JP2011217224A - Constant-temperature piezoelectric oscillator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small-sized direct piezoelectric oscillator of low power consumption, which has the frequency stability of about ±5.0×10.SOLUTION: The constant-temperature piezoelectric oscillator 1 includes a base member 25b, a first printed circuit board 22, an outer oven lower case member 15b, a second printed circuit board 20, a piezoelectric vibrator 5, a first temperature control part 8, and a semiconductor element 10. Further, the constant-temperature piezoelectric oscillator 1 includes a case member 25a for housing an outer oven 15, a third temperature control part 18 for the outer oven 15 and the first printed circuit board 22 together with the base member 25b. The first temperature control part maintains the piezoelectric vibrator 5 at a predetermined temperature, the second temperature control circuit of the semiconductor element 10 maintains the semiconductor element 10 at the predetermined temperature, and the third temperature control part maintains the outer oven 15 at the predetermined temperature.

Description

  The present invention relates to a thermostatic piezoelectric oscillator provided with a thermostatic bath.

A crystal oscillator, which is a frequency control device used in mobile communication base stations and transmission communication equipment,
Conventionally, a constant temperature piezoelectric oscillator that outputs a highly stable frequency without being affected by an external temperature change is known. However, in recent years, various devices are required to be small and light, so that the constant temperature piezoelectric oscillator is also required to be small, light and low in power consumption in order to meet this demand.
Patent Document 1 discloses a constant-temperature piezoelectric oscillation in which the oscillation frequency is not affected by a change in the outside air temperature. FIG. 9 is a cross-sectional view showing a configuration of a conventional thermostatic piezoelectric oscillator 100 using a double thermostatic bath. A conventional constant temperature piezoelectric oscillator 100 includes an oscillation circuit unit 111 including a piezoelectric vibrator 112 and an oscillation circuit component 113, and an inner oven (an inner lower case member 115a and an inner upper case member 115b) that accommodates the oscillation circuit unit 111. 115, an outer oven (outer lower case member 120a, outer upper case member 120b) 120 that accommodates the inner oven 15, a base printed circuit board 125 that supports them, and an outer side for covering the outer oven 120 and the base printed circuit board 125 A metal case (a lower metal case member 130a and an upper metal case member 130b) 130.

An inner printed board 116 is disposed in the inner oven 115, and the piezoelectric vibrator 1
12. Supports the oscillation circuit component 113. An outer printed circuit board 121 is disposed in the outer oven 120 and supports the inner oven 115, the heater 122, and the temperature control circuit components of the heater 122. The base printed circuit board 125 is the outer oven 120.
The heater 126 and the temperature control circuit component of the heater 126 are supported. The inner printed circuit board 116 and the outer printed circuit board 121 are electrically and mechanically connected by the connection pins P1, and the outer printed circuit board 121 and the base printed circuit board 125 are electrically and mechanically connected by the connection pins P2. Has been. Further, the pin P3 whose upper portion is fixed to the base printed board 125 passes through a hole provided in the lower metal case member 130a through an insulating material.
The joint between the outer lower case member 120a and the outer upper case member 120b constituting the outer oven 120 is hermetically sealed with a sealing material such as resin or solder over the entire circumference. Further, the joint 131 between the lower metal case member 130a and the upper metal case member 130b constituting the outer metal case 130 is hermetically sealed by a sealing material 140 such as resin or solder over the entire circumference. .
Since the outer metal case 130 and the outer oven 120 are hermetically sealed, the inner temperature of the outer oven 120 is kept constant even when the outside air temperature changes, and thus it is disclosed that a highly stable constant temperature piezoelectric oscillator can be realized. ing.

Japanese Patent No. 4270158

However, the constant temperature piezoelectric oscillator disclosed in Patent Document 1 is an outer oven 120.
An inner oven 115 is disposed inside the inner oven 115, and a so-called dual-structure thermostatic chamber that contains temperature-sensitive components such as a piezoelectric vibrator and an oscillation circuit with respect to frequency stability is used inside the inner oven 115. Yes. For this reason, although the frequency stability of the constant temperature type piezoelectric oscillator can be obtained, the inner oven 115 becomes large to accommodate many parts such as a piezoelectric vibrator and an oscillation circuit, and the inner oven 115 is maintained at a constant temperature. A large amount of power is required. Furthermore, the outer oven 120 that accommodates the large inner oven 115 becomes larger and consumes more power. The high power consumption constant temperature type piezoelectric oscillator has a problem of going against the recent reduction in power consumption.
In addition, when the inner oven 115 is large, there is a problem that the rise time of the constant temperature type piezoelectric oscillator (the time from when the power is turned on until the standard frequency stability is reached) becomes long.
The present invention has been made in order to solve the above-described problem. Regarding frequency stability, temperature-sensitive temperature control units are separately arranged so that the temperature is suitable for each temperature control unit. It is another object of the present invention to provide a constant temperature type piezoelectric oscillator in which a part of these is housed in a single semiconductor element, thereby reducing power consumption and shortening the rise time.

SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

Application Example 1 A constant temperature piezoelectric oscillator including the constant temperature type piezoelectric vibrator of the present invention, a base member, a first printed circuit board, a second printed circuit board, a semiconductor element, and an outer oven. The first printed circuit board is connected and supported by a first connection pin at a position separated from the upper surface of the base member, and the second printed circuit board is secondly disposed at a position separated from the upper surface of the first printed circuit board. The outer oven is connected and supported by a second connection pin, and the first temperature control unit includes a first heat generating component, a first temperature sensing element, and a first temperature control circuit. And the second temperature control unit includes a second heat generating component, a second temperature sensing element, and a second temperature control circuit, and the third temperature control unit includes a third heat generating component and a third temperature sensitive sensor. The piezoelectric vibration comprising an element and a third temperature control circuit Is supported at a position spaced apart from the second printed circuit board, the first heat generating component is disposed adjacent to the piezoelectric vibrator, and the semiconductor element includes an oscillation circuit and a second temperature control unit. And mounted on the second printed circuit board, wherein the outer oven houses the second printed circuit board, the piezoelectric vibrator, the oscillation component, the first temperature control unit, and the semiconductor element, and The heat generating component 3 is a constant temperature piezoelectric oscillator characterized in that the piezoelectric oscillator for heating the outer oven is provided.

In the conventional constant temperature type piezoelectric oscillator, the piezoelectric oven and the oscillation circuit are accommodated in the inner oven, and the double thermostatic chamber method in which the inner oven is accommodated in the outer oven is used.
In the constant temperature type piezoelectric oscillator of the present invention, a first temperature control unit that maintains the temperature of the piezoelectric vibrator at a top temperature (zero temperature coefficient temperature), and a second temperature control unit that maintains the oscillation circuit at a constant temperature, Dividing into two, each temperature control circuit is controlled to the optimum temperature independently of each other. Further, by accommodating the oscillation circuit and the second temperature control unit in one semiconductor element, the power consumption of the constant temperature type piezoelectric oscillator can be reduced, the shape and size thereof can be reduced, and the rise time can be shortened. it can.

Application Example 2 In the constant temperature piezoelectric oscillator of the present invention, the set temperature of the first temperature control unit is set to the temperature of the zero temperature coefficient of the piezoelectric vibrator, and the set temperature of the third temperature control unit Is set in the range of the upper limit of the temperature of the constant temperature type piezoelectric oscillator plus about 2 ° C. to about 5 ° C., and the set temperature of the second temperature control circuit of the semiconductor element is the first and third temperature control. It is preferable that the temperature is set between each set temperature.

The set temperature of the first temperature control unit is set to the apex temperature (zero temperature coefficient temperature) of the piezoelectric vibrator, the set temperature of the third temperature control unit is set to the use temperature upper limit plus about 2 ° C. to about 5 ° C., By setting the set temperature of the temperature control circuit to an intermediate temperature between the set temperature of the first temperature control unit and the set temperature of the third temperature control unit, the power consumption of the constant temperature type piezoelectric oscillator can be minimized. There is an effect that can be done.

Application Example 3 In the constant temperature piezoelectric oscillator of the present invention, the power consumption of each of the first temperature control unit, the second temperature control circuit, and the third temperature control unit is the third temperature control. The power consumption amount of the first temperature control unit is preferably larger than the power consumption amount of the first temperature control unit, and the power consumption amount of the first temperature control unit is preferably larger than the power consumption amount of the second temperature control circuit.

The respective power consumption amounts of the first temperature control unit, the second temperature control circuit, and the third temperature control unit are:
By increasing the power consumption of the second temperature control circuit, the power consumption of the first temperature control unit, and the power consumption of the third temperature control unit in this order, the total power consumption of the constant temperature piezoelectric oscillator is minimized. There is an effect that can be made.

