A structure and method for integrating a crystal resonator with a control circuit are disclosed. The integration is accomplished by bonding a substrate containing an upper cavity to a device wafer containing both the control circuit and a lower cavity so that a piezoelectric vibrator is sandwiched between the device wafer and the substrate. An increased degree of integration of the crystal resonator and on-chip modulation of its parameters can be achieved by further bonding a semiconductor die to the device wafer. Compared to traditional ones, in addition to being able to integrate with other semiconductor components more easily with a higher degree of integration, the crystal resonator of the present invention is more compact in size and hence less power-consuming.

A structure and method for integrating a crystal resonator with a control circuit are disclosed. The integration is accomplished by bonding a substrate containing an upper cavity to a device wafer containing both the control circuit and a lower cavity so that a piezoelectric vibrator is sandwiched between the device wafer and the substrate. An increased degree of integration of the crystal resonator and on-chip modulation of its parameters can be achieved by further bonding a semiconductor die to the device wafer. Compared to traditional ones, in addition to being able to integrate with other semiconductor components more easily with a higher degree of integration, the crystal resonator of the present invention is more compact in size and hence less power-consuming.

A piezoelectric vibrator having a piezoelectric vibration element that includes a piezoelectric piece and a pair of electrodes that face each other with the piezoelectric piece interposed therebetween; a holder that accommodates the piezoelectric vibration element; a resin layer covering at least one electrode of the pair of electrodes; and a water-repellent layer, which has a lower moisture permeability than the resin layer, between the electrode and the resin layer.

A piezoelectric vibrator having a piezoelectric vibration element that includes a piezoelectric piece and a pair of electrodes that face each other with the piezoelectric piece interposed therebetween; a holder that accommodates the piezoelectric vibration element; a resin layer covering at least one electrode of the pair of electrodes; and a water-repellent layer, which has a lower moisture permeability than the resin layer, between the electrode and the resin layer.

A method for measuring equivalent circuit parameters and resonant frequency of a piezoelectric resonator, by which the phase-frequency curve of the piezoelectric resonator is measured, and the resonant frequency and the anti-resonant frequency are obtained. Then, the slopes of the phase-frequency curve at the resonant frequency and the anti-resonant frequency are respectively measured. The resonant angular frequency and the anti-resonant angular frequency are also calculated. Finally, the equivalent circuit parameters of the piezoelectric resonator are obtained by solving a system of nonlinear equations.

A method for measuring equivalent circuit parameters and resonant frequency of a piezoelectric resonator, by which the phase-frequency curve of the piezoelectric resonator is measured, and the resonant frequency and the anti-resonant frequency are obtained. Then, the slopes of the phase-frequency curve at the resonant frequency and the anti-resonant frequency are respectively measured. The resonant angular frequency and the anti-resonant angular frequency are also calculated. Finally, the equivalent circuit parameters of the piezoelectric resonator are obtained by solving a system of nonlinear equations.

In a piezoelectric resonator device according to an embodiment, an internal space is formed by bonding a first sealing member to a crystal resonator plate and bonding a second sealing member to the crystal resonator plate. The internal space hermetically seals a vibrating part including a first excitation electrode and a second excitation electrode of the crystal resonator plate. Seal paths that hermetically seal the vibrating part of the crystal resonator plate are formed to have an annular shape in plan view. A plurality of external electrode terminals is formed on a second main surface of the second sealing member to be electrically connected to an external circuit board. The external electrode terminals are respectively disposed on and along an external frame part surrounding the internal space in plan view.

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.

A resonator device includes: a base; a resonator element that includes a resonator substrate and an electrode; a conductive layer that is disposed on the base; a metal bump that is disposed between the conductive layer and the resonator element, and that electrically couples the conductive layer and the electrode while bonding the conductive layer and the resonator element; and at least one of a first low elastic modulus layer that is interposed between the base and the conductive layer, that overlaps the metal bump in a plan view of the base, and that has an elastic modulus smaller than that of the metal bump, and a second low elastic modulus layer that is interposed between the resonator substrate and the electrode, that overlaps the metal bump in the plan view of the base, and that has an elastic modulus smaller than that of the metal bump.