JP2010183227A - Constant-temperature piezoelectric oscillator - Google Patents

Abstract

A miniaturized highly stable piezoelectric oscillator having improved frequency stability and reduced power consumption is obtained.
A printed circuit board 5 electrically and mechanically connected and supported by connection pins 8 extending from a base member 7, a piezoelectric vibrator 25 supported by the printed circuit board 5 in a thermally uncoupled state, and the printed circuit board 5 An oscillation circuit component 20, a first temperature control unit 10 for temperature control of the piezoelectric vibrator 25, a second temperature control unit 14 for temperature control of the oscillation circuit component 20, a case 9, The first temperature control unit is for heating the piezoelectric vibrator and is in a thermally uncoupled state with the printed circuit board, the first heat generating component 11, the first temperature sensing element 12, and the first temperature control unit. The temperature control circuit component 13 is included, and the second temperature control unit includes a second heat generating component 15 for heating the oscillation circuit component, a second temperature sensitive element 16, and a second temperature control circuit component 17.
[Selection] Figure 1

Description

The present invention relates to an improvement of a constant temperature type piezoelectric oscillator (highly stable piezoelectric oscillator) used as a frequency control device or the like, and in particular, a piezoelectric vibrator is heated by a heat-generating component such as a power transistor and the heating temperature is controlled by a temperature control circuit. The present invention relates to a constant-temperature piezoelectric oscillator that can solve a problem caused by insufficient temperature control on an oscillation circuit component arranged on a mounting board.

A thermostatic chamber type piezoelectric oscillator that can output a highly stable frequency without being affected by an external temperature change as a piezoelectric oscillator such as a crystal oscillator that is a frequency control device used in a mobile communication base station or transmission communication device. Is conventionally known. Furthermore, in recent years, in these fields, various devices have been required to be small and light, and accordingly, the thermostatic chamber piezoelectric oscillator is also required from the market to be small and light. .
In order to obtain a highly stable frequency, a conventional thermostatic oven type piezoelectric oscillator houses a piezoelectric vibrator in a recess of a thermostatic oven (even) such as a metal block having a large heat capacity, and further heats the metal block to a predetermined temperature with a heater. It was heated to. However, when a large metal block is used, the bulk of the entire oscillator increases, so that it has not been possible to satisfy the demand for reduction in size and weight. In addition, since the piezoelectric vibration element inside the piezoelectric vibrator is heated via the metal block, there is a problem that it takes a long time for the heat from the heater to reach the piezoelectric vibration element and reach the desired frequency. .
As a miniaturized highly stable piezoelectric oscillator that does not use a large metal block, JP-A-2
008-28619 (Patent Document 1) discloses a highly stable piezoelectric oscillator and a manufacturing method thereof. FIG. 5A is a diagram showing the structure of a piezoelectric vibrator housing case used for a highly stable piezoelectric oscillator. The storage case 61 includes a cylindrical vibrator storage section 62 that stores the crystal oscillator 72 in one end opening, and a small-diameter cylindrical thermistor storage section 63 that stores the thermistor 78 therein. A thermistor housing 63 is connected to the side surface 62 by solder 64.

FIG. 5B is a cross-sectional view showing the structure of a highly stable crystal oscillator. The highly stable crystal oscillator includes a printed circuit board 71, a crystal oscillator 72 connected to the bottom surface of the printed circuit board 71, a power transistor 73 fixed to the printed circuit board 71 for heating the crystal oscillator 12, and an oscillator case 74. (74a, 74b) and a terminal 75 connected to the printed circuit board 11. Further, various components 76 constituting the oscillation circuit and the heating control circuit are mounted on the printed circuit board 71.
The power transistor 7 is formed on the outer surface of the vibrator housing portion 62 of the housing case 61 shown in FIG.
3 is soldered to constitute a heat source unit. The crystal resonator 72 and the thermistor 78 are accommodated in the transducer accommodating portion 62 and the thermistor accommodating portion 63 of the heat source unit, respectively. Further, a through hole 80 is formed on the printed circuit board 71 at a portion overlapping the heat source unit housing the crystal resonator 72 in a plan view, and the power transistor 73 is disposed in the through hole 80. With this configuration, the thermal resistance between the metal case 72a of the crystal resonator 72 and the power transistor 73 can be minimized as much as possible without directly soldering the power transistor 73 to the crystal resonator 72. It is disclosed.

