Silver loaded glass is a die attach system used principally to attach silicon devices in hermetic package applications. First reported in 1982, the die attach paste material is 81% solids by weight of Ag flake-loaded glass in a 19% by weight organic medium.
Since the die attach material is supplied as a paste, it can be applied using conventional methods for organic die attach materials: stamping or dot transfer, screen printing, extrusion, and positive displacement syringes. Following die attach, the material is dried for approximately 15 minutes at 75°C to evolve the majority of the solvent weight. Organic burn-out of the residual solvent in the paste material is accomplished between 350 and 400°C.
Two key properties of the silver glass system are its low modulus of elasticity and the inherent void-free nature of the material. These properties make the material more attractive than gold-silicon die attach for large die applications. The material also has high temperature durability which makes it more desirable for high power applications compared with polymer die attach materials.
Also see What are the benefits of using silver loaded glass?