Abstract: The method of manufacturing a magnetic head comprises the steps of: forming a plurality of layers, which are made from prescribed materials, on a substrate; and forming a plurality of magnetic head elements 12 on the substrate. Using a first ELG element 20, whose size in a prescribed direction is bigger than that of the magnetic head elements 12, and a second ELG element 22, whose size is equal to that of the magnetic head elements, on the substrate, a work piece is lapped, while monitoring resistance of the first ELG element 20 when the resistance of the first ELG element 20 reaches a prescribed value, the amount of lapping the work piece is adjusted on the basis of resistance of the second ELG element 22. Thus, a bar-shaped member can be precisely lapped, the magnetic heads can be manufactured without scattering their characteristics, and yield rate of manufacturing can be improved.

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 present a manufacturing method of a magneto-resistive effect type head capable of manufacturing a magneto-resistive effect type head with stabilized head characteristics. A magneto-resistive effect type head is manufactured in a method comprising a step of forming a magneto-resistive effect film (30) in a trapezoidal shape (30A) having a specified abutting angle &thgr;1 by means of ion milling through a resist mask of overhang structure, a step of forming bias magnet films (31) for filling in sides of the magneto-resistive effect film (30), and a step of forming an electrode film (33) to overlap partly with the magneto-resistive effect film (30) through the resist mask. The angle of the ion milling is 5° or less to the normal of the substrate surface. The angle of ion beam sputtering when forming the electrode film (33) is 30° or less to the normal of the substrate surface.

Abstract: Within a method for forming a magnetoresistive (MR) sensor element there is first provided a substrate. There is then formed over the substrate a first magnetoresistive (MR) layer having formed contacting the first magnetoresistive (MR) layer a magnetically biased first magnetic bias layer biased in a first magnetic bias direction with a first magnetic bias field strength. There is also formed separated from the first magnetoresistive (MR) layer by a spacer layer a second magnetoresistive (MR) layer having formed contacting the second magnetoresistive (MR) layer a magnetically un-biased second magnetic bias layer.

Abstract: In fabricating magnetic heads on a wafer surface, magnetoresistive sensors having two different stripe heights and the same stripe width are formed. Additionally, two different electronic lapping guides (ELGs) having different stripe heights and the same stripe width are also formed. While the design widths and heights of the sensors and ELGs are known, the actually fabricated widths and heights of the sensors and ELGs is unknown, due to the windage in the fabrication process. In the present invention, to determine the actual track width of the sensors, the change in electrical resistance of the sensors and ELGs is experimentally determined during the application of a magnetic field to the sensors and ELGs. Through a mathematical analysis, the actual track width of the fabricated sensors is determined utilizing the design widths and heights of the sensors and ELGs, together with the experimentally determined changes in electrical resistance of the sensors and ELGs.

Abstract: A method for forming metrology structures on a wafer on which magnetic transducers are being fabricated is disclosed. The metrology structures have a measurable electrical resistance which is an accurate surrogate for a physical dimension of a structure of the magnetic transducer, such as a pole piece tip. The metrology structure is preferably a resistor with pads usable with a four point probe. The resistor is preferably formed by creating a sacrificial pole piece structure over a pad of resistive material. The narrow dimension of the pole tip is then used as a mask to replicate the width of the pole tip in the resistive material through a milling process which removes resistive material outside of the masked area of the resistor pad. Control structures with unmilled pads of resistive material are formed along with the metrology structures to provide the sheet resistance of the pads prior to milling.

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: A writing magnetic pole portion composed of a first magnetic film and a second magnetic film formed on the first magnetic film via a gap film is fabricated on a given wafer. Then, the writing magnetic pole portion is swung forward and backward around a rotation standard axis parallel to a center line of the writing magnetic pole portion in a direction parallel to a surface of the. Then, the writing magnetic pole portion is milled during the swing of the writing magnetic pole portion to define the width of the writing magnetic pole portion.

Abstract: A magnetoresistive device comprises: an MR element; two bias field applying layers that apply a longitudinal bias magnetic field to the MR element; and two electrode layers that are located adjacent to one of the surfaces of each of the bias field applying layers and overlap one of the surfaces of the MR element. The MR element incorporates a protection layer located on a soft magnetic layer. In the method of manufacturing the magnetoresistive device, a coating layer that will be removed in a later step is formed on the protection layer in advance. Before forming the electrode layers, the coating layer and an oxide layer that is formed through natural-oxidizing part of the top surface of the coating layer are removed through etching. After the electrode layers are formed, the portion of the protection layer located in the region between the two electrode layers is oxidized, and a high resistance layer is thereby formed.

