A numerical method for stress analysis in a SAW resonator

We present an analytical method of stress and strain in a SAW resonator. This can calculate the absolute values of the stress and strain at each precise point over the resonator for any driving condition and frequency. To represent the SAW resonator, we use the Mason's equivalent circuit model which has mechanical ports and electrical ports. The acoustic voltage; Vm and current; Im of the mechanical port at the observation point are obtained as a function of the F-matrices and the electrical driving condition as well as driving frequency. Vm and Im are related to all mechanical components and their absolute values of propagating SAW by Partial Wave Theory. Applying this method, we discuss the stress analysis of SAW resonator filters on several substrates. Driving frequency dependency on stress migration is also discussed.