Influence of moulding process on strength of glass frit bonded structures

The glass frit layer in wafer-bonded MEMS is subjected to mechanical and thermo mechanical stresses during production steps such as moulding. In this work the influence of the moulding process on the strength and failure of glass frit bonded devices is characterized by numerical and experimental investigations. A finite element model was developed to predict critical stress distributions in the glass frit layer. Reference and preloaded glass frit bonded micro packages were tensile tested to verify whether the stress distributions induced by the moulding process have an influence on the strength. It was shown that the strength decreases after a preload and is strongly influenced by the layout of the micro package