U.S. patent application number 11/397162 was filed with the patent office on 2006-08-03 for system and method for improving the electrical connection of a hard drive relay flexible circuit assembly to an hga flexure cable.
Invention is credited to Can Hua Chen, Yiu Sing Ho, Guo Hong Lu, Jeffery L. Wang, Liu Jun Zhang.
Application Number | 20060168796 11/397162 |
Document ID | / |
Family ID | 33569591 |
Filed Date | 2006-08-03 |
United States Patent
Application |
20060168796 |
Kind Code |
A1 |
Zhang; Liu Jun ; et
al. |
August 3, 2006 |
System and method for improving the electrical connection of a hard
drive relay flexible circuit assembly to an HGA flexure cable
Abstract
A system and method are disclosed for improving the electrical
connection of a hard drive relay flexible circuit assembly to a
head-gimbal assembly (HGA) flexure cable. In one embodiment, a
flexible circuit assembly is attached to a hard drive coil carriage
via a U-shaped connector and is electrically coupled to the HGA
flexure cable by a bonding agent, such as an Anisotropic Conductive
Film (ACF).
Inventors: |
Zhang; Liu Jun; (Dongguan
City, CN) ; Lu; Guo Hong; (Dongguan City, CN)
; Chen; Can Hua; (Dongguan City, CN) ; Ho; Yiu
Sing; (Shatin, HK) ; Wang; Jeffery L.; (Tai
PO, HK) |
Correspondence
Address: |
KENYON & KENYON LLP
RIVERPARK TOWERS, SUITE 600
333 W. SAN CARLOS ST.
SAN JOSE
CA
95110
US
|
Family ID: |
33569591 |
Appl. No.: |
11/397162 |
Filed: |
April 4, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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10767029 |
Jan 28, 2004 |
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11397162 |
Apr 4, 2006 |
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Current U.S.
Class: |
29/603.03 ;
29/603.06; 29/737; G9B/5.154 |
Current CPC
Class: |
Y10T 29/53165 20150115;
G11B 5/4846 20130101; Y10T 29/49025 20150115; G11B 5/486 20130101;
Y10T 29/49032 20150115; Y10T 29/4903 20150115 |
Class at
Publication: |
029/603.03 ;
029/603.06; 029/737 |
International
Class: |
G11B 5/127 20060101
G11B005/127; B23P 19/00 20060101 B23P019/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 14, 2003 |
WO |
PCT/CN03/00555 |
Claims
1-13. (canceled)
14. A method for manufacturing a hard disk drive arm comprising:
coupling, by a U-shaped connector, a relay flexible cable to a
voice coil carriage assembly, said U-shaped connector including a
plurality of generally parallel plates and said parallel plates
including at least one bonding pad to electrically couple said
relay flexible cable to a head gimbal assembly (HGA) flexure
cable.
15. The method of claim 14, wherein said parallel plates include a
plurality of opposing tabs.
16. The method of claim 15, wherein said voice coil carriage
assembly has a plurality of grooves, said grooves being located on
opposite sides of the voice coil carriage assembly.
17. The method of claim 16, wherein said grooves are shaped and
located to accept said tabs.
18. The method of claim 14, wherein said U-shaped connector
includes at least one alignment hole and said voice coil carriage
assembly includes at least one alignment pin, said alignment hole
shaped and located to accept said alignment pin.
19. The method of claim 14, wherein said bonding pad is to be
coupled to at least one connecting pad on said HGA flexure cable by
a conductive bonding agent.
20. The method of claim 19, wherein said bonding agent includes a
plurality of electrically conductive particles.
21. The method of claim 20, wherein said bonding agent is to be
compressed between said bonding pad and said connector pad, a
number of said particles to form an electrical path between said
bonding pad and said connector pad.
22. The method of claim 21, wherein said bonding agent is
Anisotropic Conductive Film (ACF).
23. The method of claim 14, wherein said voice coil carriage
assembly is molded polymer resin.
24. The method of claim 14, wherein said voice coil carriage
assembly is stamped aluminum.
25. The method of claim 14, wherein said U-shaped connector has
four bonding pads and said HGA flexure cable has four connecting
pads.