(A) is a schematic cross-sectional view showing the structure of a constant temperature piezoelectric oscillator according to the present invention, (b) is an oscillation circuit, a heating element, a second temperature sensing element, and a second temperature control circuit formed in a semiconductor element. The figure which shows schematic arrangement | positioning. The figure which shows the ambient temperature versus power consumption of the conventional constant temperature type piezoelectric oscillator. The figure which shows the ambient temperature vs. power consumption of the constant temperature type piezoelectric oscillator of this invention. The figure which shows the frequency temperature characteristic of a constant temperature type piezoelectric oscillator when both a piezoelectric vibrator and an oscillation circuit are set to 85 degreeC. The figure which shows the frequency temperature characteristic of the conventional constant temperature crystal oscillator when an inner oven is set to 85 degreeC and an outer oven is set to 75 degreeC. The figure which shows the frequency temperature characteristic of the constant temperature type piezoelectric oscillator 1 at the time of setting a piezoelectric vibrator to 85 degreeC and an oscillation circuit to 77 degreeC. The figure which shows the frequency temperature characteristic of the conventional constant temperature crystal oscillator when an inner oven is set to 77 degreeC and an outer oven is set to 75 degreeC. The figure which shows the frequency temperature characteristic of the constant temperature type piezoelectric oscillator of this invention when a piezoelectric vibrator is set to 85 degreeC and an oscillation circuit is set to 75 degreeC. Sectional drawing which shows the structure of the conventional constant temperature crystal oscillator.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1A is a schematic cross-sectional view showing a configuration of a constant temperature piezoelectric oscillator 1 according to an embodiment of the present invention, and FIG. 1B is a schematic view of an arrangement of circuits and the like in a semiconductor integrated device. It is. The constant temperature type piezoelectric oscillator 1 of the present invention includes a base member 25b for mounting on a motherboard of a device using the constant temperature oscillator, and a base member 25b.
A first printed circuit board 20 that is electrically and mechanically connected and supported by a first connection pin P1 extending from the base member 25b at a position separated from the upper surface, and a first position at a position separated from the upper surface of the first printed circuit board 20. The outer oven lower case member 15b that is electrically and mechanically connected and supported by the second connection pins P2 extending from the printed circuit board 20 and the holes provided in the outer oven lower case member 15b penetrate through the insulating material. And a second printed circuit board 22 that is electrically and mechanically connected and supported by the extending second connection pins P2.
Further, the constant temperature piezoelectric oscillator 1 of the present invention includes a piezoelectric vibrator 5 supported by the second printed circuit board 22 in a thermally non-coupled state, and a first temperature for controlling the temperature of the piezoelectric vibrator 5 to a constant temperature. A temperature control unit.
Furthermore, the constant temperature piezoelectric oscillator 1 according to the present invention accommodates and seals each of the components mounted and supported on the second printed circuit board 22 and the second printed circuit board 22 between the outer oven lower case member 15b. An outer oven upper case member 15a to be stopped, a third temperature control unit for controlling the internal temperature of the outer oven 15 comprising the outer oven lower case member 15b and the outer oven upper case member 15a to a constant temperature, and a base member 25b. And a case member 25a for accommodating and sealing the outer oven 15 and the first printed circuit board 22 between them.

The first temperature control unit is for maintaining the piezoelectric vibrator 5 at a constant temperature, and is a first heat generating component 6 (for example, a power transistor, a heater, etc.) that is thermally uncoupled from the second printed circuit board 20. ), A first temperature sensing element 7 for detecting the ambient temperature, and a first temperature control circuit component 8 having a function of controlling to a predetermined constant temperature.
As shown in the layout diagram of FIG. 1B, the semiconductor element 10 includes an oscillation circuit 11 on a semiconductor substrate such as silicon, a heating element 12 that heats the temperature of the semiconductor element 10 itself to a predetermined temperature, and the semiconductor element 10. The temperature sensor 13 includes a second temperature sensing element 13 that detects the temperature inside the second temperature control circuit 14 and a second temperature control circuit 14 that controls the semiconductor element 10 to a predetermined constant temperature.
The third temperature control unit includes a third heat generating component 16 (for example, a power transistor or a heater) for heating the outer oven 15, a third temperature sensing element 17 that detects the temperature of the outer oven 15, and the outer oven 15. And a third temperature control circuit component 18 for controlling the temperature of the current to a predetermined constant temperature.

