JP6756325B2 - Piezoelectric vibration device - Google Patents

Description

The present invention relates to a piezoelectric vibration device.

In recent years, the operating frequencies of various electronic devices have been increased and the packages have been made smaller (particularly lower in height). Therefore, as the frequency increases and the package becomes smaller, piezoelectric vibration devices (for example, crystal oscillators, crystal oscillators, etc.) are also required to cope with higher frequencies and smaller packages.

In this type of piezoelectric vibrating device, the housing is composed of a substantially rectangular parallelepiped package. This package is composed of a first sealing member and a second sealing member made of glass or quartz, and a crystal diaphragm made of quartz and having excitation electrodes formed on both main surfaces, and is composed of the first sealing member and the first sealing member. The two sealing members are laminated and joined via a crystal diaphragm, and the excitation electrodes of the crystal diaphragm arranged inside the package (internal space) are hermetically sealed (see, for example, Patent Document 1). .. The laminated form of such a piezoelectric vibration device is called a sandwich structure.

Japanese Unexamined Patent Publication No. 2010-252051

Conventionally, a piezoelectric vibration device with a temperature sensor in which a temperature sensor is integrally provided has also been developed. As such a temperature sensor, for example, a chip thermistor made of a sintered body (NTC thermistor or the like) is used. The chip thermistor has an advantage that the B constant is large, but there are concerns about the following problems. That is, in a piezoelectric vibration device provided with a chip thermistor as a temperature sensor, a predetermined space for accommodating the chip thermistor is required, and there is a concern that it will be difficult to cope with the reduction in the height of the package.

The present invention has been made in consideration of the above-mentioned circumstances, and an object of the present invention is to provide a piezoelectric vibration device with a temperature sensor capable of reducing the height of a package.

The present invention constitutes means for solving the above-mentioned problems as follows. That is, the present invention comprises a piezoelectric vibrating plate in which a first excitation electrode is formed on one main surface of the substrate and a second excitation electrode paired with the first excitation electrode is formed on the other main surface of the substrate. A first sealing member covering the first excitation electrode of the piezoelectric vibrating plate and a second sealing member covering the second exciting electrode of the piezoelectric vibrating plate are provided, and the first sealing member and the piezoelectric vibrating plate are provided. The second sealing member and the piezoelectric vibrating plate are joined to each other, and the vibrating portion of the piezoelectric vibrating plate including the first exciting electrode and the second exciting electrode is airtightly sealed. In the device, a temperature sensor unit having a thin film thermista is provided on one main surface of the first sealing member and not facing the piezoelectric vibrating plate, and the second sealing member of the device. The other main surface, which does not face the piezoelectric vibrating plate, is characterized in that an external terminal for a thermista and an external terminal for an excitation electrode are formed .

According to the above configuration, in the configuration in which the temperature sensor unit is arranged on the inner side where the vibration unit is airtightly sealed by the first sealing member and the second sealing member, the low profile of the package of the piezoelectric vibration device with the temperature sensor is provided. Can be achieved. Further, since the temperature sensor unit is provided in the same space as the vibrating unit, the temperature closer to the temperature of the vibrating unit can be detected, and the accuracy of the temperature detection by the temperature sensor unit can be improved.

On the other hand, even in the configuration in which the temperature sensor unit is arranged on the outer side of the space where the vibrating portion is airtightly sealed by the first sealing member and the second sealing member, the temperature sensor portion is configured to have a thin film thermistor. , It is possible to reduce the height of the package of the piezoelectric vibration device with a temperature sensor. In particular, in a configuration in which the temperature sensor unit is arranged only on one main surface of the first sealing member (the main surface not facing the piezoelectric diaphragm), the temperature sensor unit is occupied on one main surface of the first sealing member. The maximum area can be secured. That is, since it is not necessary to form a connection terminal (external terminal) for joining with the external substrate on one main surface of the first sealing member, a wider formation region of the temperature sensor portion can be secured. Further, as compared with the configuration in which the temperature sensor unit is arranged only on one main surface of the second sealing member, in the configuration in which the temperature sensor unit is arranged only on one main surface of the first sealing member, from an external substrate or the like. Since it becomes difficult for the heat of

In the piezoelectric vibration device of the above configuration, the front Symbol external terminal thermistor and electrical path between the thin film thermistor, an external terminal for the excitation electrode and the electrical path between the excitation electrodes, independently of one another It is preferable that

According to the above configuration, the temperature information from the temperature sensor unit output from the external terminal for the thermistor can be used in other electronic components mounted on the external board. For example, using the resistance value data of the temperature sensor unit output from the external terminal for the thermistor and the frequency data of the excitation electrode output from the external terminal for the excitation electrode, temperature compensation or the like is performed by the IC mounted on the external substrate. It will be possible to do.

In the piezoelectric vibration device having the above structure, the electrical path to the previous SL film thermistor, said second sealing member to form through holes, through holes formed in the piezoelectric vibrating plate, and said first sealing It is preferable that the structure includes a through hole formed in the stop member.

According to the above configuration, the electrical path to the thin film thermistor is configured to include the through holes formed in the second sealing member, the piezoelectric diaphragm, and the first sealing member, respectively, and thus the electrical path. (Wiring) can be formed without being exposed to the outside of the piezoelectric vibration device. As a result, oxidation and corrosion caused by exposure of the electrical path (wiring) to the atmosphere can be prevented, and the environmental resistance performance of the piezoelectric vibration device can be improved.

Further, in the configuration in which the temperature sensor unit is arranged on one main surface of the first sealing member, the occupied area of the temperature sensor unit on one main surface of the first sealing member can be secured to the maximum. Further, as compared with the configuration in which the temperature sensor unit is arranged only on one main surface of the second sealing member, in the configuration in which the temperature sensor unit is arranged only on one main surface of the first sealing member, from an external substrate or the like. Since it becomes difficult for the heat of the above to be conducted to the temperature sensor unit, it is possible to detect a temperature closer to the temperature of the vibrating unit, and it is possible to improve the accuracy of temperature detection by the temperature sensor unit.

In the piezoelectric vibration device having the above configuration, it is preferable that an insulating member is interposed between the first sealing member and the thin film thermistor.

According to the above configuration, since the insulating member is interposed between the first sealing member and the thin film thermistor, it is possible to suppress the influence of electrical conduction through the insulating member on the characteristics of the thin film thermistor.

