Abstract: A method is provided for preserving the transverse biasing of a GMR (or MR) read head during back-end processing. In a first preferred embodiment, the method comprises magnetizing the longitudinal biasing layers of the read head in a transverse direction, so that the resulting field at the position of the transverse biasing layer places it in a minimum of potential energy which stabilizes its direction. The field of the longitudinal biasing layer is then reset to the longitudinal direction in a manner which maintains the transverse biasing direction. In a second embodiment, a novel fixture for mounting the read head during processing includes a magnetic portion which stabilizes the transverse bias of the read head. The two methods may be used singly or in combination.

Abstract: The fixed layers of all magnetoresistive elements that are formed on the same substrate are magnetized in the same direction. Chips including magnetoresistive elements are cut out individually from the substrate. A magnetic sensor is assembled by combining cut-out chips together with consideration given to the magnetization directions of the fixed layers of the magnetoresistive elements in the chips. In this manner, the fixed layers of the magnetoresistive elements are magnetized by a sufficiently strong magnetic field for magnetization, whereby an output signal having a large absolute value is obtained from the magnetoresistive elements.

Abstract: To fabricate a magnetic field sensor, a copper barrier film is formed. A magnetic metal film is formed on the barrier film. A plurality of trenches is formed with a desired thickness in the magnetic metal film. A copper film is formed in the plurality of trenches, so that multiple layers of magnetic metal film and copper film are formed. The RF semiconductor device equipped with the magnetic field sensor includes a magnetic field sensor made by the above method. The magnetic field sensor is attached on a semiconductor substrate. Metal wirings are formed at near the both sides of the magnetic field sensor. An insulating film is formed on top. An inductor is formed on the insulating film at predetermined locations.

Abstract: A spin valve sensor is provided with a negative ferromagnetic coupling field ?HFC for properly biasing a free layer and a spin filter layer is employed between the free layer and a capping layer for increasing the magnetoresistive coefficient dr/R of the spin valve sensor. A top portion of the free layer is oxidized for improving the negative ferromagnetic coupling field ?HFC when the spin filter layer is employed for increasing the magnetoresistive coefficient dr/R.

Abstract: A method of manufacturing a spin valve film, which produces a large read out signal. After a completion of a film making process for forming a previous film of two films to be formed successively, but before an initiation of a film making process forming a succeeding film of the two the films, a step of decreasing an anisotropic magnetic field of the spin valve film is introduced by interrupting a film making process. This step may be performed by keeping a substrate within a sputtering vacuum chamber. The interruption can be shortened by exposing the substrate to a plasma, transferring the substrate in a separate vacuum chamber whose degree of vacuum is lower or whose H2O or O2 concentration is higher than that in the sputtering vacuum chamber, conducting a surface treatment with a gas containing H2O or O2, or flowing a process gas.

Abstract: In an assembly method for a disk recording apparatus, a spindle motor is driven to rotate disks and with the disk recording apparatus supported by a linear guide mechanism for movement with one degree of freedom of translation in a direction substantially in parallel to surfaces of the disks. A measuring mechanism is used to measure vibration in the direction of the one degree of freedom of translation caused by the rotation of a rotating part of the disk recording apparatus. An angular position detecting mechanism is used to detect the angular position of each disk at which vibration of a maximum amplitude is generated. The eccentricity and the direction of eccentricity of the rotating part are analyzed in accordance with the measured vibration and the detected angular position, and the base and the rotating part are moved relatively to correct the eccentricity in accordance with the result of the analysis.

Abstract: A head stack assembly installation system with a frame supporting a head stack installation tool including a robotic assembly supporting a measurement assembly communicating with a computer hosting an installation software program. The robotic assembly picks and places the head stack assembly into the head disc assembly and the measurement assembly collects and communicates process positions and force parameters to the computer, the computer calculating distance and force data. The installation software program directs and controls enactment of process steps followed by the head stack installation tool to install or abort installation of the head stack assembly based on the position and force data.

