• Title/Summary/Keyword: Polyimide

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Friction and Wear Characteristics of PTFE-Polyimide Composite (PTFE-폴리이미드 복합 재료의 마찰과 마모 특성)

  • 심현해;권오관
    • Tribology and Lubricants
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    • v.11 no.4
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    • pp.28-34
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    • 1995
  • PTFE has good mechanical and chemical stability at wide temperature range, and more over, shows a low value of friction coefficient. On the other hand, it shows cold flow and high wear rate. However, these short comings can be overcome by adding various fillers. In this experiment, PTFE and polyimide powder were mixed into composite and its tribological characteristics was investigated. 100% polyimide was also tested for comparison. The countefface material was a stainless steel (SUS304). Friction and wear tester of ring-on-block type was used at room temperature and under atmosphere. After the wear test, the worn surfaces were examined by optical microscope. The test results show that PTFE-polyimide composite generates. the wear transfer film on both sides of the friction surfaces, and, the friction coefficient and the wear rates are relatively low. 100% polyimide generated little wear transfer films, showed high friction and wear rates, and also showed some problems of vibration and noise. It even damaged the stainless steel countefface. It was concluded that 100% polyimide does not generate transfer film well because its shear resistanbe is high and it stickslips, thus, friction coefficients and wear rates are high. In case of PTFE-polyimide composite, on the other hand, transfer film containing sufficient PTFE adheres and remains on both wear surfaces well enough because PTFE has low shear resistance. Polyimide particles in the composite were proved to be able to bear normal load and does not show stick-slip because they are covered with transfer film containing much PTFE.

TEM Analysis of Interfaces between Cr Film Sputtered with RE Bias and Photosensitive Polyimide (RE 바이어스 스퍼터링한 Cr 박막과 감광성 폴리이미드 사이의 계면 TEM 분석)

  • 조성수;김영호
    • Journal of the Microelectronics and Packaging Society
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    • v.10 no.2
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    • pp.39-47
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    • 2003
  • Cr thin films were deposited on photosensitive polyimide substrates by RF bias sputtering and DC sputtering and the interfaces between Cr thin film and polyimide were observed using TEM. When the polyimide surface was in-situ RF plasma cleaned at the RF power density of 0.13-2.12 $W/cm^2$, increasing of RF power density changed the morphology of polyimide surfaces from round dig to sharp shape, and surface roughness increased by anisotropic etching. The intermixed layer-like interfaces between Cr and polyimide were observed in the RF bias sputtered specimens. This interface seems to be formed due to the RF cleaning effect; the polyimide surface was RF plasma cleaned while RF power was increased to the setting point before Cr deposition.

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Chemical reaction at Cu/polyimide interface (Cu/polyimide 계면에서의 화학반응)

  • 이연승
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.7 no.3
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    • pp.494-503
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    • 1997
  • We investigated the initial stages of formation of the Cu/polyimide interface using another two methods by X-ray photoelectron spectroscopy. : One, in-situ measurement with increasing of Cu deposition thickness onto polyimide(PI), the other, measurement with decreasing of Cu thickness of Cu/pI film by $Ar^+$ ion etching. From these results, we find that the chemical reactions exist in Cu/PI interface. However, the measured chemical reactions were different according to experimental method.

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A Study on the Fabrication and Electrical Characteristics of Polyimide Nanocomposite as an Insulator between Turns of Superconducting Transformer (초전도 변압기용 turn간 절연재료용 Polyimide Nanocomposite의 제조 및 전기적 특성 연구)

  • 박영욱;이동성;김상현
    • Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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    • pp.105-108
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    • 2002
  • Polyimide-epoxysilane (coupling agent) composites were reacted with oligomeric PDMS, a condensation product of difunctional silane, by a sol-gel process and were then dried into films. And then, the surface, mechanical, and electric properties were measured. The study showed that PDMS existed in the polyimlde matrix by the use of FT-IR. In the mechanical properties, the maximum elongation and toughness was increased in the polyimide with silane-groups. But the maximum tensile strength was slightly decreased. And the intensive dispersion of the silane-groups on the surface of polyimide was ascertained through XPS measurement. In the electric properties, AC break down voltage was increased by increasing the amount of difunctional silane. This experiment showed that PDMS added polyimide had better mechanical and electric properties than classical materials.

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A Study on the Environmental Properties of Polyimide/Silica Composites Prepared by Sol-Gel Method (졸-겔법으로 합성된 폴리이미드/실리카 복합체의 환경적 물성에 관한 연구)

  • 박성수;홍성수;이성환;김성완;박재현;김지경;박희찬
    • Journal of Environmental Science International
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    • v.12 no.4
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    • pp.481-485
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    • 2003
  • Two types of polyimide/silica composite films were prepared using sol-gel method through hydrolysis and polycondensation of tetraethoxysilane (TEOS) with the polyamic acid (PAA) and end-capped PAA solution. Samples were characterized by the means of differential thermogravimetry, X-ray diffractometry, scanning electron microscopy, universal test, impedance analyzer, chemical resistance test, etc. All of the PAA/silanol solutions heat-treated at 300$^{\circ}C$ for 6h were transformed to polyimide/silica composites. It has been demonstrated that the properties of polyimide/silica composites were affected by the amount of silica addition and the bend type existed between polyimide and silica.

