An electronic device and a method of forming the same are disclosed. An emitter resonator and a reception cap cavity are formed on and in a first wafer, and an emitter cap cavity and a reception resonator are formed in and on a second wafer. After bonding together the first and second wafers, an emitter filter is formed in an emission region, and a reception filter is formed in a receiving region. The method provided in the present invention not only can simplify the fabrication process of the device and improve its accuracy and stability, but also facilitates integration of the emitter and receives filters in a same chip, which results in a higher degree of integration of the device and a more compact package size thereof.

An electronic device and a method of forming the same are disclosed. An emitter resonator and a reception cap cavity are formed on and in a first wafer, and an emitter cap cavity and a reception resonator are formed in and on a second wafer. After bonding together the first and second wafers, an emitter filter is formed in an emission region, and a reception filter is formed in a receiving region. The method provided in the present invention not only can simplify the fabrication process of the device and improve its accuracy and stability, but also facilitates integration of the emitter and receives filters in a same chip, which results in a higher degree of integration of the device and a more compact package size thereof.

When a thick frequency adjustment metal film of a tuning fork-type vibration piece is irradiated with a beam on a wafer for frequency coarse adjustment, projections are possibly formed on a roughened end of the frequency adjustment metal film. Such projections are pressurized and pushed down not to chip off under any impact, so that the risk of frequency fluctuations is suppressed.

When a thick frequency adjustment metal film of a tuning fork-type vibration piece is irradiated with a beam on a wafer for frequency coarse adjustment, projections are possibly formed on a roughened end of the frequency adjustment metal film. Such projections are pressurized and pushed down not to chip off under any impact, so that the risk of frequency fluctuations is suppressed.

A substrate for a surface acoustic wave device or bulk acoustic wave device, comprising a support substrate and an piezoelectric layer on the support substrate, wherein the support substrate comprises a semiconductor layer on a stiffening substrate having a coefficient of thermal expansion that is closer to the coefficient of thermal expansion of the material of the piezoelectric layer than that of silicon, the semiconductor layer being arranged between the piezoelectric layer and the stiffening substrate.

A substrate for a surface acoustic wave device or bulk acoustic wave device, comprising a support substrate and an piezoelectric layer on the support substrate, wherein the support substrate comprises a semiconductor layer on a stiffening substrate having a coefficient of thermal expansion that is closer to the coefficient of thermal expansion of the material of the piezoelectric layer than that of silicon, the semiconductor layer being arranged between the piezoelectric layer and the stiffening substrate.

There is provided a piezoelectric vibrator element which is excellent in vibration characteristics, high in quality, and capable of suppressing a frequency fluctuation after a frequency adjustment. The piezoelectric vibrator element is provided with a piezoelectric plate having a pair of vibrating arm parts, an electrode film disposed on obverse and reverse surfaces of the piezoelectric plate, and weight metal films for a frequency adjustment disposed on the electrode film at the obverse surface side in the vibrating arm parts. The reverse surface of the vibrating arm part has a reverse side exposure part from which the piezoelectric plate is exposed. The obverse surface of the vibrating arm part has an obverse side exposure part from which the weight metal film and the electrode film are removed, and from which the piezoelectric plate is exposed. A whole of the obverse side exposure part overlaps the reverse side exposure part at a distance from the electrode film on the reverse surface viewed from a thickness direction of the piezoelectric plate.

There is provided a piezoelectric vibrator element which is excellent in vibration characteristics, high in quality, and capable of suppressing a frequency fluctuation after a frequency adjustment. The piezoelectric vibrator element is provided with a piezoelectric plate having a pair of vibrating arm parts, an electrode film disposed on obverse and reverse surfaces of the piezoelectric plate, and weight metal films for a frequency adjustment disposed on the electrode film at the obverse surface side in the vibrating arm parts. The reverse surface of the vibrating arm part has a reverse side exposure part from which the piezoelectric plate is exposed. The obverse surface of the vibrating arm part has an obverse side exposure part from which the weight metal film and the electrode film are removed, and from which the piezoelectric plate is exposed. A whole of the obverse side exposure part overlaps the reverse side exposure part at a distance from the electrode film on the reverse surface viewed from a thickness direction of the piezoelectric plate.

Acoustic filters, resonators and methods are disclosed. An acoustic resonator device includes a piezoelectric plate forming a diaphragm and a conductor pattern formed on the piezoelectric plate, the conductor pattern including an interdigital transducer (IDT). Interleaved fingers of the IDT are on the diaphragm. A ratio of the mark of the interleaved fingers to a pitch of the interleaved fingers is greater than or equal to 0.2 and less than or equal to 0.3.

Acoustic filters, resonators and methods are disclosed. An acoustic resonator device includes a piezoelectric plate forming a diaphragm and a conductor pattern formed on the piezoelectric plate, the conductor pattern including an interdigital transducer (IDT). Interleaved fingers of the IDT are on the diaphragm. A ratio of the mark of the interleaved fingers to a pitch of the interleaved fingers is greater than or equal to 0.2 and less than or equal to 0.3.