Abstract: Embodiments include a method for adjusting the twist of an air bearing surface of at least one slider to substantially match a target values for twist, the at least one slider having a back surface opposite the air bearing surface, the back surface including two sets of diagonally opposite corner regions, with each set including one corner region adjacent to a leading edge of the slider and one corner region adjacent to a trailing edge of the slider. The method includes forming a first mechanical scribe on the back surface extending through at least a portion of the corner regions adjacent to the leading edge of the slider and forming a second mechanical scribe on the back surface extending through at least a portion of the corner regions adjacent to the trailing edge of the slider.

Abstract: A method of manufacturing a disk drive and a disk drive made with such method where the width of the read element and the width of the write element are both measured at servo-writing time and the track pitch of the disk drive is set on the basis of those measurements. Disk drives with superior head width combinations are servo-written with a narrower track pitch in order to have a higher storage capacity. Disk drives with inferior head width combinations are detected before servo-writing so that the disk drive may be servo-written with wider track pitch rather than with a nominal track pitch that results in a subsequent drive failure during initial burn-in (IBI). The heads are used more efficiently in that heads that are more capable are used to their ability and less capable heads that would otherwise be disposed of are used at all. Fewer disk drives are required to be reworked and returned to the servo-writing process.

Abstract: A method for shaping an ABS of a magnetic head slider including a step of holding at least one row bar with a plurality of aligned thin-film magnetic head elements by adhering a first surface of the at least one row bar to an adhesive or UV tape capable of passing a laser beam there through, the first surface being opposite an ABS of the at least one row bar, a step of shaping the ABS of the at least one row bar in a convex shape by radiating a laser beam to the first surface of the at least one row bar through the adhesive or UV tape, a step of cutting the at least one row bar into individual magnetic head sliders, and a step of then, removing the magnetic head sliders from the adhesive or UV tape after weakening adhesion properties of the adhesive or UV tape.

Abstract: Method for controlling installation of a head stack assembly in a disc drive. The head stack assembly is aligned in a head stack installation tool. A base deck assembly is advanced to the head stack installation tool, the base deck assembly having a post supporting a tolerance ring. A robotic assembly is dispatched to pick and press the head stack assembly onto the tolerance ring and post while mechanical resistance and distance traveled parameters by the head stack assembly are measured. The installation is aborted or completed in relation to the mechanical resistance encountered and the distance traveled, thus allowing use of minimum and maximum force thresholds with respect to insertion distance and assuring correct installation of the head stack assembly.

Abstract: In magnetic read heads based on bottom spin valves the preferred structure is for the longitudinal bias layer to be in direct contact with the free layer. Such a structure is very difficult to manufacture. The present invention overcomes this problem by using a liftoff technique to form, on the free layer, a buffer layer having a trapezoidal cross-section, sloping sidewalls, and a central area of uniform thickness, whose width defines the read track. A suitable bias layer and leads are then deposited on this buffer layer.

Abstract: A method of measuring variation in dimensions and alignment error of thin film magnetic heads formed on a raw bar cut-off from a substrate is provided. Such method comprises illuminating a MR element and a resistance detector element which is formed for monitoring a lapping process, both of which are formed on the raw bar, with illuminating light whose wavelength is 300 nm or less; forming an image by imaging light reflected from the elements; and converting the image to an image signal through photoelectric conversion so as to detect variation in dimensions of the MR element and the resistance detector element formed on the raw bar, and alignment error between the MR element and the resistance detector element with a high degree of accuracy.

Abstract: A method of measuring and adjusting at least one of a plurality of head suspension assemblies in a head stack assembly is provided, each head suspension assembly having a pivot axis, comprising the steps of stacking a plurality of head suspension assemblies with the pivot axis of each head suspension assembly aligned with the pivot axis of at least one adjacent head suspension assembly, wherein at least one of the head suspension assemblies is rotated about its pivot axis relative to at least one adjacent head suspension assembly so that all of the plurality of head suspension assemblies are not in vertical alignment, measuring at least one parameter of at least one head suspension assembly, then rotating each of the plurality of head suspension assemblies that are not in vertical alignment with the other head suspension assemblies about its pivot axis until the plurality of head suspension assemblies are vertically aligned.

