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다양한 유무연 도금 리드프레임에 적용된 Sn-8Zn-3Bi 솔더 접합부의 열충격 신뢰성 평가
한성원,조일제,신영의,Han, Sung-Won,Cho, Il-Je,Shin, Young-Eui 한국마이크로전자및패키징학회 2007 마이크로전자 및 패키징학회지 Vol.14 No.2
Sn-8Zn-3Bi 무연 솔더 페이스트의 접합부신뢰성 및 적합성을 평가하기 위해 유(SnPb) 무연(Sn, SnBi)도금된 Cu 리드프레임 QFP(Quad Flat Packager)를 사용하여 열충격 조건 하에서의 인장 강도의 변화 및 파괴 기구에 대한 분석을 실시하였다. 리드 도금의 종류에 상관없이 모든 시험 시편에서 열충격 사이클 수의 증가에 비례하여 접합부의 취성 특성이 강화되어 인장 강도가 감소하는 것을 확인하였다. 하지만, 접합부에는 열팽창 계수의 차이에 의해 야기될 수 있는 미세 균열은 발견되지 않았다. 단면 관찰 및 변위 이력 곡선 분석을 통하여 열충격 사이클 수의 증가에 따른 인강 강도의 감소는 접합부의 파괴 기구의 변화에 기인되었음을 확인하였다. 본 실험을 통해 Sn-3Zn-3Bi 솔더의 유 무연 도금 Cu 리드프레임과의 우수한 작업 특성과 열충격 환경 하에서도 우수한 기계적 접합 특성을 유지하는 것을 확인할 수 있었다. The pull strength and fracture mechanism were investigated to evaluate the reliability and compatibility of Sn-8Zn-3Bi joints, the solder paste on lead and lead-free plating under thermal shock conditions. At the Sn-8Zn-3Bi solder joint, no crack initiation was observed during thermal shock test. After 1000 cycles, the strength of the solder joint decreased not sharply but reduced gradually compared with initial conditions. The decrement of strength was affected by ${\gamma}-Cu_5Zn_8$ IMC growth which caused the IMC fracture on the fracture surface and a change in fracture mode and initial crack point. Clearly, the Sn-8Zn-3Bi solder shows good reliability properties and compatibility with lead-free plated Cu LF under thermal shock temperatures between 248K and 423K.
생태적 개념을 도입한 환경친화적 건축 재료 구현에 관한 연구
한성원,박철민 제주대학교 공과대학 첨단기술연구소 2005 尖端技術硏究所論文集 Vol.16 No.2
Environment Friendly architecture, which will reduce shortcomings of current architectural culture, can be achieved by using natural energy and environment friendly building materials together with their environmental architecture techniques. Particularly, even though the overall building system is perfect, it cannot be considered as comfortable architectural space if the materials are polluted, harmful to human bodies and producing wastes. Therefore, in order to build environment friendly architecture, the selection of the materials is very important and necessary from the planning stage with careful reviews and concern. This study tries to define what the environment friendly materials are, to investigate and to classify them, in order to provide some guidelines for selecting them at plans to build. For example, the materials can be classified into natural materials, continuously usable materials, recycled materials from wastes, and less polluting materials mixed with natural matters. Finally, this study reviews the existing products in the market and proposes to develop new ones in the future. It will present the circulation of resources in the 21 century throuth recycled and reused materials.
한성원,박하은,정회찬,이민석,김두현 한국자동차공학회 2022 International journal of automotive technology Vol.23 No.4
An analytical model configuration, in addition to air pressure analysis and post-processing, was conducted to measure the interior wind noise by changing the exterior vehicular design. Although wind noise can be calculated accurately through the current process, it requires three to five days for each design. In this study, a convolutional neural network (CNN), which is a class of deep neural networks designed for processing image data, was applied to predict the wind noise with vehicle design images from four different views. Feature maps were extracted from the CNN models trained with images of each view and concatenated to flow through a sequence of fully connected (FC) layers to predict the wind noise. Moreover, visualization of the significant vehicle parts for wind noise prediction was provided using a gradient-weighted class activation map (Grad- CAM). Finally, we compared the performance of various CNN-based models, such as ResNet, DenseNet, and EfficientNet, in addition to the architecture of the FC layers. The proposed method can predict the wind noise using vehicle images from different views with a root-mean-square error (RMSE) value of 0.206, substantially reducing the time and cost required for interior wind noise estimation.
fcc(face-centered cubic) structure의 에너지 밴드 측정
한성원,홍진수,배형철 순천향대학교 기초과학연구소 2011 순천향자연과학연구 논문집 Vol.17 No.2
Photonic band gaps(PBGs) are investigated for face-centered cubic structure composed of dielectric spheres and air spheres. It was found that PBGs exist for both cases. PBGs lie between the 6th-7th and 13th-14th for dielectric spheres and the 8th-9th for air spheres.