• Analytical Science and Technology
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• v.18 no.3
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• pp.206-215
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• 2005

Polychlorinated biphenyls (PCBs) were commercially produced as complex mixtures beginning in 1929. The PCBs manufactured commercially are known by a variety of trade names including; Aroclor (USA), Phenoclor (France), Kaneclor (Japan), Sovol (USSR) and so on. PCBs are a class of 209 congeners that were widely used in a wide variety of applications, including dielectric fluid in transformers and large capacitors; heat transfer fluids; hydraulic fluids; lubricating and cutting oils; and as additives in pesticides, paints, adhesives, sealants, and plastics. The quantification methods of peak matching and coefficient comparison were compared using the Aroclor 1242, 1248, 1254, 1260 standards. Also, six transformer oils were analyzed as a main source of polychlorinated biphenyls (PCBs) emission into the environment. The transformer oils contained the pure and mixed of Aroclor 1242, Aroclor 1254, and Aroclor 1260. The analytical results using two quantification methods showed the little difference between the measured results.

• Journal of Sensor Science and Technology
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• v.7 no.2
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• pp.103-110
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• 1998

Pyroelectric infrared detectors based on La-modified $PbTiO_{3}$ (PLT) thin films have been fabricated by RF magnetron sputtering and rnicrornachining technology. The detectors form $Pb_{l-x}La_{x}Ti_{1-x/4}O_{3}$ (x=0.05) thin film ferroelectric capacitors epitaxially grown by RF magnetron sputtering on Pt/MgO (100) substrate. The sputtered PLT thin film exhibits highly c-axis oriented crystal structure that no poling treatment for sensing applications is required. This is an essential factor to increase the yield for realization of an infrared image sensor. Micromachining technology is used to lower the thermal mass of the detector by giving maximum sensor efficiency. Polymide is coated on top of the sensing elements to support the fragile structure and the backside of the MgO substrate is selectively etched to reduce the heat loss. The sensing element exhibited a very high detectivity D* of $8.5{\times}10^{8}cm{\cdot}\sqrt{Hz}/W$ at room temperature and it is about 100 times higher than the case of micromachining technology is not used. A sensing system that detects the position as well as the existence of a human body is realized using the array sensor.

• Journal of the Korean Ceramic Society
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• v.46 no.2
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• pp.175-180
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• 2009

Multilayer ceramic capacitors (MLCCs) have continually been made smaller in size and larger in capacity in resent years. However, the end termination electrode is still thick in many MLCCs. In this study, we used small grain glass frit to embody thin film and highly densification in the end termination by improve sintering driving force with well-dispersion and rising surface energy. Pastes were fabricated using size changed glass frit, such as 0.1 ${\mu}m$, 0.5 ${\mu}m$, 1.0 ${\mu}m$, 4.0 ${\mu}m$. Fabricated pastes were applied 05A475KQ5 chip and fired various sintering temperatures to analyze sintering behavior of pastes. Consequently, small glass frit used pastes have many merits than larger, such as well-dispersion, improve cornercoverage and surface roughness, possibility of low temperature sintering. However, we confirmed that small glass frit used pastes have narrow sintering window by rapid completion of sintering densification.

• Journal of the Korean Electrochemical Society
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• v.8 no.1
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• pp.1-5
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• 2005

Electric double layer capacitors(EDLCS) based on the charge stored at the interface between a hi팀 surface area carbon electrode and an organic electrolyte solution are widely used as a maintenance-free power source for IC memories and microcomputers. The achievement of the excellent performance of the capacitor requires an electrolyte solution which provides high conductivities over a wide temperature range and good electrochemical stabilities to allow the capacitor to be operated at high voltage. The electrochemical capacitor using a carbon material as electrodes and using an organic electrolyte with $1M-LiPF_6$ in PC-GBL-DEC(volume ratio 1:1:2) has specific capacitance of 64F/g.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.2 s.117
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• pp.177-182
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• 2007

This paper presents the InGaP/GaAs HBT differential LC VCO with low phase noise performance for adaptive feedback interference cancellation system(AF-lCS). The VCO is verified with enhanced tank structure including filtering technique. The output tuning range for proposed VCO using asymmetric inductor and symmetric capacitors withlow pass filtering technique is 207 MHz. The output powers are -6.68 including balun and cable loss. The phase noise of this VCO at 10 kHz, 100 kHz and 1 MHz are -102.02 dBc/Hz, -112.04 dBc/Hz and -130.40 dBc/Hz. The VCO is designed within total size of $0.9{\times}0.9mm^2$.

• Journal of the Microelectronics and Packaging Society
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• v.13 no.4
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• pp.9-15
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• 2006

This paper shows the impedance profile of PEEC(Partial Equivalent Electrical Circuit) PDN(Power Distribution Networks) including core and I/O circuit. Through the simulated results, we find that the core power noise having connection with I/O power is affected by I/O switching. Also, using designed $74{\times}5inch$ DLL(Delay Locked Loop) test board, we analyzed the effect of power noise on operation region of chip. Jitter of a DLL measure for frequency of $50{\sim}400MHz$ and compared with impedance obtained result of simulation. Jitter of a DLL are increased near about frequency of 100MHz. It is reason that the resonant peak of PDNs has an impedance of more the 1ohm on 100MHz. we present the impedance profile of a chip and board for the decoupling capacitor reduced the target impedance. Therefore, power supply network design should be considered not only decoupling capacitors but also core switching current and I/O switching current.

