• 한국세라믹학회지
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• 제49권4호
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• pp.279-286
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• 2012

Microstructure tailoring of filler loaded preceramic polymer systems offers a high potential for property improvement of Si-based ceramics and composites. Advancements in manufacturing of bulk materials by controlling microstructure evolution during thermal induced polymer-ceramic transforma-tion and polymer-filler reactions will be presented. Rate controlled pyrolysis, multilayer gradient laminate design and surface modification by gas solid reaction are demonstrated to yield ceramic components of high fractional density and superior mechanical properties. Emerging fields of applications are presented.

• 한국세라믹학회지
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• 제46권3호
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• pp.323-329
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• 2009

Influences of ceramic filler types and dose on the sintering, phase evolution, and dielectric properties of ceramic/CaO-$Al_2O_3-SiO_2$ glass composites were investigated. All of the specimens were sintered at $900^{\circ}C$ for 2 h, which conditions are required by the lowtemperature co-firing ceramic (LTCC) technology. Ceramic fillers of $Al_2O_3,\;SiO_2$, kaolin, and wollastonite were used. The addition of $Al_2O_3$ filler yielded the crystalline phases of alumina and wollastonite, and the densification over 95% of the relative density was achieved up to 50 wt% addition of the filler. For the cases of the fillers of $SiO_2$, kaolin, and wollastonite, crystalline phases of quartz, mullite, and wollastonite formed, while the densification decreased monotonically with the filler addition. In overall, all the investigated fillers with 10 wt% addition resulted in a reasonable sintering (over 95 %) and low dielectric constants (less than 6), demonstrating the feasibility of the investigated composites for application to a LTCC substrate material with a low dielectric constant.

• 한국재료학회지
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• 제26권7호
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• pp.359-362
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• 2016

Mineral filler is used for resin compounds, because it increases the stiffness and thermal stability of a resin compound, and it also cuts down the cost. Calcium carbonate, silica, magnesium oxide, and others are used as filler materials in general, and the type of filler material, the size, and content can affect the physical properties of compounds. Those factors also influence the viscosity of resin mixtures and the workability, and should be adjusted by changing the contents of the filler, which depends on the size. In this study, five kinds of ground calcium carbonate, which were different in size, were used to produce polyester compounds ; the physical properties were compared with the filler size and contents. The mechanical properties were measured by bending strength and tensile strength, and the heat deflection temperature was obtained for thermal stability.

• 한국세라믹학회지
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• 제35권9호
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• pp.939-944
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• 1998

실리콘함유 고분자(Polysiloxane)의 세라믹변환과정에서의 부피수축효과를 조절하기 위하여 활성화금속으로 중석을 첨가하여 열분해 및 합성반응을 통해 신 세라믹 복합체를 개발하고 이의 세라믹화 과정이나 물성을 조사하였다. 제조된 시편의 미세조직은 고분자로부터 야기된 $S_{1}$-O-C게열의 Glass기지상과, 분해잔여물(고상,기상)등과 활성화금속과의 반응르로 생성된 고경도의 탄호물로 이루어져 있어 향후 내마모재료로서의 응용을 기대할 수 있을 것이다. 제조된 복합체의 물성은 반응조건에 많이 의존함을 알 수 있었다. 1400~$1500^{\circ}C$에서 열분해 시켜 제조한 복합체의 밀도는 95% 이상의 상대밀도와, 경도 값은 7~8GPa 정도이고 탄성률은 220~230 GPa, 파괴인성응ㄴ 6~6.8$MPam^{1/2}$, 파괴강도는 380~470 MPs정도의 값을 나타내었다.

• 마이크로전자및패키징학회지
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• 제18권3호
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• pp.1-7
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• 2011

Active brazing of ceramic to metal is reviewed in this paper. As one of the key aspect in joint techniques, active brazing has been developed to simplify the manufacturing procedure of brazed joints between ceramic and metal. The active filler metal includes Ag-Cu-Ti series, Cu-Ti series, Co-Ti series and so on. The active filler metal which supplies the chemical bonds between ceramic and metal, enhances the wetting of filler metal on ceramic surface and eliminates the need for metallization treatments. The residual stress caused by difference of coefficient of thermal expansion between ceramic and metal, holds a direct influence on the bonding strength and even results in a fracture. Good joints of ceramic to metal promote the miniaturization and simplicity of electronic components with multifunction.

