Performance detection method and system for high impedance of PCB (Printed Circuit Board)

Abstract

The invention relates to the technical field of PCBs (Printed Circuit Board), in particular to a method and a system for detecting the high-impedance performance of a PCB. According to the invention, the actual resistance value of the preset measurement point is subjected to temperature compensation according to the resistance temperature coefficient to obtain a plurality of corrected resistance values, errors caused by temperature fluctuation can be eliminated, the measurement result is more accurate and consistent, the actual high-impedance performance of the PCB can be measured and evaluated more accurately in the subsequent process by compensating the temperature change, and the measurement accuracy is improved. By acquiring a signal oscillogram in real time, the actual response of a high-impedance region under a load can be effectively observed, dynamic information about circuit performance can be provided, the influence of the load on a circuit can be identified, and by applying the load and analyzing the oscillogram, the performance under the actual use condition can be evaluated. The correlation of detection results is optimized, and the high impedance characteristic of the circuit can be known more comprehensively by combining a resistance distribution diagram and real-time signal analysis, so that the measurement precision and reliability are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of PCB boards, and in particular to a method and system for detecting high impedance performance of a PCB board. Background Art

[0002] In recent years, with the rapid development of electronic products such as desktop computers (control terminals), laptops, mobile phones, digital TVs, set-top boxes, consumer electronics (MP3, MP4, game consoles, digital cameras, etc.), communication equipment and automotive electronics, the frequency and speed of signal transmission are getting faster and faster, and strict characteristic impedance test requirements are put forward for the circuit boards (PCB boards) used. Among the types of PCB board detection, PCB impedance detection is to check whether the impedance of the PCB meets the design requirements. As the signal frequency on the PCB is getting higher and higher, the noise and waveform distortion on the signal have become the main factors affecting the signal integrity. If the impedance of the PCB does not meet the requirements, it will cause signal reflection and signal loss, thereby affecting the signal integrity. Therefore, PCB impedance testing is an important step to ensure the electrical performance of the PCB. In order to control the line impedance, each generated PCB board needs to be strictly tested for characteristic impedance to check whether it meets the design and generation requirements.

[0003] At present, the high impedance performance of PCB boards is mainly tested through the voltage drop method. Specifically, a high-precision voltmeter and current source are used to first identify the test points or lines on the PCB, and then a stable current source is connected to the input end of the circuit. The two probes of the voltmeter are respectively connected to the two ends of the test points, and a known current is applied to the circuit through the current source. Then, the voltmeter is used to measure the voltage drop between the test points when the current is applied and the resistance value is calculated. The measured resistance value is then compared with the design specification or expected value to evaluate the performance of the circuit. However, in the case of high impedance, the voltage drop method has a small current and the voltage drop may be very weak. In the high impedance circuit, the small noise signal may be amplified, thereby affecting the measurement result of the voltage drop method, which leads to low measurement accuracy. Summary of the invention

[0004] The main purpose of the present invention is to provide a PCB board high impedance performance detection method and system, aiming to solve the technical problems in the prior art.

[0005] The present invention provides a method for detecting high impedance performance of a PCB board, comprising: Acquire an image of the PCB board, and acquire a plurality of preset measurement points according to the image; Obtaining an actual resistance value and an actual temperature value of each preset measurement point, wherein the plurality of preset measurement points are distributed in an array; Calculating the resistance temperature coefficient of each preset measurement point according to each of the actual resistance values ​​and the corresponding actual temperature value, and performing temperature compensation on the actual resistance value of each preset measurement point according to the resistance temperature coefficient to obtain a plurality of corrected resistance values; Plotting a plurality of the corrected resistance values ​​into a resistance distribution map, and acquiring a high impedance region according to the resistance distribution map; Obtaining a preset load application table, and applying a load to the high impedance region according to the preset load application table, wherein the preset load application table includes a plurality of load values ​​arranged in order of magnitude; Acquire in real time a total signal waveform when a load is applied to the high impedance region, and acquire a performance evaluation value according to the total signal waveform; Determining whether the performance evaluation value is within a preset performance evaluation value interval; If the performance evaluation value is within the preset performance evaluation value interval, it is determined that the high impedance performance of the PCB board is good; If the performance evaluation value is not within the preset performance evaluation value range, it is determined that the high impedance performance of the PCB board is poor.

[0006] Preferably, the step of calculating the resistance temperature coefficient of each preset measurement point according to each actual resistance value and the corresponding actual temperature value comprises: Get multiple historical temperature values ​​of the PCB board; Acquire a corresponding historical resistance value of each preset measurement point according to each of the historical temperature values; The resistance temperature coefficient is calculated according to the actual resistance value, the actual temperature value, the multiple historical temperature values ​​and the historical resistance value, wherein the calculation formula is: ; Where W(X) represents the temperature coefficient of resistance, S(D) represents the actual resistance value, and Y(D) represents the i represents the i-th historical resistance value, S(W) represents the actual temperature value, and Y(W) i represents the i-th historical temperature value, i represents the sequence number of the historical resistance value, and n represents the number of historical resistance values.

