A quartz crystal oscillator frequency jump measuring device

Abstract

The utility model provides a quartz crystal oscillator frequency mutation measuring device relates to electronic component testing technical field, this quartz crystal oscillator frequency mutation measuring device includes: constant temperature groove subassembly, constant temperature groove subassembly includes a for fixing the heat conduction fixture of measured quartz crystal oscillator, and heating control unit, heating control unit includes power semiconductor device and temperature feedback circuit, power semiconductor device is used for carrying out heating to heat conduction fixture, temperature feedback circuit is used for controlling the on -off state of power semiconductor device, frequency measurement unit, the signal input end of frequency measurement unit is used for connecting the quartz crystal oscillator of containing on heat conduction fixture, data processing and display unit, data processing and display unit with frequency measurement unit signal output end connection, data processing and display unit are used for receiving and display the frequency data of frequency measurement unit output.

Description

Technical Field

[0001] This utility model relates to the field of electronic component testing technology, specifically to a device for measuring frequency mutations in a quartz crystal oscillator. Background Technology

[0002] Quartz crystal oscillators, as high-precision frequency output components with quartz crystals as their core oscillation source, exhibit significant frequency stability within a specific temperature range thanks to the high quality factor of quartz material. However, due to design and manufacturing limitations such as electrode edge ratio or dimensional deviations, some products are prone to frequency abrupt changes due to parasitic coupling effects when temperatures change, causing their frequency-temperature curves to deviate from the normal "smooth cubic curve" characteristics. This type of defect is temperature-dependent, manifesting only in a specific temperature range, and may exhibit temporary recovery or a complete step jump as the temperature continues to change, severely affecting the reliability of the oscillator. Therefore, accurately detecting temperature-frequency abrupt changes in quartz crystal oscillators is a crucial step in ensuring their performance.

[0003] Currently, the commonly used testing methods in the industry mostly rely on high and low temperature test chambers, which select a limited number of temperature sampling points, such as 5 to 10 points within the range of -40℃ to 85℃, for testing. However, this method has significant limitations. On the one hand, each temperature point needs to be held for 5 to 10 minutes or even longer to ensure that the device under test is fully thermally balanced, resulting in a lengthy overall testing cycle. On the other hand, the temperature sampling intervals are large and discontinuous. If a sudden change in frequency happens to occur between unspecified sampling points, it is difficult to effectively identify defective devices. Utility Model Content

[0004] In view of the above problems, this utility model provides a quartz crystal oscillator frequency change measurement device, the quartz crystal oscillator frequency change measurement device comprising:

[0005] A constant temperature bath assembly includes a heat-conducting fixture for fixing a quartz crystal oscillator under test, and a heating control unit. The heating control unit includes a power semiconductor device and a temperature feedback circuit. The power semiconductor device is used to heat the heat-conducting fixture, and the temperature feedback circuit is used to control the conduction state of the power semiconductor device.

[0006] A frequency measurement unit, wherein the signal input terminal of the frequency measurement unit is used to connect to a quartz crystal oscillator housed in the heat-conducting fixture;

[0007] A data processing and display unit is connected to the signal output terminal of the frequency measurement unit. The data processing and display unit is used to receive and display the frequency data output by the frequency measurement unit.

[0008] In one possible implementation, the power semiconductor device is a medium-power transistor.

[0009] In one possible implementation, the temperature feedback circuit includes a temperature sensor and an operational amplifier. The temperature sensor is mounted on the thermostatic bath assembly, and the operational amplifier outputs a control signal to the power semiconductor device based on the detection signal from the temperature sensor.

[0010] In one possible implementation, the temperature feedback circuit is a Wheatstone bridge circuit, and the temperature sensor is a negative temperature coefficient thermistor.

[0011] In one possible implementation, the thermostatic bath assembly further includes a pressing cover for pressing and fixing the quartz crystal oscillator onto the heat-conducting fixture.

[0012] In one possible implementation, the thermally conductive fixture is made of a material with high thermal conductivity and electrical insulation.

[0013] In one possible implementation, the material of the heat-conducting fixture is aluminum nitride.

[0014] In one possible implementation, the quartz crystal oscillator frequency change measuring device further includes a metal shielding shell, and the constant temperature bath assembly and the heating control unit are disposed within the sealed space formed by the metal shielding shell.

[0015] In one possible implementation, the quartz crystal oscillator frequency mutation measurement device further includes a temperature initialization unit for providing an initial low-temperature environment for the thermostatic bath assembly.

