Hard disk drive gimbal design with high torsional frequency

Abstract

A trace gimbal is described herein. In some embodiments, the trace gimbal includes an outer strut including a forward outrigger at a distal end of the trace gimbal and an aft outrigger at a proximal end of the trace gimbal. The forward outrigger includes a distal forward outrigger and a proximal forward outrigger, and the aft outrigger includes a distal aft outrigger and a proximal aft outrigger. The trace gimbal further includes a middle strut that extends across the width of the trace gimbal and adjoins the proximal forward outrigger to the aft outrigger, and an inner strut that connects the middle strut to a slider tongue. The inner strut and the middle strut adjoin the outer gimbal strut to the slider tongue.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the field of suspensions for hard disk drives. More specifically, the present disclosure relates to the field of gimbal assemblies for suspensions.

BACKGROUND ART

[0002] In disk storage devices, rotating disks are used to store information. A disk storage device typically includes a frame that provides mounting points and orientation for other components, and a spindle motor mounted to the frame for rotating the disks. The head slider includes a read / write head for writing data to and reading data from the disk surface. The head slider is supported relative to the disk and properly oriented by a suspension that provides both the force and resiliency required for proper head slider operation. When the disk in the storage device rotates beneath the head slider and the head suspension, the air above the disk also rotates to generate an air bearing. The air bearing works in conjunction with the aerodynamic design of the suspension to generate lift. The lift is counteracted by the spring force of the suspension, thereby positioning the head slider at a desired height and alignment above the disk, which is referred to as the flying height.

[0003] A suspension for a disk drive includes a load beam and a flexure. The load beam typically includes a mounting region for attaching the suspension to the actuator of the disk drive, a rigid region, and a spring region between the mounting region and the rigid region. The spring region provides a spring force to counteract the aerodynamic lift generated in the suspension during the drive operation described above. The flexure typically includes a gimbal region having a slider mounting surface to which a head slider is attached. The gimbal region is elastically movable relative to the rest of the flexure in response to the aerodynamic forces generated by the air bearings. The gimbal region can follow fluctuations in the disk surface by moving the head slider in the pitch and roll directions.

[0004] Disk drive manufacturers continue to develop drives that are smaller and have higher storage capacity. The increase in storage capacity is achieved in part by increasing the density of information tracks on the disk (i.e., by using tracks with narrower and / or denser spacing). However, as track density increases, it becomes increasingly difficult for motor and servo control systems to quickly and accurately position the read / write head on the desired track. In an attempt to improve this situation, additional or secondary actuators have been introduced, such as piezoelectric actuators, electrostatic actuators, electromagnetic actuators, or micro-tracking motors mounted on the head suspension itself. These types of actuators, also known as microactuation devices, can be positioned on a base plate, load beam, or flexure.

[0005] In some of these attempts to improve tracking and head slider positioning control, actuators have been positioned simultaneously on both the base plate and the flexate tang. Typically, this type of suspension uses a voice coil and actuator located in the base plate area for larger movements of the read / write head, while using actuators located on the flexate tang for the finer movements desired to position the read / write head on the disk drive tracks. [Overview of the project]

[0006] This specification describes a trace gimbal. According to some embodiments of this disclosure, the trace gimbal includes an outer strut which includes a forward outrigger at the distal end of the trace gimbal and a rear outrigger at the proximal end of the trace gimbal. The forward outrigger includes a distal forward outrigger and a proximal forward outrigger, and the rear outrigger includes a distal rear outrigger and a proximal rear outrigger. The trace gimbal further includes an intermediate strut which extends in the width direction of the trace gimbal and brings the proximal forward outrigger adjacent to the rear outrigger, and an inner strut which connects the intermediate strut to a slider tongue. The inner strut and the intermediate strut bring the outer gimbal strut adjacent to the slider tongue.

[0007] According to some embodiments of the present disclosure, the trace gimbal further comprises one or more microactuators attached to a slider tongue, and an inner strut supports the slider tongue.

[0008] According to some embodiments of the present disclosure, the proximal forward outrigger includes a first cross section, and the distal forward outrigger includes a second cross section, wherein the width of the second cross section is substantially the same as that of the first cross section of the proximal forward outrigger.

[0009] According to some embodiments of this disclosure, the first and second cross-sections of the forward outrigger are 0.05 mm to 0.10 mm. According to some embodiments of the present disclosure, the distal posterior outrigger includes a first cross section, and the proximal posterior outrigger includes a second cross section that is larger than the first cross section.

