Flexible circuit board testing method and system based on multi-dimensional data

Abstract

The invention discloses a flexible circuit board testing method and system based on multi-dimensional data, and relates to the technical field of circuit board testing, and the method comprises the steps: carrying out the precise measurement of a flexible circuit board through a laser range finder, and testing the size precision of the flexible circuit board; surface protrusion and defect detection is carried out in a morphological mode; detecting whether the circuit of the flexible circuit board is short-circuited or open-circuited by applying fixed voltage and current; placing the flexible circuit board in a specific environmental test box, and observing and recording environmental parameter changes and corresponding flexible circuit board performance changes; bending, folding and stretching actions of the flexible circuit board in different application scenes are simulated, mechanical performance indexes of the flexible circuit board are recorded, and test data are collected and sorted; and multi-dimensional comprehensive analysis is carried out. By arranging the non-destructive test module and the destructive test module, the automatic detection system which is high in detection speed, high in detection precision and high in cost performance is constructed.

Description

Technical Field

[0001] The present invention relates to the technical field of circuit board testing, and in particular to a flexible circuit board testing method and system based on multi-dimensional data. Background Art

[0002] Flexible circuit boards refer to circuit boards that are mainly made of films such as polyimide. Compared with ordinary rigid circuit boards, they have the advantages of being able to bend and fold freely, being easy to transmit, and having low overall cost. Flexible circuit boards are widely used in control automation, intelligent electronic devices, modern medical devices, consumer electronics, and communications. Especially in terms of price, flexible circuit boards are only half of ordinary rigid circuit boards, which can reduce product costs. As electronic components tend to be smaller in size and circuit board designs tend to be more complex, flexible circuit boards that are mainly made of polyimide films have made great progress and are widely used in various fields such as aerospace, military communications, etc.

[0003] As electronic products develop towards smaller sizes and lighter weight, flexible circuit boards are increasingly being used. However, flexible circuit boards have high requirements for production equipment and environment during the production process, and are affected by many factors such as light and production equipment. Due to many factors such as the production environment and materials, defects are prone to occur during the production or printing process, which affects product quality and reduces corporate competitiveness. Therefore, how to achieve real-time and accurate testing of flexible circuit board defects to improve production efficiency has become the main problem to be solved in the current flexible circuit board defect testing. Summary of the invention

[0004] In order to solve the above technical problems, a flexible circuit board testing method and system based on multi-dimensional data are provided. This technical solution solves the problems raised in the above background technology.

[0005] In order to achieve the above purpose, the technical solution adopted by the present invention is:

[0006] A flexible circuit board testing method based on multidimensional data, comprising:

[0007] Using a laser rangefinder to accurately measure the flexible circuit board and test the dimensional accuracy of the flexible circuit board, the dimensional accuracy includes line width, line spacing and aperture size;

[0008] Capture the surface image of the flexible circuit board through an industrial camera;

[0009] The Sobel operator edge detection algorithm is used to pre-process the surface image of the flexible circuit board to obtain the image to be analyzed;

[0010] Based on the image to be analyzed, surface protrusions and defects are detected by morphological method;

[0011] Use electrical testing equipment to detect whether there is a short circuit or open circuit on the flexible circuit board by applying a fixed voltage and current;

[0012] Place the flexible circuit board in a specific environmental test chamber, test it according to the set environmental parameters, observe and record the changes in environmental parameters and the corresponding changes in the performance of the flexible circuit board;

[0013] Use professional mechanical testing equipment to simulate the bending, folding and stretching actions of flexible circuit boards in different application scenarios, and record their mechanical performance indicators, including bending strength, fracture toughness and tensile strength;

[0014] Collect and organize test data, conduct multi-dimensional comprehensive analysis, and evaluate the overall performance of the flexible circuit board by analyzing the correlation and weight between different test items.

