Substrate for magnetic disk and magnetic disk
US12020735B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Apr 1, 2023 |
| Grant date | Jun 25, 2024 |
| Priority date | — |
| Expiry date | Apr 1, 2043 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/73919
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A substrate for a magnetic disk has a disk shape. The substrate has a diameter D of 85 mm or more and a thickness T of 0.6 mm or less. When an impact is applied to the substrate under conditions of 70 (G) and 2 (msec) in a normal direction of main surfaces of the substrate in a state in which an inner circumferential end portion of the substrate is fixed, the maximum amplitude of vibration in a thickness direction of an outer circumferential end portion of the substrate is 0.25 mm or less, the substrate is a non-magnetic metal substrate, and regarding the Young's modulus E and the thickness T of the substrate, a value of E·T3 is 3 to 18 (GPa·mm3).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.