Printed board fault diagnosis device based on thermal simulation software and diagnosis method thereof

Abstract

The invention relates to the field of printed board testing and repairing, in particular to a printed board fault diagnosis device and method based on thermal simulation software, and the device comprises an industrial personal computer which is used for carrying out the three-dimensional modeling and thermal simulation analysis of a printed board, and carrying out the image processing of a later temperature cloud picture; the infrared detection equipment is used for detecting the temperature of the printed board during working to form an original infrared cloud picture. The method comprises the following specific steps: step S1, modeling; s2, setting parameters; s3, performing thermal simulation analysis; s4, printing a board temperature cloud picture; s5, analyzing a fault area; s6, determining a fault; step S7, analyzing a result; the three-dimensional model of the printed board is established, thermal simulation analysis is performed by utilizing finite element thermal simulation software, and the temperature cloud picture of the printed board is formed by combining professional infrared detection equipment, so that the fault of the printed board can be quickly and accurately compared and diagnosed, the efficiency and the accuracy of fault diagnosis are improved, the workload and the misjudgment rate of manual detection are reduced, and the detection efficiency is improved. And powerful support is provided for fault diagnosis of the printed board.

Description

Technical Field

[0001] The invention relates to the field of printed circuit board testing and repairing, in particular to a printed circuit board fault diagnosis device and a diagnosis method thereof based on thermal simulation software. Background Art

[0002] Printed circuit boards are an important part of electronic information products. During the entire life cycle of electronic information products, printed circuit boards may fail due to long-term operation in complex electromagnetic environments such as high and low temperatures, high air pressure, high vibration, or device aging. Currently, the existing printed circuit board failure methods are mainly divided into two types: interventional and non-intrusive:

[0003] The first method uses general instruments such as oscilloscopes, logic analyzers, and multimeters for testing, which is an intrusive test. The principle is to install the printed circuit board to be tested in the entire product, power on the entire product, and then use general equipment to test the printed circuit board to be tested. The disadvantages of this method are that it is difficult to test the printed circuit board to be tested without a switching device, it is difficult to test the fault point signal when the product failure is unstable, and the signal of the RF printed circuit board is weak, and the intrusive test is easy to bring in external noise, causing the test signal to be distorted.

[0004] The second method uses electromagnetic scanning equipment such as GTEM chamber to scan the electromagnetic radiation signal of the product to form the amplitude curve of each frequency point, which is a non-intrusive test. The principle is that when the product is working normally, the signal radiated by the product is basically in a constant state. The radiation signal of the product is collected and formed into a database. When the collected radiation signal does not match the database and the difference is large, it can be judged that the product is working abnormally. The disadvantage of this method is that it can only judge the working status of the entire product, and cannot judge the fault of the printed circuit board component level.

[0005] The third method is to use infrared detection equipment to detect the circuit board to form an infrared cloud map, and compare it with the temperature cloud map of the normal working state of the printed circuit board. This is a non-intrusive test. The principle is that when the faulty printed circuit board works abnormally, the temperature distribution of the board is abnormal, and the comparison can determine the fault during the period. The disadvantage of this method is that different printed circuit boards may have different temperature cloud maps due to differences in component parameters and working conditions, resulting in many abnormal points on the printed circuit board. If the positioning is complex electronic packaging such as BGA and other components, there is a greater risk of desoldering.

[0006] Finite element thermal simulation software is a CFD computational fluid dynamics solver for electronic thermal management. It can be used to predict airflow, temperature and heat transfer in IC packages, PCBs, electronic assemblies, etc. It is mainly used for thermal analysis and simulation.

[0007] Infrared thermal imaging technology is a mature non-intrusive fault detection technology that collects the temperature distribution of the object being tested and analyzes its working status and fault information. Summary of the invention

[0008] In order to solve the above problems, the present invention provides a printed circuit board fault diagnosis device and a diagnosis method based on thermal simulation software.

[0009] A printed circuit board fault diagnosis device based on thermal simulation software, comprising:

[0010] Industrial computer, used for 3D modeling and thermal simulation analysis of printed circuit boards and image processing of subsequent temperature cloud maps;

[0011] Infrared detection equipment is used to detect the temperature of the printed circuit board when it is working and form an original infrared cloud map.

