Abstract: Example servo interface circuitry, data storage devices, and methods to provide parallel self-servo write in a data storage device are described. The data storage device may include servo control circuitry that includes at least three digital-analog converters to provide control signals to the voice control motor (VCM) and arm actuators (e.g., micro actuators and milli actuators) of the data storage device. In data read/write mode, one actuator control signal controls the milli actuator for the target arm/head and another actuator control signal controls the micro actuator for the target arm/head. In self-servo write mode, one actuator control signal controls the micro actuator for one target arm/head and the other actuator control signal controls the micro actuator for another target arm/head for parallel self-servo writing.

Abstract: Example circuits, data storage devices, and methods to provide parallel self-servo write in a data storage device are described. The data storage device may include multiple heads actuated over respective surfaces of storage media and at least two preamplifiers and read paths to a channel circuit. Control circuitry may select heads connected through different preamplifiers for parallel self-servo write and receive read signals from the selected heads in parallel. These read signals, which may be based on self-servo write reference spirals previously written to the storage media, may be used to determine respective position error signals for the two heads and control their respective positions with corresponding control signals to a shared voice control motor and respective micro and/or milli actuators on the arms supporting the heads.

Abstract: Example storage preamplifier circuits, data storage devices, and methods for parallel self-servo write are described. The data storage device may include a pair of preamplifier circuits electrically connected to respective banks of read heads actuated over a storage media surfaces. In read/write operation, each preamplifier circuit may selectively and sequentially provide read signals from a selected head to a pair of read channel interfaces. In self-servo write operation, each preamplifier circuit may selectively and in parallel provide read signals from a selected head in their corresponding banks of read heads to the pair of read channel interfaces. For example, the pair of read channel interfaces for two-dimensional magnetic recording may receive read signals from one read sensor in a head in the first bank of heads and another read sensor for another head in the second bank of heads.

Abstract: Various illustrative aspects are directed to a data storage device including one or more disks, an actuator mechanism configured to position a selected head among one or more heads proximate to a corresponding disk surface among the one or more disks, the selected head comprising a write element and an assistive energy emitter, and one or more processing devices configured to, individually or in combination: apply an assistive energy current to the assistive energy emitter while refraining from applying a write current to the write element, and vary a level of the assistive energy current over time while refraining from applying the write current to the write element.

Abstract: Example control circuitry, data storage devices, and methods for determining wedge repeatable runout correction values for interleaved servo patterns in a data storage device are described. The data storage device may include multiple heads actuated over different surfaces of a data storage device and receive read signals from two different heads over two different surfaces in parallel. The servo wedges of the two surfaces may be offset to enable parallel learning of wedge repeatable runout correction values.

Abstract: Various illustrative aspects are directed to a data storage device, method, and one or more processing devices that are configured to: write a plurality of test servo patterns using a plurality of different write settings; select one of the plurality of different write settings based on analyzing the plurality of test servo patterns for mode hop; and write a plurality of final servo patterns using the selected one of the plurality of different write settings.

Abstract: A back plate configured to support a circuit board includes a body. The body defines a central recess formed into a top surface thereof, and a raised main support column extending from the central recess and adapted to support the circuit board.

Abstract: An electronic apparatus includes a main circuit board, an electronic device, side circuit boards, and a pressure applying unit. The electronic device is installed on and electrically connected to the main circuit board. The side circuit boards are positioned at edges of the electronic device on a side of the electronic device away from the main circuit board and electrically connected to the electronic device. The pressure applying unit is positioned on a side of the electronic device and on each of the side circuit boards away from the main circuit board. The pressure applying unit applies pressure: 1) to the side circuit boards to maintain an electrical connection between the side circuit boards and the electronic device; and 2) to side regions of the electronic device to maintain an electrical connection between the main circuit board and the electronic device.

Abstract: A pressurizing device includes a pressurizing plate having a first pressurizing plate surface and a second pressurizing plate surface opposite to each other. The first pressurizing plate surface presses an electronic element located on a first circuit board surface of a circuit board. The pressurizing device includes a plurality of peripheral pressurizing units applying pressure to a peripheral region of the second pressurizing plate surface and a plurality of central pressurizing units applying pressure to a central region of the second pressurizing plate surface.

Abstract: An electronic assembly includes an interposer assembly and a cable connector module coupled to the interposer assembly. The interposer assembly includes an array of compressible interposer contacts each having upper and lower mating interfaces defining separable mating interfaces. The cable connector module includes a cable connector having a module substrate including module contacts at a bottom of the module substrate coupled to the upper mating interfaces of the corresponding interposer contacts. The cable connector module includes a backshell including a backshell cavity that receives the cable connector. The backshell includes a compression member engaging the cable connector and pressing the cable connector in the direction of the interposer assembly to compress the interposer contacts.

