Read Rite Corporation

International Business Machines Corporation

Other

University of California

Hitachi Global Storage Technologies Netherlands B.v.

Samuel Wonder Yuan

Francis H Liu

Hua-Ching Tong

Glen A Garfunkel

Robert Earl Rottmayer

Edward Hinpong Lee

Thomas Young Chang

Marcos Moises Lederman

Joseph Francis Smyth

Minshen Tan

Edward Hin Pong Lee

Neil Leslie Robertson

Jian-Gang Zhu

Pradeep K Thayamballi

Hardayal Singh Gill

Matthew Joseph Carey

Daniel A Nepela

John David Westwood

Michael Paul Salo

Terence Tin-Lok Lam

Durga P Ravipati

Derek Jan Kroes

Vernon M Riedlin, Jr

A magnetic head assembly has an open yoke type write head constructed on top of a read head so that the write head can be constructed with a very narrow track width without restraint by the requirements of the read head. The write head has first and second pole piece portions wherein the second pole piece portion has separate front and back layer portions. A coil layer is wrapped around only the first pole piece portion and the back layer portion so that the front layer portion can be constructed separately to provide a narrow track width. Further, in a preferred embodiment the front layer portion has a reduced thickness and a higher magnetic moment than the thickness and magnetic moment of the first pole piece portion and the back layer portion. Still further, in a preferred embodiment the first pole piece portion and the back layer portion are planar due to polarization of underlying layers.

Method of making a magnetic head assembly having open yoke write head with highly defined narrow track width

The magnetic head of the present invention includes a P pole having an opening formed therethrough, and a P pole that is formed over the opening. A second magnetic pole tip is positioned relative to the first magnetic pole such that the first magnetic pole is symmetrically disposed relative to the second magnetic pole tip. Induction coils may be helically wound around portions of the first and/or second magnetic poles, or, alternatively, a planar, spiral induction coil may be fabricated for use with the first and second magnetic poles. An enhanced embodiment includes a first magnetic pole tip piece having a length that defines the throat length of the magnetic head and a thickness that increases the gap at rearward portions of the second magnetic pole tip of the magnetic head.

Magnetic head having write head with double split yoke

A thin film magnetic head employs pole tips members which are coplanar in a plane across the write gap to produce a written track whose width is determined by the thickness of the pole tip members. The coplanar write structure may be combined with a multilayer read sensor disposed in the write gap to produce a narrow trackwidth thin film magnetic head having both write and read capabilities.

Thin film read head with coplanar pole tips

Magnetic transducers are formed with common magnetic exchange layers capable of providing assertive and complementary signals. The transducers include an assertive transducer portion and a complementary transducer portion. Between the two transducer portions is a common bias portion which comprises an antiferromagnetic layer providing bias fields in different directions to the respective transducer portions. During normal operations, a current is directed into each of the transducer portions. The assertive transducer portion, being magnetically biased in one direction, generates a varying voltage as an assertive version of the electrical signal. The complementary transducer, being magnetically biased in another direction, generates another varying voltage as a complementary version of the electrical signal. In one embodiment, the transducer portions are implemented to operate as an anisotropic MR(AMR) sensor. In a second embodiment, the transducer portions operate as a giant MR(GMR) or spin valve sensor.

Magnetoresistive transducer having a common magnetic bias using assertive and complementary signals

A magnetic head assembly has an open yoke type write head constructed on top of a read head so that the write head can be constructed with a very narrow track width without restraint by the requirements of the read head. The write head has first and second pole piece portions wherein the second pole piece portion has separate front and back layer portions. A coil layer is wrapped around only the first pole piece portion and the back layer portion so that the front layer portion can be constructed separately to provide a narrow track width. Further, in a preferred embodiment the front layer portion has a reduced thickness and a higher magnetic moment than the thickness and magnetic moment of the first pole piece portion and the back layer portion. Still further, in a preferred embodiment the first pole piece portion and the back layer portion are planar due to planarization of underlying layers.

Magnetic head assembly having open yoke write head with highly defined narrow track width

A method for forming a merged thin film magnetic head having a first shield layer and a combined second shield and bottom pole piece layer arranged in a sandwich supporting a read sensor therebetween at the pole tip region. The combined second shield and bottom pole piece layer are magnetically coupled with the first shield layer at the pole tip end of the yoke region adjacent the read sensor, and overlaying and magnetically coupled with the first shield layer at the back gap region. A patterned opening is provided in the combined second shield and bottom pole piece layer at the yoke region thereof to expose the first shield layer and form a flat planarization surface thereon. A plurality of stacked thin film coil layers are provided in the patterned opening, and a top pole piece layer overlies the thin film coil at the yoke region, overlies the bottom pole piece at the pole tip region providing a pole tip and gap thereat, and overlies the bottom pole piece at the back gap region. The patterned opening which exposes the first shield layer allows the provision of a multi-layer coil while maintaining a low profile of the head.

