Hitachi Global Storage Technologies Netherlands B.v.

Hgst Netherlands, B.v.

Other

Jizhong He

Shanlin Duan

John Stephen Hopkins

Zhupei Shi

Jane Jie Zhang

Bruno Jean Marchon

Ullal Vasant Nayak

Yansheng Luo

Kenneth E Johnson

Kezhao Zhang

The present disclosure relates an inspection instrument adapted to increase testing throughput in a manufacturing process. In one embodiment, the inspection instrument includes a base plate and a vertical frame, where the base plate and the vertical frame are configured to provide structural support of the inspection instrument, a first mounting mechanism coupled to the base plate, where the first mounting mechanism is configured to hold a sample for inspection, and a second mounting mechanism coupled to the vertical frame, where the second mounting mechanism is configured to hold a set of sensors and an optical system for inspecting the sample. The first mounting mechanism and the second mounting mechanism are decoupled from each other to reduce impact of movements of the sample to the set of sensors and the optical system.

Inspection instrument

Reducing slider bounce within a hard disk drive. A force is received at a first material while the first material is in contact with a disk of a hard disk drive; the first material comprising a portion that is flexible in a first direction and is substantially non-flexible in a second direction. The first direction is a direction that is normal to the disk and the second direction is a direction that is parallel to a surface of the disk. The force is substantially absorbed by the portion that is flexible to reduce the force associated with interaction between the first material and the disk, thereby reducing slider bounce within the hard disk drive.

Reducing slider bounce in a hard disk drive

A tool for testing a magnetic disk for use in a magnetic disk drive. The tool detects surface defects or asperities by detecting a change in electrical resistance corresponding to a temperature change in a thermally sensitive layer. The apparatus includes a slider body having a thermally insulating layer formed on an air bearing surface of the slider body and a thermal sensor layer formed on the thermally insulating layer. The thermally insulating layer prevents thermal heat spikes in the thermal sensor layer (such as resulting from contact with an asperity) from dissipating quickly into the slider body itself. The thermal sensor layer is a material that exhibits a change in electrical resistance in response to a change in temperature and is preferably a PTC thermistor material which exhibits a large change in electrical resistance when a transition temperature has been reached.

High sensitivity glide sensor using frictional heating

Approaches for a testing device for selecting a discrete track media (DTM) format for use with a particular head of a hard-disk drive (HDD). The testing device comprises a continuous magnetic-recording disk, rotatably mounted on a spindle, which stores data using a continuous media format. The testing device also comprises a testing module configured to simulate reading data, stored using a discrete track media (DTM) format, from the continuous magnetic-recording medium. Advantageously, testing time and cost is reduced as both discrete track media (DTM) disks and expensive discrete track media (DTM) recording testing hardware are not required to select the optimal a discrete track media (DTM) format for use with a particular head of a hard-disk drive (HDD). In addition, embodiments may be used to optimize features of the tracks of the DTM disk, such as the land to groove ratio.

Simulating discrete track media with continuous media for head evaluation

Glide test systems and associated methods are described. A glide test system includes a glide test head that is flown over the surface of a recording disk to detect asperities on the recording disk. The glide test head includes a detection pad on the trailing end of the head. Heating elements are fabricated proximate to the detection pad. The heating elements are independently controllable to control the amount of protrusion of different regions of the detection pad. The heating elements thus provide a way to substantially flatten the detection surface of the detection pad, and compensate for an uneven topography on a detection surface.

Glide test heads using heating elements to form a planar detection surface

A method models and calibrates the fly height of a slider above the disk for disk drives. The calibration scheme uses the Wallace spacing loss equation and laser doppler velocimetry to predict fly height and detect the actual fly height of the slider. The slider is vibrated at selected resonances, such as by capacitive coupling to the disk, and the fly height is gradually reduced. In one version, contact between the slider and disk may be detected using an arm electronics sensor. The amplitude of mean-to-peak, vibration detection is used as an indication of the actual fly height and to calibrate the modeled fly height.

System, method and apparatus for direct head-disk clearance measurement by slider vibration and fly height calibration

An apparatus, system, and method are disclosed for fly height detection. The apparatus includes an actuator configured to induce vibrations in a glide head that is configured to detect physical asperities on a disk surface. The apparatus may also include a second end of the suspension arm coupled with the glide head and a sensor module that is configured to communicate with a control module in response to the glide head coming in contact with at least one physical asperity. The system includes the apparatus, a disk having a surface comprising physical asperities, and a head gimbal assembly configured to calibrate a fly height margin for the disk. The method includes inducing vibrations in a glide head, detecting physical asperities on a disk surface, and communicating with a control module in response to the glide head coming in contact with at least one physical asperity.

Apparatus, system, and method for detection of fly height margin using controlled excitation of air bearing mode

A magnetic test module runs on a spin stand to detect amplitude decay and noise evolution at the same time. Signal-to-noise ratio (SNR) decay is directly measured. The recording performance is correlated better with SNR instead of signal only. The thermal stability of the system is evaluated more accurately with this SNR decay method. A heater is placed under the media disk, and a remote sensing thermometer and temperature controller form a subsystem to set up desired environmental temperature. The heater creates a heated band and the read/write head flies above the heated band. The temperature control system may be removed when SNR decay measurement is performed under room temperature.

Growing community of inventors

San Jose, CA, United States of America

Jizhong He