[0012] The industrial computer is an industrial computer, comprising a desktop computer case, a desktop computer display screen, and a data transmission line.

[0013] The industrial computer is internally provided with finite element analysis software, printed circuit board three-dimensional modeling software, infrared original cloud image processing software, temperature cloud data comparison software and other necessary software.

[0014] A diagnostic method for a printed circuit board fault diagnostic device based on thermal simulation software, the specific steps of which are as follows:

[0015] Step S1, modeling: using 3D modeling software to build a 3D model of the printed circuit board, saving the built 3D model in a common format, and then importing it into finite element thermal simulation software;

[0016] Step S2, setting parameters: in the finite element thermal simulation software, setting corresponding parameters according to the actual working environment of the printed circuit board;

[0017] Step S3, thermal simulation analysis: running finite element thermal simulation software to perform thermal simulation analysis;

[0018] Step S4, printed circuit board temperature cloud map: use professional temperature detection equipment to actually detect the temperature of the printed circuit board, and finally form a printed circuit board temperature cloud map, extract key point data of the temperature cloud map in CSV format and input it into professional data comparison software;

[0019] Step S5, analyzing the fault area: further analyzing the area that is initially judged to have a possible fault;

[0020] Step S6, determine the fault: according to the results of the detailed analysis, determine the fault type and location of the printed circuit board, and put forward corresponding maintenance suggestions;

[0021] Step S7, analysis results: According to the detailed analysis results, if the faulty component of the printed circuit board is a high-risk package for desoldering, preset the power consumption parameters of the faulty component in the finite element thermal simulation software, re-perform the simulation analysis, and compare the newly obtained temperature cloud map with the faulty printed circuit board again.

[0022] The beneficial effects of the present invention are as follows: by establishing a three-dimensional model of a printed circuit board and performing thermal simulation analysis using finite element thermal simulation software, the present invention forms a temperature cloud map of the printed circuit board in combination with professional infrared detection equipment, thereby being able to quickly and accurately compare and diagnose faults of the printed circuit board, thereby improving the efficiency and accuracy of fault diagnosis, reducing the workload and misjudgment rate of manual detection, and providing strong support for fault diagnosis of the printed circuit board. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0024] Figure 1 It is a schematic diagram of the main structure of the present invention;

[0025] Figure 2 It is a schematic diagram of the printed circuit board fault diagnosis process of the present invention;

[0026] Figure 3 It is a schematic diagram of the temperature cloud map data processing flow of the present invention;

[0027] Figure numerals: 1. desktop computer case; 2. desktop computer display screen; 3. data transmission line; 4. infrared detection equipment. DETAILED DESCRIPTION

[0028] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further described below.

[0029] like Figures 1 to 3 As shown, a printed circuit board fault diagnosis device based on thermal simulation software includes:

[0030] Industrial computer, used for 3D modeling and thermal simulation analysis of printed circuit boards and image processing of subsequent temperature cloud maps;

[0031] The infrared detection device 4 is used to detect the temperature of the printed circuit board during operation to form an original infrared cloud map.

[0032] The industrial computer is an industrial computer, such as Figure 1 As shown, it includes a desktop computer case 1, a desktop computer display screen 2, and a data transmission line 3.

[0033] The industrial computer is internally provided with finite element analysis software, printed circuit board three-dimensional modeling software, infrared original cloud image processing software, temperature cloud data comparison software and other necessary software.

[0034] A diagnostic method for a printed circuit board fault diagnostic device based on thermal simulation software, the specific steps of which are as follows:

[0035] Step S1, modeling: using 3D modeling software to build a 3D model of the printed circuit board, ensuring the accuracy and completeness of the model, saving the built 3D model in a common format, such as STEP, IGES, and then importing it into finite element thermal simulation software;

[0036] Step S2, setting parameters: in the finite element thermal simulation software, set corresponding parameters according to the actual working environment of the printed circuit board; for example, set the working environment temperature to 25°C, the humidity to 50%, and the wind speed to 0.5m / s; at the same time, set the working power and thermal characteristic parameters of each component, such as the heating power of the chip and the thermal resistance of the resistor;

