Lead frame anti-film deviation detection device and detection method

Abstract

The invention provides a lead frame film deviation prevention detection device and detection method, and relates to the technical field of visual detection and image recognition. The detection method comprises the following steps: S1, respectively acquiring a corner I image and a corner II image of the lead frame after film pasting; s2, respectively detecting and calculating the distances between the edge of the adhesive film and the edge of the lead frame in the corner I image and the corner II image, namely a corner I distance a, a corner I distance b, a corner II distance a and a corner II distance b; and S3, the distance a at the corner I, the distance b at the corner I, the distance a at the corner II and the distance b at the corner II are compared with correspondingly set film pasting distance ranges, if the distances exceed the film pasting distance ranges, film deviation is judged, and an NG signal is output. The problems that in the prior art, an automatic lead frame film deviation prevention detection device lacks, the manual labor intensity is high, the working efficiency is low, judgment is not accurate, and the hysteresis quality is high are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of visual detection and image recognition, and in particular to a lead frame anti-film deviation detection device and a detection method. Background Art

[0002] Lead frames, as carriers of integrated circuit chips, are important basic materials in the chip industry. During lead frame production, a layer of thermoplastic film is applied to the surface of the finished lead frame to prevent surface scratches or quality problems caused by dust in the production environment. During the lead frame film application process, it is important to conduct film deviation detection after film application, because if the film is offset, part of the lead frame may be exposed, which will affect the reliability of the final product.

[0003] At present, based on the needs of modern production, automatic laminating machines have gradually appeared on the market, such as a laminating device for producing integrated circuit lead frames provided by the patent with publication number CN114171393A. However, most of these laminating machines use the laminating operation as the final process and cannot realize automatic anti-film deviation detection. Based on this, for a long time, anti-film deviation detection is usually completed by manual operation. This method has many limitations, specifically: first, the manual labor intensity is high and the work efficiency is low; second, although to assist manual visual judgment (and for other purposes at the same time, such as assembly requirements, alignment and positioning, etc.), most of the current lead frames are equipped with identification grooves (used to assist in judging whether the edge of the film is too long or too short, and the edge of the film is judged to be qualified if it is inside the identification groove), and most of the lead frame edges are equipped with identification notches (used to assist in judging whether the edge of the film exceeds the edge of the lead frame, and the edge of the film exceeds the identification notch If it is judged to be unqualified), but due to factors such as visual angle limitations and visual fatigue after long-term work, the accuracy of manual judgment cannot be guaranteed; third, this method has obvious lag, that is, abnormalities cannot be discovered in time, which often leads to rework of batch products and waste of materials.

[0004] In summary, the present invention provides a lead frame anti-film deviation detection device and detection method. Summary of the invention

[0005] The object of the present invention is to provide a lead frame anti-film deviation detection device and detection method to solve the problem mentioned in the above background technology that the prior art lacks an automated lead frame anti-film deviation detection device, so the anti-film deviation detection can only be completed by manual operation, which has the disadvantages of high manual labor intensity, low work efficiency, inaccurate judgment, and strong hysteresis.

[0006] The present invention is achieved by adopting the following technical solutions: A lead frame anti-film deviation detection method comprises the following steps: Step S1: for the lead frame after film lamination, obtain the corner I image and corner II image respectively; Among them, side angle Ⅰ and side angle Ⅱ are diagonal relationship; Step S2: Detect and calculate the distance between the edge of the film and the edge of the lead frame in the corner I image and the corner II image respectively; Among them, in each corner image, each side of the corner corresponds to a distance, and the four distances are distance a at corner I, distance b at corner I, distance a at corner II, and distance b at corner II; Step S3: Compare the distance a at corner I, the distance b at corner I, the distance a at corner II and the distance b at corner II with the corresponding set film sticking distance range. If they exceed the film sticking distance range, it is judged as film deviation and an NG signal is output.

