.
[0014] FIGS. 8a-f provide an illustration of an alternate
embodiment of a method for attaching the strips of piezoelectric
material to the metallic frame.
[0015] FIGS. 9a-e provide an illustration of an alternate
embodiment of a method for attaching the strips of piezoelectric
material to the metallic frame.
DETAILED DESCRIPTION
[0016] A fixture with a shaped molding may hold a first
micro-actuator part and a second micro-actuator part in place for
coupling while maintaining the structure of the first
micro-actuator part. The first micro-actuator part and the second
micro-actuator part may be a frame or a strip of piezoelectric
material. A vacuum nozzle system embedded in the fixture may hold
the first micro-actuator part in place. A mobile vacuum nozzle
system may hold the second micro-actuator in place and positions
the second micro-actuator part relative to the first micro-actuator
part. A camera system may monitor the process. A dispenser may
apply epoxy between the first and second micro-actuator part. An
ultraviolet source may provide ultraviolet radiation for
curing.
[0017] FIGS. 5a-e illustrate one embodiment of a method for
attaching the strips of piezoelectric material 213 to the metallic
frame 209. As shown in FIG. 5a, the metallic frame 209 may be
placed on a fixture 501 to maintain the structure of the metallic
frame 209 while the strips of piezoelectric material 213 are added.
The fixture 501 may have a shaped indentation 502 to match the
exterior of the metallic frame 209. Alternately, the fixture 501
may have a shaped protrusion that matches the interior of the
metallic frame 209. A vacuum nozzle 503 embedded within the fixture
501 may hold the metallic frame 209 in place on the fixture 501.
The base 210 may be placed on the vacuum nozzle 503. As shown in
FIG. 5b, a strip of piezoelectric material 213 may be held aloft by
a mobile vacuum nozzle 504. The mobile vacuum nozzle 504 may be
moved in all three dimensions and is rotatable along the axis of
the nozzle 504. A camera system 505 may be used to monitor the
placement of the strip of piezoelectric material 213. A dispenser
places adhesive on the metallic frame 209. In one embodiment, the
adhesive is epoxy. As shown in FIG. 5c, the mobile vacuum nozzle
504 may place the strip of piezoelectric material 213 against the
metallic frame 209. An ultraviolet source 506 may be used to cure
the epoxy bond between the strip of piezoelectric material 213 and
the metallic frame 209. After a time delay of 3-9 seconds, the
ultraviolet source 506 is turned off and the mobile vacuum nozzle
504 is removed. In an alternate embodiment, the mobile vacuum
nozzle 504 is removed and the ultraviolet source 506 is turned off.
In an alternative embodiment illustrated in FIG. 5d, the fixture
501 may maintain the structure of multiple metallic frames 209. The
mobile vacuum nozzle 504 may place the strip of piezoelectric
material 213 against the arm 211 of the first metallic frame 209.
As shown in FIG. 5e, the ultraviolet source 506 may then cure the
epoxy bond before moving to the next metallic frame 209.
[0018] One embodiment of a method for using the fixture of FIGS.
5d-e is illustrated in the flowchart of FIG. 6. To start (Block
605), the frame 209 may be laminated (Block 610). The frame 209 may
be placed upon the fixture 501 (Block 615). The strip of
piezoelectric material 213 may be picked up by the mobile vacuum
nozzle 504 (Block 620). The location of the strip of piezoelectric
material 213 may be confirmed and then adjustments are made as
necessary (Block 625). Epoxy may be added to the frame 209 (Block
630). The strip of piezoelectric material 213 may be attached to
the frame 209 (Block 635). The epoxy is cured by ultraviolet
radiation (Block 640). A camera system 505 may confirm if further
frames 209 are on the fixture 501 (Block 645). If further frames
209 are not on the fixture 501, the fixture 501 is exchanged (Block
650). Otherwise, the next frame is worked on (Block 610).