In the piezoelectric vibration device having the above configuration, the thin film thermistor preferably has a configuration including a pair of comb-shaped electrodes and a resistance film sandwiched between the pair of comb-shaped electrodes.

According to the above configuration, the path length of the resistance film sandwiched between the pair of comb-shaped electrodes can be secured longer, and thus a larger B constant can be obtained even with a thin film thermistor having a small size. it can.

In the piezoelectric vibration device having the above configuration, it is preferable that the temperature sensor unit includes a plurality of thin film thermistors connected in parallel.

According to the above configuration, since the temperature sensor unit includes a plurality of thin film thermistors connected in parallel, the combined resistance value of the temperature sensor unit can be reduced, thereby reducing the resistance value of the temperature sensor unit. It can be reduced to a practical level.

According to the present invention, in a piezoelectric vibration device equipped with a temperature sensor, the height of the package can be reduced.

FIG. 1 is a schematic configuration diagram schematically showing each configuration of a crystal oscillator according to the present embodiment. FIG. 2 is a schematic plan view of the first sealing member of the crystal oscillator on the first main surface side. FIG. 3 is a schematic plan view of the first sealing member of the crystal oscillator on the second main surface side. FIG. 4 is a schematic plan view of the crystal diaphragm of the crystal oscillator on the first main surface side. FIG. 5 is a schematic plan view of the crystal diaphragm of the crystal oscillator on the second main surface side. FIG. 6 is a schematic plan view of the second sealing member of the crystal oscillator on the first main surface side. FIG. 7 is a schematic plan view of the second sealing member of the crystal oscillator on the second main surface side. FIG. 8 is a schematic plan view showing a thin film thermistor. FIG. 9 is a schematic cross-sectional view taken along the line X1-X1 of FIG. FIG. 10 is a view corresponding to FIG. 1 of the crystal oscillator according to the modified example 1. FIG. 11 is a view corresponding to FIG. 1 of the crystal oscillator according to the modified example 2. FIG. 12 is a view corresponding to FIG. 1 of the crystal oscillator according to the modified example 3.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, a case where the present invention is applied to a crystal oscillator as a piezoelectric vibration device will be described.

As shown in FIG. 1, the crystal oscillator 101 according to the present embodiment includes a crystal diaphragm 2, a first sealing member 3, and a second sealing member 4. In the crystal oscillator 101, the crystal diaphragm 2 and the first sealing member 3 are joined, and the crystal diaphragm 2 and the second sealing member 4 are joined to form a package 12 having a substantially rectangular parallelepiped sandwich structure. Is configured.

In the crystal diaphragm 2, the first excitation electrode 221 is formed on the first main surface 211 which is one main surface, and the second excitation electrode 222 is formed on the second main surface 212 which is the other main surface. Then, in the crystal oscillator 101, the first sealing member 3 and the second sealing member 4 are joined to both main surfaces (first main surface 211 and second main surface 212) of the crystal diaphragm 2. As a result, the internal space 13 of the package 12 is formed, and the vibrating portion 22 (see FIGS. 4 and 5) including the first excitation electrode 221 and the second excitation electrode 222 is hermetically sealed in the internal space 13.

The crystal oscillator 101 according to the present embodiment has, for example, a package size of 1.0 × 0.8 mm, and is designed to be compact and low in height. Further, with the miniaturization, in the package 12, the electrodes are made conductive by using through holes (through holes) described later without forming castings. Further, the crystal oscillator 101 is configured as a crystal oscillator with a temperature sensor, and a temperature sensor unit for detecting the temperature of the vibrating unit 22 (the temperature of the internal space 13) in the package 12 of the crystal oscillator 101. 5 is provided. In the present embodiment, the temperature sensor unit 5 is provided on the first main surface 311 of the first sealing member 3 (the main surface of the first sealing member 3 opposite to the joint surface with the crystal diaphragm 2). ing.

Next, each member of the crystal diaphragm 2, the first sealing member 3, and the second sealing member 4 in the crystal oscillator 101 described above will be described with reference to FIGS. 1 to 7. In addition, here, each member which is configured as a single unit which is not joined will be described.

As shown in FIGS. 4 and 5, the crystal diaphragm 2 is a piezoelectric substrate made of quartz, and both main surfaces (first main surface 211 and second main surface 212) are flat and smooth surfaces (mirror surface processing). Is formed as. In the present embodiment, as the crystal diaphragm 2, an AT-cut quartz plate that performs thickness sliding vibration is used. In the crystal diaphragm 2 shown in FIGS. 4 and 5, both main surfaces 211 and 212 of the crystal diaphragm 2 are formed as XZ'planes. In this XZ'plane, the direction parallel to the lateral direction (short side direction) of the crystal vibrating plate 2 is the X-axis direction, and the direction parallel to the longitudinal direction (long side direction) of the crystal vibrating plate 2 is the Z'axis. It is said to be the direction. The AT cut is 35 ° around the X axis with respect to the Z axis among the three crystal axes of the artificial quartz, the electric axis (X axis), the mechanical axis (Y axis), and the optical axis (Z axis). This is a processing method that cuts out at an angle tilted by 15'. In the AT-cut quartz plate, the X-axis coincides with the crystal axis of the quartz. The Y'axis and Z'axis correspond to axes tilted 35 ° 15'from the Y and Z axes of the crystal axis of the quartz, respectively. The Y'axis direction and the Z'axis direction correspond to the cutting direction when cutting out the AT-cut quartz plate.

A pair of excitation electrodes (first excitation electrode 221 and second excitation electrode 222) are formed on both main surfaces 211 and 212 of the crystal diaphragm 2. The crystal diaphragm 2 holds the vibrating portion 22 by connecting the vibrating portion 22 formed in a substantially rectangular shape, the outer frame portion 23 surrounding the outer circumference of the vibrating portion 22, and the vibrating portion 22 and the outer frame portion 23. It has a holding portion 24 and a holding portion 24. That is, the crystal diaphragm 2 has a configuration in which the vibrating portion 22, the outer frame portion 23, and the holding portion 24 are integrally provided.

In the present embodiment, the holding portion 24 is provided only at one location between the vibrating portion 22 and the outer frame portion 23. Further, the vibrating portion 22 and the holding portion 24 are basically formed thinner than the outer frame portion 23. Due to such a difference in thickness between the outer frame portion 23 and the holding portion 24, the natural frequencies of the piezoelectric vibrations of the outer frame portion 23 and the holding portion 24 differ, and the piezoelectric vibration of the holding portion 24 causes the outer frame portion 23 to differ. Is less likely to resonate. The formation location of the holding portion 24 is not limited to one, and the holding portion 24 is formed at two locations between the vibrating portion 22 and the outer frame portion 23 (for example, both sides in the −Z ′ axial direction). It may be provided in.

