MOS 커패시터 절연막의 수명예측법에 관한 연구

이동희,이영일 수원대학교 산업기술연구소 2003 산업기술연구소논문집 Vol.18 No.-

The importance of electrical Insulation materials is increased in the field of electronic industry because of device isolation. In order to expect the exact the degree of degradation and life time, we must not only analyze the degradation mechanism of materials, but the relation equation linking to surrounding circumstance also be established. To estimate the average life, firstly, the scale (δ) and shape (β) parameters of the Weibull distribution must be estimated. The scale (α) parameter and shape (β) parameter are estimated respectively by hrMLE and grMLE. Life expectation method was made by Weibull distribution function, and also we check the possibility of life expectation method by using Arrhenius model. By using Weibull distribution method, we can expect a proper life time of insulation material.

Effects of Two-Step Annealing on Pulsed Laser Ablated PZT Films

이동희 수원대학교 산업기술연구소 2000 산업기술연구소논문집 Vol.15 No.-

Deposition of PZT with UV laser ablation was applied for realization of thin film sensors and actuators. Deposition rate of more than 20nm/min was attained by pulsed KrF excimer laser deposition, which is fairly better than those obtained by the other methods. Perovskite phase was obtained at room temperature deposition with Fast Atom Beam(FAB) treatment and annealing. Smart MEMS(Micro electro-mechanical system) is now a subject of interest in the field of micro optical devices, micro pumps, AFM cantilever devices etc. It can be fabricated by deposition of PZT thin films and micromachining. PZT films of more than 1 micron thickness is difficult to obtain by conventional methods. This is the reason why the author applied excimer laser ablation for thin film deposition. The remanent polarization Pr of 700nm PZT thin film was measured, and the relative dielectric constant was determined to about 900 and the dielectric loss tangent was also measured to be about 0.04. XRD analysis shows that, after annealing at 650 degrees Centigrade in 1 hour, the perovskite structure would be formed with some amount of pyrochlore phase, as is the case of the annealing at 750 degrees Centigrade in 1 hour.

변압기 절연유중 수소 가스 감지가스 검출장치 개발

이동희,이영일,황규현 수원대학교 산업기술연구소 2004 산업기술연구소논문집 Vol.19 No.-

In oil-filled equipment such as transformers, partial discharge or local overheating will make insulating material(oil, kraft paper, proclain and wood) be stressed and generate many sort of gases(CO, CO₂ , H₂, C₂H₄) which are dissolved in transformer oil. The ratio of this gas can make diagnostic techniques of the lifetime of transformer so, it is important to monitoring H₂ gas continuously This paper develops a system of detecting about H₂ gas by using H₂ gas sensor, and we describe operation and performance of this system.

가스 검출장치를 이용한 변압기 절연유중 수소 가스 감지에 관한 연구

이동희,황규현 水原大學校 2004 論文集 Vol.22 No.-

In oil-filled equipment such as transformers, partial discharge or local overheating will make insulating material(oil, kraft paper, proclain and wood) be stressed and generate many sort of gases(CO, CO₂. H₂, C₂H₄) which are dissolved in transformer oil. The ratio of this gas can make diagnostic techniques of the lifetime of transfomer so, it is important to monitoring H2 gas continuously. This paper developes a system of detecting about H₂ gas by using H₂ gas sensor, and we describe operation and performance of this system

Polymide系 濕度센서의 容量特性에 대한 實驗的 考察

李東熙 水原大學校 1992 論文集 Vol.10 No.-

感濕物質로 polyinide를 사용하여 含濕狀態에 따른 이 感濕薄膜의 誘電率變化로부터 相對濕度를 檢出할 수 있는 濕度센서를 製作하여 그 特性을 살펴 보았다. 素子는 IC 製造技術의 適用可能性을 檢討해 보기 위하여 Si 基板上에 設計하여 製作하였다. 實測結果를 解析하기 위해 複合誘電體의 誘電率에 대한 Looyenga 方程式과 固體 內部로의 蒸氣吸收에 대한 Dubinin 方程式을 組合하여 適用해 본 結果 理論値와 實測値가 상당히 잘 一致하였다. The design of a relative humidity sensor is studied in which the principle of operation is based on the change of dielectric constant of a thin film of polyimide. The design of the sensor is established on the Si substrate in such a way that it would be suitable for an integrated-circuit type of fabrication. The studies have shown that the experimental data are described well by the use of Looyenga equation for dielectric constant behavior of the heterogeneous dielectrics coupled with the Dubinin equation to describe the absorption of vapor as a function of relative humidity.

