SURFACE ACOUSTIC WAVE ELEMENT, SURFACE ACOUSTIC WAVE DEVICE, SURFACE ACOUSTIC WAVE DUPLEXER AND METHOD FOR MANUFACTURING SURFACE ACOUSTIC WAVE ELEMENT

PROBLEM TO BE SOLVED: To provide a surface acoustic wave element having resistance to ultrasonic vibrations, a surface acoustic wave device, a surface acoustic wave duplexer and a method for manufacturing the surface acoustic wave element. SOLUTION: In this surface acoustic element 12, at least one kind of metal among Cu, Ta, W and Ti is segregated in a thin film electrode 18 provided on a piezoelectric substrate 28 and made of single crystal aluminum. In the surface acoustic wave element 12, segregation of Cu, etc., occurs in the thin film electrode 18, and inventors newly finds out that such segregation is effective to prevent a crack occurring in the piezoelectric substrate 28 at the time of ultrasonic joining of flip chip mounting in an experiment. That is, since a crack is prevented from occurring in the piezoelectric substrate 28 in this way, resistance to ultrasonic vibrations are significantly improved in the surface acoustic wave element 12. COPYRIGHT: (C)2005,JPO&NCIPI