A multiple-actuator hard disk drive includes multiple head-stack assemblies (HSA) and a disk stack including a shared disk operated upon by both of the HSAs. Generally to provide more space between the HSAs such as for routing electrical traces, the distance between the shared disk and each of the upper and lower adjacent disks is greater than the distance between each of the upper and lower adjacent disks and the next adjacent disk. Each arm tip of the arms operating upon the shared disk may be thicker than other arm(s) operating upon other disks in the stack, so that the z-height between each head slider and corresponding disk surface is maintained in view of the differing disk spacing. Suspension tails for the arms that operate on the shared disk may be biased to offset away from the shared disk to provide for more clearance between the HSAs.

A hard disk drive includes a drive case and a cover plate, the storage media platers and a spindle, the recording heads and actuators, the connection port, the control logic board and one or more voice coil motor, where the actuators are operated via a voice coil motor; wherein the voice coil motor magnets comprise of a pair of composite permanent magnets on both sides of the voice coil, where each piece of composite permanent magnet comprising: a first core magnet M1, a cladding magnet Mc12 and a second core magnet M2; the magnetization direction of M1 and M2 are opposite to each other; the magnetization direction of Mc12 is substantially perpendicular to the magnetization direction of M1 and M2; the ratio of the width of Mc12 to the thickness or the height of Mc12 is 4:1 or less as seen from the back view.

In a multi-actuator drive, the effect of moving a first actuator (the so-called “aggressor actuator”) in on a second actuator (the so-called “victim actuator”) is reduced or compensated for. A victim feedforward signal is added to a microactuator control signal of the victim actuator in response to a voice-coil motor (VCM) control signal that is applied to the aggressor actuator. The feedforward signal is configured to compensate for disturbances to the victim microactuator caused by VCM commands provided to the aggressor actuator. The feedforward signal is based on a transfer function that models commands added to the victim microactuator, which is coupled to the head of the victim actuator, as a function of the aggressor VCM control signal applied to the aggressor actuator.

According to one embodiment, a disk device includes a first head actuator, a second head actuator, and a wiring board unit connected to the first head actuator and the second head actuator. The wiring board unit includes a flexible printed wiring board including a base portion and at least two extension portions extending from the base portion, and each of the extension portions includes a joint portion provided with connection pads and a cutting work trace portion. One joint portion is attached to a first actuator block, and the connection end portion of a first wiring member is joined to the connection pads. Another joint portion is attached to a second actuator block, and the connection end portion of a second wiring member is joined to the connection pad.

The present disclosure generally relates to a voice coil motor (VCM) yoke assembly mounted to an actuator block for a data storage device. One or more fastening mechanisms couple the VCM assembly to the actuator block. The fastening mechanisms are coupled to the VCM assembly by one or more soft mounts. The one or more soft mounts reduce undesirable movement of the magnetic recording head by spacing the VCM assembly from the actuator block, yet still ensuring the VCM assembly is properly coupled to the actuator block.

According to one embodiment, a disk device includes a plurality of recording media each including a recording layer and an actuator assembly including an actuator block rotatably supported around a rotation shaft, a plurality of arms extending from the actuator block, and suspension assemblies respectively attached to the arms and supporting respective magnetic heads. Of the plurality of arms, at least one arm has vibration characteristics different from those of the other arms.

A data storage device comprises a lead actuator that actuates a first read-write head over a first disk and a support actuator that actuates a second read-write head over a second disk. A spindle motor rotates the first and second disks. In response to an emergency power off (EPO) event, a processing device retracts and parks the actuators using an internal supply voltage generated from a back electromotive force (BEMF) voltage of the spindle motor, and egresses data from a volatile to a non-volatile semiconductor memory. Egress is throttled before the actuators are retracted and parked when the internal supply voltage falls to or below a first egress throttling threshold voltage. Egress is throttled after the actuators are retracted and parked when the internal supply voltage falls to or below a second egress throttling threshold voltage.

According to one embodiment, a disk device includes a housing with a bottom wall, magnetic disks supported on a hub of a motor, a printed circuit board provided on an outer surface of the bottom wall, and a wiring board attached on the outer surface of the bottom wall. The bottom wall includes a recess formed in the outer surface, a step located on border between the outer surface and the recess, and through holes opened to the recess. The wiring board includes one end portion disposed in the recess and connection pads on the one end portion, connected to lead wires of a coil. An adhesive is filled into the recess and the through holes, and covers the one end and a solder joint and seals the through holes.

A data storage device includes a base, a shaft that extends perpendicular from the base, and a head stack assembly (HSA) having a first end to which a head is coupled and a second end that is movably mounted on the shaft. The data storage device also includes either a first actuator assembly or a second actuator assembly. The first actuator assembly includes a first coil-permanent magnet assembly that rotatably moves the HSA about the shaft, and a second coil-permanent magnet assembly that serves as a first elevator to linearly move the HSA along the shaft. The second actuator assembly includes a third coil-permanent magnet assembly that rotatably moves the HSA about the shaft, and a second elevator that linearly moves the HSA along the shaft and also moves a data storage device ramp in unison with the HSA.

A data storage device includes a data storage medium having a data storage surface. The data storage device also includes a first actuator having a first attached slider with a writer configured to write data on the data storage surface. The writer has a media-confronting surface covered by a first non-magnetic overcoat having a first thickness. The data storage device further includes a second actuator having a second attached slider with at least one user-data reader configured to read user data from the data storage surface and no writer for writing data on the data storage surface. The at least one user-data reader has a media-confronting surface covered by a second non-magnetic overcoat having a second thickness that is less than the first thickness of the first non-magnetic overcoat.