PCB edge detection device and method

Abstract

The invention provides a PCB edge detection device and method, relates to the technical field of electronic manufacturing, and aims to solve the problems of low efficiency and insufficient accuracy of a traditional detection means. The device is mainly composed of a refrigerator, a light transmittance detection mechanism and a computer, and rapid, accurate and efficient detection of the edge of the PCB is achieved through a series of ingenious operation steps. Specifically, the method utilizes a temperature difference induced atomization and ice crystal formation mechanism to accurately capture tiny concave-convex parts at the edge of the PCB, and further ensures the accuracy of the detection result through the light transmittance map generation and image processing technology. Compared with a traditional method, the method has the advantages that the detection efficiency is remarkably improved, batch detection of the PCBs can be achieved, the detection cost is reduced, and meanwhile good adaptability and intelligent production potential are shown.

Description

Technical Field

[0001] The present invention relates to a method for detecting the edge of a PCB (printed circuit board) and a special device thereof, and is particularly suitable for automated production in the electronic manufacturing industry. Background Art

[0002] In the electronics manufacturing industry, PCB (Printed Circuit Board) is the support for electronic components and the carrier for electrical connections. Its manufacturing quality directly affects the performance and reliability of electronic products. Especially at the edge of the PCB, due to various factors in the processing process, such as cutting, grinding, welding, etc., it is easy to form tiny unevenness. Although these unevenness are tiny, they may have a significant impact on the electrical performance and mechanical strength of the circuit board.

[0003] Traditional PCB edge detection methods mainly rely on manual visual inspection or the use of simple mechanical measurement tools. These methods are not only inefficient, but also difficult to ensure the accuracy and consistency of detection. With the continuous development of automation and intelligent technology, people's demand for PCB edge detection is also increasing, hoping to achieve fast, accurate and efficient automated detection.

[0004] In recent years, some new detection methods and technologies have been gradually applied to PCB circuit board edge detection, such as detection methods based on machine vision, detection methods based on infrared thermal imaging, etc. However, these methods often have problems such as complex equipment, high cost, and cumbersome detection process, making them difficult to be widely used in actual production. Summary of the invention

[0005] The present invention proposes a new PCB circuit board edge detection device and detection method. The device uses simple equipment such as a refrigerator, a transmittance detection mechanism and a computer, and through a series of clever operation steps, realizes fast, accurate and efficient detection of the PCB circuit board edge. The method is not only simple in equipment and low in cost, but also easy to automate the detection process, greatly improving production efficiency and detection accuracy.

[0006] The above technical objectives of the present invention are achieved through the following technical solutions: a PCB circuit board edge detection device, including a refrigerator, a transmittance detection mechanism and a computer, wherein the computer is electrically connected to the refrigerator and the transmittance detection mechanism, and also includes a glass plate with a transmittance of more than 95%.

[0007] A PCB circuit board edge detection method comprises the following steps:

[0008] a) Place several PCBs in a freezer at -18°C for 10-15 minutes, then take out all the PCBs and stack them together, making sure that the side of each PCB to be tested is flush;

[0009] b) Lay a glass plate at room temperature on the side of each PCB to be tested and keep it for 60-90 seconds to make the surface of the glass plate fog and form a fogged area;

[0010] c) Place the glass plate in a freezer at -18°C for 3-5 minutes, during which time the tiny water droplets on the surface of the glass plate gradually solidify into ice crystals, fixing the shape and position of the atomized area;

[0011] d) taking the glass plate out of the refrigerator, scanning the glass plate with a transmittance detection mechanism, measuring the change in light intensity before and after the light passes through the glass plate, and forming a transmittance map;

[0012] e) converting the transmittance measurement data into a visual transmittance map and outputting it to a computer;

[0013] f) The computer further analyzes the transmittance map through an image processing system and infers the concave and convex distribution on the side surface of the PCB circuit board based on the transmittance map.

[0014] In some embodiments, in step a), the PCB circuit board can be taken out of the refrigerator after its temperature drops to -5°C.

[0015] In some embodiments, in step b), when the glass plate contacts the PCB, the temperature difference between the two is at least 20°C.

[0016] In some embodiments, in step e), the resolution of the transmittance map is set to 0.1 mm / pixel.

[0017] In some embodiments, the image processing system is an image recognition algorithm based on machine learning, which can perform feature extraction and pattern recognition on the transmittance map, thereby accurately inferring the distribution of bumps and depressions on the side surface of the PCB circuit board.

[0018] In some embodiments, in step f), when the computer further analyzes the transmittance map through the image processing system, it also includes filtering the transmittance map to remove noise and interference and improve the recognition accuracy of the concave-convex distribution.

