US Patent 7615506 Durable tungsten-doped tin-fluorophosphate glasses

Tungsten-doped tin-fluorophosphate glasses are described herein which exhibit excellent humidity resistance, thermal resistance, and have a low glass transition temperature which makes them suitable for low temperature sealing applications, such as for encapsulating electronic components. In one embodiment, these glasses comprise 55-75% Sn, 4-14% P, 6-24% O, 4-22% F, and 0.15-15% W on a weight percent elemental basis.