Low k materials for high frequency high integration modules

Glass systems based on Ca, Sr, Ba, and Zn modified alumino-boro silicates were investigated in order to improve the dielectric and mechanical properties of a typical LTCC (low temperature co-fired ceramic) which was developed for high frequency highlyintegrated modules. The glass was prepared by a typical melting procedure and then mixed with cordierite fillers to fabricate glass/ceramic composite-type LTCC materials. The amount of cordierite filler was fixed at 50 volumetric%. For an optimal glass composition of 7.5% CaO, 7.5% BaO, 5% ZnO, 10% Al₂O₃, 30% B₂O₃, and 40% SiO₂ in mole ratio, the resultant LTCC composite showed a dielectric constant of 5.8 and a dielectric loss (tanδ) of 0.0009 after firing at 900°C. An average bending strength of 160 MPa was obtained for the optimal composition.