[0010] According to some embodiments of this disclosure, the first cross-section of the distal posterior outrigger is 0.10 mm to 0.20 mm. According to some embodiments of the present disclosure, the medial strut includes a distal end and a proximal end, the distal end of the intermediate strut is connected to the distal end of the medial strut, and the proximal end of the medial strut is connected to a slider tongue.

[0011] According to some embodiments of the present disclosure, the inner strut typically connects to the slider tongue by extending from the distal end of the intermediate strut toward the proximal end of the trace gimbal.

[0012] According to some embodiments of the present disclosure, the front outriggers and intermediate struts are typically formed in a C-shape or a U-shape. According to some embodiments of the present disclosure, the cross-section of the intermediate strut is substantially the same as the first and second cross-sections of the forward outrigger.

[0013] Suspensions with a trace gimbal are also provided according to some embodiments of the present disclosure. According to some embodiments of the present disclosure, the trace gimbal further comprises one or more microactuators attached to a slider tongue, and an inner strut supports the slider tongue.

[0014] According to some embodiments of the present disclosure, the proximal forward outrigger includes a first cross section, and the distal forward outrigger includes a second cross section, wherein the width of the second cross section is substantially the same as that of the first cross section of the proximal forward outrigger.

[0015] According to some embodiments of this disclosure, the first and second cross-sections of the forward outrigger are 0.01 mm to 0.10 mm. According to some embodiments of the present disclosure, the distal posterior outrigger includes a first cross section, and the proximal posterior outrigger includes a second cross section that is larger than the first cross section.

[0016] According to some embodiments of this disclosure, the first cross-section of the distal posterior outrigger is 0.01 mm to 0.10 mm. According to some embodiments of the present disclosure, the medial strut includes a distal end and a proximal end, the distal end of the intermediate strut is connected to the distal end of the medial strut, and the proximal end of the medial strut is connected to a slider tongue.

[0017] According to some embodiments of the present disclosure, the inner strut typically connects to the slider tongue by extending from the distal end of the intermediate strut toward the proximal end of the trace gimbal.

[0018] According to some embodiments of the present disclosure, the front outriggers and intermediate struts are typically formed in a C-shape or a U-shape. According to some embodiments of the present disclosure, the cross-section of the intermediate strut is substantially the same as the first and second cross-sections of the forward outrigger.

[0019] Although several embodiments have been disclosed, further embodiments of this disclosure will become apparent to those skilled in the art from the following detailed description, which illustrates exemplary embodiments of this disclosure. Therefore, the drawings and detailed description should be considered illustrative and not restrictive in nature.

[0020] To illustrate how the above and other advantages and features of this disclosure can be obtained, a more detailed explanation of the principles described above is given by reference to specific examples shown in the accompanying drawings. These drawings are merely illustrative of the embodiments of this disclosure and should not be construed as limiting its scope. The principles are described and explained in more specific and detail with reference to the following drawings. [Brief explanation of the drawing]

[0021] [Figure 1] A diagram showing a gimbal assembly of a suspension according to some embodiments of the present disclosure. [Figure 2] A diagram showing the roll stiffness and torsional frequency of a gimbal according to some embodiments of the present disclosure. [Figure 3A] A perspective view of an exemplary mode shape of a first gimbal torsion according to some embodiments of the present disclosure. [Figure 3B] A perspective view of an exemplary mode shape of a second gimbal torsion according to some embodiments of the present disclosure. [Figure 3C] A perspective view of an exemplary mode shape of a third gimbal torsion according to some embodiments of the present disclosure. DETAILED DESCRIPTION OF EMBODIMENTS

[0022] An improved trace gimbal is described herein. The improved trace gimbal according to some embodiments of the present disclosure is part of a suspension for a magnetic or optical disk drive unit. The disk drive unit includes a rotating magnetic or optical disk having patterns of magnetic 1s and 0s that constitute data stored on the disk. The disk is driven by a drive motor. A disk drive unit according to some embodiments includes a suspension having a load beam, a base plate, and a trace gimbal, with a head slider mounted to the trace gimbal proximate a distal end of the trace gimbal. The proximal end of the suspension or load beam is the supported end, that is, the end closest to the base plate, which is swaged or otherwise attached to the actuator arm. The distal end of the suspension or load beam is the end opposite the proximal end, that is, the distal end is the cantilevered end.

