• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1993.11a
• /
• pp.49-54
• /
• 1993

This paper discusses the reliability of solder joints of electronic devices on printed circuit board. Solder application is usually done by screen printing method for the bonding between outer leads of devices and thick film(Ag/Pd) pattern on Hybrid IC as wel1 as Cu lands on PCB. As result of thermal stresses generated at the solder joints due to the differences of thermal expansion coefficients between packge body and PCB, Micro cracking often occurs due to thermal fatigue failure at solder joints. The initiation and the propagate of solder joint crack depends on the environmental conditions, such as storage temperature and thermal cycling. The principal mechanisms of the cracking pheno- mana are the formation of kirkendal void caused by the differences in diffusion rate of materials, ant the thermal fatigue effect due to the differences of thermal expansion coefficient between package body and PCB. Finally, This paper experimentally shows a way to supress solder joints cracks by using low-${\alpha}$ PCB and the packages with thin lead frame, and investigates the phenomena of diffusion near the bonding interfaces.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.22 no.2
• /
• pp.36-43
• /
• 1985

This paper describes a DRC (Design Rule Check) algorithm and its program implement-ation which requires CPU time linearly proportional to the number of rectangular patterns n the NMOS If layout. While the CPU time for conventional DRC algorithm is proportion-al to 0(nlogn) or 0(n**1.2), (n:number of rectangles it was shown that the present also-rithm only consumes CPU time linearly proportional to 0(n).

• Journal of the Korean Institute of Telematics and Electronics S
• /
• v.35S no.3
• /
• pp.120-130
• /
• 1998

In this study, we implemented a scanning capacitance decimicron micorscope(SCdM) which scans a surface of the object mechanically in two or two point five dimensions with a stylus of size 0.2.mu.m. X-Y stage and stylus driving method are used as the scanning method, and VHD disk plate and IC chip are used as the object. Experimenal resutl of these object show that SCdM obtain 0.1.mu.m resolution power which exceeds that of optical microscope, and this microscope will be used as a powerful tool for inspecting ULSI pattern or biological data as a decimicron mcirocope which zoom a function of optical microscope and guide STM. The experimental system is composed of a VHD video disk method which captures the capacitance changes of the video disk suface and converts it into video signal.

• Journal of Microbiology and Biotechnology
• /
• v.9 no.5
• /
• pp.655-660
• /
• 1999

Sphingomyelinase (SMase EC:3.l.4.l2) has been suggested to play important roles in the cell cycle, differentiation, apoptosis, inflammation, and the regulation of eukaryotic stress responses. SMase inhibitors may be a powerful tool to elucidate and regulate these cellular responses in which SMase involves. We first isolated an SMase inhibitor, named sphinin, from a strain of soil actinomycetes, F50970. Sphinin inhibited Mg/sup 2+/ -dependent neutral SMase from chicken embryo at 1.2 ㎍/㎖ of IC/sub 50/ Sphinin also inhibited acidic SMase, but it had no inhibitory activity on PI-PLC and PC-PLC, suggesting that sphinin is a specific inhibitor of SMase. The strain F50970 was identified as a Streptomyces sp. by its spiral spore chain, LL-diaminopimelic acid, menaquinone patterns of MK-9 (H'6) and MK-9 (H'8), FA-2c type of fatty acid pattern, and other morphological, physiological, and cultural characteristics.

• Journal of Ocean Engineering and Technology
• /
• v.1 no.2
• /
• pp.101-112
• /
• 1987

Fracture toughness characterization in the transition region is examined for heat-treated and ionnitrided Ni-Cr-Mo steel. After heat treatment for the specimens of Ni-Cr-Mo steel, organizations of specimens-specimens which are heat-treated and ion-nitrided for 4 hours at 500 .deg. C and 5 torr in 25%N/dub 2/-75%H/sub 2/mixed gas-, hardness variety, and X-ray diffraction pattern of the ion-nitriding compound layer are observed. Fracture toughenss test of unloading compliance method were conducted over the regions from room trmperature to -70.deg. C. The compound layer was consisted of r'=Fe/sub 4/N phase and ion-nitrided layer's depth was 200mm from surface. The transition regions of heat-treated and ion-nitrided specimens were about -30.deg. C and -50.deg. C, respectively. The transition region of ion-nitrided specimens is estimated less than that of heat-treated one, and this is the effect of ion-nitriding.

