The influence of sharp notches on the strength of directly bonded components

The influence of sharp notches in the interface of directly bonded components, of the oxide layer thickness and of the annealing temperature on the tensile strength of bonded samples was investigated. The critical notch intensity factor A(IC) was calculated from the fracture stresses using Finite Element Method (FEM) simulations. In contrast to fracture stress, A(IC) is a material property, that characterizes the atomic bond strength in the interface. Thus, determinations of A(IC) can be used to investigate the influence of bonding conditions on the bond strength, to study the homogeneity of strength properties and to predict theoretically the fracture limit of different anisotropically etched micromechanical wafer-bonded components.