Patent US4842618A successfully refreshed from Google Patents.
US4842618A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of producing magnetic disk
Assignee: HGST Japan Ltd
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Filing: 1988-06-07
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Granted: 1989-06-27
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Expires: 2008-06-07
Abstract
Abstract A method of producing a magnetic disk by lapping a magnetic disk medium, comprising the steps of: preparing a lapping tape having an abrasive particle layer provided with abrasive particle clusters and chip pockets formed between adjacent two clusters, each of said clusters having abrasive particles of Al 2 O 3 or SiC and abrasive particles of diamond, lapping the surface of said magnetic disk medium by using the thus prepared lapping tape.
Inventors
- 👤 Yasushi Ito
- 👤 Masaaki Imamura
- 👤 Yoshiki Kato
- 👤 Jun Fumioka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 20:02
CPC Classifications
B; B24; B24B; B24B37/00; B24B37/04; B24B37/07; B24B37/08; B24B7/00; B24B7/10; B24B7/16; B24B7/17; B24D; B24D11/00; B24D11/001; B24D3/00; B24D3/34; B24D3/346; G; G11; G11B; G11B5/00; G11B5/84; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24355; Y10T428/24372; Y10T428/25; Y10T428/256; Y10T428/257; Y10T428/259
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
86 words
A lapping tape comprising: a substrate made of a tape of plastics; an abrasive layer provided on the substrate and having abrasive particle clusters and chip pockets having an area of 15 to 30% of the entire surface of said abrasive layer formed between adjacent two clusters, each of said clusters having 40 to 89% by weight abrasive particles of Al 2 0 3 or SiC, abrasive particles of 1 to 10% by weight diamond and a binder resin bonding these abrasive particles to each other.
Claim 2
Dependent Claim
86 words
A lapping tape comprising: a substrate made of a tape of plastics; an abrasive layer provided on the substrate and having abrasive particle clusters and chip pockets having an area of 15 to 30% of the entire surface of said abrasive layer formed between adjacent two clusters, each of said clusters having 40 to 89% by weight abrasive particles of Al 2 0 3 or SiC, abrasive particles of 1 to 10% by weight diamond and a binder resin bonding these abrasive particles to each other.
Claim 3
Dependent Claim
92 words
A lapping tape as claimed in claim 1, wherein said abrasive layer of said lapping tape comprises: 40 to 89% by weight Al 2 0 3 abrasive particles or SiC abrasive particles; 1 to 10% by weight diamond abrasive particles; and the remainder binder resin while the total weight of these abrasive particles is 50 to 90%, the mean particle size of said Al 2 0 3 abrasive particles or said SiC abrasive particles being 2 to 9μ, the mean particle size of said diamond abrasive particles being 1 to 9 μm.
Claim 4
Dependent Claim
49 words
a lapping tape as claimed in claim 1, wherein said chip pockets have an area of 15 to 30% of the entire area of said abrasive layer provided on the surface of said lapping tape, and each of said chip pockets has a size of 10 to 100 μm.
Claim 5
Dependent Claim
16 words
A lapping tape according to claim 1, wherein said substrate is made of a polyester film.
Claim 6
Dependent Claim
18 words
A lapping tape according to claim 4, wherein said polyester film has a thickness of about 25 μm.
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) | 1992-06-26 | 1992-12-26 | 1993-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-06-26 | 1996-12-26 | 1997-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-06-26 | 2000-12-26 | 2001-06-27 | $7700.00 | Window Closed / Lapsed |