Near field magneto-optical head made using wafer processing techniques

Abstract

The method of making and self-aligning a magneto-optical head at a wafer level is as follows: A flat optical substrate is molded or heat pressed in batches as a wafer level to form the desired lens shapes. Coil cavities or depressions are simultaneously formed with the lens to accommodate the coil assembly. Conductive plugs are formed in proximity to the cutting lines, for wire bonding attachment to the coil. The plugs are filled with a conductive material such as copper. The plugs do not extend through the entire depth of the optical wafer, thus further facilitating the mass production of the integrated heads. The slider body wafer is formed from silicon or other appropriate material. The slider body wafer and the lens/coil wafer are bonded. Coils and pedestals are formed on the lens / coil plate using thin-film processing techniques. Reflective surfaces are deposited on the bottom surface of the substrate, opposite the lens. The mirror material around the pedestal areas and plugs is masked and removed. An alumina layer is then deposited to define the air bearing surface and the pedestal. Yokes are then formed by means of lithography and plating in the base and sides of the depressions to assume a desired shape. A series of alternating insulating layers and conductive coil layers is formed. A protective layer seals the coil assembly, and is lapped to correct the lens thickness and to provide proper focal plane.