Stock material or miscellaneous articles – Circular sheet or circular blank – Recording medium or carrier
Reexamination Certificate
2001-04-13
2003-07-01
Le, H. Thi (Department: 1773)
Stock material or miscellaneous articles
Circular sheet or circular blank
Recording medium or carrier
C360S122000, C360S244000, C428S690000, C428S900000
Reexamination Certificate
active
06586069
ABSTRACT:
BACKGROUND OF THE INVENTION
The invention relates to protective coatings for components of disc drive data storage systems. In particular, the invention relates to protective coatings for magnetic materials used in disc drive systems used for the storage and/or retrieval of data, including, for example, magnetic read/write heads and magnetic discs.
Advances in many technologies have created enhanced demands on materials used in the production of a variety of devices. Specifically, miniaturization has decreased tolerance levels while increasing performance requirements. Furthermore, coating technology has become extremely important since coatings can be used to alter the surface properties of the composite while maintaining desirable properties of the underlying substrate. In particular, thin coatings can serve to protect the underlying substrate from a variety of assaults.
Magnetic and optical-magnetic data storage devices generally use data storage discs and magnetic heads for reading and/or writing. In use, the heads “fly” just above the disc while the disc is spinning at a rapid rate. The read/write head generally includes an air bearing surface, which faces the disc surface. As the disc rotates, the disc drags air along the air bearing surface. As the air passes along the air bearing surface, the air pressure between the disc surface and the air bearing surface creates a hydrodynamic lifting force that causes the slider or head to lift in relation to the disc surface. The hydrodynamic lift and corresponding fly height are affected by the speed of rotation of the disc, the design of the air bearing surface of the read/write head and the preload force supplied to the head by the gimbal assembly supporting the head.
Read/write heads generally use magnetic transducers to read and/or write data from a magnetic data disc. Heads with magneto-resistive elements can also be used for asperity detection to identify imperfections on the surface of a rotating disc by identifying changes in electrical resistance after the head contacts a bump or imperfection on a disc surface. If unacceptable imperfections are detected, the disc can be smoothed or discarded. Similarly, heads with magnetic transducers can be used in combination magneto-optical disc storage systems.
Disc drives for data storage can use one or more discs with a magnetizable medium for the storage of information. The magnetic medium generally is formed by a relatively thin magnetic layer on a non-magnetic substrate. Typically, the data is stored at specific locations along concentric data tracks. The disc drive assemblies for magnetic data storage include head gimbal assemblies aligned with the disc surface. The head/gimbal assemblies support transducers, such as magnetoresistive elements, for reading data from and writing data to the data tracks near the disc surface. Information is stored in the magnetic media within the data storage zones.
Intermittent contact between the head and the disc surface causes wear of the disc surface and the head. To protect the disc surface and/or the head from wear and corrosion, overcoats can be placed over the magnetic medium on the disc surface and/or the head surface. Preferred overcoats reduce wear, friction and oxidation while maintaining proper hydrodynamic interaction between the head and the disc surface during rotation and during take-off and landing. Protective overcoats also protect the head during processing and fabrication.
To obtain higher storage densities on the disc surface, fly heights between the read/write head and the disc surface are being reduced. Reducing the fly height improves the magnetic interaction between the head and the disc surface to allow correspondingly higher data storage densities. Thus, it is important that protective coatings are thin enough not to excessively increase the effective distance between the magnetic transducers of the head and the magnetic materials near the disc surface.
Carbon coatings have been used to form protective layers on substrates. The coating, however, increases the spacing between the surface and the underlying substrate. Thus, for example in the production of magnetic discs, any performance improvement resulting from a reduction in fly height can be countered by the presence of protective coatings and the like that result in an increased distance of the magnetic medium and the disc surface.
SUMMARY OF THE INVENTION
In a first aspect, the invention pertains to a disc drive data storage system comprising a magnetic material and a means for protecting the surface of the magnetic material.
