Patent Application
20100238594
This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2009-067372, filed Mar. 19, 2009, the entire contents of which are incorporated herein by reference.
1. Field
One embodiment of the invention relates to a head suspension assembly that is incorporated into a storage device such as a hard disk drive (HDD).
2. Description of the Related Art
A head suspension is attached to a top edge of a carriage arm incorporated into a HDD. A flexure is bonded to a surface of the head suspension. The flexure includes a metal thin plate. The metal thin plate includes a fixed plate joined to the surface of the head suspension, and a supporting plate integrally formed with the fixed plate and held by a protrusion formed on the head suspension. A head slider is supported on a surface of the supporting plate. An insulating layer is formed on the metal thin plate. A wiring pattern is formed on the insulating layer.
As a rotating speed of a magnetic disk becomes higher, a flow rate of air flow generated along a surface of the magnetic disk also becomes higher. When this air flow acts on the head suspension, the flexure vibrates. The vibration degrades a positioning accuracy of the head slider. In order to damp the vibration of the flexure, a damping material is bonded to a surface of the flexure on the head suspension. The damping material includes a visco-elastic body bonded to the surface of the flexure and a restraining member bonded onto the visco-elastic body. By the damping material, the vibration of the flexure is reduced.
Conventional technology is disclosed in Japanese Patent Application Publication (KOKAI) No. 2006-221726, Japanese Patent Application Publication (KOKAI) No. 2007-26575, Japanese Patent No. 414-4196, Japanese Patent No. 414-4197, Japanese Patent No. 414-4198, Japanese Patent No. 414-4199, Japanese Patent No. 3255660, Japanese Patent No. 2739927, and Japanese Patent Application Publication (KOKAI) No. H11-185415.
The damping material is bonded to the surface of the flexure. As described above, an insulating layer and a wiring pattern are formed on the metal thin plate of the flexure. Therefore, a step is formed between the insulating layer and the metal thin plate. Likewise, a step is formed between the wiring pattern and the insulating layer. Because of the step, the visco-elastic body cannot be in close contact with the flexure. The visco-elastic body partially floats or is separated from the flexure. As a result, a damping effect of the damping material fluctuates.
A general architecture that implements the various features of the invention will now be described with reference to the drawings. The drawings and the associated descriptions are provided to illustrate embodiments of the invention and not to limit the scope of the invention.
Various embodiments according to the invention will be described hereinafter with reference to the accompanying drawings. In general, according to one embodiment of the invention, a head suspension assembly includes: a head suspension; a metal thin plate held by a surface of the head suspension; an insulating layer; a wiring pattern formed on a surface of the insulating layer; and a visco-elastic body, wherein the metal thin plate includes: a fixed plate joined to the surface of the head suspension; a supporting plate formed at a location on the front side of the fixed plate and configured to support a head slider on a front surface of the supporting plate and held on a rear surface of the supporting plate by a protrusion formed on the head suspension; and an arm extending from a front edge of the fixed plate to the supporting plate and configured to allow a change in a posture of the supporting plate, and wherein the insulating layer extends from the fixed plate to the supporting plate and is at least partially supported by the arm, and wherein the visco-elastic body is arranged on a flat surface formed on one of the arm, the insulating layer, and the wiring pattern.
According to another embodiment of the invention, a storage device comprising: a head suspension assembly, wherein the head suspension assembly includes: a head suspension; a metal thin plate held by a surface of the head suspension; an insulating layer; a wiring pattern formed on a surface of the insulating layer; and a visco-elastic body, wherein the metal thin plate has: a fixed plate joined to the surface of the head suspension; a supporting plate formed at a location on the front side of the fixed plate and configured to support a head slider on a front surface of the supporting plate and held on a rear surface of the supporting plate by a protrusion formed on the head suspension; and an arm extending from a front edge of the fixed plate to the supporting plate and configured to allow a change in a posture of the supporting plate, and wherein the insulating layer extends from the fixed plate to the supporting plate and is at least partially supported by the arm, and wherein the visco-elastic body is arranged on a flat surface formed on one of the arm, the insulating layer, and the wiring pattern.
