US5013394A
Expired / Lapsed
US
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Method for detection of end of grinding of a thin layer magnetic head
Assignee: Compagnie Europeenne de Composants Electroniques LCC CICE
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Filing: 1988-10-21
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Granted: 1991-05-07
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Expires: 2008-10-21
Abstract
Abstract The invention concerns a method for the detection of the end of grinding of at least one thin layer magnetic head, the head comprising, at the stage of implementation of said method, an active face, formed by two magnetic poles (1, 2) separated by a gap (4). The method comprises the following steps: deposition of a conductive layer (7) on the entire active face (3) etching of the active face coated with said conductive layer; deposition of a layer of dielectric material (8) on the etched active face; grinding of the active face starting from the face that is free of the layer of dielectric material (8) until total removal of that part of the conductive layer (7) located above the gap (4), this removal being detected by the sudden variation in resistivity between the two magnetic poles (1, 2).
Inventors
- 👤 Jean-Luc Rolland
- 👤 Jean-Yves Beguin
- 👤 Henriette Magna
- 👤 Alain Jacobelli
- 👤 Maurice Penot
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 09:11
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/187; G11B5/23; G11B5/31; G11B5/3109; G11B5/313; G11B5/3133; G11B5/3163; G11B5/3166; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/4902; Y10T29/49021; Y10T29/49032; Y10T29/49036; Y10T29/49048
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
143 words
Method for the detection of the end of grinding of at least one thin layer magnetic head, the head comprising, at the stage of implementation of said method, an active face, formed by two magnetic poles separated by a gap, the detection being obtained through the interruption of an electrical circuit, characterized in that it comprises the following steps: deposition of a conductive layer on the entire active face to form said electrical conduit; etching of the active face coated with said conductive layer; deposition of a layer of dielectric material on the etched active face; grinding of the active face starting from the face that is free of the layer of dielectric material until total removal of that part of the conductive layer located above said gap, said removal being detected by the sudden variation in resistivity between the two magnetic poles.
Claim 2
Dependent Claim
143 words
Method for the detection of the end of grinding of at least one thin layer magnetic head, the head comprising, at the stage of implementation of said method, an active face, formed by two magnetic poles separated by a gap, the detection being obtained through the interruption of an electrical circuit, characterized in that it comprises the following steps: deposition of a conductive layer on the entire active face to form said electrical conduit; etching of the active face coated with said conductive layer; deposition of a layer of dielectric material on the etched active face; grinding of the active face starting from the face that is free of the layer of dielectric material until total removal of that part of the conductive layer located above said gap, said removal being detected by the sudden variation in resistivity between the two magnetic poles.
Claim 3
Dependent Claim
15 words
Method according to claim 1, characterized in that the grinding is of the cylindrical type.
Claim 4
Dependent Claim
15 words
Method according to claim 1, characterized in that the grinding is of the plane type.
Claim 5
Dependent Claim
22 words
Method according to claim 2, characterized in that the grinding of the active face is achieved symmetrically with respect to said gap.
Claim 6
Dependent Claim
27 words
Method according to claim 1 characterized in that the thickness of the layer of dielectric material is at least equal to the thickness of the magnetic poles.
Claim 7
Dependent Claim
16 words
Method according to claim 1 wherein said conductive layer (7) is formed by aluminium or chromium.
Claim 8
Dependent Claim
24 words
Method according to any of the claims 1 to 6, characterized in that said layer of dielectric material is formed by alumina or silica.
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) | 1994-05-06 | 1994-11-05 | 1995-05-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-05-06 | 1998-11-05 | 1999-05-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-05-06 | 2002-11-05 | 2003-05-07 | $7700.00 | Window Closed / Lapsed |