Integrated multi-turn thin film recording head

Abstract

This paper will discuss the design and fabrication of multi-turn heads for digital data recording. Separate read and write elements are fabricated side-by-side, with separately optimized track width (50 and 100 microns), pole thickness (1 and 4 microns), and gap thickness (1 and 2 microns). The windings consist of an 8 turn bifilar, planar spiral of copper which has been electroplated through a photoresist mask. The permalloy layers are composed of 81:19 NiFe, electroplated through a photoresist window-frame pattern designed to insure uniform NiFe composition across the pattern. Insulation was fabricated from baked photoresist, which provides leveling over the high aspect ratio winding conductors. An oxidized silicon substrate and cover piece formed the air-bearing slider. Heads have been fabricated with a glass layer laminated within each permalloy leg to control closure domains. Bitter patterns demonstrating the effect of these laminations have been obtained. The heads have been flown and tested on a particulate disk. © 1979 IEEE