According to still another embodiment of the invention, a head suspension assembly includes a base plate; a load beam arranged forward of the base plate at a predetermined distance from the base plate; a hinge plate coupling the base plate to load beam and including an elastic deformation portion arranged between the base plate and the load beam; and a visco-elastic body, wherein the elastic deformation portion has: a front-side region being flat and configured to be bent along a ridge line orthogonal to a longitudinal center line of the base plate, the front-side region being formed on a front side of the ridge line in the elastic deformation portion; a rear-side region being flat and formed on a rear side of the ridge line in the elastic deformation portion, and wherein the visco-elastic body is pasted to one of the front-side region and the rear-side region.
According to still another embodiment of the invention, a storage device includes a head suspension assembly, wherein the head suspension assembly includes: a base plate; a load beam arranged forward of the base plate at a predetermined distance from the base plate; a hinge plate coupling the base plate to load beam and including an elastic deformation portion arranged between the base plate and the load beam; and a visco-elastic body, wherein the elastic deformation portion has: a front-side region being flat and configured to be bent along a ridge line orthogonal to a longitudinal center line of the base plate, the front-side region being formed on a front side of the ridge line in the elastic deformation portion; a rear-side region being flat and formed on a rear side of the ridge line in the elastic deformation portion, and wherein the visco-elastic body is pasted to one of the front-side region and the rear-side region.
Various embodiments according to the invention will be described hereinafter with reference to the accompanying drawings.
First, an inside configuration of a storage device according to one embodiment of the invention will be described.
In the storage space, at least one magnetic disk 14 is stored as a storage medium. The magnetic disk 14 is mounted on a drive shaft of a spindle motor 15. The spindle motor 15 can rotate the magnetic disk 14 at a high speed such as 5,400 rpm, 7,200 rpm, 10,000 rpm, and 15,000 rpm. For example, the magnetic disk 14 is configured as a vertical magnetic recording disk. That is to say, an easy axis of magnetization in a recording magnetic film of the magnetic disk 14 is set in a direction orthogonal to a surface of the magnetic disk 14.
In the storage space, a carriage 16 is also stored. The carriage 16 includes a carriage block 17. The carriage block 17 is rotatably connected to a support shaft 18 extending in the vertical direction. In the carriage block 17, a plurality of carriage arms 19 are arranged extending horizontally from the support shaft 18. The carriage block 17 may be formed of aluminum by extrusion molding, for example.
A head suspension assembly 21 is attached to a top end of each carriage arm 19. The head suspension assembly 21 includes a head suspension 22 attached to a top end of the carriage arm 19. The head suspension 22 extends forward from the top end of the carriage arm 19. As described later, a flexure is attached to a top end of the head suspension 22. A posture of a flying head slider 23 can be changed with respect to the head suspension 22 by an action of the flexure. Ahead element, or an electromagnetic conversion element, is mounted on the flying head slider 23.
When air flow is generated on a surface of the magnetic disk 14 by rotation of the magnetic disk 14, a positive pressure, or a buoyant force, and a negative pressure are applied to the flying head slider 23 by an action of the air flow. When the buoyant force and the negative pressure are balanced with a pressing force of the head suspension 22, the flying head slider 23 can be flying with relatively high rigidity during rotation of the magnetic disk 14.
A power source such as a voice coil motor (VCM) 24 is connected to the carriage block 17. The carriage block 17 can be rotated around the support shaft 18 by the VCM 24. Swing motions of the carriage arm 19 and the head suspension 22 are realized based on the rotation of the carriage block 17.
As illustrated in
When magnetic information or binary information is read, a sense current is provided from the head IC 27 to the read element of the electromagnetic conversion element. In a similar way, when binary information is written, a write current is provided from the head IC 27 to the write element of the electromagnetic conversion element. A voltage value of the sense current is set to a specific value. A current is provided to the head IC 27 from a small-sized circuit board 29 arranged in the storage space and a printed circuit board (not illustrated) attached to a bottom surface of a bottom plate of the base 13.
