A resonant member of a MEMS resonator oscillates in a mechanical resonance mode that produces non-uniform regional stresses such that a first level of mechanical stress in a first region of the resonant member is higher than a second level of mechanical stress in a second region of the resonant member. A plurality of openings within a surface of the resonant member are disposed more densely within the first region than the second region and at least partly filled with a compensating material that reduces temperature dependence of the resonant frequency corresponding to the mechanical resonance mode.

A moveable micromachined member of a microelectromechanical system (MEMS) device includes an insulating layer disposed between first and second electrically conductive layers. First and second mechanical structures secure the moveable micromachined member to a substrate of the MEMS device and include respective first and second electrical interconnect layers coupled in series, with the first electrically conductive layer of the moveable micromachined member and each other, between first and second electrical terminals to enable conduction of a first joule-heating current from the first electrical terminal to the second electrical terminal through the first electrically conductive layer of the moveable micromachined member.

A moveable micromachined member of a microelectromechanical system (MEMS) device includes an insulating layer disposed between first and second electrically conductive layers. First and second mechanical structures secure the moveable micromachined member to a substrate of the MEMS device and include respective first and second electrical interconnect layers coupled in series, with the first electrically conductive layer of the moveable micromachined member and each other, between first and second electrical terminals to enable conduction of a first joule-heating current from the first electrical terminal to the second electrical terminal through the first electrically conductive layer of the moveable micromachined member.

An acoustic resonator assembly and a filter are disclosed. The acoustic resonator assembly includes at least two acoustic resonators vertically connected to each other. The acoustic resonator includes: an acoustic mirror, a bottom electrode layer, a piezoelectric layer, and a top electrode layer that are arranged on a substrate. An active area of the acoustic resonator is defined by an overlapping area of the acoustic mirror, the bottom electrode layer, the piezoelectric layer, and the top electrode layer. The acoustic resonator further includes a support layer arranged on the substrate or the piezoelectric layer on a periphery of a projection of the acoustic mirror on the substrate. The at least two acoustic resonators are vertically connected to each other through the support layer. The filter significantly reduces the volume and the area of a device, improves design freedom and reduces design difficulty, enhances product performance and greatly reduces costs.

An acoustic wave device includes a support substrate, a piezoelectric layer on the support substrate and including a main surface, a cavity portion between the support substrate and the piezoelectric layer, an IDT electrode on the main surface and including first and second busbars, and first and second electrode fingers respectively connected to the first and second busbars, a wiring electrode on the main surface and connected to the IDT electrode, and a high thermal conductive film in the piezoelectric layer and having a thermal conductivity higher than a thermal conductivity of the piezoelectric layer. A portion of the IDT electrode is in a region overlapping the cavity portion, the high thermal conductive film is in a region overlapping the cavity portion, and at least one of the IDT electrode and the wiring electrode is connected to the high thermal conductive film directly or via a metal.

An acoustic wave device includes a support substrate, a piezoelectric layer on the support substrate and including a main surface, a cavity portion between the support substrate and the piezoelectric layer, an IDT electrode on the main surface and including first and second busbars, and first and second electrode fingers respectively connected to the first and second busbars, a wiring electrode on the main surface and connected to the IDT electrode, and a high thermal conductive film in the piezoelectric layer and having a thermal conductivity higher than a thermal conductivity of the piezoelectric layer. A portion of the IDT electrode is in a region overlapping the cavity portion, the high thermal conductive film is in a region overlapping the cavity portion, and at least one of the IDT electrode and the wiring electrode is connected to the high thermal conductive film directly or via a metal.

An acoustic wave device includes a package substrate including first and second principal surfaces, an acoustic wave element at the first principal surface, a sealing resin layer covering at least a portion of the acoustic wave element, and a metal shield film covering the sealing resin layer. The package substrate includes a ground connection electrode in the package substrate, electrically connected to the acoustic wave element, and connected to a ground potential. The package substrate includes a side surface and a connection portion connected to at least a portion of an end edge on a side with the second principal surface in the side surface and at least a portion of an outer peripheral edge in the second principal surface. The shield film reaches the side surface of the package substrate and does not reach the connection portion, and the shield film is connected to the ground connection electrode.

An acoustic wave device includes a package substrate including first and second principal surfaces, an acoustic wave element at the first principal surface, a sealing resin layer covering at least a portion of the acoustic wave element, and a metal shield film covering the sealing resin layer. The package substrate includes a ground connection electrode in the package substrate, electrically connected to the acoustic wave element, and connected to a ground potential. The package substrate includes a side surface and a connection portion connected to at least a portion of an end edge on a side with the second principal surface in the side surface and at least a portion of an outer peripheral edge in the second principal surface. The shield film reaches the side surface of the package substrate and does not reach the connection portion, and the shield film is connected to the ground connection electrode.

A method for packaging a chip and a chip packaging structure. A passivation layer is provided on bonding pads of a wafer, a first metal bonding layer is formed on the passivation layer, and a second metal bonding layer is formed on a substrate. The substrate and the wafer are bonded via the first metal bonding layer and the second metal bonding layer, and are packaged as a whole. A first shielding layer is provided on the substrate, and the first shielding layer is in contact with the second metal bonding layer. After the wafer and the substrate are bonded, the wafer is subject to half-cutting to expose the first metal bonding layer. Then, the second shielding layer electrically connected to the first metal bonding layer is formed.

A method of manufacturing a resonance device includes preparing a resonance device and adjusting a frequency of the resonator. The resonance device includes a lower lid, an upper lid joined to the lower lid, and a resonator with vibration arms that vibrate in bending vibration in an interior space between the lower and upper lids. The adjusting of the frequency of the resonator includes vibrating the vibration arms in bending vibration and thereby causing respective ends of the arms to strike the lower lid at an impact speed of 3.5×10.sup.3 μm/sec or more. The ends of the vibration arms are made of silicon oxide, and the lower lid is made of silicon.