US-20260128059-A1 - Disk Drive Suspension Assembly With Base Plate For Improved Sway Frequency

US20260128059A1US 20260128059 A1US20260128059 A1US 20260128059A1US-20260128059-A1

Abstract

A suspension assembly comprises a load beam including a proximal end terminating in a hinge, a gimbal assembly mounted to the load beam, a base plate, and PZT actuators. The base plate comprising a distal portion connected to the hinge, a proximal portion, and a neck portion disposed between the distal portion and the proximal portion, wherein the neck portion comprising side edges facing away from each other, wherein the side edges, the distal portion and the proximal portion define openings, wherein each of the side edges includes a protrusion at a center of the neck portion facing one of the openings. Each of the PZT actuators is disposed in one of the openings and mounted to the proximal portion and the distal portion.

Inventors

Kuen Chee Ee

Assignees

MAGNECOMP CORPORATION

Dates

Publication Date: 20260507
Application Date: 20251030

Claims (17)

1 . A suspension assembly comprising: a load beam including a proximal end terminating in a hinge; a gimbal assembly mounted to the load beam; a base plate comprising: a distal portion connected to the hinge, a proximal portion, and a neck portion disposed between the distal portion and the proximal portion, wherein the neck portion comprising side edges facing away from each other, wherein the side edges, the distal portion and the proximal portion define openings, wherein each of the side edges includes a protrusion at a center of the neck portion facing one of the openings; and PZT actuators each disposed in one of the openings and mounted to the proximal portion and the distal portion.
2 . The suspension assembly of claim 1 , wherein the neck portion comprises: a first width at the center of the neck portion, a second width adjacent the proximal portion, a third width adjacent the distal portion, and the first width is greater than the second width and the third width.
3 . The suspension assembly of claim 1 , wherein each of the protrusions is bonded to one of the PZT actuators.
4 . The suspension assembly of claim 1 , wherein the distal portion includes a distal edge facing away from the proximal portion, and wherein the distal edge includes a notch.
5 . The suspension assembly of claim 1 , wherein the distal portion includes a distal edge facing away from the proximal portion, and wherein the distal edge includes two notches.
6 . The suspension assembly of claim 5 , wherein the distal edge includes a protrusion disposed between the two notches.
7 . The suspension assembly of claim 5 , wherein the distal portion has a first thickness except for two thin portions of the distal portion which have a second thickness less than the first thickness, and wherein the two notches are disposed between the two thin portions.
8 . The suspension assembly of claim 1 , wherein the distal portion comprises: a distal edge facing away from the proximal portion; and a first thickness except for two thin portions of the distal portion which have a second thickness less than the first thickness, wherein the two thin portions are disposed along the distal edge.
9 . The suspension assembly of claim 1 , wherein the distal portion comprises: a distal edge facing away from the proximal portion; and a first thickness except for a thin portion of the distal portion which has a second thickness less than the first thickness, wherein the thin portion is disposed along the distal edge.
10 . The suspension assembly of claim 9 , wherein the thin portion is disposed along a center portion of the distal edge.
11 . A suspension assembly comprising: a load beam including a proximal end terminating in a hinge; a gimbal assembly mounted to the load beam; a base plate comprising: a distal portion connected to the hinge, a proximal portion, and a neck portion disposed between the distal portion and the proximal portion, wherein the neck portion comprising side edges facing away from each other, wherein the side edges, the distal portion and the proximal portion define openings, wherein the distal portion includes a distal edge facing away from the proximal portion, wherein the distal edge includes a notch; and PZT actuators each disposed in one of the openings and mounted to the proximal portion and the distal portion.
12 . The suspension assembly of claim 11 , wherein the neck portion has a uniform width.
13 . The suspension assembly of claim 11 , wherein the side edges are straight.
14 . The suspension assembly of claim 11 , wherein the distal edge terminates in two sharp corners.
15 . The suspension assembly of claim 14 , wherein the notch is disposed between the two sharp corners.
16 . The suspension assembly of claim 11 , wherein: the distal portion has a first width; the proximal portion has a second width; and the first width is less than the second width.
