Quartz crystal oscillator frequency abrupt change measuring method and device

Abstract

The invention provides a quartz crystal oscillator frequency abrupt change measuring method and device, and relates to the technical field of electronic component testing. The method comprises the following steps that a thermostatic bath assembly is provided, the thermostatic bath assembly comprises a heat conduction jig, and the heat conduction jig is used for fixing a tested quartz crystal oscillator; controlling the thermostatic bath assembly to heat from the initial temperature to the target temperature at a preset heating rate; in the heating process, the output frequency of the quartz crystal oscillator is measured in real time at a preset sampling rate, and sequence data of the frequency changing along with time are obtained; generating a frequency-time relation curve based on the sequence data; and analyzing the smoothness or slope change of the frequency-time relation curve so as to detect whether the quartz crystal oscillator has frequency abrupt change or not. According to the method, the key problem of frequency mutation leak detection is solved, effective data support is provided for optimizing product design, and the technical bottleneck restricting the quality improvement of the quartz crystal oscillator product is broken through on the whole.

Description

Technical Field

[0001] This invention relates to the field of electronic component testing technology, and in particular to a method and apparatus for measuring frequency mutations in a quartz crystal oscillator. Background Technology

[0002] Quartz crystal oscillators, as high-precision frequency output components based on quartz wafers, possess excellent frequency stability at specific temperatures due to their high Q value. However, within the actual operating temperature range, their output frequency is often affected by temperature variations, resulting in a phenomenon known as temperature drift. Ideally, the frequency-temperature characteristic exhibits a smooth cubic curve without abrupt frequency changes. However, improper design of structural parameters such as electrode side ratio and dimensions can easily induce parasitic coupling effects under specific temperature conditions, leading to abrupt frequency changes, disrupting the original smooth temperature characteristic curve, and resulting in defective products. This type of frequency abrupt defect is temperature-dependent, appearing only around a specific temperature point. Once the temperature exceeds this point, the frequency characteristics may return to normal, or a permanent frequency step jump may occur.

[0003] Currently, the industry commonly uses high and low temperature chambers combined with discrete temperature sampling points for temperature characteristic testing. For example, 5 to 10 test points are selected within the range of -40℃ to 85℃, and each temperature point needs to be held at that temperature for 5 to 10 minutes to ensure thermal equilibrium. This method is time-consuming and inefficient. Due to the limited number of sampling points and large intervals, if a frequency change occurs at a non-test temperature point, this method cannot effectively identify defective oscillators, resulting in missed detections. Therefore, existing technologies struggle to achieve continuous, rapid, and comprehensive temperature and frequency change detection, becoming a key bottleneck restricting product quality improvement. Summary of the Invention

[0004] The purpose of this invention is to provide a method and apparatus for measuring frequency mutations in quartz crystal oscillators, in order to solve the technical problem mentioned in the background art: the existing technology is unable to achieve continuous, rapid, and full-coverage temperature and frequency mutation detection, which has become a key bottleneck restricting the improvement of product quality.

[0005] To achieve the above objectives, according to one aspect of the present invention, a method for measuring frequency abrupt changes in a quartz crystal oscillator is provided, comprising the following steps:

[0006] A constant temperature bath assembly is provided, the constant temperature bath assembly including a heat-conducting fixture, the heat-conducting fixture being used to fix the quartz crystal oscillator under test;

[0007] The thermostatic bath assembly is controlled to heat from the initial temperature to the target temperature at a predetermined heating rate.

[0008] During the heating process, the output frequency of the quartz crystal oscillator is measured in real time at a predetermined sampling rate to obtain sequence data of frequency change over time.

[0009] Based on the sequence data, a frequency-time relationship curve is generated;

[0010] Analyze the smoothness or slope changes of the frequency-time relationship curve to detect whether there are frequency abrupt changes in the quartz crystal oscillator.

[0011] In one possible implementation, the step of controlling the thermostatic bath assembly to heat at a predetermined heating rate includes:

[0012] The heating control unit controls the power semiconductor device to heat the heat-conducting fixture. The heating control unit includes a temperature feedback circuit for adjusting the conduction state of the power semiconductor device according to the real-time temperature of the thermostatic bath assembly, so as to achieve the predetermined heating rate.