The holding portion 24 extends (projects) from only one corner portion of the vibrating portion 22 located in the + X direction and the −Z ′ direction to the outer frame portion 23 in the −Z ′ direction. As described above, since the holding portion 24 is provided at the corner portion of the outer peripheral end portion of the vibrating portion 22 in which the displacement of the piezoelectric vibration is relatively small, the holding portion 24 is provided at a portion other than the corner portion (center portion of the side). It is possible to suppress the leakage of the piezoelectric vibration to the outer frame portion 23 via the holding portion 24, and it is possible to vibrate the vibrating portion 22 more efficiently as compared with the case where the vibration portion 22 is provided. Further, as compared with the case where two or more holding portions 24 are provided, the stress acting on the vibrating portion 22 can be reduced, and the frequency shift of the piezoelectric vibration caused by such stress is reduced to stabilize the piezoelectric vibration. The sex can be improved.

The first excitation electrode 221 is provided on the first main surface 211 side of the vibrating portion 22, and the second excitation electrode 222 is provided on the second main surface 212 side of the vibrating portion 22. Lead-out wirings (first lead-out wiring 223, second lead-out wiring 224) for connecting these excitation electrodes to external electrode terminals are connected to the first excitation electrode 221 and the second excitation electrode 222. The first lead-out wiring 223 is drawn out from the first excitation electrode 221 and is connected to the connection joint pattern 27 formed on the outer frame portion 23 via the holding portion 24. The second lead-out wiring 224 is drawn out from the second excitation electrode 222 and is connected to the connection joint pattern 28 formed on the outer frame portion 23 via the holding portion 24. As described above, the first lead-out wiring 223 is formed on the first main surface 211 side of the holding portion 24, and the second lead-out wiring 224 is formed on the second main surface 212 side of the holding portion 24.

On both main surfaces (first main surface 211, second main surface 212) of the crystal diaphragm 2, a vibrating side seal for joining the crystal diaphragm 2 to the first sealing member 3 and the second sealing member 4 is provided. Each stop is provided. As the vibration-side sealing portion of the first main surface 211, a vibration-side first joining pattern 251 for joining to the first sealing member 3 is formed. Further, as the vibration side sealing portion of the second main surface 212, a vibration side second joining pattern 252 for joining to the second sealing member 4 is formed. The vibration side first joint pattern 251 and the vibration side second joint pattern 252 are provided on the outer frame portion 23, and are formed in an annular shape in a plan view. The first excitation electrode 221 and the second excitation electrode 222 are not electrically connected to the vibration side first junction pattern 251 and the vibration side second junction pattern 252.

Further, as shown in FIGS. 4 and 5, the crystal diaphragm 2 is formed with five through holes (through holes) penetrating between the first main surface 211 and the second main surface 212. Specifically, the four first through holes 261 are provided in the regions of the four corners (corners) of the outer frame portion 23, respectively. The second through hole 262 is an outer frame portion 23, and is provided on one side of the vibrating portion 22 in the Z'axis direction (in the FIGS. 4 and 5, the −Z'direction side). A connection pattern 253 is formed around the first through hole 261. Further, around the second through hole 262, a connection joint pattern 254 is formed on the first main surface 211 side, and a connection joint pattern 28 is formed on the second main surface 212 side. A first through hole 261 is formed on the outside of the vibration side first joint pattern 251 and the vibration side second joint pattern 252, and a second through hole 262 is formed inside the vibration side first joint pattern 251 and the vibration side second joint pattern 252. Is formed.

In the first through hole 261 and the second through hole 262, through electrodes for conducting the electrodes formed on the first main surface 211 and the second main surface 212 are provided along the inner wall surface of each of the through holes. It is formed. Further, the central portion of each of the first through hole 261 and the second through hole 262 is a hollow through portion that penetrates between the first main surface 211 and the second main surface 212. The through electrode is not limited to the one having the through portion, and may be formed in a solid state without the through portion.

In the crystal diaphragm 2, the first excitation electrode 221 and the second excitation electrode 222, the first lead-out wiring 223, the second lead-out wiring 224, the first joint pattern 251 and the vibration-side second joint pattern 252, and the connection joint pattern 253. , 254, 27, 28 can be formed by the same process. Specifically, these are formed by laminating a base film formed by physical vapor deposition on both main surfaces 211 and 212 of the crystal diaphragm 2 and a physical vapor phase growth on the base film. It can be formed from a bonded film. In this embodiment, Ti (or Cr) is used as the base film, and Au is used as the bonding film.

As shown in FIGS. 2 and 3, the first sealing member 3 is a substantially rectangular parallelepiped substrate formed of quartz, and the second main surface 312 of the first sealing member 3 (on the crystal diaphragm 2). The surface to be joined) is formed as a flat smooth surface (mirror surface processing). In the present embodiment, the same AT-cut quartz plate as the quartz diaphragm 2 described above is used as the first sealing member 3.

As shown in FIG. 2, on the first main surface 311 (outer main surface not facing the crystal diaphragm 2) of the first sealing member 3, in order to detect the temperature of the vibrating portion 22 of the crystal diaphragm 2. The temperature sensor unit 5 of the above is provided. Further, two electrode patterns 37 and two electrode patterns 38 connected to the temperature sensor unit 5 are formed on the first main surface 311 of the first sealing member 3. In the present embodiment, the temperature sensor unit 5 has a structure having a thin film thermistor, but the details of the temperature sensor unit 5 will be described later.

As shown in FIGS. 2 and 3, the first sealing member 3 is connected to the electrode patterns 37 and 38, respectively, and has six throughs penetrating between the first main surface 311 and the second main surface 312. A hole (through hole) is formed. Specifically, four third through holes 322 are provided in the regions of the four corners (corners) of the first sealing member 3. The fourth and fifth through holes 323 and 324 are provided in the A2 direction and the A1 direction of FIGS. 2 and 3, respectively. The directions A1 and A2 in FIGS. 2, 3, 6 and 7 coincide with the −Z ′ direction and the + Z ′ direction in FIGS. 4 and 5, respectively, and are in FIG. 2, FIG. 3, FIG. The B1 and B2 directions of the above correspond to the −X direction and the + X direction of FIGS. 4 and 5, respectively.

