• Journal of Powder Materials
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• v.23 no.1
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• pp.26-32
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• 2016

Powder injection molding (PIM), which combines the advantages of powder metallurgy and plastic injection molding technologies, has become one of the most efficient methods for the net-shape production of both metal and ceramic components. In this work, plasma display panel glass bodies are prepared by the PIM process. After sintering, the hot isostatic pressing (HIP) process is adopted for improving the density and mechanical properties of the PIMed glass bodies. The mechanical and thermal behaviors of the prepared specimens are analyzed through bending tests and dilatometric analysis, respectively. After HIPing, the flexural strength of the prepared glass body reaches up to 92.17 MPa, which is 1.273 and 2.178 times that of the fused glass body and PIMed bodies, respectively. Moreover, a thermal expansion coefficient of $7.816{\times}10^{-6}/^{\circ}C$ is obtained, which coincides with that of the raw glass powder ($7.5-8.0{\times}10^{-6}/^{\circ}C$), indicating that the glass body is fully densified after the HIP process.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.4 no.1
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• pp.37-42
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• 2005

The localization of manufacturing technique development is actualizing for low cost with supplies of display devices. We need more high cutting technique because consumers want flat glasses of various sizes. Recently, most general two methods are normal wheel cutting and laser cutting, but both of them have some faults. First, the wheel cutting has cracks and sharp edges of sections. Second, it is easy for laser cutting to cut curved lines. however, it has thermal damage and low traverse speed. I suggest a new cutting method by high-wave frequency vibration wheel cutting(HFVC), which is good for quality improvement. Vertical cracks and crack depth is observed, after HFVC. When the average of the crack depth is $30{\mu}m$ and the average of the wallner liner depth is $200{\mu}m$, it has the most high quality of the sections in this experiment. As a result, when we consider between the normal wheel cutting method and the HFVC method, the latter has low cracks and good quality.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.92-92
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• 2008

PDP의 저가화, 친환경화, 고화질화는 타 디스플레이와 경쟁을 위해 필수적이고 그로 인한 소재의 개발이 필요하다. 저가화는 부품, 공정에서도 가능하지만 소재에서의 원가가 상당부분을 차지하고 있기 때문에 소재 개발이 중요하며, 친환경화는 현재 유전체에서 많이 사용되고 있는 유해소재를 친환경 소재로 대체함으로써 개발이 이루어지고 있다. 그래서 우리는 현재 PDP에서 전극물질로 사용되어지는 고가의 Ag를 Gu입자에 Ag 박막으로 코팅한 Ag/Cu 전극 powder를 사용하여 저가의 전극 paste를 만들고 스크린 프린터와 노광장비를 사용하여 전극을 형성하였다. 그 후 친환경적인 Pb free 투명유전체를 입히고 전극과의 상호 매칭성을 연구 하였다. 결과적으로 기존 PDP 공정에서 볼 수 없었던 황변현상, 전극착색현상, 전극입자의 터짐성 등 많은 현상이 일어났지만, 기존 공정 온도보다 낮은 온도로 공정한 결과, 이러한 문제들이 줄어드는 것을 확인하였다. 이로써 공정단가의 저가화와 제품의 친환경을 가면서도 기존과 차이가 제품을 실현할 수 있을 것이다.

• Journal of the Korean Chemical Society
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• v.44 no.5
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• pp.453-459
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• 2000

FED has deserved an intensive attentioD as a new flat panel display. The present investigationaims at undemtanding the photoluminescence and cathodoluminescent properties of hGaO$_3$: $Eu^{3+}$ phosphor bytaking into account the possibility that this phosphor could be applied for FED. In onler to investigate on.sucha detailed behavior; 8everM experimental skil18 Je conducted to the LaGaO$_3$:$Eu^{3+}$ phosphoL The excimtion srectrum artd emission spectmn were rnezsured in the UV range and then decay curve of $^5D_0$+$^7F_j$transitions\vas examined. The decay behavior of $^5D_0$ emission was anMyzed by a newly Iuoposed cross-relaxation mech-ani8In in asswiation with inteFwnter di1ffision (or migration). The cross-mlaxation from $^5D_0$ to CTB (Cha'geTransfer Band) wuld be a quite retsonable by considering the excitation spectrum. It could be also found thatthe quenching type was changed from ditfrsion controlled process to the direct quenching process -s inJeasing $Eu^{3+}$ oncntration.

• Journal of the Korean Ceramic Society
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• v.39 no.8
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• pp.721-727
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• 2002

In order to overcome trade-off among compositions, process and properties of the glasses with high PbO-base composition for PDP Rib, we studied glass crystallization and crystallization kinetics by Differential Thermal Analysis(DTA). Glass powder was obtained through melting/cooling/grinding, with 3 wt%TiO2 addition for the crystal nucleation and growth in $62PbO-19B_2O_3-10SiO_2-9(Al_2O_3-K_2O-BaO-ZnO)$(in wt%) composition glass. This powder was heat-treated for 1 to 10 h at $445^{\circ}C$ for nucleation. DTA measurements were performed to obtain the crystallization peak with $5∼25^{\circ}C/min$ heating rates. DTA crystallization peak temperature increased with increasing the heating rate and decreased with increasing the heating time. Because the Avrami parameter (n) was approximately 1, the surface crystallization occurred. The maximum nucleation time was 2 h.

