Seagate Technology Incorporated

Industry-Academic Cooperation Foundation, Dankook University

Ju Yong Lee

Shi Jung Kim

Won Choul Yang

YoungJin Son

Dong Wook Lee

Jae Hyoung Park

Clifford Jayson Bringas Camalig

Mui Chong Chai

Seung Ki Lee

A data storage device may have increased signal-to-noise ratio contact detection by employing a transducing head assembly separated from a data storage medium by an air bearing with the transducing head assembly receiving an alternating current as directed from a controller. The alternating current can be configured to induce random transducing head motion when the air bearing has a greater than zero size and a cyclical transducing head motion when the air bearing has a zero size.

Data storage device with high signal-to-noise ratio contact detection

A data storage device may have increased signal-to-noise ratio contact detection by employing a transducing head associated with a data storage medium each connected to a controller. The transducing head can have an alternating current heater excited to a first frequency for a first revolution of the data storage medium and to a different second frequency for a second revolution of the data storage medium. The second frequency may produce lateral transducing head motion as a result of physical contact of the transducing head with the data storage medium. The controller can issue a contact status in response to comparing a first plurality of position error signals logged during the first frequency to a second plurality of position error signals logged during the second frequency.

Data storage device using high and low frequencies AC heat produce position-error-signals for head contact detection

A current temperature of a data storage device having a heat assisted recording (HAMR) device is measured while in idle. A threshold laser diode power output of the HAMR device is calculated at the current temperature when there is a change between a previous temperature and the current temperature. A new laser diode current that produced the calculated threshold laser diode power output is applied to the HAMR device when there is a change between the currently applied laser diode current and the new laser diode current.

Adaptive laser output control in a HAMR device

An apparatus comprises a read/write head having a heater, wherein a low- or non-modulation interface is defined between the head and a magnetic recording medium. A microactuator is coupled to the head. A main actuator is coupled to the microactuator and the head. A controller is coupled to the main actuator, the microactuator, and the head. The controller is configured to control movement of the main actuator and the microactuator in response to a position error signal. The controller is further configured to induce an oscillation in the heater at a predetermined frequency. A detector is coupled to the controller. The detector is configured to sense a disturbance in the PES supplied to the microactuator resulting from the induced heater oscillation, and detect contact between the head and the medium using the PES disturbance.

Head-medium contact detection using high frequency heater oscillation

An apparatus comprises a slider that includes a fly height sensor. A signal generator is coupled to the slider. The signal generator is configured to generate an AC electrical signal having a DC offset voltage and to adjust the DC offset of the AC electrical signal to a plurality of DC offset voltages. Circuitry is coupled to the fly height sensor and the signal generator. The circuitry is configured to measure fly height of the slider in response to application of the AC electrical signal with varying DC offset voltages to the slider. The circuitry is further configured to determine an extremum of the measured fly heights and generate an output that includes the DC offset voltage associated with the fly height extremum.

Apparatus and method for measuring surface charge of a slider

The disclosure is related to an apparatus and methods for addressing variations in bit error rates amongst data storage segments. In a particular embodiment, an apparatus includes a controller that detects variations in bit error rates amongst different segments of a plurality of segments in a storage medium. The controller also adjusts a read/write operation parameter according to the detected variations amongst the bit error rates in the plurality of segments.

Addressing variations in bit error rates amongst data storage segments

Technologies are described herein for adaptive write pole tip protrusion compensation in a storage device having magnetic recording media. Variations in temperature of a head of a storage device are measured for various combinations of values of write-channel parameters during multiple test writes to the recording media. Sensitivity of the head temperature to change in value of the write-channel parameters is determined from the temperature measurements. A ratio of change in write pole tip protrusion of the head to change in head temperature is also determined. From the sensitivity of the head temperature to change in value of the write-channel parameters and the ratio of change in write pole tip protrusion of the head to change in head temperature, a coefficient corresponding to each write-channel parameter is calculated for the head to be utilized in a write pole tip protrusion compensation mechanism of the storage device.

Adaptive write pole tip protrusion compensation

A through substrate structure, an electronic device package using the same, and methods for manufacturing the same are disclosed. First, a via hole pattern is formed by etching an upper surface of a first substrate. A pattern layer of a second substrate is formed on the first substrate by filling the via hole pattern with a material for the second substrate by reflow. A via hole pattern is formed in the pattern layer of the second substrate by patterning the upper surface of the first substrate. Moreover, a via plug filling the via hole pattern is formed by a plating process, for example, thereby forming a through substrate structure, which can be used in an electronic device package.

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Yongin, South Korea

Ju Yong Lee