JP 2008-28619 A

The highly stable piezoelectric oscillator disclosed in Patent Document 1 constitutes a piezoelectric oscillator capable of outputting a highly stable frequency by integrating a piezoelectric vibrator, a heating part for heating the piezoelectric vibrator, and a temperature sensing element. However, this conventional example can reduce the power consumption because the heating target is restricted locally, but when the ambient temperature changes, the temperature of the oscillation circuit component changes and the load capacity of the oscillation circuit component changes. Frequency stability is degraded. In other words, since the object to be heated is limited to only the piezoelectric vibrator, the oscillation circuit component is easily affected by the temperature change due to the ambient temperature change, and there is a limit in realizing further high frequency stabilization. was there.
The present invention has been made to solve the above-described problems, and it is an object of the present invention to provide a miniaturized highly stable piezoelectric oscillator with high frequency stability and low power consumption.

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 type piezoelectric oscillator according to the present invention has a base member for mounting on a mother board in order to realize a miniaturized highly stable piezoelectric oscillator with high frequency stability and low power consumption, A printed circuit board electrically and mechanically connected and supported by a connection pin extending from the base member at a position spaced from the upper surface of the base member; a piezoelectric vibrator supported by the printed circuit board in a thermally uncoupled state; and the print Between the oscillation circuit component mounted on the substrate, the first temperature control unit for temperature control of the piezoelectric vibrator, the second temperature control unit for temperature control of the oscillation circuit component, and the base member And a case for forming a thermostatic chamber for sealing each of the above components, wherein the first temperature control unit is for heating the piezoelectric vibrator and the printed circuit board. Thermal The first heat generating component, the first temperature sensing element, and the first temperature control circuit component in a non-coupled state, wherein the second temperature control unit is a second heat generating component for heating the oscillation circuit component. A constant temperature type piezoelectric oscillator comprising a second temperature sensing element and a second temperature control circuit component and mounted on a printed circuit board.

By providing two temperature control units, a first temperature control unit for controlling the temperature of the piezoelectric vibrator and a second temperature control unit for controlling the temperature of the oscillation circuit component, and controlling each separately, It is possible to individually set the piezoelectric vibrator to an optimum temperature and the temperature of the oscillation circuit component to be approximately 2 ° C. higher than the upper limit of the temperature range of the constant temperature piezoelectric oscillator. While improving the stability of the oscillator, it is also effective in saving power. In addition, the deterioration of the oscillation circuit component can be delayed by not raising the temperature of the oscillation circuit component more than necessary.

Application Example 2 In the constant temperature type 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, and the set temperature of the second temperature control unit is The constant temperature piezoelectric oscillator according to Application Example 1, wherein the upper limit of the use temperature of the constant temperature piezoelectric oscillator is set to approximately 2 ° C.

For example, in the case of an SC cut crystal resonator, the set temperature of the first temperature control unit is set to the apex temperature indicating the zero temperature coefficient, thereby improving the stability of the constant temperature piezoelectric oscillator. . In addition, by setting the temperature of the oscillation circuit component to be approximately 2 ° C higher than the upper limit of the operating temperature range of the constant temperature type piezoelectric oscillator, the value of the load capacity of the oscillation circuit component is stabilized, and the stability of the constant temperature type piezoelectric oscillator is increased. In addition to increasing the power, it is also effective for power saving.

Application Example 3 In the constant temperature type piezoelectric oscillator, a variable capacitance element for changing an oscillation frequency is mounted on the printed circuit board, and a heating target by the second temperature control unit is used as a mounting area of the variable capacitance element. The constant temperature piezoelectric oscillator according to Application Example 1, which is characterized by being limited.

By limiting the heating target by the second temperature control unit to the periphery of the printed circuit board on which the variable capacitance element is mounted, there is an effect that the power consumed by the second temperature control unit can be reduced. .

