High-precision PCB mounting equipment and control method thereof

Abstract

The application relates to a high-precision PCB mounting device and a control method thereof, which comprises a rack, a moving workbench, a first mounting module and a second mounting module; each mounting module comprises a feeding unit, a piece taking unit, a calibration unit, a mounting unit, a visual detection unit and a control unit; when the pose deviation of any path island area exceeds a preset threshold value, the control unit only freezes the path queue of the corresponding path island area, and re-establishes the local reference matrix of the path island area, while keeping the remaining path island areas continuously mounting. The application divides the PCB into multiple independent path island areas, and establishes a local reference matrix for each path island, so that different areas can independently perform position compensation, thermal drift compensation and angle correction. The application reduces downtime and improves the continuous production capacity of the device. Different compensation strategies can be adopted for different path island areas, which improves the adaptability of the device to different mounting process areas and reduces mounting errors.

Description

Technical Field

[0001] This invention relates to the field of wafer mounting technology, and more specifically, to a high-precision PCB mounting equipment and its control method. Background Technology

[0002] With the development of semiconductor packaging, Mini LED, Micro LED, and high-density integrated circuits, PCB wafer mounting equipment is gradually moving towards high precision and high-speed collaboration. However, most existing mounting equipment adopts a globally unified coordinate control method, meaning the entire PCB board shares the same mounting reference coordinate system. When local areas experience pose deviations due to thermal deformation, clamping errors, dispensing accumulation errors, or differences in mounting density, it is usually necessary to re-perform global path correction or overall visual recalibration of the entire PCB board. However, in actual production processes, due to differences in device density, package type, and heat distribution in different areas, uneven thermal drift and local deformation are prone to occur in local areas of the PCB board. For example, BGA areas, high-density IC areas, and continuous dispensing areas are more prone to local cumulative errors. When traditional equipment uses a global compensation method, local errors can easily spread to the entire board area, not only leading to a decrease in overall mounting accuracy but also causing machine downtime, increased recalibration time, and reduced production cycle time.

[0003] Furthermore, existing dual-head placement equipment typically employs a fixed master control mode or a completely independent operation mode. When one placement head experiences deviation, film replacement failure, or visual calibration failure, the entire equipment often needs to be suspended, affecting the normal placement operation of the other placement head and reducing the equipment's continuous operation capability. Simultaneously, existing equipment usually updates the entire board path uniformly during path correction, lacking independent path freezing and local reference reconstruction mechanisms for specific areas, making it difficult to achieve continuous placement operation under local anomalies. Therefore, there is an urgent need for a high-precision PCB placement device capable of independent compensation for local areas, local path freezing, dynamic master-slave switching, and continuous placement operation. Summary of the Invention

[0004] The technical problem to be solved by the present invention is that when existing PCB chip mounting equipment adopts a global compensation method, it is easy to spread local errors to the entire board area, resulting in a decrease in overall mounting accuracy, easy to cause the whole machine to stop, affecting production efficiency, and making it difficult to achieve continuous mounting operation under local abnormal conditions. In view of the above-mentioned defects of the prior art, a high-precision PCB mounting equipment and its control method are provided.

[0005] The technical solution adopted by this invention to solve its technical problem is: A high-precision PCB mounting equipment is constructed, comprising: a frame; a motion stage mounted on the frame and used to support the PCB board, the motion stage having a global mounting coordinate system; a first mounting module and a second mounting module respectively located on both sides of the motion stage; wherein each mounting module includes: a feeding unit for conveying a wafer carrier film; a wafer picking unit for picking up a wafer from the wafer carrier film; a calibration unit for acquiring wafer position deviation information; a mounting unit for mounting the wafer to the corresponding position on the PCB board; a vision inspection unit for acquiring wafer pose data and acquiring position deviation information of the path island region; and a control unit for... The PCB board is divided into multiple independent path island regions; a local reference matrix is ​​established for each path island region; either the first mounting module or the second mounting module is set as the master reference module, and the other is set as the slave reference module; the master reference module is used to update the local reference matrix of the corresponding path island region in real time; the slave reference module performs mounting path following based on the corresponding local reference matrix; when the pose deviation of any path island region exceeds a preset threshold, the control unit freezes only the path queue of the corresponding path island region and re-establishes the local reference matrix of the path island region, while maintaining the continuous mounting operation of the remaining path island regions.

