Patent US4841401A successfully refreshed from Google Patents.
US4841401A
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Amorphous magnetic head
Assignee: Panasonic Holdings Corp
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Filing: 1984-02-09
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Granted: 1989-06-20
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Expires: 2004-02-09
Abstract
Abstract PCT No. PCT/JP84/00037 Sec. 371 Date Oct. 9, 1984 Sec. 102(e) Date Oct. 9, 1984 PCT Filed Feb. 9, 1984 PCT Pub. No. WO84/03167 PCT Pub. Date Aug. 16, 1984.A magnetic head includes magnetic cores formed by sputter layers of an amorphous magnetic alloy formed on a non-magnetic substrate (1). A non-magnetic ceramic layer is provided on one amorphous magnetic alloy layer, and a non-magnetic substrate is bonded thereon by a bonding glass layer. The one amorphous magnetic alloy sputter layer is isolated from the bonding glass layer by the non-magnetic ceramic layer to prevent the quality of the bonding glass layer from deteriorating thus a stronger bonding force is maintained. The bonding of the amorphous ceramic layer with respect to the one amorphous magnetic alloy layer is strong, thus providing a magnetic head having high reliability.
Inventors
- 👤 Mitsuo Satomi
- 👤 Akio Kuroe
- 👤 Eisuke Sawai
- 👤 Masaru Higashionji
- 👤 Hiroshi Sakakima
- 👤 Kenji Kondo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 06:18
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/147
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
141 words
In a magnetic head having a magnetic core comprising a first substrate of non-magnetic material, at least one layer of an amorphous magnetic alloy material directly formed on said first substrate, and a second substrate of non-magnetic material bonded to said layer of amorphous magnetic alloy material by a bonding glass layer formed of a glass material containing lead and having a low melting point, the improvement of means for preventing deterioration of said bonding glass layer and resultant weakening of adhesion of the bond between said second substrate of non-magnetic material and said layer of amorphous magnetic alloy material, said means comprising: a layer of non-magnetic ceramic material, separate from said bonding glass layer, between said layer of amorphous magnetic alloy material and said bonding glass layer, said non-magnetic ceramic layer having a thickness δ defined by 2000 Å<δ≦5000 Å.
Claim 2
Dependent Claim
141 words
In a magnetic head having a magnetic core comprising a first substrate of non-magnetic material, at least one layer of an amorphous magnetic alloy material directly formed on said first substrate, and a second substrate of non-magnetic material bonded to said layer of amorphous magnetic alloy material by a bonding glass layer formed of a glass material containing lead and having a low melting point, the improvement of means for preventing deterioration of said bonding glass layer and resultant weakening of adhesion of the bond between said second substrate of non-magnetic material and said layer of amorphous magnetic alloy material, said means comprising: a layer of non-magnetic ceramic material, separate from said bonding glass layer, between said layer of amorphous magnetic alloy material and said bonding glass layer, said non-magnetic ceramic layer having a thickness δ defined by 2000 Å<δ≦5000 Å.
Claim 3
Dependent Claim
47 words
The improvement claimed in claim 1, wherein said non-magnetic ceramic layer is composed of at least one material selected from a group composed of SiO 2 , Al 2 O 3 , TiO 2 , ZrO 2 , titanium-barium oxide, forsterite, WC, TiC, SiC and titanium-calcium oxide.
Claim 4
Dependent Claim
16 words
The improvement claimed in claim 1, wherein said non-magnetic ceramic layer is composed of ceramic oxide.
Claim 5
Dependent Claim
23 words
The improvement claimed in claim 1, wherein the softening temperature of said lead-containing, low-melting point bonding glass layer is 500° C. or lower.
Claim 6
Dependent Claim
43 words
The improvement claimed in claim 1, wherein said lead-containing, low-melting point bonding glass layer has a composition of 50 to 90 weight % of PbO and the remainder at least SiO 2 , Al 2 O 3 and B 2 O 3 .
Claim 7
Dependent Claim
17 words
The improvement claimed in claim 1, wherein said non-magnetic ceramic layer is formed by a sputtering operation.
Claim 8
Dependent Claim
22 words
The improvement claimed in claim 1, wherein said layer of amorphous magnetic alloy material comprises a laminated structure formed of plural layers.
Claim 9
Dependent Claim
17 words
The improvement claimed in claim 7, wherein said amorphous magnetic alloy material comprises a Co-Nb series alloy.
Claim 10
Dependent Claim
16 words
The improvement claimed in claim 8, wherein said Co-Nb series alloy is a Co-Nb-Zr series alloy.
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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) | 1992-06-19 | 1992-12-19 | 1993-06-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-06-19 | 1996-12-19 | 1997-06-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-06-19 | 2000-12-19 | 2001-06-20 | $7700.00 | Window Closed / Lapsed |