Fabrication and characterization of low temperature co-fired cordierite glass-ceramics from potassium feldspar

Cordierite glass-ceramics for low temperature co-fired ceramic (LTCC) substrates were fabricated successfully using potassium feldspar as the main raw material. The sintering and crystallization behaviors of the glass-ceramics were investigated by the differential scanning calorimetry (DSC), X-ray diffraction (XRD), and field emission scanning electron microscope (FESEM). The results indicated that the glass-ceramics could be highly densified at 850 °C and the cordierite was the main crystalline phase precipitated from the glasses in the temperature range between 900 and 925 °C. The study also evaluated the physical properties including dielectric properties, thermal expansion and flexural strength of the glass-ceramics. The glass-ceramics showed low dielectric constants in the range of 6-8 and low dielectric losses in the range of 0.0025-0.01. The coefficients of thermal expansion (CTEs) are between 4.32 and 5.48 × 10−6 K−1 and flexural strength of the glass-ceramics are 90-130 MPa. All of those qualify the glass-ceramics for further research to be used as potential LTCC substrates in the multilayer electronic substrate field. Additionally, the excess SiO2 acted as a great role in improving the sinterability of the glasses, and the microstructure and dielectric properties of the relevant glass-ceramics.