Abstract: A method for manufacturing a disk drive includes assembling the head disk assembly in a clean room, performing servo writing upon the head disk assembly in the clean room, and performing a head disk assembly test upon the head disk assembly in the clean room. The head disk assembly is then connected to the controller printed circuit board assembly to form a drive-under-test. The drive-under-test is then transported to an integrated test system and electrically connected thereto. The integrated tests system then performs substantially all of the required manufacturing tests upon the drive-under-test, thereby substantially reducing the labor and floor space associated therewith.

Abstract: Longitudinal edges of an actuator arm are provided with stiffening elements in order to raise natural resonant frequencies of the arm so as to prevent resonance from occurring. The stiffening element is shaped and positioned so as to be able to individually “tune” the natural resonant frequency of a given bending mode without significantly affecting the natural frequencies in other bending modes.

Abstract: The present invention is 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 the actual pole utilizing the same fabrication conditions and parameters, 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 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: An apparatus and method 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: In fabricating magnetic heads on a wafer surface, magnetoresistive sensors having two different stripe heights and the same stripe width are formed. Additionally, two different electronic lapping guides (ELGs) having different stripe heights and the same stripe width are also formed. While the design widths and heights of the sensors and ELGs are known, the actually fabricated widths and heights of the sensors and ELGs is unknown, due to the windage in the fabrication process. In the present invention, to determine the actual track width of the sensors, the change in electrical resistance of the sensors and ELGs is experimentally determined during the application of a magnetic field to the sensors and ELGs. Through a mathematical analysis, the actual track width of the fabricated sensors is determined utilizing the design widths and heights of the sensors and ELGs, together with the experimentally determined changes in electrical resistance of the sensors and ELGs.

Abstract: A method for forming metrology structures on a wafer on which magnetic transducers are being fabricated is disclosed. The metrology structures have a measurable electrical resistance which is an accurate surrogate for a physical dimension of a structure of the magnetic transducer, such as a pole piece tip. The metrology structure is preferably a resistor with pads usable with a four point probe. The resistor is preferably formed by creating a sacrificial pole piece structure over a pad of resistive material. The narrow dimension of the pole tip is then used as a mask to replicate the width of the pole tip in the resistive material through a milling process which removes resistive material outside of the masked area of the resistor pad. Control structures with unmilled pads of resistive material are formed along with the metrology structures to provide the sheet resistance of the pads prior to milling.

Abstract: A method for manufacturing a magnetic encoder is disclosed, wherein the magnetic encoder may be used with a sensor on a semiconductor sensor chip that may be placed opposite the magnetic encoder, and is capable of providing codes as represented by a sequence of pulses generated by the magnetic forces. According to the method, an unvulcanized raw rubber is provided, to which a magnetic ferrite powder is added. The resulting mixture composed of the unvulcanized raw rubber and magnetic ferrite powder is then passed through a rolling machine or an extruding machine where the mixture is formed into a sheet blank that contains the magnetic ferrite powder aligned regularly in a particular orientation, or alternatively may be passed through the extruding machine, followed by being passed through the rolling machine, where the mixture is formed into a sheet blank that contains the magnetic ferrite powder aligned regularly in the particular orientation.

Abstract: Providing a method for manufacturing magneto-resistive effect type magnetic heads which can suppress the electrostatic destructions due to the ESD and EOS, and can properly manufacture magneto-resistive effect type magnetic heads without deteriorating characteristics. In a layered type magnetic head forming step S1, a short circuit pattern for making a short circuit in the element circuit of an MR head is formed. And the short circuit pattern is cut off before a fine polishing step S4, or at a wafer bar cutting off step S6.

Abstract: A method and apparatus for processing a magnetic disc prior to assembly of the disc in a disc drive storage assembly includes measuring a physical characteristic of the magnetic disc and encoding an information pattern within the magnetic disc. The information pattern is associated with the measured physical characteristic.