[0007] Furthermore, the step S2 includes the following sub-steps: Step S2-1: extracting the lead frame area not covered with the adhesive film in each corner image based on the difference between the lead frame area covered with the adhesive film and the lead frame area not covered with the adhesive film in each corner image; Step S2-2: Filling the lead frame area not covered with adhesive film in each corner image, and then performing area screening to screen out an area with a number of pixels within a set range, and the area is used as a film deviation judgment area; Step S2-3: convert the film bias judgment area into an XLD contour and then segment it into several line segments, and perform contour screening to obtain four edge contour lines in each corner image; Step S2-4: For the four edge contour lines in each corner image, the distances between the two edge contour lines on the same side are calculated to obtain distance a at corner I, distance b at corner I, distance a at corner II, and distance b at corner II.

[0008] Further, when the lead frame is provided with a marking groove and the edge of the lead frame is provided with a marking notch, step S2-3 includes the following sub-steps: Step S2-3-1: convert the film bias judgment area into an XLD contour and then divide it into several line segments; Step S2-3-2: screening the contour lengths of a plurality of line segments, screening out line segments whose contour lengths are within a set range, and removing corner line segments formed by connecting the edge of the film with the edge of the identification groove, and the corner line segments formed by connecting the edge of the identification notch with the edge of the lead frame; Step S2-3-3: In step S2-3-1, the line segment of the edge of the lead frame provided with the marking notch is broken into a plurality of lines by the marking notch, and in this step, the broken plurality of line segments are connected; Step S2-3-4: Perform contour screening again to remove the line segments marking the edges of the grooves and the line segments marking the edges of the notches, and finally obtain four edge contour lines.

[0009] Furthermore, the difference between the film-coated area and the lead frame area not coated with the film is the different colors presented. Specifically, after being irradiated with blue light, the film-coated area in the image appears dark, and the lead frame area not coated with the film appears white.

[0010] A lead frame anti-film deviation detection device is used to implement the lead frame anti-film deviation detection method described above, comprising a visual detection module, a display module, a mechanical module and an electrical module, wherein the visual detection module and the display module are communicatively connected, and the electrical module is electrically connected to the visual detection module and the display module respectively; the visual detection module is used to collect images and determine whether there is film deviation, and output an NG signal when it is determined that there is film deviation; the display module is used to realize human-computer interaction; the mechanical module is used to support and fix the visual detection module; the electrical module is used to provide external power supply and trigger signal for the visual detection module, and input the NG signal output by the visual detection module into a film pasting device to cause the film pasting device to alarm and shut down.

[0011] Furthermore, the visual inspection module includes two sets of visual components, and the positional relationship between the two sets of visual components is adapted to the positional relationship between corners I and II of the lead frame after film pasting, and the two sets of visual components are used to collect images of corners I and II, respectively; each set of visual components includes an industrial camera, a telecentric lens and a ring-shaped blue light source, and the telecentric lens is connected to the industrial camera.

[0012] Furthermore, the mechanical module includes two sets of mechanical components, which are respectively adapted to two sets of visual components; each set of mechanical components includes a magnetic base, a magnetic bottom plate, a height bracket, a camera bracket and a camera connecting plate, the magnetic base is slidably connected to the magnetic bottom plate, the magnetic base is provided with a height bracket, the height bracket is vertically slidably connected to the camera bracket, the camera bracket is horizontally slidably connected to the camera connecting plate, and the camera connecting plate is connected to the industrial camera.

[0013] Furthermore, the display module includes a touch screen industrial control integrated machine and a software interface; the electrical module includes a power supply and a trigger circuit, the trigger circuit includes a delay circuit, and the delay circuit controls two sets of visual components to collect corner I images and corner II images respectively by setting different delay times.