[0019] In some embodiments, the method further includes a step of verifying the detection results, that is, verifying the accuracy and reliability of the detection method by comparing the detection results with a PCB circuit board with a known edge position.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The present invention realizes a fast and continuous detection process through an automated detection process, including batch cooling, atomization, ice crystal formation, light transmission scanning and image analysis. Compared with traditional manual visual inspection or mechanical measurement, the detection efficiency is greatly improved, thereby effectively shortening the production cycle and improving the overall production efficiency.

[0022] The present invention utilizes the mechanism of atomization and ice crystal formation induced by temperature difference, and can accurately capture the tiny bumps and depressions on the edge of the PCB circuit board. The generation of the transmittance map and the application of image processing technology further ensure the accuracy of the detection results. Compared with the limitations of traditional methods, the present invention provides more reliable and consistent detection results.

[0023] The device used in the present invention is simple and easy to operate, and does not require a complex mechanical structure or expensive testing instruments. The combination of the light transmittance testing mechanism and the refrigerator, as well as the application of computer image processing technology, makes the entire testing process economical and efficient, greatly reducing the testing cost. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0025] Figure 2 It is a flowchart of the detection method of the present invention.

[0026] In the figure: 1. Refrigerator; 2. Light transmittance detection mechanism; 3. Computer. DETAILED DESCRIPTION

[0027] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0028] In the description of the present invention, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0029] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0030] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0031] like Figure 1 As shown, this embodiment provides a PCB circuit board edge detection device, including a refrigerator 1, a transmittance detection mechanism 2 and a computer 3, wherein the computer 3 is electrically connected to the refrigerator 1 and the transmittance detection mechanism 2, and also includes a glass plate with a transmittance of more than 95%.

[0032] The refrigerator 1 is used to cool down the PCB circuit board and the glass plate to create a temperature difference condition, which is the basis for the occurrence of the atomization phenomenon. The refrigerator 1 is equipped with a temperature control system that can be accurately adjusted to -18°C to meet the cooling demand;

[0033] The transmittance detection mechanism 2 is used to scan the glass plate, measure the change in light intensity before and after the light passes through the glass plate, and generate a transmittance map, which is a key link in the detection process. The transmittance detection mechanism 2 is equipped with a high-precision light source and a light intensity measurement sensor to ensure the accuracy of the transmittance measurement;

[0034] Computer 3, as the core of data processing and analysis, receives transmittance measurement data, performs image processing and infers concave-convex distribution. Computer 3 has built-in image processing algorithms based on machine learning for feature extraction and pattern recognition;

[0035] The glass plate ensures that light can pass through smoothly and forms a clear transmittance map, which is an important guarantee for detection accuracy. High transmittance materials, such as optical glass, can be selected to ensure light transmission performance.

[0036] like Figure 2As shown, this embodiment also provides a PCB circuit board edge detection method. During the detection, several PCB circuit boards need to be placed in a refrigerator 1 for cooling. After the temperature reaches the set temperature, all PCB circuit boards are taken out of the refrigerator 1, and each PCB circuit board is stacked together so that the side of each PCB circuit board to be detected is kept flush. Then, a normal temperature glass plate is taken. The temperature of the glass plate needs to reach a set temperature difference with the PCB circuit board. The glass plate is attached to the side of each PCB circuit board to be detected and kept for a set time. After the surface of the glass plate is fogged and an atomized area is formed, the glass plate is placed in the refrigerator 1. During this period, the tiny water droplets on the surface of the glass plate will gradually solidify into ice crystals. This process is the process of water molecules changing from liquid to solid, accompanied by the release of heat. The formation of ice crystals fixes the shape and position of the atomized area. Then, the glass plate is taken out of the refrigerator 1, and the glass plate is scanned by the transmittance detection mechanism 2. A beam of light is emitted from the light source to pass through the glass, and then the light intensity change before and after the light passes through is measured. Since the ice crystal area has a strong scattering and absorption effect on light, the transmittance of these areas is low. The transmittance measurement data is converted into a visual transmittance map and output to computer 3 for further analysis through image processing technology. Based on the transmittance map, the concave-convex distribution on the side surface of the PCB circuit board can be inferred. Since the protruding position corresponds to the area with lower transmittance (ice crystal area), and the concave position corresponds to the area with higher transmittance (non-ice crystal area), the concave-convex situation of the PCB circuit board can be indirectly reflected by comparing the transmittance of different areas. In this way, the edge position of the PCB circuit board can be detected, and the whole process can realize batch detection with high detection efficiency.