[0007] Preferably, the step of performing temperature compensation on the actual resistance value of each preset measurement point according to the resistance temperature coefficient to obtain a plurality of corrected resistance values ​​comprises: Get the resistance temperature coefficient and actual temperature value; Obtaining a reference temperature value of the PCB board, and obtaining a temperature compensation value according to the reference temperature value, the resistance temperature coefficient, the actual temperature value, and the actual resistance value; Determining whether the temperature compensation value is a positive number; If the temperature compensation value is a positive number, the corrected resistance value is obtained according to the difference between the actual temperature value and the temperature compensation value; If the temperature compensation value is a negative number, the corrected resistance value is obtained according to the sum of the actual temperature value and the temperature compensation value.

[0008] Preferably, the step of plotting the plurality of corrected resistance values ​​into a resistance distribution map and obtaining the high impedance region according to the resistance distribution map comprises: Acquire a corresponding temperature value according to each of the corrected resistance values; The temperature value is the X-axis and the corrected resistance value is the Y-axis to establish a resistance distribution coordinate axis, and each corrected resistance value and the corresponding temperature value are plotted on the resistance distribution coordinate axis through a curve to obtain a resistance distribution diagram; Obtaining a preset corrected resistance value, and drawing a segmentation line on the resistance distribution map according to the preset corrected resistance value; Acquire first position information of each corrected resistance value located above the dividing line in the image and second position information of each corrected resistance value located below the dividing line in the image; Marking the plurality of first position information as white in the image, and connecting the plurality of first position information marked in white by horizontal and vertical lines to obtain a first area; Marking a plurality of the second position information as black in the image, and connecting the plurality of the second position information marked as black through horizontal lines and vertical lines to obtain a second area; The overlapping area between the first area and the second area is removed from the first area to obtain a high impedance area.

[0009] Preferably, the step of obtaining in real time the total signal waveform when a load is applied to the high impedance region comprises: Obtain a load waveform diagram of the high impedance region at each load value within a preset time; Acquire multiple peak values ​​and valley values ​​of each load waveform diagram; Acquire a corresponding falling time point according to each of the peak values, and acquire a corresponding rising time point according to the valley value; Draw a total signal waveform graph based on multiple peak values, corresponding falling time points, valley values, and corresponding rising time points.

[0010] Preferably, the step of obtaining a performance evaluation value according to the total signal waveform diagram comprises: The highest peak value and the lowest valley value of the total signal waveform are obtained, and the signal amplitude attenuation percentage is calculated according to the highest peak value and the lowest valley value, wherein the calculation formula is: ; Among them, F(S) represents the signal amplitude attenuation percentage, Z(G) represents the highest peak value, and Z(D) represents the lowest valley value; Get the ideal phase value; Acquire an actual phase value according to the total signal waveform diagram, and obtain a phase distortion degree according to a difference between the actual phase value and an ideal phase value; The noise amplitude at each time point is obtained according to the total signal waveform diagram, and the noise level value is calculated according to the multiple noise amplitudes, wherein the calculation formula is: ; Among them, Z(S) represents the noise level value, Z(F) m represents the mth noise amplitude, M represents the number of noise amplitudes, and m represents the sequence number of the noise amplitude; Obtaining a first weight of the signal amplitude attenuation percentage, obtaining a second weight of the phase distortion degree, and obtaining a third weight of the noise level value; The performance evaluation value is calculated according to the noise level value, the phase distortion, the signal amplitude attenuation percentage, the first weight, the second weight and the third weight, wherein the calculation formula is: ; Wherein, X(P) represents the performance evaluation value, Z(S) represents the noise level value, F(S) represents the signal amplitude attenuation percentage, X(S) represents the phase distortion, a represents the first weight, b represents the second weight, and c represents the third weight.

[0011] The present application also provides a PCB board high impedance performance detection system, comprising: A first acquisition module is used to acquire an image of the PCB board and acquire a plurality of preset measurement points according to the image; A second acquisition module is used to acquire an actual resistance value and an actual temperature value of each preset measurement point, wherein the plurality of preset measurement points are distributed in an array; a calculation module, used for calculating the resistance temperature coefficient of each preset measurement point according to each of the actual resistance values ​​and the corresponding actual temperature value, and performing temperature compensation on the actual resistance value of each preset measurement point according to the resistance temperature coefficient to obtain a plurality of corrected resistance values; A drawing module, used for drawing a plurality of the corrected resistance values ​​into a resistance distribution map, and obtaining a high impedance area according to the resistance distribution map; An application module, used to obtain a preset load application table, and apply a load to the high impedance area according to the preset load application table, wherein the preset load application table includes a plurality of load values ​​arranged in order of magnitude; A third acquisition module is used to acquire in real time a total signal waveform when a load is applied to the high impedance region, and to acquire a performance evaluation value according to the total signal waveform; A judging module, used to judge whether the performance evaluation value is within a preset performance evaluation value interval; If the performance evaluation value is within the preset performance evaluation value interval, it is determined that the high impedance performance of the PCB board is good; If the performance evaluation value is not within the preset performance evaluation value range, it is determined that the high impedance performance of the PCB board is poor.

