Summary: | 碩士 === 國立交通大學 === 材料科學與工程研究所 === 86 ===
Multi-layers and miniaturization of High frequency dielectiric devices can improve volume effects. Lower sintering temeperature can be co-fired with conductors. like Au, Ag and so on having low dielectric loss. Due to the rapid growth of communications industry using microwave frequencies, cellular phones with small volume and light weight become necessary trend.
In this study, first, we fabricate high-temp. sintering bulks of BaO-Re2O3-TiO2 (Re=La, Nd, Sm) ternary systems, after analyzing calcined powders (T=900-1300℃) microstructures and phase transitions. These bulks' microwave properties have been measured. BaO-Nd2O3-4TiO2 system owning needed mecrowave properites., which εr=67, Q=1138 (3 Ghz), τf=+24ppm/℃ (1300℃ sinter 1hr) is the favorite ceramic system for low-temp.sintering fabrications. Microwave properties of ceramic bulks containing different components (5-20vol%) commercial glasses GP032 (ZnO-B2O3-SiO2) sintering at low temperature (900-1000℃) have also been studied. Based on dense bulks with 15vol% GP032 addition, which εr=42, Q=648 (3 GHz) (1000℃ sinter 4hr) and adding proper binder (HEC) and plasticizer (Glycerin) the apueous slurry was formed to be slips using doctor tape casting method. The sinitered substrates, whose green tape contains 4 pressed layer, have density, 4.99g/cm3 lower than high-temp.sintered bulks (5.22g/cm3).
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