Fabrication and characterization of B2O3–Al2O3–Na2O glass system for transparent dielectric layer

Glasses within the B 2 O 3 –Al 2 O 3 –Na 2 O system were examined as potential replacements for PbO-based glass frits with low firing temperature (500–600   °C) for transparent dielectric layer of plasma display panel (PDP). The glasses were evaluated for glass transition ( T g ), softening temperature ( T f ), thermal coefficient of expansion ( α ) and dielectric constant ( ε ). The dielectric constant of these glasses was also compared with theoretical data calculated by Appen and Bresker's equation. T g of the glasses varied between 330 and 460   °C and T f was in the region of 350–500   °C. The thermal coefficient of expansion ranged from 7×10 −6 to 10×10 −6   K −1 . The dielectric constant of these glasses was 6–8 within the region of the theoretical value. The T g , T f , α , ε of the selected glass, which was used to prepare transparent dielectric layer in 20   μm thickness, were found to be 449   °C, 476   °C, 8.284×10 −6 /k, 6.84, respectively. All the results suggest that B 2 O 3 –Al 2 O 3 –Na 2 O glasses would be suitable as a potential candidate for Pb-free dielectric layer in PDPs.