26. The method of claim 25, wherein said bonding pads and said
connecting pads are gold coated.
27-30. (canceled)
Description
BACKGROUND INFORMATION
[0001] The present invention relates to hard disk drives. More
specifically, the invention relates to a system and method for
improving the electrical connection of a hard drive relay flexible
circuit assembly to a head-gimbal assembly (HGA) flexure cable.
[0002] FIG. 1 provides an illustration of a typical hard disk
drive. Hard disk drive storage devices typically include a rotating
disk 1 mounted for rotation by a spindle motor 2. A slider 3,
supported by an actuator arm 5, `flies` over the surface of the
magnetic disk 1 at a high velocity reading data from and writing
data to concentric data tracks on the disk 1. The slider 3 is
positioned radially by a voice coil 7 embedded in a voice coil
carriage 8.
[0003] In typical hard disk drives, electrical control signals are
communicated to the voice coil 7 by a relay flexible circuit 9.
Typically, the relay flexible circuit 9 also communicates
read/write data to the slider/head(s) 3. A printed circuit board
(PCB) 11 operates to control the position of the arm(s) 5 with
head/slider(s) 3 (also known as the head stack assembly (HSA)).
[0004] FIG. 2 shows a more detailed view of a head stack assembly
(HSA) typical in the art. The actuator arm 5 is mounted on the
actuator assembly (not shown) and affixed to a pivot member 6. The
actuator arms 5 each have a suspension flexure cable (HGA flexure
cable) 20 running from the heads/sliders 3 to a plurality
connecting pads 19. The connecting pads 19 are electrically coupled
to the flexible circuit assembly 9 by bonding (e.g., by solder bump
or gold ball bonding 15) the flexure cable connecting pads 19 to a
plurality of flexible circuit bonding pads 16.
[0005] FIG. 3 provides a more detailed illustration of the voice
coil actuator assembly as is typical in the art. A relay flexible
circuit 9 is aligned upon the coil carriage 8 by an alignment pin
17 protruding from the coil carriage 8 (inserted in a hole in a
circuit board 14 terminating the flexible circuit assembly 9).
After positioning, the flexible circuit assembly 9 may be
electrically coupled to the HGA (not shown), as illustrated in
FIGS. 2 and 4.
[0006] FIG. 4 illustrates electrically coupling the HGA flexure
cable connecting pads to flexible circuit bonding pads as is
typical in the art. Typically, bonding methods 15, such as solder
bump or gold ball bonding, are utilized to electrically couple the
HGA flexure cable connecting pads 19 to the flexible circuit
bonding pads 16. As stated above, an alignment pin 17 is utilized
to position the circuit board 14 of the relay flexible circuit
assembly (not shown). As stated above, the circuit board 14 bonding
pads 16 are electrically coupled to the flexure cable connecting
pads 19 by methods such as solder bump or gold ball bonding 15.
[0007] Because this design requires the electrical bonds 15 to be
placed on the inside corners formed by the extended plates 18 of
the HGA flexure cable (not shown) and the circuit board 14, it is
difficult to create the bonds. It is a very limited space in which
to operate. The alignment of the pads 16,18 and their electrical
coupling is a great challenge. The quality and efficiency of the
process is adversely affected by this challenge. The tooling and
equipment costs can be great because of this. In addition, a
problem with soldering the electrical connection 15 between the
pads 16,18 is that the bonds must be cleaned immediately after
soldering. Soldering flux, which is necessary for effective
soldering, must be removed. Removing the flux can be difficult and
costly. Solder, which consists primarily of tin, can cause
component contamination. During soldering, tin may splash out,
causing damage to surrounding electrical components and/or disk
media.
[0008] It is therefore desirable to have a system and method for
improving the electrical connection of a hard drive relay flexible
circuit assembly to a head-gimbal assembly (HGA) flexure cable that
avoids the above-mentioned problems, as well as having additional
benefits.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 provides an illustration of a typical hard disk
drive.
[0010] FIG. 2 shows a more detailed view of a head stack assembly
(HSA) typical in the art.
[0011] FIG. 3 provides a more detailed illustration of the voice
coil actuator assembly as is typical in the art.
