Piezoelectric disk drive suspension motors having plated stiffeners
Various embodiments concern a gimbaled flexure having a dual stage actuation structure. The flexure comprises a gimbal on which a motor is mounted. The motor comprises a first terminal, one or more layers of piezoelectric material, and a metal stiffener disposed directly on the first terminal. The stiffener comprises a layer of metal defining a majority of a top side of the motor. The first terminal can be gold sputtered on the piezoelectric material while the stiffener can be nickel plated on the gold. The stiffener can cause the motor, and the flexure on which it is mounted, to curl upon electrical activation of the motor.
1. A suspension structure, comprising:
a gimbaled flexure; and
a motor mounted on a gimbaled portion of the flexure, the motor having a first major broad side and a second major broad side opposite the first major broad side, the motor comprising at least one layer of piezoelectric material located between the first and second major broad sides, and a metal stiffener layer plated onto and in contact with the first major broad side.
2. The suspension structure of claim 1 , wherein the stiffener layer defines a majority of the first major broad side.
3. The suspension structure of claim 1 , wherein the motor further comprises a first long side, a second long side opposite the first long side, a first end side, and a second end side opposite the first end side.
4. The suspension structure of claim 3 , wherein the stiffener layer is formed from a first type of metal, and the first type of metal is only located along the first major broad side of the motor and is not located along any of the second major broad side, the first long side, the second long side, the first end side, or the second end side.
5. The suspension structure of claim 3 , wherein a width of the stiffener layer extends from the first long side to the second long side.
6. The suspension structure of claim 1 , wherein the stiffener layer is formed from a first type of metal, the motor comprises a conductive layer, the conductive layer defines a portion of the first major broad side, the conductive layer is formed from a second type of metal, and the metal stiffener layer is plated directly on the conductive layer along the first major broad side.
7. The suspension structure of claim 6 , wherein the first type of metal is different than the second type of metal.
8. The suspension structure of claim 7 , wherein the first type of metal comprises nickel.
9. The suspension structure of claim 8 , wherein the second type of metal comprises gold.
10. The suspension structure of claim 6 , wherein the second type of metal has a lower elastic modulus than the first type of metal.
11. The suspension structure of claim 10 , wherein the first type of metal has a lower electrical conductivity than the second type of metal.
12. The suspension structure of claim 6 , wherein the stiffener layer is thicker than the conductive layer.
13. The suspension structure of claim 6 , wherein the stiffener layer is at least five times thicker than the conductive layer.
14. The suspension structure of claim 1 , wherein the thickness of the stiffener layer is approximately equal to the thickness of any one of the at least one layer of piezoelectric material.
15. The suspension structure of claim 1 , wherein the stiffener layer is raised relative to all other parts of the motor that form the first major broad side.
16. The suspension structure of claim 1 , wherein the stiffener layer is only in contact with the motor and is free from contact with any other parts of the flexure.
17. The suspension structure of claim 1 , wherein the motor is configured to at least partially curl while expanding or contracting upon application of an electrical signal to the motor.
18. A suspension structure, comprising:
a gimbaled flexure; and
a motor mounted on a gimbaled portion of the flexure, the motor comprising:
at least one layer of piezoelectric material;
a conductive layer, the conductive layer formed from a first type of metal; and
a metal stiffener layer plated on and in contact with the conductive layer, the stiffener layer formed from a second type of metal, wherein the first type of metal has a lower elastic modulus and a higher electrical conductivity than the second type of metal, and the stiffener layer is thicker than the conductive layer.
19. The suspension structure of claim 18 , wherein, with respect to the motor, the second type of metal is disposed only on the conductive layer.
20. A suspension structure, comprising:
a gimbaled flexure; and
a motor mounted on a gimbaled portion of the flexure, the motor comprising:
at least one layer of piezoelectric material;
a conductive layer, the conductive layer formed from a first type of metal;
a metal stiffener layer plated on and in contact with the conductive layer, the stiffener layer formed from a second type of metal that is different than the first type of metal, wherein the second type of metal comprises nickel.