[0013] In one possible implementation, the temperature feedback circuit is a Wheatstone bridge circuit, including a negative temperature coefficient thermistor and an operational amplifier. The negative temperature coefficient thermistor is used to detect the temperature of the thermostatic bath assembly, and the operational amplifier controls the power semiconductor device according to the output signal of the Wheatstone bridge.

[0014] In one possible implementation, the step of analyzing the frequency-time relationship curve includes:

[0015] Calculate the frequency difference between adjacent sampling time points in the sequence data;

[0016] Determine whether the frequency difference exceeds a preset threshold;

[0017] If the frequency exceeds the limit, it is determined that the quartz crystal oscillator has a frequency mutation.

[0018] In one possible implementation, the step of analyzing the frequency-time relationship curve includes:

[0019] Calculate the rate of change of frequency over multiple time intervals;

[0020] Determine whether the rate of change of frequency has abruptly changed;

[0021] If a mutation occurs, it is determined that a frequency mutation exists.

[0022] In one possible implementation, the predetermined sampling rate is from 10 times / second to 100 times / second.

[0023] In one possible implementation, the predetermined heating rate is 15°C / min to 25°C / min.

[0024] In one possible implementation, prior to the step of providing the thermostatic bath assembly, the following is also included:

[0025] The thermostatic bath assembly is cooled to the initial temperature by a temperature initialization unit, wherein the initial temperature is lower than the ambient temperature.

[0026] According to another aspect of the present disclosure, a quartz crystal oscillator frequency mutation measuring device is provided, the device comprising:

[0027] A thermostatic bath assembly includes a heat-conducting fixture and a heating control unit. The heat-conducting fixture is used to fix the quartz crystal oscillator under test, and the heating control unit is used to control the thermostatic bath assembly to heat from an initial temperature to a target temperature at a predetermined heating rate.

[0028] A frequency measurement unit is used to measure the output frequency of the quartz crystal oscillator in real time at a predetermined sampling rate during the heating process, so as to obtain the sequence data of frequency change over time.

[0029] The data processing and display unit is used to generate a frequency-time relationship curve based on the sequence data, and analyze the smoothness or slope changes of the frequency-time relationship curve to detect frequency abrupt changes.

[0030] In one possible implementation, the heating control unit includes a power semiconductor device and a temperature feedback circuit, the temperature feedback circuit being used to adjust the conduction state of the power semiconductor device according to the real-time temperature of the thermostatic bath assembly.

[0031] 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:

[0032] This invention provides a method for measuring frequency mutations in quartz crystal oscillators. By controlling a constant temperature bath assembly to continuously heat at a predetermined heating rate and measuring the output frequency in real time at a predetermined sampling rate throughout the process, it achieves continuous monitoring of the temperature characteristics of the quartz crystal oscillator across the entire range. This eliminates detection blind spots caused by sparse sampling points and significantly improves the detection capability for frequency mutation defects. Simultaneously, this method eliminates the long-term heat preservation required at each temperature point in traditional methods, drastically shortening the testing cycle from several hours to a single rapid continuous scan, greatly improving detection efficiency. The frequency-time relationship curve generated based on the acquired high-density sequence data clearly shows the complete trajectory of frequency changes. By analyzing the curve's smoothness or slope changes, instantaneous frequency mutations can be accurately identified, providing a more reliable basis for product quality judgment. This method not only solves the key problem of missed frequency mutation detection but also provides effective data support for optimizing product design, thus breaking through the technical bottleneck restricting the improvement of quartz crystal oscillator product quality.

[0033] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and in order to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0034] Figure 1 This is a flowchart of a method for measuring frequency abrupt changes in a quartz crystal oscillator according to an exemplary embodiment.

[0035] Figure 2 This is a schematic diagram of a quartz crystal oscillator frequency change measurement device according to an exemplary embodiment;

[0036] Figure 3 This is a schematic diagram of a module for measuring frequency abrupt changes of a quartz crystal oscillator according to an exemplary embodiment;

[0037] Figure 4 This is a schematic diagram of the heating control unit circuit of a quartz crystal oscillator frequency change measuring device according to an exemplary embodiment.

[0038] Figure 5 This is a frequency-time relationship curve of a normal, non-frequency-hopping crystal oscillator according to an exemplary embodiment.

[0039] Figure 6 A frequency-time relationship curve of a quartz crystal oscillator with abnormal frequency hopping provided according to an exemplary embodiment.

