Characterization of Thermally Actuated Pole Tip Protrusion for Head-Media Spacing Adjustment in Hard Disk Drives

Lee, Sung-Chang; Strom, Brian

doi:10.1115/1.2842248

Cited by 13 publications

(12 citation statements)

References 17 publications

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“…T HERMAL fly-height control (TFC) describes technology that enables ultra-high density recordings in hard-disk drives (HDD) by thermomechanically actuating the read/write elements of the slider closer to the rotating disk surface [1]. Using TFC technology, the slider body flies at a predescribed nominal flying height of the order of 10 nm away from the rotating disk surface, reducing the clearance between the read/write element and the disk surface to less than few nm, thus, enabling higher recording densities.…”

Section: Introductionmentioning

confidence: 99%

Dynamic Head-Disk Interface Instabilities With Friction for Light Contact (Surfing) Recording

2009

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Recent advances in hard-disk drive technology involve the use of a thermal fly-height control (TFC) pole tip protrusion to bring the read/write recording elements of the slider closer to the disk surface and thus achieve Terabit per square inch recording densities. A dynamic, contact mechanics-based friction model of the head-disk interface (HDI) that includes roughness and accounts for the TFC geometry and its influence on the HDI dynamics is presented. The model is based on physical parameters and does not include any empirical coefficients. Experimental flyability/touchdown measurements were performed and used to examine in detail the HDI contact criterion in the presence of surface roughness and dynamic microwaviness. Using the model, a procedure is outlined that identifies the optimal clearance and light contact conditions, i.e., the amount of thermal actuation that minimizes, both, the clearance, as well as the flying height modulation. Through calculation of the time varying interfacial forces, mean pressure and shear stress at the HDI can be predicted and used to characterize the contact regime. Based on our results, a light contact regime with reduced bouncing vibrations and low stresses (thus, low wear) that would enable surfing recording is identified.Index Terms-Dynamic model, friction, hard-disk drive (HDD), head-disk interface (HDI), thermal fly-height control (TFC).

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Section: Introductionmentioning

confidence: 99%

Dynamic Head-Disk Interface Instabilities With Friction for Light Contact (Surfing) Recording

2009

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“…Note that the sub-3 DID HMS, equal to the TP FH, is within the projected specifications for ultra-high density recording [1].…”

Section: Resultsmentioning

confidence: 75%

Dynamic contact with friction of an ultra-low flying head-disk interface with thermal protrusion

Vakis

Lee

Polycarpou

2009

2009 Asia-Pacific Magnetic Recording Conference

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Take-down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. Abstract-A dynamic two-degree-of-freedom contact with friction model of the head-disk interface (llD1) is presented accounting for slider thermal protrusion and its influence on the IIDI dynamics. Using this model, which includes roughness, the applied power to the thermal protrusion is calculated that leads to minimum flying-height modulations. The model predictions are verified by drive-level experimental results.Index Terms-dynamic model; magnetic storage; head-disk interface; thermal protrusion.

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“…In the hard disk drive industry, there have been many efforts to reduce the gap between the read/write head and the magnetic disk -flying height-to increase the recording density of hard disk drives (Liu et al 2007; Lee and Strom 2008;Hua et al 2010;Vakis and Polycarpou 2010). Nowadays, the flying height has been reduced to less than 10 nm and is being decreased to contact (Wood 2000).…”

Section: Introductionmentioning

confidence: 97%

Investigation of wear resistance and lifetime of diamond-like carbon (DLC) coated glass disk in flying height measurement process

2011

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Flying height has been greatly reduced to less than 10 nm to achieve high-density magnetic storage. This leads to significant disk wear especially, glass disks used in flying height measurement process. This paper reports the utilization of diamond-like carbon (DLC) overcoat to increase the wear resistance and lifetime of commercial glass disks in a flying height tester. Wear resistance of the DLC coated glass disks was investigated in wear test using a triboindentor. The results showed significant wear resistance improvement of the coated disk where the wear depth reduced from 62.2 nm on an uncoated disk to 5-7 nm on 15-nm thick DLC coated disks. Furthermore, lifetime measurement of the coated disk has been performed in a flying height tester. As a result, lifetime of the coated disk has been drastically improved by more than 30 times in comparison to an uncoated disk.

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Characterization of Thermally Actuated Pole Tip Protrusion for Head-Media Spacing Adjustment in Hard Disk Drives

Cited by 13 publications

References 17 publications

Dynamic Head-Disk Interface Instabilities With Friction for Light Contact (Surfing) Recording

Dynamic Head-Disk Interface Instabilities With Friction for Light Contact (Surfing) Recording

Dynamic contact with friction of an ultra-low flying head-disk interface with thermal protrusion

Investigation of wear resistance and lifetime of diamond-like carbon (DLC) coated glass disk in flying height measurement process

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