[0015] Preferably, the preprocessing of the flexible circuit board surface image by using the Sobel operator edge detection algorithm to obtain the image to be analyzed specifically includes:

[0016] Obtaining red, green and blue color components of each pixel through the surface image of the flexible circuit board;

[0017] Obtain the weighted coefficients of human eye sensitivity to red, green and blue;

[0018] Calculate the grayscale value of each pixel point on the surface of the flexible circuit board according to the grayscale value formula, wherein the grayscale value range is [0, 255];

[0019] Based on the grayscale values ​​of each pixel point of the surface image of the flexible circuit board, the grayscale image to be processed is obtained by summarizing and drawing;

[0020] Get the Sobel operator transverse matrix and longitudinal matrix;

[0021] The edge threshold of the grayscale image to be processed is calculated using the Sobel operator edge threshold formula;

[0022] Based on the edge threshold of the grayscale image to be processed, the grayscale image to be processed is divided into a target area and a background area, and the target area and the background area are output as the image to be analyzed;

[0023] The gray value formula is:

[0024] Gray(i,j)=ε1R(i,j)+ε2G(i,j)+ε3B(i,j),

[0025] Where Gray(i, j) is the gray value of the pixel in the i-th row and j-th column, ε1, ε2, ε3 are the weighted coefficients of the human eye sensitivity to red, green and blue, respectively, and R(i, j), G(i, j), B(i, j) are the red, green and blue components of the pixel in the i-th row and j-th column, respectively;

[0026] The Sobel operator transverse matrix is:

[0027]

[0028] In the formula, H x is the Sobel operator transverse matrix;

[0029] The vertical matrix is:

[0030]

[0031] In the formula, H y is the Sobel operator longitudinal matrix;

[0032] The Sobel operator edge threshold formula is:

[0033]

[0034] Where H0 is the edge threshold, and A is the grayscale matrix corresponding to the grayscale image to be processed.

[0035] Preferably, the detection of surface protrusions and defects by morphological means based on the image to be analyzed specifically includes:

[0036] For each background area, calculate its maximum size in the vertical direction of the line;

[0037] Determine whether the maximum size is greater than 4 / 3 times the standard line spacing. If so, output the part as a defective part. If not, do not output it.

[0038] Determine whether the maximum size is less than 2 / 3 times the standard line spacing. If so, output the part as a protrusion. If not, do not output it.

[0039] Preferably, the use of electrical measuring equipment to detect whether there is a short circuit or open circuit in the circuit of the flexible circuit board by applying a fixed voltage and current specifically includes:

[0040] Get the open circuit resistance threshold and the short circuit resistance threshold;

[0041] Divide the flexible circuit board into at least one part;

[0042] Apply a fixed voltage and current to each flexible circuit board;

[0043] Use a multimeter to measure the resistance of each flexible circuit board;

[0044] Determine whether the resistance is higher than the open circuit resistance threshold. If so, output that the circuit has an open circuit. If not, no output is made.

[0045] Determine whether the resistance is lower than the short-circuit resistance threshold. If so, output that there is a short circuit in this part of the line. If not, no output is made.

[0046] Preferably, placing the flexible circuit board in a specific environmental test box, testing according to set environmental parameters, and observing and recording changes in environmental parameters and corresponding changes in performance of the flexible circuit board specifically include:

[0047] Apply high voltage to the flexible circuit board to test the insulation performance of the flexible circuit board;

[0048] Put the flexible circuit board into temperature cycle to test its heat resistance and cold resistance;

[0049] Simulate the corrosion of flexible circuit boards in a salt spray environment and evaluate their anti-corrosion performance;

[0050] By simulating the vibration environment of vehicle driving, the reliability of flexible circuit boards under long-term vibration is tested;

[0051] The flexible circuit board is subjected to accelerated aging experiments under high temperature, high humidity and high voltage conditions to test the long-term stability of the flexible circuit board.

[0052] Preferably, the use of professional mechanical testing equipment to simulate the bending, folding and stretching actions of the flexible circuit board in different application scenarios and record its mechanical performance indicators specifically include:

[0053] Cut off a portion of the flexible circuit board and process it into three rectangular samples of set sizes;

[0054] The three-point bending method is used to apply pressure to the two ends and the middle of one of the rectangular samples;

[0055] The maximum load just before the sample breaks is recorded as the first breaking load;

[0056] Calculate the bending strength of the flexible circuit board using the bending strength formula;

[0057] A small cut was made in the middle of one of the rectangular samples using the single-edge notched beam method as an artificial preset crack;

[0058] Apply pressure to both ends of the rectangular sample and record the maximum load just before the sample breaks as the second breaking load;

[0059] The fracture toughness of flexible circuit boards is calculated using the fracture toughness formula;

[0060] Install one of the rectangular samples on the fixture of the tensile testing machine;

[0061] Apply tensile force step by step according to the set test parameters, and record the maximum load just before the sample breaks as the third breaking load;

[0062] Use the tensile strength formula to calculate the tensile strength of the flexible circuit board;

[0063] The bending strength formula is:

[0064]

[0065] In the formula, γ is the bending strength of the flexible circuit board, F1 is the first breaking load of the flexible circuit board, L is the length of the rectangular sample, H is the thickness of the rectangular sample, and B is the width of the rectangular sample;

[0066] The fracture toughness formula is:

[0067]

[0068] Where K is the fracture toughness of the flexible circuit board, F2 is the second fracture load of the flexible circuit board, and D is the incision length;

[0069] The tensile strength formula is:

[0070]

[0071] Wherein, M is the tensile strength of the flexible circuit board, and F3 is the third breaking load of the flexible circuit board.

