Miniature patch inductor bubble-free vacuum potting device and processing method thereof

Abstract

The application discloses a micro patch inductor bubble-free vacuum potting device and a processing method thereof, and relates to the technical field of mutual inductors. The device comprises a workbench and a mold. A sealed cabin is arranged on the top surface of the workbench. A fixing frame is vertically arranged on one side of the workbench. A mounting plate is horizontally fixedly connected to the top of the fixing frame. An industrial camera is arranged at the center of the mounting plate. Air cylinders are fixedly connected to both ends of the mounting plate. The extension rods of the air cylinders are fixedly connected with sealed covers. The micro patch inductor bubble-free vacuum potting device and the processing method thereof are characterized in that the 7-shaped limiting plates are matched with the limiting grooves on the two sides of the mold, and the push plates driven by the belts are matched with the push grooves on the two sides of the mold, so that the mold is quickly positioned, installed and automatically pushed into and fixed. The type changing speed is fast, and the problem of quick type changing production of different inductor products is effectively solved.

Description

Technical Field

[0001] This invention relates to the field of current transformer technology, specifically to a miniature patch inductor bubble-free vacuum potting device and its processing method. Background Technology

[0002] Miniature surface mount inductors, as core passive components in surface mount technology, are widely used in power management, signal filtering, and radio frequency circuits in smartphones, smart wearable devices, medical electronics, and automotive electronics. As electronic products become increasingly smaller, thinner, and higher-performance, the size of miniature surface mount inductors continues to shrink, leading to increasingly higher requirements for their potting quality.

[0003] Currently, the potting process for miniature surface mount inductors mainly employs atmospheric pressure potting. Existing potting equipment is typically single-station manual or semi-automatic, exhibiting the following prominent problems: First, during potting at atmospheric pressure, air bubbles easily form in the potting compound during mixing and conveying. Air in the tiny gaps between coil turns and between the coil and the magnetic core inside the miniature surface mount inductor cannot be completely expelled, forming internal bubbles or voids after being sealed by the potting compound, severely affecting the product's thermal conductivity and insulation performance. Second, different models of miniature surface mount inductors have significant size variations. Traditional potting equipment involves cumbersome mold changes and low positioning accuracy, making rapid product changeover difficult. Third, existing potting equipment lacks visual positioning capabilities, failing to automatically identify the position and quantity of inductors on the mold. The injection path relies on manual setting, resulting in low production efficiency and poor consistency. Summary of the Invention

[0004] (a) Technical problems to be solved The purpose of this invention is to provide a bubble-free vacuum potting device for micro-surface inductors and its processing method, so as to solve the problems mentioned in the background art, such as the difficulty in eliminating bubbles during the potting process, the cumbersome mold replacement and inaccurate positioning, and the lack of automated visual positioning and path planning capabilities.

[0005] (II) Technical Solution To achieve the above objectives, the present invention provides the following technical solution: a miniature patch inductor bubble-free vacuum potting device and its processing method, comprising a worktable and a mold, wherein a sealing chamber is provided on the top surface of the worktable, a fixed frame is vertically provided on one side of the worktable, a mounting plate is horizontally fixedly connected to the top of the fixed frame, an industrial camera is provided at the center of the mounting plate, cylinders are fixedly connected to both ends of the mounting plate, a sealing cover is fixedly connected to the telescopic rod end of the cylinder, an L-shaped bracket is provided at the bottom of the sealing cover, two fixed brackets are symmetrically provided at the horizontal end of the L-shaped bracket, and a T-shaped limiting plate is provided at the top edge of the fixed bracket; The mold has limiting grooves on both sides that engage with the limiting plate, and multiple placement grooves on the top surface of the mold.

[0006] Preferably, the fixed bracket is T-shaped, with an internal cavity and an open top. First pulleys are rotatably connected to both horizontal ends of the fixed bracket, and a second pulley is rotatably connected to the bottom of the vertical end of the fixed bracket. The first and second pulleys are connected by a belt drive. A motor is installed on one side of one of the fixed brackets, and a rotating shaft is fixedly connected to the motor's output shaft. Two second pulleys are respectively fixedly connected to the two ends of the rotating shaft. A positioning plate and a push plate are fixedly connected to the belt at the front end of the fixed bracket. Push grooves are formed on both sides of the bottom of the mold, and the push plate is adapted to the push grooves.

[0007] Preferably, the sealed chamber is provided with a displacement assembly, and the displacement assembly is provided with a glue injection gun. The displacement assembly includes an X-axis linear module, a Y-axis linear module and a Z-axis linear module, and the glue injection gun is installed at the end of the displacement assembly.

[0008] Preferably, the sealed chamber is connected to a vacuum pump group and a vacuum pressure control system. The vacuum pressure control system includes a PLC controller, a vacuum sensor, and a pressure regulating valve. The vacuum sensor is located inside the sealed chamber, and the pressure regulating valve is located on the vacuum pipeline connecting the sealed chamber and the vacuum pump group. The PLC controller is electrically connected to the vacuum sensor, the pressure regulating valve, and the vacuum pump group.