Abstract: A data tape drive for recording information on the data tape of a tape cartridge has a transducer head with air bleed slots that define side walls, a tape guide, and a device for detecting damage to the transducer head and tape guide. The damage detection device has a conductor loop that is located along the outer edges of the air bleed slots and tape guide for detecting any brittle fracture damage that may be present. The conductor loop is a thin filament of wire that is preferably attached to the ends of the side walls. When the transducer head or tape guide experiences a fracture, such as a fracture in one of the side walls, the delicate filament breaks and forms an open circuit. The open circuit in the conductor loop is detected by the data tape drive so that remedial actions can be taken.

Abstract: A manufacturing method is provided for manufacturing a head material including: a plurality of rows of head-to-be sections to be thin-film magnetic heads; an inter-row cutting section provided to be a position at which adjacent ones of the rows are to be separated; and an intra-row cutting section provided to be a position at which adjacent ones of the head-to-be sections in each of the rows are to be separated. The method includes the steps of: providing a detection element to be used for detecting an amount of processing when specific processing is performed on the head material; an electrode for electrically connecting the detection element to an external device; and a conductor for electrically connecting the electrode to the detection element; and forming the electrode in the inter-row section.

Abstract: A method for determining a characteristic of a magnetic head during its fabrication process on the surface of a wafer substrate. The method involves the fabrication of a test magnetic pole artifact in a field area of the substrate surface adjacent to the actual magnetic pole that is being fabricated. A test pole structure is fabricated simultaneously with, and utilizing the same fabrication conditions and parameters as, the actual pole such that the test pole is nearly identical to the actual pole. During a field etch step undertaken in the fabrication of the actual pole, portions of the test pole structure are removed, leaving a test pole artifact on the wafer surface. The test pole artifact can thus be easily measured as an accurate indication of characteristics of the actual magnetic pole that are difficult to measure directly, thereby saving time and expense in the magnetic head fabrication process.

Abstract: The present invention provides an MR element bar that permits the fabrication of MR elements in which a variation in characteristics is suppressed, as well as an MR element bar exposure method and formation method enabling the fabrication of the MR element bar. The MR element bar exposure method according to the present invention comprises the steps of: detecting the positions of a plurality of alignment marks P1 to P4 formed on a wafer W; correcting an exposure position correction region R on the basis of the positions of detected alignment marks P1′ to P4′; and exposing a resist which is formed on the wafer W, wherein an MR element bar region B comprises a plurality of MR elements (patterns MRE) aligned in the longitudinal direction of the region B, and one exposure position correction region R is established for one MR element bar region B.

Abstract: A method of manufacturing a magnetic recording medium having a disc-shaped flexible slave medium accommodated in a case, onto which servo signals are effectively recorded by a magnetic transfer method with high quality. The method includes a slitting step for cutting an original sheet into discrete webs; a punching step for obtaining a disc-shaped slave medium; a thermo step for removing distortion; a burnishing step for smoothing a surface of the slave medium; a center core attachment step; a magnetic transfer step for performing a magnetic transfer while a master medium is allowed to be brought into close contact with one of the web and the slave medium; an assembly step for incorporating slave medium into the case; a cleaning step for cleaning a surface of the slave medium; a verifying step for checking the servo signals; and a packing step.

Abstract: A method of manufacturing a ferromagnetic tunnel junction element, having an insulating film, a first ferromagnetic film and a second ferromagnetic film, including a step of turning the ferromagnetic tunnel junction element on electricity for a given period before a practical operation of the ferromagnetic tunnel junction element, so that a resistance of the insulating film is stabilized.