[0072] Furthermore, a flexible circuit board testing system based on multidimensional data is proposed, which is used to implement the flexible circuit board testing method based on multidimensional data as described above, including:

[0073] A non-destructive testing module, wherein the non-destructive testing module is used to accurately measure the flexible circuit board using a laser rangefinder, test the dimensional accuracy of the flexible circuit board, collect the surface image of the flexible circuit board using an industrial camera, pre-process the surface image of the flexible circuit board using a Sobel operator edge detection algorithm to obtain an image to be analyzed, perform surface protrusion and defect detection in a morphological manner based on the image to be analyzed, and use an electrical measuring device to detect whether there is a short circuit or a break in the circuit of the flexible circuit board by applying a fixed voltage and current;

[0074] Destructive testing module, the destructive testing module is used to place the flexible circuit board in a specific environmental test chamber, perform tests according to the set environmental parameters, observe and record changes in environmental parameters and corresponding changes in the performance of the flexible circuit board, use professional mechanical testing equipment to simulate the bending, folding and stretching actions of the flexible circuit board in different application scenarios, record its mechanical performance indicators, collect and organize test data, conduct multi-dimensional comprehensive analysis, and evaluate the overall performance of the flexible circuit board by analyzing the correlation and weight between different test items.

[0075] Optionally, the non-destructive testing module specifically includes:

[0076] A dimensional accuracy testing unit, which is used to accurately measure the flexible circuit board using a laser rangefinder to test the dimensional accuracy of the flexible circuit board;

[0077] A surface image acquisition unit, wherein the surface image acquisition unit is used to acquire a surface image of the flexible circuit board through an industrial camera;

[0078] An image preprocessing unit, wherein the image preprocessing unit is used to preprocess the surface image of the flexible circuit board using a Sobel operator edge detection algorithm to obtain an image to be analyzed;

[0079] A protrusion and defect testing unit, which is used to detect surface protrusions and defects in a morphological manner based on the image to be analyzed;

[0080] A short circuit and open circuit testing unit is used to detect whether there is a short circuit or open circuit phenomenon in the circuit of the flexible circuit board by using an electrical measuring device and applying a fixed voltage and current.

[0081] Optionally, the destructive testing module specifically includes:

[0082] An environmental performance testing unit, which is used to place the flexible circuit board in a specific environmental test box, perform a test according to set environmental parameters, and observe and record changes in environmental parameters and corresponding changes in performance of the flexible circuit board;

[0083] A mechanical performance testing unit, which is used to simulate the bending, folding and stretching actions of the flexible circuit board in different application scenarios using professional mechanical testing equipment, and record its mechanical performance indicators;

[0084] The overall performance evaluation unit is used to collect and organize test data, conduct multi-dimensional comprehensive analysis, and evaluate the overall performance of the flexible circuit board by analyzing the correlation and weight between different test items.

[0085] Compared with the prior art, the present invention has the following beneficial effects:

[0086] Introduce automated testing equipment and intelligent analysis systems to improve testing efficiency and accuracy. By setting up non-destructive testing modules and destructive testing modules, an automatic testing system with fast detection rate, high detection accuracy and high cost performance is constructed. This system covers test data in multiple dimensions including mechanical, appearance, size, electrical and environmental. This method can be used to comprehensively evaluate various performance indicators of flexible circuit boards to ensure that their quality meets design requirements and market demands. BRIEF DESCRIPTION OF THE DRAWINGS

[0087] Figure 1 A flow chart of a flexible circuit board testing method based on multi-dimensional data of the present invention;

[0088] Figure 2 It is a flow chart of the Sobel operator edge detection algorithm method of the present invention;

[0089] Figure 3 This is a flow chart of the method for detecting surface protrusions and defects by morphological means according to the present invention;

[0090] Figure 4 A flow chart of a method for detecting whether a flexible circuit board circuit has a short circuit or a broken circuit according to the present invention;

[0091] Figure 5 This is a flow chart of a method for placing a flexible circuit board in a specific environmental test box and performing a test according to set environmental parameters;

[0092] Figure 6 The present invention is a flow chart of a method for simulating the bending, folding and stretching actions of a flexible circuit board in different application scenarios and recording its mechanical performance indexes. DETAILED DESCRIPTION

[0093] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art may think of other obvious variations.

