International Business Machines Corporation

Other

Hitachi Global Storage Technologies Netherlands B.v.

Patrick M McCaffrey

Lubomyr Taras Romankiw

Nathaniel C Anderson

Eugene E Castellani

Larry E Daby

Douglas Howard Piltingsrud

Aloysius T Pfeiffer

Bruce A Murray

Vincent D Gravdahl

Bruce W Wright

Ronald L Anderson

Gene A Johnson

A plurality of disks include a first disk and a second disk stacked upon the first disk. The first disk and the second disk are each formed from glass or glass-ceramic. A powder is disposed between the first disk and the second disk. The powder is selected from the group including calcium carbonate, calcium magnesium carbonate, calcium phosphate, magnesium carbonate, magnesium borate, magnesium oxide, magnesium phosphate, and clay.

Powder for disks

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

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

A method of constructing a relatively thick, self-supporting mask suitable for electron beam projection processes. Thickness is achieved by multiple steps of coating with resist, exposure, development and plating. First an intermediate or lift off layer is deposited on a substrate. A plating or a cathode layer may then be deposited. Resist is then applied. A first mask layer comprises metal plated in accordance with the first pattern. For the second exposure a geometrically similar pattern is employed to generate larger apertures. Thus, if the first mask layer has 0.20 mil apertures, the second layer might have corresponding 0.21 mil to 0.22 mil apertures. For initial mask patterns of about 2 mil the second layer might be 2.02 mils. If desired, a third exposure can be employed with a third pattern, similar to the first two, but having larger apertures (by 0.02 to 0.03 mils) than the second pattern.

Method for forming thick self-supporting masks

A method for increasing the magnetic permeability of a magnetic alloy having an easy axis and a hard axis which comprises subjecting a body of the magnetic alloy to a magnetic field of at least about 40 Gauss oriented in the direction of the hard axis while the body is maintained at a temperature at or above that required to deposit the alloy on a substrate.

Method for treating magnetic alloy to increase the magnetic permeability

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Rochester, MN, United States of America

Patrick M McCaffrey