Soft underlayer structure for magnetic recording
US6890667B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 28, 2002 |
| Grant date | May 10, 2005 |
| Priority date | — |
| Expiry date | Oct 28, 2022 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/26
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A magnetic recording medium having a soft magnetic underlayer structure that includes two soft underlayers is presented. A thick first soft underlayer, disposed on the medium substrate, is made of material which provides a low magnitude of magnetization saturation (Bsat) and high permeability. The first soft underlayer can be formed by plating or high-rate sputtering. The second soft underlayer, which has a lesser thickness than the first soft underlayer, is made of a material which provides a relatively high magnitude of Bsat and low permeability. The second soft underlayer can be formed by low-rate sputtering. The first soft under layer can be isolated from other layers in the medium by an exchange isolation layer. The second soft underlayer can be exchange coupled to a radial exchange pin layer disposed on the exchange isolation layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.