A surface acoustic wave element includes a thin film electrode composed of
monocrystal aluminum disposed on a piezoelectric substrate. At least one
metal of Cu, Ta, W, and Ti is segregated in the thin film electrode
composed of monocrystal aluminum. In this surface acoustic wave element,
segregation of Cu or the like occurs in the thin film electrode. Such
segregation is effective to reduce the occurrence of cracks on the
piezoelectric substrate during ultrasonic wave connection for flip chip
mounting. That is, because the occurrence of cracks on the piezoelectric
substrate is reduced, tolerance against the ultrasonic vibration is
advantageously improved in the surface acoustic wave element.