Circuit board fault rapid detection system and detection method

Abstract

The invention provides a circuit board fault rapid detection system and method, and the system comprises a monitoring and data collection and comparison system, a detection module, an XYZ three-axis displacement system, a pose adjustment system, and a motion control system, and the pose adjustment system is fixed on an X motion assembly of the XYZ three-axis displacement system. A circuit board to be detected is fixed at the top of the pose adjusting system, and the detection module is fixed at the bottom of a Z-axis movement assembly of the XYZ three-axis displacement system. The detection module is used for measuring a voltage value between each pin on the to-be-detected circuit board and the GND end of the to-be-detected circuit board; the motion control system controls the XYZ three-axis displacement system to move so as to adjust the position of the detection module, and an intact pin volt-ampere characteristic database of the same type of circuit board is established in the monitoring and data acquisition comparison system. By adopting the system, the in-situ fault detection of the circuit board to be detected can be realized, the circuit board cannot be damaged, the circuit fault area can be accurately positioned, the detection efficiency is high, and the cost is low.

Description

Technical Field

[0001] The present invention belongs to the technical field of circuit board faults, and particularly relates to a rapid circuit board fault detection system and a detection method. Background Art

[0002] With the rapid development of electronic technology, circuit boards in modern electronic devices undertake more and more complex functions. In high-reliability application fields such as aircraft, aerospace, and medical, faults in circuit boards may directly affect the safety and stability of devices, and even cause serious accidents. Therefore, accurately and efficiently detecting circuit board faults is crucial for ensuring the reliable operation of electronic systems.

[0003] Currently, circuit board fault detection methods mainly include visual inspection, functional testing, voltage and current detection, thermal imaging, and signal analysis, etc. Visual inspection relies on manual or machine vision and is suitable for detecting appearance defects (such as solder joint detachment, component breakage, etc.), but it is difficult to detect internal micro-damage or electrical performance abnormalities. Functional testing is carried out by simulating the working state of the circuit, but it cannot accurately locate the fault point. Voltage and current detection can reflect the working state of the circuit, but it is not sensitive enough to intermittent faults or small parameter changes. Thermal imaging technology identifies abnormally heated components through temperature distribution, but the equipment cost is high and it is easily affected by the environment. Signal analysis methods (such as spectrum analysis, time-domain reflection, etc.) are suitable for high-frequency circuit fault detection, but the operation is complex and the technical requirements for testers are relatively high.

[0004] Detection methods based on electrical characteristics have received extensive attention because they directly reflect the physical state of the circuit. Among them, resistance detection is one of the most basic means. Changes in resistance values can effectively characterize faults such as solder joint looseness, open circuit, short circuit, and poor contact in circuit boards. However, traditional resistance detection methods usually only measure single components or local circuits, and it is difficult to be applicable to the global detection of complex circuit boards. In complex circuit boards, due to numerous components and complex wiring, the traditional point-to-point resistance test is inefficient and cannot comprehensively reflect the overall health status of the circuit. Summary of the Invention

[0005] In order to overcome the deficiencies of existing circuit board fault detection methods, the present invention provides a rapid circuit board fault detection system and a detection method. By using the system of the present invention to detect the resistance between each pin of the circuit board to be tested and the ground terminal, and comparing the detection results with the resistance values between the pins and the ground terminal in a fault-free circuit board, in-situ diagnosis of the circuit board is realized, with high detection efficiency and accurate fault diagnosis results.

[0006] To achieve the above object, the technical solution provided by the present invention is:

[0007] A rapid circuit board fault detection system, comprising a monitoring and data acquisition and comparison system, a detection module, an XYZ three-axis displacement system, a pose adjustment system, and a motion control system; the circuit board to be tested is installed on the pose adjustment system;

[0008] The pose adjustment system is fixed on the X-axis motion component of the XYZ three-axis displacement system, and the pose adjustment system is used to adjust the spatial pose of the circuit under test;

[0009] The detection module is fixed on the Z-axis motion component of the XYZ three-axis displacement system and faces the circuit board to be tested; the detection module is used to measure the voltage value between each pin on the circuit board to be tested and the GND terminal of the circuit board to be tested;

[0010] The XYZ three-axis displacement system is used to adjust the spatial position of the detection module;

[0011] The monitoring and data acquisition and comparison system is connected to the motion control system and the detection module, and is used to monitor the motion state of the XYZ three-axis displacement system and send motion control commands to the motion control system; it is also used to receive the volt-ampere characteristic data of each pin of the circuit board to be tested output by the detection module; and a volt-ampere characteristic database of pins of a good circuit board of the same model is pre-stored in the monitoring and data comparison system, and the database contains pin numbers and corresponding volt-ampere characteristic reference ranges;

[0012] The motion control system can control the motion of the XYZ three-axis displacement system according to the motion control commands sent by the monitoring and data acquisition and comparison system.

[0013] Further, the pose adjustment system includes a mounting base, a fine adjustment platform, and a height-adjustable mounting component; the mounting base is fixed on the X-axis motion component at the bottom of the XYZ three-axis displacement system, and the mounting base, the fine adjustment platform, and the height-adjustable mounting component are fixedly connected in sequence from bottom to top; the fine adjustment platform is used to adjust the spatial pose of the height-adjustable mounting component; the circuit board to be tested is installed on the top of the height-adjustable mounting component.

