A tin paste printing detection device for a PCB substrate

Abstract

The utility model relates to image detection technical field especially is related to a kind of solder paste printing detection device for PCB substrate, including cabinet, the conveying belt for conveying PCB substrate is horizontally penetrated in the length direction along it in cabinet, visual inspection mechanism for photographing detection is arranged in the upper of conveying belt, visual inspection mechanism includes fixed bolster, CCD camera component and illumination light source, CCD camera component includes at least two CCD cameras, two CCD cameras are movably connected on fixed bolster, and angle adjusting assembly is transmissionally connected between one end of CCD camera and fixed bolster. The utility model is photographed detection to solder paste on PCB substrate by adopting multiple oblique setting CCD camera, and the photographing angle of CCD camera is flexibly adjusted by setting angle adjusting assembly, so that it can capture the characteristic information of solder paste under different visual angle, to realize the all-round photographing of solder paste, not only improve detection precision, also promote the processing accuracy of PCB substrate.

Description

Technical Field

[0001] This utility model relates to the field of image detection technology, and in particular to a solder paste printing detection device for PCB substrates. Background Technology

[0002] PCBs are crucial components in products such as computers, microcomputers, PLCs, and embedded systems. As these products evolve towards smaller size, higher quality, better performance, and higher efficiency, PCBs are becoming increasingly precise, miniaturized, and multi-layered. This significantly increases the challenges of PCB component soldering and inspection. Although PCB soldering has shifted from manual to machine soldering, various factors can occasionally lead to defects such as incomplete soldering, cold solder joints, and bridging. These defects pose a significant threat to the solderability of PCBs and are difficult to detect visually.

[0003] Currently, existing image inspection devices typically employ vision inspection systems to detect soldering defects in PCBs. For example, patent CN215678051U discloses a PCB solder paste printing inspection device. This device moves an inspection camera to align with the PCB and then uses a lifting cylinder to bring the camera closer to the PCB, thus inspecting the PCB during its transport and completing the inspection before it leaves the chassis. However, this inspection camera is usually set parallel to the PCB, limiting its shooting angle range. It is not suitable for PCB substrates with special shapes or structures. Furthermore, when dealing with issues such as short circuits, broken solder, and poor solder tip formation, the small size and low height (below 40µm) of the solder wires make it difficult to accurately identify specific problems in the planar images, easily leading to false short circuits and large errors in the inspection results, which in turn affects the processing accuracy of the PCB. Utility Model Content

[0004] In order to address the technical deficiencies mentioned in the background art, the purpose of this utility model is to provide a solder paste printing inspection device for PCB substrates, which aims to solve the problems of narrow shooting range, inability to adjust angle, and limited applicability of existing inspection devices.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A solder paste printing inspection device for PCB substrates, wherein a conveyor belt for transporting PCB substrates runs transversely through the length of the chassis, and a visual inspection mechanism for photographic inspection is disposed above the conveyor belt. The visual inspection mechanism comprises a fixed bracket, a CCD camera assembly, and an illumination source. The CCD camera assembly includes at least two CCD cameras, which are movably connected to the fixed bracket, and one end of each CCD camera is connected to the fixed bracket via an angle adjustment component. The illumination source is located below the CCD cameras and fixedly connected to the bottom end of the fixed bracket, and the illumination source has a ring structure.

[0007] The angle adjustment assembly includes a fixed base, a hinge, and a swing cylinder. The fixed base is fixedly connected to a fixed bracket, and the hinge is hinged to the fixed base. One end of the hinge is connected to the CCD camera, and the other end is connected to the output end of the swing cylinder.

[0008] The chassis is also equipped with a three-axis moving mechanism for controlling the visual inspection mechanism to move along the X-axis, Y-axis and Z-axis. The three-axis moving mechanism includes a Y-axis moving component set along the width of the chassis, an X-axis moving component set along the length of the chassis, and a Z-axis moving component set along the height of the chassis. The three-axis moving mechanism, in conjunction with the angle adjustment component, enables the CCD camera to capture an all-around image of the solder paste.

