Investigation of the structure evolution process in sol–gel derived CaO–B2O3–SiO2 glass ceramics

A sol–gel method was used to prepare CaO–B2O3–SiO2 (CBS) glass powder for making low-temperature cofired ceramics. This paper was focused on the mechanism of hydrolysis and polymerization and also on the structural evolution of xerogel at various temperatures. The xerogel was transformed into glass ceramics containing CaSiO3 and CaB2O4 crystalline phases through nucleation and crystallization processes. The results indicated that the xerogel exhibits [BO4] or [SiO4] based three-dimensional network structure whose interstices Ca ions fill in, which becomes more orderly and stable after heat treatments. The CBS glass ceramics through controlled crystallization have a potential as electronic packaging materials.

Research Highlights
► A sol-gel route used for the preparation of Ca-B-S-O glass powder.
► How chemical bonds react during the sol and gel formation was investigated.
► How the sol-gel structure evolves and further adjusted during heat treatment was reported.