Abstract: An automated production process for the screening of the read-width (RW) and/or the stripe-height (SH) for every magnetoresistive (MR) read sensor element in a wafer substrate. The method of this invention uses the RW and/or SH values found with optical examination by electron microscopy of several of the MR sensor elements to estimate two substrate coefficients that relates the optical RW and SH measurements to heating-delta measurements, &dgr;=(RH−RC)/RC, where RH is the sensor resistance when hot and RC is the sensor resistance when cold, both of which can be measured using automated equipment. These relationships are sufficiently similar among all MR sensor elements manufactured on a single wafer substrate during a single manufacturing procedure that, when the hot resistance RH is measured at a constant applied voltage, the heating-delta, may be used with a first substrate coefficient to estimate the read-width RW of each MR sensor element for quality-control purposes during manufacture.

Abstract: The present invention provides a method for improving the static attitude of a head suspension assembly by improving the manufacture of electrical interconnects by providing a laterally directed tension on the electrical interconnect during manufacture, thereby substantially inhibiting deformation of the gimbal region of the interconnect and the creation of non-planar slider standoffs.

Abstract: A spin valve sensor with a continuous junction is provided which has a sensor portion of a free layer longitudinally biased by first and second AFM biasing layers that are exchange coupled to first and second side portions of the free layer and a sensor portion of an AFM pinning layer that pins a sensor portion of a pinned layer perpendicular to the ABS in either a top spin valve or a bottom spin valve sensor.

Abstract: A magneto-resistive device with built-in test structure. The magneto-resistive device includes a slider having first and second lower termination pads and first and second upper termination pads. A first conductive trace element electrically couples the first lower termination pad to the first upper termination pad and a second conductive trace element electrically couples the second lower termination pad to said second upper termination pad. The magneto-resistive device also includes a magneto-resistive transducer deposited on the slider and the resistance of the magneto-resistive transducer is obtained by passing an electrical current between the first and second lower termination pads and measuring a voltage across the first and second upper termination pads.

Abstract: A head is fabricated using photolithography, and the head is purposely powered up during a material removal process, such as lapping, so that the head's expansion (that would be formed on being powered up during normal usage in a drive) is planarized. Specifically, the head is energized in a manner identical (or similar) to energization of circuitry in the head during normal operation in a drive, even though fabrication of the head has not yet been completed. When energized, a shape that the head would have during normal operation is replicated (or approximated). Therefore, the head's shape includes a expansion of the pole tip region, although the head is only partially fabricated. Thereafter, a portion of the head in the expansion is partially or completely removed, by lapping while energized. The depth of material removal from the head is monitored e.g.

Abstract: An apparatus and a method for calibrating the position of a wafer platform in an ion implanter, and particularly in a medium current ion implanter. The apparatus is constructed by a curvilinear piece formed in a half-circular shape, a pair of linear rods for supporting the curvilinear piece, and at least one cross-bracing rod connected in-between the pair of linear rods for providing rigidity of the apparatus. When the inside peripheral surface of the curvilinear piece intimately engages an outside peripheral surface of the wafer platform of the ion implanter, or when the first and second linear rods fit snugly on the implanter indicative that the wafer platform is properly calibrated at a zero-angle position. When such fitting is not possible, the wafer platform is then adjusted until a snug fitting is made possible.

Abstract: In a production process of an MR head using the tunnel junction film basically consisting of a free layer, a barrier layer, and a pinned layer, the resistance between the free layer and the pined layer reduced beforehand and increased afterward up to a resistance value necessary when actually used. While the resistance between the free layer and the pinned layer is low, current can easily flow, suppressing charge up, thus preventing insulation destruction of the barrier layer. This significantly increases a production yield of a recording/reproduction head using a ferromagnetic tunnel junction element.

Abstract: Thermal pole tip protrusion is caused by the materials in and around the head slider expanding during write operations till part of those materials protrude, leading to contact with the rotating disk surface, altering the flying height and often wearing down part of the disk surface. While it is well known that read-write heads expand during writing, the inventors are unaware of anyone else who recognized this situation's significance, particularly as the flying height decreases and the data rates increase, both of which are required for high areal density disk drives. The inventors realized that they could detect the problem at the spin stand level by testing head gimbal assemblies to reliably, and inexpensively, predict the tendency for thermal pole tip protrusion. This leads to selection of head gimbal assemblies, which do not have the thermal pole tip protrusion tendency.

