• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.6
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• pp.45-54
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• 2004

Usually, according as accumulation degree of semi-conductor element increases, dynamic mistake test time increases sharply, and use of pattern generator is essential at manufacturing process to solve these problem. In this paper, we designed the PLD(Programmable Logic Device) circuit of pattern generator to examine dynamic mistake of semi-conductor element. Such all item got result that is worth verified action of return trip and function through simulation, and satisfy.

• Transactions of the Korean hydrogen and new energy society
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• v.31 no.5
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• pp.480-488
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• 2020

This study was conducted to improve the flow uniformity inside the chip tester through changing the flow path formation according to the inlet and outlet position of chamber. The internal flow and velocity distributions of the modified chamber models (Cases 1-3) were compared with the reference chamber model through three-dimensional Reynolds-averaged Navier-Stokes equations with k-ε turbulence model. The modified chamber models showed the superior flow uniformity characteristics compared to the reference chamber model. To investigate the flow uniformity in the chip tester, the standard deviation of the velocity was defined and compared. Through the internal flow analysis and assesment of the standard deviation, Case 2 among the test cases including the reference model showed the best flow uniformity generally.

• Journal of the Korean institute of surface engineering
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• v.41 no.1
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• pp.38-42
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• 2008

316L stainless steel welding tube was electrolytically polished and the inner surface characteristics of the tube were tested. Electro-polishing variables such as current, voltage, concentration of electrolyte and electropolishing time were changed to seek for optimum condition. These makes a optimum conditions for the electro-polishing as 4000 A, 9 V, 1.7 specific gravity of electrolyte, and 30 minute of electro-polishing time. It makes the surface roughness as Ra < $0.25{\mu}m$. XPS test resulted as the ratio of CrO/FeO equals or more to 3/1. AES test resulted as the thickness of CrO film of $38{\AA}$. DTA test resulted as the tube did not react with $N_2,\;H_2\;and\;O_2$ gas below 1073K. As summarize above results, the electro- polished 316L stainless steel welding tube satisfied the conditions to apply as a pipeline for semi- conductor production facility and clean room.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.613-617
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• 2001

The test items like as endurance, air leakage and oil endurance test is requested for reliability evaluation about O-ring which is a kind of core machinery accessories of semi-conduct manufacturing equipment. For verification of these, we design and manufactured a test system for endurance, air leakage and oil endurance of O-ring for semi-conduct manufacturing equipment, and also performed the test for two kinds of O-ring, as it were Viton and Kalretz. The characteristics of this test equipment consist in realization of the test conditions of semi-conduct manufacturing equipment and satisfying the test method. The test conditions are cut gas, vacuum grade, temperature and revolution numbers in the endurance test system, vacuum grade and temperature in the air leakage test system, temperature and time in the oil endurance test system. The separating test results for wearing which is an oil endurance test item, the wearing index of domestic produced Viton O-ring is higher than foreign product by 2%, wearing rate of Kalretz O-ring better than Viton O-ring by 17%, and particles existed in various place. The test result of air leakage which is measured through the RGA sensor used Helium, the vacuum grade was $10^-3$Torr. And the test result of oil endurance, the volume change rate was 7~15%. Hereafter, we intend to analysis the reliability test evaluation and to utilize for domestic manufacturing companies by establishing data base and developing reliability softwares.

• 대한공업교육학회지
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• v.38 no.2
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• pp.1-26
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• 2013

This study inquired following research questions by a narrative research method : What was the job of an engineer in mechanical design field? How did he fulfill his job-related learning in his workplace? What were the context and the characteristic of the job-related learning in the workplace? And some implications of the job-related learning on engineering education were discussed. We identified that the research participant's career as a mechanical engineer has developed through three stages. At first, he engaged on conceptual design of a semi-conductor test machine through self-initiated learning from basic to whole system of the machine. At second stage, he leaded a design group for the concrete design of a ball type semi-conductor test machine. In this stage he learned the meaning of cooperation and cooperative learning. At third stage, he initiated to found an entrepreneur company that was specified to design a semi-conductor test machine. He became CEO of the company. He learned the R & D policy making through contacts with global company, visiting exhibition in abroad. Eventually his main task as a mechanical engineer was the problem solving in the process of machine design. He had experienced and learned through his works : project management, independent fulfilling of tasks, functional analysis and reverse engineering, conceptualizing and test, cohesive cooperation, dialogue and discussion, mediation of conflict, human relationship, leadership. The implication of the narrative analysis on engineering education is, proposed, to give the students more chances to experience and to learn such activities.

