An acoustic wave element (100) according to certain examples includes a piezoelectric body (130), an interdigital transducer (IDT) electrode (140, 150) disposed above the piezoelectric body (130), and a connection electrode (160) disposed above the piezoelectric body (130) and connected to the IDT electrode (140, 150). A first insulation layer (172) covers the connection electrode (160), and a second insulation layer (174a, 174b) covers the IDT electrode (140, 150). The first insulation layer (172) disposed above the connection electrode (160) has a first thickness T in a direction perpendicular to an upper surface of the piezoelectric body (130) and the second insulation layer (174b) disposed above the IDT electrode (150) has a second thickness K in the direction perpendicular to the upper surface of the piezoelectric body (130). The first thickness T is less than the second thickness K based on FIG. 2C and the relevant description.

Described herein is a method of bonding a piezoelectric substrate to a support substrate to form a composite substrate. The piezoelectric substrate has one surface which is positively polarized, and a second surface which is negatively polarized. The method described herein includes the steps of bonding the positively polarized surface of the piezoelectric substrate to one surface of the support substrate by a direct bonding method.

Embodiments of a Surface Acoustic Wave (SAW) device having a guided SAW structure that provides spurious mode suppression and methods of fabrication thereof are disclosed. In some embodiments, a SAW device includes a non-semiconductor support substrate, a piezoelectric layer on a surface of the non-semiconductor support substrate, and at least one interdigitated transducer on a surface of the piezoelectric layer opposite the non-semiconductor support substrate. A thickness of the piezoelectric layer, a SAW velocity of the piezoelectric layer, and an acoustic velocity of the non-semiconductor support substrate are such that a frequency of spurious modes above a resonance frequency of the SAW device is above a bulk wave cut-off frequency of the SAW device. In this manner, the spurious modes above the resonance frequency of the SAW device are suppressed.

An electronic component device includes first and second mount boards, and first, second, and third electronic components. The first electronic component includes a first major surface and a second major surface, and is disposed on the first mount board. The first major surface is positioned closer to the first mount board than the second major surface. The second electronic component includes a third major surface and a fourth major surface, and is disposed on the second mount board. The third major surface is positioned closer to the second mount board than the fourth major surface. The third electronic component includes a fifth major surface and a sixth major surface, and is disposed on the second mount board. The fifth major surface is positioned closer to the second mount board than the sixth major surface. The second major surface directly contacts the fourth and sixth major surfaces, or indirectly contacts the fourth and sixth major surfaces with a bonding layer interposed therebetween.

In an X-ray diffraction diagram of a cordierite sintered body of the present invention, the ratio of the total of the maximum peak intensities of components other than cordierite components to the peak top intensity of the (110) plane of cordierite is 0.0025 or less. Since having a significantly small amount of different phases other than the cordierite components, this cordierite sintered body has a high surface flatness when the surface thereof is mirror-polished.

An electronic component includes an electronic component element including first and second main surfaces, a heat-dissipation accelerating member on the first main surface, a sealing resin layer sealing the electronic component element, and a shielding member provided on the sealing resin layer and electrically connected to the heat-dissipation accelerating member. The heat-dissipation accelerating member includes fourth and fifth main surfaces. The electronic component includes a connecting member disposed on the fifth main surface of the heat-dissipation accelerating member and electrically connecting at least one portion of the heat-dissipation accelerating member and the shielding member. The connecting member has a higher thermal conductivity than the sealing resin layer. The contact area between the heat-dissipation accelerating member and the connecting member is smaller than the area of the fifth main surface.

A surface acoustic wave resonator includes: a piezoelectric substrate; a plurality of metal structures formed on a top surface of the piezoelectric substrate to have a negative profile; and a temperature compensation layer covering the top surface of the piezoelectric substrate and the plurality of metal structures. The surface acoustic wave resonator according to an embodiment of the present invention has a frequency characteristic insensitive to change of profile and has an effect of having a high semi-resonance Q value characteristic.

Methods are described for constructing a mechanical resonating structure by applying an active layer on a surface of a compensating structure. The compensating structure comprises one or more materials having an adaptive resistance to deform that reduces a variance in a resonating frequency of the mechanical resonating structure, wherein at least the active layer and the compensating structure form a mechanical resonating structure having a plurality of layers of materials A thickness of each of the plurality of layers of materials results in a plurality of thickness ratios therebetween.

A filter circuit comprises a main operating unit (MU) arranged in the series signal line providing most of the filter function of the filter circuit. A micro acoustic last series resonator (RL.sub.s) as a last element of the main operating unit in the series signal line is prone to excite a spurious mode that is damped with a final series capacitance (CE.sub.s) circuited between the last element and the antenna terminal (AT).

A surface acoustic wave (SAW) device includes a first interdigital transducer (IDT) and a second IDT each including interdigital electrodes disposed on a first surface of a substrate of piezoelectric material. The SAW device includes a diamond bridge enclosing an air cavity over a wave propagation region on the first surface of the substrate. The diamond bridge has a reduced height and provides improved thermal conductivity to avoid a reduction in performance and/or life span caused by heat generated in the SAW device. A process of fabricating a SAW device includes forming the first IDT and the second IDT in a metal layer on a first surface of a substrate comprising a piezoelectric material, the first IDT and the second IDT disposed in a wave propagation region of the first surface of the substrate, and forming a diamond bridge disposed above the wave propagation region.