• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2002.11a
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• pp.169-172
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• 2002

Silver pastes for inner conductor in the Low Temperature Co-fired Ceramics (LTCC) are composed of silver powder, binder, solvent and additives. The composition of the chemicals have influence on rheology, printability, shrinkage rate, etc. In this study, commercial Ag pastes and Ag pastes made in KETI were investigated to find the relationship between characteristics of Ag paste and solid contents. Ag pastes with 68~90 wt% Solid Contents were tested. Substrate/paste matching property and conductivity of the conductor lines showed large dependence on solid contents of Ag paste.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.3
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• pp.200-207
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• 2011

Abstract: The effect of lead free glass frit compositions on the properties of thick film conductor and resistor pastes were investigated. Two types lead free frits, HBF-A(without $Bi_2O_3$) and HBF-B(with $Bi_2O_3$) were made from $SiO_2$, $B_2O_3$, $Al_2O_3$, CaO, MgO, $Na_2O$, $K_2O$, ZnO, MnO, $ZrO_2$, $Bi_2O_3$. And Ag based conductor pastes and $RuO_2$ based resistor paste were prepared by mixed with these frits and functional phase(Ag and $RuO_2$), and organic vehicle. The properties of thick film conductor and resistor sintered at $850^{\circ}C$ were studied after printing on $Al_2O_3$ substrate. The morphology of the sintered films surface were SEM and EDS were carried out to analysis the chemical composition on resistor surface and state of Ru atom in frit matrix.

• Progress in Superconductivity and Cryogenics
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• v.11 no.1
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• pp.1-4
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• 2009

Mechanical and electrical properties of silver stabilizer layer of coated conductor, which as prepared with nano silver paste as starting materials, have been investigated, Nano silver paste was coated on a YBCO film by dip coating process at a diping speed of 20m/min. Coated film was dried in air and heat treated at $400{\sim}700^{\circ}C$ in an oxygen atmosphere. Adhesion strength between YBCO and silver layer was measured by a tape est(ASTM D 3359). Hardness and electrical conductivity of the samples were measured by pencil hardness test (ASTM D 3363) and volume resistance test by LORESTA-GP (MITSHUBISHD, respectively. The sample heat-treated at $500^{\circ}C$ showed poor adhesion 1B, but samples heat treated at higher than $600^{\circ}C$ showed enhanced adhesion of 5B. The silver layer heat-treated at $700^{\circ}C$ showed the high hardness value larger than 9 H, low volume resistance, surface resistance value as well as superior current carrying capacity compared to sputtered silver. SEM observations showed that a dense silver layer was formed with a thickness of about $2{\mu}m$. Dip coated silver layer prepared by using nano silver paste showed superior electrical and mechanical characteristics.

• Journal of the Microelectronics and Packaging Society
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• v.18 no.4
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• pp.63-70
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• 2011

Anorthite forming glass frits in amounts up to 25 vol% of the silver powder were added to improve the adhesion between the conductor pattern formed by thick film photoimageable process and the low temperature co-fired ceramics (LTCC) substrate. The sheet resistance of the conductor pattern was raised from 0.13 ${\Omega}/{\square}$ to 2.25 ${\Omega}/{\square}$ as the volume percentage of glass frit increased up to 25 vol%. The adhesion strength was improved with this glass frit increase, but it decreased when the glass content exceeded 20 vol% which are possibly attributed to the liquid pool effect and the reduced fracture toughness in the interface between conductor and LTCC layer. The shrinkage of the width of the conductor pattern decreased with the addition of glass contents.

• 한국초전도학회:학술대회논문집
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• 2008.08a
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• pp.68-68
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• 2008

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.208-208
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• 2008

Micro patterning of conductor line/space on LTCC green sheet in the LTCC module is an important process for miniaturization in 3D integrated circuits. This work presented the effect of inorganic binders on the microstructure, adhesion, electrical resistivity, shrinkage and line/space resolution, which is a part of study in photoimageable conductor paste. The photoimageable conductor paste contains silver powder, polymer binder, monomer, photo-initiator, UV absorber, and solvent. The inorganic binders were furnished with varied weight percentage of anorthite, diopside and MLS-62 glass frits from 0% to 7%. The Line/space sizes thus obtained was under 25 micron.