[0014] The beneficial effects achieved by the present invention are: Provided is a lead frame anti-film deviation detection device and detection method. By setting a visual detection module, a display module, a mechanical module and an electrical module, and executing a visual detection method, it is possible to timely and automatically determine whether there is film deviation after film pasting is completed, and output a corresponding signal when it is determined that there is film deviation. Compared with the existing technology that can only complete anti-film deviation detection by manual operation, the present invention liberates a large amount of manual work by realizing automated work, greatly reducing the intensity of manual labor, and can also ensure high work efficiency and judgment accuracy; and there is no obvious hysteresis, thereby avoiding rework of batch products and waste of materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a schematic diagram of the overall structure of the detection device according to an embodiment of the present invention; Figure 2 It is a partial structural schematic diagram of the mechanical component I in the detection device according to the embodiment of the present invention; Figure 3 is a schematic diagram of four distances in the detection method described in an embodiment of the present invention; Figure 4 is a schematic structural diagram of a lead frame after film pasting in the detection method according to an embodiment of the present invention; Figure 5 It is a schematic diagram of the process effect of the detection method described in the embodiment of the present invention; Figure 6 is a schematic diagram of the software interface of the detection method described in the embodiment of the present invention; Figure 7 It is a reference diagram of the algorithm principle when connecting and disconnecting line segments in the detection method described in the embodiment of the present invention; In the figure: 1, loading platform; 2, lead frame; 3, camera position I; 4, camera position II; 5, film pasting device; 6, cutter; 7, conveyor track; 8, lead frame area not pasted with film; 9, film pasted area; 10, identification groove; 11, identification notch; 12, lead frame bevel; 13, hole; 301, magnetic base I; 302, height bracket I; 303, camera bracket I; 304, camera connecting plate I; 305, magnetic base I; 306, height bracket I; 307, camera bracket I; 308, camera connecting plate I; 309, camera bracket II; 310, camera bracket II; 311, camera bracket II; 312, camera bracket II; 313, camera bracket II; 314, camera bracket II; 315, camera bracket II; 316, camera bracket II; 317, camera bracket II; 318, camera bracket II; 319, camera bracket II; 320, camera bracket II; 321, camera bracket II; 322, camera bracket II; 323, camera bracket II; 324, camera bracket II; 325, camera bracket II; 326, camera bracket II; 327, camera bracket II; 328, camera bracket II; 329, camera bracket II; 330, camera bracket II; 331, camera bracket II; 332, camera bracket II; 333, camera bracket II; 334, camera bracket II; 335, camera bracket II; 336, camera bracket II; 337, camera bracket II; 338, camera bracket II; 339, camera bracket II; 340, camera bracket II; 341, camera bracket II; 342, camera bracket II; 343, camera bracket II; 344, camera bracket II; 345, camera bracket II; 34 05. Prism connecting plate Ⅰ; 306. 45° prism; 307. High-angle annular blue light source Ⅰ; 308. Industrial camera Ⅰ; 309. Telecentric lens Ⅰ; 401. Magnetic base Ⅱ; 402. Height bracket Ⅱ; 403. Light source bracket; 404. Light source connecting plate; 405. High-angle annular blue light source Ⅱ; 406. Telecentric lens Ⅱ; 407. Industrial camera Ⅱ; 408. Camera bracket Ⅱ; 409. Camera connecting plate Ⅱ. DETAILED DESCRIPTION

[0016] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0017] Example 1 The first aspect of this embodiment provides a lead frame anti-film deviation detection device, including a visual detection module, a display module, a mechanical module and an electrical module. The visual detection module and the display module are in communication connection, and the electrical module is electrically connected to the visual detection module and the display module respectively. The visual detection module is used to collect images and determine whether there is film deviation, and output an NG signal when it is determined that there is film deviation; the display module is used to realize human-computer interaction; the mechanical module is used to support and fix the visual detection module; the electrical module is used to provide external power supply and trigger signal for the visual detection module, and input the NG signal representing film deviation output by the visual detection module into the film pasting device 5, so that the film pasting device 5 alarms and stops.

[0018] Specifically: The visual inspection module includes two sets of visual components, namely, visual component I and visual component II. The positional relationship between the two sets of visual components is adapted to the diagonal positional relationship between corners I and II of the lead frame 2 after film pasting. Visual component I is used to collect the image of corner I, and visual component II is used to collect the image of corner II. Correspondingly, the mechanical module includes two sets of mechanical components, namely, mechanical component I and mechanical component II. The two sets of mechanical components are respectively adapted to the two sets of visual components, that is, visual component I and mechanical component I constitute camera position I3, and visual component II and mechanical component II constitute camera position II4.

