Suspension assembly and disk device

Abstract

According to one embodiment, a suspension assembly capable of improving positioning accuracy of a magnetic head and a disk device provided with the suspension assembly are provided. According to one embodiment, a suspension assembly is provided with: a support plate; a wiring member provided on the support plate and having an elastically deformable universal joint portion having a tongue portion on which a magnetic head is mounted and an overhang bracket connected to the tongue portion; and the viscoelastic material is filled in a gap between the overhanging bracket and the supporting plate to form a damping piece.

Description

[0001] This application enjoys the priority of Japanese patent application No. 2023-204483 applied for on December 4, 2023, and the entire contents of this Japanese patent application are cited in this application. Technical Field

[0002] The present embodiment generally relates to a suspension assembly and a disk device including the suspension assembly. Background Art

[0003] A disk device such as a hard disk drive (HDD) includes a plurality of magnetic disks rotatably arranged in a housing, a plurality of magnetic heads for reading and writing information from the magnetic disks, and a head actuator for movably supporting the magnetic heads relative to the magnetic disks.

[0004] The head actuator has a plurality of suspension assemblies (sometimes also referred to as gimbal assemblies) supporting the magnetic head at the front end (top end). The suspension assembly has a suspension composed of a metal support plate and a flexible member (wiring member) disposed on the suspension. The flexible member has a freely displaceable gimbal portion, on which the magnetic head is mounted. In addition, in recent years, piezoelectric elements such as piezoelectric transducers (Piezoelectric Element) are mounted on the flexible member to form a microactuator. Summary of the invention

[0005] A suspension assembly involved in one embodiment comprises: a support plate; a wiring member, which is arranged on the support plate and has a universal joint portion that can be elastically deformed, and the universal joint portion has a tongue portion for mounting a magnetic head and an outrigger connected to the tongue portion; and a viscoelastic material that fills a gap between the outrigger and the support plate to form a damper.

[0006] According to one embodiment, it is possible to provide a suspension assembly and a disk device capable of improving head positioning accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 It is a perspective view showing a hard disk drive (HDD) according to the first embodiment.

[0008] Figure 2 It is a perspective view showing an actuator assembly of the HDD.

[0009] Figure 3 It is a plan view showing a head suspension assembly of the actuator assembly.

[0010] Figure 4 It is a plan view showing an enlarged front end portion of the suspension assembly.

[0011] Figure 5 It is a plan view showing the root portion of the outrigger of the universal joint portion before being filled with the viscoelastic material.

[0012] Figure 6 It is a plan view showing the root portion of the outrigger of the universal joint portion after being filled with the viscoelastic material.

[0013] Figure 7 It is a side view schematically showing a front end portion and a universal joint portion of the suspension assembly.

[0014] Figure 8 This is a diagram showing the vibration characteristics of the suspension assembly according to the present embodiment having the damping member and the suspension assembly according to the comparative example having no damping member in comparison.

[0015] Fig. 9 It is a plan view showing an enlarged front end portion of a suspension assembly of a HDD according to a second embodiment.

[0016] Fig.10 It is a plan view showing the front end portion of the outrigger of the gimbal portion in the HDD according to the second embodiment before the viscoelastic material is filled.

[0017] Fig.11 It is a plan view showing the front end portion of the outrigger of the gimbal portion after the viscoelastic material is filled in the HDD according to the second embodiment.

[0018] Fig.12 It is a side view schematically showing a front end portion and a universal joint portion of the suspension assembly in the HDD according to the second embodiment.

[0019] Fig.13 A cross-sectional view schematically showing a portion filled with a viscoelastic material of a suspension assembly in a HDD according to a third embodiment.

[0020] Description of Reference Numerals

[0021] 10 housing; 12 base; 17 head; 18 magnetic disk; 19 spindle motor; 22 actuator assembly; 30 suspension assembly; 32 arm; 34 suspension; 38 load beam; 42 flexible member (wiring member); 44 universal joint; 44c outrigger; 44d fixed pad (front end); 45 root; 46 metal plate; 47 through hole (through hole); 48 wiring substrate (FPC, circuit board); 50 piezoelectric element; 60 viscoelastic material (damping member); 64 recess. DETAILED DESCRIPTION

[0022] Hereinafter, a disk device according to an embodiment will be described with reference to the drawings.