Application Example 4 In the constant temperature type piezoelectric oscillator, the base member is a lower metal case member that forms the constant temperature bath in cooperation with the case, and the connection pin is provided in the lower metal case member. The constant temperature piezoelectric oscillator according to any one of Application Examples 1 to 3, wherein a hole is passed through an insulating material and a lower end portion is protruded to the outside.

The base member is formed of a lower metal case member, and the thermostatic chamber is formed by the cooperation of the base member and the case, so that a robust and highly stable constant temperature type piezoelectric oscillator is configured. . Furthermore, the metallic case and the base member are effective in blocking external noise and preventing noise from radiating to the outside.

Application Example 5 In the constant temperature piezoelectric oscillator, any one of Application Examples 1 to 3, wherein the base member is a surface-printed base printed board and supports a lower end portion of the connection pin. A constant temperature piezoelectric oscillator according to claim 1.

By constructing a thermostatic piezoelectric oscillator using a surface-mounting base printed circuit board as a base member, a surface-mounting type thermostatic piezoelectric oscillator can be realized, and the mounting on a mother board can be automated.

BRIEF DESCRIPTION OF THE DRAWINGS It is the figure which showed the structure of the constant temperature type piezoelectric oscillator 1 of a 1st Example, (a) is a top view of a printed circuit board, (b) is the side view, (c) is a side view of a piezoelectric vibrator block body. (D) is a side view of a base member and a connection pin, (e) is sectional drawing of the constant temperature type piezoelectric oscillator 1. FIG. It is the figure which showed the structure of the constant temperature type piezoelectric oscillator 2 of 2nd Example, (a) is a top view of a printed circuit board, (b) is the side view, (c) is a side view of a piezoelectric vibrator block body (D) is a side view of a base member and a connection pin, (e) is sectional drawing of the constant temperature type piezoelectric oscillator 2. FIG. Sectional drawing of the constant temperature type piezoelectric oscillator 3 of a 3rd Example. Sectional drawing of the constant temperature type piezoelectric oscillator 4 of a 4th Example. (A) is the figure which showed the structure of the piezoelectric vibrator storage case, (b) is sectional drawing which shows the structure of the conventional highly stable piezoelectric oscillator.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic diagram showing the configuration of a constant temperature piezoelectric oscillator (highly stable piezoelectric oscillator) 1 according to an embodiment of the present invention. Figure 1
(a) is a top view of the printed circuit board, (b) is a side view of the printed circuit board, and (c) is a state in which the first heat generating component and the first temperature sensing element are attached to the piezoelectric vibrator. Side view shown, (d)
FIG. 4 is a side view of a member in which a connection pin is attached to a base member via an insulating material, and FIG. 3E is a cross-sectional view of the constant temperature piezoelectric oscillator 1 according to the present invention.
As shown in FIG. 1 (e), the constant temperature type piezoelectric oscillator 1 includes an electric machine including a base member 7 for mounting on a motherboard and a connection pin 8 extending from the base member 7 at a position spaced from the upper surface of the base member 7. Printed circuit board 5 that is connected and supported, a piezoelectric vibrator 25 that is supported by the printed circuit board 5 in a thermally non-coupled state, and an oscillation circuit component 20 mounted on the printed circuit board 5.
(20a, 20b) and the first temperature control unit 10 (11, 1 for temperature control of the piezoelectric vibrator 25).
2, 13) and the second temperature control unit 14 (15, 16, 1) for controlling the temperature of the oscillation circuit component 20.
7) and a case 9 that forms the thermostatic chamber by sealing each of the above components between the base member 7;
It has.

The first temperature control unit 10 is for heating the piezoelectric vibrator 25 and is thermally coupled to the printed circuit board 5 and is thermally coupled to the first heat generating component 11 (for example, a power transistor) and a first thermistor, for example. And a first temperature control circuit component 13 for controlling the first heat-generating component 11 based on a temperature detection signal from the first temperature sensitive device 12, and the printed circuit board 5.
It is mounted on.
The second temperature control unit 14 is a second heat generating component 15 for heating the oscillation circuit component 20 (for example,
A chip resistor that generates Joule heat, a heater, and the like), a second temperature sensing element 16 such as a thermistor, and a temperature detection signal from the second temperature sensing element 16 to control the second heat generating component 15. A second temperature control circuit component 17, and is mounted on the upper surface of the printed circuit board 5.
The oscillation circuit component 20 includes an oscillation circuit element 2 that is an IC for causing the piezoelectric vibrator 25 to oscillate.
0a and a variable capacitance element 20b such as a varicap diode, for example. The reason why the variable capacitance element 20b is provided is to vary the oscillation frequency of the constant temperature piezoelectric oscillator 1 as necessary.