• Proceedings of the KIEE Conference
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• 1999.11d
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• pp.1105-1107
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• 1999

The purpose of termination for high voltage tests of XLPE power cable is to prevent flashover during the breakdown test of specimen as well as to withstand the specified voltage between its conductor and screen without failure. For easier treatment and simpler construction of testing termination, resistivity grading method using semi-conductive material was employed. Based on the fundamental theory, its failure characteristics by changing the resistivity of semi-conductive material on the insulation surface was investigated. With two layers construction by difference resistivity on their surfaces, much improved result than that of one resistivity was obtained through the experiment for MV cable.

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.2020-2022
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• 2000

The cross-linked polyethylene(herein after XLPE) insulated power cable emit the methane($CH_4$)gas in the course of chemical cross-linking process. The general stranded conductor easily discharge this methane gas through the gap of each stranded wires. But the special stranded conductor that filled with semi-conducting rubber compound to prevent water penetration which is applied to water proof type of cable(22.9kV CN/CV-W), disturb the methane gas emission. The pre-mold type cable joint shall be expanded gradually by emit of gas left in XLPE insulation. For example, sometimes the corona problem outbreak on a new power distribution line, resulted from the gap between the sleeve and semi-conductive layer of cable joint. If above mentioned problem especially happened on the way of operating. We have to shut down the line and try to discharge the methane gas in cable joint. In this point, we would like to explain the mechanism of methane gas & cable joint and our test result briefly. At last, we are pleased to introduce the solution for preventing reoccurrence of this problem.

• Journal of the Korean institute of surface engineering
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• v.29 no.1
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• pp.60-72
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• 1996

A photoetching process is widely used for small and high precision parts in machinery, electronic and semi-conductor industries. One of the high precision parts, grid is very important part of digitron which use electron display, and it is fabricated by only photoetching process because of high precision. In this study, to develop high precision digitron grid, characteristics of etching solution were investigated with electrochemical test, that was potentiodynamic test and immersion test in the ferric chloride solution and added some additives. Based on the electrochemical etching test, grid was fabricated by continuous photoetching process at various etching condition. From the result of measured line width and etching depth under-cut and etching factor were calculated. For the fabrication of 25$\mu\textrm{m}$ line width, optimal etching condition was etching temperature 40~$45^{\circ}C$, spray pressure 1.5kg/$\textrm{cm}^2$ and etching time 3~4min.

• Journal of the Semiconductor & Display Technology
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• v.2 no.2
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• pp.25-30
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• 2003

In the case of a vibration sensitive equipment, it require a vibration free environment to provide its proper function. Especially, lithography and inspection device, which have sub-nanometer class high accuracy and resolution, have come to necessity for producing more improved Giga Class semi conductor wafers. This high technology equipments require very strict environmental vibration criteria in proportion to the accuracy of the manufacturing. In this paper, the dynamic analysis and modal test were performed to evaluate the dynamic properties of the constructing clean room structure. Based on these results, a structural dynamic modification(SDM) were required to satisfiy the vibration allowable limit for pression machine. Therefore, in order to improve the dynamic stiffness of clean room structure, the VSD system which can control the force applied on structure, were adopted and its utility were proved from dynamic test results of the improved structure after a modification work.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.19 no.3
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• pp.280-287
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• 2009

High-tech microelectronics industry is known as one of the most chemical-intensive industries. In Korea, Microelectronics industry occupied 38% of export and 16% of working employees work in microelectronics industry. But, chemical information and health hazards of high-tech microelectronics manufacturing are poorly understood because of rapid development and its penchant for secrecy. We need to investigate on chemical use and exposure control. We Site-visits to 6 high-tech microelectronics manufacturing company which have cleanroom work using over 1,000kg organic solvents (5 semi-conductor chips and its related parts company, 1 liquid crystal display (LCD)). We reviewed their data on chemical use and ventilation system, and measured TVOCs (Total Volatile Organic Compounds) and carbon dioxide concentration. All cleanroom air passed through hepa filters to acheive low particle levels and only 1 cleanroom uses carbon filters to minimize the organic solvents exposures In TVOC screening test, Cleanroom for semi-conductor chips and its related parts company with laminar down flow system (e.g. class 1~100) showed nondetectable level of TVOCs concentration, but Cleanroom for liquid crystal display (LCD) with conventional flow system (e.g. class 1,000~10,000) showed 327 ppm as TVOCs. Acetone concentration in cleanroom for Jig cleaning, LC Injection, Sealing processes were 18.488ppm (n=14), 49.762 ppm (n=15), 8.656 ppm (n=14) as arithmetric mean. Acetone concentration in cleanroom for LCD inspection process was 40ppm (n=55) as geometric mean, where the range was 7.8~128.7ppm and weakly correlated with ventilation rate efficiency(r=0.44, p<0.05). To control organic solvents in cleanrooms, chemical and carbon filters should be installed with hepa filters. Even though their volatile organic compounds concentration was not exceed to occupational exposure limits, considering of entrance limited cleanroom environment, long-term period exposure effects and adverse health effects of cleanroom worker need further reseach.