• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07b
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• pp.1142-1145
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• 2004

ZnO surge arresters continuously endure the operating voltages during the operation course, and in the mean time, which need to withstand occasionally transient voltages of lightning and switching overvoltages. Under these voltages, the ZnO varistors inside arresters would have aging phenomena, one important result of aging phenomena is the increasing of resistive currents of varistors, which leads to the increasing of power losses of varistors. And the operating voltage is continuously applied on the ZnO varistors, there is a degradation phenomenon existing in ZnO varistors. When the degradation reaches a certain degree, then the arrester must stop operation. The degradation is related to the applied voltage ratio, the applied voltage ratio is high, the degradation is quickly. When the power loss is higher than the thermal dispersion ability of house of arrester, then the arrester will thermally breakdown. In this study the thermal stability characteristics of surge arresters for high power wil be discussed on the view point of watt losses and thermal breakdown.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.30 no.2
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• pp.86-90
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• 2017

This work reports the phase-change behavior and thermal stability of doped GeSbTe/GeSbTe bilayers. We prepared the bilayers using RF sputtering, and annealed them at annealing temperature ranging from $100^{\circ}C$ to $400^{\circ}C$. The sheet resistance of the bilayer decreased and saturated with increasing annealing temperature, and the saturated value was close to that of pure GeSbTe film. The surface of the bilayer roughened at $400^{\circ}C$, which corresponds to the surface roughening of doped GeSbTe film. Mixed phases of face-centered cubic and hexagonal close-packed crystalline structures were identified in the bilayers annealed at elevated temperature. These results indicate that the phase-change behavior of the bilayer depends on the concurrent phase-transitions of the two GeSbTe-based films. The dopants in the doped GeSbTe film were diffused out at annealing temperatures of $300^{\circ}C$ or higher, which implies that the thermal stability of the bilayer should be considered for its application in phase-change electronic devices.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11b
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• pp.467-471
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• 2001

DC accelerated aging characteristics of $Pr_{6}O_{11}$-based ZnO varistors, which are composed of $ZnO+Pr_{6}O_{11}+CoO+Cr_{2}O_{3}+Dy_{2}O_{3}$ ceramics were investigated with CoO content in the range of 0.5 - 5.0 mol%. The varistors doped with 1.0 mol% revealing maximum value(66.61) in the nonlinear exponent exhibited excellent stability, in which the variation rates of the varistor voltage, the nonlinear exponent and leakage current are -1.93%, -10.48%, and +288.79%, respectively, under DC accelerated aging stress, such as $(0.85V_{lmA}/115^{\circ}C/24h)+(0.90V_{lmA}120^{\circ}C/24h)+(0.95V_{lmA}/125^{\circ}C/24h)+(0.95V_{lmA}/150^{\circ}C/24h)$. Next the varistors doped with 2.0 mol% exhibiting the nonlinear exponent of 47.39 showed high stability.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.12
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• pp.979-986
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• 2001

This paper was researched the effect of slurry stability on the mechanical and electrical property of the porcelain insulator with various raw materials such as feldspar, quartz, clay and l7wt% alumina. The slurry was fabricated after ball milling the mixed raw materials. Green compacts were made by the extrusion and were sintered at 1300$\^{C}$ for 60min in the tunnel kiln. All of the specimens were densified 96% of the theoretical density. The 3-point flexural strength($\sigma$$\_$B/) of the specimen stabilized slurry pH 7.8 was 1650 k9/㎠ and the vickers hardness(Hv) and the fracture toughness(K$\_$IC/) were 27.5 GPa and 2.2 MPa$.$m$\^$$\sfrac{1}{2}$/, respectively. The mechanical properties of the specimen stabilized slurry PH 9.3 were 1716 kg/㎠($\sigma$$\_$B/), 27.6 GPa(Hv) and 3.0 MPa$.$m$\^$$\sfrac{1}{2}$/(K$\_$IC/), respectively. The dielectric strength was increased from 8.3kV/mm to 13.2kV/mm as the increase of the slurry pH from 7.8 to 9.3. Therefore the physical properties of the specimen stabilized slurry pH 9.3 were improved.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.11
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• pp.1000-1004
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• 2006

In this paper, thermal stability of Ni-silicide formed on the SOI substrate with $B_{11}$ has been characterized. The sheet resistance of Ni-silicide on un-doped SOI and $B_{11}$ implanted bulk substrate was increased after the post-silicidation annealing at $700^{\circ}C$ for 30 min. However, in case of $B_{11}$ implanted SOI substrate, the sheet resistance showed stable characteristics after the post-silicidation annealing up to $700^{\circ}C$ for 30 min. The main reason of the excellent property of $B_{11}$ sample is believed to be the retardation of Ni diffusion by the boron and bottom oxide layer of SOI. Therefore, retardation of Ni diffusion is highly desirable lot high performance Ni silicide technology.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.467-471
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• 2001

