Analysis of Contact Deformation and Stiction Between Textured Disk and Textured Slider

2000 ◽  
Vol 123 (2) ◽  
pp. 350-357 ◽  
Author(s):  
Mingwu Bai ◽  
Koji Kato
Keyword(s):  
Physical Model ◽  
Contact Area ◽  
Surface Texture ◽  
Flying Height ◽  
Loading Conditions ◽  
Contact Deformation ◽  
Head Disk Interface ◽  
Disk Interface ◽  
Recording Density ◽  
Texture Parameters

To meet the ever-increasing magnetic recording density, the hard disk industry is focusing on reducing flying height. Texturing the slider surface to reduce the head–disk contact area is one of the most challenging and promising techniques in the current industry. In this study, a mathematical–physical model based on an extension of the Greenwood–Tripp model is proposed for predicting and analyzing the contact deformation and stiction between both textured disk and slider. The contact deformation and stiction of the head–disk interface is analyzed in considering surface texture parameters, lubricant properties, and loading conditions.

Head-Disk Interface Performance With a Starved Liquid Bearing—Analytical Solution to Reynolds Equation in the Near-Contact Regime

1996 ◽  
Vol 118 (3) ◽  
pp. 492-497 ◽  
Author(s):  
J. L. Streator
Keyword(s):  
Analytical Solution ◽  
Rheological Behavior ◽  
Reynolds Equation ◽  
Equilibrium Configuration ◽  
Static Equilibrium ◽  
Flying Height ◽  
Head Disk Interface ◽  
Disk Interface ◽  
Recording Density ◽  
20 Nm

Further increase in magnetic recording density requires a reduction in slider flying height. The current study employs the short-bearing approximation to determine analytically the static equilibrium configuration of a slider supported by a starved liquid bearing that operates between ideally smooth surfaces. The solution incorporates rheological behavior based on previously acquired data. The accuracy of the short-bearing approximation is assessed by determining how well the resulting solution satisfies the Reynolds equation. The analysis suggests a means of designing a slider to achieve head/medium spacings in the neighborhood of 20 nm.

Paper 17: Microtopography of Surfaces

1967 ◽  
Vol 182 (11) ◽  
pp. 21-30 ◽  
Author(s):  
J. B. P. Williamson
Keyword(s):  
Gaussian Distribution ◽  
Contact Area ◽  
Surface Texture ◽  
Glass Surface ◽  
Surface Density ◽  
Radius Of Curvature ◽  
Height Distribution ◽  
Digital Analysis ◽  
Texture Parameters ◽  
Combining Data

This paper describes an approach to the study of surfaces based on the digital analysis of data obtained from profilometric examinations. This technique is used to determine several new surface texture parameters, including the surface density, height distribution, and mean radius of curvature of the asperities. Recent theories have shown that these are the parameters which control the nature of surface contact. The implications which these ideas have for the science of metrology are discussed. The study also shows that many surfaces have height distributions which are Gaussian, and in particular that the heights of the upper half of most surfaces closely follow a Gaussian distribution. By combining data obtained from many closely spaced parallel profiles it has been possible to reconstruct detailed maps of the surface texture. Two examples are discussed: bead-blasted aluminium, and a glass surface lightly blasted with alumina. One of the advantages of microcartography is that it permits the geometry of the contact between rough surfaces to be studied in detail. A map is given showing the manner in which the contact area between two bead-blasted aluminium surfaces splits into sub-areas, and how these sub-areas are distributed with respect to the surface features of the contacting solids.

Effect of Head–Disk Interface Biasing and Relative Humidity on Wear of Thermal Flying Height Control Sliders

2017 ◽  
Vol 65 (2) ◽  
Author(s):  
Liane M. Matthes ◽  
Frederick E. Spada ◽  
Andrey Ovcharenko ◽  
Bernhard E. Knigge ◽  
Frank E. Talke
Keyword(s):  
Relative Humidity ◽  
Flying Height ◽  
Head Disk Interface ◽  
Disk Interface ◽  
Height Control ◽  
Thermal Flying Height Control

