Thin-film electro-magnetic coil design for use in a flying magneto-optical head

摘要

A thin-film coil for use in a flying magneto-optical data storage system is formed on an undercoat layer, and includes an underside and a conductor deposited on the undercoat layer. The conductor is covered by an insulation layer on which a yoke is formed for providing a path to a magnetic field generated by the conductor. The yoke is formed of three sections: an upper section, an intermediate section, and the tip. The yoke tip defines an optical opening and has its underside substantially flush with the underside of the undercoat layer for increasing the density of the magnetic field at a target distance from the coil. The yoke tip underside is defined by an inner edge that delineates the optical opening, and that is formed of two semi-circular sections and two linear sections tangential to the semi-circular sections. The yoke can optionally include an outer section that extends over the peripheral side of the insulation layer and that further extends in an enlarged toe section.