[0014] Further, the height-adjustable mounting component includes an adapter plate, a circuit board mounting bracket, and a plurality of adjustable components;

[0015] The circuit board mounting bracket is installed on the top of the adapter plate through the adjustable components;

[0016] The adjustable component includes a guiding screw and a locking nut, a spring, and an adjustable nut sequentially installed on the guiding screw; the guiding screw passes through the guiding screw holes opened on the adapter plate and the circuit board mounting bracket, and the lower end surface of the locking nut is attached to the top surface of the adapter plate to lock and fix the adapter plate;

[0017] The spring is sleeved on the guiding screw, and both ends of the spring abut between the upper end surface of the locking nut and the bottom of the circuit board mounting bracket; the tail of the guiding screw extends out of the guiding screw hole on the circuit board mounting bracket and is screwed with the adjustable nut; the circuit board to be tested is mounted on the top of the circuit board mounting bracket.

[0018] Further, the top of the circuit board mounting bracket has a hollow groove for accommodating the circuit board to be tested, and the size of the hollow groove is larger than that of the circuit board to be tested; a plurality of threaded holes are provided on the side wall of the circuit board mounting bracket; further included are a plurality of positioning screws, and the positioning screws are used to cooperate with the threaded holes on the side wall of the circuit board mounting bracket to horizontally fix the circuit board to be tested.

[0019] Further, the detection module includes an embedded controller, a voltage measurement circuit, a probe, an adapter resistor, a voltage stabilizing circuit, a micro display, a photoelectric switch, a signal shielding block, and a mounting box; the embedded controller, the voltage measurement circuit, the adapter resistor, and the voltage stabilizing circuit are integrally mounted in the mounting box; the embedded controller is used to communicate and transmit data with the monitoring and data acquisition and comparison system, and is used to supply power to the voltage measurement circuit and the voltage stabilizing circuit;

[0020] The VCC output terminal of the voltage stabilizing circuit is sequentially connected in series with the adapter resistor and the probe, and the GND terminal of the voltage stabilizing circuit is connected to the GND terminal of the circuit board to be tested; the positive and negative electrodes of the voltage measurement circuit are respectively connected to the probe and the GND terminal of the circuit board to be tested, and are used to obtain the measured volt-ampere characteristic data of the pins of the circuit board to be tested and transmit them to the embedded controller; the probe is vertically fixed at the bottom of the mounting box and is used to contact the pins in the circuit board to be tested.

[0021] The photoelectric switch and the signal shielding block are used to detect the relative position information between the probe and the pins of the circuit board to be tested and transmit it to the embedded controller to determine whether the probe is in contact with the pins to be measured.

[0022] The micro display is connected to the embedded controller and is used to display the pin numbers, voltage values, and resistance values of the circuit board to be tested in real time.

[0023] A method for quickly detecting circuit board faults is implemented by using the above-mentioned circuit board fault quick detection system; the method for quickly detecting circuit board faults includes the following steps:

[0024] Step 1: Collect the volt-ampere characteristic data of the pins of several intact circuit boards of the same model, perform data distribution analysis to obtain the volt-ampere characteristic reference range of each pin, and establish a volt-ampere characteristic database for the pins of intact circuit boards;

[0025] The data library contains pin numbers and corresponding reference ranges of volt-ampere characteristics;

[0026] Step 2: Measure the voltage values between each pin of the circuit board to be tested and the GND terminal of the circuit board to be tested, and calculate the resistance values between each pin and the GND terminal of the circuit board to be tested. Use the voltage values and resistance values as the measured volt-ampere characteristic data of each pin;

[0027] Step 3: Compare the measured volt-ampere characteristic data of each pin with the database established in Step 1. If the measured volt-ampere characteristic data of all pins are within the reference ranges of the volt-ampere characteristics of the corresponding pins, it is determined that the circuit board to be tested has no faults; otherwise, it is determined that the circuit board to be tested has faults.

[0028] Further, in Step 1, collect the volt-ampere characteristic data of the pins of no less than 10 intact circuit boards of the same model.

[0029] Further, in Step 1, the specific method for obtaining the reference range of the volt-ampere characteristics of each pin according to the collected volt-ampere characteristic data of the pins of the intact circuit boards of the same model is as follows:

[0030] Conduct statistical analysis on the collected volt-ampere characteristic data of the corresponding pins. Assume that the data distribution conforms to a normal distribution, calculate the average value and standard deviation of the volt-ampere characteristic data. Take the difference between the average value and n times the standard deviation as the lower limit of the reference range of the volt-ampere characteristics of the corresponding pins, and take the sum of the average value and n times the standard deviation as the upper limit of the reference range of the volt-ampere characteristics of the corresponding pins; where the value range of n is 1 ≤ n ≤ 3.

