Flexure assembly and disk drive suspension including the flexure assembly - Patents.com

The flexure assembly with a gimbal portion and microactuators enhances disk drive suspension performance by reducing stiffness and improving tracking accuracy through optimized actuator placement and circuit design.

JP7619769B2Active Publication Date: 2025-01-22MAGNECOMP CORP
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Patent Information

Application Number
JP2020089104
Authority / Receiving Office
JP · JP
Patent Type
Patents
Current Assignee / Owner
Priority Date
2020-05-13
Filing Date
2020-05-21
Publication Date
2025-01-22
Estimated Expiration
2040-05-21

AI Technical Summary

Technical Problem

Existing disk drive suspensions face challenges in accurately positioning the head slider over data tracks due to sensitivity to disk vibrations and surface irregularities, and dual-stage actuated suspensions require improvements in actuator placement and stiffness reduction.

Method used

A flexure assembly with a gimbal portion, microactuator elements, and an unsupported conductive circuit portion is introduced, which simplifies manufacturing and reduces stiffness by optimizing the placement of microactuators and conductive circuits, enhancing the suspension's ability to follow data tracks.

Benefits of technology

The flexure assembly improves the suspension's responsiveness and tracking accuracy by minimizing deflection and stiffness, allowing for better alignment and reduced sensitivity to disk vibrations.

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Abstract

To provide a disk drive suspension including a flexure assembly, a load beam, and a flexure assembly.SOLUTION: A suspension 10 includes a gimbal portion 30 configured to receive a slider 11. The gimbal portion includes a first surface and a second surface which is opposite to the first surface. The slider is mounted on the second surface. The suspension includes a pair of microactuator elements 31, 32. The suspension also includes a tongue-shaped portion of the gimbal portion on which the slider is mounted. The tongue-shaped portion includes a dimple point which represents the center of the tongue. The suspension includes a pair of first supporting portions and a pair of second supporting portions of the gimbal portion. A pair of end portions are individually secured to the tongue-shaped portion, the first supporting portions and the pair of second supporting portions. A flexure assembly includes a conductive circuit portion 41 unsupported between a first stationary part and the pair of end portions.SELECTED DRAWING: Figure 2
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Description

[Technical field]

[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) This application claims priority to U.S. Provisional Patent Application No. 62 / 852,783, filed May 24, 2019, and U.S. Patent Application No. 15 / 931,412, filed May 13, 2020, all of which are incorporated by reference herein.

[0002] FIELD OF THE DISCLOSURE Embodiments of the present disclosure relate to the field of suspension devices for disk drives. More specifically, the present disclosure relates to the field of dual-actuated gimbal configurations for suspension devices. [Background technology]

[0003] A typical disk drive unit includes a rotating magnetic disk that contains a pattern of ones and zeros on a magnetic storage medium. The pattern of ones and zeros on the magnetic storage medium constitutes the data stored on the disk drive. The magnetic disk is driven by a drive motor. The disk drive unit also includes a disk drive suspension on which a magnetic read / write head is mounted proximate to a tip of a load beam. The "base" end of the suspension or load beam is the end that is supported, i.e., the end closest to the base plate that is swaged or otherwise attached to the actuator arm. The "tip" end of the suspension or load beam is the end opposite the base end, i.e., the "tip" end is the cantilevered end.

[0004] The suspension is coupled to an actuator arm, which is coupled to a voice coil motor that moves the suspension in an arc to position the head slider over the correct data track on the data disk. The head slider is mounted on a gimbal so that it can pitch and roll to follow the proper data track on the disk and accommodate variations in the disk, such as vibrations, inertial events such as bumping, and surface irregularities of the disk.

[0005] In a dual stage actuated (DSA) suspension, a small actuator on the suspension moves the head slider to position it over the correct data track. The actuator positions the head slider more accurately than a voice coil motor and provides higher servo bandwidth than a voice coil motor. The actuator can be located in various locations on the suspension depending on the particular DSA suspension design. Typically, the left and right actuators act in a push-pull fashion to rotate the load beam or the tip of the load beam. Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present invention is to provide a suspension device for a disk drive which further improves the above-mentioned disk drive suspension. [Means for solving the problem]

[0007] Provided herein is a flexure assembly. The flexure assembly includes a gimbal portion to which a slider is attached. The gimbal portion includes a first surface and a second surface opposite the first surface. The slider is attached to the second surface. The flexure assembly also includes a pair of microactuator elements. Each of the pair of microactuator elements is disposed on a respective side of the slider, each including a first end portion and a second end portion. The microactuator elements are attached to the second surface. The flexure assembly also includes a tongue of the gimbal portion to which the slider is attached. The tongue includes a dimple point representing a center of the tongue. The flexure assembly also includes a pair of first support portions and a pair of second support portions of the gimbal portion. The pair of end portions are individually secured to the tongue and to the first support portion and the pair of second support portions. The flexure assembly also includes a conductive circuit portion that is unsupported between the first stationary portion and the pair of end portions.