복합 스트레스 Weibull 함수 모델에 의한 절연체의 수명 예측 기법

이동희 수원대학교 산업기술연구소 2002 산업기술연구소논문집 Vol.17 No.-

In this paper, a general approach to obtain probabilistic life models is given, starting from the Weibull distribution function and considering the combined stress life model based on inverse power and Arrhenius model, which is combined stress Weibull function model. To reduce cost and time in life test, step stress pattern can be adapted in accelerated life test, also this paper presents a model that relates the life time distribution under step stressing to that relates under constant stress. The parameters in combined stress Weibull function model are estimated by maximum likelihood(ML) method, and that is popular for analysing data. Maximum likelihood method take the value that maximize the likelihood function as parameter estimation. Performance of the combined stress Weibull function model derived in this paper is verified by several data from the accelerated life test of XLPE films.

서지보호소자의 설치방식에 따른 기기의 뇌보호효과 검토

이동희,이영일,황규현 수원대학교 산업기술연구소 2004 산업기술연구소논문집 Vol.19 No.-

Lightning surge damages of low voltage equipments in building are increasing due to increase in electrical and communication networks in the information-oriented society. And electronic equipments contained electrical circuits with semiconductor are very weak against lightning surge. The surge protective devices for electronic circuit in electronic equipments and AC power lines are becoming more widely. To achieve effective method of surge protection, there are needs for correlation between lightning surge protective effect of electronic equipment and Installation method of surge protective device. This paper describes as a result of experiments for correlation between lightning surge protective effect and installation method of surge protective device.

모의가옥을 이용한 옥내 뇌서지 억제 대책 검토

이동희,이석우 水原大學校 2004 論文集 Vol.22 No.-

Present-day lightning surge damages of low voltage equipments in building are increasing due to increase in electrical and communication networks in the information-oriented society. And electronic equipments contained electrical circuits with semiconductor are very weak against lightning surge. To achieve effective method of surge protection, there are needs for make an experiments on the lightning surge protective effect of the inside of a house, using simulated house. Therefore this paper describes as a result of experiments for the lightning surge protective effect of the inside of a house, using simulated house.

SF6 대체용 혼합가스의 절연특성에 관한 실험적 고찰

이동희 수원대학교 산업기술연구소 2003 산업기술연구소논문집 Vol.18 No.-

The use of SF6 gas with excellent dielectric and arc-quenching propertiesare getting to be suppressed from the viewpoint of mitigating global warming phenomena. For the development of environmentally-benign electric power equipment and system, novel gases or gas mixtures are strongly required as the substitute of SF6 gas. The authors investigate the insulating properties and their breakdown mechanism of the alternative gas mixtures, and to assess their technical feasibility to power equipment and systems for the next generation. Mixture gas of 50%SF_6/49%N₂/l%CO₂ reveals a little higher LI breakdown voltage than that of 50%SF_6/50%N₂ mixture gas, but shows rather lower values than that of pure SF_6 gas.

DO 센서의 온도보상 방안에 관한 연구

李東熙 水原大學校 1995 論文集 Vol.13 No.-

Methods are described for the design and fabrication of the temperature compensation circuits on the Clark electrodes for measuring the dissolved oxygen(DO) concentration. The discussion includes a method of the sensor interface circuits for the DO sensor. Typical polarograms for the DO probes under test using this sensor circuits are presented. High accuracy over 99% of the Ⅰ to Ⅴ conversion using the proposed circuit is verified. Temperature dependence for the test DO probe is well compensated automatically in the temperature range of the 0-50℃.