Abstract: 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).

Abstract: 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).

Abstract: A piezo-electric substrate is mainly comprised of a base material and a film formed on one main surface of the base material. In the base material, the main surface on which the film is formed is a roughed main surface. The piezo-electric substrate is obtained by forming the film comprised of a material with a coefficient of linear expansion smaller than a coefficient of linear expansion of the base material on the roughened main surface using a thermal spraying method.

Abstract: A piezo-electric substrate is mainly comprised of a base material and a film formed on one main surface of the base material. In the base material, the main surface on which the film is formed is a roughed main surface. The piezo-electric substrate is obtained by forming the film comprised of a material with a coefficient of linear expansion smaller than a coefficient of linear expansion of the base material on the roughened main surface using a thermal spraying method.