LTCC glass-ceramic composites for microwave application

Advanced materials of rare earth derived glass–and reactive bonded glass–ceramic composites are exceptionally interesting for IC packaging, radar, antennas and wireless technologies for the next generation of miniature electronic devices. Glass–ceramic composites in the system 1:1:4 BaO–Nd2O3–TiO2 and modified rare earth glasses based on boron oxide for passive integration in LTCC demonstrate excellent dielectric properties in the middle permittivity ε range of 20–70 with high quality factor Q and low temperature coefficient TCf at microwave frequencies. Depending on the glass–ceramic system, concentration, significant processing parameters e.g. powder preparation techniques and sintering of dense composite at temperatures <900°C were achieved. Dielectric properties were studied by a cavity resonator method at frequencies 1–6 GHz in correlation of the crystalline microstructure. This work was supported by tridimensional modeling systems to estimate dielectric behavior of multiphase glass–ceramic composites.