[0008] In some embodiments, the conductive circuit portion includes a conductor connected to an element of the slider. The conductor is configured to connect to electrodes of a pair of microactuator elements. The first surface is configured to face the load beam. The slider, the microactuator elements, and the conductive circuit portion are all disposed on a second surface away from the load beam.

[0009] A disk drive suspension is also provided. The disk drive suspension includes a load beam and a flexure assembly. The load beam includes a first stationary portion and a dimple. The flexure assembly includes a gimbal portion. The gimbal portion includes a first surface and a second surface opposite the first surface. The first surface faces the load beam. The flexure assembly also includes a tongue portion of the gimbal portion. The tongue portion has a dimple point. The dimple point is on a first axis passing through a center of the dimple of the load beam. The flexure assembly also includes a pair of first support portions and a pair of second support portions of the gimbal portion, to which a pair of end portions are individually secured to the tongue. The flexure assembly also includes an unsupported conductive circuit portion between the first stationary portion and the pair of end portions.

[0010] In some embodiments, the pair of first support portions are individually fixed and supported by the first stationary portion. The pair of second support portions are individually fixed and supported by the second stationary portion. The pair of end portions may be U-shaped. The tongue portion includes a fixed first tongue portion, a movable second tongue portion, and a movable third tongue portion. The tongue portion also includes a first hinge portion formed between the fixed first tongue portion and the movable second tongue portion. The tongue portion further includes a second hinge portion formed between the movable second tongue portion and the movable third tongue portion.

[0011] To illustrate how the advantages and features of the present disclosure can be obtained, embodiments of the present disclosure will be described with reference to specific examples shown in the accompanying drawings. These drawings depict only exemplary aspects of the embodiments of the present disclosure and are therefore not intended to limit its scope. The principles will be described and explained with additional specificity and detail using the following drawings. [Brief description of the drawings]

[0012] [Figure 1] 1 is a perspective view of a disk drive including a suspension according to an embodiment of the present disclosure. [Diagram 2] FIG. 2 is a top perspective view of a micro-actuator mounting portion of a suspension according to an embodiment of the present disclosure. [Diagram 3] FIG. 2 is a bottom perspective view of a micro-actuator mounting portion of a suspension according to an embodiment of the present disclosure. [Figure 4] FIG. 2 is a top view of a micro-actuator mounting portion of a suspension according to an embodiment of the present disclosure. [Diagram 5] FIG. 13 is a side view of a load beam of a suspension according to an embodiment of the present disclosure during low excitation of a torsional mode. [Figure 6] FIG. 13 is a side view of a load beam of a suspension according to an embodiment of the present disclosure during high excitation of a torsional mode. [Figure 7] 1 is a graphical representation of a resonant frequency (FRF) of a suspension according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The embodiments of the present disclosure are described with reference to the accompanying drawings, in which like reference numerals are used throughout to denote similar or equivalent elements. The drawings are not drawn to scale and are provided as an exemplary illustration. Some aspects of the embodiments are described below with reference to exemplary applications, which are not intended to limit the scope of the disclosure. Numerous specific details, relationships, and methods are set forth in order to provide a thorough understanding of the embodiments.

[0014] The embodiments described herein relate to a flexure assembly. The flexure assembly includes a gimbal portion to which a slider is attached. The gimbal portion includes a first surface and a second surface opposite the first surface. The slider is attached to the second surface. The flexure assembly also includes a pair of microactuator elements. Each of the pair of microactuator elements is disposed on a respective side of the slider, each including a first end portion and a second end portion. The microactuator elements are attached to the second surface. The flexure assembly also includes a tongue of the gimbal portion to which the slider is attached. The tongue has a dimple point, the dimple point representing a point of alignment between a dimple of the load beam and the flexure assembly. The flexure assembly also includes a pair of first support portions and a pair of second support portions of the gimbal portion. The pair of end portions are individually secured to the tongue and the first support portion and the pair of second support portions. The flexure assembly also includes an unsupported conductive circuit portion between the first stationary portion and the pair of end portions.

