• Proceedings of the KSME Conference
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• 2008.11a
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• pp.585-589
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• 2008

This study is performed to analyze the fluid flow about 150mm shower heads of semiconductor device. Under the air pressure, the ideal gas of moving fluid is injected as 5m/s velocity into inlet of shower heads and the flow distribution in shower heads is measured according to pitch of plasma distribution device. As results, the maximum and minimum value of fluid velocity are investigated with their position. The velocity values at outlet are also studied. From two experiment using the plasma distribution device, the results of CFD are compared with the experimental results. That results shows stable flow of fluid in that case of corrected design from CFD.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.459-460
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• 2011

• Transactions of the Korean Society of Mechanical Engineers B
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• v.23 no.3
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• pp.419-430
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• 1999

Measurements of local blowing ratio and ammonia-diazo flow visualizations have been conducted for a shower-head film cooling on a first-stage turbine stator. In this study, six rows of normal holes are drilled symmetrically on the semicircular leading edge of a simulated blunt body. The measurements show that for an average blowing ratio based on freestream velocity, M, of 0.5, local average mass flow rate through the first two rows of the holes is less than those through the second and third two rows of the holes, and the fraction of mass flow rate through the first two rows to total mass flow rate has a tendency to increase with the increment of M. The flow visualizations reveal that the injection through the first two row results in inferior film coverage even In the case of M = 0.5, meanwhile the row of holes situated at farther downstream location provides higher film-cooling performances for all tested M. This is because film-cooling effectiveness depends on local mainflow velocity at the hole location as well as the mass flow rate through each row.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.24 no.2
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• pp.177-187
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• 2000

Measurements of temperature fields and film-cooling effectiveness have been conducted for a shower-head film cooling on the leading edge of a blunt body, which simulates a first-stage turbine stator. In this study, three injection cases are employed for an average blowing ratio based on freestream velocity, M, of 0.5, 1.0 and 1.5. Two (Case 1), four (Case 2) and six (Case 3) rows of normal holes are symmetrically drilled on the three tested circular-cylinder leading edges. The measurements show that regardless of M, the film-cooling effectiveness increases as the injection row is situated at farther downstream location. In Case 1, the film-cooling effectiveness is highest for M = 0.5 and lowest for M = 1.5. On the contrary, in Case 3, the film-cooling effectiveness is highest for M = 1.0 and lowest for M = 0.5. When M = 0.5, the film coverage by the first row of the injection holes deteriorates as the number of the injection row increases. In particular, the film-cooling effectiveness due to the injection through the first row of the holes in Case 3, has a nearly zero value.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.1475-1480
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• 2004

Plasma Enhanced Chemical Vapor Deposition (PECVD) process uses unique property of plasma to modify surfaces and to achieve the high deposition rates. In this study, a vertical thermal RF-PECVD (Radio Frequency-PECVD) reactor is modeled to investigate thermal flow and the deposition rates with various shapes of the showerhead. The showerhead in the CVD reactor has the shape of a ring and gases are injected in parallel with the susceptor, which is a rotating disk. In order to achieve the high deposition rates, we have simulated the thermal flow fields in the reactor with several showerhead models. Especially the effects of the number of injection holes and the rotating speed of the susceptor are studied. Using a commercial code, CFDACE, which uses FVM (Finite Volume Method) and SIMPLE algorithm, governing equations have been solved for the pressure, mass-flow rates and temperature distributions in the CVD reactor. With the help of the Nusselt number and Sherwood number, the heat and mass transfers on the susceptor are investigated. In order to characteristics of measure the flatness of the layer, furthermore, the relative growth rate (RGR) is considered.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.479-483
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• 2010

In this paper, a study for hybrid rocket combustion with cylindrical multi-port grain and swirl injector was performed to take advantage of regression rate. Change of the regression rate in the multi-port grain the placement of a swirl Injector experiments were performed. The results of multi-port grain using swirl injector were showed that the regression rate was increased compare with the shower head type injector.

• Journal of the Semiconductor & Display Technology
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• v.19 no.2
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• pp.16-21
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• 2020

How accurately reproducible energy is delivered to the wafer in the process of making thin films using PE-CVD (Plasma enhanced chemical vapor deposition) during the semiconductor process. This is the most important technique, and most of the reaction on the wafer surface is made by thermal energy. In this study, we studied the method of monitoring the change of thermal energy transferred to the wafer surface by monitoring the temperature change according to the change of the thin film formed on the showerhead facing the wafer. Through this research, we could confirm the monitoring of wafer thin-film which is changed due to abnormal operation and accumulation of equipment, and we can expect improvement of semiconductor quality and yield through process reproducibility and equipment status by real-time monitoring of problem of deposition process equipment performance.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.33 no.5
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• pp.344-349
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• 2020

Modern thin film deposition processes require high deposition rates, low costs, and high-quality films. Atmospheric pressure plasma-enhanced chemical vapor deposition (AP-PECVD) meets these requirements. AP-PECVD causes little damage on thin film deposition surfaces compared to conventional PECVD. Moreover, a higher deposition rate is expected due to the surface heating effect of atomic hydrogens in AP-PECVD. In this study, polycrystalline silicon thin film was deposited at a low temperature of 100℃ and then AP-PECVD experiments were performed with various plasma powers and hydrogen gas flow rates. A deposition rate of 15.2 nm/s was obtained at the VHF power of 400 W. In addition, a metal foam showerhead was employed for uniform gas supply, which provided a significant improvement in the thickness uniformity.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.05a
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• pp.61-64
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• 2009

A study on the variation of combustion performance by oxidizer/fuel ratio was conducted. Shower head type injector was used. Injector propelled by liquid kerosene and liquid hydrogen peroxide. The designed operation condition for thrust and combustion pressure were 200N and 10bar. It is found that optimum oxidizer/fuel ratio.

• Journal of the Korean Applied Science and Technology
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• v.34 no.2
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• pp.394-399
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• 2017

The goal of this study is to suggest the technology and the way of developing ergonomic shampoo device, which is able to adjust the height and to be devided, and it uses ozone water. As a result of developing the device, it can complete better the effect of preventing water splash than existing devices by making neck holding part higher. And it is also made with ergonomic design, therefore, the head of shampoo candidate can be drawn into it more easily. By adjusting water temperature($38^{\circ}C$) to candidate's taste through water heater attached to water bucket, when a candidate is being shampooed, it can help keep warm shampooing without delaying. We could know the process through temperature sensor. And we could also know the utility of its own sterilization(1PPM) and purification. Finally, ozone water was measured for 20 minutes and the ozone concentration was measured to be less than 1 PPM to ensure stability. All parts of the mobile shampoo stand together with the hot water device and the ozonated water conversion device were designed so as not to be inconvenient for the user to use.