• Title/Summary/Keyword: Heated substrate

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Evaporation Characteristics of Paired Sessile Droplets on a Heated Substrate (가열된 표면에 고착된 한 쌍의 액적 증발 특성)

  • Hyung Ju Lee;Won Yeong Hwang;Jing Hao Jin;Chang Kyoung Choi;Seong Hyuk Lee
    • Journal of ILASS-Korea
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    • v.28 no.3
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    • pp.113-118
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    • 2023
  • This study investigates the evaporation characteristics of paired sessile droplets on a heated substrate. In particular, the evaporation time and contact line behaviors were analyzed based on the droplet-to-droplet distance and substrate temperature. The contact line behavior and volume variations were visualized using the shadowgraph method. It was observed that the contact diameter and contact angle exhibited similar behavior for both single and paired droplets regardless of the droplet-to-droplet distance and substrate temperature. The paired droplets demonstrated a longer evaporation time than the single droplet due to the vapor accumulation between the droplets. Furthermore, the scaled lifetime, defined as the ratio of evaporation time between paired and single droplets, increased as the droplet-to-droplet distance decreased and decreased as the substrate temperature increased, attributed natural convection.

The Natural Cooling Effects of Pre-heated Substrate during RF Magnetron Sputter Deposition of ZnO (ZnO 박막의 RF 마그네트론 스퍼터 증착 중 미리 가열된 기판의 자연냉각 효과)

  • Park, Sung-Hyun;Lee, Neung-Hun
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.56 no.5
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    • pp.905-909
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    • 2007
  • Crystalline and micro-structural characteristics of ZnO thin films which were deposited on p-Si(100) with cooling naturally down of pre-heated substrate during RF magnetron sputter deposition, were investigated by XRD and SEM in this paper. The film which was prepared on the substrate which was pre-heated to $400^{\circ}C$ before deposition and then cooled naturally down during deposition, showed the most outstanding c-axis preferred orientation. The ZnO thin film having the best crystalline result were applied to SMR type FBAR device and resonance properties of the device were investigated by network analyzer. It showed that resonance frequency was 2.05 GHz, return loss was -30.64 dB, quality factor was 3169 and electromechanical coupling factor was 0.4 %. This deposition method would be very useful for application of surface acoustic wave filter or film bulk acoustic wave resonator.

Effect of Substrate Temperature on Electrical Properties of Ink-Jet Printed OTFTs (Substrate 온도에 따른 Ink-Jet Printed OTFT의 특성 변화)

  • Kim, Yong-Hoon;Gong, Ju-Yeong;Park, Sung Kyu;Ju, Byeong-Kwon;Han, Jeong-In
    • Proceedings of the KIEE Conference
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    • 2008.07a
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    • pp.1274-1274
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    • 2008
  • In this report, the effect of substrate temperature on the electrical properties of ink-jet printed triisopropylsilyl (TIPS) pentacene organic thin-film transistors (OTFTs) has been investigated. The electrical properties such as mobility and on/off ratio were decreased as the substrate was heated above room temperature. The field-effect mobility of decreased from $10^{-2}cm^2/Vs$ to $10^{-5}cm^2/Vs$ and the on/off ratio decreased from $10^6$ to $10^4$ when the substrate temperature was heated from room temperature to 60$^{\circ}C$.

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Focused-Infrared-Light Assisted Roll-to-Roll Hot Embossing (Focused Infrared Light를 이용한 롤투롤 핫엠보싱)

  • Jo, Jeongdai;Kim, Wooseop;Kim, Kwang-Young;Choi, Young-Man
    • Journal of the Korean Society for Precision Engineering
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    • v.34 no.3
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    • pp.199-203
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    • 2017
  • Hot embossing techniques are used to engrave patterns on plastic substrates. Roll based hot embossing uses a heated roll for a continuous process. A heated roll with relief patterns is impressed on a preheated plastic substrate. Then, the substrate is cooled down quickly to prevent thermal shrinkage. The roll speed is normally very slow to ensure substrate temperature increase up to the glass transition temperature. In this paper, we propose a noncontact preheating technique using focused infrared light. The infrared light is focused as a line beam on a plastic substrate using an elliptical mirror just before entering the hot embossing roll. The mid range infrared light efficiently raises the substrate temperature. For preliminary tests, substrate deformation and temperature changes were monitored according to substrate speed. The experiments show that the proposed technique is a good possibility for high speed hot embossing.

