US3886052A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making a magnetic recording disc
Assignee: Digital Equipment Corp
•
Filing: 1973-02-12
•
Granted: 1975-05-27
•
Expires: 1993-02-12
Abstract
Abstract A magnetic recording disc and method of making the same is disclosed wherein a prepared aluminum substrate is first anodized and then plated with a nonmagnetic copper alloy to provide an electroplatable surface. The disc is then electroplated with a ferromagnetic material and heat treated to form a thin oxide over the outer surface which provides a hard, wear resistant coating for the disc.
Inventors
- 👤 Robert Samuel Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 12:05
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/84; Y; Y10; Y10S; Y10S205/00; Y10S205/917; Y10S428/00; Y10S428/922; Y10S428/9265; Y10S428/928; Y10T; Y10T428/00; Y10T428/12; Y10T428/12493; Y10T428/12535; Y10T428/12611
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
165 words
A method for producing a magnetic film on an aluminum substrate to form a magnetic information storage member which has information recorded thereon or read therefrom by a magnetic head while moving with respect to said head comprising the steps of polishing the surface of the aluminum substrate, cleaning the polished surface in a soap solution to remove residue and particulate matter, anodizing the substrate in a phosphoric acid solution to remove alloying precipitates from the surface of the aluminum and to form a porous oxide film on said surface, said pores extending through the oxide film surface to the aluminum surface, plating a film of copper on said porous oxide film surface, electroplating a layer of ferromagnetic material on said copper film to form said magnetic film, and heating said substrate at an elevated temperature for a selected time period to form an oxide layer on the surface of said ferromagnetic layer whereby a thin wear resistant surface is formed on said magnetic film.
Claim 2
Independent Claim
165 words
A method for producing a magnetic film on an aluminum substrate to form a magnetic information storage member which has information recorded thereon or read therefrom by a magnetic head while moving with respect to said head comprising the steps of polishing the surface of the aluminum substrate, cleaning the polished surface in a soap solution to remove residue and particulate matter, anodizing the substrate in a phosphoric acid solution to remove alloying precipitates from the surface of the aluminum and to form a porous oxide film on said surface, said pores extending through the oxide film surface to the aluminum surface, plating a film of copper on said porous oxide film surface, electroplating a layer of ferromagnetic material on said copper film to form said magnetic film, and heating said substrate at an elevated temperature for a selected time period to form an oxide layer on the surface of said ferromagnetic layer whereby a thin wear resistant surface is formed on said magnetic film.
Claim 3
Dependent Claim
18 words
The method as claimed in claim 1 wherein the storage member is movable relative to the magnetic head.
Claim 4
Dependent Claim
22 words
The method as claimed in claim 1 wherein the step of plating the film of copper on said oxide film comprises electroplating.
Claim 5
Dependent Claim
26 words
A method as claimed in claim 1 wherein said elevated temperature is about 570* F and said selected time period is at least 2 1/2 hours.
Claim 6
Dependent Claim
30 words
A method as claimed in claim 1 wherein the step of polishing the surface of the aluminum substrate comprises polishing the surface to a smoothness of at least three microinches.
Claim 7
Dependent Claim
26 words
A method as claimed in claim 1 wherein said elevated temperature is about 570* F and said selected time period is at least 2 1/2 hours.
Claim 8
Dependent Claim
16 words
The method as claimed in claim 1 wherein said ferromagnetic material comprises a nickel cobalt alloy.
