Integrated MEMS optical flying head with lens positioning actuator for small form factor optical data storage

Abstract

An integrated and miniaturized optical flying head (OFH) is presented for a small form factor with high-density portable optical data storage. It is composed of a high numerical aperture (NA) objective lens, a microlens actuator for adjusting the position of the objective lens, an integrated air-bearing-slider (ABS), and an embedded magnetic-field-modulation (MFM) coil for magneto-optical recording. To adjust the optimal focal length of the lens, a parallel-plate vertical actuator is adopted. In addition, the area-optimized torsion type H-shape spring is used for vertical actuation. The glass ABS structure and the double metal layer MFM coil are fabricated on a transparent substrate, bonded to the silicon actuator. The overall size of the integrated OFH, assembled with the high numerical aperture (NA=0.85) objective lens, is 3 mm×1.6 mm×0.5 mm (length×width×thickness), which makes it small enough to be furnished in a portable optical data storage device. A prototype of small optical drive is also developed to satisfy the form factor of PCMCIA type II. The prototype includes the integrated and miniaturized OFH and the basic operation of the drive is tested.