Read Rite Corporation

Western Digital (fremont), Inc.

Hitachi Global Storage Technologies Netherlands B.v.

Hgst Netherlands, B.v.

Alliance Fiber Optic Products, Inc.

Alliance Fiber Optics Products, Inc.

Zhupei Shi

Billy W Crue, Jr

Mark David Thomas

Shanlin Duan

Jane Jie Zhang

Syed A Hossain

Renuka Apparao

Qunwen Leng

Lien-Chang Wang

Ming Mao

Kenneth E Knapp

Yuqiao Liu

Carlos Corona

Bill W Crue, Jr

Yingjian Chen

Ronald A Barr

Xiaoping Bian

Chih-Huang Lai

Chun He

Billy Wayne Crue

Wei-Shin Tsay

Li Tang

Jizhong He

Aiguo Feng

Minh Quang Tran

Bill Crue

Lijun Tong

Jack Jyh-Kau Chang

Kezhao Zhang

Mark S Miller

Zi-Weng Dong

Mark Seymour

Ken Young

Sean Yao

Yiming Huai

Liubo Hong

Tai Min

Kai Tang

Yong Shen

Robert Earl Rottmayer

Hua-Ching Tong

Peter C Chang

William D Jensen

Zi-Wen Dong

Li Wang

Charles W Miller

Thomas C Arnoldussen

Vijay K Dhingra

Jyh-Kau Chang

Tongxin Lu

Jerry Lee

Arien Michael Ghaderi

Song Pang

Lin Wu

Weikang Shen

Qun Wen Leng

Lee Zhang

Jay Dehkordi

Sonny Tran

Chuck Rose

According to one embodiment, a soft underlayer structure includes a coupling layer, at least one outer soft underlayer positioned above and below the coupling layer, and at least one inner soft underlayer positioned above and below the coupling layer between the coupling layer and the associated outer soft underlayer, where the inner soft underlayers have a saturation magnetic flux density and/or a thickness that is different than a saturation magnetic flux density and/or a thickness of the outer soft underlayers.

Soft underlayer having a multilayer structure for high areal density perpendicular recording media

Perpendicular magnetic recording media has been enhanced by controlling the initial growth of magnetic oxide layers and increased magnetic isolation between the grains in the initial magnetic layer. An onset magnetic oxide layer is sputter deposited in an argon-oxygen gas mixture between the main CoPtCr-oxide magnetic layers and the underlying Ru layer. The insertion of the onset magnetic oxide layer enhances the coercivity of the oxide magnetic layers and also improves the nucleation field. The media signal-to-noise ratio and bit error rate also are significantly improved due to the improvement of the initial segregation of Co magnetic grains in the magnetic oxide layers.

System, method and apparatus for onset magnetic oxide layer for high performance perpendicular magnetic recording media

Perpendicular magnetic recording (PMR) media and methods of fabricating PMR media are described. The PMR media includes, among other layers, an underlayer, a first onset layer on the underlayer, a second onset layer on the first onset layer, and a perpendicular magnetic recording layer on the second onset layer. The second onset layer has a magnetic moment which is higher than both a magnetic moment of the first onset layer and a magnetic moment of the perpendicular magnetic recording layer.

Perpendicular magnetic recording media having a dual onset layer

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

Methods and test systems are disclosed for determining the quality of an erase process for perpendicular magnetic recording (PMR) disks. After performing an erase process on a PMR disk and before the PMR disk is assembled into a hard disk drive, a first test pattern of magnetization pulses is written to a region of the PMR disk. A second test pattern is subsequently read from the region of the PMR disk. The second pattern of magnetization pulses is analyzed in relation to the first test pattern and measured to determine the quality of the erase process.

Determination of the quality of an erase process for perpendicular magnetic recording disks

Spinstand test improvement that measures Functional Byte Error Rate (F-BER) of a disk. The F-BER is correlated to the BER of a disk. The F-BER test is faster than a BER test. The F-BER test is incorporated into a spinstand tester or the software associated with a spinstand tester.

Method and system for testing of magnetic disks using F-BER

A method for determining whether a spike in a read back signal from a read head positioned over a perpendicular recording disk having a magnetically soft underlayer (SUL) is caused by a defect in the SUL or by a thermal asperity (TA). A first read back signal with the spike is obtained in the absence of a local magnetic field near the read head. Then, a permanent magnet or electromagnet is used to induce a small local magnetic field by the read head, and a second signal is obtained. If the signals are substantially similar, a thermal asperity is indicated. Otherwise a defect in the 13 magnetically soft underlayer of the disk is indicated.

System and method for determining whether defect in perpendicular recording disk drive is from thermal asperity or defect in magnetically soft underlayer

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.

