• Title/Summary/Keyword: Electrode microstructure

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Fabrication of Low Temperature Cofired Ceramic (LTCC) Chip Couplers for High Frequencies ; II. Effect of Sintering Process on Ag Diffusion (고주파용 저온 동시소성 세라믹(LTCC)칩 커플러 제조: II. Ag 이온 확산에 대한 소결공정의 영향)

  • 이선우;김경훈;심광보;구기덕
    • Journal of the Korean Ceramic Society
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    • v.36 no.5
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    • pp.490-496
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    • 1999
  • The sintering behavior of LTCC (low temperature cofired ceramics) chip couplers was investigated in relation with Ag diffusion at the interface of glass ceramic substrate-Ag electrode. Sintering temperature was in the range of 825$^{\circ}C$-975$^{\circ}C$. The commercial green sheet and silver electrode were used. Below 875$^{\circ}C$ the diffusion of the Ag ion into the substrate and the penetration of glassy phases into the electrode occurred due to an increase of fluidity. Thus the lectrode line was severely deformed and damaged. At 975$^{\circ}C$ the transformation of crystalline phases into glassy phases and the melting of the Ag electrode resulted in the diffusion of the considerable amount of Ag ions.

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Fabrication of the Diffusion Barrier for Bus Electrode of Plasma Display by Electroless Ni-B Plating (무전해 Ni-B 도금을 이용한 플라즈마 디스플레이 버스 전극의 확산 방지막 제조)

  • Choi, Jae-Woong;Hong, Seok-Jun;Lee, Hee-Yeol;Kang, Sung-Goon
    • Korean Journal of Materials Research
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    • v.13 no.2
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    • pp.101-105
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    • 2003
  • In this study, we have investigated the availability of the electroless Ni-B plating for a diffusion barrier of the bus electrode. The Ni-B layer of 1$\beta$: thick was electroless deposited on the electroplated Cu bus electrode for AC plasma display. The layer was to encapsulate Cu bus electrode to prevent from its oxidation and to serve as a diffusion barrier against Cu contamination of the transparent dielectric layer in AC plasma display. The microstructure of the as-plated barrier layer was made of an amorphous phase and the structure was converted to crystalline at about 30$0^{\circ}C$. The concentration of boron was about 5∼6 wt.% in the electroless Ni-B deposit regardless of DMAB concentration. The electroless Ni-B deposit was coated on the surface of the electroplated Cu bus electrode uniformly. And the electroless Ni-B plating was found to be an appropriate process to form the diffusion barrier.

Fabrication of LTCC Multi-layer Circuit Board made of Glass-Al2O3 Composites (Glass-Al2O3 복합소재를 원료로 한 LTCC 다층회로 기판의 제조)

  • Kwak, Hun;Jeon, Hyung-Do;Kim, Hwan;Lee, Won-Jae;Shin, Byoung-Chul;Kim, Il-Soo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.21 no.6
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    • pp.509-516
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    • 2008
  • Multi-layer circuit card for semiconductor inspection was fabricated by LTCC technology. After a proper impedance design without electrical interference, ceramic tapes with the composition of $CaO-Al_2O_3-SiO_2-B_2O_3$ glass and $Al_2O_3$ were prepared. The electrode with silver paste printed on the tape. Printed ceramic sheets were then laminated and sintered. Densities and dielectric properties were measured. The microstructure, fracture surface of the region of via and matching state of substrate-electrode were observed. The durability of plated outside electrode were examined by hardness and scratch test.

Characterization of Artificial Graphite Electrodes

  • Park, Sei-Min;Han, Sang-Moo;Oh, Seh-Min
    • Carbon letters
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    • v.1 no.2
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    • pp.76-81
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    • 2000
  • Physical properties of artificial graphite electrodes were evaluated along three different directions; circumferential (X), radial (Y), and axial (Z) directions. Four kinds of commercial electrode products were used in this study for the evaluation; pole (AP) and nipple (AN) of manufacturer A, pole (BP) and nipple (BN) of manufacturer B. The mechanical, electrical, and thermal properties in X and Y directions were very similar to each other. In Z direction, however, the mechanical properties, including flexural strength and compressive strength, were higher, and electric resistance and thermal expansion were much lower than those in the other directions. The microstructures observed by optical microscope and scanning electron microscope revealed that the differences in properties by the measuring direction were caused by the preferential alignment of needle cokes along the Z direction. When comparing the properties of the electrode samples in the same direction, the mechanical properties mainly depended on the bulk density or porosity of the samples as well as preferential alignment of needle cokes.

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The Electrochemical Characteristics of $LiCoO_2$Cathode Materials as a function of Polyaniline contents (Polyaniline을 첨가한 $LiCoO_2$정극활물질의 전기화학적 특성)

  • 임동규;임석범;김영호;김은옥;류광선
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.07a
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    • pp.667-670
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    • 2000
  • The electrochemical characterization was conducted by the addition of chemically synthesized polyaniline on LiCoO$_2$electrode. From the results of XRD and SEM, the phase transition and microstructure were not found. Initial electrochemical characteristics of LiCoO$_2$electrode for lithium secondary battery were evaluated through the charge/discharge within the range of 4.3 V to 3.0 V versus Li/Li$^{+}$. Discharge capacity of LiCoO$_2$electrode without addition of Polyaniline were 160.21 mAh/g. But after addition of polyaniline, lower discharge capacities 25.7 mAh/g was found.d.

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Effect of carrier collector on the Efficiency of DSSCs

  • Ramasamy, Easwaramoorthi;Lee, Won-Jae;Lee, Dong-Yun;Song, Jae-Sung
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.07a
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    • pp.633-634
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    • 2005
  • Transparent conducting glasses exhibit high ohmic losses that are apparent in the case of large size Dye Sensitized Solar Cells (DSSCs). In this study, we investigated the impact of current collectors over the efficiency of DSSCs. The Silver current collectors were prepared on both counter electrode and working electrode surface by screen printing method. For long term stability in electrolyte environment and also to avoid the charge recombination, current collectors are protected by sodium silicate overcoat layer. These current collectors were characterized for their microstructure parameters. Also current collector's stability in electrolyte environment has been investigated.

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A Study on Microwave Dielectric Properties of Low-temperature Sintered (1-x) $ZnNb_2$$O_6$-$xPb_5$$Nb_4$$O_{15}$ and Microstructure (저온소결형 (1-x)$ZnNb_2$$O_6$-$xPb_5$$Nb_4$$O_{15}$계 세라믹스의 유전특성과 미세구조에 관한 연구)

  • 김현학;김경용;김병호
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.13 no.11
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    • pp.926-931
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    • 2000
  • The microwave dielectric properties and the microstructures as a mole fraction of (1-x)ZnNb$_2$O$_{6}$-xPb$_{5}$Nb$_4$O$_{15}$ ceramics with CuV$_2$O$_{6}$, Sb$_2$O$_3$ and glass(ZNPN ceramics) was investigated. 0.98ZN-0.02PN ceramics containing 1.5 wt% CuV$_2$O$_{6}$ 1.0 wt% Sb$_2$O$_3$ and 1.0 wt% glass had a dielectric constant($\varepsilon$$_{r}$) of 23, Qxf$_{o}$ value of 15000 and TCF(Temperature Coefficient of resonance Frequency) of -25 ppm/$^{\circ}C$ and it is possible to be co-fired with Ag electrode at 90$0^{\circ}C$. As sintered temperature increases over 90$0^{\circ}C$ the grain size of ZNPN ceramics was increasing for growth and it has poor co-fired properties with Ag electrode.e.ctrode.e.e.

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