• Proceedings of the Korean Magnestics Society Conference
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• 2011.12a
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• pp.150-150
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• 2011

• Journal of the Korean Ceramic Society
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• v.30 no.11
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• pp.979-985
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• 1993

Diamond films were synthesized using CH4-H2-Ar mixture gases by MWCVD, and cutting ability was tested after brazing them onto WC tools. Growth rates were in the range of 0.5~10${\mu}{\textrm}{m}$/hr depending on the deposition conditions, and diamond films with thickness of 100~300${\mu}{\textrm}{m}$ were obtained. Diamond tools brazed by RF induction method showed an enhanced cutting ability in the cutting test of Si single crystal rod.

• Journal of the Korean institute of surface engineering
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• v.50 no.6
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• pp.523-530
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• 2017

In this study, we developed the h-BN interphase for ceramic matrix composites (CMCs) through a wet chemical coating method, which has excellent price competitiveness and is a simple process as a departure from the existing high cost chemical vapor deposition method. The optimum condition for nitriding an h-BN interphase using boric acid and urea as precursors were derived, and the h-BN interphase coating through a wet method on a carbon preform of 2.5 D was conducted to apply the optimum conditions to the CMCs. In order to control the coating property via the wet coating method, four parameters were investigated such as dipping time of the specimen in the precursor solution, the ratio of boric acid and urea in the precursor, the concentration of solution where the precursor was dissolved, and the cycle of dipping and dry process. The CMCs was fabricated through polymer impregnation and pyrolysis (PIP) processes and a three-point flexural strength test was conducted to verify the role of the coated h-BN interphase.

• Journal of the Korean institute of surface engineering
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• v.52 no.6
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• pp.310-315
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• 2019

The use of a silicon carbide (SiC)-based composite ceramic layer for the mold of a curved cover glass was demonstrated. The stress of SiC/VDR/graphite-based mold structure was evaluated via finite element analysis. The results revealed that the maximum tensile stress primarly occured at the edge region. Moreover, the stress can be reduced by employing a relatively thick SiC coating layer and, therefore, layers of various thicknesses were deposited by means of chemical vapor deposition. During growth of the layer, the orientation of the facets comprising the SiC grain became dominant with additional intense SiC(220) and SiC(004). However, the roughness of the SiC layer increased with increasing thickness of the layer and. Hence, the thickness of the SiC layer needs to be adjusted by values lower than the tolerance band of the curved cover glass mold.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.2
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• pp.87-95
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• 2000

By using AIP(Arc Ion Plating) of a physical vapor deposition for the first time in Korea a ceramic tool whose surface is coated single layeredly with TiN is developed. In addition cutting resistance appearing in the process of finishing cut of hardened carbon tool steel STC3 is studied. The principal and radial components of cutting resistance in those cutting conditions appear to be the same or similar and the feed component is relatively small. The feed component is found to be in proportion to cutting width and the radial component in proportion to cutting thickness. Owing to coating the cutting resistance of a TiN coated ceramic tool increas-es compared with that of a general ceramic tool.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1999.10a
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• pp.307-314
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• 1999

By using AIP(Arc Ion Plating) of a physical vapor deposition for the first time in Korea a ceramic tool whose surface is coated single layeredly with TiN is developed. In addition, cutting resistance appearing in the process of finishing cut of hardened carbon tool steel, STC3 is studied. The principal and radial components of cutting resistance in those cutting conditions appear to be the same or similar, and the feed component is relatively small. The feed component is found to be in proportion to cutting width, and the radial component in proportion to cutting thickness. Owing to coating the cutting resistance of a TiN coated ceramic tool increases compared with that of a general ceramic tool.

