Classifications

• • G—PHYSICS
  • G11—INFORMATION STORAGE
  • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
  • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
  • G11B5/62—Record carriers characterised by the selection of the material
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C18/00—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating
  • C23C18/16—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating by reduction or substitution, e.g. electroless plating
  • C23C18/31—Coating with metals
  • C23C18/32—Coating with nickel, cobalt or mixtures thereof with phosphorus or boron
  • C23C18/34—Coating with nickel, cobalt or mixtures thereof with phosphorus or boron using reducing agents
  • C23C18/36—Coating with nickel, cobalt or mixtures thereof with phosphorus or boron using reducing agents using hypophosphites
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
  • H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
  • H01F41/14—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for applying magnetic films to substrates
  • H01F41/24—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for applying magnetic films to substrates from liquids
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T29/00—Metal working
  • Y10T29/49—Method of mechanical manufacture
  • Y10T29/49002—Electrical device making
  • Y10T29/4902—Electromagnet, transformer or inductor
  • Y10T29/49069—Data storage inductor or core

Definitions

• the present invention relates generally to the process of fabricating magnetic data-storage devices, and more specifically relates to a new and improved process for fabricating magnetic devices of the high density storage type which are readily adaptable for use in present-day electronic computers and data processors.
• a more specific object of the present invention is to devise a new and improved chemical deposition process capable of producing magnetic data-storage devices which possess highly desirable characteristics such as: a magnetic coercivity greater than 200 oersteds; a substantially rectangular magnetic hysteresis loop; and having substantially uniform physical and magnetic properties, in addition to high resistance to physical wear.
• a new and improved process for fabricating new and improved magnetic data-storage devices of the high density storage type comprises the steps of first providing a catalytically active substrate capable of receiving a metallic deposit thereon by the process of chemical reduction. Thereafter, the catalytically active substrate is immersed in a complexed aqueous solution having a pH in the alkaline range and including as essential constituents cobalt and hypophosphite ions.
• the combined concentration of cobalt and hypophosphite ions is maintained substantially constant in the range of 2.0 to 8.2 grams/liter, and, additionally, the ratio of cobalt ion concentration to hypophosphite ion concentration is maintained substantially constant in the range of .2 to 1.7.
• the substrate is maintained in the solution for a time sufficient to effect chemical reduction of a cobalt deposit on the surface thereof having a coercive force of at least 200 oersteds.
• the cobalt coated substrate is thereafter rinsed and dried and is then ready to be incorporated in present day electronic computers and data processors as a data storage device.
• the particular substrate onto which the desired cobalt coating is to be chemically deposited may be any of the various shapes and sizes presently being utilized by the computer industry and may either be metallic or nonmetaliic. However, in order to fabricate a storage device in accordance with applicants intended uses, it is preferred that the substrate be a relatively thin sheet or ribbon of polyethylene terephthalate, commonly sold under the trademark Mylar, having a thickness in the order of 0.003 inch.
• the substrate first be rigorously cleaned by immersion in a one molar concentration sodium hydroxide solution, followed by a thorough rinsing in distilled water, a subsequent immersion in a 1/1 dilution of hydrochloric acid solution, again followed by a thorough rinsing in distilled water, and thereafter thoroughly rinsed in acetone.
• a specific cleaning operation is shown and described, it is, of course, to be appreciated that any of the 3,219,47 i Patented Nov. 23, 1965 well known alkaline-acid cleaning procedures may be used with equal success.
• the substrate next be coated with a suitable commercially available adhesive prior to deposition of metallic cobalt thereon.
• a suitable commercially available adhesive any of the various commercially available adhesives may be used with equal success, it is preferred that the adhesive be prepared by mixing one part of Shipleys No. ZOOTF adhesive, currently manufactured by the Shipley Company, Inc., of Wellesley, Massachusetts, United States of America, with three parts of methyl ethyl ketone.
• Shipleys No. ZOOTF adhesive is a well-known Buna-N type adhesive consisting essentially of a thermo plastic base of nitrile-rubber and a small amount of a phenolic thermosetting resin.
