CN106546597A - Weld quality prediction system and method - Google Patents

Abstract

The invention provides a kind of weld quality prediction system and method.The weld quality prediction system includes：Workbench (110)；Objective table (120), for placing the sample (10) with welding point (14) to be detected thereon, the objective table is supported on workbench and can be relative to movable workbench；2D imaging devices (130), the welding point for the sample to being placed on objective table are imaged to obtain 2D images；3D imaging devices (140), the welding point for the sample to being placed on objective table are imaged to obtain 3D rendering；And processing meanss, for receiving 2D images and 3D rendering and processing them to judge the welding quality of welding point.

Description

Welding quality inspection system and method

technical field

Embodiments of the present invention relate generally to the field of product inspection, and more particularly, to systems and methods for reliably and accurately inspecting the quality of welded joints of products.

Background technique

The welding process is a commonly used process in the manufacture of electronic products such as circuit boards. It can be used for welding circuit leads or pins. The welding quality is directly related to the quality of the product. Poor welding problems will occur in actual production, including virtual welding, false welding, empty welding, weak welding, etc., which may cause the circuit to not work normally, so it is necessary to inspect the welding quality. Due to solder flow, solder joints or pads may have irregular shapes, which is a challenge for solder quality inspection.

Existing welding inspection technologies mainly include destructive inspection and non-destructive or nondestructive inspection. Non-destructive testing techniques include manual visual testing, ultrasonic testing, automatic optical testing, etc., and can perform appearance inspections, including dimensional inspections, geometric shape inspections, and surface scar inspections. In the automatic optical inspection technology, by imaging the solder joints or solder joints on the product, the inspection of the welding quality is realized by analyzing the image. At present, automatic optical inspection mainly uses traditional two-dimensional (2D) cameras to image solder joints or solder joints, which can only obtain X-Y plane information. For solder joint shapes with irregular or complex spatial contours, it cannot be accurately determined from 2D images. Determine which factor is responsible for the features in the image. For example, 2D imaging inspection techniques cannot determine whether dark spots in a 2D image are caused by bumps or depressions in the weld profile.

Contents of the invention

In view of this, the present invention provides a welding quality detection system and method, which can relatively reliably and accurately detect the quality of solder joints or joints of products.

One aspect of the present invention provides a welding quality detection system, comprising: a workbench; Relative to the table movement; 2D imaging device, used to image the welded joint of the sample placed on the stage to obtain a 2D image; 3D imaging device, used to image the welded joint of the sample placed on the stage imaging to obtain a 3D image; and processing means for receiving the 2D image and the 3D image and processing them to determine the welding quality of the welded joint.

Preferably, the processing means may be configured to analyze the 3D image to obtain height information of the welded joint, and to determine protrusions or depressions in the welded joint based on the height information.

Preferably, the processing means may be configured to analyze the 2D image and/or the 3D image to obtain width information of the welded joint.

Preferably, the welding quality detection system may further include a display device for displaying 2D images and 3D images and/or for displaying a judgment result indicating the welding quality of the welded joint.

Preferably, the welding quality detection system may also include: a slide rail fixed on the workbench; and a bracket supporting the object table, the bracket is configured to be driven by the driving device to move along the slide rail under the control of the control device. moving relative to the worktable to respectively position the stage at positions suitable for imaging welded joints of samples on the stage by the 2D imaging device and the 3D imaging device.

In another aspect of the present invention, a method for detecting welded joints using the above-mentioned welding quality inspection system is provided, including the following steps:

placing the sample with the welded joint to be inspected on the stage;

moving the stage to the first detection position, so that the welding joint of the sample placed on the stage is imaged by a 2D imaging device to obtain a 2D image;

moving the stage to a second detection position, so that the welding joint of the sample placed on the stage is imaged by a 3D imaging device to obtain a 3D image; and

2D and 3D images are received and processed to determine the weld quality of the welded joint.

Preferably, the step of processing the image to determine the welding quality of the welded joint may include analyzing the 3D image to obtain height information of the welded joint, and determining protrusions or depressions in the welded joint based on the height information.

The solder joint may be formed by soldering the wire on the pad of the sample with solder, and preferably, the step of analyzing the 3D image to obtain the height information of the solder joint may include: A vertical cross-section parallel to the height direction is divided into a plurality of vertical sub-regions; determining the sub-height of the edge of the part of the solder in each vertical sub-region; Height distribution information within the cross section.

Preferably, the step of processing the image to determine the welding quality of the welded joint may include analyzing the 2D image and/or the 3D image to obtain width information of the welded joint.