[0094] Reference Figure 1 As shown, a flexible circuit board testing method based on multi-dimensional data includes:

[0095] Using a laser rangefinder to accurately measure the flexible circuit board and test the dimensional accuracy of the flexible circuit board, the dimensional accuracy includes line width, line spacing and aperture size;

[0096] Capture the surface image of the flexible circuit board through an industrial camera;

[0097] The Sobel operator edge detection algorithm is used to pre-process the surface image of the flexible circuit board to obtain the image to be analyzed;

[0098] Based on the image to be analyzed, surface protrusions and defects are detected by morphological method;

[0099] Use electrical testing equipment to detect whether there is a short circuit or open circuit on the flexible circuit board by applying a fixed voltage and current;

[0100] Place the flexible circuit board in a specific environmental test chamber, test it according to the set environmental parameters, observe and record the changes in environmental parameters and the corresponding changes in the performance of the flexible circuit board;

[0101] Use professional mechanical testing equipment to simulate the bending, folding and stretching actions of flexible circuit boards in different application scenarios, and record their mechanical performance indicators, including bending strength, fracture toughness and tensile strength;

[0102] Collect and organize test data, conduct multi-dimensional comprehensive analysis, and evaluate the overall performance of the flexible circuit board by analyzing the correlation and weight between different test items.

[0103] Reference Figure 2 As shown, the Sobel operator edge detection algorithm is used to preprocess the surface image of the flexible circuit board, and the image to be analyzed specifically includes:

[0104] Obtaining red, green and blue color components of each pixel through the surface image of the flexible circuit board;

[0105] Obtain the weighted coefficients of human eye sensitivity to red, green and blue;

[0106] Calculate the grayscale value of each pixel point on the surface of the flexible circuit board according to the grayscale value formula, wherein the grayscale value range is [0, 255];

[0107] Based on the grayscale values ​​of each pixel point of the surface image of the flexible circuit board, the grayscale image to be processed is obtained by summarizing and drawing;

[0108] Get the Sobel operator transverse matrix and longitudinal matrix;

[0109] The edge threshold of the grayscale image to be processed is calculated using the Sobel operator edge threshold formula;

[0110] Based on the edge threshold of the grayscale image to be processed, the grayscale image to be processed is divided into a target area and a background area, and the target area and the background area are output as the image to be analyzed;

[0111] The gray value formula is:

[0112] Gray(i,j)=ε1R(i,j)+ε2G(i,j)+ε3B(i,j),

[0113] Where Gray(i, j) is the gray value of the pixel in the i-th row and j-th column, ε1, ε2, ε3 are the weighted coefficients of the human eye sensitivity to red, green and blue, respectively, and R(i, j), G(i, j), B(i, j) are the red, green and blue components of the pixel in the i-th row and j-th column, respectively;

[0114] The Sobel operator transverse matrix is:

[0115]

[0116] In the formula, H x is the Sobel operator transverse matrix;

[0117] The vertical matrix is:

[0118]

[0119] In the formula, H y is the Sobel operator longitudinal matrix;

[0120] The Sobel operator edge threshold formula is:

[0121]

[0122] Where H0 is the edge threshold, and A is the grayscale matrix corresponding to the grayscale image to be processed.

[0123] The Sobel edge detection algorithm is relatively simple. In practical applications, its efficiency is higher than that of the Canny edge detection, but its edge is not as accurate as that of the Canny detection. However, in many practical applications, the Sobel edge is the first choice. The Sobel operator is a combination of Gaussian smoothing and differential operations, so it has strong noise resistance and many uses, especially when efficiency requirements are high and fine textures are not of much concern.

[0124] Reference Figure 3 As shown, based on the image to be analyzed, the surface protrusion and defect detection by morphological method specifically includes:

[0125] For each background area, calculate its maximum size in the vertical direction of the line;

[0126] Determine whether the maximum size is greater than 4 / 3 times the standard line spacing. If so, output the part as a defective part. If not, do not output it.

[0127] Determine whether the maximum size is less than 2 / 3 times the standard line spacing. If so, output the part as a protrusion. If not, do not output it.

