• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 1988년도 춘계학술대회 논문집
• /
• pp.7-9
• /
• 1988

This paper considers problems which must be overcome to produce long lengths of superconductor wire from the 90K Tc superconducting ceramic material, $Y_1Ba_2Cu_3Ox$. Attention is focused on the powder-in-tube process where the superconducting powder is placed in a tube which is then formed into wire. Two major problems are considered, control of the oxygen level and improvement of Jc in the final wire. The results show that Jc of the wire were $400A/cm^2$ at liquid nitrogen temp.

• 한국전기전자재료학회논문지
• /
• 제15권4호
• /
• pp.289-300
• /
• 2002

In this study, the experiments are carried out by boron ion implantation at energies ranging from 700keV to 2MeV in silicon. The distribution of boron profiles are measured by SIMS(Cameca 6f). Boron dopants profiles after high temp]erasure annealing are also explained by comparisons of experimental and simulated data. A new electronic stopping model for Monte Carlo simulation of high energy implantation is presented. Also the comparisons of profiles by profiles boron ion implantations are demonstrated and interpreted with theoretical models. Finally range moments of SIMS and SRP profiles are calculated and compared with simulation results.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1997년도 추계학술대회 논문집 학회본부
• /
• pp.279-281
• /
• 1997

The properties of Platinum dry etching were investigated in MICP(Magnetized Inductively Coupled Plasma). The problem with Platinum etching is the redeposition of sputtered Platinum on the sidewall. Because of the redeposits on the sidewall, the etching of patterned Platinum structure produce feature sizes that exceed the original dimension of the PR size and the etch profile has needle-like shape.[1] Generally, $Cl_2$ plasma is used for the fence-free etching.[1][2][3] The main object of this study was to investigate a new process technology for the fence-free Pt etching. Platinum was etched with Ar plasma at the cryogenic temperature and with Ar/$SF_6$ plasma at room temperature. In cryogenic etching, the height of fence was reduced to 20% at $-190^{\circ}C$ compared with that of room temp., but the etch profile was not fence-free. In Ar/$SF_6$ Plasma, chemical reaction took part in etching process. The trend of properties of Ar/$SF_6$ Plasma etching is similar to that of $Cl_2$ Plasma etching. Fence-free etching was possible, but PR selectivity was very low. A new gas chemistry for fence-free Platinum etching was proposed in this study.

• 한국전기전자재료학회논문지
• /
• 제17권6호
• /
• pp.575-579
• /
• 2004

Package reliability test was conducted to investigate the effect of solder paste composition at BGA Package. It was found that the shape and size of the phase form are affected by the processing parameters. The material have used to fill in the via was Sn/36Pb/2Ag and Sn/0.75Cu type solder paste. Sn/36Pb/2Ag and Sn/0.75Cu paste were fabricated on Tape-BGA substrates by screen printing process, and via ball mount data were characterized with variations of dwell time of 85 seconds at reflow peak temperature at 22$0^{\circ}C$ or 24$0^{\circ}C$. The test condition was MRT 30 $^{\circ}C$/60 %RH/96 HR. Failures formed of a ball-off in solder paste process were observed by using a Optical Microscope and SEM(Scanning Electron Microscope). It was concluded that intermetallic layer growth played important roles in increasing solder fatigue strength for addition of Ag composition. The degradation of shear strength of solder composition is discussed.

• Design & Manufacturing
• /
• 제15권3호
• /
• pp.7-12
• /
• 2021

Plastic injection molds used for rapid heating and cooling must minimize surface damage due to friction and maintain excellent thermal and low electrical conductivity. Accordingly, various surface treatments are being applied. The properties of Al₂O₃ coating and DLC coating were compared to find the optimal surface treatment method. Al₂O₃ coating was deposited by thermal spray method. DLC films were deposited by sputtering process in room temperature and high temperature PECVD (Plasma enhanced chemical vapor deposition) process in 723 K temperature. For the evaluation of physical properties, the electrical and thermal conductivity including surface hardness, adhesion and wear resistance were analyzed. The electrical resistance of the all coated samples was showed insulation properties of 24 MΩ/sq or more. Especially, the friction coefficient of high temp. DLC coating was the lowest at 0.134.

• 한국구조물진단유지관리공학회 논문집
• /
• 제13권1호통권53호
• /
• pp.88-96
• /
• 2009

본 연구에서는 FBG 센서 및 PDA를 이용하여 새로운 안전관리 시스템인 무선 계측 시스템을 개발하기 위해 FBG 센서를 이용하여 광섬유 변위(FBG-LVDT) 센서, 광섬유 변형률(FBG-STRAIN) 센서, 광섬유 온도(FBG-TEMP) 센서 그리고 광섬유 가속도(FBG-ACC) 센서를 특별 제작하였다. 또한, 신호처리 시스템에는 적용된 FBG 센서들의 무선송신 시스템이 가능하도록 신호처리 시스템을 구성하였으며, PDA를 이용하여 원격 거리에서도 display가 가능할 수 있도록 프로그램을 개발하였다. 개발된 FBG 센서들과 무선계측 모니터링 시스템의 현장 적용성, 정확성 및 활용 가능성을 검증하고자 현장 교량에서 정적, 동적 재하시험을 실시하였다. 또한, FBG-LVDT 센서, FBG-ACC 센서에 의하여 측정된 동적 데이터들은 Meister의 진동등감각 곡선에 적용시킴으로서 교량의 진동에 대한 사용성 평가를 실시하였고 교량의 진동 사용성을 고려하여 진동 제한 기준을 제시하여 대상 교량의 진동 평가를 위한 방법을 마련하였다.

