Electrical and resonant characteristics of modified PbTiO3 ceramics for SMD-type high frequency resonators using 3rd overtone thickness vibration mode

摘要

The micro-structural, electrical and resonant properties of (Pb, La, Nd)(Ti, Mn, Sb)O-3 ceramics were investigated as a function of CuO addition and internal electrode weight. The best properties for the resonator application were observed from the 0.25 wt.% CuO added specimen sintered at 1200 degreesC. Curie temperature and density of the specimen were measured to be 325 degreesC and 7.72 g/cm(3), respectively. Dynamic characteristics of energy-trapped 30 MHz surface mount device (SMD) type resonators using 3rd overtone thickness vibration mode were also investigated as a function of internal electrode weight and CuO addition. Ceramic wafers for resonator were fabricated by evaporating electrode weights of 0.66, 1.765, 2.32, and 3.87 x 10(-4) g/cm(2) with silver, respectively. And then, 30 MHz SMD-type ceramic resonators were fabricated with the size of 3.7 turn x 3.1 mm and electrode diameter of 0.77 mm. With increasing electrode weight, resonant resistance was gradually decreased. At the electrode weight of 2.32 x 10(-4) g/cm(2), mechanical quality factor (Q(mt3)) and dynamic range (DR) for the 3rd overtone thickness vibration mode showed the maximum value of 2152 and 49 dB, respectively. (C) 2003 Elsevier Science B.V. All rights reserved. [References: 9]