This study investigates the effect of dielectric layer thickness on the electrical and reliability characteristics of BaTiO₃- based X8R multilayer ceramic capacitors (MLCCs) for automotive applications. MLCCs with 30 dielectric layers and thicknesses ranging from 5 to 30 μm were fabricated, and key parameters―including capacitance, equivalent series resistance (ESR), insulation resistance (IR), breakdown voltage (BDV), DC-bias characteristics, temperature coefficient of capacitance (TCC), and ripple current-induced heating―were evaluated. The dielectric constant (~2,000) and sintering shrinkage (~-25%) were nearly independent of thickness, confirming stable microstructure formation. ESR increased with thickness, while normalized BDV (V/μm) decreased due to defect accumulation. IR improved with increasing thickness but dropped sharply above 125℃. Dielectrics thinner than 10 μm exhibited significant capacitance degradation under DC-bias and temperature variation, reflecting strong internal field effects. Ripple-induced heating correlated directly with ESR. These results indicate that, although thinner layers enhance capacitance density, reducing the thickness below 10 μm compromises bias stability and thermal reliability. A minimum dielectric thickness of 10 μm is therefore recommended to achieve an optimal balance between electrical performance and durability in high-reliability X8R MLCCs.
Multilayer ceramic capacitors (MLCCs) are essential for high-capacitance, miniaturized, and reliable electronic applications. This study examines the impact of layer stacking on the dielectric and electrical properties of MLCCs using a BaTiO₃-based dielectric with MgO, Mn₃O₄, Yb₂O₃, V₂O5, and (BaCa)SiO₃ glass additives. MLCCs with 10 um-thick dielectric layers and varying Ni electrode layers (10, 30, 50, and 100 layers) were fabricated. The dielectric constant increases significantly up to 30 layers due to compressive stress and sintering densification but it becomes linear beyond 30 layers. Dissipation factor and ESR decrease with higher stacking due to improved sinterability, while breakdown voltage declines exponentially from defect accumulation and thermal stress. Insulation resistance decreases but stabilizes relative to capacitance. C-V results show stress-induced polarization suppression, which reduces the dielectric constant under high voltage. Optimized stacking and sintering conditions are crucial for MIL-PRF-32535 compliant MLCC designs.
In this study, the dielectric and electrical properties of high-capacitance base metal electrode (BME) multilayer ceramic capacitors (MLCCs) fabricated using a BaTiO₃-MgO-Mn₃O₄-(Na₀.₅Bi₀.₅)TiO₃ (NBT)-(BaCa)SiO₃ dielectric system were investigated under reducing atmospheres with oxygen partial pressures (PO₂) ranging from 10⁻1⁰ to 10⁻12 MPa. By incorporating NBT, the dielectric performance remained stable across the entire range of reducing atmospheres. The fabricated MLCCs exhibited consistent capacitance values, low dielectric loss (<2.8%), and high insulation resistance, reaching up to 2.4 GΩ at 25℃ and 0.675 GΩ at 125℃. Furthermore, excellent breakdown voltage performance (up to 550 V at 25℃) and Class II-compatible temperature coefficient of capacitance (TCC) behavior were observed, meeting the X8R specification. The BaTiO₃-MgO-Mn₃O₄-NBT-(BaCa)SiO₃ dielectric system demonstrates that NBT can serve as a promising alternative to conventional rare-earth dopants in BME MLCCs, enabling excellent thermal and electrical stability, high capacitance, and longterm reliability even under reducing conditions. These results confirm the feasibility of developing cost-effective, sustainable, and rare-earth-free MLCCs for high-performance applications in automotive, industrial, and energy storage systems.
