Bimorph piezoelectric microactuator head and flexure assembly

• US 6,108,175 A
• Filed: 05/01/1997
• Issued: 08/22/2000
• Est. Priority Date: 12/16/1996
• Status: Expired due to Term

• Current Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Original Assignee: Seagate Technology plc (Seagate Technology Holdings Plc)
• Inventors: Hawwa, Muhammad A., Mohajerani, Khosrow, Sampietro, Joseph M., Barina, Jeffrey G., Fard, Anoush M.
• Primary Examiner(s): EVANS, JEFFERSON A
• Application Number:
  US08/836,265
• Time in Patent Office: 1,209 Days
• Field of Search: 360/103, 360/104, 360/106, 360/109, 360/294.1-294.6
• US Class Current: 360/294.4
• CPC Class Codes: G11B 5/4813 Mounting or aligning of arm assemblies, e.g. actuator arm supported by bearings, multiple arm assemblies, arm stacks or multiple heads on single arm G11B5/484 takes precedence
• CPC Class Codes: G11B 5/5552 using fine positioning means for track acquisition separate from the coarse (e.g. track changing) positioning means
• CPC Class Codes: G11B 5/596 for track following on disks G11B5/5526, G11B5/5552, G11B5/5565, G11B5/5582 take precedence
• CPC Class Codes: G11B 5/59605 Circuits G11B5/59627 - G11B5/59688 take precedence
• CPC Class Codes: G11B 5/6005 Specially adapted for spacing from a rotating disc using a fluid cushion

Abstract

A head flexure assembly for positioning a transducing head over a selected track of a rotatable disc in a disc drive system having an actulator arm and head suspension includes a bimorph piezoelectric microactuator having first and second ends. The first end of the microactuator is attached to the actuator arm, and a flexure is attached to the second end of the microactuator. A slider carrying the transducing head is attached to the flexure.

Claims

1. A head flexure assembly for radially positioning a transducing head over a selected track of a rotatable disc in a disc drive system having an actuator arm and head suspension, the head flexure assembly comprising:

a bimorph piezoelectric microactuator having first and second ends, the microactuator being bendable in response to a control signal in a plane generally parallel to the rotatable disc;

attachment means attaching the first end of the microactuator to the actuator arm;

a flexure attached to the second end of the bimorph piezoelectric microactuator; and

a slider attached to the flexure, the slider carrying the transducing head.

2. The head flexure assembly of claim 1, wherein the attachment means includes a swage plate having flaps swaged to clamp the first end of the bimorph piezoelectric microactuator.

3. The head flexure assembly of claim 1, wherein the flexure includes swaged flaps connected to the second end of the bimorph piezoelectric microactuator.

4. The head flexure assembly of claim 1, wherein the bimorph piezoelectric microactuator comprises:

a first piezoelectric layer poled in a first direction and having a first terminal to receive a first electrical potential;

a second piezoelectric layer poled in the first direction and having a second terminal to receive the first electrical potential; and

a metal shim attached between the first and second piezoelectric layers and having a third terminal for receiving a second electrical potential.

5. The head flexure assembly of claim 4, wherein the bimorph piezoelectric microactuator further comprises:

a first conductive layer covering the first piezoelectric layer and electrically connected to the first terminal;

a first insulating coating covering the first conductive layer;

a second conductive layer covering the second piezoelectric layer and electrically connected to the second terminal; and

a second insulating coating covering the second conductive layer.

6. The head flexure assembly of claim 5, wherein the first and second insulating coatings are epoxy bonded to the attachment means.

7. The head flexure assembly of claim 1, wherein the bimorph piezoelectric microactuator comprises:

a first piezoelectric layer poled in a first direction and having a first terminal to receive a first electrical potential;

a second piezoelectric layer poled in a second direction opposite the first direction and having a second terminal to receive a second electrical potential; and

a metal shim attached between the first and second piezoelectric layers.

8. The head flexure assembly of claim 7, wherein the bimorph piezoelectric microactuator further comprises:

a first conductive layer covering the first piezoelectric layer and electrically connected to the first terminal;

a first insulating coating covering the first conductive layer;

a second conductive layer covering the second piezoelectric layer and electrically connected to the second terminal; and

a second insulating coating covering the second conductive layer.

9. The head flexure assembly of claim 8, wherein the first and second insulating coatings are epoxy bonded to the attachment means.