US4550353A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thin-film magnetic head and method for fabricating the same
Assignee: HGST Japan Ltd
•
Filing: 1983-12-07
•
Granted: 1985-10-29
•
Expires: 2003-12-07
Abstract
Abstract A thin-film magnetic head having a magnetic core of double step structure and a method of fabricating it. A first magnetic core is formed on a substrate, which has a predetermined thickness at a pole chip region thereof and a thickness larger than the predetermined thickness at a back region thereof; a magnetic gap is formed thereon, a conductor coil is formed on the magnetic gap, which is encircled by an inter-layer, insulating film; a first magnetic film is formed thereon, which constitutes one layer of a second magnetic core and is connected with the first magnetic core at the back region; and a second magnetic film is formed thereon through an inorganic insulating film, which constitutes another layer of the second magnetic core and is removed at the pole chip region. When the second magnetic film is removed, the inorganic insulating film serves to protect the first magnetic film, and hence the thickness of the first magnetic film is maintained unvaried. Thus, there is obtained the thin-film magnetic head having a magnetic film which is of a predetermined thickness at the pole chip region and a thickness larger than the predetermined thickness at the back region. This structure enhances the conversion efficiency of the head as well as boosts the resolution for reproduction and relaxes the magnetization saturation for recording.
Inventors
- 👤 Osamu Hirai
- 👤 Tetsuo Kobayashi
- 👤 Shunichiro Kuwatsuka
- 👤 Saburo Suzuki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 01:00
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/31; G11B5/3109; G11B5/313; G11B5/3143; G11B5/3146; G11B5/3153; G11B5/3116; G11B5/3163; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/4902; Y10T29/49021; Y10T29/49032; Y10T29/49036; Y10T29/49043; Y10T29/49044; Y10T29/49046
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
133 words
A thin-film magnetic head having a magnetic core of double step structure comprising: a substrate; a first magnetic core formed on the substrate which has a predetermined thickness at a pole chip region thereof and a thickness larger than the predetermined thickness at a back region thereof; a magnetic gap film formed on the first magnetic core; a conductor coil formed over the magnetic gap film, which is encircled by an inter-layer insulating film; and a first magnetic film formed on the inter-layer insulating film and connected with the first magnetic core at the back region; an insulating film formed on the first magnetic film; and a second magnetic film formed on the insulating film, and removed at the pole chip region, said first and second magnetic films constituting a second magnetic core.
Claim 2
Dependent Claim
133 words
A thin-film magnetic head having a magnetic core of double step structure comprising: a substrate; a first magnetic core formed on the substrate which has a predetermined thickness at a pole chip region thereof and a thickness larger than the predetermined thickness at a back region thereof; a magnetic gap film formed on the first magnetic core; a conductor coil formed over the magnetic gap film, which is encircled by an inter-layer insulating film; and a first magnetic film formed on the inter-layer insulating film and connected with the first magnetic core at the back region; an insulating film formed on the first magnetic film; and a second magnetic film formed on the insulating film, and removed at the pole chip region, said first and second magnetic films constituting a second magnetic core.
Claim 3
Dependent Claim
18 words
A thin-film magnetic head according to claim 1, wherein said inter-layer insulating film is made of organic resin.
Claim 4
Dependent Claim
21 words
A thin-film magnetic head according to claim 1, wherein said insulating film is made of an insulator having slow etching speed.
Claim 5
Dependent Claim
21 words
A thin-film magnetic head according to claim 2, wherein said insulating film is made of an insulator having slow etching speed.
Claim 6
Dependent Claim
29 words
A thin-film magnetic head according to claim 3, wherein said insulating film is an inorganic insulator selected from the group consisting of a metal oxide and a metal nitride.
Claim 7
Dependent Claim
29 words
A thin-film magnetic head according to claim 4, wherein said insulating film is an inorganic insulator selected from the group consisting of a metal oxide and a metal nitride.
Claim 8
Dependent Claim
16 words
A thin-film magnetic head according to claim 5, wherein said inorganic insulator is alumina or titania.
Claim 9
Dependent Claim
16 words
A thin-film magnetic head according to claim 6, wherein said inorganic insulator is alumina or titania.
Claim 10
Independent Claim
143 words
A method of fabricating a thin-film magnetic head having a magnetic core of double step structure comprising the steps of: forming a first magnetic core on a substrate, said first magnetic core having a predetermined thickness at a pole chip region thereof and a thickness larger than the predetermined thickness at a back region thereof; forming a magnetic gap film formed on the first magnetic core; forming a conductor coil over the magnetic gap film, which is encircled by an inter-layer insulating film; forming a first magnetic film on the inter-layer insulating film, which is connected with the first magnetic core at the back region; forming an insulating film on the first magnetic film; and forming a second magnetic film on the insulating film, which is removed at the pole chip region, said first and second magnetic films constituting a second magnetic core.