[0012] Preferably, the drawing module comprises: A first acquisition unit, used for acquiring a corresponding temperature value according to each of the corrected resistance values; A drawing unit, used for establishing a resistance distribution coordinate axis with the temperature value as the X-axis and the corrected resistance value as the Y-axis, and drawing each corrected resistance value and the corresponding temperature value on the resistance distribution coordinate axis through a curve to obtain a resistance distribution diagram; A second acquisition unit, used to acquire a preset modified resistance value, and draw a segmentation line on the resistance distribution map according to the preset modified resistance value; A third acquisition unit, used for acquiring first position information of each corrected resistance value located above the dividing line in the image and second position information of each corrected resistance value located below the dividing line in the image; A first marking unit, used for marking the plurality of first position information as white in the image, and connecting the plurality of first position information marked as white through horizontal and vertical lines to obtain a first area; A second marking unit, used for marking the plurality of second position information as black in the image, and connecting the plurality of second position information marked as black through horizontal and vertical lines to obtain a second area; The elimination unit is used to eliminate the overlapping area of ​​the first area and the second area in the first area to obtain a high impedance area.

[0013] The present invention also provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the above-mentioned PCB board high impedance performance detection method when executing the computer program.

[0014] The present invention also provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the steps of the above-mentioned PCB board high impedance performance detection method are implemented.

[0015] The beneficial effects of the present invention are as follows: the present invention calculates the resistance temperature coefficient of a preset measurement point according to the actual resistance value and the corresponding actual temperature value, and performs temperature compensation on the actual resistance value of the preset measurement point according to the resistance temperature coefficient to obtain multiple corrected resistance values, which can eliminate the error caused by temperature fluctuation, making the measurement result more accurate and consistent. By compensating for the temperature change, it is convenient to more accurately measure and evaluate the actual high impedance performance of the PCB in the subsequent period, thereby improving the overall measurement accuracy. By drawing multiple corrected resistance values ​​into a resistance distribution map, obtaining a high impedance area according to the resistance distribution map, applying a load to the high impedance area through a preset load application table, and then obtaining a total signal waveform when the high impedance area is loaded in real time, and obtaining a performance evaluation value according to the total signal waveform. By obtaining the signal waveform in real time, it is possible to effectively observe the actual response of the high impedance area under the load, provide dynamic information about the circuit performance, and identify the influence of the load on the circuit. By applying the load and analyzing the waveform, it is possible to evaluate the performance under actual use conditions, optimize the correlation of the detection results, and combine the resistance distribution map with the real-time signal analysis to more comprehensively understand the high impedance characteristics of the circuit, thereby improving the measurement accuracy and reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The figure is a schematic diagram of a method flow according to an embodiment of the present invention.

[0017] Figure 2 FIG. 1 is a schematic diagram of a device structure according to an embodiment of the present invention.

[0018] Figure 3 A schematic diagram of the internal structure of a computer device according to an embodiment of the present application.

[0019] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0020] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0021] like Figure 1-Figure 3 As shown, the present application provides a method for detecting high impedance performance of a PCB board, comprising: S1. Acquire an image of a PCB board, and acquire a plurality of preset measurement points according to the image; S2, obtaining an actual resistance value and an actual temperature value of each preset measurement point, wherein the plurality of preset measurement points are distributed in an array; S3, calculating the resistance temperature coefficient of each preset measurement point according to each of the actual resistance values ​​and the corresponding actual temperature value, and performing temperature compensation on the actual resistance value of each preset measurement point according to the resistance temperature coefficient to obtain a plurality of corrected resistance values; S4, plotting the multiple corrected resistance values ​​into a resistance distribution map, and obtaining a high impedance area according to the resistance distribution map; S5, obtaining a preset load application table, and applying a load to the high impedance area according to the preset load application table, wherein the preset load application table includes a plurality of load values ​​arranged in order of magnitude; S6. Acquire a total signal waveform when a load is applied to the high impedance region in real time, and acquire a performance evaluation value according to the total signal waveform; S7, determining whether the performance evaluation value is within a preset performance evaluation value interval; If the performance evaluation value is within the preset performance evaluation value interval, it is determined that the high impedance performance of the PCB board is good; If the performance evaluation value is not within the preset performance evaluation value range, it is determined that the high impedance performance of the PCB board is poor.

