MODIFIED OXIDE SOL-GEL (MOSG) SYNTHESIS OF BOROPHOSPHOSILICATE GLASSES AND GLASS-CERAMICS

A modified oxide sol-gel (MOSG) process was used to synthesize boropho sphosilicate glasses and glass-ceramics using boron oxide and phosphor ous pentoxide as starting precursors. The oxide precursors were used t o form alkoxides in situ, which were then hydrolysed and condensed to form borophosphosilicate gels. The dried gels were analysed for their thermal properties and were heat treated accordingly, at a temperature of 800 degrees C, to crystallize the boron phosphate phase. The resul tant xerogels were then analysed for their microstructure. Both pressu reless and hot-pressing techniques were used to sinter the calcined ge ls to form glass-ceramics. The sintered samples were characterized for their microstructure using electron microscopy and evaluated for thei r dielectric properties. Dielectric measurements indicate that the sin tered glass-ceramics possess dielectric constants less than 5 and diss ipation factors less than 0.001 at a frequency of 1 MHz. The results o f these studies show the potential of the oxide sol-gel-derived boroph osphosilicate glass-ceramics for use as substrate materials in microel ectronic packaging.