In the case of the embodiment shown in FIG. 1, the case member 25a and the base member 25b, the outer oven upper case member 15a, and the outer oven lower case member 15b are all examples made of metal. Each of the case member 25b and the outer oven lower case member 15b is provided with a plurality of holes,
A hermetic terminal or the like is soldered to these holes to form a first connection pin P1 and a second connection pin P2, respectively.
In the assembly of the constant temperature type piezoelectric oscillator 1 of the present invention, a predetermined hermetic terminal or the like is soldered to the base member 25b and the outer oven lower case member 15b. Next, after mounting the first temperature control circuit component 8 and the semiconductor element 10 on the surface of the second printed circuit board 22, the cover member 9 covers the upper part of the semiconductor element 10 as necessary with respect to frequency stability. And is fixed to the second printed circuit board 22.

Next, the back surface of the second printed circuit board 22 (surface opposite to the surface on which the semiconductor element 10 is mounted)
The piezoelectric vibrator 5 is mounted on the first and the first heat generating component 6 and the first temperature sensing element 7 are bonded and fixed to the can case of the piezoelectric vibrator 5, and the respective terminals are soldered to the second printed circuit board 22. To do. Outer oven lower case member 15b in a plurality of holes provided in the second printed circuit board 22 on which the component is mounted.
The second connection pin P2 is passed through and fixed by soldering or the like. The outer oven lower case member 15b is covered with the outer oven upper case member 15a, and resin (for example, epoxy resin), solder, or the like is formed over the entire circumference of the joint portion between the outer oven upper case member 15a and the outer oven lower case member 15b. Hermetically seal with the sealing material. The third heat generating component 16 and the third temperature sensing element 17 are bonded and fixed to the outside of the outer oven upper case member 15a.
Next, after mounting the third temperature control circuit component 18 on the first printed circuit board 20, the second connection pin P <b> 2 extending from the outer oven 15, the heat generating component 16 and the third temperature sensing element 17.
The terminal extending from the terminal is connected and fixed to the first printed circuit board 20.
The first connection pin P1 of the base member 25b is passed through a hole provided in the first printed circuit board 20 and soldered. Covering the base member 25b with the case member 25a, the case member 25a,
The constant temperature piezoelectric oscillator 1 is completed by hermetically sealing with a sealing material such as resin (for example, epoxy resin) or solder over the entire circumference of the joint with the base member 25b.
In the above description, the case member 25a and the base member 25b are made of metal. However, the base member 25b may be a base printed board for surface mounting.

In the semiconductor element 10, an oscillation circuit 11, a heating element 12, a second temperature sensing element 13, and a second temperature control circuit 14 are formed in proximity to a semiconductor substrate such as silicon. Since the heat conductivity of silicon material is about twice that of iron, heat can be directly transferred from the heating element 12 to the oscillation circuit 11 through the substrate, so that heat loss compared to heat conduction by radiant heat. The oscillation circuit 11 can be held at a predetermined constant temperature with a small amount of power. As the second temperature sensing element 13, one diode characteristic or characteristics of several diodes connected in series may be used, or a transistor element may be used as a diode. A thermistor may be disposed in the vicinity of the semiconductor element 10 and used as the second temperature sensitive element 13.
For example, when an SC cut crystal resonator is used as the piezoelectric vibrator 5, an example of the apex temperature Tp indicating the zero temperature coefficient is around 85 ° C., and the set temperature of the first temperature control unit (piezoelectric vibrator 5) is 85 ° C.
Set near. On the other hand, an example of the use temperature range of the constant temperature type piezoelectric oscillator 1 is −30 ° C. to 70 ° C., and an example of the set temperature of the third temperature control unit (outer oven 15) is approximately 2 than the upper limit temperature of the use temperature range. The temperature is set to about 5 ° C., for example, about 75 ° C. The set temperature of the second temperature control unit (the oscillation circuit 11 of the semiconductor element 10) is the third temperature in consideration of the required frequency stability.
The temperature is set between the set temperature 75 ° C. of the temperature control unit and the set temperature 85 ° C. of the first temperature control unit.