As shown in FIG. 1 (a), a plurality of through holes 6a are formed in the printed circuit board 5 at the periphery thereof for penetrating connection pins 8 to be connected and fixed. The printed circuit board 5 includes a plurality of through holes 6b for the lead terminals 25a of the piezoelectric vibrator 25, and a terminal 1 of the first heat generating component.
A plurality of through holes 6c for 1a, a plurality of through holes 6d for the terminals 12a of the first temperature sensing element, and the like are formed.
As shown in FIGS. 1A and 1B, the first temperature control circuit component 13, the second heat generating component 15, and the second temperature sensing element 16 are formed on one surface of the printed circuit board 5. And a second temperature control circuit component 17 are mounted. On the other surface, an oscillation circuit component 20 including an oscillation circuit element 20a and a variable capacitance element 20b is mounted.

As shown in FIG. 1C, the first heat generating component (for example, a power transistor) 11 is bonded to the upper surface of the piezoelectric vibrator 25 using cream solder or an adhesive having good heat conduction.
The piezoelectric vibrator block body 23 is configured by fixing and bonding the first temperature sensing element 12 (for example, a thermistor) to the side surface of the piezoelectric vibrator 25 using an adhesive having good heat conduction. The lead terminals 11a (three in the case of a power transistor) of the first heat generating component 11 of the piezoelectric vibrator block body 23 are bent at a substantially right angle with respect to the main surface of the first heat generating component 11 from a predetermined position. Yes. Similarly, the lead terminals 25a (usually two) of the piezoelectric vibrator 25 are also bent at a substantially right angle with respect to the main surface from a predetermined position. The terminals 12a (two) of the first temperature sensing element are thinner and more flexible than the other lead terminals 11a and 25a, and need not be bent in advance.
The lead terminals 11a, 12a and 25a of the piezoelectric vibrator block body 23 are passed through the through holes 6c, 6d and 6b of the printed circuit board 5, and the upper surface of the first heat generating component 11 is the oscillation circuit element 20.
a and the variable capacitance element 20b are brought into contact with the respective surfaces, and lead terminals 11a, 12a,
25a is fixed to the through holes 6c, 6d and 6b with solder to constitute a printed board block.
The piezoelectric vibrator 25 is, for example, a crystal vibrator, and a piezoelectric vibration element (crystal vibration element) is hermetically sealed in a metal case, and the piezoelectric vibration element is formed by an inner end portion of a lead terminal 25a extending into the metal case. The structure is supported in a non-contact manner with the metal case. A piezoelectric vibration element is an element in which excitation electrodes are formed on the main surface of a piezoelectric substrate (quartz crystal substrate).

As shown in FIG.1 (d), the base member 7 and the connection pin 8 are connected through an insulating material. Specifically, when a metal plate is used as the base member 7, a plurality of holes 7 a are formed in the metal plate, and the holes 7
The connection pin 8 is inserted and supported in a through a hermetic seal material (insulating material).
When an insulating material such as a surface mounting printed board or a ceramic substrate is used as the base member 7, a plurality of through holes are formed in these insulating materials, and metal connection pins 8 are passed through the through holes. The connection pin 8 and the through hole are soldered with a predetermined length. In this case, the lower end portion of the connection pin 8 is supported so as not to protrude from the base member 7.
Through the connecting pin 8 extending orthogonally from the surface of the base member 7 shown in FIG. 1D, the through hole 6a of the printed board block is passed, and the piezoelectric vibrator 25 of the printed board block is separated from the base member 7, The through hole 6a and the connection pin 8 are connected and fixed with solder.
Then, as shown in the sectional view of FIG. 1 (e), a metal case 9 is covered so as to cover the printed board block, and the outer peripheral edge of the base member 7 and the lower part of the case 9 are soldered, so that a constant temperature piezoelectric oscillator is obtained. Complete 1 In addition, the example of FIG.1 (e) is sectional drawing supposing the metal base member 7. FIG.
In the illustrated example, the base member 7 is a lower metal case member that forms a thermostatic chamber in cooperation with a metal case (upper metal case) 9, and the connection pins insulate holes provided in the lower metal case member 7. The lower end is protruded outside through the material.

