US5103553A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making a magnetic recording head
Assignee: PHC Corp
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Filing: 1991-02-20
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Granted: 1992-04-14
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Expires: 2011-02-20
Abstract
Abstract The head includes a read pole disposed between a pair of write poles spaced apart to form a gap therebetween. The read pole conducts flux to a flux sensor that is located away from the gap. The head can be utilized for both longitudinal and perpendicular recording and the readback function can be carried out by an inductive coil or flux sensing devices such as a Hall sensor or an MR sensor. The recording head achieves high readback resolution, high write field gradients, and the capability for write wide-read narrow. The read pole and write poles are laminated structures.
Inventors
- 👤 Michael Mallary
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 14:25
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/33; G11B5/332; G11B5/1278; G11B5/187; G11B5/245; G11B5/31; G11B5/3109; G11B5/312; G11B5/313; G11B5/3143; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/4902; Y10T29/49021; Y10T29/49032; Y10T29/49036; Y10T29/49043; Y10T29/49055
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
78 words
A method for making a multi-pole magnetic recording head comprising: preparing a thin laminated seed layer structure comprising at least two magnetic layers separated by a non-magnetic layer, depositing another magnetic layer on the prepared seed layer structure by electroplating through a mask defining a pole shape, and removing by ion milling the laminated seed layer structure not covered by said depositing step to leave a first pole comprising coextensive laminated seed layers and said another magnetic layer.
Claim 2
Independent Claim
78 words
A method for making a multi-pole magnetic recording head comprising: preparing a thin laminated seed layer structure comprising at least two magnetic layers separated by a non-magnetic layer, depositing another magnetic layer on the prepared seed layer structure by electroplating through a mask defining a pole shape, and removing by ion milling the laminated seed layer structure not covered by said depositing step to leave a first pole comprising coextensive laminated seed layers and said another magnetic layer.
Claim 3
Dependent Claim
36 words
The method of claim 1 wherein said step of preparing said seed layer structure comprises preparing said layer to comprise two magnetic layers separated by a non-magnetic layer that is substantially thinner than said magnetic layers.
Claim 4
Dependent Claim
28 words
The method of claim 1 wherein said step of preparing said seed layer structure comprises preparing said non-magnetic layer to be on the order of 50 Angstroms thick.
Claim 5
Dependent Claim
34 words
The method of claim 1 wherein said step of preparing said seed layer structure comprises preparing said layer to comprise two layers of NiFeCo separated by a layer of Al 2 O 3 .
Claim 6
Dependent Claim
24 words
The method of claim 4 wherein said layer of Al 2 O 3 is prepared to be on the order of 50 Angstroms thick.
Claim 7
Dependent Claim
33 words
The method of claim 4 wherein said seed layer structure is further prepared to comprise a second layer of Al 2 O 3 and a further layer comprising one of NiFe and NiFeCo.
Claim 8
Dependent Claim
27 words
The method of claim 6 wherein said step of depositing a pole includes depositing said further layer until it is on the order of 20,000 Angstroms thick.
Claim 9
Dependent Claim
21 words
The method of claim 1 wherein said step depositing another magnetic layer includes depositing layer comprising one of NiFe and NiFeCo.
Claim 10
Dependent Claim
26 words
The method of claim 1 wherein said step of depositing another magnetic layer includes depositing a layer until it is the order of 20,000 Angstroms thick.
Claim 11
Dependent Claim
33 words
The method of claim 1 wherein said step of depositing another magnetic layer includes depositing a layer comprising one of NiFe and NiFeCo until it is on the order of 20,000 Angstroms thick.
Claim 12
Dependent Claim
24 words
The method of claim 1 further including the steps of repeating the previous steps of preparing, depositing and ion milling, to yield further poles.
Claim 13
Dependent Claim
22 words
The method of claim 11 wherein said step of repeating the previous steps is performed twice to yield a three pole head.
Claim 14
Dependent Claim
32 words
The method of claim 1 further including depositing a thin ceramic layer over the pole followed by depositing a thin ferromagnetic layer over the ceramic layer to form a saturable side shield.
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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) | 1995-04-14 | 1995-10-14 | 1996-04-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-04-14 | 1999-10-14 | 2000-04-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-04-14 | 2003-10-14 | 2004-04-14 | $7700.00 | Window Closed / Lapsed |