• 한국마이크로전자및패키징학회:학술대회논문집
• /
• 한국마이크로전자및패키징학회 2001년도 The IMAPS-Korea Workshop 2001 Emerging Technology on packaging
• /
• pp.151-156
• /
• 2001

Using the photoimageable thick film conductors, $25\mu\textrm{m}$ line widths and $25\mu\textrm{m}$ spaces can be obtained. Test patterns are made by green tape lamination, paste printing, exposing to UV light, developing in an aqueous process and cofiring. Postfiring method using alumina substrate can be also applied to fine line formation. Series gap resonator formed by photopatterning process showed the improved signal transmission characteristics compared to that obtained by conventional screen printing.

• 한국전기전자재료학회논문지
• /
• 제33권5호
• /
• pp.411-417
• /
• 2020

In this study, we introduce a Na β"-alumina composite thick film as a solid electrolyte, to reduce the resistance of electrolyte for a Na/S battery. An alumina/zirconia composite material was used to enhance the mechanical properties of the electrolyte. A solid electrolyte of about 40 ㎛ thick was successfully fabricated through the conversion and tape-casting methods. In order to investigate the effect of the surface treatment process of the solid electrolyte on the battery performance, the electrolyte was polished by dry and wet processes, respectively, and then the Na/S batteries were prepared for analyzing the battery characteristics. The battery with the dry process performed much better than the battery made with the wet process. As a result, the battery manufactured by the dry process showed excellent performance. Therefore, it is confirmed that the surface treatment process of the solid electrolyte has an important effect on the battery capacity and coulombic efficiency, as well as the interface reaction.

• 한국분말야금학회:학술대회논문집
• /
• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
• /
• pp.908-909
• /
• 2006

The HTCC based multilayer structure plasma head unit have some difficulties in fabrication due to complicated post-processes, such as heat treatment at reduced atmosphere, re-bonding of each layer, and silver metallization. On the other hand, LTCC based technology provides relatively simple process for multilayer plasma unit except weak mechanical properties. To overcome this problem a combined scheme using both LTCC and HTCC technology has been developed in our group, recently. In this work, we report the structural design, materials selection, joining of LTCC with HTCC substrate, and co-firing process for the fabrication of multilayered atmospheric plasma head unit.

• 한국세라믹학회지
• /
• 제40권9호
• /
• pp.832-836
• /
• 2003

Multi-layer ceramic composites were prepared by tape casting followed by hot pressing using silicon nitride layer with silicon nitride whiskers, silicon nitride layer with silicon carbide particles and boron nitride-alumina layer. The whiskers were aligned during the casting. As the whisker content of the silicon nitride layer was increased up to 10 wt％, the flexural strength of the multi-layer composite was increased. However, further increase of the whisker content in the layer resulted in a rapid decrease of the strength of the composite. The results suggest that the strength of multi-layer ceramic composite showing non-catastrophic failure behavior can be significantly improved by incorporating the aligned whiskers in the layers.

• 폴리머
• /
• 제36권3호
• /
• pp.268-274
• /
• 2012

실란 커플링제를 사용하여 알루미나 나노 입자의 표면을 처리하였다. 표면을 개질한 나노 입자를 in-mold decoration(IMD) 포일의 경질 코팅 층에 도입하여 표면 경도 및 내마모성을 중심으로 도막의 물성 변화를 평가하였다. 전자빔(electron beam, EB) 조사가 IMD 포일을 구성하는 color layer 및 anchor layer에 미치는 영향을 색도변화와 cross-cut tape 시험을 통하여 평가하였다. 또한 EB 조사 온도에 따른 경화 거동을 표면 물성 변화 평가 및 Fourier transform infrared(FTIR) spectroscopy 관찰을 통해 정량적으로 분석함으로써 EB 경화 공정의 실용화에 필요한 데이터베이스를 구축하였다.

• 한국해양공학회지
• /
• 제23권5호
• /
• pp.32-38
• /
• 2009

Silicon nitride samples with aligned whisker seeds were prepared with different amounts of yttria and alumina as the sintering additives. Their sintering behaviors and the microstructural developments between $1850^{\circ}C$ and $2050^{\circ}C$ were examined. The sample with larger amount of the sintering additives showed faster densification and grain growth. Even though addition of the aligned whisker seeds slightly retarded densification of silicon nitride, it improved the flexural strength and the fracture toughness. Both the flexural strength and the fracture toughness of silicon nitride with the aligned whisker seeds were increased as the amount of the sintering additives was increased.