• Korean Journal of Materials Research
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• v.23 no.11
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• pp.643-648
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• 2013

Activated carbon (AC) was synthesized from rice husks using the chemical activation method with KOH, NaOH, a combination of (NaOH + $Na_2CO_3$), and a combination of (KOH + $K_2CO_3$) as the chemical activating reagents. The activated carbon with the highest surface area (around $2000m^2/g$) and high porosity, which allows the absorption of a large number of ions, was applied as electrode material in electric double layer capacitors (EDLCs). The AC for EDLC electrodes is required to have a high surface area and an optimal pore size distribution; these are important to attain high specific capacitance of the EDLC electrodes. The electrodes were fabricated by compounding the rice husk activated carbons with super-P and mixed with polyvinylidene difluoride (PVDF) at a weight ratio of 83:10:7. AC electrodes and nickel foams were assembled with potassium hydroxide (KOH) solution as the electrolyte. Electrochemical measurements were carried out with a three electrode cell using 6 M KOH as electrolyte and Hg/HgO as the reference electrode. The specific capacitance strongly depends on the pore structure; the highest specific capacitance was 179 F/g, obtained for the AC with the highest specific surface area. Additionally, different activation times, levels of heating, and chemical reagents were used to compare and determine the optimal parameters for obtaining high surface area of the activated carbon.

• Journal of Digital Convergence
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• v.12 no.11
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• pp.365-372
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• 2014

In this paper, We implement a power-saving and efficient measures in buildings using the smart-meter. In order to save electric power energy, We propose an improved automatic power-factor controller(APFC) and demand control measures. This is achieved by controlling directly circuit breakers and the capacitor bank feeders in real time via a two-way smart-meter's ICT skills. Improved APFC is minimizing installation costs by series-parallel connecting heterologous capacitors to form a more diverse capacitor banking and controlling using the smart-meter. In order to suppress the demand power, We have designed a smart-meter with communication functions using Atmel's AVR465 and tested an operated lodging building for 24-hours. As a result, We made sure to always retained more than 95% power factor and did not occur over compensation.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.03a
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• pp.21-21
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• 2010

(Ba,Sr)$TiO_3$ (BST) thin film with a perovskite structure has potential for the practical application in various functional devices such as nonvolatile-memory components, capacitor, gate insulator of thin-film transistors, and electro-optic devices for display. Normally, the BST thin films derived from sol-gel and sputtering are amorphous or partially crystalline when processed below $600^{\circ}C$. For the purpose of integrating BST thin film directly into a Si-based read-out integrated circuit (ROIC), it is necessary to process the BST film below $400^{\circ}C$. The microstructural and electrical properties of low-temperature crystallized BST film were studied. The BST thin films have been fabricated at $350^{\circ}C$ by UV-assisted rapidly thermal annealing (RTA). The BST films are in a single perovskite phase and have well-defined electrical properties such as high dielectric constant, low dielectric loss, low leakage current density, and high breakdown voltage. Photoexcitation of the organics contained in the sol-gel-derived films by high-intensity UV irradiation facilitates elimination of the organics and formation of the single-crystalline phase films at low temperatures. The amorphous BST thin film was transformed to a highly (h00)-oriented perovskite structure by high oxygen pressure processing (HOPP) at as low as $350^{\circ}C$. The dielectric properties of BST film were comparable to (or even better than) those of the conventionally processed BST films prepared by sputtering or post-annealing at temperature above $600^{\circ}C$. When external pressure was applied to the well-known contractive BST system during annealing, the nucleation energy barrier was reduced; correspondingly, the crystallization temperature decreased. The UV-assisted RTA and HOPP, as compatible with existing MOS technology, let the BST films be integrated into radio-frequency circuit and mixed-signal integrated circuit below the critical temperature of $400^{\circ}C$.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.31A no.6
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• pp.117-127
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• 1994

In this paper, electrical and reliability properties of N$_2$O oxides, grown at the temperature of 95$0^{\circ}C$ and 100$0^{\circ}C$ to 74$\AA$, and 82$\AA$. respectively, using NS12TO gas in a conventional furnace, have been compared with those of pure oxide grown at the temperature of 850 to 84$\AA$ using O$_2$ gas. Initial IS1gT-VS1gT characteristics of N$_2$O oxides were similar to those of pure oxide, and reliability properties of N$_2$O oxides, such as charge trapping, interface state density and leakage current at low electric field under F-N stress, were improved much better than those of pure oxide. But, with increasing capacitor area. TDDB characteristics of N$_2$O oxides were more degraded than those of pure oxide and this degradation of TDDB characteristics was more severe in 100$0^{\circ}C$ N$_2$Ooxide than in 95$0^{\circ}C$ N$_2$O oxide. The improvement of reliability properties excluding TDDB in N$_2$Ooxides was attributed to the hardness of the interface improved by nitrogen pile-up at the interface of Si/SiO$_2$, but on the other hand, the degradation of TDDB characteristics in N$_2$O oxides was obsered due to the increase of local thinning spots caused by excessive nitrogen at interface during the growth of N$_2$O oxides.