• 제목/요약/키워드: thermal vacuum

검색결과 1,509건 처리시간 0.037초

M/CGS 이중구조를 갖는 박막소자의 온도특성분석 (The Analysis of temperature characteristics on M/CGS thin film devices)

  • 권영호;문형돈;김화영;김영호
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.2
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    • pp.826-829
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    • 2003
  • Metal/chalcogenide glass semiconductor(CGS) thin film devices were produced in the vacuum evaporator by the methode of vacuum thermal evaporation. We investigated the influence of the correlations of thickness of metal and CGS upon the concentration of Metal in a CGS thin film. It has shown that M/CGS thin film devices were very sensitive to temperature.

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단열을 고려한 초저온 액체질소 저장 탱크의 지지대 용접부 설계 (Weldment Design of Supports for Cryogenic Storage Tank considering Insulation)

  • 최동준;오정택;정재현;조종래
    • Journal of Advanced Marine Engineering and Technology
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    • 제32권1호
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    • pp.131-136
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    • 2008
  • The double-walled steel vessel with powder insulation in the space between the walls is used to minimize heat transfer by radiation and conduction in cryogenic storage tank. The vacuum required the insulation is much less extreme than with high-vacuum or multilayer insulations. The solid supports are used to bear the weight of the inner container. Thermal and structural analysis of the tank have been carried out to study the effect of vacuum and weldment geometry of the internal supports. Heat flux in wall is increased with increasing of thermal conductivity of perlite. Heat flux and stress of support is not affected by weldment geometry.

Large Cryosorption Pump for the NBI Test Stand

  • In, S.R.;Shim, H.J.
    • Journal of Korean Vacuum Science & Technology
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    • 제7권2호
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    • pp.27-32
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    • 2003
  • A large cryo-pumping system composed of 4 cryosorption pumps was designed and manufactured to satisfy the pressure requirements of the NBI test stand. The cryosorption pump consists of a thermal shield/baffle assembly and a cryopanel coated with activated carbon granules. The thermal shield is cooled by liquid nitrogen, and the cryopanel by a commercial helium refrigerator. The operation characteristics and vacuum performance of the cryosorption pump were investigated. The cooling down time of the cryopanel to 20 K was about 6 hours with a liquid nitrogen consumption rate of about 35 L/hr. The maximum pumping speed of the cryosorption pump for the hydrogen gas measured by the steady pressure method was about 90,000 L/s.

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다양한 조건하에서의 진공청소기 흡입구 커버의 열변형 해석 (Thermal Analysis of Vacuum Cleaner Suction Nozzle Cover under Variable Conditions)

  • 강형선
    • 한국산학기술학회논문지
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    • 제8권5호
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    • pp.973-978
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    • 2007
  • 본 논문에서 가정용 진공청소기의 여러 조건하에서의 열변형 형태를 유한요소해석을 통해서 예측하고 이를 실험을 통하여 비교하였다. 유한요소해석에 있어서 (1) 벨트장력에 의한 압축력이 작용하였을 경우 (2) 벨트와 회전축의 마찰열 (3) 벨트장력과 열하중이 각각 고려되었을 경우의 3가지 조건을 대입하여 흡입구 커버의 변형 상태를 예측하였다. 또한 해석 결과를 실(real) 제품의 성능테스트를 통하여 비교하였고 내부 온도 상승을 방지할 수 있는 근본적인 개선 대책을 제시하였다.

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Retort Pouch 쌀밥의 가열살균시(加熱殺菌時) 파우치 포장내(包裝內)의 진공도(眞空度)가 열전달(熱傳達) 및 물성(物性)에 미치는 영향(影響) (The Effect of the Levels of Package Vacuum on the Heat Penetration and Texture of Cooked Rice Packed in Retort Pouch during Thermal Process)

