Monitoring and controlling the electrochemical wear at the head-disk interface
US9460739B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 30, 2015 |
| Grant date | Oct 4, 2016 |
| Priority date | — |
| Expiry date | Nov 30, 2035 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/40
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for determining the wear on a hard disk drive. Specifically, determining the overcoat wear of a head and/or disk during operation. In one embodiment, the magnetic head is disposed adjacent to the disk. A slider voltage is applied between a disk having a first overcoat and a head having a second overcoat as the disk is spinning By monitoring in real time a change in both touchdown power and a change in an interfacial current at a head disk interface, an electrochemical oxidation of the first overcoat can be determined. Additionally, by changing the polarity of the slider voltage, an electrochemical oxidation of the second overcoat can be determined. Finally, by measuring a passivation current produced between the head and the disk, the precise location of a touchdown event can be determined.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.