Hitachi Global Storage Technologies Netherlands B.v.

Western Digital Technologies, Inc.

International Business Machines Corporation

Hitachi Global Storage Technologies

Hgst Netherlands, B.v.

Jih-Shiuan Luo

Hardayal Singh Gill

Wen-Chien David Hsiao

Chin-Yu Yeh

Kim Yang Lee

Ciaran Avram Fox

Tsann Lin

David Eugene Heim

Peter John Melz

Mustafa Pinarbasi

Quang Le

Kuok San Ho

James Mac Freitag

Joey Martin Poss

Thao Anh Nguyen

Yunfei Ding

Ian Robson McFadyen

Robert Langland Smith

Lydia Baril

Ali Sanayei

Chun-Ming Wang

Darrick Taylor Smith

Joseph Francis Smyth

Samuel Wei-san Yuan

David Ernest Call

The present disclosure generally relates to a magnetic media drive employing a magnetic recording head. The magnetic recording head comprises a first write head and a second write head each coupled to a first pad and a second pad of a slider pad and an electrical circuit coupled to the first and second pads. The first write head is a wide writing write head, and the second write head a narrow writing write head. The electrical circuit comprises a first sub-circuit and a second sub-circuit connected in parallel. The first sub-circuit comprises a capacitor and a connection to a first thermal fly height control (TFC) of the first write head. The second sub-circuit comprises an inductor and a connection to a second TFC of the second write head. The electrical circuit is further connected to a third TFC of a read head, the second write head comprising the read head.

Optimized dual thermal fly-height design for dual writers for advanced magnetic recording

The present disclosure generally relates to a magnetic media drive employing a magnetic recording head. The magnetic recording head comprises a first write head and a second write head each coupled to a first pad and a second pad of a slider pad and an electrical circuit coupled to the first and second pads. The first write head comprises a first main pole and a first thermal fly height (TFH) element, and the second write head comprises a second main pole and a second TFH element. The electrical circuit comprises a capacitor and a connection to the first TFH element of the first write head, and an inductor and a connection to the second TFH element of the second write head. The electrical circuit is configured to independently power the first TFH element and the second TFH element.

A data storage device is disclosed comprising a first head actuated over a first disk surface, the first head comprising a plurality of elements including a first element. During a first write operation of the first head, a first bias signal having a first polarity is applied to the first element, and a write interval of the first write operation is measured. During a non-write mode of the first head, a second bias signal having a second polarity opposite the first polarity is applied to the first element during a reverse bias interval that is based on the write interval of the first write operation.

Data storage device reverse biasing head element to counter electro-migration

A method for enhancing thermal stability, improving biasing and reducing damage from electrical surges in self-pinned abutted junction heads. The method includes forming a free layer, forming first hard bias layers abutting the free layer and forming second hard bias layers over the first hard bias layers discontiguous from the free layer, the second hard bias layers being anti-parallel to the first hard bias layers, the first and second hard bias layers providing a net longitudinal bias on the free layer.

Method for enhancing thermal stability, improving biasing and reducing damage from electrostatic discharge in self-pinned abutted junction heads

A narrow track-width magnetoresistive sensor by defining a trench formed between first and second hard bias layers and depositing the sensor into the trench. The sensor can include a sensor stack sandwiched between first and second electrically conductive lead layers. First and second electrically insulating side walls are formed at either side of the sensor stack. First and second hard bias layers extend from the sides of the sensor stack, being separated from the sensor stack by the first and second electrically insulating side walls. First and second physically hard insulation layers are provided over each of the hard bias layers.

Magnetic sensor having a physically hard insulation layer over a magnetic bias structure

A method for testing a magnetic head to determine whether the magnetic head is unacceptably affected by temperature variations. The test includes testing the magnetic head at different temperatures and measuring either or both of a signal amplitude and a signal asymmetry of a signal from the magnetic head at the different temperatures. If signal amplitude or signal asymmetry vary excessively as a result of the temperature change then the head can be scrapped.