[0006] Furthermore, the local reference matrix includes local coordinate origin parameters, rotation compensation parameters, thermal drift compensation parameters, and mounting scaling parameters; the control unit dynamically updates the local reference matrix based on the regional reference point information obtained by the visual detection unit.

[0007] Furthermore, after the path island region is frozen, the control unit controls the corresponding mounting module to enter the reference reconstruction mode; the reference reconstruction mode includes: re-acquiring at least three reference points in the path island region, and regenerating the local reference matrix based on multiple reference points.

[0008] Furthermore, during the local reference matrix update, the control unit controls the non-frozen path island regions to continue performing the mounting operation and prevents the frozen path island regions from participating in path scheduling.

[0009] Furthermore, the control unit establishes a path island priority queue; when multiple path island regions simultaneously exhibit deviation anomalies, reference matrix reconstruction is preferentially performed on the path island regions with higher mounting accuracy levels.

[0010] Furthermore, the feeding unit includes a blue film gripping assembly and an automatic film changing assembly. The blue film gripping assembly includes a first gripper, a second gripper, a transfer table, and a waste tray. A rack for placing wafer carrier films is provided on one side of the first gripper. The first gripper rotates on the frame and moves vertically to grip the wafer carrier films from the rack onto the transfer table. The waste tray is located between the transfer table and the automatic film changing assembly. The second gripper is horizontally movable on the frame and is used to grip the wafer carrier films from the transfer table onto the transfer table. An automatic film changing assembly may be used to place the wafer carrier film above the automatic film changing assembly into a waste tray; the automatic film changing assembly includes a first moving track, a second moving track, a cylinder, and a plurality of gripping components, the gripping components being electrically connected to the cylinder, the cylinder driving the gripping components to move closer to or further away in opposite directions to grip or release the wafer carrier film, so as to switch the wafer carrier film to be mounted without stopping the machine; the first moving track and the second moving track are located at the bottom of the cylinder, and are used to move the wafer carrier film to the wafer picking position or film changing position of the wafer picking unit.

[0011] Furthermore, the calibration unit includes an upward-viewing camera for acquiring the wafer edge contour and a calibration stage for acquiring the mounting angle deviation; wherein the upward-viewing camera and the calibration stage correspond to compensation updates for different path island regions; the visual inspection unit includes a downward-viewing camera disposed above the automatic film changing assembly, the calibration stage, and the motion stage; wherein the downward-viewing camera disposed above the automatic film changing assembly and the calibration stage is used to acquire wafer pose data, and the downward-viewing camera disposed above the motion stage is used to acquire position deviation information of the path island region.

[0012] Furthermore, when the main reference module experiences a deviation anomaly, the control unit controls the corresponding module to take over as the new main reference module and reallocates the reference relationships of each path island region.

[0013] Furthermore, the wafer picking unit is equipped with a wafer picking rotating arm, and the placement unit is equipped with a placement rotating arm. Both the wafer picking and placement rotating arms are equipped with suction nozzles for adsorbing wafers. Each suction nozzle is connected to a vacuum tube. The wafer picking rotating arm is movably positioned between the automatic film changing assembly and the calibration stage to adsorb wafers on the wafer carrier film and place them on the upward-viewing camera and calibration stage for calibration. The placement rotating arm is movably positioned between the motion stage and the calibration stage to place the wafers on the calibration stage onto the die-bonding position on the motion stage. The placement unit also includes a dispensing needle and a glue tray. The dispensing needle is movably positioned above the motion stage. The glue tray is located on one side of the dispensing needle and contains silver paste. The dispensing needle picks up silver paste from the glue tray and applies it to the die-bonding position to complete die bonding. The placement rotating arms and dispensing needles of the first and second placement modules respectively perform differentiated angle compensation and dispensing position compensation for different path island regions.

[0014] A control method based on a high-precision PCB mounting equipment is constructed, which includes: S1: Establish the global mounting coordinate system for the motion worktable; S2: Divide the PCB board into multiple path island regions; S3: Establish a local reference matrix for each path island region; S4: Set one of the first mounting module and the second mounting module as the main reference module; S5: The local reference matrix of the corresponding path island region is updated in real time by the main reference module; S6: Controls the path following placement from the reference module based on the corresponding local reference matrix; S7: When the pose deviation of any path island region exceeds the threshold, only the path queue of the corresponding path island region is frozen. S8: Reacquire the benchmark information of the island area along the path and reconstruct the local reference matrix; S9: During local reference matrix reconstruction, maintain continuous mounting of non-frozen path island regions; S10: After the local reference matrix is ​​updated, resume the mounting operation of the frozen path island area.

