Acoustic wave device and method for manufacturing the same

摘要

Provided are an acoustic wave device and a method for manufacturing the same, the acoustic wave device being effectively prevented from expanding and contracting due to temperature change and having a small frequency shift. The acoustic wave device of the present invention has a piezoelectric substrate (1) having an IDT (2) formed on one principal surface of the piezoelectric substrate (1), and a thermal spray film (3) formed on an opposite principal surface (1b) of the piezoelectric substrate (1), the thermal spray film being of a material having a smaller linear thermal expansion coefficient than the piezoelectric substrate (1) and having grain boundaries and pores (4), at least a part of which is filled with a filling material (5).