[0009] Preferably, the industrial camera is electrically connected to the PLC controller. The industrial camera is used to acquire images of the placement slots on the mold through the sealing cover. The PLC controller has a built-in image processing module for identifying the number and position coordinates of the placement slots and generating a glue injection path based on the identification results.

[0010] Preferably, the bottom of the sealed chamber is provided with an air extraction port, which is connected to the vacuum pump unit through a vacuum pipe; a sealing ring is provided between the sealing cover and the sealed chamber, and the sealing cover is made of transparent material.

[0011] A method for bubble-free vacuum potting of miniature surface mount inductors includes the following steps: Step S1: Mold installation and positioning - Place the mold containing the miniature chip inductor to be potted on the L-shaped bracket, so that the limiting grooves on both sides of the mold engage with the T-shaped limiting plates on the fixed bracket. Start the motor, and the motor drives the second pulley to rotate through the rotating shaft. The second pulley drives the first pulley to rotate through the belt. The push plate on the belt moves with the belt and engages in the push grooves on both sides of the mold, pushing the mold to the preset potting position and fixing it. Step S2: Visual Recognition and Path Planning - The industrial camera captures images of the placement slots on the mold through the sealing cover. The captured images are transmitted to the image processing module of the PLC controller. The image processing module identifies the position coordinates of each placement slot through a template matching algorithm and counts the total number of placement slots. The PLC controller generates the glue injection path of the glue gun based on the identified position coordinates. Step S3: Vacuuming - The cylinder drives the sealing cover to descend and close the sealing chamber to form a sealed space. The vacuum pump group is started to evacuate the sealing chamber until the vacuum degree inside the sealing chamber reaches the preset vacuum degree P1. Step S4: Vacuum potting - Maintain the vacuum level in the sealed chamber at no less than P1. The PLC controller controls the displacement component to drive the dispensing gun to move sequentially above each placement slot according to the dispensing path generated in step S2. The dispensing gun injects potting glue into the miniature patch inductor in the placement slot to complete the potting operation of all placement slots. Step S5: Pressure Holding and Settling - After potting, maintain the vacuum level in the sealed chamber at P1 and settling time t1 to allow the potting compound to eliminate residual air bubbles and fully fill the chamber under vacuum. Step S6: Breaking and Curing – Dry gas is slowly injected into the sealed chamber to atmospheric pressure through the pressure regulating valve. The cylinder drives the sealing cover to rise and open, and the mold is taken out for heat curing.

[0012] Preferably, in step S2, the specific process of the image processing module identifying the position coordinates of the placement slot is as follows: First, the acquired image is processed by grayscale and binarization to extract the edge contour features of the placement slot; then, normalized cross-correlation matching is performed through the pre-stored placement slot template image to calculate the pixel coordinates of the center point of each placement slot; finally, the pixel coordinates are converted into physical coordinates in the world coordinate system through camera calibration parameters.

[0013] Preferably, in step S4, the glue injection path is generated using an S-shaped path or a serpentine path. The PLC controller uses the position coordinates of all placement slots as path points and uses the nearest neighbor algorithm to calculate the shortest movement path that traverses all path points.

[0014] 10. A bubble-free vacuum potting method for a micro-surface inductor according to claim 7, characterized in that: in step S4, the vacuum potting adopts multi-stage vacuum control: in the first potting stage, the vacuum degree is maintained at P1, and the dispensing gun injects potting glue at a first flow rate V1 to complete the rapid filling of the main space of the potting cavity; in the second potting stage, the vacuum degree is reduced to P2 (P2 < P1), and the dispensing gun injects potting glue at a second flow rate V2 (V2 < V1) to promote the wetting and filling of the potting glue in the micro gaps inside the micro-surface inductor; in the third potting stage, the vacuum degree is restored to P1 and maintained for time t2 to allow the potting glue to spread fully in the micro gaps.

[0015] (III) Beneficial Effects Compared with the prior art, the present invention provides a bubble-free vacuum potting device for miniature patch inductors and its processing method, which has the following beneficial effects: 1. This miniature surface mount inductor bubble-free vacuum potting device and its processing method, by setting a 7-shaped limiting plate and engaging with the limiting grooves on both sides of the mold, combined with the belt-driven push plate and the push grooves on both sides of the mold, realizes the rapid positioning and installation of the mold and automatic push-in and fixation. It has fast changeover speed and accurate positioning, effectively solving the problem of rapid changeover production of different models of inductor products.

[0016] 2. The miniature patch inductor bubble-free vacuum potting device and its processing method use an industrial camera to capture images of the placement slots on the mold through a transparent sealing cover. Combined with the image processing module of the PLC controller, the device automatically identifies the number and position coordinates of the placement slots and generates the dispensing path, realizing fully automatic vision-guided potting without the need for manual path setting, which significantly improves production efficiency and product consistency.