[0128] A protrusion is an excess component of a standard circuit whose notch size does not reach the level of a short circuit. Since a single protrusion of a circuit does not affect the performance of the entire circuit board, protrusion detection is based on the ability to detect protrusions between parallel circuits. Incompleteness is a type of defect that does not meet size requirements. When the notch size is larger than a certain range, weak conductivity may occur, resulting in poor contact.

[0129] Reference Figure 4 As shown, electrical measuring equipment is used to detect whether there is a short circuit or open circuit in the flexible circuit board by applying a fixed voltage and current. Specifically, the following are included:

[0130] Get the open circuit resistance threshold and the short circuit resistance threshold;

[0131] Divide the flexible circuit board into at least one part;

[0132] Apply a fixed voltage and current to each flexible circuit board;

[0133] Use a multimeter to measure the resistance of each flexible circuit board;

[0134] Determine whether the resistance is higher than the open circuit resistance threshold. If so, output that the circuit has an open circuit. If not, no output is made.

[0135] Determine whether the resistance is lower than the short-circuit resistance threshold. If so, output that there is a short circuit in this part of the line. If not, no output is made.

[0136] When low resistance is detected between component pins, it may be a short circuit. At this time, the component can be removed from the flexible circuit board circuit for special testing. If the resistance is still very low, the component may be the cause of the short circuit. The same is true for the open circuit.

[0137] Reference Figure 5 As shown, the flexible circuit board is placed in a specific environmental test chamber, tested according to the set environmental parameters, and the changes in environmental parameters and the corresponding changes in the performance of the flexible circuit board are observed and recorded, including:

[0138] Apply high voltage to the flexible circuit board to test the insulation performance of the flexible circuit board;

[0139] Put the flexible circuit board into temperature cycle to test its heat resistance and cold resistance;

[0140] Simulate the corrosion of flexible circuit boards in a salt spray environment and evaluate their anti-corrosion performance;

[0141] By simulating the vibration environment of vehicle driving, the reliability of flexible circuit boards under long-term vibration is tested;

[0142] The flexible circuit board is subjected to accelerated aging experiments under high temperature, high humidity and high voltage conditions to test the long-term stability of the flexible circuit board.

[0143] Various environmental performance tests on flexible circuit boards can detect the product quality of flexible circuit boards from many aspects, thereby improving the market competitiveness of flexible circuit boards.

[0144] Reference Figure 6 As shown, professional mechanical testing equipment is used to simulate the bending, folding and stretching actions of flexible circuit boards in different application scenarios, and the mechanical performance indicators are recorded, including:

[0145] Cut off a portion of the flexible circuit board and process it into three rectangular samples of set sizes;

[0146] The three-point bending method is used to apply pressure to the two ends and the middle of one of the rectangular samples;

[0147] The maximum load just before the sample breaks is recorded as the first breaking load;

[0148] Calculate the bending strength of the flexible circuit board using the bending strength formula;

[0149] A small cut was made in the middle of one of the rectangular samples using the single-edge notched beam method as an artificial preset crack;

[0150] Apply pressure to both ends of the rectangular sample and record the maximum load just before the sample breaks as the second breaking load;

[0151] The fracture toughness of flexible circuit boards is calculated using the fracture toughness formula;

[0152] Install one of the rectangular samples on the fixture of the tensile testing machine;

[0153] Apply tensile force step by step according to the set test parameters, and record the maximum load just before the sample breaks as the third breaking load;

[0154] Use the tensile strength formula to calculate the tensile strength of the flexible circuit board;

[0155] The bending strength formula is:

[0156]

[0157] In the formula, γ is the bending strength of the flexible circuit board, F1 is the first breaking load of the flexible circuit board, L is the length of the rectangular sample, H is the thickness of the rectangular sample, and B is the width of the rectangular sample;

[0158] The fracture toughness formula is:

[0159]

[0160] Where K is the fracture toughness of the flexible circuit board, F2 is the second fracture load of the flexible circuit board, and D is the incision length;

[0161] The tensile strength formula is:

[0162]

[0163] Wherein, M is the tensile strength of the flexible circuit board, and F3 is the third breaking load of the flexible circuit board.

[0164] It is very difficult to prefabricate an ideal native crack on a flexible circuit board sample. Therefore, when using the single-sided notch beam method to test the fracture performance of the material, an artificial incision of a certain length is usually prefabricated on the specimen as a substitute. The artificial incision has a curvature radius much larger than that of the natural crack, which will cause the stress concentration to decrease. The measured fracture toughness value will be too large and will increase with the increase of the incision width. This effect is called the "incision passivation effect."