In the third through hole 322 and the fourth and fifth through holes 323 and 324, through electrodes for conducting the electrodes formed on the first main surface 311 and the second main surface 312 are provided in each of the through holes. It is formed along the inner wall surface. Further, the central portion of each of the third through hole 322 and the fourth and fifth through holes 323 and 324 is a hollow through portion penetrating between the first main surface 311 and the second main surface 312. The through electrode is not limited to the one having the through portion, and may be formed in a solid state without the through portion.

On the second main surface 312 of the first sealing member 3, a sealing-side first joining pattern 321 is formed as a sealing-side first sealing portion for joining to the crystal diaphragm 2. The first bonding pattern 321 on the sealing side is formed in an annular shape in a plan view. A third through hole 322 is formed on the outside of the sealing-side first joining pattern 321, and fourth and fifth through holes 323 and 324 are formed on the inside of the sealing-side first joining pattern 321.

Further, on the second main surface 312 of the first sealing member 3, a connection pattern 34 is formed around the third through hole 322, respectively. A connection pattern 351 is formed around the fourth through hole 323, and a connection joint pattern 352 is formed around the fifth through hole 324. Further, a connection joint pattern 353 is formed on the opposite side (A2 direction side) of the first sealing member 3 in the long axis direction with respect to the connection joint pattern 351, and the connection joint pattern 351 and the connection joint are joined. It is connected to the pattern 353 by a wiring pattern 33. The connection pattern 353 is not connected to the connection pattern 352.

In the first sealing member 3, the sealing-side first joining pattern 321 and the connecting joining patterns 34, 3513 to 353, and the wiring pattern 33 can be formed by the same process. Specifically, these are formed by laminating a base film formed by physical vapor deposition on the second main surface 312 of the first sealing member 3 and a physical vapor phase growth on the base film. It can be formed from the bonded film. In this embodiment, Ti (or Cr) is used as the base film, and Au is used as the bonding film.

As shown in FIGS. 6 and 7, the second sealing member 4 is a substantially rectangular parallelepiped substrate formed of quartz, and the first main surface 411 (on the crystal diaphragm 2) of the second sealing member 4 The surface to be joined) is formed as a flat smooth surface (mirror surface processing). In the present embodiment, the same AT-cut quartz plate as the quartz diaphragm 2 described above is used as the second sealing member 4.

On the first main surface 411 of the second sealing member 4, a sealing side second joining pattern 421 is formed as a sealing side second sealing portion for joining to the crystal diaphragm 2. The second bonding pattern 421 on the sealing side is formed in an annular shape in a plan view.

The second main surface 412 (outer main surface not facing the crystal diaphragm 2) of the second sealing member 4 is provided with four external electrode terminals 43a to 43d that are electrically connected to the outside. The external electrode terminals 43a to 43d are located at the four corners (corners) of the second sealing member 4, respectively.

As shown in FIGS. 6 and 7, the second sealing member 4 is formed with four through holes (through holes) penetrating between the first main surface 411 and the second main surface 412. Specifically, the four sixth through holes 44 are provided in the regions of the four corners (corners) of the second sealing member 4. The sixth through hole 44 is formed on the outside of the sealing-side second joint pattern 421.

In the sixth through hole 44, through electrodes for conducting conduction of the electrodes formed on the first main surface 411 and the second main surface 412 are formed along the inner wall surface of each of the through holes. Further, the central portion of each of the sixth through holes 44 is a hollow through portion that penetrates between the first main surface 411 and the second main surface 412. Further, on the first main surface 411 of the second sealing member 4, a connection pattern 45 is formed around the sixth through hole 44, respectively. The through electrode is not limited to the one having the through portion, and may be formed in a solid state without the through portion.

In the second sealing member 4, the sealing-side second joining pattern 421 and the connecting joining pattern 45 can be formed by the same process. Specifically, these are laminated with a base film formed by physical vapor deposition on the first main surface 411 of the second sealing member 4 and physically vapor-deposited on the base film. It can be formed from the bonded film. In this embodiment, Ti (or Cr) is used as the base film, and Au is used as the bonding film.

In the crystal oscillator 101 including the crystal diaphragm 2, the first sealing member 3, and the second sealing member 4, the crystal diaphragm 2 and the first sealing member 3 have the vibrating side first bonding pattern 251 and the first sealing member 3. Diffusion bonding (Au-Au bonding) is performed in a state where the sealing side first bonding pattern 321 is overlapped, and the crystal diaphragm 2 and the second sealing member 4 are connected to the vibrating side second bonding pattern 252 and the sealing side second. A package 12 having a sandwich structure shown in FIG. 1 is manufactured by diffusion bonding (Au-Au bonding) in a state where the bonding patterns 421 are overlapped. As a result, the annular sealing portion formed by the diffusion joining of the vibrating side first joining pattern 251 and the sealing side first joining pattern 321 and the vibrating side second joining pattern 252 and the sealing side second joining pattern 421 The internal space of the package 12, that is, the accommodation space of the vibrating portion 22, is hermetically sealed by the annular sealing portion formed by the diffusion bonding of the above. In FIG. 1, the sealing portion formed by the diffusion bonding of the vibrating side first bonding pattern 251 and the sealing side first bonding pattern 321 and the vibrating side second bonding pattern 252 and the sealing side second bonding pattern 251 The illustration of the sealing portion formed by the diffusion bonding of 421 is omitted.

At this time, diffusion bonding (Au-Au bonding) is performed in a state in which the above-mentioned connection bonding patterns are also superposed. Then, by joining the connection patterns to each other, the crystal oscillator 101 can obtain electrical conduction of the first excitation electrode 221 and the second excitation electrode 222, and the external electrode terminals 43c and 43d. Further, electrical conduction of the counter electrodes 51 and 51 of the temperature sensor unit 5 and the external electrode terminals 43a and 43b can be obtained.

