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Title:
CO-LOCATED GIMBAL-BASED DSA DISK DRIVE SUSPENSION WITH TRACES ROUTED AROUND SLIDER PAD
Document Type and Number:
WIPO Patent Application WO/2017/197030
Kind Code:
A1
Abstract:
A suspension having a DSA structure on a gimbaled flexure includes a loadbeam and a flexure attached to the loadbeam. The flexure includes a metal layer with a pair of spring arms, a tongue including a slider mounting surface, and a pair of struts connecting the pair of spring arms to the tongue. The suspension further includes a pair of traces including one or more insulated conductors and being routed around opposite sides of the slider mounting surface, over the pair of struts to a set of terminal contacts on a distal portion of the tongue. The suspension also includes a motor mounted on the flexure, the motor having opposite lateral ends, the motor orientated laterally across the flexure such that the opposite lateral ends of the motor are on opposite lateral sides of the flexure. Electrical activation of the motor rotates the slider mounting surface relative to the loadbeam.

Inventors:
BJORSTROM JACOB D (US)
POKORNOWSKI ZACHARY A (US)
WHEATLEY JOSEPH C (US)
Application Number:
PCT/US2017/032024
Publication Date:
November 16, 2017
Filing Date:
May 10, 2017
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
HUTCHINSON TECHNOLOGY (US)
International Classes:
G11B5/48
Foreign References:
US20140098440A12014-04-10
Attorney, Agent or Firm:
MOONEY, Christopher M. (US)
Download PDF:
Claims:
CLAIMS

What is claimed is:

1. A suspension having a dual stage actuation (DSA) structure on a gimbaled flexure comprising:

a loadbeam;

a flexure attached to the loadbeam, the flexure including a metal layer, the metal layer comprising:

a pair of spring arms;

a tongue comprising a slider mounting surface; and

a pair of struts including a first strut and a second strut, the pair of struts connecting the pair of spring arms to the tongue, the first strut having a distal-most edge, the second strut having a proximal-most edge;

a pair of traces, each trace in the pair of traces including one or more insulated conductors, the pair of traces being routed around opposite sides of the slider mounting surface, over the pair of struts to a set of terminal contacts on a distal portion of the tongue; and

a motor mounted on the flexure, the motor having opposite lateral ends, the motor orientated laterally across the flexure such that the opposite lateral ends of the motor are on opposite lateral sides of the flexure, wherein electrical activation of the motor rotates the slider mounting surface relative to the loadbeam.

2. The suspension of claim 1, further comprising:

a first electrical contact pad in electrical communication with the motor; and a second electrical contact pad in electrical communication with the motor, wherein the first electrical contact pad is in electrical communication with at least one of the insulated conductors of the traces and provides a power supply to drive the motor, and wherein the second electrical contact pad is in electrical communication with the metal layer and provides a ground connection to the motor.

3. The suspension of claim 2, wherein the first electrical contact pad and the second electrical contact pad are separate from the tongue and on opposite sides of the tongue in an approximately symmetrical arrangement about a longitudinal midline of the flexure.

4. The suspension of claim 3, further comprising tethers connecting the each of the traces to the adjacent one of the first electrical contact pad and the second electrical contact pad.

5. The suspension of claim 2,

wherein each spring arm comprises an outer arm portion, an inner arm portion, and a distal bend that connects the inner arm portion to the outer arm portion,

wherein the pair of struts respectively connect to the inner arm portions of the pair of spring arms, and

wherein the first and second electrical contact pads are located between the outer arm portion the inner arm portion of each spring arm on opposing sides of the flexure.

6. The suspension of claim 5, further comprising conductive adhesive electrically connecting the first electrical contact pad to the at least one of the insulated conductors, wherein the first electrical contact pad is separated by gaps between both the outer arm portion and the inner arm portion of an adjacent spring arm of the pair of spring arms, the gap being configured to mitigate electrical shorting between the metal layer and the at least one of the insulated conductors caused by spillover of the conductive adhesive during a manufacturing process.

7. The suspension of claim 1, wherein the pair of traces are routed around opposite sides of the tongue.

8. The suspension of claim 1, wherein electrical activation of the motor bends the pair of struts to rotate the tongue relative to the loadbeam.