As the piezoelectric vibrator used in the constant temperature type piezoelectric oscillator (highly stable piezoelectric oscillator) 1 according to the present invention, for example, an SC cut crystal vibrator is used. The SC cut crystal resonator is a crystal resonator using a quartz substrate that is rotated twice. Three vibration modes are excited, and the main vibration, which is the lowest frequency, is the thickness shear vibration mode (C mode). . A thickness torsion mode (B mode), a thickness longitudinal mode (A mode), and the like are present on the higher frequency side than the vibration mode. The resonance frequency (f2) of the B mode adjacent to the C mode (resonance frequency f1) of the main vibration is about 9 to 10% higher than the resonance frequency f1 of the C mode, and thus does not cause a frequency jump phenomenon or the like. Thus, it is necessary to devise the oscillation circuit.
The frequency temperature characteristic of the SC cut vibrator (C mode) exhibits a cubic curve, and the inflection point temperature (Ti) is about 95 ° C. And the vertex temperature Tp which shows a zero temperature coefficient in the low temperature side from an inflection point temperature (Ti) depends on the 2nd rotation angle to cut | disconnect, and the setting range of the vertex temperature Tp is 70 degreeC-
It becomes about 85 ° C. Accordingly, the set temperature of the first temperature control unit 10 is set in the vicinity of the apex temperature Tp.

The constant temperature type piezoelectric oscillator (highly stable piezoelectric oscillator) 1 of the present invention is characterized by a first temperature control unit 10 that maintains the temperature of the piezoelectric vibrator 25 at a vertex temperature Tp that indicates a zero temperature coefficient, and an oscillation circuit component 20.
Is maintained at approximately 2 ° C. higher than the upper limit of the operating temperature range of the constant temperature piezoelectric oscillator 1.
4 and two temperature control units are provided. Moreover, the piezoelectric vibrator 25 is a printed circuit board 5.
The first heat generating component 11 of the first temperature control unit 10 is also in contact with the printed circuit board 5 via the oscillation circuit component 20 (oscillation circuit element 20a, variable capacitance element 20b).
This is to suppress conduction of heat generated from the heat generating component 11 to the printed circuit board 5.
When the temperature around the constant-temperature type piezoelectric oscillator 1 changes, the temperature of the oscillation circuit component 20 changes, and the load capacity viewed from the piezoelectric vibrator 25 changes. Even if the load capacitance of the oscillation circuit component 20 slightly changes, the oscillation frequency of the constant temperature piezoelectric oscillator 1 varies. With this in mind, the thermal distribution of the constant temperature piezoelectric oscillator 1 was designed.
Conventional double thermostat type highly stable piezoelectric oscillators house a piezoelectric vibrator in an inner thermostat,
Oscillator circuit parts are housed in the outer temperature chamber, the temperature change of the inner temperature chamber is kept at about 0.1 ° C, the temperature change of the outer temperature chamber is kept at about 1 ° C, and the stability is about 10 ^-10 . I was getting. This also shows that it is important to keep the temperature of the oscillation circuit component constant with respect to the ambient temperature change.
However, it is small for mobile communication such as a WCDMA base station (for example, 25 mm × 20 m
m × 12) A low-cost, variable-frequency ^highly stable piezoelectric oscillator having a frequency stability of about 10 ⁻⁹ is required. Variable capacitance element (varicap diode, etc.) for frequency variable type
Need to be installed.