• Corrosion Science and Technology
• /
• 제20권6호
• /
• pp.475-483
• /
• 2021

Additively manufactured titanium alloy is one of the promising materials in advanced medical industries. However, these additively manufactured alloys show corrosion properties different from those of conventional materials due to their unique microstructure. In this study, the effect of surface roughness and masking conditions on the results of the potentiodynamic polarization tests on additively manufactured or conventional Ti-6Al-4V alloys in artificial saliva solution with or without fluoride was investigated. The results showed that the corrosion potential was slightly lower with a flat cell with an O-ring than with masking tape. The corrosion rate was decreased with decreases in the surface roughness. Localized corrosion involving delamination of the surface layer occurred at 7 ~ 9 V (SSC) on the additively manufactured alloy in solution with or without fluoride when the samples were finished with 1000-grit SiC paper, whereas localized corrosion was not observed in the specimens finished with 1-㎛ alumina paste.

• 한국재료학회지
• /
• 제11권6호
• /
• pp.519-526
• /
• 2001

Al$_2$O$_3$/ZrO$_2$ 비수성 현탁액의 분산과 레올로지에 미치는 methyl isobutyl ketone (MIBK) /ethanol (EtOH) 용매혼합의 영향을 침전밀도, 점도를 측정함으로써 조사하였다. 분산제 'Hypermer' KD-1이 첨가된 다량의 MIBK를 함유하는 용매 ($\geq$60vol%)에서 $Al_2$O$_3$와 ZrO$_2$ 입자의 침전밀도는 증가하였다. 80MIBK/20EtOH(vol%)에서 ball milling한 현탁액이 좁고 unimodal한 입자크기분포를 나타내었다. 모든 현탁액은 의가소성유동을 나타내었으나 shear thinning은 $Al_2$O$_3$/ZrO$_2$의 혼합비, MIBK/EtOH의 혼합비에 따라서 다소 다르게 거동하였다. 순수한 MIBK를 사용한 $Al_2$O$_3$(<300 s$^{-1}$ ) 및 ZrO$_2$(<3000 s$^{-1}$ ) 현탁액은 주어진 전단속도범위내에서 가장 강한 shear thinning을 나타내었다. 동일한 용매 (80MIBK/20EtOH, vol%)를 사용한 경우의 shear thinning은 $Al_2$O$_3$/ZrO$_2$의 혼합비에 거의 의존하지 않았다.

• 전기화학회지
• /
• 제9권3호
• /
• pp.124-131
• /
• 2006

기존의 용융탄산염 연료전지용 연료극인 Ni-Cr전극은 제조과정이 복잡하며, 운전조건에서 전극의 소결과 creep현상으로 인하여 전극의 기공률과 두께가 감소하는 문제점이 있어 상용화에 걸림돌이 되고 있다. 이에 본 연구에서는 Ni-Cr계 전극보다 creep저항성이 우수하다고 알려져 있는 Ni-Al계 합금을 사용하였다. 또한 공정의 단순화로 비용을 절감시키기 위해, 소성과정을 제외하고 tape casting과 건조과정을 거친 green sheet를 단위전지에 장착하여 전처리 과정 중에 소결시키는 in-situ 소결법에 대해 연구하였다. 그러나 기존의 전처리 방법을 이용한 단위전지 평가에서 Ni-Al 합금의 상분리 현상으로 인해 기대하였던 creep저항성 향상을 확인하지 못했고, 운전중 Ni-Al합금 연료극에 단위전지의 구성요소인 matrix 기공크기보다 작은 기공(${\leq}0.4{\mu}m$)이 다량 생성되어 전해질 재분배를 일으켜 성능이 하락하는 문제점이 나타났다. 따라서 이러한 문제점을 해결하고자 전처리 조건을 변화시키며 실험을 수행하였다. 그 결과, 비활성 기체인 질소를 일정한 구간에 사용함으로써 기존 전처리에서 발생하였던 Ni-Al 합금의 상분리 현상을 억제할 수 있었으며 이로 인해 creep저항성 또한 향상시킬 수 있었다. 그러나 운전 중 생성되는 matrix기공크기보다 작은 기공(${\leq}0.4{\mu}m$) 형성비율은 억제할 수 없었다. 위의 전처리 조건을 가지고 단위전지 운전실험을 하였고, 전해질 함침비율을 조절함에 따라 성능을 향상시킬 수 있었으며 2000시간 동안 일정하게 유지함을 확인하였다. 이로부터 기존의 소성전극과 비교하여 많은 장점을 가지고 있는 in-situ 소결법의 가능성을 확인할 수 있었다.