• 한국표면공학회:학술대회논문집
• /
• 한국표면공학회 2018년도 춘계학술대회 논문집
• /
• pp.140-140
• /
• 2018

The 3D interconnect technologies have been appeared, as the density of Integrated Circuit (IC) devices increases. Through Silicon Via (TSV) process is an important technology in the 3D interconnect technologies. And the process is used to form a vertically electrical connection through silicon dies. This TSV process has some advantages that short length of interconnection, high interconnection density, low electrical resistance, and low power consumption. Because of these advantages, TSVs could improve the device performance higher. The fabrication process of TSV has several steps such as TSV etching, insulator deposition, seed layer deposition, metallization, planarization, and assembly. Among them, TSV metallization (i.e. TSV filling) was core process in the fabrication process of TSV because TSV metallization determines the performance and reliability of the TSV interconnect. TSVs were commonly filled with metals by using the simple electrochemical deposition method. However, since the aspect ratio of TSVs was become a higher, it was easy to occur voids and copper filling of TSVs became more difficult. Using some additives like an accelerator, suppressor and leveler for the void-free filling of TSVs, deposition rate of bottom could be fast whereas deposition of side walls could be inhibited. The suppressor was adsorbed surface of via easily because of its higher molecular weight than the accelerator. However, for high aspect ratio TSV fillers, the growth of the top of via can be accelerated because the suppressor is replaced by an accelerator. The substitution of the accelerator and the suppressor caused the side wall growth and defect generation. The suppressor was used as Single additive electrodeposition of TSV to overcome the constraints. At the electrochemical deposition of high aspect ratio of TSVs, the suppressor as single additive could effectively suppress the growth of the top surface and the void-free bottom-up filling became possible. Generally, copper was used to fill TSVs since its low resistivity could reduce the RC delay of the interconnection. However, because of the large Coefficients of Thermal Expansion (CTE) mismatch between silicon and copper, stress was induced to the silicon around the TSVs at the annealing process. The Keep Out Zone (KOZ), the stressed area in the silicon, could affect carrier mobility and could cause degradation of the device performance. Cobalt can be used as an alternative material because the CTE of cobalt was lower than that of copper. Therefore, using cobalt could reduce KOZ and improve device performance. In this study, high-aspect ratio TSVs were filled with cobalt using the electrochemical deposition. And the filling performance was enhanced by using the suppressor as single additive. Electrochemical analysis explains the effect of suppressor in the cobalt filling bath and the effect of filling behavior at condition such as current type was investigated.

• Korean Chemical Engineering Research
• /
• 제60권2호
• /
• pp.208-216
• /
• 2022

우리나라 전통 숯가마로부터 제조된 검탄 및 백탄의 표면형상과 흡착특성을 정량적으로 분석한 결과, 모든 시료의 열분석과 원소분석 등 물성은 제조회사마다 차이가 났고 백탄은 검탄에 비하여 확실히 열분해온도와 탄소함유량이 높았다. 숯의 표면형상으로부터 활성화는 목재의 축방향을 따라 발생하고 활성화정도가 증가함에 따라 대기공의 벽면에 반경방향으로 새로운 기공이 발달하여 기공들이 서로 관통됨을 알 수 있었다. BET 등온흡.탈착곡선은 대부분 낮은 상대압력에서 탈착이 안되는 이력현상을 보이므로서 미세공이 많이 발달된 Type I으로 분류되기 보다는 Type IV의 이력현상 경로와 겹쳐지는 숯 만의 독특한 탈착곡선을 보이고 있다. 낮은 압력 이력(low-pressure hysteresis)현상은 흡착질이 숯의 미세공 입구를 팽창시켜 끼이고는 탈착시에 빠져나오지 않기 때문이다. 따라서 분석된 비표면적값과 세공크기분포도 등 숯의 흡착특성은 정확한 값을 나타내지 않는다. 이러한 특성값은 제조회사에 따라 다를 뿐만아니라 한 조각의 숯이라도 채취한 부위에 따라 크게 달랐다. 따라서, 우리나라 전통숯의 정량적 특성값을 제시하는 일은 쉽지 않고 흡착제나 특수한 용도로 응용하기 위하여는 각각의 목적에 맞는 일정 수준의 성능을 갖도록 품질기준을 제시할 필요가 있다.