[0016] The above-described one or more technical solutions in the embodiments of this application have at least one or more of the following technical effects:

[0017] This utility model provides a quartz crystal oscillator frequency mutation measurement device. The thermally conductive fixture of the constant temperature bath assembly ensures reliable fixation and uniform heat conduction of the oscillator under test. The heating control unit integrates power semiconductor devices and a temperature feedback circuit. Utilizing the high heating efficiency and fast response of semiconductors, it achieves linear temperature control of the thermally conductive fixture. This not only allows for adjustable heating slope and avoids temperature mutations but also significantly shortens the thermal equilibrium time, improving testing efficiency. The frequency measurement unit acquires the oscillator output frequency in real time. Combined with the data processing and display unit, it plots the frequency data of the continuous time series, accurately capturing temperature-dependent frequency mutation defects. That is, defect-free devices exhibit regular curves due to smooth frequency changes, while defective devices show abrupt slope changes or discontinuous curves due to frequency mutations, thus solving the problem of easy missed detection in traditional discrete sampling.

[0018] The above description is merely an overview of the technical solution of this utility model. In order to better understand the technical means of this utility model and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this utility model more obvious and understandable, specific embodiments of this utility model are given below. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the structure of the quartz crystal oscillator frequency change measurement device in the embodiment of this utility model;

[0021] Figure 2 This is a schematic diagram of the quartz crystal oscillator frequency mutation measurement device in an embodiment of the present invention;

[0022] Figure 3 This is a schematic diagram of the heating control unit circuit of the quartz crystal oscillator frequency change measurement device in this embodiment of the present invention.

[0023] Explanation of reference numerals in the attached drawings: 100, constant temperature bath assembly; 110, heat-conducting fixture; 111, quartz crystal oscillator; 120, heating control unit; 121, power semiconductor device; 130, clamping cover; 200, frequency measurement unit; 300, data processing and display unit; 400, metal shielding housing. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this utility model clearer, the embodiments of this utility model will be described in further detail below with reference to the accompanying drawings.

[0025] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. In the following description, when referring to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this invention. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this invention as detailed in the appended claims.

[0026] The overall concept of the technical solution provided by this utility model is as follows:

[0027] Please see Figures 1 to 2The quartz crystal oscillator frequency change measurement device includes:

[0028] The thermostatic bath assembly 100 includes a thermally conductive fixture 110 for fixing the quartz crystal oscillator 111 under test, and a heating control unit 120. The thermostatic bath assembly 100 is used to provide a stable and uniform temperature field for the quartz crystal oscillator 111 under test. The thermally conductive fixture 110 is made of a material with high thermal conductivity, and its function is to provide mechanical fixation for the quartz crystal oscillator 111 under test and establish an effective heat conduction path.

[0029] In one embodiment, the thermally conductive fixture 110 is provided with a groove or clamp whose shape matches that of the quartz crystal oscillator 111, for accommodating and fixing the quartz crystal oscillator 111.

[0030] The heating control unit 120 includes a power semiconductor device 121 and a temperature feedback circuit. The power semiconductor device 121 is used to heat the thermally conductive fixture 110, and the temperature feedback circuit is used to control the conduction state of the power semiconductor device 121. In one embodiment, the power semiconductor device 121 is mounted on a PCB and thermally coupled to the thermally conductive fixture 110. The power semiconductor device 121 is used to convert electrical energy into heat energy according to the current flowing through it and to heat the thermally conductive fixture 110.

[0031] The temperature feedback circuit is electrically connected to the power semiconductor device 121. The temperature feedback circuit is used to generate a control signal based on the received temperature signal, and to regulate the conduction state of the power semiconductor device 121 through the control signal.

[0032] By adjusting the conduction state of the power semiconductor device 121, the heating power applied to the heat-conducting fixture 110 can be controlled, thereby achieving temperature control of the fixture.

[0033] In one embodiment, the temperature feedback circuit continuously or discretely adjusts the conduction level of the power semiconductor device 121 by changing the voltage or current signal applied to the control terminal of the power semiconductor device 121, thereby achieving linear temperature control.

[0034] The frequency measurement unit 200 has a signal input terminal for connecting to the quartz crystal oscillator 111 housed in the heat-conducting fixture 110. The frequency measurement unit 200 is used to acquire and measure the frequency signal generated by the quartz crystal oscillator 111 during temperature changes in real time.

[0035] In one embodiment, the frequency measurement unit 200 may be a high-precision frequency meter or counter, whose signal input terminal is electrically connected to the signal output pin of the quartz crystal oscillator 111 via a coaxial cable, a high-frequency probe or a dedicated test fixture to capture its output signal.