[0040] 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

[0041] To make the objectives, technical solutions, and advantages of this disclosure clearer, the embodiments of this disclosure will be described in further detail below with reference to the accompanying drawings.

[0042] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates 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 disclosure. Rather, they are merely examples of systems and methods consistent with some aspects of this disclosure as detailed in the appended claims.

[0043] Figure 1 For a flowchart of a method for measuring frequency abrupt changes in a quartz crystal oscillator according to an exemplary embodiment, please refer to [link / reference needed]. Figures 1 to 3 The method includes the following steps:

[0044] In step S100, a constant temperature bath assembly 100 is provided. The constant temperature bath assembly 100 includes a thermally conductive fixture 110, which is used to fix the quartz crystal oscillator 111 under test. Specifically, the constant temperature 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.

[0045] 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.

[0046] In one specific embodiment of the present invention, the thermostatic bath assembly 100 further includes a pressing cover 120, which is used to press and fix the quartz crystal oscillator 111 onto the heat-conducting fixture 110.

[0047] The clamping cover 120 is positioned above the heat-conducting fixture 110 via a movable connector, such as a hinge or guide post. When the clamping cover 120 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.

[0048] By setting the pressure cover 120, 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.

[0049] In one specific embodiment of the present invention, 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.

[0050] In step S200, the thermostatic bath assembly 100 is controlled to heat from the initial temperature to the target temperature at a predetermined heating rate. Specifically, the thermostatic bath assembly 100 also includes a heating control unit 200, which controls the thermostatic bath assembly 100 to heat from the initial temperature to the target temperature at a predetermined heating rate.

[0051] In step S300, during the heating process, the output frequency of the quartz crystal oscillator 111 is measured in real time at a predetermined sampling rate to obtain sequence data of frequency changes over time; specifically, the above frequency measurement process is implemented through a frequency measurement unit 300. The signal input terminal of the frequency measurement unit 300 is used to connect to the quartz crystal oscillator 111 housed in the heat-conducting fixture 110;

[0052] Throughout the process of the constant temperature bath assembly 100 being continuously heated from the initial temperature to the target temperature, the frequency measurement unit 300 continuously measures the output frequency of the quartz crystal oscillator 111 in real time at a predetermined sampling rate and records the frequency measurement value corresponding to each sampling moment, thereby obtaining a set of frequency change sequence data over time.

[0053] In one embodiment, the frequency measurement unit 300 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.

[0054] In step S400, a frequency-time relationship curve is generated based on the sequence data; specifically, the curve generation process is implemented through a data processing and display unit 400. The data processing and display unit 400 is connected to the signal output terminal of the frequency measurement unit 300, and is used to receive and display the frequency data output by the frequency measurement unit 300. The data processing and display unit 400 is used to receive the frequency data output from the frequency measurement unit 300 and display the data.

[0055] In one embodiment, the data processing and display unit 400 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 300 via a standard data interface, such as USB, GPIB, or LAN, to receive frequency measurement values ​​output in a time-series manner.

[0056] The data processing and display unit 400 is equipped with a display device, such as an LCD screen. It visualizes the received frequency data in real-time as a frequency-time curve. The data processing and display unit 400, through its internal software system, converts the received frequency measurements arranged in a time series into a continuous curve graph, where the horizontal axis represents time and the vertical axis represents the frequency measurement value.

[0057] Through the above settings, this step converts the collected discrete frequency sequence data into an intuitive continuous curve, providing a visual analytical basis for subsequent identification of frequency abrupt changes by observing the curve's morphological characteristics.

[0058] In step S500, the smoothness or slope change of the frequency-time relationship curve is analyzed to detect whether there is a frequency abrupt change in the quartz crystal oscillator 111. Specifically, the analysis process is completed by observing the morphological characteristics of the frequency-time relationship curve displayed on the data processing and display unit 400.

[0059] When the quartz crystal oscillator 111 does not have a frequency change defect, its frequency-time relationship curve presents a smooth and continuous change trajectory; when the quartz crystal oscillator 111 has a temperature-dependent frequency change defect, its frequency-time relationship curve will show a sudden change in slope or discontinuity at a specific moment.