Abstract: Disclosed is a magnetic head manufacturing method for accurately measuring resistance value whereby magnetic heads are processed while measuring the resistance values of process monitoring element. After forming on a wafer magnetic head elements and monitoring element, in which resistance values change in analog fashion in line with processing, these elements are cut from the wafer. Next, the magnetic heads are processed to a prescribed height while measuring the resistance values of the monitoring element. In the forming process, the difference &Dgr;I between the positions of the magnetic head elements and monitoring element is measured in advance, and this difference &Dgr;I is used to convert the resistance values of the monitoring element to the height of the magnetic head elements. This makes it possible to correct errors in masks. Furthermore, patterns can be formed accurately by setting the position of the monitoring element to the same position as the magnetoresistive film of the magnetic heads.

Abstract: A method for manufacturing a disk drive includes assembling the head disk assembly in a clean room, performing servo writing upon the head disk assembly in the clean room, and performing a head disk assembly test upon the head disk assembly in the clean room. The head disk assembly is then connected to the controller printed circuit board assembly to form a drive-under-test. The drive-under-test is then transported to an integrated test system and electrically connected thereto. The integrated tests system then performs substantially all of the required manufacturing tests upon the drive-under-test, thereby substantially reducing the labor and floor space associated therewith.

Abstract: With negative pressure sliders having step bearings, there are variations in flying height resulting from variations in shape factors, such as the step bearing depth. In order to achieve lower flying height, it is considered necessary to reduce the variation in flying height caused by the variation in curvature of the air bearing surface and the variation in flying height caused by the variation in the shapes of the step bearings. The curvature of the air bearing surface of the slider can be observed in the pre-cut row bar condition or in a unit product condition. Shape data of the magnetic head slider can be input, such as the step bearing depth, etc., so as to calculate the predicted flying height of the slider An arithmetic processing unit calculates an adjusted target curvature from the difference between the predicted flying height and the target flying height.

Abstract: With negative pressure sliders having step bearings, there are variations in flying height resulting from variations in shape factors, such as the step bearing depth. In order to achieve lower flying height, it is considered necessary to reduce the variation in flying height caused by the variation in curvature of the air bearing surface and the variation in flying height caused by the variation in the shapes of the step bearings. The curvature of the air bearing surface of the slider can be observed in the pre-cut row bar condition or in a unit product condition. Shape data of the magnetic head slider can be input, such as the step bearing depth, etc., so as to calculate the predicted flying height of the slider An arithmetic processing unit calculates an adjusted target curvature from the difference between the predicted flying height and the target flying height.

Abstract: A magnetic head slider with at least one thin-film magnetic head element on a suspension is mounted. This mounting includes electrically connecting the magnetic head slider with the suspension with ball bonding connections. Electrical property of the thin-film magnetic head element is inspected, and then the ball bonding connections are separated when it is judged that the thin-film magnetic head element has defective electrical property. Then, the magnetic head slider is detached from the suspension, and thereafter a new magnetic head slider with at least one thin-film magnetic head element is mounted on the suspension from which the magnetic head slider was detached.

Abstract: Methods and apparatus are described relating to an electronic device which includes at least one configurable resistive element. Each such configurable resistive element includes at least one multi-layer thin film element exhibiting giant magnetoresistance. The resistance value of each configurable resistive element is configurable over a resistance value range by application of at least one magnetic field which manipulates at least one magnetization vector associated with the thin film element. One embodiment is an adjustable output gate. Another embodiment is a differential amplifier in which the gain of each channel is adjustable.

Abstract: Herein is disclosed a method and apparatus for controlling a lapping process, so as to create a read/write head that contains a primary magnetoresistive read element with a desired stripe height. An improved lapping guide is achieved by incorporating a secondary magnetoresistive element into a read/write head. By virtue of its location on the same read/write head as a primary magnetoresistive element (used for reading data during operation of the disc drive), the secondary element is located in close proximity to the primary element, resulting in smaller tolerances in aligning or relating the top edges of the primary and secondary elements. Accordingly, the secondary magnetoresistive element more reliably serves as a proxy for the primary element. Optionally, the secondary magnetoresistive element may be fashioned with identical dimensions as the primary element, so as to render the secondary element equivalent to the primary element with regard to magnetic sensitivity.