Abstract: A method and computer program to calculate a reproduction track width of a MR head. This method begins by subdividing the magnetic domain control layer of a MR element and lead conductors into several polyhedral elements. Thereafter, electric potentials are calculated for each of the polyhedral elements based on the resistance at each layer. A current density is determined for each of the polyhedral elements based on the calculated electric potentials. The current densities are integrated to calculate an initial resistance value. Further, the resistance of a local block is changed by a predetermined amount. The electric potential is calculated for each of the polyhedral elements, current density is acquired, and the acquired current densities is calculated to determine a resistance value. Finally, the reproduction track width is obtained based on the initial acquired resistance value and the acquired resistance value.

Abstract: A system for manufacturing a thin-film magnetic head having a means for cutting a wafer into bars, each bar having a plurality of thin-film magnetic head sliders which are sequentially coupled with each other, a means for identifying the bar to be worked to generate an identification signal which indicates identity of said bar, a means for obtaining data of said bar in a unit of bar depending upon said identification signal, and a means for processing at least one working of said bar on the basis of said obtained data of said bar.

Abstract: A magnetic head positioning apparatus for adjusting the position of a head member relative to its support member by determining the boundary lines for the edge portion of the head body and the center of the pivot in the support member. Luminance variations near the boundary line between areas different in light reflections are derivated so as to determine the position of the boundary line with a high accuracy at a distance shorter than the unit block pitch of the camera photodetectors used to detect the image of the head body and the support member.

Abstract: A disk drive recording device comprises at least two platters for storing magnetic recording data and a spindle motor rotating at high speed for mounting the platters. The disk drive is assembled by using pushing devices to push the platters toward the center of the spindle motor in respective directions to bring a portion of an inside circumference of a concentric center hole of each of the platters in contact with an outer circumference of the spindle motor so that the center of gravity of each platter coincides with a center axis of the spindle motor.

Abstract: An aerodynamic slider has at least one side surface that is continuously curved between the leading and trailing surfaces to substantially eliminate off-track forces on the side surface due to changing skew orientations. A slider profile is modeled, and a numerical simulation of airflow on the modeled profile is generated for each of a plurality of skew orientations within a range of skew orientations at which the slider will fly. The modeled slider profile is repeatedly adjusted based on the numerical simulations until a vibration analysis on the modeled profile indicates vibration does not exceed a predetermined minimum.

Abstract: The present invention relates to the method of optimizing of planar type write heads for ultra high density magnetic recording. More particularly, the invention relates to a planar type write head for an ultra high density drive which can record information on a medium with high magneto-crystalline anisotropy.

Abstract: A method for assembling a disk drive using a multifunctional push-pin hole is disclosed. A push-pin of a servo writer is directed through the push-pin hole of the disk drive for executing a servo writing operation. The push-pin is withdrawn from the push-pin hole at the completion of the servo writing operation. A filter is disposed within the push-pin hole so as to be disposed within an interior of the disk drive. This filter may provide one or more of a humidity control/adjustment function and a chemical filtering function (e.g., an integrated chemical filter). Moreover, this filter may work as a sound barrier. That is, this filter may be used to reduce sound intensity outside the disk drive on top of the push-pin hole in relation to those prior art push-pin holes which were sealed by only a piece of tape on an exterior surface of the disk drive.

Abstract: Methods for adjusting the curvature of a slider may include providing a first slider including an air bearing surface and a back surface opposite the air bearing surface. The camber and crown of the first slider are measured, and a plurality of scribes are made at positions on the back surface of the first slider. The change in camber and crown due to each scribe on the first slider is measured. The scribe position and change in crown and camber per position is recorded in a data structure. A second slider is provided, the second slider including an air bearing surface and a back surface opposite the air bearing surface. The camber and crown of the second slider are measured. A desired amount of change in crown and camber is determined. Scribe positions are selected based on information from the data structure so that the desired amount of change in crown and camber will be obtained. The back surface of the second slider is scribed at the selected scribe positions.