[0017] 3. The bubble-free vacuum potting device and its processing method for miniature surface mount inductors effectively eliminate air bubbles in the potting compound by performing vacuum potting in a sealed chamber and using multi-stage vacuum pressure control. This allows the potting compound to fully fill the tiny gaps inside the miniature surface mount inductor, significantly improving the insulation performance and reliability of the product. Attached Figure Description

[0018] Figure 1 This is an isometric schematic diagram of the present invention; Figure 2 This is a cross-sectional schematic diagram of the fixed support structure of the present invention; Figure 3 This is an isometric schematic diagram of the mold structure of the present invention; Figure 4 This is a schematic diagram of the installation of the mold structure of the present invention.

[0019] In the diagram: 1. Workbench; 2. Sealed chamber; 3. Fixed bracket; 4. Fixed frame; 5. Sealing cover; 6. Cylinder; 7. Industrial camera; 8. Mounting plate; 9. L-shaped bracket; 10. Motor; 11. Positioning plate; 12. Push plate; 13. Second pulley; 14. Rotating shaft; 15. First pulley; 16. Limiting plate; 17. Belt; 18. Mold; 19. Placement groove; 20. Limiting groove; 21. Push groove; 22. Displacement component; 23. Glue gun. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Please see Figure 1-4 As shown, a miniature patch inductor bubble-free vacuum potting device and its processing method are disclosed. A sealed chamber 2 is provided on the top surface of the workbench 1. The sealed chamber 2 is a closed container with an air extraction port at its bottom. The air extraction port is connected to a vacuum pump group through a vacuum pipe. The sealed chamber 2 is used to provide the working environment for vacuum potting. A displacement component 22 is provided inside the sealed chamber 22. A glue gun 23 is provided on the displacement component 22. The displacement component 22 includes an X-axis linear module, a Y-axis linear module and a Z-axis linear module. The glue gun 23 is installed at the end of the displacement component 22. The displacement component 22 is used to drive the glue gun 23 to move to the target potting position in the three-dimensional space inside the sealed chamber 2. The glue gun 23 is connected to a glue supply system, which includes a glue storage tank, a metering pump and a glue supply pipe, for delivering potting glue to the glue gun 23.

[0022] A mounting bracket 4 is vertically installed on one side of the workbench 1. A mounting plate 8 is horizontally fixed to the top of the mounting bracket 4. An industrial camera 7 is installed at the center of the mounting plate 8, with its lens pointing vertically downwards towards the sealed chamber 2. Cylinders 6 are fixedly connected to both ends of the mounting plate 8. A sealing cover 5 is fixedly connected to the telescopic rod end of the cylinder 6. A sealing ring is provided between the sealing cover 5 and the sealed chamber 2 to ensure that a reliable airtight space is formed after the sealing cover 5 and the sealed chamber 2 are closed. The sealing cover 5 is made of transparent material, which allows the industrial camera 7 to capture images of the mold 18 inside the sealed chamber 2 through the sealing cover 5. The bottom of the sealing cover 5 is provided with an L-shaped bracket 9, and two fixed brackets 3 are symmetrically arranged at the horizontal end of the L-shaped bracket 9. A 7-shaped limiting plate 16 is provided at the top edge of the fixed bracket 3. like Figure 2 As shown, the fixed bracket 3 has a T-shaped structure with a hollow interior and an open top. The horizontal ends of the fixed bracket 3 are rotatably connected to the first pulley 15, and the bottom of the vertical end of the fixed bracket 3 is rotatably connected to the second pulley 13. The first pulley 15 and the second pulley 13 are connected by a belt 17. A motor 10 is provided on one side of one of the fixed brackets 3. The output shaft of the motor 10 is fixedly connected to the rotating shaft 14. The two second pulleys 13 are respectively fixedly connected to the two ends of the rotating shaft 14. A positioning plate 11 and a push plate 12 are fixedly connected to the belt 17 at the front end of the fixed bracket 3. The positioning plate 11 is used to provide lateral limit during the process of pushing the mold 18 in, and the push plate 12 is used to push the mold 18 to move in a preset direction.

[0023] The mold 18 has limiting grooves 20 on both sides that engage with the limiting plate 16. The cross-sectional shape of the limiting grooves 20 matches the cross-sectional shape of the 7-shaped limiting plate 16. When the mold 18 is placed on the L-shaped bracket 9, the limiting grooves 20 slide into the limiting plate 16 in the horizontal direction, thereby positioning the mold 18 in the vertical and lateral directions. Push grooves 21 are provided on the bottom of both sides of the mold 18. The push plate 12 is adapted to the push groove 21. When the belt 17 moves, the push plate 12 moves with the belt 17 and engages in the push groove 21, pushing the mold 18 to the preset potting position. At this time, the positioning plate 11 abuts against the side wall of the mold 18, thereby achieving precise positioning and fixing of the mold 18 in the horizontal movement direction. Multiple placement grooves 19 are provided on the top surface of the mold 18. The placement grooves 19 are arranged in an array. The shape and size of each placement groove 19 match the shape of the miniature chip inductor to be potted, and are used to accommodate the miniature chip inductor to be potted.

