MODIFIED OXIDE SOL-PRECIPITATION (MOSP) APPROACH FOR SYNTHESIZING BOROPHOSPHOSILICATE GLASSES AND GLASS-CERAMICS

A modified oxide sol-precipitation process (MOSP) was used to synthesi ze borophosphosilicate glasses and glass-ceramics utilizing boron oxid e and phosphorous pentoxide precursors. The oxide precursors were used to form alkoxides in situ, which were then partially hydrolyzed. Exce ss ammonium hydroxide was added to initiate a precipitation reaction, The resultant precipitate was centrifuged and separated from the super natant liquid. The thermal properties of the dried precipitates were a nalyzed and the precipitates were accordingly heat treated to 800 degr ees C, in order to crystallize the boron phosphate phase. Pressureless sintering was used to sinter the powders and form glass-ceramics, Mic ro-structures of the sintered samples were then characterized using el ectron microscopy, and the dielectric properties were measured. Dielec tric measurements indicate that the sintered glass-ceramics possess di electric constants less than 4.0 and dissipation factors less than 0.0 01 at a frequency of 1 MHz. Results of these studies show that the mod ified oxide sol-precipitation is a viable approach for synthesizing bo rophosphosilicate glass-ceramics for use as substrate materials in mic roelectronic packaging.