9. The suspension of claim 1, wherein the metal layer further comprises a base portion from which the pair of spring arms extend distally.

10. The suspension of claim 9, wherein the pair of traces extend from the base portion to the tongue without extending laterally beyond the pair of spring arms.

11. The suspension of claim 1, wherein each trace comprises at least one tether connecting the trace to an adjacent spring arm of the pair of spring arms.

12. The suspension of claim 1, further comprising a slider mounted on the slider mounting surface of the tongue, wherein the motor is located along an opposing side of the tongue relative to the slider mounting surface.

13. The suspension of claim 1, wherein the pair of struts are the only part of the metal layer that connects between the pair of spring arms and the tongue.

14. The suspension of claim 1, wherein each trace in the pair of traces is routed to avoid contact with the slider mounting surface.

15. A suspension having a dual stage actuation (DSA) structure on a gimbaled flexure comprising:

a loadbeam;

a flexure attached to the loadbeam, the flexure including a metal layer, the metal layer comprising:

a pair of spring arms;

a tongue comprising a slider mounting surface; and

a pair of struts including a first strut and a second strut, the pair of struts connecting the pair of spring arms to the tongue, the first strut having a distal-most edge, the second strut having a proximal-most edge;

a pair of traces, each trace including one or more insulated conductors routed to a set of terminal contacts on a distal portion of the tongue;

a motor mounted on the flexure, the motor having opposite lateral ends, the motor orientated laterally across the flexure such that the opposite lateral ends of the motor are on opposite lateral sides of the flexure, wherein electrical activation of the motor rotates the slider mounting surface relative to the loadbeam;

a first electrical contact pad in electrical communication with the motor;

conductive adhesive electrically connecting the first electrical contact pad to the at least one of the insulated conductors; and a second electrical contact pad in electrical communication with the motor, wherein the first electrical contact pad is in electrical communication with at least one of the insulated conductors of the traces and provides a power supply to drive the motor, wherein the second electrical contact pad is in electrical communication with the metal layer and provides a ground connection to the motor, and

wherein the first electrical contact pad is separated by gap from an adjacent spring arm of the pair of spring arms, the gap being configured to mitigate electrical shorting between the metal layer and the at least one of the insulated conductors caused by spillover of the conductive adhesive during a manufacturing process.

16. The suspension of claim 15, wherein the first electrical contact pad and the second electrical contact pad are separate from the tongue and on opposite sides of the tongue in an approximately symmetrical arrangement about a longitudinal midline of the flexure.

17. The suspension of claim 16, further comprising tethers connecting the each of the traces to the adjacent one of the first electrical contact pad and the second electrical contact pad.

18. The suspension of claim 15,

wherein each spring arm comprises an outer arm portion, an inner arm portion, and a distal bend that connects the inner arm portion to the outer arm portion,

wherein the pair of struts respectively connect to the inner arm portions of the pair of spring arms,

wherein the first and second electrical contact pads are located between the outer arm portion the inner arm portion of each spring arm on opposing sides of the flexure.

19. The suspension of claim 18, wherein the first electrical contact pad is separated by gaps between both the outer arm portion and the inner arm portion of an adjacent spring arm of the pair of spring arms, the gap being configured to mitigate electrical shorting between the metal layer and the at least one of the insulated conductors caused by spillover of the conductive adhesive during a manufacturing process.

20. The suspension of claim 15, further comprising a slider mounted on the slider mounting surface of the tongue, wherein the motor is located along an opposing side of the tongue relative to the slider mounting surface.

Description:
CO-LOCATED GIMBAL-BASED DSA DISK DRIVE SUSPENSION

WITH TRACES ROUTED AROUND SLIDER PAD

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims priority to Provisional Application No. 62/335,150, filed May 12, 2016, which is herein incorporated by reference in its entirety.

TECHNICAL FIELD

[0002] The present disclosure relates to disk drives and suspensions for disk drives.