[0022] As described in the above steps S1-S7, in recent years, with the rapid development of electronic products such as desktop computers, laptops, mobile phones, digital televisions, set-top boxes, consumer electronics, communication equipment and automotive electronics, the signal transmission frequency and speed are getting faster and faster, which puts forward strict characteristic impedance test requirements for the PCB boards used. Among the types of PCB board detection, PCB impedance detection is to check whether the impedance of the PCB meets the design requirements. At present, the impedance of the PCB is mainly detected by the voltage drop method to detect the high impedance performance of the PCB board. Specifically, the test points or lines on the PCB are first identified by using a high-precision voltmeter and a current source, and then a stable current source is connected to the input end of the circuit, and the two probes of the voltmeter are respectively connected to the two ends of the test points. A known current is applied to the circuit through the current source, and then the voltage drop between the test points when the current is applied is measured by the voltmeter and the resistance value is calculated. The measured resistance value is then compared with the design specification or the expected value to evaluate the performance of the circuit. However, in the case of high impedance, the measurement accuracy of the voltage drop method may be limited by the current source and the voltmeter, thereby affecting the test results.In the present invention, the actual resistance values ​​and actual temperature values ​​of multiple preset measurement points on the PCB board image are obtained, and then the resistance temperature coefficient of each preset measurement point is calculated according to each actual resistance value and the corresponding actual temperature value, and the actual resistance value of each preset measurement point is temperature compensated according to the resistance temperature coefficient to obtain multiple corrected resistance values, wherein the multiple preset measurement points are distributed in an array, which means that these preset measurement points are arranged in a grid array according to a certain rule or pattern (for example, horizontally or vertically distributed with equal spacing). This is because random or uneven distribution of measurement points may lead to inaccurate positioning of high impedance areas, especially in areas where resistance changes dramatically, so that detection of other areas may be ignored, resulting in incomplete detection results. Since the resistance value is usually The resistance value of a PCB is different from that of a PCB in that it is made of a material such as a PCB material. The resistance value of a PCB material is different from that of a PCB material. The resistance value of a PCB material is different from that of a PCB material. The resistance value of a PCB material is different from that of a PCB material. The resistance value of a PCB material is different from that of a PCB material. The resistance value of a PCB material is different from that of a PCB material. The resistance value of a PCB material is different from that of a PCB material. The resistance value of a PCB material is different from that of a PCB material. The resistance value of a PCB material is different from that of a PCB material. The resistance value of a PCB material is different from that of a PCB material. The resistance value of a PCB material is different from that of a PCB material. The resistance value of a PCB material is different from that of a PCB material. The load application table applies a load to the high impedance area, and then obtains the total signal waveform when the high impedance area is loaded in real time, and obtains the performance evaluation value based on the total signal waveform. The resistance distribution diagram can effectively identify the high impedance area, ensuring that the test and load application are concentrated in the key areas, so as to more accurately evaluate the performance of these areas. By obtaining the signal waveform diagram in real time, it is possible to effectively observe the actual response of the high impedance area under load, provide dynamic information about the circuit performance, and identify the impact of the load on the circuit. By applying the load and analyzing the waveform diagram, the performance under actual use conditions can be evaluated, making the test closer to the actual working environment and optimizing the relevance of the test results. Combining the resistance distribution diagram and real-time signal analysis can provide a more comprehensive understanding. The high impedance characteristics of the circuit can improve measurement accuracy and reliability. By summarizing the signal waveforms under different load conditions, the behavior of the high impedance area under various load conditions can be fully understood, which helps to identify the impact of load changes on the high impedance area, thereby providing a more accurate evaluation of the performance under actual working conditions. It can also provide a more comprehensive view of the performance of the high impedance area. This comprehensive view can more accurately reflect the performance in the actual use environment, improve the reliability and accuracy of the performance evaluation, and then judge whether the performance evaluation value is within the preset performance evaluation value range. If the performance evaluation value is within the preset performance evaluation value range, it is determined that the high impedance performance of the PCB board is good, otherwise it is determined that the high impedance performance of the PCB board is poor.

[0023] In one embodiment, the step S3 of calculating the resistance temperature coefficient of each preset measurement point according to each actual resistance value and the corresponding actual temperature value includes: S31, obtaining multiple historical temperature values ​​of the PCB board; S32, obtaining a corresponding historical resistance value of each preset measurement point according to each of the historical temperature values; S33, calculating the resistance temperature coefficient according to the actual resistance value, the actual temperature value, a plurality of historical temperature values ​​and historical resistance values, wherein the calculation formula is: ; Where W(X) represents the temperature coefficient of resistance, S(D) represents the actual resistance value, and Y(D) represents the i represents the i-th historical resistance value, S(W) represents the actual temperature value, and Y(W) i represents the i-th historical temperature value, i represents the sequence number of the historical resistance value, and n represents the number of historical resistance values.

[0024] As described in the above steps S31-S33, the present invention obtains multiple historical temperature values ​​of the PCB board and the corresponding historical resistance values ​​of each preset measurement point, and then calculates the resistance temperature coefficient according to the actual resistance value, the actual temperature value, the multiple historical temperature values ​​and the historical resistance value. The calculated resistance temperature coefficient can more accurately compensate for the influence of temperature on the resistance value, thereby reducing the interference of temperature changes on high impedance measurement and improving measurement accuracy. By considering the resistance changes at different temperatures, the performance of the high impedance area in the actual working environment can be more comprehensively evaluated to ensure the accuracy and reliability of the test data.

[0025] In one embodiment, the step S3 of performing temperature compensation on the actual resistance value of each preset measurement point according to the resistance temperature coefficient to obtain a plurality of corrected resistance values ​​includes: S34, obtaining the resistance temperature coefficient and the actual temperature value; S35, obtaining the reference temperature value of the PCB board; S36, calculating a temperature compensation value according to the reference temperature value, the resistance temperature coefficient, the actual temperature value and the actual resistance value, wherein the calculation formula is: ; Wherein, W(B) represents the temperature compensation value, S(D) represents the actual resistance value, W(X) represents the resistance temperature coefficient, S(W) represents the actual temperature value, and J(W) represents the reference temperature value; S37, determining whether the temperature compensation value is a positive number; If the temperature compensation value is a positive number, the corrected resistance value is obtained according to the difference between the actual temperature value and the temperature compensation value; If the temperature compensation value is a negative number, the corrected resistance value is obtained according to the sum of the actual temperature value and the temperature compensation value.