Drain Induced Barrier Lowering (DIBL) was analyzed when the channel of Gate-All-Around (GAA) FET, which is the most promising in the miniaturizing transistor structure, has an elliptic cross-section. The oxide film structure used a stacked Metal-Ferroelectric-Metal-Insulator-Semiconductor (MFMIS) structure using SiO2 and ferroelectric. An analytical DIBL model was presented to analyze the DIBL in elliptic GAA FET with ferroelectric. Its validity was proven by comparing the results of other papers. As a result, the Drain Induced Barrier Rising (DIBR) effect, that is, the negative DIBL effect, appeared depending on the ferroelectric thickness tfe, and the ratio of the remanent polarization Pr and coercive field Ec in the ferroelectric, Pr/Ec. The DIBL varied linearly with tfeEc/Pr, and the slope depended on the rate of change for the drain voltage of the ferroelectric charge Q, dQ/dVds. The tfeEc/Pr value satisfying DIBL=0 mV/V decreased as eccentricity increased. The ferroelectric thickness tfe will have to be decreased because the subthreshold swing increases if the Pr/Ec is increased to reduce the tfeEc/Pr value. The threshold voltage increased at this time, but the effect was minimal.
This paper presented an analytical SS model to determine the subthreshold swing (SS) of an elliptic junctionless Gate- All-Around (GAA) FET using ferroelectric. Analyzing a GAA FET with an elliptic cross-section was essential because it is difficult to manufacture a perfectly circular GAA FET. The results of the proposed SS model agreed well with 2D numerical simulation. Using this analytical SS model, SS was analyzed for the eccentricity and the ratio (Pr/Ec) of permanent polarization Pr and coercive electric field Ec in an elliptic junctionless GAA FET with an MFMIS (Metal-Ferroelectric-Metal-Isulator- Semiconductor) structure using ferroelectric. As a result, the changing rate of the average surface potential due to the gate voltage increased and SS decreased as the eccentricity increased. It was found that the inner gate voltage amplified more than the outer gate voltage due to the ferroelectricity, better controlling the carriers in the channel, thereby reducing SS. As the Pr/Ec decreased, the changing rate of the ferroelectric charge for the outer gate voltage increased and SS decreased. As the eccentricity increased, the changing rate of SS for Pr/Ec decreased. There was no significant change in SS until the eccentricity was about 0.5. The SS began to decline above 0.5 due to the changes in ferroelectric charge, inner gate voltage, and average surface potential for the outer gate voltage.
This study examined the crystallinity and potential of BaTiO₃ powder, prepared by hydrothermal synthesis at 60 nm, as a dielectric material for automotive MLCCs under varying heat treatment temperatures. At temperatures above 850℃, the powder exhibited an orthorhombic structure, with crystallinity and particle size increasing as the temperature rose. In the range of 850~900℃, the powder displayed a uniform particle size distribution and minimal agglomeration, with particles ranging between 150~200 nm. Additionally, it was confirmed that the heat treatment temperature significantly impacts the properties of BaTiO₃ powder, which are critical for the dielectric performance required in X7R MLCCs used in automotive applications. Specifically, high-temperature treatment (above 850℃) was essential for enhancing the powder's crystallinity and forming a stable core-shell structure, which is crucial for achieving stable TCC (Temperature Coefficient of Capacitance) characteristics. It was confirmed that increased crystallinity at temperatures above 850℃ facilitated the development of the core-shell structure through interactions with additives, thereby achieving the necessary characteristics required for highly reliable automotive MLCCs.
This review addresses the development trends of dielectric ceramics, the key material for Multilayer Ceramic Capacitors (MLCCs), which are essential components in high-performance electronic devices. Traditional MLCCs have employed BaTiO3 (BT)-based dielectrics to achieve high dielectric constant and low resistance. By minimizing oxygen vacancies and suppressing grain growth in BT materials, the temperature and voltage stability of MLCCs have been improved, leading to the development of MLCCs with diverse properties. However, the maximum dielectric constant of approximately 3000 in BT materials poses a limitation in overcoming the trade-off between rated voltage and capacitance density. Therefore, ultra-high permittivity dielectric materials have gained attention to meet the requirements of ultra-high-performance MLCCs, and ongoing research focuses on enhancing the temperature and frequency stability of these materials. This review analyzes the characteristics and limitations of conventional BT materials and explores recent research trends and future potential in developing new MLCCs based on ultra-high dielectric constant materials.
