A Constant Temperature Crystal Oscillator

Abstract

The present invention relates to the technical field of electronic components, and discloses a constant temperature crystal oscillator, including a constant temperature oscillation module and a housing assembly, wherein the constant temperature oscillation module includes: a PCB substrate, arranged in a horizontal direction, the PCB substrate including a first surface provided with an etching circuit and a second surface opposite to the first surface; a heat-conducting metal plate, arranged on the second surface of the PCB substrate, the heat-conducting metal plate including a heat-conducting main board and a hollow heat-conducting pipe; a crystal, connected to the heat-conducting main board on a side away from the PCB substrate; a temperature sensor, arranged in the hollow heat-conducting pipe, the temperature sensor is connected to the etching circuit; and a heating element, arranged on the first surface of the PCB substrate, the heating element is connected to the etching circuit. The constant temperature crystal oscillator provided by the present invention has higher temperature control accuracy and temperature stability, and the production process is simpler, the manufacturing cost is lower, and it is more suitable for mass production.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic components, and in particular, to a temperature-controlled crystal oscillator. Background Art

[0002] A quartz crystal oscillator, abbreviated as a crystal oscillator, has advantages such as high frequency stability, high reliability, small size, and light weight, and is widely used in the field of modern electronic technology. With the rapid development of electronic technology, the requirements for the frequency stability and accuracy of the system reference signal are getting higher and higher, and temperature is the most important factor affecting this performance.

[0003] The working principle of a temperature-controlled crystal oscillator is to control the heating transistor and the temperature sensor through a temperature control circuit to control the internal temperature of the temperature-controlled crystal oscillator at a constant temperature. When the external environmental temperature changes, the internal working environment temperature of the temperature-controlled crystal oscillator also changes. When the temperature sensor senses the change in the environmental temperature, it will feedback to the temperature control circuit to control the heating tube to increase or decrease the heating amount to control the internal temperature of the temperature-controlled crystal oscillator to be stable in a constant temperature environment and maintain the frequency stability of the temperature-controlled crystal oscillator. Due to the extremely high frequency stability and low aging rate of the temperature-controlled crystal oscillator, it is widely used.

[0004] The existing temperature-controlled crystal oscillators generally adopt the method of wrapping the crystal with a thermostatic bath, and the temperature sensor senses the temperature of the bath and the environment to achieve the purpose of temperature control. However, due to the large volume of the thermostatic bath and the relatively complex production process, the temperature-controlled crystal oscillator will have higher process requirements and production costs during the production process, and it is difficult to achieve mass production.

[0005] Therefore, there is an urgent need for a temperature-controlled crystal oscillator to solve the above technical problems. Summary of the Invention

[0006] Based on the above, the purpose of the present invention is to provide a temperature-controlled crystal oscillator, which can improve the temperature control accuracy and temperature stability, simplify the production process, and reduce the manufacturing cost.

[0007] To achieve the above object, the present invention adopts the following technical solutions:

[0008] Provide a temperature-controlled crystal oscillator, including a temperature-controlled oscillation module, and the temperature-controlled oscillation module includes:

[0009] A PCB substrate, arranged horizontally, the PCB substrate includes a first surface provided with an etched circuit and a second surface opposite to the first surface;

[0010] A heat-conducting metal plate, arranged on the second surface of the PCB substrate, the heat-conducting metal plate includes a heat-conducting main board and a hollowed-out heat-conducting tube;

[0011] A crystal, connected to the heat-conducting main board on a side facing away from the PCB substrate;

[0012] A temperature sensor, disposed in the hollow heat-conducting tube, and the temperature sensor is connected to the etched circuit; and

[0013] A heating element, disposed on a first surface of the PCB substrate, and the heating element is connected to the etched circuit.

[0014] As an alternative solution of the constant-temperature crystal oscillator, a relief hole penetrating through the first surface and the second surface of the PCB substrate is provided on the PCB substrate, and the hollow heat-conducting tube is inserted through the relief hole.

[0015] As an alternative solution of the constant-temperature crystal oscillator, the heat-conducting metal plate further includes a heat-conducting block, the heat-conducting block is connected to the heat-conducting main board and the hollow heat-conducting tube, and one end of the heat-conducting block passes through the first surface of the PCB substrate via the relief hole.

