Silicon ultrasonic horns for thin film accelerated stress testing

A technique for generating controlled stress on thin films for accelerated stress testing is presented. Silicon-based ultrasonic horn transducers are designed and used to test thin film wires integrated on the transducers. The Webster horn equation was solved using the inverse design method to generate a constant strain area in the horn. A change of 5 /spl Omega/ (12.5% change) was measured on a gold wire integrated on the horn transducers after a 2 hours cyclic load. Stresses high enough to brake the horn could be generated for fracture study.