[0015] The beneficial effects of this invention are as follows: This invention divides the PCB board into multiple independent path island regions and establishes a local reference matrix for each path island, enabling different regions to independently perform position compensation, thermal drift compensation, and angle correction. Compared to traditional global unified coordinate control methods, this invention achieves independent reference control for local regions, effectively reducing the spread of local errors to the entire board, thereby improving the placement accuracy in high-density and high-precision areas. When any path island region experiences an abnormal pose deviation, only the path queue of the corresponding path island region is frozen, and the local reference matrix for that path island region is re-established, rather than stopping the entire machine. Simultaneously, the remaining unfrozen path island regions continue to perform placement actions, achieving localized frozen path updates. This reduces downtime caused by traditional whole-board pauses and overall recalibration, improving the equipment's continuous production capacity. Furthermore, different compensation strategies can be adopted for different path island regions, thereby improving the equipment's adaptability to different placement process areas and reducing cumulative placement errors under complex operating conditions.

[0016] This invention sets up a master reference module and a slave reference module and establishes a real-time status synchronization mechanism. When the master reference module experiences deviation, visual calibration failure, or film replacement abnormality, the slave reference module can take over as the new master reference module and redistribute the reference relationship of the path island area. This avoids the entire machine from stopping due to the abnormality of a single mounting module, thereby improving the stability and fault tolerance of the equipment.

[0017] The first and second mounting modules of this application have a symmetrical structure, which enables simultaneous die bonding and dispensing operations on both sides when dealing with larger PCD boards, thereby improving production efficiency. Attached Figure Description

[0018] Figure 1 This is an overall structural diagram of a high-precision PCB mounting device according to one embodiment of the present invention; Figure 2 This is a schematic diagram of the path island region in one embodiment of the present invention; Figure 3 This is a three-dimensional schematic diagram of a high-precision PCB mounting device according to another embodiment of the present invention; Figure 4 This is a three-dimensional schematic diagram of a high-precision PCB mounting device from another angle in one embodiment of the present invention; Figure 5 This is the present invention. Figure 3 A magnified view of a portion of point Q; Figure 6 This is the present invention. Figure 3 A magnified view of a portion of point I in the middle; Figure 7 This is a flowchart of the method steps of a control method based on a high-precision PCB mounting equipment according to an embodiment of the present invention; Figure 8 This is a schematic diagram of a display interface of a high-precision PCB mounting device according to an embodiment of the present invention.

[0019] Labeling Explanation: Frame 1, Motion Worktable 2, First Placement Module 3, Second Placement Module 4, Feeding Unit 5, Pick-up Unit 6, Calibration Unit 7, Placement Unit 8, Vision Inspection Unit 9, Top-View Camera 71, Calibration Table 72, Bottom-View Camera 91, Blue Film Gripping Assembly 51, Automatic Film Changing Assembly 52, First Claw 511, Second Claw 512, Transfer Table 513, Waste Tray 514, Material Rack 515, First Moving Track 521, Second Moving Track 522, Cylinder 523, Gripping Part 524, Pick-up Rotating Arm 61, Placement Rotating Arm 81, Suction Nozzle Rod 611, Vacuum Tube 612, Dispensing Needle 82, Glue Tray 83. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0021] Please refer to Figure 1 This invention proposes a high-precision PCB mounting equipment, including a frame 1; a motion stage 2, mounted on the frame 1 and used to support the PCB board, the motion stage 2 establishing a global mounting coordinate system; a first mounting module 3 and a second mounting module 4 respectively located on both sides of the motion stage 2; wherein each mounting module includes: a feeding unit 5 for conveying a wafer carrier film; a wafer picking unit 6 for picking up a wafer from the wafer carrier film; a calibration unit 7 for acquiring wafer position deviation information; a mounting unit 8 for mounting the wafer to the corresponding position on the PCB board; a vision inspection unit 9 for acquiring wafer pose data and acquiring position deviation information of path island regions; and a control unit for dividing the PCB board into multiple independent path island regions; each path island region establishing a local reference matrix; either the first mounting module 3 or the second mounting module 4 is set as the master reference module, and the other is set as the slave reference module; the master reference module is used to update the local reference matrix of the corresponding path island region in real time; the slave reference module performs mounting path following based on the corresponding local reference matrix. When the pose deviation of any path island region exceeds a preset threshold, the control unit freezes only the path queue of the corresponding path island region and re-establishes the local reference matrix of the path island region, while keeping the other path island regions continuously mounted.

