Digital Equipment Corporation

Other

Das Devices, Inc.

Shyam C Das

Michael L Mallary

Jamaluddin Khan

Process for fabricating a thin film head for high track density recording defines an easy axis parallel to the track in the narrow poletip without a need of a very high magnetic field in the plating cell. Narrow poletips of equal widths of P1 and P2 are obtained. The process includes sheet depositing a magnetic layer, then depositing a sheet of gap material, and then depositing a sheet of another magnetic layer. This operation can be done either by a vacuum technique or by an electroplating process. If it is done by vacuum processing, all the three depositions can be done in one pumpdown. Since the sheet magnetic films are deposited, the demagnetizing field is very small, and a small orienting field is necessary unlike the large field required in the prior art.

Narrow track thin film head for high track density recording

Method of making a narrow track thin film head

A microlithographic process of fabricating electronic components, such as, for example, integrated circuit chips and thin film read/write heads for computer disk systems, in which a laser is used to etch features defined by a mask. The laser is selected whose radiation will be absorbed by the workpiece being etched, and the masking material is selected so as to be highly reflective of the laser radiation. The masking material is patterned in a conventional manner so as to expose the portions of the workpiece material to be etched. When the laser is directed to the workpiece, the laser radiation etches the portions of the workpiece not protected by the mask. A preferred process of scanning with a laser is disclosed. Etching may be improved if performed under a liquid transparent to the laser radiation.

Lithographic technique using laser scanning for fabrication of

A read-write head comprising a magneto-resistive element and a conductor for producing a longitudinal magnetic bias field along said MR element. The conductor may also be arranged to produce a transverse magnetic bias field.

Biasing conductor for MR head

A magnetic recording head including a read pole disposed in a gap between a pair of write poles, and a sensor spaced away from the gap, the read pole adapted to conduct flux to the sensor, each write pole forming a respective cavity between itself and the read pole where the outside of at least one pole is tapered down toward the pole tip, the poles being closer together at their tips than they are near the sensor.

Three-pole magnetic head with reduced flux leakage

A combined transverse and longitudinal biasing conductor for MR element, and a thin film head including same.

A recording head includes at least one magnetic pole and magnetic side shields adjacent to the pole, the side shields disposed to shield the pole from adjacent tracks on a magnetic medium. Embodiments are disclosed for both longitudinal and vertical recording in monopole, two-pole, and three-pole heads, including inductive, MR and Hall-type read elements. A magnetic head capable of detecting flux from a target source among a group of sources, includes at least one magnetic pole and a magnetic shield, the shield providing to the pole 360.degree. of magnetic shielding against sensing by the pole of flux other than the target source. Also disclosed is an alternate flux return conductor being separated at the pole tip from the shield section by a non-magnetic insulation layer. A shielded magnetic head may have two outer magnetic poles, the two outer poles acting as the magnetic shield for a center pole, whereby the outer poles can be used for writing and the center pole can be used for reading.

Method of making recording heads with side shields

A new read/write head for use in a mass storage device in a digital data processing system. The head is a thin-film head having a solenoidal coil around one or both of the pole pieces. Sets of planar conductive traces are formed on planar layers of insulating material on opposing sides of a pole piece, with vias connecting the ends of selected traces to thereby form a solenoidal coil around the pole piece.

Solenoidal thin film read/write head for computer mass storage device

Having a solenoidal energizing coil

Side shields are provided adjacent to the magnetic poles of recording heads. The side shields are used for read and write operations for both longitudinal and vertical recording. During read, the side shields intercept flux from adjacent tracks and shunts it around the sensor to magnetic ground. During write, side shields contain the write field of the head so that it does not corrupt the data on adjacent tracks. Embodiments are disclosed for both longitudinal and perpendicular or vertical recording.

Recording heads with side shields

The mask through which the pole piece is deposited by through mask plating has a yoke region, a narrower pole tip region and a bulb region adjacent the pole tip region. The bulb region results in substantially uniform current density during the through mask plating which results in substantially uniform composition and thickness of the pole piece material across the pole piece. In particular, the composition difference between the pole tip and the yoke region is reduced from that according to prior art techniques. The combination of the composition uniformity and the different (than the prior art) stress distribution in the pole tip material results in favorable domain structure in the pole tip. The magnetic domains formed conduct flux by coherent rotation of the magnetization direction in the domains without changing the location of wall boundaries thereby reducing Barkhausen noise.

Method of producing a pole piece with improved magnetic domain structure

A read/write head for use in a magnetic storage device in a digital data processing system for writing data in the form of magnetic flux onto, and reading data from a spinning magnetic disk. The head has two magnetic pole pieces each with a yoke region which tapers to a pole tip and an energizable coil situated between the pole pieces in the yoke region for generating magnetic flux. One of the pole pieces has a slot in the yoke region, and a strip of magneto-resistive material is situated adjacent the slot. The magneto-resistive strip is adapted to be connected to sensing equipment which measures variations in the resistance of the magneto-resistive strip in response to the variations in the magnetic flux recorded on the media. Several slots may be formed in the pole pieces, and an elongated magneto-resistive strip may be situated adjacent the slots.

Thin film head having a magneto-restrictive read element

A microlithographic process of fabricating electronic components, such as, for example, integrated circuit chips and thin film read/write heads for computer disk systems, in which a laser is used to etch features defined by a mask. The laser is selected whose radiation will be absorbed by the workpiece being etched, and the masking material is selected so as to be highly reflective of the laser radiation. The masking material is patterned in a conventional manner so as to expose the portions of the workpiece material to be etched. When the laser is directed to the workpiece, the laser radiation etches the portions of the workpiece not protected by the mask. The depth of the recess formed by the laser can be limited by depositing an etch stop layer of reflective The depth of the recess formed by the laser can be limited by depositing an etch stop layer of reflective material on a substrate, followed by an intermediate layer of workpiece material to be etched, and then the reflective mask. The laser radiation etches the intermediate layer through the mask to the etch stop layer, which prevents radiation from etching the workpiece further. Depending on the material being etched, the etch may be improved if performed under a liquid transparent to the laser radiation. The liquid may carry away the products produced by the etch.

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Sudbury, MA, United States of America

Shyam C Das