LAUSR

Silver sintering is used to bond five components together in order to form a piezoelectric sensor. A description is provided of the preparation of these components, and of the manufacturing steps, which are carried out at a low temperature (280 °C). The resulting sensor assemblies are then characterized: Cross-sectional views show that the silver layer has a very dense structure, with less than 1% porosity, although further focused ion beam investigations show that this porosity is closer to 15%. The shear strength is approximately 30 MPa. Young's modulus of the silver bondline is measured using nanoindentation, and is found to be comparable to that of bulk silver (56.6 GPa). Finally, a silver-sintered sensor is compared to a sensor bonded using conventional techniques, showing that an improvement in sensitivity by a factor of more than 3 is achieved.