• 한국결정성장학회지
• /
• 제23권5호
• /
• pp.246-254
• /
• 2013

LED 조명등의 내구성 문제를 개선할 목적으로 광 확산판에 사용되는 폴리카보네이트 소재를 대체하기 위하여 반투명 유백유리를 제조하였다. 유백유리의 유백제로서 인산칼슘을 사용하였고, $1550^{\circ}C$ 전기로에서 2시간 용융하였다. 유백유리는 용융유리가 성형된 후 냉각 열처리 과정에서 상분리 및 유백입자의 성장에 의해 만들어진다. 따라서 성형 및 냉각온도를 상온, $850^{\circ}C$, $1100^{\circ}C$ 및 $1200^{\circ}C$ 로 변화시키면서 유백특성의 영향을 확인하였다. 결과적으로 가장 고온인 $1200^{\circ}C$에서 성형 및 냉각을 한 샘플에서 가장 양호한 특성을 갖는 유백유리가 얻어졌다. 이 유리는 82 % 이상의 높은 Haze 값과 10 % 미만의 낮은 평행광 투과도에 의해 직사광 투과에 의한 눈부심이 없이 LED 조명용 광확산판으로서 우수한 광특성을 나타내었다. 또한 열적특성으로서 $6.309{\times}10^{-6}/^{\circ}C$의 열팽창 계수와 $839^{\circ}C$의 연화점을 나타내었다.

• 한국세라믹학회지
• /
• 제52권6호
• /
• pp.410-416
• /
• 2015

Recently, a new $Y_2O_3$ coating deposited using the EB-PVD method has been developed for erosion resistant applications in fluorocarbon plasma environments. In this study, surface crack formation in the $Y_2O_3$ coating has been analyzed in terms of residual stress and elastic modulus. The coating, deposited on silicon substrate at temperatures higher than $600^{\circ}C$, showed itself to be sound, without surface cracks. When the residual stress of the coating was measured using the Stoney formula, it was found to be considerably lower than the value calculated using the elastic modulus and thermal expansion coefficient of bulk $Y_2O_3$. In addition, amorphous $SiO_2$ and crystalline $Al_2O_3$ coatings were similarly prepared and their residual stresses were compared to the calculated values. From nano-indentation measurement, the elastic modulus of the $Y_2O_3$ coating in the direction parallel to the coating surface was found to be lower than that in the normal direction. The lower modulus in the parallel direction was confirmed independently using the load-deflection curves of a micro-cantilever made of $Y_2O_3$ coating and from the average residual stress-temperature curve of the coated sample. The elastic modulus in these experiments was around 33 ~ 35 GPa, which is much lower than that of a sintered bulk sample. Thus, this low elastic modulus, which may come from the columnar feather-like structure of the coating, contributed to decreasing the average residual tensile stress. Finally, in terms of toughness and thermal cycling stability, the implications of the lowered elastic modulus are discussed.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
• /
• pp.1164-1167
• /
• 2003

Recently CRT is getting flatted, As change of CRT trend from normal type to Flat type, the material of Shadow Mask was also changed from AK(Aluminum Killed) to Invar(Fe-Ni alloy) materials Until now we have used just AK(Aluminum Killed) for normal type TV(not flat type), but main raw material of shadow mask component was changed. . However recently Invar(Fe-Ni alloy) materials, which has advantage of Low Thermal Expansion and High Strength, has been developed as well as applying in mass production as CRT's trend has become more flat and fine pitch. As main raw material of shadow mask component was changed, conditions of process were changed. One of them, the importance of pre-etching process (assistant process for developing & etching) is improved because there are so many particles in the pre-etching bath because of Ni compounds. Since the solubility of Ni in pre-etching solvent is very low related to Fe's, so the compounds of Ni happen to make particles.(the solubility of Fe is twenty times Ni's) that particles happen to make process troubles and NG productions so to clear the particles we had to established high cost filtering system, but it is useless. As time goes by the quantity of particles (Ni compounds) was increased because of the capability of filtering system was not enough, the particles was produced continuous in bath, and it make quality problems. Hence we tried to develop the new pre-etching solution to remove the particles (Ni compounds) and to cost down the filtering system's running cost. But in improving the solution we discovered the new pre-etching solution made the PR developing better. In former solution there were three kinds of chemistry (COOH)2 , H2O2 , H2S04 .first the function of (COOH)2 is drilling the surface of Invar, during this mechanism Ni compounds occurred. Second the function of H202 is removing the PR fringe (half UV exposure zone on PR(PVA)), Third the function of H2S04 is the catalysis of (COOH)2 In those, (COOH)2 was the main reason to make the Ni compounds. So to improve the solutions we had to change (COOH)2 to the other material. the chemistry we improved was a complex chemistry based on H2S04 . after using this chemistry the particles problem was disappeared and there was another advantage cut down the PR fringe. The New solution made the function of H202 better so the PR developing improved. To be direct the catalyst of the new solution helped the H202. anyway First thing after change the solution the quality of shadow Mask for flat color TV was improved & the yield also improved. But the more important thing is how to control the new solution. So we accepted the new concept which was the degree of freshness. The degree of freshness is based on non-reacted solution which was 100% ( the degree of freshness) and calculated the melted Ni quantity as time goes by. So we made the gauging liner plot. In conclusion, many companies tried to make fine pitched Shadow Mask ,generally to make quality jump up it needed a lot of cost & persons .in this case the shift of core material made it possible.