[0009] Preferably, the lens of the CCD camera is angled toward the axis of the illumination source, and the angle between the CCD camera and the axis of the illumination source is adjustable in the range of 30-60°.

[0010] Preferably, the Y-axis moving component is fixedly connected to the inner side of the chassis; the X-axis moving component is arranged across the top of the conveyor belt, and both ends of the X-axis moving component are slidably connected to the Y-axis moving component; one side of the Z-axis moving component is slidably connected to the X-axis moving component, and the other side is connected to the vision inspection mechanism for adjusting the height of the vision inspection mechanism.

[0011] Preferably, the Y-axis moving component includes a first bidirectional linear slide rail, a first sliding plate, and a first drive motor. The first bidirectional linear slide rail is fixed to the side wall of the chassis. The first sliding plate is slidably connected to the first bidirectional linear slide rail, and the first sliding plate and the first drive motor are connected by a synchronous belt assembly.

[0012] Preferably, the X-axis moving assembly includes a slide table, a second bidirectional linear slide rail disposed on the slide table, and a nut seat slidably connected to the second bidirectional linear slide rail. A transmission screw is disposed between the second bidirectional linear slide rails, and one end of the transmission screw is drivenly connected to a second drive motor. The nut seat is threadedly connected to the transmission screw, and a second sliding plate is disposed on the nut seat. One end of the second sliding plate is slidably connected to the second bidirectional linear slide rail by a second slider, and the other end is fixedly connected to the Z-axis moving assembly.

[0013] Preferably, the Z-axis moving assembly includes a lifting cylinder, a third guide plate, and a connecting plate. The lifting cylinder is disposed on one side of the third guide plate, and a connecting block is connected to the output end of the lifting cylinder. The connecting block is fixedly connected to the connecting plate. A third slider is disposed at the bottom end of the third guide plate and is slidably connected to the second bidirectional linear slide rail. The connecting plate is stacked on the third guide plate, and one side of the connecting plate is connected to the fixed bracket.

[0014] Preferably, a plurality of feed adjustment components that move along the Y-axis are arranged parallel to each other on one side of the conveyor belt inside the chassis. The feed adjustment components are used to compensate for the movement of the PCB substrate in the Y-axis direction, and the feed adjustment components are arranged parallel to the Y-axis moving components.

[0015] Preferably, the feed adjustment assembly includes a plurality of parallel sliding rods, a receiving plate connected to the sliding rods, and a pulley drive assembly for driving the sliding rods to rotate. The two ends of the sliding rods are connected to bearing seats, and one end of the sliding rod is drivenly connected to the pulley drive assembly. The receiving plate is slidably connected to the sliding rods, and one end of the receiving plate abuts against the conveyor belt.

[0016] In summary, the beneficial effects of this utility model are as follows:

[0017] This invention allows for flexible adjustment of the CCD camera's shooting angle via an angle adjustment component, and precise control of the visual inspection mechanism's position via a three-axis movement mechanism. This enables the inspection device to adapt to the inspection needs of PCB substrates of different sizes and types. Furthermore, by employing multiple obliquely positioned CCD cameras to photograph the solder paste on the PCB substrate, it captures the characteristic information of the solder paste from different angles, achieving omnidirectional imaging of the solder paste. This allows for rapid detection of problems such as short circuits, broken solder, and poor solder joints, improving both inspection accuracy and the processing precision of the PCB substrate. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the solder paste printing inspection device for PCB substrates according to this utility model;

[0019] Figure 2This is a schematic diagram of the internal structure of the solder paste printing inspection device for PCB substrates according to this utility model;

[0020] Figure 3 yes Figure 2 Enlarged view of the visual inspection mechanism at point a;

[0021] Figure 4 This is a top view of the solder paste printing inspection device for PCB substrates according to this utility model;

[0022] Figure 5 yes Figure 4 A cross-sectional view of the AA plane;

[0023] Figure 6 This is a schematic diagram of the angle adjustment component in this utility model.