In a further aspect, the invention pertains to a disc drive data storage system comprising a magnetic material having a coating surface of a material selected from the group consisting of metals, semiconductors and mixtures thereof. The coating surface has an approximate monolayer of fullerene molecules bonded to the coating surface with a bond strength greater than fullerene-fullerene intermolecular bond strength.
In another aspect, the invention pertains to a method for protecting a surface of a magnetic material in a disc drive data storage system. The method includes depositing an approximate monolayer of fullerene molecules on the surface of the magnetic material. The surface comprises a material selected from the group consisting of metals, semiconductors and combinations thereof, and the surface is substantially free of contaminants.
In an additional aspect, the invention pertains to another method for protecting a surface of a magnetic material in a disc drive data storage system. The method includes depositing fullerene molecules on a surface of the magnetic material under ultrahigh vacuum with a pressure no more than about 1×10
−7
torr.
REFERENCES:
patent: 4503125 (1985-03-01), Nelson et al.
patent: 4641841 (1987-02-01), Regan
patent: 5316636 (1994-05-01), Bunshah et al.
patent: 5374463 (1994-12-01), Bethune et al.
patent: 5447796 (1995-09-01), Tsukamoto et al.
patent: 5538763 (1996-07-01), Ueba et al.
patent: 5558903 (1996-09-01), Bhushan et al.
patent: 5744399 (1998-04-01), Rostoker et al.
patent: 5744431 (1998-04-01), Diaz et al.
patent: 5876790 (1999-03-01), Kats
patent: 5886854 (1999-03-01), Diaz et al.
patent: 5985105 (1999-11-01), Smoliar
patent: 6014288 (2000-01-01), Cha et al.
patent: 6017630 (2000-01-01), Tanaka et al.
patent: 6045596 (2000-04-01), Holland, Jr. et al.
patent: 6086949 (2000-07-01), Hwang et al.
patent: 6303214 (2001-10-01), Chour et al.
patent: 6416935 (2002-07-01), Hsiao et al.
patent: 6421202 (2002-07-01), Tanaka et al.
patent: 6433965 (2002-08-01), Gopinathan et al.
patent: 6479111 (2002-11-01), Dykes et al.
patent: 2 461 997 (1980-07-01), None
patent: 05282660 (1993-10-01), None
patent: 05314451 (1993-11-01), None
patent: 05342570 (1993-12-01), None
patent: 06044556 (1994-02-01), None
patent: 07235045 (1995-05-01), None
patent: 08212539 (1996-08-01), None
patent: 09211862 (1997-08-01), None
patent: 09211862 (1997-08-01), None
patent: 10049885 (1998-02-01), None
patent: 11125904 (1999-05-01), None
“Molecular Brush Assembly”, IBM Technical Disclosure Bulletin, vol. 37, No. 1, pp. 261-262, Jan. 1994.
“Molecular Ball Bearing system for Magnetic Head/Disc Interface”,IBM Technical Disclosure Bulletin, vol. 37, No. 7, Jul. 1994.
Fartash, “Growth and Microstructure of Interfacially Oriented Large-Crystalline-Grain C60Sheets”Applied Physics Letters, vol. 64, No. 14, pp. 1877-1879 Apr. 4, 1994.
Altman et al., “Nucleation, Growth and Structure of Fullerene Films on Au(111)”,Surface Science, No. 279, pp. 49-67, 1992.
Sellidj et al., Vibrational and Electronic Properties of Monolayer and Mulilayer C60Films on Rh(111),Journal of Physical Chemistry, vol. 97, No. 39, pp. 10076-10082, 1993.
Chen et al., “Growth of C60 Films on Silicon Surfaces”,Surface Science, No. 318, pp. 74-82, 1994.
Tannigaki et al., “Crystal Growth of C60thin films on layered substrates”,Applied Physics Letters, vol. 63, No. 17, pp. 2351-2353, Oct. 25, 1993
“The Evaluation of Carbon-60 as a Lubricant for Thin-Film Magnetic Disks” by
Angelo James E.
Dykes John W.
Hoehn Joel W.
Mosley William D.
Le H. Thi
Seagate Technology LLC
Westman Champlin & Kelly P.A.
LandOfFree
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