Preferably, the step of analyzing the 2D image and/or the 3D image to obtain the width information of the welded joint may include: taking a horizontal cross-section of the 3D image parallel to the lengthwise direction in the length direction of the welded joint or taking the 2D image dividing into a plurality of horizontal sub-regions; determining the sub-width of the part of the solder in each horizontal sub-region; and obtaining width distribution information of the solder along the length direction according to the sub-width of the solder in each horizontal sub-region.

Preferably, the above method may further include displaying the 2D image and 3D image of the welded joint, width/height distribution information, and/or a determination result indicating the welding quality of the welded joint on a display device.

Description of drawings

The above and other aspects, features and advantages of various embodiments of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a plan view showing an exemplary product with a weld area to be inspected;

2 is a perspective view schematically showing the arrangement of a welding quality inspection system according to an exemplary embodiment of the present invention;

Fig. 3 is a three-dimensional (3D) photo of the welding area obtained by the welding quality inspection system according to an embodiment of the present invention;

Fig. 4 is a flowchart schematically showing a welding quality detection method according to an exemplary embodiment of the present invention;

5 is a schematic diagram illustrating a method for horizontally analyzing an image according to an exemplary embodiment of the present invention;

6 is a schematic diagram illustrating a method of vertically analyzing an image according to an exemplary embodiment of the present invention; and

FIG. 7 is a schematic diagram showing the profile of a welded joint obtained according to the method shown in FIGS. 5 and 6 .

detailed description

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. In this specification, the same or similar components are denoted by the same or similar reference numerals. The following descriptions of various embodiments of the present invention with reference to the accompanying drawings are intended to illustrate the general concept of the present invention, but should not be construed as a limitation of the present invention.

Furthermore, in the following detailed description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the embodiments of the invention. It may be evident, however, that one or more embodiments may be practiced without these specific details. In other instances, well-known structures and devices are shown in diagrammatic form to simplify the drawings.

FIG. 1 shows an example of a sample 10 with a weld area A to be inspected. The sample 10 can be various electronic products with solder joints, including circuit boards, PCB boards, etc., which is not limited herein. As shown, the sample 10 includes a substrate 11 and conductive traces 12 formed on the substrate 11, and in the soldering area A, a suitable solder can be used by various soldering methods, including laser welding, soldering iron soldering, hot melting Soldering etc., solder the wire or pin 13 on the pad connected to the trace 12.

In order to detect the welding area A, an embodiment of the present invention provides a welding quality detection system 100, as shown in FIG. and processing means (not shown). A sample having a welded joint to be inspected, sample 10 as described above, may be placed on stage 120, which is supported on table 110 and movable relative to table 120 so that when moving to After a proper position, the welding joint of the sample on the stage 120 is imaged by the 2D imaging device 130 and the 3D imaging device 140 .

Different from the conventional inspection technology that only uses 2D imaging device, according to the embodiment of the present invention, both 2D imaging device 130 and 3D imaging device 140 are combined in welding quality inspection system 100, wherein 2D imaging device 130 is used to The welding joint of the sample on the stage 120 is imaged to obtain a 2D image, and the 3D imaging device 140 is used to image the welding joint of the sample placed on the stage 120 to obtain a 3D image. The processing device communicates with the 2D imaging device 130 and the 3D imaging device 140 to receive the obtained 2D images and 3D images therefrom, and perform image processing and analysis to determine the welding quality of the welded joint.

In the present invention, there is no limitation on the form and arrangement of the 2D imaging device 130 and the 3D imaging device 140 , and any camera or imaging device that can provide suitable 2D images and 3D images can be used. In one example, the 2D imaging device 130 and/or the 3D imaging device 140 may be fixed relative to the table 110; alternatively, the 2D imaging device 130 and/or the 3D imaging device 140 may be arranged to be vertical relative to the table 110 Move to facilitate the focus of the welding joints, or can also be arranged to be able to move in the horizontal direction relative to the worktable 110, so as to detect products with different sizes, specifications, and number of welding joints, or to detect products with different sizes or diameters Solder wires or pins etc.

FIG. 3 shows a 3D photo of a welded joint obtained by the welding quality inspection system according to an embodiment of the present invention, from which it can be seen that there is a protrusion 15 on the welded joint 14 . Obviously, in a 2D image, the existence of such protrusions or depressions cannot be determined with certainty. It is understood that the presence of irregular features such as bumps or depressions indicates a soldering defect in the solder joint, for example a bump may indicate insufficient solder or a void elsewhere, while a depression may indicate insufficient solder there Or flow out of the welding area, resulting in bad sites such as false welding, false welding, empty welding, and weak welding.