[0031] Further, in Step 2, the measured volt-ampere characteristic data of each pin of the circuit board to be tested are obtained in the following manner:

[0032] Step 2.1: When the probe of the detection module contacts the pin to be measured, the voltage measurement circuit of the detection module measures the voltage values between the pin to be measured and the GND terminal of the circuit board to be tested multiple times within a set time period, and filters the voltage values;

[0033] Step 2.2: Calculate the resistance value between the corresponding pin and the GND terminal of the circuit board to be tested according to the value of the matching resistance, the output voltage of the voltage stabilizing circuit, and the measured voltage value between the pin and the GND terminal of the circuit board to be tested;

[0034] Step 2.3: The XYZ three-axis displacement system controls the movement of the probe, and measures all the pins on the circuit board to be tested in sequence to obtain the measured volt-ampere characteristic data of each pin.

[0035] Further, if it is determined in Step 3 that the circuit board to be tested has no faults, it also includes the step of optimizing the database established in Step 1 using the measured volt-ampere characteristic data of the pins of this circuit board to be tested. The specific process is as follows:

[0036] Add the measured volt-ampere characteristic data of all pins to the pin volt-ampere characteristic data collected in step 1, recalculate the average value and standard deviation of the volt-ampere characteristic data of the corresponding pins, and update the volt-ampere characteristic reference ranges of all pins in the database.

[0037] The advantages of the present invention are as follows:

[0038] The circuit fault rapid detection system of the present invention includes a detection module, an XYZ three-axis displacement system, a 3T1R pose adjustment system, a motion control system, and a monitoring and data acquisition and comparison system; a volt-ampere characteristic database of pins of a same-type intact circuit board is pre-established in the monitoring and data acquisition and comparison system. The detection module includes a probe and a voltage measurement circuit for measuring the voltage value and resistance value between the pins of the circuit board to be measured and the GND terminal of the circuit board. The XYZ three-axis displacement system is used to adjust the position of the probe of the detection module to achieve the measurement of all pins. The advantages of using the circuit fault detection system designed by the present invention for fault detection are as follows:

[0039] 1. High detection efficiency and low cost: In the present invention, a method of comparing resistance values is adopted, avoiding the dependence on complex devices (such as oscilloscopes, thermal imagers, etc.) for fault diagnosis. The detection of all pins of the circuit board can be completed with one installation. Compared with the traditional functional tests that need to be carried out in a specific working environment, the method of the present invention can be carried out without relying on external complex systems. Therefore, the detection cost can be greatly reduced, and the speed of fault location can be improved.

[0040] 2. Non-destructive detection and high safety: The method of the present invention realizes fault detection by measuring the voltage value and resistance value between the pins of the circuit board and its grounding terminal, and will not cause damage to the circuit board or its components. It is very suitable for high-reliability fields (such as aerospace, medical equipment, etc.), reducing the risk of damage to the circuit board and its components during the fault detection process, and ensuring the integrity and safety of the circuit board during the detection process.

[0041] 3. Can accurately locate the circuit fault area: By comparing the voltage values and resistance values of the circuit board to be measured and the intact circuit board, the fault area (specific pins) existing in the circuit can be directly found. The method of the present invention helps to accurately locate fault types such as welding problems, poor contact, open circuit, and short circuit, avoiding the problems of over-wide range and inability to accurately locate that may occur in traditional fault detection methods. Especially in complex circuits, by comparing resistance values, the scope of fault troubleshooting can be quickly narrowed, saving time and improving maintenance efficiency.

[0042] The additional aspects and advantages of the present invention will be partially given in the following description, partially become obvious from the following description, or be understood through the practice of the present invention. Brief Description of the Drawings

[0043] The above and / or additional aspects and advantages of the present invention will become apparent and be readily understood from the description of the embodiments in conjunction with the following drawings, where:

[0044] Figure 1 is a schematic structural diagram of a rapid circuit board fault detection system of the present invention;

[0045] Figure 2 is a block diagram of a rapid circuit board fault detection system of the present invention;

[0046] Figure 3 is a schematic electrical architecture diagram in a rapid circuit board fault detection system of the present invention;

[0047] Figure 4 is a partial view of a rapid circuit board fault detection system of the present invention;

[0048] Figure 5 is a partial exploded view of a rapid circuit board fault detection system of the present invention;

[0049] Figure 6 is a schematic structural diagram of an XYZ three-axis displacement system in the present invention;

[0050] Figure 7 is a flowchart of a rapid circuit board fault detection method of the present invention;

[0051] Figure 8 is Figure 7 a specific process diagram for detecting pins of a circuit board to be tested in

[0052] Description of the reference numerals in the drawings: 1 - Detection module, 101 - Installation box, 102 - Micro display, 103 - Photoelectric switch, 104 - Probe, 105 - Ground wire, 106 - Signal shielding block; 2 - XYZ three-axis displacement system, 21 - X-axis movement component, 22 - Y-axis movement component, 23 - Z-axis movement component; 2100 - X-axis base, 2101 - X-axis placement table, 2102 - X-axis ball screw, 2103 - X-axis nut, 2104 - X-axis slider, 2105 - X-axis guide rod, 2106 - X-axis limit switch, 2107 - X-axis motor; 2200 - Y-axis base, 2201 - Y-axis connecting plate, 2202 - Y-axis ball screw, 2203 - Y-axis nut, 2204 - Y-axis slider, 2205 - Y-axis guide rod, 2206 - Y-axis limit switch, 2207 - Y-axis motor; 2300 - Z-axis base A, 2301 - Z-axis base B, 2302 - Z-axis ball screw, 2303 - Z-axis nut, 2304 - Z-axis slider, 2305 - Z-axis guide rod, 2306 - Z-axis limit switch, 2307 - Z-axis motor; 3 - 3T1R pose adjustment system, 30 - Installation base, 31 - 2T1R fine adjustment platform, 32 - Height adjustable installation component; 3201 - Adapter plate, 3201A - Guide screw hole, 3202 - Guide screw, 3203 - Locking nut, 3204 - Spring, 3205 - Adjustable nut, 3206 - Circuit board mounting bracket, 3206A - Hollow groove, 3206B - Threaded hole, 3207 - Positioning screw; 4 - Motion control system, 5 - Monitoring and data acquisition and comparison system, 6 - Signal line, 7 - Circuit board to be tested, 701 - Pin, 702 - GND terminal of the circuit board to be tested. Detailed implementation manners