Method for forming low profile multi-layer coil merged thin film magnetic head

A magnetic transducer employs a giant magnetoresistive sensor whose sensing surface is separated by a dielectric layer from a magnetically recorded surface carrying recorded data signals to be read back by the transducer. The dielectric layer serves to protect the sensing layer from corrosion, electrostatic discharge from the record surface, mechanical damage from asperities, thermal asperities from heating resulting from close contact between the transducer and the record surface, and damage from exposure during lapping operations. This structure also reduces the readback pulse width and offtrack assymmetry, and improves servo linearity, thereby increasing recording density. The reduced signal amplitude is compensated for by the use of a giant magnetoresistive transducer with an intrinsically large output. The use of the recessed transducer reduces saturation of the transducer due to the record medium flux at reduced signal amplitudes, thereby increasing readback efficiency.

High density giant magnetoresistive transducer with recessed sensor

A high moment bilayer first pole piece layer of a write head has high magnetic stability for promoting read signal symmetry of a read sensor of a read head. The bilayer first pole piece layer has a first layer of nickel iron and a second layer of iron nitride. The iron nitride has a high magnetic moment for conducting more flux per volume than the nickel iron first layer. In a first aspect of the invention, the nickel iron first layer is highly stabilized by providing it with a negative magnetostriction so that a stress induced anisotropy (H.sub.K) supports an intrinsic uniaxial anisotropy (H.sub.K) of the nickel iron first layer. The iron nitride second layer is formed directly on the nickel iron first layer so that by magnetic coupling the iron nitride second layer has significantly improved magnetic stability. In a second aspect of the invention the iron nitride second layer is provided with a positive magnetostriction which still further increases the magnetic stability of the bilayer first pole piece layer. In a preferred embodiment a net magnetostriction is zero or near zero. Each aspect of the invention improves the asymmetry sigma of the read head.

High moment bilayer first pole piece layer of a write head with high

A method of manufacturing a thin film magnetic head which employs pole tips members which are coplanar in a plane across the write gap to produce a written track whose width is determined by the thickness of the pole tip members. The coplanar write structure may be-combined with a multilayer read sensor disposed in the write gap to produce a narrow trackwidth thin film magnetic head having both write and read capabilities.

Disclosed is a merged thin film magnetic head having a first shield layer and a combined second shield and bottom pole piece layer arranged in a sandwich supporting a read sensor therebetween at the pole tip region. The combined second shield and bottom pole piece layer are magnetically coupled with the first shield layer at the pole tip end of the yoke region adjacent the read sensor, and overlaying and magnetically coupled with the first shield layer at the back gap region. A patterned opening is provided in the combined second shield and bottom pole piece layer at the yoke region thereof to expose the first shield layer and form a flat planarization surface thereon. A plurality of stacked thin film coil layers are provided in the patterned opening, and a top pole piece layer overlies the thin film coil at the yoke region, overlies the bottom pole piece at the pole tip region providing a pole tip and gap thereat, and overlies the bottom pole piece at the back gap region. The patterned opening which exposes the first shield layer allows the provision of a multi-layer coil while maintaining a low profile of the head.

Low profile multi-layer coil merged thin film magnetic head

A magnetoresistive (MR) read sensor fabricated on a substrate comprises an MR layer of magnetoresistive material, a soft adjacent layer (SAL) of soft magnetic material, and a manganese-based metallic antiferromagnetic (AFM) layer between the MR layer and the SAL layer. The AFM layer is in direct contact with the SAL layer and is separated from the MR layer by a non-magnetic spacer layer. A non-magnetic texturing layer is disposed between the SAL layer and the substrate. This structure exhibits a much larger pinning field than read sensors using oxide-based antiferromagnets.

Magnetoresistive sensor having a pinned soft magnetic layer

A compact read/write head having a biased giant magnetoresistive sensor. Permanent magnet films are placed adjacent to the giant magnetoresistive sensor operating in the current-perpendicular-to the-plane (Cpp) mode and spaced with respect to the sensor by conducting films. These permanent magnet films provide a magnetic bias. The bias field is substantial and fairly uniform across sensor height. Biasing of the giant magnetoresistive sensor provides distinguishable response to the rising and falling edges of a recorded pulse on an adjacent recording medium, improves the linearity of the response, and helps to reduce noise. This read/write head is much simpler to fabricate and pattern and provides an enhanced uniformity of the bias field throughout the sensor.

Read/write head having a GMR sensor biased by permanent magnets located

Magnetoresistive transducer having a common magnetic bias using

A magnetic thin film head employing giant magnetoresistance (GMR) includes alternating layers of ferromagnetic material and nonmagnetic material coupled by magnetostatic and exchange interactions to produce an antiparallel orientation between the magnetic layers in the absence of an external field. Magnetic biasing is applied by a permanent magnet to the alternating layers to obtain a scissor-like configuration of the adjacent magnetic layers. The magnet is placed in contiguous junction with the multilayered GMR structure edge which is away from the air bearing surface, and is separated from the sensor by a nonmagnetic, nonconductive spacer.

CIP GMR sensor coupled to biasing magnet with spacer therebetween

A magnetoresistive (MR) read transducer includes an MR sensor element having end regions and a center active region. The end regions are pinned both top and bottom by an exchange coupling antiferromagnetic material. This pinning action causes the end regions to act as permanent magnets having the same remanent magnetic moment M.sub.r as that of the center active region, thereby resulting in suppression of magnetic edge effects in the transducer. A magnetic soft bias layer adjacent to the magnetoresistive sensor element also has its ends pinned by exchange coupling antiferromagnetic material.

Growing community of inventors

San Carlos, CA, United States of America

Samuel Wonder Yuan