Patent US6170149B1 successfully refreshed from Google Patents.
US6170149B1
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Magnetoresistive type magnetic head and method of manufacturing the same and apparatus for polishing the same
Assignee: Fujitsu Ltd
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Filing: 1997-01-30
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Granted: 2001-01-09
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Expires: 2017-01-30
Abstract
Abstract According to a method of manufacturing a magnetic head, a magnetoresistive device is formed on a substrate, a top end portion of the magnetoresistive device is placed in an external magnetic field, and a height of the magnetic head is adjusted by ceasing a polishing operation at an instant when change in resistance of the magnetoresistive device relative to change in the external magnetic field comes up to a predetermined value.
Inventors
- 👤 Mitsumasa Oshiki
- 👤 Nobuo Iijima
- 👤 Motoichi Watanuki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 14:25
CPC Classifications
B; B24; B24B; B24B37/00; B24B37/005; B24B37/013; B24B37/04; B24B37/048; B24B49/00; B24B49/02; B24B49/04; B24B49/10; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/4902; Y10T29/49021; Y10T29/49032; Y10T29/49036; Y10T29/49043; Y10T29/49046; Y10T29/49048; Y10T29/53; Y10T29/5313; Y10T29/53165
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
86 words
A method of manufacturing a magnetic head containing a magnetoresistive head, the method comprising the steps of: forming on a substrate a magnetoresistive device which constitutes a major part of said magnetoresistive head; polishing a top end portion of said magnetoresistive device while applying an external magnetic field whose intensity is changing and monitoring a change in resistance of said magnetoresistive device relative to a change in said external magnetic field; and ceasing said polishing step when a monitored change in resistance reaches a predetermined value.
Claim 2
Independent Claim
86 words
A method of manufacturing a magnetic head containing a magnetoresistive head, the method comprising the steps of: forming on a substrate a magnetoresistive device which constitutes a major part of said magnetoresistive head; polishing a top end portion of said magnetoresistive device while applying an external magnetic field whose intensity is changing and monitoring a change in resistance of said magnetoresistive device relative to a change in said external magnetic field; and ceasing said polishing step when a monitored change in resistance reaches a predetermined value.
Claim 3
Dependent Claim
18 words
The method according to claim 1 , wherein said reproducing head uses said magnetoresistive device for reproduction only.
Claim 4
Dependent Claim
36 words
The method according to claim 1 , further comprising a step of forming a monitoring pattern having the same structure as said magnetoresistive device on at least one side of said magnetoresistive device on said substrate.
Claim 5
Dependent Claim
36 words
The method according to claim 1 , wherein the change in said external magnetic field is caused by flowing an electric current through an electromagnetic coil and changing a magnitude or direction of said electric current.
Claim 6
Dependent Claim
25 words
The method according to claim 1 , wherein the change in said external magnetic field is caused by changing a position of a permanent magnet.
Claim 7
Dependent Claim
41 words
The method according to claim 1 , further comprising a step of forming an inductive type magnetic head on said substrate, wherein said external magnetic field is generated by causing an electric current to flow through said inductive type magnetic head.
Claim 8
Independent Claim
74 words
An apparatus for polishing a magnetoresistive head, comprising: polishing means for polishing a top end portion of a magnetoresistive device which is formed on a substrate and which constitutes a major part of said magnetoresistive head; applying means for applying an external magnetic field to said magnetoresistive device while changing its intensity; and detecting means for detecting a change in resistance of said magnetoresistive device relative to a change in said external magnetic field.
Claim 9
Independent Claim
74 words
An apparatus for polishing a magnetoresistive head, comprising: polishing means for polishing a top end portion of a magnetoresistive device which is formed on a substrate and which constitutes a major part of said magnetoresistive head; applying means for applying an external magnetic field to said magnetoresistive device while changing its intensity; and detecting means for detecting a change in resistance of said magnetoresistive device relative to a change in said external magnetic field.
Claim 10
Dependent Claim
28 words
The apparatus according to claim 7 , wherein said applying means is a permanent magnet arranged so as to periodically change its position relative to said magnetoresistive device.
Claim 11
Dependent Claim
24 words
The apparatus according to claim 7 , wherein said applying means is an electromagnetic coil arranged so as to generate a variable magnetic field.
Claim 12
Dependent Claim
22 words
The apparatus according to claim 7 , wherein said applying means is an inductive type magnetic head formed near said magnetoresistive head.
Claim 13
Dependent Claim
48 words
The apparatus according to claim 7 , wherein a plurality of said magnetoresistive devices are formed on said substrate, and further comprising a mechanism for detecting a difference in said change in resistance between at least two magnetoresistive devices and adjusting a weighted distribution to reduce the difference.
Claim 14
Independent Claim
98 words
An apparatus for polishing a plurality of magnetoresistive heads, comprising: polishing means for polishing a top end portion of a plurality of magnetoresistive devices formed on a substrate; applying means for applying an external magnetic field to each said magnetoresistive device while changing an intensity of the magnetic field; detecting means for detecting a change in resistance of each said magnetoresistive device relative to a change in said external magnetic field; and a mechanism for detecting a difference in said change in resistance between at least two magnetoresistive devices and adjusting a weighted distribution to reduce the difference.
Claim 15
Independent Claim
98 words
An apparatus for polishing a plurality of magnetoresistive heads, comprising: polishing means for polishing a top end portion of a plurality of magnetoresistive devices formed on a substrate; applying means for applying an external magnetic field to each said magnetoresistive device while changing an intensity of the magnetic field; detecting means for detecting a change in resistance of each said magnetoresistive device relative to a change in said external magnetic field; and a mechanism for detecting a difference in said change in resistance between at least two magnetoresistive devices and adjusting a weighted distribution to reduce the difference.
Claim 16
Independent Claim
105 words
An apparatus for polishing a magnetoresistive head, comprising: a polishing member for polishing a top end portion of a magnetoresistive device formed on a substrate; a variable strength magnetic member for applying a variable intensity magnetic field to the magnetoresistive device; an electric resistance detector for detecting a change in resistance of the magnetoresistive device relative to a change in the external magnetic field; a controller operably connected to said electric resistance detector and said polishing member, wherein said controller terminates a polishing operation of said polishing member when a change in resistance detected by said electric resistance detector reaches up to a predetermined value.
Claim 17
Independent Claim
105 words
An apparatus for polishing a magnetoresistive head, comprising: a polishing member for polishing a top end portion of a magnetoresistive device formed on a substrate; a variable strength magnetic member for applying a variable intensity magnetic field to the magnetoresistive device; an electric resistance detector for detecting a change in resistance of the magnetoresistive device relative to a change in the external magnetic field; a controller operably connected to said electric resistance detector and said polishing member, wherein said controller terminates a polishing operation of said polishing member when a change in resistance detected by said electric resistance detector reaches up to a predetermined value.
References Cited (Backward Citations)
US3706926A
Cited
US4122505A
Cited
US4489484A
Cited
JPS60191418A
Cited
JPS60202513A
Cited
US4829658A
Cited
US4914868A
Cited
US4978938A
Cited
US4972284A
Cited
US5264980A
Cited
US5306573A
Cited
US5243316A
Cited
US5737155A
Cited
JPH06274837A
Cited
US5808273A
Cited
JPH07240010A
Cited
JPH07249210A
Cited
US5609511A
Cited
US5500590A
Cited
US5621320A
Cited
US5772493A
Cited
US5722155A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2004-01-09 | 2004-07-10 | 2005-01-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-01-09 | 2008-07-10 | 2009-01-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-01-09 | 2012-07-10 | 2013-01-09 | $7700.00 | Window Closed / Lapsed |