Abstract: An elastic wave device includes a multilayer film provided on a support substrate and including a piezoelectric thin film and a layer other than the piezoelectric thin film, an interdigital transducer electrode provided on one surface of the piezoelectric thin film, and an external connection terminal electrically connected to the interdigital transducer electrode. In a plan view, the multilayer film is partially absent or omitted in a region outside a region where the interdigital transducer electrode is provided, and the elastic wave device further includes a first insulating layer provided on the support substrate in at least a portion of a region where the multilayer film is absent or omitted.

Abstract: In an elastic wave device, a multilayer film including a piezoelectric thin film is provided on a support substrate, an interdigital transducer electrode is provided on one surface of the piezoelectric thin film, a wiring electrode is connected to the interdigital transducer electrode, the wiring electrode includes a lead electrode portion and a pad electrode portion, an external connection terminal is located above the pad electrode portion, the external connection terminal is electrically connected to the pad electrode portion, and the external connection terminal is bonded onto the pad electrode portion on the support substrate so that at least the piezoelectric thin film of the multilayer film is not present below the pad electrode portion.

Abstract: In an elastic wave device, a multilayer film including a piezoelectric thin film is provided on a support substrate, an interdigital transducer electrode is provided on one surface of the piezoelectric thin film, a wiring electrode is connected to the interdigital transducer electrode, the wiring electrode includes a lead electrode portion and a pad electrode portion, an external connection terminal is located above the pad electrode portion, the external connection terminal is electrically connected to the pad electrode portion, and the external connection terminal is bonded onto the pad electrode portion on the support substrate so that at least the piezoelectric thin film of the multilayer film is not present below the pad electrode portion.

Abstract: An elastic wave device includes a multilayer film provided on a support substrate and including a piezoelectric thin film and a layer other than the piezoelectric thin film, an interdigital transducer electrode provided on one surface of the piezoelectric thin film, and an external connection terminal electrically connected to the interdigital transducer electrode. In a plan view, the multilayer film is partially absent or omitted in a region outside a region where the interdigital transducer electrode is provided, and the elastic wave device further includes a first insulating layer provided on the support substrate in at least a portion of a region where the multilayer film is absent or omitted.

Abstract: An elastic wave device includes a piezoelectric substrate and an interdigital transducer electrode. The piezoelectric substrate includes a principal surface with a groove tapered in lateral cross section. The interdigital transducer electrode is arranged on the principal surface such that at least one portion thereof is located in the groove. The interdigital transducer electrode is a laminate including a first conductive layer, a second conductive layer, and a diffusion-preventing layer located between the first conductive layer and the second conductive layer and made of an oxide or nitride of Ti or Cr.

Abstract: A manufacturing method for a boundary acoustic wave device is provided which includes, an IDT electrode, a first dielectric layer, and a second dielectric layer on a piezoelectric substrate. The first dielectric layer is made of a deposited film. A thickness of the IDT electrode is about 10% or more of ?. A difference between a height of the first dielectric layer, measured from an upper surface of the piezoelectric substrate, above a center of an electrode finger of the IDT electrode and a height of the first dielectric layer, measured from the upper surface of the piezoelectric substrate, above a center of a gap between adjacent electrode fingers, i.e., a magnitude of unevenness in an upper surface of the first dielectric layer, is about 5% or less of ?.

Abstract: In the boundary acoustic wave device, an IDT electrode, a first dielectric layer, and a second dielectric layer are provided on a piezoelectric substrate. The first dielectric layer is made of a deposited film. A thickness of the IDT electrode is about 10% or more of ?. A difference between a height of the first dielectric layer, measured from an upper surface of the piezoelectric substrate, above a center of an electrode finger of the IDT electrode and a height of the first dielectric layer, measured from the upper surface of the piezoelectric substrate, above a center of a gap between adjacent electrode fingers, i.e., a magnitude of unevenness in an upper surface of the first dielectric layer, is about 5% or less of ?.

Abstract: In the boundary acoustic wave device, an IDT electrode, a first dielectric layer, and a second dielectric layer are provided on a piezoelectric substrate. The first dielectric layer is made of a deposited film. A thickness of the IDT electrode is about 10% or more of ?. A difference between a height of the first dielectric layer, measured from an upper surface of the piezoelectric substrate, above a center of an electrode finger of the IDT electrode and a height of the first dielectric layer, measured from the upper surface of the piezoelectric substrate, above a center of a gap between adjacent electrode fingers, i.e., a magnitude of unevenness in an upper surface of the first dielectric layer, is about 5% or less of ?.