[0019] In this embodiment, please refer to Figure 1 A film pasting device 5 is provided between camera position Ⅰ3 and camera position Ⅱ4, and a loading platform 1 for conveying lead frame 2 reaches camera position Ⅰ3, loading platform 1 and camera position Ⅱ4 respectively through a conveying track 7; wherein, since the positional relationship between the two sets of visual components is adapted to the diagonal positional relationship between corners Ⅰ and Ⅱ of the lead frame 2 after film pasting, camera position Ⅰ3 and camera position Ⅱ4 are respectively arranged on both sides of the conveying track 7.

[0020] Please refer to Figure 1 and Figure 2In this embodiment, the visual component I in the camera position I3 includes an industrial camera I308, a telecentric lens I309, a high-angle annular blue light source I307 and a 45° prism 306, and the mechanical component I includes a magnetic base plate I, a magnetic base I301, a height bracket I302, a camera bracket I303, a camera connecting plate I304 and a prism connecting plate I305; in the above structure, a magnetic base I301 is slidably installed above the magnetic base plate I, a vertical height bracket I302 is installed on the magnetic base I301, and a camera bracket I303 is vertically slidably connected to the height bracket I302. A camera connecting plate Ⅰ304 is horizontally slidably connected to the camera bracket Ⅰ303, a horizontally placed industrial camera Ⅰ308 is connected above the camera connecting plate Ⅰ304, a horizontally placed telecentric lens Ⅰ309 is connected to the front end of the industrial camera Ⅰ308, a 45° prism 306 connected to the prism connecting plate is provided on the front side of the telecentric lens Ⅰ309, a high-angle annular blue light source Ⅰ307 is adhered to the lower surface of other working platforms arranged above the camera position Ⅰ3 by glue, and the high-angle annular blue light source Ⅰ307 is uniformly illuminated towards the position where the lead frame 2 on the loading platform 1 below it will pass.

[0021] Please refer to Figure 1 In this embodiment, the visual component II in the camera position II4 includes an industrial camera II407, a telecentric lens II406 and a high-angle annular blue light source II405, and the mechanical component II includes a magnetic base II, a magnetic base II401, a height bracket II402, a light source bracket 403, a light source connecting plate 404, a camera bracket II408 and a camera connecting plate II; in the above structure, a magnetic base II401 is slidably installed on the top of the magnetic base II, a vertical height bracket II402 is installed on the magnetic base II401, and the light source bracket 403 and the camera bracket II are vertically slidably connected to the height bracket II402. 408, the light source bracket 403Ⅱ is located below the camera bracket Ⅱ408, the light source bracket 403 is horizontally slidably connected with a light source connecting plate 404, one side surface of the light source connecting plate 404 is connected with a high-angle annular blue light source Ⅱ405, the high-angle annular blue light source Ⅱ405 is directed toward the position where the lead frame 2 on the loading platform 1 below it will pass through for uniform illumination, the camera bracket Ⅱ408 is horizontally slidably connected with a camera connecting plate Ⅱ, a vertically placed industrial camera Ⅱ407 is connected below the camera connecting plate Ⅱ, and a vertically placed telecentric lens Ⅱ406 is connected to the front end of the industrial camera Ⅱ407.

[0022] Among them: the above-mentioned vertical sliding connection and horizontal sliding connection are realized in this embodiment through the cooperation of sliding rails, slides and bolt fixing components. Technical personnel in this field can flexibly choose other suitable methods in actual applications, and the present invention does not make special limitations on this; by limiting the vertical sliding connection of the camera bracket on the height bracket and the horizontal sliding connection of the camera connecting plate on the camera bracket, the position of the industrial camera can be finely adjusted in a small range in the height and horizontal directions to ensure the field of view and clarity of the camera; by limiting the sliding installation of the magnetic base on the magnetic bottom plate, the horizontal position of the industrial camera can be moved in a large range to adapt to various models of lead frames 2 with different lengths and widths. Conventional visual acquisition systems usually require the camera to be perpendicular to the plane of the photographed object. In this embodiment, since other working platforms are provided above the camera position Ⅰ3, the installation height of the industrial camera Ⅰ308 is limited, which makes it impossible to install the telecentric lens Ⅰ309 in the vertical direction. The lead frame 2 is placed horizontally on the loading platform 1, so it is necessary to install a 45° prism 306 with a light path refraction function so that the industrial camera Ⅰ308 set parallel to the plane of the lead frame 2 can capture the required complete image of the corner Ⅰ of the lead frame 2 after the film is applied.