• 한국환경보건학회지
• /
• 제34권5호
• /
• pp.374-381
• /
• 2008

In this study, the factors affecting biological N and P removal using SND (simultaneous nitrification and denitrification) process were investigated and evaluated to examine the possibility of treating N and P through SND with NADH by surveying N and P traces in an aeration tank. Variations of $NH_4^+$-N+$NO_3^-$-N concentration were used to estimate the degree of SND in each point (P2, P3, P4, P5) of the aeration tank and these variations showed that denitrification efficiency in P2 (front zone), nitrification and denitrification efficiencies in P4 (middle zone) were 67%, 86% and 39%, respectively. When $PO_4^{-3}$-P concentration was analyzed in each point of the aeration tank, it was shown that $PO_4^{-3}$-P concentration coming into P2 was 1.25 mg/L, which increased to 2.22 mg/L by P release in P2 zone and then decreased to 0.74 mg/L by P uptake in P4. Consequently, we were able to estimate which high P removal efficiency observed in this study was caused by biological phosphorus removal. To determine the operating factors affecting effluent T-N, we analyzed the correlation among FN/M ratio, C/N ratio, Temp., SRT etc and these results showed that the correlation among FN/M ratio, C/N ratio and Temp was not high. However, the relationship of SRT and other parameters (effluent $NH_4^+$-N and effluent BOD) and the short SRT could have an affect on effluent $NH_4^+$-N and so effluent BOD could be increased. Thus, SRT operation should be controlled over 10 days. The results for analyzing the correlation between SRT and influent $NO_3^-$-N in order to investigate the operating factors affecting effluent T-P showed that T-P or $PO_4^{-3}$-P was not highly correlation with SRT, whereas $PO_4^{-3}$-P concentration increased along with increasing $NO_3^-$-N concentration into P2. Based on these results, we concluded, using regression analysis (R2=0.97), that effluent $PO_4^{-3}$-P concentration depends on $NO_3^-$-N concentration into P2.

• 한국식품과학회지
• /
• 제30권4호
• /
• pp.739-744
• /
• 1998

볶음장치(로타리킬른)를 사용하여 참깨볶음온도 $225{\pm}2^{\circ}C$, 볶음시간 15분으로 볶아서 나온 참깨를 착유하여 얻은 기름을 1차압착유, 1차착유하고 남은 참깨박을 재착유하여 얻은 기름을 2차압착유, 1차압착유와 2차압착유를 혼합해서 여과한 참기름을 1차여과유, 1차여과유의 침전물을 제거하기 위해서 정치시켜서 얻은 정치유, 정치유를 여과해서 얻은 참기름을 2차여과유로 구분하여 이들의 공정에 따른 참기름 향의 변화를 실험하였다. 전체향기성분량은 1차압착유 536.3 ppm, 2차압착유 266.8 ppm, 1차여과유 472.2 ppm, 정치유 472.4 ppm, 2차여과유 443.0 ppm으로 가공공정이 진행됨에 따라 점차 감소하였으며, 특히 1차압착하고 남은 참깨박을 재착유할 경우 2차압착유에는 약 50%의 향기성분만이 잔존하여 향성분의 손실이 크게 증가하였다. 특히 관능적으로 중요한 top note감소(초기함량치 70.67% 감소)가 현저함을 알수 있었으며, 그 중에서도 pyrazines의 손실이 초기함량의 66.9%로 가장 현저하였다.

• 자원리싸이클링
• /
• 제12권2호
• /
• pp.3-10
• /
• 2003

PCB (Printed Circuit Board) 산업에서 배출되는 산성 염화동 폐액으로부터 농약원제로 사용이 가능한 고순도의 copper oxycloride를 제조하였다. PCB제조 산업은 구리 소재를 이용한 전자 부품 가공 산업으로서 제조 공정인 부식 과정에서 다량의 구리가 함유된 에칭 폐액이 발생한다. 환경과 경제적인 측면에서 폐액으로부터 구리성분을 재회수하는 기술의 개발은 매우 중요하다. 본 연구에서는 가성소다로 폐액을 중화하여 copper oxychloride를 회수하는 공정의 반응 조건을 확립하였다. 반응 온도 2$0^{\circ}C$-4$0^{\circ}C$, pH 5-7 사이에서 순수한 copper oxychloride제조가 가능하였고 이때 수득율은 95% 이상이었다. 생성물의 물리적 특성을 SEM, XRD, TGA, ICP 그리고 원자 흡수 분광기를 사용하여 분석하였다.

• 센서학회지
• /
• 제22권6호
• /
• pp.433-438
• /
• 2013

In this paper, we found surface shapes are affected by several parameters of RIE, such as RF power, pressure, temp, and process times. The reflectance of pyramid and half sphere structures show differences among shapes, size, height, and depth of those structures. We made about $1{\mu}m$ pyramid and half sphere shapes of silicon surface with RIE. For comparing the reflectance, pyramid and half sphere structures are fabricated with same height. Pyramid structure cell shows higher cell efficiency of 12.5% by 1.1% than one of half sphere structure of 11.4%. The light absorption is more increased through the pyramid structure than half sphere structure.