The above mentioned flexure 28 is bonded to a surface of the head suspension 22. The flexure 28 includes a metal thin plate 35. The metal thin plate 35 includes a fixed plate 36 partially joined to the surfaces of the load beam 32 and the hinge plate 33, and a supporting plate 37 supporting a rear surface of the flying head slider 23 with a surface of the supporting plate 37. The rear surface of the supporting plate 37 faces the surface of the load beam 32 at a location on a front side of the fixed plate 36. The rear surface of the supporting plate 37 is not joined to the surface of the load beam 32. The flying head slider 23 is bonded to a front surface of the supporting plate 37. In the joining of the fixed plate 36, spot welding is performed at a plurality of spot positions of the fixed plate 36, for example.
As illustrated in
An expanded portion 38c that is wider than the arm portion 38a is formed at the base edge of the arm portion 38a. The expanded portion 38c is formed in a round shape, for example. The expanded portion 38c is placed at a location corresponding to a loop of a vibration generated in the metal thin plate 35. A positioning hole 39 is formed in the expanded portion 38c. The positioning hole 39 is formed in a round shape, for example. A damper member 41 is bonded to a rear surface of the expanded portion 38c outside the outline of the load beam 32. The positioning hole 39 is used to determine a mounting position of the damper member 41. In the metal thin plate 35, the fixed plate 36, the supporting plate 37, and the arms 38 are formed from a single stainless steel plate.
The flexure 28 includes an insulating layer 42 formed on a surface of the metal thin plate 35. The insulating layer 42 extends from a surface of the fixed plate 36 to the surface of the supporting plate 37. The insulating layer 42 is made of an insulating material such as polyimide resin. The insulating layer 42 includes two lines of aerial portions 42a, 42a. The supporting plate 37 is placed between the aerial portions 42a, 42a. Each of the aerial portions 42a, 42a is placed outside the arm 38 between the fixed plate 36 and the supporting plate 37, and do not overlap with the arm 38. Apart of the aerial portion 42a is located outside the outline of the load beam 32. The aerial portions 42a are at least partially supported by the protruding portions 38b of the arms 38, respectively.
A plurality of lines of wiring patterns 43 are formed on a surface of the insulating layer 42. The wiring patterns 43 extend parallel to each other. The wiring patterns 43 are made of a conductive material such as copper. One end of each of the wiring pattern 43 is connected to the flying head slider 23. The other end of each of the wiring pattern 43 is connected to the flexible printed board 26. With the wiring patterns 43, the sense current and the write current are supplied from the head IC 27 to the flying head slider 23. A protecting layer 44 covers the wiring patterns 43 on the fixed plate 36. The protecting layer 44 is made of an insulating material such as polyimide resin.
As illustrated in
A diameter of the damper member 41 is set at 300 μm or more, for example. A thickness of the visco-elastic body 46 is set between 25 μm and 50 μm, for example. A thickness of the restraining plate 47 is set between 25 μm and 50 μm, for example. Accordingly, a thickness of the damper member 41 is set between 50 μm and 100 μm, for example. On the other hand, a width of the arm portion 38a is set at approximately 100 μm, for example. A The diameter of the expanded portion 38c can be set depending on the diameter of the damper members 41.
As illustrated in
The hinge plate 33 produces predetermined elasticity or bending force based on the bending of the elastic deformation portion 34 along the ridge line R. By the bending force, pressing force acting toward the surface of the magnetic disk 14 is applied to a front edge of the load beam 32. The pressing force acts on the flying head slider 23 from behind the supporting plate 37 by the protrusion 48. A posture of the flying head slider 23 can be changed based on the buoyant force produced by the air flow. In this time, the arms 38 are deformed depending on the change in the posture of the supporting plate 37, as described above. At the same time, the aerial portions 42a of the insulating layer 42 are deformed.
