Non-silicon applications of direct bonding

Abstract

Four examples of direct bonding in non-silicon applications will be considered. Fusing, locally by laser scribing or integrally by annealing, gives an increased bond strength, since a chemical reaction or interdiffusion process takes place at the interface. Direct bonding of magnetic materials is a special case due to the contribution of magnetic forces to the bond strength. This process has been used to design an optimized axial-field motor. Direct bonding of an optical-fibre plate and a fluorescent-garnet substrate makes it possible to achieve an electron-microscopic detector with a high resolving power. A polymer direct-bonded to a superfinish-polished metal can be used in an x-ray reflector as a surface-protective element.