• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.1575-1578
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• 2005

As GA(Galvannealed sheet steel, GA) has good corrosion resistance, weldability and paintability as well as excellent stamping formability it's demand is rapidly increasing for automotive panel. But the layer of the Galvannealed sheet steel is easy to have a coating layer such as powdering and flaking in the press process because it is composed of Fe-Zn alloy. Therefore, the process condition is properly required to form the surface treated sheet steel. The frictional characteristics with dies are changed according to the annealing temperature, $505^{\circ}C,\;515^{\circ}C\;and\;540^{\circ}C$ during the process. To obtain the frictional characteristics of GA sheet steel in this study, on flat friction test is conducted. The friction coefficient is compared with the variation of pressure and velocity, viscosity of lubricant at the various galvannealed temperatures.

• Design & Manufacturing
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• 제2권1호
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• pp.15-19
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• 2008

While recent industrial structure is various, it is small quantity batch production structure, and products requiring of various functions are increasing. In order to improve the quality of the sheared surface in cutting of inner structure bonded sheet metal the cut-off operation is mainly investigated, which is the typical shearing process in sheet metal forming technology. The sandwich sheet metals considered have inner structure which is constructed in the form of crimped expanded metal and woven metal. The inner structure is bonded between solid sheet by resistance welding or adhesive bonding. The shearing process is visualized by the computer vision system installed in front of the cut-off die and the sheared surface is measured and quantitatively compared with the help of the optical microscope after cut-off operation. From test results we found that the influence of sheared position can be observed and explained clearly and this result can be utilized to get the better sheared surface.

• 반도체디스플레이기술학회지
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• 제14권1호
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• pp.55-59
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• 2015

This study demonstrates hybrid-type transparent electrodes for touch screen panels. The hybrid-type electrodes were fabricated by coating carbon nanotubes (CNTs) on metal meshes. To form the metal-meshes, thin films of silver (Ag) were deposited on glass substrates using the sputtering method and then patterned via photolithography to obtain mesh structures whose line width was $10{\mu}m$ and line-to-line spacing was $300{\mu}m$. CNTs were coated on Ag-meshes by using two different methods, such as spray coating and electrophoretic deposition (EPD). For the samples of a Ag-meshes and CNTs-coated Ag-meshes, their surface morphologies, electrical sheet resistances, and visible-range transmittances and reflectances were characterized and compared. The experimental results indicated that the reflectance of Ag-mesh electrodes was substantially reduced by coating of CNTs. Especially, the hybrid electrodes of Ag-meshes with EPD-coated CNTs showed excellent properties such as sheet resistance lower than $20{\Omega}/{\Box}$, transmittance higher than 90 %, and reflectance lower than 8%.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.1014-1017
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• 2001

In recent years, The tantalum nitride(TaN) thin-film has been developed for the electronic resistor and capacitor. In this papers, The effect of thermal annealing in the temperature range of 300∼700$^{\circ}C$ on the sheet resistor properties and microistructure of tantalum nitride(TaN) thin-film deposited by RF sputtering was studied. XRD(X-ray diffractometer) and AFM were used to observe electrical properties and microstructrue of the TaN film and sheet resistance. The TCR properties of the TaN films were discussed in terms of annealing temperature, ratio of nitrogen, crystallization and thin films surface morphology due to annealing temperature. The leakage current of the TaN thin film annealed 400 $^{\circ}C$ was stabilized in the study. How its was found that the sheet resistance in the polycrystalline TaN thin film decreased with increasing the annealing temperature above 600 $^{\circ}C$ after sudden peak upen 400 $^{\circ}C$.

• 한국재료학회지
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• 제14권11호
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• pp.769-774
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• 2004

15 nm-Co/15 nm-Ni/P-Si(100)[Type I] and 15 nm-Ni/15 nm-Co/P-Si(100)(Type II) bilayer structures were annealed using a rapid thermal annealer for 40sec at $700/sim1100^{\circ}C$. The annealed bilayer structures developed into composite NiCo silicides and resulting changes in sheet resistance, composition and microstructure were investigated using Auger electron spectroscopy and transmission electron microscopy. Prepared NiCoSix films were further treated in a sequential annealing set up from $900\sim1100^{\circ}C$ with 30 minutes. The sheet resistances of NiCoSix from Type I maintained less than $7\;{\Omega}/sq$. even at the temperature of $1100{\circ}C$, while those of Type II showed about $5\;{\Omega}/sq$. with the thinner and more uniform thickness. With the additive post annealing, the sheet resistance for all the composite silicides remained small up to $900^{\circ}C$. The proposed NiCoSix films were superior over the conventional single-phased silicides and may be easily incorporated into the sub-0.1 ${\mu}m$ process.