[0037] Step S3, thermal simulation analysis: run the finite element thermal simulation software to perform thermal simulation analysis; the finite element thermal simulation software will calculate the temperature distribution of the printed circuit board under normal working conditions according to the set parameters and models, and output it in the form of graphics and data;

[0038] Step S4, PCB temperature cloud map: Use professional temperature detection equipment to actually detect the temperature of the PCB, and finally form a PCB temperature cloud map. Extract key point data of the temperature cloud map in CSV format and input it into professional data comparison software. The data comparison software compares the data with the temperature distribution obtained by simulation analysis. The method for extracting temperature cloud map data is as follows: Figure 2 As shown, when the actual temperature of a certain area is significantly higher or lower than the simulated temperature, and the deviation exceeds a certain threshold, such as 10°C, it is preliminarily judged that there may be a fault in the area;

[0039] Step S5, analyzing the fault area: further analyzing the area that is initially judged to have a possible fault;

[0040] Step S6, determine the fault: according to the results of the detailed analysis, determine the fault type and location of the printed circuit board, and make corresponding repair suggestions. For example, if it is a cold soldering fault, it is recommended to re-solder the relevant circuit; if it is an overheating fault, it is recommended to replace the faulty components;

[0041] Step S7, analysis results: According to the detailed analysis results, if the faulty component of the printed circuit board is a high-risk package for desoldering, preset the power consumption parameters of the faulty component in the finite element thermal simulation software, re-perform the simulation analysis, and compare the newly obtained temperature cloud map with the faulty printed circuit board again to confirm the faulty component again from the simulation perspective, reduce the risk of desoldering, and improve positioning accuracy.

[0042] By establishing a three-dimensional model of the printed circuit board and using finite element thermal simulation software to perform thermal simulation analysis, combined with professional infrared detection equipment to form a printed circuit board temperature cloud map, it is possible to quickly and accurately compare and diagnose printed circuit board faults, improve the efficiency and accuracy of fault diagnosis, reduce the workload and misjudgment rate of manual inspection, and provide strong support for printed circuit board fault diagnosis.

[0043] The steps for processing the temperature cloud data generated by professional temperature detection equipment are as follows: Figure 3 As shown:

[0044] Step S1: using infrared imaging equipment to obtain an original infrared cloud image of the printed circuit board to be inspected;

[0045] Step S2: pre-processing the original infrared cloud image, and correcting the image to ensure that the shape and size of all printed circuit board areas are consistent;

[0046] Step S3: grid the infrared cloud image, identify the temperature values ​​of key points of the printed circuit board, and output the parameters of each point of the temperature cloud image in the form of data.

[0047] The printed circuit board diagnostic method is non-intrusive, reducing secondary product failures caused by false touches during product testing.

[0048] The preprocessing of the original infrared cloud image includes the following steps:

[0049] Step S1: background removal, removing the area outside the printed circuit board in the infrared cloud image;

[0050] Step S2: Angle correction, using the central projection method, which includes projection transformation and affine transformation, to correct the tilted image in three-dimensional coordinates into a plane image with a viewing angle perpendicular to the surface of the circuit board, and then transform the size into a uniform size to obtain a pre-processed infrared cloud image.

[0051] The three-dimensional model of step S1 needs to include circuit board layers, various components, and wiring types. The various components include chips, resistors, and capacitors.

[0052] The professional temperature detection equipment in step S4 includes infrared thermal imagers and thermocouples.

[0053] The step S5 specifically checks whether the connection of components in the area is good, whether there are cold solder joints or short circuits; checks whether the wiring is reasonable, whether there are crossovers or too thin problems; checks whether the heat dissipation measures, such as heat sinks and fans, are effective, and whether there are blockages or damage.

[0054] The fault types in step S6 include short circuit fault, open circuit fault and overheat fault.

[0055] By simulating and analyzing the thermal performance of electronic equipment, combining key indicators such as temperature and heat flux density, a temperature cloud map is simulated. By comparing the infrared cloud map of professional infrared detection equipment, potential fault points in the equipment can be accurately diagnosed and key point data can be extracted. The grid size and number of key points can be adjusted as needed to improve the comparison speed and quality.