[0023] In addition, the disclosure is always just an example, and the technical solutions that can be appropriately changed and easily thought of by those skilled in the art while maintaining the gist of the invention are of course included in the scope of the present invention. In addition, in order to make the description clearer, the size, shape, etc. of each part are sometimes schematically indicated in the drawings compared with the actual technical solutions, but it is always just an example and does not limit the interpretation of the present invention. In addition, in this specification and each figure, the same elements as those described in the previous drawings are sometimes marked with the same figure numbers, and the detailed description is appropriately omitted.

[0024] (First embodiment)

[0025] A hard disk drive (HDD) according to the first embodiment will be described in detail as a disk device.

[0026] Figure 1 This is a perspective view of the HDD according to the first embodiment, showing the HDD with a top cover removed.

[0027] As shown in the figure, the HDD has a rectangular housing 10. The housing 10 has a rectangular box-shaped base 12 with an open top surface, and a top cover 14. The base 12 has a rectangular bottom wall 12a and a plurality of side walls 12b erected along the periphery of the bottom wall 12a, and is integrally formed of, for example, aluminum. The top cover 14 is formed of, for example, stainless steel in a rectangular plate shape. The top cover 14 is screwed to the side wall 12b of the base 12 by a plurality of screws 13, and closes the upper opening of the base 12.

[0028] In the housing 10, a plurality of magnetic disks 18 as disk-shaped recording media and a spindle motor 19 that supports and rotates the magnetic disks 18 are provided. The spindle motor 19 is disposed on the bottom wall 12a. Each magnetic disk 18 is made of a non-magnetic body, such as glass or aluminum, and is formed, for example, in the shape of a disk with a diameter of 96 mm (3.5 inches), and has a substrate and a magnetic recording layer formed on the upper surface and / or the lower surface of the substrate. The magnetic disks 18 are coaxially engaged with the unillustrated hub of the spindle motor 19, and are clamped by a clamping spring 20. Thus, the magnetic disks 18 are supported in a state of being located parallel to the bottom wall 12a of the base 12. The plurality of magnetic disks 18 are rotated at a predetermined rotation speed by the spindle motor 19.

[0029] In the present embodiment, for example, five magnetic disks 18 are arranged in the housing 10 , but the number of magnetic disks 18 is not limited thereto, and may be four or less, or six or more.

[0030] In the housing 10, a plurality of magnetic heads 17 for writing and reading information on the magnetic disk 18 and an actuator assembly 22 for supporting the magnetic heads 17 in a manner that allows them to move freely relative to the magnetic disk 18 are provided. In addition, in the housing 10, a voice coil motor (VCM) 24 for rotating and positioning the actuator assembly 22, a ramp loading mechanism 25 for holding the magnetic head 17 at an unloading position away from the magnetic disk 18 when the magnetic head 17 moves to the outermost periphery of the magnetic disk 18, and a substrate unit (FPC unit) 21 on which electronic components such as a conversion connector are mounted are provided. The actuator assembly 22 and the VCM 24 constitute a head actuator. The ramp loading mechanism 25 has a ramp provided on the base 12 and a lifting piece provided on the actuator assembly 22.

[0031] The actuator assembly 22 includes an actuator block 29 supported to be rotatable, a plurality of arms 32 extending from the actuator block 29, and a suspension assembly 30 extending from each arm 32. A magnetic head 17 is supported at the front end of each suspension assembly 30. The magnetic head 17 includes a read head, a write head, an auxiliary element, a heater, etc. The suspension assembly 30 is an assembly including the magnetic head 17, and is sometimes referred to as a head suspension assembly.

[0032] A printed circuit board (not shown) is screwed onto the outer surface of the bottom wall 12 a of the base 12 . The printed circuit board constitutes a control unit that controls the operation of the spindle motor 19 and controls the operations of the VCM 24 and the magnetic head 17 via the board unit 21 .

