Abstract: The invention includes a testing method which may be applied to at least one writer in a disk drive during the self-test phase to generate write parameters, focused on the Over Shoot Control (OSC) of the write current parameter to improve the reliability of write operations by that writer. The Minimum OSC is used for write operations in normal temperatures. The Optimum OSC is used for a first lower temperature range, preferably between essentially 15° Centigrade and essentially 5° Centigrade. The Maximum OSC is preferred below essentially 5° C. The Minimum OSC should preferably guarantee both an Adjacent Track Write (ATW) criteria, as well as guarantee a Write Induced Instability (WII) criteria. The invention includes the write parameter collection, as well as the disk drive containing the generated write parameter collection.

Abstract: The invention includes a testing method which may be applied to at least one writer in a disk drive during the self-test phase to generate write parameters, focused on the Over Shoot Control (OSC) of the write current parameter to improve the reliability of write operations by that writer. The Minimum OSC is used for write operations in normal temperatures. The Optimum OSC is used for a first lower temperature range, preferably between essentially 15 degrees Centigrade and essentially 5 degrees Centigrade. The Maximum OSC is preferred below essentially 5 degrees Centigrade. The Minimum OSC should preferably guarantee both an Adjacent Track Write (ATW) criteria, as well as guarantee a Write Induced Instability (WII) criteria. The invention includes the write parameter collection, as well as the disk drive containing the generated write parameter collection.

Abstract: A method for determining and varying the capacity, track per inch and bit per inch values of a hard disk drive. The method includes determining an optimal track per inch value for each head of the drive. The method then determines whether each head does not exceed a threshold BER value. If one or more heads do not exceed the threshold BER value then the BPI (data rates) of the non-performing heads are decreased until an acceptable BER is achieved. The BPI of performing heads may be increased to insure that the capacity of the disk drive still meets a target value. Likewise, if all of the heads are above the threshold value, the BPI of one or more of the performing heads may be decreased to improve the BER of the heads. The reduction in BPI is limited so that the drive always meets the target capacity value. The BPI and TPI values are stored in memory for use during the operation of the drive.

Abstract: a method for determining and varying the capacity, track per inch and bit per inch values of a hard disk drive. The method includes determining an optimal track per inch value for each head of the drive. The method then determines whether each head does not exceed a threshold BER value. If one or more heads do not exceed the threshold BER value then the BPI (data rates) of the non-performing heads are decreased until an acceptable BER is achieved. The BPI of performing heads may be increased to insure that the capacity of the disk drive still meets a target value. Likewise, if all of the heads are above the threshold value, the BPI of one or more of the performing heads may be decreased to improve the BER of the heads. The reduction in BPI is limited so that the drive always meets the target capacity value. The BPI and TPI values are stored in memory for use during the operation of the drive.

Abstract: The present invention is a method and system to optimize a write channel in a hard disk drive. The method comprises providing a disk having a at least one side with a plurality of tracks, and selecting a target track from the plurality of tracks. Data is written at least once on a predetermined plurality of tracks adjacent to either side of the target track and on the target track. Data is also written a predetermined number of times on tracks immediately adjacent to the target track. Data written on the predetermined plurality of tracks adjacent to either side of the target track and on the target track is then read. The process then determines if a number of errors on the tracks is greater than a predetermined criteria, if so, a write current value of the write channel is decreased, otherwise the write current value is increased.

Abstract: Today, the servo tracks are written successively in one of two directions. The inventors discovered that both servo track writing directions have problems. These problems increase in severity as the TPI increases. The discovered problems also increase in severity as the read-write head diminishes in size. The invention includes a method of writing the servo tracks of a rotating disk surface by writing the servo tracks from the Outside Position to essentially the Middle Position and by writing the servo tracks from the Inside Position to essentially the Middle Position. Writing the servo tracks with this method significantly decreases the erase band overhead. The invention includes program systems and apparatus implementing the method of servo track writing.

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: The invention includes a testing method which may be applied to at least one writer in a disk drive during the self-test phase to generate write parameters, focused on the Over Shoot Control (OSC) of the write current parameter to improve the reliability of write operations by that writer. The Minimum OSC is used for write operations in normal temperatures. The Optimum OSC is used for a first lower temperature range, preferably between essentially 15° Centigrade and essentially 5° Centigrade. The Maximum OSC is preferred below essentially 5° C. The Minimum OSC should preferably guarantee both an Adjacent Track Write (ATW) criteria, as well as guarantee a Write Induced Instability (WII) criteria. The invention includes the write parameter collection, as well as the disk drive containing the generated write parameter collection.