In the present invention, the 3D imaging device 140 images the welding joint 14 of the sample placed on the stage 120 to obtain its 3D image or data, which includes height information at various positions of the welding joint. In one example, the obtained 3D image is analyzed by the processing device to extract height information of the welded joint therefrom, so that it can be determined or determined whether there is a defect such as a protrusion or a depression in the welded joint based on the extracted height information. For example, when the height at a certain position of the solder joint exceeds a threshold value, it indicates that there is too much solder at this position or there is a protrusion, resulting in insufficient or unsoldered solder at other positions; Below another threshold, it indicates that there is not enough solder at that location, which can lead to problems such as empty soldering, poor soldering, or solder flow to undesired areas.

In another example, the processing device may also be configured to analyze the obtained 2D image and/or 3D image to extract width or span information of the welded joint. It can be understood that a weld joint that is too wide may cause problems such as weak welds, empty welds, empty welds, or welded to undesired positions, and a weld joint that is too narrow may also cause problems such as weak welds and false welds. In addition, the combination or fusion of 2D and 3D images can also be used to accurately determine the location of defects on the welded joint.

As shown in Figure 1, the welding quality detection system provided by the embodiment of the present invention may also include a display device 150, such as a display, which may communicate with a 2D imaging device 130 and/or a 3D imaging device 140 for displaying the 2D image of a welded joint. images and 3D images, height and/or width information for welded joints, etc., and/or used to display judgment results indicating welding quality of welded joints.

In the example illustrated in FIG. 1 , the welding quality inspection system 100 also includes a slide rail 160 and a bracket 170, the slide rail 160 can be fixed on the workbench 110, and the bracket 170 supports the stage 120 and can be controlled by a control device (not shown). out) is driven by a driving device (not shown) to move relative to the worktable 110 along the slide rail 160, so that the object stage 120 is respectively moved and positioned in a position suitable for being used by the 2D imaging device 130 and the 3D imaging device 140. The location to image the welded joint 14 of the sample on the stage 120 . It can be understood that, in the embodiment of the present invention, the processing device and the control device may be separate devices, or both may also be integrated together, such as being combined in a processor. Exemplarily, the processing device, the control device and the display device may be integrated in a computer, and they communicate with each other to realize operations such as imaging control, image processing, analysis, and display of the welded joint. In addition, the driving device may be in the form of a hydraulic cylinder or a motor, which is not limited herein.

Fig. 4 schematically shows the flow of a welding quality inspection method according to an exemplary embodiment of the present invention, which can inspect the quality of a welded joint with the welding quality inspection system described in the above embodiments. The method mainly includes the following steps:

In step S101, the sample with the welded joint to be tested is placed on the stage;

In step S102, the stage is moved to a first detection position, so that the welding joint of the sample placed on the stage is imaged by a 2D imaging device to obtain a 2D image;

In step S103, the stage is moved to a second detection position, so that the welding joint of the sample placed on the stage is imaged by a 3D imaging device to obtain a 3D image; and

In step S104, the 2D image and the 3D image are received by the processing device and processed and analyzed to determine the welding quality of the welded joint.

In one example, step S104 may include processing and analyzing the 2D image and/or the 3D image by the processing device to extract width information of the welded joint. Fig. 5 shows a horizontal analysis method for obtaining width information according to an exemplary embodiment of the present invention. As shown, a horizontal cross-section of the obtained 2D image 20 or 3D image parallel to the longitudinal direction of the welded joint 14 can be divided into a plurality of horizontal sub-regions 20-1, 20-2 ... 20-n, then for example by determining the coordinates of the edge of the part of the solder 16 in each horizontal sub-region, the sub-width of the part of the solder 16 in each horizontal sub-region can be determined (indicated by W in the figure that the solder is in Width on one side of the conductive wire 13), thus the width distribution information of the solder along the length direction can be obtained according to the sub-width of the solder 16 in each horizontal sub-region. Each horizontal sub-region may have the same or different shapes and intervals, and the number thereof may be appropriately selected according to factors such as the structure of the welded joint and the processing capacity of the processing device.

In another example, step S104 may include analyzing and processing the obtained 3D image by the processing device to extract height information of the welded joint, and determining protrusions or depressions in the welded joint based on the height information. Exemplarily, the vertical analysis method shown in FIG. 6 may be used to acquire height information and/or width information of the welded joint. As shown in the figure, the vertical cross-section of the obtained 3D image 30 parallel to the height direction of the welded joint 14 can be divided into a plurality of vertical sub-regions 30-1, 30-2 ... 30-m, The sub-height h of the edge of the portion of solder 16 in each vertical sub-area can then be determined, for example by determining the coordinates of the edge of the portion of solder 16 in each horizontal sub-area, and/or determine the position of solder 16 in each vertical sub-area. The sub-width of the part in the sub-region (the width of the solder on the wire 13 side is indicated by W in the figure), thus the height distribution information of the solder in the vertical cross-section can be obtained according to the sub-height of the solder in each vertical sub-region and/or width distribution information. Likewise, each vertical sub-region may have the same or different shapes and intervals, and the number thereof may be appropriately selected according to factors such as the structure of the welded joint and the processing capacity of the processing device. In addition, the obtained 3D image may be divided into multiple vertical cross-sections along the length direction of the welded joint, and height information and/or width information of the welded joint may be extracted for each vertical cross-section.

