Investigation of accelerated aging characteristics of a SAW filter

The aging characteristics of a longitudinally coupled SAW resonator on 64° LiNbO₃ are examined. The aging of these devices was accelerated by applying a high RF power until catastrophic failure occurred. The insertion was measured while the devices were being aged. A LabView program was used to automate equipment control and data acquisition during the experiment. After the devices had been tested, damage to the electrode metalization was observed using both optical and scanning electron microscopy. The observed damage included acoustically-induced metal migration and substrate damage. A device that had not been aged was laser probed to record the distribution of acoustic power across the device. The relation between the distribution of acoustic power and damage to the electrode metalization is discussed