In view of the above, the constant-temperature piezoelectric oscillator 1 of the present invention has the second on the printed circuit board 5.
The second temperature control unit 14 including the heat generating component 15, the second temperature sensing element 16, and the second temperature control circuit component 17 is provided, and the oscillation circuit component 2 including the oscillation circuit element 20a and the variable capacitance element 20b.
The temperature change of 0 can be maintained within a predetermined temperature range. That is, the temperature holding of the piezoelectric vibrator 25 is performed by the first temperature control unit 10, and the temperature holding of the oscillation circuit component 20 is performed by the second temperature control unit 14.
And we decided to control each one individually. By individually controlling in this way, the piezoelectric vibrator 25 is set to the optimum temperature, that is, the apex temperature Tp indicating the zero temperature coefficient, and the temperature of the oscillation circuit component 20 is substantially lower than the upper limit of the operating temperature range of the constant temperature piezoelectric oscillator 1. It is possible to set each temperature higher by 2 ° C., which improves the stability of the constant temperature piezoelectric oscillator 1 and is suitable for power saving. In addition, the characteristic deterioration of the oscillation circuit component 20 can be delayed by not raising the temperature of the oscillation circuit component 20 more than necessary.

The first and second heat generating components 11 and 15 contribute to improving the stability of the thermostatic piezoelectric oscillator 1.
It is a configuration that suppresses conduction of heat generated in the outside to the outside, and it is necessary to consider fine points such as increasing the thermal resistance by reducing the thickness of the connection pin 8 that connects the printed circuit board 5 and the base member 7. .
Further, in the cross-sectional view of the constant temperature type piezoelectric oscillator 1 shown in FIG. 1E, the first heat generating component 11 and the oscillation circuit component 20 are shown in contact with each other, but the first heat generating component 11 and the oscillation circuit are shown. A space may be provided between the component 20 and heat generated from the first heat-generating component 11 may be concentrated on the piezoelectric vibrator 25 to reduce heat conduction to the oscillation circuit component 20, the printed circuit board 5, and the like.
Further, a part of the printed circuit board 5 is cut out, and the piezoelectric vibrator block body 23 including the piezoelectric vibrator 25, the first heat generating component 11, and the first temperature sensing element 12 is attached to the cutout portion. Then, conduction of heat generated from the first heat-generating component 11 to the printed circuit board 5 can be suppressed, and it contributes to a reduction in the height of the constant temperature piezoelectric oscillator 1.
The constant temperature bath is formed by the cooperation of the metal base member 7 and the case 9 and the first and second temperature control units, and a robust and highly stable constant temperature type piezoelectric oscillator is configured. There is. Furthermore, the metallic case and the base member are effective in blocking external noise and preventing noise from radiating to the outside.

FIG. 2 is a schematic diagram showing the configuration of the constant temperature piezoelectric oscillator 2 of the second embodiment. 2A is a top view of the printed circuit board, FIG. 2B is a side view of the printed circuit board, and FIG.
A piezoelectric vibrator block body 23 having the first heat generating component 11 and the first temperature sensing element 12 attached thereto.
FIG. 4D is a side view of a member in which the connection pin 8 is attached to the base member 7 with an insulating material interposed therebetween, and FIG. 4E is a cross-sectional view of the constant temperature type piezoelectric oscillator 2 of the second embodiment. It is. Parts having the same functions in the same parts as in FIG. The constant temperature type piezoelectric oscillator 2 of the second embodiment is different from the constant temperature type piezoelectric oscillator 1 shown in FIG. 1 in the arrangement of the second temperature control unit 14, particularly the second heat generating component 15. In the constant temperature type piezoelectric oscillator 2, attention is paid to maintaining the temperature of the oscillation circuit component 20, particularly the variable capacitance element 20 b (varicap diode or the like). Second temperature control unit 1
4, maintaining the temperature of the local printed circuit board 5 around the variable capacitor 20 b particularly sensitive to frequency stability among the oscillation circuit components 20 at a predetermined temperature greatly increases the stability of the constant temperature piezoelectric oscillator 1. Contribute. That is, the variable capacitor 20 is heated by the second temperature controller.
This is limited to the mounting area b. Since only the local temperature of the printed circuit board 5 is maintained, the power consumption can be reduced.

