Magnetic core comprising a bond magnet including magnetic powder whose particle's surface is coated with oxidation-resistant metal
US6621398B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 28, 2001 |
| Grant date | Sep 16, 2003 |
| Priority date | — |
| Expiry date | Dec 26, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01F2003/103
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Disposed in a magnetic gap of a magnetic core, a magnetically biasing permanent magnet is a bond magnet comprising rare-earth magnetic powder and a binder resin. The rare-earth magnetic powder has an intrinsic coercive force of 5 kOe or more, a Curie temperature of 300° C. or more, and an average particle size of 2.0-50 &mgr;m. The rare-earth magnetic power has a surface coated with a metallic layer containing an oxidation-resistant metal. In order to enable a surface-mount to reflow, the rare-earth magnetic powder may have the intrinsic coercive force of 10 kOe or more, the Curie temperature of 500° C. and the average particle size of 2.5-50 &mgr;m. In addition, to prevent specific resistance from degrading, the metallic layer desirably may be coated with a glass layer consisting of low-melting glass having a softening point less than a melting point of the oxidation-resistant metal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.