[0060] By controlling the constant temperature bath assembly 100 to continuously heat at a predetermined heating rate and measuring the output frequency in real time at a predetermined sampling rate throughout the process, continuous monitoring of the temperature characteristics of the quartz crystal oscillator 111 across the entire range is achieved. This eliminates the detection blind zone caused by sparse sampling points and significantly improves the detection capability for frequency abrupt defects. Simultaneously, this method eliminates the long-term heat preservation required at each temperature point in traditional methods, drastically shortening the testing cycle from several hours to a single rapid continuous scan, greatly improving detection efficiency. The frequency-time relationship curve generated based on the acquired high-density sequence data clearly shows the complete trajectory of frequency changes. By analyzing the curve's smoothness or slope changes, instantaneous frequency abrupt changes can be accurately identified, providing a more reliable basis for product quality judgment. This method not only solves the key problem of missed frequency abrupt changes but also provides effective data support for optimizing product design, breaking through the technical bottleneck restricting the improvement of the quartz crystal oscillator 111 product quality.

[0061] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0062] In one embodiment, the step of controlling the thermostatic bath assembly 100 to heat at a predetermined heating rate includes:

[0063] The heating control unit 200 controls the power semiconductor device 210 to heat the heat-conducting fixture 110. The heating control unit 200 includes a temperature feedback circuit, which adjusts the conduction state of the power semiconductor device 210 according to the real-time temperature of the thermostatic bath assembly 100 to achieve a predetermined heating rate.

[0064] Specifically, the heating control unit 200 includes a power semiconductor device 210 and a temperature feedback circuit. The power semiconductor device 210 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 210. In one embodiment, the power semiconductor device 210 is mounted on a PCB and thermally coupled to the thermally conductive fixture 110. The power semiconductor device 210 is used to convert electrical energy into heat energy according to the current flowing through it and to heat the thermally conductive fixture 110.

[0065] The temperature feedback circuit is electrically connected to the power semiconductor device 210. The temperature feedback circuit is used to adjust the conduction state of the power semiconductor device 210 according to the real-time temperature of the thermostat assembly 100 in order to achieve a predetermined heating rate.

[0066] Furthermore, the temperature feedback circuit acquires a real-time temperature signal through a temperature sensor located on the constant temperature bath assembly 100, compares the signal with a preset temperature threshold, generates a corresponding control signal based on the comparison result, and continuously controls the conduction degree of the power semiconductor device 210 by adjusting the voltage or current applied to the control terminal, thereby achieving linear temperature control.

[0067] In one specific embodiment of the present invention, the power semiconductor device 210 is a medium-power transistor. The medium-power transistor is thermally connected to the thermally conductive 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.

[0068] 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.

[0069] 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.

[0070] When the actual temperature of the heat-conducting fixture 110 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.

[0071] 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.

[0072] This closed-loop control mechanism enables precise regulation of the heating power of the medium-power transistor, thereby ensuring that the heat-conducting fixture 110 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 111.

[0073] 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.

[0074] In one specific embodiment of the present invention, the heat generated by the power semiconductor device 210 can be transferred to the heat-conducting fixture 110 through direct contact conduction. For example, the power semiconductor device 210 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 thermal vibration of molecules between solids. This is the most important heat transfer path.

[0075] In another embodiment, the metal substrate or heat sink of the power semiconductor device 210 is permanently connected to the heat-conducting fixture 110 by welding or high-temperature sintering, achieving molecular-level thermal bonding and forming a heat transfer path.

[0076] In one specific embodiment of the present invention, the temperature feedback circuit is a Wheatstone bridge circuit, including a negative temperature coefficient thermistor and an operational amplifier. The negative temperature coefficient thermistor is used to detect the temperature of the thermostatic bath assembly 100, and the operational amplifier controls the power semiconductor device 210 according to the output signal of the Wheatstone bridge. For details, please refer to... Figure 4 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.

[0077] 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 210, to conduct and generate heat.

[0078] 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.

[0079] Through the aforementioned closed-loop control mechanism, the temperature feedback circuit can precisely control the heat-conducting fixture 110 to achieve continuous and uniform heating from the initial temperature to the target temperature according to the predetermined heating rate, providing a stable and reliable temperature change environment for subsequent frequency change detection.

[0080] In one specific embodiment of the present invention, the step of analyzing the frequency-time relationship curve includes:

[0081] Calculate the frequency difference between adjacent sampling time points in the sequence data;

[0082] Determine whether the frequency difference exceeds a preset threshold;

[0083] If the frequency exceeds the limit, it is determined that there is a frequency abrupt change in the quartz crystal oscillator 111.