[0024] The sealed chamber 2 is connected to a vacuum pump group and a vacuum pressure control system. The vacuum pump group adopts a two-stage configuration of rotary vane mechanical pump and molecular pump, which can achieve a vacuum level of less than 10 Pa. The vacuum pressure control system includes a PLC controller, a vacuum sensor, and a pressure regulating valve. The vacuum sensor is located inside the sealed chamber 2 to detect the vacuum level in the sealed chamber 2 in real time. The pressure regulating valve is located on the vacuum pipeline connecting the sealed chamber 2 and the vacuum pump group to adjust the pumping rate and control the vacuum level. The PLC controller is electrically connected to the vacuum sensor, the pressure regulating valve, and the vacuum pump group, and is used to perform closed-loop control and multi-stage regulation of the vacuum level in the sealed chamber 2 according to the preset vacuum pressure curve.

[0025] Industrial camera 7, employing a CCD industrial camera with over 5 megapixels, is equipped with a telecentric lens and a ring LED light source. It is electrically connected to the PLC controller. Industrial camera 7 is used to acquire images of the placement slot 19 on the mold 18 through the transparent sealing cover 5. The PLC controller has a built-in image processing module for processing and analyzing the acquired images, specifically including: The industrial camera 7 completes single-frame image acquisition with the ring light source on, and the acquired color image is transmitted in real time to the image processing module of the PLC controller via the GigE interface.

[0026] The image processing module first performs grayscale conversion on the original color image. Since the human eye is most sensitive to green and least sensitive to blue, a weighted average method is used to convert the RGB three-channel image into a single-channel grayscale image. The conversion formula is denoted as Equation (1):

[0027] In the formula: R, G, B—pixel values ​​of the red, green, and blue channels of the color image, ranging from [0, 255]; Gray—pixel grayscale value of the grayscale image, ranging from [0, 255]. Grayscale conversion reduces the three-channel image to a one-dimensional grayscale matrix, compressing the data volume to one-third of the original, significantly improving the processing speed of subsequent algorithms.

[0028] The grayscale image is then subjected to Gaussian filtering for noise reduction to eliminate random noise introduced by fine dust particles or minor scratches on the surface of the sealing cover 5 that may exist inside the sealed chamber 2. The two-dimensional Gaussian filter kernel function is denoted as:

[0029] In the formula: (x, y) — the coordinate offset of a pixel within the filtering window relative to the center of the window; σ — the standard deviation of the Gaussian kernel, which in this embodiment is taken as 1.0 to 1.5, used to control the filtering smoothing intensity. The Gaussian filtering is implemented by convolving the Gaussian kernel with the grayscale image, replacing each pixel value with the weighted average of its neighboring pixels; the larger the value of σ, the higher the smoothness of the image. Gaussian filtering can effectively suppress high-frequency random noise while completely preserving the edge contour features of the placement slot 19.

[0030] After filtering, the image contrast is enhanced by histogram equalization, which stretches the image grayscale dynamic range to the full grayscale level [0,255], maximizing the grayscale difference between the placement slot 19 and the substrate surface of the mold 18, thus providing a basis for subsequent edge detection.

[0031] The edge contour of placement slot 19 is extracted using the Canny edge detection operator. The Canny algorithm is a multi-stage algorithm, and the specific steps are as follows: The first step is to use a 5×5 Gaussian filter to smooth and denoise the image, with the filter kernel function being the same as in equation (2).

[0032] The second step is to calculate the image intensity gradient, using the Sobel operator to solve for the gradient matrices in the horizontal (x) and vertical (y) directions respectively:

[0033]

[0034] In the formula: A—input grayscale image matrix; *—two-dimensional convolution operator.

[0035] The formulas for calculating the gradient magnitude G and gradient direction θ are as follows:

[0036]

[0037] The third step is non-maximum suppression: local extrema are filtered along the gradient direction, and only the local maximum gradient point with a single pixel width is retained to complete the edge thinning.

[0038] The fourth step is dual-threshold screening and edge connection: set a high threshold Th = 150~200 and a low threshold Tl = 50~80; pixels with gradient magnitudes greater than Th are judged as strong edges, those less than Tl are directly removed, and pixels with magnitudes between Tl and Th are tracked through 8-neighborhood connectivity and stitched together to form a complete closed edge contour.

