• 한국정보디스플레이학회:학술대회논문집
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• 2005.07a
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• pp.328-329
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• 2005

Inorganic alignment layer (IAL) was deposited on an indium-tin-oxide (ITO) by using reactive sputtering deposition method. After deposited, IAL was irradiated by $Ar^+$ ion beam (IB) for liquid crystal (LC) alignment. IAL treated by various conditions such as IB energy, IB incident angle, and IB irradiation time had excellent alignment property and electro-optical property the same as that of PI. We investigated into the stability of ion beam treated IAL after a lapse of long time. However IAL irradiated IB did not occur degradation of electro-optical property. The results implied that IAL irradiated IB was adopted as LC alignment layer instead of rubbed polyimide.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.324-327
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• 2001

Liquid crystal alignments on a rubbed polyimide layer were investigated by using optical transmission method. Using this technique, we also studied the pretilt angle of the polymer molecules near the surface of a side-chain polymer layer as a function of the rubbing strength. In particular, we obtained the optical characteristics of liquid crystal orientations and pretilt angles for LC cell photo-aligned by UV as well after rubbing alignment. High pretilt angle of 3.84 degree was obtained on the weekly rubbed polymide layer during UV irradation time of 60min.

• Carbon letters
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• v.14 no.4
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• pp.247-250
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• 2013

In this study, we present a facile method of fabricating graphene oxide (GO) films on the surface of polyimide (PI) via layer-by-layer (LBL) assembly of charged GO. The positively charged amino-phenyl functionalized GO (APGO) is alternatively complexed with the negatively charged GO through an electrostatic LBL assembly process. Furthermore, we investigated the water vapor transmission rate and oxygen transmission rate of the prepared (reduced GO $[rGO]/rAPGO)_{10}$ deposited PI film (rGO/rAPGO/PI) and pure PI film. The water vapor transmission rate of the GO and APGO-coated PI composite film was increased due to the intrinsically hydrophilic property of the charged composite films. However, the oxygen transmission rate was decreased from 220 to 78 $cm^3/m^2{\cdot}day{\cdot}atm$, due to the barrier effect of the graphene films on the PI surface. Since the proposed method allows for large-scale production of graphene films, it is considered to have potential for utilization in various applications.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.816-819
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• 2008

A negative photoresist formulation was developed utilizing synthesized UV monomers containing imide linkage, photoinitiator, UV oligomer, and alkali developable polymer matrix. It was found that via-holes with good resolution, high transmittance and thermal resistance could be obtained by photolithographic process utilizing the negative-type photoresist formulations.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.314-316
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• 2008

We examine the surface alignment of liquid crystals (LC's) by a double linearly polarized ultraviolet (LPUV) light expose process. Exposing polarized light induces a surface anisotropy to polyimide (PI) layer surfaces and hence determines the alignment direction. LPUV exposes with angular difference of $45^{\circ}$ between two polarization directions make LC director change.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2014.11a
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• pp.135-135
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• 2014

폴리이미드 필름 위에 습식도금으로 형성된 구리피막에서 시효처리 시간에 따른 박리강도의 변화를 실험적으로 확인하였다. 그 결과, 시효처리 4시간까지 큰 변화가 없다가 4시간부터 10시간 사이에서 급격히 증가하는 경향을 나타내었다. 시효처리 시간에 따른 박리강도 증가의 원인을 구리-폴리이미드 사이 계면 및 구리도금 피막 자체의 특성 변화의 관점에서 해석하였다.

• Proceedings of the KIEE Conference
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• 1994.11a
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• pp.422-424
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• 1994

A comb drive electrostatic micro gripper was designed and fabricated. We designed it analytically using electrostatic force and cantilever deflection equation. In fabrication, we used LIGA-like technology consisted of Ni electroplating through polyimide patterned by $O_2$ Plasma RIE and Al sacrificial layer. This micro gripper was designed to handle an optical fiber which is $125{\mu}m$ in diameter.

• 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.

• Polymer(Korea)
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• v.30 no.2
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• pp.97-107
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• 2006

In spite of excellent thermomechanical performance the majority of aromatic polyimides are so poor in processability due to their high backbone rigidity that their applications are greatly limited. The introduction of long side chains not only enhances their processiblity but also makes useful contribution to discovering new application fields. In this article, a variety of novel aromatic polyimides with flexible side chains were prepared either from new dimines or new dianhydrides to measure the influence of the side chains on structure and properties of the polymers and their new applications as liquid crystal alignment layers, photosensitive polymers, alternating multilayer nano-films and photoluminescent materials are discussed.

• Polymer(Korea)
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• v.37 no.4
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• pp.547-552
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• 2013

Polyimide (PI) containing carboxyl functional group was prepared and reacted with diaminosiloxane during high temperature film casting. The morphology of resulting film was observed by using transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDX), which revealed that globular 100 nm-sized PI domains and continuous polysiloxane phase were formed. X-ray photoelectron spectroscopy (XPS) study indicated that air-film interface mainly consisted of polysiloxane blocks. Poly(imidesiloxane) thin layer was thermostable until $400^{\circ}C$ and its pressure- sensitive adhesive property was retained up to $300^{\circ}C$. The comparative experiments revealed that grafting between carboxyl groups of polyimide and aminosiloxane was crucial for formation of microdomain structure and pressure-sensitive adhesive property.