摘要:
A magnetic write head for magnetic data recording that includes a structure having a low coefficient of thermal expansion for controlling thermal expansion of the write head. The structure having a low coefficient of thermal expansion has a shape that substantially conforms to the shape of the write coil, such that both the write coil and the structure having a low coefficient of thermal expansion have a central portion that is located closest to the air bearing surface and outer end portions that bend away from the air bearing surface to form a horseshoe shape.
摘要:
A magnetic head includes a magnetic write structure having a first magnetic layer having a first pole, a second magnetic layer having a second pole spaced apart from the first pole, and a third magnetic layer having a third pole contacting the second pole. The third pole has a third-pole width greater than a second-pole width. An inductive coil positioned adjacent to the third magnetic layer controllably magnetizes the third magnetic layer. The third magnetic layer is nonuniformly thick such that a thickness of the third pole is less than a thickness of the third magnetic layer at locations in registry with the inductive coil. The magnetic write structure is conveniently fabricated by depositing the magnetic layers and the inductive coil, masking the third magnetic layer other than the third pole, and removing a portion of the thickness of the third pole.
摘要:
A magnetic write head for perpendicular magnetic data recording having a notched write pole for reduced magnetic core width (MCW) dependence on skew. The write pole is configured with a notch that can extend to or slightly beyond the flare point of the write pole, and is formed on the leading portion of the write pole. The notch can have a notch depth, as measured from the ABS of 50-200 nm or about 120 nm. The notch can have a notch height, measured in the down track direction that is 40-90 nm or 20-90 percent of the write pole height.
摘要:
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.
摘要:
A magnetic write head for perpendicular magnetic data recording having a notched write pole for reduced magnetic core width (MCW) dependence on skew. The write pole is configured with a notch that can extend to or slightly beyond the flare point of the write pole, and is formed on the leading portion of the write pole. The notch can have a notch depth, as measured from the ABS of 50-200 nm or about 120 nm. The notch can have a notch height, measured in the down track direction that is 40-90 nm or 20-90 percent of the write pole height.
摘要:
An apparatus for reader characterization is described. The apparatus includes a rotator for rotating a media. The media can contain a signal having a value for a function of a read/write head being assessed. The rotator is operable in conjunction with said apparatus. The apparatus also includes a proximator for proximalizing the media to the read/write head. The proximator is operable in conjunction with said apparatus. The apparatus further includes a writer operable in conjunction with said assembly. The writer writes the signal upon the media. The signal emits the value of the function. The signal is detectable by a reader of the read/write head. The apparatus additionally includes an interface operable in the apparatus for providing removable orientation of the read/write head in an assessing position. The assessing position enables a reader of the read/write head to detect the signal upon rotation of the signal through the assessing position.
摘要:
A hard disk drive (HDD) detects and measures external stray magnetic fields with existing HDD components. After detecting a strong external magnetic field, read and write operations of the HDD are suspended, and/or other proper corrective actions are taken to minimize loss of data. To measure the stray magnetic field, the magnetic head reader is used as a field sensor. The resistance of the reader changes in the presence of the field, such as with the preamp in the HDD. The resistance also changes with temperature. If the temperature inside the HDD is measured, the resistance change due to temperature is normalized. Even without being able to measure the HDD temperature, the stray magnetic field can be measured with a top head and a bottom head in the HDD. The temperature sensitivity of the reader is thereby cancelled out.
摘要:
According to one embodiment, a system comprises a magnetic pole having a media-facing end and a wrap around shield spaced from the magnetic pole, wherein the wrap around shield has a media-facing end positioned along three sides of the media-facing end of the magnetic pole and has inner, second, and middle regions separated by transitional regions. The inner region is closest to the media facing end of the magnetic pole, the second region is farthest from the media facing end of the magnetic pole, and the middle region is between the inner and second regions. A cross-sectional height of the inner region measured perpendicularly to the wrap around shield's media-facing end is less than a cross-sectional height of the second region, and a cross-sectional height of the middle region is greater than the cross-sectional height of the inner region and less than the cross-sectional height of the second region.
摘要:
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.
摘要:
One embodiment of the invention provides a system that characterizes cells within an integrated circuit. During operation, the system obtains a number of input noise signals to be applied to the cell. The system then simulates responses of the cell to each of the input noise signals, and stores a representation of the responses. This allows a subsequent analysis operation to access the stored representation to determine a response of the cell instead of having to perform a time-consuming simulation operation.