[0022] In this embodiment, such as Figure 1As shown, the frame 1 is equipped with a motion worktable 2, which can move along three axes: X, Y, and Z. A first mounting module 3 and a second mounting module 4 are respectively located on both sides of the worktable, and the first mounting module 3 and the second mounting module 4 are symmetrically arranged. Simultaneous die bonding and dispensing operations using the mounting modules on both sides significantly improve efficiency. Furthermore, when dealing with larger PCBs, two or more symmetrical mounting groups can also be set up, allowing for the selection of corresponding mounting components based on the PCB size, thereby improving chip mounting efficiency. This invention establishes a master reference module and a slave reference module, and establishes a real-time status synchronization mechanism. When the master reference module experiences deviation anomalies, visual calibration failures, or film replacement anomalies, the slave reference module can take over as the new master reference module and reallocate the reference relationships of the path island areas, thereby preventing the entire machine from stopping due to an anomaly in a single mounting module, improving equipment stability and fault tolerance.

[0023] In one embodiment, each mounting module includes a feeding unit 5 for conveying a wafer carrier film, a wafer picking unit 6 for picking up wafers from the wafer carrier film, a calibration unit 7 for acquiring wafer position deviation information, a mounting unit 8 for mounting wafers to corresponding positions on the PCB board, a visual inspection unit 9 for acquiring wafer pose data, and a control unit for dividing the PCB board into multiple independent path island regions.

[0024] Specifically, after importing the PCB mounting data, the control unit performs regional discretization processing on the PCB board to generate multiple independent path island regions. The control unit can be a PLC controller, an IPC industrial computer, or an ARM controller. More specifically, the control unit first reads the PCB board's Gerber file, mounting coordinate file, and component type information; the Gerber file includes routing layers, solder mask layers, silkscreen layers, etc. Next, based on at least one parameter among mounting point density, component package type, local heat capacity distribution, substrate deformation, dispensing area concentration, wafer size differences, and mounting accuracy level, a path island partitioning model is established. Finally, the control unit aggregates path island regions with the same process characteristics into a single path island region.

[0025] By dividing the PCB board into multiple independent path island regions and establishing a local reference matrix for each path island, different regions can independently perform position compensation, thermal drift compensation, and angle correction. Thermal drift is the slow, irregular change in electronic components or devices caused by temperature variations. Thermal drift compensation measures the drift at a given temperature and then actively applies a correction in the opposite direction to offset or reduce the impact of temperature changes on device or circuit performance. The goal is to correct drift, ensuring stable and accurate operation of the device at different temperatures and improving device precision. Compared to traditional globally unified coordinate control methods, this invention effectively reduces the spread of local errors across the entire board, thereby improving the mounting accuracy in high-density and high-precision areas.

[0026] In one embodiment, a path island refers to an independent local placement control area formed by the control unit during the PCB placement process, based on placement accuracy requirements, component distribution characteristics, thermal deformation characteristics, or placement cycle time requirements. Each path island corresponds to independent local reference coordinates, an independent path execution queue, independent compensation parameters, independent visual calibration parameters, and independent path freeze permissions. Different path islands can perform path updates, error compensation, reference reconstruction, placement pause, and master-slave reference module switching respectively. Figure 2 As shown, the PCB is ultimately divided into three path island regions: path island A is the BGA region, path island B is the high-density IC region, and path island C is the resistor-capacitor region. Furthermore, those with the same process characteristics are aggregated into the same path island region.

[0027] In one specific embodiment, the path island region is divided according to the BGA region on the PCB. For package areas with a large number of solder joints and small mounting spacing on the PCB, the control unit divides the corresponding area into high-precision path islands and increases the visual inspection frequency and local reference matrix update frequency of the path island region, while ordinary discrete device areas are divided into standard path island regions.

