Development of Nanometer Flying-Height Slider for Small Magnetic Disk Drives

2005 ◽  
Vol 17 (5) ◽  
pp. 517-522
Author(s):  
Yoshinori Takeuchi ◽  
◽  
Katsuyuki Tanaka ◽  
Keyword(s):  
Negative Pressure ◽  
Hard Disk Drives ◽  
Hard Disk ◽  
Flying Height ◽  
Basic Design ◽  
Disk Drives ◽  
Magnetic Disk ◽  
Design Guide

The 90nm and 15nm flying-height sliders we designed for small magnetic disk drives are based on a basic design guide we previously proposed that covers (1) a very small slider, (2) a multipad slider or side-step slider, and (3) a negative-pressure slider use in low spacing mode alone. These experimentally prototyped sliders were confirmed to fly stably on the disk at the prescribed 90nm and 15nm heights, and have been commercialized for 3.5-inch and 2.5-inch hard disk drives. These practical results demonstrate the feasibility of the proposed basic design guide.

Basic Design Guide Proposal on Nanometer Flying-Height Slider for Small Magnetic Disk Drives

2005 ◽  
Vol 17 (5) ◽  
pp. 509-516
Author(s):  
Yoshinori Takeuchi ◽  
◽  
Katsuyuki Tanaka ◽  
Keyword(s):  
Negative Pressure ◽  
Flying Height ◽  
Constant Density ◽  
Basic Design ◽  
Disk Drives ◽  
Magnetic Media ◽  
Magnetic Disk ◽  
Design Guide ◽  
Sudden Decrease ◽  
Yaw Angle

We propose a basic design guide to design a very low spacing slider for small magnetic disk drives. The design features; (1) A multipad or side-step slider to avoid a sudden decrease in flying height due to the yaw angle of the swing actuator. (2) The slider must be as small as possible to be stable because the very low flying height makes the slider tend to vibrate unstably. (3) High spacing mode must be avoided to stabilize the negative-pressure slider used in constant density recording (CDR) suitable for high-density magnetic media.

Depletion of Moleculary Thin Lubricant Under Flying Head in Hard Disk Drives

2007 ◽  
Author(s):  
Kenji Yanagisawa ◽  
Youichi Kawakubo ◽  
Masato Yoshino
Keyword(s):  
Thin Film ◽  
Hard Disk Drives ◽  
Hard Disk ◽  
Lubricant Film ◽  
Simulation Program ◽  
Disk Drives ◽  
Lubricant Thickness ◽  
Magnetic Disk ◽  
Lubricant Depletion ◽  
Lubricant Films

In Hard Disk Drives, lubricants are very important materials to reduce head and disk wear. Therefore, it is necessary to know the lubricant depletion under flying heads. Lubricant depletion due to flying heads has been studied experimentally. We developed simulation program to calculate numerically the change in lubricant thickness under a flying head on a thin-film magnetic disk from 10nm thick lubricant film. In recent HDDs, the lubricants thickness has become molecularly thin and polar lubricants have been used. In this paper, we took account of thickness-dependent lubricants diffusion and viscosity in our simulations to calculate a 1.2 nm thick polar lubricant film used in recent HDDs. The simulated results considering the thickness-dependent diffusion and viscosity showed that depletion was small in molecularly thin lubricant films. We considered it necessary to include thickness-dependent diffusion and viscosity in lubricant depletion simulation.

Contact and temperature rise of thermal flying height control sliders in hard disk drives

2012 ◽  
Vol 18 (9-10) ◽  
pp. 1693-1701 ◽  
Author(s):  
Liane Matthes ◽  
Uwe Boettcher ◽  
Bernhard Knigge ◽  
Raymond de Callafon ◽  
Frank E. Talke
Keyword(s):  
Temperature Rise ◽  
Hard Disk Drives ◽  
Hard Disk ◽  
Flying Height ◽  
Disk Drives ◽  
Height Control ◽  
Thermal Flying Height Control

Design and Dynamics of Flying Height Control Slider With Piezoelectric Nanoactuator in Hard Disk Drives

2006 ◽  
Vol 129 (1) ◽  
pp. 161-170 ◽  
Author(s):  
Jia-Yang Juang ◽  
David B. Bogy ◽  
C. Singh Bhatia
Keyword(s):  
Numerical Study ◽  
Hard Disk Drives ◽  
Hard Disk ◽  
Areal Density ◽  
Flying Height ◽  
Air Bearing ◽  
Disk Drives ◽  
Adhesion Forces ◽  
Surface Design ◽  
Ultrahigh Density

To achieve the areal density goal in hard disk drives of 1Tbit∕in.2 the minimum physical spacing or flying height (FH) between the read/write element and disk must be reduced to ∼2nm. A brief review of several FH adjustment schemes is first presented and discussed. Previous research showed that the actuation efficiency (defined as the ratio of the FH reduction to the stroke) was low due to the significant air bearing coupling. In this paper, an air bearing surface design, Slider B, for a FH control slider with a piezoelectric nanoactuator is proposed to achieve virtually 100% efficiency and to increase dynamics stability by minimizing the nanoscale adhesion forces. A numerical study was conducted to investigate both the static and dynamic performances of the Slider B, such as uniformity of gap FH with near-zero roll over the entire disk, ultrahigh roll stiffness and damping, low nanoscale adhesion forces, uniform FH track-seeking motion, dynamic load/unload, and FH modulation. Slider B was found to exhibit an overall enhancement in performance, stability, and reliability in ultrahigh density magnetic recording.

scholarly journals Servo signal processing for flying height control in hard disk drives

2011 ◽  
Vol 17 (5-7) ◽  
pp. 937-944 ◽  
Author(s):  
Uwe Boettcher ◽  
Christopher A. Lacey ◽  
Hui Li ◽  
Kensuke Amemiya ◽  
Raymond A. de Callafon ◽  
...  
Keyword(s):  
Signal Processing ◽  
Hard Disk Drives ◽  
Hard Disk ◽  
Flying Height ◽  
Disk Drives ◽  
Height Control ◽  
Servo Signal

Flying height measurement while seeking in hard disk drives

1998 ◽  
Vol 34 (4) ◽  
pp. 1765-1767 ◽  
Author(s):  
B.C. Schardt ◽  
E. Schreck ◽  
R. Sonnenfeld ◽  
Q. Haddock ◽  
J.R. Haggis
Keyword(s):  
Hard Disk Drives ◽  
Hard Disk ◽  
Flying Height ◽  
Disk Drives ◽  
Height Measurement

An Efficient FE Analysis for Complex Low Flying Air-Bearing Slider Designs in Hard Disk Drives—Part I: Static Solution

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
Puneet Bhargava ◽  
David B. Bogy
Keyword(s):  
Hard Disk Drives ◽  
Hard Disk ◽  
Static Solution ◽  
Flying Height ◽  
Air Bearing ◽  
Pressure Gradients ◽  
Disk Drives ◽  
Bearing Stiffness ◽  
Novel Method ◽  
Mesh Refinements

Prediction of the steady state flying height and attitude of air-bearing sliders in hard disk drives via simulations is the basis of their design process. Over the past few years air-bearing surfaces have become increasingly complex incorporating deep etches and steep wall profiles. In this paper we present a novel method of solving the inverse problem for air-bearing sliders in hard disk drives that works well for such new designs. We also present a new method for calculating the static air-bearing stiffness by solving three linear systems of equations. The formulation is implemented, and convergence studies are carried out for the method. Mesh refinements based on flux jumps and pressure gradients are found to work better than those based on other criteria.

Sign in / Sign up

Export Citation Format

Share Document