Influence of fillers on the re-crystallization and dielectric properties of 60ZnO-30B 2 O 3 -10SiO 2 glass

This paper reports re-crystallization behaviour of 60ZnO-30B2O3-10SiO2 pure glass. Influence of different fillers on the re-crystallization is also highlighted. Irrespective of the nature of the filler, glass transition temperature (Tg) remains the same as that of the pure glass at 570 °C. The onset crystallization temperature is enhanced by 15 to 25 °C owing to filler addition. The peak crystallization temperature corresponding to Zn3B2O6, ZnB2O4 and willemite occurs at 735, 810 and 851 °C for the pure glass. In the presence of alumina, gahnite emerges first at 700 °C followed by ZnB2O4 phase. With mullite as filler, initially ZnB2O4 and willemite formed at 700 °C and gahnite phase emerged only at 750 °C and peaks at 787 °C. In the presence of fused silica only ZnB2O4 and willemite phases were observed. The dielectric properties of the pure glass and that of the glass + fillers are also reported. Re-crystallization of various low K phases ensures good dielectric porpertis with reduced glass content after sintenring.