Fine-sized BaO-ZnO-B2O3-SiO2 (BZBS) glass powders doped with various amount of Na2O were directly prepared by spray pyrolysis at a temperature of 1400 oC. The BZBS glass powders prepared with low amounts of Na2O below 5.7 wt.% of the product had a glass structure with amorphous phases. The glass transition temperature (T g) of the BZBS glass powders was changed from 517.3 to 468 oC when the amount of Na2O added to the product was changed from 0 to 5.7 wt.%. Melting of the glass powders with 1.9 wt.% Na2O occurred at a temperature of 560 oC. On the other hand, melting of the glass powders with 3.8 and 5.7 wt.% Na2O occurred at temperatures of 540 and 520 oC, respectively. The dielectric layers formed from the glass powders with an amount of Na2O added below 5.7 wt.% of the product had high transparencies, above 80%, at a firing temperature of 580 oC. The addition of Na2O to the glass powders improved the transparencies of the dielectric layers at low firing temperatures.

Keywords: Glass powder, Spray pyrolysis, Gas phase reaction.