• 한국전기전자재료학회논문지
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• 제28권11호
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• pp.711-714
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• 2015

In this paper, high quality AlN layers were regrown on AlN nanopillar structure with $SiO_2$-dots by HVPE. Surface morphology of AlN layer regrown exhibited flatter than a conventional AlN template. The laterally overgrown AlN regions would consist of a continuous well coalesced layer with lower dislocation density than in the template because of the dislocation blocking and dislocation bending effects. Moreover, result of Raman spectroscopy suggest that the AlN nanopillar structure with $SiO_2$-dots relieves the strain in the AlN layer regrown by HVPE.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.337-337
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• 2009

가시광선영역에서 매우 균일한 높은 투과성뿐만 아니라 근적외선영역에서 가파른 홉수성 엣지와 함께 낮은 투과율을 제공하는 산화구리(II)를 함유하는 포스페이트 유리는 컬러 비디오 카메라의 컬러 보정 필터, 발광 컬러 디스플레이용 보호판(sheild), 모노크로메이터의 미광 필터, 플라스틱 복합재 필터의 무기 성분 및 CCD(전하 결합 소자) 및 CMOS(상보성 금속 산화물 반도체) 카메라 및 검출기 분야용 필터 유리로서 사용된다. 용융온도 및 산화구리(II) 첨가량에 따른 투과율을 측정하기 위해 포스페이트 유리 시료를 $1100\sim1500^{\circ}C$ 용융한 후 $400^{\circ}C$에서 2시간 동안 어닐링 공정을 거쳐 제조하였다. 제조된 시료는 두께 0.3mm로 폴리싱하여 자외선-적외선 분광 광도기를 이용하여 광학적 특성을 측정하였다. 본 실험을 통하여 용융온도에 따라 가시광선영역 및 근적외선영역에서의 투과율 거동을 비교한 결과 $1100\sim1200^{\circ}C$에서의 우수한 투과율 특성을 나타냈다. 용융온도가 내려감에 따른 가시광선영역 (400~600nm)에서 높은 투과율 및 근적외선영역 (750~1100nm)에서 낮은 투과율과 가파른 흡수성 엣지를 나타냈다.

• 한국세라믹학회지
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• 제52권1호
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• pp.23-27
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• 2015

Recently, the use of ion-exchange strengthened glass has increased sharply, as it is now used as the cover glass for smart phone devices. Therefore, many researchers are focusing on methods that can be used to strengthen ion-exchange glass. However, research on how the improved strength can be maintained under thermal environment of device manufacturing is still insufficient. We tested the degradation of the characteristics of ion-exchange soda-lime glass samples, including their surface compressive stress characteristics, the depth of the ion-exchange layer (DOL), flexural strength, hardness, and modulus of rupture (MOR) values. Degradation of the characteristics of the ion-exchange glass samples occurred when they were heat-treated at a temperature that exceeded $350^{\circ}C$.

• 한국세라믹학회지
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• 제26권1호
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• pp.13-20
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• 1989

After sintering Si3N4 containing 20wt% of variable composition ratio of Y2O3 and Al2O3 at 1$600^{\circ}C$, the specimens were annealed at 125$0^{\circ}C$ and 135$0^{\circ}C$ for 5, 10, 15 hours in order to crystallize the remanining oxynitride glass phases. The main grain-boundary crystalline phases in the Si3N4-Y2O3-Al2O3 system were melilite and YAG. By annealing 15hrs. at 125$0^{\circ}C$, almost all of the glasses were crystallized. During the growth of melilite, lattice volyume of $\beta$-Si3N4 was increased as Al3+ and O2- ions in the oxynitride glass diffuse into $\beta$-Si3N4 lattice, but during the growth of YAG, lattice volume of $\beta$-Si3N4 was decreased by reverse diffusion of Al3+ and O2- ions. In case of crystallization of glass phase to melilite, thermal expansion of sample was decreased, but in case of crystallization to YAG, inverse phenomen on was observed.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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• pp.177-177
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• 2008