[0016] As an alternative solution of the constant-temperature crystal oscillator, a limiting convex ring is provided at one end of the crystal, a limiting groove is provided on a side of the heat-conducting metal plate facing away from the PCB substrate, and the limiting convex ring is snap-fitted with the limiting groove.

[0017] As an alternative solution of the constant-temperature crystal oscillator, the hollow heat-conducting tubes are arranged at intervals in a horizontal direction at one end of the heat-conducting main board, and the heat-conducting main board, the hollow heat-conducting tubes and the heat-conducting block enclose to form the limiting groove.

[0018] As an alternative solution of the constant-temperature crystal oscillator, the hollow heat-conducting tube is filled with a heat-conducting colloid.

[0019] As an alternative solution of the constant-temperature crystal oscillator, the heating element adopts a surface-mounted heating transistor.

[0020] As an alternative solution of the constant-temperature crystal oscillator, the heat-conducting metal plate is made of copper.

[0021] As an alternative solution of the constant-temperature crystal oscillator, the constant-temperature crystal oscillator further includes a housing assembly, the housing assembly includes a base and an upper cover, the base and the upper cover are hermetically connected to form a cavity, and the constant-temperature oscillation module is disposed in the cavity.

[0022] As an alternative solution of the constant-temperature crystal oscillator, the constant-temperature crystal oscillator further includes a support rod, and the PCB substrate is connected to the base through the support rod.

[0023] The beneficial effects of the present invention are:

[0024] The constant-temperature crystal oscillator provided by the present invention mainly uses a heat-conducting metal plate to sense temperature and transfer heat to the crystal. When the ambient temperature inside the constant-temperature crystal oscillator changes, the temperature sensor detects the amplitude of the ambient temperature change via a hollow heat-conducting tube, and then the temperature sensor transmits the detection signal to the heating element through the etched circuit on the PCB substrate. By adjusting the operating power of the heating element, the heat generation of the heating element is adjusted so that the ambient temperature inside the constant-temperature crystal oscillator is maintained within a preset range, and the change in the ambient temperature can be quickly conducted to the crystal through the heat-conducting metal plate. Compared with the existing method of wrapping the crystal with a constant-temperature bath, the constant-temperature crystal oscillator provided by the present invention has higher temperature control accuracy and temperature stability, and the production process is simpler, the manufacturing cost is lower, and it is more suitable for mass production. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments of the present invention. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on the content of the embodiments of the present invention and these drawings.

[0026] Figure 1 is a schematic structural diagram (front view) of the constant-temperature crystal oscillator provided by the present invention;

[0027] Figure 2 is a schematic structural diagram (top view) of the constant-temperature oscillation module provided by the present invention;

[0028] Figure 3 is a schematic structural diagram of the heat-conducting metal plate provided by the present invention Figure 1 ;

[0029] Figure 4 is a schematic structural diagram of the heat-conducting metal plate provided by the present invention Figure 2 .

[0030] In the figure:

[0031] 1, PCB substrate; 11, relief hole; 2, heat-conducting metal plate; 21, heat-conducting main board; 22, hollow heat-conducting tube; 23, heat-conducting block; 24, limiting groove; 3, crystal; 31, limiting convex ring; 4, temperature sensor; 5, heating element; 6, electronic component; 7, base; 8, upper cover; 9, support rod. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0032] To make the technical problems solved by the present invention, the technical solutions adopted, and the achieved technical effects clearer, the technical solutions of the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present invention.

[0033] As Figures 1 - 4 shown, this embodiment provides a temperature-controlled crystal oscillator, which includes a housing assembly and a temperature-controlled oscillation module. The housing assembly includes a base 7 and an upper cover 8. The base 7 and the upper cover 8 are hermetically connected to form a cavity, and the temperature-controlled oscillation module is disposed in the cavity. The temperature-controlled oscillation module includes a PCB substrate 1, a heat-conducting metal plate 2, a crystal 3, a temperature sensor 4, and a heating element 5. Among them, the PCB substrate 1 is arranged in the horizontal direction. The PCB substrate 1 includes a first surface provided with an etched circuit and a second surface opposite to the first surface; the heat-conducting metal plate 2 is disposed on the second surface of the PCB substrate 1. The heat-conducting metal plate 2 includes a heat-conducting main board 21 and a hollow heat-conducting tube 22; the crystal 3 is connected to the heat-conducting main board 21 on the side facing away from the PCB substrate 1; the temperature sensor 4 is disposed in the hollow heat-conducting tube 22, and the temperature sensor 4 is connected to the etched circuit; the heating element 5 is disposed on the first surface of the PCB substrate 1, and the heating element 5 is connected to the etched circuit.