[0039] The Suzuki contour tracking algorithm is applied to the detected edges to extract all closed contours in the image. Geometric feature parameters are calculated for each closed contour and then matched against pre-stored slot template features for selection. The core geometric parameters include: contour area A, contour perimeter P, and circularity C. The circularity calculation formula is:

[0040] The closer the roundness value is to 1, the closer the outline geometry is to a standard circle; the rectangular placement slot uses the aspect ratio of the outline's circumscribed rectangle to complete feature selection. False outlines caused by noise, scratches, and debris are eliminated through template feature comparison, retaining only the valid outline of placement slot 19.

[0041] For the selected single placement slot contour, the geometric center in the pixel coordinate system is solved using the image moment method. The p+q order moment of the contour region is defined by the following equation:

[0042] In the formula: I(x,y) — the gray value of pixel (x,y) in the binary image, which is either 0 or 1; p, q — the order of the moment, which are non-negative integers.

[0043] Zeroth moment First moment , expression:

[0044]

[0045]

[0046] Represents the total pixel area of ​​the outline region; , Let be the first-order spatial moment of the contour. The formula for calculating the centroid (pixel-level center coordinates) of the contour pixel coordinate system is:

[0047]

[0048] The centroid of a circular placement slot is equivalent to the center of a circle, and the centroid of a rectangular placement slot is equivalent to the geometric center of a rectangle.

[0049] (iv) Subpixel precision positioning To improve positioning accuracy to the sub-pixel level of 0.1 to 0.01 pixels, a 3×3 pixel window is selected in the neighborhood of the pixel-level centroid (i,j), and sub-pixel interpolation is achieved using two-dimensional quadratic surface fitting. The two-dimensional quadratic surface function is:

[0050] In the formula: (x,y) — the coordinate offset relative to the center pixel (i,j), with a value set {-1,0,1}; a, b, c, d, e, f — 6 unknown coefficients to be fitted.

[0051] Substituting the coordinate-grayscale values ​​of 9 groups within a 3×3 window into a system of overdetermined equations, and solving for all fitting coefficients using the least squares method. Taking the first-order partial derivative of the surface function and setting it to zero, the grayscale extrema are determined; the partial derivative equation is given by:

[0052]

[0053]

[0054]

[0055]

[0056]

[0057] The recognition coordinates output by industrial cameras are sub-pixel coordinates in a pixel coordinate system, which can only represent the position of image pixels and cannot be directly used for equipment motion control. In order to drive the displacement component to move the dispensing gun accurately, the pixel coordinates need to be converted into physical coordinates (unit: mm) in a three-dimensional world coordinate system. This coordinate mapping and correction process is achieved through camera calibration.

[0058] This paper employs a nine-point calibration method to establish the mapping relationship between the pixel coordinate system and the world coordinate system. Simultaneously, it combines the Zhang Zhengyou calibration method to correct minor lens distortions, ensuring high-precision positioning. During calibration, a calibration board with a 3×3 array of nine high-precision feature points is placed on the support plane of an L-shaped bracket. This mounting plane is defined as the Z=0 reference plane of the world coordinate system, and the standard spacing between adjacent feature points on the calibration board is a fixed value.

[0059] The camera imaged perpendicularly to the calibration board, and after acquiring the image of the calibration board, it identified 9 sets of sub-pixel coordinates of feature points. Matching corresponding known standard world coordinates The device is equipped with a telecentric lens, resulting in almost no perspective distortion. Pixel coordinates and world coordinates satisfy a two-dimensional affine transformation relationship, and the homogeneous matrix transformation formula is:

[0060] In the formula The matrix is ​​a 3rd-order affine transformation, specifically in the form of:

[0061] The explicit formula for converting pixel coordinates to world physical coordinates through matrix expansion is as follows:

[0062]

[0063] Using pixel-world coordinate pairing data from 9 calibration points, the six unknown parameters of the transformation matrix are solved using the least squares method. The optimal matrix parameters are then fitted by minimizing the global reprojection error. The objective function for the error is:

[0064] The native distortion of the telecentric lens is less than 0.1%. To further improve positioning accuracy, Zhang Zhengyou's calibration method is introduced to correct the radial and tangential distortion of the lens. The distortion correction formula is:

[0065]

[0066] In the formula: ( , —Coordinates of the principal point of the camera; , Radial distortion coefficient; — Tangential distortion coefficient; The distance from a pixel to the principal point is calculated using the following formula:

[0067] Coordinate transformation process: First, perform distortion correction on the original sub-pixel coordinates, and then substitute them into the affine transformation formula to solve for the world coordinates.

[0068] For any identified sub-pixel center of the placement slot ( , ), corresponding world coordinates:

[0069] The glue gun completes the filling operation by using a preset fixed height for its Z-axis.

[0070] Synchronous verification logic: The image processing module counts and identifies the total number of slots N, and compares it with the preset rated number of slots (N_0) of the mold. If N≠N_0, the system triggers an alarm; calculates the Euclidean distance between the centers of adjacent slots and verifies it with the theoretical spacing; fits the row and column reference lines of the slot array with least squares to verify that all recognition coordinates fall on the array reference lines, ensuring that the visual recognition results are accurate and reliable.

