International Business Machines Corporation

Other

Larry E Daby

Nathaniel C Anderson

Patrick M McCaffrey

Bruce A Murray

Bruce W Wright

Robert B Chesnut

Vincent D Gravdahl

Gene A Johnson

A film transducer head design is formed on a substrate where the first yoke layer and electric terminal strip that connects the coil center pad to the head exterior are formed at the same time followed by successive layers that form the transducer gap, coil insulation, coil, coil insulation and the second yoke layer. This sequence allows the coil to be tested immediately after deposition of the coil material and at a time in the fabrication sequence when it can be reworked or replaced if a discontinuity (open) or shorted turn(s) is (are) identified.

Thin film transducer

Process for lift-off fabrication of sputtered dielectric or nonmagnetic gap materials and thin-film heads for either a single-element thin-film head or side-by-side elements on a thin-film head. The lift-off process utilizes a copper coating that is removed by a twenty percent solution of ammonium persulfate with a pH in the range of seven to nine to assure complete removal of gap material from the back closure of the thin-film head without damage to the underlying permalloy. The process can also be utilized to obtain a multiple layer deposits on a single thin-film had by repeating the steps of the process. The process provides for a clean hole, no dielectric on the surface nor any attacking on the magnetic material.

Process of lift off of material

A process for producing a reactive ion-etched structure with height and width dimensions of the order of 25 microns or less on a ferrite substrate surface is disclosed. A mask of positive water saturated photoresist is formed on the substrate. A metal taken from the group consisting of nickel and a nickel-iron alloy is plated through the mask. The photoresist mask is removed to leave a pattern in the plated metal. The ferrite substrate surface that is exposed by the pattern is reactive ion etched with a power density of &gt;1w/cm.sup.2 and a bias voltage &lt;-100 volts.

Thin film techniques for fabricating narrow track ferrite heads

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Rochester, MN, United States of America

Larry E Daby