BACKGROUND

[0003] Dual stage actuation (DSA) suspension disk drive head suspensions and disk drives incorporating DSA suspensions are generally known and commercially available. For example, DSA suspensions having an actuation structure on the baseplate or other mounting portion of the suspension, i.e., proximal to the spring or hinge region of the suspension, are described in the Okawara U.S. Patent 8,199,442, the Shum U.S. Patent 8,665,567, the Fuchino U.S. Patent 8,405,934 and the Imamura U.S. Patent 5,764,444. DSA suspensions having actuation structures located on the loadbeam or gimbal portions of the suspension, i.e., distal to the spring or hinge region, are also known and disclosed, for example, in the Jurgenson U.S. Patent 5,657,188, the Krinke U.S. Patent 7,256,968 and the Yao U.S. Patent Publication No. 2008/0144225. Co-located gimbal-based DSA suspensions are disclosed in the Miller U.S. Patents 8,681,456, 8,896,970 and 9,147,413. All of the above-identified patents and patent applications are incorporated herein by reference in their entirety for all purposes.

[0004] There remains a continuing need for improved DSA suspensions. DSA suspensions with enhanced performance capabilities are desired. The suspensions should be capable of being efficiently manufactured.

SUMMARY

[0005] Various examples concern a suspension having a DSA structure on a gimbaled flexure includes a loadbeam and a flexure attached to the loadbeam. The flexure includes a metal layer, the metal layer including a pair of spring arms, a tongue including a slider mounting surface, and a pair of struts including a first strut and a second strut. The pair of struts connects the pair of spring arms to the tongue, the first strut having a distal-most edge, the second strut having a proximal-most edge. The suspension further includes a pair of traces, each trace in the pair of traces including one or more insulated conductors, the pair of traces being routed around opposite sides of the slider mounting surface, over the pair of struts to a set of terminal contacts on a distal portion of the tongue. The suspension also includes a motor mounted on the flexure, the motor having opposite lateral ends, the motor orientated laterally across the flexure such that the opposite lateral ends of the motor are on opposite lateral sides of the flexure. Electrical activation of the motor rotates the slider mounting surface relative to the loadbeam.

[0006] Various examples concern suspension having a DSA structure on a gimbaled flexure comprising a loadbeam, and a flexure attached to the loadbeam, the flexure comprising a metal layer. The metal layer includes a pair of spring arms, a tongue comprising a slider mounting surface, and a pair of struts including a first strut and a second strut, the pair of struts connecting the pair of spring arms to the tongue, the first strut having a distal- most edge, the second strut having a proximal-most edge. The suspension further includes a pair of traces, each trace including one or more insulated conductors routed to a set of terminal contacts on a distal portion of the tongue. The suspension also includes a motor mounted on the flexure, the motor having opposite lateral ends, the motor orientated laterally across the flexure such that the opposite lateral ends of the motor are on opposite lateral sides of the flexure, wherein electrical activation of the motor rotates the slider mounting surface relative to the loadbeam. The suspension also includes a first electrical contact pad in electrical communication with the motor, conductive adhesive electrically connecting the first electrical contact pad to the at least one of the insulated conductors, and a second electrical contact pad in electrical communication with the motor. The first electrical contact pad is in electrical communication with at least one of the insulated conductors of the traces and provides a power supply to drive the motor. The second electrical contact pad is in electrical communication with the metal layer and provides a ground connection to the motor. The first electrical contact pad is separated by gap from the adjacent spring arm, the gap being configured to mitigate electrical shorting between the metal layer and the at least one of the insulated conductors caused by spillover of the conductive adhesive during a manufacturing process.

[0007] Further features and modifications of the various examples are further discussed herein and shown in the drawings. While examples are disclosed, still other embodiments of the present disclosure will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative examples of this disclosure. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] FIG. 1 is an isometric view of the loadbeam side of a suspension assembly having a DSA gimbal in accordance with examples of the invention.

[0009] FIG. 2 is a detailed isometric view of the loadbeam side of the suspension of

FIG. 1.

[0010] FIG. 3 is an isometric view of a distal portion of the gimbal side of the suspension of FIGs. 1 and 2.

[0011] FIG. 4 is a top view of the flexure and DSA structure of FIG. 3 illustrating conductive traces within the flexure.