A feature of the present invention is that a variable capacitance element (varicap) that varies the temperature of the piezoelectric vibrator (first temperature control unit) 5 related to the frequency stability of the constant temperature piezoelectric oscillator 1 and the output frequency of the constant temperature piezoelectric oscillator 1. Semiconductor element (second temperature control unit) 1 in which an oscillation circuit 11 including a diode or the like is formed
An outer oven 15 that controls the temperature of 0 independently of each other and further accommodates the piezoelectric vibrator (first temperature control unit) 5 and the semiconductor element (second temperature control unit) 12 is provided. This is a constant-temperature piezoelectric oscillator that is reduced and downsized.
The set temperature of the piezoelectric vibrator (first temperature control unit) 5 is preferably set to the apex temperature (zero temperature coefficient temperature) Tp of the frequency temperature characteristic, and the set temperature of the semiconductor element (second temperature control unit) 12 is Although it is necessary to set the outer oven (third temperature control unit) 15 higher than the outer oven (15), it is only necessary that the second temperature control unit 10 can always maintain a constant temperature with respect to a change in the external ambient temperature. In other words,
The set temperature of the piezoelectric vibrator (first temperature control unit) 5 and the set temperature of the semiconductor element (second temperature control unit) 10 do not need to be the same temperature. Thus, by dividing the temperature control unit and controlling the temperature to a suitable temperature, it is possible to reduce power consumption.
The power consumption of the constant temperature piezoelectric oscillator 1 of the present invention having the same frequency stability (± 5 × 10 ⁻¹⁰ ) is compared with the power consumption of the conventional constant temperature piezoelectric oscillator 100 shown in FIG. FIG.
Indicates the set temperature of the inner oven 115 of the constant temperature type piezoelectric oscillator 100 as a piezoelectric vibrator (SC
The top temperature Tp (zero temperature coefficient temperature) of the cut crystal resonator 112 is set to 85 ° C., and the set temperature of the outer oven 120 is 75 ° C. higher by 5 ° C. than the upper limit 70 ° C. of the operating temperature range.
It is the figure which plotted the power consumption of oven with respect to ambient temperature, when setting to (degreeC). The black triangle ▲ is the power consumption of the inner oven 115, and the white square □ is the outer oven 120
The black diamond ◆ indicates the total power consumption.

3 shows the set temperature of the piezoelectric vibrator 5 (first temperature control unit) of the constant temperature piezoelectric oscillator 1 shown in FIG. 1 as the apex temperature (zero temperature coefficient temperature) of the piezoelectric vibrator (SC cut crystal vibrator) 5. ) Set to 85 ° C., which is an example of Tp, and set the set temperature of the outer oven 15 (third temperature control unit) to 75 ° C., which is 5 ° C. higher than 70 ° C., which is an example of the upper limit of the operating temperature range. (Second temperature control unit) FIG. 10 is a diagram in which power consumption is plotted against ambient temperature (external temperature) when the set temperature of 10 is set to an intermediate between 75 ° C. and 85 ° C. The black triangle ▲ indicates the power consumption of the first temperature control unit (piezoelectric vibrator 5), the x mark indicates the power consumption of the second temperature control unit (semiconductor element 10), and the white square □ indicates the power consumption of the outer oven 15. The black diamond ◆ indicates the total power consumption.
The power consumption of the conventional constant temperature type piezoelectric oscillator 100 with respect to changes in the ambient temperature, and the power consumption of the constant temperature type piezoelectric oscillator 1 of the present invention using the oscillation circuit unit 11 and the second temperature control unit 14 as semiconductor elements, Comparison was made in FIG. 2 and FIG. As in the constant temperature type piezoelectric oscillator 1 of the present invention, the temperature control unit in the outer oven 15 is divided into temperature-sensitive parts with respect to frequency stability, and each part sets a temperature suitable for the frequency stability. It was found that the total power consumption can be reduced by doing so. In addition, if the temperature control unit is divided in this way and at least one of them is formed as a semiconductor element, the constant temperature piezoelectric oscillator can be reduced in size.
Next, the temperature of the piezoelectric vibrator (first temperature control unit) 5 of the constant temperature type piezoelectric oscillator 1 of the present invention is set to 85 ° C. of the apex temperature (zero temperature coefficient point) Tp, and the outer oven 15 (third temperature control unit). ) Is set to 75 ° C., and the frequency temperature characteristic of the thermostatic piezoelectric oscillator 1 changes when the set temperature of the semiconductor element (second temperature control unit) 10 including the oscillation circuit 11 is changed. It was measured.

