• ETRI Journal
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• 제36권4호
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• pp.617-624
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• 2014

Through-silicon via (TSV) technology provides much of the benefits seen in advanced packaging, such as three-dimensional integrated circuits and 3D packaging, with shorter interconnection paths for homo- and heterogeneous device integration. In TSV, a destructive cross-sectional analysis of an image from a scanning electron microscope is the most frequently used method for quality control purposes. We propose a quantitative evaluation method for TSV etch profiles whereby we consider sidewall angle, curvature profile, undercut, and scallop. A weighted sum of the four evaluated parameters, nominally total score (TS), is suggested for the numerical evaluation of an individual TSV profile. Uniformity, defined by the ratio of the standard deviation and average of the parameters that comprise TS, is suggested for the evaluation of wafer-to-wafer variation in volume manufacturing.

• JSTS:Journal of Semiconductor Technology and Science
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• 제8권3호
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• pp.244-250
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• 2008

An inductively coupled plasma etching process to replace an existing slower rate reactive ion etching process for $60{\mu}m$ diameter via-holes using Cl2/BCl3 gases has been investigated. Process pressure and platen power were varied at a constant ICP coil power to reproduce the RIE etched $200{\mu}m$ deep via profile, at high etch rate. Desired etch profile was obtained at 40 m Torr pressure, 950 W coil power, 90W platen power with an etch rate ${\sim}4{\mu}m$/min and via etch yield >90% over a 3-inch wafer, using $24{\mu}m$ thick photoresist mask. The etch uniformity and reproducibility obtained for the process were better than 4%. The metallized via-hole dc resistance measured was ${\sim}0.5{\Omega}$ and via inductance value measured was $\sim$83 pH.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2009년도 정보 및 제어 심포지움 논문집
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• pp.228-230
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• 2009

Lane extraction is basically required for a driving car to understand its external road environments via a camera. In this paper, a lane extraction method using "Sobel Intensity Profile" is described. The Sobel intensity profile is obtained using only vertical edge components of Sobel edge outputs, and used to yield fitted lines for lanes. The RANAC algorithm is applied to fit lines using only inliers. Experimental results have shown the reliability of the proposed lane extraction method.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제6권2호
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• pp.43-52
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• 2002

By the use of Taylor's expansion formula with the integral remainder, an accurate approximation for the fiber refractive index profile is given.

• Korea-Australia Rheology Journal
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• 제21권3호
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• pp.149-153
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• 2009

Profile development of the melt spinning process of poly(ethylene terephthalate) (PET) was simulated by a numerical method under the consideration of two constitutive equations of Newtonian and upper convected Maxwell (UCM) models. The viscoelastic characteristics of the polymer were considered via UCM constitutive equation that considered relaxation time as a function of temperature and molecular weight. The UCM model predicted the diameter profile better than the Newtonian, while velocity development was slower than the Newtonian model. Viscoelasticity played an important role in accurately predicting diameter profile. However, even though neck-like deformation was observed in the UCM model, the exact position of the deformation under high speed spinning was not obtained.

• 대한금속재료학회지
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• 제48권11호
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• pp.1028-1034
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• 2010

In the development of 3D package, through silicon via (TSV) formation technology by using deep reactive ion etching (DRIE) is one of the key processes. We performed the Bosch process, which consists of sequentially alternating the etch and passivation steps using $SF_6$ with $O_2$ and $C_4F_8$ plasma, respectively. We investigated the effect of changing variables on vias: the gas flow time, the ratio of $O_2$ gas, source and bias power, and process time. Each parameter plays a critical role in obtaining a specified via profile. Analysis of via profiles shows that the gas flow time is the most critical process parameter. A high source power accelerated more etchant species fluorine ions toward the silicon wafer and improved their directionality. With $O_2$ gas addition, there is an optimized condition to form the desired vertical interconnection. Overall, the etching rate decreased when the process time was longer.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.191-192
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• 2006

The deformation under radial pressure of rectangular dies for metal powder compaction has been investigated by FEM. The explored variables have been: aspect ratio of die profile, ratio between diagonal of the profile and die height, insert and ring thickness, radius at die corners, interference, different insert materials, i. e. conventional HSS, HSS from powders, cemented carbide (10% Co). The analyses have ascertained the unwanted appearance of tensile normal stress on brittle materials, also "at rest", and even some dramatic changes of stress patterns as the die height increases with respect to the rectangular profile dimensions. Different materials behave differently, mainly due to difference of thermal expansion coefficients. Profile changes occur when the dies are heated up to the temperature required for warm compaction. The deformation patterns depend on compaction temperature and thermal expansion coefficients.

• 대한기계학회논문집A
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• 제35권8호
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• pp.855-861
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• 2011

본 연구에서는 극박 압연 이론과 6 단 압연기 수식 모델을 이용하여 압연 후 판 형상 예측에 대하여 제안하였다. 폭 방향에서 롤 사이의 접촉 압력과 판과 워크롤 사이의 압연하중은 6 단 압연기의 형상학적 구조와 경계조건을 이용한 수식모델을 통하여 계산된다. 그리고 압연 방향의 압연하중 분포는 Fleck 의 극박 압연 이론을 이용하여 계산하였다. 워크롤의 3 차원 탄성 변형량은 폭 과 압연방향의 압력분포에 의하여 계산된다. 이때, 3 차원 판 형상은 워크롤의 탄성변형에 의하여 얻어진다. 또한 3 차원 판 형상은 극박 압연 실험과 유한요소해석을 통하여 검증하였다.

• Computers and Concrete
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• 제15권6호
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• pp.951-972
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• 2015

The focus of the present study is to investigate both local and global behaviour of a precast concrete sandwich panel. The selected prototype consists of two reinforced concrete layers coupled by a system of cold-drawn steel profiles and one intermediate layer of insulating material. High-definition nonlinear finite element (FE) models, based on 3D brick and 2D interface elements, are used to assess the capacity of this technology under shear, tension and compression. Geometrical nonlinearities are accounted via large displacement-large strain formulation, whilst material nonlinearities are included, in the series of simulations, by means of Von Mises yielding criterion for steel elements and a classical total strain crack model for concrete; a bond-slip constitutive law is additionally adopted to reproduce steel profile-concrete layer interaction. First, constitutive models are calibrated on the basis of preliminary pull and pull-out tests for steel and concrete, respectively. Geometrically and materially nonlinear FE simulations are performed, in compliance with experimental tests, to validate the proposed modeling approach and characterize shear, compressive and tensile response of this system, in terms of global capacity curves and local stress/strain distributions. Based on these experimental and numerical data, the structural performance is then quantified under various loading conditions, aimed to reproduce the behaviour of this solution during production, transport, construction and service conditions.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2012년도 추계학술대회
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• pp.632-634
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• 2012

무선 네트워크 연결을 위해서는 무선 AP 프로파일 리스트에서 우선순위의 AP를 자동 선택하여 연결하는 방식이 사용되는데, 이는 프로파일 등록시점에 따라 결정되어 변화하는 사용자의 요구에 대처하지 못하는 부분이 있다. 본 연구에서는 사용자의 접속 빈도에 따른 무선 AP 프로파일을 작성함으로써, 사용자의 요구에 부합되는 적응적 네트워크 접속에 관해 연구한다.