Claim 9
Independent Claim
199 words
A METHOD FOR PRODUCING A MAGNETIC FILM ON AN ALUMINUM SUBSTRATE TO FORM A MAGNETIC INFORMATION STORAGE MEMBER WHICH HAS INFORMATION RECORDED THEREON OR READ THEREFROM BY A MAGNETIC HEAD WHILE MOVING WITH RESPECT TO SAID HEAD COMPRIING THE STEPS OF POLISHING THE SURFACE OF THE ALUMINUM SUBSTRATE TO A SMOOTHNESS OF AT LEAST THREE MICROINCHES, CLEANING THE POLISHED SURFACE IN A SOAP SOLUTION TO REMOVE RESIDUES AND PARTICULATE MATTER, ANODIZING THE SUBSTRATE SURFACE IN A PHOSPHORIC ACID SOLUTION TO REMOVE ALLOYING PRECIPITATES FROM THE SURFACE OF THE ALUMINUM AND TO FORM A POROUS OXIDE FILM ON SAID SURFACE, SAID PORES EXTENDING THROUGH THE OXIDE FILM SURFACE TO THE ALUMINUM SURFACE, PLATING A FILM OF COPPER ON THE OXIDE FILM SURFACE FROM A COPPER PLATING BATH CONTAINING COPPER SULFATE AND SULFURIC ACID, POLISHING THE SURFACE OF SAID COPPER FILM, ETCHING SAID COPPER FILM IN AN ACID SOLUTION, ELECTROPLATING A LAYER OF FERROMAGNETIC MATERIAL ON SAID COPPER FILM TO FORM SAID MAGNETIC FILM, AND HEATING SAID SUBSTRATE AT AN ELEVATED TEMPERATURE FOR A SELECTED TIME PERIOD TO FORM AN OXIDE LAYER ON THE SURFACE OF SAID FERROMAGNETIC LAYER WHEREBY A THIN WEAR RESISTANT SURFACE IS FORMED ON SAID MAGNETIC FILM.
Claim 10
Independent Claim
199 words
A METHOD FOR PRODUCING A MAGNETIC FILM ON AN ALUMINUM SUBSTRATE TO FORM A MAGNETIC INFORMATION STORAGE MEMBER WHICH HAS INFORMATION RECORDED THEREON OR READ THEREFROM BY A MAGNETIC HEAD WHILE MOVING WITH RESPECT TO SAID HEAD COMPRIING THE STEPS OF POLISHING THE SURFACE OF THE ALUMINUM SUBSTRATE TO A SMOOTHNESS OF AT LEAST THREE MICROINCHES, CLEANING THE POLISHED SURFACE IN A SOAP SOLUTION TO REMOVE RESIDUES AND PARTICULATE MATTER, ANODIZING THE SUBSTRATE SURFACE IN A PHOSPHORIC ACID SOLUTION TO REMOVE ALLOYING PRECIPITATES FROM THE SURFACE OF THE ALUMINUM AND TO FORM A POROUS OXIDE FILM ON SAID SURFACE, SAID PORES EXTENDING THROUGH THE OXIDE FILM SURFACE TO THE ALUMINUM SURFACE, PLATING A FILM OF COPPER ON THE OXIDE FILM SURFACE FROM A COPPER PLATING BATH CONTAINING COPPER SULFATE AND SULFURIC ACID, POLISHING THE SURFACE OF SAID COPPER FILM, ETCHING SAID COPPER FILM IN AN ACID SOLUTION, ELECTROPLATING A LAYER OF FERROMAGNETIC MATERIAL ON SAID COPPER FILM TO FORM SAID MAGNETIC FILM, AND HEATING SAID SUBSTRATE AT AN ELEVATED TEMPERATURE FOR A SELECTED TIME PERIOD TO FORM AN OXIDE LAYER ON THE SURFACE OF SAID FERROMAGNETIC LAYER WHEREBY A THIN WEAR RESISTANT SURFACE IS FORMED ON SAID MAGNETIC FILM.
Claim 11
Dependent Claim
18 words
The method as claimed in claim 8 wherein the storage member is movable relative to the magnetic head.
Claim 12
Dependent Claim
22 words
The method as claimed in claim 8 wherein the step of plating the film of copper on said oxide film comprises electroplating.
Claim 13
Dependent Claim
26 words
A method as claimed in claim 8 wherein said elevated temperature is about 570* F and said selected time period is at least 2 1/2 hours.
Claim 14
Dependent Claim
21 words
A method as claimed in claim 8 wherein said phosphoric acid solution is from 5 to 20% phosphoric acid by volume.
Claim 15
Dependent Claim
19 words
A method as claimed in claim 8 wherein said film of copper is from 150 to 500 microinches thick.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-05-26 | 1978-11-25 | 1979-05-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-26 | 1982-11-25 | 1983-05-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-26 | 1986-11-25 | 1987-05-27 | $7700.00 | Window Closed / Lapsed |