System, method, and apparatus for detecting signal-to-noise ratio decay in perpendicular magnetic recording

Optical devices and methods for regulating optical channel signals with specified wavelengths are disclosed. According to one aspect of the present invention, a number of variable optical apparatuses are employed. Each of the variable optical apparatuses includes a first and a second optical channel module, both configured at a wavelength &#x3bb;. Each of the variable optical apparatuses further includes an optical regulator (i.e. a neutral density filter controlled by a stepper motor) coupled between the first and second optical channel modules. When signals with different wavelengths arrive, only the signal with the wavelength &#x3bb;will transmit through the first optical channel module and the rest are reflected off. The transmitted signal is regulated (i.e. attenuated or strengthened) accordingly by the optical regulator before transmitting through the second optical channel module. Hence, the signals with different wavelengths can be respectively regulated by one of the variable optical apparatuses.

Dynamic multi-channel power equalizer and regulator

A trailing pole-tip for an electromagnetic transducer is formed as a layer oriented substantially perpendicular to other layers of the transducer, allowing the pole-tip to be made much thinner than conventional pole-tips. The novel pole-tip is formed on an edge or sidewall of a base layer instead of being formed on top of an existing layer. Potential errors in pole-tip thickness are much less than standard error tolerances for conventional pole-tip thickness. Having a greatly reduced pole-tip width significantly reduces the track width so that many more tracks can fit on a media surface, providing a large increase in areal density.

Submicron track-width pole-tips for electromagnetic transducers

A method of forming a head comprises forming a write transducer on a wafer, cutting the wafer to produce a slider bar with a cut surface, and planarizing the cut surface of the slider bar. Forming the write transducer can include forming a first pole layer and forming a first pole pedestal layer over the first pole layer, where the first pole pedestal layer includes a tapered portion defined by a first end having a nose width less than a desired final nose width, and a second end having a zero throat width greater than the desired final nose width. Planarizing the cut surface of the slider bar exposes the first pole pedestal layer until a width thereof approximately equals the desired final nose width.

Method of forming a magnetoresistive device

A compact write element includes a conductive shield layer, an insulating write gap layer, a pole pedestal, a coil, and a conductive pole layer, and, in some embodiments also includes a backgap. The pole pedestal and the coil, and, in some embodiments the backgap, constitute a self-aligned array of components that may be formed in a single masking operation to allow for very tight tolerances between the components for a shorter yoke length. The pole layer is substantially flat and parallel to the conductive shield layer, providing for a shorter stack height. Also, a compact MR read/write head includes such a write element and a magnetic data storage and retrieval system includes the compact MR read/write head having such a write element.

Compact MR write structure

A magnetoresistive device having a first pole, a second pole, and a first tapered pole pedestal therebetween and magnetically connected to the second pole. The first tapered pole has a width that increases with increasing distance away from the air bearing surface, ABS. The magnetoresistive device can also include a second tapered pole pedestal magnetically connected to the first pole, and separated from the first tapered pole pedestal by a write gap. The second tapered pole pedestal has a width that increases with increasing distance away from the air bearing surface. A method of the present invention includes defining the trackwidth of a write element by lapping a tapered pole pedestal. More specifically, the trackwidth is given by a known taper angle, a zero throat width, and a throat height, wherein the throat height is controlled precisely by lapping.

Techniques for bonding aligned optical parts to a substrate are disclosed. According to one embodiment, one or more wedges are used to fill in gaps between aligned optical parts and a substrate. Using an appropriate material, the wedges are respectively slid in till respective contacts between the aligned optical parts and the wedges are established, a small amount of a bonding agent is then only applied to the respect contacts. As a result, the shrinkage that may be caused by the bonding agent to destabilize the aligned optical parts is minimized and the alignments among the optical parts are preserved and can sustain under very high environmental stresses.

Method for bonding aligned optical parts and apparatus thereof

A GMR spin valve is provided for reading a magnetic signal from a magnetic recording medium. The spin valve includes a non-magnetic layer such as for example copper, separated by first and second magnetic layers. The spin valve includes a pinned magnetic layer and a free magnetic layer, the resistance of the spin valve changing with the relative angle between the direction of magnetization of free and pinned layers. Extremely smooth surfaces are provided at the interfaces between the non-magnetic layer and the adjacent magnetic layers. This smooth interface greatly enhances the performance and reliability of the spin valve by allowing extremely tight control of the thickness of the non-magnetic layer and by preventing atomic diffusion between the non-magnetic and magnetic layers. This smooth interface is achieved by including a surfactant in the deposition of the non-magnetic layer.

Method for manufacturing a GMR spin valve having a smooth interface between magnetic and non-magnetic layers

Growing community of inventors

San Jose, CA, United States of America

Zhupei Shi