Patent ID: 8169121

Claim:
A surface acoustic wave device comprising: a piezoelectric substance including a plurality of grooves in a surface thereof; and an IDT electrode including a plurality of electrode fingers partially disposed in the plurality of grooves; wherein each of the electrode fingers includes a first electrode layer located in the grooves and a second electrode layer disposed on the first electrode layer and located at a position higher than an upper opening of the grooves; and a one-half power of a product of a cube of an average density (ρ a ) of the first electrode layer and an average stiffness (C44 a ) of the first electrode layer [(ρ a 3 ×C44 a ) 1/2 ] is greater than a one-half power of a product of a cube of an average density (ρ b ) of the second electrode layer and an average stiffness (C44 b ) of the second electrode layer [(ρ b 3 ×C44 b ) 1/2 ].