• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.3
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• pp.255-259
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• 2006

In this paper, the inorganic-organic thin film encapsulation layer was newly adopted to protect the organic layer from moisture and oxygen. Using the electron beam, Sputter and Spin-Coater system, the various kinds of inorganic and organic thin-films were deposited onto the Ethylene Terephthalate(PET) and their interface properties between organic and inorganic layer were investigated. In this investigation, the SiON and Polyimide(PI) layer showed the most suitable properties. Under these conditions, the WVTR(water vapour transition rate) for PET can be reduced from level of $0.57\;g/m^2{\cdot}day$ (bare subtrate) to $1{\times}10^{-5}\;g/m^2{\cdot}day$ after application of a SiON and Polyimide layer. These results indicates that the SiON/PI/SiON/PI/PET barrier coatings have high potential for flexible organic light-emitting diode(OLED) applications.

• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.243-243
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• 2007

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.11a
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• pp.313-314
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• 2006

In this paper, the inorganic-organic thin film encapsulation layer was newly adopted to protect the organic layer from moisture and oxygen. Using the electron beam, Sputter and Spin-Coater system, the various kinds of inorganic and organic thin-films were deposited onto the Ethylene Terephthalate(PET) and their interface properties between organic and inorganic layer were investigated Results indicates that the SiON/PI/SiON/PI/PET barrier coatings have high potential for flexible organic light-emitting diode(OLED) application.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.176-176
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• 2010

One of the critical issues for applications of flexible organic thin film transistors (OTFTs) for flexible electronic systems is the electrical stabilities of the OTFT devices, including variation of the current on/off ratio (Ion/Ioff), leakage current, threshold voltage, and hysteresis under repetitive mechanical deformation. In particular, repetitive mechanical deformation accelerates the degradation of device performance at the ambient environment. In this work, electrical stability of the pentacene organic thin film transistors (OTFTs) employing multi-stack hybrid encapsulation layers was investigated under mechanical cyclic bending. Flexible bottom-gated pentacene-based OTFTs fabricated on flexible polyimide substrate with poly-4-vinyl phenol (PVP) dielectric as a gate dielectric were encapsulated by the plasma-deposited organic layer and atomic-layer-deposited inorganic layer. For cyclic bending experiment of flexible OTFTs, the devices were cyclically bent up to 105 times with 5mm bending radius. In the most of the devices after 105 times of bending cycles, the off-current of the OTFT with no encapsulation layers was quickly increased due to increases in the conductivity of the pentacene caused by doping effects from $O_2$ and $H_2O$ in the atmosphere, which leads to decrease in the Ion/Ioff and increase in the hysteresis. With encapsulation layers, however, the electrical stabilities of the OTFTs were improved significantly. In particular, the OTFTs with multi-stack hybrid encapsulation layer showed the best electrical stabilities up to the bending cycles of $10^5$ times compared to the devices with single organic encapsulation layer. Changes in electrical properties of cyclically bent OTFTs with encapsulation layers will be discussed in detail.

• Journal of the Microelectronics and Packaging Society
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• v.25 no.1
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• pp.1-10
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• 2018

Recently, there has been rapid development in the field of flexible electronic devices, such as organic light emitting diodes (OLEDs), organic solar cells and flexible sensors. Encapsulation process is added to protect the flexible electronic devices from exposure to oxygen and moisture in the air. Using numerical simulation, we investigated the effects of the encapsulation layer on mechanical stability of the silicon chip, especially the fracture performance of center crack in multi-layer package for various loading condition. The multi-layer package is categorized in two type - a wide chip model in which the chip has a large width and encapsulation layer covers only the chip, and a narrow chip model in which the chip covers both the substrate and the chip with smaller width than the substrate. In the wide chip model where the external load acts directly on the chip, the encapsulation layer with high stiffness enhanced the crack resistance of the film chip as the thickness of the encapsulation layer increased regardless of loading conditions. In contrast, the encapsulation layer with high stiffness reduced the crack resistance of the film chip in the narrow chip model for the case of external tensile strain loading. This is because the external load is transferred to the chip through the encapsulation layer and the small load acts on the chip for the weak encapsulation layer in the narrow chip model. When the bending moment acts on the narrow model, thin encapsulation layer and thick encapsulation layer show the opposite results since the neutral axis is moving toward the chip with a crack and load acting on chip decreases consequently as the thickness of encapsulation layer increases. The present study is expected to provide practical design guidance to enhance the durability and fracture performance of the silicon chip in the multilayer package with encapsulation layer.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.11
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• pp.905-910
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• 2011