It can be understood that, in other embodiments, the above-mentioned horizontal analysis method and vertical analysis method may be combined so as to more accurately extract the height information and/or width information of the welded joint. For example, the obtained image may be first divided into multiple horizontal sub-regions, and then vertically divided for each horizontal sub-region in combination with the 3D image; alternatively, the obtained 3D image may be firstly divided into multiple vertical sub-regions, Combined with horizontal division for each vertical sub-region, the height information and/or width information can be extracted more finely.

In addition, according to the obtained height and width information of the solder joint, it is possible to analyze whether the angle, inclination or profile of the solder at various positions on the solder joint meets the solder quality standard.

Although the embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that changes can be made to these embodiments without departing from the principle and spirit of the present invention. The scope is defined by the claims appended hereto and their equivalents. It should also be noted that the words "comprises", "comprises" and "having" used herein do not exclude other elements or steps, and the words "a" or "an" do not exclude a plurality, unless otherwise specified. In addition, any element numbers in the claims should not be construed as limiting the protection scope of the present invention.

Claims (11)

1. A welding quality inspection system (100), comprising: workbench (110); a stage (120) for placing a sample (10) having a welded joint (14) to be inspected thereon, the stage being supported on the workbench and capable of moving relative to the workbench; 2D imaging device (130), for imaging the welding joint of the sample placed on the stage to obtain a 2D image; 3D imaging device (140) for imaging the welding joint of the sample placed on the stage to obtain a 3D image; and The processing device is used to receive the 2D image and the 3D image and process them to judge the welding quality of the welded joint. 2. The welding quality inspection system according to claim 1, wherein the processing device is configured to analyze the 3D image to obtain height information of the welded joint, and determine protrusions or depressions in the welded joint based on the height information. 3. The welding quality inspection system according to claim 1 or 2, wherein the processing device is configured to analyze the 2D image and/or the 3D image to obtain width information of the welded joint. 4. The welding quality inspection system according to claim 1, further comprising a display device (150) for displaying 2D images and 3D images and/or for displaying a judgment result indicating the welding quality of the welded joint. 5. The welding quality detection system according to claim 1, further comprising: Slide rails (160) secured to the workbench; and A bracket (170) supporting the object stage, the frame is configured to be driven by the driving device under the control of the control device to move relative to the worktable along the slide rail, so as to position the object stage at a position suitable for being used by the 2D imaging device and 3D imaging device to image the position of the welded joint of the sample on the stage. 6. A method for detecting welded joints using the welding quality inspection system according to claim 1, comprising the steps of: placing the sample with the welded joint to be inspected on the stage; moving the stage to the first detection position, so that the welding joint of the sample placed on the stage is imaged by a 2D imaging device to obtain a 2D image; moving the stage to a second detection position, so that the welding joint of the sample placed on the stage is imaged by a 3D imaging device to obtain a 3D image; and 2D and 3D images are received and processed to determine the weld quality of the welded joint. 7. The method according to claim 6, wherein the step of processing the image to determine the welding quality of the welded joint comprises analyzing the 3D image to obtain height information of the welded joint, and determining protrusions in the welded joint based on the height information or sunken. 8. The method according to claim 7, wherein the solder joint is formed by soldering a wire (13) to a solder pad of the sample by solder (16), and the step of analyzing the 3D image to obtain height information of the solder joint comprises : dividing a vertical cross-section of the 3D image parallel to the height direction into a plurality of vertical sub-regions in the height direction of the welded joint; determining the sub-height of the edge of the portion of solder within each vertical sub-region; and The height distribution information of the solder in the vertical cross section is obtained according to the sub-heights of the solder in each vertical sub-region. 9. The method according to any one of claims 6-8, wherein the step of processing the image to determine the welding quality of the welded joint comprises analyzing the 2D image and/or the 3D image to obtain width information of the welded joint. 10. The method according to claim 9, wherein the solder joint is formed by soldering a wire onto a solder pad of the sample, and the step of analyzing the 2D image and/or the 3D image to obtain width information of the solder joint comprises: dividing a horizontal cross-section of the 3D image parallel to said length direction or dividing the 2D image into horizontal sub-regions in the length direction of the welded joint; determining the sub-width of the portion of solder within each horizontal sub-region; and The width distribution information of the solder along the length direction is obtained according to the sub-width of the solder in each horizontal sub-region. 11. The method according to claim 6, further comprising displaying the 2D image and the 3D image and/or a judgment result indicating the welding quality of the welded joint on a display device.