[0036] The data processing and display unit 300 is connected to the signal output terminal of the frequency measurement unit 200. The data processing and display unit 300 is used to receive and display the frequency data output by the frequency measurement unit 200.

[0037] In one embodiment, the data processing and display unit 300 may be a general-purpose computer, an embedded industrial computer, or a dedicated test instrument with display capabilities. It establishes a communication connection with the frequency measurement unit 200 via a standard data interface, such as USB, GPIB, or LAN, to receive frequency measurement values ​​output in a time-series manner.

[0038] The data processing and display unit 300 is equipped with a display device, such as an LCD screen. It visualizes the received frequency data in real time as a frequency-time relationship curve.

[0039] By observing the frequency-time relationship curve displayed on the data processing and display unit 300, the operator can determine whether there is a sudden frequency change in the quartz crystal oscillator 111 housed in the heat-conducting fixture 110 during temperature changes.

[0040] The thermally conductive fixture of the constant temperature bath assembly 100 ensures that the oscillator under test is reliably fixed and that heat conduction is uniform. The heating control unit 120 integrates a power semiconductor device 121 and a temperature feedback circuit. Utilizing the high heating efficiency and fast response of semiconductors, it achieves linear temperature control of the thermally conductive fixture 110. This not only allows for adjustable heating slope and avoids sudden temperature changes, but also significantly shortens the thermal equilibrium time and improves testing efficiency. The frequency measurement unit 200 collects the oscillator output frequency in real time. Combined with the data processing and display unit 300, it plots the frequency data of the continuous time series. This can accurately capture temperature-dependent frequency change defects. That is, defect-free devices exhibit regular curves due to smooth frequency changes, while defective devices show sudden slope changes or discontinuous curves due to frequency changes. This solves the problem of easy missed detection in traditional discrete sampling.

[0041] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0042] In one specific embodiment of this utility model, the power semiconductor device 121 is a medium-power transistor. The medium-power transistor is thermally connected to the heat-conducting fixture 110, and the conduction current from its collector to its emitter can be precisely adjusted by controlling the conduction voltage between the base and emitter of the medium-power transistor.

[0043] When a medium-power transistor is turned on, there is an inherent internal resistance between its collector and emitter. According to Joule's law, the large current flowing through the collector-emitter path of the medium-power transistor, together with its internal resistance, continuously converts electrical energy into heat energy. In this operating mode, the function of the medium-power transistor is equivalent to a heating wire that can be precisely controlled by an electrical signal.

[0044] Specifically, the temperature feedback circuit provides a precise control current or voltage signal to the base of the medium-power transistor through its output. The magnitude of this control signal is calculated in real time by the temperature feedback circuit based on the difference between the detected actual temperature and the set temperature.

[0045] When the actual temperature of the heat-conducting fixture 101 is lower than the set value, the temperature feedback circuit outputs an increased control signal to the base of the medium-power transistor, which increases the base current, thereby deepening the collector-emitter conduction, increasing the conduction current, and correspondingly increasing the heating power.

[0046] Conversely, when the actual temperature approaches or exceeds the set value, the temperature feedback circuit outputs a reduced control signal to the base, which weakens the conduction of the transistor and reduces the heating power.

[0047] This closed-loop control mechanism enables precise regulation of the heating power of the medium-power transistor, thereby ensuring that the heat-conducting fixture 101 can change according to the preset temperature characteristic curve, providing a stable and reliable temperature environment for the frequency hopping test of the quartz crystal oscillator.

[0048] By using a medium-power transistor as the actuator and combining it with a temperature feedback circuit for closed-loop control of its base current, this embodiment can achieve rapid and stable temperature control of the heat-conducting fixture 110, meeting the requirements for linear temperature rise in the frequency change test of the quartz crystal oscillator 111.

[0049] In one specific embodiment of this utility model, the heat generated by the power semiconductor device 121 can be transferred to the heat-conducting fixture 110 through direct contact conduction. For example, the power semiconductor device 121 is in direct and close contact with the mounting surface of the heat-conducting fixture 110 through its package shell, and the heat energy is transferred between the two through the inter-solid molecular thermal motion, which is the most important heat transfer path.

[0050] In another embodiment, the metal substrate or heat sink of the power semiconductor device 121 is connected to the heat-conducting fixture 110 by welding to achieve thermal bonding at the molecular level and form a heat transfer path.

