Dielectric breakdown behavior of oxynitride glass

This study presents the first direct measurement of the dielectric breakdown strength (DBS) of oxynitride glass, providing new insights into its electrical insulation properties. Oxynitride glass was prepared using a blend of Si3N4, SiO2, Y2O3, and MgO powders and formed into thin glass substrates of varying thicknesses. The DBS measurement was conducted by using circular column shape and McKewon electrodes. DBS measurements revealed that the oxynitride glass exhibited consistently slightly lower DBS values than Si3N4 sintered bodies across all tested thicknesses. This finding suggests that DB in Si3N4 predominantly occurs within the grain boundary glass phase. These results, aligning with previous studies on the dielectric breakdown mechanisms of silicon nitride ceramics, confirmed the critical role of the grain boundary glass phase in determining their electrical insulation performance.