• Title/Summary/Keyword: Polyimide

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Active-matrix Flexible Display on Plastic Substrate Fabricated by Glass Line

  • Lee, Cheng-Chung;Yeh, Yung-Hui;Lee, Tzong-Ming
    • 한국정보디스플레이학회:학술대회논문집
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    • pp.348-351
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    • 2007
  • A pure polyimide substrate and polyimide substrate with nano-silica additive have been formed on glass by coating. The a-Si:H TFT arrays have been formed on such polyimide substrate for driving TNLCD.

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A study on the synthesis and characterization of PI/$\textrm{TiO}_2$ nano-composite (폴리이미드/$\textrm{TiO}_2$ 나노 복합재의 합성 및 특성에 관한 연구)

  • 이중희;이봉신;허석봉
    • Proceedings of the Korean Society For Composite Materials Conference
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    • pp.137-140
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    • 2001
  • Oragnic/inorganic hybrid materials prepared by sol-gel method have rapidly become a fasci nating research field in materials science. In this study, Polyimide/$\textrm{TiO}_2$ composites were synthesized from nano-sized anatase $\textrm{TiO}_2$ and two types of Polyimide (BTDA-PPD, PMDA-ODA) by Sol-gel method. Nano-sized $\textrm{TiO}_2$ particles were prepared from $\textrm{TiOEt}_4$ solution. The composites were charcaterized by using XRD, TGA, IR, TEM, and Atomic Force Microscope(AFM). $\textrm{TiO}_2$ nano particles were dispersed well in polyimide matrix and the thermal stability of polyimide was improved with $\textrm{TiO}_2$ nano-sized particles.

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Application of the Axiomatic Design Methodology to the Design of PBGA Package with Polyimide Coating Layer

  • Yang, Ji-Hyuck;Lee, Kang-Yong;Dong, C. Y.
    • Journal of Mechanical Science and Technology
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    • v.18 no.9
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    • pp.1572-1581
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    • 2004
  • The purposes of the paper are to apply the axiomatic design methodology to the design of PBGA package with polyimide coating under hygrothermal loading in the IR soldering process and to suggest more reliable design conditions by stress analysis. The analysis model is a 256-pin perimeter Plastic Ball Grid Array (PBGA) package with the polyimide coating surrounding chip and above surface of BT-substrate. The polyimide coating is suggested to depress the maximum stresses occurred on the stress concentration positions. The axiomatic design methodology is proved to be useful to find the more reliable design conditions for PBGA package. Finally, the optimal values of design variables to depress the stress in the PBGA package are obtained.

가용성 폴리이미드의 합성과 내유기용매성 분리막의제조

  • 박광우;전종영;탁태문
    • Proceedings of the Membrane Society of Korea Conference
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    • pp.31-31
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    • 1993
  • 지금까지 내유기용매성 분리막의 소재로는 Polysulfone이 많이 사용되었으나 내유기용매성이 고도로 요구되는 분야에는 적합하지 않았다. 이의 해결을 위해서 Polyimide를 소재로한 분리막의 개발에 대한 연구가 많이 진행되고 있다. 그러나 Polyimide는 내열성, 내유기용매성 등이 우수한 반면 T$_g$가 높고 용해되지 않아서 가공하는데 많은 제약이 있는 단점을 가지고 있다. 또한 기존에 널리 사용되었던 2단계 합성방법, 즉 Polyimide 전구체인 Polyamic acid를 합성하고 이를 casting하여 film을 얻은 뒤 다시 고온으로 열처리하여 Polyimide를 제조하는 방법은 공정이 번거롭고 부분적으로 불용성을 나타내기도 하였다. 본 연구에서는 1단계 용액 증합법으로 용융성 Polyimide를 합성하여 이를 소재로 내유기용매성 분리막을 제조하였다. 1단계 중합벙는 Polyamic acid를 합성하고 이를 film으로 만드는 공정이 필요치 않으며, 공정이 비교적 간단하고 경제적으로 유리한 잇점이 있다.

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PREPARATION OF ASYMMETRIC POLYIMIDE MEMBRANTES BY THE PHASE INVERSION PROCESS

  • Nakane, Takashi;Yanagishita, Hiroshi
    • Proceedings of the Membrane Society of Korea Conference
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    • pp.7-12
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    • 1993
  • Preparation of asymmetric polyimide membranes by the phase inversion process was investigated to develop ultrafiltration, reverse osmosis and pervaporation membranes for organic solutions, using a commercially available solvent-soluble polymaide. The influences of the various factors such as the composition of a cast solution, casting conditions, gelating solutions and others on membrane structure and performance were studied in detail, and it was made clear that a wide variety of asymmetric polyimide membranes ranging from UF to RO for organic solutions could be prepared from the aromatic polyimide used. It was also found that the chemical stability and separation performance of the asymmetric polyimide membranes could be improved by annealing in a liquid or a vacuum at above 200$\circ$. The membrane annealed at 300$\circ$ in a vacuum exhibited the separation factor $\alpha(H_2O/EtOH)$ of 900 with the flux of 1.0 kg/$m^2\cdot h$ at 60$\circ$C for an aqueous ethanol solution of 95 vol%.