[0026] As described in the above steps S34-S37, the present invention obtains the resistance temperature coefficient, the actual temperature value and the reference temperature value of the PCB board, and then calculates the temperature compensation value according to the reference temperature value, the resistance temperature coefficient, the actual temperature value and the actual resistance value, and then determines whether the temperature compensation value is a positive number. If it is a positive number, the corrected resistance value is obtained according to the difference between the actual temperature value and the temperature compensation value, otherwise, the corrected resistance value is obtained according to the sum of the actual temperature value and the temperature compensation value. The temperature compensation value calculated by using the resistance temperature coefficient, the actual temperature value and the reference temperature value can accurately adjust the resistance value and eliminate the resistance value deviation caused by temperature changes, which ensures that the measured value is closer to the true value, thereby improving the measurement accuracy of high impedance performance. By compensating for the resistance value change caused by temperature changes, the measurement error caused by temperature fluctuations can be greatly reduced, making the test results more consistent and reliable at different ambient temperatures. Through temperature compensation processing, consistent measurement results can be obtained under different temperature conditions, thereby improving the repeatability and consistency of the test.

[0027] In one embodiment, the step S4 of mapping the plurality of modified resistance values ​​into a resistance distribution map and obtaining a high impedance region according to the resistance distribution map comprises: S41, obtaining a corresponding temperature value according to each of the corrected resistance values; S42, establishing a resistance distribution coordinate axis with the temperature value as the X-axis and the corrected resistance value as the Y-axis, and plotting each corrected resistance value and the corresponding temperature value on the resistance distribution coordinate axis through a curve to obtain a resistance distribution diagram; S43, obtaining a preset corrected resistance value, and drawing a segmentation line on the resistance distribution map according to the preset corrected resistance value; S44, acquiring first position information of each corrected resistance value located above the dividing line in the image and second position information of each corrected resistance value located below the dividing line in the image; S45, marking the plurality of first position information as white in the image, and connecting the plurality of first position information marked in white by horizontal and vertical lines to obtain a first area; S46, marking the plurality of second position information as black in the image, and connecting the plurality of second position information marked as black through horizontal lines and vertical lines to obtain a second area; S47: Eliminate the overlapping area between the first area and the second area in the first area to obtain a high impedance area.

[0028] As described in the above steps S41-S47, in the test of the PCB board, high impedance usually refers to that certain paths, signal lines or areas on the circuit board have very high resistance values. If the entire PCB board is directly measured, not only will a large amount of data be generated, resulting in low efficiency and reduced accuracy, but it may also be interfered by signals in other areas, making it difficult to identify the high impedance area, thereby resulting in inaccurate detection results. Therefore, the present invention obtains the corresponding temperature value according to each corrected resistance value, and then establishes a resistance distribution coordinate axis with the temperature value as the X-axis and the corrected resistance value as the Y-axis, and plots each corrected resistance value and the corresponding temperature value on the resistance distribution coordinate axis through a curve to obtain a resistance value. Resistance distribution map, the resistance distribution map can intuitively display the changing trend of resistance value at different temperatures, help identify the law of resistance change with temperature, and facilitate the analysis of the performance of high impedance areas. By observing the resistance distribution map, you can more accurately understand the change of resistance at different temperatures, thereby optimizing the temperature compensation strategy and improving the accuracy and reliability of measurement. The distribution map can help identify the nonlinear behavior or abnormal mode of resistance change with temperature, and timely discover potential design defects or material problems for correction. Draw a segmentation line on the resistance distribution map by presetting the corrected resistance value, and then obtain the first position of each corrected resistance value above the segmentation line in the image. The information and the second position information of each corrected resistance value located below the dividing line in the image can be used to distinguish normal and abnormal resistance values ​​through the dividing line, so that abnormal resistance values ​​are easy to identify and locate, thereby improving the measurement accuracy. By comparing the resistance values ​​above and below the dividing line, the resistance performance of different areas can be more clearly evaluated, thereby optimizing the performance evaluation. It is clear which corrected resistance values ​​are on both sides of the dividing line, which can help adjust the temperature compensation strategy to make it more suitable for different resistance areas and improve the overall measurement accuracy. After marking multiple first position information as white in the image, they are connected by horizontal and vertical lines to obtain the first area, and multiple second position information is marked as black in the image and connected by horizontal and vertical lines to obtain the second area. Finally, the overlapping area between the first area and the second area is eliminated in the first area to obtain the high impedance area. By marking and connecting different areas, the position of the high impedance area on the PCB board can be accurately determined, making optimization and maintenance of these areas more efficient. Distinguishing between the first area and the second area helps to analyze the performance under different resistance ranges, ensure that the resistance characteristics of the high impedance area are consistent with expectations, and improve the accuracy of data analysis. By identifying the high impedance area, the test can be concentrated in these key areas, improve the detection efficiency, and reduce invalid detection.

[0029] In one embodiment, the step S6 of acquiring in real time the total signal waveform when a load is applied to the high impedance region comprises: S61, obtaining a load waveform diagram of the high impedance region at each load value within a preset time; S62, obtaining a plurality of peak values ​​and valley values ​​of each of the load waveform graphs; S63, acquiring a corresponding falling time point according to each of the peak values, and acquiring a corresponding rising time point according to the valley value; Draw a total signal waveform graph based on multiple peak values, corresponding falling time points, valley values, and corresponding rising time points.