[0053] The embodiments of the present invention will be described in detail below. The embodiments are exemplary and are intended to explain the present invention, but should not be construed as a limitation to the present invention.

[0054] Refer to Figures 1 - 3, an embodiment of the present invention provides a fast circuit board fault detection system, including a detection module 1, an XYZ three-axis displacement system 2, a 3T1R pose adjustment system 3, a motion control system 4, and a monitoring and data acquisition and comparison system 5. The circuit board to be tested 7 is installed on the top of the 3T1R pose adjustment system 3; the 3T1R pose adjustment system 3 is fixed on the X-axis moving component of the XYZ three-axis displacement system 2, and the 3T1R pose adjustment system is used to adjust the spatial pose of the circuit under test. The detection module 1 is fixed on the Z-axis moving component of the XYZ three-axis displacement system and faces the circuit board 7 to be tested; the detection module is used to measure the voltage value between each pin on the circuit board to be tested and its GND terminal. The XYZ three-axis displacement system 2 is used to adjust the spatial position of the detection module to realize the detection of all pins on the circuit board to be tested. The monitoring and data acquisition and comparison system 5 is connected to the motion control system 4 and the detection module 1, and is used to monitor the motion state of the XYZ three-axis displacement system and send motion control commands to the motion control system; it is also used to receive the volt-ampere characteristic data of each pin of the circuit board to be tested output by the detection module; and a volt-ampere characteristic database of the pins of the intact circuit board is pre-stored in the monitoring and data comparison system, and the database contains the pin numbers and the corresponding volt-ampere characteristic reference ranges. The motion control system 4 can control the motion of the XYZ three-axis displacement system according to the motion control commands sent by the monitoring and data acquisition and comparison system 5.

[0055] Specifically, referring to Figure 4 , the detection module 1 includes an installation box 101, a micro display 102, a photoelectric switch 103, a probe 104, an embedded controller, a voltage measurement circuit, a matching resistor, and a voltage stabilizing circuit. The embedded controller, the voltage measurement circuit, the matching resistor, and the voltage stabilizing circuit are arranged in the installation box 101, and the micro display 102 is arranged on the outer side wall of the installation box to facilitate observing the detection data of the circuit board to be tested during the detection process.

[0056] The voltage measurement circuit is connected to the embedded controller and powered by the embedded controller. The VCC output terminal of the voltage measurement circuit is sequentially connected in series with an adaptation resistor and a probe 104. The GND terminal of the voltage stabilizing circuit is connected to the GND terminal 702 of the circuit board under test through a ground wire 105. The probe 104 is used to contact a pin 701 in the circuit board under test to detect the voltage value between the pin and the GND terminal of the circuit board under test. The positive and negative poles of the voltage measurement circuit are respectively connected to the probe 104 and the GND terminal of the circuit board under test. The voltage measurement circuit is used to calculate the corresponding resistance value according to the voltage value between the pin detected by the probe and the GND terminal of the circuit board under test, and transmit the voltage value and the resistance value as the measured volt-ampere characteristic data of the corresponding pin to the embedded controller. The voltage measurement circuit obtains the measured volt-ampere characteristic data of each pin of the circuit board under test in the following manner: when the probe contacts the pin to be measured, the voltage measurement circuit measures the voltage value between the pin to be measured and the GND terminal of the circuit board under test multiple times within a set time period (the starting moment is the moment when the signal of the optoelectronic switch 103 is blocked by the signal blocking block 106), and filters the voltage value; then, according to the resistance value of the adaptation resistor, the output voltage of the voltage stabilizing circuit, and the measured voltage value between the pin and the GND terminal of the circuit board under test, calculates the resistance value between the corresponding pin and the GND terminal 702 of the circuit board under test; the XYZ three-axis displacement system controls the movement of the probe to measure all the pins on the circuit board under test in sequence.

[0057] The voltage stabilizing circuit is connected to the embedded controller and powered by the embedded controller. The resistance value of the adaptation resistor and the output voltage of the voltage stabilizing circuit are known, and those skilled in the art can determine them according to the maximum current and maximum voltage that the circuit board under test can withstand. In this embodiment, the output voltage of the voltage stabilizing circuit is twice the maximum voltage that the GND terminal and the pin terminal of the intact circuit board under test can withstand, and the resistance value of the adaptation resistor is calculated according to the output voltage of the voltage stabilizing circuit and the maximum current that the intact circuit board under test can withstand.