[0023] The trace gimbal is coupled to the base plate, and the base plate is coupled to the voice coil motor. The voice coil motor is configured to move the suspension in an arcuate manner to position the head slider over the correct data track of the magnetic disk. The head slider is carried on the gimbal that enables the slider to pitch and roll to follow the appropriate data track on the rotating disk, so that such variations can be accommodated without degrading performance. The variations typically include disk vibration, inertial events such as impacts, and irregularities on the disk surface.

[0024] In some embodiments, the trace gimbal described herein is part of a DSA (dual-stage actuation), three-stage, or other type of actuated suspension. The suspension may include a base plate and a load beam. The load beam includes the trace gimbal. The trace gimbal may include a mounted actuator and a gimbal assembly. The actuator is operable to act directly on the gimbal assembly of the suspension configured to include the read / write head slider.

[0025] In some embodiments, the trace gimbal may include one or more actuator joints configured to receive the actuator. The trace gimbal, according to some embodiments, includes two actuator joints located on both sides of the trace gimbal. Each actuator joint includes an actuator mounting shelf.

[0026] In some embodiments, each actuator is spread out into the respective gap in the actuator joint. The actuators are fixed to the slider tongue by adhesive. The adhesive may include conductive or non-conductive epoxy, which is appropriately applied to each end of the actuator. Positive and negative electrical connections can be made from the actuators to the trace gimbal by various techniques. As the actuated actuators extend and retract, they move the read / write head mounted on the distal end of the suspension, thereby changing the length of the gap between the mounting ends.

[0027] In some embodiments, the suspension may be configured as a single-stage suspension, a two-stage actuator, a three-stage actuator, or other configurations. In some embodiments, the three-stage suspension includes actuators positioned on the mounting plate area and the trace gimbal, respectively. Any modification of the actuators may be incorporated into the suspensions of the embodiments disclosed herein. In other words, the suspension may include more or fewer components than those shown without departing from the scope of this disclosure. However, the components shown are sufficient to disclose exemplary embodiments for carrying out the disclosed principles.

[0028] Figure 1 shows a trace gimbal 100 according to several embodiments of the present disclosure. The trace gimbal 100 includes one or more microactuators 450 attached to a slider tongue 130. The trace gimbal 100 includes an outer gimbal strut. The outer gimbal strut includes a forward outrigger 110 at the distal end of the trace gimbal 100. In some embodiments, the forward outrigger includes a proximal forward outrigger 114 and a distal forward outrigger 112. In some embodiments, the distal forward outrigger 112 and the proximal forward outrigger 114 are defined by a bend or nonlinear feature of the forward outrigger 110. In some embodiments, the distal forward outrigger 112 and the proximal forward outrigger 114 may be indistinguishable and adjacent in a linear feature where the two features are not physically distinct.

[0029] In some embodiments, the proximal forward outrigger 114 includes a first cross section, and the distal forward outrigger 112 includes a second cross section, the width of which is approximately the same as that of the first cross section of the proximal forward outrigger. In some embodiments, the first and second cross sections of the forward outrigger are 0.01 mm to 0.10 mm in width.

[0030] In some embodiments, the outer strut also includes a rear outrigger 140 at the proximal end of the trace gimbal 100. In some embodiments, the rear outrigger 140 includes a proximal rear outrigger 144 and a distal rear outrigger 142. In some embodiments, the longitudinal direction of the trace gimbal 100 is defined as the direction extending from the proximal end to the distal end of the trace gimbal 100.

[0031] In some embodiments, the distal rear outrigger 142 and the proximal rear outrigger 144 are defined by a bend or nonlinear feature of the rear outrigger 140. In some embodiments, the rear outrigger 140 is a linear feature. In some embodiments, the distal rear outrigger 142 and the proximal rear outrigger 144 may be indistinguishable and adjacent in a linear feature where the two features are not physically separated.

[0032] In some embodiments, the distal rear outrigger 142 includes a first cross section, and the proximal rear outrigger 144 includes a second cross section that is larger than the first cross section. In some embodiments, the first cross section of the distal rear outrigger is 0.01 mm to 0.10 mm. In some embodiments, the first cross section of the distal rear outrigger is substantially the same as the first and second cross sections of the forward outrigger.