Impact of Touchdown Detection on Bit Patterned Media Robustness

2013 ◽  
Author(s):  
Jia-Yang Juang ◽  
Kuan-Te Lin
Keyword(s):  
Areal Density ◽  
Flying Height ◽  
Head Disk Interface ◽  
Bit Patterned Media ◽  
Patterned Media ◽  
Disk Interface ◽  
Recording Process ◽  
Friction Temperature ◽  
The Media ◽  
The Impact

Bit patterned media (BPM) is considered as a revolutionary technology to enable further increase of areal density of magnetic recording beyond 1 Tbits/in2 [1]. Implementing BPM technology, however, significantly increases the complexity of the recording process, but also poses tremendous tribological challenges on the head-disk interface (HDI) [2]. One of the major challenges facing BPM is touchdown detection by thermal flying-height control (TFC), in which a minute heater located near the read/write transducers is used to thermally protrude a small portion of the slider into contact with the disk, and the contact is then detected by directly or indirectly measuring the friction, temperature rise or vibration caused by the contact [3]–[7]. Most recording heads rely on touchdown detection to achieve a desired flying height (FH), which approaches sub-1-nm regime for many of today’s commercial drives. As a result sensitive and accurate touchdown detection is of critical importance for a reliable head-disk interface by reducing contact duration and unnecessary interaction between the slider and the disk. However, the impact of touchdown on the mechanical robustness of the media has not been properly studied.

Head-Disk Interface Issues for Near Contact Recording

2001 ◽  
Author(s):  
R. H. Wang ◽  
V. Raman ◽  
U. V. Nayak
Keyword(s):  
Ambient Pressure ◽  
Disk Drive ◽  
Flying Height ◽  
Head Disk Interface ◽  
Disk Interface ◽  
Magnetic Spacing ◽  
Wear And Corrosion ◽  
Disk Lubricant ◽  
Contact Recording

Abstract As the magnetic recording density increases towards hundreds of Gb/in2, both the magnetic spacing and head-disk clearance decrease to < 10 nm. By one estimate, the magnetic spacing for 1 Tb/in2 is about 6 nm and the read width is ∼ 30 nm. There are at least two different approaches to achieving this. The first one is an extension of the traditional flying interface and the second is contact recording. In the former case one needs to be concerned about maintaining adequate clearance both at sea level and at higher elevation whereas in the latter case the wear and corrosion of the heads and disks may pose major challenges. In the flying regime, an accelerated test to assess the relative integrity of the head-disk interface is described here. This is accomplished by monitoring the acoustic emission, capacitance or friction between the head and the disk as the ambient pressure is reduced. The pressure at which an abrupt change in the above signals takes place is called take-off pressure (TOP). This is also known as altitude avalanche measurement. With this method it is possible to compare different disk and head designs at the full velocity of the slider. We present results correlating the TOP with disk roughness and the influence of disk lubricant. An example of how head-disk interference takes place in a disk drive will be given for an experimental 10 nm flying slider. The effects of radial flying height profile, take-off height of the disk, and the disk curvature on mechanical spacing are presented. The results of changes occurring on the air bearing surface and the disks after long term flyability test are discussed.

Simulation of Contact at Head and Multilayer Disk Interface Under Quasi-Static Condition

2016 ◽  
Author(s):  
Ao Hongrui ◽  
Han Zhiying ◽  
Zhang Kai ◽  
Jiang Hongyuan
Keyword(s):  
Normal Load ◽  
Static Condition ◽  
Flying Height ◽  
Lubricant Layer ◽  
Magnetic Storage ◽  
Multilayer Thin Film ◽  
Head Disk Interface ◽  
Principal Stresses ◽  
Disk Interface ◽  
Von Mises

The reduction of head-media separation (HMS) results in a decreased flying height. Consequently, the contact probability between the slider and the lubricant layer or hard overcoat surface on the disks will increase greatly. Therefore, investigating the contact stress of the disk is vital for improving the reliability of the head disk interface. In this study, a rigid hemisphere sliding over a multilayer thin film half-space is implemented to simulate the contact between the recording slider and the magnetic storage multilayer disk under the quasi-static condition. The effects of different parameters such as normal load, friction coefficient and radius of slider on the von Mises, shear and principal stresses in the multilayer system are analyzed by using finite element method (FEM).

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