[0058] The micro display 102 is connected to the embedded controller, and the micro display is used to display information such as the pin number, voltage value, and resistance value in real time. The optoelectronic switch 103 is connected to the embedded controller, and the optoelectronic switch is used to detect the relative position information between the probe and the pins of the circuit board under test and transmit it to the embedded controller. When the signal of the optoelectronic switch is blocked, it indicates that the probe contacts the pin that needs to be measured on the circuit board under test, the probe stops moving, and the voltage measurement circuit and the probe measure the current pin.

[0059] The embedded controller is connected to the monitoring and data acquisition and comparison system 5 through a signal line 6 for communication and data transmission, and at the same time, the monitoring and data acquisition and comparison system powers the embedded controller.

[0060] Refer to Figure 4 andFigure 5 The 3T1R pose adjustment system 3 includes a mounting base 30, a 2T1R fine adjustment platform 31, and a height-adjustable mounting component 32. The mounting base 30 is fixed on the top plane of the X-axis moving component of the XYZ three-axis displacement system. The 2T1R fine adjustment platform 31 is fixedly installed on the top of the mounting base 30, and the height-adjustable mounting component 32 is fixedly arranged on the top of the 2T1R fine adjustment platform 31. The circuit board to be tested is installed on the top of the height-adjustable mounting component 32.

[0061] Specifically, the 2T1R fine adjustment platform 31 can mechanically adjust the position of the height-adjustable mounting component 32 in the X and Y directions, as well as the spatial angle around the Z axis, that is, to realize the position of the circuit board to be tested mounted on the height-adjustable mounting component in the X and Y directions and the spatial angle around the Z axis.

[0062] Specifically, the height-adjustable mounting component 32 includes an adapter plate 3201, a circuit board mounting bracket 3206, and several adjustable components. The circuit board mounting bracket 3206 is installed on the top of the adapter plate 3201 through the adjustable components. The adjustable components include a guide screw 3202, and a lock nut 3203, a spring 3204, and an adjustable nut 3205 that are sequentially installed on the guide screw. The guide screw 3202 passes through the guide screw holes 3201A opened on the adapter plate 3201 and the circuit board mounting bracket 3206. The lower end surface of the lock nut 3203 fits against the top surface of the adapter plate 3201 and is used to cooperate with the head of the guide screw to lock and fix the adapter plate 3201.

[0063] The spring 3204 is sleeved on the guide screw 3202, and both ends of the spring abut between the upper end surface of the lock nut 3203 and the bottom of the circuit board mounting bracket 3206. By adjusting the screwing length of the adjustable nut 3203, the compression state of the spring can be adjusted, and then the height of the circuit board to be tested in the Z-axis direction can be adjusted through the compression deformation of the spring. The tail of the guide screw 3202 extends out of the guide screw hole on the circuit board mounting bracket and is screwed with the adjustable nut 3205. The circuit board to be tested is fixedly installed on the top of the circuit board mounting bracket. The height-adjustable mounting component 32 realizes the height adjustment of the circuit board to be tested in the vertical direction through the compression deformation of the spring, preventing the rigid contact between the probe and the circuit board to be tested and avoiding structural damage to the circuit board to be tested.

[0064] Specifically, the top of the circuit board mounting bracket has a hollow groove 3206A for accommodating the circuit board to be tested, and the size of the hollow groove is larger than the size of the circuit board to be tested. A number of threaded holes 3206B are opened on the side wall of the circuit board mounting bracket. It also includes a number of positioning screws 3207, and the positioning screws 3207 are used to cooperate with the threaded holes 3206B on the side wall of the circuit board mounting bracket to horizontally fix the circuit board to be tested.

[0065] Refer to Figure 6, the XYZ three-axis displacement system includes an X-axis motion component 21, a Y-axis motion component 22, and a Z-axis motion component 23. The X-axis motion component includes an X-axis base 2100, an X-axis placement table 2101, an X-axis ball screw 2102, an X-axis nut 2103, an X-axis slider 2104, an X-axis guide rod 2105, an X-axis limit switch 2106, and an X-axis motor 2107 (including a reducer). The X-axis ball screw 2102 is located within the frame of the X-axis base 2100, and its two ends are respectively hinged to the side walls at both ends of the X-axis base 2100. One end of the X-axis ball screw is fixedly connected to the X-axis motor 2107 (including a reducer). An X-axis nut 2103 that matches it is provided on the X-axis ball screw body. Two X-axis guide rods 2105 are symmetrically provided on the X-axis base, and the two X-axis guide rods are parallel and located on both sides of the X-axis ball screw. An X-axis slider 2104 that cooperates with it is provided on the X-axis guide rod 2105, and the X-axis slider can slide along the X-axis guide rod. The X-axis placement table 2101 is located above the X-axis base 2100 and is fixedly connected to the tops of the X-axis nut 2103 and the X-axis slider 2104. The X-axis motor 2107 drives the X-axis ball screw to rotate, driving the X-axis nut to reciprocate linearly, and thus can drive the X-axis placement table 2101 to reciprocate along the X-axis. An X-axis limit switch is provided at the end of the X-axis base near the X-axis motor, which is used to limit the motion stroke of the XYZ three-axis displacement system in the X direction.

