• 한국윤활학회:학술대회논문집
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• 한국윤활학회 1998년도 제28회 추계학술대회
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• pp.166-174
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• 1998

The distribution of oil film thickness in piston were measured by induced fluorescence method. A Xe lamp was used as light source. Coumarine-6 was mixed with oil as the fluorescent dye. Fluorescent signal which is proportional to the oil film thickness was acquired by CCD camera and transmitted to the personal computer as video signal. In order to solve the problem of measurement system, irregular distribution and unstability of light intensity, as well as to know the relationship between the oil film thickness and output signal, three different calibration techniques were used. Motoring and firing tests were performed in a single cylinder research engine with transparent liner. By analyzing the oil film thickness converted from the photographed image, it was observed that each of three piston rings scrapes the oil both upward and downward and oil film thickness is not uniform horizontally at a given piston land. The amount of oil in each land was considerably affected by the engine load. It is thought that the blow-by gas blows the oil down to the crankcase.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집 Vol.14 No.1
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• pp.176-180
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• 2001

There are several factors causing re-work in CMP process such as improper polish time calculation by operator. removal rate decline of the polisher, unstable in-suit pad conditioning, slurry supply module problem and wafer carrier rotation inconsistancy. And conclusively those fundimental reason for the re-work rate increasement is mainly from the cycle time delay between wafer polish and post measurement. Therefore, Wafer thickness measurement in wet condition could be able to remove those improper process conditions which may happen during the process in comparison with the conventional dried wafer measurement system and it can be able to reduce the CMP process cycle time. CMP scrap reduction by overpolish, re-work rate reduction, thickness control efficiency also can be easily achieved. CMP Equipment manufacturer also trying to develop integrated system which has multi-head & platen, cleaner, pre & post thickness measure and even control the polish time from the calculated removal rate of each polishing head by software. CMP re-work problem such as over & under polish by target thickness may result in the cycle time delay. By reducing those inefficient factors during the process and establish of the automatic process control, CLC system need to be adopted to maximize the process performance. Wafer to Wafer Polish Time Feed Back Control by measuring the wafer right after the polish shorten the polish time calculation for the next wafer and it lead to the perfact Post CMP target thickness control capability. By Monitoring all of the processed the wafer, CMP process will also be stabilize itself.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집
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• pp.176-180
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• 2001

There are several factors causing re-work in CMP process such as improper polish time calculation by operator, removal rate decline of the polisher, unstable in-suit pad conditioning, slurry supply module problem and wafer carrier rotation inconsistency. And conclusively those fundimental reason for the re-work rate increasement is mainly from the cycle time delay between wafer polish and post measurement. Therefore, Wafer thickness measurement in wet condition could be able to remove those improper process conditions which may happen during the process in comparison with the conventional dried wafer measurement system and it can be able to reduce the CMP process cycle time. CMP scrap reduction by overpolish, re-work rate reduction, thickness control efficiency also can be easily achieved. CMP Equipment manufacturer also trying to develop integrated system which has multi-head & platen, cleaner, pre & post thickness measure and even control the polish time from the calculated removal rate of each polishing head by software. CMP re-work problem such as over & under polish by target thickness may result in the cycle time delay. By reducing those inefficient factors during the process and establish of the automatic process control, CLC system need to be adopted to maximize the process performance. Wafer to Wafer Polish Time Feed Back Control by measuring the wafer right after the polish shorten the polish time calculation for the next wafer and it lead to the perfect Post CMP target thickness control capability. By Monitoring all of the processed the wafer, CMP process will also be stabilize itself.

