Patent US5236735A successfully refreshed from Google Patents.
US5236735A
Expired / Lapsed
US
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Method of producing a thin film magnetic head
Assignee: TDK Corp
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Filing: 1991-06-13
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Granted: 1993-08-17
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Expires: 2011-06-13
Abstract
Abstract A method of producing a thin film magnetic head comprises forming a thin film magnetic circuit including a magnetic film and a conductive coil film on a substrate, and heating the thin film magnetic circuit at a temperature in a range of from 270° C. to 400° C. before forming a protective layer covering the thin film magnetic circuit.
Inventors
- 👤 Makoto Yoshida
- 👤 Yuzuru Iwai
- 👤 Noboru Yamanaka
- 👤 Jun Shouzi
- 👤 Tsutomu Koyanagi
- 👤 Mikio Matsuzaki
- 👤 Nobuya Ohyama
- 👤 Yoshiaki Tanaka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 19:03
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/31; G11B5/3103; G11B5/3106; G11B5/3109; G11B5/3113; G11B5/3163
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
115 words
A method of producing a thin film magnetic head which has a reduced popcorn noise comprising the steps of: forming a lower magnetic film on a substrate; forming a gap film on said lower magnetic film; forming a conductive coil film on said gap film; forming an upper magnetic film on said conductive coil film, wherein said substrate, said lower magnetic film, said gap film, said conductive coil film and said upper magnetic film comprise an intermediate structure; heating said intermediate structure to a temperature in a range of from 270° C. to 400° C. and for a time sufficient to produce the reduced popcorn noise; forming a protective layer on said heated intermediate structure.
Claim 2
Independent Claim
115 words
A method of producing a thin film magnetic head which has a reduced popcorn noise comprising the steps of: forming a lower magnetic film on a substrate; forming a gap film on said lower magnetic film; forming a conductive coil film on said gap film; forming an upper magnetic film on said conductive coil film, wherein said substrate, said lower magnetic film, said gap film, said conductive coil film and said upper magnetic film comprise an intermediate structure; heating said intermediate structure to a temperature in a range of from 270° C. to 400° C. and for a time sufficient to produce the reduced popcorn noise; forming a protective layer on said heated intermediate structure.
Claim 3
Dependent Claim
27 words
The method of producing a thin film magnetic head according to claim 1, wherein the time sufficient to produce the reduced popcorn is for 10 minutes-200 minutes.
Claim 4
Dependent Claim
33 words
The method of producing a thin film magnetic head according to claim 1, wherein the thin film magnetic circuit is heated in a degree of vacuum of about 10 -4 -10 -6 Torr.
Claim 5
Dependent Claim
33 words
The method of producing a thin film magnetic head according to claim 3, wherein the thin film magnetic head is heated in a degree of vacuum of about 10 -3 -10 -5 Torr.
Claim 6
Independent Claim
120 words
A method of producing a thin film magnetic head which has a reduced popcorn noise, comprising the steps of: forming a lower magnetic film on a substrate; forming a gap film on said lower magnetic film; forming a conductive coil film on said gap film; forming an upper magnetic film on said conductive coil film, wherein said substrate, said lower magnetic film, said gap film, said conductive coil film and said upper magnetic film comprise an intermediate structure; heating said intermediate structure to a temperature in a range of from 270° C. to 400° C. and for a time between 10 and 200 minutes to produce the reduced popcorn noise; and forming a protective layer on said heated intermediate structure.
Claim 7
Independent Claim
120 words
A method of producing a thin film magnetic head which has a reduced popcorn noise, comprising the steps of: forming a lower magnetic film on a substrate; forming a gap film on said lower magnetic film; forming a conductive coil film on said gap film; forming an upper magnetic film on said conductive coil film, wherein said substrate, said lower magnetic film, said gap film, said conductive coil film and said upper magnetic film comprise an intermediate structure; heating said intermediate structure to a temperature in a range of from 270° C. to 400° C. and for a time between 10 and 200 minutes to produce the reduced popcorn noise; and forming a protective layer on said heated intermediate structure.
Claim 8
Dependent Claim
27 words
The method of producing a thin film magnetic head according to claim 5, wherein said intermediate structure is heated for a time between 10 and 120 minutes.
Claim 9
Dependent Claim
31 words
The method of producing a thin film magnetic head according to claim 6, wherein said intermediate structure is heated for a time of 60 minutes at a temperature of 320° C.
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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) | 1996-08-16 | 1997-02-15 | 1997-08-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-08-16 | 2001-02-15 | 2001-08-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-08-16 | 2005-02-15 | 2005-08-17 | $7700.00 | Window Closed / Lapsed |