[0024] Explanation of the reference numerals in the figure:

[0025] 1. Chassis; 2. Conveyor belt; 3. Vision inspection mechanism; 31. Fixed bracket; 32. CCD camera; 33. Light source; 4. Angle adjustment assembly; 41. Fixed seat; 42. Hinge; 43. Swing cylinder; 5. Y-axis moving assembly; 51. First bidirectional linear slide rail; 52. First slide plate; 53. First drive motor; 54. Synchronous belt assembly; 6. X-axis moving assembly; 61. Slide table; 62. Second bidirectional linear slide rail; 63. Nut seat; 64. Transmission screw; 65. Second drive motor; 7. Z-axis moving assembly; 71. Lifting cylinder; 72. Third guide plate; 73. Connecting plate; 74. Connecting block; 8. Feed adjustment assembly; 81. Slide rod; 82. Support plate; 83. Pulley drive assembly; 84. Bearing seat; 9. Image display. Detailed Implementation

[0026] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model are within the protection scope of the present utility model.

[0027] Those skilled in the art should understand that, in the disclosure of this utility model, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the above terms should not be construed as limitations on this utility model.

[0028] In the description of this utility model, the use of terms such as "several" means one or more, with "multiple" meaning two or more. Terms like "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of terms like "first," "second," and "third" is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, the quantity of indicated technical features, or the sequential relationship between indicated technical features.

[0029] The following is in conjunction with the appendix Figure 1-6 The present invention provides a more detailed description of an embodiment of a solder paste printing inspection device for PCB substrates.

[0030] A solder paste printing inspection device for PCB substrates, such as Figures 1 to 3 As shown, the device includes a chassis 1, with a conveyor belt 2 running horizontally through its length for transporting PCB substrates. Above the conveyor belt 2, a vision inspection mechanism 3 for photographic inspection is installed. The vision inspection mechanism 3 includes a fixed bracket 31, a CCD camera assembly, and an illumination source 33. The CCD camera assembly includes at least two CCD cameras 32, which are movably connected to the fixed bracket 31. An angle adjustment assembly 4 is connected between one end of the CCD camera 32 and the fixed bracket 31. The lens of the CCD camera 32 is obliquely oriented towards the axis of the illumination source 33, and the angle between the axes of the CCD camera 32 and the illumination source 33 is adjustable from 30° to 60°. The illumination source 33 is located below the CCD camera 32 and is fixedly connected to the bottom end of the fixed bracket 31. The illumination source 33 has a ring structure.

[0031] Specifically, this inspection device can quickly and accurately complete the inspection work during the transport of PCB substrates, significantly shortening the inspection time compared to traditional manual inspection or some less efficient equipment. Furthermore, the improved inspection accuracy reduces the number of repeated inspections and rework caused by misjudgments, further improving production efficiency. During the inspection process, the illumination source 33 continuously emits light, providing a stable and uniform lighting environment for the CCD camera 32 to capture images. Its ring structure illuminates the solder paste on the PCB substrate from multiple directions, avoiding shadows caused by uneven lighting, thus ensuring that the CCD camera 32 can capture clear and accurate images.

[0032] By setting up multiple oblique CCD cameras 32 and flexibly adjusting their angles using the angle adjustment component 4, omnidirectional imaging of solder paste can be achieved. CCD cameras 32 at different angles can capture characteristic information of the solder paste from different perspectives. For example, one angled CCD camera 32 may focus more on detecting the flatness of the solder paste surface, while another angled camera may be better at detecting defects such as short circuits in solder wires. By comprehensively analyzing the image information captured by multiple CCD cameras 32, multi-angle images of the solder paste can be obtained comprehensively and accurately. Compared to traditional detection methods that can only acquire images of a single plane, this detection device can more effectively detect problems such as short circuits in solder wires, broken solder, and poor solder joints. Because images captured from different angles can complement each other, blind spots caused by a single perspective are avoided, thus greatly improving the accuracy and reliability of the detection.

