Acoustic wave device

An acoustic wave device comprising:

• piezoelectric substrate;
• a comb-shaped electrode located on the piezoelectric substrate;
• a wiring layer located on the piezoelectric substrate and electrically connected with the comb-shaped electrode;
• a first insulating film located on the piezoelectric substrate, the first insulating film covering the comb-shaped electrode, having an aperture on the wiring layer, and being thicker than the comb-shaped electrode;
• a second insulating film covering an upper surface of the first insulating film and at least a part of a side surface of the first insulating film in the aperture and having a higher moisture resistance than the first insulating film;
• and
• a pad being in contact with the wiring layer exposed by the aperture,
• wherein a width of a part being in contact with the wiring layer of the second insulating film is greater than a thickness of the second insulating film located on an upper part of the side surface of the first insulating film.

An acoustic wave device comprising:

• a piezoelectric substrate;
• a comb-shaped electrode located on the piezoelectric substrate;
• a wiring layer located on the piezoelectric substrate and electrically connected with the comb-shaped electrode;
• a first insulating film located on the piezoelectric substrate, the first insulating film covering the comb-shaped electrode, having an aperture on the wiring layer, and being thicker than the comb-shaped electrode;
• a second insulating film covering an upper surface of the first insulating film and a part of a side surface of the first insulating film in the aperture and having a higher moisture resistance than the first insulating film;
• and
• a pad being in contact with the wiring layer exposed by the aperture, covering at least a part of a portion of the second insulating film that covers the part of the side surface of the first insulating film in the aperture and covering another part of the side surface of the first insulating film that is not covered by the second insulating film.