Thin film coil head assembly with protective planarizing cocoon structure

Abstract

A thin film head is disclosed which is miniaturized to fit within a reduced size window or circumferential slot in a rotary head assembly. The thin film head and window or slot can be made so small that undesired tape cupping into the window or slot is significantly reduced. The thin film head includes a substrate of electrically insulative material. In one embodiment, a substantially helical thin film coil structure is situated atop the substrate. A magnetic core extends through the coil structure so that the coil structure can magnetically excite the core. The core includes first and second side pole members. A protective cocoon of electrically insulative material covers the coil structure and the core except for ends of the first and second side pole members. The cocoon includes an upper planar surface which exposes the ends of the first and second side pole members to permit coupling thereto by a magnetic gap structure. An elevated thin film magnetic gap structure is positioned atop the coil structure and the upper planar surface of the protective cocoon. Protection from ambient conditions is thus provided to both the coil structure and the magnetic core while simultaneously enhancing the planarity of the layers above the planar upper surface of the protective cocoon.