[0071] After obtaining the world coordinates (X_i,Y_i), i=1,2,...,N of all placement slots, the PLC controller path planning module generates the continuous motion trajectory of the glue gun 23.

[0072] For a regular array of slots, a serpentine S-shaped path is used. Slots are grouped by row, with each row sorted unidirectionally along the X-axis. Adjacent rows alternate in direction of movement. The first row is traversed from left to right, with a vertical jump to the starting point of the next row at the end. Subsequent rows are traversed from right to left, repeating this process to form a folded S-shaped trajectory. This path has the shortest total distance, minimizes large jumps in servo movement, and improves equipment stability. For irregularly scattered slots, the Traveling Salesman's Plane (TSP) path is solved using the nearest neighbor approximation algorithm. Starting from the current coordinates of the dispensing gun, the point with the closest Euclidean distance among the untraversed slots is selected as the next target. This process iterates through all N slots to generate the globally shortest movement path.

[0073] After the path point sequence is generated, the PLC controller performs linear and circular interpolation calculations on the coordinate sequence and converts them into pulse motion commands for each servo motor of the displacement component 22, driving the glue gun 23 to move sequentially above each placement slot 19 to perform the potting process.

[0074] The overall working principle of the device of the present invention is as follows: First, the operator places the mold 18 containing the miniature chip inductor to be potted on the L-shaped bracket 9, so that the limiting grooves 20 on both sides of the mold 18 engage with the 7-shaped limiting plates 16 on the fixed bracket 3, thus achieving the initial positioning of the mold 18. The motor 10 is started, and the motor 10 drives the two second pulleys 13 to rotate synchronously through the rotating shaft 14. The second pulleys 13 drive the first pulley 15 to rotate through the belt 17. The push plate 12 on the belt 17 moves with the belt 17 and engages in the push grooves 21 on both sides of the mold 18, pushing the mold 18 to the preset potting position. At this time, the positioning plate 11 abuts against the side wall of the mold 18, thus achieving precise fixation of the mold 18.

[0075] Then, cylinder 6 drives the sealing cover 5 to descend, closing with the sealing chamber 2 to form a sealed space. Industrial camera 7 captures images of the placement slots 19 on the mold 18 through the transparent sealing cover 5. The image processing module of the PLC controller identifies the number and position coordinates of the placement slots 19 and generates the glue injection path.

[0076] Next, the vacuum pump unit evacuates the sealed chamber 2 to the preset vacuum level. The PLC controller controls the displacement component 22 to drive the glue gun 23 to move sequentially above each placement slot 19 according to the generated glue injection path. The glue gun 23 injects potting glue into the miniature patch inductor in the placement slot 19. During the potting process, the PLC controller adjusts the vacuum level in the sealed chamber 2 in multiple stages according to the preset vacuum pressure curve.

[0077] After the potting is completed, keep the vacuum stationary, then break the vacuum, open the sealing cap 5, and take out the mold 18 for curing.

[0078] A method for bubble-free vacuum potting of miniature surface mount inductors, using the aforementioned apparatus, includes the following steps: Step S1: Mold Installation and Positioning The mold 18 containing the miniature chip inductor to be potted is placed on the L-shaped bracket 9, so that the limiting grooves 20 on both sides of the mold 18 engage with the L-shaped limiting plates 16 on the fixed bracket 3. The motor 10 is started, and the motor 10 drives the second pulley 13 to rotate through the rotating shaft 14. The second pulley 13 drives the first pulley 15 to rotate through the belt 17. The push plate 12 on the belt 17 moves with the belt 17 and engages in the push grooves 21 on both sides of the mold 18, pushing the mold 18 to the preset potting position and fixing it.

[0079] Step S2: Visual Recognition and Path Planning Industrial camera 7 captures images of the placement slot 19 on mold 18 through transparent sealing cover 5. The captured images are transmitted to the image processing module of PLC controller, which identifies the position coordinates of placement slot 19 through the following steps: (1) Perform grayscale processing on the acquired images to convert color images into grayscale images, thereby reducing the amount of data computation; (2) Binarize the grayscale image, segment the image into foreground and background by setting an appropriate grayscale threshold, and extract the edge contour features of the placement slot 19; (3) Calculate the center pixel coordinates of each placement slot 19 by performing normalized cross-correlation matching on the pre-stored placement slot template image; (4) Convert pixel coordinates to physical coordinates in the world coordinate system using camera calibration parameters; (5) Count the total number of placement slots 19 and record the position coordinates of each placement slot 19.

[0080] The PLC controller generates the dispensing path of the dispensing gun 23 based on the identified position coordinates: using the position coordinates of all placement slots 19 as path points, the nearest neighbor algorithm is used to calculate the shortest movement path that traverses all path points, generating an S-shaped path or a serpentine path, so that the dispensing gun 23 moves the shortest distance and is most efficient during the potting process.

