Disk drive head suspension assembly with embedded in-plane actuator at flexure tongue
View Patent ↗A head gimbal assembly (HGA) for a disk drive includes a mounting plate configured to be attachable to an actuator arm, a load beam extending from the mounting plate, a laminated flexure, first and second piezoelectric elements, and a read head. The laminated flexure includes a fixed portion that is attached to the load beam, and a head mounting tongue that is connected to the fixed portion by first and second compliant members. The read head is bonded to the head mounting tongue. The laminated flexure also includes first and second piezoelectric element receiving windows, each adjacent a respective one of the first and second compliant members. The first and second piezoelectric elements are each disposed within a respective one of the first and second piezoelectric element receiving windows.
1. A head gimbal assembly (HGA) comprising:
a mounting plate configured to be attachable to an actuator arm;
a load beam extending from the mounting plate;
a laminated flexure including a tongue and an actuator frame, the actuator frame including a fixed portion that is attached to the tongue, and a head mounting surface that is connected to the fixed portion by first and second compliant members; the actuator frame including first and second piezoelectric element receiving windows, each adjacent a respective one of the first and second compliant members;
first and second piezoelectric elements, each being disposed within a respective one of the first and second piezoelectric element receiving windows; and
a read head bonded to the head mounting surface.
2. The HGA of claim 1 wherein the first piezoelectric element defines a piezoelectric element thickness, and a mid-plane of the piezoelectric element thickness is aligned with a neutral plane of the actuator frame.
3. The HGA of claim 2 wherein the piezoelectric element thickness is greater than the laminated flexure thickness.
4. The HGA of claim 2 wherein the piezoelectric element thickness is in the range 30 microns to 150 microns.
5. The HGA of claim 2 wherein the laminated flexure thickness is in the range 18 microns to 80 microns.
6. The HGA of claim 1 wherein the head mounting tongue, the fixed portion, and the first and second compliant members are a single component having material continuity rather than being an assembly of sub-components.
7. The HGA of claim 6 wherein the head mounting tongue, the fixed portion, the head mounting platform, and the first and second compliant members are distinct regions of a contiguous stainless steel layer, each distinct region being at least partially bounded and defined by etched openings through the contiguous stainless steel layer.
8. The HGA of claim 7 wherein the etched openings include the first and second piezoelectric element receiving windows.
9. The HGA of claim 1 wherein the laminated flexure further includes a structural layer, a dielectric layer, and a conductive layer that defines a plurality of conductive traces, and wherein the read head is electrically connected to more than one of the plurality of conductive traces, and the first and second piezoelectric elements are each electrically connected to at least one of the plurality of conductive traces.
10. The HGA of claim 1 wherein each of the first and second piezoelectric elements is a laminated piezoelectric element that comprises a plurality of layers of piezoelectric material disposed between pairs of a plurality of electrically conductive electrode layers.
11. The HGA of claim 1 wherein each of the first and second piezoelectric elements comprises a piezoelectric material selected from the group consisting of lead zirconate titanate, lead scandium tantalite, lanthanum gallium silicate, lithium tantalite, barium titanate, gallium phosphate and potassium sodium tartrate.
12. The HGA of claim 1 wherein at least one edge of the first piezoelectric element is bonded by an adhesive to an edge of the actuator frame that faces into the first piezoelectric element receiving window.
13. The HGA of claim 12 wherein the adhesive is electrically non-conductive, and is selected from the group consisting of cyanoacrylates, epoxies, polyimide adhesives, and acrylic adhesives.
14. The HGA of claim 1 wherein the first and second piezoelectric elements are disposed closer to the read head than are the first and second compliant members, wherein each of the first and second piezoelectric elements has a length in the range 0.5 mm to 1.5 mm and a width in the range 150 microns to 350 microns, and wherein the first and second piezoelectric elements are separated from each other by a separation distance in the range 0.5 mm to 1.5 mm.
15. A disk drive comprising:
a disk drive base;
a spindle attached to the disk drive base;
a disk mounted on the spindle;
a first actuator pivotally attached to the disk drive base, the first actuator including a conductive coil and an actuator arm; and
a head gimbal assembly (HGA) comprising
a mounting plate attached to the actuator arm;
a load beam extending from the mounting plate;
a laminated flexure including a tongue and an actuator frame, the actuator frame including a fixed portion that is attached to the tongue, and a head mounting surface that is connected to the fixed portion by first and second compliant members; the actuator frame including first and second piezoelectric element receiving windows, each adjacent a respective one of the first and second compliant members;
first and second piezoelectric elements, each being disposed within a respective one of the first and second piezoelectric element receiving windows; and
a read head bonded to the head mounting surface and disposed adjacent a surface of the disk.
16. The disk drive of claim 15 wherein the first piezoelectric element defines a piezoelectric element thickness, and a mid-plane of the piezoelectric element thickness is aligned with a neutral plane of the actuator frame.
17. The disk drive of claim 16 wherein the piezoelectric element thickness is greater than the laminated flexure thickness.
18. The disk drive of claim 16 wherein the piezoelectric element thickness is in the range 30 microns to 150 microns.
19. The disk drive of claim 16 wherein the laminated flexure thickness is in the range 18 microns to 80 microns.
20. The disk drive of claim 15 wherein the head mounting tongue, the fixed portion, and the first and second compliant members are a single component having material continuity rather than being an assembly of sub-components.
21. The disk drive of claim 20 wherein the head mounting tongue, the fixed portion, the head mounting platform, and the first and second compliant members are distinct regions of a contiguous stainless steel layer, each distinct region being at least partially bounded and defined by etched openings through the contiguous stainless steel layer.
22. The disk drive of claim 21 wherein the etched openings include the first and second piezoelectric element receiving windows.
23. The disk drive of claim 15 wherein the laminated flexure further includes a structural layer, a dielectric layer, and a conductive layer that defines a plurality of conductive traces, and wherein the read head is electrically connected to more than one of the plurality of conductive traces, and the first and second piezoelectric elements are each electrically connected to at least one of the plurality of conductive traces.
24. The disk drive of claim 15 wherein each of the first and second piezoelectric elements is a laminated piezoelectric element that comprises a plurality of layers of piezoelectric material disposed between pairs of a plurality of electrically conductive electrode layers.
25. The disk drive of claim 15 wherein each of the first and second piezoelectric elements comprises a piezoelectric material selected from the group consisting of lead zirconate titanate, lead scandium tantalite, lanthanum gallium silicate, lithium tantalite, barium titanate, gallium phosphate and potassium sodium tartrate.
26. The disk drive of claim 15 wherein at least one edge of the first piezoelectric element is bonded by an adhesive to an edge of the actuator frame that faces into the first piezoelectric element receiving window.
27. The disk drive of claim 26 wherein the adhesive is electrically non-conductive, and is selected from the group consisting of cyanoacrylates, epoxies, polyimide adhesives, and acrylic adhesives.
28. The disk drive of claim 15 wherein the first and second piezoelectric elements are disposed closer to the read head than are the first and second compliant members, wherein each of the first and second piezoelectric elements has a length in the range 0.5 mm to 1.5 mm and a width in the range 150 microns to 350 microns, and wherein the first and second piezoelectric elements are separated from each other by a separation distance in the range 0.5 mm to 1.5 mm.