Abstract: Lead-free glass in SnO-CaO-P₂O₅ ternary system were fabricated by melt quenching method. The glass-forming region, coefficient of thermal expansion (CTE), volume resistivity as well as chemical durability of the glass were investigated by the methods of X-ray diffractometer, thermal expansion instrument, insulation resistance instrument, and grain mass loss method. The results show that the glass-forming region is larger than that of SnO-ZnO-P₂O₅ ternary system. The minimum content of P₂O₅ to form glass phase should be 25mol%, while it increases rapidly to about 40mol% with the increase of CaO amount. Softening temperature (about 445℃) and CTE (9.0×10?6-10.0×10^-6/℃) of the glass are equivalent with those of Pb-based sealing glass. The volume resistivity presents a maximum at about 50mol% P₂O₅ content with the increase of P₂O₅ amount, while it decreases with the increase of SnO amount. Research on the samples of 10SnO-40CaO-50P₂O₅-xSiO₂ system show that with the increase of SiO₂ amount, the CTE decreases from 9.8×10^-6/℃ to 7.6×10^-6/℃ and the volume resistivity increases gradually, while the mass loss decreases gradually in acid and neutral condition and increases in basic condition.

Key words: SnO-CaO-P₂O₅ glass, glass-forming region, modification by doping, lead-free sealing glass