Abstract: Various illustrative aspects are directed to a data storage device, comprising one or more disks; an actuator mechanism configured to position one or more heads proximate to a corresponding disk surface of the one or more disks; and one or more processing devices. The selected head comprises a write element and an assistive energy emitter. The one or more processing devices are configured to apply an assistive energy current to the assistive energy emitter while refraining from applying a write current to the write element.

Abstract: Various illustrative aspects are directed to a data storage device, method, and one or more processing devices that are configured to: determine a first burst value based on a first set of bursts within a servo pattern, the first set of bursts comprising two bursts having a first length in a longitudinal direction of a track containing the servo pattern and at least one burst having a second length in the longitudinal direction of the track and different than the first length; determine a second burst value based on a second set of bursts within the servo pattern, the second set of bursts comprising at least two bursts having the second length; generate a position error signal (PES) based on the determined first burst value and the determined second burst value; and control a position of at least one head among the one or more heads based on the PES.

Abstract: Example storage medium servo patterns, data storage devices, and methods to provide servo tracks with continuously varying frequency in a data storage device are described. The data storage device may include storage media, such as magnetic disks, having servo sectors that define servo tracks, where adjacent servo tracks have continuously varying frequency as the head moves from one servo track to the next. As the head is actuated over the storage medium, a target track frequency may be determined based on the radial position of a target servo track and the channel frequency may be set to the target track frequency to follow the target servo track.

Abstract: A circuit board assembly includes a chip, a first loading board, a circuit board, an intermediate board and a second loading board. The first loading board is arranged on the chip, and the circuit board is electrically connected to the chip. The intermediate board is arranged on the circuit board and positions the chip. The second loading board is arranged on a side of the circuit board opposite the intermediate board. The second loading board includes a plurality of protrusions and indentations formed on a first side thereof opposing the circuit board.

Abstract: Various illustrative aspects are directed to a data storage device, comprising one or more disks; an actuator mechanism configured to position one or more heads proximate to a corresponding disk surface of the one or more disks; and one or more processing devices. The one or more processing devices are configured to apply a pre-bias current to the assistive energy emitter at a first value while the selected head is positioned proximate to one or more spiral patterns on the corresponding disk surface. The one or more processing devices are further configured to apply the pre-bias current to the assistive energy emitter at a boosted value while the selected head is not positioned proximate to the one or more spiral patterns, wherein the boosted value is greater than the first value.

Abstract: Various illustrative aspects are directed to a data storage device, comprising one or more disks; an actuator mechanism configured to position one or more heads proximate to a corresponding disk surface of the one or more disks; and one or more processing devices. The one or more processing devices are configured to: select a sector on the corresponding disk surface to which to write data, wherein the sector is selected in accordance with a data erosion mitigation pattern; and output, while the head is positioned proximate to a preceding sector that precedes the selected sector, a laser pre-bias current to a laser-generating component of the head, wherein the laser pre-bias current is sufficient to induce significant data erosion on the preceding sector.

Abstract: Various illustrative aspects are directed to a data storage device, comprising one or more disks; an actuator mechanism configured to position one or more heads proximate to a corresponding disk surface of the one or more disks; and one or more processing devices. The selected head comprises a write element and an assistive energy emitter. The one or more processing devices are configured to apply an assistive energy current to the assistive energy emitter while refraining from applying a write current to the write element.

Abstract: Various illustrative aspects are directed to a data storage device including one or more disks, an actuator mechanism configured to position a selected head among one or more heads proximate to a corresponding disk surface among the one or more disks, the selected head comprising a write element and an assistive energy emitter, and one or more processing devices configured to, individually or in combination: apply an assistive energy current to the assistive energy emitter while refraining from applying a write current to the write element, and vary a level of the assistive energy current over time while refraining from applying the write current to the write element.

Abstract: Various illustrative aspects are directed to a data storage device, comprising one or more disks; an actuator mechanism configured to position one or more heads proximate to a corresponding disk surface of the one or more disks; and one or more processing devices. The one or more processing devices are configured to: select a sector on the corresponding disk surface to which to write data, wherein the sector is selected in accordance with a data erosion mitigation pattern; and output, while the head is positioned proximate to a preceding sector that precedes the selected sector, a laser pre-bias current to a laser-generating component of the head, wherein the laser pre-bias current is sufficient to induce significant data erosion on the preceding sector.

Abstract: A pressure-exerting device includes a first pressure-exerting unit adapted to press an electronic element on a circuit board. The first pressure-exerting unit has a pressure-exerting member defining a central opening sized to at least partially surround the electronic element, and a pressing elastic sheet arranged at an edge of the central opening of the pressure-exerting member and adapted to press the electronic element.