Hoa M 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:

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:

6835476, Dec 28, 2004

Filed:

Mar 11, 2003

Appl. No.:

10/386834

Inventors:

Hoa Van Do - Fremont CA
Mary F. Doerner - Santa Cruz CA
Eric Edward Fullerton - Morgan Hill CA
David T. Margulies - Los Gatos CA
Natacha F. Supper - Campbell CA

Assignee:

Hitachi Global Storage Technologies Netherlands B.V. - Amsterdam

International Classification:

G11B 566

US Classification:

428694TS, 428694 TM, 428611, 428212, 428900

Abstract:

A magnetic recording medium for data storage uses a magnetic recording layer having at least two ferromagnetic films exchange coupled together antiferromagnetically across a nonferromagnetic spacer film. In this antiferromagnetically-coupled (AFC) recording layer the magnetic moments of the two ferromagnetic films are oriented antiparallel, and thus the net remanent magnetization-thickness product (Mrt) of the AFC recording layer is the difference in the Mrt values of the two ferromagnetic films. This reduction in Mrt is accomplished without a reduction in thermal stability of the recording medium. The lower ferromagnetic film in the AFC recording layer is a ferromagnetic CoCrFe alloy that does not require a nucleation layer between it and the Cr alloy underlayer. The medium with the CoCrFe alloy as the first or lower ferromagnetic film in the AFC recording layer has reduced intrinsic media noise.

US Patent:

7081309, Jul 25, 2006

Filed:

Mar 23, 2004

Appl. No.:

10/808020

Inventors:

Hoa Van Do - Fremont CA, US
Eric Edward Fullerton - Morgan Hill CA, US
David Margulies - Los Gatos CA, US
Andreas Moser - San Jose CA, US

Assignee:

Hitachi Global Storage Technologies Netherlands B.V. - Amsterdam

International Classification:

G11B 5/673

US Classification:

4288281, 428829

Abstract:

A magnetic recording disk has an antiferromagnetically-coupled (AFC) structure that has an upper ferromagnetic layer (UL), and a lower ferromagnetic layer structure formed of two ferromagnetically-coupled lower layers (LL, LL). The UL is antiferromagnetically-coupled to the lower layer structure across an antiferromagnetically-coupling layer. LL and LL are ferromagnetically coupled across a ferromagnetic coupling layer so the magnetizations of LL and LL remain parallel in each remanent magnetic state, but are antiparallel to the magnetization of the UL in each remanent magnetic state. The UL has an Mrt greater than the sum of the Mrt values of LL and LL.

US Patent:

7125616, Oct 24, 2006

Filed:

Feb 26, 2004

Appl. No.:

10/788687

Inventors:

Hoa Van Do - Fremont CA, US
Eric Edward Fullerton - Morgan Hill CA, US
David Margulies - Los Gatos CA, US
Andreas Moser - San Jose CA, US

Assignee:

Hitachi Global Storage Technologies Netherlands B.V. - Amsterdam

International Classification:

G11B 5/66

US Classification:

4288281

Abstract:

A magnetic recording disk has an antiferromagnetically-coupled (AFC) structure that has three lower ferromagnetic layers (LL, LL, LL) and an upper ferromagnetic layer (UL), all four ferromagnetic layers being antiferromagnetically-coupled together across corresponding antiferromagnetically-coupling layers. The UL has a magnetization-remanence-thickness product (Mrt) greater than the Mrt each of the three lower layers LL, LL, LL, and greater than the sum of the Mrt values of LL and LL. The middle lower layer LL has an Mrt less than the Mrt of each of the other lower layers LL and LL, and as a result the composite Mrt of the AFC structure is less than the composite Mrt of a conventional AFC structure having only a single lower layer. The AFC structure achieves this composite Mrt reduction without increasing the Mrt of any of the three lower layers above the maximum Mrt of the single lower layer in the conventional AFC structure.