http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
오부국(B. K. Oh),김동식(D. S. Kim),김재구(J. G. Kim),이제훈(J. H. Lee) 한국정밀공학회 2006 한국정밀공학회 학술발표대회 논문집 Vol.2006 No.5월
Although there are many numerical models to simulate fs laser ablation of metals, no model can analyze the ablation phenomena over a wide range of fluence. In this work, a numerical code for simulating the fs laser ablation phenomena of metals has been developed. The two temperature model is employed to predict the ablation rate and the crater shape of metals using phase explosion mechanism in the relatively high fluence regime. Also, the ultrashort thermoelastic model is used for the low fluence regime to account for spallation of the sample by high strain rate. It has been demonstrated that the thermoelastic stress generated within the sample can exceed the yield stress of the material even near the threshold fluence. Numerical computation results are compared with the experiment for Cu and Ni and show good agreement. Discussions are made on the hydrodynamic model considering phase change and hydrodynamic flow.
오부국(B.K. Oh),이승기(S.K. Lee),송민규(M.K. Song),김종원(J.W. Kim),홍순국(S.K. Hong) 한국레이저가공학회 2009 한국레이저가공학회지 Vol.12 No.4
Conventional patterning based on wet-process for multi-layered film is a relatively complex and costly process though it is a necessary step for fabrication of TFT-LCD module. Recently, a direct pattering by laser has been studied because it is low cost and simple process compared to the wet process. In this work, the selective removal process of multi-layered film (polyimide/indium tin oxide/glass) is studied by modeling the thermal and mechanical behavior for multi-layered structure. Especially, the effects of thickness of polyimide layer are examined.
피코초 레이저를 이용한 양극산화 알루미늄 미세 홀 가공의 실험적 연구
오부국,방준호,김종기,임성묵,이승기,정수화,홍순국,Oh, B.K.,Bang, J.H.,Kim, J.K.,Lim, S.M.,Lee, S.K.,Jeong, S.H.,Hong, S.K. 한국레이저가공학회 2014 한국레이저가공학회지 Vol.17 No.2
Aluminum has been widely used in the electric applications because of light metals. When mechanical element is periodically moving with contacting other surfaces, the anodizing process for aluminum is useful for avoiding the abrasive damage. The anodized element has quietly different characteristics with respect to the distribution of hardness and crystal structure. In this work, the laser drilling of anodized surface is studied experimentally. Fusion drilling method - laser drilling with inert gas blowing - is used. The effect of various process parameters (gas pressure, laser power, focus position) is investigated with respect to the hole size and circularity.
고정수(J. S. Ko),오부국(B. K. Oh),김두영(D. Y. Kim),이재영(J. Y. Lee),이승기(S. K. Lee),정수화(S. H. Jung),홍순국(S. K. Hong) 한국레이저가공학회 2011 한국레이저가공학회지 Vol.14 No.3
As an active emission display using emissive polymer has had much attention recently, needs for a selective patterning of emissive layer for those displays have been increased abruptly. Therefore, the various laser sources in terms of its wavelength has been used for laser direct patterning. In this work, the feasibility of those processes is examined using numerical analysis and the experimental investigation. A sample has multi-layered structure, emissive polymer on aluminum which is deposited on a glass substrate. Key factors for optimizing the laser patterning of the emissive polymer are considered into the control of ablation products, large-sized particle, and the choice of the appropriate wavelength for minimizing the heat affected zone and the remnant layer.
김동식,오부국 한국레이저가공학회 2001 한국레이저가공학회지 Vol.4 No.3
Microbump formation during CO2 laser texturing of glass substrates is examined in this paper. Experimental results show that different bump shapes (dome-shaped, with a central dimple, and with a peripheral rim) are generated depending on the laser fluence. A theoretical model for the process is suggested based on thermoelastic behavior but limited only to the dome-shaped bump. The dimensions (maximum height and base area) of the bump shows a logarithmic dependence on laser fluence as expected from the theory. Numerical computation reveals that the effect of thermal diffusion is not negligible for relatively long laser pulses.