In this paper, in order to analyze the PMU data of the accident section, we collected the raw data of a total of 35 PMU installed at the Yeonggwang substation and tried to find a way to analyze the data, and analyzed the data using Excel format and formula. As a result, the three-phase voltage and current data of the PMU were calculated using formulas in Excel and interpreted as effective and reactive power, and it was possible to check the effective and reactive power of the accident section through the graph to see why it was different from before the accident. As a result, it was confirmed that each power was greatly reduced in the graph of the effective and reactive power of the accident section, and it was confirmed that the loss occurred as the power of the accident section was greatly reduced.
Multilayer Ceramic Capacitors (MLCCs) are essential passive components in the electronics industry, known for their high capacitance due to the multilayer structure comprising inner electrodes and dielectric layers. Nickel electrodes are commonly used in MLCCs as the inner electrodes, and to prevent oxidation during the co-firing of the dielectric layers with nickel electrodes, reducing atmosphere is required. However, reducing atmosphere sintering can also induce a reduction of the dielectric, necessitating precise control of oxygen partial pressure. To explore the possibility of using oxide electrodes that do not require reducing atmosphere sintering, we analyze the electrical properties of nickel oxide (NiO) as a potential candidate. As a preliminary study on its use as an alternative inner electrode, the correlation between microstructure and electrical properties of bulk NiO under different sintering conditions was investigated to gain insights into the conduction mechanisms of the material.
Integrating dielectric materials into LTCC is a convenient method to increase the integration density in electronic circuits. To enable co-firing of the high-k and low-k dielectric LTCC materials in a multi-material hetero-laminate, the shrinkage characteristics of both materials should be similar. Moreover, thermal expansion mismatch between materials during co-firing should be minimized. The alternating stacking of an LTCC with silica filler and that with calcium-zirconate filler was observed to examine the use of the same glass in different LTCCs to minimize the difference in shrinkage and thermal expansion coefficient. For the LTCC of silica filler with a low dielectric constant and that of calcium zirconate filler with a high dielectric constant, the amount of shrinkage was examined through a thermomechanical analysis, and the predicted appropriate fraction of each filler was applied to green sheets by tape casting. The green sheets of different fillers were alternatingly laminated to the thickness of 500 ㎛. As a result of examining the junction, it was observed through SEM that a complete bonding was achieved by constrained sintering in the structure of ‘calcium zirconate 50 vol%-silica 30 vol%-calcium zirconate 50 vol%’.
Ultrasonic sensor is suitable as a next-generation autonomous driving assist device because its lower price compared to that of other sensors and its sensing stability in the external environment. Although Pb(Zr, Ti)O3 (PZT)-relaxor ferroelectric system has excellent piezoelectric properties, the change in capacitance is large in the daily operating temperature range due to the low phase transition temperature. Recently, many studies have been conducted to improve the temperature stability of ferroelectric ceramics by controlling the grain size and crystal structure, so it is necessary to study the effect of the grain size on the piezoelectric properties and the temperature stability of PZT-relaxor ferroelectric system. In this study, the piezoelectric properties, phase transition temperature, and temperature coefficient of capacitance (TCC) of 0.9 Pb(Zr1-xTix)O3-0.1 Pb(Zn1/3Nb2/3)O3 (PZTx-PZN) ceramics with various grain sizes were investigated. PZTx-PZN ceramics with larger grain size showed higher piezoelectric properties and temperature stability, and are expected to be suitable for ultrasonic devices in the future.