[0019] FIGS. 7a-e illustrate an alternate embodiment of a method
for attaching the strips of piezoelectric material 213 to multiple
metallic frames 209. As shown in FIG. 7a, a first metallic frame
209 is placed on a first fixture 701 and a second metallic frame
209 is placed on the second fixture 702 to maintain the structure
of the metallic frames 209 while the strips of piezoelectric
material 213 are added. The first fixture 701 and the second
fixture 702 may have shaped indentations 703 to match the exterior
of the metallic frame 209. Alternately, the first fixture 701 and
the second fixture 702 may have a shaped protrusion that matches
the interior of the metallic frame 209. A first vacuum nozzle 704
embedded within the first fixture 701 may hold a metallic frame 209
in place on the first fixture 701 and a second vacuum nozzle 705
embedded within the first fixture 702 may hold a metallic frame 209
in place on the second fixture 702. As shown in FIG. 7b, two strips
of piezoelectric material 213 may be held aloft by a mobile dual
vacuum nozzle 706. The mobile dual vacuum nozzle 706 may be moved
in all three dimensions. A camera system 505 may be used to monitor
the placement of the strip of piezoelectric material 213. A
dispenser places adhesive on the metallic frame 209. In one
embodiment, the adhesive is epoxy. As shown in FIG. 7c, the mobile
dual vacuum nozzle 706 may place the strips of piezoelectric
material 213 against the metallic frames 209. A first ultraviolet
source 707 and a second ultraviolet source 708 may be used to cure
the epoxy bonds between the strips of piezoelectric material 213
and the metallic frames 209. After a time delay of 3-9 seconds, the
mobile dual vacuum nozzle 706 is removed and the first ultraviolet
source 707 and the second ultraviolet source 708 are turned off. In
an alternative embodiment illustrated in FIG. 7d, the first fixture
701 and the second fixture 702 may each maintain the structure of
multiple metallic frames 209. The mobile dual vacuum nozzle 706 may
place the strip of piezoelectric material 213 against the arm 211
of a first and second metallic frame 209. As shown in FIG. 7e, the
first ultraviolet source 707 and the second ultraviolet source 708
may then cure the epoxy bond before moving to the next two metallic
frames 209.
[0020] FIGS. 8a-f illustrate an alternate embodiment of a method
for attaching the strips of piezoelectric material 213 to the
metallic frame 209. As shown in FIG. 8a, the two strips of
piezoelectric material 213 may be placed on the fixture 801. The
fixture 801 may have a shaped indentation 802 to match the exterior
of the metallic frame 209 and the two strips of piezoelectric
material 213. A vacuum nozzle system 803 embedded within the
fixture 501 may hold the two strips of piezoelectric material 213
in place on the fixture 801. As shown in FIG. 8b, a frame 209 may
be held aloft by a mobile vacuum nozzle 804, with the arms oriented
downward. The mobile vacuum nozzle 804 may be moved in all three
dimensions and is rotatable along the axis of the nozzle 804. A
camera system 805 may be used to monitor the placement of the frame
209. As shown in FIG. 8c, a first dispenser 806 and a second
dispenser 807 may place adhesive on the metallic frame 209. In one
embodiment, the adhesive is epoxy. As shown in FIG. 8d, the mobile
vacuum nozzle 804 may move about to spread the epoxy evenly on the
frame 209. As shown in FIG. 8e, the mobile vacuum nozzle 804 may
place the metallic frame 209 against the strip of piezoelectric
material 213. As shown in FIG. 8f, a first ultraviolet source 808
and a second ultraviolet source 809 may be used to cure the epoxy
bond between the strip of piezoelectric material 213 and the
metallic frame 209. After a time delay of 3-9 seconds, the mobile
vacuum nozzle 804 may be removed after the first ultraviolet source
808 and the second ultraviolet source 809 are turned off. In an
alternate embodiment, the mobile vacuum nozzle 804 may be removed
before the first ultraviolet source 808 and the second ultraviolet
source 809 are turned off.
[0021] FIGS. 9a-e illustrate an alternate embodiment of a method
for attaching the strips of piezoelectric material 213 to the
metallic frame 209. As shown in FIG. 9a, the two strips of
piezoelectric material 213 may be placed on the fixture 801. The
fixture 801 may have a shaped indentation 802 to match the exterior
of the metallic frame 209 and the two strips of piezoelectric
material 213. A vacuum nozzle system 803 embedded within the
fixture 501 may hold the two strips of piezoelectric material 213
in place on the fixture 801. A frame 209 may be held aloft by a
mobile vacuum nozzle 804, with the arms oriented upward. The mobile
vacuum nozzle 804 may be moved in all three dimensions and is
rotatable along the axis of the nozzle 804. A camera system 805 may
be used to monitor the placement of the frame 209. As shown in FIG.
9b, a first dispenser 806 and a second dispenser 807 may place
adhesive on the metallic frame 209. In one embodiment, the adhesive
is epoxy. As shown in FIG. 9c, the mobile vacuum nozzle 804 may
move about to spread the epoxy evenly on the frame 209. As shown in
FIG. 9d, the mobile vacuum nozzle 804 may place the metallic frame
209 against the strip of piezoelectric material 213. As shown in
FIG. 9e, a first ultraviolet source 808 and a second ultraviolet
source 809 may be used to cure the epoxy bond between the strip of
piezoelectric material 213 and the metallic frame 209. After a time
delay of 3-9 seconds, the mobile vacuum nozzle 804 may be removed
after the first ultraviolet source 808 and the second ultraviolet
809 may be turned off. In an alternate embodiment, the mobile
vacuum nozzle 804 may be removed before the first ultraviolet
source 808 and the second ultraviolet source 809 are turned
off.
[0022] Although several embodiments are specifically illustrated
and described herein, it will be appreciated that modifications and
variations of the present invention are covered by the above
teachings and within the purview of the appended claims without
departing from the spirit and intended scope of the invention.
* * * * *