[0030] As described in the above steps S61-S63, the present invention obtains the load waveform diagram of the high impedance region within a preset time at each load value, obtains multiple peaks and corresponding falling time points and valley values ​​and corresponding rising time points of each load waveform diagram, and then draws a total signal waveform diagram based on the multiple peaks, corresponding falling time points, valley values ​​and corresponding rising time points, so that the signal characteristics of the high impedance region, including peak values, valley values ​​and response time, can be more comprehensively analyzed, and a more detailed performance evaluation can be provided. By comparing the waveform diagrams under different load conditions, potential problems in the high impedance region, such as inconsistent responses or abnormal fluctuations, can be identified, so as to make targeted adjustments and optimizations. Understanding the signal waveform characteristics under various load conditions is helpful to optimize the design and temperature compensation strategy. Comprehensive consideration of the signal waveforms under different load conditions is helpful to improve the measurement accuracy of the high impedance region performance and reduce the measurement error caused by load changes. Summarizing the signal waveform diagrams under different conditions can verify the reliability of the high impedance region under various working conditions and ensure the robustness of the design and the consistency of performance.

[0031] In one embodiment, the step S6 of acquiring the performance evaluation value according to the total signal waveform diagram comprises: S64, obtaining the highest peak value and the lowest valley value of the total signal waveform, and calculating the signal amplitude attenuation percentage according to the highest peak value and the lowest valley value, wherein the calculation formula is: ; Among them, F(S) represents the signal amplitude attenuation percentage, Z(G) represents the highest peak value, and Z(D) represents the lowest valley value; S65, obtaining an ideal phase value; S66, obtaining an actual phase value according to the total signal waveform diagram, and obtaining a phase distortion degree according to a difference between the actual phase value and an ideal phase value; S67, obtaining the noise amplitude at each time point according to the total signal waveform diagram, and calculating the noise level value according to the multiple noise amplitudes, wherein the calculation formula is: ; Among them, Z(S) represents the noise level value, Z(F) m represents the mth noise amplitude, M represents the number of noise amplitudes, and m represents the sequence number of the noise amplitude; S68, obtaining a first weight of the signal amplitude attenuation percentage, obtaining a second weight of the phase distortion degree, and obtaining a third weight of the noise level value; S69, calculating a performance evaluation value according to the noise level value, the phase distortion, the signal amplitude attenuation percentage, the first weight, the second weight and the third weight, wherein the calculation formula is: ; Wherein, X(P) represents the performance evaluation value, Z(S) represents the noise level value, F(S) represents the signal amplitude attenuation percentage, X(S) represents the phase distortion, a represents the first weight, b represents the second weight, and c represents the third weight.

[0032] As described in the above steps S64-S69, the present invention obtains the highest peak value and the lowest valley value of the total signal waveform, and calculates the signal amplitude attenuation percentage based on the highest peak value and the lowest valley value. The signal amplitude attenuation percentage provides a measure of signal attenuation in the high impedance region under different load conditions, making the performance evaluation more quantitative and accurate. The calculation of amplitude attenuation helps to identify and quantify the performance degradation of the high impedance region. Through the amplitude attenuation analysis, the stability and reliability of the high impedance region under different working conditions can be verified. The calculation of the amplitude attenuation percentage can more accurately evaluate the actual performance of the high impedance region and reduce the measurement error caused by signal fluctuations. By obtaining the ideal phase value, the actual phase value is obtained according to the total signal waveform, and the phase distortion is obtained according to the difference between the actual phase value and the ideal phase value. The calculation of the phase distortion can quantify the phase deviation of the signal during the transmission process in the high impedance region of the PCB, thereby providing an accurate evaluation of the signal integrity and transmission quality. The calculation of the phase distortion helps to more finely adjust the test process and equipment settings, thereby improving the accuracy of the measurement. , reduce the error caused by phase distortion, obtain the noise amplitude at each time point according to the total signal waveform, and calculate the noise level value according to multiple noise amplitudes. The noise level value provides a quantitative evaluation of the impact of noise in the high impedance area, so that the degree of interference of noise on the signal can be accurately understood. By calculating the noise level value, the overall accuracy of the measurement can be improved. The performance evaluation value is calculated according to the noise level value, phase distortion, signal amplitude attenuation percentage, the first weight, the second weight and the third weight. A comprehensive evaluation is performed by combining multiple performance indicators such as noise level, phase distortion, and signal attenuation. The performance of the high impedance area can be fully understood, providing a more accurate overall performance view. Weights are used to weight different performance indicators so that the evaluation value can reflect the relative importance of each indicator to the overall performance, thereby providing an objective performance evaluation standard. By combining various indicators, the performance of the high impedance area of ​​the PCB can be more accurately evaluated, reducing the errors that may be caused by a single indicator, thereby improving the overall measurement accuracy. This method makes the performance evaluation more comprehensive and accurate.

[0033] The present application also provides a PCB board high impedance performance detection system, comprising: A first acquisition module is used to acquire an image of the PCB board and acquire a plurality of preset measurement points according to the image; A second acquisition module is used to acquire an actual resistance value and an actual temperature value of each preset measurement point, wherein the plurality of preset measurement points are distributed in an array; a calculation module, used for calculating the resistance temperature coefficient of each preset measurement point according to each of the actual resistance values ​​and the corresponding actual temperature value, and performing temperature compensation on the actual resistance value of each preset measurement point according to the resistance temperature coefficient to obtain a plurality of corrected resistance values; A drawing module, used for drawing a plurality of the corrected resistance values ​​into a resistance distribution map, and obtaining a high impedance area according to the resistance distribution map; An application module, used to obtain a preset load application table, and apply a load to the high impedance area according to the preset load application table, wherein the preset load application table includes a plurality of load values ​​arranged in order of magnitude; A third acquisition module is used to acquire in real time a total signal waveform when a load is applied to the high impedance region, and to acquire a performance evaluation value according to the total signal waveform; A judging module, used to judge whether the performance evaluation value is within a preset performance evaluation value interval; If the performance evaluation value is within the preset performance evaluation value interval, it is determined that the high impedance performance of the PCB board is good; If the performance evaluation value is not within the preset performance evaluation value range, it is determined that the high impedance performance of the PCB board is poor.