Recently many efforts have been made to develop a novel class of non-fullerene electron acceptor materials for highperformance organic solar cells. In this work, anthraquinone derivatives, TMAQ and THAQ, were prepared and their availability as electron acceptor materials for organic solar cells were investigated in terms of optical, thermal, electrochemical properties, and solar cell devices. Compared to TMAQ, a significant bathochromic shift of absorption band was observed for THAQ owing to intramolecular hydrogen-bond-assisted CT interactions. Thanks to the fused aromatic ring structure and benzoquinone unit, both TMAQ and THAQ exhibited a high thermal stability and an efficient electron reduction process. In particular, the intramolecular O-H---O=C hydrogen bond of THAQ plays an important role in improving the thermal stability and electron reduction properties. In the P3HT:acceptor solar cell system, THAQ-based devices had more than ca. 6 times higher power conversion efficiency than TMAQ -based devices. These results serve as a guide for developing high-efficient anthraquinonebased electron acceptor materials.
With the recent increase in demand for electronic devices, multi-layer ceramic capacitors (MLCCs) have become the most important core component. In particular, the next-generation MLCC with extremely high reliability is required for the 4th industrial revolution and electric vehicle applications. Therefore, it is necessary to develop dielectric ceramic materials with high dielectric properties and reliability. During the decades, electrical properties of BaTiO3 based dielectric ceramics, which have been widely used in MLCC industrial field, have been improved by microstructure and defect chemistry control. However, electrical properties of BaTiO3 have reached their limits, and new types of dielectric materials have been widely studied. Based on these backgrounds, this report presents the recent development trends of BaTiO3-based dielectric materials for the nextgeneration MLCCs, and suggests promising candidates to replace BaTiO3 ceramics.
In this study, we investigated the optical, electrical and exothermic characteristics of ITO/Ag/ITO multilayer structures prepared with various Ag thicknesses on quartz and PI substrates. The transparent conducting properties of the ITO/Ag/ITO multilayer films depended on the thickness of the mid-layer metal film. The ITO/Ag (14 nm)/ITO showed the highest Haccke’s figure of merit (FOM) of approximately 19.3×10-3 Ω-1. In addition, the exothermic property depended on the substrate. For an applied voltage of 3.7 V, the ITO/Ag (14 nm)/ITO multilayers on quartz and PI substrates were heated up to 110℃ and 200℃, respectively. The bending tests demonstrated a comparable flexibility of the ITO/Ag/IT multilayer to other transparent electrodes, indicating the potential of ITO/Ag/ITO multilayer as a flexible transparent conducting heater.
Phase evolution, sintering behavior, microstructure, and microwave dielectric properties of (1-x) mol Ba3V4O13 - (x) mol BaV2O6 system were investigated. The sintered specimens of all compositions consisted of Ba3V4O13 and BaV2O6, and no secondary phase was observed. As x increased, the linear shrinkage decreased to the composition of x=0.5, and then increased again, implying that Ba3V4O13 and BaV2O6 phases interfered mutually with each other during sintering. All compositions showed a dense microstructure with a large grain growth. Cracks were observed in some compositions because of the relatively high sintering temperature of 620~640℃. As x increased, the dielectric constant increased, while the quality factor was maintained from about 50,000 GHz to about 70,000 GHz up to the composition of x=0.9, and then decreased to 20,987~27,180 GHz at the composition of x=1.0. As x increased, the temperature coefficient of the resonance frequency showed a (+) value from a (-) value. The dielectric constant, the quality factor, and the temperature coefficient of resonant frequency of x=0.7 composition sintered at 640℃ for 4 hours were 10.61, 71,126 GHz, and -4.9 ppm/℃, respectively. This composition showed a good chemical compatibility with Al powder, indicating that the Ba3V4O13-BaV2O6 ceramics are a candidate material for ULTCC (Ultra-Low Temperature Co-fired Ceramics) applications.
In recent years, the challenge of higher energy efficiency has emerged as urban buildings have become taller, and the area of window glasses has increased. To address the problem of energy efficiency in buildings, research on smart windows is being actively conducted. In this study, an accelerated experiment for thermal stability was conducted to fabricate a liquid crystal cell applicable to external windows. It was confirmed from the study that the function is maintained even in a high-temperature external environment through the change in transmittance by voltage. Compared with the initial transmittance, after the passage of time, the smart window cell to which the sealant was applied showed a small change in transmittance of 1~2%. This result confirmed the thermal stability of the liquid crystal-based smart window.