  • 최광수;김창식
    • 한국식품영양과학회지
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    • 제11권4호
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    • pp.17-24
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    • 1982
  • retort pouch 쌀밥 제조 시간을 단축시키고 가열살균 중의 진공도가 열전달 속도 및 물성에 미치는 영향을 조사하기 위하여 본 연구를 실시하였다. 쌀의 수침시 평형수분 함량에 도달하는 시간이 품종에 별로 관계 없이 실온$(24^{\circ}C)$에서는 $2.5{\sim}3$시간이고 증미를 실온에서 침지하여 약 60% 수분의 최적 쌀밥 수분함량에 도달하는 시간이 약 1시간이라는 것을 발견하였다. $111^{\circ}C$에서 49분간 살균했을때 고진공 포장에서의 Fo값은 3.16분이고 저진공포장 쌀밥의 2.90분으로써 고진공 포장에서의 살균값이 더 컸다. fh 값도 $111^{\circ}C$ 살균시 고진공포장은 8.5분(j값=1.08), 저진공포장에서는 12.9분(j값=1.18)로서 고진공포장이 열전달 속도가 빠르다는 것을 알았고 $121.1^{\circ}C$에서도 진공도의 영향은 같은 경향을 보였다. 고진공포장 쌀밥이stickiness/Hardness의 비율로 봐서는 우수하게 보였으나 저진공포장의 쌀밥보다 stickiness, adhesiveness가 현저히 증가하고 쌀알이 파괴되고 엉켜서 품질이 좋지 않았다.

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Influence of Surface Morphology and Substrate on Thermal Stability and Desorption Behavior of Octanethiol Self-Assembled Monolayers

  • ;강훈구;;;노재근
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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    • pp.219-219
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    • 2012
  • The formation and thermal desorption behaviors of octanethiol (OT) SAMs on single crystalline Au (111) and polycrystalline Au, Ag, and Cu substrates were examined by X-ray photoelectron microscopy (XPS), thermal desorption spectroscopy (TDS), and contact angle (CA) measurements. XPS and CA measurements revealed that the adsorption of octanethiol (OT) molecules on these metals led to the formation of chemisorbed self-assembled monolayers (SAMs). Three main desorption fragments for dioctyl disulfide (C8SSC8+, dimer), octanethiolate (C8S+), and octanethiol (C8SH+) were monitored using TDS to understand the effects of surface morphology and the nature of metal substrates on the thermal desorption behavior of alkanethiols. TDS measurements showed that a sharp dimer peak with a very strong intensity on single crystalline Au (111) surface was dominantly observed at 370 K, whereas a broad peak on the polycrystalline Au surface was observed at 405 K. On the other hand, desorption behaviors of octanethiolates and octanethiols were quite similar. We concluded that substrate morphology strongly affects the dimerization process of alkanethiolates on Au surfaces. We also found that desorption intensity of the dimer is in the order of Au>>Ag>Cu, suggesting that the dimerization process occurs efficiently when the sulfur-metal bond has a more covalent character (Au) rather than an ionic character (Ag and Cu).

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혼합초단열재에서 진공분말패널의 외피형상 및 패널배열에 따른 단열성능해석 (The Numerical Analysis on Insulation Performance with Respect to the Envelope Geometries and Array of Evacuated Powder Panel in Rigid Foam/Evacuated Powder Composite Panels)

  • 홍진관
    • 설비공학논문집
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    • 제8권4호
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    • pp.497-509
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    • 1996
  • Evacuated powder insulations have long been known to have better thermal performance than existing commercially available insulators, such as fiber glass and CFC-blown foam. To make a composite powder panel, a series of individually evacuated panels was encapsulated in a rigid closed cell foam matrix. The panels were encapsulated in a thin glass sheet barrier to preserve the vacuum. The thermal conductivity of the individual panel was found to be $0.0062W/m^{\circ}K$ by experiment and the polyurethane foam above had a thermal conductivity of $0.024W/m^{\circ}K$. In this study, numerical analysis using finite element method was carried out to investigate insulation performance of rigid foam/evacuated powder composite panel with respect to panel geometries such as panel pitch, panel aspect ratio and panel area ratio. Numerical analysis has indicated that more optimal vacuum panel geometries, much lower overall thermal conductivities can be achieved.

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Thermal Stability of Self-formed Barrier Stability Using Cu-V Thin Films

  • 한동석;문대용;김웅선;박종완
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2011년도 제40회 동계학술대회 초록집
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    • pp.188-188
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    • 2011
  • Recently, scaling down of ULSI (Ultra Large Scale Integration) circuit of CMOS (Complementary Meta Oxide Semiconductor) based electronic devices, the electronic devices, become much faster and smaller size that are promising property of semiconductor market. However, very narrow interconnect line width has some disadvantages. Deposition of conformal and thin barrier is not easy. And metallization process needs deposition of diffusion barrier and glue layer for EP/ELP deposition. Thus, there is not enough space for copper filling process. In order to get over these negative effects, simple process of copper metallization is important. In this study, Cu-V alloy layer was deposited using of DC/RF magnetron sputter deposition system. Cu-V alloy film was deposited on the plane SiO2/Si bi-layer substrate with smooth surface. Cu-V film's thickness was about 50 nm. Cu-V alloy film deposited at $150^{\circ}C$. XRD, AFM, Hall measurement system, and AES were used to analyze this work. For the barrier formation, annealing temperature was 300, 400, $500^{\circ}C$ (1 hour). Barrier thermal stability was tested by I-V(leakage current) and XRD analysis after 300, 500, $700^{\circ}C$ (12 hour) annealing. With this research, over $500^{\circ}C$ annealed barrier has large leakage current. However vanadium-based diffusion barrier annealed at $400^{\circ}C$ has good thermal stability. Therefore thermal stability of vanadium-based diffusion barrier is desirable for copper interconnection.

