US4898774A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Corrosion and wear resistant magnetic disk
Assignee: WD Media LLC
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Filing: 1986-12-17
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Granted: 1990-02-06
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Expires: 2006-12-17
Abstract
Abstract A film of magnetic recording media is covered with a layer comprising ZrO 2 . Advantageously, the ZrO 2 layer inhibits corrosion in the underlying magnetic recording media. The ZrO 2 layer is wear resistant and also exhibits reduced static friction. In one embodiment of our invention, an intermediate layer is sputtered onto the media and the ZrO 2 is sputtered onto the intermediate layer. Advantageously, the intermediate layer adheres strongly to both the media and the ZrO 2 . We have discovered that by providing the intermediate layer, static and dynamic friction between a read-write head and the disk tends to remain consistently low, and reliability of the disk is enhanced.
Inventors
- 👤 Tsutomu T. Yamashita
- 👤 Ching-Cheng Shir
- 👤 Tu Chen
- 👤 Ga-Lane Chen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:05
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/72; G11B5/722; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/26; Y10T428/263; Y10T428/264; Y10T428/265
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
66 words
Structure comprising: a film of magnetic recording media on a substrate; and a second layer formed above said film, said second layer comprising sputtered ZrO 2 , a stabilizer and Al 2 O 3 , said structure being constructed for the recording of data in said film of magnetic recording media by magnetic induction recording, said second layer being the uppermost vacuum-deposited layer on said structure.
Claim 2
Dependent Claim
66 words
Structure comprising: a film of magnetic recording media on a substrate; and a second layer formed above said film, said second layer comprising sputtered ZrO 2 , a stabilizer and Al 2 O 3 , said structure being constructed for the recording of data in said film of magnetic recording media by magnetic induction recording, said second layer being the uppermost vacuum-deposited layer on said structure.
Claim 3
Dependent Claim
16 words
The structure of claim 1 wherein said second layer is the top overcoating of said structure.
Claim 4
Dependent Claim
19 words
The structure of claim 1 wherein said second layer has a thickness greater than or equal to 5 nm.
Claim 5
Dependent Claim
16 words
Structure of claim 1 wherein said second layer has a thickness between 10 and 60 nm.
Claim 6
Dependent Claim
13 words
Structure of claim 1 wherein said recording media is a cobalt based alloy.
Claim 7
Dependent Claim
13 words
Structure of claim 1 wherein said recording media is an iron based alloy.
Claim 8
Dependent Claim
14 words
Structure of claim 1 wherein said film is part of a hard magnetic disk.
Claim 9
Dependent Claim
14 words
The structure of claim 1 wherein said film is part of a floppy disk.
Claim 10
Dependent Claim
15 words
The structure of claim 1 wherein said film is part of a magnetic recording tape.
Claim 11
Dependent Claim
15 words
The structure of claim 1 wherein said film is part of a magnetic recording drum.
Claim 12
Dependent Claim
24 words
Structure of claim 1 wherein the concentration of Al 2 O 3 in said second layer is less than or equal to about 20%.
Claim 13
Dependent Claim
109 words
Structure comprising: a film of magnetic recording media on a substrate; and a second layer formed above said film, said second layer comprising sputtered ZrO 2 , Al 2 O 3 and a stabilizer, said structure being constructed for the recording of data in said film of magnetic recording media by magnetic induction recording, said structure further comprising a third layer formed between said recording media and said second layer, said third layer enhancing the adhesion of said second layer to the rest of said structure, said third layer being less than about 100 Å thick and wherein said second layer is the uppermost vacuum-deposited layer on said structure.
Claim 14
Dependent Claim
109 words
Structure comprising: a film of magnetic recording media on a substrate; and a second layer formed above said film, said second layer comprising sputtered ZrO 2 , Al 2 O 3 and a stabilizer, said structure being constructed for the recording of data in said film of magnetic recording media by magnetic induction recording, said structure further comprising a third layer formed between said recording media and said second layer, said third layer enhancing the adhesion of said second layer to the rest of said structure, said third layer being less than about 100 Å thick and wherein said second layer is the uppermost vacuum-deposited layer on said structure.
