JP2005286892A - Piezoelectric vibrator with built-in temperature sensor and piezoelectric oscillator using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a piezoelectric vibrator in which a temperature sensor is accommodated in a package for accommodating the piezoelectric blank plate of the piezoelectric vibrator and placed near the piezoelectric blank plate, and to provide a piezoelectric oscillator using the same. <P>SOLUTION: In order to achieve the above object, in the piezoelectric vibrator formed by accommodating the piezoelectric blank plate and hermetically sealing it, the temperature sensor is placed near the piezoelectric blank plate in a piezoelectric vibrator container and the output of the aforementioned temperature sensor is outputted to a terminal outside the piezoelectric vibrator. Also, in the piezoelectric oscillator, the temperature sensor is placed near the piezoelectric blank plate inside the piezoelectric vibrator container and the piezoelectric vibrator is mounted. Thus, the problem can be solved. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

       The present invention relates to a piezoelectric vibrator in which a temperature sensor is housed in a package of a piezoelectric vibrator and placed in the vicinity of a piezoelectric element plate, and a piezoelectric oscillator using the same.

       The piezoelectric vibrator has a temperature characteristic in which the frequency changes depending on the environmental temperature. As an example, an AT-cut quartz crystal unit has characteristics with less frequency deviation over a wider temperature range than other cut quartz crystal units. Among oscillators equipped with crystal resonators with these characteristics, for example, oscillators used in mobile phone terminals, which are one of mobile communication devices, have very high fluctuations in oscillation frequency due to ambient temperature changes. Since it is required to be small and highly accurate, a highly accurate temperature compensated crystal oscillator (Temperature Compensated Crystal Oscillator) with a circuit that compensates the frequency change due to the temperature of the crystal unit in the oscillator has been used. There are many oscillators called Oven Temperature Compensated Crystal Oscillators, which are used in equipment and require a high-accuracy and very stable frequency output. Exists.

       In the temperature compensated crystal oscillator and the thermostatic chamber crystal oscillator described above, a temperature sensor such as a thermistor element or a diode is conventionally used to detect the temperature. In the temperature compensated crystal oscillator described above, a crystal is used as shown in FIG. As shown in FIG. 6, the temperature sensor was placed near the outside of the package of the vibrator, and the temperature sensor was kept at a high temperature by winding a heater that was heated through the current constituting the high-temperature tank, as shown in FIG. 6. It was buried in a heat cylinder made of aluminum die casting.

JP 2001-308640 A JP 2001-60828 A

       The applicant has not found any prior art documents related to the present invention other than the prior art documents specified by the prior art document information described above by the time of filing of the present application.

       However, conventionally, in the above-described temperature compensated crystal oscillator or thermostatic chamber crystal oscillator, the temperature sensor is outside the package of the piezoelectric vibrator, and there is a slight gap between the crystal base plate of the piezoelectric vibrator and the temperature sensor. There is a slight temperature difference between the temperature of the quartz base plate itself to be detected and the detected temperature of the temperature sensor, and as a result, such a temperature sensor is mounted on the piezoelectric vibrator package. There is a problem that the output frequency of the oscillator mounted outside may become unstable with respect to temperature.

       Conventionally, in the above-described temperature compensated crystal oscillator or thermostatic chamber crystal oscillator, the temperature sensor is outside the package housing the piezoelectric element plate of the piezoelectric vibrator, and the crystal element plate of the piezoelectric vibrator and the temperature sensor There is a slight distance between them, and there is a small but obvious temperature difference between the temperature of the quartz base plate itself to be detected and the temperature detected by the temperature sensor. Due to the difference in the thermal time constant of the oscillator, there is a phenomenon in which temperature compensation becomes excessive or insufficient in the case of a temperature compensated crystal oscillator, and in the case of a thermostat crystal oscillator, temperature control is not possible. As a result, the temperature of the thermostatic chamber rises and falls, and as a result, the output frequency of the oscillator may be unstable with respect to the temperature. There has been a Tsu was a problem.