[0033] In some embodiments, the trace gimbal 100 also includes an intermediate strut 120 that extends in the width direction of the trace gimbal 100 (in some embodiments substantially perpendicular to the length direction of the trace gimbal 100) and connects the front outrigger 110 to the rear outrigger 140. In other words, the front outrigger 110 and the rear outrigger 140 are adjacent at the proximal end of the intermediate strut 120. In some embodiments, the front outrigger 110 and the intermediate strut 120 are typically formed in a substantially C-shape or U-shape. In some embodiments, the cross-section of the intermediate strut 120 is 0.01 mm to 0.10 mm. In some embodiments, the cross-section of the intermediate strut 120 is substantially the same as the first and second cross-sections of the front outrigger.

[0034] In some embodiments, the trace gimbal 100 also includes an inner strut 150 that extends from the slider tongue 130 and connects an intermediate strut 120 to the slider tongue 130. The inner strut 150 (and the intermediate strut 120) support the slider tongue 130 on which the read / write head is assembled. In some embodiments, the inner strut 150 includes a distal end 152 and a proximal end 154. In some embodiments, the distal end of the intermediate strut 120 connects to the distal end 152 of the inner strut 150, and the proximal end 154 of the inner strut 150 connects to the slider tongue 130. In some embodiments, the inner strut 150 typically connects to the slider tongue 130 by extending from the distal end of the intermediate strut 120 toward the proximal end of the trace gimbal 100.

[0035] In some embodiments, the cross-sectional width of the central portion of the inner strut 150 is greater than the cross-sectional width of the proximal front outrigger 114, the distal front outrigger 112, and the intermediate strut 120. In some embodiments, the first and second cross-sectional widths of the front outriggers are 0.01 mm to 0.10 mm. In some embodiments, the first cross-sectional width of the distal rear outrigger is 0.01 mm to 0.10 mm. In some embodiments, the cross-sectional width of the intermediate strut 120 is 0.01 mm to 0.10 mm. In some embodiments, the cross-sectional width of the central portion of the inner strut is 0.10 mm to 0.25 mm.

[0036] Without being bound by any particular theory, the gimbal torsion frequency may be related to the mass and stiffness of the gimbal configuration (e.g., outriggers, intermediate struts, and inner struts). A stiffer gimbal structure can generally provide a higher gimbal torsion frequency, but high stiffness is undesirable because it reduces the flexibility of the gimbal tongue, which pitches and rolls freely. Shorter and narrower forward outriggers, according to some embodiments of this disclosure, can increase the gimbal torsion frequency in the section where there is more movement in the gimbal torsion frequency, while maintaining roll stiffness. A narrower width can increase the gimbal torsion frequency while reducing the mass of the outriggers. A narrower width can also maintain gimbal roll stiffness within an appropriate range. Intermediate struts connecting the outriggers can increase the gimbal stiffness, increase the gimbal torsion frequency, and maintain gimbal roll stiffness.

[0037] As shown in Figure 2, gimbals according to some embodiments of the present disclosure exhibit improved gimbal torsion frequencies. Specifically, the first gimbal torsion is 14.1 kHz (kilohertz) (an increase of 1.5 kHz compared to the gimbal torsion of the present gimbal configuration), the second gimbal torsion is 17.0 kHz (an increase of 1.5 kHz compared to the second gimbal torsion of the present gimbal configuration), and the third gimbal torsion is 28.6 kHz (an increase of 4.3 kHz compared to the third gimbal torsion of the present gimbal configuration).

[0038] Figures 3A to 3C show exemplary mode shapes for the first gimbal torsion, the second gimbal torsion, and the third gimbal torsion. While several embodiments have been disclosed, further embodiments within the scope of this disclosure will become apparent to those skilled in the art from the detailed description provided herein, illustrating with exemplary embodiments. Therefore, the drawings and detailed description should be considered essentially illustrative and not restrictive. Various features and variations of embodiments are discussed herein and illustrated in the drawings. While several embodiments have been disclosed, further embodiments within this disclosure will become apparent to those skilled in the art from the following detailed description, illustrating with exemplary embodiments. Therefore, the drawings and detailed description should be considered essentially illustrative and not restrictive.