[0033] It is worth noting that the conveyor belt 2 can be driven by a servo motor to maintain a uniform and low speed during the transmission process, ensuring sufficient time to acquire the PCB board. The conveyor belt 2 is a common transportation device in the prior art, including but not limited to chain conveyor belt 2, belt conveyor belt 2, or magnetic levitation conveyor belt 2, etc., so its structure and principle will not be described in detail.

[0034] In this embodiment, as Figure 6 As shown, the angle adjustment assembly 4 includes a fixed base 41, a hinge 42, and a swing cylinder 43. The fixed base 41 is fixedly connected to the fixed bracket 31, and the hinge 42 is hinged to the fixed base 41. One end of the hinge 42 is connected to the CCD camera 32, and the other end is connected to the output end of the swing cylinder 43.

[0035] Specifically, the shooting angle of the CCD camera 32 can be flexibly adjusted via the angle adjustment component 4, and the three-axis movement mechanism can precisely control the position of the vision inspection mechanism 3, enabling the inspection device to adapt to the inspection needs of PCB substrates of different sizes and types. Whether it is a small mobile phone PCB board or a large industrial control board, accurate inspection can be achieved by adjusting the parameters of the device. At the same time, for some PCB substrates with special shapes or structures, all-round inspection can be achieved by reasonably setting the angle and position of the CCD camera 32, greatly enhancing the application flexibility of the inspection device.

[0036] In this embodiment, as Figures 3 to 5As shown, the housing 1 is equipped with a three-axis moving mechanism for controlling the visual inspection mechanism 3 to move along the X-axis, Y-axis and Z-axis directions. The three-axis moving mechanism includes a Y-axis moving component 5 arranged along the width direction of the housing 1, an X-axis moving component 6 arranged along the length direction of the housing 1, and a Z-axis moving component 7 arranged along the height direction of the housing 1. The Y-axis moving component 5 is fixedly connected to the inner side of the housing 1. The X-axis moving component 6 is arranged across the top of the conveyor belt 2, and both ends of the X-axis moving component 6 are slidably connected to the Y-axis moving component 5. One side of the Z-axis moving component 7 is slidably connected to the X-axis moving component 6, and the other side is connected to the visual inspection mechanism 3 for adjusting the height of the visual inspection mechanism 3.

[0037] Specifically, when it is necessary to inspect solder paste at different locations on the PCB substrate, the three-axis moving mechanism will work together. First, the Y-axis moving component 5 will be used to adjust the position of the vision inspection mechanism 3 in the width direction. Then, the X-axis moving component 6 will be used to move it above the target area in the length direction. Finally, the height will be adjusted by the Z-axis moving component 7 to bring the CCD camera 32 closer to or further away from the PCB substrate in order to obtain a clear image.

[0038] The Y-axis moving assembly 5 includes a first bidirectional linear slide rail 51, a first slide plate 52, and a first drive motor 53. The first bidirectional linear slide rail 51 is fixed to the side wall of the housing 1. The first slide plate 52 is slidably connected to the first bidirectional linear slide rail 51, and the first slide plate 52 and the first drive motor 53 are connected by a synchronous belt assembly 54. The X-axis moving assembly 6 includes a slide table 61, a second bidirectional linear slide rail 62 disposed on the slide table 61, and a nut seat 63 slidably connected to the second bidirectional linear slide rail 62. A transmission screw 64 is disposed between the second bidirectional linear slide rails 62, and one end of the transmission screw 64 is connected to a second drive motor 65. The nut seat 63 is threadedly connected to the transmission screw 64, and a second slide plate is disposed on the nut seat 63. One end of the second slide plate is slidably connected to the second bidirectional linear slide rail 62 by a second slider, and the other end is fixedly connected to the Z-axis moving assembly 7. Z-axis moving assembly 7 includes a lifting cylinder 71, a third guide plate 72, and a connecting plate 73. The lifting cylinder 71 is disposed on one side of the third guide plate 72, and the output end of the lifting cylinder 71 is connected to a connecting block 74, which is fixedly connected to the connecting plate 73. The bottom end of the third guide plate 72 is provided with a third slider, which is slidably connected to the second bidirectional linear slide rail 62. The connecting plate 73 is stacked on the third guide plate 72, and one side of the connecting plate 73 is connected to the fixed bracket 31.

