• Journal of the Microelectronics and Packaging Society
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• v.30 no.2
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• pp.43-51
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• 2023

In this paper, we introduce the development trends of power devices which is the key component for power conversion system in electric vehicles, and discuss the characteristics of the next-generation wide-bandgap (WBG) power devices. We provide an overview of the characteristics of the present mainstream Si insulated gate bipolar transistor (IGBT) devices and technology roadmap of Si IGBT by different manufacturers. Next, recent progress and advantages of SiC metal-oxide-semiconductor field-effect transistor (MOSFET) which are the most important unipolar devices, is described compared with conventional Si IGBT. Furthermore, due to the limitations of the current GaN power device technology, the issues encountered in applying the power conversion module for electric vehicles were described.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.32 no.10
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• pp.831-835
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• 2008

We present a continuous electrical cell lysis chip, using a DC bias voltage to generate the focused high electric field for cell lysis as well as the electroosmotic flow for cell transport. The previous cell lysis chips apply an AC voltage between micro-gap electrodes for cell lysis and use pumps or valves for cell transport. The present DC chip generates high electrical field by reducing the width of the channel between a DC electrode pair, while the previous AC chips reducing the gap between an AC electrode pair. The present chip performs continuous cell pumping without using additional flow source, while the previous chips need additional pumps or valves for the discontinuous cell loading and unloading in the lysis chambers. The experimental study features an orifice whose width and length is 20 times narrower and 175 times shorter than the width and length of a microchannel. With an operational voltage of 50 V, the present chip generates high electric field strength of 1.2 kV/cm at the orifice to disrupt cells with 100% lysis rate of Red Blood Cells and low electric field strength of 60 V/cm at the microchannel to generate an electroosmotic flow of $30{\mu}m/s{\pm}9{\mu}m/s$. In conclusion, the present chip is capable of continuous self-pumping cell lysis at a low voltage; thus, it is suitable for a sample pretreatment component of a micro total analysis system or lab-on-a-chip.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2003.10a
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• pp.118-118
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• 2003

In a rolling wire probe, a key component of an inspection apparatus for PDP electrode patterns, the electric performance of it is known to be strongly dependent on the surface condition of a collet pin, a needle pin, and a wire. However, the collet and needle pins rotate very rapidly in contact with each other, which results in the degradation of the surface by the heat and friction and finally the formation of black wear marks on the surface after a several hundred hours test. Once the black wear marks appear on the surface, the electric resistance of the probe increases sharply and so the integrity of the probe is severely damaged. In this experiment, TiN coating, which has excellent electric conductances and good wear-resistance, has been applied on the surface of collect and needle pins for preventing the surface damages. In order to achieve the homogeneous coating with a good adhesion property, special coating substrate stages and jigs were designed and applied during coating. TiN has been deposited using 99.999% Titanium target by a DC reactive sputtering method. According to the components and jigs, processing parameters, such as DC power, RF bias and the flow rate ratio of Ar and N$_2$ used as reactive gases, has been controlled to obtain good TiN films. Detailed problems and solutions for applying the new substrate stages and jigs will be discussed.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.7 no.2
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• pp.105-116
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• 1996

The design and analysis of the transversely fed EMC(electromagnetically coupled) microstrip dipole have been accomplished by using the integral equation and MOM(method of moment)in frequency domain in order to find the current distribution of the dipole. In this study, we proposed the possibilities for design and analysis of EMC micro-strip dipole array antenna by means of calculating the current distribution of each dipole directly using the FDTD(finite difference time domain) method. In this case, we applied the formulation which is the finite difference expression of the Maxwell's integral equation. From the current distribution of each dipole, we calculated the far field electric component and showed that the calculation process and running time was reduced with respect to the method which calculates the radiation field with surface electric and magnetic current density.

• Journal of Electrical Engineering and Technology
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• v.13 no.3
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• pp.1123-1130
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• 2018

Voltage stabilization is an essential component of power quality in low voltage DC (LVDC) microgrid. The microgrid demands the interconnection of a number of small distributed power resources, including variable renewable generators. Therefore, the voltage can be maintained in a stable manner through the control of these distributed generators. In this study, we did research on the new advanced operating method for a photovoltaic (PV) simulator in order to achieve interconnection to a bipolar LVDC microgrid. The validity of this voltage stabilization method, using the distributed generators, is experimentally verified. The test LVDC microgrid is configured by connecting the developed PV simulator and DC load, DC line, and AC/DC rectifier for connecting the main AC grid. The new advanced control method is applied to the developed PV simulator for the bipolar LVDC grid in order to stabilize the gird voltage. Using simulation results, the stabilization of the grid voltage by PV simulator using the proposed control method is confirmed the through the simulation results in various operation scenarios.

• 한국신재생에너지학회:학술대회논문집
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• 2006.06a
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• pp.195-198
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• 2006

The technology of Solar Power conversion System is defined as a solar cell that changes the sol ar energy into the direct electric energy, power conversion and control technology that convert the dc power into ac power The solar cell module, power conversion, and a control part in component parts consisting a solar power conversion system have influence on its performance. The roles of power conversion and a control part supply the direct current generated by solar cell module for a load with high efficiency as conveniently as possible in this study, the power conversion systen that can generate solar power using DSC module was developed and its characteristics was experimented. The characteristics of the DSC power conversion system including MOSFET and DSP micro processor, high speed devices, was simulated using Psim. According to the results, converter and inverter was manufactured in detail and the performance characteristics were studied.