[0165] Further, based on the same inventive concept as the above-mentioned flexible circuit board testing method based on multi-dimensional data, the present solution also proposes a flexible circuit board testing system based on multi-dimensional data, including:

[0166] A non-destructive testing module, wherein the non-destructive testing module is used to accurately measure the flexible circuit board using a laser rangefinder, test the dimensional accuracy of the flexible circuit board, collect the surface image of the flexible circuit board using an industrial camera, pre-process the surface image of the flexible circuit board using a Sobel operator edge detection algorithm to obtain an image to be analyzed, perform surface protrusion and defect detection in a morphological manner based on the image to be analyzed, and use an electrical measuring device to detect whether there is a short circuit or a break in the circuit of the flexible circuit board by applying a fixed voltage and current;

[0167] Destructive testing module, the destructive testing module is used to place the flexible circuit board in a specific environmental test chamber, perform tests according to the set environmental parameters, observe and record changes in environmental parameters and corresponding changes in the performance of the flexible circuit board, use professional mechanical testing equipment to simulate the bending, folding and stretching actions of the flexible circuit board in different application scenarios, record its mechanical performance indicators, collect and organize test data, conduct multi-dimensional comprehensive analysis, and evaluate the overall performance of the flexible circuit board by analyzing the correlation and weight between different test items.

[0168] The non-destructive testing modules include:

[0169] A dimensional accuracy testing unit, which is used to accurately measure the flexible circuit board using a laser rangefinder to test the dimensional accuracy of the flexible circuit board;

[0170] A surface image acquisition unit, wherein the surface image acquisition unit is used to acquire a surface image of the flexible circuit board through an industrial camera;

[0171] An image preprocessing unit, the image preprocessing unit is used to preprocess the surface image of the flexible circuit board using a Sobel operator edge detection algorithm to obtain an image to be analyzed;

[0172] A protrusion and defect testing unit, which is used to detect surface protrusions and defects in a morphological manner based on the image to be analyzed;

[0173] A short circuit and open circuit testing unit is used to detect whether there is a short circuit or open circuit phenomenon in the circuit of the flexible circuit board by using an electrical measuring device and applying a fixed voltage and current.

[0174] The destructive testing module specifically includes:

[0175] An environmental performance testing unit, which is used to place the flexible circuit board in a specific environmental test box, perform a test according to set environmental parameters, and observe and record changes in environmental parameters and corresponding changes in performance of the flexible circuit board;

[0176] A mechanical performance testing unit, which is used to simulate the bending, folding and stretching actions of the flexible circuit board in different application scenarios using professional mechanical testing equipment, and record its mechanical performance indicators;

[0177] The overall performance evaluation unit is used to collect and organize test data, conduct multi-dimensional comprehensive analysis, and evaluate the overall performance of the flexible circuit board by analyzing the correlation and weight between different test items.

[0178] Furthermore, the present solution also proposes a computer-readable storage medium on which a computer-readable program is stored. When the computer-readable program is called, the above-mentioned flexible circuit board testing method based on multi-dimensional data is executed.

[0179] It is understandable that the storage medium may be a magnetic medium, such as a floppy disk, a hard disk, or a magnetic tape; an optical medium, such as a DVD; or a semiconductor medium, such as a solid state drive (SSD).

[0180] In summary, the advantages of the present invention are: introducing automated testing equipment and intelligent analysis systems to improve test efficiency and accuracy, and constructing an automatic detection system with fast detection rate, high detection accuracy and high cost performance by setting non-destructive test modules and destructive test modules, covering test data in multiple dimensions of mechanical, appearance, size, electrical and environmental. Through this method, the various performance indicators of the flexible circuit board can be comprehensively evaluated to ensure that its quality meets the design requirements and market demand.

[0181] 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. The present invention may be subject to various changes and improvements without departing from the spirit and scope of the present invention. These changes and improvements fall within the scope of the present invention. The scope of protection claimed by the present invention is defined by the attached claims and their equivalents.

