Tetsuo Yoshimoto

Characterization of a new dielectric ceramic material for a smaller Y-5V MLC

Abstract Powders of 20PMN-60PNN-20PT were prepared using an alkoxide process and a oxide process, and their compositional homogeneity was studied with SEM-EDS, EPMA and TEM-EDS. The homogeneities of the green powders prepared by the oxide process were greatly affected by Mg and Ni components of this system. The green powders prepared using an alkoxide process, however, maintained good homogeneity, and were suitable for a smaller sized Y-5V multilayer ceramic capacitor with relatively high specific capacitance.

Y5U multilayer ceramic capacitors with high-specific capacitance and low-equivalent series resistance

A dielectric powder material, for Y5U multilayer ceramic capacitors was developed in the Pb(Mg/sub 1/3/Nb/sub 2/3/)O/sub 3/-Pb(Ni/sub 1/3/Nb/sub 2/3/)O/sub 3/-PbTiO/sub 3/ ternary system by using an alkoxide process. Multilayer ceramic chip capacitors (10 mu F) with high specific capacitances were fabricated using this powder. A Ag80%-Pd20% alloy was used for the internal electrodes. The alkoxide-derived capacitor had an extremely high specific capacitance of about 500 mu F/cm/sup 3/ and a small temperature dependence meeting Y5U specifications of the EIA standard. The equivalent series resistance was approximately 20 m Omega at 500 kHz. The breakdown voltages of the capacitor were 300 V or higher. In accelerated load life tests and load humidity tests, no degradation of insulation resistance was found during 1000 h of testing.<<ETX>>

The effect of Nb(V) addition on the properties of PZT prepared by an alkoxide process

The PZT (53/47) ceramic was prepared by an alkoxide process and its properties were evaluated in comparison with the PZT prepared by a mixed oxide process. The alkoxide PZT was superior to the oxide PZT from the viewpoint of sintering temperature and properties, but neither sample reached a high value of the planar coupling factor. To improve such piezoelectric properties, Nb(V) addition to PZT was studied, and 1 mol.% addition to PZT was effective in improving the properties by aiding lower temperature sintering. The role of the Nb(V) additives which caused such improvements is discussed.<<ETX>>