US 2010/0165496 A1 · SYSTEM, METHOD AND APPARATUS FOR SECTOR GRADING OF DEFECTIVE BIT PATTERNED MAGNETIC MEDIA IN HARD DISK DRIVES

Abstract

A system for grading defective bit patterned magnetic media by disk sector in hard disk drives recovers a portion of any defective sectors at a lower areal density. The invention reduces the track pitch density for sectors containing amalgamated islands while leaving the remainder of the defect-free sectors in the zone optimized for linear bit density. This recovers a portion of the defective sector, approximately in proportion to the ratio of amalgamated islands over the original number of islands. A typical zone is first optimized for tracks per inch during formatting of the patterned media disk drive. The zone is then broken up into sectors that can each be optimized separately for linear bit density to ensure the maximum sustainable capacity for each sector.

Claims17

Dependent claims

A method of grading defective bit patterned magnetic media by disk sector in a hard disk drive, comprising:

(a) providing a disk with bit patterned magnetic media having tracks of bits that are divided into sectors;
(b) determining if any of the sectors have tracks that are not concentric such that the bits on adjacent ones of the tracks are amalgamated;
(c) designating sectors having amalgamated bits as “defective;” and
(d) recovering a portion of the defective sectors such that the defective sectors have an areal density that is lower than an areal density of other ones of the sectors

1 more element

A method of grading defective bit patterned magnetic media by disk sector in a hard disk drive, comprising:

(a) providing a disk with bit patterned magnetic media having tracks of bits that are divided into sectors;
(b) optimizing the bit patterned magnetic media for tracks per inch (TPI) during formatting, dividing the bit patterned magnetic media into sectors, and separately optimizing the sectors for track density to ensure a maximum sustainable capacity for each sector despite any defects therein;
(c) formatting hard disk drive parameters, optimizing write current, calculating a default TPI to allow for TPI selection by zone based on magnetic core width, measuring soft error rate and overwrite to optimize bits per inch per zone to achieve a desired data storage capacity of the hard disk drive;
(d) determining if any of the sectors have bits on adjacent tracks that are amalgamated;
(e) designating sectors having amalgamated bits as “defective;” and
(f) recovering a portion of the defective sectors such that the defective sectors have an areal density that is lower than an areal density of other ones of the sectors, reducing a track bit density of the defective sectors from a track bit density of said other ones of the sectors, such that the defective sectors have reduced TPI, and wherein the defective sectors have a TPI approximately in proportion to a ratio of amalgamated bits to a total number of bits.

3 more elements

Dependencies are inferred from the claim text.

System, method and apparatus for sector grading of defective bit patterned magnetic media in hard disk drives

Life of this patent

System, method and apparatus for sector grading of defective bit patterned magnetic media in hard disk drives

Life of this patent

Abstract

Claims17