Electrodeposited magnetic thin film heads: A quantum jump for magnetic recording; Immense impact on development of electrochemical technology

Abstract

In 1957 the read-write heads in IBM's first disk drive system used ferrite yokes individually wound with thin copper wire. The introduction of electroplated thin film batch fabricated heads in 1979 was the first major paradigm shift in the commercial fabrication of inductive heads and resulted in an order of magnitude increase of bit density, faster data access, and smaller, less expensive systems. A second paradigm shift in 1989 introduced integrated MR read, inductive-write heads and enabled even more rapid improvements in performance along with continued decreases in size and cost. The fabrication process for the electroplated heads, which is based on a combination of thin sputtered seed layers, high aspect ratio lithography and novel concepts in electrochemical technology, proved so extendable that it was carried over in the second paradigm shift. It remains the basis of magnetic head fabrication today and will also be the underlying technology for perpendicular recording heads. The success of electroplated thin film heads led to new recognition for the capabilities of electrodeposition and for the interdisciplinary approach used in developing the manufacturing process. Electrodeposition has become a technology based on predictable science and engineering capable of tailoring material properties to specific requirements and is the process of choice for a broad range of applications both within and beyond electronics. As we approach the limits of longitudinal recording, we are on the verge of a third paradigm shift to perpendicular recording. We expect the manufacture of perpendicular recording heads will continue to be based on the highly extendable technology introduced for the original thin film head.