• Transactions of the Korean Society of Automotive Engineers
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• v.2 no.5
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• pp.1-10
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• 1994

By applying of total electric capacitance method on engine connecting rod bearing during engine operating, the influence of engine operating conditions and lubricants on bearing oil film thickness was investigated. Minimum oil film thickness increases with kinematic viscosity, but as increasing of viscosity, the increasing ratio of film thickness is reduced. Also minimum oil film thickness increases with engine speed but there is a limit. Above this limit, film thickness decreases in opposition because of crankshaft inertia. As increasing of engine torque and oil temperature, munimum oil film thickness decreases linearly. For non-Newtonian oils, the correlation between $100{\circ}C$ kinematic viscosity and munimum oil film thickness is very poor.

• 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.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1997.11a
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• pp.364-368
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• 1997

We have investigated Pt and RuO$_2$as a bottom electrode for a device application of PZT thin film. The bottom electrodes were prepared by using an RF magnetron sputtering method. We studied some of the property influencing factors such as substrate temperature, gas flow rate, and RF power. An oxygen partial pressure from 0 to 50% was investigated. The results show that only Ru metal was grown without supp1ying any O$_2$gas. Both Ru and RuO$_2$phases were formed for O$_2$partial pressure between 10∼40%. A Pure RuO$_2$ phase was obtained with O$_2$partial pressure of 50%. A substrate temperature from room temperature to 400$^{\circ}C$ was investigated with XRD for the film crystallinity examination. The substrate temperature influenced the surface morphology and the resistivity of Pt and RuO$_2$as well as the film crystal structure. From the various considerations, we recommend the substrate temperature of 300$^{\circ}C$ for the bottom electrode growth. Because PZT film growth on top of bottom electrode requires a temperature process higher than 500$^{\circ}C$, bottom electrode properties were investigated as a function of post anneal temperature. As post anneal temperature was increased, the resistivity of Pt and RuO$_2$was decreased. However, almost no change was observed in resistivity for an anneal temperature higher than 700$^{\circ}C$. From the studies on resistivity and surface morphology, we recommend a post anneal temperature less than 600$^{\circ}C$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11a
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• pp.539-542
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• 2004

The $ZnGa_2O_4$ phosphor target is synthesized through solid-state reactions at the calcine temperature of $700^{\circ}C$ and sintering temperature of $1300^{\circ}C$ in order to deposit $ZnGa_2O_4$ phosphor thin film by rf magnetron sputtering system. The $ZnGa_2O_4$ phosphor thin film is deposited on Si(100) substrate and prepared $ZnGa_2O_4$ phosphor thin film is annealed by rapid thermal processor(RTP) at $700^{\circ}C$, 15sec. The x-ray diffraction patterns of $ZnGa_2O_4$ phosphor target and thin film show the position of (311) main peak. The cathodoluminescenre(CL) spectrums of $ZnGa_2O_4$ phosphor thin film show main peak of 420nm and maximum intensity at the substrate temperature of $500^{\circ}C$ and annealing temperature of $700^{\circ}C$ 15sec.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.381.1-381.1
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• 2014

In this study, we investigated the deposition behavior and the etch resistivity of plasma polymerized carbon hardmask (ppCHM) film with the variation of process temperature. The etch resistivity of deposited ppCHM film was analyzed by thickness measurement before and after direct contact reactive ion etching process. The physical and chemical properties of films were characterized on the Fourier transform infrared (FT-IR) spectroscope, Raman spectroscope, stress gauge, and ellipsometry. The deposition behavior of ppCHM process with the variation of temperature was correlated refractive index (n), extinction coefficient (k), intrinsic stress (MPa), and deposition rate (A/s) with the hydrocarbon concentration, graphite (G) and disordered (D) peak by analyzing the Raman and FT-IR spectrum. From this experiment we knew an optimal deposition condition for structure of carbon hardmask with the higher etch selectivity to oxide. It was shown the density of ppCHM film had 1.6~1.9 g/cm3 and its refractive index was 1.8~1.9 at process temperature, $300{\sim}600^{\circ}C$. The etch selectivity of ppCHM film was shown about 1:4~1:8 to undoped siliconoxide (USG) film (etch rate, 1300 A/min).