[0039] It should be noted that the X-axis moving component 6, Y-axis moving component 5, and Z-axis moving component 7 are all linear slide transmission modules and ball screw transmission modules commonly used in the prior art. Their structure, transmission method, and principle are the same as those in the prior art, so they will not be described in detail.

[0040] In this embodiment, a plurality of feed adjustment components 8 that move along the Y-axis are arranged parallel to one side of the conveyor belt 2 inside the chassis 1. The feed adjustment components 8 are used to compensate for the movement of the PCB substrate in the Y-axis direction, and the feed adjustment components 8 are arranged parallel to the Y-axis moving components 6.

[0041] Specifically, the feed adjustment assembly 8 includes multiple parallel sliding rods 81, a receiving plate 82 connected to the sliding rods 81, and a pulley drive assembly 83 for driving the sliding rods 81 to rotate. Bearing seats 84 are connected to both ends of the sliding rods 81, and one end of the sliding rod 81 is connected to the pulley drive assembly 83 for transmission. The receiving plate 82 is slidably connected to the sliding rods 81, and one end of the receiving plate 82 abuts against the conveyor belt 2. By setting the feed adjustment assembly 8, the movement compensation of the PCB substrate in the Y-axis direction is achieved, thereby significantly improving the detection efficiency.

[0042] It is worth mentioning that the chassis 1 is also equipped with an image display 9 for displaying captured images. The image display 9 is a computer with built-in image processing software, and the computer is connected to the vision inspection mechanism 3 via electrical signals.

[0043] Specifically, the image processing software possesses functions such as image acquisition, preprocessing, feature extraction, and defect detection. In image acquisition, the computer should be able to communicate effectively with the CCD camera 32 to acquire image data captured by the camera in real time. In the preprocessing stage, the image processing software can perform filtering, noise reduction, and enhancement on the image to improve image quality for subsequent feature extraction and defect detection. In the feature extraction stage, a line-by-line scanning algorithm is used to extract features such as the shape, height, and edges of the solder paste. Finally, these features are used for defect detection to determine if there are problems such as short circuits, broken solder, or poor solder joints. It is worth noting that the image processing software can utilize existing image processing algorithm libraries, such as OpenCV, to improve development efficiency and software performance.

[0044] The working principle of this utility model:

[0045] The core detection principle of this device utilizes the characteristic that when a striped grating emitted by a CCD camera 32 illuminates solder paste surfaces at different heights, the grating image will be misaligned. When the light from the striped grating illuminates the solder paste on the PCB substrate, due to variations in the solder paste surface height (such as the height of normally printed solder paste, or height abnormalities caused by poor solder joints), the grating image formed after the light is reflected from the solder paste surface will exhibit a misalignment phenomenon. After the CCD camera 32 captures these images containing misalignment information, it sends the images to a computer with built-in image processing software for analysis. The image processing software can calculate the height of the solder paste at different positions based on the degree of misalignment in the grating image and known mathematical models. For example, for normally printed solder paste, its height is within a certain range, but when poor solder joints occur, the height of the solder paste at the solder joint will exceed the normal range. By analyzing the misalignment in the grating image, it is possible to accurately determine whether the height of the solder paste is abnormal, thus providing an important basis for detecting the quality of the solder paste.

[0046] The embodiments described in this specific implementation are preferred embodiments of this application and are not intended to limit the scope of protection of this application. Identical components are represented by the same reference numerals. Therefore, all equivalent changes made to the structure, shape, and principle of this application should be covered within the scope of protection of this application.