Claim 11
Independent Claim
143 words
A method of fabricating a thin-film magnetic head having a magnetic core of double step structure comprising the steps of: forming a first magnetic core on a substrate, said first magnetic core having a predetermined thickness at a pole chip region thereof and a thickness larger than the predetermined thickness at a back region thereof; forming a magnetic gap film formed on the first magnetic core; forming a conductor coil over the magnetic gap film, which is encircled by an inter-layer insulating film; forming a first magnetic film on the inter-layer insulating film, which is connected with the first magnetic core at the back region; forming an insulating film on the first magnetic film; and forming a second magnetic film on the insulating film, which is removed at the pole chip region, said first and second magnetic films constituting a second magnetic core.
Claim 12
Independent Claim
188 words
A method of fabricating a thin-film magnetic head having a magnetic core of double step structure comprising the steps of: forming an under-film on a substance; forming a first magnetic film on the under-film; removing the first magnetic film at the pole chip region; forming a second magnetic film so as to cover the first magnetic film and to extend to the said pole chip region; forming a magnetic gap film on the second magnetic film; forming an exposed region of the second magnetic film on said magnetic gap film at the back region; forming an inter-layer insulating film on the magnetic gap film; forming a conductor coil on the inter-layer film; forming another inter-layer insulating film to cover the conductor coil; removing a part of the inter-layer insulating film corresponding to said exposed region; forming a third magnetic film on the inter-layer insulating film, which is connected with the second magnetic film at the exposed region; forming an inorganic insulating film on the third magnetic film; forming a fourth magnetic film on the inorganic insulating film; and removing the fourth magnetic film at the pole chip region.
Claim 13
Independent Claim
188 words
A method of fabricating a thin-film magnetic head having a magnetic core of double step structure comprising the steps of: forming an under-film on a substance; forming a first magnetic film on the under-film; removing the first magnetic film at the pole chip region; forming a second magnetic film so as to cover the first magnetic film and to extend to the said pole chip region; forming a magnetic gap film on the second magnetic film; forming an exposed region of the second magnetic film on said magnetic gap film at the back region; forming an inter-layer insulating film on the magnetic gap film; forming a conductor coil on the inter-layer film; forming another inter-layer insulating film to cover the conductor coil; removing a part of the inter-layer insulating film corresponding to said exposed region; forming a third magnetic film on the inter-layer insulating film, which is connected with the second magnetic film at the exposed region; forming an inorganic insulating film on the third magnetic film; forming a fourth magnetic film on the inorganic insulating film; and removing the fourth magnetic film at the pole chip region.
Claim 14
Dependent Claim
25 words
A method according to claim 9, wherein said second magnetic core and the insulating film intervening therein are subjected to successive film formation and patterning.
Claim 15
Dependent Claim
28 words
A method according to claim 10, wherein said third magnetic film, said inorganic insulating film and said fourth magnetic film are subjected to successive film formation and patterning.
Claim 16
Dependent Claim
16 words
A method according to claim 9, wherein said inter-layer insulating film is made of organic resin.
Claim 17
Dependent Claim
16 words
A method according to claim 10, wherein said inter-layer insulating film is made of organic resin.
Claim 18
Dependent Claim
15 words
A method according to claim 11, wherein said inter-layer film is made of organic resin.
Claim 19
Dependent Claim
16 words
A method according to claim 12, wherein said inter-layer insulating film is made of organic resin.
Claim 20
Dependent Claim
18 words
A method according to claim 9, wherein said insulating film is of an insulator having low etching speed.
Claim 21
Dependent Claim
18 words
A method according to claim 11, wherein said insulating film is of an insulator having low etching speed.
Claim 22
Dependent Claim
26 words
A method according to claim 17, wherein said insulator is of an inorganic insulator selected from the group consisting of a metal oxide and metal nitride.
Claim 23
Dependent Claim
26 words
A method according to claim 18, wherein said insulator is of an inorganic insulator selected from the group consisting of a metal oxide and metal nitride.
Claim 24
Dependent Claim
15 words
A method according to claim 19, wherein said inorganic insulator is of alumina or titania.
Claim 25
Dependent Claim
15 words
A method according to claim 20, wherein said inorganic insulator is of alumina or titania.
Claim 26
Dependent Claim
28 words
A method according to claim 10, wherein said inorganic insulating film is of an inorganic insulator selected from the group consisting of a metal oxide and metal nitride.
Claim 27
Dependent Claim
28 words
A method according to claim 12, wherein said inorganic insulating film is of an inorganic insulator selected from the group consisting of a metal oxide and metal nitride.
Claim 28
Dependent Claim
15 words
A method according to claim 23, wherein said inorganic insulator is of alumina or titania.
Claim 29
Dependent Claim
15 words
A method according to claim 24, wherein said inorganic insulator is of alumina or titania.
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) | 1988-10-28 | 1989-04-29 | 1989-10-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-10-28 | 1993-04-29 | 1993-10-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-10-28 | 1997-04-29 | 1997-10-29 | $7700.00 | Window Closed / Lapsed |