Abstract
The positioning accuracy of head-positioning system of hard disk drives (HDD) has been improved to meet the demand for larger data capacity. The recent positioning accuracy is less than 100 nm (±3σ) and non-repeatable runout is less than 50 nm. The accuracy of HDD is close to that of XY-stage in semi-conductor equipment devices. The author shows that some of the error sources in HDD and XY-stage are the same, but the difference is in the dynamical error sources such as the vibrations. According to this comparison, the author then shows the several unified mechanics and control technologies ("nano-mechatronics") to achieve nanometer order precise positioning.
