Low temperature sintering densification and properties of CaO-B2O3-SiO 2 -ZrO 2 glass/Ca 0.99 Cu 0.01 SiO 3 composites for LTCC application

The sintering shrinkage behavior, viscosity, microstructures, phase composition, dielectric properties and chemical compatibility with Ag of a novel low-temperature co-fired ceramic (LTCC) material, (1- x ) CaO-B 2 O 3 -SiO 2 -ZrO 2 (CBSZ) +  x Ca 0.99 Cu 0.01 SiO 3 ( x  = 0, 5, 10, 15 and 20 wt%) glass/ceramics were discussed. The partial dissolution of the Ca 0.99 Cu 0.01 SiO 3 ceramic powder in CBSZ glass will form additional liquid phase and make viscosity decrease, which could promote the densification of CBSZ/Ca 0.99 Cu 0.01 SiO 3 composite. The introduction of Ca 0.99 Cu 0.01 SiO 3 will form heterogeneous nucleus and promote the crystallization of samples. The CBSZ/Ca 0.99 Cu 0.01 SiO 3 composite with 10 wt% Ca 0.99 Cu 0.01 SiO 3 content sintered at 875 ºC for 30 min has a dielectric constant ε r = 6.05, a dielectric loss tan δ  = 1.18 × 10 −3 @ 13.76 GHz, flexural strength = 176 MPa, CTE = 7.7258 × 10 −6 /ºC, and shows good chemical compatibility when co-fired with Ag electrode. These results indicate that CBSZ glass/Ca 0.99 Cu 0.01 SiO 3 ceramic composites have a potential to meet the demand of LTCC applications.