US4652954A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for making a thin film magnetic head
Assignee: International Business Machines Corp
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Filing: 1985-10-24
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Granted: 1987-03-24
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Expires: 2005-10-24
Abstract
Abstract A method for making a thin film magnetic head assembly comprising the steps of depositing a first magnetic pole piece layer, depositing a nonmagnetic material gap forming layer, and depositing a protective layer of etch resistant material. A layer of insulation is deposited upon which is formed a conductive coil. A leveling pad of insulation is deposited over the conductive coil, and the part of the protective layer which is not covered by the insulation is removed. The gap forming layer is therefore protected during the processing steps so that a desired gap length is produced. The second magnetic pole piece layer is then deposited to complete the magnetic circuit.
Inventors
- 👤 Mark A. Church
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 18:09
CPC Classifications
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; Y10T29/49046; Y10T29/4906; Y10T29/49064
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
141 words
A method for making a thin film magnetic head comprising the steps of: depositing a first layer of magnetic material to form a first pole piece having a front gap portion and a back gap portion; depositing a gap forming layer of nonmagnetic material over said first layer of magnetic material; depositing a gap protective layer of an etch resistant material covering at least said front gap portion of said magnetic head; depositing a first layer of insulation material; forming a conductive coil on said first layer of insulating material; depositing a second layer of insulation material over said conductive coil to provide a leveling pad; removing said gap protection layer in at least the front gap portion of said magnetic head; and depositing a second layer of magnetic material to form a second pole piece to complete the magnetic head.
Claim 2
Independent Claim
141 words
A method for making a thin film magnetic head comprising the steps of: depositing a first layer of magnetic material to form a first pole piece having a front gap portion and a back gap portion; depositing a gap forming layer of nonmagnetic material over said first layer of magnetic material; depositing a gap protective layer of an etch resistant material covering at least said front gap portion of said magnetic head; depositing a first layer of insulation material; forming a conductive coil on said first layer of insulating material; depositing a second layer of insulation material over said conductive coil to provide a leveling pad; removing said gap protection layer in at least the front gap portion of said magnetic head; and depositing a second layer of magnetic material to form a second pole piece to complete the magnetic head.
Claim 3
Dependent Claim
14 words
The method of claim 1 wherein said gap protective layer is formed of chromium.
Claim 4
Dependent Claim
18 words
The method of claim 1 wherein said gap forming layer is formed of Al 2 O 3 .
Claim 5
Dependent Claim
39 words
The method of claim 1 comprising the additional step, performed after the step of depositing said gap protective layer, of patterning said gap protective layer to cover only said front gap portion of said first layer of magnetic material.
Claim 6
Dependent Claim
21 words
The method of claim 4 wherein said step of depositing said second layer of insulation is executed in two separate depositions.
Claim 7
Dependent Claim
26 words
The method of claim 5 wherein said gap protection layer is removed after the first of said two separate depositions of said second layer of insulation.
Claim 8
Dependent Claim
12 words
The thin film magnetic head made up the process of claim 1.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-03-23 | 1990-09-22 | 1991-03-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-03-23 | 1994-09-22 | 1995-03-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-03-23 | 1998-09-22 | 1999-03-24 | $7700.00 | Window Closed / Lapsed |