• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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• pp.1779-1783
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• 2006

The hybrid thin-film (HTF) passivation layer composed of the UV curable acrylate layer and MS-31 (MgO:SiO2=3:1wt%) layer was adopted in organic light emitting diode (OLED) to protect organic light emitting materials from penetrations of oxygen and water vapors. The moisture resistance of the deposited HTF layer was measured by the water vapor transmission rate (WVTR). The results showed that the HTF layer possessed a very low WVTR value of lower than $0.007g/m^2$ per day at $37.8^{\circ}C$ and 100% RH. Therefore, the HTF on the OLED was found to be very effective in protect what from the penetrations of oxygen and moisture.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.899-901
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• 2009

The magnesium fluoride ($MgF_2$) has very higher optical transmission than oxide or nitride material applied for gas barrier, so we manufactured Mg-Zn-F films with Mg-Zn-F target mixed in the various ratio of $MgF_2$ to Zn and characterized films' properties. Zn is used to increase packing density of barrier film. Thickness and optical transmission of Mg-Zn-F are 200 nm and over 90 %, respectively. The result of water vapor transmission rate at 38, RH 90 ~ 100% of the Mg-Zn-F film deposited with 4 : 6 ($MgF_2$ : Zn) ratio target reached below $1{\times}10^{-3}g$/($m^2{\cdot}day$), measuring limit of instrument.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2010년도 제39회 하계학술대회 초록집
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• pp.160-160
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• 2010

Organic electronic devices require a passivation layer to ensure sufficient lifetime. Specifically, flexible organic electronic devices need a barrier layer that transmits less than $10^{-6}\;g/m^2/day$ of water and $10^{-5}\;g/m^2/day$ of oxygen. To increase the lifetime of organic electronic device, therefore, it is indispensable to protect the organic materials from water and oxygen. Severe groups have reported on multi-layerd barriers consisting inorganic thin films deposited by plasma enhenced chemical deposition (PECVD) or sputtering. However, it is difficult to control the formation of granular-type morphology and microscopic pinholes in PECVD and sputtering. On the contrary, atomic layer deoposition (ALD) is free of pinhole, highly uniform, conformal films and show good step coverage. In this study, the passivation layer was deposited using single-process PEALD. The passivation layer, in our case, was a bilayer system consisting of $Al_2O_3$ films and a $TiO_2$ buffer layer on a poly (ether sulfon) (PES) substrate. Because the deposition temperature and plasma power have a significant effect on the properties of the passivation layer, the characteristics of the $Al_2O_3$ films were investigated in terms of density under different deposition temperatures and plasma powers. The effect of the $TiO_2$ buffer layer also was also addressed. In addition, the water vapor transmission rate (WVTR) and organic light-emitting diode (OLEDs) lifetime were measured after forming a bilayer composed of $Al_2O_3/TiO_2$ on a PES substrate.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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• pp.374-374
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• 2012

Nowadays, Active Matrix Organic Light-Emitting Diodes (AM-OLEDs) are the superior display device due to their vivid full color, perfect video capability, light weight, low driving power, and potential flexibility. One of the advantages of AM-OLED over Liquid Crystal Display (LCD) lies in its flexibility. The potential flexibility of AM-OLED is not fully explored due to its sensitivity to moisture and oxygen which are readily present in atmosphere, and there are no flexible encapsulation layers available to protect these. Therefore, we come up with a new concept of Inorganic-Organic hybrid thin film as the encapsulation layer. Our Inorganic layer is Al2O3 and Organic layer is F-Alucone. We deposited these layers in vacuum state using Atomic Layer Deposition (ALD) and Molecular Layer Deposition (MLD) techniques. We found the results are comparable to commercial requirement of 10-6 g/m2 day for Water Vapor Transmission Rate (WVTR). Using ALD and MLD, we can control the exact thin film thickness and fabricate more dense films than chemical or physical vapor deposition methods. Moreover, this hybrid encapsulation layer potentially has both the flexibility of organic layers and superior protection properties of inorganic layer.

• 한국결정성장학회지
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• 제33권3호
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• pp.97-103
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• 2023

수분 차단성이 우수한 투명 포장재용 배리어성 필름을 개발하기 위하여, 상온 진공하에서 플라즈마 활성화 표면처리 공정의 전처리 공정을 거친 후에, 나노클레이 분산 적층 코팅층을 형성한다. 접착력 향상을 위한 코팅 공정의 적절한 가교공정과 최적분산공정을 통한 커플링 첨가제를 최적화하는 데 중점을 두었다. 기능성 코팅 박막에 대하여 분석한 결과는 수분 투과도 10 g/m²/24 hrs(ASTM F-1249) 이하, 산소 투과도 30 cc/m²/24 hrs(ASTM D3985) 이하임을 보여주었다. 이는 종래의 무처리 필름의 10배 이상 수분 차단성이 우수한 투명 포장용 표면기능성 코팅박막에 해당됨을 보였다. 아울러, 투명가스 차단 필름의 두께는 0.1 mm 이내이며, 투명가스차단 복합층은 2개의 층으로 구성되었다. PET 박막 계면 특성연구에서, FT-IR의 실험분석에 의하면 R DS 1.125 %에서 반응 활성도가 최적화임을 나타내고 있다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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• pp.163-163
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• 2012

