US4894742A
Expired / Lapsed
US
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Thin-film laminated magnetic heads of Fe-Si-Al alloy
Assignee: Eneos Corp
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Filing: 1986-10-03
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Granted: 1990-01-16
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Expires: 2006-10-03
Abstract
Abstract A magnetic film of Fe-Si-Al alloy comprises a substrate and an Fe-Si-Al alloy film in which argon is entrapped. A thin-film laminated magnetic head comprises a pair of opposed substrates, and alternately laminated Fe-Si-Al alloy films entrapping argon therein and non-magnetic insulating films between the substrates. In the magnetic film and the head the substrates have a thermal expansion coefficient lower than that of the Fe-Si-Al alloy films and the amount of argon entrapped in the alloy films is controlled within the range of about 0.01 to about 0.3 wt. % so that internal stresses in the alloy films are substantially zeroed.
Inventors
- 👤 Kazuhiro Saito
- 👤 Taiichi Mori
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 21:12
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/31; G11B5/3109; G11B5/313; G11B5/147; G11B5/3163; H; H01; H01F; H01F10/00; H01F10/08; H01F10/10; H01F10/12; H01F10/14; H01F10/142; H01F10/145; H01F10/26; H01F10/265; H01F41/00; H01F41/14; H01F41/18; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/4902; Y10T29/49021; Y10T29/49032; Y10T29/49036; Y10T29/49043; Y10T29/49055
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
111 words
A thin-film laminated magnetic head comprising a pair of half blocks which are mated and bonded through a non-magnetic gap spacer, at least one of the half blocks formed with a groove for receiving coil winding, each of said half blocks having a pair of opposed substrates, and alternately laminated Fe-Si-Al alloy films and non-magnetic insulating films therebetween and entrapping in each alloy film an amount of argon ranging between about 0.01 to about 0.3 wt % based upon the weight of the alloy film, so that internal stresses in said alloy films are substantially zeroed said substrates having a thermal expansion coefficient lower than that of said Fe-Si-Al alloy films.
Claim 2
Dependent Claim
111 words
A thin-film laminated magnetic head comprising a pair of half blocks which are mated and bonded through a non-magnetic gap spacer, at least one of the half blocks formed with a groove for receiving coil winding, each of said half blocks having a pair of opposed substrates, and alternately laminated Fe-Si-Al alloy films and non-magnetic insulating films therebetween and entrapping in each alloy film an amount of argon ranging between about 0.01 to about 0.3 wt % based upon the weight of the alloy film, so that internal stresses in said alloy films are substantially zeroed said substrates having a thermal expansion coefficient lower than that of said Fe-Si-Al alloy films.
Claim 3
Dependent Claim
66 words
The thin-film laminated magnetic head of claim 1 wherein said substrates have a thermal expansion coefficient of 100×10 -7 to 135×10 -7 deg -1 , and said Fe-Si-Al alloy films are each a composition containing 83 wt % or more Fe and having a high level of saturation magnetization, the thermal expansion coefficient of the alloy films being 110×10 -7 to 170×10 -7 deg -1 .
Claim 4
Dependent Claim
47 words
The thin-film laminated magnetic head of claim 1 or 2 wherein said substrates are made of crystalized glass, and said Fe-Si-Al alloy films are each a composition of 83 to 94 wt % Fe, 4 to 11 wt % Si and 2 to 6 wt % Al.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1993-01-15 | 1993-07-17 | 1994-01-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-01-15 | 1997-07-17 | 1998-01-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-01-15 | 2001-07-17 | 2002-01-16 | $7700.00 | Window Closed / Lapsed |