       The present invention has been made on the basis of the technical background as described above. Accordingly, the object of the present invention is to accommodate a temperature sensor in a package that accommodates a piezoelectric element plate of a piezoelectric vibrator. A piezoelectric vibrator placed in the vicinity of a base plate and a piezoelectric oscillator having the piezoelectric vibrator mounted thereon are provided.

       In order to achieve the above object, according to the present invention, there is provided a piezoelectric vibrator comprising a piezoelectric element plate and hermetically sealed, wherein a temperature sensor is placed in the vicinity of the piezoelectric element plate inside the piezoelectric vibrator container. The output of the temperature sensor is output to a terminal outside the piezoelectric vibrator.

       The temperature sensor is a piezoelectric oscillator having a piezoelectric vibrator mounted in the vicinity of the piezoelectric element plate inside the piezoelectric vibrator container.

       With the piezoelectric vibrator of the present invention, the difference between the temperature of the piezoelectric base plate itself to be detected and the temperature detected by the above-described temperature sensor measures the atmosphere inside the hermetically sealed piezoelectric vibrator container, and the piezoelectric base plate Since the temperature sensor is mounted in the vicinity of, the output becomes extremely small. As a result, the output of the temperature sensor can be made extremely stable and accurate with respect to the temperature.

       In addition, with the piezoelectric vibrator of the present invention, the manufacturing yield of the piezoelectric oscillator on which it is mounted can be significantly increased.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
In addition, the same code | symbol in each figure shall show the same object.

       FIG. 1 is a schematic side view of a piezoelectric vibrator 2 in which a temperature sensor 7 of the present invention is placed in the vicinity of a piezoelectric element plate 1 inside a piezoelectric vibrator 2 container. As shown in this figure, the temperature sensor 7 is placed on the inside of the piezoelectric vibrator 2 container on which the piezoelectric element plate 1 is placed, for example, on the insulating substrate directly below the piezoelectric element plate 1, thereby making it possible to compare with the conventional case. The difference between the temperature of the piezoelectric element 1 to be detected and the temperature detected by the temperature sensor 7 is measured, the atmosphere inside the hermetic piezoelectric vibrator 2 container is measured, and the temperature sensor 7 is located in the vicinity of the piezoelectric element 1. Can be very small. The output of the temperature sensor 7 is output to the terminal 8 outside the piezoelectric vibrator 2 and can be connected to the temperature compensation circuit of the piezoelectric oscillator 6. In the schematic drawings of the oscillator and the piezoelectric vibrator 2 according to the present invention, depictions of electrical components and circuit boards for oscillating or controlling the temperature in the thermostat are omitted.

       FIG. 2 shows a piezoelectric vibrator 2 in which a temperature sensor 7 according to another embodiment of the present invention is placed in the vicinity of the piezoelectric base plate 1 inside the piezoelectric vibrator 2 container. It is the schematic front schematic diagram seen from. When the support structure for holding the quartz base plate 1 is in the shape of a rod such as a support pin as shown in this figure, the heat conduction between the outside of the piezoelectric vibrator 2 and the piezoelectric base plate 1 is the inside of the piezoelectric vibrator 2. When there is a vacuum, there is no heat conduction due to the convection of the gas inside the piezoelectric vibrator 2, and most of the heat conduction through the support pin described above is placed on the immediate side of the support pin. It is necessary. In FIG. 3, the temperature sensor 7 is placed on the metal plate 5, but the temperature sensor 7 and the metal plate 7 are electrically insulated and do not short-circuit.