Effects of Cooling Rate of Pre-heated Substrate on C-Axis Orientation of ZnO Prepared by RF Sputter Deposition (RF 스퍼터를 이용하여 ZnO 증착 시 기판의 냉각율이 박막의 c-축 배향성에 미치는 영향)

  • Park, Sung-Hyun;Lee, Neung-Hun
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.55 no.12
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    • pp.560-564
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    • 2006
  • ZnO thin films were prepared by RF magnetron sputter deposition on p-Si(100) wafer with various cooling rates of substrate temperature such as the substrates were pre-heated to $400^{\circ}C$ before the deposition and then cooled down naturally or slowly to $300^{\circ}C,\;200^{\circ}C,\;100^{\circ}C$, and R.T. by the temperature controller during the deposition. Crystalline and micro-structural characteristics of the films were investigated by XRD and SEM. ZnO films which cooled down naturally or slowly by the temperature controller during the deposition, especially the film were deposited with cooling down from $400^{\circ}C\;to\;200^{\circ}C$ slowly. showed the most outstanding c-axis preferred orientation.

Formation of SiC layer on Single Crystal Si Using Hot-Filament Reactor

  • Kim, Hong-Suk;Park, In-Hoon;Eun, Kwang-Yong;Baik, Young-Joon
    • The Korean Journal of Ceramics
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    • v.4 no.1
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    • pp.25-27
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    • 1998
  • The effect of gas activation on the formation of SiC layer on Si substrate using methane as a carbon source was investigated. Tungsten filaments, heated above 200$0^{\circ}C$, were used to activate the methane-hydrogen mixed gas. The dissociation of methane gas by the heated filament was enough to form a SiC layer successfully, which was very difficult without any activation. The SiC layer formed on the Si substrate was crystalline and nearly epitaxial as measured by X-ray diffraction. The SiC layer formed on the Si substrate was crystalline and nearly epitaxial as measured by X-ray diffraction. The stoichiometry was also close to 1:1. However, the characteristic of the SiC layer was dependent on the heat-treatment condition. The general behavior of the layer growth with the variables was discussed.

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Improvement of c-axis orientation of ZnO thin film prepared on pre-heated substrate with cooling during RF sputter deposition (RF 스퍼터를 이용하여 미리 가열된 기판을 냉각하며 증착한 ZnO 박막의 c축 배향성 향상에 관한 연구)

  • Park, Sung-Hyun;Lee, Soon-Beom;Shin, Young-Hwa;Lee, Neung-Heon;Ji, Seung-Han;Kwon, Sang-Jik
    • Proceedings of the KIEE Conference
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    • 2006.10a
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    • pp.24-25
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    • 2006
  • In this paper, ZnO thin films were prepared on p-Si(100) by RF magnetron sputtering. Before the depostion, the substrates were pre-heated to 500, 400, 300, $200^{\circ}C$ or not. During the deposition, the substrates were cooled down naturally or kept and then the films were investigated by XRD(X-ray diffraction) and SEM (scanning micro scope). It is showed the most outstanding result that the film was prepared on the substrate were cooled from $400^{\circ}C$. When the substrate was cooled from a certain temperature during deposition, it could be improve the c-axis orientation and useful for application of SAW(surface acoustic wave) filter and FBAR(film bulk acoustic wave resonator) device.