Specifically, the first excitation electrode 221 includes a first lead-out wiring 223, a joint portion between a connection joint pattern 27 and a connection joint pattern 353, a wiring pattern 33, a connection joint pattern 351 and a fourth through hole 323. It is connected to the electrode pattern 37 of the first main surface 311 of the first sealing member 3 via the through electrodes inside. The second excitation electrode 222 includes a second lead-out wiring 224, a connection pattern 28, a through electrode in the second through hole 262, a joint portion between the connection joint pattern 254 and the connection joint pattern 352, and a fifth through hole. It is connected to the electrode pattern 37 of the first main surface 311 of the first sealing member 3 via the through electrodes in the 324 in order. The electrode patterns 37 and 37 are the through electrode in the third through hole 322, the joint portion between the connection joint pattern 34 and the connection joint pattern 253, the through electrode in the first through hole 261, and the connection joint pattern 253, respectively. It is connected to the external electrode terminals 43c and 43d via the joint portion with the connection pattern 45 and the through electrode in the sixth through hole 44 in order.

Further, the counter electrodes 51 and 51 of the temperature sensor unit 5 are the electrode pattern 38, the through electrode in the third through hole 322, the joint portion between the connection joint pattern 34 and the connection joint pattern 253, and the first through hole 261. It is connected to the external electrode terminals 43a and 43b via the inner through electrode, the joint portion between the connection joint pattern 253 and the connection joint pattern 45, and the through electrode in the sixth through hole 44 in this order.

In the package 12 manufactured by diffusion bonding, the first sealing member 3 and the crystal diaphragm 2 have a gap of 1.00 μm or less, and the second sealing member 4 and the crystal diaphragm 2 are separated from each other. It has a gap of 1.00 μm or less. That is, the thickness of the bonding material 11 between the first sealing member 3 and the crystal diaphragm 2 is 1.00 μm or less, and the bonding material 11 between the second sealing member 4 and the crystal diaphragm 2 The thickness is 1.00 μm or less (specifically, 0.15 μm to 1.00 μm in the Au-Au junction of the present embodiment). For comparison, the conventional metal paste encapsulant using Sn is 5 μm to 20 μm.

As a result, it is possible to prevent variations in the height of the package 12 of the crystal oscillator 101. For example, unlike the present embodiment, the Sn bonding material in which the gap between the sealing member (the first sealing member 3 and the second sealing member 4 in the present embodiment) and the crystal diaphragm 2 is larger than 1 μm. When such a metal paste encapsulant is used, the metal paste encapsulant is patterned (vibration side first bonding pattern 251 and vibration side second bonding pattern 252, sealing side first bonding pattern 321 and sealing side second. Joining pattern 421) There are variations in the height when forming on the top. Further, even after joining, the heat capacity distribution of the formed patterns (vibration side first joining pattern 251, vibration side second joining pattern 252, sealing side first joining pattern 321, sealing side second joining pattern 421) The gap does not become uniform (the gap between the first sealing member 3 and the crystal diaphragm 2 in the present embodiment, or the gap between the second sealing member 4 and the crystal diaphragm 2 in the present embodiment). Therefore, in the conventional technique, in the case of a structure in which three members of the first sealing member, the second sealing member, and the crystal diaphragm are laminated, a difference occurs in each of the three members. As a result, the three laminated members are joined in a state where they cannot be kept parallel. In particular, this problem becomes remarkable as the height of the package 12 is lowered. Therefore, in the present embodiment, since the upper limit of the gap is set to 1.00 μm, the three members of the first sealing member 3, the second sealing member 4, and the crystal diaphragm 2 are kept in parallel. It can be laminated and joined in a state, and this embodiment can cope with the reduction in height of the package 12. That is, in the present embodiment, it is possible to provide the crystal oscillator 101 having a thin thickness and superior dimensional accuracy even if the package 12 is made low in height. Further, it is possible to suppress the variation in the capacitance between the layers of the crystal unit 101, and it is also possible to suppress the frequency variation caused by this.

In the present embodiment, the crystal oscillator 101 having the above configuration is characterized in that the temperature sensor unit 5 having a thin film thermistor is provided on the first main surface 311 of the first sealing member 3. The features of this embodiment will be described below.

As shown in FIG. 2, the temperature sensor unit 5 has a resistance film (feeling) sandwiched between a pair of counter electrodes 51 and 51 provided in parallel with a predetermined facing interval and a pair of counter electrodes 51 and 51. It is configured to include a hot film) 52. Each counter electrode 51 has a base film (for example, Ti) formed by physical vapor deposition on the first main surface 311 of the first sealing member 3, and a physical vapor phase growth on the base film. It is formed from a laminated electrode film (for example, Au). The counter electrode 51 may be formed integrally with the electrode pattern 38.

The resistance film 52 is formed of a PVD film formed by physical vapor deposition on the first main surface 311 of the first sealing member 3. More specifically, the resistance film 52 can be formed as a reactive sputter film formed by reactive DC magnetron sputtering or reactive RF magnetron sputtering. The resistance film 52 is formed of a material having a predetermined temperature characteristic. For example, the resistance film 52 is formed of a material having a characteristic that the resistance value decreases substantially proportionally as the temperature rises. Examples of the material of such a resistance film 52 include a nitride semiconductor and an oxide semiconductor. For example, there are AlN, CrN, SiN, ZrN and the like. A resistance film 52 may be formed on the first main surface 311 of the first sealing member 3, and a pair of counter electrodes 51, 51 may be formed on the resistance film 52.

According to the present embodiment, the temperature sensor unit 5 is arranged on the outer side of the internal space 13 in which the vibrating unit 22 is airtightly sealed by the first sealing member 3 and the second sealing member 4. Since the portion 5 has a thin film thermistor, the height of the package 12 of the crystal oscillator 101 with a temperature sensor can be reduced. In particular, in a configuration in which the temperature sensor unit 5 is arranged only on the first main surface (the main surface not facing the crystal diaphragm 2) 311 of the first sealing member 3, the first main surface of the first sealing member 3 is provided. The occupied area of the temperature sensor unit 5 on the surface 311 can be secured to the maximum. That is, since it is not necessary to form a connection terminal (external terminal) for joining with the external substrate on the first main surface 311 of the first sealing member 3, a wider formation region of the temperature sensor unit 5 is secured. be able to. Further, the temperature sensor unit 5 is arranged only on the first main surface 311 of the first sealing member 3, as compared with the configuration in which the temperature sensor unit 5 is arranged only on the other main surface 412 of the second sealing member 4. In the configuration, since the heat from the external substrate or the like is less likely to be conducted to the temperature sensor unit 5, the temperature closer to the temperature of the vibrating unit 22 can be detected, and the accuracy of the temperature detection by the temperature sensor unit 5 can be improved.

