US4966648A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing thin film magnetic head
Assignee: Sharp Corp
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Filing: 1989-06-23
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Granted: 1990-10-30
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Expires: 2009-06-23
Abstract
Abstract An improved process for producing a thin film magnetic head includes forming a nonmagnetic material layer over a lower magnetic core layer with an electrically conductive coil layer embedded in the nonmagnetic material layer. It further includes forming an upper magnetic core layer of a predetermined pattern by a specific method over the resultant to provide the thin film magnetic head.
Inventors
- 👤 Tsuneo Nakamura
- 👤 Kazuyoshi Imae
- 👤 Haruhiko Deguchi
- 👤 Tohru Kira
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 21:03
CPC Classifications
H; H01; H01F; H01F41/00; H01F41/32; H01F41/34; G; G11; G11B; G11B5/00; G11B5/127; G11B5/31; 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; Y10T29/4906; Y10T29/49064
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
165 words
A process for producing a thin film magnetic head by forming a nonmagnetic material layer over a lower magnetic core layer with an electrically conductive coil layer embedded in the nonmagnetic material layer, and forming an upper magnetic core layer of a predetermined pattern over the resultant to provide the thin film magnetic head, the upper magnetic core layer of the predetermined pattern being formed by the steps of: (a) forming a resin film over an area including and wider than the area of the predetermined pattern; (b) etching the resin film to form a resin film pattern, reverse to that of the predetermined pattern; (c) forming a layer of magnetic material over the resin film pattern to thereby form a resultant; and (d) subjecting the resultant to plasma etching using an oxygen-containing gas, to remove both resin film remaining from step (b) and the magnetic material previously formed on the remaining resin film to thereby leave a magnetic material layer in the predetermined pattern.
Claim 2
Dependent Claim
165 words
A process for producing a thin film magnetic head by forming a nonmagnetic material layer over a lower magnetic core layer with an electrically conductive coil layer embedded in the nonmagnetic material layer, and forming an upper magnetic core layer of a predetermined pattern over the resultant to provide the thin film magnetic head, the upper magnetic core layer of the predetermined pattern being formed by the steps of: (a) forming a resin film over an area including and wider than the area of the predetermined pattern; (b) etching the resin film to form a resin film pattern, reverse to that of the predetermined pattern; (c) forming a layer of magnetic material over the resin film pattern to thereby form a resultant; and (d) subjecting the resultant to plasma etching using an oxygen-containing gas, to remove both resin film remaining from step (b) and the magnetic material previously formed on the remaining resin film to thereby leave a magnetic material layer in the predetermined pattern.
Claim 3
Dependent Claim
35 words
The process of claim wherein the resin film is made of a polyimide resin, a polyimido-siloxane resin, a photosensitive resin, a UV resist, a Deep-UV resist or a curable resin with electron beams or x-rays.
Claim 4
Dependent Claim
30 words
The process of claim 1 wherein the resin film has a thickness of about a half to 2 times the thickness of the upper magnetic core layer to be formed.
Claim 5
Dependent Claim
17 words
The process of claim 1 wherein the resin film has a thickness of 5 to 50 μm.
Claim 6
Dependent Claim
17 words
The process of claim 1 wherein the resin film has a thickness of 10 to 30 μm.
Claim 7
Dependent Claim
27 words
The process of claim 1 wherein the layer of magnetic material is made of an iron alloy such as Ni-Fe or Fe-Al-Si, or an cobalt-based amorphous alloy.
Claim 8
Dependent Claim
29 words
The process of claim 1 wherein the layer of magnetic material is formed by electroplating, vacuum evaporation or sputtering under a substrate temperature of 100° C. to 400° C.
Claim 9
Dependent Claim
19 words
The process of claim 1 wherein the layer of magnetic material has a thickness of 5 to 50 μm.
Claim 10
Dependent Claim
19 words
The process of claim 1 wherein the layer of magnetic material has a thickness of 10 to 30 μm.
Claim 11
Dependent Claim
19 words
The process of claim 1 wherein the plasma etching is effected under a pressure of 0.1 to several torr.
Claim 12
Dependent Claim
41 words
The process of claim 1 wherein the oxygen-containing gas is composed of pure O 2 gas or N 2 --O 2 gas, optionally containing H 2 O, H 2 , CH 4 , CF 4 or C 2 F 6 .
Claim 13
Dependent Claim
24 words
The process of claim 1 wherein the lower magnetic core layer is one formed over a substrate of a material having high wear resistance.
Claim 14
Dependent Claim
31 words
The process of claim 1 wherein the nonmagnetic material layer is made of an insulating material such as Si0 2 , Al 2 O 3 or Si 3 N 4 .
Claim 15
Dependent Claim
23 words
The process of claim 1 wherein the nonmagnetic material layer provides a magnetic gap for the head and a magnetic head connecting opening.
Claim 16
Dependent Claim
22 words
The process of claim 1 wherein the coil layer is made of a conductive material such as Cu, Al, Au or Ag.
Claim 17
Dependent Claim
29 words
The process of claim 1 wherein the layer of magnetic material is partially formed over the resin film pattern formed area covering an opening of the resin film pattern.
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) | 1993-10-29 | 1994-04-30 | 1994-10-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-10-29 | 1998-04-30 | 1998-10-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-10-29 | 2002-04-30 | 2002-10-30 | $7700.00 | Window Closed / Lapsed |