The Surface Effect of Polyimide Thin Film by Vapor Deposition Polymerization Method With Plasma Treatment (진공증착중합법에 의해 제조된 폴리이미드 박막의 플라즈마 처리에 의한 표면의 변화)

  • Kim, Hyeong-Gweon;Lee, Boong-Joo;Kim, Jong-Teak;Kim, Yong-Bong;Lee, Duck-Chool
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.11 no.5
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    • pp.340-346
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    • 1998
  • In this study, we intended to investigate aging effect of polyimide prepared by VDPD(vapor deposition polymerized method). The prepared polymide was treated by the oxygen and argon gas plasma. And we evaluated the polyimide treated by plasma from contact angle, surface leakage current, FT-IR and SEM. We know that the structure of polyimide at surface are changed to amide structure by plasma treating. It seems that strong energy of plasma causes breaking the molecular chin of the polyimide. And surface roughness increases with plasma treating time increased and sequentially the wettability and leakage current increases.

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A Study on the Surface Modification of Polyimide Film by lon Implantation (이온주입법에 의한 폴리이미드박막의 표면 개질에 대한 연구)

  • 김종택;이덕출
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.11 no.4
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    • pp.293-297
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    • 1998
  • The influence of ion implantation on surface properties of polymers was studied. We investigated microhardness, friction, wear and wettablility of polyimide. Energies of 50, 200keV were used with doses range from $1{\times}10^{13} to 1{\times}10^{16} [ions/cm^2]$. The implanted ion species were B, N and Ar. The microhardness of polyimide was increased after implantation for doses of $1{\times}10^{15}\; [ions/cm^2]$. A reduction of the friction coefficient was in most case correlated with a reduction of wear. The contact angles of water for $B^+,N^+$ implanted polyimide decreased from $76^{\circ}C$ to zero, as the fluencies increased at energies of 50 and 200 KeV. However, the contact angle of Ar ion implanted polyimide did not change under ambient room conditions even if the time elapsed. SEM measurement was performed to characterize the modified surface layer.

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Fabrication of Flexible CIGS thin film solar cells using Polyimide substrate (Polyimide 기판을 이용한 Flexible CIGS 박막 태양전지 제조)

  • Jung, Seung-Chul;Ahn, Se-Jin;Yun, Jae-Ho;Gwak, Ji-Hye;Kim, Do-Jin;Yoon, Kyung-Hoon
    • 한국신재생에너지학회:학술대회논문집
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    • pp.153-155
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    • 2009
  • In this study, we fabricated the $Cu(In,Ga)Se_2$ (CIGS) thin-film solar cells by using a polyimide substrate. The CIGS thin-film was deposited on Mo coated polyimide substrate by a 3-stage co-evaporation technique. Because the polyimide shows thermal transformation at about $400^{\circ}C$, the substrate temperature of co-evaporation process was set to below $400^{\circ}C$. Corresponding solar cell showed a conversion efficiency of 7.08 % with $V_{OC}$ of 0.58 V, $J_{SC}$ of 24.99 $mA/cm^2$ and FF of 0.49.

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Properties of Interlayer Low Dielectric Polyimide during Aluminum Etching with Electron Cyclotron Resonance Etcher System

  • Kim, Sang-Hoon;Ahn, Jin-Ho
    • Proceedings of the International Microelectronics And Packaging Society Conference
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    • pp.87-96
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    • 2000
  • The properties of polyimide for interlayer dielectric applications are investigated during plasma etching of aluminum on it. Chlorine-based plasma generally used for aluminum etching results in an increase in the (dielectric constant of polyimide, while $SF_6$ plasma exhibits a high polyimide etch rate and a reducing effect of the dielectric constant. The leakage current of polyimide is significantly suppressed after plasma exposure. An optimal combination of Al etch with $Cl_6$ plasma and polyimide etch with $SF_6$ plasma is expected to be a good tool for realizing multilevel metallization structures.

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Generation of Pretilt angles on the Polyimide surface using plymer flims (고분자 필름을 이용한 폴리이미드 표면에서의 프리틸트각 발생)

  • Hwang, Jeoung-Yeon;Nam, Ki-Hyung;Seo, Dae-Shik
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.81-83
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    • 2003
  • We have investigated the generation of pretilt angle for a nematic liquid crystal (NLC) alignment with rubbing alignment method on polyimide surfaces using thin plastic substrates. It was found that monodomain alignment of LNC is obtained with rubbing alignment method on polyimide surfaces using thin plastic substrates. The generated NLC pretilt angles are about $3^{\circ}$ by the rubbing alignment method on thin plastic substrates, However, the pretilt angle measured at about $1.7^{\circ}$ lower on the glass substrate than by thin plastic substrate. It is considered that this alignment may be attributed to roughness of micro groove substrate. The tilt angle increases with increasing baking temperature for making polyimide layer using glass substrate. It was concluded that pretilt angle in the polyimide surface is attributable to the increasing of imide rato.

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