[0066] The Y-axis moving component includes a Y-axis base 2200, a Y-axis connecting plate 2201, a Y-axis ball screw 2202, a Y-axis nut 2203, a Y-axis slider 2204, a Y-axis guide rod 2205, a Y-axis limit switch 2206, and a Y-axis motor 2207 (including a reducer). The Y-axis base 2200 is arranged in a direction perpendicular to the X-axis and is located below the X-axis placing table 2101. The bottom of the Y-axis base 2200 is fixedly connected to the tops of the X-axis nut 2103 and the X-axis slider 2104. At the top ends of both sides of the Y-axis base 2200, the Y-axis connecting plates 2201 are vertically fixed respectively. The Y-axis ball screw 2202 is arranged in parallel on the top of the Y-axis connecting plates, and both ends are respectively hinged to the side walls of the Y-axis connecting plates. One end of the Y-axis ball screw is fixedly connected to the Y-axis motor 2207 (including a reducer); the Y-axis motor housing is fixedly installed on the outer wall of one of the Y-axis connecting plates. A Y-axis nut 2203 that matches it is arranged on the Y-axis ball screw 2202. On both sides of the Y-axis ball screw, a Y-axis guide rod 2205 is arranged in parallel, and both ends of the Y-axis guide rod 2205 are fixedly connected to the two Y-axis connecting plates 2201 respectively. A Y-axis slider 2204 that matches it is arranged on the Y-axis guide rod 2205, and the Y-axis slider can slide along the Y-axis guide rod. In this embodiment, the Y-axis nut and the Y-axis slider adopt an integrated structure. The Y-axis motor drives the Y-axis ball screw 2202 to rotate, and thus can drive the combination of the Y-axis nut and the slider to move linearly back and forth. On the top of the Y-axis connecting plate close to the Y-axis motor, a Y-axis limit switch 2206 is arranged, which is used to limit the movement stroke of the XYZ three-axis displacement system in the Y direction.

[0067] The Z-axis moving component 23 includes a Z-axis first base 2300, a Z-axis second base 2301, a Z-axis ball screw 2302, a Z-axis nut 2303, a Z-axis slider 2304, a Z-axis guide rod 2305, a Z-axis limit switch 2306, and a Z-axis motor 2307 (including a reducer). Both ends of the Z-axis ball screw 2302 are respectively hinged to the Z-axis first base

[0068] The combined connection relationships of the X-axis motion component, Y-axis motion component, Z-axis motion component, and detection module are as follows: The Y-axis base 2200 of the Y-axis motion component is fixedly connected to the top of the X-axis nut 2103 and the X-axis slider 2104 of the X-axis motion component. The Z-axis first base 2300 and the Z-axis second base 2301 of the Z-axis motion component are respectively fixedly connected to the upper and lower ends of the nut and slider assembly of the Y-axis motion component. The mounting box 101 of the detection module is fixedly installed on the side wall of the Z-axis nut and slider assembly. The signal shielding block 106 of the detection module is vertically arranged, and its bottom is fixedly connected to the side wall of the Z-axis second base 2301. The spatial movement of the probe position of the detection module can be realized by the movement of the X-axis motion component, Y-axis motion component, and Z-axis motion component.

[0069] Refer to Figure 7 and Figure 8 , the process of using the detection system of the present invention to detect faults in the circuit board to be tested is as follows:

[0070] Step 1: Establish a volt-ampere characteristic database for the pins of a good circuit board.

[0071] First, collect the volt-ampere characteristic data of all pins of no less than 10 good circuit boards of the same model, and perform data distribution analysis to obtain the volt-ampere characteristic reference range for each pin. In this embodiment, according to the collected volt-ampere characteristic data of the pins of the good circuit board of the same model, the specific method for obtaining the volt-ampere characteristic reference range for each pin is: perform statistical analysis on the collected volt-ampere characteristic data of the corresponding pin, assume that the data distribution conforms to a normal distribution, calculate the average value and standard deviation of the volt-ampere characteristic data, use the difference between the average value and n times the standard deviation as the lower limit of the volt-ampere characteristic reference range, and use the sum of the average value and n times the standard deviation as the upper limit of the volt-ampere characteristic reference range, where the value range of n is 1 ≤ n ≤ 3. Then number each pin, and establish a volt-ampere characteristic database for the pins of the good circuit board with the pin numbers and the corresponding volt-ampere characteristic reference ranges.

[0072] Step 2: Measure and obtain the voltage value between each pin of the circuit board to be tested and the GND terminal of the circuit board to be tested, and calculate and obtain the resistance value between each pin and the GND terminal of the circuit board to be tested, and use the voltage value and the resistance value as the measured volt-ampere characteristic data for each pin. The specific process is as follows:

[0073] Step 2.1: Place the circuit board to be tested in the hollow groove of the top circuit board mounting bracket of the 3T1R pose adjustment system, and fasten it with the positioning screw 3207.

[0074] Connect the GND terminal of the circuit board to be tested to the negative pole of the voltage measurement circuit, turn on the motion control system and the monitoring and data acquisition and comparison system, and initialize the detection system.