[0034] Specifically, the temperature-controlled crystal oscillator provided in this embodiment mainly uses the heat-conducting metal plate 2 to sense temperature and transfer heat to the crystal 3. When the ambient temperature inside the temperature-controlled crystal oscillator changes, the temperature sensor 4 detects the amplitude of the ambient temperature change through the hollow heat-conducting tube 22, and then the temperature sensor 4 transmits the detection signal to the heating element 5 through the etched circuit on the PCB substrate 1. By adjusting the working power of the heating element 5 to adjust the heat generation of the heating element 5, the ambient temperature inside the temperature-controlled crystal oscillator is maintained within a preset range. The change in the ambient temperature can be quickly conducted to the crystal 3 through the heat-conducting metal plate 2. Compared with the existing method of using a temperature-controlled bath to wrap the crystal 3, the temperature control accuracy and temperature stability of the temperature-controlled crystal oscillator provided in this embodiment are higher, and the production process is simpler, the production efficiency is higher, the manufacturing cost is lower, and it is more suitable for mass production.

[0035] In this embodiment, the first surface of the PCB substrate 1 is the upper surface, and the second surface of the PCB substrate 1 is the lower surface. The PCB substrate 1, the heat-conducting metal plate 2, and the crystal 3 are stacked from top to bottom.

[0036] Optionally, the PCB substrate 1 is provided with a relief hole 11 penetrating through the first surface and the second surface of the PCB substrate 1, and the hollow heat-conducting tube 22 is inserted into the relief hole 11.

[0037] Optionally, the heat-conducting metal plate 2 further includes a heat-conducting block 23, which is connected to the heat-conducting main board 21 and the hollow heat-conducting pipe 22, and one end of the heat-conducting block 23 passes through the first surface of the PCB substrate 1 through the clearance hole 11. The provision of the heat-conducting block 23 can speed up the heat transfer speed between the hollow heat-conducting pipe 22 and the internal environment of the cavity and the heat-conducting main board 21, and improve the sensitivity of the temperature sensor 4 provided in the hollow heat-conducting pipe 22 to detect temperature changes, thereby further improving the temperature control accuracy.

[0038] Optionally, the hollow heat pipe 22 is filled with a heat-conducting colloid to accelerate the heat transfer speed between the temperature sensor 4 and the hollow heat pipe 22, further improve the sensitivity of the temperature sensor 4 in detecting temperature changes, and thus further improve the temperature control accuracy.

[0039] Optionally, the temperature sensor 4 is a plug-in temperature sensor, which is connected to an etching circuit on the PCB substrate 1 via a wire.

[0040] Optionally, a limiting convex ring 31 is provided at one end of the crystal 3, and a limiting groove 24 is provided on the side of the heat-conducting metal plate 2 facing away from the PCB substrate 1. The limiting convex ring 31 is clamped with the limiting groove 24 to achieve the installation, connection and positioning of the crystal 3 and the heat-conducting metal plate 2, thereby avoiding the crystal 3 from shifting relative to the heat-conducting metal plate 2.

[0041] Specifically, the hollow heat pipe 22 is arranged at intervals at one end of the heat conductive main board 21 along the horizontal direction, the lowest point of the heat conductive block 23 is higher than the lowest point of the heat conductive main board 21 and the lowest point of the hollow heat conductive pipe 22, and the heat conductive main board 21, the hollow heat conductive pipe 22 and the heat conductive block 23 are surrounded to form a limiting groove 24.

[0042] Optionally, the crystal 3 is connected to the heat-conducting metal plate 2 by reflow soldering.

[0043] Optionally, the heating element 5 uses a surface-mount heating transistor, which simplifies the production process compared to a plug-in heating transistor.

