Magnetic heads with monolithic gaps

A new technology for making wear resistant magnetic heads is described. The procedure consists of depositing a thick-film of a non-magnetic zinc ferrite (10 to 100 μm thick) between two magnetic nickel-zinc ferrite plates previously prepared by hot-pressing. The assembly is then bound by hot-pressing. A machining process is described providing several advantages : - an exact alignment of the gaps on multiple track heads, - a perfect alignment of the plates on each side of the gap. The maximum misalignment is 2 μm for plates of 60 mm in diameter, - a good parallelism of several gaps (less than 0.2 μm). Beside the high structural homogeneity of such magnetic heads, this technology makes possible the manufacturing of multiple track heads with narrow inter-gap separations and small track width (100 μm).