[0033] Figure 2 1 is a perspective view showing the actuator assembly 22 and the FPC unit 21. As shown in the figure, the actuator assembly 22 includes: an actuator block 29 having a through hole 31; a bearing unit 28 disposed in the through hole 31; a plurality of, for example, six arms 32 extending from the actuator block 29; and ten suspension assemblies 30 mounted on the arms 32. A support shaft (pivot) 26 is provided upright on the bottom wall 12a. The actuator block 29 is supported by the bearing unit 28 so as to be rotatable around the support shaft 26.

[0034] In this embodiment, the actuator block 29 and the six arms 32 are integrally formed of aluminum or the like to form a so-called E-block. The arm 32 is formed, for example, in the shape of an elongated flat plate, and extends from the actuator block 29 in a direction perpendicular to the support shaft 26. The six arms 32 are arranged in parallel with gaps therebetween.

[0035] The actuator assembly 22 has a support frame 33 extending from the actuator block 29 in a direction opposite to the arm 32, and a voice coil 35 is supported by the support frame 33. Figure 1 As shown, the voice coil 35 is located between a pair of yokes 39, one of which is fixed to the base 12. The voice coil 35, the yokes 39, and the magnet fixed to one of the yokes constitute the VCM 24.

[0036] like Figure 2 As shown, ten suspension assemblies 30 are respectively mounted on the front end portion 32a of each arm 32. The plurality of suspension assemblies 30 include an upward head suspension assembly that upwardly supports the magnetic head 17, and a downward head suspension assembly that downwardly supports the magnetic head 17. The upward head suspension assembly and the downward head suspension assembly are configured by changing the vertical direction of the suspension assembly 30 of the same structure.

[0037] The FPC unit 21 integrally includes a substantially rectangular base portion 70, a thin and long strip-shaped relay portion 72 extending from one side edge of the base portion 70, and a substantially rectangular joint portion (FPC joint portion) 74 provided continuously to the front end portion of the relay portion 72. The base portion 70, the relay portion 72, and the joint portion 74 are formed of a flexible printed wiring substrate (FPC).

[0038] On one surface (outer surface) of the base 70, electronic components such as a conversion connector not shown and a plurality of capacitors 73 are mounted and electrically connected to wiring not shown. On the other surface (inner surface) of the base 70, two metal plates 75 and 76 that function as reinforcing plates are attached. The base 70 is arranged on the bottom wall 12a of the housing 10 and is screwed to the bottom wall 12a by two screws. The conversion connector on the base 70 is connected to the control circuit substrate provided on the bottom side of the housing 10.

[0039] The relay portion 72 extends from the base portion 70 toward the actuator assembly 22. The joint portion 74 provided at the extended end of the relay portion 72 is formed into a rectangular shape having a height and a width substantially equal to the side surface (installation surface) of the actuator block 29. The joint portion 74 is attached to the installation surface of the actuator block 29 via a backing plate formed of aluminum or the like, and is then threadedly fastened to the installation surface by fixing screws 65. A head IC (head amplifier) ​​59 is mounted on the joint portion 74. A pair of connection pads 55 and a plurality of connection pad groups not shown are provided on the joint portion 74. The head IC 59 is connected to the connection pad group and the base portion 70 via a plurality of wirings not shown. The voice coil 35 is connected to the connection pad 55. The connection end portion 42c of the flexible member 42 described later is joined to the connection pad group.

[0040] Next, an example of the suspension assembly 30 will be described in detail.

[0041] Figure 3 is a plan view showing a head suspension assembly, Figure 4 This is a plan view showing an enlarged front end portion of the head suspension assembly.

[0042] like Figure 3As shown, the suspension assembly 30 has a suspension 34 extending from an arm 32, and a magnetic head 17 is mounted on the front end of the suspension 34. The suspension 34, which functions as a support plate, has a rectangular base plate 36 made of a metal plate, and a load beam 38 in the shape of an elongated leaf spring made of a metal plate. The load beam 38 is overlapped and arranged at the front end of the base plate 36 by its base end and fixed to the base plate 36 by welding at multiple locations. The front end of the load beam 38 constitutes the front end of the support plate, and the base end of the load beam 38 and the base plate 36 constitute the base end of the support plate. The load beam 38 is formed to become thinner as it moves forward, and a rod-shaped lifting piece 40 is protrudingly provided at the front end.