[0012] FIG. 5 illustrates the flexure and DSA structure of FIG. 4 with the addition of the head slider.

[0013] FIG. 6 is an isometric view of the metal layer of the flexure of FIGs. 1-3 prior to the formation of the T-shaped sway limiter.

[0014] FIG. 7 is an isometric view of the flexure and DSA structure of FIGs. 1-3 from the loadbeam side of the suspension.

[0015] FIG. 8 illustrates the flexure and DSA structure of FIG. 7 with the addition of the motor.

DESCRIPTION OF THE INVENTION

[0016] Disk drive suspensions can be susceptible to unwanted swaying, particularly

DSA suspensions designed to articulate laterally over disk media. Various features that can be employed to prevent unwanted sway and/or arrest sway motion in DSA suspensions are presented herein. Disclosed techniques further facilitate efficient manufacturing of such DSA suspensions.

[0017] FIG. 1 is an isometric view of the loadbeam side of a suspension 10 having a flexure 12 with a co-located or gimbal-based DSA structure 14. FIG. 2 is a detailed isometric view of the loadbeam 18 and the DSA structure 14 of FIG. 1. The suspension 10 includes a baseplate 16 as a proximal mounting structure and a loadbeam 18 having a rigid or beam region 20 coupled to the baseplate 16 along a spring or hinge region 22. Each of the baseplate 16 and the loadbeam 18 can be formed from metal, such as stainless steel. A gimbal 24 is located at the distal end of the flexure 12. A DSA structure 14 is located on the gimbal 24, adjacent the distal end of the loadbeam 18. A head slider 32 (FIG. 5) is mounted to the gimbal 24 on the side of the flexure 12 that is opposite the loadbeam 18. One or more transducers (not shown) for reading and/or writing to disk media are located on and/or in the head slider 32. A T-shaped sway limiter 26 extends from the flexure 12 and limits the relative motion of the flexure 12 and the head slider 32 relative to beam region 20 of loadbeam 18.

[0018] The axes key shown in FIG. 2 indicates X, Y, and Z axes. The suspension 10 is generally elongated along the X axis in distal and proximal directions. A longitudinal axis of the suspension 10 accordingly extends lengthwise along the suspension 10, parallel with the X-axis. Proximal and distal, as used herein, refers to the relative direction or position along the longitudinal axis of the suspension 10 while lateral refers to the left and right directions (along the Y-axis) orthogonal to the longitudinal axis of the suspension 10. For example, the baseplate 16 is proximal of the loadbeam 18 as shown in FIG. 1 while opposite ends of the motor 34 extend laterally. The suspension 10, including the flexure 12 and the loadbeam 18, has a generally planar orientation co-planar with the X-Y plane. The Z axis represents height or bottom and top orientations.

[0019] The distal end of the flexure 12 is cantilevered from the base portion 50. The spring arms 52 apply a force through the tongue 33 and the motor 34, to maintain contact between the motor 34 and the beam region 20 of the loadbeam 18, e.g., such as contact between the motor 34 and a dimple (not shown) on the beam region 20. Contact between the motor 34 and a dimple allows the tongue 33 and the head slider 32 to pitch and roll as needed during operation of the suspension 10, such as in response to vibration and/or wind generated by spinning disk media, as well as rotate in response to activation of the motor 34. The head slider 32 is mounted on the tongue 33. For example, the top side of the head slider 32 can be attached with adhesive to a slider mounting surface on the bottom side of the tongue 33.

[0020] The suspension 10 may utilize energy-assisted magnetic recording (EAMR) element, which uses various types of energy to selectively change the coercively of disk media, such as by heating a small area of the disk media to temporarily change the coercivity of the area just before writing. Various types of EAMR exist, such as heat-assisted magnetic recording (HAMR) and microwave assisted magnetic recording (MAMR). An EAMR element can be mounted on the tongue 33 (e.g., on a top surface of the tongue 33) and can project vertically up through the window 15 in the loadbeam 18. Examples of the present disclosure can include an EAMR element, such as in any manner disclosed in the commonly assigned Bennin U.S. Patent 8,717,712, which is incorporated by reference herein in its entirety for all purposes.