[0051] In one specific embodiment of this utility model, the temperature feedback circuit includes a temperature sensor and an operational amplifier. The temperature sensor is disposed on the thermostatic bath assembly 100 and is used to detect the temperature of the heat-conducting fixture 110 and generate a corresponding detection signal. The input terminal of the operational amplifier is electrically connected to the output terminal of the temperature sensor, and outputs a control signal to the control terminal of the power semiconductor device 121 based on the detection signal.

[0052] The power semiconductor device 121 employs a medium-power transistor. The base of this medium-power transistor, with its collector-emitter circuit connected in series, is connected to the output of the operational amplifier.

[0053] With the above settings, the temperature feedback circuit can monitor the temperature change of the heat-conducting fixture 110 in real time, and precisely control the conduction state of the medium-power transistor through the operational amplifier, thereby realizing closed-loop control of the temperature of the heat-conducting fixture 110 and ensuring that it operates according to the predetermined temperature change law during the test.

[0054] In one specific embodiment of this utility model, the temperature feedback circuit is a Wheatstone bridge circuit, and the temperature sensor is a negative temperature coefficient thermistor.

[0055] Specifically, please refer to Figure 3 Resistors R20, R21, R22 and negative temperature coefficient thermistor R23 together constitute a Wheatstone bridge circuit. Among them, the negative temperature coefficient thermistor R23 is located on the thermostatic bath assembly 100 and is used to sense the temperature change of the heat-conducting fixture 110.

[0056] The output of the Wheatstone bridge circuit is connected to the input of the operational amplifier U7. When the temperature of the thermally conductive fixture 110 is lower than the set value, the change in the resistance of the negative temperature coefficient thermistor R23 causes the bridge to become unbalanced, causing the operational amplifier U7 to output a control signal, which drives the transistors Q3 and Q4, which are power semiconductor devices 121, to conduct and generate heat.

[0057] As the temperature rises to the set value, the resistance of the negative temperature coefficient thermistor R23 decreases further, causing the output control voltage of operational amplifier U7 to decrease accordingly, thereby reducing the conduction current of transistors Q3 and Q4 and realizing automatic adjustment of heat generation.

[0058] Through the above-mentioned closed-loop control mechanism, this embodiment can keep the temperature of the heat-conducting fixture 110 within a stable set range, effectively preventing it from exceeding the specified value due to overheating, and ensuring the accuracy and reliability of temperature control.

[0059] In one specific embodiment of this utility model, the constant temperature bath assembly 100 further includes a pressing cover 130, which is used to press and fix the quartz crystal oscillator 111 onto the heat-conducting fixture 110.

[0060] The clamping cover 130 is positioned above the heat-conducting fixture 110 via a movable connector, such as a hinge or guide post. When the clamping cover 130 is in the closed state, it can clamp and fix the quartz crystal oscillator 111 to the mounting position of the heat-conducting fixture 110.

[0061] By setting the pressure cover 130, a tight contact between the outer shell of the quartz crystal oscillator 111 under test and the surface of the heat-conducting fixture 110 is ensured, minimizing the contact thermal resistance and thus significantly improving the heat conduction efficiency.

[0062] In one specific embodiment of this utility model, the thermally conductive fixture 110 is made of a material with high thermal conductivity and electrical insulation. In a preferred embodiment, the material of the thermally conductive fixture 110 is aluminum nitride. By using a material such as aluminum nitride, which has both excellent thermal conductivity and reliable electrical insulation, efficient heat conduction between the quartz crystal oscillator 111 and the fixture is ensured, guaranteeing the response speed and uniformity of temperature changes, while also achieving electrical isolation between the two.

[0063] In one specific embodiment of this utility model, please refer to Figure 2 The quartz crystal oscillator frequency change measurement device also includes a metal shielding housing 400.

[0064] The metal shielding shell 400 forms a sealed space, in which the constant temperature bath assembly 100 and the heating control unit 120 are disposed.

[0065] By setting up a metal shielding housing 400, the thermostatic bath assembly 100 and the heating control unit 120 are electromagnetically isolated from the external environment. This structural design can effectively shield the influence of external electromagnetic interference on temperature control and frequency measurement, while suppressing the interference of electromagnetic noise generated by the heating control unit 120 during operation on external measuring equipment.

[0066] The metal shielding housing 400 is preferably made of a highly conductive material, such as an aluminum or copper plate, and its shielding effect is ensured by reliable grounding measures. This design significantly improves the electromagnetic compatibility of the entire measurement system, provides a clean electrical environment for the frequency measurement of the quartz crystal oscillator 111, and further guarantees the accuracy and reliability of the test results.

