Abstract: Glass is widely used in the field of electronic sealing due to its excellent electrical properties. The low dielectric sealing glass was prepared by high temperature melting method under aluminoborosilicate glass. The properties of the samples were characterized by Raman spectroscopy, thermal expansion coefficient tester, densitometer, bending beam low temperature tester and precision impedance analyzer. The effect of alkali metal oxides on the structure and properties of low dielectric glass was studied. The result shows that when the total content of R₂O remains unchanged, with the increase of Li₂O content, the content of [BO₃] in the glass structure decreases first and then increases, the content of [AlO₄] increases and the content of [AlO₆] decreases. The thermal expansion coefficient of glass decreases first and then increases, and the trend of density change is opposite to the thermal expansion coefficient. All of the above variables have extreme values in the LN-3 (the mass ratio of Na₂O and Li₂O is 1.0:1.0) group. The characteristic temperature of glass increases first and then decreases, and finally increases again when Na₂O is completely replaced. The dielectric constant and dielectric loss of glass decrease first and then increase, and the dielectric constant and dielectric loss of the glass containing mixed alkali metals are lower than that of the glass containing single alkali metal.

Key words: alkali metal oxide, sealing glass, network structure of glass, thermal expansion coefficient, dielectric constant, dielectric loss, density