[0028] In another specific embodiment, the control unit establishes a density distribution map based on the number of mounting points per unit area. When the mounting point density in a local area exceeds a preset threshold, an independent path island area is automatically generated.

[0029] Furthermore, by reducing the step distance of the placement head within the path island area, improving the local path sampling accuracy, and reducing the synchronization speed of the two heads, the cumulative error caused by high-speed placement is reduced.

[0030] Furthermore, a boundary transition zone is provided between adjacent path islands to prevent abrupt changes in compensation parameters between different path islands and to prevent motion conflicts between the two placement heads at the region boundary, thus maintaining placement continuity. When the placement head enters the boundary transition zone, the control unit performs a progressive interpolation switch on the local reference matrices of the current path island and the target path island. In one specific embodiment, a linear weighted interpolation method is used: the compensation weight of the current path island gradually decreases, while the compensation weight of the target path island gradually increases, thereby avoiding abrupt changes in the placement trajectory.

[0031] In this embodiment, the slave reference module performs placement path following based on the corresponding local reference matrix; wherein, the following adopts a periodic synchronization request mechanism. Specifically, the slave reference module requests the latest local reference matrix of the corresponding path island region from the master reference module once every time a placement cycle is completed; if the request is successful, the slave reference module recalculates the coordinates of the next placement point of the current path island based on the latest local reference matrix and continues execution; if the request times out or the master reference module is in an abnormal state, the slave reference module continues to perform placement using the most recently successfully obtained local reference matrix until the master reference module recovers or a master-slave switch is triggered. In another specific embodiment, the synchronization period can be: the slave reference module sends a synchronization request to the master reference module every N placement actions (N is a preset positive integer, such as N=5) or every fixed time interval T (such as T=200ms). It should be noted that the above synchronization period and triggering conditions are only examples, and other methods are also possible.

[0032] In one embodiment, the local reference matrix includes local coordinate origin parameters, rotation compensation parameters, thermal drift compensation parameters, and mounting scaling parameters; the control unit dynamically updates the local reference matrix based on the regional reference point information obtained by the vision detection unit 9.

[0033] In this embodiment, an independent local reference matrix is ​​established for each path island region to describe the real-time mounting reference state within the corresponding path island region. The local reference matrix includes local coordinate origin parameters, rotation compensation parameters, thermal drift compensation parameters, and mounting scaling parameters. The local coordinate origin parameters refer to the data of visual positioning markers (such as pre-set circular holes, cross-shaped pads, or other alignment marks on the PCB board) set for each independent path island region, used to determine the local reference center of the current path island region; the rotation compensation parameters are used to correct angular offsets caused by clamping errors on the PCB board; the thermal drift compensation parameters are used to correct local thermal deformation errors generated during continuous dispensing and continuous mounting; and the mounting scaling parameters are used to correct local dimensional changes on the PCB board caused by thermal expansion or material stress.

[0034] Specifically, the visual inspection unit 9 acquires the position data of multiple regional reference points within the path island area; the control unit dynamically updates the corresponding local reference matrix based on the positional change relationship between the multiple regional reference points.

[0035] In one specific embodiment, when an overall rotation trend is detected in the path island region, the control unit increases the weight of the rotation compensation parameter; when a proportional deviation is detected between the edge and center of the region, the control unit updates the mounting scaling parameter, thereby improving the mounting accuracy of the local area.

[0036] In another specific embodiment, each path island corresponds to an independent local reference matrix, which includes: ; in, This represents the local offset in the X direction. This represents the local offset in the Y direction. This is a local rotation compensation angle; This is the local scaling compensation coefficient; The control unit updates the corresponding parameters in real time based on the visual detection results to provide thermal drift compensation parameters.

[0037] In one embodiment, after the path island region is frozen, the control unit controls the corresponding mounting module to enter the reference reconstruction mode; the reference reconstruction mode includes: re-acquiring at least three reference points in the path island region, and regenerating the local reference matrix based on the multiple reference points.

[0038] In practical implementation: when the control unit detects that the mounting deviation in the path island area exceeds a preset threshold... The corresponding path island area enters a frozen state; at this time, the control unit controls the corresponding mounting module to enter the reference reconstruction mode. The reference reconstruction mode includes: re-acquiring the position data of multiple regional reference points within the path island area, and re-establishing a local reference matrix based on the multiple regional reference points.

