Abstract: An low profile inductive write head is provided to improve track definition and head efficiency and to reduce overcoat and pole tip protrusion and cracking caused by thermal expansion. A first insulation layer of an insulation stack enclosing the coil layer is formed of an non-magnetic inorganic insulator material such as aluminum oxide, silicon dioxide or titanium dioxide having a thickness of in the range of 0.2-0.3 microns. The thinner first insulation layer results in a significantly reduced slope of the insulation stack which decreases reflective notching during processing of the second pole tip to improve track definition. Improved thermal conduction properties of the inorganic insulator material improves heat sinking of the write coil reducing overcoat and pole tip protrusion and cracking at the pole tip/write gap layer interface.

Abstract: An low profile inductive write head is provided to improve track definition and head efficiency and to reduce overcoat and pole tip protrusion and cracking caused by thermal expansion. A first insulation layer of an insulation stack enclosing the coil layer is formed of an non-magnetic inorganic insulator material such as aluminum oxide, silicon dioxide or titanium dioxide having a thickness of in the range of 0.2-0.3 microns. The thinner first insulation layer results in a significantly reduced slope of the insulation stack which decreases reflective notching during processing of the second pole tip to improve track definition. Improved thermal conduction properties of the inorganic insulator material improves heat sinking of the write coil reducing overcoat and pole tip protrusion and cracking at the pole tip/write gap layer interface.

Abstract: To protect the MR read head element from ESD damage during wafer level manufacturing, a lead from the MR element is electrically connected to one or both of the read head element shields during manufacturing. In a preferred embodiment of the present invention, the electrical connection is fabricated in the kerf area between adjacent magnetic heads as they are fabricated upon a wafer substrate. Thereafter, when the magnetic heads are separated by saw cutting through the kerf areas, the electrical connections are thereby removed, such that the MR element electrical leads and the shields are electrically isolated. In an alternative embodiment, one or more of the shields, as well as the MR element leads can also be electrically connected to the substrate upon which the magnetic head is fabricated.

Abstract: To protect the MR read head element from ESD damage during wafer level manufacturing, a lead from the MR element is electrically connected to one or both of the read head element shields during manufacturing. In a preferred embodiment of the present invention, the electrical connection is fabricated in the kerf area between adjacent magnetic heads as they are fabricated upon a wafer substrate. Thereafter, when the magnetic heads are separated by saw cutting through the kerf areas, the electrical connections are thereby removed, such that the MR element electrical leads and the shields are electrically isolated. In an alternative embodiment, one or more of the shields, as well as the MR element leads can also be electrically connected to the substrate upon which the magnetic head is fabricated.

Abstract: 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.

Abstract: A fully-pinned, flux-closed spin valve (SV) magnetoresistive sensor having a reference (pinned) layer with magnetization fixed by a first antiferromagnetic (AFM1) layer, and a keeper layer with magnetization fixed by a second antiferromagnetic (AFM2) layer. The magnetization of the keeper layer is saturated and fixed in an antiparallel orientation to the pinned layer magnetization by an exchange interaction with the AFM2 layer. The magnetic moments of the pinned layer and the keeper layer are approximately matched to form a flux-closed magnetic configuration wherein demagnetizing fields in the pinned layer are largely canceled and magnetostatic interaction with the free layer is reduced. Saturation of the keeper layer magnetization by exchange coupling with the AFM2 layer eliminates or reduces magnetization canting at the edges of the keeper layer which can result in signal field shunting through the keeper layer.

Abstract: 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.

Abstract: An SV sensor having a reference (pinned) layer formed of a first high uniaxial anisotropy ferromagnetic material, such as Co--Fe, and a keeper layer formed of a second high uniaxial anisotropy ferromagnetic material, such as Ni--Fe--Nb. Lapping induced stress in the Co--Fe layer having high positive magnetostriction generates a stress-induced uniaxial anisotropy field in the reference layer resulting in enhanced reference layer magnetization. This uniaxial anisotropy field is capable by itself of maintaining a substantial transverse reference layer saturation even at elevated temperatures. Lapping induced stress in the Ni--Fe--Nb layer having high positive magnetostriction generates a stress-induced uniaxial anisotropy field in the keeper layer providing more uniform magnetization and therefore better flux cancellation. The high electrical resistivity of the Ni--Fe--Nb keeper layer has the further benefit of reducing sense current shunting by the keeper layer.

Abstract: 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.

Abstract: An orthogonal spin valve read head is provided wherein a spin valve sensor is asymmetrically located between first and second shield layers so that image currents in the first and second shield layers produce a resultant image field which partially or completely counterbalances a stiffening field from antiferromagnetic, pinned and spacer layers in the MR sensor when sense current is conducted therethrough. Accordingly, the spin valve sensor may be located a greater distance from the second shield layer by providing a mid-gap layer between the spin valve sensor and a second gap layer. In one example, the total thickness of the mid-gap and second gap layer is four times as thick as the first gap layer which results in the image fields from the first and second shield layers completely counterbalancing the field from the antiferromagnetic, pinned and spacer layers due to the sense current.

Abstract: A monitoring apparatus is provided for determining permeabilities of a vacuum-deposited second pole piece of a magnetic head at the wafer level by providing wafer-mounted monitors which have layers formed by the same masking and deposition steps employed in making the magnetic heads so that the layers of the monitors are replicated layers, except for a shaping layer on top of a replicated second pole piece of some of the monitors. Each monitor is a transformer wherein each of a primary winding and a secondary winding comprises essentially a replicated magnetic head. The first and second pole pieces of the replicated magnetic heads are joined so as to magnetically couple the primary and secondary windings that constitute the transformer.

Abstract: An orthogonal spin valve read head is provided wherein a spin valve sensor is asymmetrically located between first and second shield layers so that image currents in the first and second shield layers produce a resultant image field which partially or completely counterbalances a stiffening field from antiferromagnetic, pinned and spacer layers in the MR sensor when sense current is conducted therethrough. Accordingly, the spin valve sensor may be located a greater distance from the second shield layer by providing a mid-gap layer between the spin valve sensor and a second gap layer. In one example, the total thickness of the mid-gap and second gap layer is four times as thick as the first gap layer which results in the image fields from the first and second shield layers completely counterbalancing the field from the antiferromagnetic, pinned and spacer layers due to the sense current.