Hoa Thi Do

US Patent:

6372330, Apr 16, 2002

Filed:

Jul 26, 2000

Appl. No.:

09/626097

Inventors:

Hoa Van Do - Fremont CA
Eric Edward Fullerton - Morgan Hill CA
David Thomas Margulies - Gilroy CA
Hal Jervis Rosen - Los Gatos CA

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G11B 566

US Classification:

428212, 428213, 428694 TM, 428694 TS, 428694 TP

Abstract:

A laminated magnetic recording medium for data storage uses a magnetic recording layer having at least two antiferromagnetically-coupled (AFC) layers spaced apart by a nonferromagnetic spacer layer. Each AFC layer is formed as two ferromagnetic films antiferromagnetically coupled together across an antiferromagnetically coupling film that has a composition and thickness to induce antiferromagnetic coupling of the second film to the first film. The magnetic moments of the two antiferromagnetically-coupled films in each AFC layer are oriented antiparallel, and thus the net remanent magnetization-thickness product (Mrt) of each AFC layer is the difference in the Mrt values of the two ferromagnetic films. The nonferromagnetic spacer layer between neighboring AFC layers has a composition and thickness to prevent any antiferromagnetic coupling of the ferromagnetic films of one AFC layer with the ferromagnetic films of the neighboring AFC layer.

US Patent:

6537638, Mar 25, 2003

Filed:

Dec 13, 2000

Appl. No.:

09/681056

Inventors:

Hoa Do - Fremont CA
Yoshihiro Ikeda - San Jose CA
Yoshiaki Sonobe - San Jose CA
Kentaro Takano - San Jose CA

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G11B 566

US Classification:

428 653, 428 656, 428694 TS, 428694 TM, 428900

Abstract:

A perpendicular magnetic recording disk has an underlayer structure that causes the magnetic layer to have perpendicular magnetic anisotropy and high signal-to-noise ratio (SNR). The underlayer structure comprises a B2 type body-centered-cubic (BCC) material, such as the binary alloys NiAl, RuAl and RuTi, as an underlayer, and a Ti or TiCr alloy sublayer formed directly on the underlayer. The magnetic layer, such as a CoCrPt alloy, is deposited directly on the sublayer. The magnetic layer has perpendicular magnetic anisotropy due to the sublayer yet excellent SNR because of the smaller grain size of the sublayer material formed directly on the B2 type underlayer.

US Patent:

6670032, Dec 30, 2003

Filed:

Sep 13, 2001

Appl. No.:

09/952788

Inventors:

David Thomas Margulies - Gilroy CA
Timothy Martin Reith - San Jose CA
Hoa Do - Fremont CA
Tim Minvielle - San Jose CA
James A. Hagan - Rochester MN

Assignee:

Hitachi Global Storage Technologies Netherlands B.V. - Amsterdam

International Classification:

G11B 566

US Classification:

428332, 428336, 428694 TS, 428694 T, 428694 SG, 428900, 427128, 427129, 427130

Abstract:

This invention provides a disk which has an in-plane oriented magnetic recording layer on a glass, ceramic, or other nonmetallic substrate and a method for making the disk. A thin layer of material is deposited on the substrate to form a texture stop layer. A texturable layer is then deposited on the texture stop layer. This texturable layer is textured before the magnetic layer is deposited. The disk combines all the advantages of a glass or ceramic substrate along with the advantages of an oriented magnetic medium.

US Patent:

6721144, Apr 13, 2004

Filed:

Jan 4, 2001

Appl. No.:

09/755556

Inventors:

Matthew Joseph Carey - San Jose CA
Hoa Van Do - Fremont CA
Robin Frederick Charles Farrow - San Jose CA
Bruce Alvin Gurney - San Rafael CA
David Thomas Margulies - Gilroy CA
Ronald Franklin Marks - San Jose CA
Philip Milton Rice - San Jose CA
Ren Xu - San Jose CA

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G11B 539

US Classification:

36032411, 3603242

Abstract:

An exchange-coupled magnetic structure of a cobalt-ferrite layer adjacent a magnetic metal layer is used in magnetorestive sensors, such as spin valves or tunnel junction valves. The exchange-coupled magnetic structure is used in a pinning structure pinning the magnetization of a ferromagnetic pinned layer, or in an AP pinned layer. A low coercivity ferrite may be used in an AP free layer. Cobalt-ferrite layers may be formed by co-sputtering of Co and Fe in an oxygen/argon gas mixture, or by sputtering of a CoFe composition target in an oxygen/argon gas mixture. Alternatively, the cobalt-ferrite layer may be formed by evaporation of Co and Fe from an alloy source or separate sources along with a flux of oxygen atoms from a RF oxygen atom beam source. Magnetoresistive sensors including cobalt-ferrite layers have small read gaps and produce large signals with high efficiency.