[0075] Step 2.2: Fine-tune the position and spatial attitude of the circuit board to be tested through the 3T1R pose adjustment system, so that the circuit board to be tested faces the probe of the detection module 1.

[0076] Step 2.3: The monitoring and data acquisition comparison system outputs a motion control instruction according to the current position of the detection module 1. The motion control system drives the XYZ three-axis movement system to move according to the received motion control instruction, and continuously adjusts the position of the probe on the detection module. When the probe contacts any pin on the circuit board to be tested, the detection module collects the voltage data between the pin and the GND terminal of the circuit board to be tested, filters and calculates the collected voltage data to obtain the corresponding resistance value, and feeds back the volt-ampere characteristics (voltage value and resistance value) of the pin to the monitoring and data acquisition comparison system. Specifically, when the probe of the detection module contacts the pin to be measured, the voltage measurement circuit of the detection module measures the voltage value between the pin to be measured and the GND terminal of the circuit board to be tested multiple times within a set time period and filters the voltage value.

[0077] In the above manner, the detection module completes the measurement of the volt-ampere characteristics of all pins on the circuit board to be tested.

[0078] Step 3: The monitoring and data acquisition comparison system compares the volt-ampere characteristics of all pins of the circuit board to be tested received with the volt-ampere characteristic reference ranges of the corresponding pins of the same type of intact circuit board established in advance. If the volt-ampere characteristics of all pins do not exceed the volt-ampere characteristic reference ranges of the corresponding pins, it is determined that the circuit board to be tested has no fault; if the volt-ampere characteristic of any one pin exceeds the volt-ampere characteristic reference range of the corresponding pin, it is determined that the circuit board to be tested has a fault.

[0079] Step 4: Database optimization.

[0080] To further improve the detection accuracy of subsequent circuit boards of the same type to be tested, this embodiment also includes a process of optimizing the established database. If it is determined that the circuit board to be tested has no fault this time, the measured volt-ampere characteristic data of the pins of the circuit board to be tested is used to optimize the database. The specific optimization method is as follows:

[0081] Add the measured volt-ampere characteristic data of all pins to the volt-ampere characteristic data of the pins collected in Step 1, recalculate the average value and standard deviation of the volt-ampere characteristic data of the corresponding pins, and update the volt-ampere characteristic reference ranges of all pins in the database.

[0082] As described above, the above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of various equivalent modifications or substitutions, and these modifications or substitutions should all be covered within the protection scope of the present invention.

Claims

1. A rapid circuit board fault detection system, characterized in that, It includes a monitoring and data acquisition and comparison system, a detection module, an XYZ three-axis displacement system, a pose adjustment system, and a motion control system; The circuit board to be tested is installed on the pose adjustment system; The pose adjustment system is fixed on the X-axis motion component of the XYZ three-axis displacement system, and the pose adjustment system is used to adjust the spatial pose of the circuit under test; The detection module is fixed on the Z-axis motion component of the XYZ three-axis displacement system and faces the circuit board to be tested; the detection module is used to measure the voltage value between each pin on the circuit board to be tested and the GND terminal of the circuit board to be tested; The XYZ three-axis displacement system is used to adjust the spatial position of the detection module; The monitoring and data acquisition and comparison system is connected to the motion control system and the detection module, and is used to monitor the motion state of the XYZ three-axis displacement system and send motion control instructions to the motion control system; it is also used to receive the volt-ampere characteristic data of each pin of the circuit board to be tested output by the detection module; and a volt-ampere characteristic database of pins of a good circuit board of the same model is pre-stored in the monitoring and data comparison system, and the database contains pin numbers and corresponding volt-ampere characteristic reference ranges; The motion control system can control the motion of the XYZ three-axis displacement system according to the motion control instructions sent by the monitoring and data acquisition and comparison system.

2. The circuit board fault rapid detection system according to claim 1, wherein The pose adjustment system includes a mounting base, a fine-tuning platform, and a height-adjustable mounting component; The mounting base is fixed on the X-axis motion component at the bottom of the XYZ three-axis displacement system, and the mounting base, the fine-tuning platform, and the height-adjustable mounting component are fixedly connected in sequence from bottom to top; The fine-tuning platform is used to adjust the spatial pose of the height-adjustable mounting component; The circuit board to be tested is installed on the top of the height-adjustable mounting component.

3. The circuit board fault rapid detection system according to claim 2, wherein, The height-adjustable mounting component includes an adapter plate, a circuit board mounting bracket, and several adjustable components; The circuit board mounting bracket is installed on the top of the adapter plate through the adjustable components; The adjustable component includes a guide screw and a locking nut, a spring, and an adjustable nut that are sequentially installed on the guide screw; The guide screw passes through the guide screw holes opened on the adapter plate and the circuit board mounting bracket, and the lower end surface of the locking nut fits against the top surface of the adapter plate to lock and fix the adapter plate; The spring is sleeved on the guide screw, and both ends of the spring abut between the upper end surface of the locking nut and the bottom of the circuit board mounting bracket; The tail of the guide screw extends out of the guide screw hole on the circuit board mounting bracket and is screwed with the adjustable nut; The circuit board to be tested is installed on the top of the circuit board mounting bracket.