In the above described HDD 11, the air flow is generated along the surface of the magnetic disk 14 while the magnetic disk 14 is rotating. To position the electromagnetic conversion element mounted on the flying head slider 23, the head suspension assembly 21 is placed on the magnetic disk 14. The air flow acts on the arms 38. The damper members 41 are bonded to the base edges of the arms 38. The arm 38 functions as a base member. As a result, vibration of the arm 38 or the flexure 28 is suppressed. Further, because the damper members 41 are bonded to the flat surfaces 45 on the arms 38, the visco-elastic bodies 46 are in close contact with the arms 38. No spaces are left between the visco-elastic bodies 46 and the arms 38. The damper members 41 produce a large damping effect. The electromagnetic conversion element is positioned above a target recording track with high precision. Accordingly, binary information is written and read with high precision.
Next, a manufacturing method of the head suspension assembly 21 is described. First, the head suspension 22 is assembled. In the meantime, the flexure 28 is assembled. The flexure 28 is joined to a predetermined position of the surface of the head suspension 22. In the joining, spot welding is performed. After the joining, the surface of the metal thin plate 35 is supported by a front side of the head suspension 22. Because the surface of the metal thin plate 35 has a relatively large area, the metal thin plate 35 is supported with relative ease. A robot to supply the damper members 41 (not illustrated) positions a center of the damper member 41 to the center of positioning hole 39 from a rear side of the metal thin plate 35. In this manner, the robot bonds the damper members 41 onto the flat surfaces 45. After that, the flying head slider 23 is bonded to the surface of the supporting plate 37.
To manufacture the head suspension assembly 21c, the flexure 28 is joined to the surface of the head suspension 22, as in the first embodiment. After the joining, the arms 38 and the expanded portions 51 are supported from a rear side of the head suspension 22 outside the outline of the load beam 32. A robot to supply the damper members 41 positions a center of the damper member 41 to the center of positioning hole 53 from a rear side of the insulating layer 42. In this manner, the robot bonds the damper members 41 onto the flat surfaces 52. After that, the flying head slider 23 is bonded to the surface of the supporting plate 37. In this manner, the head suspension assembly 21c is manufactured.
In the head suspension assembly 21d, the hinge plate 33 functions as a base member. As a result, vibration of the hinge plate 33 is suppressed. Further, because the damper members 41 are bonded to the flat surfaces 54 on the hinge plate 33, the visco-elastic bodies 46 are in close contact with the hinge plate 33. No spaces are left between the visco-elastic bodies 46 and the hinge plate 33. The damper members 41 produce a large damping effect. The electromagnetic conversion element is positioned above a target recording track with high precision. Accordingly, binary information is written and read with high precision.
Furthermore, the damper members 41 are bonded to the hinge plate 33 in the rear-side region 34b on a rear side of the ridge line R. The damper members 41 are not bonded onto the ridge line R. Accordingly, the elasticity or the bending force of the elastic deformation portion 34 does not change. The pressing force applied to the front edge of the load beam 32 does not change either. A floating posture of the flying head slider 23 is established as designed. Still furthermore, because the rear-side region 34b unfolds parallel to the base plate 31, the surface of the base plate 31 can be readily supported when the damper members 41 are bonded. Thus, the damper members 41 can be readily bonded to the rear surface of the hinge plate 33.
The above head suspension assemblies 21 to 21e may be combined with each other. For example, while being bonded onto the flexure 28, the damper members 41 may be bonded onto the hinge plate 33. Flat surfaces may be formed on the wiring patterns 42. The damper members 41 may be bonded to the flat surfaces formed on the wiring patterns 42. The shape of each of the damper members 41 is a round but is not limited thereto. The shape of each of the damper members 41 may be a rectangle, for example. Such rectangular damper members 41 may be bonded to flat surfaces formed on the arm portions 38a, for example.
The various modules of the systems described herein can be implemented as software applications, hardware and/or software modules, or components on one or more computers, such as servers. While the various modules are illustrated separately, they may share some or all of the same underlying logic or code.
While certain embodiments of the inventions have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel methods and systems described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the methods and systems described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2009-067372 | Mar 2009 | JP | national |