In this study, a TiO2/TiO2-x-based resistance variable memory was fabricated using a DC/RF magnetron sputtering system and ALD. In order to analyze the effect of oxygen plasma treatment on the performance of resistance random access memory (ReRAM), the TiO2/TiO2-x-based ReRAM was evaluated by applying RF power to the TiO2-x oxygen-holding layer at 30, 60, 90, 120, and 150 W, respectively. The ReRAM was fabricated, and the electrical and surface area performances were compared and analyzed. In the case of ReRAM without oxygen plasma treatment, the I-V curve had a hysteresis curve shape, but the width was very small, with a relatively high surface roughness of the oxygen-retaining layer. However, in the case of oxygen plasma treatment, the HRS/LRS ratio for the I-V curve improved as the applied RF power increased; stable improvement was also noted in the surface roughness of the oxygen-retaining layer. It was confirmed that the low voltage drive was not smooth due to charge trapping in the oxygen diffusion barrier layer owing to the high intensity ReRAM applied with an RF power of approximately 150 W.
We investigate a fog-detection CCT control system using low deck lighting as a solution to the forward visibility of pole-type street lamps employed on existing roads. The lighting standards were met with a light source that has less compared with those of pole-type street lamps. The results show that the transmission rate was increased by changing the color temperature by automatically recognizing fog in bad weather and minimizing the phenomenon of lighting. In addition, it was allowed to create a safer and more comfortable driving environment for drivers owing to flicker or light pollution of existing pole-type street lamps. As a result, if lighting is used at a lower level than pole-type street lamps, the accident rate caused by securing the driver’s forward visibility can be reduced sharply and existing problems can be resolved.
Metal oxide varistors (MOVs) protect circuits and devices from transient overvoltages in electric power systems. However, a MOV continuously deteriorates owing to manufacturing defects or repetitive protective operations from transient overvoltages. A deteriorated MOV may result in a short circuit or a line-ground accident. Previous studies focused on the analysis of deterioration mechanisms and condition diagnosis techniques for MOVs owing to their recent growth of use. An accelerated deterioration experiment under the same conditions in which a MOV operates is essential. In this study, we designed and fabricated a surge generator that can apply a surge current to a MOV connected to AC mains. The coupling network operates at a low impedance against the surge current from the surge generator and transfers the surge current to the MOV under test. It also acts as a high impedance against AC mains for the AC voltage not to be applied to the surge generator. The decoupling network operates at a high impedance against the surge current and blocks the surge current from AC mains. It also acts as a low impedance against AC mains for the AC voltage to be applied to the MOV under test. The prototype surge generator can apply the 8/20 us up to 15 kA on AC voltages in the approximate range of 110~450 V, and it fully operates on a LabVIEW-based program.
As a ZnO varistor is subjected to electrical and environmental stresses, it degrades gradually, which may result in power interruption by short circuit. This study investigates changes in the electrical characteristics of ZnO varistors due to deterioration owing to energy absorption, and determines the optimal parameters for on-line diagnosis of the varistor. Two types of varistors were used for an accelerated aging experiment involving the application of the 8/20 μs standard lightning impulse current. The electrical characteristics in terms of the reference voltage, total leakage current, resistive leakage current, and third-harmonic component of the total leakage current were measured, and their change rates were analyzed. The results revealed that the total leakage current increased slightly with an increase in the varistor absorbed energy, while the resistive leakage current and the third-harmonic component increased apparently. Therefore, the third-harmonic component of the total leakage current was proposed as the optimal parameter for on-line monitoring of ZnO varistor conditions.
