Crystal zone texture of glass-ceramic substrates for magnetic recording disks
US6589609B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | May 25, 2000 |
| Grant date | Jul 8, 2003 |
| Priority date | — |
| Expiry date | May 25, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/82
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A glass-ceramic substrate for magnetic recording media is textured employing a continuous wave laser light beam to uniformly heat a surface zone, thereby forming a continuously roughened zone defined by recrystallized microcrystals. Embodiments include impinging a continuous wave CO2 laser light beam on a rotating glass-ceramic substrate to uniformly heat an annular zone at a temperature between the crystallization temperature and melting point of the glass-ceramic substrate followed by air cooling to induce a continuous surface roughness having an Ra of about 5 å to about 20 å, thereby enabling a glide height of about 0.2 to 0.5 &mgr; in.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.