• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.33 no.6
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• pp.500-504
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• 2020

Heating films were prepared with composites of poly (methyl methacrylate) and conductive graphite. The as-prepared composite was deposited on a PET film and then fabricated using a bar coater to produce a film with uniform thickness. Copper electrodes were attached to both ends of the as-prepared film, and the heating characteristics of the film were analyzed while applying a DC voltage. The electrical conductivity and heating temperature of the heating films depended on the size, structure, content, and the dispersion characteristics of the graphite in the composite. The thermal energy was adjusted by controlling the electrical energy, based on the Joule heating theory. The electrical resistance of the film was altered in proportion to Ohm's law, and the heating temperature was changed according to the structure of the film (interelectrode spacing or electrode length) and the conductive graphite content. When the content of conductive graphite in the film increases, the electrical resistance decreases, and the heating temperature increases; however, there is no significant change above a certain content (50%).

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.106-106
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• 2009

Al-doped ZnO (AZO) thin films were grown on glass substrates by co-sputtering at room temperature. We made ZnO and Al target and ZnO:Al film is deposited with sputter which has two RF gun source. The Al content was controlled by varying Al RF power and effect of Al contents on the properties of ZnO:Al film was investigated. Crystallinity and orientation of the ZnO:Al films were investigated by X-ray diffraction (XRD), surface morphology of the ZnO:Al films was observed by atomic force microscope. Electrical properties of the ZnO:Al films were measured at room temperature by van der Pauw method and hall measurement. Optrical properties of ZnO:Al films were measured by UV-vis-NIR spectrometer.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.52 no.9
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• pp.378-382
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• 2003

Transparent conductive oxides (TCO) are necessary as front electrode for most thin film solar cell. In our paper, transparent conducting aluminum-doped Zinc oxide films (ZnO:Al) were prepared by rf magnetron sputtering on glass (Corning 1737) substrate as a variation of the deposition condition. After deposition, the smooth ZnO:Al films were etched in diluted HCI (0.5%) to examine the electrical and surface morphology properties as a variation of the time. The most important deposition condition of surface-textured ZnO films by chemical etching is the processing pressure md the substrate temperature. In low pressures (0.9mTorr) and high substrate temperatures ($\leq$$300^{\circ}C$), the surface morphology of films exhibits a more dense and compact film structure with effective light-trapping to apply the silicon thin film solar cells.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07a
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• pp.391-394
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• 2002

Transparent conductive oxides (TCO) are necessary as front electrode for most thin film solar cell. In our paper, transparent conducting aluminum-doped Zinc oxide films (ZnO:Al) were prepared by rf magnetron sputtering on glass (Corning 1737) substrate as a variation of the deposition condition. After deposition, the smooth ZnO:Al films were etched in diluted HCl (0.5%) to examine the electrical and surface morphology Properties as a variation of the time. The most important deposition condition of surface-textured ZnO films by chemical etching is the processing pressure and the substrate temperature. In low pressures (0.9 mTorr) and high substrate temperatures ($\leq$30$0^{\circ}C$), the surface morphology of films exhibits a more dense and compact film structure with effective light-trapping to apply the silicon thin film solar cells.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2007-2010
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• 2008

Vanadium pentoxide ($V_2O_5$) powder was prepared and mixed with Molybdenum Oxides ($MoM_3$) to form Mo-doped and -undoped $VO_2$ films by a sol-gel method on graphite conductive substrates. X-Ray diffraction (XRD) and scanning electron microscopy (SEM) was used to investigate the chemical compositions and microstructures of the Mo-doped and -undoped $VO_2$ films. The variation of electrical resistance was measured as a function of temperature and stoichiometric composition between vanadium and molybdenum. In this study, it was found that Mo-doped and -undoped $VO_2$ shows the typical negative temperature coefficient (NTC) behavior. As the amount of the molybdenum increases, the electrical resistance of Modoped $VO_2$ film gets reduced under the transition temperature and a linear decrease in the transition temperature is observed. From these experimental results, we can conclude that the electrical resistance behavior with temperature change of $VO_2$ films can be utilized as a self-heating source with the electrical current flowing through the graphite substrate.

• Journal of the Korean institute of surface engineering
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• v.42 no.3
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• pp.128-132
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• 2009

Transparent conducting thin films of indium tin oxide(ITO) co-sputtered with aluminum-doped zinc oxide(AZO) were deposited on glass substrate by dual magnetron sputtering. It was found that the electrical properties and structural characteristics of the films are significantly changed according to the sputtering power of the AZO target. The IAZTO film prepared with D.C power of ITO at 100 W and R.F power of AZO at 50 W shows an electrical resistivity of $4.6{\times}10^{-4}{\Omega}{\cdot}cm$ and a sheet resistance of $30{\Omega}/{\square}$ (for 150 nm thick). Besides of the improvement of the electrical properties, compared to the ITO films deposited at the same process conditions, the IAZTO films have very smooth surface, which is due to the amorphous nature of the films. However, the electrical conductivity of the IAZTO films was found to be deteriorated along with the crystallization in case of the high temperature deposition (above $310^{\circ}C$). In this work, high quality amorphous transparent conductive oxide layers could be obtained by mixing AZO with ITO, indicating possible use of IAZTO films as the transparent electrodes in OLED and flexible display devices.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2000.04a
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• pp.105-108
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• 2000

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.799-802
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• 2008

The metal films ink-jetted using the conductive ink based on a mixture of copper and silver nanoparticles were investigated. The porosity and resistivity of films were minimized by adjusting the mixing ratio of Cu and Ag nanoparticles. We demonstrated that the printed tracks with good conductivity could be obtained at sufficiently lower annealing temperatures where plastic substrates could be used.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1996.05a
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• pp.269-272
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• 1996

The electrochemical behavior of Ru complex and PD complex monolayer, deposited on conductive substrate by the Langmuir-Blodgett(LB) technique as monolayer and multilayer, has been studied by cyclic voltammetry. Monolayer films show stable reversible state. Atomic resolution imaging of LB highly-conductive, environmently stable organic films has been obtained by atomic force microscopy (AFM) showing their closely packed structure,

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.3
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• pp.199-204
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• 2009

The effect of temperature on ACF thermocompression bonding for FPD assembly was investigated, It was found that Au bumps on driver IC's were not bonded to the glass substrate when the bonding temperature was below $140^{\circ}C$ so bonds were made at temperatures of $163^{\circ}C$, $178^{\circ}C$ and $199^{\circ}C$ for further testing. The bonding time and pressure were constant to 3 sec and 3.038 MPa. To test bond reliability, FPD assemblies were subjected to thermal shock storage tests ($-30^{\circ}C$, $1\;Hr\;{\leftrightarrow}80^{\circ}C$, 1 Hr, 10 Cycles) and func! tionality was verified by driver testing. It was found all of FPDs were functional after the thermal cycling. Additionally, Au bumps were bonded using ACF's with higher conductive particle densities at bonding temperatures above $163^{\circ}C$. From the experimental results, when the bonding temperature was increased from $163^{\circ}C$ to $199^{\circ}C$, the curing time could be reduced and more conductive particles were retained at the bonding interface between the Au bump and glass substrate.