We investigated the structure of an ultra-thin insulating board with low thermal conductivity along z-axis, which was based on the idea of void layers created during the glass infiltration process for the zero-shrinkage low-temperature co-fired ceramic (LTCC) technology. An alumina and four glass powders were chosen and prepared as green sheets by the tape casting method. After comparison of the four glass powders, bismuth glass was selected for the experiment. Since there is no notable reactivity between alumina and bismuth glass, alumina was selected as the supporting additive in glass layers. With 2.5 vol% of alumina powder, glass green sheets were prepared and stacked alternately with alumina green sheet to form the ‘alumina/glass (including alumina additive)/alumina’ structure. The stacked green sheets were sintered into an insulating substrate. Scanning electron microscopy revealed that the additive alumina formed supporting bridges in void layers. The depth and number of the stacking layers were varied to examine the insulating property. The lowest thermal conductivity obtained was 0.23 W/mK with a 500-㎛-thick substrate.
We investigated the rewritable operation of a non-volatile memory device composed of Al (top)/TiO2/ indium-zinc-oxide (IZO)/Al (bottom). The oxygen-deficient IZO layer of the device was spin-coated with 0.1 M indium nitrate hydrate and 0.1 M zinc acetate dehydrate as precursor solutions, and the TiO2 layer was fabricated by atomic layer deposition. The oxygen vacancies IZO layer of an active component annealed at 400℃ using thermal annealing and it was proven to be in oxygen vacancies and oxygen binding environments with OH species and heavy metal ions investigated by X-ray photoelectron spectroscopy. The device, which operates at low voltages (less than 3.5 V), exhibits non-volatile memory behavior consistent with resistive-switching properties and an ON/OFF ratio of approximately 3.6×103 at 2.5 V.
In this work, static characteristics of 4H-SiC SJ-ACCUFETs were obtained by adjusting the p-pillar region. The structure of this SJ-ACCUFET was designed by using a two-dimensional simulator. The static characteristics of SJ-ACCUFET, such as the breakdown voltages, on-resistance, and figure of merits, were obtained by varying the p-pillar doping concentration from 1×1015 cm-3 to 5×1016 cm-3 and the thickness from 0 μm to 9 μm. The doping concentration and the thickness of p-pillar region are closely related to the break down voltage and on-resistance and threshold voltages. Hence a silicon carbide SJ-ACCUFET structure with highly intensified breakdown voltages and low on-resistances with good figure of merits can be achieved by optimizing the p-pillar thickness and doping concentration.
With trend of the miniaturization and the high-functionalizing of mobile communication system, low-loss microwave dielectric materials are widely used for high frequency communication components. These dielectric materials should be co-sintered with highly electric-conducting metal such as silver or copper for high-frequency and thick film process application. Sintering temperature of Ca[(Li1/3Nb2/3)1-xTix]O3-δ, which has excellent dielectric properties such as εr above 40, quality factor (Q·f0) above 16,000 GHz, and TCF (temperature coefficient of resonant frequency) of -20~-10 ppm/℃, is reported as high as 1,175℃, so it could not be co-sintered with silver or copper. Therefore in this study, low-temperature melting glasses of Zn-B-O and Zn-B-Si-O systems were added to Ca[(Li1/3Nb2/3)1-xTix]O3-δ to lower its sintering temperature under 900℃ without losing excellency of dielectric properties. With 15 weight % of Zn-B-Si-O glass and sintered at 875℃, specimen showed density of 4.11 g/cm3,ε r of 40.1, Q·f0 of 4,869 GHz, and TCF of -5.9 ppm/℃. With 15 weight % of Zn-B-O glass and sintered at 87 5℃, specimen showed density of 4.14 g/cm3, εr of 40.4, Q·f0 of 7,059 GHz, and TCF of -0.92 ppm/℃.
Hole explosion behaviors were observed during drilling fine holes with laser beam on the LTCC green bar of 320 ㎛ thick after lamination of green sheets prepared by tape casting of thick film process. The incidence of these hole explosions was inversely proportional to hole sizes. The incidence of hole explosion was 20 % number of hole with the size of 60 ㎛ exploded for the UV radiation, while the explosion did not appear for hole sizes over 100 ㎛. To prevent hole explosion behavior during laser-drilling of fine holes, carbon black powder was added as an additive in the LTCC composition, which has superior thermal durability. As a consequence, hole explosion rate was suppressed to 0.8 % for the hole size of 50 ㎛ green sheet with the carbon black amount of 10 weight % and the laser power of 3 watt. Added carbon is thought to reduce the heat-affected region during laser drilling.