Claims

1. A flexible circuit board testing method based on multidimensional data, characterized in that: include: Using a laser rangefinder to accurately measure the flexible circuit board and test the dimensional accuracy of the flexible circuit board, the dimensional accuracy includes line width, line spacing and aperture size; Capture the surface image of the flexible circuit board through an industrial camera; The Sobel operator edge detection algorithm is used to pre-process the surface image of the flexible circuit board to obtain the image to be analyzed; Based on the image to be analyzed, surface protrusions and defects are detected by morphological method; Use electrical testing equipment to detect whether there is a short circuit or open circuit on the flexible circuit board by applying a fixed voltage and current; Place the flexible circuit board in a specific environmental test chamber, test it according to the set environmental parameters, observe and record the changes in environmental parameters and the corresponding changes in the performance of the flexible circuit board; Use professional mechanical testing equipment to simulate the bending, folding and stretching actions of flexible circuit boards in different application scenarios, and record their mechanical performance indicators, including bending strength, fracture toughness and tensile strength; Collect and organize test data, conduct multi-dimensional comprehensive analysis, and evaluate the overall performance of the flexible circuit board by analyzing the correlation and weight between different test items.

2. A flexible circuit board testing method based on multidimensional data according to claim 1, characterized in that: The method of preprocessing the surface image of the flexible circuit board using the Sobel operator edge detection algorithm to obtain the image to be analyzed specifically includes: Obtaining red, green and blue color components of each pixel through the surface image of the flexible circuit board; Obtain the weighted coefficients of human eye sensitivity to red, green and blue; Calculate the grayscale value of each pixel point on the surface of the flexible circuit board according to the grayscale value formula, wherein the grayscale value range is [0, 255]; Based on the grayscale values ​​of each pixel point of the surface image of the flexible circuit board, the grayscale image to be processed is obtained by summarizing and drawing; Get the Sobel operator transverse matrix and longitudinal matrix; The edge threshold of the grayscale image to be processed is calculated using the Sobel operator edge threshold formula; Based on the edge threshold of the grayscale image to be processed, the grayscale image to be processed is divided into a target area and a background area, and the target area and the background area are output as the image to be analyzed; The gray value formula is: Gray(i,j)=ε1R(i,j)+ε2G(i,j)+ε3B(i,j), Where Gray(i, j) is the gray value of the pixel in the i-th row and j-th column, ε1, ε2, ε3 are the weighted coefficients of the human eye sensitivity to red, green and blue, respectively, and R(i, j), G(i, j), B(i, j) are the red, green and blue components of the pixel in the i-th row and j-th column, respectively; The Sobel operator transverse matrix is: In the formula, H x is the Sobel operator transverse matrix; The vertical matrix is: In the formula, H y is the Sobel operator longitudinal matrix; The Sobel operator edge threshold formula is: Where H0 is the edge threshold, and A is the grayscale matrix corresponding to the grayscale image to be processed.

3. A flexible circuit board testing method based on multidimensional data according to claim 2, characterized in that: The detection of surface protrusions and defects based on the image to be analyzed by morphological means specifically includes: For each background area, calculate its maximum size in the vertical direction of the line; Determine whether the maximum size is greater than 4 / 3 times the standard line spacing. If so, output the part as a defective part. If not, do not output it. Determine whether the maximum size is less than 2 / 3 times the standard line spacing. If so, output the part as a protrusion. If not, do not output it.

4. A flexible circuit board testing method based on multidimensional data according to claim 3, characterized in that:The method of using an electrical measuring device to detect whether there is a short circuit or a break in the circuit of the flexible circuit board by applying a fixed voltage and current specifically includes: Get the open circuit resistance threshold and the short circuit resistance threshold; Divide the flexible circuit board into at least one part; Apply a fixed voltage and current to each flexible circuit board; Use a multimeter to measure the resistance of each flexible circuit board; Determine whether the resistance is higher than the open circuit resistance threshold. If so, output that the circuit has an open circuit. If not, no output is made. Determine whether the resistance is lower than the short-circuit resistance threshold. If so, output that there is a short circuit in this part of the line. If not, no output is made.

5. A flexible circuit board testing method based on multidimensional data according to claim 4, characterized in that: Placing the flexible circuit board in a specific environmental test box, testing according to set environmental parameters, and observing and recording changes in environmental parameters and corresponding changes in performance of the flexible circuit board specifically include: Apply high voltage to the flexible circuit board to test the insulation performance of the flexible circuit board; Put the flexible circuit board into temperature cycle to test its heat resistance and cold resistance; Simulate the corrosion of flexible circuit boards in a salt spray environment and evaluate their anti-corrosion performance; By simulating the vibration environment of vehicle driving, the reliability of flexible circuit boards under long-term vibration is tested; The flexible circuit board is subjected to accelerated aging experiments under high temperature, high humidity and high voltage conditions to test the long-term stability of the flexible circuit board.

