Hitachi Global Storage Technologies Netherlands B.v.

Hgst Netherlands, B.v.

Synopsys, Inc.

Yansheng Luo

Wen-Chien David Hsiao

Xiaodong Che

Xiaoyu Sui

Quan-chiu Harry Lam

Vladimir Nikitin

Aron Pentek

Yimin Hsu

Changqing Shi

Peivand Fallah-Tehrani

William Chiu-Ting Shu

Jindrich Zejda

Terence T L Lam

Mahmoud Shahram

Alexander Gyure

Wenyuan Wang

Chi-Chong Lo

Seyed Alireza Kasnavi

Edward Hin Pong Lee

Na Young Kim

Jyh-Shuey Jerry Lo

Savas Gider

Shanlin Duan

Honglin Zhu

Terence Tin-Lok Lam

Samuel Weisan Yuan

Katalin Pentek

Samuel Wei-san Yuan

Jizhong He

Zhen Jin

John Stephen Hopkins

Venkata R K Gorantla

Zhihao Li

Wenchien David Hsiao

Hin P E Lee

In one embodiment, an apparatus includes a main pole, at least one side shield positioned on sides of the main pole, and a trailing shield having a multi-bump structure positioned near a trailing side of the main pole, wherein the multi-bump structure has six junctures along the trailing shield facing the main pole, a first juncture positioned at a media-facing surface, a sixth juncture positioned away from the media-facing surface, and second, third, fourth, and fifth junctures positioned along the side of the trailing shield facing the main pole between the first and sixth juncture, wherein an element height of a first face of the trailing shield positioned between the fourth and fifth juncture is less than an element height of a second face of the trailing shield positioned at an end of the trailing shield positioned opposite the media-facing surface of the trailing shield.

Magnetic head having a double bump wrap around shield

In one general embodiment, a magnetic head includes a stitch pole; and a main pole formed adjacent the stitch pole, wherein an end region of the stitch pole closest to an air bearing surface of the head tapers towards the main pole. In another general embodiment, a magnetic head includes a stitch pole being a laminate of at least two magnetic layers separated by a nonmagnetic layer; and a main pole formed adjacent the stitch pole. An end region of the stitch pole closest to an air bearing surface of the head tapers towards the main pole. An average angle of the taper of the end region of the stitch pole is between about 20 and about 45 degrees. Such head may be implemented in a data storage system.

Stitched pole having a tapered tip

A perpendicular magnetic write head having improved Bit Error Rate (BER), Adjacent Track Interference (ATI) and Far Track Interference (FTI). The write head includes a write pole and a trailing wrap-around magnetic shield. A permanent magnetic is located at either outer side of the shield. These magnets are magnetized to have magnetizations that are oriented in the same direction, in a direction that is perpendicular to the track direction and parallel with the air bearing surface.

Perpendicular magnetic write head having a trailing wrap-around magnetic shield magnetically biased in a cross track direction

A method and apparatus for providing a write head with an improved pole tip to improve overwrite and/or adjacent track interference. A cross pole tip writer is provided with a shape that is designed to reduce the saturation on the pole tip and aid in the concentration of flux to the down track.

Method and apparatus for providing a write head with an improved pole tip to improve overwrite and/or adjacent track interference

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.

Magnetic head having a stepped or segmented wrap around shield and methods of formation thereof

A magnetic write head having a magnetic return pole that is configured to prevent wide area track erasure. The magnetic return pole has a throat region with a relatively narrow width and has a inner and outer wing portions formed near the air bearing surface. The inner wing portion has a front edge that is disposed at the air bearing surface, whereas the outer wing portion has a front edge that is recessed from the air bearing surface.

Perpendicular magnetic write head having a novel trailing return pole for reduced wide-area-track-erasure

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.

Perpendicular magnetic write head with stepped write pole for reduced MCW dependency on skew angle

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 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.

Magnetic reader recording characterization at slider or bar level

One embodiment of the invention provides a system that analyzes the propagation of noise through an integrated circuit. During operation, the system obtains an input noise signal to be applied to a cell within the integrated circuit. The system then looks up parameters specifying how noise affects the cell, and then uses the parameters to determine how the input noise signal affects the cell. This can involve determining if the input noise signal will cause the cell to fail and/or determining a propagated noise signal that emanates from the cell.

Method and apparatus for detecting and analyzing the propagation of noise through an integrated circuit

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.

System, method, and apparatus for in-situ stray magnetic field measurement

A method and apparatus for optimizing data record quality on a disk for a pair of read and write heads, in which the write head is bigger, by adaptively varying linear and track density of overlapping recorded tracks to achieve a target storage capacity. In the method, target storage capacity and radial writing direction are selected. Read and write widths of heads are determined. A linear density and offset distance pairing for optimizing record quality at target storage capacity is determined, wherein offset distance is less than write width but greater than read width. The write head writes a track at the linear density, is offset in the radial direction by the offset distance, and the offset distance is stored. The write head writes a new track at the linear density. Offsetting, storing offset, and writing a new track are repeated until desired data is written into a cluster.

Method and apparatus for optimizing record quality with varying track and linear density by allowing overlapping data tracks

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.

Magnetic head with magnetic layers of differing widths and third pole with reduced thickness

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.

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Fremont, CA, United States of America

Yansheng Luo