[0084] Specifically, the frequency difference is calculated by performing a difference operation on the frequency measurements at two adjacent sampling time points. Let the frequency value of the i-th sampling point be f(i), and the frequency value of the (i+1)-th sampling point be f(i+1), then the frequency difference Δf = |f(i+1) - f(i)|.

[0085] The preset threshold is set based on the maximum permissible frequency drift rate of the quartz crystal oscillator 111 under normal temperature change conditions. Considering that the normal frequency drift caused by temperature change during continuous heating is relatively slow, while frequency abrupt changes are instantaneous abnormal jumps, the preset threshold should be greater than the maximum frequency difference between adjacent sampling points caused by normal temperature drift, while being less than the minimum value of the identifiable frequency abrupt change.

[0086] In one embodiment, the judgment process is performed by the data processing and display unit 400, which compares each calculated frequency difference Δf with a preset threshold. When Δf exceeds the preset threshold, the abnormal time point is recorded, and it is determined that a frequency change has occurred in the quartz crystal oscillator 111 at the temperature corresponding to this time point.

[0087] In another embodiment, to avoid misjudgment caused by accidental interference, a frequency change can be determined only when the frequency difference of multiple consecutive sampling points exceeds a threshold.

[0088] The above technical solution enables quantitative analysis of frequency-time relationship curves, accurately and objectively identifying frequency abrupt changes, improving the accuracy and reliability of detection, and effectively solving the subjectivity and missed detection problems caused by reliance on manual interpretation in traditional methods.

[0089] In one specific embodiment of the present invention, the step of analyzing the frequency-time relationship curve may further include:

[0090] Calculate the rate of change of frequency over multiple time intervals;

[0091] Determine whether the rate of change of frequency has abruptly changed;

[0092] If a mutation occurs, it is determined that a frequency mutation exists.

[0093] Specifically, the rate of change of frequency is calculated by selecting frequency data within a fixed time window and calculating the slope. Let the length of the time window be Δt, and the corresponding frequency change be Δf, then the rate of change of frequency k = Δf / Δt.

[0094] The determination of abrupt changes in the rate of frequency change is based on the difference in the rate of frequency change within adjacent time windows. Let the rate of frequency change in the i-th time window be k(i), and the rate of frequency change in the (i+1)-th time window be k(i+1), then the difference in the rate of change Δk = |k(i+1) - k(i)|.

[0095] In one embodiment, when the rate of change difference Δk exceeds a preset rate of change threshold, it is determined that a sudden change in the frequency rate of change has occurred. The rate of change threshold is set based on the maximum permissible difference in the rate of change of the quartz crystal oscillator 111 under normal temperature variation conditions.

[0096] The calculation and judgment process of the frequency change rate is performed by the data processing and display unit 400. This unit marks the identified frequency change rate mutation points on the frequency-time relationship curve and records the corresponding occurrence time.

[0097] The above technical solution enables quantitative analysis of the slope characteristics of the frequency-time relationship curve, accurately identifying instantaneous frequency mutations caused by temperature-dependent defects, and improving the accuracy and reliability of detection.

[0098] Preferably, the predetermined sampling rate is between 10 times / second and 100 times / second. Specifically, this sampling rate range is set based on the following technical considerations: the sampling rate needs to be high enough to ensure that instantaneous frequency changes that may occur during continuous heating are captured. When the sampling rate is below 10 times / second, short-duration frequency jumps may not be reliably captured due to excessively large sampling intervals, resulting in a risk of missed detections. When the sampling rate is above 100 times / second, although it can theoretically capture more instantaneous changes, it will generate an excessively large amount of data, placing excessive demands on the performance of the data processing unit, while the improvement in detection effect is not significant.

[0099] In one specific embodiment, the predetermined sampling rate is set to 50 times / second. This sampling rate can balance the burden on the data processing system while ensuring effective capture of frequency mutations, thereby optimizing detection efficiency and reliability.

[0100] The frequency measurement unit 300 is configured to continuously sample the output frequency of the quartz crystal oscillator 111 at equal intervals throughout the continuous heating process of the thermostatic bath assembly 100 according to a selected predetermined sampling rate, thereby obtaining high time resolution frequency sequence data and providing a data basis for subsequent accurate identification of frequency abrupt changes.

