Domain wall free shields of MR sensors
US7236333B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 11, 2003 |
| Grant date | Jun 26, 2007 |
| Priority date | — |
| Expiry date | Jun 14, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/59627
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A magnetic reader of the present invention comprises an MR sensor shielded by a magnetic shield including single domain soft magnetic materials. The domain wall free magnetic shield includes an unbiased soft magnetic layer and a biased soft magnetic layer separated by a non-magnetic layer. The easy axis of the biased layer is oriented to create a path for magnetic flux through the biased and unbiased layers thereby reducing the demagnetization field of the shield. A biasing layer maintains the first and second magnetic layers as single domain magnets. The biasing layer is further shaped to define a quiet zone where the biasing layer does not overlay the MR sensor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.