[0043] The base plate 36 has a circular opening 36a and an annular protrusion 36b located around the opening 36a at its base end. The protrusion 36b is connected to a circular rivet hole 37 (see FIG. 1 ) formed on the rivet seat surface of the arm 32. Figure 2 ) is fitted and the protrusion 36b is riveted, and the base plate 36 is fastened to the front end portion 32a of the arm 32. The base plate 36 may also be fixed to the front end portion 32a of the arm 32 by laser welding, spot welding or bonding.

[0044] The suspension assembly 30 includes a flexible member (wiring member) 42 in the form of an elongated strip for transmitting recording signals, reproduction signals, and driving signals of the piezoelectric element, and a pair of piezoelectric elements (e.g., PZT elements) 50 mounted on the flexible member 42. The flexible member 42 includes a front end side portion 42a disposed on the load beam 38 and the base plate 36, a base end side portion 42b extending outward from the side edge of the base plate 36 and extending along the side edge of the arm 32 to the actuator block 29, and a connection end portion (trailing connection end portion) 42c extending from the extended end of the base end side portion 42b. The connection end portion 42c includes a plurality of connection terminals (electrode pads) 43 arranged in an array. These connection terminals 43 are electrically connected to a group of connection pads provided in a joint portion 74 of the actuator block 29.

[0045] The flexible member 42 includes a metal thin plate (metal plate) 46 such as stainless steel as a base, and a strip-shaped wiring substrate (flexible printed wiring substrate: FPC) 48 attached or fixed to the metal plate 46, forming an elongated laminate. The wiring substrate (FPC) 48 includes a base insulating layer mostly fixed to the metal plate 46, a conductive layer (wiring pattern) formed on the base insulating layer, and a cover insulating layer laminated on the base insulating layer to cover the conductive layer. For example, copper foil is used as the conductive layer, and a plurality of wirings (signal wiring, drive wiring, ground wiring), a plurality of connection pads, and a plurality of connection terminals are formed by patterning the copper foil.

[0046] like Figure 3 as well as Figure 4As shown in FIG. 1 , at the front end side portion 42a of the flexible member 42, the metal plate 46 is attached to the surface of the load beam 38 and the base plate 36, or spot welded to the surface of the load beam 38 and the base plate 36 through a plurality of welding points. In one example, the front end portion of the metal plate 46 has six welding points (first welding portions) B1, B2, and B3 (see FIG. 1 ) welded to the base end portion of the load beam 38. Figure 4 ); and a welding point (second welding portion) B4 welded to the front end portion of the load beam 38.

[0047] The front end of the flexible member 42 is located above the front end of the load beam 38, forming a universal joint portion 44 that functions as an elastic support portion. The magnetic head 17 is mounted and fixed on the universal joint portion 44, and is supported by the load beam 38 via the universal joint portion 44. A pair of piezoelectric elements 50 constituting a microactuator are mounted on the universal joint portion 44 and arranged on both sides of the magnetic head 17.

[0048] like Figure 4 As shown in FIG. 1 , in the universal joint 44, a metal plate 46 integrally includes: a substantially rectangular tongue (supporting portion) 44a located on the front end side of the load beam 38, a base end 44b located on the base end side of the load beam 38 at a distance from the tongue 44a, a pair of outriggers 44c extending from the base end 44b through the outside of the tongue 44a to the front end of the load beam 38 and connected to each other on the front end side, and a substantially rectangular fixing pad 44d extending from the front end of the outrigger 44c to the tongue 44a side and facing the front end of the tongue 44a. The fixing pad 44d constitutes the front end of the outrigger 44c. Each outrigger 44c integrally includes a spring-shaped connecting portion 44e connecting the middle portion in the longitudinal direction thereof to the tongue 44a.

[0049] The base end 44b of the metal plate 46 is attached to the surface of the load beam 38 and is welded to the load beam 38 at the aforementioned welding points B1, B2, and B3. The fixing pad 44d is arranged between the front end of the outrigger 44c and the tongue 44a so as to overlap with the load beam 38 (overlap in a direction substantially perpendicular to the surface of the load beam 38) and is welded to the load beam 38 at the aforementioned welding point B4. In one example, the welding point B4 is located on the central axis C of the suspension 34.