• 반도체디스플레이기술학회지
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• 제13권1호
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• pp.19-25
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• 2014

This study demonstrates transparent electrodes with characteristics desirable for touch screen panels using carbon nanotubes (CNTs). This has been accomplished by depositing CNTs on glass substrates via spray coating and then depositing thin conductive polymer films on the CNTs via spin coating. For all of the samples, such as CNTs, conductive polymers, and polymer-coated CNTs, the surface morphologies, sheet resistances, visible transmittances, chromatic properties are characterized as functions of their preparation conditions, such as the spray times for CNTs and the spin speeds for conductive polymers. The experimental results confirm that only the polymer-coated CNTs can satisfy all of the requirements that are required for electrodes of touch screen panels, such as the sheet resistance lower than $100{\Omega}/sq$, the visible transmittance higher than 80 %, and the yellowness smaller than 1.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 추계학술대회 논문집
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• pp.231-232
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• 2007

Nickel oxide thin films were deposited by the DC magnetron reactive sputtering process under the conditions such as various oxygen flow rates(0, 3, 6, 8, 10 sccm) with constant 33 sccm argon flow rate for the sputtering time of 40 second with the power of 0.3 kW. Sheet resistances were measured by the four point probes. In order to observe discharge voltage characteristics according to the oxygen flow rates, the sputtering processes were performed under the powers of 0.2kW and 0.3kW. The feasibility of the coating system for high quality ferromagnetic thin films was tested through the electromagnetic simulation and the thin film thickness measurement from the experiment. It was shown that a discharge voltage was decreased under the low power and low oxygen flow rate, since the oxygen was quickly saturated on nickel target surface. The sheet resistance was increased as oxygen flow rate increased. The film thickness deposited by the coating system for ferromagnetic target was improved approximately 10% in comparison with previous coating systems.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2009년도 제38회 동계학술대회 초록집
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• pp.268-268
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• 2010

The performance dependence of the P3HT:PCBM based bulk hetero-junction (BHJ) organic solar cells (OSCs) on the electrical and the optical properties of amorphous InZnSnO (a-IZTO) electrodes as a difference in film thicknesses are examined. With an increasing of the a-IZTO thickness, the series resistance ($R_{series}$) of the OSCs is reduced because of the reduction of sheet resistance ($R_{sheet}$) of a-IZTO electrodes. Additionally, It was found that the photocurrent density ($J_{sc}$) and the fill factor (FF) in OSCs are mainly affected by the electrical conductivity of the a-IZTO anode films rather than the optical transparency at thinner a-IZTO films. On the other hand, despite the much lower $R_{series}$ comes from thicker anode films, the dominant factor affecting the $J_{sc}$ became average optical transmittance of a-IZTO electrodes as well as power conversion efficiency (PCE) in same device configuration due to the thick anode films had as sufficiently low $R_{sheet}$ to extract the hole carrier from the active material.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2000년도 특별강연 및 추계학술발표대회 개요집
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• pp.43-45
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• 2000

Resistance Spot Welding has been one of the important process in the sheet metal fabrication of auto-body industry It is well known that the nugget formation of RSW is the major factor for the strength of the body. A high speed camera was used to consider initial melting and growth of the weld nugget in order to find out the nugget formation mechanism. It was observed that such mechanism had an effect on the dynamic resistance, which was a process parameter of resistance spot welding. Also, the relationship between the mechanism and process parameter was considered for the industrial application.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 추계학술대회 논문집
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• pp.275-278
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• 2000

We were fabricated of NiCr thin film resistors(TFR) on A1$_2$O$_3$(99.5%) substrates by dc magnetic sputtering system. The characteristics of electrical resistance (Sheet resistance & Temperature-Coefficient of the resistance-value:TCR) by annealing condition and reactive gas on the resistors were studied.