FIG. 3 is a schematic cross-sectional view showing the structure of a surface-mount type constant temperature piezoelectric oscillator 3 of the third embodiment. A difference from the constant temperature type piezoelectric oscillator 1 shown in FIG. 1 is an example in which a connection pin 8 penetrating the printed circuit board 5 is soldered to a land electrode formed on the upper surface of the base member 7 to be a surface mount type. A plurality of terminal electrodes connected to the mother board are formed on the lower surface of the base member 7. The oscillation circuit element 20a, the first and second temperature control units 10 are connected via the terminal electrode.
, 14 is supplied, and the generated oscillation frequency is supplied to the motherboard side.
By constructing a thermostatic piezoelectric oscillator using a surface-mounting base printed circuit board as a base member, a surface-mounting type thermostatic piezoelectric oscillator can be realized, and the mounting on a mother board can be automated.

FIG. 4 is a schematic cross-sectional view showing the structure of a surface-mount type constant temperature piezoelectric oscillator 4 of the fourth embodiment. A difference from the constant temperature type piezoelectric oscillator 2 shown in FIG. 2 is an example in which a connection pin 8 penetrating the printed board 5 is soldered to a land electrode formed on the upper surface of the base member 7 to be a surface mount type. A plurality of terminal electrodes are formed on the lower surface of the base member 7. The constant temperature type piezoelectric oscillator 4 is thermally designed so as to hold only the temperature of the mounting area of the variable capacitance element 20b, that is, the local temperature of the printed circuit board 5, and is effective in reducing power consumption. Further, there is an effect that the constant temperature type piezoelectric oscillator 4 can be automatically mounted.

1, 2, 3, 4, constant temperature piezoelectric oscillator, 5, printed circuit board, 6 a, 6 b, 6 c, 6 d, through hole, 7, base member, 8, connection pin, 9, case, 10, first temperature control Part, 1
DESCRIPTION OF SYMBOLS 1 ... 1st heat-emitting component, 11a ... Terminal of 1st heat-generating component, 12 ... 1st temperature sensitive element, 12a ...
Terminal of the first temperature sensing element, 13... First temperature control circuit component, 14... Second temperature control unit, 15
DESCRIPTION OF SYMBOLS 2nd heat-emitting component, 16 ... 2nd temperature sensing element, 17 ... 2nd temperature control circuit component, 20 ... Oscillation circuit component, 20a ... Oscillation circuit element, 20b ... Variable capacitance element, 23 ... Piezoelectric vibrator block Body, 25 ... piezoelectric vibrator, 25a ... lead terminal

Claims (5)

A base member for mounting on a motherboard, a printed circuit board electrically and mechanically connected and supported by a connection pin extending from the base member at a position spaced from the upper surface of the base member, and a thermally uncoupled state by the printed circuit board A piezoelectric vibrator supported on the printed circuit board, an oscillation circuit component mounted on the printed circuit board, a first temperature control unit for temperature control of the piezoelectric vibrator, and a second temperature control unit for controlling the temperature of the oscillation circuit part. A thermostatic piezoelectric oscillator comprising: a temperature control unit; and a case for forming a thermostatic chamber that seals each of the components between the base member,
The first temperature control unit is for heating the piezoelectric vibrator and is in a thermally uncoupled state with the printed circuit board, a first heat generating component, a first temperature sensing element, and a first temperature control circuit Including parts,
The second temperature control unit includes a second heat generating component for heating the oscillation circuit component, a second temperature sensing element, and a second temperature control circuit component, wherein the constant temperature piezoelectric oscillator is provided. . 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 second temperature control unit is the upper limit of the use temperature of the constant temperature type piezoelectric oscillator plus about 2
The constant temperature piezoelectric oscillator according to claim 1, wherein the constant temperature piezoelectric oscillator is set to ° C. The variable capacitance element for changing the oscillation frequency is mounted on the printed circuit board, and a heating target by the second temperature control unit is limited to a mounting area of the variable capacitance element. The constant temperature type piezoelectric oscillator as described. The base member is a lower metal case member that forms the thermostatic chamber in cooperation with the case, and the connection pin penetrates a hole provided in the lower metal case member through an insulating material and has a lower end portion. The constant temperature type piezoelectric oscillator according to any one of claims 1 to 3, characterized in that is protruded to the outside. The constant temperature piezoelectric oscillator according to any one of claims 1 to 3, wherein the base member is a surface-printed base printed circuit board and supports a lower end portion of the connection pin.

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