Head stack assembly with a laminated flexure having a snap-through feature

1. A head stack assembly (HSA), comprising:

an actuator;

a flex cable attached to the actuator, the flex cable including a hole therethrough, a first side, and an opposing second side,

a head gimbal assembly (HGA) attached to the actuator, the HGA including

a load beam;

a laminated flexure attached to the load beam, the laminated flexure including a plurality of layers; and

a head attached to the laminated flexure;

wherein the laminated flexure includes a first snap-through feature, the first snap-through feature including:

a snap-through feature central portion that comprises a portion of at least one of the plurality of layers;

a plurality of windows in the laminated flexure, the snap-through feature central portion being centric to the plurality of windows; and

a plurality of lobes, each lobe extending out from the snap-through feature central portion radially into one of the plurality of windows; and

wherein the laminated flexure overlies and contacts the flex cable on the first side, but the first snap-through feature is disposed through the hole in the flex cable so that each of the plurality of lobes contacts the flex cable on the second side.

2. The HSA of claim 1 wherein the plurality of layers includes a structural layer, a conductive layer, and a dielectric layer disposed between the structural and conductive layers, and the conductive layer is electrically coupled to the first side of the flex cable.

3. The HSA of claim 2 wherein each of the plurality of lobes comprises a portion of the dielectric layer.

4. The HSA of claim 2 wherein each of the plurality of lobes comprises a portion of the structural layer.

5. The HSA of claim 2 wherein the dielectric layer comprises polyimide, the structural layer comprises stainless steel, the conductive layer comprises copper, and the load beam comprises stainless steel.

6. The HSA of claim 1 wherein the plurality of lobes includes at least two lobes but no more than six lobes.

7. The HSA of claim 1 wherein the plurality of lobes includes three lobes.

8. The HSA of claim 1 wherein the plurality of lobes includes four lobes.

9. The HSA of claim 1 wherein each of the plurality of windows extends away from the snap-through feature central portion for a radial distance that is at least 30 microns greater than the maximum radial extension of any of the plurality of lobes away from the snap-through feature central portion.

10. The HSA of claim 1 wherein the hole in the flex cable has a radius that is at least 0.25 mm but no greater than 0.5 mm.

11. The HSA of claim 1 wherein each of the plurality of lobes extends radially beyond the circumference of the hole in the flex cable by a radial distance that is at least 0.1 mm but no more than 0.3 mm.

12. The HSA of claim 1 wherein the laminated flexure has a gimbal region adjacent one end and a tail region adjacent an opposing end, the head being attached to the laminated flexure in the gimbal region, and the tail region including the first snap-through feature.

13. A head stack assembly (HSA), comprising:

an actuator;

a flex cable attached to the actuator, the flex cable including a hole therethrough, a first side, and an opposing second side,

a head gimbal assembly (HGA) attached to the actuator, the HGA including

a load beam;

a laminated flexure attached to the load beam; and

a head attached to the laminated flexure;

wherein the laminated flexure includes a first snap-through feature, the first snap-through feature including:

a snap-through feature central portion;

a plurality of windows in the laminated flexure, the snap-through feature central portion being centric to the plurality of windows; and

a plurality of lobes, each lobe extending out from the snap-through feature central portion radially into one of the plurality of windows; and

wherein the laminated flexure overlies and contacts the flex cable on the first side, but the first snap-through feature is disposed through the hole in the flex cable so that each of the plurality of lobes contacts the flex cable on the second side; and

wherein the laminated flexure further comprises a second snap-through feature.

14. The HSA of claim 13 wherein the flex cable further comprises a slot therethrough, and the second snap-through feature is aligned with the slot.

15. A head stack assembly (HSA), comprising:

an actuator;

a flex cable attached to the actuator, the flex cable including a hole therethrough, a first side, and an opposing second side,

a head gimbal assembly (HGA) attached to the actuator, the HGA including

a load beam;

a laminated flexure attached to the load beam; and

a head attached to the laminated flexure;

wherein the laminated flexure includes a first snap-through feature, the first snap-through feature including:

a snap-through feature central portion;

a plurality of windows in the laminated flexure, the snap-through feature central portion being centric to the plurality of windows; and

a plurality of lobes, each lobe extending out from the snap-through feature central portion radially into one of the plurality of windows; and

wherein the laminated flexure overlies and contacts the flex cable on the first side, but the first snap-through feature is disposed through the hole in the flex cable so that each of the plurality of lobes contacts the flex cable on the second side; and

wherein two of the plurality of windows are separated from another by a web of the first snap-through feature that spans a radial extent of those two windows and is connected to the snap-through feature central portion, and the web is serpentine in shape.

16. The HSA of claim 14 wherein the second snap-through feature has fewer lobes than the first snap-through feature.