[0081] Step S3: Vacuuming Cylinder 6 drives the sealing cover 5 to descend, and the sealing cover 5 closes with the sealing chamber 2 to form a sealed space. The vacuum pump group is started to evacuate the sealing chamber 2. The vacuum sensor monitors the vacuum level in the sealing chamber 2 in real time and feeds it back to the PLC controller until the vacuum level in the sealing chamber 2 reaches the first preset vacuum level P1.

[0082] Step S4: Vacuum filling Maintain the vacuum level inside the sealed chamber 2 at no less than P1. The PLC controller controls the displacement component 22 to drive the dispensing gun 23 to move sequentially above each placement slot 19 according to the dispensing path generated in step S2, and the dispensing gun 23 injects potting compound into the miniature patch inductor in the placement slot 19.

[0083] During the potting process, the PLC controller adjusts the vacuum level inside the sealed chamber 2 in multiple stages according to the preset vacuum pressure curve: First potting stage: Maintaining the vacuum level at P1, the dispensing gun 23 injects potting compound at the first flow rate V1 to complete the rapid filling of the main space of the potting cavity; Second potting stage: The vacuum level is reduced to P2, and the potting gun 23 injects potting compound at a second flow rate V2 to promote the potting compound to penetrate and fill the fine gaps between coil turns and between coil and magnetic core inside the micro patch inductor. The third potting stage: restore the vacuum to P1 and maintain it for time t2 to allow the potting compound to spread fully in the micro-gap.

[0084] Complete the potting operation of all placement tanks 19 in sequence according to the glue injection path.

[0085] Step S5: Hold pressure and let stand After potting is completed, turn off the glue gun 23, maintain the vacuum degree in the sealed chamber 2 at P1, and let it stand for 5 min to 15 min to allow the potting glue to further eliminate residual air bubbles and fully fill all gaps in a vacuum environment.

[0086] Step S6: Breaking the void and solidifying Dry gas is slowly introduced into the sealed chamber 2 to atmospheric pressure through the pressure regulating valve, with an inflation rate not exceeding 5 kPa / min. Cylinder 6 drives the sealing cover 5 to rise and open, allowing the mold 18 to be removed for heat curing. Curing is performed using a stepped heating method: first, pre-curing at 60℃~80℃ for 30min~60min; then curing at 100℃~120℃ for 60min~120min; and finally, post-curing at 150℃ for 30min~60min. It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0087] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A bubble-free vacuum potting device for miniature surface mount inductors, characterized in that: The device includes a workbench (1) and a mold (18). A sealed chamber (2) is provided on the top surface of the workbench (1). A fixed frame (4) is vertically provided on one side of the workbench (1). An installation plate (8) is horizontally fixedly connected to the top of the fixed frame (4). An industrial camera (7) is provided at the center of the installation plate (8). A cylinder (6) is fixedly connected to both ends of the installation plate (8). A sealing cover (5) is fixedly connected to the telescopic rod end of the cylinder (6). An L-shaped bracket (9) is provided at the bottom of the sealing cover (5). Two fixed brackets (3) are symmetrically provided at the horizontal end of the L-shaped bracket (9). A 7-shaped limiting plate (16) is provided at the top edge of the fixed bracket (3). The mold (18) has limiting grooves (20) on both sides that engage with the limiting plate (16), and multiple placement grooves (19) on the top surface of the mold (18).

2. The miniature patch inductor bubble-free vacuum potting device and its processing method according to claim 1, characterized in that: The fixed bracket (3) is T-shaped, with an internal cavity and an open top. The horizontal ends of the fixed bracket (3) are rotatably connected to the first pulley (15), and the bottom of the vertical end of the fixed bracket (3) is rotatably connected to the second pulley (13). The first pulley (15) and the second pulley (13) are connected by a belt (17). One side of the fixed bracket (3) is provided with a motor (10), and the output shaft of the motor (10) is fixedly connected to a rotating shaft (14). The two second pulleys (13) are respectively fixedly connected to the two ends of the rotating shaft (14). The belt (17) is fixedly connected to the front end of the fixed bracket (3) with a positioning plate (11) and a push plate (12). The bottom of both sides of the mold (18) is provided with push grooves (21), and the push plate (12) is adapted to the push grooves (21).

3. The miniature patch inductor bubble-free vacuum potting device and its processing method according to claim 1, characterized in that: The sealed chamber (2) is equipped with a displacement assembly (22), and a glue gun (23) is provided on the displacement assembly (22). The displacement assembly (22) includes an X-axis linear module, a Y-axis linear module and a Z-axis linear module, and the glue gun (23) is installed at the end of the displacement assembly (22).

4. The bubble-free vacuum potting device for miniature surface mount inductors according to claim 1, characterized in that: The sealed chamber (2) is connected to a vacuum pump group and a vacuum pressure control system. The vacuum pressure control system includes a PLC controller, a vacuum sensor and a pressure regulating valve. The vacuum sensor is located inside the sealed chamber (2), and the pressure regulating valve is located on the vacuum pipeline connecting the sealed chamber (2) and the vacuum pump group. The PLC controller is electrically connected to the vacuum sensor, the pressure regulating valve and the vacuum pump group respectively.