[0050] Each outrigger 44c is formed to have a substantially constant width W1 except for a root 45 connected to the base end 44b described later, and is formed to be elastically deformable. A pair of outriggers 44c connects the base end 44b to the tongue 44a and supports the tongue 44a in a displaceable manner. The magnetic head 17 is mounted and fixed on the tongue 44a.

[0051] The approximate center of the tongue 44a contacts a dimple 52 protruding from the front end of the load beam 38. The tongue 44a can be displaced in various directions with the dimple 52 as a fulcrum by elastic deformation of a pair of outriggers 44c. Thus, the magnetic head 17 mounted on the tongue 44a can flexibly follow the surface changes of the magnetic disk 18 and be displaced in the rolling direction or the pitching direction, and a small gap is maintained between the surface of the magnetic disk 18 and the magnetic head 17.

[0052] In the universal joint part 44, the wiring substrate 48 of the flexible member 42 is arranged on the metal plate 46, extending from the base end 44b to the tongue 44a along the central axis C of the suspension assembly 30. That is, the wiring substrate 48 has a base end 48a attached to the base end 44b, a front end 48b attached to the tongue 44a, and a pair of strip-shaped bridges 48c extending from the base end 48a to the front end 48b in a bifurcated shape. The magnetic head 17 and the piezoelectric element 50 are installed on the front end 48b. The magnetic head 17 is placed on the tongue 44a, and a part of it is installed on the front end 48b. A pair of piezoelectric elements 50 are respectively arranged on the bridge 48c, and arranged on both sides of the width direction of the magnetic head 17.

[0053] At the front end portion 48b, a plurality of connection pads (electrode pads) 53 are arranged in the width direction. In addition, at the front end portion 48b, a plurality of connection pads (electrode pads) not shown are provided for connecting the piezoelectric element 50. The wiring substrate 48 has a plurality of signal wirings WL extending from the connection pads 53 around the two side edges of the front end portion 48b to the base end portion 48a side, and a plurality of signal wirings WL extending from the connection pads to the base end portion 48a side. These signal wirings WL extend over substantially the entire length of the flexible member 42 and are connected to a plurality of connection terminals 43 provided at the connection end portion 42c (see Figure 3 ).

[0054] like Figure 4 As shown, the magnetic head 17 has a substantially rectangular head slider, and a recording element (write head), a reading element (read head), and an auxiliary element (heater) which are not shown and are arranged on the head slider. The magnetic head 17 is mounted on the front end portion 48b on the tongue portion 44a. The recording element (write head), the reading element (read head), and the auxiliary element (heater) are electrically connected to a plurality of connection pads 53 of the front end portion 48b via wiring, electrodes, and conductive adhesives which are not shown. Thus, the magnetic head 17 is connected to the signal wiring WL of the wiring substrate 48 via the connection pads 53.

[0055] The pair of piezoelectric elements 50 uses, for example, a thin film piezoelectric element (PZT element) in the shape of a rectangular plate. The piezoelectric element 50 is not limited to a thin film type (thickness of about 10 μm), and a bulk type or a bulk laminated type (thickness of 40 μm or more) piezoelectric element may be used. In addition, the piezoelectric element 50 is not limited to a PZT element, and other piezoelectric elements may be used. Furthermore, the driving element is not limited to a piezoelectric element, and other driving elements that can be expanded and contracted by applying an electric current may be used.

[0056] The piezoelectric element 50 is arranged so that its longitudinal direction (extension direction) is parallel to the central axis C of the suspension 34. The two piezoelectric elements 50 are arranged on both sides of the magnetic head 17 in the width direction and are arranged parallel to each other.

[0057] The suspension assembly 30 includes a viscoelastic material (sometimes referred to as a damper) 60 provided at an overlapping portion of the outrigger 44c at a position overlapping with the load beam 38. The root portion 45 of the outrigger 44c connected to the base end portion 44b of the metal plate 46 is located at a position overlapping with the load beam 38. That is, the root portion 45 constitutes an overlapping portion located at a position overlapping in a direction perpendicular to the surface of the load beam 38. In the present embodiment, the viscoelastic material (damper) 60 is provided at a pair of the root portions 45.

