Disk drive head suspension tail with ground pad outside of bonding region
View Patent ↗A head gimbal assembly for a disk drive includes a flexure tail terminal region having flexure bond pads in electrical communication with the head. Each of the flexure bond pads is aligned with one of a plurality of flexible printed circuit (FPC) bond pads. An anisotropic conductive film is disposed between the FPC and the flexure tail terminal region. The flexure tail terminal region overlaps the anisotropic conductive film in a bonding area. Each of the flexure bond pads is bonded to one of the plurality of FPC bond pads by the anisotropic conductive film in a bonding area. A conductive layer of the flexure tail terminal region includes an exposed conductive ground pad that is disposed outside of the bonding area, and/or disposed outside of an application area of a thermode tool that is pressed against the flexure tail terminal region during the bonding process.
1. A disk drive comprising:
a disk drive base;
a disk rotably mounted to the disk drive base;
an actuator rotably mounted to the disk drive base, the actuator including at least one actuator arm and a flexible printed circuit (FPC) that includes a plurality of electrically conductive FPC bond pads; and
at least one head gimbal assembly attached to the at least one actuator arm, the at least one head gimbal assembly comprising
a head for reading data on the disk; and
a suspension assembly that comprises
a load beam; and
a laminated flexure that comprises a structural layer, a conductive layer, and a dielectric layer between the structural layer and the conductive layer, the laminated flexure including a tongue portion that connects to the read head and a flexure tail that extends to the plurality of FPC bond pads;
wherein the flexure tail includes a flexure tail terminal region that at least partially overlaps the FPC, the flexure tail terminal region including a plurality of flexure bond pads in electrical communication with the head, each of the plurality of flexure bond pads being aligned with a corresponding one of the plurality of FPC bond pads;
wherein the flexure tail terminal region overlaps and is bonded to the FPC in a bonding area; each of the plurality of flexure bond pads being bonded to the corresponding one of the plurality of FPC bond pads in the bonding area; and
wherein the conductive layer further comprises, in the flexure tail terminal region, an exposed conductive ground pad that is disposed outside of the bonding area, and that is electrically connected to the structural layer by a via through the dielectric layer in the flexure tail terminal region.
2. The disk drive of claim 1 wherein the plurality of flexure bond pads are defined in the conductive layer, and the structural layer includes a plurality of discontinuous bond pad backing islands that are disposed in alignment with the plurality of flexure bond pads.
3. The disk drive of claim 1 wherein the structural layer comprises stainless steel, the dielectric layer comprises polyimide, and the conductive layer comprises copper.
4. The disk drive of claim 3 wherein the thickness of the structural layer is less than 20 microns, the thickness of the dielectric layer is less than 15 microns, the thickness of the conductive layer is less than 15 microns, and a total thickness at each of the plurality of flexure bond pads is at least 25 microns.
5. A disk drive comprising:
a disk drive base;
a disk rotably mounted to the disk drive base;
an actuator rotably mounted to the disk drive base, the actuator including at least one actuator arm and a flexible printed circuit (FPC) that includes a plurality of electrically conductive FPC bond pads; and
at least one head gimbal assembly attached to the at least one actuator arm, the at least one head gimbal assembly comprising
a head for reading data on the disk; and
a suspension assembly that comprises
a load beam; and
a laminated flexure that comprises a structural layer, a conductive layer, and a dielectric layer between the structural layer and the conductive layer, the laminated flexure including a tongue portion that connects to the read head and a flexure tail that extends to the plurality of FPC bond pads;
wherein the flexure tail includes a flexure tail terminal region that at least partially overlaps the FPC, the flexure tail terminal region including a plurality of flexure bond pads in electrical communication with the head, each of the plurality of flexure bond pads being aligned with a corresponding one of the plurality of FPC bond pads;
wherein the flexure tail terminal region overlaps and is bonded to the FPC in a bonding area; each of the plurality of flexure bond pads being bonded to the corresponding one of the plurality of FPC bond pads in the bonding area;
wherein the conductive layer further comprises an exposed conductive ground pad that is disposed outside of the bonding area, and
wherein the total longitudinal span of the flexure tail terminal region is in the range of 3 mm to 8 mm, including a bonding area longitudinal span in the range of 2 mm to 7 mm, and an adjacent area of the flexure tail terminal region outside the bonding area having an adjacent area longitudinal span in the range of 1 mm to 3 mm, the exposed conductive ground pad being disposed within the adjacent area.
6. The disk drive of claim 5 wherein the adjacent area of the flexure tail terminal region includes a bent portion extending approximately normally from a major plane of the flexure tail terminal region, the bent portion longitudinally spanning the exposed conductive ground pad.
7. A disk drive comprising:
a disk drive base;
a disk rotably mounted to the disk drive base;
an actuator rotably mounted to the disk drive base, the actuator including at least one actuator arm and a flexible printed circuit (FPC) that includes a plurality of electrically conductive FPC bond pads; and
at least one head gimbal assembly attached to the at least one actuator arm, the at least one head gimbal assembly comprising
a head for reading data on the disk; and
a suspension assembly that comprises
a load beam; and
a laminated flexure that comprises a structural layer, a conductive layer, and a dielectric layer between the structural layer and the conductive layer, the laminated flexure including a tongue portion that connects to the read head and a flexure tail that extends to the plurality of FPC bond pads;
wherein the flexure tail includes a flexure tail terminal region that at least partially overlaps the FPC, the flexure tail terminal region including a plurality of flexure bond pads in electrical communication with the head, each of the plurality of flexure bond pads being aligned with a corresponding one of the plurality of FPC bond pads;
wherein the flexure tail terminal region overlaps and is bonded to the FPC in a bonding area; each of the plurality of flexure bond pads being bonded to the corresponding one of the plurality of FPC bond pads in the bonding area;
wherein the conductive layer further comprises an exposed conductive ground pad that is disposed outside of the bonding area, and
wherein the exposed conductive ground pad is not bonded to any of the plurality of FPC bond pads.