[0023] The display module includes a touch screen industrial control integrated machine and a software interface; it can realize real-time and intuitive display of the film image and film position, and display relevant information such as the total number of films currently pasted, the number of qualified products and the number of defective products, and can also provide an entry for manually setting relevant parameters, such as setting different film distance ranges according to different product models. The electrical module includes a DC24V power supply, a trigger circuit and a communication circuit, and the trigger circuit includes a delay circuit; the DC24V power supply is used to power two industrial cameras, and different delay times are set through the delay circuit to control the two sets of visual components to collect corner I images and corner II images respectively, and the visual inspection module outputs the NG signal through the communication circuit and inputs it into the film device 5 to cause the film device 5 to alarm and stop.

[0024] A second aspect of the present embodiment provides a lead frame anti-film deviation detection method, which uses the lead frame anti-film deviation detection device described above, and includes the following steps: Step S1: for the lead frame 2 after film lamination, obtain its corner I image and corner II image respectively; wherein corner I and corner II are in a diagonal relationship. Specifically: Please refer to Figure 1In the film laminating process of this embodiment, the loading platform 1 first carries the lead frame 2 without film laminating, and moves from the camera position I3 to the camera position II4 along the conveying track 7. When passing through the film laminating device 5, it will laminating the lead frame 2, and cut the film with the cutter 6 after the film laminating is completed; then the loading platform 1 moves back to the camera position I3 from the camera position II4. Since the speed of the loading platform 1 is fixed during the process of moving from the camera position II4 to the camera position I3, the signal of the cutter 6 cutting the film can be used as the trigger signal for the industrial camera I308 and the industrial camera II407 to shoot and take pictures. In this way, only one electrical signal is needed, and the industrial camera I308 and the industrial camera II407 can be started in sequence by setting different delay times; in this embodiment, the industrial camera II407 is set to delay 0.5s after receiving the trigger signal to shoot and take pictures, and the industrial camera I308 is set to delay 3.5s after receiving the trigger signal to shoot and take pictures.

[0025] Step S2: Detect and calculate the distance between the edge of the film and the edge of the lead frame 2 in the corner image I and the corner image II respectively; wherein, please refer to Figure 3 , in each corner image, each side of the corner corresponds to a distance, and the four distances are distance a at corner I, distance b at corner I, distance a at corner II, and distance b at corner II. Specifically: The principle of visual inspection and judgment process of industrial camera I308 and industrial camera II407 is the same. Here, industrial camera II407 is taken as an example to explain the specific process of obtaining the distance a at corner II and the distance b at corner II and making subsequent judgments. Please refer to Figure 4 and Figure 5 , based on the Halcon visual platform, step S2 includes the following sub-steps: Step S2-1: Based on the difference between the adhesive film-coated area 9 and the lead frame 2 area not coated with the adhesive film in the corner II image, the lead frame 2 area not coated with the adhesive film in the corner II image is extracted.

[0026] Among them, the difference between the film-coated area 9 and the lead frame area 8 not coated with the film is the different colors presented, that is, after being irradiated with blue light from the high-angle annular blue light source II405, the film-coated area 9 in the image appears dark, and the lead frame area 8 not coated with the film appears white because the blue light has the highest contrast with the orange-yellow thermoplastic film in the imaging effect; in this way, not only the lead frame area 8 not coated with the film can be extracted, but also the interference of the internal patterns and patterns of the lead frame 2 on the edge extraction can be effectively avoided. In this embodiment, the lead frame 2 area not coated with the film can be roughly extracted by using binary segmentation (calling the threshold algorithm) to extract pixels with gray values ​​between 200 and 255.

[0027] Step S2-2: Fill the area of ​​the lead frame 2 that is not covered with the adhesive film, and then perform area screening to screen out an area where the number of pixels is within a set range, and the area is used as a film deviation judgment area.