[0037] The method is based on the above detection device, and its specific steps are as follows:

[0038] a) Place several PCBs in a freezer at 1-18°C for 10-15 minutes, then take out all the PCBs and stack them together, making sure that the side of each PCB to be tested is flush;

[0039] b) Lay a glass plate at room temperature on the side of each PCB to be tested and keep it for 60-90 seconds to make the surface of the glass plate fog and form a fogged area;

[0040] c) Place the glass plate in a freezer at 1-18°C for 3-5 minutes, during which time the tiny water droplets on the surface of the glass plate gradually solidify into ice crystals, fixing the shape and position of the atomized area;

[0041] d) taking the glass plate out of the refrigerator 1, scanning the glass plate through the transmittance detection mechanism 2, measuring the change in light intensity before and after the light passes through the glass plate, and forming a transmittance map;

[0042] e) converting the transmittance measurement data into a visual transmittance map and outputting it to the computer 3;

[0043] f) Computer 3 further analyzes the transmittance map through an image processing system, and infers the distribution of bumps and grooves on the side surface of the PCB circuit board based on the transmittance map. Computer 3 uses a preset algorithm to perform edge detection processing on the transmittance map, and identifies areas where the transmittance changes significantly, which correspond to the positions of the edges of the PCB circuit board; then, based on the identified edge position information, computer 3 generates an edge contour map of the PCB circuit board and calculates the specific size and shape parameters of each edge; then, the edge contour map and the size and shape parameters are compared with the preset standard PCB circuit board edge data to detect any possible edge defects, irregularities or size deviations; finally, based on the comparison results, computer 3 outputs a test report, including the edge detection results of the PCB circuit board, whether there are defects, and the specific location and type of the defects; if an edge defect is detected, computer 3 further analyzes the nature of the defect and provides possible repair suggestions or indicates whether further manual inspection is required.

[0044] Through the above technical scheme, the present invention realizes a fast and continuous detection process through an automated detection process, including batch cooling, atomization, ice crystal formation, light transmission scanning and image analysis. Compared with traditional manual visual inspection or mechanical measurement, the detection efficiency is greatly improved, thereby effectively shortening the production cycle and improving the overall production efficiency. The present invention also utilizes the atomization and ice crystal formation mechanism induced by temperature difference, and the present invention can accurately capture the tiny bumps on the edge of the PCB circuit board. The generation of the transmittance map and the application of image processing technology further ensure the accuracy of the test results. Compared with the limitations of traditional methods, the present invention provides more reliable and consistent test results. In addition, the equipment used in the present invention is simple and easy to operate, without the need for complex mechanical structures or expensive detection instruments. The combination of the transmittance detection mechanism 2 and the refrigerator 1, and the application of computer 3 image processing technology, make the entire detection process both economical and efficient, and greatly reduce the detection cost.

[0045] In some embodiments, in step a), the PCB circuit board can be taken out of the refrigerator 1 after its temperature drops to -5°C. This is to ensure that the surface of the PCB circuit board is cooled enough to form a significant temperature difference effect while avoiding material stress or damage that may be caused by excessive cooling. After taking out, the PCB circuit boards are quickly stacked neatly to ensure that the surface to be tested is flat and tightly fitted so that a uniform and clear atomization effect can be formed in subsequent steps. In addition, when stacking, care must be taken to avoid mutual squeezing between the PCB circuit boards to avoid unnecessary deformation of the edge shape. Through such temperature control and processing methods, the detection process can be further optimized and the accuracy and reliability of the detection results can be improved.

[0046] In some embodiments, in step b), when the glass plate contacts the PCB circuit board, the temperature difference between the two is at least 20°C to ensure that a significant atomization effect is formed on the surface of the glass plate. The greater the temperature difference, the more significant the atomization phenomenon, which helps to improve the clarity and contrast of the transmittance map during subsequent light transmission scanning. In order to achieve this temperature difference, the glass plate can be preheated at room temperature or slightly higher temperature for a period of time before being attached to the PCB circuit board to ensure that a sufficient temperature difference is formed with the cooled PCB circuit board. In addition, the control of the temperature difference can also be achieved by adjusting the cooling time of the PCB circuit board in the refrigerator 1 to achieve the best atomization effect and detection sensitivity. Through such a temperature difference control strategy, the atomization process can be further optimized and the accuracy and efficiency of edge detection can be improved.

[0047] In some embodiments, in step e), the resolution of the transmittance map is set to 0.1 mm / pixel to ensure that the tiny details and concave-convex changes of the edge of the PCB circuit board can be captured. Such a high-resolution setting helps to more accurately identify and locate the edge position in the subsequent image processing process, thereby improving the accuracy and reliability of the test results. At the same time, the high-resolution transmittance map also helps to better distinguish defects and irregularities of different sizes, making the information in the test report more detailed and accurate. Through such a high-resolution setting, the image processing and analysis process can be further optimized to improve the overall detection performance.

