Method of varying capacity of head disk drive during manufacturing process by checking head/disk combinations for defects

A method of varying the capacity of a hard disk drive, having a plurality of head/disk combinations, during a manufacturing process, comprising the steps of:

• performing a performance test on each of the head/disk combinations;
• determining a head/disk combination to be defective if the performance test result of the head/disk combination is smaller than a reference performance value;
• and
• eliminating from usage each defective head/disk combination.

A method of varying the capacity of a hard disk drive, having a plurality of head/disk combinations, during a manufacturing process, comprising the steps of:

• scanning, servo fields of disk surfaces of all of the head/disk combinations to detect defects;
• determining position and number of servo defects of each head/disk combination;
• determining whether the number of detected servo defects is greater than a predetermined servo defect reference number;
• upon the number of detected servo defects being greater than the servo defect reference number, determining if the defects exist only in a specific disk surface and if not, determining the hard disk drive to be totally defective and if so, eliminating the head/disk combinations having the defective disk surface from usage;
• scanning data fields of disk surfaces of all of the head/disk combinations to detect scan defects;
• determining the number of scan defects;
• determining whether the number of detected scan defects is greater than a predetermined scan defect reference number;
• upon the number of detected scan defects being greater than the scan defect reference number, determining whether the scan defects exist in a specific disk surface and if not, determining the hard disk drive to be totally defective and if so, eliminating from usage the head/disk combination having the defective disk surface;
• determining the overall capacity of the hard disk drive;
• and
• recording information on the determined capacity in one of a maintenance zone of a disk surface and a flash read only memory.

A method of varying the capacity of a hard disk drive, having a plurality of head/disk combinations, during a manufacturing process, comprising the steps of:

• measuring error rate and performing performance tests on each head/disk combination;
• determining if the error rate is greater than a predetermined reference error rate;
• upon the error rate being determined to be greater than the reference error rate, determining whether only a specific head/disk combination has failed to meet the reference error rate and if so eliminating from usage each head/disk combination corresponding to the defective disk surface and if not, determining whether only two head/disk combinations fail to meet the reference error rate and if not, determining the hard disk drive to be totally defective and if so, eliminating from usage the two head/disk combinations corresponding to the two defective disk surfaces;
• determining the capacity of the hard disk drive;
• recording information on the determined capacity in one of a maintenance zone of a disk surface and a flash read only memory;
• changing a mode for a corresponding capacity upon determining that a mode must be changed for the determined capacity;
• performing a test sequence;
• and
• determining if all disk surfaces have been used and if so, determining the drive capacity to be a first predetermined value, and if not, determining if one head/disk combination has been eliminated from usage and if so, determining the hard disk drive capacity to be a second predetermined value and if not, determining if two head/disk combinations have been eliminating from usage and if so, determining the hard disk drive capacity to be a third predetermined value and if not, determining the hard disk drive to be totally defective.

A hard disk drive, comprising:

• a memory comprising a plurality of disks each exhibiting a plurality of major surfaces, a plurality of tracks and a maintenance zone;
• a plurality of heads with each of said heads disposed to selectively read information from different corresponding ones of said surfaces, with corresponding ones of said heads and major surfaces forming a multiplicity of pairs of head and major surface combinations;
• a plurality of arms movably supporting said heads to seek and follow said tracks on said surfaces;
• a read channel circuit generating position error signals in response to servo information read by said heads from disks;
• and
• a controller testing each of said of said plurality of disks, making a first determination of whether each of said plurality of disks meets a reference standard, making a second determination whenever said first determination indicates a failure by any of said surfaces of any of said plurality of disks to meet said reference standard, of whether said failure is attributable to a single one of said major surfaces, when said second determination establishes that said failure is attributable to a single one of said major surfaces, varying capacity of said memory by initiating an elimination of said single one of said major surfaces and a corresponding one of said plurality of heads from use, and determining capacity of said memory in dependence upon elimination.

A hard disk drive, comprising:

• a memory comprising a plurality of disks each exhibiting a plurality of major surfaces, a plurality of tracks and a maintenance zone;
• a plurality of heads with each of said heads disposed to selectively read data from different corresponding ones of said surfaces, with corresponding ones of said heads and major surfaces forming a multiplicity of pairs of said heads and corresponding said major surfaces;
• a plurality of arms movably supporting said heads to seek and follow said tracks on said surfaces;
• a read channel circuit generating position error signals in response to servo information read by said heads from said disks;
• and
• a controller driven to perform testing each of said of said plurality of disks by identifying defects attributable to said memory while driving said plurality of arms to scan said plurality of heads along each of said plurality of major surfaces, making a comparison of said defects to a reference value, and in dependence upon said comparison, making an initial determination of whether said defects are attributable to a single pair of said pairs of heads and corresponding major surfaces, varying a nominal capacity of said memory by initiating an elimination of said single pair from use within said hard disk drive when said initial determination establishes that said defects are attributable to a single pair, making a subsequent determination of a resulting capacity of said memory in dependence upon said elimination, and marking said hard disk drive with information indicative of said resulting capacity.