[0028] Among them, by performing area filling (calling the fill_up algorithm), the circular hole 13 on the top of the lead frame 2 can be filled to avoid interference. In this embodiment, when performing area screening (calling the select_shape algorithm), the area with the number of pixels between 50,000 and 400,000 is screened out, thereby filtering out the film-pasting error situation (that is, the situation that is more serious than the film deviation situation, such as no film or the film obviously exceeds the lead frame 2) where the area of ​​the unpasted film area 9 is too large or too small; at the same time, since the lead frame 2 in this embodiment is provided with an identification groove 10, the influence of the identification groove 10 is also effectively avoided by area screening.

[0029] Step S2-3: convert the film bias judgment area into an XLD contour and then segment it into several line segments, and perform contour screening to obtain four edge contour lines in the corner II image.

[0030] In this embodiment, when the lead frame 2 is provided with a marking groove 10 and the edge of the lead frame 2 is provided with a marking notch 11, step S2-3 includes the following sub-steps: Step S2-3-1: Convert the membrane deviation judgment area into an XLD contour (call gen_contour_region_xld algorithm), and then divide it into several line segments (call segment_contours_xld).

[0031] Step S2-3-2: Filter the contour lengths of several line segments (call the select_contours_xld algorithm) to filter out line segments with contour lengths between 150 and 20,000 pixels to remove interfering line segments with smaller contour length values, i.e., the corner line segments formed by the edge of the film connecting the edge of the identification groove 10, and the corner line segments formed by the edge of the identification notch 11 connecting the edge of the lead frame 2.

[0032] Step S2-3-3: In step S2-3-1, the line segments at the edge of the lead frame 2 provided with the marking notch 11 are broken into a plurality of lines by the marking notch 11. In this step, the broken plurality of line segments are connected.

[0033] In this embodiment, when connecting several disconnected line segments, the following calculation method is used: Figure 7, the figure shows a longer line segment and a shorter line segment, with the contour of the longer line segment in the figure as the reference contour, a is the length of the reference contour, b is the length of the projection of the gap between the two contour lines on the reference contour, c is the maximum distance between the second contour and the reference contour's fitted line, θ is the angle between the two contours' fitted lines, where the length, distance and other information are expressed in pixels, and the angle is expressed in radians; there are four main parameters used to control the collinearity conditions of the contours, MaxDistAbs determines the upper limit of the absolute distance between the two contours, MaxDistRel determines the upper limit of the relative distance between the two contours, MaxShift determines the upper limit of the maximum distance between the second contour and the reference contour's fitted line, and MaxAngle determines the upper limit of the angle between the two contours' fitted lines; according to empirical values, set MaxDistAbs to 400, MaxDistRel to 2, MaxShift to 10, and MaxAngle to 0.1. Through the following four limiting conditions, the contours that are approximately collinear can be connected and merged after calculation: ; ; ; .

[0034] Step S2-3-4: Perform contour screening again to filter out line segments with contour width and height less than 100 pixels, so as to remove line segments of the lead frame bevel 12, line segments of the edge of the identification groove 10 and line segments of the edge of the identification notch 11, and finally obtain four edge contour lines.

[0035] Step S2-4: For the four edge contour lines, respectively calculate the distance between two edge contour lines on the same side to obtain the distance a at the corner II and the distance b at the corner II.

[0036] In this embodiment, the distance calculation is performed in the following manner: the four edge contour lines are sorted by row (calling the sort_contours_xld algorithm), and a straight line fitting is performed (calling the fit_line_contour_xld algorithm), and the normal vector (A, B) of each straight line and the intercept C of the straight line with the Y axis are obtained, then Figure 5 The general straight line equations of the four edge contour lines Lines1, Lines2, Lines3, and Lines4 are: Line1: ; Line2: ; Line3: ; Line4: ; Among them, the two edge contour lines on the same side are approximately parallel, so the distance between the lines can be determined by calculating the minimum distance between the two lines (calling the distance_cc_min_points algorithm). When calculating the minimum distance between the two lines, the distance from each point in the contour of one line to the point of the contour of the other line is calculated, and the minimum distance is obtained by polling and comparison. Taking Line1 and Line2 as an example, the coordinates of a point on Line1 are known to be (x0, y0), and the equation of Line2 is known. The general point-to-line distance d is calculated as: ; In this way, the distance between Lines1 and Lines2 can be finally calculated as the distance a at corner II, and the distance between Lines3 and Lines4 can be calculated as the distance b at corner II. Through the sub-steps of step S2 above, the distance a at corner I and the distance b at corner I can be obtained in the same way. Please refer to Figure 6 The software interface of the display module can display the calculated distance a at corner I in real time (corresponding to Figure 6 The left length in the middle), the distance b at the corner I (corresponding to Figure 6 The rear width in the middle), the distance a at the corner II (corresponding to Figure 6 The right length in the middle) and the distance b at the corner II (corresponding to Figure 6 width in the middle).

