Disk drive head suspension assembly with piezo element stress relief features
View Patent ↗A head suspension assembly for a disk drive includes a mounting plate that may include an annular swage boss. A load beam is attached to and extends from the mounting plate in a longitudinal direction. A first piezoelectric element is disposed within a first piezoelectric element receiving window in the mounting plate. The load beam includes a first etched region that is elongated in a transverse direction that is transverse to the longitudinal direction. The first etched region neighbors the first piezoelectric element and is disposed closer to the annular swage boss than is the first piezoelectric element.
1. 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 suspension assembly comprising
a mounting plate attached to the actuator arm;
a load beam attached to and extending from the mounting plate in a longitudinal direction;
a first piezoelectric element disposed within a first piezoelectric element receiving window in the mounting plate;
wherein the load beam includes a first etched region that is elongated in a transverse direction that is transverse to the longitudinal direction, the first etched region neighboring the first piezoelectric element and being disposed closer to the actuator arm than is the first piezoelectric element; and
a read head supported by the load beam and disposed adjacent a surface of the disk.
2. The disk drive of claim 1 wherein the first etched region is a slot opening.
3. The disk drive of claim 1 wherein the first etched region is a partially-etched trench.
4. The disk drive of claim 1 wherein the first etched region has a lateral span of 0.5 to 1.25 times that of the first piezoelectric element.
5. The disk drive of claim 1 wherein the HGA further comprises a second piezoelectric element disposed within a second piezoelectric element receiving window in the mounting plate; and wherein the load beam includes a second etched region that is elongated in a transverse direction that is transverse to the longitudinal direction, the second etched region neighboring the second piezoelectric element and being disposed closer to the actuator arm than is the second piezoelectric element.
6. The disk drive of claim 5 wherein the second etched region is a slot opening.
7. The disk drive of claim 5 wherein the second etched region is a partially-etched trench.
8. The disk drive of claim 5 wherein the load beam further includes a third etched region that is elongated in the longitudinal direction, the third etched region neighboring the first piezoelectric element and being disposed closer to a bisecting centerline of the load beam than is the first piezoelectric element, the bisecting centerline being parallel to the longitudinal direction.
9. The disk drive of claim 8 wherein the third etched region is a slot opening.
10. The disk drive of claim 8 wherein the third etched region is a partially-etched trench.
11. The disk drive of claim 8 wherein the third etched region has a longitudinal span of 0.5 to 1.5 times that of the first piezoelectric element.
12. The disk drive of claim 1 wherein the load beam includes a through-opening over the first piezoelectric element, the through-opening having an inner periphery that includes a gap that is disposed along an outer edge of the first piezoelectric element, the outer edge facing away from a bisecting centerline of the load beam that is parallel to the longitudinal direction, the gap spanning no more than half of a length of the first piezoelectric element measured in the longitudinal direction.
13. The disk drive of claim 1 wherein a largest face of the first piezoelectric element defines a first piezoelectric element surface area, and the load beam overlaps the first piezoelectric element by an overlap area that is in the range 10% to 40% of the first piezoelectric element surface area.
14. The disk drive of claim 1 wherein the first piezoelectric element 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.
15. The disk drive of claim 1 wherein the first piezoelectric element is rectangular having four edges that are encapsulated by an encapsulate, the four edges consisting of two transverse edges and two longitudinal edges, and wherein the two longitudinal edges are bonded by an adhesive to corresponding edges of the mounting plate that face into the first piezoelectric element receiving window.
16. The disk drive of claim 15 wherein the adhesive is selected from the group consisting of cyanoacrylates, epoxies, polyimide adhesives, and acrylic adhesives, and wherein the encapsulate is electrically non-conductive epoxy.
17. A head suspension assembly comprising:
a mounting plate that includes an annular swage boss;
a load beam attached to and extending from the mounting plate in a longitudinal direction; and
a first piezoelectric element disposed within a first piezoelectric element receiving window in the mounting plate;
wherein the load beam includes a first etched region that is elongated in a transverse direction that is transverse to the longitudinal direction, the first etched region neighboring the first piezoelectric element and being disposed closer to the annular swage boss than is the first piezoelectric element.
18. The head suspension assembly of claim 17 wherein the first etched region is a slot opening.
19. The head suspension assembly of claim 17 wherein the first etched region is a partially-etched trench.
20. The head suspension assembly of claim 17 wherein the first etched region has a lateral span of 0.5 to 1.25 times that of the first piezoelectric element.
21. The head suspension assembly of claim 17 wherein a largest face of the first piezoelectric element defines a first piezoelectric element surface area, and the load beam overlaps the first piezoelectric element by an overlap area that is in the range 10% to 40% of the first piezoelectric element surface area.