[0015] 1 is a perspective view of a disk drive 1 according to an embodiment of the present disclosure. Disk drive 1 can include a case 2, a disk 4, a carriage 6, and a positioning motor (voice coil motor) 7. The disk 4 is rotatable about a spindle 3. The carriage 6 is turnable about a pivot 5. A positioning motor (voice coil motor) 7 is provided to actuate the carriage 6, etc., and the case 2 is shown without a cover to show all the features therein.

[0016] The carriage 6 typically includes two or more carriage arms 8. A suspension 10 is attached to the tip of each arm 8. A slider (shown in FIG. 2) constituting one or more read / write heads is provided at the tip of the suspension 10. When each disk 4 is rotating at high speed, air flows between the disk 4 and the slider 11, forming an air bearing between the disk 4 and the slider 11. When the positioning motor 7 rotates the carriage 6, the suspension 10 moves in the radial direction relative to the disk 4. As a result, the slider 11 moves to the desired track on the disk 4.

[0017] FIG. 2 is a perspective view of a microactuator mounting portion 23 of the suspension 10. The suspension 10 may be supported by a load beam (not shown). The suspension may include a flexure 22. The flexure 22 supports a head gimbal assembly including a mounting portion 23. The mounting portion 23 of the suspension 10 is provided with a slider 11 that constitutes a read / write head. In some embodiments, the slider 11 includes a magnetoresistive (MR) element 28 that can convert between magnetic and electrical signals. The MR element 28 is located at the end of the slider 11 that constitutes a magnetic head. These elements 28 access data, i.e., write data to and read data from a disk (shown in FIG. 1).

[0018] The microactuator mounting portion 23 includes a gimbal portion 30 formed at a tip portion of the flexure 22. The microactuator elements 31, 32 are individually disposed on opposite sides of the slider 11 of the gimbal portion 30. According to some embodiments, the microactuator elements 31, 32 are formed from piezoelectric plates such as lead zirconate titanate ("PZT"). The microactuator elements 31, 32 function to rotate the slider 11 in the rocking direction by construction. By mounting the microactuator elements 31, 32 on the tongue on the same side as the slider 11, the manufacturing process is simplified. Furthermore, the location of the microactuator elements 31, 32 eases the requirement for adhesive thickness control or vertical position control since the microactuator is not between the slider and the load beam as in the conventional case.

[0019] The suspension 10 may be configured as a dual stage actuator (DSA) type, meaning two microactuator elements 31, 32 mounted on a microactuator mount 23. Any configuration of microactuator elements may be implemented herein. The microactuator mount 23 may support the microactuator elements 31, 32 and the slider 11.

[0020] The flexure 22 includes a metal base 40. In some embodiments, the metal base 40 is formed from a stainless steel plate. The suspension 10 also includes a conductive circuit portion 41 that includes one or more conductors, such as traces. The conductive circuit portion 41 includes conductors that connect to the slider 11. The conductors may also connect to electrodes of the microactuator elements 31, 32.

[0021] The majority of the length of the conductive circuit portion 41 is not supported by the metal base 40. The conductive circuit portion 41 includes a first portion 41A that overlaps the metal base 40 and a second portion 41B that does not overlap the metal base 40. The longer path of the second portion 41B makes the second portion 41B flexible. As a result, the conductive circuit portion 41 contributes less to the stiffness, and this configuration reduces stiffness compared to conventional designs. This point will be explained in more detail in relation to FIG. 7.

[0022] FIG. 3 is a bottom view of the microactuator mounting portion 23 from the opposite side of the conductive circuit portion 41. The flexure 22 has a first stationary portion 22A and a second stationary portion 22B. The metal base 40 of the flexure 22 includes a pair of first arms 51, 52 and a pair of second arms 53, 54. The first arms 51, 52 connect to the first stationary portion 22A. The second arms 53, 54 connect to the second stationary portion 22B. The pair of first arms 51, 52 include tip portions 51A, 52A. Each tip portion 51A, 52A is U-shaped. The rear ends of the second arms 53, 54 are adjacent to the tip portions 51A, 52A, respectively. The conductive circuit portion 41 is partially supported by the tip portions 51A, 52A at the first portion 41A of the first stationary portion 22A. In some embodiments, tip portions 51A, 52A are connected to tongue 90 within 30% of the length of the slider, measured from the dimple point.