FIG. 4 shows the temperature of the semiconductor element (second temperature control unit) 10 as a piezoelectric vibrator (first temperature control unit).
5 is a diagram illustrating frequency temperature characteristics of the constant temperature piezoelectric oscillator 1 when set to 85 ° C., which is the same as the set temperature of FIG. At this time, the total power consumption at 25 ° C. was 4.24 W. The frequency stability of the constant temperature piezoelectric oscillator 1 when the ambient temperature Ta is changed in the range of −30 ° C. to + 70 ° C. is ±
It is about 1.4 × 10 ⁻¹⁰ .
FIG. 5 shows an inner oven 11 of the conventional constant temperature piezoelectric oscillator 100 shown in FIG. 9 for comparison.
When the temperature of 5 is set to 85 ° C. and the temperature of the outer oven 120 is set to 75 ° C.,
It is a figure which shows the frequency temperature characteristic of the conventional constant temperature type piezoelectric oscillator 100. FIG. At this time, the total power consumption at 25 ° C. was 5.5 W. The frequency stability of the conventional constant temperature piezoelectric oscillator 100 when the ambient temperature Ta is changed in the range of −30 ° C. to + 70 ° C. is about ± 2.8 × 10 ⁻¹⁰ . 4 and 5, the total power consumption at 25 ° C. is improved by about 23% in the constant temperature piezoelectric oscillator 1 of the present invention over the conventional constant temperature piezoelectric oscillator 100, and the frequency stability is also improved. Are better.

FIG. 6 shows the temperature of the semiconductor element (second temperature control unit) 10 of the constant temperature piezoelectric oscillator 1 according to the present invention as 7.
It is a figure which shows the frequency temperature characteristic of the constant temperature type piezoelectric oscillator 1 of this invention at the time of setting to 7 degreeC.
At this time, power consumption at 25 ° C. is 4.2 W. Ambient temperature Ta is -30 ° C to + 70 ° C
The frequency stability of the constant-temperature type piezoelectric oscillator 1 of the present invention when changed in the range of ± 2.9 × 1
0 is about ^-10.
FIG. 7 shows an inner oven 1 for reducing the power consumption of a conventional constant temperature type piezoelectric oscillator 100.
It is a figure which shows the frequency temperature characteristic of the conventional constant temperature type piezoelectric oscillator 100 when the temperature of 15 is set to 77 degreeC and the temperature of the outer oven 120 is set to 75 degreeC. At this time, the power consumption at 25 ° C. was 5.25 W. The frequency stability of the conventional constant temperature piezoelectric oscillator 100 when the ambient temperature Ta is changed in the range of −30 ° C. to + 70 ° C. is about ± 9.2 × 10 ⁻¹⁰ . 6 and 7, the power consumption of the constant temperature piezoelectric oscillator 1 of the present invention is improved by about 20% compared to the conventional constant temperature piezoelectric oscillator 100, and the frequency stability is also constant temperature type of the present invention. It can be seen that the piezoelectric oscillator 1 is significantly superior.

In FIG. 8, the temperature of the semiconductor element (second temperature control unit) 10 of the constant temperature piezoelectric oscillator 1 of the present invention is set to 75 ° C., which is the same as the set temperature 75 ° C. of the outer oven 15 (third temperature control unit). It is a figure which shows the frequency temperature characteristic of the constant temperature type piezoelectric oscillator 1 of this invention in a case. At this time, the total power consumption at 25 ° C. was 4.18 W. When the ambient temperature Ta is changed in the range of −30 ° C. to + 70 ° C., the frequency stability of the constant temperature piezoelectric oscillator 1 of the present invention is + 3.1 × 10 ⁻¹⁰ to
It is about −5.5 × 10 ⁻¹⁰ . A set temperature of the semiconductor element (second temperature control unit) 10;
Since the temperature of the outer oven 15 (third temperature control unit) is set to the same temperature, the temperature of the semiconductor element (second temperature control unit) 10 cannot be finely controlled when the ambient temperature reaches a high temperature of 40 ° C. or higher. It is presumed that the frequency temperature characteristic is deteriorated due to a ripple in the temperature.

