KJ Ceramics 31

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Detailed Program

Paper Number : EL-P11

Time Frame : 12:00~13:30

Presentation Date : Friday, 28, November

Session Name : Electronic Ceramics

Session Chair 1# : -

Session Chair 2# : -

CuO/V2O5 Doped BZN Ceramic for Embedded Capacitor Layer in Integrated LTCC Modules

Prof. Kyoungho Lee

Soonchunhyang University

Sintering additives for Bi3/2ZnNb3/2O7 (BZN) ceramic were studied in order to facilitate the use of BZN as an integrated decoupling capacitor in high density multilayer LTCC modules for mobile communication systems. Among the additives, CuO/V2O5 mixture was the most promising sintering additive for co-firing BZN ceramic with a commercial LTCC sheet (MLS-22, NEG Co., Japan) and Ag electrode. 0.5 wt% CuO/V2O5 doped BZN was successfully densified at 860C due to a reactive liquid phase sintering. During the liquid phase sintering, ZnNb2O6 and BiVO4 phases were formed as minor phases but the resulted dielectric properties were acceptable for using the CuO/V2O5 doped BZN as the embedded capacitor; permittivity (r) at 1 MHz was 148 and C/C25 was less than  5%. The physical and chemical compatibilities of the CuO/V2O5 doped BZN with heterogeneous layers in LTCC modules (low r LTCC layer and Ag electrode layer) were also examined. Co-firing test of the doped BZN ceramic with the MLS-22 LTCC sheet revealed that symmetric piling configuration was much safer than asymmetric configuration for avoiding the warpage during co-firing process. It was also revealed that the thickness control of two heterogeneous layers was the critical factor to avoid crack formations during co-firing. The optimum thickness ratio of the doped BZN and MLS-22 layers was less than 0.1. Chemical compatibility test revealed that there was no severe reaction between both the doped BZN/MLS-22 and the doped BZN/Ag electrode. After co-fired at 860C for 20 min, ~15 m of reaction layer was formed at the interface of BZN/MLS-22 layers, and the main diffused ions were Al, Nb, and Bi. The co-firing test of the BZN/Ag electrode revealed that BZN was very stable to the Ag electrode.

Acknowledgements :

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