[0058] Figure 5 This is a plan view showing an enlarged view of the root portion of the outrigger before filling with viscoelastic material. Figure 6 This is an enlarged plan view showing the root portion of the outrigger after filling with the viscoelastic agent. Figure 7 It is a side view schematically showing a universal joint portion of the suspension assembly.

[0059] like Figure 5 As shown, the root 45 of the outrigger 44c has a width W2 that is wider than the width W1 of the other parts of the outrigger 44c. In one example, the root 45 has a substantially triangular shape whose width gradually narrows from the base end 44b toward the extension side of the outrigger 44c. The root 45 as an overlapping portion is located at a position overlapping with the load beam 38. That is, the root 45 faces the surface of the load beam 38 with a gap therebetween. In addition, a substantially triangular through hole 47 is provided in the root 45. The through hole 47 faces the load beam 38. The through hole 47 may be formed to have an area smaller than that of the root 45, and its shape is not limited to a triangle, but may be any other shape such as a circle or an ellipse.

[0060] like Figure 6 as well as Figure 7As shown, the gap between the root 45 of the outrigger and the load beam 38 is filled with a viscoelastic material 60 through the through hole 47. The viscoelastic material 60 is held in the gap, the through hole 47, and the surface side of the root 45, and is extended to the area around the through hole 47. The viscoelastic material 60 forms a damping member with the load beam 38 as a constraining layer, and has a function of attenuating the vibration of the outrigger 44c by its viscosity. As the viscoelastic material 60, for example, a resin adhesive such as a thermosetting adhesive can be used.

[0061] like Figure 7 As shown in FIG. 1 , when the metal plate 46 of the flexible member 42 is welded to the load beam 38, the tongue 44a contacts the recess 52 of the load beam 38, so that the pair of outriggers 44c are also lifted up, and a gap is generated between the load beam 38 and the root 45 of the outriggers 44c. The viscoelastic material 60 filled into the gap from the through hole 47 spreads in the gap to the outside of the outer edge of the through hole 47. That is, in the gap, the viscoelastic material 60 spreads to an area larger than the area of ​​the through hole 47. Thus, the viscoelastic material 60 is adhered to the surface of the load beam 38 and the opposing surface around the through hole 47 of the root 45 in a tightly attached state in the gap.

[0062] Furthermore, on the upper surface side and the lower surface side of the root portion 45 , the viscoelastic material 60 preferably extends within a range that does not exceed the side edge of the root portion 45 .

[0063] According to the suspension assembly 30 constructed as described above, the viscoelastic material 60 is provided, and the viscoelastic material 60 is filled in the overlapping portion of the load beam 38 and the outrigger 44c, for example, between the base 45. The viscosity of the viscoelastic material 60 acts as a damper for the torsion mode of the universal joint, and can suppress the generation of the torsion mode. Thus, the positioning accuracy of the magnetic head can be improved.

[0064] Figure 8 This is a diagram comparing the vibration characteristics of the suspension assembly (with damping member) involved in the embodiment and the suspension assembly (without damping member) involved in the comparative example. As shown in the figure, in the suspension assembly involved in the comparative example, a vibration mode of universal joint torsion occurs at around 10 kHz. In contrast, it can be seen that in the suspension assembly involved in the present embodiment, the vibration at around 10 kHz is attenuated, and the torsion vibration mode of the universal joint is suppressed.

[0065] In addition, according to the suspension assembly 30 of the present embodiment, by providing the viscoelastic material 60 only at the root of the outrigger 44c, the above-mentioned positioning accuracy improvement effect can be obtained while suppressing the risk of increasing the mass of the universal joint and causing contamination. By setting a configuration in which the through hole 47 is provided in the outrigger 44c and the viscoelastic material 60 is filled into the gap from the through hole 47, the viscoelastic material 60 can be provided between the outrigger 44c and the load beam 38 after the metal plate 46 is positioned and fixed to the load beam 38 by welding. Therefore, the damping member can be provided without reducing the conventional assembly accuracy and manufacturability of the suspension assembly 30. Furthermore, in the outrigger 44c, the portion where the through hole 47 is provided is formed to have a wider width than other portions. Therefore, even when the through hole 47 is provided, the strength of the outrigger 44c does not decrease. In addition, the damping member structure can be formed without changing the gap between the outrigger 44c and the load beam 38, so the influence on other vibration modes can also be suppressed.