[0067] In an extended embodiment of this invention, the quartz crystal oscillator frequency mutation measuring device further includes a temperature initialization unit for providing an initial low-temperature environment for the thermostatic bath assembly 100.

[0068] The temperature initialization unit includes, but is not limited to, embodiments employing an integrated semiconductor cooling unit or an external low-temperature environment providing device, wherein:

[0069] The integrated semiconductor cooling unit works in conjunction with the heating control unit 120. By using an independent semiconductor cooling chip, the heat-conducting fixture 110 is first cooled to a set initial low temperature, and then switched to the heating mode to achieve a continuous heating process from low temperature to high temperature.

[0070] An external cryogenic environment provision device refers to an external cryogenic chamber, which allows the entire measuring device or at least the portion containing the thermostat assembly 100 to reach and stabilize at the required initial low temperature before the start of the test by placing the entire measuring device inside an external cryogenic chamber.

[0071] Regardless of the specific implementation method, the core function of the temperature initialization unit is to provide the quartz crystal oscillator 111 under test with an initial test temperature lower than room temperature. Based on this, the heating control unit 120 implements precise linear heating control of the heat-conducting fixture 110, thereby creating a temperature change environment for the quartz crystal oscillator 111 that continuously and slowly rises from an initial low temperature to a target high temperature.

[0072] This improvement enables continuous scanning testing over a wider temperature range, fully covering the entire temperature range where the quartz crystal oscillator 111 may experience frequency abrupt defects, further enhancing the comprehensiveness and reliability of defect detection. By observing the frequency output characteristics of the quartz crystal oscillator 111 during this continuous temperature variation process, it is possible to effectively identify whether it has temperature-dependent frequency abrupt defects.

[0073] Although preferred embodiments of the present invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the present invention.

[0074] Obviously, those skilled in the art can make various modifications and variations to the embodiments of this utility model without departing from the spirit and scope of the embodiments of this utility model. Therefore, if these modifications and variations to the embodiments of this utility model fall within the scope of the claims of this utility model and their equivalents, then this utility model also intends to include these modifications and variations.

Claims

1. A device for measuring frequency mutations in a quartz crystal oscillator, characterized in that, include: A constant temperature bath assembly includes a heat-conducting fixture for fixing a quartz crystal oscillator under test, and a heating control unit. The heating control unit includes a power semiconductor device and a temperature feedback circuit. The power semiconductor device is used to heat the heat-conducting fixture, and the temperature feedback circuit is used to control the conduction state of the power semiconductor device. A frequency measurement unit, wherein the signal input terminal of the frequency measurement unit is used to connect to a quartz crystal oscillator housed in the heat-conducting fixture; A data processing and display unit is connected to the signal output terminal of the frequency measurement unit. The data processing and display unit is used to receive and display the frequency data output by the frequency measurement unit.

2. The quartz crystal oscillator frequency mutation measuring device according to claim 1, characterized in that, The power semiconductor device is a medium-power transistor.

3. The quartz crystal oscillator frequency mutation measuring device according to claim 1, characterized in that, The temperature feedback circuit includes a temperature sensor and an operational amplifier. The temperature sensor is mounted on the constant temperature bath assembly, and the operational amplifier outputs a control signal to the power semiconductor device based on the detection signal from the temperature sensor.

4. The quartz crystal oscillator frequency mutation measuring device according to claim 3, characterized in that, The temperature feedback circuit is a Wheatstone bridge circuit, and the temperature sensor is a negative temperature coefficient thermistor.

5. The quartz crystal oscillator frequency mutation measuring device according to claim 1, characterized in that, The thermostatic bath assembly also includes a pressing cover, which is used to press and fix the quartz crystal oscillator onto the heat-conducting fixture.

6. A quartz crystal oscillator frequency mutation measuring device according to any one of claims 1 to 5, characterized in that, The heat-conducting fixture is made of a material with high thermal conductivity and electrical insulation.

7. The quartz crystal oscillator frequency mutation measuring device according to claim 6, characterized in that, The material of the heat-conducting fixture is aluminum nitride.

8. The quartz crystal oscillator frequency mutation measuring device according to claim 1, characterized in that, It also includes a metal shielding shell, and the constant temperature bath assembly and the heating control unit are disposed in the sealed space formed by the metal shielding shell.

9. The quartz crystal oscillator frequency mutation measuring device according to claim 1, characterized in that, It also includes a temperature initialization unit for providing an initial low-temperature environment for the thermostatic bath assembly.

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