Grooved magnetic substrates and method for producing the same
US4875987A · kind A · utility
24Cited by
7References
12Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jun 29, 1988 |
| Grant date | Oct 24, 1989 |
| Priority date | — |
| Expiry date | Jun 29, 2008 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/24537
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A grooved magnetic substrate including an alumina film layer having a Knopp hardness of 600 kg/mm.sup.2 to 1200 kg/mm.sup.2 charged in at least one groove formed in a surface of a magnetic substrate. The magnetic substrate may be Mn-Zn or Ni--Zn base ferrite. The alumina film layer is formed by sputtering.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.