Method for testing the acceptability of a magnetic read sensor

A system, method and computer program product provide an annealing process for setting a magnetization condition of a read head. An amount of heat for stabilizing magnetization condition of a read head is calculated. A width and amplitude of a voltage pulse that generates the calculated amount of heat in the read head are calculated. A voltage pulse of the calculated width and amplitude is applied to the read head for generating Joule heating in the read head. The width of the voltage pulse is less than one second.

System and method for pre-stressing a read head for improving performance thereof

A method is disclosed for fabricating a read sensor for a magnetic head for a hard disk drive having a read sensor stack and two lateral stacks. The method of fabrication includes forming lateral stacks on a gap layer, surrounding a groove to form a template. The read sensor stack is then formed in the groove, which defines the lateral dimensions of the read sensor stack, and lead layers are then formed on the lateral stacks. Also disclosed is a read head for a disk drive having a sensor stack defined by pre-established lateral stacks, and a disk drive having the read head.

Method for fabricating a magnetic head having a sensor stack and two lateral stack

In one illustrative example, a spin valve (SV) sensor of the self-pinned type includes a free layer; an antiparallel (AP) self-pinned layer structure; and a non-magnetic electrically conductive spacer layer in between the free layer and the AP self-pinned layer structure. The AP self-pinned layer structure includes a first AP pinned layer having a first thickness; a second AP pinned layer having a second thickness; and an antiparallel coupling (APC) layer formed between the first and the second AP pinned layers. The first thickness is slightly greater than the second thickness. Configured as such, the AP pinned layer structure provides for a net magnetic moment that is in the same direction as a magnetic field produced by the sense current flow, which reduces the likelihood of amplitude flip in the SV sensor.

Self-pinned spin valve sensor having its first AP pinned layer thicker than its second AP pinned layer to reduce the likelihood of amplitude flip

A method of constructing a small trackwidth magnetorsesistive sensor by defining a trench between first and second hard bias layers and depositing the sensor into the trench.

Topographically defined thin film CPP read head fabrication

A magnetic read/write head having a heating element to induce a desired amount of thermal protrusion in the read and write elements to control the fly height of the read and write elements over a magnetic medium. The heating element is connected with circuitry that provides an electrical bias (voltage or current) that switches polarity in order to prevent electromigration, thereby greatly increasing the life of the heating element. The polarity of the heating element can be switched upon the occurrence of a predetermined event such as between read or write events or upon activating deactivating the disk drive device or could be performed at regular, predetermined time intervals. The dual polarity bias could also be provided by applying an AC bias to the heating element.

Dual polarity bias for prolonging the life of a heating element in magnetic data storage devices

A magnetic head and method for forming the same. Leads are added to a wafer stack having a free layer, a bias layer, and a spacer layer between the free layer and bias layer. A gap is formed between the leads. A protective layer is added to the wafer stack such that the gap is covered, as well as facing ends of the leads. Material is removed from at least one side area of the wafer stack using the protective layer as a mask. The protective layer is removed. A portion of the bias layer below the gap is processed for reducing a magnetic moment of the bias layer in the portion of the bias layer below the gap for forming a sensor in which magnetic moments of end portions of the free layer are pinned by magnetic moments of end portions of the bias layer, and preferably antiparallel thereto.

Method for creating a magnetic head

Systems and methods of testing individual sliders are disclosed. One embodiment is a test system that includes a mechanical stress system, a quasi-static measurement system, a transport system, and a slider holder. The individual sliders to be tested are aligned in a row in the slider holder, and the slider holder secures the sliders. The measurement system performs quasi-static measurements on sliders in the slider holder simultaneously. The transport system then transports the slider holder to the mechanical stress system. The mechanical stress system applies mechanical stress to the sliders in slider holder. The transport system then transports the slider holder again to the quasi-static measurement system. This process repeats a desired number of times to complete testing.

Individual slider testing

A method and apparatus for enhancing thermal stability, improving biasing and reducing damage from electrical surges in self-pinned abutted junction heads. The head includes a sandwiched hard bias layer having a first hard bias layer coupled to a free layer and a second, anti-parallel hard bias layer disposed away form the free layer to provide a net longitudinal bias on the free layer.

Self-pinned abutted junction heads having an arrangement of a second hard bias layer and a free layer for providing a net net longitudinal bias on the free layer

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San Jose, CA, United States of America

Jih-Shiuan Luo