[0101] Preferably, the predetermined heating rate is 15°C / min to 25°C / min. Specifically, this heating rate range is set based on the following technical considerations: significantly improving testing efficiency while ensuring effective excitation and detection of temperature-dependent frequency abrupt changes. A heating rate of 15°C / min to 25°C / min, compared to the traditional testing method which requires holding at each temperature point for 5-10 minutes, can control the complete scan time of the -40°C to 85°C temperature range to within 10 minutes, achieving an order-of-magnitude improvement in testing efficiency.

[0102] In one specific embodiment, the predetermined heating rate is set to 20°C / minute. At this rate, scanning the 125°C temperature range takes only 6.25 minutes, and with a sampling rate of 50 times / second, more than 18,000 valid data points can be obtained across the entire temperature range, fully ensuring the reliability of frequency change detection.

[0103] The heating rate is precisely controlled by the heating control unit 200, which uses a temperature feedback circuit to precisely control the power semiconductor device 210, ensuring that the heat-conducting fixture 110 maintains a uniform heating rate according to the set heating rate, thus providing optimized temperature change conditions for rapid and accurate detection of frequency mutations.

[0104] In one specific embodiment of the present invention, prior to the step of providing the thermostatic bath assembly 100, the method further includes:

[0105] The temperature initialization unit cools the thermostatic bath assembly 100 to an initial temperature, which is lower than the ambient temperature. Specifically, the temperature initialization unit includes an integrated semiconductor refrigeration unit or an external low-temperature environment supply device. When an integrated semiconductor refrigeration unit is used, the heat-conducting fixture 110 is actively cooled by thermal coupling between the semiconductor refrigeration chip and the heat-conducting fixture 110. When an external low-temperature environment supply device is used, the entire thermostatic bath assembly 100 is placed in an external low-temperature chamber, and the overall temperature is reduced by an external refrigeration system.

[0106] In one embodiment, the temperature initialization unit and the heating control unit 200 work together to form a complete temperature control system. After the temperature initialization unit completes the initial low temperature setting, the system automatically switches to the operating mode of the heating control unit 200 and begins to execute a continuous heating process from the initial temperature to the target temperature at a predetermined heating rate.

[0107] By setting a temperature initialization unit, the test process is ensured to start from an initial temperature lower than the ambient temperature, enabling complete detection of the frequency characteristics of the quartz crystal oscillator 111 across the entire operating temperature range. In particular, it can effectively detect frequency abrupt changes that may occur in the low-temperature region.

[0108] In one specific embodiment, Figure 5 and Figure 6 The frequency-time relationship curve provided according to an exemplary embodiment of the present invention is obtained by linearly heating the thermostat assembly at a predetermined heating rate after it is powered on during the test, and continuously acquiring the output frequency of the quartz crystal oscillator at a predetermined sampling rate by the frequency measurement unit. After receiving the frequency data, the data processing and display unit calculates the deviation value relative to the nominal frequency and plots the curve in real time with time as the abscissa and frequency deviation as the ordinate.

[0109] like Figure 5 As shown, a normal quartz crystal oscillator without frequency hopping defects exhibits a smooth frequency-time curve with a continuously changing slope throughout the entire heating process. In particular, within the critical observation range of 40 to 100 seconds, the curve's upward slope remains gentle and without any abrupt changes.

[0110] like Figure 6 As shown, a quartz crystal oscillator with frequency hopping defects exhibits a significant steep change in slope in its frequency-time curve within a corresponding time period, such as from 40 seconds to 100 seconds. This is manifested as a discontinuity in the curve trajectory or a sudden change in local slope. This abnormal morphology indicates that a frequency jump has occurred near a specific temperature point.

[0111] By constructing a frequency-time relationship curve instead of the traditional frequency-temperature curve, the method cleverly utilizes the characteristic that time and temperature strictly correspond under controllable linear heating conditions, and that temperature will not change abruptly. This ensures that as long as a sufficiently high frequency sampling rate is maintained, any transient frequency jump will inevitably be captured and manifested on the curve as a sudden change in slope or a non-smooth feature, thus solving the problem of missed detection caused by the large temperature interval in traditional temperature point testing.