Further, in the present embodiment, of the four external electrode terminals 43a to 43d formed on the second main surface 412 of the second sealing member 4, the two external electrode terminals 43a and 43b are of the temperature sensor unit 5. It is formed as an external terminal for the thermistor that is electrically connected to the thin film thermistor. In this example, the external electrode terminal 43a at the end in the A2 direction and the end in the B1 direction shown in FIG. 7 and the external electrode terminal 43b at the end in the A1 direction and the end in the B2 direction serve as the thermistor external terminal. ing.

On the other hand, the remaining two external electrode terminals 43c and 43d are formed as external terminals for the excitation electrode that are electrically connected to the first excitation electrode 221 and the second excitation electrode 222. In this example, the external electrode terminal 43c at the end in the A1 direction and the end in the B1 direction shown in FIG. 7 and the external electrode terminal 43d at the end in the A2 direction and the end in the B2 direction serve as the external terminal for the excitation electrode. It has become.

Then, the electrical path for the thermistor between the external terminal for the thermistor and the thin film thermistor of the temperature sensor unit 5, and the electricity for the excitation electrode between the external terminal for the excitation electrode and the first excitation electrode 221 and the second excitation electrode 222. The target pathways are independent of each other. The electrical path for the thermistor is a through hole 44 formed in the second sealing member 4 (in this case, a through hole 44 at the end in the A2 direction and the end in the B1 direction shown in FIGS. 6 and 7 and the through hole 44 in the A1 direction. Through hole 44 at the end in the B2 direction and at the end in the B2 direction, and through hole 261 formed in the crystal diaphragm 2 (in this case, the end in the −X direction and the end in the + Z ′ direction shown in FIGS. Through hole 261 and through hole 261 at the end in the + X direction and the end in the −Z ′ direction), and the through hole 322 formed in the first sealing member 3 (in this case, FIGS. 2 and 3). The configuration includes a through hole 322 at the end in the A2 direction and the end in the B1 direction, and a through hole 322) at the end in the A1 direction and the end in the B2 direction.

On the other hand, the electrical path for the exciting electrode includes the through hole 44 formed in the second sealing member 4 (in this case, the through hole 44 at the end in the A1 direction and the end in the B1 direction shown in FIGS. 6 and 7). , A2 direction end and B2 direction end through hole 44), through hole 261 formed in the crystal diaphragm 2 (in this case, the + X direction end and the + Z'direction shown in FIGS. 4 and 5). Through hole 261 at the end, through hole 261 at the end in the −X direction and the end in the −Z ′ direction), and the through hole 322 formed in the first sealing member 3 (in this case, FIG. 2, FIG. The configuration includes a through hole 322 at the end in the A1 direction and the end in the B1 direction shown in FIG. 3 and a through hole 322) at the end in the A2 direction and the end in the B2 direction.

According to the present embodiment, since the electric path for the thermistor and the electric path for the excitation electrode are provided independently of each other, the temperature information from the temperature sensor unit 5 output from the external terminal for the thermistor can be obtained. , It becomes possible to use it with other electronic parts mounted on an external board. For example, using the resistance value data of the temperature sensor unit 5 output from the external terminal for the thermistor and the frequency data of the first excitation electrode 221 and the second excitation electrode 222 output from the external terminal for the excitation electrode, the external substrate is used. It becomes possible to perform temperature compensation and the like by the IC mounted on the.

Further, since the electrical path for the thermistor is configured to include through holes formed in the second sealing member 4, the crystal diaphragm 2, and the first sealing member 3, respectively, the electrical path (wiring). Can be formed without being exposed to the outside of the crystal oscillator 101. As a result, oxidation and corrosion caused by exposure of the electrical path (wiring) to the atmosphere can be prevented, and the environmental resistance performance of the crystal unit 101 can be improved.

Further, in the present embodiment, the thin film thermistor of the temperature sensor unit 5 is directly formed on the first main surface 311 of the first sealing member 3. This eliminates the need for a bonding material such as solder for mounting the temperature sensor unit 5, unlike the configuration in which the temperature sensor unit having the chip thermistor is used. Further, it is possible to suppress the displacement of the mounting position of the temperature sensor unit 5 at the time of mounting, and it is possible to prevent problems such as a short circuit caused by this.

Here, as shown in FIGS. 8 and 9, for example, the thin film thermistor of the temperature sensor unit 5 includes a pair of comb-shaped electrodes 51a and 51a and a resistance film 52a sandwiched between the pair of comb-shaped electrodes 51a and 51a. It is possible to 8 and 9 show a thin film thermistor formed on an insulating member 5a such as a quartz plate, but the thin film thermistor is formed directly on the first main surface 311 of the first sealing member 3. You may.

As shown in FIGS. 8 and 9, the thin film thermistor is formed over substantially the entire first main surface 511 of the insulating member 5a. The resistance film 52a is formed of a PVD film formed by physical vapor deposition on the first main surface 511 of the insulating member 5a, as in the case of the resistance film 52 (see FIG. 2) described above. More specifically, the resistance film 52a can be formed as a reactive sputter film formed by reactive DC magnetron sputtering or reactive RF magnetron sputtering. Similar to the case of the counter electrode 51 (see FIG. 2) described above, the comb-shaped electrode 51a has a base film (for example, Ti) formed by physical vapor deposition on the resistance film 52a and a physical base film on the base film. It is formed from an electrode film (for example, Au) that is laminated by vapor phase growth. The comb-shaped electrode 51a may be formed on the first main surface 511 of the insulating member 5a, and the resistance film 52a may be formed on the comb-shaped electrode 51a.

The comb-shaped electrode 51a of the thin film thermistor has a configuration in which a large number of branch portions 51c extend in parallel from a base portion 51b provided along the long side direction of the insulating member 5a. Then, the branch portion 51c of one comb-shaped electrode 51a and the branch portion 51c of the other comb-shaped electrode 51a are arranged alternately with a predetermined gap so as not to come into contact with each other. The resistance film 52a is exposed from this gap. That is, the resistance film 52a is provided between the pair of comb-shaped electrodes 51a and 51a facing each other. The width L (FIG. 9) where the resistance film 52a is exposed is such that the pair of comb-shaped electrodes 51a and 51a face each other.

The resistance film 52a is formed in a meandering state from the end portion in the A2 direction and the end portion in the B1 direction of the insulating member 5a to the end portion in the A1 direction and the end portion in the B2 direction. Further, the resistance film 52a is formed in a state of a constant width L (FIG. 9) and a straight road. The path length W of the resistance film 52a is the sum of the lengths at which the pair of comb-shaped electrodes 51a and 51a face each other.