• 설비공학논문집
• /
• 제19권1호
• /
• pp.94-131
• /
• 2007

A review on the papers published in the Korean Journal of Air-Conditioning and Refrigerating Engineering in 2004 and 2005 has been done. Focus has been put on current status of research in the aspect of heating, cooling, air-conditioning, ventilation, sanitation and building environment. The conclusions are as follows. (1) Most of fundamental studies on fluid flow were related with heat transportation of facilities. Drop formation and rivulet flow on solid surfaces were interesting topics related with condensation augmentation. Research on micro environment considering flow, heat, humidity was also interesting for comfortable living environment. It can be extended considering biological aspects. Development of fans and blowers of high performance and low noise were continuing topics. Well developed CFD and flow visualization(PIV, PTV and LDV methods) technologies were widely applied for developing facilities and their systems. (2) The research trends of the previous two yews are surveyed as groups of natural convection, forced convection, electronic cooling, heat transfer enhancement, frosting and defrosting, thermal properties, etc. New research topics introduced include natural convection heat transfer enhancement using nanofluid, supercritical cooling performance or oil miscibility of $CO_2$, enthalpy heat exchanger for heat recovery, heat transfer enhancement in a plate heat exchanger using fluid resonance. (3) The literature for the last two years($2004{\sim}2005$) is reviewed in the areas of heat pump, ice and water storage, cycle analysis and reused energy including geothermal, solar and unused energy). The research on cycle analysis and experiments for $CO_2$ was extensively carried out to replace the Ozone depleting and global warming refrigerants such as HFC and HCFC refrigerants. From the year of 2005, the Gas Engine Heat Pump(GHP) has been paid attention from the viewpoint of the gas cooling application. The heat pipe was focused on the performance improvement by the parametric analysis and the heat recovery applications. The storage systems were studied on the performance enhancement of the storage tank and cost analysis for heating and cooling applications. In the area of unused energy, the hybrid systems were extensively introduced and the life cycle cost analysis(LCCA) for the unused energy systems was also intensively carried out. (4) Recent studies of various refrigeration and air-conditioning systems have focused on the system performance and efficiency enhancement. Heat transfer characteristics during evaporation and condensation are investigated for several tube shapes and of alternative refrigerants including carbon dioxide. Efficiency of various compressors and expansion devices are also dealt with for better modeling and, in particular, performance improvement. Thermoelectric module and cooling systems are analyzed theoretically and experimentally. (5) According to the review of recent studies on ventilation systems, an appropriate ventilation systems including machenical and natural are required to satisfied the level of IAQ. Also, an recent studies on air-conditioning and absorption refrigeration systems, it has mainly focused on distribution and dehumidification of indoor air to improve the performance were carried out. (6) Based on a review of recent studies on indoor environment and building service systems, it is noticed that research issues have mainly focused on optimal thermal comfort, improvement of indoor air Quality and many innovative systems such as air-barrier type perimeter-less system with UFAC, radiant floor heating and cooling system and etc. New approaches are highlighted for improving indoor environmental condition as well as minimizing energy consumption, various activities of building control and operation strategy and energy performance analysis for economic evaluation.

• 한국결정성장학회지
• /
• 제23권4호
• /
• pp.180-188
• /
• 2013

삼척도계지역의 탄광에서 석탄채굴시에 부산물로 발생되는 사암계 석탄폐석을 원료로 사용하여 E-glass fiber 조성의 유리를 제조하였다. 본 연구에서는 카본함량이 비교적 적은 실리카-알루미나질의 사암계 석탄폐석을 사용하였으며, 폐석의 투입량을 0~35 %까지 변화시켰다. 서로 다른 석탄폐석 투입량을 갖는 배치원료를 $1550^{\circ}C$에서 2시간 용융하여 E-glass조성을 갖는 투명하고 맑은 유리가 얻어졌고, 81~84 %의 높은 가시광투과율, $5.39{\sim}5.61{\times}10^{-6}/^{\circ}C$의 열팽창계수, 851~$860^{\circ}C$의 연화점을 나타내었다. 유리섬유 시편은 $1150^{\circ}C$에서 섬유인상장치를 통해 얻어졌고, 복합재료의 보강용 유리섬유로서 내화학성 시험과 기계적 특성평가를 위한 인장강도를 측정하였다. 그 결과 석탄폐석을 사용한 E-glass fiber의 특성이 석탄폐석을 사용하지 않은 보통 E-glass 섬유에 비해 충분히 양호한 특성을 나타내어 E-glass 섬유용 원료로서 석탄폐석의 활용가능성을 확인할 수 있었다.

