• Journal of the Korean Society for Precision Engineering
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• v.13 no.11
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• pp.46-56
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• 1996

Planarization technique is rapidly recognized as a critical step in chip fabrication due to the increase in wiring density and the trend towards a three dimensional structure. Global planarity requires the preferential removal of the projecting features. Also, the several materials i.e. Si semiconductor, oxide dielectric and sluminum interconnect on the chip, should be removed simultaneously in order to produce a planar surface. This research has investihgated the development of the chemical mechanical polishing(CMP) machine with uniform pressure and velocity mechanism, and the pad insensitive to pattern topography named hard grooved(HG) pad for global planarization. Finally, a successful result of uniformity less than 5% standard deviation in residual oxide film and planarity less than 15nm in residual step height of 4 inch device wafer, is achieved.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11a
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• pp.125-128
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• 2004

Chemical Mechanical Polishing(CMP) in semiconductor production is characterized its output property by Removal Rate(RR) and Non-Uniformity(NU). Some Previous works shows that RR is determined by production of pressure and velocity and NC is also largely affected by velocity of flow-field during CMP. This study is about the direct measurement of velocity of slurry during CMP and reconstruction whole flow-field by Particle Image Velocimetry(PIV) Techniques. Typical PIV system is tuned adequately for inspecting CMP and Slurry Flow-field is measured by changing both Pad RPM and Carrier RPM. The results show that velocity is majorly determined not by Carrier RPM, but by Pad RPM.

• Proceedings of the KSME Conference
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• 2001.11b
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• pp.405-409
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• 2001

An experimental analysis of the flow inside the refrigeration compartment of a home refrigerator was conducted in order to achieve better performances in terms of uniform temperature distribution and cooling speed. 2D PIV and stereoscopic PIV were used for the experiments on an actual-size refrigerator at operating conditions. Two CCD cameras were employed for a wider field of view in the measurement of the shelf, and stereoscopic PIV was used to measure the three velocity components at the various cooling duct outlets and the mean velocity fields were area-integrated to calculate the flow-rates. 50 to 100 instantaneous velocity fields were time averaged for the mean velocity fields. With the result of this analysis, a new cooling duct system was developed, with the refrigerator's cooling performance increasing 11% in terms of cooling speed, and 25% in temperature uniformity.

• Journal of the Korean Society for Precision Engineering
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• v.33 no.8
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• pp.611-616
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• 2016

Computational fluid dynamic simulation based on the ABAQUS software was conducted to observe the inside flow of slot-die nozzle. The slot-die nozzle was modeled as 3-dimensional structure and three significant parameters were determined: inlet velocity of fluid, reservoir angles, number of strips none of which have been mentioned previously in the literature. The design of experiment, full factorial analysis was performed within determined design and process levels. The simulation result shows the inlet fluid velocity is most significant factor for the flows of inside nozzle. As an interaction effect, reservoir angle is closely related with number of strip that should address when the nozzle is designed. Moreover, the optimized values of each determined parameter were obtained as 35 mm/s of inlet velocity, 3 of strip numbers, and $22^{\circ}$ of reservoir angles. Based on these parameters, the outlet velocity was obtained as 0.53% of outlet uniformity which is improved from 8.67% of nominal results.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.26 no.2
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• pp.245-252
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• 2002

Numerical analysis was conducted to characterize particle deposition on a horizontal rotating disk with thermophorectic effect under laminar flow field. The particle transport mechanisms considered were convection, Brownian diffusion, gravitational settling and thermophoresis. The averaged particle deposition velocities and their radial distributions for the upper surface of the disk were calculated from the particle concentration equation in a Eulerian frame of reference for rotating speeds of 0∼1000rpm and temperature differences of 0∼5K. It was observed from the numerical results that the rotation effect of disk increased the averaged deposition velocities, and enhanced the uniformity of local deposition velocities on the upper surface compared with those of the disk at rest. It was also shown that the heating of the disk with ΔT=5K decreased deposition velocity over a fairly broad range of particle sizes. Finally, an approximate deposition velocity model for the rotating disk was suggested. The comparison of the present numerical results with the results of the approximate model and the available experimental results showed relatively good agreement between them.

• Korean Journal of Remote Sensing
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• v.35 no.1
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• pp.15-28
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• 2019

By applying the method of SAR interferometry to X-band synthetic aperture radar (SAR) image of COSMO-SkyMed, detailed motion patterns of five glaciers in the Parlung Zangbo River basin, Tibetan Plateau, in January 2010 have been derived. The results indicate that flow patterns are generally constrained by the valley geometry and terrain complexity. The maximum of $123.9ma^{-1}$ is observed on glacier No.1 and the minimum of $39.4ma^{-1}$ is found on glacier No.3. The mean values of five glaciers are between 22.9 and $98.2ma^{-1}$. Glaciers No.1, No.2, No.4 and No.5 exhibit high velocities in their upper sections with big slope and low velocities in the lower sections. A moraine lake accelerates the speed of mass exchange leading to a fast flow at the terminal of glacier No.3. These glaciers generally move along the direction of decreased elevation and present a macroscopic illustration of the motion from the northwest to the southeast. The accuracy of DEM and registration conditions of DEM-simulated terrain phases has certain effects on calculations of glacier flow direction and velocity. The error field is relatively fragmented in areas inconsistent with the main flow line of the glaciers, and the shape and uniformity of glacier are directly related to the continuous distribution of flow velocity errors.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11b
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• pp.38-41
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• 2001

The combustion characteristics of the disilicides molybdenum system have been studied experimentally. The pertinent reaction parameters that control self-propagating high temperature synthesis reactions have been examined. These include reactant particle size, powder mixing and compaction, reaction stoichiometry, diluents. The influence of experimental variables on integrity, uniformity, structure, and related material properties will be discussed. Formation mechanism of $MoSi_2$ during SHS might be different and depending on experimental conditions.

• Journal of Advanced Marine Engineering and Technology
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• v.20 no.4
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• pp.81-89
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• 1996

In the present study, the unsteady in a square-selctional 180.deg. curved duct are experimentally investigated. The experimental study using air in a square-sectional 180.deg. curved duct is carried out to measure axial velocity distributions with data acquisition and processing system. In this system, Rotating Machinery Resolver(RMR) and PHASE Software are used to obtain the results of unsteady flows. In conclusion, the exact measurement of unsteady flow using LDV system depends upon uniformity of metreials, duct thickness, and scattered particles.

• Proceedings of the Korean Fiber Society Conference
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• 1996.10a
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• pp.29-34
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• 1996

In the present paper, the flow distribution in the hot air drying chamber of a sizing machine was numerically analyzed with respect to the geometries of the intake duct to obtain the more uniform flow distribution in the chamber. The result shows that the velocity distribution in the inlet of the chamber was significantly dependent on the the geometry of the intake duct. The degree of the non-uniformity in the chamber was reduced as the incident angle of the intake duct became to be smaller.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.38-41
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• 2001

The combustion characteristics of the disilicides molybdenum system have been studied experimentally. The pertinent reaction parameters that control self-propagating high temperature synthesis reactions have been examined. These include reactant particle size, powder mixing and compaction, reaction stoichiometry, diluents. The inf1uence of experimental variables on integrity, uniformity, structure, and related material properties will be discussed. Formation mechanism of MoSi$_2$ during SHS might be different and depending on experimental conditions.