[0023] The gimbal portion 30 of the flexure 22 includes a fixed first tongue portion 91, a movable second tongue portion 92, a movable third tongue portion 94, a first hinge portion 93, and a second hinge portion 95. The first hinge portion 93 is formed between the tongue portion 91 and the tongue portion 92. The second hinge portion 95 is formed between the tongue portion 92 and the tongue portion 94. The gimbal portion 30 is formed with first support portions 70 and 71. Specifically, the first support portions 70 and 71 are connected to the first stationary portion 22A of the flexure 22 via first arms 51 and 52, respectively.

[0024] Further, tip portions 51A, 52A of the first arms 51, 52 are connected to the second stationary portion 22B of the flexure 22 via the second arms 53, 54, respectively. In this manner, the first support portions 70, 71 are supported on the stationary portions 22A, 22B by the first arms 51, 52 and the second arms 53, 54, and are elastically deformed with respect to the load beam.

[0025] The microactuator elements 31, 32 are fixed to a pair of second support portions 72, 73 formed on the gimbal portion 30. A first tongue portion 91 is formed between the first support portions 70 and 71, and a second tongue portion 92 is formed between the second support portions 72 and 73. A first hinge portion 93 is formed between the first tongue portion 91 and the second tongue portion 92. A second hinge portion 95 is formed between the second tongue portion 92 and a third tongue portion 94. The first support portions 70, 71, the second support portions 72, 73, the third support portions 74, 75, the first tongue portion 91, the second tongue portion 92, the third tongue portion 94, and the hinge portions 93, 95 all form part of a metal base. The contours of each of these components are formed, for example, by etching, laser ablation, or other methods of forming and shaping metal. First tongue portion 91, second tongue portion 92, third tongue portion 94 and hinge portions 93, 95 form a tongue 90 configured to have a slider (shown in FIG. 2) disposed thereon.

[0026] FIG. 4 is a plan view of the microactuator mounting portion 23 according to an embodiment of the present disclosure. The tongue 90 includes a dimple point 12 that indicates the alignment point of the dimple on the load beam and the flexure assembly. In some embodiments, the dimple point 12 is on the same axis through the center of the dimple on the load beam and on the same axis as the axis of rotation of the hinge portion 93. The length of the conductive circuit portion 41 that is not supported by the metal base 40 is maximized by connecting the conductive circuit portion 41 to the tongue 90 near the dimple point 12. In some embodiments, the dimple point 12 is centered on the axis of rotation of the hinge portion 93. This connection also reduces the contribution to the stiffness of the gimbal portion. In some embodiments, the conductive circuit portion 41 connects to the tongue 90 at a point within 30% of the slider length measured from the dimple point 12. The connection of the metal base 40 to the tongue 90 is also near the dimple point 12. The configuration of the pair of first arms 51, 52, second arms 53, 54, and tongue 90 minimizes deflection of the tongue 90 when the suspension 10 is at different z-heights.

[0027] The microactuator elements 31, 32 can be relatively smaller than the slider 11 and are located on the leading edge side of the dimple point 12 for better mass balance. In some embodiments, each of the microactuator elements 31, 32 may have dimensions of 0.051×0.23×0.63 mm. The slider 11 has dimensions of 0.16×0.7×1.235 mm. This configuration improves mass balance of the tongue 90 for lower wobble and baseplate torsional mode gain. Referring to FIG. 7, the suspension resonant frequency (FRF) is shown for a z-height variation of + / - 0.15 mm. In some embodiments, the length of the microactuator is configured to not exceed 60% of the slider length. The gimbal portion 30 is configured to mount the microactuator such that the position of the microactuator is within 30% of the slider length measured from the dimple point 12.

[0028] FIG. 5 is a side view of the load beam 200 of the suspension 10 at a low z-height (closer to the disk) according to an embodiment of the present disclosure. The load beam 200 includes a dimple. FIG. 6 is a side view of the load beam 200 of the suspension 10 at a high z-height (away from the disk) according to an embodiment of the present disclosure. As shown, the flexure 22 is disposed along the load beam 200. As described above, the slider 11 is connected to the flexure 22. In the disclosed configuration, the stationary portions 22A, 22B along with the load beam 200 have different angles to the disk at different z-heights while the slider remains parallel to the disk in an under flying condition as if the load beam 200 were "rotating" about the dimple. Because the arms 51A, 52A and the circuit portion 41B are connected to the tongue 90 near the dimple point 12, the tongue 90 has minimal structural deflection at different z-heights. In other words, even if the load beam 200 is bending, the tongue 90 can remain significantly horizontal.