[0044] Preferably, at least two heating elements 5 are provided on the PCB substrate 1 to improve the efficiency of regulating the internal ambient temperature of the cavity and improve the temperature stability.

[0045] Optionally, a plurality of electronic components 6 such as resistors and capacitors are further provided on the first surface of the PCB substrate 1 , and the electronic components 6 are electrically connected to the etching circuit.

[0046] Optionally, the etching circuit on the PCB substrate 1 is also connected to the crystal 3 through a wire.

[0047] Preferably, the heat-conducting metal plate 2 is made of copper.

[0048] Optionally, the temperature-controlled crystal oscillator further includes a support rod 9, and the PCB substrate 1 is connected to the base 7 through the support rod 9. Specifically, the four corners of the PCB substrate 1 are respectively connected to the base 7 through a support rod 9.

[0049] In the temperature-controlled crystal oscillator provided in this embodiment, the temperature control accuracy is improved to 0.1 °C, and the temperature stability is improved to ±0.3 ppb.

[0050] Note that the above are only the preferred embodiments of the present invention and the technical principles applied. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein. Various obvious changes, re-adjustments, and substitutions can be made by those skilled in the art without departing from the protection scope of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments. Without departing from the concept of the present invention, more other equivalent embodiments can be included, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A constant temperature crystal oscillator, It is characterized in that It includes a constant temperature oscillation module, and the constant temperature oscillation module includes: A PCB substrate (1) is arranged in a horizontal direction, the PCB substrate (1) comprising a first surface provided with an etched circuit and a second surface opposite to the first surface; A heat-conducting metal plate (2) is arranged on the second surface of the PCB substrate (1), and the heat-conducting metal plate (2) comprises a heat-conducting main board (21) and a hollow heat-conducting pipe (22); A crystal (3) connected to the heat-conducting main board (21) at a side facing away from the PCB substrate (1); A temperature sensor (4) is disposed in the hollow heat-conducting pipe (22), and the temperature sensor (4) is connected to the etching circuit; and A heating element (5) is disposed on the first surface of the PCB substrate (1), and the heating element (5) is connected to the etching circuit; The PCB substrate (1) is provided with a clearance hole (11) penetrating the first surface and the second surface of the PCB substrate (1), and the hollow heat conducting pipe (22) is passed through the clearance hole (11); The heat-conducting metal plate (2) further comprises a heat-conducting block (23), wherein the heat-conducting block (23) is connected to the heat-conducting main board (21) and the hollow heat-conducting pipe (22), and one end of the heat-conducting block (23) passes through the first surface of the PCB substrate (1) via the clearance hole (11).

2. The oven controlled crystal oscillator according to claim 1, It is characterized in that A limiting convex ring (31) is provided at one end of the crystal (3), a limiting groove (24) is provided on the side of the heat-conducting metal plate (2) facing away from the PCB substrate (1), and the limiting convex ring (31) is snap-fitted with the limiting groove (24).

3. The oven controlled crystal oscillator according to claim 2, It is characterized in that The hollow heat-conducting pipe (22) is arranged at intervals at one end of the heat-conducting main board (21) in the horizontal direction, and the heat-conducting main board (21), the hollow heat-conducting pipe (22) and the heat-conducting block (23) are combined to form the limiting groove (24).

4. The oven controlled crystal oscillator according to claim 1, It is characterized in that The hollow heat-conducting pipe (22) is filled with heat-conducting colloid.

5. The oven controlled crystal oscillator according to claim 1, It is characterized in that The heating element (5) is a surface mounted heating transistor.

6. The oven controlled crystal oscillator according to claim 1, It is characterized in that The heat-conducting metal plate (2) is made of metal copper.

7. The oven controlled crystal oscillator according to any one of claims 1 to 6, It is characterized in that The constant temperature crystal oscillator also includes a housing component, the housing component includes a base (7) and an upper cover (8), the base (7) and the upper cover (8) are sealed and connected to form a cavity, and the constant temperature oscillation module is arranged in the cavity.

8. The oven controlled crystal oscillator according to claim 7, It is characterized in that The oven-controlled crystal oscillator further comprises a support rod (9), and the PCB substrate (1) is connected to the base (7) via the support rod (9).

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