• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.78-81
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• 2004

A technical performance of the coating depends greatly on the thickness of painting film or coating film. Therefore the confirmed report of the technique to measure accurately is essential to the coating film thickness for the assessment about a coating quality performance. In this paper, two gap sensors - eddy current gap sensor and capacitance gap sensor - which has a different operating principle were used to measure the thickness of a nonmagnetic substance coating film such as paint, enamel or ceramic that was coated on the metallic material. A capacitance gap sensor was used to measure the distance between the sensor head and a coating film and an eddy current gap sensor to measure the distance between the sensor head and a base metal. Then the thickness of a coating film was obtained by the difference of two measurement value. At this result, the suggested dual sensor can measure an arbitrary film thickness to be coated on a base metal as the measurement value of coating thickness exists accurately within the 2％ error.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2003.11a
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• pp.368-376
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• 2003

In this research, DLC thin films are produced as several hundred nm thickness by PE-CVD method. And then these thin films are estimated tribological characteristics to find out useful possibilities as a protecting film for high-quality function and life extension at MEMs by mechanical properties observation . These are measured thickness and residual stress of DLC coating. Compared after measuring friction coefficient, adhesion force, hardness, cohesive force of coating films. As results all test, we can decide several conclusions. First, friction coefficient decreased, as the load increased. otherwise, friction coefficient increased, as thickness of coating film increased under low load$(1\~50mN)$. Secod, adhesion force increased as thickness of coating films. Third, hardness of coating film is affected by substrate coating film when it is less than thickness of 300nm and it has general hardness of DLC coating film when it is more than thickness of 500nm. Fourth, cohesive force of coating film is complexly affected by hardness, adhesion force, residual stress, etc.

• Journal of the Semiconductor & Display Technology
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• v.2 no.1
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• pp.25-29
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• 2003

The fluid flow, mass transfer, heat transfer and film thickness variation during the spin coating process are numerically studied. The model is said to be I-dimensional because radial variations in film thickness, concentration and temperature are ignored. The finite difference method is employed to solve the equations that are simplified using the similarity transformation. In early time, the film thinning is due to the radial convective outflow. However that slows during the first seconds of spinning so the film thinning due to evaporation of solvent becomes sole. The time varing film thickness is analyzed according to the wafer spin speed, the various solvent fraction in the coating liquid, and the various solvent vapor fraction in the bulk of the overlying gas during the spin coating is estimated.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.6
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• pp.425-428
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• 2013

In this paper, we present a novel hydrophilic coating material (Wellture Finetech, Korea) which can be utilized as a coating layer for anti-contamination for electrical and electronic system. The coating material was deposited on 4 inch silicon wafer with several different film thickness. The film thickness was controlled by spin coating speed. After curing of the film, we have scratched by permanent marker to check self-cleaning property of the film. Also we have executed several mechanical tests of the films. As the spin coating speed is increased, the film thickness was thinned from 230 nm to 125 nm. Contact angle of the film was lowered from $30^{\circ}$ to $12^{\circ}$ as the spin coating speed is increased from 700 to 2,500 rpm. On permanent marker scratched film surface coated at 1,000 rpm, we have poured regular city water to investigate self cleaning property of the film. The scratches were gradually separated from the film surface due to super-hydrophilicity of the film. Hardness of spin coated film was 9H measured by ASTM D3363 method. and adhesion of all film was 5B tested by ASTM D3359 method. Also, to get exact hardness value of the film, we have utilized a nano-indenter. As spin speed is increased, the hardness of film was increased from 3 GPa to 5 GPa.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.11a
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• pp.129-132
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• 1998

In this paper, we have studied the effect of electron reflection on shadow mask on which tungsten oxide film is coated and have studied the variation of beam mislanding with coating thickness in CRT. We found the method to be able to control coating thicknessed and optimum coating thickness of tungsten oxide film was 1∼2$\mu\textrm{m}$. Mislanding of electron beam was reduced about 20∼48% with increasing coating thickness in CRT

• Corrosion Science and Technology
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• v.21 no.2
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• pp.121-129
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• 2022

A study on water-based epoxy coated on mild steel using the electroplating method was conducted to optimize the process parameters for dry film thickness to achieve superior paint quality at optimal cost in an automotive plant. The regression model was used to adjust various parameters such as electrode voltage, bath temperature, processing time, non-volatile matter, and surface area to optimize the dry film thickness. The average dry film thickness computed using the model was in the range of 15 - 35 ㎛. The error in the computed dry film thickness with reference to the experimentally measured dry film thickness value was - 0.5809%, which was well within the acceptable limits of all paint shop standards. Our study showed that the dry film thickness on mild steel was more sensitive to electrode voltage and bath temperature than processing time. Further, the presence of non-volatile matter was found to have the maximum impact on dry film thickness.

• Journal of Korean Ophthalmic Optics Society
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• v.7 no.2
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• pp.175-180
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• 2002

Use spctrophotometer to estimate thin film uniformity of lens, Compare, and analyze thin film uniformity availability selecting two peaks of Reflectance(R%) measuring on spectrum. Wavelength dependence's Reflectance in position of center, middle and edge of lens etc... obtain thin film's thickness (t) from Wavelength region (${\lambda}_1,{\lambda}_2$) of two peaks of Reflectance. $$t=\frac{1}{2(n^2-\sin^2{\theta})^{1/2}}{\times}\frac{{\lambda}_1{\lambda}_2}{{\lambda}_2-{\lambda}_1}$$ If Reflectance pattern is uniformity value in position of center middle of lens, edge etc... thin film has uniformity. Applied thin film uniformity estimation method to 1st layer $MgF_2$(n=1.38) coating lens. It was about thin film's thickness difference 360nm. Can analyze coating lens' thin film uniformity easily from Reflectance relationship measurement about Wavelength dependence.

• Tribology and Lubricants
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• v.25 no.6
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• pp.414-420
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• 2009

In this study, using the general expressions predicting the pressure under a blade and the volume of coating fluid passing through the blade edge, it is predicted the change of the coating wet film thickness related with various parameters determining the characteristics of this blade coating process. Using the results of this research, it can be found the optimized coating wet film thickness taking into account the parameters related with various coating process on various metal surfaces will be able to be predicted.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2002.11a
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• pp.20-26
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• 2002

The fluid flow, mass transfer, heat transfer and film thickness variation during the spin coating process are numerically studied. The model is said to be 1-dimensional because radial variations in film thickness, concentration and temperature are ignored. The finite difference method is employed to solve the equations that are simplified using the similarity transformation. In early time film thinning is due to the radial convective outflow. However that slows during the first seconds of spinning so the film thinning due to evaporation of solvent becomes sole. The time various film thickness is analyzed according to the var ious solvent fraction in the coating liquid and in the bulk of the overlying gas and the temperature variation in the liquid film during the spin coating is estimated.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1997.04a
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• pp.101-110
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• 1997

An experimental study was performed to discover the tribological behaviors of pure silver coated 52100 bearing steel. Pure silver coatings ranging from 80 nm to several micrometers were produced by a thermal evaporation coating method. Experiments using a thrust ball bearing-typed rolling test-rig were performed for the investigations of the influence of coating thickness on the tribological rolling behavior. The existence of optimum film thickness which revealed minimum rolling resistance was discovered. A careful analysis on the contact surfaces for the optimum film thickness has been performed. The contact patches produced by the transferred silver films played an important role for the rolling resistance to keep low.