International Business Machines Corporation

Sol Krongelb

Lubomyr Taras Romankiw

Daniel A Nepela

Dean A Herman, Jr

John Casimir Slonczewski

Bernell E Argyle

Hin P Lee

Bojan Petek

Thomas J Beaulieu

Thomas C Arnoldussen

David A Thompson

Robert D Hempstead

Timothy Joseph Chainer

Donald Francis Canaperi

David Lee Rath

Emanuel Israel Cooper

Edward John Yarmchuk

Carlos Juan Sambucetti

Mahadevaiyer Krishnan

Ravi F Saraf

Steven Paul Ostrander

Christopher H Bajorek

Judith Marie Roldan

Richard B Booth

Robert A Scranton

Erich P Valstyn

Mark R Kordus

Edward A Giess

Ashok Frank Mayadas

Lubomyr T Romakiw

An integrated data storage disk and disk drive assembly includes a rotatably supported magnetic disk for storing data. A rotor is fixedly joined to the disk for rotating the disk, and includes a plurality of rotor poles. A stator includes a plurality of stator poles positioned around the rotor for sequentially cooperating with respective ones of the rotor poles for rotating the rotor to rotate the disk. The disk and drive may be fabricated using lithographic and electroplating techniques, and a plurality of coaxial disks may be driven by a single disk drive in exemplary embodiments.

Integrated data storage disk and disk drive

Laminates of magnetic and magnetic quenching laminae are provided for use as magnetic thin film laminates for use in magnetic recording heads. The use of these films significantly reduces the number of domains and Barkhausen noise levels in such recording heads.

Inductive head lamination with layer of magnetic quenching material

The present invention is directed to a process of a method for the full metallization of thru-holes in a polymer structure comprising the steps of applying a film-forming amount of a conductive polymer-metal composite paste to a metal cathode; bonding a patterned polymer structure to said paste; subjecting said polymer structure to an electrolytic plating bath for a time sufficient to fully metallize thru-hole surfaces in said patterned polymer structure and removing the structure from the cathode assembly. The fully metallized thru-hole polymer structure can then be cleaned and polished to produce a finished product.

Fabrication of double side fully metallized plated thru-holes, in

Magnetic thin film structures are disclosed including a laminate of a layer of nonmagnetic material sandwiched between first and second layers of magnetic material and at least one edge closure layer of magnetic material disposed on a side edge of the laminate with the edge closure layer being in magnetic contact with the first and second layers of magnetic material. The edge closure layer eliminates magnetic edge closure domains and magnetic edge-curling walls in the yoke and poletip regions, or in a fluxguide of a magnetic recording head to substantially eliminate Barkhausen noise and wall network instabilities. Multiple layer laminates are also disclosed having a plurality of nonmagnetic layers each of which are sandwiched between layers of magnetic material and wherein the laminate includes edge closure layers that contact all the magnetic layers. Several methods are disclosed for fabricating the laminate. In one class of technique, the side edges are deposited together with a top layer in a single plating operation. In an another embodiment, the side edge closure layers are separately plated. Another embodiment provides for a layer of antiferromagnetic material deposited between the nonmagnetic layer and one of the magnetic layers to provide additional anisotropy.

Magnetic thin film structures fabricated with edge closure layers

Magnetic thin film structures including a laminate of a layer of nonmagnetic material sandwiched between first and second layers of magnetic material and at least one edge closure layer of magnetic material disposed on a side edge of the laminate with the edge closure layer being in magnetic contact with the first and second layers of magnetic material. The edge closure layer eliminates magnetic edge closure domains and magnetic edge-curling walls in the yoke and poletip regions, or in a fluxguide of a magnetic recording head to substantially eliminate Barkhausen noise and wall network instabilities. Multiple layer laminates are also disclosed having a plurality of nonmagnetic layers each of which are sandwiched between layers of magnetic material and wherein the laminate includes edge closure layers that contact all the magnetic layers. Several methods are disclosed for fabricating the laminate. In one class of technique, the side edges are deposited together with a top layer in a single plating operation. In an another embodiment, the side edge closure layers are separately plated. Another embodiment provides for a layer of antiferromagnetic material deposited between the nonmagnetic layer and one of the magnetic layers to provide additional anisotropy.

Method of fabricating magnetic thin film structures with edge closure

A magnetic recording disk is formed on a rigid aluminum substrate coated with a polymeric dielectric layer. A thin film metallic position-indicating track is applied to the upper surface of the dielectric layer. The dielectric material is coated with a magnetic recording medium. A thin film of aluminum forms the patterned capacitive and optically reflective track. The dielectric layer is composed of a very similar material to the matrix material in the magnetic recording medium. The disk can be flexible or floppy and it is not necessary to have the extra dielectric layer in such a case, where the substrate is a dielectric.

Structure to provide optical and capacitive contrast on magnetic

In thin film magnetic transducers, e.g., inductive or magnetoresistive recording heads, at least a pair of layers of a ferromagnetic material and an antiferromagnetic material are deposited upon one another and exchange coupled to retain a unidirectional bias in the plane of the ferromagnetic material. When multiple pairs of layers are used, they are separated by layers of nonmagnetic material. In some cases, successive pairs of layers of material with unidirectional bias have their directions of bias pointing in opposite directions. The domain walls in the layers of material are minimized by this technique.

Antiferromagnetic-ferromagnetic exchange bias films

A magnetoresistive permalloy film is deposited upon a substrate and coated with a separating layer composed of titanium or a similar high resistivity, conductive material. A soft biasing layer of a material such as permalloy or a hard biasing material such as cobalt chromium is deposited upon the separating layer to complete a sandwich. All layers are coextensive in outline because their outlines are formed by a single etching step.

Magnetoresistive sandwich including sensor electrically parallel with

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Katonah, NY, United States of America

Sol Krongelb