[0112] A constant-temperature bath technology is employed to achieve continuous and controllable heating, resulting in a simple structure, low cost, and high efficiency. This method precisely regulates the heating rate by controlling the heating power and automatically reduces the power after reaching the target temperature to maintain temperature stability, thus avoiding the risk of overheating. The entire testing process eliminates the need for time-consuming temperature holding at discrete temperature points, enabling rapid, comprehensive, and blind-zone-free detection of the temperature characteristics of quartz crystal oscillators. This provides an efficient and reliable solution for accurately identifying products with defects such as parasitic coupling and offers researchers an intuitive and accurate basis for design improvements.

[0113] Furthermore, refer to Figures 2 to 4This disclosure also provides a device for measuring frequency mutations in a quartz crystal oscillator, comprising:

[0114] The thermostatic bath assembly 100 includes a heat-conducting fixture 110 and a heating control unit 200. The heat-conducting fixture 110 is used to fix the quartz crystal oscillator 111 under test, and the heating control unit 200 is used to control the thermostatic bath assembly 100 to heat from the initial temperature to the target temperature at a predetermined heating rate.

[0115] The frequency measurement unit 300 is used to measure the output frequency of the quartz crystal oscillator 111 in real time at a predetermined sampling rate during the heating process, and to obtain the sequence data of frequency change over time.

[0116] The data processing and display unit 400 is used to generate frequency-time relationship curves based on sequence data and analyze the smoothness or slope changes of the frequency-time relationship curves to detect frequency abrupt changes.

[0117] Specifically, the thermally conductive fixture 110 in the thermostatic bath assembly 100 is made of a material with high thermal conductivity and has a positioning structure that matches the shape of the quartz crystal oscillator 111 under test. The heating control unit 200 includes a power semiconductor device 210 and a temperature feedback circuit, which achieves precise temperature control of the thermally conductive fixture 110 through closed-loop control.

[0118] In one embodiment, the frequency measurement unit 300 is a high-precision frequency meter, which is connected to the quartz crystal oscillator 111 under test via a shielded cable to continuously collect frequency data at a preset sampling rate.

[0119] In another embodiment, the data processing and display unit 400 includes an industrial computer and a display device, receives sequence data transmitted by the frequency measurement unit 300 through a data interface, generates a frequency-time relationship curve in real time, and automatically identifies frequency abrupt changes by analyzing the slope changes of the curve.

[0120] The components of this measuring device work together to achieve continuous and rapid detection of the frequency characteristics of the quartz crystal oscillator 111 across the entire temperature range, effectively solving the problems of low efficiency and missed detection in traditional discrete temperature point testing methods.

[0121] In one specific embodiment of the present invention, the heating control unit 200 includes a power semiconductor device 210 and a temperature feedback circuit. The temperature feedback circuit is used to adjust the conduction state of the power semiconductor device 210 according to the real-time temperature of the constant temperature bath assembly 100. Specifically, the temperature feedback circuit acquires a real-time temperature signal through a temperature sensor disposed on the heat-conducting fixture 110, compares the signal with a preset threshold, generates a corresponding control signal based on the comparison result, and continuously controls the conduction degree of the power semiconductor device 210 by adjusting the voltage or current applied to the control terminal of the power semiconductor device 210.

[0122] In one embodiment, the temperature feedback circuit includes a Wheatstone bridge circuit and an operational amplifier. One arm of the Wheatstone bridge uses a negative temperature coefficient thermistor as a temperature sensing element. The operational amplifier detects the imbalance voltage of the bridge and amplifies it before outputting a control signal to the control terminal of the power semiconductor device 210.

[0123] The temperature feedback circuit monitors the temperature change of the heat-conducting fixture 110 in real time and dynamically adjusts the conduction state of the power semiconductor device 210 to ensure that the heat-conducting fixture 110 achieves continuous and uniform heating from the initial temperature to the target temperature according to the predetermined heating rate, providing a stable and reliable temperature change environment for frequency change detection.

[0124] In one specific embodiment of the present invention, the quartz crystal oscillator frequency change measurement device further includes a metal shielding housing 500.

[0125] The metal shielding shell 500 forms a sealed space, in which the constant temperature bath assembly 100 and the heating control unit 200 are disposed.

