Read Rite Corporation

Western Digital (fremont), Inc.

Other

Western Digital Technologies, Inc.

Mark David Thomas

Zhupei Shi

Billy W Crue, Jr

Carlos Corona

William D Jensen

Yiming Huai

Durga P Ravipati

David John Seagle

Kroum Stanimirov Stoev

Ronald A Barr

Kenneth E Knapp

Billy Wayne Crue

David L Thomas

Yining Hu

Renuka Apparao

Jun Liu

Mohamad Towfik Krounbi

Yingjian Chen

Francis H Liu

Lien-Chang Wang

Patrick J Lee

Marcos Moises Lederman

Ming Zhao

Peng Luo

Amritpal Singh Rana

Eric R Katz

Lei Zhang

Luc Chung

Bill Crue

Myron R Cagan

Son Tran

Kenneth Kung

Chen Lee

Sandra Sankar

Pei Zou

Sonny Tran

Robert E Caddy, Jr

A serial number detector is disclosed for detecting an encoded serial number written on a wafer. A scanner scans the wafer to generate a raster image representing the encoded serial number, and an optical character recognition (OCR) system detects a detected serial number comprising a plurality of detected data characters and a plurality of detected redundancy characters. A character-to-binary converter converts the detected data characters and the detected redundancy characters into codeword symbols. A syndrome generator generates a plurality of error syndromes in response to the codeword symbols, and an error corrector, responsive to the error syndromes, detects and corrects errors in the codeword symbols.

Using optical character recognition augmented by an error correction code to detect serial numbers written on a wafer

Methods are provided for fabricating an electrical lapping guide, and for using the electrical lapping guide to fabricate a transducer of a magnetic recording head. Additionally, transducers comprising an electrical lapping guide are also provided. Methods of fabricating the electrical lapping guide comprise forming a resistive element proximate to a shield pedestal. Accordingly, the resistive element is both aligned with the shield pedestal in a transverse direction, and closely spaced from the shield pedestal in a longitudinal direction. The resistance of the resistive element correlates well with a throat height of the shield pedestal, and the correlation is utilized in the methods of fabricating the transducer. When a magnetoresistive stripe is uses as a second electrical lapping guide while fabricating the transducer, the two can be used to control a tilt angle in the transverse direction during lapping.

Electrical lapping guide disposed laterally relative to a shield pedestal

A recording head comprises a write element, including a coil and a dynamic fly-height heater, and two electrical lapping guides. The head also comprises a number of bonding pads including a DFH bonding pad and a shared bonding pad both electrically connected to the dynamic fly-height heater. Each lapping guide defines a circuit between the shared bonding pad and a dedicated bonding pad and each includes a resistive element. The resistive elements of the two lapping guides can be vertically aligned to be used to control a lapping tilt angle when a bar of unfinished heads is lapped. After lapping, a channel is defined into the transducer of the recording head. Forming the channel can remove at least a portion of each lapping guide in order to break the electrical circuit of that guide.

Dual electrical lapping guides with common bonding pad

A head including a write element for writing data to a magnetic media, and methods for its production are provided. A write element of the invention includes one or more of a recessed first pole, a heat sink layer, and a shortened yoke length. A method of the invention provides forming an anti-reflective layer before forming a mask layer. During photolithography the anti-reflective layer suppresses undesirable reflections off of features, such as vertical sidewalls, that otherwise limit how closely to such features portions of the mask layer can be formed.

Write element with recessed pole and heat sink layer for ultra-high density writing

A method for manufacturing a reader/writer is provided having a substrate with an undercoat formed thereon. A first shield is formed over a portion of the undercoat and a pair of reader leads is formed over the first shield and undercoat. A read sensor is formed between the reader leads and a first pole/second shield is formed over the reader leads. A mid coat is formed over the undercoat and the reader leads. A second pole is formed over and in contact with the mid coat. A lead is formed over the second pole. A pedestal is formed over the reader lead and an overcoat is formed over the second pole and the lead and around the pedestal. A pad is then formed over the pedestal.

Reader/writer for magnetic memory

Modular convertible furniture systems include a pair of similar open-ended box frame assemblies which are nestable one within the other. A pair of slotted support rails are attached pivotally at respective opposing corners of one of the box frame assemblies so as to be movable between raised and lowered positions. When in a raised position, the rails provide a support for a solid board plank thereby becoming a seat back (e.g., for a chair, love seat, or sofa-type arrangement). When the rails are in a lowered position substantially parallel to the ground, the two box frame assemblies may be oriented back-to-back so as to provide a support for a mattress thereby converting the structure into a bed arrangement, for example. The box frame assemblies can be positioned on different sides and ends thereby allowing formation of tables and/or shelving as may be desired.

Convertible furniture system comprised of modular convertible box frames and methods of forming various furniture configurations therefrom

A method of forming a head comprises forming a write transducer on a wafer, cutting the wafer to produce a slider bar with a cut surface, and planarizing the cut surface of the slider bar. Forming the write transducer can include forming a first pole layer and forming a first pole pedestal layer over the first pole layer, where the first pole pedestal layer includes a tapered portion defined by a first end having a nose width less than a desired final nose width, and a second end having a zero throat width greater than the desired final nose width. Planarizing the cut surface of the slider bar exposes the first pole pedestal layer until a width thereof approximately equals the desired final nose width.

