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 flexure, including:
first and second spring arms;
a tongue having a slider mounting region supported by and located between the spring arms; and
a plurality of electrical traces including first and second traces;
a motor mounted to the flexure, including:
one or more piezoelectric material actuator layers defining first and second major broad sides;
a first conductive layer on the first major broad side, wherein the first conductive layer is a first metal, has a thickness and an elastic modulus, and is electrically connected to the first electrical trace;
a second conductive layer on the second major broad side, wherein the second conductive layer is the first metal, has a thickness and an elastic modulus, and is electrically connected to the second electrical trace; and
a metal stiffener layer on and in contact with one of the first and second conductive layers, wherein the metal stiffener layer extends over a majority of one of the first and second major broad sides, is a second metal that is different than the first metal, has an elastic modulus that is higher than the elastic modulus of the first metal, and has a thickness that is greater than the thicknesses of the first and second conductive layers.
2. The suspension structure of claim 1 wherein:
the one or more piezoelectric material actuator layers define first and second ends;
the first end is coupled to the first spring arm; and
the second end is coupled to the second spring arm.
3. The suspension structure of claim 2 and further including:
a first connector mounting the first end of the one or more piezoelectric material actuator layers to the first spring arm and electrically connecting the first conductive layer to the first electrical trace; and
a second connector mounting the second end of the one or more piezoelectric material actuator layers to the second spring arm and electrically connecting the second conductive layer to the second electrical trace.
4. The suspension structure of claim 1 wherein the metal stiffener layer is a plated metal layer.
5. The suspension structure of claim 4 wherein the stiffener layer has a thickness that is at least five times thicker than the thicknesses of the first and second conductive layers.
6. The suspension structure of claim 1 wherein the stiffener layer has a thickness that is at least five times thicker than the thicknesses of the first and second conductive layers.
7. The suspension structure of claim 1 wherein:
the first metal includes copper; and
the second metal includes nickel.