Abstract: A hard disk drive that includes a heater to heat an internal cavity of the drive. The disk drive may also have a temperature sensor to sense the temperature of the internal cavity, and a control circuit to control the heater and maintain the disk drive cavity, to be no less than a threshold temperature. The threshold temperature may correspond to a point where the heads of the drive undergo a significant degradation of performance. Maintaining the disk drive cavity temperature at or above the threshold temperature insures that the heads will not degrade due to temperature.

Abstract: The present invention is a method and system to optimize a write channel in a hard disk drive. The method comprises providing a disk having a at least one side with a plurality of tracks, and selecting a target track from the plurality of tracks. Data is written at least once on a predetermined plurality of tracks adjacent to either side of the target track and on the target track. Data is also written a predetermined number of times on tracks immediately adjacent to the target track. Data written on the predetermined plurality of tracks adjacent to either side of the target track and on the target track is then read. The process then determines if a number of errors on the tracks is greater than a predetermined criteria, if so, a write current value of the write channel is decreased, otherwise the write current value is increased.

Abstract: A method and system to optimize the performance of a read/write head in a hard disk drive. The method comprises providing a disk having at least one side with a plurality of tracks, selecting a current value, and applying the current value to the read/write head. The performance of the read/write head is then measured and the method determines if the current value has been applied to the read/write head a predetermined number of times. If not, the current value is applied to the read/write head a predetermined number of times. The best performance value of the read/write head and a corresponding current value are then stored.

Abstract: A magneto-resistive (MR) head of a new structure provides a linear output according to the variation of a recording magnetic flux. The magneto-resistive head generates an electrical output corresponding to the variation of a recording magnetic flux recorded on a disk, and includes an MR element portion disposed in such a manner that the forward (easy) direction of the MR element portion parallels the direction of the recording magnetic flux, and conductors coupled to the MR element portion through which a measured current flows. The MR head has linear output characteristics with respect to the variation of the recording magnetic flux. Also, the MR head does not need a bias means as does the conventional MR head.

Abstract: There is provided a magneto-resistive head in a hard disk drive. In the magneto-resistive head, an upper write pole has a write track width, and a lower write pole is positioned under the upper write pole, separated by a predetermined write gap. A magneto-resistive sensor is positioned under the lower write pole, apart by a predetermined gap and orthogonally to the length of the write gap, and has a predetermined read track width, for efficiently reading data from a disk. A shield is positioned under the magneto-resistive sensor, separated by a predetermined gap.

Abstract: An MR head is biased to a soft adjacent layer so that deflection angles at any point around the MR element are made uniform. The SAL-biased MR head includes a SAL divided into a plurality of layers for applying a transverse bias field, insulators disposed between each of the SAL layers, an MR element in which resistance varies according to the direction and magnitude of the magnetic flux which is detected, an insulator disposed between the SAL and the MR element, and a current source for providing current to the respective SAL layers and the MR element. Thus, since a plurality of layers are used, a bias angle in the MR element becomes almost equal at any position.

Abstract: A servo burst recording and servo control method for a magnetic storage device having a magneto resistive (MR) head comprises the steps of recording an additional burst signal having a magnitude as large as the quantity of track shift caused by a displacement angle of the MR head around each center line of each track, and using the additional burst signal as position identification information for the MR head during servo control thereof. The additional burst signal can be used during a read operation only or during a write operation only.

Abstract: A method of removing a polymer of a semiconductor device is disclosed including the steps of: forming a photoresist pattern on a to-be-etched layer; etching the to-be-etched layer using a mixed gas containing carbon/fluorine compound and oxygen gas with the use of the photoresist pattern; and removing the photoresist pattern at a temperature of below 200 C., and at the same time, dry-etching a polymer, the polymer being generated during the etching of the to-be-etched layer, the photoresist pattern being removed in a dry etching chamber.

Abstract: Disclosed is a method for forming a fine contact hole, and more particularly, a method capable of minimizing the loss of a silicon substrate. In the method for forming the contact hole according to the present invention, since the spacer is formed on the sidewall in the contact hole at the time of performing the dry etching process which makes it wide the approach to the contact hole, the contact area is hardly damaged by the etchant. Then, the dry etching process in accordance with the present invention can minimizes the loss of the substrate because the substrate to be exposed is under the protection of the insulating layer 43.

Abstract: A head suspension mechanism having a load beam and a layer of piezoelectric material on at least one surface of a resilient portion of the load beam adjacent an arm of an actuator in a hard disk drive. A controller apparatus provides a control signal to the piezoelectric material to induce a piezoelectric effect of the piezoelectric material which causes the load beam to raise the head slider from the surface of a disk in a start mode before the disk begins to rotate, and also causes the load beam to keep the head slider from contacting the surface of a disk until the disk comes to a complete stop in a stop mode.