Thin film magnetic head with crystallized glass substrate
US5136447A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 20, 1990 |
| Grant date | Aug 4, 1992 |
| Priority date | — |
| Expiry date | Nov 20, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/3103
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A magnetic head having a substrate, a magnetic core means including a magnetic thin film deposited on one surface of the substrate, and a protective plate formed on the magnetic thin layer in a way that the magnetic thin film is interposed between the protective plate and the substrate. At least a portion of the substrate, or of the protective plate or of the both substrate and protective plate is made by crystallized glass. The crystallized glass is obtained by thermally treating glass containing the following oxides on % by weight basis: PA1 SiO.sub.2 : 42.about.52%, PA1 ZnO: 5.about.15%, PA1 Al.sub.2 O.sub.3 : 28.about.38%, PA1 TiO.sub.2 : 5.about.15%, PA1 MgO: no more than 10%, PA1 PbO: no more than 10% and has a Vickers hardness of from 800 to 1,100 kg/mm.sup.2.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.