Seagate Technology Incorporated

Control Data Corporation

John Bortins

Nurul Amin

Beat G Keel

Ying D Yan

Gerald L Weispfenning

Lance Eugene Stover

Nathan Curland

Tim Madsen

Frank Edgar Stageberg

G Patrick Bonnie

Kenneth N Bergan

Dale O Larson

A thin film magnetic head is carried in a recessed region which is etched in a basecoat. The thin film magnetic head includes upper and lower pole pieces having an upper pole tip and a lower pole tip, respectively. The upper and lower pole tips form a magnetic flux gap. Electrical conductors are carried in an insulating layer between the upper and lower pole pieces. The magnetic flux gap defines a plane which is generally parallel with a plane defined by the conductors. The electrical conductors lie on either side of the plane.

Method for forming a magnetic thin film head with recessed basecoat

A servo head in a disk file data storage system includes two servo transducers which are connected so that noise induced by a nearby writing data head cancels. The first servo transducer, mounted on a slider, reads information stored on a servo disk. A second servo transducer, also located on the slider, is connected to the first servo transducer to produce an output signal so that noise signals induced in the first servo transducer by operation of the data transducer tend to be canceled by noise signals induced in the second servo transducer by operation of the data transducer. The two servo transducers are located such that they are closely spaced relative to the size of the servo transducers. The close proximity of the two servo transducers reduces the effect of unequal shielding from noise signals induced in the two servo transducers by the data head.

Servo head with close servo transducer placement for improved passive

A thin film magnetic read/write head is manufactured using Al.sub.2 O.sub.3 dams. The Al.sub.2 O.sub.3 dams are formed using a sacrificial layer which is deposited upon a bottom pole layer. An Al.sub.2 O.sub.3 layer is deposited over the sacrificial layer. When the sacrificial layer is removed, the Al.sub.2 O.sub.3 layer forms dams between which a top pole piece is deposited. The sacrificial layer is removed using lapping and a selected chemical etch; etch of the sacrificial layer which lifts-off overlying partial lapping or chemical etch followed by chemical Al.sub.2 O.sub.3 ; depositing photoresist dams and chemically, etching the encapsulation layer and the sacrificial layer; or removal through physical or thermal shock of the Al.sub.2 O.sub.3 layer sputtered at zero bias followed by a selective chemical etch of the sacrificial layer. The thin film magnetic head of the present invention has pole tips which provide an outside pole face contour that is significantly different from a pole tip contour along a gap region. This reduces an undershoot effect in readback pulses in a readback signal. The altered contour can be used on both top and bottom pole tips to eliminate both leading and trailing undershoots. Additionally, in shielded probe heads for vertical recording a gap region contour can be altered to achieve a similar reduction in leading undershoot.

Thin film head with contoured pole face edges for undershoot reduction

A thin film magnetic read/write head deposited upon a non-magnetic substrate reduces leading edge undershoots in readback pulse signal. A magnetic layer is deposited between the thin film magnetic read/write head and the non-magnetic substrate. Undershoots are reduced by making the leading edge of the thin film head less sensitive to the magnetization transitions in a magnetic storage medium.

Leading edge undershoot elimination in thin film heads

A servo head in a disk file data storage system includes two servo transducers which are connected so that noise induced by a nearby writing data head will cancel. The two servo transducers are located an equal distance from the data transducer. The pole tips of the first servo transducer are positioned to read servo information stored on an adjacent servo disk. The pole tips of the second servo transducer are oriented away from the servo disk surface to prevent the second servo transducer from reading an unwanted signal from the servo disk.

Methods of improved servo head passive noise cancellation by placement

A servo head in a disk file data storage system includes at least one shield which acts to block radiation emanating from a nearby data head and thus reduce noise induced in the servo head. The shield is located on either side of an essentially flat conducting coil in a servo transducer, or a data transducer or both. The shield may be either a single layer of material or multiple layers.

Shielded servo heads with improved passive noise cancellation

A thin film magnetic read/write head is manufactured using Al.sub.2 O.sub.3 dams. The Al.sub.2 O.sub.3 dams are formed using a sacrificial layer which is deposited upon a bottom pole layer. An Al.sub.2 O.sub.3 layer is deposited over the sacrificial layer. When the sacrificial layer is removed, the Al.sub.2 O.sub.3 layer forms dams between which a top pole piece is deposited. The sacrificial layer is removed using lapping and a selected chemical etch; partial lapping or chemical etch followed by chemical etch of the sacrificial layer which lifts-off overlying Al.sub.2 O.sub.3 ; depositing photoresist dams and chemically etching the encapsulation layer and the sacrificial layer; or removal through physical or thermal shock of the Al.sub.2 O.sub.3 layer sputtered at zero bias followed by a selective chemical etch of the sacrificial layer. The thin film magnetic head of the present invention has pole tips which provide an outside pole face contour that is significantly different from a pole tip contour along a gap region. This reduces an undershoot effect in readback pulses in a readback signal. The altered contour can be used on both top and bottom pole tips to eliminate both leading and trailing undershoots. Additionally, in shielded probe heads for vertical recording a gap region contour can be altered to achieve a similar reduction in leading undershoot.

Method of making a thin film head with contoured pole face edges for

A thin film magnetic read/write head is manufactured using Al.sub.2 O.sub.3 dams. The Al.sub.2 O.sub.3 dams are formed using a sacrificial layer which is deposited upon a bottom pole layer. An Al.sub.2 O.sub.3 layer is deposited over the sacrificial layer. When the sacrificial layer is removed, the Al.sub.2 O.sub.3 layer forms dams between which a top pole piece is deposited. The sacrificial layer is removed using lapping and a selected chemical etch; partial lapping or chemical etch followed by chemical etch of the sacrificial layer which lifts-off overlying Al.sub.2 O.sub.3 ; depositing photoresist dams and chemically etching the encapsulation layer and the sacrificial layer; or removal through physical or thermal shock of the Al.sub.2 O.sub.3 layer sputtered at zero bias followed by a selective chemical etch of the sacrificial layer.

Method for aligning thin film head pole tips

A bubble memory package is comprised of a nonmagnetizable heat sink formed with a pocket for receiving the field coil and magnetic chip carrier assemblies. The heat sink is massive and capable of dissipating the heat generated by a high density memory operating at a high frequency. The heat sink is not closed over the top of the coil and memory carrier assemblies to reduce eddy and circulating electrical currents formed in an electrically conductive heat sink. The heat sink is formed with a track guide for receiving a heat sink plate which may be of electrically nonconductive material but which has sufficient heat conductivity to assist in transferring heat into the heat sink. The top of the heat sink plate is formed with a pocket for receiving a permanent magnet to generate the bias field and the bottom of the heat sink is formed with a second pocket for receiving a magnet assembly. The entire package is surrounded by a magnetic shield container.

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Bloomington, MN, United States of America

John Bortins