[0034] In one embodiment, the drawing module includes: A first acquisition unit, used for acquiring a corresponding temperature value according to each of the corrected resistance values; A drawing unit, used for establishing a resistance distribution coordinate axis with the temperature value as the X-axis and the corrected resistance value as the Y-axis, and drawing each corrected resistance value and the corresponding temperature value on the resistance distribution coordinate axis through a curve to obtain a resistance distribution diagram; A second acquisition unit, used to acquire a preset modified resistance value, and draw a segmentation line on the resistance distribution map according to the preset modified resistance value; A third acquisition unit, used for acquiring first position information of each corrected resistance value located above the dividing line in the image and second position information of each corrected resistance value located below the dividing line in the image; A first marking unit, used for marking the plurality of first position information as white in the image, and connecting the plurality of first position information marked as white through horizontal and vertical lines to obtain a first area; A second marking unit, used for marking the plurality of second position information as black in the image, and connecting the plurality of second position information marked as black through horizontal and vertical lines to obtain a second area; The elimination unit is used to eliminate the overlapping area of ​​the first area and the second area in the first area to obtain a high impedance area.

[0035] The present invention also provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the above-mentioned PCB board high impedance performance detection method when executing the computer program.

[0036] The present invention also provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the steps of the above-mentioned PCB board high impedance performance detection method are implemented.

[0037] Those of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media provided in this application and used in the embodiments may include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (SSRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0038] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, device, article or method including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, device, article or method. In the absence of further restrictions, an element defined by the sentence "includes a ..." does not exclude the presence of other identical elements in the process, device, article or method including the element.

[0039] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for detecting high impedance performance of a PCB board, characterized in that: include: Acquire an image of the PCB board, and acquire a plurality of preset measurement points according to the image; Obtaining an actual resistance value and an actual temperature value of each preset measurement point, wherein the plurality of preset measurement points are distributed in an array; Calculating the resistance temperature coefficient of each preset measurement point according to each of the actual resistance values ​​and the corresponding actual temperature value, and performing temperature compensation on the actual resistance value of each preset measurement point according to the resistance temperature coefficient to obtain a plurality of corrected resistance values; Plotting a plurality of the corrected resistance values ​​into a resistance distribution map, and acquiring a high impedance region according to the resistance distribution map; Obtaining a preset load application table, and applying a load to the high impedance region according to the preset load application table, wherein the preset load application table includes a plurality of load values ​​arranged in order of magnitude; Acquire in real time a total signal waveform when a load is applied to the high impedance region, and acquire a performance evaluation value according to the total signal waveform; Determining whether the performance evaluation value is within a preset performance evaluation value interval; If the performance evaluation value is within the preset performance evaluation value interval, it is determined that the high impedance performance of the PCB board is good; If the performance evaluation value is not within the preset performance evaluation value range, it is determined that the high impedance performance of the PCB board is poor.

2. The method for detecting high impedance of a PCB according to claim 1, characterized in that: The step of calculating the resistance temperature coefficient of each preset measurement point according to each actual resistance value and the corresponding actual temperature value comprises: Get multiple historical temperature values ​​of the PCB board; Acquire a corresponding historical resistance value of each preset measurement point according to each of the historical temperature values; The resistance temperature coefficient is calculated according to the actual resistance value, the actual temperature value, the multiple historical temperature values ​​and the historical resistance value, wherein the calculation formula is: ； Where W(X) represents the temperature coefficient of resistance, S(D) represents the actual resistance value, and Y(D) represents the i represents the i-th historical resistance value, S(W) represents the actual temperature value, and Y(W) i represents the i-th historical temperature value, i represents the sequence number of the historical resistance value, and n represents the number of historical resistance values.

3. The method for detecting high impedance performance of a PCB board according to claim 1, characterized in that: The step of performing temperature compensation on the actual resistance value of each preset measurement point according to the resistance temperature coefficient to obtain a plurality of corrected resistance values ​​comprises: Get the resistance temperature coefficient and actual temperature value; Obtaining a reference temperature value of the PCB board, and obtaining a temperature compensation value according to the reference temperature value, the resistance temperature coefficient, the actual temperature value, and the actual resistance value; Determining whether the temperature compensation value is a positive number; If the temperature compensation value is a positive number, the corrected resistance value is obtained according to the difference between the actual temperature value and the temperature compensation value; If the temperature compensation value is a negative number, the corrected resistance value is obtained according to the sum of the actual temperature value and the temperature compensation value.

