Integrated Electromagnetic Second Stage Microactuator for a Hard Disk Recording Head

A slider with an integrated microactuator (SLIM) allows actuating a read-write element of a hard disk drive (HDD) in both the vertical direction allowing a flying height adjustment as well as in the lateral direction allowing a second stage actuation. The microactuator system consists of a pair of electromagnetic variable reluctance (VR) micro actuators. The microactuator system is fabricated using thin-film technology. Each actuator has a permalloy C-core carrying a two-layer spiral Cu coil with a total of 16 turns. The insulation materials are SU-8 (in the lateral direction) and Si $_{3}$N $_{4}$ (in the vertical direction). The total size of one magnetic VR microactuator is 460 $\, \mu$m$\, \times \,$300 $\, \mu$m$\, \times \,$61 $\mu$m. This paper discusses design considerations, presents the FEM simulation conducted, describes the fabrication technology, and provides experimental results.