To study encapsulation method for large-area organic light emitting diodes (OLEDs), red emitting OLEDs were fabricated, on which LiF and Al were deposited as inorganic protective films. And then the OLED was attached to flat glass by printing method using epoxy. In case of direct coating of epoxy onto OLED by printing method, luminance and current efficiency were remarkably decreased because of the damage to the OLED by epoxy. In case of depositing LiF and Al as inorganic protective films and then coating of epoxy onto OLED, luminance and current efficiency were not changed. OLED lifetime was more increased through inorganic protective films between OLED and flat glass than that without any encapsulation (8.8 h), i.e., 47 (LiF/Al/epoxy/glass), 62 (LiF/Al/LiF/epoxy/glass), and 84 h (LiF/Al/Al/epoxy/glass). The characteristics of OLED encapsulated with inorganic protective films (attached to flat glass) showed the possibility of application of protective films.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.04a
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• pp.60-61
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• 2006

In this paper, the inorganic-organic thin film encapsulation layer was newly adopted to protect the organic layer from moisture and oxygen. Using the electron beam, Sputter and Spin-Coater system, the various kinds of inorganic and organic thin-films were deposited onto the Ethylene Terephthalate(PET) and their interface properties between organic and inorganic layer were investigated. Results indicates that the SiON/PI/SiON/PI/PET barrier coatings have high potential for flexible organic light-emitting diode(OLEO) applications.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.516-516
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• 2013

Flexible Display를 제작하기 위해서는 유기소자를 보호하는 보호막이 필요하다. 유기소자는 산소 및 수분에 매우 취약하기 때문에 장수명을 확보하기 위해서는 추가적인 보호층이 필요하다. 본 논문에서는 이를 위해 Encapsulation 중 한 방법인 Barrier Film을 제작하고 그에 따른 광학적인 특성 및 수분 투습율을 조사하였다. Barrier film의 광학적 분석 방법으로는 XPS, SEM, AFM, Transmittance를 측정하였으며, XPS는 박막내의 화학적인 결합을 알기 위해서 사용되었고, SEM은 박막의 두께 및 박막내의 결함을 파악하고자 하였다. SEM을 통해 증착속도가 32.6 nm/m이라는 것을 관찰할 수 있었다. AFM을 통해 증착된 박막의 표면 거칠기를 파악하였다. Transmittance는 PET 기판을 사용하여 가시광 영역에서 80%이상의 투과도를 나타내었다. PECVD 장비를 사용하여 SiH4, NH3, N2가스를 사용하여 PET 필름 위에 박막을 증착하였으며, 유량을 10~400 sccm 내에서 변화시키고, RF Power는 각각 30~300 W 15분간 증착하였다. 제작된 보호막의 수분투습율은 $2{\times}10{_2}^{-2}g/m^2/day$ 이하의 값을 나타내었다.

• Korean Chemical Engineering Research
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• v.50 no.3
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• pp.574-581
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• 2012

The relatively short lifetime is a major obstruction for the commercial applications of OLED. One of the reason for the short lifetime is that the organic materials are interacted with water or oxygen in the atmosphere. Protection of water or oxygen from diffusing into the organic material layers are necessary to increase the lifetime of OLED. Although encapsulation of OLED with glass or metal cans has been established, passivation methods of OLED by organic/inorganic thin films are still being developed. In this paper we have developed in-situ passivation system and thin film passivation method using PECVD by which deposition can be performed at room temperature. We have analyzed the characteristics of the passivated OLED device also. The WVTR (Water Vapor Transmission Rate) for the inorganic thin film mono-layer can be reached down to $1{\times}10^{-2}g/m^2{\cdot}day$ and improved lifetime can be obtained. Thin film passivation methods are expected to be applied to flexible display.

• Journal of Sensor Science and Technology
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• v.21 no.4
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• pp.311-317
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• 2012

Disposable amperometric screen-printed biosensor strips have been fabricated by a sol-gel encapsulation for the analysis of glucose. The glucose oxidase(GOx) is entrapped in the gel matrix through sol-gel transition of tetraethoxysliane(TEOS). The biosensor is fabricated by GOx containing thin film of TEOS gel on the surface of screen-printed carbon electrode(SPCE). The GOx-containing thin film of TEOS gel offers a one-step modification process on the surface of SPCE. The optimum conditions for glucose determination have been characterized with respect to the applied potential, enzyme loading ratio, and pH. The linear range and detection limit of glucose detection were from 2.0 mM to 16.0 mM and 0.25 mM, respectively.