Dual silver layer Low-E glass coating system and insulating glass units made therefrom

摘要

A sputter-coated glass layer system particularly useful in insulating glass units ("IGs"), which includes dual layers of silver separated by a layer of Si.sub.3 N.sub.4 having a thickness of about 700 -1,100 . ANG. and further including an undercoat and an overcoat of Si.sub.3 N.sub. 4 having thicknesses of about 300 -550 and about 350 -700 respectively, such that a glass so coated achieves normal emissivity values (E.sub.n 's) of less than about 0.02-0.09 with good durability and very low reflectance.