• Nuclear Engineering and Technology
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• v.33 no.2
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• pp.241-253
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• 2001

Under severe accidents, the pressure and temperature response has an important role for the integrity of a nuclear power plant containment. The history of the pressure and temperature is characterized by the amount and state of steam/air mixture in a containment. Recently, the heat transfer rate to the structure surface is supposed to be increased by the wavy interface formed on condensate film. However, in the calculation by using CONTAIN code, the condensation heat transfer on a containment wall is calculated by assuming the smooth interface and has a tendency to be underestimated for safety. In order to obtain the best- estimate heat transfer calculation, we investigated the condensation heat transfer model in CONTAIN 1.2 code and adopted the new forced convection correlation which is considering wavy interface. By using the film tracking model in CONTAIN 1.2 code, the condensate film is treated to consider the effect of wavy interface. And also, it was carried out to investigate the effect of the different cell modelings - 5-cell and 10-cell modeling - for KNGR(Korean Next Generation Reactor) containment phenomena during a severe accident. The effect of wavy interface on condensate film appears to cause the decrease of peak temperature and pressure response . In order to obtain more adequate results, the proper cell modeling was required to consider the proper flow of steam/air mixture.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.1014-1017
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• 2001

In recent years, The tantalum nitride(TaN) thin-film has been developed for the electronic resistor and capacitor. In this papers, The effect of thermal annealing in the temperature range of 300∼700$^{\circ}C$ on the sheet resistor properties and microistructure of tantalum nitride(TaN) thin-film deposited by RF sputtering was studied. XRD(X-ray diffractometer) and AFM were used to observe electrical properties and microstructrue of the TaN film and sheet resistance. The TCR properties of the TaN films were discussed in terms of annealing temperature, ratio of nitrogen, crystallization and thin films surface morphology due to annealing temperature. The leakage current of the TaN thin film annealed 400 $^{\circ}C$ was stabilized in the study. How its was found that the sheet resistance in the polycrystalline TaN thin film decreased with increasing the annealing temperature above 600 $^{\circ}C$ after sudden peak upen 400 $^{\circ}C$.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07b
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• pp.1474-1476
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• 2005

ZnO:Al(AZO) has been investigated for the photovoltaic cell or TCO(Transparent Conductive Oxide) of the display, because it has good electrical and optical properties. In this study, the ZnO:Al(AZO) thin film prepared on variation of substrate temperature by FTS(Facing Targets Sputtering) system. In case of TCO, because resistivity and roughness values affect the lighting of the OLED, their factors are very important. Therefore, in this paper, the electrical and optical properties of the AZO thin film were investigated with the deposition conditions and its roughness was investigated on variation of the substrate temperature. In results, AZO thin film deposited with the transmittance over 80% and the resistivity was reduced from $1.36{\times}10^{-3}$ [O-cm] to $4{\times}10^{-4}$ [O-cm] with increasing the substrate temperature from R.T to $200[^{\circ}C]$. Especially, we could obtain the resistivity $4{\times}10^{-4}$ [O-cm] of AZO thin film prepared at working pressure 1[mTorr], input current 0.4[A] and substrate temperature $200[^{\circ}C]$.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.10
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• pp.2675-2685
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• 1994

A study has been conducted to provide the experimental information for the velocity and temperature profiles of steam-air mixutre and to investigate their roles on the film condensation with wavy interface. Saturated gas mixture of steam-air was made to flow through the nearly horizontal$(4.1^{\circ})$ square duct of 0.1m width and 1.56m length at atmospheric pressure, and was condensated on the bottom cold plate. The air mass fraction in the gas mixture was changed from zero(W =0, pure steam) to one(W =1, pure air), and the bulk velocity was varied from 2 to 4 m/s. Water film was injected concurrently to investigate the effect of wavy interface on the condensation. The velocity and temperature profiles were measured by LDA system and thermocouples along the three parameters ; air mass fraction, mixture velocity and film flow rate. The profiles moved toward the interface with increasing steam mass fraction, mixture velocity and film flow rate. The Prandtl and Schmidt numbers were near one in the present experimental range, however there was no complete similarity between the velocity and temperature profiles of gas mixture. And the heat transfer characteristics and interfacial structure were coupled with each other.

• Electrical & Electronic Materials
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• v.10 no.10
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• pp.1005-1010
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• 1997

ZnS:Mn thin film was made by coevaporation with Electron Beam Evaparation(EBE) method. And structural and optical characteristics of ZnS:Mn thin films were investigated by substrate temperature annealing temperature and dopant Mn. When ZnS:Mn thin film was well deposited with cubic crystalline at substrate temperature of 30$0^{\circ}C$ its surface index was [111] and its lattice constant of a was 5.41$\AA$. Also When ZnA:Mn thin film was well made with hexagonal crystalline at substrate temperature of 30$0^{\circ}C$annealing temperature of 50$0^{\circ}C$and annealing time of 60min its miller indices were (0002) (1011), (1012) and (1120). And its lattice constant of a and c was 3.88$\AA$and 12.41$\AA$ respectively. Finally hexagonal ZnS:Mn thin film with dopant Mn of 0.5wt% had fundamental absorption wavelength of 342nm. And so its energy bandgap was about 3.62eV.