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CRT 부품용 탈가스 및 Thermal Desorption 측정장치 개발 (Outgassing and thermal desorption measurement system for parts of CRT)

  • 신용현;홍승수;문성주;서일환;정광화
    • 한국진공학회지
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    • 제6권4호
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    • pp.298-307
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    • 1997
  • CRT부품 탈가스(outgassing)를 온도를 변화 시켜가며 측정할 수 있고 시료의 열탈착 특성을 측정할 수 있는 TDS(Thermal Desorption Spectroscopy) 측정 장치를 설계 제작하였다. 제작된 시스템은 유효 배기속도를 조절할 수 있는 진공 장치와 시료의 온도조절 장치, 탈가스 측정 가치로 구성되어 있다. 제작된 시스템의 최저 도달 진공도는 $1{\times}10^{-7}$Pa 이하였고 가변 콘덕탄스(conductance)를 채택하여 유효 배기 속도를 조절 할 수 있도록 제작되었다. 가변 콘덕탄스 조절에 따른 시료위치에서의 유효 배기 속도 변화를 측정하였다. 텅스텐 히터와 온도조절기를 이용하여 시료의 온도는 600℃까지 ±1℃ 이내 오차로 조절 할 수 있었으며 온도 상승률도 조절할 수 있었다. 측정계기로 사용한 이온 진공계(ion gauge)와 사중극 질량분석기(quadrupole mass spectrometer)의 감도를 측정하여 정량적인 측정을 할 수 있도록 하였다. 제작된 시스템을 이용하여 CRT 공정에서의 부품별 온도별 측정 예와 공정분석에의 적용 예를 보였다.

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The effect of thermal anneal on luminescence and photovoltaic characteristics of B doped silicon-rich silicon-nitride thin films on n-type Si substrate

  • Seo, Se-Young;Kim, In-Yong;Hong, Seung-Hui;Kim, Kyung-Joong
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2009년도 제38회 동계학술대회 초록집
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    • pp.141-141
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    • 2010
  • The effect of thermal anneal on the characteristics of structural properties and the enhancement of luminescence and photovoltaic (PV) characteristics of silicon-rich silicon-nitride films were investigated. By using an ultra high vacuum ion beam sputtering deposition, B-doped silicon-rich silicon-nitride (SRSN) thin films, with excess silicon content of 15 at. %, on P-doped (n-type) Si substrate was fabricated, sputtering a highly B doped Si wafer with a BN chip by N plasma. In order to examine the influence of thermal anneal, films were then annealed at different temperature up to $1100^{\circ}C$ under $N_2$ environment. Raman, X-ray diffraction, and X-ray photoemission spectroscopy did not show any reliable evidence of amorphous or crystalline Si clusters allowing us concluding that nearly no Si nano-cluster could be formed through the precipitation of excess Si from SRSN matrix during thermal anneal. Instead, results of Fourier transform infrared and X-ray photoemission spectroscopy clearly indicated that defective, amorphous Si-N matrix of films was changed to be well-ordered thanks to high temperature anneal. The measurement of spectral ellipsometry in UV-visible range was carried out and we found that the optical absorption edge of film was shifted to higher energy as the anneal temperature increased as the results of thermal anneal induced formation of $Si_3N_4$-like matrix. These are consistent with the observation that higher visible photoluminescence, which is likely due to the presence of Si-N bonds, from anneals at higher temperature. Based on these films, PV cells were fabricated by the formation of front/back metal electrodes. For all cells, typical I-V characteristic of p-n diode junction was observed. We also tried to measure PV properties using a solar-simulator and confirmed successful operation of PV devices. Carrier transport mechanism depending on anneal temperature and the implication of PV cells based on SRSN films were also discussed.

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