[0048] In some embodiments, the image processing system is an image recognition algorithm based on machine learning, which can perform feature extraction and pattern recognition on the transmittance map, so as to accurately infer the distribution of bumps and grooves on the side surface of the PCB circuit board. In order to improve the recognition accuracy and adaptability of the algorithm, a large amount of sample data is used in the training process, including various types of PCB circuit board edge shapes and defect patterns. In this way, the algorithm can learn the complex mapping relationship between different features in the transmittance map and the actual edge shape of the PCB circuit board, and then achieve high-precision edge recognition and defect detection in the actual detection process. In addition, the algorithm also has a certain generalization ability and can handle new types of PCB circuit board edge shapes and defects, further improving the practicality and flexibility of the detection system.

[0049] In some embodiments, in step f), when the computer 3 further analyzes the transmittance map through the image processing system, it also includes filtering the transmittance map to remove noise and interference and improve the recognition accuracy of the concave-convex distribution. The filtering process can use Gaussian filtering, median filtering and other methods. These methods can effectively smooth the random noise in the transmittance map while retaining edge information, making subsequent edge detection and defect recognition more accurate and reliable. By preprocessing the transmittance map, the stability and robustness of the entire detection process can be further improved, ensuring the consistency and accuracy of the detection results.

[0050] In some embodiments, the method also includes a verification step for the test result, that is, by comparing the test result with a PCB circuit board with a known edge position, the accuracy and reliability of the test method are verified. This verification step can be used as a quality control link, and the detection system is regularly verified in practical applications to ensure the stability and consistency of the test result. Specifically, some PCB circuit boards with standard edge shapes and sizes can be selected as verification samples, and the edge positions of these samples have been accurately calibrated by high-precision measuring equipment. Then, these verification samples are detected using the detection device and method of the present invention, and the test result is compared with the known edge position data. By calculating the deviation between the test result and the known data, the accuracy and reliability of the detection method can be evaluated. If the deviation is within an acceptable range, the detection method can be considered to be effective and reliable. Such a verification step helps to improve the user's trust in the test result and provides strong support for quality control in practical applications.

[0051] This specific embodiment is merely an explanation of the present invention and is not a limitation of the present invention. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed. However, as long as they are within the scope of the claims of the present invention, they are protected by the patent law.

Claims

1. A PCB circuit board edge detection device, characterized in that: The invention comprises a refrigerator, a light transmittance detection mechanism and a computer, wherein the computer is electrically connected with the refrigerator and the light transmittance detection mechanism, and also comprises a glass plate with a light transmittance of more than 95%.

2. A PCB circuit board edge detection method, the method is based on the detection device according to claim 1, characterized in that: The following steps are involved: a) Place several PCBs in a freezer at -18°C for 10-15 minutes, then take out all the PCBs and stack them together, making sure that the side of each PCB to be tested is flush; b) Lay a glass plate at room temperature on the side of each PCB to be tested and keep it for 60-90 seconds to make the surface of the glass plate fog and form a fogged area; c) Place the glass plate in a freezer at -18°C for 3-5 minutes, during which time the tiny water droplets on the surface of the glass plate gradually solidify into ice crystals, fixing the shape and position of the atomized area; d) taking the glass plate out of the refrigerator, scanning the glass plate with a transmittance detection mechanism, measuring the change in light intensity before and after the light passes through the glass plate, and forming a transmittance map; e) converting the transmittance measurement data into a visual transmittance map and outputting it to a computer; f) The computer further analyzes the transmittance map through an image processing system and infers the concave and convex distribution on the side surface of the PCB circuit board based on the transmittance map.

3. A PCB circuit board edge detection method according to claim 2, characterized in that: In step a), the PCB circuit board can be taken out of the refrigerator after its temperature drops to -5°C.

4. A PCB circuit board edge detection method according to claim 2, characterized in that: In step b), when the glass plate is in contact with the PCB circuit board, the temperature difference between the two is at least 20°C.

5. A PCB circuit board edge detection method according to claim 2, characterized in that: In step e), the resolution of the transmittance map is set to 0.1 mm / pixel.

6. A PCB circuit board edge detection method according to claim 2, characterized in that: The image processing system is an image recognition algorithm based on machine learning, which can perform feature extraction and pattern recognition on the transmittance map, thereby accurately inferring the distribution of bumps and depressions on the side surface of the PCB circuit board.

7. A PCB circuit board edge detection method according to claim 2, characterized in that: In step f), when the computer further analyzes the transmittance map through the image processing system, it also includes filtering the transmittance map to remove noise and interference and improve the recognition accuracy of the concave-convex distribution.

8. A PCB circuit board edge detection method according to claim 2, characterized in that: The method also includes a step of verifying the detection result, that is, verifying the accuracy and reliability of the detection method by comparing the detection result with a PCB circuit board with a known edge position.

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