Kroum S Stoev

US Patent:

6791793, Sep 14, 2004

Filed:

Sep 14, 2001

Appl. No.:

09/952989

Inventors:

Yingjian Chen - Fremont CA
Xiaozhong Dang - Fremont CA
Francis H. Liu - Fremont CA
Kroum Stoev - Fremont CA
Hai Jiang - Fremont CA
Yugang Wang - Milpitas CA
Xizeng Shi - Fremont CA

Assignee:

Western Digital (Fremont), Inc. - Fremont CA

International Classification:

G11B 5147

US Classification:

360126

Abstract:

A read/write head and method of making the same, are used in a data storage system, such as a disk drive, for perpendicular magnetic recording of data. The head employs a two-layer pole design with a main pole made of sputtered high moment magnetic material, and an adjunct pole made of electroplated soft magnetic film. The adjunct pole is substantially recessed from the air bearing surface. The present head design significantly enhances the magnetic write field, and substantially reduces side-writing that result in accidental erasure of data in adjacent tracks on the magnetic recording medium.

US Patent:

6906894, Jun 14, 2005

Filed:

Jul 29, 2004

Appl. No.:

10/903977

Inventors:

Yingjian Chen - Fremont CA, US
Xiaozhong Dang - Fremont CA, US
Francis H. Liu - Fremont CA, US
Kroum Stoev - Fremont CA, US
Hai Jiang - Fremont CA, US
Yugang Wang - Milpitas CA, US
Xizeng Shi - Fremont CA, US

Assignee:

Western Digital (Fremont), Inc. - Fremont CA

International Classification:

G11B005/147
G11B005/127

US Classification:

360126, 360123, 360125, 360317, 2960308, 2960314

Abstract:

A read/write head and method of making the same are used in a data storage system, such as a disk drive, for perpendicular magnetic recording of data. The head employs a two-layer pole design with a main pole made of sputtered high moment magnetic material, and an adjunct pole made of electroplated soft magnetic film. The main pole is used to write data onto the medium, and is formed over the write coil. The adjunct pole is substantially recessed from the air bearing surface and is formed over the main pole. The present head design significantly enhances the magnetic write field, and substantially reduces side-writing that result in accidental erasure of data in adjacent tracks on the magnetic recording medium.

US Patent:

6912106, Jun 28, 2005

Filed:

Aug 6, 2002

Appl. No.:

10/213532

Inventors:

Yingjian Chen - Fremont CA, US
Qing He - Fremont CA, US
Yugang Wang - Milpitas CA, US
Kroum Stoev - Fremont CA, US
Francis Liu - Fremont CA, US
Xiaozhong Dang - Fremont CA, US

Assignee:

Western Digital (Fremont), Inc. - Lake Forest CA

International Classification:

G11B005/147

US Classification:

360126

Abstract:

A method and system for providing a recording head is disclosed. The method and system include providing a first pole, a second pole, a write gap and at least one coil. The write cap separates the first pole from the second pole. The coil(s) include a plurality of turns and is between the first and second poles. The first pole includes a pedestal that has a first portion and a second portion. The first portion includes a high moment electroplated material. The second portion includes a hot seed layer that has a high moment sputtered material. The second portion of the first pole is adjacent to the write gap.

US Patent:

6989972, Jan 24, 2006

Filed:

Sep 30, 2002

Appl. No.:

10/261119

Inventors:

Kroum Stoev - Fremont CA, US
Mathew Gibbons - Livermore CA, US
Francis Liu - Fremont CA, US
Bogdan M. Simion - Pleasanton CA, US
Aparna C. Vadde - Fremont CA, US
Jing Zhang - San Jose CA, US
Yiming Huai - Pleasanton CA, US
Marcos M. Lederman - San Francisco CA, US

Assignee:

Western Digital (Fremont), Inc. - Fremont CA

International Classification:

G11B 5/39

US Classification:

360322

Abstract:

Magnetoresistive (MR) sensors have leads that overlap a MR structure and distribute current to the MR structure so that the current is not concentrated in small portions of the leads. An electrically resistive capping layer can be formed between the leads and the MR structure to distribute the current. The leads can include resistive layers and conductive layers, the resistive layers having a thickness-to-resistivity ratio that is greater than that of each of the conductive layers. The resistive layers may protect the conductive layers during MR structure etching, so that the leads have broad layers of electrically conductive material for connection to MR structures. The broad leads conduct heat better than the read gap material that they replace, further reducing the temperature at the connection between the leads and the MR structure.