Abstract: To measure positions of a plurality of thin film magnetic head elements formed in a line on a bar, the quantity of positions of samples in the bar is estimated from the magnetic head elements the amount of deviation in position of the next element, and the distance between the elements are obtained, and the amount of deviation and distance are estimated by a primary approximate linear or several-order approximate curve. The estimated amount and the distance between the elements are moved simultaneously, and an image formed by a lens optical system is photo-converted to an image signal, and dimensions are computed. The conversion step is carried out immediately after movement of the next element and is continuously repeated, and the computing step is processed in parallel with the conversation step.

Abstract: A head slider of a suspension supports a read/write head for data transfer to and from a data storage disk. A mounting structure is conventionally used for holding the suspension. A positioning finger applies a force to the suspension for and thereby positions a head slider to a static height for simulating the “flying” action of the head slider in the data storage device. A measuring device measures the static height of the head slider and transmits the same to a controller which generates a control strategy for positioning the head slider of the suspension to the fly-height. An embodiment of the invention uses a common mounting assembly for receiving a plurality of suspensions. The use of a common positioning assembly for simultaneously positioning the head sliders of the plurality of suspensions substantially reduces time consumed and improves efficiency.

Abstract: A device and method for testing a slider of a head-gimbal assembly during disc drive manufacturing. The device includes a test disc, an actuator arm and a control module. The test disc has a first circumferential area for detecting contact between the slider and the test disc and a second circumferential area for burnishing sliders that contact the first circumferential area as the test disc rotates at or above the predetermined velocity. The head-gimbal assembly is affixed to a support, or flexure, on the actuator arm such that the slider is operable to move between an inner diameter and an outer diameter of the test disc. The control module controls rotation of the test disc and movement of the actuator arm, and thus the slider, relative to the test disc. The control module monitors the slider-disc interface for contact therebetween. If contact is detected, the slider is either burnished or the head-gimbal assembly is discarded altogether.

Abstract: An apparatus for adjusting curvature of a disc head slider having a bearing surface is provided. The apparatus includes a light source and an apparatus for controlling the light source. The light source is adapted to produce a light beam capable of altering material stresses in a working surface of the slider. The apparatus for controlling the light source is adapted for obtaining a measure of first and second curvature characteristics of the bearing surface and for scanning the light beam across the working surface in a pattern to alter the material stresses in the working surface such that the first and second curvature characteristics move to within predetermined specifications. The pattern is based on the measures of the first and second curvature characteristics and estimates of responses in the first and second curvature characteristics to the pattern.

Abstract: A method for producing magnetoresistive heads includes the steps of placing a substrate having a plurality of transducers in an environment including a focused ion beam. The focused ion beam is directed onto the first MR element. A property level, generally the resistance associated with the MR stripe, of the first MR element is monitored until the resistance reaches a desired level. The focused ion beam is redirected onto a second area of the substrate which includes the second MR element. The electrical resistance of the second MR element is monitored as the focused ion beam acts on the second MR element until the resistance of the MR element reaches a desired level. Using this process, the resistivity of individual MR elements within the substrate can be tightly controlled.

Abstract: Methods are provided for adjusting flying characteristics of magnetic recording media, e.g., sealed disk drives. Adjustment may be made by changing at least one environmental condition within the drive enclosure of the disk drive prior to sealing. Alternatively, adjustment may be made by changing the speed of the disk drive, i.e., the speed at which the disk spins. Methods are also provided for error correction within sealed disk drives.

