Laminated hard magnet in MR sensor
US6144534A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 30, 1997 |
| Grant date | Nov 7, 2000 |
| Priority date | — |
| Expiry date | Dec 30, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/3932
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A magneto-resistive sensor has a magneto-resistive element with an active area with an electrical resistance sensitive to changes in magnetic flux. Two hard magnets on opposing sides of the magneto-resistive element magnetically bias the magneto-resistive element. Each hard magnet includes a seed layer of a soft magnetic, electrically conductive material between two magnet layers of a hard magnetic, electrically conductive material laminated longitudinally together such that the seed layer and the magnet layers exhibit unified magnetic properties. The seed layer is preferably an amorphous material such as nitrided sendust. The laminated structure allows for a thicker magnet structure with low electrical resistance but without degradation of magnetic properties due to the increased thickness.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.