US Patent:

7092195, Aug 15, 2006

Filed:

May 28, 2004

Appl. No.:

10/856403

Inventors:

Francis H. Liu - Fremont CA, US
Kroum S. Stoev - Pleasanton CA, US
Mohamad T. Krounbi - San Jose CA, US

Assignee:

Western Digital (Fremont), Inc. - Fremont CA

International Classification:

G11B 21/02

US Classification:

360 75

Abstract:

A method adjusts a flying-height distance between a magnetic write head and a magnetic medium. The method includes positioning the write head in a location spaced from the magnetic medium by the flying-height distance. The write head includes a magnetic yoke and a proximal region in proximity to the magnetic medium. The write head further includes a resistive heater and at least a portion of the resistive heater is within the magnetic yoke and is in proximity to the proximal region. The resistive heater is configured to heat the proximal region. The proximal region has a coefficient of thermal expansion. The proximal region is configured to expand and to contract in response to a temperature of the proximal region. The method further includes flowing an electric current through the resistive heater. The method further includes controlling the electric current to adjust the temperature of the proximal region to selectively expand and contract the proximal region and thereby control the flying-height distance.

US Patent:

7113366, Sep 26, 2006

Filed:

Nov 7, 2002

Appl. No.:

10/290880

Inventors:

Yugang Wang - Milpitas CA, US
Kroum Stoev - Fremont CA, US
Francis Liu - Fremont CA, US
Yingjian Chen - Fremont CA, US

Assignee:

Western Digital (Fremont), Inc. - Fremont CA

International Classification:

G11B 5/187

US Classification:

360126

Abstract:

A thin film electromagnetic head has an inductive transducer with a double-nosed ferromagnetic trailing pole layer. The trailing pole layer has a trailing pole tip disposed adjacent to a media-facing surface, a trailing pole yoke disposed distal to the media-facing surface, and a trailing pole nose disposed between the trailing pole tip and the trailing pole yoke. The media-facing surface extends as a substantially flat surface in all directions from the trailing pole tip. The length of the trailing pole nose may be at least twice as long as the trailing pole tip length. The width of the trailing pole nose can be 10 to 30 times as wide as the trailing pole tip width. An inductive transducer having a double-nosed trailing pole layer provides a higher ratio of on-track to off-track write fields, thereby improving the density with which data can be written to the recording media. Such a double-nosed trailing pole layer can be used in transducers for either longitudinal or perpendicular magnetic recording.

US Patent:

7126788, Oct 24, 2006

Filed:

Nov 26, 2003

Appl. No.:

10/724385

Inventors:

Francis H. Liu - Fremont CA, US
Kroum S. Stoev - Fremont CA, US
Yugang Wang - Milpitas CA, US

Assignee:

Western Digital (Fremont), Inc. - Fremont CA

International Classification:

G11B 5/17
G11B 5/147

US Classification:

360123, 360126

Abstract:

A magnetic head for writing information on perpendicular media has a write pole tip, a return pole tip and a deflection pole tip is disclosed. The return pole tip has a media-facing area at least two orders of magnitude greater than that of the write pole tip, and the deflection pole tip is spaced from a trailing corner of the write pole tip by a submicron nonferromagnetic gap. Magnetic flux emanating from the write pole tip is strongest adjacent the trailing corner and directed at an angle that is not perpendicular to the write pole tip. The angled flux provides increased torque to rotate magnetic dipoles in the adjacent media layer that are oriented substantially perpendicular to the disk surface. The media may have a soft magnetic underlayer that is spaced from the write pole tip by a distance similar to the gap spacing.

US Patent:

7126790, Oct 24, 2006

Filed:

Nov 26, 2003

Appl. No.:

10/724309

Inventors:

Francis H. Liu - Fremont CA, US
Kroum S. Stoev - Fremont CA, US
Yugang Wang - Milpitas CA, US

Assignee:

Western Digital (Fremont), Inc. - Fremont CA

International Classification:

G11B 5/147

US Classification:

360126

Abstract:

A magnetic head for writing information on perpendicular media has a write pole tip and a return pole tip with a media-facing area at least two orders of magnitude greater than that of the write pole tip, the return pole tip is spaced from a trailing corner of the write pole tip by a submicron nonferromagnetic gap. Magnetic flux emanating from the write pole tip is strongest adjacent the trailing corner and directed at an angle that is not perpendicular to the write pole tip. The angled flux provides increased torque to rotate magnetic dipoles in the adjacent media layer that are oriented substantially perpendicular to the disk surface. The media may have a soft magnetic underlayer that is spaced from the write pole tip by a distance similar to the gap spacing.