Abstract: A method for improving the operational performance of a disc drive through the identification of vital product information associated with a head-disc assembly (HDA) of the disc drive. The disc drive comprises a printed wiring assembly (PWA) housing control circuitry for the disc drive. The HDA of the disc drive is operably coupled to the printed wiring assembly and includes a rotatable disc to which data are written by a controllably positionable head. A non-volatile memory device is mounted on the HDA and operably coupled to the PWA so that, when the disc drive is initialized, the PWA verifies the configuration of the HDA before proceeding with the initialization of the disc drive, thereby preventing errors and damage to the disc drive as a result of the installation of a new, replacement PWA in the disc drive, or the downloading of new, incorrect firmware to the PWA.

Abstract: The invention includes a method and apparatus repairing read heads of a merged magnetoresistive read-write head without the use of external magnets nor the exclusive use of read bias current to heat the read head.

Abstract: A manufacturing method is provided for manufacturing thin film magnetic heads through the use of a thin-film magnetic head material, the head material including: a plurality of rows of head-to-be sections to be thin-film magnetic heads; an inter-row cutting section provided to be a position at which adjacent ones of the rows are to be separated; and an intra-row cutting section provided to be a position at which adjacent ones of the head-to-be sections in each of the rows are to be separated.

Abstract: A media rework tool for discs and/or a spindle motor carrying a disc pack is disclosed that has a slider plate mounted on a base for lateral movement between a retracted position and an extended position. The slider plate holds a spindle motor with a disc pack mounted on it, and moves between the two positions. The tool includes a gripper assembly having a plurality of opposing arms for grasping predetermined discs within a disc pack on the spindle motor when the slider plate is in the retracted position. The gripper assembly raises the predetermined discs and any intermediate spacer rings upward for temporary storage on a media guide to allow the remainder of the disc pack to be reworked, such as for replacement of a defective disc or spindle motor when the slider plate is laterally moved to the extended position. Following reworking of the remainder of the disc pack, the spindle motor is returned to its centered position relative to the media guide and the gripper assembly.

Abstract: A process of forming a combination-type thin film magnetic head on a wafer is disclosed wherein plural polished amount-monitoring elements are formed at the same time as formation of the members which constitute the inductive-type thin film magnetic head. The plural polished amount-monitoring elements each have a different distance from the inside edge opposite to he air bearing surface of the joined surface between a pair of electrode members to the standard position of the zero-throat height. After the magneto-resistive-effective-type thin film magnetic head is formed, the wafer is cut into plural bars, each having plural arranged combination type thin film magnetic head units.

Abstract: In assembling a disk recording apparatus, a spindle motor is driven to rotate disks and with the disk recording apparatus supported by a linear guide mechanism for movement with one degree of freedom of translation in a direction substantially in parallel to surfaces of the disks. A measuring mechanism is used to measure vibration in the direction of the one degree of freedom of translation caused by the rotation of a rotating part of the disk recording apparatus. An angular position detecting mechanism is used to detect the angular position of each disk at which vibration of a maximum amplitude is generated. The eccentricity and the direction of eccentricity of the rotating part are analyzed in accordance with the measured vibration and the detected angular position, and the base and the rotating part are moved relatively to correct the eccentricity in accordance with the result of the analysis.

Abstract: A method and system for the rapid automatic screening of GMR heads for Barkhausen noise during production. This system rapidly and repeatedly measures associated noise in a GMR head subjected to a smoothly-varying external transverse magnetic field. The repeated Transverse Magnetic-field Excited Noise (TMEN) measurements are automatically sorted into bins to form a histogram, which is then automatically evaluated to develop TMEN range and weighted sum measures, which are then compared with predetermined standards for automatic acceptance or rejection of the GMR head under test. The GMR sensor Barkhausen noise is quantified through the use of a bandpass filter to remove all direct sensor responses, leaving only the noise signals, which are then repeatedly sampled to develop valid statistical Barkhausen noise measures suitable for automated analysis.

Abstract: The present invention relates to a head tester for testing heads having a read element and a write element. The tester comprises a substrate on which a read coil is positioned to be sensitive to the write element of the head. A write coil is also formed on the substrate and this coil is positioned such that the read element of the head to be tested is sensitive to the write coil.