In the conventional constant temperature type piezoelectric oscillator, a double thermostatic chamber method in which the piezoelectric vibrator and the oscillation circuit are accommodated in the inner oven and the inner oven is accommodated in the outer oven is used. In the constant temperature piezoelectric oscillator 1 of the present invention, a semiconductor element 1 including a first temperature control unit that maintains the temperature of a piezoelectric vibrator at a top temperature (zero temperature coefficient temperature) in an internal oven, a variable capacitance element, and an oscillation circuit 11.
The second temperature control unit that maintains 0 at a constant temperature is divided into two parts, and the first temperature control unit and the second temperature control unit are controlled at set temperatures independent of each other. Furthermore, by accommodating the oscillation circuit and the second temperature control unit in one semiconductor element, the power consumption of the constant temperature type piezoelectric oscillator can be reduced and the shape and size thereof can be reduced. The time until the frequency stability of the standard is reached) can be shortened.
The set temperature of the first temperature control unit is set to the apex temperature (zero temperature coefficient temperature) of the piezoelectric vibrator, the set temperature of the third temperature control unit is set to the use temperature upper limit plus about 2 ° C. to about 5 ° C., By setting the set temperature of the temperature control unit (semiconductor element) 10 to an intermediate temperature between the set temperature of the first temperature control unit and the set temperature of the third temperature control unit, the power consumption of the constant temperature piezoelectric oscillator can be reduced. There is an effect that it can be minimized.
The power consumption amounts of the first temperature control unit, the semiconductor element 10 and the third temperature control unit are the power consumption amount of the semiconductor element 10, the power consumption amount of the first temperature control unit, and the third temperature control unit, respectively. By increasing the power consumption in order, there is an effect that the total power consumption of the constant temperature piezoelectric oscillator can be minimized.

DESCRIPTION OF SYMBOLS 1 ... Constant temperature type piezoelectric oscillator of this invention, 5 ... Piezoelectric vibrator, 6 ... 1st heat-emitting component, 7 ... 1st temperature sensing element, 8 ... 1st temperature control circuit component, 10 ... Semiconductor element, 11 ... Oscillating circuit, 12 ... heat generating element, 13 ... second temperature sensing element, 14 ... temperature control circuit, 15 ... outer oven, 15a ... outer oven upper case member, 15b ... outer oven lower case member, 16 ... third heat generation Components: 17 ... third temperature sensing element, 18 ... third temperature control circuit component, 20 ... first printed circuit board, 22 ... second printed circuit board, 25a ... case member, 25b ... base member, P1 ... first 1 connection pin, p2 ... 2nd connection pin

Claims (3)

A constant-temperature piezoelectric oscillator comprising a piezoelectric vibrator, a base member, a first printed board, a second printed board, a semiconductor element, and an outer oven,
The first printed circuit board is connected and supported by a first connection pin at a position spaced from the upper surface of the base member,
The second printed circuit board is connected and supported by second connection pins at a position spaced from the upper surface of the first printed circuit board,
The outer oven is connected and supported by a second connection pin,
The first temperature control unit includes a first heat generating component, a first temperature sensing element, and a first temperature control circuit,
The second temperature control unit includes a second heat generating component, a second temperature sensing element, and a second temperature control circuit,
The third temperature control unit includes a third heat generating component, a third temperature sensing element, and a third temperature control circuit,
The piezoelectric vibrator is supported at a position spaced apart from the second printed circuit board, and the first heat generating component is disposed adjacent to the piezoelectric vibrator,
The semiconductor element includes an oscillation circuit and a second temperature control unit, and is mounted on the second printed circuit board,
The outer oven houses the second printed circuit board, the piezoelectric vibrator, the oscillation component, the first temperature control unit, and the semiconductor element.
The third heat generating component heats the outer oven, and is a constant temperature piezoelectric oscillator. The set temperature of the first temperature control unit is set to the temperature of the zero temperature coefficient of the piezoelectric vibrator,
The set temperature of the third temperature control unit is the upper limit of the use temperature of the constant temperature type piezoelectric oscillator plus about 2
Set in the range of ℃ to about 5 ℃,
The constant temperature according to claim 1, wherein the set temperature of the second temperature control circuit of the semiconductor element is set between the set temperatures of the first and third temperature control units. Type piezoelectric oscillator. The power consumption amount of each of the first temperature control unit, the second temperature control circuit unit, and the third temperature control unit is the same as that of the first temperature control unit. 3. The constant temperature piezoelectric oscillator according to claim 1, wherein a power consumption amount is larger than a power consumption amount, and a power consumption amount of the first temperature control unit is larger than a power consumption amount of the second temperature control circuit.

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