• Transactions of Materials Processing
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• v.31 no.4
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• pp.240-245
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• 2022

In this study, to achieve good electrical conductivity of a charging terminal component in electric vehicles, we investigated the microstructure evolution of pure-Cu subjected to metal injection molding by controlling the sintering variables, such as temperature and time. Thus, three samples were sintered at temperatures ranging from 1000 ℃ to 1050 ℃ near to the melting temperature of 1085 ℃ for 1 and 10 h after thermal evaporation of binder at 730 ℃. Both procedures were made using a unified furnace under Ar+H₂ gas with high purity. The structural observation displayed that the grain size as well as the compactness (a reciprocal of porosity) increased simultaneously as temperature and time increased. This gave rise to high thermal conductivity of 90% IACS together with high density, which was mainly attributed to decrease in fractions of grain boundaries and micro-pores working as effective scattering center for electron movement.

• Design & Manufacturing
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• v.14 no.4
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• pp.71-77
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• 2020

Various manufacturing technologies, including over-molding and insert-injection molding, are used to produce hybrid plastics and metals. However, there are disadvantages to these technologies, as they require several steps in manufacturing and are limited to what can be reasonably achieved within the complexities of part geometry. This study aims to determine a practical approach for producing metal/plastic hybrid components by combining plastic injection molding and metal die casting to create a new hybrid metal/plastic molding process. The integrated metal/plastic hybrid injection molding process developed in this study uses the proven method of multi-component technology as a basis to combine plastic injection molding with metal die casting into one integrated process. In this study, the electrical conductivity and ampacity were verified to qualify the new process for the production of parts used in electronic devices. The electrical conductivity was measured, contacting both sides of the test sample with constant pressure, and the resistivity was measured using a micro ohmmeter. Also, the specific conductivity was subsequently calculated from the resistivity and contact surface of the conductor path. The ampacity defines the maximum amount of current a conductive path can carry before sustaining immediate or progressive deterioration. The manufactured hybrid multi-components were loaded with increasing currents, while the temperature was recorded with an infrared camera. To compare the measured infrared images, an electro-thermal simulation was conducted using commercial CAE software to predict the maximum temperature of the power loaded parts. Overall, during the injection molding process, it was demonstrated that multifunctional parts can be produced for electric and electronic applications.

• Korean Chemical Engineering Research
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• v.57 no.2
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• pp.253-258
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• 2019

Several materials are used to design the sorbents applied in a fast-fluidized bed process for post-combustion $CO_2$ capture. In this study, $K_2CO_3$-based dry sorbent (KMC) was prepared by using Micro-cell C (MCC), one of the materials used to design the sorbent, and then its $CO_2$ sorption and regeneration properties were evaluated. KMC sorbent showed a low $CO_2$ capture capacity of 21.6 mg $CO_2/g$ sorbent, which is about 22% of the theoretical value (95.4 mg $CO_2/g$ sorbent) even at 1 cycle, and showed a low $CO_2$ capture capacity of 13.7 mg $CO_2/g$ sorbent at 5 cycles. It was confirmed that the KMC sorbent was deactivated due to the formation of a $K_2Ca$ $(CO_3)_2$ phase, resulting from the reaction of the $K_2CO_3$ with the Ca component contained in the MCC. In order to solve the deactivation of sorbent, and KM8 sorbent was prepared by adding the process of calcining the MCC at $850^{\circ}C$. The KM8 sorbent showed a high $CO_2$ capture capacity of 95.2 mg $CO_2/g$ sorbent and excellent regeneration property. Thus, it was confirmed that the deactivation of the sorbent could be solved by adding the calcining step to remove the side reaction causing material.

• Journal of Technology Innovation
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• v.26 no.3
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• pp.37-68
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• 2018

Since the 20th century, automobiles, which are the most common means of transportation, have been evolving as the use of electronic control devices and automotive semiconductors increases dramatically. Automotive semiconductors are a key component in automotive electronic control devices and are used to provide stability, efficiency of fuel use, and stability of operation to consumers. For example, automotive semiconductors include engines control, technologies for managing electric motors, transmission control units, hybrid vehicle control, start/stop systems, electronic motor control, automotive radar and LIDAR, smart head lamps, head-up displays, lane keeping systems. As such, semiconductors are being applied to almost all electronic control devices that make up an automobile, and they are creating more effects than simply combining mechanical devices. Since automotive semiconductors have a high data rate basically, a microprocessor unit is being used instead of a micro control unit. For example, semiconductors based on ARM processors are being used in telematics, audio/video multi-medias and navigation. Automotive semiconductors require characteristics such as high reliability, durability and long-term supply, considering the period of use of the automobile for more than 10 years. The reliability of automotive semiconductors is directly linked to the safety of automobiles. The semiconductor industry uses JEDEC and AEC standards to evaluate the reliability of automotive semiconductors. In addition, the life expectancy of the product is estimated at the early stage of development and at the early stage of mass production by using the reliability test method and results that are presented as standard in the automobile industry. However, there are limitations in predicting the failure rate caused by various parameters such as customer's various conditions of use and usage time. To overcome these limitations, much research has been done in academia and industry. Among them, researches using data mining techniques have been carried out in many semiconductor fields, but application and research on automotive semiconductors have not yet been studied. In this regard, this study investigates the relationship between data generated during semiconductor assembly and package test process by using data mining technique, and uses data mining technique suitable for predicting potential failure rate using customer bad data.