5. The bubble-free vacuum potting device for miniature surface mount inductors according to claim 1, characterized in that: The industrial camera (7) is electrically connected to the PLC controller. The industrial camera (7) is used to capture images of the placement slots (19) on the mold (18) through the sealing cover (5). The PLC controller has a built-in image processing module for identifying the number and position coordinates of the placement slots (19) and generating a glue injection path based on the identification results.

6. The bubble-free vacuum potting device for miniature surface mount inductors according to claim 1, characterized in that: The bottom of the sealed chamber (2) is provided with an air extraction port, which is connected to the vacuum pump group through a vacuum pipe; a sealing ring is provided between the sealing cover (5) and the sealed chamber (2), and the sealing cover (5) is made of transparent material.

7. A method for bubble-free vacuum potting of miniature surface mount inductors, implemented using the apparatus described in any one of claims 1 to 6, characterized in that, Includes the following steps: Step S1: Mold installation and positioning - Place the mold (18) containing the micro patch inductor to be potted on the L-shaped bracket (9), so that the limiting grooves (20) on both sides of the mold (18) are engaged with the 7-shaped limiting plate (16) on the fixed bracket (3). Start the motor (10), and the motor (10) drives the second pulley (13) to rotate through the rotating shaft (14). The second pulley (13) drives the first pulley (15) to rotate through the belt (17). The push plate (12) on the belt (17) moves with the belt (17) and is engaged in the push grooves (21) on both sides of the mold (18), pushing the mold (18) to the preset potting position and fixing it. Step S2: Visual recognition and path planning - The industrial camera (7) captures images of the placement slots (19) on the mold (18) through the sealing cover (5). The captured images are transmitted to the image processing module of the PLC controller. The image processing module identifies the position coordinates of each placement slot (19) through the template matching algorithm and counts the total number of placement slots (19). The PLC controller generates the glue injection path of the glue gun (23) based on the identified position coordinates. Step S3: Vacuuming - Cylinder (6) drives the sealing cover (5) to descend and close with the sealing chamber (2) to form a sealed space. Start the vacuum pump group to evacuate the sealing chamber (2) until the vacuum degree in the sealing chamber (2) reaches the preset vacuum degree P1. Step S4: Vacuum potting - Keep the vacuum level in the sealed chamber (2) not lower than P1. The PLC controller controls the displacement component (22) to drive the dispensing gun (23) to move sequentially above each placement slot (19) according to the dispensing path generated in step S2. The dispensing gun (23) injects potting glue into the micro patch inductor in the placement slot (19) to complete the potting operation of all placement slots (19). Step S5: Pressure holding and standing - After potting is completed, maintain the vacuum degree in the sealed chamber (2) at P1 and the standing time t1, so that the potting compound can eliminate residual air bubbles and fully fill in the vacuum environment; Step S6: Breaking the air and curing - Dry gas is slowly injected into the sealed chamber (2) to normal pressure through the pressure regulating valve. The cylinder (6) drives the sealing cover (5) to rise and open, and the mold (18) is taken out for heat curing treatment.

8. The method for bubble-free vacuum potting of a miniature surface mount inductor according to claim 7, characterized in that: In step S2, the specific process of the image processing module identifying the position coordinates of the placement slot (19) is as follows: First, the acquired image is processed by grayscale and binarization, and the edge contour features of the placement slot (19) are extracted. Then, normalized cross-correlation matching is performed using the pre-stored placement slot template image to calculate the center point pixel coordinates of each placement slot (19); finally, the pixel coordinates are converted into physical coordinates in the world coordinate system using camera calibration parameters.

9. The method for bubble-free vacuum potting of a miniature surface mount inductor according to claim 7, characterized in that: In step S4, the glue injection path is generated using an S-shaped path or a serpentine path. The PLC controller uses the position coordinates of all placement slots (19) as path points and uses the nearest neighbor algorithm to calculate the shortest movement path that traverses all path points.

10. The method for bubble-free vacuum potting of a micro-surface inductor according to claim 7, characterized in that: In step S4, vacuum potting adopts multi-stage vacuum control: in the first potting stage, the vacuum level is maintained at P1, and the dispensing gun (23) injects potting glue at the first flow rate V1 to complete the rapid filling of the main space of the potting cavity; in the second potting stage, the vacuum level is reduced to P2 (P2 < P1), and the dispensing gun (23) injects potting glue at the second flow rate V2 (V2 < V1) to promote the wetting and filling of the potting glue in the micro gaps inside the micro patch inductor; in the third potting stage, the vacuum level is restored to P1 and maintained for time t2 to allow the potting glue to spread fully in the micro gaps.

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