• Transactions on Electrical and Electronic Materials
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• v.4 no.6
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• pp.13-16
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• 2003

Mn-doped $ZnGa_{2}O_{4}$:$Mn^{2+}$ (M=S, Se) thin film phosphors have been grown using a pulsed laser deposition technique under various growth conditions. The structural characterization carr~ed out on a series of $ZnGa_{2}O_{4}$:$Mn^{2+}$ (M=S, Se) films grown on MgO(l00) substrates usmg Zn-rich ceramic targets. Oxygen pressure was varied from 50 to 200 mTorr and Zn/Ga ratio was the function of oxygen pressure. XRD patterns showed that the lattice constants of the $ZnGa_{2}O_{4}$:$Mn^{2+}$ (M=S, Se) thin film decrease with the substitution of sulfur and selenium for the oxygen in the $ZnGa_2O_4$. Measurements of photoluminescence (PL) properties of $ZnGa_{2}O_{4}$:$Mn^{2+}$ (M=S, Se) thin films have indicated that MgO(100) is one of the most promised substrates for the growth of high quality $ZnGa_2O_{4-x}M_{x}$:$Mn^{2+}$ (M=S, Se) thin films. In particular, the incorporation of Sulfur or Selenium into $ZnGa_2O_4$ lattice could induce a remarkable increase in the intensity of PL. The increasing of green emission intensity was observed with $ZnGa_2O_{3.925}Se_{0.075}:$Mn^{2+}$ and $ZnGa_2O_{3.925}S_{0.05}$:$Mn^{2+}$ films, whose brightness was increased by a factor of 3.1 and 1.4 in comparison with that of $ZnGa_{2}O_{4}$:$Mn^{2+}$ films, respectively. These phosphors may promise for application to the flat panel displays.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.4
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• pp.110-115
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• 2010

Transparent conducting gallium-doped zinc oxide (GZO) thin films which were deposited on Corning glass substrate using an Gun-type rf magnetron sputtering deposition technology. The GZO thin films were fabricated with an GZO ceramic target (Zn : 97[wt%], $Ga_2O_3$ : 3[wt%]). The GZO thin films were deposited by varying the growth conditions such as the substrate temperature, oxygen pressure. Among the GZO thin films fabricated in this study, the one formed at conditions of the substrate temperature of 200[$^{\circ}C$], Ar flow rate of 50[sccm], $O_2$ flow rate of 5[sccm], rf power of 80[W] and working pressure of 5[mtorr] showed the best properties of an electrical resistivity of $2.536{\times}10^{-4}[{\Omega}{\cdot}cm]$, a carrier concentration of $7.746{\times}10^{20}[cm^{-3}]$, and a carrier mobility of 31.77[$cm^2/V{\cdot}S$], which indicates that it could be used as a transparent electrode for thin film transistor and flat panel display applications.

• Fire Science and Engineering
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• v.33 no.3
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• pp.105-111
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• 2019

In Korea, the results of a field survey on the construction of flammable exterior materials implemented in 2018 revealed that 147,559 buildings belong to this category. It was found that the fire spreading cases in upper and adjacent constructions are about 3,500 per year, the fires of starting in flammable exterior material are about 1,500 per year. In this study, we investigated the repair method of buildings constructed by flammable exterior material and conducted performance verification of each repair materials for prevention of similar fire. In the case of the repair method, a method of reinforcing with a repair material after removing the existing building finishing material and a method of attaching the repair material after performing the face finishing are proposed. In addition, we conducted cone calorimeter tests of 6 materials such as fireproof gypsum board, mineral wool, hard urethane foam, ceramic board and ALC panel as dryvit and repairing materials, and investigated basic combustion performance of that materials.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.66-66
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• 2008

Most of the properties of ITO films depend on their substrate nature, deposition techniques and ITO film composition. For the display panel application, it is normally deposited on the glass substrate which has high strain point (>575 degree) and must be deposited at a temperature higher than $250^{\circ}C$ and then annealed at a temperature higher than $300^{\circ}C$ in order to high optical transmittance in the visible region, low reactivity and chemical duration. But the high strain point glass (HSPG) used as FPDs is blocking popularization of large sizes FPDs because it is more expensive than a soda lime glass (SLG). If the SLG could be used as substrate for FPDs, then diffusion of Na ion from the substrate occurs into the ITO films during annealing or heat treatment on manufacturing process and it affects the properties. Therefore proper care should be followed to minimize Na ion diffusion. In this study, we investigate the electrical, optical and structural properties of ITO films deposited on the SLG and the Asahi glass(PD200) substrate by rf magnetron sputtering using a ceramic target ($In_2O_3:SnO_2$, 90:10wt.%). These films were annealed in $N_2$ and air atmosphere at $400^{\circ}C$ for 20min, 1hr, and 2hrs. ITO films deposited on the SLG show a high electrical resistivity and structural defect as compared with those deposited on the PD200 due to the Na ion from the SLG on diffuse to the ITO film by annealing. However these properties can be improved by introducing a barrier layer of $SiO_2$ or $Al_2O_3$ between ITO film and the SLG substrate. The characteristics of films were examined by the 4-point probe, FE-SEM, UV-VIS spectrometer, and X-ray diffraction. SIMS analysis confirmed that barrier layer inhibited Na ion diffusion from the SLG.