Abstract: A wafer manufacturing method, an epitaxial wafer manufacturing method, and a wafer and epitaxial wafer manufactured thereby, are provided. The wafer manufacturing method enables the manufacture of a wafer with a low density of micropipe defects and minimum numbers of particles and scratches. The epitaxial wafer manufacturing method enables the manufacture of an epitaxial wafer that has low densities of defects such as downfall, triangular, and carrot defects, exhibits excellent device characteristics, and improves the yield of devices.

Abstract: A wafer manufacturing method, an epitaxial wafer manufacturing method, and a wafer and epitaxial wafer manufactured thereby, are provided. The wafer manufacturing method enables the manufacture of a wafer with a low density of micropipe defects and minimum numbers of particles and scratches. The epitaxial wafer manufacturing method enables the manufacture of an epitaxial wafer that has low densities of defects such as downfall, triangular, and carrot defects, exhibits excellent device characteristics, and improves the yield of devices.

Abstract: This application discloses a hard disk drive, a head stack assembly, and a printed circuit board configured to include impedance patches on the flex ground plane, the flex power plane, the printed circuit ground plane and/or the printed circuit power plane over or under a connector site in the disk base that conveys access read and write differential signals for the sliders' access of rotating disk surfaces. These impedance patches minimize impedance discontinuities in the read and/or write differential signals through the connector site, which may improve the ability of the hard disk drive to transmit these signals at higher frequencies.

Abstract: This application discloses a hard disk drive, a head stack assembly, and a printed circuit board configured to include impedance patches on the flex ground plane, the flex power plane, the printed circuit ground plane and/or the printed circuit power plane over or under a connector site in the disk base that conveys access read and write differential signals for the sliders' access of rotating disk surfaces. These impedance patches minimize impedance discontinuities in the read and/or write differential signals through the connector site, which may improve the ability of the hard disk drive to transmit these signals at higher frequencies.

Abstract: A hard disk drive is disclosed with a slider containing a Flying height On Demand (FOD) heater using two heater sheets configured to be driven by electric currents flowing in essentially opposite directions, causing the magnetic field induced by the FOD heater to be much smaller than prior art FOD heaters using just one sheet with a single current direction. Also disclosed are the slider, the head gimbal assembly, and the head stack assembly, where both assemblies include at least one instance of the slider. Also disclosed, the methods of operating the hard disk drive and the slider and making the slider, the head gimbal assembly, the head stack assembly and the hard disk drive.

Abstract: A hard disk drive is disclosed with a slider including a wide track eraser for erasing neighboring tracks and the servo patterning around a track on the accessed disk surface. Using the wide track eraser reduces the time to erase a disk surface by at least a factor of N, where N is at least 4, and may preferably be successively larger to at least 64. Embodiments include the slider, a head gimbal assembly, a main flex circuit, an integrated circuit for the main flex circuit for stimulating the wide track eraser, a head stack assembly including the main flex circuit coupling through the head gimbal assembly to the wide track eraser, a control circuit, and a processor within the control circuit controlling the stimulus of the wide track eraser to erase part or all of a disk surface.

Abstract: A slider comprising a platinum layer including a first end and a second end, where slider temperature may be estimated based upon the platinum layer resistance. A head gimbal assembly including the slider. A head stack assembly including the head gimbal assembly. A preamplifier including an analog to digital converter for measuring the platinum layer resistance. An embedded circuit for electrically coupling to the head stack assembly to use the platinum layer to successively estimate slider temperature and estimate head disk impact events and maintain a head disk impact count. A hard disk drive including the slider and measuring the resistance of the platinum layer to estimate slider temperature and/or head disk impact events and increment and maintain a head disk impact count.

Abstract: Operating a write head by slew rate determining a slew rate control based upon a slew rate and the track being written and controlling the write current waveform based upon the slew rate control for the write head to write data to the track on disk surface. An embedded circuit supporting these operations. Hard disk drive including the embedded circuit electrically coupled to preamplifier driving the write head based upon the write current waveform. Methods of manufacturing the embedded circuit and the hard disk drive, and the products of these processes.