Claims

1. It is a tracing gimbal, An outer strut comprising a forward outrigger at the distal end of the trace gimbal and a rear outrigger at the proximal end of the trace gimbal, wherein the forward outrigger comprises a distal forward outrigger and a proximal forward outrigger, and the rear outrigger comprises a distal rear outrigger and a proximal rear outrigger, and the longitudinal direction of the trace gimbal is defined as the direction extending from the proximal end to the distal end, An intermediate strut extending in the width direction of the trace gimbal and toward the slider tongue, wherein the width direction is perpendicular to the length direction, and the intermediate strut includes a first end connecting the proximal forward outrigger to the rear outrigger, An inner strut comprising an inner strut that connects the intermediate strut to the slider tongue such that the second end of the intermediate strut is connected to the inner strut, The inner strut connects the outer strut to the slider tongue via the intermediate strut. A trace gimbal in which the width of the cross-section of the central portion of the inner strut is greater than the width of the cross-sections of the proximal forward outrigger, the distal forward outrigger, and the intermediate strut.

2. The trace gimbal according to claim 1, comprising one or more microactuators attached to the slider tongue, wherein the inner strut supports the slider tongue.

3. The trace gimbal according to claim 1, wherein the proximal forward outrigger includes a first cross section, and the distal forward outrigger includes a second cross section, the width of which the second cross section is substantially the same as the width of which the first cross section of the proximal forward outrigger.

4. The trace gimbal according to claim 3, wherein the first and second cross-sections of the forward outrigger are 0.01 mm to 0.10 mm.

5. The trace gimbal according to claim 1, wherein the distal rear outrigger includes a first cross section, and the proximal rear outrigger includes a second cross section that is larger than the first cross section.

6. The trace gimbal according to claim 5, wherein the first cross-section of the distal rear outrigger is 0.01 mm to 0.10 mm.

7. The trace gimbal according to claim 1, wherein the inner strut includes a distal end and a proximal end, the intermediate strut is connected to the distal end of the inner strut, and the inner strut is connected to the slider tongue.

8. The trace gimbal according to claim 7, wherein the inner strut extends from the intermediate strut toward the proximal end of the trace gimbal and connects to the slider tongue.

9. The trace gimbal according to claim 1, wherein the forward outrigger and the intermediate strut together form a C-shape or a U-shape.

10. The trace gimbal according to claim 3, wherein the cross-section of the intermediate strut is the same as the first and second cross-sections of the front outrigger.

11. A suspension including a tracing gimbal, The aforementioned trace gimbal is An outer strut including a front outrigger at the distal end of the trace gimbal and a rear outrigger at the proximal end of the trace gimbal, wherein the front outrigger includes a distal front outrigger and a proximal front outrigger, and the rear outrigger includes a distal rear outrigger and a proximal rear outrigger, and the direction extending from the proximal end to the distal end is defined as the longitudinal direction, An intermediate strut extending in a width direction perpendicular to the longitudinal direction and extending toward the slider tongue, the intermediate strut including a first end connecting the proximal forward outrigger to the rear outrigger, An inner strut comprising an inner strut that connects the intermediate strut to the slider tongue such that the second end of the intermediate strut is connected to the inner strut, The inner strut connects the outer strut to the slider tongue via the intermediate strut. A suspension in which the width of the cross-section of the central portion of the inner strut is greater than the width of the cross-sections of the proximal front outrigger, the distal front outrigger, and the intermediate strut.

12. The suspension according to claim 11, comprising one or more microactuators attached to the slider tongue, wherein the inner strut supports the slider tongue.

13. The suspension according to claim 11, wherein the proximal forward outrigger includes a first cross section, and the distal forward outrigger includes a second cross section, the width of the second cross section being the same as the width of the first cross section of the proximal forward outrigger.

14. The suspension according to claim 13, wherein the first and second cross-sections of the forward outrigger are 0.01 mm to 0.10 mm.

15. The suspension according to claim 11, wherein the distal rear outrigger includes a first cross section, and the proximal rear outrigger includes a second cross section that is larger than the first cross section.

16. The suspension according to claim 15, wherein the first cross-section of the distal rear outrigger is 0.01 mm to 0.10 mm.

17. The suspension according to claim 11, wherein the inner strut includes a distal end and a proximal end, the intermediate strut is connected to the distal end of the inner strut, and the proximal end of the inner strut is connected to the slider tongue.

18. The suspension according to claim 17, wherein the inner strut extends from the intermediate strut toward the proximal end of the trace gimbal and connects to the slider tongue.

19. The suspension according to claim 11, wherein the front outrigger and the intermediate strut together form a C-shape or a U-shape.

20. The suspension according to claim 13, wherein the cross-section of the intermediate strut is substantially the same as the first and second cross-sections of the front outrigger.

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