Abstract
Recording media with grooves, such as discrete track media (DTM) and bit-patterned media (BPM), are considered to be promising media for achieving ultrahigh recording densities. It is thus important to analyze the static and dynamic characteristics of flying head sliders on DTM and BPM using the molecular gas film lubrication equation and the van der Waals (vdW) equation. In this study, we consider BPM with rectangular bits. We express the disk recess as a Fourier series and determine the quasi-static and time-dependent components. We also develop a perturbation method for small groove depths for calculating static slider attitudes and dynamic responses in the frequency domain. The numerical results predict that the grooves will significantly reduce the quasi-static flying height h 0. They also predict that for a small groove depth h groove, flying height decrease Δh 0 almost agree with the value of uniform disk recess obtained by a Fourier series expansion, which also agrees with empirical results. Dynamic slider characteristics obtained by the frequency domain analysis is useful for sliders suffering from excitations of several tens of kHz such as sliders flying at transition between data zone and servo zone, although the dynamic spacing fluctuation by realistic BPM media is negligible.
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Duwensee M, Suzuki S, Lin J, Wachenschwanz D, Talke FE (2007) Simulation of the head disk interface for discrete track media. Microsyst Technol 13:1023–1030
Duwensee M, Talke FE, Suzuki S, Lin J, Wachenschwanz D (2009) Direct simulation Monte Carlo method for the simulation of rarefied gas flow in discrete track recording head/disk interface. Trans ASME J Tribol 131:012001-1–012001-7. doi:10.1115/1.2991166
Fukui S, Kaneko R (1988) Analysis of ultra-thin gas film lubrication based on linearized Boltzmann equation: first report—derivation of a generalized lubrication equation including thermal creep flow. Trans ASME J Tribol 110:253–262
Fukui S, Kaneko R (1990a) A database for interpolation of Poiseuille flow rates for high knudsen number lubrication problems. Trans ASME J Tribol 112:78–83
Fukui S, Kaneko R (1990b) Dynamic analysis of flying head sliders with ultra-thin spacing based on the Boltzmann equation (comparison with two limiting approximations). JSME Int J Ser III 33:76–82
Fukui S, Matsui H, Yamane K, Matsuoka H (2005) Dynamic characteristics of flying head slider with ultra thin spacing (CIP method and linearized method). Microsyst Technol 11:812–818
Fukui S, Kanamaru T, Matsuoka H (2008) Dynamic analysis schemes for flying head sliders over discrete track media. IEEE Trans Mag 44:3671–3674
Israelachvili JN (1992) Intermolecular and surface forces, 2nd edn. Academic Press, Dublin
Knigge BE, Bandic ZZ, Kercher D (2008) Flying characteristics on discrete track and bit-patterned medium with a thermal protrusion slider. IEEE Trans Mag 44:3656–3662
Li L, Bogy DB (2011) Dynamics of air bearing sliders flying on partially planarized bit patterned media in hard disk drives. Microsyst Technol 17(5–7):805–812. doi:10.1007/s00542-010-1191-9
Li H, Talke FE (2009) Numerical simulation of the head/disk interface for bit patterned media. IEEE Trans Mag 45:4984–4989
Li J, Xu J, Shimizu Y (2007) Performance of sliders flying over discrete-track media. Trans ASME J Tribol 129:712–719
Li H, Zheng H, Yoon Y, Talke FE (2009) Air bearing simulation for bit patterned media. Tribol Lett 33:199–204
Li H, Amemiya K, Talke FE (2010) Slider flying characteristics over bit patterned media using the direct simulation Monte Carlo method. J Adv Mech Des Syst Manuf 4:49–55
Matsuoka H, Ohkubo S, Fukui S (2004) Corrected expression of the van der Waals pressure for multilayered system with application to analyses of static characteristics of flying head sliders with an ultrasmall spacing. Microsyst Technol 11:824–829
Murthy AN, Duwensee M, Talke FE (2010) Numerical simulation of the head/disk interface for patterned media. Tribol Lett 38:47–55
Myo KS, Zhou W, Yu S, Hua W (2012) Direct Monte Carlo simulations of air bearing characteristics on patterned media. IEEE Trans Mag 47(10):2660–2663
Ono K (1975) Dynamic characteristics of air-lubricated slider bearing for noncontact magnetic recording. Trans ASME J Lubr Tech 97:250–258
Tagawa N, Bogy DB (2002) Air film dynamics for micro-textured flying head slider bearings in magnetic hard disk drives. Trans ASME J Tribol 124:568–574
Tagawa N, Mori A (2003) Thin film gas lubrication characteristics of flying head slider bearings over patterned media in hard disk drives. Microsyst Technol 9:362–368
Wachenschwanz D, Jiang W, Roddick E, Homola A, Dorsey P, Harper B, Treves D, Bajorek CJ (2005) Design of a manufacturable discrete track recording medium. IEEE Trans Mag 41:670–675
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The authors would like to thank Mr. A. Oono for assistance with the numerical calculations.
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Fukui, S., Sato, A. & Matsuoka, H. Static and dynamic flying characteristics of a slider on bit-patterned media (dynamic responses based on frequency domain analysis). Microsyst Technol 18, 1633–1643 (2012). https://doi.org/10.1007/s00542-012-1601-2
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DOI: https://doi.org/10.1007/s00542-012-1601-2