International Business Machines Corporation

Hitachi Global Storage Technologies Netherlands B.v.

Other

Douglas Howard Piltingsrud

James Aloysius Hagan

Steven F Starcke

John David Amundson

Dennis Leonard Fox

Karl Robert Erickson

John C Shen

Douglas Allan Kuchta

Frederick Paul Benning

David C Paurus

Steven L Maynard

Jon Edward Podolske

Janice Blue Ostrom

Ullal Vasant Nayak

Patrick M McCaffrey

John Patrick Hagen

Terry Lee Jensen

Rick Allan Sprague

John William Marier

Douglas Allen Kuchta

Bradley J Offuh

Paul Henry Hanson

Theresa Marie Lewis

R Paul Thicke

A self-cleaning colloidal slurry and process for finishing a surface of a glass, ceramic, glass-ceramic, metal or alloy substrate for use in a data storage device, for example. The slurry comprises a carrying fluid, colloidal particles, etchant, and a surfactant adsorbed and/or precipitated onto a surface of the colloidal particles and/or substrate. The surfactant has a hydrophobic section that forms a steric hindrance barrier and substantially prevents contaminates, including colloidal particles, from bonding to the substrate surface. The slurry is applied to the surface of the substrate while a pad mechanically rubs the surface. Subsequent cleaning with standard soap solutions removes substantially all remaining contamination from the substrate surface. In an exemplary embodiment, the slurry is used to superfinish a glass disk substrate to a surface roughness of less than 2 &#x212b;, with substantially no surface contamination as seen by atomic force microscopy (AFM) after standard soap cleaning steps.

Self-cleaning colloidal slurry composition and process for finishing a surface of a substrate

A plurality of disks include a first disk and a second disk stacked upon the first disk. The first disk and the second disk are each formed from glass or glass-ceramic. A powder is disposed between the first disk and the second disk. The powder is selected from the group including calcium carbonate, calcium magnesium carbonate, calcium phosphate, magnesium carbonate, magnesium borate, magnesium oxide, magnesium phosphate, and clay.

Powder for disks

A method for making a magnetic disk, without chemical mechanical polishing to remove asperities, includes the steps of placing an annular-shaped element in a vacuum chamber, exposing a surface of the element to a beam of gas clusters while it is in the vacuum chamber, and thereafter applying a magnetic coating. The annular-shaped element may be a substrate, or it may be a substrate with a base coating such as glassy carbon or amorphous carbon. The substrate may be made of glass, preferably high quality fusion glass. The surface of the annular element may be textured by forming a sequence of concentric annular valleys, with plateaus being left between the valleys, before the magnetic coating is applied. A semiconductor wafer may also be smoothed by a beam of gas clusters to prepare the wafer for photolithography.

Disk, method for making it free of asperities utilizing a step of exposing a surface of the disk to a gas cluster ion beam and disk drive unit for using the disk

A method of adjusting the pH of a strengthening melt to provide an adjusted melt for use in microetching glass substrates, such as glass disk substrates for use in data storage devices. A base is added to the strengthening melt to raise its pH. A desired degree of microetch is provided on an aluminosilicate glass disk substrate, for example, by immersion for 2-4 hours at 360&#xb0; C. in a melt adjusted to have a pH of 10. This single operation both strengthens and microetches the glass substrate. A slight etching of the surface of a glass substrate, i.e., microetching, improves the performance and durability of a data storage disk made from the substrate. To avoid an overly aggressive etch that can create undesirable damage to the substrate surface, an acid may be added to the melt if the pH is subsequently determined to have shifted to above an upper limit.

pH adjustment of a melt for use in microetching glass substrates

A method for texturing substrate surfaces and a substrate product, such as for computer disk drives. Microbump textured substrates are produced having a Rp value of about 20-200 &angst; and a ratio of Rmax:Rp of about 1.4 or less. In an exemplary embodiment, a microbump textured substrate is produced having colloidal particles on a surface thereof at a density of at least about 25 particles per 25 &mgr;m , wherein the surface topography includes a Rp value of about 20-200 &angst;, a micro-roughness Rq of about 10 &angst; or less, and a ratio of Rmax:Rp of about 1.4 or less. An exemplary method includes first providing a substrate surface having a surface micro-roughness Rq of about 10 &angst; or less and depositing colloidal particles on the surface to provide a Rp value of about 20-200 &angst; and a ratio of Rmax:Rp of about 1.4 or less. In a further exemplary embodiment, the method increases the micro-roughness Rq, but to a value that is still less than about 10 &angst; with Rmax:Rp still of about 1.4 or less.