The effect of several $SiO_2-B_2O_3-Al_2O_3$-R(R;Ca, Sr, Ba) borosilicate glass system on sintering behavior, dielectric properties and mechanical properties of glass/ceramic composites were investigated. The amount of '+2 valency' metal elements(Ca, Sr, Ba) were examined in LTCC composite of low k glass with cordierite filler. It was sintered for 60minutes in temperature range from 850C to 950. Properties of frit and glass/ceramic composites were analyzed by DTA, XRD, SEM, Network Analyzer, UTM and so on. Dielectric constant ($\varepsilon_r$) and $Q{\times}f_0$ (Q) of the composite with 50% glass contents demonstrated $\varepsilon_r$ = 5.4 $Q{\times}f_0$ = 1600 GHz. Sintering was complete and maximum bending strength of 160MPa was obtained.

• 한국전기전자재료학회논문지
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• 제28권12호
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• pp.826-830
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• 2015

Transparent Ag nanowire conducting thin films with high surface hardness were fabricated by bar coating method. When coating speed was changed from 35 mm/sec to 50 mm/sec, the transmittance of coated glass increased from 65.3% to 80.8% in visible light range and the surface resistance was changed from $10.1{\Omega}/sq$ to $23.3{\Omega}/sq$. The surface hardness and adhesion of thin film were 5H and 5B.

• 한국전기전자재료학회논문지
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• 제28권12호
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• pp.821-825
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• 2015

Anti-reflective (AR) thin film was fabricated on a glass substrate by sol-gel method. The coating solution was synthesized with TEOS (tetraethlyorthosilicate) and poly ethylene glycol (PEG, 4.0 wt%). As the withdrawal speed of coating was changed from 0.1 mm/sec to 0.3 mm/sec, the thickness and refractive index of prepared thin films were changed. The reflectance and transmittance of coating glass fabricated by the withdrawal speed of 0.1 mm/sec were 0.62% and 95.0% in visible light range. The refractive index and thickness of single layer thin film were n= 1.29 and ca. 99.0 nm.

• 한국세라믹학회지
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• 제43권10호
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• pp.635-639
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• 2006

Dispersion behavior of the slurries consisted of Pb or Bi-based glass frits, which are used for the fabrication of green sheet as PDP front panel transparent dielectric, was examined in non-aqueous solvent system. Measurements of sedimentation height and viscosity were conducted to determine proper dispersion condition in the various solvent and dispersant system. Azotropic compound and ethyl acetate were used as the solvent and ammonium-type dispersant was applied to the slurries. All slurries were dispersed well in azotropic solvent system involving 20$\sim$50 vol% ethyl acetate at 2$\sim$3 wt% dispersant content. Especially, dispersion behavior was notably improved in the addition of ethyl acetate in the Bi-based frit slurry.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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• pp.328-328
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• 2008

As a low K material for high frequency high integration modules, glass/ceramic composites were investigated. Glass composition were selected from $SiO_2-B_2O_3-Al_2O_3-R_2O$-RO system which having very low dielectric constant and cordierite was used as a ceramic filler. These composites were sintered at temperature range from $850^{\circ}$ to $950^{\circ}$ and XRD, SEM microstructure analysis of sintered bodies were performed for understanding sintering behavior. Any crystallization was not occurred and dense sintered bodies were attained. Dielectric and mechanical properties of these sintered glass/cordierite composites were analysed by network analyzer and UTM. Glass/ceramic composite with 50 wt% cordierite showing a dielectric constant (${\varepsilon}_r$) of 5.4, Q${\times}f_0$ (Q) of 1600 at 1 GHz and maximum bending strength of 163 MPa was attained.

• 한국전기전자재료학회논문지
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• 제29권1호
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• pp.40-43
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• 2016

Transparent color coating films were fabricated on a glass substrate by using sol-gel hybrid binder and organic dye. Sol-gel hybrid binder coating film fabricated with PTMS of 0.03 mole showed a very high pencil hardness of 9 H. As the withdrawal speed increased from 1.0 mm/s to 5.0 mm/sec, The yellowness ($b^*$) of coating glass also gradually increased. The transmittance of yellow color coating glass was 82.6% and the haze of coating glass was 0.35%. Red and blue color coating glasses also showed the high transmittance of 62.4% and 80.6% respectively. The surface hardness of color coating films was 6 H.