4. The circuit board fault rapid detection system according to claim 3, wherein The top of the circuit board mounting bracket has a hollow groove for accommodating the circuit board to be tested, and the size of the hollow groove is larger than the size of the circuit board to be tested; several threaded holes are opened on the side wall of the circuit board mounting bracket; It also includes several positioning screws, and the positioning screws are used to cooperate with the threaded holes on the side wall of the circuit board mounting bracket to horizontally fix the circuit board to be tested.

5. The circuit board fault rapid detection system according to claim 1, characterized in that, The detection module includes an embedded controller, a voltage measurement circuit, a probe, an adapter resistor, a voltage stabilization circuit, a micro display, an optoelectronic switch, a signal shielding block, and an installation box; The embedded controller, the voltage measurement circuit, the adapter resistor, and the voltage stabilization circuit are integrally installed in the installation box; the embedded controller is used to communicate and transmit data with the monitoring and data acquisition and comparison system, and is used to supply power to the voltage measurement circuit and the voltage stabilization circuit; The VCC output terminal of the voltage stabilization circuit is sequentially connected in series with an adapter resistor and a probe, and the GND terminal of the voltage stabilization circuit is connected to the GND terminal of the circuit board to be tested; The positive and negative electrodes of the voltage measurement circuit are respectively connected to the probe and the GND terminal of the circuit board to be tested, and are used to obtain the measured volt-ampere characteristic data of the pins of the circuit board to be tested and transmit them to the embedded controller; The probe is vertically fixed at the bottom of the installation box and is used to contact the pins in the circuit board to be tested; The optoelectronic switch and the signal shielding block are used to detect the relative position information between the probe and the pins of the circuit board to be tested and transmit it to the embedded controller to determine whether the probe is in contact with the pins to be measured; The micro display is connected to the embedded controller and is used to display the pin number, voltage value, and resistance value of the circuit board to be tested in real time.

6. A method for quickly detecting circuit board faults, characterized in that, Implemented by using the circuit board fault rapid detection system according to any one of claims 1-5; the circuit board fault rapid detection method includes the following steps: Step 1: Collect the volt-ampere characteristic data of the pins of several intact circuit boards of the same model, perform data distribution analysis to obtain the volt-ampere characteristic reference range of each pin, and establish a volt-ampere characteristic database for the pins of intact circuit boards; The data library contains the pin numbers and the corresponding volt-ampere characteristic reference ranges; Step 2: Measure and obtain the voltage value between each pin of the circuit board to be tested and the GND terminal of the circuit board to be tested, and calculate the resistance value between each pin and the GND terminal of the circuit board to be tested, and use the voltage value and the resistance value as the measured volt-ampere characteristic data of each pin; Step 3: Compare the measured volt-ampere characteristic data of each pin with the database established in Step 1. If the measured volt-ampere characteristic data of all pins are within the volt-ampere characteristic reference range of the corresponding pins, it is determined that the circuit board to be tested has no fault; otherwise, it is determined that the circuit board to be tested has a fault.

7. The method for quickly detecting circuit board faults according to claim 6, characterized in that, In Step 1, collect the volt-ampere characteristic data of the pins of no less than 10 intact circuit boards of the same model.

8. The method for quickly detecting circuit board faults according to claim 7, characterized in that In Step 1, the specific method for obtaining the volt-ampere characteristic reference range of each pin according to the collected volt-ampere characteristic data of the pins of intact circuit boards of the same model is as follows: Perform statistical analysis on the collected volt-ampere characteristic data of the corresponding pins. Assume that the data distribution conforms to a normal distribution, calculate the average value and standard deviation of the volt-ampere characteristic data, use the difference between the average value and n times the standard deviation as the lower limit of the volt-ampere characteristic reference range of the corresponding pin, and use the sum of the average value and n times the standard deviation as the upper limit of the volt-ampere characteristic reference range of the corresponding pin; where the value range of n is 1≤n≤3.

9. The method for quickly detecting circuit board faults according to claim 6, characterized in that, In Step 2, obtain the measured volt-ampere characteristic data of each pin of the circuit board to be tested according to the following method: Step 2.1: When the probe of the detection module contacts the pin to be measured, the voltage measurement circuit of the detection module measures the voltage value between the pin to be measured and the GND terminal of the circuit board to be measured multiple times within a set time period, and filters the voltage value; Step 2.2: Calculate the resistance value between the corresponding pin and the GND terminal of the circuit board to be measured according to the value of the adapter resistance, the output voltage of the voltage stabilizing circuit, and the measured voltage value between the pin and the GND terminal of the circuit board to be measured; Step 2.3: The XYZ three-axis shifting system controls the movement of the probe, and measures all the pins on the circuit board to be measured in sequence to obtain the measured volt-ampere characteristic data of each pin.

10. The method for quickly detecting circuit board faults according to claim 8, wherein, If it is determined in Step 3 that the circuit board to be measured has no fault, it further includes the step of optimizing the database established in Step 1 by using the measured volt-ampere characteristic data of the pins of the circuit board to be measured. The specific process is as follows: Add the measured volt-ampere characteristic data of all pins to the volt-ampere characteristic data of the pins collected in Step 1, recalculate the average value and standard deviation of the volt-ampere characteristic data of the corresponding pins, and update the volt-ampere characteristic reference range of all pins in the database.

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