[0056] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions only describe the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A printed circuit board fault diagnosis device based on thermal simulation software, characterized in that: include: Industrial computer, used for 3D modeling and thermal simulation analysis of printed circuit boards and image processing of subsequent temperature cloud maps; The infrared detection device (4) is used to detect the temperature of the printed circuit board during operation and form an original infrared cloud map.

2. A printed circuit board fault diagnosis device based on thermal simulation software according to claim 1, characterized in that: The industrial computer is an industrial computer, comprising a desktop computer case (1), a desktop computer display screen (2), and a data transmission line (3).

3. A printed circuit board fault diagnosis device based on thermal simulation software according to claim 2, characterized in that: The industrial computer is internally provided with finite element analysis software, printed circuit board three-dimensional modeling software, infrared original cloud image processing software, temperature cloud data comparison software and other necessary software.

4. A diagnostic method for a printed circuit board fault diagnostic device based on thermal simulation software according to any one of claims 1 to 3, characterized in that: The specific steps are as follows: Step S1, modeling: using 3D modeling software to build a 3D model of the printed circuit board, saving the built 3D model in a common format, and then importing it into finite element thermal simulation software; Step S2, setting parameters: in the finite element thermal simulation software, setting corresponding parameters according to the actual working environment of the printed circuit board; Step S3, thermal simulation analysis: running finite element thermal simulation software to perform thermal simulation analysis; Step S4, printed circuit board temperature cloud map: use professional temperature detection equipment to actually detect the temperature of the printed circuit board, and finally form a printed circuit board temperature cloud map, extract key point data of the temperature cloud map in CSV format and input it into professional data comparison software; Step S5, analyzing the fault area: further analyzing the area that is initially judged to have a possible fault; Step S6, determine the fault: according to the results of the detailed analysis, determine the fault type and location of the printed circuit board, and put forward corresponding maintenance suggestions; Step S7, analysis results: According to the detailed analysis results, if the faulty component of the printed circuit board is a high-risk package for desoldering, preset the power consumption parameters of the faulty component in the finite element thermal simulation software, re-perform the simulation analysis, and compare the newly obtained temperature cloud map with the faulty printed circuit board again.

5. The diagnostic method of a printed circuit board fault diagnostic device based on thermal simulation software according to claim 4, characterized in that: The three-dimensional model of step S1 needs to include circuit board layers, various components, and wiring types, and the various components include chips, resistors, and capacitors.

6. The diagnostic method of a printed circuit board fault diagnostic device based on thermal simulation software according to claim 4, characterized in that: The professional temperature detection equipment in step S4 includes infrared thermal imagers and thermocouples.

7. The diagnostic method of a printed circuit board fault diagnostic device based on thermal simulation software according to claim 4, characterized in that: The temperature cloud map data processing steps in step S4 are as follows: Step S1: using infrared imaging equipment to obtain an original infrared cloud image of the printed circuit board to be inspected; Step S2: pre-processing the original infrared cloud image, and correcting the image to ensure that the shape and size of all printed circuit board areas are consistent; Step S3: grid the infrared cloud image, identify the temperature values ​​of key points of the printed circuit board, and output the parameters of each point of the temperature cloud image in the form of data.

8. The diagnostic method of a printed circuit board fault diagnostic device based on thermal simulation software according to claim 7, characterized in that: The original infrared cloud image preprocessing comprises the following steps: Step S1: background removal, removing the area outside the printed circuit board in the infrared cloud image; Step S2: Angle correction, using the central projection method, which includes projection transformation and affine transformation, to correct the tilted image in three-dimensional coordinates into a plane image with a viewing angle perpendicular to the surface of the circuit board, and then transform the size into a uniform size to obtain a pre-processed infrared cloud image.

9. The diagnostic method of a printed circuit board fault diagnostic device based on thermal simulation software according to claim 4, characterized in that: The step S5 specifically checks whether the connection of the components in the area is good, whether there are cold solder joints or short circuits; checks whether the wiring is reasonable, whether there are crossovers or too thin problems; checks whether the heat dissipation measures are effective, whether there are blockages or damage.

10. The diagnostic method of a printed circuit board fault diagnostic device based on thermal simulation software according to claim 4, characterized in that: The fault types in step S6 include short circuit fault, open circuit fault and overheat fault.

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