17 . The suspension assembly of claim 14 , wherein: the distal portion has a first width; the proximal portion has a second width; and the first width is less than the second width.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of, and priority to, U.S. Provisional Application No. 63/716,907 filed on Nov. 6, 2024, which is hereby incorporated by reference in its entirety. FIELD OF THE INVENTION The present disclosure relates generally to suspension assemblies for supporting read/write heads over recording media in magnetic disk drive storage devices. BACKGROUND OF THE INVENTION Storage devices such as magnetic disk drive storage devices (“disk drives”) store data on, and read data from, a spinning disk medium using a read/write head positioned over the surface of the spinning disk medium. A suspension assembly is used to position the read/write head over concentric tracks of the spinning disk medium. As an example, as shown in FIG. 1, a suspension assembly 2 can include a load beam 4 with a gimbal assembly 6 (containing a read/write head) mounted near the distal end of the load beam 4 that allows the read/write head to fly closely over the surface of the spinning disk medium during operation. The proximal end of the load beam 4 terminates in a hinge 8 that is connected to a distal portion 10a of a base plate 10. A proximal portion 10b of the base plate 10 is connected to an actuator arm 12, which is connected to an actuator motor (not shown) that rotates the actuator arm 12, thus moving the entire suspension assembly 2 relative to the spinning disk medium. During operation, the actuator motor is used to move the read/write head in a side-to-side direction, to position the read/write head over a desired concentric track of the spinning disk to write data to, or read data from, the desired concentric track. As disk drive manufactures continue to develop smaller yet higher storage capacity drives, the density of the concentric tracks on the disk increases, making them narrower and more closely spaced. As track density increases, however, it becomes increasingly difficult for the actuator motor to quickly and accurately position the read/write head over the desired concentric track. Therefore, it has become known to use a pair of piezoelectric (PZT) actuators 14 mounted between the proximal portion 10b and distal portion 10a of the base plate 10 to move the position of the read/write head, as shown in FIG. 2. Specifically, the base plate 10 includes a neck portion 10c extending between, and having a smaller width than, the proximal portion 10b and distal portion 10a, defining openings 10d in which the PZT actuators 14 are mounted. The PZT actuators 14 expand and contract in response to electrical signals, to displace the distal portion 10a relative to the proximal portion 10b by flexing the neck portion 10c, which in turn displaces the read/write head located near the distal end of the load beam 4. Thus, higher track positioning resolution can be achieved by complimenting the course positioning of the read/write head by the actuator motor with the fine positioning of the read/write head by the PZT actuators 14. In a disk drive suspension assembly, the “sway frequency” refers to the natural frequency at which the read/write head oscillates sideways, essentially a side-to-side vibration mode of the suspension assembly. Sway frequency is a key parameter indicating the stability and performance of the read/write head movement during data access. A higher sway frequency generally corresponds to better stability and performance. Another parameter of disk drive suspension assemblies is the total operational displacement of the distal portion 10a of base plate 10 caused by the expanding/contracting PZT actuators, which is also referred to as stroke sensitivity. A higher stroke sensitivity also generally corresponds to better stability and performance. However, design modifications to increase sway frequency can decrease stroke sensitivity, and vice versa. For example, increasing the width of neck portion 10c can increase the sway frequency, but will decrease stroke sensitivity. There is a need to improve the performance of the fine positioning by the PZT actuators by increasing sway frequency with only a minimal impact on stroke sensitivity. BRIEF SUMMARY OF THE INVENTION The aforementioned problems and needs are addressed by a suspension assembly comprising a load beam including a proximal end terminating in a hinge, a gimbal assembly mounted to the load beam, a base plate, and PZT actuators. The base plate comprises a distal portion connected to the hinge, a proximal portion, and a neck portion disposed between the distal portion and the proximal portion. The neck portion comprises side edges facing away from each other; and the side edges, the distal portion and the proximal portion define openings, and each of the side edges includes a protrusion at a center of the neck portion facing one of the openings. Each of the PZT actuators is disposed in one of the openings and mounted to the proximal portion and the distal portion. In other embodiments, a suspension assem