In the temperature sensor unit 5 having such a thin film thermistor, it is possible to secure a longer path length W of the resistance film 52a sandwiched between the pair of comb-shaped electrodes 51a and 51a, whereby the thin film thermistor having a minute size can be used. Even if there is, a larger B constant can be obtained. Specifically, the resistance value of the thin film thermistor is proportional to the width L of the resistance film 52a and inversely proportional to the path length W. Therefore, the resistance value of the thin film thermistor having a larger B constant can be lowered by making the path length W of the resistance film 52a longer and making the width L of the resistance film 52a narrower. Although it is possible to make the path length W of the resistance film 52a longer by forming a thin film thermistor on substantially the entire first main surface 511 of the insulating member 5a, the first main surface 511 of the insulating member 5a A thin film thermistor may be formed only in a part of the region.

Further, as shown in FIG. 8, through holes 53 are provided at the ends of the insulating member 5a in the A2 direction and the B1 direction and the ends in the A1 direction and the B2 direction, respectively. .. In the through hole 53, through electrodes for conducting conduction of the electrodes formed on the first main surface 511 and the second main surface 512 are formed along the inner wall surface of the through hole 53. Further, the central portion of the through hole 53 is a hollow through portion that penetrates between the first main surface 511 and the second main surface 512. The through electrode is not limited to the one having the through portion, and may be formed in a solid state without the through portion.

As shown in FIG. 10, the through electrode of the through hole 53 shown in FIG. 8 is electrically connected when the insulating member 5a of the temperature sensor unit 5 is mounted on the first main surface 311 of the first sealing member 3. Used for. That is, in the modified example 1 shown in FIG. 10, the thin film thermistor is not directly formed on the first main surface 311 of the first sealing member 3, but the first main surface 311 and the thin film of the first sealing member 3 are formed. An insulating member 5a is interposed between the thermistor. When the insulating member 5a is mounted on the first sealing member 3, the directions A1 and A2 in FIG. 8 coincide with the directions A1 and A2 in FIGS. 2 and 3.

Specifically, the joining between the insulating member 5a of the temperature sensor unit 5 and the first sealing member 3 is the case where the above-mentioned first sealing member 3 and the crystal diaphragm 2 are joined (see FIG. 1). Similarly, diffusion bonding (Au-Au bonding) is performed. The connection joining pattern formed on the first main surface 311 of the first sealing member 3 and the connecting joining pattern formed on the second main surface 512 of the insulating member 5a are diffusively joined in a superposed state. Will be done. By joining the connecting joint patterns to each other, electrical conduction of the comb-shaped electrodes 51a and 51a and the external electrode terminals 43a and 43b of the temperature sensor unit 5 can be obtained. The comb-shaped electrodes 51a and 51a of the temperature sensor unit 5 are connected to the through electrode in the through hole 53, the connection pattern for connecting the second main surface 512 of the insulating member 5a, and the first main surface 311 of the first sealing member 3, respectively. Joint with the joint pattern for use, through electrode in the third through hole 322, joint portion between the connection joint pattern 34 and the connection pattern 253, through electrode in the first through hole 261, and the connection pattern 253. It is connected to the external electrode terminals 43a and 43b via the joint portion with the connection pattern 45 and the through electrode in the sixth through hole 44 in order. The bonding between the insulating member 5a and the first sealing member 3 may be a bonding using a brazing material.

According to this modification 1, the insulating member 5a is interposed between the first sealing member 3 and the thin film thermistor of the temperature sensor unit 5, so that the electric conduction through the insulating member 5a is a characteristic of the thin film thermistor. Can be suppressed from affecting. That is, the insulating member 5a can be suitably used as the base material for forming the thin film thermistor of the temperature sensor unit 5. By using the insulating member 5a as a quartz plate, the first sealing member 3, the crystal diaphragm 2, the second sealing member 4, and the insulating member 5a are made of the same material, and strain due to temperature changes is generated. Can be reduced. As a result, the distortion of the entire crystal unit 101 due to the temperature change can be alleviated.

Here, from the viewpoint of reducing the resistance value of the temperature sensor unit 5, it is preferable that the temperature sensor unit 5 includes a plurality of thin film thermistors connected in parallel. 11 and 12 show a modified example in which three thin film thermistors are connected in parallel. In the modified example 2 shown in FIG. 11, the three insulating members 5a of the temperature sensor unit 5 are mounted on the first main surface 311 of the first sealing member 3. On the other hand, in the modified example 3 shown in FIG. 12, two insulating members 5a of the temperature sensor unit 5 are mounted on the first main surface 311 of the first sealing member 3. The number of thin film thermistors may be two or four or more.

Specifically, in the modified example 2 shown in FIG. 11, three insulating members 5a having the same configuration as the insulating member 5a (see FIG. 10) of the above-mentioned modified example 1 are provided, and the first insulating member 5a is provided. A thin film thermistor is formed on 1 main surface 511. The bonding between the insulating member 5a of the temperature sensor unit 5 and the first sealing member 3 is performed by diffusion bonding (Au-Au bonding) as in the case of the above-described modification 1. Similarly, the bonding of the insulating members 5a of the temperature sensor unit 5 is also performed by diffusion bonding (Au-Au bonding). The thin film thermistors formed on the three insulating members 5a are connected in parallel. As a result, the combined resistance value of the temperature sensor unit 5 can be reduced, and the resistance value of the temperature sensor unit 5 can be reduced to a practical level.

In the modified example 3 shown in FIG. 12, a recess 54 is formed on the first main surface 511 of the insulating member 5b mounted on the first main surface 311 of the first sealing member 3, and the bottom surface of the recess 54 is formed. A thin film thermistor is formed on 513. Further, a wall electrode 55 extending to the thin film thermistor is formed on the inner wall surface of the recess 54. An insulating member 5c is further mounted on the insulating member 5b. The insulating member 5c is formed with thin film thermistors on both main surfaces of the first main surface 511 and the second main surface 512. Also in this modification 3, the bonding between the insulating member 5b of the temperature sensor unit 5 and the first sealing member 3 is performed by diffusion bonding (Au-Au bonding) as in the case of modification 1 described above. Will be. Similarly, the bonding of the insulating member 5b and the insulating member 5c of the temperature sensor unit 5 is also performed by diffusion bonding (Au-Au bonding). A total of three thin film thermistors formed on the two insulating members 5b and 5c are connected in parallel. As a result, the combined resistance value of the temperature sensor unit 5 can be reduced, and the resistance value of the temperature sensor unit 5 can be reduced to a practical level. Further, in the modified example 3, the number of insulating members can be reduced by one as compared with the modified example 2, and the height of the package 12 of the crystal oscillator 101 can be reduced.