• Nuclear Engineering and Technology
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• 제17권1호
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• pp.25-33
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• 1985

경수형 원자로의 운전과 안전성 해석을 위해 열수력학적 모형을 개발하는 것이 하나의 중요한 과제이다. 특히, 2상류의 열수력학적 모형을 개발하기 위해서는 기포율, 액체막 두께, 유동 영역과 같은 중요한 변수들을 실제로 측정한 값이 필요하다. 본 연구의 목적은 초음파 Pulse-echo 방법을 이용하여 액체 두께를 실험적으로 측정하고, 이론치와 비교 분석하여 (1) 관벽의 두께, (2) 초음파의 주파수, (3) 관벽의 재질 등이 액체막 두께 측정에 미치는 영향을 분석하는 데에 있다. 평판협 (Plate-type)과 관(Tube-type)으로 된 시험관을 이용하여 수평으로 놓인 물-공기의 층류계 (a horizontal airwater stratified system)를 만들어 일련의 액체막 두께 측정 실험을 수행하였다. 시험관의 벽 두께와 초음파 Pulse-echo 의 주파수를 변화시키면서 액체막 두께 측정을 반복하였다. 또한, 관벽의 acoustic impedance가 초음파 Pulse-echo 방법으로 액체막 두께를 측정할 때, 어떠한 영향을 주는가도 아울러 파악하기 위해서 스텐레스 강과 폴리아크릴 (Polyacrylate) 등 재질이 다른 두 개의 격리봉 (Standonff rod) 을 사용하여 액체막 두께를 측정하였다. 이렇게 하여 얻은 실험 결과를 제시하고 실제로 측정한 액체막 두께와 비교 분석하였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.565-568
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• 2005

We describe a new scheme of dispersive white-light interferometer that is capable of measuring the thickness profile of thin-film layers, for which not only the top surface height profile but also the film thickness of the target surface should be measured at the same time. The interferometer is found useful particularly for in-situ inspection of micro-engineered surfaces such as liquid crystal displays, which requires for high-speed implementation of 3-D surface metrology.

• 반도체디스플레이기술학회지
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• 제2권2호
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• pp.9-15
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• 2003

This paper proposes a thickness measurement method of silicon-oxide and poly-silicon film deposited on 12" silicon wafer for spin etcher. Halogen lamp is used as a light source for generating a wide-band spectrum, which is guided and focused on the wafer surface through a optical fiber cable. Interference signal from the film is detected by optical sensor to determine the thickness of the film using spectrum analysis and several signal processing techniques including curve-fitting and adaptive filtering. Test wafers with three kinds of priori-known films, polysilicon(300 nm), silicon-oxide(500 nm) and silicon-oxide(600 nm), are measured while the wafer is spinning at 20 Hz and DI water flowing on the wafer surface. From experiment results the algorithm presented in the paper is proved to be effective with accuracy of maximum 0.8% error.rror.

• Journal of information and communication convergence engineering
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• 제15권4호
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• pp.250-255
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• 2017

In this paper, we propose a method of detecting the region for measuring intima-media thickness (IMT). The existing methods for IMT measurement are automatic, but the region used for measuring IMT is not detected automatically but often set by the user. Therefore, research on detecting the intima-media region is needed for fully automated IMT measurement. The proposed method uses a morphological feature of the carotid artery visible as two long high-brightness horizontal lines at the upper and lower parts. It uses Gaussian blurring, ends-in search stretching, color quantization using a color-importance-based self-organizing map, and morphological operations to emphasize and to detect the morphological feature. The experimental results for evaluating the performance of the proposed method showed a 97.25% (106/109) success rate. Therefore, the proposed method can be used to develop a fully automated IMT measurement system.

• Journal of Mechanical Science and Technology
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• 제15권9호
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• pp.1268-1273
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• 2001

To successfully establish the ELID-grinding, it is important to properly select the electrolytic condition according to grinding conditions. Currently, the selection of electrolytic condition is mainly dependent on the operators experience, which is one of difficulties preventing the successful application of ELID technique. In this study, an in-process measurement system of the insulating layer using two gap sensors-a capacitance type and an eddy current type-are developed and the change of the thickness of insulating layer during ELID grinding is detected. Evaluation experiments show the possibility to control the electrolytic condition through the in-process measurement of the layer status.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2012년도 추계학술대회 논문집
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• pp.409-410
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• 2012

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2009년도 춘계학술대회 논문집
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• pp.249-250
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• 2009