[0012] FIG. 4 illustrates electrically coupling the head-gimbal
assembly HGA flexure cable connecting pads to flexible circuit
bonding pads as is typical in the art.
[0013] FIG. 5 illustrates a head-gimbal assembly (HGA) with a
U-shaped relay flexible circuit-to-flexure cable connector
according to an embodiment of the present invention.
[0014] FIG. 6 provides an illustration of the voice coil actuator
assembly (without the flexure cables or arms attached) according to
an embodiment of the present invention.
[0015] FIG. 7 illustrates the attachment of a U-shaped connector
for a relay flexible cable to a coil carriage according to an
embodiment of the present invention.
[0016] FIG. 8 illustrates a detailed illustration of the relay
flexible circuit according to an embodiment of the present
invention.
[0017] FIG. 9 provides an illustration of the attachment of a relay
flexible circuit to a U-shaped connector and the attachment of the
connector to a coil carriage according to an embodiment of the
present invention.
[0018] FIG. 10 illustrates the electrical coupling of bonding pads
on the relay flexible circuit to connector pads on the HGA flexure
cable according to an embodiment of the present invention.
DETAILED DESCRIPTION
[0019] FIG. 5 illustrates a head-gimbal assembly (HGA) with a
U-shaped relay flexible circuit-to-flexure cable connector
according to an embodiment of the present invention. In one
embodiment, a U-shaped connector 21 is seated to a portion of the
coil carriage 8 (as explained below with respect to FIG. 6). The
U-shaped connector 21 is assured correct positioning by one or more
alignment pins 17. In this embodiment, pads (not shown) on each of
the extended plates 18 of the flexure cables are bonded to pads
(not shown) on the top/bottom of the connector 21 (described
below).
[0020] FIG. 6 provides an illustration of the voice coil actuator
assembly (without the flexure cables or arms attached) according to
an embodiment of the present invention. In one embodiment, the
U-shaped connector 21, which is attached to the relay flexible
cable 9, is coupled to the coil carriage 8. In this embodiment, the
connector 21 is placed over a portion of the coil carriage 8, where
opposing tabs 25 on opposite sides of the connector 21 seat into
grooves 23 located on the top and bottom of the coil carriage 8 (as
described in FIG. 7).
[0021] FIG. 7 illustrates the attachment of a U-shaped connector
for a relay flexible cable to a coil carriage according to an
embodiment of the present invention. In one embodiment, as stated
above, the connector 21 is placed over the coil carriage 8. In this
embodiment, opposing tabs 25 on the connector 21 are shaped and
located to seat in grooves 23 on the top and bottom of the coil
carriage 8. In this embodiment, alignment pins 17 on the coil
carriage 8 fit into alignment holes 30 on the connector 21 to
assure proper positioning.
[0022] FIG. 8 illustrates a detailed illustration of the relay
flexible circuit according to an embodiment of the present
invention. In one embodiment, the relay flexible circuit 9 is
attached to the connector 21 by epoxy 31 (further described
below).
[0023] FIG. 9 provides an illustration of the attachment of a relay
flexible circuit to a U-shaped connector and the attachment of the
connector to a coil carriage according to an embodiment of the
present invention. In one embodiment, as explained above, the relay
flexible circuit 9 is attached to the U-shaped connector 21 by
epoxy. In this embodiment, bonding pads 16 on the relay flexible
circuit 9 are covered with an electrically conductive film 24, such
as Anisotropic Conductive Film (ACF). The film 24, which in one
embodiment is tacky, adheres to the pads 16.
[0024] FIG. 10 illustrates the electrical coupling of bonding pads
on the relay flexible circuit to connector pads on the HGA flexure
cable according to an embodiment of the present invention. In one
embodiment, the conductive film 24, which is adhered to the bonding
pads 16 is pressed against the connecting pads 19 of the flexure
cable extended plates 18. In this embodiment, after positioning the
flexure cable extended plates 18, the pads 16,18 are bonded. In
this embodiment, a heated bonding tip 32 is pressed against the
extended plate 18. The tip 32 heats and compresses the conductive
film 24 to bring about the curing process.
[0025] 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.
* * * * *