DC accelerated aging characteristics of Pr$_{6}$O$_{11}$-based ZnO varistors, which are composed of ZnO+Pr$_{6}$O$_{11}$+CoO+Cr$_2$O$_3$+Dy$_2$O$_3$ ceramics were investigated with CoO content in the range of 0.5~5.0 mol%. The varistors doped with 1.0 mol% revealing maximum value(66.61) in the nonlinear exponent exhibited excellent stability, in which the variation rates of the varistor voltage, the nonlinear exponent and leakage current are -1.93%, -10.48%, and 288.79%, respectively, under DC accelerated aging stress, such as (0.85 V$_{1mA}$/115$^{\circ}C$/24h)+(0.90 V$_{1mA}$/12$0^{\circ}C$/24h)+(0.95 V$_{1mA}$/1$25^{\circ}C$/24h)+(0.95 V$_{1mA}$/15$0^{\circ}C$/24h). Next the varistors doped with 2.0 mol% exhibiting the nonlinear exponent of 47.39 showed high stability,ity,ability,ity,

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.20 no.6
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• pp.487-490
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• 2007

In this paper, the formation and thermal stability characteristics of Ni silicide using Ni-V alloy on Boron cluster ($B_{18}H_{22}$) implanted bulk and SOI substrate were examined in comparison with pure Ni for nano-scale CMOSFET. The Ni silicide using Ni-V alloy on $B_{18}H_{22}$ implanted SOI substrate after high temperature post-silicidation annealing showed the lower sheet resistance, no agglomeration interface image and lower surface roughness than that using pure Ni. The thermal stability of Ni silicide was improved by using Ni-V alloy on $B_{18}H_{22}$ implanted SOI substrate.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.20 no.6
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• pp.508-513
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• 2007

The electrical properties and stability of $ZnO-Pr_6O_{11}-CoO-Cr_2O_3-based$ varistors were investigated for different $Tb_4O_{11}$ amounts in the range of $0{\sim}1.0\;mol%$. As the $Tb_4O_{11}$ amount increased, the sintered density increased in the range of $99.1{\sim}101.1%$ of theoretical density and the average grain size decreased in the range of $7.7{\sim}4.8{\mu}m$. The varistor voltage increased in the range of $280.9{\sim}715.8V/mm$ and the nonlinear coefficient increased in the range of $26.4{\sim}44.4$ with the increased of $Tb_4O_{11}$ amount. The 0.25 mol% $Tb_4O_{11}$-doped varistors exhibited the high electrical stability, with -0.1% in variation rate of varistor voltage, -0.7% in variation rate of nonlinear coefficient, and +17.4% in variation rate of leakage current for specified dc accelerated aging stress of $0.95V_{1mA}/150^{\circ}C/24h$.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.29 no.1
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• pp.35-39
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• 2016

In this research, we focused on the improvement of cy3 dye's characteristics for LCD color filter. Solubility and thermal stability are main characteristics of dyes for LCD color filter. We performed experiment to change counter cation of cy3 dyes with alkoxy substituent for these purposes. These cy3 dyes (1b~5b) were prepared through the synthetic procedure of three steps. The synthesized new cy3 dyes were charaterized by using NMR, FT-IR, UV/Vis spectroscopy, and TGA. These cy3 dyes showed purple color and maximum absorption wavelength (${\lambda}_{max}$) in the range of 578~590 nm in UV/Vis spectrum. We confirmed that solubility and thermal stability of cy3 dyes were dependent on the structure of counter cation. Cy3 dyes with alkoxy substituent have good solubility in organic solvents such as dichloromethane, methanol, and acetone. Especially, Cy3 dye with 4-nitrobenzyl counter cation (5b) gave excellent solubility characteristics.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.27-28
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• 2007

In this paper, Ni-Co alloy was used for improvement of thermal stability of Ni silicide. The proposed Ni/Ni-Co structure exhibited wide temperature window of rapid thermal process. Sheet resistance as well as cross-sectional profile showed stable characteristics in spite of high temperature annealing up to $700^{\circ}C$ for 30min. Therefore, the proposed Ni/Ni-Co structure is highly promising for highly thermal immune Ni silicide for nano-scale CMOSFET technology.