EP2658123

• Murata Manufacturing Co., Ltd.since Sep 27, 2013; EPO record ends Dec 20, 2019

[0001] Provided is an elastic wave device which can be used at high frequencies and in which the Q factor can be enhanced. An elastic wave device (1) includes a supporting substrate (2); a high-acoustic-velocity film (3) stacked on the supporting substrate (2), in which the acoustic velocity of a bulk wave propagating therein is higher than the acoustic velocity of an elastic wave propagating in a piezoelectric film (5); a low-acoustic-velocity film (4) stacked on the high-acoustic-velocity film (3), in which the acoustic velocity of a bulk wave propagating therein is lower than the acoustic velocity of a bulk wave propagating in the piezoelectric film (5); the piezoelectric film (5) stacked on the low-acoustic-velocity film (4); and an IDT electrode (6) stacked on a surface of the piezoelectric film (5).