• 에너지공학
• /
• 제11권1호
• /
• pp.1-9
• /
• 2002

우리나라에 보급된 축냉시스템 이용효율 향상과 전력사용 합리화 방안을 제시함으로써 빙축열 시스템의 보급활성화를 통한 하절기 피크부하 경감에 기여코자 빙축열 설비의 성능시험을 실시한 결과 COP주간 3.8, 축열 3.0대비 30% 이상 성능이 감퇴한 주간 2.6∼3.4, 축열 2.1∼3.0정도로 냉동기가 가동되고 있으며, 축열율은 15개 건물 중 3개 건물(21.4%)만이 축열능력 대비 40% 이상의 축열을 실시하고 있는 것으로 분석되었다. 이처럼 운전성능 감퇴를 개선하기 위하여는 축냉(빙축열)설비 운전시 빈번히 발생하는 3-Way 밸브오동작, 냉각능력 감소, 팽창밸브 동작 부적절, 운전모드별 제어설정 오류 등에 의한 축냉능력 감퇴현상을 시정하고, 냉동기의 브라인배관 By-pass, Ice Slurry system운전모드별 배관분리, 냉온수펌프의 회전수제어 등의 배관계통 개선검토가 필요하며, 축냉(비축열) 시스템특징 별로는 Ice on Coil system은 냉방부하 확장성에 제약, Ice Ball system은 축열조의 수밀유지, Ice lens system의 제빙운전시 COP 저하, Ice Slurry system은 주간 운전시 저온운전에 따른 낮은 COP, Ice Harvest system은 Hot Gas 탈빙으로 동력손실증가 등에 대한 개선이 향후 축냉(빙축열)시스템의 운전성능 향상을 위해 필요한 것으로 도출되었다.

• 한국광물학회지
• /
• 제15권4호
• /
• pp.315-327
• /
• 2002

벤토나이트에 포함된 몬모릴로나이트의 층간에 Al산화물의 기둥(pillar)을 만든 Al-층간가교 점토를 합성하였다. 이 Al-층간가교점토에 대해 XRD, DTA, 화학분석 등을 실시하여 광물학적 특성을 검토하였으며, 그리고 이 가교점토에 대하여 Batch법의 흡착실험을 통하여 인산이온의 흡착성을 검토하였다. X-선 회절분석의 결과, Al-층간가교점토는 상온에서 층간격이 $18.03 \AA$으로 증가되어 나타났고, $550\AA$가열에서도 약 $17\AA$을 나타내어 열적 안정성이 크며, 글리세롤에 의한 층간격의 팽윤은 매우 미약한 것으로 나타났다. 열분석 결과, 이 점토에는 pillar부분에 관련된 물의 탈수에 의한 것으로 보이는 $270^{\circ}C$와 $420^{\circ}C$의 특징적인 흡열반응이 나타났다. Al-층간가교 점토의 인산 이온에 대한 흡착실험의 결과, 몬모릴로나이트는 거의 흡착능력을 보이지 않는데 비하여 월등히 우수한 인산이온($PO_{4}^{3－}$ /)성을 나타냈다. 시료 2 g에 용액 20 mL의 실험에서 300 mg/L 이하의 인산 농도에서는 거의 100%의 흡착효율을 나타냈다. 그리고 인산 이온에 흡착된 시료를 $500^{\circ}C$로 가열한 후 재차 흡착실험을 행한 결과, 역시 매우 높은 흡착효율을 나타냈다. 따라서 Al-층간가교 점토의 인산 이온 흡착에 대한 재활용의 가능성이 큰 것으로 나타났다

• 한국재료학회지
• /
• 제10권6호
• /
• pp.415-421
• /
• 2000

실리카 바인더 함량이 지르콘 쉘 주형의 기계적 특성에 미치는 영향을 고찰하였다. 실리카 졸/지르콘 함량비 $R_w$는 0.18~0.43 범위에서 변화시켰으며, 주형의 소결온도는 $871^{\circ}C~1400^{\circ}C$ 범위에서 변화시켰다. 생형의 상온강도는 실리카 졸/지르콘 함량비 $R_w$에 비례하여 증가하였다. 소결온도가 $1300^{\circ}C$ 이하인 경우, $R_w$가 증가함에 따라 소결된 주형의 상온강도와 치밀화는 증가하였다. 그러나 $R_w$가 0.43이고 $1400^{\circ}C$에서 3시간 동안 소결시킨 경우 주형의 상온강도와 치밀화가 오히려 감소하였다. 이는 소결 중 내화물 입자와 실리카 바인더와 열팽창계수의 차이에 기인하는 것으로 판단된다. 정밀주조용 지르콘 쉘 주형 제작을 의한 최적의 $R_w$ 값은 0.33인 것으로 나타났다.