Patent US4677036A successfully refreshed from Google Patents.
US4677036A
Expired / Lapsed
US
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Method of production of thin film magnetic head and magnetic head
Assignee: Sharp Corp
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Filing: 1986-01-29
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Granted: 1987-06-30
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Expires: 2006-01-29
Abstract
Abstract There provides a process for preparing a coil type thin film magnetic head having high density record by planarization differences in level caused by an electroconductive coil holded between upper and lower magnetic cores.
Inventors
- 👤 Tsuneo Nakamura
- 👤 Hidenori Yamasaki
- 👤 Tohru Kira
- 👤 Mitsuhiko Yoshikawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 03:18
CPC Classifications
H; H01; H01F; H01F41/00; H01F41/32; G; G11; G11B; G11B5/00; G11B5/127; G11B5/31; G11B5/3163; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/4902; Y10T29/49021; Y10T29/49032; Y10T29/49036; Y10T29/49043; Y10T29/49044; Y10T29/4906; Y10T29/49062; Y10T29/49064; Y10T428/00; Y10T428/11; Y10T428/1171; Y10T428/31504; Y10T428/31678
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
110 words
A process for preparing a layered coil type thin film magnetic head, comprising: forming a lower magnetic core on a substrate; providing a first insulation layer on said lower magnetic core; providing an electroconductive coil on said first insulation layer; providing a second insulation layer on said electroconductive core said second insulation layer being a SiO 2 layer formed by means of sputtering, plasma-CVD or electron beam evaporation; coating a liquid type SiO 2 on said second insulation layer, curing said coated SiO 2 layer by heat, and dry-etching the cured SiO 2 layer to plane its surface and, forming an upper magnetic core on said coated SiO 2 layer.
Claim 2
Dependent Claim
110 words
A process for preparing a layered coil type thin film magnetic head, comprising: forming a lower magnetic core on a substrate; providing a first insulation layer on said lower magnetic core; providing an electroconductive coil on said first insulation layer; providing a second insulation layer on said electroconductive core said second insulation layer being a SiO 2 layer formed by means of sputtering, plasma-CVD or electron beam evaporation; coating a liquid type SiO 2 on said second insulation layer, curing said coated SiO 2 layer by heat, and dry-etching the cured SiO 2 layer to plane its surface and, forming an upper magnetic core on said coated SiO 2 layer.
Claim 3
Dependent Claim
30 words
The process of claim 1, further including coating with a second coating of liquid type SiO 2 , followed by heat curing, and dry-etching said second cured SiO 2 layer.
Claim 4
Dependent Claim
14 words
A coil type thin film magnetic head prepared by the process of claim 2.
Claim 5
Dependent Claim
14 words
A coil type thin film magnetic head prepared by the process of claim 1.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-06-29 | 1990-12-29 | 1991-06-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-06-29 | 1994-12-29 | 1995-06-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-06-29 | 1998-12-29 | 1999-06-30 | $7700.00 | Window Closed / Lapsed |