Abstract: In detecting a boundary line between areas different in light reflectance, it has so far been impossible to specify the boundary line at a distance shorter than the arrangement pitch of photodetectors (pixels) arranged in the camera. In the present invention, luminance variations near the boundary line between areas different in light reflectance are derivated. Further, in unit blocks G corresponding to pixels and arranged in a direction (Y direction) in which the boundary line extends, derivated values of luminance for each row of unit blocks are added and then a variation curve of the added values of derivated luminance values in unit block rows is drawn to specify a peak position thereof and also specify the position of the boundary line X0. Thus, it is possible to specify the position of the boundary line with a high accuracy at a distance shorter than the unit block pitch.

Abstract: A method for controlling a machining process of a workpiece includes a step of measuring amounts of machining of the workpiece by a plurality of sensors located at different positions on the workpiece, the sensors providing detection signals which represent the respective measured amounts, a step of removing the detection signal when the detection signal has an abnormal value which is extremely different in comparison with values of the other detection signals by using a smoothing method, and a step of controlling the machining of the workpiece depending upon the remaining detection signals from the sensors.

Abstract: A method for adjusting the curvature of an air bearing surface (ABS) of a slider having a back surface opposite the ABS. The method includes steps of repeatedly measuring the curvature of the ABS and scribing lines (e.g. with a laser scribing tool) on the back surface to partially adjust the curvature of the ABS. In each measuring/scribing installment, the curvature of the ABS is measured and compared with a final target curvature to determine a curvature difference between the measured curvature and final target curvature. Each installment of scribing lines corrects for a predetermined percentage of the curvature difference. The predetermined percentage may be different in succeeding installments. Alternatively, each installment changes the curvature of the slider to match an intermediate target curvature. In a three-installment process, for example, there will be two intermediate target curvatures and a final target curvature.

Abstract: A number of transducers are produced on a substrate, the transducers positioned on the substrate in non-linear rows. The substrate is then sliced into rows. Each row is then lapped with a curved lapping plate. Finally, each row is sliced into individual sliders, each slider now having an air bearing surface with non-zero camber.

Abstract: A magnetic signal reproducing apparatus which can lessen fluctuation of reproduced outputs in reproducing magnetic signals recorded in a magnetic tape by a magneto-resistance effect type magnetic head even if a magnetic tape sliding face of the magneto-resistance effect type magnetic head is abraded. A current value of a sense current when a voltage fluctuation level of the sense current caused when a magnetic field in the normal direction is applied to a magneto-resistance effect element of the magneto-resistance effect type magnetic head is equal with a voltage fluctuation level of the sense current caused when a magnetic field in the opposite direction is applied thereto is set to a predetermined value I0. Then, the current value of the sense current supplied to the magneto-resistance effect element of the magneto-resistance effect type magnetic head is set to be greater than I0 in reproducing the magnetic signals recorded in the magnetic tape.

Abstract: A method of manufacturing a disk drive which includes a disk having first and second magnetic surfaces and first and second read/write transducers for writing information on and reading information from the magnetic surfaces. The method includes determining a track width performance characteristic to be measured for the read/write transducers, establishing ranges of values for the performance characteristic to define a plurality of performance groups. The performance characteristic is measured for a plurality of read/write transducers from which the first and second read/write transducers for the disk drive are to be selected and the read/write transducers are segregated into groups based on the performance characteristic value falling within the range of the group. The disk drive is assembled using read/write transducers from only one of the groups. The measurement of the performance characteristic is accomplished either electrically or optically.

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

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

Abstract: In this method of manufacturing magnetic head elements, the width of the ELG elements can be narrower and the number of magnetic head elements manufactured can be increased. The method includes the steps of: lapping a bar-shaped member in which magnetic head element sections and ELG elements are alternately formed; monitoring resistance of the ELG elements; and removing the ELG elements so as to divide the bar-shaped member into a plurality of the magnetic head element sections. A lead layer of each ELG element is connected to the nearest inner lead layer of the adjacent magnetic head element section, and a connecting pad is connected to a pad for monitoring the ELG element. Terminal pillars in the lead layers act as a common terminal pillar of the magnetic head element section and the ELG element.

Abstract: According to a method of manufacturing a magnetic head, a magnetoresistive device is formed on a substrate, a top end portion of the magnetoresistive device is placed in an external magnetic field, and a height of the magnetic head is adjusted by ceasing a polishing operation at an instant when change in resistance of the magnetoresistive device relative to change in the external magnetic field comes up to a predetermined value.