       FIG. 3 is a schematic top view schematically showing the piezoelectric vibrator 2 in which the temperature sensor 7 of the present invention is placed in the vicinity of the piezoelectric element plate 1 inside the container of the piezoelectric vibrator 2 shown in the second embodiment. When viewed from the upper surface direction, that is, the main surface direction of the mounted piezoelectric element 1, the temperature sensor 7 is mounted on the bottom of the concave container 4 directly below the piezoelectric element 1. The temperature sensor 7 may not be placed on the bottom of the piezoelectric vibrator 2 container, but may be placed on the metal plate 5 that forms a lid on the side surface inside the piezoelectric vibrator 2 container or the upper portion of the piezoelectric element plate 1. Needless to say, these cases are also included in the technical scope of the present invention.

       FIG. 4 is a schematic side view of a temperature-compensated oscillator equipped with the piezoelectric vibrator 2 in which the temperature sensor 7 of the present invention is mounted in the vicinity of the piezoelectric element plate 1 inside the container of the piezoelectric vibrator 2. As shown in this figure, a temperature sensor 7 such as a thermistor element or a diode is placed near the piezoelectric element plate 1 inside the piezoelectric vibrator 2 container mounted inside the oscillator. As a result, the difference between the temperature of the piezoelectric element 1 itself to be detected and the temperature detected by the temperature sensor 7 becomes very small, and the output frequency of the oscillator can be remarkably stabilized with respect to the temperature.

       FIG. 5 is a schematic side view of a conventional temperature compensated oscillator, which is a piezoelectric oscillator 6 having a configuration in which the temperature sensor 7 is mounted outside the container of the piezoelectric vibrator 2 as viewed from the side.

       FIG. 6 is a schematic side view of a conventional thermostatic oven oscillator, which is a piezoelectric oscillator 6 having a configuration in which the temperature sensor 7 is placed outside the container of the piezoelectric vibrator 2 as viewed from the side. In FIG. 6, the heat insulating material 9 is inserted so as not to affect the thermostatic bath from changing its temperature from the outside.

FIG. 3 is a schematic side view of a piezoelectric vibrator in which a temperature sensor according to the present invention is placed in the vicinity of a piezoelectric element plate inside a piezoelectric vibrator container. FIG. 5 is a schematic front view schematically showing a piezoelectric vibrator in which a temperature sensor according to another embodiment of the present invention is placed in the vicinity of a piezoelectric element plate inside a piezoelectric element container as viewed from a main surface direction of the inner piezoelectric element plate. is there. FIG. 2 is a schematic top schematic view of the piezoelectric vibrator shown in FIG. 1 in which the temperature sensor of the present invention is placed in the vicinity of the piezoelectric element plate inside the piezoelectric vibrator container. When viewed from the upper surface direction, that is, the main surface direction of the mounted piezoelectric element plate, the temperature sensor is placed on the bottom of the concave container just below the piezoelectric element plate. 1 is a schematic side view of a temperature compensated oscillator equipped with a piezoelectric vibrator in which a temperature sensor according to the present invention is mounted in the vicinity of a piezoelectric element plate inside a piezoelectric vibrator container. FIG. 6 is a schematic side view of a conventional temperature-compensated oscillator having a configuration in which a temperature sensor is placed outside a piezoelectric vibrator container as viewed from the side. FIG. 6 is a schematic side view of a conventional thermostatic oven type oscillator having a configuration in which a temperature sensor is mounted outside a piezoelectric vibrator container, as viewed from the side.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Piezoelectric base plate 2 Piezoelectric vibrator 3 Semiconductor component 4 Concave container 5 Metal plate 6 Piezoelectric oscillator 7 Temperature sensor 8 Outer terminal 9 Heat insulating material

Claims (2)

In a piezoelectric vibrator that houses a piezoelectric element plate and is hermetically sealed,
A piezoelectric vibrator, wherein a temperature sensor is placed in the vicinity of the piezoelectric element plate inside the piezoelectric vibrator container, and an output of the temperature sensor is output to a terminal outside the piezoelectric vibrator.        A piezoelectric oscillator mounting the piezoelectric vibrator according to claim 1.

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