• Journal of the Korean Vacuum Society
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• v.6 no.3
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• pp.187-193
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• 1997

We investigated the initial growth mode of Cu deposited on polyimide at room temperature using x-ray photoelectron spectroscopy. We could find that when Cu is sputter-deposited on the polymide, Cu-N-O complex of strong interaction is mainly formed first, Cu-oxide of weak interaction is formed successively, and then finally metallic Cu grow. From these results, we could conclude that Cu/polyimide interface consists of Cu-N-O complex and Cu-oxide.

• Journal of the Korean Vacuum Society
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• v.7 no.2
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• pp.135-140
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• 1998

We investigated the initial growth mode of Cu deposited on polyimide at high temperature($350^{\circ}C$) using x-ray photoelectron spectroscopy. We could find that when Cu is sputter-deposited on the polyimide at high temperature, Cu-C-N complex is formed first, Cu-N-O complex and Cu-oxide are mainly formed successively, and then funally metallic Cu grows. In the chemical reaction point of view, the interface of Cu/polyimide at high temperature is than that at room temperature.

• Korean Journal of Materials Research
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• v.9 no.1
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• pp.65-72
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• 1999

In order to minimize flexible printed circuit(FPC), which is used in computer, communication, medical facility, aviation space industry, it is required to improve the interfacial adhesion of polymide/epoxy or polyimide/polyimide consists of FPC. In this study, it was considered to improve the adhesion strength of polyimide/epoxy joint by introducing functional group on polyimide film and improving mechanical property of epoxy. Functional group on polyimide film was introduced by changing polyimide film surface to polyamic acid in KOH aqueous solution. The optimum conditions for surface modification were the concentration of 1M KOH and treatment time of 5min. Also, the optimum adhesion strength of polyimide/epoxy joint was obtained using rubber modified epoxy and polyamic acid as a base resin and curing agent of epoxy adhesive, respectively. The degree of surface modification of polyimide film examined with contact angle measurement of FTIR, thus modification of polyimide to polyamic acid was identified. Fracture surface of plymide/epoxy joint was analyzed by scanning electron microscopy, and modified polyamic acid reimidezed to polymide as increasing curing temperature.

• Korean Journal of Materials Research
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• v.17 no.12
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• pp.664-668
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• 2007

The magnetron sputtering was used to deposit Ni buffer layers on the polyimide surfaces to increase the adhesion strength between Cu thin films and polyimide as well as to prevent Cu diffusion into the polyimide. The Ni layer thickness was varied from 100 to $400{\AA}$. The adhesion strength increased rather significantly up to $200{\AA}$ of Ni thickness, however, there was no significant increase in strength over $200{\AA}$. The XPS analysis revealed that Ni thin films could increase the adhesion strength by reacting with the polar C=O bonds on the polyimide surface and also it could prevent Cu diffusion into the polyimide. The Cu/Ni/ polyimide multilayer thin films showed a high stability even at the high heating temperature of $200^{\circ}C$, however, at the temperature of $300^{\circ}C$, Cu diffused through the Ni buffer layer into polyimide, resulting in the drastic decrease in adhesion strength.

• Bulletin of the Korean Chemical Society
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• v.31 no.8
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• pp.2279-2282
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• 2010

In this work, the electrical and thermal properties of polyimide/multi-walled carbon nanotube (MWNT) nanocomposites were investigated. The polyimide/MWNT nanocomposites contained from 0 to 2.0 wt % of MWNT. The electrical properties of the polyimide films were characterized by a specific resistance measurement. The thermal properties were evaluated using thermogravimetric analysis (TGA) and a differential scanning calorimeter (DSC). It was found that the thermal properties of the polyimide nanocomposites increased with increasing MWNT content and specific resistance as well. This result indicated that the crosslinking of polyimide/MWNT nanocomposites was enhanced by good distribution of the MWNT in the polyimide resins, resulting in the increase of the electrical and thermal properties of the nanocomposites.

• Journal of the Korean institute of surface engineering
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• v.26 no.2
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• pp.71-81
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• 1993

Thed effects of Ar or Oxygen RF plasma treatment on the adhesion behavior of Cr films to polyimide sub-strates have been investigated by using SEM, XRD, AES, and $90^{\circ}$peel test. By applying RF plasma treatment of the polyimide surface prior to metal deposition, the peel adhesion strength of Cu/Cr films sputtered onto the fully cured BPDA-PDA polyimide was highly increased from about 3g/mm to 90 ~ 100g/mm. Improved peel adhesion strength of Cr/polyimide interfaces due to RF plasma treatment was attributed to the contributions from surface cleaning, Cr-polyimide bonding at the interface, and force required for plastic deformation of the film. While the surface topology change of the polyimide caused by RF plasma treatment makes a little contri-bution to the improved adhesion.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.2
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• pp.196-200
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• 2004

Using polyimide Langmuir-Blodgett(LB) films as a tunneling harrier, we fabricated Au/Polyimide/1-layer arachidic acid/Pb structure in order to investigate electron transport properties through a junction. It was found that 9-layer polyimide LB films function as a good tunneling harrier in a study of current-voltage(I-V) chararteristics. And several peaks originating in the vibrational modes of the constituent molecules of 1-layer arachidic acid LB films were clearly observed in d$^2$V/dI$^2$- V corves.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.337-340
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• 2001

The control of high pretilt angle for nematic liquid crystal (NLC) with negative dielectric anisotropy on the rubbed blending polyimide (homeotropic and homogeneous alignment) surface were studied. High NLC pretilt angle generated on the blending polyimide (homeotropic polyimide and SE-7492 surface was measured and the NLC pretilt angle increases with blending ratio and rubbing strength. However, the NLC pretilt angle generated on the blending polyimide (homeotropic polyimide and SE-150 surface was not varied. The high pretilt angle the NLC using blending polyimide surface can be achieved.

• Journal of Sensor Science and Technology
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• v.22 no.5
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• pp.357-363
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• 2013

An ultraviolet pulsed laser ablation of polyimide film coated with platinum has been used to enhance the sensitivity for the application as an electrochemical biosensor. Densely packed cones are formed on polyimide surface after UV irradiation which results in increase of surface area. In order to apply the sensitivity improvement of laser ablated polyimide film electrodes, the glucose oxidase modified biosensor was fabricated by using an encapsulation in the gel matrix through sol-gel transition of tetraethoxysliane on the surface of laser ablated polyimide film. The optimum conditions for glucose determination have been characterized with respect to the applied potential and pH. The linear range and detection limit of glucose detection were from 2.0 mM to 18.0 mM and 0.18 mM, respectively. The sensitivity of glucose biosensors fabricated with laser ablated polyimide film is about three times higher than that of plain polyimide film due to increase in surface area by laser ablation.

• Journal of the Korean institute of surface engineering
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• v.39 no.4
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• pp.166-172
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• 2006

Metallized Polyimide films are extensively used as base materials in microelectronics, optical and automotive applications. However it is difficult to deposit metals on those because of their structural stabilities. In this work, polyimide films are modified by a wet process with alkalinemetalhydroxide and additives to introduce functional groups. The surface molecular structures of polyimide are investigated using X-ray photoelectron spectroscopy(XPS), fourier transform infrared reflection spectroscopy(FTIR-ATR), atomic force micro-scopic(AFM). XPS spectra and FTIR spectra show that the surface structure of polyimide is converted into potassium polyamate. AFM image and AFM cross-sectional analyses reveal the increased roughness on the modified surface of polyimide films. As a result, it is shown that the adhesion strength between polyimide surface and electroless nickel layer is increased by the nano-anchoring effect.