[0021] FIG. 3 is an isometric view of a distal portion of the gimbal side of the suspension 10. FIG. 4 is a top view of the flexure 12 with the co-located or gimbal-based DSA structure 14 illustrating a pair of sets of conductive traces 60 within the flexure. FIG. 5 illustrates the flexure 12 and the DSA structure 14 with the addition of the head slider 32.

[0022] The flexure 12 includes a stainless steel layer 40 (or other metal layer) that forms the main structure support of the flexure 12. The flexure 12 further includes traces 60, which include a dielectric base layer and individual conductors, the individual conductors within traces 60 being electrically isolated from the stainless steel layer 40 by the dielectric base layer.

[0023] The stainless steel layer 40 includes a base portion 50 which can be attached

(e.g., by welding) to the loadbeam 18. The stainless steel layer 40 further includes a pair of spring arms 52, a tongue 33, and struts 56, 57 that respectively connect the pair of spring arms 52 to the tongue 33. The strut 56 is offset proximally of the strut 57. In this way, the pair of struts 56, 57 can be referred to as a proximal strut 56 with the proximal-most edge and a distal strut 57 with the distal-most edge.

[0024] The traces 60 extend along the distal end of the flexure 12 between the pair of spring arms 52 and around the tongue 33. The traces 60 comprise a dielectric base layer (e.g., a polymer such as polyimide) and at least one conductor extending along the base layer. The conductors can further be covered by a cover coat of the dielectric material. The traces 60 route the conductors along the suspension 10 to electrically connect components of the suspension 10 (e.g., transducers of the head slider 32) to control circuitry of the hard disk drive. Routing the traces 60 between the spring arms 52 minimizes the width of the distal end of the flexure 12 and minimizes the use of material as compared to routing the traces 60 outside of the pair of spring arms 52. In some examples, no part of either trace 60 extends laterally beyond either of the spring arms 52. For example, each trace 60 can extend from the base portion to the tongue 33 while being entirely between the lateral spring arms 52. In some examples, each trace 60 extends from the base portion 50 to the tongue 33 while no part of the trace 60 is laterally beyond either spring arm 52, wherein the trace 60 may overlap with a spring arm 52. In some alternative examples, each of the traces 60 extends from the base portion 50 to the tongue 33 substantially between the lateral spring arms 52, wherein a portion of each of the traces 60 may extend laterally beyond a spring arm 52 to a minor degree. It is noted that routing the traces 60 between the spring arms 52 may have a tendency to increase sway gain.

[0025] As shown in FIGS. 3 - 5, the pair of conductive traces 60 are routed around opposite sides of the slider mounting surface 31, over the pair of struts 56, 57 and include distal bends 63 to reach a set of terminal contacts 62 on a distal portion of the tongue 33. In this example, not only are the conductive traces 60 are routed around opposite sides of the slider mounting surface 31, but the conductive traces 60 are also routed around opposite sides of the tongue 33. By routing the conductive traces 60 around opposite sides of the slider mounting surface 31, contact is avoided with the slider mounting surface 31.

[0026] The conductive traces 60 include optional tethers 61 within the dielectric base layer that provide an intermediate mechanical contact point with the adjacent lateral spring arm 52 over the span between the base portion 50 and the struts 56, 57. The tethers 61 function to help maintain the traces 60 in a flat planar configuration rather than a twisted configuration.

[0027] The motor 34 is located along an opposing side of the tongue 33 relative to the slider mounting surface 31. One or more conductors of the conductive traces 60 provide a power supply to drive the motor 34. The one or more insulated conductors of the conductive traces 60 further connect, via a conductive contact pad 64 of the conductive traces 60 to an electrical contact pad 44 of the stainless steel layer 40. Contact pad 44 serves as the positive terminal for the motor 34. A conductive adhesive may connect at least one of the insulated conductors within the conductive traces 60 to the electrical contact pad 44 such that the least one of the insulated conductors within the conductive traces 60 is in electrical communication with the electrical contact pad 44.