[0029] The present disclosure is provided to enable any person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other variations without departing from the scope of the disclosure. Thus, the disclosure is not intended to be limited to the examples and designs described herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. 1. A flexure assembly comprising: a gimbal portion configured to receive a slider, the gimbal portion including a first surface and a second surface opposite the first surface, the gimbal portion configured to receive the slider at the second surface; a pair of microactuator elements, each of the pair of microactuator elements disposed on each side of the slider, each of the pair of microactuator elements including a first end portion and a second end portion, the pair of microactuator elements attached to a second surface of the gimbal portion; a tongue of the gimbal portion to which the slider is attached; and a pair of first support portions and a pair of second support portions of the gimbal portion, the pair of first support portions and the pair of second support portions having a pair of end portions respectively fixed to the tongue; a conductive circuit portion unsupported between a first stationary portion and the pair of end portions, the conductive circuit portion initially connecting with a base end side of the tongue at a point within a length of the slider.

2. 2. The flexure assembly of claim 1, wherein the conductive circuit portion includes a conductor connected to an element of the slider.

3. The flexure assembly of claim 2 , wherein the conductors connect to electrodes of the pair of microactuator elements.

4. The flexure assembly of claim 1 , wherein the pair of first support portions are individually fixed and supported by a first stationary portion.

5. The flexure assembly of claim 1 , wherein the pair of second support portions are individually fixed and supported by a second stationary portion.

6. The flexure assembly of claim 1 , wherein said pair of end portions are U-shaped.

7. The flexure assembly of claim 1 , wherein the tongue includes a fixed first tongue portion and a movable second tongue portion.

8. The flexure assembly of claim 7 , wherein the tongue further includes a first hinge portion formed between the fixed first tongue portion and the movable second tongue portion.

9. 2. The flexure assembly of claim 1, wherein said first surface faces a load beam, and said slider, said microactuator element, and said conductive circuit portion are all disposed on said second surface.

10. 1. A disk drive suspension comprising: Load beam, and The flexure assembly includes: a gimbal portion having a slider attached thereto, the gimbal portion including a first surface and a second surface opposite the first surface, the slider being attached to the second surface; a pair of microactuator elements disposed on respective sides of the slider, each of the pair of microactuator elements including a first end portion and a second end portion, the pair of microactuator elements attached to the second surface; a gimbal portion tongue to which the slider is attached, the gimbal portion tongue including a dimple indicating a center of the tongue; a pair of first support parts and a pair of second support parts of the gimbal part, the pair of end parts of which are respectively fixed to the tongue; a conductive circuit portion unsupported between a first stationary portion and the pair of end portions, the conductive circuit portion initially connecting with a base side of the tongue at a point within a length of the slider.

11. 11. The disk drive suspension of claim 10, wherein the conductive circuit portion includes a conductor connected to an element of the slider.

12. The disk drive suspension of claim 11 , wherein the conductors connect to electrodes of the pair of microactuator elements.

13. 11. The disk drive suspension of claim 10, wherein the first surface faces the load beam, and the slider, the microactuator element, and the conductive circuit portion are all disposed on the second surface.

14. The disk drive suspension of claim 10 , wherein the pair of first support portions are individually fixed and supported by a first stationary portion.

15. The disk drive suspension of claim 10 , wherein the pair of second support portions are individually fixed and supported by a second stationary portion.

16. 11. The disk drive suspension of claim 10, wherein the pair of end portions are U-shaped.

17. The disk drive suspension of claim 10 , wherein the tongue includes a fixed first tongue portion and a movable second tongue portion.

18. 20. The disk drive suspension of claim 17, wherein the tongue further includes a first hinge portion formed between the fixed first tongue portion and the movable second tongue portion.

19. 1. A flexure assembly comprising: a gimbal portion configured to receive a slider and including a first surface and a second surface opposite the first surface; a tongue portion of the gimbal portion; a pair of first support parts and a pair of second support parts of the gimbal part, the pair of end parts of which are respectively fixed to the tongue; a conductive circuit portion unsupported between a first stationary portion and the pair of end portions, the conductive circuit portion initially connecting with a base end side of the tongue at a point within a length of the slider.

Citation Information

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