[0037] Step S3: respectively compare the distance a at corner I, the distance b at corner I, the distance a at corner II and the distance b at corner II with the corresponding set film sticking distance range; if any distance exceeds the film sticking distance range, it is judged as film deviation, and the corresponding industrial camera outputs an NG signal; then the display module displays the film deviation information, and the electrical module inputs the NG signal into the film sticking device 5 to cause the film sticking device 5 to alarm and shut down.

[0038] Among them, the four distances obtained in step S2 are pixel distances. In this embodiment, according to the selection parameters of the known industrial camera and telecentric lens, the pixel accuracy is 0.001mm, then the actual distance = pixel distance * pixel accuracy, and the actual distance is used for comparison.

[0039] In summary, the lead frame 2 anti-film deviation detection device and detection method provided in this embodiment can timely and automatically determine whether there is film deviation after film pasting is completed by setting a visual detection module, a display module, a mechanical module and an electrical module, and executing a visual detection method, and output a corresponding NG signal when it is determined that there is film deviation. Compared with the existing technology that can only complete anti-film deviation detection by manual operation, it has the following advantages: first, the detection accuracy of film deviation is high, and according to data statistics, 100% film deviation can be detected, thereby effectively avoiding the outflow of film deviation products; second, the film deviation can be detected in time and the film pasting device 5 can be linked to stop, avoiding the waste of materials caused by rework of batch products. According to data statistics, the average monthly waste of thermoplastic film is reduced by 5km, that is, the production cost is reduced by more than 50,000 yuan; third, the work efficiency is high and the labor intensity is greatly reduced. According to data statistics, one operator can watch 6 devices, and the personnel utilization rate is increased by 6 times. In the subsequent period, it only needs to spot check whether there is film deviation, and the overall detection time of a single box lead frame 2 is shortened to 20% of the original.

[0040] It should be noted that the parts not described in detail or expanded in the above scheme are all existing technologies, which do not belong to the improvements made by the present invention on the existing technologies, nor do they belong to the protection scope of the technical scheme of the present invention. Therefore, they will not be described in detail in this article.

[0041] Of course, the above contents are only preferred embodiments of the present invention and cannot be considered to limit the scope of the embodiments of the present invention. The present invention is not limited to the above examples, and equal changes and improvements made by ordinary technicians in the technical field within the essential scope of the present invention should all fall within the scope of the patent coverage of the present invention.

Claims

1. A lead frame anti-film deviation detection method, characterized in that: The steps include: Step S1: for the lead frame (2) after film lamination, obtain the image of corner I and the image of corner II respectively; Among them, side angle Ⅰ and side angle Ⅱ are diagonal relationship; Step S2: respectively detecting and calculating the distance between the edge of the adhesive film and the edge of the lead frame (2) in the corner I image and the corner II image; Among them, in each corner image, each side of the corner corresponds to a distance, and the four distances are distance a at corner I, distance b at corner I, distance a at corner II, and distance b at corner II; Step S3: Compare the distance a at corner I, the distance b at corner I, the distance a at corner II and the distance b at corner II with the corresponding set film sticking distance range. If they exceed the film sticking distance range, it is judged as film deviation and an NG signal is output.