[0028] The electrical contact pad 44 within the stainless steel layer 40 is separated by gaps between both the outer arm portion and the inner arm portion of the adjacent spring arm 52, and in the illustrated example the electrical contact pad 44 is an island within the stainless steel layer 40. The gap 68 between the inner arm portion of the adjacent spring arm 52 and the electrical contact pad 44. The gap 68 is configured to mitigate electrical shorting between the stainless steel layer 40 and the at least one of the insulated conductors caused by spillover of the conductive adhesive during a manufacturing process. This may improve the repeatability of the manufacturing process and result in a higher proportion of useable suspensions. The conductive traces 60 further include a tether 66 within the dielectric layer that extends between the electrical contact pad 44 and the adjacent spring arm 52. The tether 66 may help maintain the electrical contact pad 44 within a common plane as the stainless steel layer 40 of the flexure 12 during assembly of the suspension 10.

[0029] The stainless steel layer 40 further includes an electrical contact pad 45 within the stainless steel layer 40 opposite the electrical contact pad 44. The electrical contact pad 45 is an extension of the spring arms 52, and serves as the negative terminal for the motor 34 by providing a ground connection for the motor 34. As the negative terminal, the electrical contact pad 45 directly connects to the adjacent spring arm 52 of the stainless steel layer 40 (the stainless steel layer 40 is connected to ground). Otherwise, the configuration of the electrical contact pad 45, the adjacent spring arm 52 and the adjacent conductive trace 60 is approximately symmetrical to that of the electrical contact pad 44 and its adjacent spring arm 52 and conductive trace 60. For example, both the electrical contact pad 44 and the electrical contact pad 45 are separate from the tongue 33 and on opposite sides of the tongue 33 in an approximately symmetrical arrangement about a longitudinal midline of the flexure 12.

[0030] The arrangement of the conductive traces 60 and the spring arm 52 adjacent the electrical contact pad 45 is largely to provide symmetry with the structures adjacent the electrical contact pad 44 within the dielectric layer of conductive traces 60. For example, the conductive traces 60 include a nonconductive contact pad 65, which is approximately symmetrical to the conductive contact pad 64. Within conductive traces 60, the electrical contact pad 45 is separated by gaps between both the outer arm portion and the inner arm portion of the adjacent spring arm 52. However, while the gap 68 functions to mitigate electrical shorting between the stainless steel layer 40 and the at least one of the insulated conductors caused by spillover of the conductive adhesive applied during a manufacturing process to connect the conductive contact pad 64 with the electrical contact pad 44, it is not necessary to use conductive adhesive to connect the nonconductive contact pad 65 to the electrical contact pad 45. Instead, the gap 69 is included to provide symmetry with the gap 68. As another example, the conductive traces 60 further include a tether 67 within the dielectric layer that extends between the electrical contact pad 45 and the adjacent spring arm 52. However, while the tether 66 may help maintain the electrical contact pad 44 within a common plane as the stainless steel layer 40 of the flexure 12 during assembly, the contact pad 45 is directly connected to the stainless steel layer 40 of the flexure 12 such that the tether 67 is not needed to constrain the electrical contact pad 45 during assembly. Instead, the tether 67 is included to provide symmetry with the tether 66

[0031] In comparison to alternative designs in which the conductive traces 60 run through a slider mounting surface, the DSA structure 14 limits or eliminates traces or polymer layers from between the stainless steel layer 40 of the flexure 12 and the head slider 32. Such a configuration reduces a standoff height for the head slider 32, and may also facilitate HAMR compatibility in that the stainless steel layer 40 remains uncovered by conductive traces 60 to allow room for HAMR components adjacent window 15. In addition, the configuration of the conductive traces 60 provides for approximate symmetry between conductive traces 60.

[0032] FIG. 6 is an isometric view of the stainless steel layer 40 of the flexure 12 prior to the formation of the T-shaped sway limiter 26. FIG. 7 is an isometric view of the flexure 12 and the DSA structure 14 from the loadbeam side of the suspension 10. FIG. 8 illustrates the flexure 12 and the DSA structure 14 as shown in FIG. 7 with the addition of the motor 34.