4. The method for detecting high impedance performance of a PCB board according to claim 1, characterized in that: The step of plotting the plurality of corrected resistance values ​​into a resistance distribution map and obtaining a high impedance region according to the resistance distribution map comprises: Acquire a corresponding temperature value according to each of the corrected resistance values; The temperature value is the X-axis and the corrected resistance value is the Y-axis to establish a resistance distribution coordinate axis, and each corrected resistance value and the corresponding temperature value are plotted on the resistance distribution coordinate axis through a curve to obtain a resistance distribution diagram; Obtaining a preset corrected resistance value, and drawing a segmentation line on the resistance distribution map according to the preset corrected resistance value; Acquire first position information of each corrected resistance value located above the dividing line in the image and second position information of each corrected resistance value located below the dividing line in the image; Marking the plurality of first position information as white in the image, and connecting the plurality of first position information marked in white by horizontal and vertical lines to obtain a first area; Marking a plurality of the second position information as black in the image, and connecting the plurality of the second position information marked as black through horizontal lines and vertical lines to obtain a second area; The overlapping area between the first area and the second area is removed from the first area to obtain a high impedance area.

5. The method for detecting high impedance performance of a PCB board according to claim 1, characterized in that: The step of obtaining in real time a total signal waveform diagram when a load is applied to the high impedance region comprises: Obtain a load waveform diagram of the high impedance region at each load value within a preset time; Acquire multiple peak values ​​and valley values ​​of each load waveform diagram; Acquire a corresponding falling time point according to each of the peak values, and acquire a corresponding rising time point according to the valley value; Draw a total signal waveform graph based on multiple peak values, corresponding falling time points, valley values, and corresponding rising time points.

6. The method for detecting high impedance performance of a PCB board according to claim 1, characterized in that: The step of obtaining a performance evaluation value according to the total signal waveform diagram comprises: The highest peak value and the lowest valley value of the total signal waveform are obtained, and the signal amplitude attenuation percentage is calculated according to the highest peak value and the lowest valley value, wherein the calculation formula is: ； Among them, F(S) represents the signal amplitude attenuation percentage, Z(G) represents the highest peak value, and Z(D) represents the lowest valley value; Get the ideal phase value; Acquire an actual phase value according to the total signal waveform diagram, and obtain a phase distortion degree according to a difference between the actual phase value and an ideal phase value; The noise amplitude at each time point is obtained according to the total signal waveform diagram, and the noise level value is calculated according to the multiple noise amplitudes, wherein the calculation formula is: ； Among them, Z(S) represents the noise level value, Z(F) m represents the mth noise amplitude, M represents the number of noise amplitudes, and m represents the sequence number of the noise amplitude; Obtaining a first weight of the signal amplitude attenuation percentage, obtaining a second weight of the phase distortion degree, and obtaining a third weight of the noise level value; The performance evaluation value is calculated according to the noise level value, the phase distortion, the signal amplitude attenuation percentage, the first weight, the second weight and the third weight, wherein the calculation formula is: ； Wherein, X(P) represents the performance evaluation value, Z(S) represents the noise level value, F(S) represents the signal amplitude attenuation percentage, X(S) represents the phase distortion, a represents the first weight, b represents the second weight, and c represents the third weight.

7. A PCB board high impedance performance detection system, characterized in that: include: A first acquisition module is used to acquire an image of the PCB board and acquire a plurality of preset measurement points according to the image; A second acquisition module is used to acquire an actual resistance value and an actual temperature value of each preset measurement point, wherein the plurality of preset measurement points are distributed in an array; a calculation module, used for calculating the resistance temperature coefficient of each preset measurement point according to each of the actual resistance values ​​and the corresponding actual temperature value, and performing temperature compensation on the actual resistance value of each preset measurement point according to the resistance temperature coefficient to obtain a plurality of corrected resistance values; A drawing module, used for drawing a plurality of the corrected resistance values ​​into a resistance distribution map, and obtaining a high impedance area according to the resistance distribution map; An application module, used to obtain a preset load application table, and apply a load to the high impedance area according to the preset load application table, wherein the preset load application table includes a plurality of load values ​​arranged in order of magnitude; A third acquisition module is used to acquire in real time a total signal waveform when a load is applied to the high impedance region, and to acquire a performance evaluation value according to the total signal waveform; A judging module, used to judge whether the performance evaluation value is within a preset performance evaluation value interval; If the performance evaluation value is within the preset performance evaluation value interval, it is determined that the high impedance performance of the PCB board is good; If the performance evaluation value is not within the preset performance evaluation value range, it is determined that the high impedance performance of the PCB board is poor.

8. The PCB board high impedance performance detection system according to claim 7, characterized in that: The drawing module comprises: A first acquisition unit, used for acquiring a corresponding temperature value according to each of the corrected resistance values; A drawing unit, used for establishing a resistance distribution coordinate axis with the temperature value as the X-axis and the corrected resistance value as the Y-axis, and drawing each corrected resistance value and the corresponding temperature value on the resistance distribution coordinate axis through a curve to obtain a resistance distribution diagram; A second acquisition unit, used to acquire a preset modified resistance value, and draw a segmentation line on the resistance distribution map according to the preset modified resistance value; A third acquisition unit, used for acquiring first position information of each corrected resistance value located above the dividing line in the image and second position information of each corrected resistance value located below the dividing line in the image; A first marking unit, used for marking the plurality of first position information as white in the image, and connecting the plurality of first position information marked as white through horizontal and vertical lines to obtain a first area; A second marking unit, used for marking the plurality of second position information as black in the image, and connecting the plurality of second position information marked as black through horizontal and vertical lines to obtain a second area; The elimination unit is used to eliminate the overlapping area of ​​the first area and the second area in the first area to obtain a high impedance area.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 6 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

Images