• Journal of the Korean Ceramic Society
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• v.32 no.5
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• pp.601-607
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• 1995

The bond strength between the low-firing-substrate and Cu conductor depended on the softening point and the amount of frit added to the metal paste. The addition of 3 wt% frit (softening point: 68$0^{\circ}C$) to the metal paste resulted in the improvement of bond strength, which was approximately 3 times higher (3kg/$\textrm{mm}^2$) than that of non frit condition. It was also found that fracture surface shifted to the ceramic substrate in the interface region. These phenomena were attributed to the frit migration into the metal-ceramic interface. It was thought that the migration of glass frit occurred extensively when the softening point of glass firt was 68$0^{\circ}C$. The sheet resistance of Cu conductor remained constant by the addition of 4 wt% frit regardless of softening point of frit. For all samples with more than 4 wt% frit, the sheet resistance increased abruptly.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.335-335
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• 2010

$SiO_2$, $B_2O_3$, $Al_2O_3$, CaO, MgO, $Na_2O$, $ZrO_2$, $Bi_2O_3$를 이용하여 성질이 다른 두 종류의 무연계 프릿트를 제조하여 특성을 표준화 하였고, 이들 무연계 프릿트를 이용하여 Ag계 도체 및 $RuO_2$계 저항페이스트롤 제조하여 특성에 미치는 프릿트 조성의 영향을 연구하였다. $B_2O_3$를 첨가하여 퍼짐특성이 큰 프릿트의 경우 더 우수한 페이스트 특성을 나타내었다.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.2
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• pp.130-136
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• 2000

Generally, the build-up printed circuit board manufactured by the sequential process with etching, plating, drilling etc. requires many types of equipments and lead time. Etching process is suitable for mass production, however, it is not adequate for manufacturing prototype in the developing stage. In this study, we introduce a screen printing technology to prototyping a build-up printed circuit board. As for the material, photo/thermal curable resin and conductive paste are used for the formation of dielectric and conductor. The build-up structure is made by subsequent processes such as the formation of liquid resin thin layer, the solidification by UV/IR light, and via filling with conductive paste. By use of photo curable resin, productivity is greatly enhanced compared with thermal curable resin. Finally, the basic concept and the possibility of build-up printed circuit board prototyping are proposed in comparison with to the conventional process.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.302-302
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• 2008

다층 세라믹 기판은 내열성, 내마모성 및 우수한 전기적 특성으로 인하여 기존의 PCB의 대체품으로 많이 이용되며 그 수요가 점점 늘어가고 있는 추세이다. 이에 고집적 다층 세라믹 기판을 보다 다기능화, 고밀도화, 고성능화하기 위해서는 세라믹 층간 정밀도가 아주 중요한 요소로 부각되고 있으며, 무수촉 기판 소성기술을 이용한 층간 정밀도를 높이는 연구가 진행되어지고 있다. 그러나 무수축 기판에서 이러한 정밀도를 유지하기 위해서는 전극의 수축률을 기판의 수축율과 같은 0%에 가깝게 제어하여야 하며 이를 위해서 여러 가지 Frit을 이용하여 수축율을 제어를 시도되고 있다. Ag 전극은 낮은 비저항 우수한 접착성 등의 장점을 가지고 있을 뿐 아니라 가격이 저렴하여 전극재료로서 많은 연구가 이루어졌다. 특히 Infiltration법에 의한 무수축소성의 경우 Glass가 Ag paste로 Infiltration되어 Ag paste와 세라믹의 matching성 확보에 많은 문제가 발생하였다. 이에 본 실험에서는 제조된 Ag conductor paste 에 첨가되는 frit이 무수축 기판과의 매칭성에 어떠한 영향이 있는지에 대하여 고찰하였다. 시편의 준비는 frit이 첨가된 Ag paste를 기판에 screen printing 한 후 $900^{\circ}C$에서 소결한 것을 사용하였으며 Ag 전극의 미세구조를 관찰하고 전기적 특성과 미세구조와의 연관성에 관해 고찰하였다.