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Photothermal and Photochemical Investigation on Laser Ablation of the Polyimide by 355nm UV Laser Processing (355nm UV 레이저 가공에 의한 폴리이미드의 광화학적 및 광열적 어블레이션에 관한 연구)

  • Oh, Jae-Yong;Shin, Bo-Sung
    • Journal of the Korean Society for Precision Engineering
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    • v.24 no.4
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    • pp.147-152
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    • 2007
  • UV laser ablation of polyimide is a combination of photochemical and photothermal mechanism. Photochemical mechanism is that molecular bonds are broken by photon energy and photothermal is evaporation and melt expulsion. When the laser processing, the etching depth needs to be calculated for prediction of processing result. In this paper, in order to predict the laser etching depth of polyimide by UV laser with the wavelength of 355nm, the theoretical model which includes both the photothermal and the photochemical effect was introduced. The model parameters were obtained by comparing with experimental results. The 3rd harmonic $Nd:YVO_4$ laser system was used in the experiment. From these experimental and theoretical results, the laser ablation of a polyimide was verified to achieve the highest quality microstructure.

Microsturctures of copper thin films sputtered onto polyimide (폴리이미드 위에 스퍼터 증착된 구리 박막의 미세구조)

  • Chung, Tae-Gyeong;Kim, Young-Ho;Yu, Jin
    • Journal of the Korean institute of surface engineering
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    • v.25 no.2
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    • pp.90-96
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    • 1992
  • Thed effects of sputter gas pressure and substrate surface micro-roughness on the microstructure and surface topography have been investigated in the Cu thin films sputter deposited onto polyimide substrates. The surface roughness of polyimide was controlled by oxygen rf plasma treatment. In the Cu film deposited at the pressure of 5 mtorr, the surface is smooth and the columnar structure is not visible regardless of polyimide surface more open boundaries. The polyimide surface roughness enhances these effects, These phenomena can be explained in therm of atomic shadowing effect.

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Inorganic Salt Doped Soluble Polyimide Type Alignment Layer for Improving Panel Reliability and DC Image Sticking Properties

  • Lee, Tae-Rim;Roh, Seung-Kwang;Lim, Young-Nam;Kim, Kyeong-Jin;Shin, Hyun-Ho
    • 한국정보디스플레이학회:학술대회논문집
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    • pp.672-676
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    • 2009
  • Polymide is widely used alignment material of recent commercial LCD panel structure. Generally, polyimide alignment material is classified soluble polyimide type and polyamic acid type with their main bond structure of solution state. specially, compared to polyamic acid alignment layer, soluble polyimide type alignment layer have excellent reliability during long term LCD driving cause of their high imidazation ratio(%), high voltage holding ratio(%) and low ion density. The other side, this type alignment materials has significant DC image stickicng side effect for using in-plane switching mode lcd structure cause of their slow DC discharging property. we applied inorganic salt to usual soluble polyimide type alignment layer and found out this technique had good DC image sticking property without any loss of reliability property in inplane switching LCD cell structure. This approach leads excellent DC image sticking property with maintaining high reliability property this approach confirmed improves an image sticking and a reliability simultaneously from the horizontality aligned LCD mode whose relatively bad image sticking property.

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A Study on the Deposition Conditions on Joint Strength of Polyimide Substrate and ZnO Thin Film (Polyimide 기판과 ZnO 박막의 접합강도에 미치는 증착조건에 관한 연구)

  • Hur, Jang-Wook
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.12 no.2
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    • pp.62-67
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    • 2013
  • The influence of internal stress and joint strength(shear, tensile) according to the deposition conditions was investigated by the Polyimide substrate and ZnO thin film. Deposition thickness and temperature affect the internal stress and the internal stress was minimum at the 60nm and $200^{\circ}C$ of the deposition conditions. Tensile strength is large at the deposition condition that shear strength is large and the shear strength was about 50% of the tensile strength. The shear strength and tensile strength were large at deposition condition that internal stress was small. Crack occurred near the joint interface of Polyimide substrate and progressed along the interface until the final fracture.