[0033] As shown in FIG. 6, the stainless steel layer 40 forms the spring arms 52, the struts 56, 57, and the tongue 33. Each spring arm 52 is elongated along the gimbal 24. The spring arms 52 are respectively on opposite lateral sides of the gimbal 24. The spring arms 52 support the tongue 33. The tongue 33 is an elongated portion (elongated along the X axis) that is located between the spring arms 52.

[0034] As shown in FIG. 6, each of the spring arms 52 includes an outer arm portion

41 and an inner arm portion 42. Each outer arm portion 41 is continuous with a respective inner arm portion 42 via a distal bend 43 in the spring arm 52. The pair of struts 56, 57 connects and supports the tongue 33 between the spring arms 52 within the stainless steel layer 40. Specifically, in this example, the struts 56, 57 can be the sole structural linkage between the spring arms 52 and the tongue 33. Also in this example, the struts 56, 57, in connecting with the tongue 33, can be the only part of the stainless steel layer 40 that connects between the spring arms 52 distal of the base portion 50. As shown, the struts 56, 57 can each be the narrowest part of the stainless steel layer 40 in an X-Y plane while the thickness of the stainless steel layer 40 can be consistent along the flexure 12. As shown, the struts 56, 57 are offset from one another. Specifically, the strut 56 is located proximally with respect to the strut 57. This offset arrangement facilitates rotational movement of the tongue 33. [0035] For example, as the motor 34 (FIG. 8) expands or contracts, the spring arms

52, on which opposite ends of the motor 34 are mounted, are laterally pushed outward or pulled inward, which correspondingly laterally pulls the struts 56, 57 outward or pushes the struts 56, 57 inward at the offset points at which the struts 56, 57 connect to the tongue 33. The pushing or pulling of the struts 56, 57 on the tongue 33 at the offset points applies a torque or moment to the tongue 33 between the struts 56, 57, which rotates the tongue 33. The motor 34 can be a piezoelectric element. The motor 34 expands and contracts when electrically activated by a drive signal delivered by control circuitry of the hard disk drive. The motor 34 is mounted to the gimbal 24 of the flexure 12 between the loadbeam 18 and the head slider 32. Activation of the motor 34 actuates the tongue 33, and the head slider 32 mounted thereon. Rotation or other tracking of the head slider 32 provides fine position control of the read/write transducers of the head slider 32 to selectively scan over specific sectors of disk media. For example, rotation of head slider relative to a beam region of a loadbeam 18 is described in the commonly assigned Miller U.S. Patent 8,896,970, which is incorporated by reference herein in its entirety for all purposes.

[0036] Also, the manner in which the traces 60 are routed to connect with the tongue

33, or elements fixed to the tongue 33, can imbalance the tongue 33. For example, tension within the traces 60 can apply a force to the tongue 33, offsetting the rotational balance of the tongue 33. Rotational imbalance of the tongue 33 can increase sway gain. Routing the traces 60 between the spring arms 52 to minimize suspension width and/or adding an EAMR element, risks misbalancing the tongue 33 and increasing sway gain. However, the present disclosure provides features that counteract such misbalancing.

[0037] For example, stainless steel layer 40 may be designed to be as symmetric as possible about its midline. Minimal exceptions to the symmetry of stainless steel layer 40 include struts 56, 57 being asymmetrical from one another. In addition, electrical contact pad 45 is an extension of the spring arms 52 and serves as the negative terminal for the motor 34, whereas the electrical contact pad 44 is separated from the spring arms 52.

[0038] Although the present disclosure has been described with reference to the examples, those skilled in the art will recognize that changes can be made in form and detail without departing from the spirit and scope of the disclosure. For example, although described in connection with certain co-located DSA structures, stiff eners and associated features described herein can be used in connection with motors on other DSA structures, including other co-located DSA structures. In addition, the examples of the present disclosure can be modified with any feature disclosed in commonly owned Miller U.S. Patent 8,675,314; Miller U.S. Patent 8,681,456; Miller U.S. Patent 8,891,206; and Miller U.S. Patent 8,896,968, each of which is incorporated herein in its entirety for all purposes. Moreover, any of the examples of such disclosures can be modified in view the present disclosure.