• Title/Summary/Keyword: Aerosol deposition

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Composite Thick Films Based on Highly-Packed Nano-Porous Ceramics by Aerosol Deposition and Resin Infiltration

  • Kim, Hong-Gi;Kim, Hyeong-Jun;Nam, Song-Min
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.02a
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    • pp.111-111
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    • 2010
  • 최근 전자 소자의 집적기술은 기존의 2차원에서 System on package (SOP) 개념에 기반을 둔 3차원 집적 기술로 발전 되어가고 있다. 소자의 3차원 실장을 실현시키는 과정에서 세라믹의 여러 유용성이 언급되어져 왔지만, 취성이 매우 크다는 등의 단점이 있었다. 이러한 이유로 연성을 가지는 폴리머와 세라믹을 합성한 복합체 기판에 대하여 많은 연구가 되고 있다. 그러나 세라믹 제작을 위해서는 높은 공정온도가 요구되고 있고 이러한 높은 공정상에서의 온도는 3차원 실장에 있어서 문제점이 되고 있다. 이러한 문제점을 극복하기 위하여 상온에서 치밀한 세라믹 후막을 제작할 수 있는 공정인 Aerosol Deposition Method (ADM)방법으로 세라믹-폴리머 후막의 제조를 시도하였다. 일반적으로 ADM은 수백 나노의 출발 파우더를 사용하여 치밀한 세라믹 막을 형성하는데 사용된다. 본 연구에서는 ADM으로 100 nm미만의 나노 세라믹 파우더를 사용하여 다공성의 세라믹 후막을 제조한 후 resin을 함침시키는 방법으로 세라믹-폴리머 후막의 제조를 시도하였다. 그 결과 운송가스, aerosol 농도 등의 공정조건을 변화시켜 다공성의 $Al_2O_3$ 후막을 제조하였고, 이 다공성 후막은 반투명의 특성을 보이며 고충전율로 형성되었다. 이렇게 제조된 나노 다공성 $Al_2O_3$ 후막에 cyanate ester resin을 함침시키는 방법을 사용하여 $Al_2O_3$-cyanate ester 복합체 후막을 제조하였으며, 이의 비유전율 및 품질계수는 각각 1 MHz에서 6.7, 1000으로 우수한 유전특성을 보임이 확인되었다.

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Single Crystal Growth Behavior in High-Density Nano-Sized Aerosol Deposited Films

  • Lim, Ji-Ho;Kim, Seung-Wook;Kim, Samjung;Kang, Eun-Young;Lee, Min Lyul;Samal, Sneha;Jeong, Dae-Yong
    • Korean Journal of Materials Research
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    • v.31 no.9
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    • pp.488-495
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    • 2021
  • Solid state grain growth (SSCG) is a method of growing large single crystals from seed single crystals by abnormal grain growth in a small-grained matrix. During grain growth, pores are often trapped in the matrix and remain in single crystals. Aerosol deposition (AD) is a method of manufacturing films with almost full density from nano grains by causing high energy collision between substrates and ceramic powders. AD and SSCG are used to grow single crystals with few pores. BaTiO3 films are coated on (100) SrTiO3 seeds by AD. To generate grain growth, BaTiO3 films are heated to 1,300 ℃ and held for 10 h, and entire films are grown as single crystals. The condition of grain growth driving force is ∆Gmax < ∆Gc ≤ ∆Gseed. On the other hand, the condition of grain growth driving force in BaTiO3 AD films heat-treated at 1,100 and 1,200 ℃ is ∆Gc < ∆Gmax, and single crystals are not grown.

Prestenotic Bronchial Radioaerosol Deposition: A New Lung Scan Sign of Bronchial Obstruction (기관지 협착 근위부의 연무 침착: 폐스캔에서 기관지 폐색의 특이한 지표)

  • Chung, Soo-Kyo;Kim, Hak-Hee;Choi, Byung-Gil;Lee, Sang-Hoon;Kang, Si-Won;Bahk, Yong-Whee
    • The Korean Journal of Nuclear Medicine
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    • v.29 no.3
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    • pp.307-312
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    • 1995
  • The present study has been carried out to assess the diagnostic usefulness of radioaerosol lung scan in complete bronchial obstruction (n=7) and bronchial narrowing (n=1) of varying causes. $^{99m}Tc$-phytate lung scan was performed using the aerosol generated by a BARC nebulizer. Scan alterations were correlated with those of chest radiography, bronchography, lung CT and/or brochoscopy. In every case scan showed characteristic intense deposition of radioaerosol in a short slightly dilated, bronchial segment immediately proximal to obstruction or stenosis. Characteristically it was accompanied by an airspace aerosol deposition defect distally. The finding of a short, clubbed, bronchial radioaerosol deposition with distal airspace defect is a sensitive, specific indicator of bronchial obstruction or stenosis. It was especially useful in the detection of the obstruction of a small bronchus at the lobar and sublobar levels. We propose to name it the prestenotic aerosol deposition sign.

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Room temperature-processed TiO2 coated photoelectrodes for dye-sensitized solar cells

  • Kim, Dae-gun;Lee, Kyung-min;Lee, Hyung-bok;Lim, Jong-woo;Park, Jae-hyuk
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.30 no.2
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    • pp.61-65
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    • 2020
  • The depletion of fossil fuels and the increase in environmental awareness have led to greater interest in renewable energy. In particular, solar cells have attracted attention because they can convert an infinite amount of solar energy into electricity. Dye-sensitize solar cells (DSSCs) are low cost third generation solar cells that can be manufactured using environmentally friendly materials. However, DSSC photoelectrodes are generally produced by screen printing, which requires high temperature heat treatment, and low temperature processes that can be used to produce flexible DSSCs are limited. To overcome these temperature limitations, this study fabricated photoelectrodes using room-temperature aerosol deposition. The resulting DSSCs had an energy conversion efficiency of 4.07 %. This shows that it is possible to produce DSSCs and flexible devices using room-temperature processes.

Etching Characteristics of Er-doped Sodium Borosilicate Glass Film Fabricated by Aerosol Flame Deposition Method (Aerosol Flame Deposition 법에 의해 제조된 Er 첨가 Soldium Borosilicate 유리박막의 식각 특성에 관한 연구)

  • 박강희;정형곤;이정우;이형종;박현수;문종하
    • Journal of the Korean Ceramic Society
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    • v.36 no.9
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    • pp.946-953
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    • 1999
  • The etching characteristics of Er-doped sodium borosilicate glass film for the planar optical waveguides were investigated using reactive ion etching. The etch rate decreased as the pressure in creased but increased as the RF power increased. The etch rate increased as the flow rate C2F gas and the amount of O2 addition increased but decreased over critical point (C2F6 7,5 accm O2 20%) The etch rate was 180${\AA}$/min under C2F6 7.5 sccm O2 20% RF power 270 W, pressure 150 mTorr. With this optimum etching condition and subsequent heat treatment at 975$^{\circ}C$ for 30 minutes planar optical waveguides having improved sidewall roughness were fabricated successfully.

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