[0066] As described above, according to the present embodiment, it is possible to provide a suspension assembly capable of improving head positioning accuracy and a disk device including the suspension assembly.

[0067] In the other embodiments described below, the same parts as those in the first embodiment are denoted by the same reference numerals, and their detailed description is omitted or simplified, and the description focuses on the parts different from the first embodiment.

[0068] (Second embodiment)

[0069] Fig. 9 It is a plan view showing an enlarged front end portion of a suspension assembly according to a second embodiment.

[0070] As shown in the figure, according to the second embodiment, the viscoelastic material 60 is disposed at the tip end of the outrigger 44c, here, the base end of the fixing pad 44d, in the overlapping portion of the outrigger 44c overlapping the load beam 38 to form a damper.

[0071] Fig.10 This is a plan view showing an enlarged front end of the outrigger before filling with the viscoelastic agent. Fig.11 This is an enlarged plan view showing the front end of the outrigger after filling with the viscoelastic agent. Fig.12 It is a side view schematically showing a universal joint portion of the suspension assembly.

[0072] like Fig.10As shown in FIG. 1 , the fixing pad 44d integrally connected to the front end of the outrigger 44c is located at a position overlapping with the load beam 38 and is welded to the load beam 38 at a welding point B4. The base end of the fixing pad 44d connected to the outrigger 44c has a width W3 greater than the width W1 of the other part of the outrigger 44c. The base end faces the load beam 38 with a gap therebetween. A substantially rectangular through hole 51 is provided at the base end of the fixing pad 44d. The through hole 51 is not limited to a rectangular shape as long as it is formed with an area smaller than that of the base end, and may be any other shape.

[0073] like Fig.11 as well as Fig.12 As shown, the gap between the front end of the outrigger 44c and the load beam 38 is filled with a viscoelastic material 60 through the through hole 51. The viscoelastic material 60 is held in the gap, in the through hole 51, and on the surface side of the fixing pad 44d so as to spread toward the area around the through hole 51. The viscoelastic material 60 forms a damping member with the load beam 38 as a constraining layer, and has the function of attenuating the vibration of the outrigger 44c by its viscosity.

[0074] like Fig.12 As shown in FIG. 1 , when the fixing pad 44d is welded to the load beam 38, the tongue 44a contacts the recess 52 of the load beam 38, so that the base end of the pair of outriggers 44c and the fixing pad 44d are also lifted, and a gap is generated between the base end of the fixing pad 44d and the load beam 38. The viscoelastic material 60 filled into the above gap from the through hole 51 spreads in the above gap and spreads to the outside of the outer edge of the through hole 51. That is, in the above gap, the viscoelastic material 60 spreads to an area larger than the area of ​​the through hole 51. Thus, the viscoelastic material 60 is adhered to the surface of the load beam 38 and the opposing surface around the through hole 51 of the fixing pad 44d in the above gap in a close contact state.

[0075] Furthermore, the viscoelastic material 60 preferably extends on the upper surface side and the lower surface side of the base end portion of the fixing pad 44d within a range not exceeding the side edge of the outrigger 44c including the fixing pad 44d.

[0076] According to the suspension assembly 30 constructed as described above, there is a viscoelastic material 60 filled between the front end of the outrigger 44c and the load beam 38. The viscosity of the viscoelastic material 60 acts as a damping member for the torsion mode of the universal joint, and can suppress the generation of the torsion mode. Thus, the positioning accuracy of the magnetic head can be improved. In addition, in the suspension assembly involved in the second embodiment, the same effect as the suspension assembly involved in the first embodiment can also be obtained.

[0077] As described above, according to the second embodiment, it is possible to provide a suspension assembly capable of improving head positioning accuracy and a disk device including the suspension assembly.