2. The lead frame anti-film deviation detection method according to claim 1, characterized in that: The step S2 includes the following sub-steps: Step S2-1: based on the difference between the adhesive film-coated area (9) and the lead frame area (8) not coated with the adhesive film in each corner image, extract the lead frame area (8) not coated with the adhesive film in each corner image; Step S2-2: Filling the lead frame area (8) not covered with adhesive film in each corner image, and then performing area screening to screen out an area with a number of pixels within a set range, and the area is used as a film deviation judgment area; Step S2-3: convert the film bias judgment area into an XLD contour and then segment it into several line segments, and perform contour screening to obtain four edge contour lines in each corner image; Step S2-4: For the four edge contour lines in each corner image, the distances between the two edge contour lines on the same side are calculated to obtain distance a at corner I, distance b at corner I, distance a at corner II, and distance b at corner II.

3. The lead frame anti-film deviation detection method according to claim 2, characterized in that: When the lead frame (2) is provided with a marking groove (10) and the edge of the lead frame (2) is provided with a marking notch (11), step S2-3 comprises the following sub-steps: Step S2-3-1: convert the film bias judgment area into an XLD contour and then divide it into several line segments; Step S2-3-2: screening the contour lengths of a plurality of line segments, screening out line segments whose contour lengths are within a set range, and removing corner line segments formed by connecting the edge of the adhesive film with the edge of the identification groove (10), and corner line segments formed by connecting the edge of the identification notch (11) with the edge of the lead frame (2); Step S2-3-3: In step S2-3-1, the line segment of the edge of the lead frame (2) provided with the marking notch (11) is broken into a plurality of lines by the marking notch (11), and in this step, the broken plurality of line segments are connected; Step S2-3-4: Perform contour screening again, remove the line segments at the edge of the marking groove (10) and the line segments at the edge of the marking notch (11), and finally obtain four edge contour lines.

4. The lead frame anti-film deviation detection method according to claim 2, characterized in that: The difference between the adhesive film-coated area (9) and the lead frame area (8) not coated with the adhesive film is the different colors presented. Specifically, after being irradiated with blue light, the adhesive film-coated area (9) in the image appears dark, while the lead frame area (8) not coated with the adhesive film appears white.

5. A lead frame anti-film deviation detection device, used to implement the lead frame anti-film deviation detection method according to any one of claims 1 to 4, characterized in that: It includes a visual detection module, a display module, a mechanical module and an electrical module, wherein the visual detection module and the display module are communicatively connected, and the electrical module is electrically connected to the visual detection module and the display module respectively; The visual inspection module is used to collect images and determine whether there is film deviation, and output an NG signal when it is determined that there is film deviation; the display module is used to realize human-computer interaction; the mechanical module is used to support and fix the visual inspection module; the electrical module is used to provide external power supply and trigger signal for the visual inspection module, and input the NG signal output by the visual inspection module into the film pasting device (5), so that the film pasting device (5) alarms and stops.

6. The lead frame anti-film deviation detection device according to claim 5, characterized in that: The visual inspection module comprises two sets of visual components, the positional relationship between the two sets of visual components is adapted to the positional relationship between corners I and II of the lead frame (2) after film pasting, and the two sets of visual components are used to collect images of corners I and II respectively; each set of visual components comprises an industrial camera, a telecentric lens and an annular blue light source, and the telecentric lens is connected to the industrial camera.

7. The lead frame anti-film deviation detection device according to claim 6, characterized in that: The mechanical module includes two sets of mechanical components, which are respectively adapted to two sets of visual components; each set of mechanical components includes a magnetic base, a magnetic bottom plate, a height bracket, a camera bracket and a camera connecting plate, the magnetic base is slidably connected to the magnetic bottom plate, the magnetic base is provided with a height bracket, the height bracket is vertically slidably connected to the camera bracket, the camera bracket is horizontally slidably connected to the camera connecting plate, and the camera connecting plate is connected to the industrial camera.

8. The lead frame anti-film deviation detection device according to claim 6, characterized in that: The display module includes a touch screen industrial control integrated machine and a software interface; the electrical module includes a power supply and a trigger circuit, the trigger circuit includes a delay circuit, and the delay circuit controls two sets of visual components to collect corner I image and corner II image respectively by setting different delay times.

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