• Journal of Mechanical Science and Technology
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• 제16권9호
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• pp.1078-1083
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• 2002

Ceramics are significantly used in many industrial applications due to their excellent mechanical and thermal properties such as high temperature strength, low density, high hardness, low thermal expansion, and good corrosion resistive properties, while their disadvantages are brittleness, poor formability and high manufacturing cost. To combine advantages of ceramics with those of metals, they are often used together as one composite component, which necessiates reliable joining methods between metal and ceramic. Direct brazing using an active filler metal has been found to be a reliable and simple technique, producing strong and reliable joints. In this study, the fracture characteristics of Si$_3$N$_4$ ceramic joined to ANSI 304L stainless steel with a Ti-Ag-Cu filler and a Cu (0.25-0.3 mm) interlayer are investigated as a function of strain rate and temperature. In order to evaluate a local strain a couple of strain gages are pasted at the ceramic and metal sides near joint interface. As a result the 4-point bending strength and the deflection of interlayer increased at room temperature with increasing strain rate. However bending strength decreased with temperature while deflection of interlayer was almost same. The fracture shapes were classified into three groups ; cracks grow into the metal-brazing filler line, the ceramic-brazing filler line or the ceramic inside.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.304-304
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• 2007

고주파 모률에서 사용되는 기판소재는 저유전율과 낮은 loss 특성을 요구함으로 지속적인 연구를 필요로 한다. 지금까지의 ceramic/glass composite 에서 주로 사용된 ceramic filler는 Al2O3로 낮은 유전률을 구현에 한계가 있었다. Cordierite는 낮은 유전율 (${\varepsilon}_r$ < 4)을 나타내는 filler로서 그 가능성이 높지만 아직까지 보고된 결과들이 미흡한 실정이다. 따라서 본 연구에서는 cordierite filler와 SiO2-B2O3-Al2O3-RO (R : Zn, Sr, Ba, Ca)계의 glass를 혼합하여 LTCC용 기판소재로서의 가능성을 확인하고자 저온 동시소성이 가능한 소결온도인 $850^{\circ}C{\sim}1.000^{\circ}C$ 사이에서 소재의 소결실험을 진행하였다. 소결온도에 따른 상변화, 유전특성을 확인한 결과 filler로 사용된 cordierite상만이 관찰 되었으며 소결조건에 따라 5.0~5.5의 낮은 유전율과 1.000~1,500의 Q를 나타내는 것을 확인 하였다.

• 한국전기전자재료학회논문지
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• 제36권2호
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• pp.151-157
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• 2023

Integrating dielectric materials into LTCC is a convenient method to increase the integration density in electronic circuits. To enable co-firing of the high-k and low-k dielectric LTCC materials in a multi-material hetero-laminate, the shrinkage characteristics of both materials should be similar. Moreover, thermal expansion mismatch between materials during co-firing should be minimized. The alternating stacking of an LTCC with silica filler and that with calcium-zirconate filler was observed to examine the use of the same glass in different LTCCs to minimize the difference in shrinkage and thermal expansion coefficient. For the LTCC of silica filler with a low dielectric constant and that of calcium zirconate filler with a high dielectric constant, the amount of shrinkage was examined through a thermomechanical analysis, and the predicted appropriate fraction of each filler was applied to green sheets by tape casting. The green sheets of different fillers were alternatingly laminated to the thickness of 500 ㎛. As a result of examining the junction, it was observed through SEM that a complete bonding was achieved by constrained sintering in the structure of 'calcium zirconate 50 vol%-silica 30 vol%-calcium zirconate 50 vol%'.

• 한국재료학회지
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• 제21권9호
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• pp.502-508
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• 2011

The goal of the present work was to investigate the development of a geopolymeric ceramic material from a mixture of mine residue, coal fly ash, blast furnace slag, and alkali activator solution by the geopolymer technique. The results showed that the higher compressive strength of geopolymeric ceramic material increased with an increase in active filler (blast furnace slag + coal fly ash) contents and with a reduction of mine residue contents. The geopolymeric ceramic had very high early age strength. The compressive strength of the geopolymeric ceramic depended on the added active filler content. The maximum compressive strength of the geopolymeric ceramic containing 20 wt.% mine residue was 141.2 MPa. The compressive strength of geopolymeric ceramic manufactured by adding mine residue was higher than that of portland cement mortar, which is 60 MPa, when cured for 28 days. SEM observation showed the possibility of having amorphous aluminosilicate gel within geopolymeric ceramic. XRD patterns indicate that the geopolymeric ceramic was composed of amorphous aluminosilicate, calcite, quartz, and muscovite. The Korea Standard Leaching Test (KSLT) was used to determine the leaching potential of the geopolymeric ceramic. The amounts of heavy metals were noticeably reduced after the solidification of mine residue with active filler.

• 한국세라믹학회지
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• 제42권2호
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• pp.110-116
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• 2005

본 연구는 $BaO-B_{2}O_3-ZnO$계에서 저온소성이 가능한 조성을 탐색하고, 여기에 $Al_{2}O_3$를 filler로 첨가하여 복합체를 제조할 경우의 소결거동과 물성에 미치는 영향을 조사하였다. 이때 첨가하는 알루미나 분체는 입자크기가 서로 다른 두 종류를 이용함으로서 알루미나 입자 크기의 효과도 동시에 조사하였다. 알루미나 첨가량이 증가하는 경우 복합체의 치밀화정도, 유전상수, 열팽창계수, 그리고 경도 값이 감소하였다. 또한 첨가되는 알루미나 입자의 크기가 미세할 경우 그 감소율은 증가되었다. 한편 파괴인성값은 알루비나 첨가량이 많을수록, 알루미나 입자 크기가 작을수록 오히려 증가하였는데 이는 기공과 filler의 crack전파 억제 효과에 의한 것으로 해석하였다.