[0078] (Third embodiment)

[0079] Fig.13 It is a cross-sectional view schematically showing a portion filled with a viscoelastic material in a suspension assembly of an HDD according to a third embodiment.

[0080] As shown in the drawing, in the third embodiment, an annular recess (or groove) 64 is provided, for example, on the surface side of the load beam 38 in the region filled with the viscoelastic material 60. The recess 64 or the groove is formed, for example, by etching.

[0081] The viscoelastic material 60 filled between the outrigger 44c and the load beam 38 is extended to the position of the recess 64, and is arranged in a state where the peripheral edge portion is located in the recess 64. The recess 64 is provided to limit excessive extension of the viscoelastic material 60. Thus, the viscoelastic material 60 can be arranged at a desired position and size, and a damping member having a desired vibration attenuation effect can be formed.

[0082] The other configurations of the suspension assembly according to the third embodiment are the same as those of the suspension assembly according to the first embodiment. Therefore, the suspension assembly according to the third embodiment can also achieve the same effects as those of the suspension assembly according to the first embodiment.

[0083] The present invention is not limited to the above-mentioned embodiments per se, and in the implementation stage, the constituent elements can be deformed and concretized within the scope of the gist thereof. In addition, various inventions can be formed by appropriate combinations of a plurality of constituent elements disclosed in the above-mentioned embodiments. For example, several constituent elements can also be deleted from all constituent elements shown in the embodiments. Moreover, the constituent elements in different embodiments can also be appropriately combined.

[0084] For example, the material, shape, size, etc. of the elements constituting the suspension assembly are not limited to the above-mentioned embodiments, and various changes can be made as needed. The piezoelectric element is not limited to a pair, and can be one, or three or more. The location where the viscoelastic material is set is not limited to the root or front end of the outrigger, as long as it is a location overlapping with the load beam, that is, a location opposite to the load beam across a gap, and can also be set at other locations.

Claims

1. A suspension assembly comprising: Support plate; a wiring member, which is disposed on the support plate and has an elastically deformable universal joint portion, wherein the universal joint portion has a tongue portion for mounting a magnetic head and an outrigger connected to the tongue portion; and The viscoelastic material fills the gap between the outrigger and the support plate to form a damping member.

2. The suspension assembly according to claim 1, The outrigger includes an overlapping portion located at a position overlapping with the support plate and a through hole arranged at the overlapping portion and opposite to the support plate. The viscoelastic material fills the gap between the overlapping portion and the support plate and the through hole.

3. The suspension assembly according to claim 2, The overlapping portion has a width greater than a width of other portions of the outrigger.

4. The suspension assembly according to claim 3, The support plate has a recess, which is disposed at a position opposite to the overlapping portion of the outrigger and limits the expansion of the viscoelastic material.

5. The suspension assembly according to claim 2, The outrigger has a root portion located on a base end side relative to the tongue portion and a front end portion located on a front end side relative to the tongue portion, the root portion constituting the overlapping portion.

6. The suspension assembly according to claim 2, The outrigger has a root portion located on the proximal side with respect to the tongue portion and a front end portion located on the front end side with respect to the tongue portion, and the front end portion constitutes the overlapping portion.

7. A disk device comprising: a disk-shaped recording medium having a recording layer; and A head actuator having a suspension assembly, The suspension assembly comprises: Support plate; a wiring member, which is disposed on the support plate and has an elastically deformable universal joint portion, wherein the universal joint portion has a tongue portion for mounting the magnetic head and an outrigger connected to the tongue portion; and The viscoelastic material fills the gap between the outrigger and the support plate to form a damping member.

8. The disk device according to claim 7, The outrigger includes an overlapping portion located at a position where the outrigger overlaps with the support plate, and a through hole provided at the overlapping portion and opposite to the support plate. The viscoelastic material fills the gap between the overlapping portion and the support plate and the through hole.

9. The disk device according to claim 8, The overlapping portion has a width greater than a width of other portions of the outrigger.

10. The disk device according to claim 9, The support plate has a recess, which is disposed at a position opposite to the overlapping portion of the outrigger and limits the expansion of the viscoelastic material.

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