Claim 15
Dependent Claim
25 words
The structure of claim 12 wherein said third layer comprises a material selected from the group consisting of chromium, titanium, tantalum, zirconium, tungsten, and hafnium.
Claim 16
Dependent Claim
16 words
The structure of claim 12 wherein said third layer is less than about 40 Å thick.
Claim 17
Dependent Claim
20 words
Structure of claim 12 wherein said second layer reduces friction exhibited by said disk and prevents corrosion in said media.
Claim 18
Dependent Claim
12 words
Structure of claim 12 wherein said structure is a hard magnetic disk.
Claim 19
Independent Claim
74 words
A method for forming a magnetic data storage device comprising the steps of: forming a film of magnetic recording media on a substrate such that data can be recorded in said media by magnetic induction recording; and sputtering a second layer on said magnetic recording media, said second layer comprising ZrO 2 , a stabilizer and Al 2 O 3 , and wherein said second layer is the uppermost vacuum-deposited layer on said device.
Claim 20
Independent Claim
74 words
A method for forming a magnetic data storage device comprising the steps of: forming a film of magnetic recording media on a substrate such that data can be recorded in said media by magnetic induction recording; and sputtering a second layer on said magnetic recording media, said second layer comprising ZrO 2 , a stabilizer and Al 2 O 3 , and wherein said second layer is the uppermost vacuum-deposited layer on said device.
Claim 21
Dependent Claim
31 words
The method of claim 17 wherein said step of sputtering a second layer comprises a step of sputtering said second layer using a sputtering target, said sputtering target including a stabilizer.
Claim 22
Dependent Claim
16 words
The method of claim 17 wherein said second layer has a thickness greater than 5 nm.
Claim 23
Dependent Claim
16 words
The method of claim 17 wherein said second layer is between 10 and 60 nm thick.
Claim 24
Dependent Claim
15 words
Method of claim 17 wherein said magnetic data storage device is a hard magnetic disk.
Claim 25
Dependent Claim
24 words
Method of claim 17 wherein the concentration of Al 2 O 3 in said second layer is less than or equal to about 20%.
Claim 26
Independent Claim
115 words
A method for forming a magnetic data storage device comprising the steps of: forming a film of magnetic recording media on a substrate such that data can be recorded in said media by magnetic induction recording; and sputtering a second layer on said magnetic recording media, said second layer comprising ZrO 2 , Al 2 O 3 and a stabilizer, wherein said method further comprises the step of forming an intermediate layer between said media and said second layer, said intermediate layer enhancing adhesion between said second layer and the rest of said device, said intermediate layer being less than about 100 Å thick, said second layer being the uppermost vacuum-deposited layer on said device.
Claim 27
Independent Claim
115 words
A method for forming a magnetic data storage device comprising the steps of: forming a film of magnetic recording media on a substrate such that data can be recorded in said media by magnetic induction recording; and sputtering a second layer on said magnetic recording media, said second layer comprising ZrO 2 , Al 2 O 3 and a stabilizer, wherein said method further comprises the step of forming an intermediate layer between said media and said second layer, said intermediate layer enhancing adhesion between said second layer and the rest of said device, said intermediate layer being less than about 100 Å thick, said second layer being the uppermost vacuum-deposited layer on said device.
Claim 28
Dependent Claim
25 words
The method of claim 23 wherein said intermediate layer comprises a material selected from the group consisting of zirconium, titanium, tantalum, chromium, tungsten and hafnium.
Claim 29
Dependent Claim
16 words
The method of claim 23 wherein said intermediate layer is less than about 40 Å thick.
Claim 30
Dependent Claim
20 words
Method of claim 23 wherein said second layer reduces friction exhibited by said disk and prevents corrosion in said media.
Claim 31
Dependent Claim
15 words
Method of claim 23 wherein said magnetic data storage device is a hard magnetic disk.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-02-05 | 1993-08-07 | 1994-02-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-02-05 | 1997-08-07 | 1998-02-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-02-05 | 2001-08-07 | 2002-02-06 | $7700.00 | Window Closed / Lapsed |