Claims

1. A solder paste printing inspection device for PCB substrates, comprising a chassis, wherein a conveyor belt for transporting PCB substrates is transversely passed through the chassis along its length, and a vision inspection mechanism for photographic inspection is disposed above the conveyor belt, characterized in that, The visual inspection mechanism includes a fixed bracket, a CCD camera assembly, and an illumination source. The CCD camera assembly includes at least two CCD cameras, which are movably connected to the fixed bracket. An angle adjustment assembly is connected to one end of each CCD camera and the fixed bracket. The illumination source is located below the CCD cameras and is fixedly connected to the bottom of the fixed bracket. The illumination source has a ring structure. The angle adjustment assembly includes a fixed base, a hinge, and a swing cylinder. The fixed base is fixedly connected to a fixed bracket, and the hinge is hinged to the fixed base. One end of the hinge is connected to the CCD camera, and the other end is connected to the output end of the swing cylinder. The chassis is also equipped with a three-axis moving mechanism for controlling the visual inspection mechanism to move along the X-axis, Y-axis and Z-axis. The three-axis moving mechanism includes a Y-axis moving component set along the width of the chassis, an X-axis moving component set along the length of the chassis, and a Z-axis moving component set along the height of the chassis. The three-axis moving mechanism, in conjunction with the angle adjustment component, enables the CCD camera to capture an all-around image of the solder paste.

2. The solder paste printing inspection device for PCB substrates according to claim 1, characterized in that, The lens of the CCD camera is obliquely oriented toward the axis of the illumination source, and the angle between the CCD camera and the axis of the illumination source can be adjusted within the range of 30-60°.

3. The solder paste printing inspection device for PCB substrates according to claim 1, characterized in that, The Y-axis moving component is fixedly connected to the inner side of the chassis; the X-axis moving component is arranged across the top of the conveyor belt, and both ends of the X-axis moving component are slidably connected to the Y-axis moving component; one side of the Z-axis moving component is slidably connected to the X-axis moving component, and the other side is connected to the vision inspection mechanism for adjusting the height of the vision inspection mechanism.

4. The solder paste printing inspection device for PCB substrates according to claim 3, characterized in that, The Y-axis moving component includes a first bidirectional linear slide rail, a first sliding plate, and a first drive motor. The first bidirectional linear slide rail is fixed to the side wall of the chassis. The first sliding plate is slidably connected to the first bidirectional linear slide rail, and the first sliding plate and the first drive motor are connected by a synchronous belt assembly.

5. The solder paste printing inspection device for PCB substrates according to claim 1, characterized in that, The X-axis moving assembly includes a slide table, a second bidirectional linear slide rail disposed on the slide table, and a nut seat slidably connected to the second bidirectional linear slide rail. A transmission screw is disposed between the second bidirectional linear slide rails, and one end of the transmission screw is drivenly connected to a second drive motor. The nut seat is threadedly connected to the transmission screw, and a second sliding plate is disposed on the nut seat. One end of the second sliding plate is slidably connected to the second bidirectional linear slide rail by a second slider, and the other end is fixedly connected to the Z-axis moving assembly.

6. The solder paste printing inspection device for PCB substrates according to claim 1, characterized in that, The Z-axis moving assembly includes a lifting cylinder, a third guide plate, and a connecting plate. The lifting cylinder is located on one side of the third guide plate, and a connecting block is connected to the output end of the lifting cylinder. The connecting block is fixedly connected to the connecting plate. The bottom end of the third guide plate is slidably connected to a second bidirectional linear slide rail via a third slider. The connecting plate is stacked on the third guide plate, and one side of the connecting plate is connected to a fixed bracket.

7. The solder paste printing inspection device for PCB substrates according to claim 1, characterized in that, Inside the chassis, on one side of the conveyor belt, there are multiple feed adjustment components that move along the Y-axis. These feed adjustment components are used to compensate for the movement of the PCB substrate in the Y-axis direction, and they are arranged parallel to the Y-axis moving components.

8. The solder paste printing inspection device for PCB substrates according to claim 7, characterized in that, The feed adjustment assembly includes multiple parallel sliding rods, a receiving plate connected to the sliding rods, and a pulley drive assembly for driving the sliding rods to rotate. The two ends of the sliding rods are connected to bearing seats, and one end of the sliding rod is connected to the pulley drive assembly for transmission. The receiving plate is slidably connected to the sliding rods, and one end of the receiving plate abuts against the conveyor belt.

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