• 한국정밀공학회지
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• 제20권4호
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• pp.183-188
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• 2003

Particulate contamination is known to be a significant cause of failures of removable storage media. In this work, the effect of particles on the surface damage of removable hard disk media was investigated. The particles of different materials and size were introduced to the Head Disk Interface (HDI) using a particle injection system. It was round that the particles of particulate size and property serious damaged the media. This study showed that cleaning pad is effective for reducing particle contamination, except fer the particles of specific size and property. As a means to remove the particles of specific sire. the concept of using a stepped taper at the leading edge of the slider is proposed.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.946-949
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• 2002

Particulate contamination is known to be a significant cause of failures of removable storage media. In this work, The effect of particles on the surface damage of removable hard disk media was investigated. The particles of different materials and size were introduced to the head-disk interface using a particle injection system. It was found that the particles of particulate size and property serious damaged the media. This study showed that cleaning pad is effective for reducing particle contamination, except for the particles of specific size and property. As a means to removed the particles of specific size, the concept of using a stepped taper at the leading edge of the slider is proposed.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 추계학술대회논문집
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• pp.413-418
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• 2004

Recently, the development of mobile devices demands information storage systems to use micro drive devices. 1-inch micro drive hard disk uses the load/unload(L/UL) technology to increase area recording density and reduce power consumption. Because micro drive has light actuator, effects of the flexible cable that is ignored in 3.5-inch hard disk drive is important to load/unload performances. In this paper, effects of flexible cable on load/unload performances are studied.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.664-669
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• 2003

Recently, the recording density of hard disk drives has improved at an annual percentage rate of 100%. Therefore for faster access, higher disk rotational speeds will be required. The influence of the airflow produced by the rotation of a disk on the positioning accuracy has become a serious topic of research and the aerodynamic aspect of hard disk drives is now quite considerable with the increases in recording density and higher rotational speeds. Unsteady airflow in an actual hard disk drive is numerically simulated by using LES(Large Eddy Simulation) technique, we could predicted and aerodynamic mechanism that was related actuators' surroundings in HDD. At a result, with modifying the various shapes of the E-block and Damper, we estimated the characteristic of the influence of airflow in HDDs.

• 한국정밀공학회지
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• 제18권3호
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• pp.107-114
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• 2001

The durability of head/disk interface is an important issue for hard disk drives. Currently, there are several means of assessing the performance and integrity of the head/disk interface. In this work Track Average Amplitude(TAA) signal was used to analyzed the head/disk interface with respect to variations in disk velocity, slider pre-load and preformed scratch on the disk. Particularly, TAA variation due to disk defect in the form of a scratch was investigated.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.990-994
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• 2004

This paper presents a method to predict the transient characteristic of the air lubricated slider head in a hard disk drive by using optimization technique. The time dependent modified Reynolds equation based on the molecular slip flow approximation equations was used to describe the fluid flow within the air bearing and the implicit finite difference scheme is applied to calculate the pressure distribution under the slider head. The exhaustive search combined with the Broyden-Fletcher-Goldfarb-Shanno method were employed to obtain optimum design variables which are taper angle, rail width and taper length in order to keep the forces and moments acting on the slider head in dynamic equilibrium. The results show that the optimal head slider of the magnetic head has good stability characteristic that can reach the steady state within 0.5 microsecond.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2004년도 학술대회지
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• pp.143-148
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• 2004

The numerical analysis of the hard disk drive slider is presented. The pressure distribution was calculated using the finite element method. The generalized Reynolds equation was applied in order to include the gas rarefaction effect. The balance of the air bearing force and preload force was considered. The characteristics of the small vibrations near the equilibrium were studied using the perturbation method. Triangular mesh with variable element size was employed to model the two-rail slider. The flying height, pitching angle, rolling angle, stiffness and damping of the two-rail slider were calculated for radial position changing from the inner radius to the outer radius and for a wide range of the slider crown values. It was found that the flying height, pitching angle and rolling angle were increased with radial position while the stiffness and damping coefficients were decreased. The higher values of crown resulted in increased flying height, pitching angle and damping and decreased stiffness.

• Tribology and Lubricants
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• 제16권5호
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• pp.395-402
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• 2000

The effect of particulate contamination on friction and wear between a negative-pressure picoslider and a laser-textured disk was studied. Particles of different concentrations, materials and sizes were injected to the head-disk interface (HDI), consisting of disks with various textures, at the same speed. In a contaminated environment, durability of head-disk interface gradually decreased as the particle concentration increased. Large particles caused HDI failure early and resulted in an extensive damage to the slider and disk surfaces. Hard particles also caused HDI failure earlier and damages more extensive than soft ones. Based on the test results, mechanisms of HDI failure with picoslider were presented.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 1998년도 제28회 추계학술대회
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• pp.278-284
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• 1998

In order to measure the real contact force between head and disk on hard disk drive quantitatively, many technique of measurement have been developed. Acoustic Emission Sensor can be used for detect elastic energy of head/disk contact as arms value. In this study using pencil breaking test is proposed for finding contact force using transfer function between calibrated force and real contact force. And real AE data of subambient and tripad slider shows bending and torsional mode and their energy are dominant in hard disk and head contact.

• 대한기계학회논문집A
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• 제26권1호
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• pp.196-202
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• 2002

In this work, we propose a new type of HDD suspension featuring shape memory alloy (SMA) actuator in order to prevent the contact between the slider and disk. The principal design parameters are obtained from the modal analysis using finite element analysis, and then the dynamic model is established to formulate the control scheme for Non-Contact Start/stop mode drive. Subsequently, a robust H$\_$$\infty$/ control algorithm is designed by integrating experimentally-Obtained SMA actuator dynamics to the proposed HDD suspension system. The controller is empirically realized and control results for the load/unload profiles are presented in time domain. In addition, the contact signal between the slider and disk is measured by the electrical resistance method.