Effect of NH4H2PO4 content on properties of P-Sn-W-B glass system with ultra-low melting sealing temperature

Abstract The glass structure, thermal and electrical properties and water durability of the P-Sn-W-B glasses, prepared by traditional melt-quenching technique, were examined. The glasses exhibited relatively low transition temperatures (90–150 °C), ultra low sealing temperature (250–300 °C), high electrical resistivity (ρ v  = 10 11–13 Ω·cm), high coefficient of thermal expansion(CTE = 182–230*10 −7 /K), and excellent water durability, could be used as low melting sealing material. With the increasing NH 4 H 2 PO 4 /P 2 O 5 ratio, the O/P ratio increased, from the EDX analysis. The glass structure changed with the composition, the infrared spectra showed that the P O double bonds, O H bending vibration decreased whereas new bonds like P-O-W formed, enhancing the glass structure, also, the water durability of glass was improved.