Preparation of forsterite-based glass ceramics for LTCC from potassium feldspar

Abstract

A forsterite-based glass ceramic material has been developed from potassium feldspar for low temperature co-fired ceramics (LTCC). The crystalline phases and microstructure of forsterite-based glass ceramics were investigated using X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). The results show only forsterite was formed in temperature range 900–1,050 °C, and sapphirine was formed in temperature range 1,080–1,100 °C. The glass compact could be well densified at 950 °C, and full densification samples were obtained in temperature range 1,000–1,050 °C. The physical properties including dielectric properties, bending strength and thermal expansion of the specimens were also evaluated. The dielectric constants are in the range 7.00–8.25 and dielectric loss is below 0.01 in the frequency range 1–10 MHz. The specimens obtained in temperature range 950–1,100 °C are of high bending strength (69–106 MPa). The linear coefficient of thermal expansion of the specimen sintered at 1,080 °C is 9.76 × 10−6 K−1. All of these qualify the forsterite-based glass ceramic for further investigation as a candidate suitable for applications in LTCC field.