US3787964A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for manufacturing a magnetic head
Assignee: International Business Machines Corp
•
Filing: 1971-12-23
•
Granted: 1974-01-29
•
Expires: 1991-12-23
Abstract
Abstract This disclosure relates to a method for manufacturing a magnetic head. The steps of the method comprise forming a transformer having a first magnetic layer, a primary winding, a secondary winding separated from the primary winding, the primary and secondary windings being disposed on the first magnetic layer, and a second magnetic layer disposed over the primary and secondary windings. The first and second magnetic layers encircle portions of the primary and secondary windings thus forming a continuous magnetic path. Tests determinative of its magnetic properties are made on the transformer. Thereafter, the transformer is severed between the primary and the secondary windings and the secondary is discarded. The primary is then lapped to form a thin-film magnetic head.
Inventors
- 👤 P Simon
- 👤 R Jones
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 20:30
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/31; G11B5/3109; G11B5/313; G11B5/3133; G11B5/17; G11B5/3163; G11B5/3166; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49004; Y10T29/4902; Y10T29/49021; Y10T29/49032; Y10T29/49036; Y10T29/49043; Y10T29/49044; Y10T29/49046; Y10T29/4906; Y10T29/49064
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
120 words
A method of fabricating a magnetic recording head comprising the steps of: depositing a first magnetic layer; depositing a primary conductive winding over a portion of said first magnetic layer; depositing a secondary conductive winding spaced from said primary winding over a portion of said first magnetic layer; depositing a second magnetic layer over adjacent portions of said primary and said secondary windings and against selected portions of said first magnetic layer, said first and second magnetic layers forming a continuous magnetic body, thus creating a transformer; energizing one of said conductive windings with an electrical current; measuring the electromagnetically-induced voltage across the other of said windings; and then severing said transformer between said first winding and said second winding.
Claim 2
Independent Claim
120 words
A method of fabricating a magnetic recording head comprising the steps of: depositing a first magnetic layer; depositing a primary conductive winding over a portion of said first magnetic layer; depositing a secondary conductive winding spaced from said primary winding over a portion of said first magnetic layer; depositing a second magnetic layer over adjacent portions of said primary and said secondary windings and against selected portions of said first magnetic layer, said first and second magnetic layers forming a continuous magnetic body, thus creating a transformer; energizing one of said conductive windings with an electrical current; measuring the electromagnetically-induced voltage across the other of said windings; and then severing said transformer between said first winding and said second winding.
Claim 3
Dependent Claim
15 words
The method set forth in claim 1 wherein said transformer is formed by thin-film depositions.
Claim 4
Dependent Claim
32 words
The method set forth in claim 1 wherein said severing step cuts said transformer in a plane perpendicular to the direction of the layers through said first and said second magnetic layers.
Claim 5
Dependent Claim
24 words
The method set forth in claim 1 wherein said first and second magnetic layers and said primary winding are substantially parallel to one another.
Claim 6
Dependent Claim
28 words
The method set forth in claim 1 and including the step of comparing said voltage with a predetermined level to determine whether said transformer has acceptable magnetic properties.
Claim 7
Dependent Claim
39 words
The method set forth in claim 1, wherein said second magnetic layer is spaced closer to said first magnetic layer in a region between said primary and said secondary windings than it is in the region over the windings.
Claim 8
Dependent Claim
51 words
The method set forth in claim 1 and further comprising the steps of depositing a first insulating layer on said first magnetic layer, and depositing a second insulating layer over said primary and said secondary windings so as to electrically isolate said windings from said first and said second magnetic layers.
Claim 9
Dependent Claim
31 words
The method set forth in claim 1 and further comprising the step of lapping said severed assembly to accurately define a transducing gap between said first and said second magnetic layers.
Claim 10
Dependent Claim
21 words
The method set forth in claim 1 wherein said first magnetic layer is deposited on a surface of a nonmagnetic substrate.
Claim 11
Dependent Claim
20 words
The method set forth in claim 9 and further including the step of dicing said nonmagnetic substrate around said transformer.
References Cited (Backward Citations)
US3344237A
Cited
US3187411A
Cited
US3249987A
Cited
US3400386A
Cited
US3564522A
Cited
US3685144A
Cited
US3706926A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-01-28 | 1977-07-30 | 1978-01-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-28 | 1981-07-30 | 1982-01-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-28 | 1985-07-30 | 1986-01-29 | $7700.00 | Window Closed / Lapsed |