• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.33 no.5
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• pp.350-354
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• 2020

In this study, a pressure sensor for each displacement was fabricated based on the silicon-based pressure sensor obtained through simulation results. Wires were bonded to the pressure sensor, and a piezoresistive pressure sensor was inserted into the printed circuit board (PCB) base by directly connecting a micro-electro-mechanical system (MEMS) sensor and a readout integrated circuit (ROIC) for signal processing. In addition, to prevent exposure, a non-conductive liquid silicone was injected into the sensor and the entire ROIC using a pipette. The packaging proceeded to block from the outside. Performing such packaging, comparing simple contact with strong contact, and confirming that the measured pulse wavelength appears accurately.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.4
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• pp.641-644
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• 2007

The electro-mechanical mercury relay is used as an auxiliary relay of power facility because it is superior to operating time and no-bounce. So the KEPCO had used the mercury relay for operating HVDC(High Voltage Direct Current) system. But it has many problems with facility operation by occurrence of mercury evaporation, held contact point and malfunction according to long term use, furthermore it is forbidden to produce for fear of environmental pollution in 2002. This paper presents the no-mercury relay development, comparison test and application.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.50-53
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• 2001

In this study, gate leakage current mechanism has been analyzed for GaAs MESFET with different temperatures ranging from 27$^{\circ}C$ to 300$^{\circ}C$ . It is expected that the thermionic and field emission at the MS contact will dominate the current flow. Thermal cycle is applied to test the reliability of the device. From the results, it is proved that thermal stress gradually increases the gate leakage current at the same bias conditions and leads to the breakdown and failure mechanism which is critical in the field equipment. Finally the gate contact under the repeated thermal shock has been tested to check the quality of Schottky barrier and the current will be expressed in the analytical from to associate with the electrical characteristics of the device.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.201-201
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• 2010

볼로미터 제작 공정 중 One step via 공정 시 via hole 모양에 의해 정기적 연결 및 구조적 안정성에 문제를 해결하기 위하여 다른 via 식각 방식으로 공정을 진행하였으며 그에 따른 via 공정 차이에 대한 결과를 연구하였다.

• JSTS:Journal of Semiconductor Technology and Science
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• v.4 no.1
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• pp.12-17
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• 2004

The body-tied FinFETs (bulk FinFETs) implemented on bulk Si substrate were characterized through 3-dimensional device simulation. By controlling the doping profile along the vertical fin body, the bulk FinFETs can be scaled down to sub-30 nm. Device characteristics with the body shape were also shown. At a contact resistivity of $1{\times}10^{-7}\;{\Omega}\;cm^2$, the device with side metal contact of fin source/drain showed higher drain current by about two. The C-V results were also shown for the first time.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.12
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• pp.2233-2239
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• 2007

The pantograph-catenary system is one of important components for high-speed rail system that are powered electrically. Electrical power is delivered from a catenary structure to the train via a pantograph and thus it is very important to regulate the contact force between catenary and pantograph. Although a lot of research results for active pantograph have been reported, most of them have made an unrealistic assumption that the catenary displacement is constant with respect to the time. In this paper, we present a new pantograph model that regards the catenary displacement as an unknown disturbance input. Moreover, a disturbance observer based controller is proposed to remove the effect of disturbance, i.e., the catenary displacement variation. The computer simulation result shows that the substantial improvement in regulating the contact force can be achieved by the proposed controller.

• Journal of Electrical Engineering and Technology
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• v.6 no.3
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• pp.402-407
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• 2011

The current paper describes a simpler ground-type, single-plate electrowetting configuration for droplet transport in digital microfluidics without performance degradation. The simplified fabrication process is achieved with two photolithography steps. The first step simultaneously patterns both a control electrode array and a reference electrode on a substrate. The second step patterns a dielectric layer at the top to expose the reference electrode for grounding the liquid droplet. In the experiment, a $5{\mu}m$ thick photo-imageable polyimide, with a 3.3 dielectric constant, is used as the dielectric layer. A 10 nm Teflon-AF is coated to obtain a hydrophobic surface with a high water advancing angle of $116^{\circ}$ and a small contact angle hysteresis of $5^{\circ}$. The droplet movement of 1 mM methylene blue on this simplified device is successfully demonstrated at control voltages above the required 45 V to overcome the contact angle hysteresis.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11b
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• pp.266-269
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• 2001

This paper investigated the aging characteristic under long-term corona discharge on roan temperature vulcanized silicone rubber, which has been using as a protective coating material for solving the contaminant problem. The applied electrical field is 10kV/cm ac and corona discharge treatment was applied on RTV silicone rubber sheet for maximum 250 hours. With the duration of corona discharge. the diffusible low molecular weight species increased, which was determined the usage of n-hexane extraction method. In addition, the contaminant layer was formed on the treated surface, and then measured the contact angle. We investigated the relation of contact angle and diffusible low molecular weight species. It is found that scissor of main chain PDMS and side chains $(CH_3)$ and the generation of LMW species were occurred by a corona discharge. The improvement of hydrophobicity rate is thought due to the increase of diffusible LMW species.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.11
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• pp.1001-1007
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• 2003

The silicone fluids have been generally used as processing agent in silicone rubber(SIR) compounding. The addition of hydroxy silicone (HS) fluids to SIR for insulator housing material is required to meet the good electrical performance and the good processability. In this study, SIR with HS fluids was evaluated to investigate how the kinds of them affect insulation properties. The contact angle of the virgin sample of 40-HS SIR was low and its recovery rate was also slow. The recovery rate of 50-HS SIR was the highest being decreased with the viscosity increase of HS fluids. The tracking resistances and the corona aging resistance of 70-HS SIR and 1,040-HS SIR were excellent Tracking resistance depended largely on heat resistance of silicone fluids. But arc resistance didn't depend merely on the kind of silicone fluids.

• Journal of the Semiconductor & Display Technology
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• v.16 no.1
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• pp.70-74
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• 2017

To research the electrical properties of ZnS thin films with various annealing conditions, ZnS was prepared by RF magnetron sputtering system and annealed in a vacuum for 10 minutes. All films were analyzed by the XRD, PL and I-V measurement system. The XRD pattern of ZnS film annealed at $100^{\circ}C$ was shifted to lower 2 theta because of the formation of a depletion region at the interface between a substrate and ZnS thin film, and the capacitance was abruptly increased. However, the pattern of XRD of ZnS film annealed at $100^{\circ}C$ with a Schottky contact was showed the amorphous structure, and the current-voltage characteristics were non-linearly observed by the Schottky contact.