Method of forming a magnetoresistive device

A magnetoresistive device having a first pole, a second pole, and a first tapered pole pedestal therebetween and magnetically connected to the second pole. The first tapered pole has a width that increases with increasing distance away from the air bearing surface, ABS. The magnetoresistive device can also include a second tapered pole pedestal magnetically connected to the first pole, and separated from the first tapered pole pedestal by a write gap. The second tapered pole pedestal has a width that increases with increasing distance away from the air bearing surface. A method of the present invention includes defining the trackwidth of a write element by lapping a tapered pole pedestal. More specifically, the trackwidth is given by a known taper angle, a zero throat width, and a throat height, wherein the throat height is controlled precisely by lapping.

Methods for reducing feature sizes of devices such as electromagnetic sensors are disclosed. A track width of a MR sensor is defined by a mask having an upper layer with a reduced width and a lower layer with a further reduced width. Instead of or in addition to being supported by the lower layer in the area defining the sensor, the upper layer is supported by the lower layer in areas that do not define the sensor width. In some embodiments the upper layer forms a bridge mask, supported at its ends by the lower layer, and the lower layer is completely removed over an area that will become a sensor. Also disclosed is a mask having more than two layers, with a bottom layer completely removed over the sensor area, and a middle layer undercut relative to a top layer.

Magnetoresistive sensors having submicron track widths and method of making

A magnetic head is fabricated by providing a substrate with a planar surface, forming at least one cavity in the planar substrate, depositing a second yoke layer in the cavity, forming a second pole tip in the cavity in contact with the second yoke layer, patterning an inductive coil in the cavity, depositing a gap layer over the second pole tip, sputtering a first pole tip over the gap layer, etching the first and second pole tips and the gap layer to form a stack of layers, depositing a protective layer over the stack of layers, leveling the protective layer to expose the first pole tip, and patterning a first yoke layer in contact with the first pole tip.

Method of making a magnetic head with aligned pole tips

In at least one embodiment, a thin film write head having a conductor with a coil structure having a central axis perpendicular to an air bearing surface. The conductor having a first contact centrally located at a first end of the conductor. The conductor having plurality of contacts located distal from the first contact. The plurality of contacts having at least one contact on either side of the central axis of the write head.

Thin film write head with universal coil design

A magnetoresistive head having a split coil structure including multiple, similar coil layers separated by an insulator and joined at their ends to define parallel electrical paths. The coil passes through a magnetic yoke having an open end and a closed end and is electrically insulated from the yoke. The parallel electrical paths of the separate coil layers can each be modeled as a resistor in series with an inductor, each of the paths also being in parallel with a capacitor. The split coil has a much faster current rise time than a comparable single layer coil or than multiple coils connected in series. Since the coil current provides the magneto-motive force for imparting a signal on a passing recording medium, the decreased current rise time corresponds to an increased data recording rate.

Magnetic write head having a splitcoil structure

A magnetoresistive write element has a plurality of coils disposed between a first and second pole. A first coil having inner and outer contacts is provided on top of a layer of insulation on top of the first pole. A write gap material above the first coil separates the poles at a yoke tip region to form a write gap therebetween. Second and third coils wound in the form of a single bifilar coil are provided on top of the write gap material, each having an inner and an outer contact portion. Electrical connection between the inner contact of the first coil and the inner contact of the second coil is provided through a via in the write gap material. An insulation layer above the second and third coils provides separation from a fourth coil provided thereabove. The fourth coil also has inner and outer contact portions. The outer contact of the fourth coil electrically connects with the outer contact of the second coil through one of the vias in the second insulation layer separating the second and third coil from the fourth coil. Similarly, the inner contact of the fourth coil connects electrically with the inner contact of the third coil. An insulation layer is deposited on top of the fourth coil and the second pole is formed on top thereof such that the first and second poles make electrical connection with one another at back gap portion.

High density multi-coil magnetic write head having a reduced yoke length and short flux rise time

In a preferred embodiment, a thin film write head having upper and lower pole structures. In the preferred embodiment of the present invention, a middle coat insulation layer is located over a yoke of the lower pole structure and adjacent a pedestal pole tip of the lower pole structure. A trench is formed in the middle coat layer by etching part way into the middle coat layer. A conductor coil is formed on the middle coat so that a portion of the coil is located within the trench and a portion above the trench. Preferably, the middle coat is planarized and then etched using a resist mask to form the trench. With one method, the resist mask is removed after etching the trench, a conductor seed layer deposited, a resist mask formed on the seed layer, a conductor coil formed within the mask, and the seed layer etched after resist mask removal to electrically isolate the turns of the coil. In another method, after trench etching and resist mask removal, conductor material may be deposited on the middle coat and planarized to form the portion of the coil within the trench. With this method, additional conductor material is deposited on the conductor material in the trench using a resist mask to form the coil. The additional conductor material provided in the trench can significantly reduce the coil resistance without increasing stack height or yoke lengths to improve write head performance.

Thin film write having reduced resistance conductor coil partially recessed within middle coat insulation

A write element for recording data on a magnetic medium is provided having an impedance designed to substantially match the impedance of an electrical interconnection between it and a pre-amp chip located nearby on the load beam. Additional embodiments are directed to incorporating a read element with the write element to form a read/write head, and to further incorporate the read/write head into a magnetic disk drive. Further embodiments are directed towards the fabrication of the write element.

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Hollister, CA, United States of America

Mark David Thomas