• Applied Chemistry for Engineering
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• v.33 no.2
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• pp.229-233
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• 2022

In this study, a gas-liquid hybrid atmospheric pressure plasma reactor of the dielectric barrier discharge method was fabricated and characterized. The solubility of copper oxide in the organic acid solution was increased when argon having a larger atomic weight than helium was used during plasma discharge. There was no significant effect of mixing organic acid solutions under plasma discharge treatment on the variation of copper oxide's solubility. As the applied voltage for plasma discharge and the concentration of the organic acid solution increased, the dissolution and removal power of the copper oxide layer increased. Solubility of copper oxide was more affected by the concentration in organic acid solution rather than the variation of plasma applied voltage. The usefulness of hybrid plasma reactor for the surface cleaning process was confirmed.

• Journal of Applied Reliability
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• v.18 no.1
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• pp.66-71
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• 2018

Purpose: Performance recovered from SCR through cleaning was studied, measuring differential pressure, NOx reduction efficiency, fuel consumption and engine power before and after cleaning. Ideal cleaning intervals are proposed based on SCR mileage and differential pressure. SCR endurance and reliability improvements through cleaning were studied through physicochemical testing of SCR durability at 43,000km 50,000km, and 110,000km respectively. Methods: Engine power, fuel consumption and exhaust gas were measured using engine full load tests and ND-13 MODE by installing the SCR before cleaned at total engine mileages of 400,000 km, 300,000km and 200,000km. The same tests were performed after cleaning the SCR catalytic converter. Endurance and reliability of the SCR cleaning was studied through the same test by SCR catalyst after each 43,000km 50,000km, 110,000km, durability test on SCR cleaning. Conclusion: We confirmed the low-performance of the SCR due to clogging is restored by SCR cleaning technology. The NOx reduction efficiency was restored to 82%, 86% and 88% from 69%, 72% and 79%. As well as the NOx reduction efficiency, it was confirmed that the engine power, fuel consumption and back pressure was restored to fresh SCR levels. As a result of the durability and reliability achieved through SCR cleaning, we confined the appearance and reduction efficiency through visual inspection and ND-13 MODE are similar to new SCR catalysts. Finally, it was judged that there was no change in performance even when driving the SCR without cleaning throughout the 100,000 km mileage warranty.

• Journal of the Microelectronics and Packaging Society
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• v.11 no.1
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• pp.77-85
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• 2004

To evaluate the effect of plasma cleaning on the soldering reliability the plasma cleaning using Ar-10vol%$H_2$ gas was applied on a UBM(Under Bump Metallization). The UBM consisted of Au/ Cu/ Ni/ Al layers which were deposited on a Si-wafer with 20 nm/ 4 $\mu\textrm{m}$/ 4 $\mu\textrm{m}$/ 0.4 $\mu\textrm{m}$ thickness respectively. Sn-3.5%Ag, Sn-3.5%Ag-0.7%Cu and Sn-37%Pb solder balls sized of 500 $\mu\textrm{m}$ in diameter were used. Solder balls on the UBM were plasma reflowed under Ar-10%$H_2$ plasma (with or without plasma cleaning). They were compared with air reflowed solder balls with flux. The spreading ratios of plasma reflowed solder with plasma cleaning was 20-40% higher than that of plasma reflowed solder without plasma cleaning. The shear strength of plasma reflowed solder with plasma cleaning was about 58-65MPa. It showed 60-80% higher than that of plasma reflowed solder without plasma cleaning and 15-35% higher than that of air reflowed solder. Thus it was believed that plasma cleaning for the UBM using Ar-10vol%$H_2$ gas was considerably effective for the improvement of the strength of solder ball.

• Proceedings of the Membrane Society of Korea Conference
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• 1999.10b
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• pp.9-14
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• 1999

• Journal of the Korean Home Economics Association
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• v.20 no.4
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• pp.113-124
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• 1982

We have investited on the efficiency of the electric vacuum cleaners for household use. On this experiment, we have used the Expired Gas Analyer IHO6(SAN-EI, K.K) to get energy expenditure of house cleaning. The testing items are, (1) The difference of energy expenditure of cleaning for the each types of the test floors: Which are P-tile, Tatami, and 4 kinds of carpets. (2) The energy expenditure of cleaning for the room with a given quantity of furnitures: The volumes of furnitures are 0, 3, 10, 20% of the room with 2 kinds of chair. The results of the experiments are as follows. 1. The energy expenditure of cleaning for the types of test floors: Setting the energy expenditure on the basis of P-tile, Tatami needs 20~24% energy expenditure than P-tile, and carpet needs 60~64% energy expenditure than P-tile. 2. Cleaning time: The more the room has many furnitures, the more it takes longer. The types of vacuum cleaners, the Shoulder-type cleaner needs 1.19 times of the Upright-type, and the Cylender-type needs 1.08 times of the Upright-type. 3. The energy expenditure of cleaning for a given quantity of furnitures: The more the rooms has many furnitures, the more the energy expenditure increase. A 10% (20%) increases in the volume of the furniture causes a 100% (200%) increases in the energy expenditure of vacuum cleaners.

• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.796-799
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• 2007

In the bench scale test unit consisting of four commercial filter elements, the traces of the transient pressure around the nozzle and overpressure in the filter cavity were measured to estimate the effect of nozzle on pulse cleaning. For the given pulse cleaning system, the convergent nozzle displayed better performance than the straight one. The optimum ratio of outlet to inside diameter of convergent nozzle was determined, which minimized the pulse gas consumption and maximized the entrainment effect. The angle and height of nozzle convergent part was also optimum operational condition, which is meaningful to the industrial applying.

• Korean Journal of Materials Research
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• v.24 no.8
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• pp.429-433
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• 2014

As the fabrication technology used in FPDs(flat-panel displays) advances, the size of these panels is increasing and the pattern size is decreasing to the um range. Accordingly, a cleaning process during the FPD fabrication process is becoming more important to prevent yield reductions. The purpose of this study is to develop a FPD cleaning system and a cleaning process using a two-phase flow. The FPD cleaning system consists of two parts, one being a cleaning part which includes a two-phase flow nozzle, and the other being a drying part which includes an air-knife and a halogen lamp. To evaluate the particle removal efficiency by means of two-phase flow cleaning, silica particles $1.5{\mu}m$ in size were contaminated onto a six-inch silicon wafer and a four-inch glass wafer. We conducted cleaning processes under various conditions, i.e., DI water and nitrogen gas at different pressures, using a two-phase-flow nozzle with a gap distance between the nozzle and the substrate. The drying efficiency was also tested using the air-knife with a change in the gap distance between the air-knife and the substrate to remove the DI water which remained on the substrate after the two-phase-flow cleaning process. We obtained high efficiency in terms of particle removal as well as good drying efficiency through the optimized conditions of the two-phase-flow cleaning and air-knife processes.

• Journal of Surface Science and Engineering
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• v.54 no.6
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• pp.365-370
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• 2021

In this research, we proceeded with research on plasma resistance of the cleaning process of APS(Atmospheric Plasma Spray)-Y₂O₃ coated parts used for semiconductor and display plasma process equipment. CF₄, O₂, and Ar mixed gas were used for the plasma environment, and respective alconox, surfactant, and piranha solution was used for the cleaning process. After APS-Y₂O₃ was exposed to CF₄ plasma, the surface changed from Y₂O₃ to YF₃ and a large amount of carbon was deposited. For this reason, the plasma corrosion resistance was lowered and contamination particles were generated. We performed a cleaning process to remove the defect-inducing surface YF₃ layer and carbon layer. Among three cleaning solutions, the piranha cleaning process had the highest detergency and the alconox cleaning process had the lowest detergency. Such results could be confirmed through the etching amount, morphology, composition, and accumulated contamination particle analysis results. Piranha cleaning process showed the highest detergency, but due to the very large thickness reduction, the base metal was exposed and a large number of contaminated particles were generated. In contrast, the surfactant cleaning process exhibit excellent properties in terms of surface detergency, etching amount, and accumulated contamination particle analysis.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.3
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• pp.163-170
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• 2016

Regulations for the exhaust gas of diesel vehicles are being strengthened every year. Recently, diesel emission regulations for HC, CO, NOx, and particulate matter (PM) have been subject to very strict standards. In the future, the regulation of PM is expected to become stricter. Accordingly, diesel particulate filters (DPFs) have been applied to most diesel vehicles for PM reduction. With increasing engine mileage, ash and soot from the engine exhaust gas accumulate inside the DPF. This accumulation can damage the DPF or degrade engine performance. Therefore, efficient cleaning of the DPF is critical for the maintenance of the engine. If the DPF is well managed through regular cleaning, it can improve the power and fuel economy of the engine and reduce maintenance costs. Therefore, this study was performed to develop a high-efficiency cleaning method for DPFs and an apparatus that can more effectively clean out the accumulated ash and soot.

• Proceedings of the KIPE Conference
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• 2003.07a
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• pp.260-263
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• 2003

When ICP(Inductive Coupled Plasma type etching and wafer manufacturing is being processed in semiconductor process, a noxious gas in PFC and CFC system is generated. Gas cleaning dry scrubber is to remove this noxious gas. This paper describes a power source device, 2MHz switching frequency class 2kW RF Generator, used as a main power source of the gas cleaning dry scrubber. The power stage of DC/DC converter is consist of full bridge type converter with 100kHz switching frequency Power amplifier is push pull type inverter with 2MHz switching frequency, and transmission line transformer. The adequacy of the circuit type and the reliability of generating plasma in various load conditions are verified through 50$\Omega$ dummy load and chamber experiments result.