Defect inspection method of magnetic disk, device therefor, and magnetic disk drive device
US7636217B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 12, 2007 |
| Grant date | Dec 22, 2009 |
| Priority date | — |
| Expiry date | Jul 15, 2028 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R33/1207
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Embodiments of the present invention efficiently conduct a test for detecting defects on a magnetic disk more accurately. According to one embodiment, a HDD carries out defect inspection of a magnetic disk using thermal fly height control (TFC). Changing a clearance by the TFC achieves defect inspection tests under varied test conditions without much decrease of throughput in manufacturing HDDs. First, a self analysis test (SAT) is carried out in a state that a heater power of P2 is supplied to a heater. Then, another SAT is carried out in a state that a heater power of P1 is supplied to the heater. The heater power P2 is larger than the heater power P1.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.