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 epsilon 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 degreesC 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. (C) 2001 Elsevier Science Ltd.