• Journal of Electrical Engineering and Technology
• /
• v.9 no.4
• /
• pp.1360-1364
• /
• 2014

In this paper, RCS characteristics on defect pattern of crossed dipole slot FSS having a finite size have been analyzed. To analyze RCS, we applied the electric field integral equation analysis which applies BiCGSTab algorithm with iterative method and uses RWG basis function. To verify the validity of this paper, RCS of PEC sphere has been compared to the theoretical results and FSSs with defect patterns are fabricated and measured. As defect patterns in FSS, missing one column, missing some elements, and discontinuity in surfaces are simulated and compared with the measurement results. Resonant frequency shifts in pass band and changes in bandwidth are observed. From the results, precisely predicting and designing frequency characteristics over defect patterns are essential when applying FSS structures such as FSS radomes.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2006.05a
• /
• pp.255-258
• /
• 2006

In this paper, a novel physical structure for planar spiral inductors is proposed. The spiral inductors were designed and fabricated on multi-layered substrate Bragg-reflector/silicon (BR/Si) wafer. The impacts of multi-layered structure substrate and pattern on characteristics of inductor were studied. Experimental results show that the inductor embedded on Bragg reflector/silicon substrate can achieve the best improvement. At 0.4-1.6 GHz, the Bragg reflector seems to significantly increase the $S_{11}-parameter$ of the inductor.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
• /
• 2003.05a
• /
• pp.88-93
• /
• 2003

IC 패키지 기술중 Underfilling 은 칩과 기판사이에 Encapsulant의 표면장력을 이용하여 주입하고 경화시킴으로써 전기적 기계적 보강력을 제공하는 기술로서 시스템 칩의 발전과 함께 차세대 패키징 기술중의 하나이다. 본 연구에서는 기존의 Underfilling 공정을 개선하여 충전시간을 획기적으로 줄일 수 있는 가압식 Underfilling 공정을 이용하여 차세대 반도체 패키징에 적용할 수 있는 가능성을 파악하였다. 이를 위하여 칩과 기판사이에 주입되고 경화되는 Encapsulant의 유동특성을 파악하였다. 가압식 Underfilling기술은 아직까지 상용화되지 않은 미래기술로써 효율적인 몰드 설계를 위하여 Encapsulant 종류에 따라 Gate 위치, Bump Pattern 및 개수, 칩과 기판 사이의 거리, Side Region에 따른 유동특성등의 파악이 중요하다. 본 연구에서는 $DEXTER^{TM}(US)$의 Encapsulant FP4511 을 사용하여 Cavity 내에 Void 를 없앨 수 있는 주입조건을 찾아내고 Underfilling 시간을 감소시킬 수 있는 모사를 진행하였다.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.66 no.4
• /
• pp.682-691
• /
• 2017

In this paper, we propose the fusion design methodology of both pedestrian detection and object tracking system realized with the aid of HOG-PCA based RBFNN pattern classifier. The proposed system includes detection and tracking parts. In the detection part, HOG features are extracted from input images for pedestrian detection. Dimension reduction is also dealt with in order to improve detection performance as well as processing speed by using PCA which is known as a typical dimension reduction method. The reduced features can be used as the input of the FCM-based RBFNNs pattern classifier to carry out the pedestrian detection. FCM-based RBFNNs pattern classifier consists of condition, conclusion, and inference parts. FCM clustering algorithm is used as the activation function of hidden layer. In the conclusion part of network, polynomial functions such as constant, linear, quadratic and modified quadratic are regarded as connection weights and their coefficients of polynomial function are estimated by LSE-based learning. In the tracking part, object tracking algorithms such as mean shift(MS) and cam shift(CS) leads to trace one of the pedestrian candidates nominated in the detection part. Finally, INRIA person database is used in order to evaluate the performance of the pedestrian detection of the proposed system while MIT pedestrian video as well as indoor and outdoor videos obtained from IC&CI laboratory in Suwon University are exploited to evaluate the performance of tracking.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.27 no.5
• /
• pp.1077-1086
• /
• 2017

Malware mutants based on existing malware is widely used because it can easily avoid the existing security system even with a slight pattern change. These malware appear on average more than 1.6 million times a day, and they are gradually expanding to IoT / ICS as well as cyber space, which has a large scale of damage. In this paper, we propose an analytical method based on features of PE Section and DLL that do not give much significance, rather than pattern-based analysis, Sandbox-based analysis, and CFG, Strings-based analysis. It is expected that the proposed model will be able to cope with effective malicious code in case of combined operation of various existing analysis technologies.