Abstract: A head protection circuit that protects a write head and a magnetoresistive (MR) read head by bypassing electrostatic charge applied to the write head when the power of a preamplifier is turned “off” includes: a first differential mode switch and a first differential mode resistance connected between each end of the write head; and a first common mode switch and a first common mode resistance connected between one end of the write head and a ground potential. The first differential mode switch and the first common mode switch installed in the preamplifier are turned “on” when the preamplifier is turned “off” and vice versa. The head protection circuit has an effect of protecting the write head and the MR read head by bypassing common mode electrostatic charge and differential electrostatic charge generated at the ends of the write head when the preamplifier is turned “off.

Abstract: An interconnect for connecting a magnetic head slider and a flexible printed circuit, and a head gimbal assembly having the interconnect are provided. The interconnect includes a ground layer, a first insulation layer formed on the ground layer, and a pair of signal transferring layers formed on the first insulation layer and spaced apart from each other, in which the ground layer has an outer ground layer portion formed at an outside of the pair of signal transferring layers and not superposed on the pair of signal transferring layers, and an inner ground layer portion formed between the pair of the signal transferring layers.

Abstract: A head protection circuit that protects a write head and a magnetoresistive (MR) read head by bypassing electrostatic charge applied to the write head when the power of a preamplifier is turned “off” includes: a first differential mode switch and a first differential mode resistance connected between each end of the write head; and a first common mode switch and a first common mode resistance connected between one end of the write head and a ground potential. The first differential mode switch and the first common mode switch installed in the preamplifier are turned “on” when the preamplifier is turned “off” and vice versa. The head protection circuit has an effect of protecting the write head and the MR read head by bypassing common mode electrostatic charge and differential electrostatic charge generated at the ends of the write head when the preamplifier is turned “off.

Abstract: The invention includes at least one head arm providing head electrical interconnection as essentially parallel traces on at least one face of the head arm using the metallic body of the head arm as a ground plane. This insures that the neighboring pairs of parallel traces used for differential read and write interconnection have essentially matched impedance, lowering crosstalk between the write and read signal pairs. The invention includes voice coil actuator arms comprising at least one of these head arms, as well as, disk drives made using these voice coil actuator arms.

Abstract: The invention includes operating a merged read/write head in a disk drive by determining both the maximum read bias current and maximum write current, based upon the measured read resistance of the read mechanism and the write current in use with the write mechanism. Both the read mechanism and write mechanism are near each other in the merged read/write head.

Abstract: A single flex interconnection circuit bonds to a connector, to electronic components including at least preamplifier, and to at least one MR read-write head. The flex interconnection circuit provides the least number of bonds for each of the lines involved. The least number of bonds provides the least parasitic capacitance and inductance on these lines. The method of making the flex interconnection circuit requires the least number of bonding steps, minimizing the manufacturing cost. The invention includes the flex interconnection substrate, flex interconnection circuit built on the substrate, the actuator and disk built from the flex interconnection circuit.

Abstract: A single flex interconnection circuit bonds to a connector, to electronic components including at least preamplifier, and to at least one MR read-write head. The flex interconnection circuit provides the least number of bonds for each of the lines involved. The least number of bonds provides the least parasitic capacitance and inductance on these lines. The method of making the flex interconnection circuit requires the least number of bonding steps, minimizing the manufacturing cost. The invention includes the flex interconnection substrate, flex interconnection circuit built on the substrate, the actuator and disk built from the flex interconnection circuit.

Abstract: A test system and method determining performance of a merged magnetoresistive read-write head based upon operating the write inductive head of the merged read-write head, measuring the resistance of the read head under certain read current bias conditions and finding which read heads have been damaged by ESD.

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: The invention includes operating a merged read/write head in a disk drive by determining both the maximum read bias current and maximum write current, based upon the measured read resistance of the read mechanism and the write current in use with the write mechanism. Both the read mechanism and write mechanism are near each other in the merged read/write head.

Abstract: The invention includes at least one head arm providing head electrical interconnection as essentially parallel traces on at least one face of the head arm using the metallic body of the head arm as a ground plane. This insures that the neighboring pairs of parallel traces used for differential read and write interconnection have essentially matched impedance, lowering crosstalk between the write and read signal pairs. The invention includes voice coil actuator arms comprising at least one of these head arms, as well as, disk drives made using these voice coil actuator arms.