6. A flexible circuit board testing method based on multidimensional data according to claim 5, characterized in that: The professional mechanical testing equipment is used to simulate the bending, folding and stretching actions of the flexible circuit board in different application scenarios, and the mechanical performance indicators recorded include: Cut off a portion of the flexible circuit board and process it into three rectangular samples of set sizes; The three-point bending method is used to apply pressure to the two ends and the middle of one of the rectangular samples; The maximum load just before the sample breaks is recorded as the first breaking load; Calculate the bending strength of the flexible circuit board using the bending strength formula; A small cut was made in the middle of one of the rectangular samples using the single-edge notched beam method as an artificial preset crack; Apply pressure to both ends of the rectangular sample and record the maximum load just before the sample breaks as the second breaking load; The fracture toughness of flexible circuit boards is calculated using the fracture toughness formula; Install one of the rectangular samples on the fixture of the tensile testing machine; Apply tensile force step by step according to the set test parameters, and record the maximum load just before the sample breaks as the third breaking load; Use the tensile strength formula to calculate the tensile strength of the flexible circuit board; The bending strength formula is: In the formula, γ is the bending strength of the flexible circuit board, F1 is the first breaking load of the flexible circuit board, L is the length of the rectangular sample, H is the thickness of the rectangular sample, and B is the width of the rectangular sample; The fracture toughness formula is: Where K is the fracture toughness of the flexible circuit board, F2 is the second fracture load of the flexible circuit board, and D is the incision length; The tensile strength formula is: Wherein, M is the tensile strength of the flexible circuit board, and F3 is the third breaking load of the flexible circuit board.

7. A flexible circuit board testing system based on multidimensional data, used to implement the flexible circuit board testing method based on multidimensional data as claimed in any one of claims 1 to 6, characterized in that: include: A non-destructive testing module, wherein the non-destructive testing module is used to accurately measure the flexible circuit board using a laser rangefinder, test the dimensional accuracy of the flexible circuit board, collect the surface image of the flexible circuit board using an industrial camera, pre-process the surface image of the flexible circuit board using a Sobel operator edge detection algorithm to obtain an image to be analyzed, perform surface protrusion and defect detection in a morphological manner based on the image to be analyzed, and use an electrical measuring device to detect whether there is a short circuit or a break in the circuit of the flexible circuit board by applying a fixed voltage and current; Destructive testing module, the destructive testing module is used to place the flexible circuit board in a specific environmental test chamber, perform tests according to the set environmental parameters, observe and record changes in environmental parameters and corresponding changes in the performance of the flexible circuit board, use professional mechanical testing equipment to simulate the bending, folding and stretching actions of the flexible circuit board in different application scenarios, record its mechanical performance indicators, collect and organize test data, conduct multi-dimensional comprehensive analysis, and evaluate the overall performance of the flexible circuit board by analyzing the correlation and weight between different test items.

8. A flexible circuit board testing system based on multidimensional data according to claim 7, characterized in that: The non-destructive testing module specifically includes: A dimensional accuracy testing unit, which is used to accurately measure the flexible circuit board using a laser rangefinder to test the dimensional accuracy of the flexible circuit board; A surface image acquisition unit, wherein the surface image acquisition unit is used to acquire a surface image of the flexible circuit board through an industrial camera; An image preprocessing unit, the image preprocessing unit is used to preprocess the surface image of the flexible circuit board using a Sobel operator edge detection algorithm to obtain an image to be analyzed; A protrusion and defect testing unit, which is used to detect surface protrusions and defects in a morphological manner based on the image to be analyzed; A short circuit and open circuit testing unit is used to detect whether there is a short circuit or open circuit phenomenon in the circuit of the flexible circuit board by using an electrical measuring device and applying a fixed voltage and current.

9. A flexible circuit board testing system based on multidimensional data according to claim 8, characterized in that: The destructive test module specifically includes: An environmental performance testing unit, which is used to place the flexible circuit board in a specific environmental test box, perform a test according to set environmental parameters, and observe and record changes in environmental parameters and corresponding changes in performance of the flexible circuit board; A mechanical performance testing unit, which is used to simulate the bending, folding and stretching actions of the flexible circuit board in different application scenarios using professional mechanical testing equipment, and record its mechanical performance indicators; The overall performance evaluation unit is used to collect and organize test data, conduct multi-dimensional comprehensive analysis, and evaluate the overall performance of the flexible circuit board by analyzing the correlation and weight between different test items.

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