• Tribology and Lubricants
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• v.4 no.2
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• pp.44-51
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• 1988

Titanium carbide(TiC), Titanium nitride(TiN), and Titanium carbonnitride(Ti(C,N)) films were deposited on $Si_3N_4$-TiC composite cutting tools by chemical vapor deposition(CVD) using $TiCl_4-CH_4-H_2$, $TiCl_4-N_2-H_2$, and $TiCl_4-CH_4-N_2-H_2$ gas mixtures, respectively. The experimental results indicate that TiC coatings compared with TiN coatings on $Si_3N_4$ -TiC ceramic have an improved microstructural property, good thermal shock resistance, and good interfacial bonding. However TiN coatings compared with TiC coatings have a low friction coefficient with steel and good chemical stability. It is found by cutting test that coated insert compared with $Si_3N_4$-TiC ceramic have a superior flank and crater wear resistance. And multilayer coating compared with monolayer coating shows a improved wear resistance.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.313-313
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• 2008

Aerosol Deposition(AD) method is based on the impact consolidation phenomenon of ceramic fine particles at room temperature. AD is promising technology for the room temperature deposition of the dielectrics thin films with high quality. Embedding of passive components such as capacitors into printed circuit board is becoming an important strategy for electronics miniaturization and device reliability, manufacturing cost reduction. So, passive integration using aerosol deposition. In this study, we examine the effects of the characteristics of raw powder on the thickness, roughness, electrical properties of $BaTiO_3$ thin films. Thin films were deposited on the copper foil and copper plate. Electrical and material properties was investigated as a change of annealing temperature. We final aim the effects of before and after of laminated on the electrical properties and suit of embedded capacitor.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.346-346
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• 2008

최근 디지털 컨버젼스에 의해서 정보 단말기 network가 디지털 기술을 기반으로 유기적으로 융 복합화 되고 있으며 BT, NT, ET, IT의 융합 기술의 필요성이 점차적으로 증대되고 있다. 이러한 환경 하에서 다양한 정보 및 서비스의 송신 및 수신이 가능한 휴대 단말기의 필요성에 부응하여 기존의 전화 기능, 카메라, DMB 이외에도 홈 네트워크, mobile internet 등 더욱 다양한 기능들이 요구되고 있다. 종래에는 수동 부품과 능동 부품의 실장을 별개로 추진했으나 최근에는 수동 및 능동 부품을 하나의 패키지 내에 실장 가능하도록 하는 3-D Integration을 추진하고 있다. 지금까지 여러 부품들을 실장 시키기 위한 공정들의 대부분은 높은 온도에서 공정이 이루어졌으나 여러 부품들을 손상 없이 집적화하고 실장하기 위해서는 저온화 공정이 필요하다. 최근 많은 저온 공정 중에서 Aerosol Deposition Method는 상온에서 세라믹 후막을 성막할 수 있어 가장 주목받고 있는 공정중의 하나이다. 본 연구에서는 3-D Integration을 실현하기 위해 이종 접합에 유리하고 상온에서 성막 공정이 이루어지는 Aerosol Deposition Method를 이용하여 금속 기판 위에 금속, 폴리머, 세라믹 후막을 성막시켰다. 기판 재료로는 Cu 기판을 사용하였으며 출발 파우더로는 Polyimide 파우더와 $Al_2O_3$ 파우더, Ag 파우더를 사용하였으며 이종 접합간의 메커니즘의 양상을 보기 위해 같은 조건에서 이종 접합간의 성막률을 비교하였으며 FE-SEM으로 미세 구조를 관찰하였다. 또한 기판의 표면 거칠기에 따른 메커니즘의 양상을 연구하였다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.171-171
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• 2009

We have investigated the impact of coffee ring effect on the inkjet-printed $Al_2O_3$ thick films. In a single solvent system such as Dimethylformamide, the coffee-ring-pattern has appeared on the edge of sessile drop after evaporation. The peak-to-valley height difference in $Al_2O_3$ coffee ring is over 2um. This non-uniform deposition of $Al_2O_3$ over the surface leads to sever surface roughness of the inkjet-printed films. However, we have manipulated our printing parameters to improve the surface roughness and the packing density of the printed $Al_2O_3$ films. Our inkjet-printed $Al_2O_3$ films show 10 times smoother surface than the initially printed sample's surface. Also the packing density of the printed Ah03 film becomes 70% of high packed $Al_2O_3$. In this presentation, we would like to present the key process parameters of the inkjet printing process to overcome the genetic coffee ring problem.