Patterned-media perpendicular magnetic recording disk with servo regions having magnetized servo pillars and oppositely-magnetized servo trenches
US7960044B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 27, 2009 |
| Grant date | Jun 14, 2011 |
| Priority date | — |
| Expiry date | Jul 16, 2029 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/855
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A patterned perpendicular magnetic recording disk has a pre-patterned disk substrate with pillars and trenches arranged in data regions and servo regions. In the data regions, the height of the data pillars is equal to or greater than the spacing between the data pillars, while in the servo regions the height of the servo pillars is less than the spacing between the servo pillars. A magnetic recording material with perpendicular magnetic anisotropy is deposited over the entire disk substrate, which results in magnetic material on the tops of the data pillars and servo pillars and in the servo trenches. The material in the data trenches is either nonmagnetic or discontinuous. After the application of a high DC magnetic field in one perpendicular direction and a low DC magnetic field in the opposite direction, the resulting disk has patterned servo sectors with servo pillars all magnetized in the same perpendicular direction and servo trenches magnetized in the opposite perpendicular direction.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.