• the substrate is then dipped into the adhesive solution and slowly withdrawn at a rate of approximately 0.33 inch/second, then air dried for approximately 30 minutcs, and thereafter cured for approximately 10 hours at a temperature of approximately degrees centigrade.
• the particular manner of applying the adhesive coating to the supporting substrate is not critical; the only restriction is that the adhesive coating be uniformly distributed on the surface thereof.
• chemical reduction of metallic ions is essentially a controlled autocatalytic reduction process of the depositing species on an active metal such as aluminum, iron, nickel, cobalt, palladium, and the like, in the presence of hypophosphite ions; non-active metals such as copper and alloys thereof are normally activated by immersion deposition of palladium onto the depositing surface thereof.
• active metal such as aluminum, iron, nickel, cobalt, palladium, and the like
• non-active metals such as copper and alloys thereof are normally activated by immersion deposition of palladium onto the depositing surface thereof.
• non-conducting materials such as the mentioned Mylar activation is normally accomplished by chemical or vacuum deposition thereon of either a copper or a silver film, followed by immersion deposition of palladium onto the surface of the film.
• the substrate be activated by first being immersed in a stannous chloride solution whereby stannous ions are adsorbed on the surface thereof. Thereafter, the substrate is immersed in a palladium chloride solution whereby the palladium ions in solution are spontaneously reduced by the adsorbed stannous ions, thereby rendering the substrate catalytical- 1y active.
• the adhesive coated Mylar substrate be activated by immersion for a period of ap proximately 5 minutes in a 20 gram/liter aqueous stannous chloride solution containing approximately 10 milliliters/ liter of concentrated hydrochloride acid, with the temperature of the stannous chloride solution being maintained substantially constant at approximately 25 degrees centigrade. Thereafter, the substrate is immersed for a period of approximately 5 minutes in an aqueous palladium chloride solution having a concentration of approximately 0.5 gram/liter and containing approximately 5 milliliters of concentrated hydrochloric acid per liter of solution, with the temperature of the palladium chloride solution being maintained substantially constant at approximately 25 degrees centigrade.
• the final step in the present process is the immersion of the thus activated substrate in an aqueous solution having constituent concentrations in accordance with the teacl1 ings of the present invention.
• GOC12'6H20 NttHgPOa-HgO, 11 0411 0711 0, NHrOl, Co++, H2PO2 C0++lHgPOr C0+++Hg H0, Br, BS,
• citric acid be utilized in an amount sufli-cient to supply citrate ions in a concentration at least equal to the concentration of cobalt ions utilized, whereby soluble cobalt complexes are formed thereby preventing precipitation of the cobalt ions.
• ammonium ions be present in the plating solution of a concentration at least equal to .3 gram/liter of aqueous solution.
• the operating temperature thereof is maintained substantially constant devices of the high density storage type, comprising the steps of:
• a high density magnetic data-storage device fabricated in accordance with the process of claim 1.
• aqueous solution having a pH in the range of 7 to 9 and including as essential constituents cobalt ions and hypophosphite ions, the combined concentration of said cobalt and hypophosphite ions being in the range of 2.0 to 8.2 grams/ liter and the ratio of cobalt ion concentration to hypophosphite ion concentration being in the range of .2 to 1.7, all the metal plating ions consisting essentially of cobalt and said solution further includ ing ammonium ions in a concentration of at least .3 gram/liter and citrate ions in a concentration at least equal to the concentration of said cobalt ions;
• aqueous solution having a pH approximately 8.2, a temperature approximately 80 degrees centigrade, and ineluding as essential constituents cobalt ions and hypophosphite ions, the combined concentration of said cobalt and hypophosphite ions being approximately 4 grams/liter and the ratio of cobalt ionic concentration to hypophosphite ionic concentration being approximately .9, all the metal plating ions consisting essentially of cobalt and said solution further including ammonium ions in a concentration of at least .3 gram/liter and citrate ions in a concentration at least equal to the cobalt ionic concentration;

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• General Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Manufacturing & Machinery (AREA)
• Chemically Coating (AREA)

Priority Applications (5)

Applications Claiming Priority (1)

Publications (1)

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ID=22479828

Family Applications (1)

Country Status (4)

Cited By (10)

Families Citing this family (10)

Citations (8)

• 0
  • NL NL283192D patent/NL283192A/xx unknown
• 1961
  • 1961-09-14 US US137965A patent/US3219471A/en not_active Expired - Lifetime
• 1962
  • 1962-07-17 GB GB27354/62A patent/GB953987A/en not_active Expired
  • 1962-09-05 CH CH1056962A patent/CH405521A/fr unknown

Patent Citations (8)

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