US Patent:

6723450, Apr 20, 2004

Filed:

Mar 19, 2002

Appl. No.:

10/103186

Inventors:

Hoa Van Do - Fremont CA
Mary F. Doerner - Santa Cruz CA
Eric Edward Fullerton - Morgan Hill CA
David Thomas Margulies - Gilroy CA
William G. McChesney - San Jose CA
Manfred Ernst Schabes - Campbell CA
Kai Tang - San Jose CA

Assignee:

Hitachi Global Storage Technologies Netherlands B.V. - Amsterdam

International Classification:

G11B 566

US Classification:

428611, 428637, 428667, 428668, 428669, 428672, 428673, 428 653, 428215, 428694 TM

Abstract:

A magnetic recording medium for data storage uses a magnetic recording layer having at least two ferromagnetic films with different remanent magnetization-thickness (Mrt) values that are coupled antiparallel across a nonferromagnetic spacer film predominantly by the dipole field (H ) from the grains of the higher-Mrt ferromagnetic film. The material compositions and thicknesses of the ferromagnetic films and the nonferromagnetic spacer film are selected so that H predominates over any antiferromagnetic exchange coupling field (H ) and is greater than the coercive field of the lower-Mrt ferromagnetic film. As a result, the magnetizations of the two ferromagnetic films are antiparallel in the two remanent magnetic states, and thus the net remanent magnetization-thickness product (Mrt) of the recording layer is the difference in the Mrt values of the two ferromagnetic films.

US Patent:

6744131, Jun 1, 2004

Filed:

Apr 22, 2003

Appl. No.:

10/421486

Inventors:

Lan Hoang Hoang - Fremont CA
Hoa Lap Do - Herald CA
Leilei Zhang - Sunnyvale CA

Assignee:

Xilinx, Inc. - San Jose CA

International Classification:

H01L 2312

US Classification:

257704, 257778, 257723, 257724, 257786, 257693, 257678

Abstract:

An IC package provides structural rigidity to a flexible substrate, but still allows access to mounted capacitors after package assembly. In a flip chip package, the IC die is mounted face down on a flexible laminate substrate. A metal lid is mounted above and in contact with the die. The metal lid includes openings over portions of an outer region of the substrate to accommodate the capacitors. However, portions of the metal lid extend to the corners of the substrate to provide structural rigidity to the flexible substrate. Some embodiments are directed to packages configured as described above, but in which an IC die has yet to be mounted.

US Patent:

6773834, Aug 10, 2004

Filed:

Jan 29, 2002

Appl. No.:

10/059527

Inventors:

Hoa Van Do - Fremont CA
Eric Edward Fullerton - Morgan Hill CA
David Thomas Margulies - Gilroy CA
Hal Jervis Rosen - Los Gatos CA

Assignee:

Hitachi Global Storage Technologies Netherlands B.V. - Amsterdam

International Classification:

G11B 566

US Classification:

428694TM, 428694 TS, 428336, 428611, 428900

Abstract:

A laminated magnetic recording medium for data storage has an antiferromagnetically-coupled (AFC) layer and a single ferromagnetic layer spaced apart by a nonferromagnetic spacer layer. The AFC layer is formed as two ferromagnetic films antiferromagnetically coupled together across an antiferromagnetically coupling film that has a composition and thickness to induce antiferromagnetic coupling. In each of the two remanent magnetic states, the magnetic moments of the two antiferromagnetically-coupled films in the AFC layer are oriented antiparallel, and the magnetic moment of the single ferromagnetic layer and the greater-moment ferromagnetic film of the AFC layer are oriented parallel. The nonferromagnetic spacer layer between the AFC layer and the single ferromagnetic layer has a composition and thickness to prevent antiferromagnetic exchange coupling. The laminated medium has improved thermal stability and reduced intrinsic media noise.

US Patent:

6803119, Oct 12, 2004

Filed:

Sep 13, 2001

Appl. No.:

09/952822

Inventors:

David Thomas Margulies - Gilroy CA
Timothy Martin Reith - San Jose CA
Hoa Do - Fremont CA
Tim Minvielle - San Jose CA
James A. Hagan - Rochester MN

Assignee:

Hitachi Global Storage Technologies Netherlands B.V. - Amsterdam

International Classification:

G11B 582

US Classification:

428668, 428680, 428 653, 428141, 428336, 428694 SG, 428694 ST

Abstract:

This invention provides a disk which has an in-plane oriented magnetic recording layer on a glass, ceramic, or other nonmetal substrate and a method for making the disc. A thin layer of texturable NiP is sputtered on the substrate. This NiP layer is textured before the magnetic layer is deposited. The disk combines all the advantages of a glass or ceramic substrate along with the advantages of an oriented magnetic medium.