The embodiments disclosed this time are exemplary in all respects and do not provide a basis for limited interpretation. The technical scope of the present invention is not construed solely by the above-described embodiments, but is defined based on the description of the claims. In addition, the technical scope of the present invention includes all modifications within the meaning and scope equivalent to the claims.

In the above embodiment, the temperature sensor unit 5 having the thin film thermistor is provided on the first main surface 311 of the first sealing member 3, but the temperature sensor unit 5 may be provided at other locations. That is, a temperature sensor unit 5 having a thin film thermistor is provided on at least one main surface of both main surfaces 311, 312 of the first sealing member 3 and both main surfaces 411 and 412 of the second sealing member 4. I just need to be there. In this case, the temperature sensor unit 5 may be provided on only one of the main surfaces 311, 312 of the first sealing member 3 and both main surfaces 411 and 412 of the second sealing member 4. Alternatively, the temperature sensor unit 5 may be provided on two or more main surfaces. For example, the temperature sensor unit 5 may be provided on the first main surface 311 of the first sealing member 3 and the second main surface 412 of the second sealing member 4, respectively.

In a configuration in which the temperature sensor unit 5 is provided on the second main surface 312 of the first sealing member 3 or the first main surface 411 of the second sealing member 4, the first sealing member 3 and the second sealing member 3 and the second sealing member 3 are provided. Since the temperature sensor unit 5 is arranged on the internal space 13 side where the vibrating unit 22 is airtightly sealed by the member 4, the height of the package 12 of the crystal oscillator 101 with the temperature sensor can be reduced. Further, since the temperature sensor unit 5 is provided in the same internal space 13 as the vibrating unit 22, the temperature closer to the temperature of the vibrating unit 22 can be detected, and the accuracy of the temperature detection by the temperature sensor unit 5 can be improved.

In the above embodiment, the temperature sensor unit 5 having the thin film thermistor may be provided with a resistor connected in parallel. The number of resistors may be one or may be plural. The location where the resistor is provided is not particularly limited, and may be provided on the second main surface 412 of the second sealing member 4, for example. By providing such a resistor, the combined resistance value of the temperature sensor unit 5 can be reduced.

In the above embodiment, an electrical path for the excitation electrode between the external terminal for the excitation electrode and the first excitation electrode 221 and the second excitation electrode 222 is provided on the first main surface 311 of the first sealing member 3. Although it is configured to pass through the electrode pattern 37, the electrical path for the excitation electrode may be configured not to pass through the first main surface 311 of the first sealing member 3. In this case, inside the vibrating side first joining pattern 251 and the vibrating side second joining pattern 252 constituting the sealing portion that seals the vibrating portion 22, in other words, inside the internal space 13 in a plan view. It is possible to form a through hole that constitutes an electrical path for the excitation electrode.

In the above embodiment, an AT-cut crystal is used as the crystal diaphragm, but the present invention is not limited to this, and a crystal other than the AT-cut crystal may be used. Further, although AT-cut quartz was used as the first sealing member 3 and the second sealing member 4, the present invention is not limited to this, and crystals other than AT-cut quartz and brittle materials other than quartz (for example, glass and the like) are used. ) May be used. Further, although a quartz plate is used as the insulating member, the present invention is not limited to this, and for example, a glass plate or the like may be used.

Although the case where the present invention is applied to the crystal oscillator has been described above, the present invention can also be applied to a piezoelectric vibration device (for example, a crystal oscillator) other than the crystal oscillator.

The present invention can be used in piezoelectric vibration devices with temperature sensors.

101 Crystal oscillator (piezoelectric vibration device)
2 Crystal diaphragm (piezoelectric diaphragm)
22 Vibrating part 23 Outer frame part 24 Holding part 211 First main surface (one main surface)
212 2nd main surface (other main surface)
221 First excitation electrode 222 Second excitation electrode 3 First sealing member 311 First main surface (one main surface)
312 2nd main surface (other main surface)
4 Second sealing member 411 First main surface (one main surface)
412 2nd main surface (other main surface)
5 Temperature sensor part 51 Opposite electrode 52 Resistance film

Claims (6)

A piezoelectric diaphragm in which a first excitation electrode is formed on one main surface of the substrate and a second excitation electrode paired with the first excitation electrode is formed on the other main surface of the substrate.
A first sealing member covering the first excitation electrode of the piezoelectric diaphragm, and
A second sealing member for covering the second excitation electrode of the piezoelectric diaphragm is provided.
The first sealing member and the piezoelectric vibrating plate are joined, and the second sealing member and the piezoelectric vibrating plate are joined so that the piezoelectric vibrating plate including the first exciting electrode and the second exciting electrode is included. In a piezoelectric vibration device in which the vibrating part of the
A temperature sensor unit having a thin film thermistor is provided on one main surface of the first sealing member that does not face the piezoelectric diaphragm.
Piezoelectricity characterized in that an external terminal for a thermistor and an external terminal for an excitation electrode are formed on the other main surface of the second sealing member that does not face the piezoelectric diaphragm. Vibration device. In the piezoelectric vibration device according to claim 1,
A piezoelectric path characterized in that the electrical path between the external terminal for the thermistor and the thin film thermistor and the electrical path between the external terminal for an excitation electrode and the excitation electrode are independent of each other. Vibration device. In the piezoelectric vibration device according to claim 2,
The electrical path to the thin film thermistor includes a through hole formed in the second sealing member, a through hole formed in the piezoelectric diaphragm, and a through hole formed in the first sealing member. A piezoelectric vibration device characterized by having a configuration including. In the piezoelectric vibration device according to claim 3,
A piezoelectric vibration device characterized in that an insulating member is interposed between the first sealing member and the thin film thermistor. In the piezoelectric vibration device according to any one of claims 1 to 4.
The thin film thermistor is a piezoelectric vibration device having a configuration including a pair of comb-shaped electrodes and a resistance film sandwiched between the pair of comb-shaped electrodes. In the piezoelectric vibration device according to any one of claims 1 to 5.
The temperature sensor unit is a piezoelectric vibration device including a plurality of thin film thermistors connected in parallel.

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