Disk substrate with monosized microbumps

A fluid jet cutting method and apparatus for cutting an object from a sheet. In one embodiment, a fluid jet stream is directed against a glass sheet to cut an annular disk substrate for use in a data storage device. The sheet is supported by first, second and third support members. The support surfaces of the second and third support members are respectively positioned inside central openings in the first and second support members. A vacuum pulls the sheet against the support surface of at least the second support member. Preferably, plural central openings in the first support member accommodate plural second and third support members, whereby plural substrates are cut from the sheet. The sheet preferably includes plural layers removably adhered to one another, whereby plural substrates are simultaneously formed by a single fluid jet stream. A protective layer may cover at least one surface to the sheet.

Fluid jet cutting method and apparatus

An apparatus and method of reclaiming a disk substrate. The cost of reclaiming a disk substrate can be lower, and the quality higher, than making a new one from a blank. A layer of a data storage disk is stripped, e.g., by acid/oxidizing bath immersion. The stripped disk is polished in a carrier between polishing pads, with the relative velocity of the polishing pads as seen by the disk being precisely controlled so that an equal amount of stock is removed from each side. Preferably, several stripped disks are sorted into groups based on disk thickness, and disks from one of the groups are simultaneously polished in the carrier. Sorting improves stock removal uniformity from disk to disk. The polished disks are cleaned and, preferably, ordered in a cassette for stacking in a storage device based on disk thickness to more easily meet a mean center specification.

Apparatus and method for reclaiming a disk substrate for use in a data storage device

A method and product for computer disk drives. Glass substrates are provided having low content of residual polishing particles on the surfaces thereof. An exemplary method includes reduction of residual polishing particle content by immersion of the glass substrate in an acid bath containing nitric acid, hydrogen peroxide and an organic acid having a carboxylic acid group.

Lanthanide oxide dissolution from glass surface

The invention is a method of plating a nonmetallic substrate comprising the steps of depositing an adhesion enhancing film on the substrate, treating the adhesion enhancing film to make the film catalytic, and forming an outer coating and passivating plate on the adhesion enhancing film. The resulting plated, nonmetallic substrates may comprise any number of materials used as an inner substrate such as compounds of oxide, nitride, phosphide, carbide, glass, ceramic, and mixtures thereof. In use, the resulting substrate may find application in any number of data storage and retrieval application.

Plating on nonmetallic disks

A disk substrate fabricated front an inner substrate having a specific stiffness greater than about 7.6 Mpsi/gm/cc and an encapsulating layer deposited over the inner substrate. The inner substrate may include materials such as alumina, silicon carbide, beryllium, boron carbide, aluminum, and mixtures thereof. The encapsulating layer may be made from aluminum, magnesium, copper, zinc, and mixtures thereof. The disk substrate may additionally comprise a finishing layer deposited on the encapsulating layer fabricate from a material such as nickel or an alloy thereof. The invention also comprises use of the disk substrate in a data storage and retrieval device and a method of fabricating a disk

Composite disk substrates

An edge strengthened substrate of a data storage disk and a method for fabricating same is disclosed. A strengthening agent is preferably applied to selected portions of a disk-shaped glass substrate to increase the overall strength of the glass substrate. In one embodiment, a strengthening agent is preferably applied along an inner diameter portion of a disk-shaped glass substrate. A binder is preferably mixed with the strengthening agent to limit the mobility of the strengthening agent to the selected inner diameter portion of the substrate during the strengthening process. The glass substrate is then heated to a diffusion temperature for a sufficient duration of time to permit diffusion of the strengthening agent into the glass substrate. Selective application of a strengthening agent to an outer diameter portion of the glass substrate may be performed to further strengthen the glass substrate. Further application of a strengthening agent to an intermediate diameter surface portion of the glass substrate defined substantially between the inner and outer diameter portions may be performed to further increase the strength of the glass substrate.

Edge strengthened substrate of a data storage disk and method for

The invention is a method for improving the flatness of nonmetallic substrates and preferably glass disks. The method comprises the steps of mounting the glass disk on a support. The support preferably comprises a refractory metal having a cooling rate substantially similar to the disk. The disk is then subjected to heating to a temperature in the anneal region for the given material for a period ranging from about 0.5 hours to 12 hours or longer, and then the disk is controllably cooled. The glass disk is preferably cooled at a rate of about 0.25.degree. C./minute to 1.5.degree. C./minute to room temperature. The invention also comprises a hard disk glass memory element and a data storage and retrieval device comprising this element.

Method for improving the flatness of glass disk substrates

A rigid magnetic storage media coating composition using a high concentration of magnetic particles includes a dual thermoset binder system. The two polymers forming the dual binder system cure during mutually exclusive temperature ranges to form polymer networks that are interpenetrated and entangled. The thermoset polyurethane-melamine/polyester polymer binder system possesses improved properties including the ability to retain liquid fluorinated polyether lubricant without spin-off. The addition of a small amount of silicone wax to the uncured coating composition enhances composition rheology during spin coating on a rigid substrate.

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Eyota, MN, United States of America

Douglas Howard Piltingsrud