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 Si₃N₄ (in the vertical direction). The total size of one magnetic VR microactuator is 460 mum times 300 mum times 61 mum. This paper discusses design considerations, presents the FEM simulation conducted, describes the fabrication technology, and provides experimental results.