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On-Chip Process and Characterization of the Hermetic MEMS Packaging Using a Closed AuSn Solder-Loop (사각고리형상의 AuSn 합금박막을 이용한 MEMS 밀봉 패키징 및 특성 시험)

  • Seo, Young-Ho;Kim, Seong-A;Cho, Young-Ho;Kim, Geun-Ho;Bu, Jong-Uk
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.28 no.4
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    • pp.435-442
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    • 2004
  • This paper presents a hermetic MEMS on-chip package bonded by a closed-loop AuSn solder-line. We design three different package specimens, including a substrate heated specimen without interconnection-line (SHX), a substrate heated specimen with interconnection-line (SHI) and a locally heated specimen with interconnection-line (LHI). Pressurized helium leak test has been carried out for hermetic seal evaluation in addition to the critical pressure test for bonding strength measurement. Substrate heating method (SHX, SHI) requires the bonding time of 40min. at 400min, while local heating method (LHI) requires 4 min. at the heating power of 6.76W. In the hermetic seal test. SHX, SHI and LHI show the leak rates of 5.4$\pm$6.7${\times}$$^{-10}$ mbar-l/s, 13.5$\pm$9.8${\times}$$^{-10}$ mbar-l/s and 18.5$\pm$9.9${\times}$$^{-10}$ mbar-l/s, respectively, for an identical package chamber volume of 6.89$\pm$0.2${\times}$$^{-10}$. In the critical pressure test, no fracture is found in the bonded specimens up to the applied pressure of 1$\pm$0.1MPa, resulting in the minimum bonding strength of 3.53$\pm$0.07MPa. We find that the present on-chip packaging using a closed AuSn solder-line shows strong potential for hermetic MEMS packaging with interconnection-line due to the hermetic seal performance and the shorter bonding time for mass production.

Fabrication of Barium Ferrite Films by Sol-Gel Dip Coating and Its Properties.

  • T. B. Byeon;W. D. Cho;Kim, T. O.
    • Journal of Magnetics
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    • v.2 no.1
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    • pp.16-21
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    • 1997
  • Those were investigated, the crystallographic, morphological, and magnetic properties of barium ferrite film (SiO2/Si substrate) prepared by sol-gel dip coating. Appropriate sol was prepared by dissolvin barium and iron nitrate in ethylene glycol at 80$^{\circ}C$. To obtain the films, thermally oxidized p-type silicon substrate with (111) of crystallographic orientation were dipped into the sol, dried at 250$^{\circ}C$ to remove organic material, and heated at 800$^{\circ}C$ for 3 hours in air for the crystallization of barium ferrite. It was found that the particles of barium ferrite formed on the substrate exhibited needle-like shape placing parallel to the substrate and its c-axis is long axis direction. There was tendency that the coercive force in horizontal direction to the substrate was higher than that in vertical direction to it. This tendency was profound in large thickness.

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Protein Qualities of Loach as Affected by Cooking Methods (가열 처리한 미꾸라지 단백질의 품질)

  • 류홍수;문숙임;이수정;서재수
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.28 no.1
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    • pp.145-152
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    • 1999
  • To explore the possibility of using freeze dried loach for instant choo o tang(Korean traditional loach soup), protein qualities and fatty acid composition were evaluated on boiled and steamed loach. Total lipid and ash content were lowered in both heated(boiled and steamed) loaches due to deboning and eviscerating during cooked meat preparation. Profiles of total amino acids were not changed seriously by the type of cooking, but the amount of essential amino acids were comparable in all samples. Two times more free amino acids were quantified in cooked samples compared to raw meat. Available lysine was marginally decreased by cooking, and that caused some measurable change in typsin indigestible substrate(TI) in streamed whole loach. In vitro protein digestibility of the heated loaches was not altered drastically and the protein quality determined as computed protein efficiency ratio(C PER) was similar for the raw, boiled and steamed loach. The ratios of unsaturated to saturated fatty acids changed measurably in heated whole loach. The results shows that heating caused apparent oxidative deterioration of the polyunsaturated fatty acids.

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