In an elastic wave device, a substrate includes a piezoelectric predetermined region in a first main surface facing one side in a normal direction of the substrate. An excitation electrode is positioned on the predetermined region. A cover covers the excitation electrode and the first main surface from the one side. A surrounding portion covers a side surface of the substrate and a side surface of the cover, and has insulating properties. A wiring layer includes an external terminal exposed toward the one side, and overlaps the cover and the surrounding portion from the one side. A connection conductor connects the excitation electrode and the external terminal to each other. The connection conductor includes a first portion extending to the external terminal from a position that is closer to the substrate than an upper surface of the cover on the one side. The first portion has a melting point higher than or equal to 450° C.

A packaged surface acoustic wave device is disclosed. the packaged surface acoustic wave device can include a support substrate that includes a conductive via formed therein, a piezoelectric layer over the support substrate, an interdigital transducer electrode over the piezoelectric layer, a roof structure over the interdigital transducer electrode, and a conductive pillar between the support substrate and the roof structure. The conductive pillar supports the roof structure and defines at least a portion of an electrical pathway between the interdigital transducer electrode and the conductive via. The roof structure is configured such that there is no signal communication between the conductive pillar and the roof structure.

Embodiments of the present application provide a wafer level surface acoustic wave filter and a package method, the surface acoustic wave filter includes a wafer, an electrode layer, a supporting wall and a cover plate; wherein, the wafer includes a substrate layer and a piezoelectric thin film layer combined together by wafer bonding, the electrode layer is arranged on a surface of the piezoelectric thin film layer, the supporting wall surrounds between the piezoelectric thin film layer and the cover plate to form a sealed cavity; and the cover plate includes at least a first material layer, which uses the same material as the substrate layer.

A high-frequency module includes a module substrate including an internal wiring pattern, and a SAW filter including a piezoelectric substrate, an electrode pattern on the piezoelectric substrate, a support surrounding the electrode pattern, and a cover on the support covering the electrode pattern to define a hollow space together with the support and the piezoelectric substrate. The module substrate, the cover, and the piezoelectric substrate are disposed in this order in a perpendicular or substantially perpendicular direction with respect to the module substrate, and a shield electrode is provided on a surface of the cover that faces the module substrate or on a surface of the cover that faces the piezoelectric substrate.

An acoustic wave device includes a piezoelectric substrate including a support substrate and a piezoelectric layer on the support substrate, the piezoelectric substrate including a first principal surface on the piezoelectric layer side, and a second principal surface on the support substrate side, an IDT electrode on the first principal surface, a support layer on the support substrate, a cover on the support layer, a through-via electrode provided through the support substrate and electrically connected to the IDT electrode, a first wiring electrode on the second principal surface of the piezoelectric substrate and electrically connected to the through-via electrode, and a protective film on the second principal surface to cover at least a portion of the first wiring electrode. The protective film is provided on an inner side of the support layer when viewed in a direction normal or substantially normal to the second principal surface.

An elastic wave device includes an interdigital transducer electrode, a dielectric film, and a frequency adjustment film are disposed on a LiNbO.sub.3 substrate. When Euler Angles of the LiNbO.sub.3 substrate are within a range of about 0°±5°, within a range of about θ±1.5°, within a range of about 0°±10°, the interdigital transducer electrode includes a main electrode, a film thickness of the main electrode normalized by a wavelength determined in accordance with an electrode finger pitch of the interdigital transducer electrode is denoted as T, and a density ratio of a material of the main electrode to Pt is denoted as r, the film thickness of the main electrode and θ of the Euler Angles satisfy θ=−0.05°/(T/r−0.04)+31.35°.

An acoustic wave device includes an element substrate having piezoelectricity, an interdigital transducer electrode provided on the element substrate, and a mold resin covering the element substrate. When viewed in a cross section, the element substrate includes an interdigital transducer formation region in which the interdigital transducer electrode is provided and a pair of interdigital transducer non-formation regions in which the interdigital transducer electrode is not provided and located on both sides of the interdigital transducer formation region, and a thickness dimension of a center portion, in a width direction, of the interdigital transducer formation region is less than at least one of thickness dimensions of center portions, in the width direction, of the interdigital transducer non-formation regions.

An elastic wave device includes an interdigital transducer electrode, a dielectric film, and a frequency adjustment film are disposed on a LiNbO.sub.3 substrate. When Euler Angles of the LiNbO.sub.3 substrate are within a range of about 0° ± 5°, within a range of about θ ± 1.5°, within a range of about 0° ± 10°, the interdigital transducer electrode includes a main electrode, a film thickness of the main electrode normalized by a wavelength determined in accordance with an electrode finger pitch of the interdigital transducer electrode is denoted as T, and a density ratio of a material of the main electrode to Pt is denoted as r, the film thickness of the main electrode and θ of the Euler Angles satisfy θ = -0.05°/(T/r - 0.04) + 31.35°.

An insulating layer includes a cavity in a portion covering a conductive layer. A through conductor includes an insertion portion inside the cavity and a shoulder portion on a virtual boundary surface with the insertion portion when viewed in a direction parallel or substantially parallel to a main surface. The cavity is located alternately outside and inside an edge of the shoulder portion in a circumferential direction of the shoulder portion when viewed in a direction orthogonal or substantially orthogonal to the main surface. A portion between a portion of the cavity located outside the edge of the shoulder portion and the insertion portion is filled with a portion of the support when viewed in the direction orthogonal or substantially orthogonal to the main surface.

An elastic wave device includes an elastic wave element that includes first support layers provided on a piezoelectric substrate, a second support layer provided on the piezoelectric substrate so as to surround the first support layers when viewed in a plan view, and a cover member provided on the first support layers and the second support layer, a mounting substrate on which the elastic wave element is mounted, and a mold resin provided on the mounting substrate and sealing the elastic wave element. A thickness of each of the first support layers is less than a thickness of the second support layer. The cover member convexly curves towards the piezoelectric substrate so as to be spaced away from the mounting substrate. A space between the mounting substrate and the cover member is filled with the mold resin.