[0126] By incorporating a metal shielding housing 500, the thermostatic bath assembly 100 and the heating control unit 200 are electromagnetically isolated from the external environment. This structural design effectively shields the effects of external electromagnetic interference on temperature control and frequency measurement, while also suppressing the interference of electromagnetic noise generated by the heating control unit 200 during operation on external measuring equipment.

[0127] The metal shielding housing 500 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.

[0128] Any aspects of this invention not described in detail are well-known to those skilled in the art.

[0129] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A method for measuring frequency abrupt changes in a quartz crystal oscillator, characterized in that, Includes the following steps: A constant temperature bath assembly is provided, the constant temperature bath assembly including a heat-conducting fixture, the heat-conducting fixture being used to fix the quartz crystal oscillator under test; The thermostatic bath assembly is controlled to heat from the initial temperature to the target temperature at a predetermined heating rate. During the heating process, the output frequency of the quartz crystal oscillator is measured in real time at a predetermined sampling rate to obtain sequence data of frequency change over time. Based on the sequence data, a frequency-time relationship curve is generated; Analyze the smoothness or slope changes of the frequency-time relationship curve to detect whether there are frequency abrupt changes in the quartz crystal oscillator.

2. The method for measuring frequency mutations in a quartz crystal oscillator according to claim 1, characterized in that, The step of controlling the thermostat assembly to heat at a predetermined heating rate includes: The heating control unit controls the power semiconductor device to heat the heat-conducting fixture. The heating control unit includes a temperature feedback circuit for adjusting the conduction state of the power semiconductor device according to the real-time temperature of the thermostatic bath assembly, so as to achieve the predetermined heating rate.

3. The method for measuring frequency mutations in a quartz crystal oscillator according to claim 2, characterized in that, The temperature feedback circuit is a Wheatstone bridge circuit, including a negative temperature coefficient thermistor and an operational amplifier. The negative temperature coefficient thermistor is used to detect the temperature of the constant temperature bath assembly, and the operational amplifier controls the power semiconductor device according to the output signal of the Wheatstone bridge.

4. The method for measuring frequency mutations in a quartz crystal oscillator according to claim 1, characterized in that, The steps for analyzing the frequency-time relationship curve include: Calculate the frequency difference between adjacent sampling time points in the sequence data; Determine whether the frequency difference exceeds a preset threshold; If the frequency exceeds the limit, it is determined that the quartz crystal oscillator has a frequency mutation.

5. The method for measuring frequency mutations in a quartz crystal oscillator according to claim 1, characterized in that, The steps for analyzing the frequency-time relationship curve include: Calculate the rate of change of frequency over multiple time intervals; Determine whether the rate of change of frequency has abruptly changed; If a mutation occurs, it is determined that a frequency mutation exists.

6. The method for measuring frequency mutations in a quartz crystal oscillator according to claim 1, characterized in that, The predetermined sampling rate is from 10 times / second to 100 times / second.

7. The method for measuring frequency mutations in a quartz crystal oscillator according to claim 1, characterized in that, The predetermined heating rate is 15°C / minute to 25°C / minute.

8. The method for measuring frequency mutations in a quartz crystal oscillator according to claim 1, characterized in that, Prior to the step of providing the thermostatic bath assembly, the method further includes: The thermostatic bath assembly is cooled to the initial temperature by a temperature initialization unit, wherein the initial temperature is lower than the ambient temperature.

9. A device for measuring frequency mutations in a quartz crystal oscillator, characterized in that, include: A thermostatic bath assembly includes a heat-conducting fixture and a heating control unit. The heat-conducting fixture is used to fix the quartz crystal oscillator under test, and the heating control unit is used to control the thermostatic bath assembly to heat from an initial temperature to a target temperature at a predetermined heating rate. A frequency measurement unit is used to measure the output frequency of the quartz crystal oscillator in real time at a predetermined sampling rate during the heating process, so as to obtain the sequence data of frequency change over time. The data processing and display unit is used to generate a frequency-time relationship curve based on the sequence data, and analyze the smoothness or slope changes of the frequency-time relationship curve to detect frequency abrupt changes.

10. A quartz crystal oscillator frequency mutation measuring device according to claim 9, characterized in that, The heating control unit includes a power semiconductor device and a temperature feedback circuit. The temperature feedback circuit is used to adjust the conduction state of the power semiconductor device according to the real-time temperature of the constant temperature bath assembly.

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