차세대 모바일용 전자디스플레이로 각광받고 있는 FOLED (flexible organic light emitting display)의 연구에서 display의 신뢰성과 수명은 매우 중요한 연구 테마이다. OLED의 수명단축에 영향을 미치는 요소는 수분에 의한 열화가 가장 치명적이다. Barrier layer를 통한 수분의 주요 침투경로는 pin-hole과 void 등과 같은 defect에 의한 것으로 보인다. 수분의 침투 경로를 제어하는 OLED용 barrier layer의 요구조건은 WVTR (water vapor transmission rate)이 $10^{-6}g/m^2{\cdot}day$ 이하로 낮아야 한다. Barrier layer가 가져야 할 핵심적인 조건은 유연성을 가지면서 동시에 WVTR 값이 매우 낮아야 하는데, 아직까지 이를 만족하는 barrier layer의 개발은 아직 덜된 실정이다. 본 연구에서는 PET (polyethylene terephthalate) 기판에 sputtering법으로 barrier layer를 제조하였다. 증착에 이용한 타겟은 두가지 종류인 Al과 $Al_2O_3$를 사용하였으며, 다층박막으로 제조하였다. 제조된 barrier layer의 수분침투 특성은 WVTR의 측정으로, 유연성의 평가는 in-situ fatigue test를 수행하여 측정하였다. 종합적인 특성 평가를 위하여 SEM과 AFM (atomic force microscope) 관찰도 하였다.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2007년도 추계학술대회 논문집
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• pp.33-34
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• 2007

DLC를 포함한 탄소 박막은 우수한 특성으로 인해 세계적으로 많은 연구들이 진행 되고 있다. 본 연구에서는 탄소 박막의 산소 및 수분 차단 특성 및 광투과율의 특성과 플라즈마 변수와의 상관관계를 규명 하고자 하였으며, 이러한 상관관계를 Langmuir probe, UV-spectroscopy, MOCON 의 분석기구를 통하여 플라즈마 변수와 박막의 특성을 분석 하였으며, 수분 투과도는 4g/m$^2$/day까지 감소하는 결과를 얻었다.

• 반도체디스플레이기술학회지
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• 제21권1호
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• pp.39-43
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• 2022

In this paper, a study was conducted on encapsulation technology for high mechanical stability of flexible displays. First, unlike conventional encapsulation barrier that exclude cracks as much as possible for low water vapor transmission rate (WVTR), mechanical properties were improved by using a defect suppression mechanism introduced with crack arresters. The zero-stress encapsulation barrier optimizes the residual stress of the thin film based to improve the internal mechanical stability. The zero-stress encapsulation barrier was applied to the organic light emitting diodes (OLEDs) to confirm its characteristics and lifetime. Due to improved internal mechanical stability, it has a longer lifetime more than 35% compared to conventional encapsulation technologies. As the zero-stress encapsulation barrier proposed in this study does not require additional deposition process, it is not difficult to apply it. Based on various advantages, it is expected to play an important role in flexible displays.

• 한국식품저장유통학회:학술대회논문집
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• 한국식품저장유통학회 2003년도 제23차 추계총회 및 국제학술심포지움
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• pp.192.1-192
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• 2003

The aim of this study was to develop a model that could be used in the design of modified atmosphere packaging (MAP) for Mandarin oranges. Respiratory data at 5, 10, 20$^{\circ}C$ for mandarin oranges were gathered and altered for create useful respiration model. The maximum rate of oxygen uptake increased with increasing temperature. The packaging materials were conventional low density polyethylene and polypropylene with anti-fog, and anti-fungi treatments, and thickness was 30 $\mu\textrm{m}$ and 50 $\mu\textrm{m}$. Permeability tests were performed to find their oxygen, carbon dioxide, water vapor transmission rate as increases in temperature. Test results were then converted to logarithm format for MAP modeling. Optimum gas composition in the package system for fruits were set according to literature and upper or lower limits of oxygen and dioxide established. To predict gas composition at certain storage time, weight of fruits, film thickness, film type, and other variables, respiration rate was studied at various storage conditions. The validity of the model was tested experimentally by observing actual atmospheric changes inside packages. It is concluded that the strategy developed is of use in designing dynamic gas exchange MAP systems, and also has potential uses in similar agricultural products.

• 한국식품영양과학회지
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• 제22권4호
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• pp.476-483
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• 1993

상업적으로 생산되는 조미김의 흡습특성을 조사하기 위하여 조미김과 2종의 흡습제 (silica gel, zeolite)의 등온흡습곡선을 30, 40, 5$0^{\circ}C$에서 포화염용액을 사용하여 측정하였다. 실험온도 및 상대습도 범위내에서 평형수분함량에 도달하는데 조미김은 4~6시간, silica gel은 20~25시간, zeolite는 43~46시간이 소요되었다. 조미김과 흡습제의 등온흡습곡선은 모두 전형적인 sigmoid형 곡선을 나타냈다. BET식을 활용하여 구한 단분자층 수분함량은 조미김이 각 온도(30, 40, 5$0^{\circ}C$)에서 5.26, 4.46, 3.49% (d.b.)이었고, silica gel은 17.32, 15.24, 12.89% (d.b.), 그리고 zeolite가 16.87, 14.92, 14.33%(d.b.)로서 조미김에 비해 흡습제가 높은 범위의 단분자층 수분함량을 나타냈다. 또한 단분자층 수분함량은 온도가 증가함에 따라 실험온도 범위 내에서 직선적으로 감소함이 발견되었다 포장재의 투습도 역시 온도의 영향을 받음을 알 수 있었는데, 조미김 포장재의 투습계수의 온도의존성은 Arrhenius식으로 표시할 수 있었다.