In this paper, we analyzed the power consumption and the accumulated energy in HTSC (high-TC superconducting elements) according to the resistance of HTSC element and the winding current of transformer type SFCL (superconducting fault current limiter) using double quench. For the analysis, two different inductances of the one secondary winding among two secondary windings comprising the transformer type SFCL were selected and the short-circuit tests were carried out. The consumed power and the accumulated energy in HTSC element connected into the secondary winding with larger inductance were analyzed to be larger compared to the one connected into the secondary winding with lower inductance.
In this work, LiMn2O4 and LiNi1/3Mn1/3Co1/3O2 cathode materials are mixed by some specific ratios to enhance the practical capacity, energy density and cycle performance of battery. At present, the most used cathode material in lithium ion batteries for EVs is spinel structure-type LiMn2O4. LiMn2O4 has advantages of high average voltage, excellent safety, environmental friendliness, and low cost. However, due to the low rechargeable capacity (120 mAh/g), it can not meet the requirement of high energy density for the EVs, resulting in limiting its development. The battery of LiMn2O4-LiNi1/3Mn1/3Co1/3O2 (50:50 wt%) mixed cathode delivers a energy density of 483.5 mWh/g at a current rate of 1.0 C. The accumulated capacity from 1st to 150th cycles was 18.1 Ah/g when the battery is cycled at a current rate of 1.0 C in voltage range of 3.2~4.3 V.
Among several types of energy saving smart window technologies, the leader, the dynamic EC (electrochromic) window one needs integrated PV (photovoltaics), to minimize expensive electrical wiring as well as to obviate the need for external energy. Self-powered smart windows were reviewed according to PV types used. DSSCs (dye sensitized solar cells) were found to be compatible with EC cells, to have several categories of next generation smart windows such as PECCs (photoelectrochromic cells), PVCCs (photovoltachromic cells), EC polymer PECCs. In addition silicon solar cells and third generation solar cells were investigated. They are summarized in a table showing their advantages and disadvantages respectively for a fast comparison. The strategy to expedite the commercialization of these next generation smart windows includes developing retrofit smart window coverings for use on flexible polymer substrates adhered to the inside surface of a window and easily replaced after use for upto 10 years.
In this paper, we designed and fabricated low cost imprinting process for micro patterning on FCCL (flexible copper clad laminate). Compared to conventional imprinting process, developed fabrication method processing imprint and UV photolithography step simultaneously and it does not require resin etch process and it can also reduce the fabrication cost and processing time. Based on proposed method, patterns with 10 ㎛ linewidth are fabricated on 180 ㎜ × 180 ㎜ FCCL. Compared to conventional methods using LDI (laser direct imaging) equipment that showed minimum line with 10 ∼ 20 ㎛, proposed method shows comparable pattern resolution with very competitive price and shorter processing time. In terms of mass production, it can be applied to fabrication of large-area low cost applications including FPCB.
The vegetable insulating oils are substitute for the mineral oil in power transformer. Vegetable insulating oils has higher flash/fire point and biodegradability than conventional mineral oils. In this paper, we investigated the dissolved gas analysis of vegetable oils. In the experiment, I had to accelerated aging under the same conditions mineral oil and vegetable oils. Accelerated aging proceeded to about 100% of the life of oil-filled transformer. In addition, we performed gas analysis of insulating oil of accelerated aging progress. The experiment results of the five gases was measured with the exception of Hydrogen and Acetylene. The mineral oil and vegetable oils gas is generated in a similar tendency depending on the accelerated aging. As a result, vegetable oils, can be dissolved gas analysis by method such as mineral oil.