Dual stage microactuator flexure feature for minimizing electrical shorts
Approaches to a flexure gimbal assembly for a hard-disk drive (HDD), having a feature for reducing the risk of electrical shorts, include a flexure having an electrically conductive layer and an insulating layer having a flexure tongue with which one or more microactuator piezo actuating device is coupled, where the flexure tongue comprises a gap positioned to inhibit contact between the conductive adhesive and the conductive layer of the flexure which may otherwise cause an electrical short.
1. A flexure gimbal assembly for a hard disk drive, comprising:
a flexure comprising:
an electrically conductive spring layer, and
an insulating layer comprising a flexure tongue;
a microactuator comprising at least one piezo actuating device coupled to said insulating flexure tongue with electrically conductive adhesive, said microactuator configured to provide a moment force for rotating a head slider; and
wherein said flexure tongue comprises a gap in said insulating layer of said flexure tongue and entirely enclosed by said flexure tongue, said gap positioned such that said gap inhibits contact and a corresponding electrical short between said conductive adhesive and said conductive spring layer.
2. The flexure gimbal assembly of claim 1 , wherein said gap is positioned between said at least one piezo actuating device and said conductive spring layer thereby inhibiting the flow of said conductive adhesive into contact with said conductive spring layer.
3. The flexure gimbal assembly of claim 1 , wherein said conductive adhesive comprises an adhesive having a dynamic viscosity in a range of 10 Pascal-second (Pa-s) to 60 Pascal-second (Pa-s).
4. A hard disk drive, comprising:
a disk media rotatably mounted on a spindle;
a suspension coupled to an actuator arm, said suspension comprising a flexure gimbal assembly comprising:
a flexure comprising:
an electrically conductive spring layer, and
an insulating layer comprising a flexure tongue,
a microactuator comprising at least one piezo actuating device coupled to said insulating flexure tongue with electrically conductive adhesive, said microactuator configured to provide a moment force for rotating a head slider,
wherein said flexure tongue comprises a gap in said insulating layer of said flexure tongue and entirely enclosed by said flexure tongue, said gap positioned such that said gap inhibits contact and a corresponding electrical short between said conductive adhesive and said conductive spring layer; and
a voice coil motor configured to move said suspension and said head slider to access portions of said disk media.
5. The hard disk drive of claim 4 , wherein said gap of said flexure tongue is positioned between said at least one piezo actuating device and said conductive spring layer thereby inhibiting the flow of said conductive adhesive into contact with said conductive spring layer.
6. The hard disk drive of claim 4 , wherein said conductive adhesive comprises an adhesive having a dynamic viscosity in a range of 10 Pascal-second (Pa-s) to 60 Pascal-second (Pa-s).
7. A method for manufacturing a flexure gimbal assembly for a hard disk drive, the method comprising:
attaching, using an electrically conductive adhesive, at least one piezo actuating device to an insulating flexure tongue of a flexure comprising an electrically conductive spring layer and an insulating layer comprising said flexure tongue, wherein said flexure tongue comprises a gap in said insulating layer of said flexure tongue and entirely enclosed by said flexure tongue, said gap positioned such that said gap inhibits contact and a corresponding electrical short between said conductive adhesive and said conductive spring layer.
8. The method of claim 7 , wherein said attaching includes attaching said at least one piezo actuating device to said insulating flexure tongue having said gap in said insulating layer of said flexure tongue positioned between said at least one piezo actuating device and said conductive spring layer thereby inhibiting the flow of said conductive adhesive into contact with said conductive spring layer.
9. The method of claim 7 , wherein said attaching includes attaching using said conductive adhesive having a dynamic viscosity in a range of 10 Pascal-second (Pa-s) to 60 Pascal-second (Pa-s) to inhibit said at least one piezo actuating device from over-floating on said adhesive over said flexure tongue and to inhibit said adhesive from overflowing to underneath said flexure tongue.