[0039] Specifically, the multiple regional reference points include at least: a first edge reference point, a second edge reference point, and a center reference point. Establishing local geometric relationships through multiple regional reference points avoids error accumulation caused by single-point calibration.

[0040] Furthermore, the control unit recalculates the local coordinate offset, local rotation angle, local thermal drift, and local scaling ratio based on multiple regional reference points, and generates a new local reference matrix. After the new local reference matrix is ​​generated, the frozen path islands are re-added to the mounting scheduling queue. This invention, when an anomaly occurs in the path island region, re-collects multiple regional reference points and regenerates the local reference matrix. Compared to traditional single-point correction methods, this invention can establish local geometric relationships based on multiple reference points, thereby improving the accuracy of local path compensation and reducing cumulative errors.

[0041] In one embodiment, during a local reference matrix update, the control unit controls the non-frozen path island regions to continue performing mounting operations and prevents the frozen path island regions from participating in path scheduling.

[0042] In this embodiment, freezing a path island does not halt the entire placement equipment; rather, it only suspends the path execution permissions for the corresponding path island region. Specifically, during the local reference matrix update, the control unit continues to control the non-frozen path islands to perform placement actions, maintaining continuous operation of the placement unit, continuous material supply from the material supply unit 5, and normal placement by another placement module. Simultaneously, the frozen path islands are temporarily removed from the global path scheduling queue. Furthermore, the control unit establishes a path island status table, including running status, frozen status, reconstruction status, and pending recovery status. The control unit dynamically allocates placement resources based on the path island status, thereby reducing the impact of local anomalies on the overall machine cycle time. When any path island region experiences a pose deviation anomaly, this invention only freezes the path queue for the corresponding path island region and re-establishes the local reference matrix for that path island region, rather than halting the entire machine's operation. Meanwhile, the remaining non-frozen path island regions continue to perform placement actions, thereby reducing downtime caused by traditional whole-board pauses and overall recalibration, and improving the equipment's continuous production capacity. Specifically, the control unit sets the path queue flag corresponding to the frozen path island area to pause, skips the interpolation calculation of the queue during the path scheduling cycle, and keeps the path queues of other path island areas scheduled normally, thereby freezing only the area without affecting other areas.

[0043] In one specific embodiment, the PCB board is divided into "path island A (BGA area)", "path island B (high-density IC area)" and "path island C (resistor-capacitor area)". These three areas are three independent path island areas. Each path island area is independently visually calibrated and path planning is performed. When thermal drift occurs in the BGA area, only that area is frozen, while the resistor-capacitor area continues to be mounted.

[0044] In one embodiment, the control unit establishes a path island priority queue; when multiple path island regions simultaneously exhibit deviation anomalies, reference matrix reconstruction is preferentially performed on the path island regions with higher mounting accuracy levels.

[0045] In this embodiment, the control unit establishes a path island priority queue. When multiple path islands simultaneously experience deviation anomalies, the reference matrix reconstruction order is determined. Specifically, the control unit establishes priorities based on device mounting accuracy level, current path island mounting density, device package type, current production cycle time, degree of thermal deformation, and current abnormal deviation. In one specific embodiment, the priority of BGA area path islands is higher than that of ordinary resistor-capacitor areas; the priority of high-density path island areas is higher than that of low-density areas. In practical implementation, the control unit prioritizes visual recalibration, reference matrix reconstruction, and path recovery for high-priority path islands, while low-priority path islands enter a waiting reconstruction state, thereby reducing the cumulative mounting error in high-precision areas.

[0046] In one embodiment, the calibration unit 7 includes an upward-viewing camera 71 for acquiring the wafer edge contour and a calibration stage 72 for acquiring the mounting angle deviation; wherein the upward-viewing camera 71 and the calibration stage 72 correspond to the compensation update of different path island regions; the visual inspection unit 9 includes a downward-viewing camera 91 disposed above the automatic film changing assembly 52, the calibration stage 72 and the motion stage 2, wherein the downward-viewing camera 91 disposed above the automatic film changing assembly 52 and the calibration stage 72 is used to acquire wafer pose data, and the downward-viewing camera 91 disposed above the motion stage 2 is used to acquire position deviation information of the path island region.

[0047] In this embodiment, as Figure 3 As shown, the top-view camera 71 is located on one side of the calibration stage 72. The wafer pick-up unit 6 places the wafer above the top-view camera 71 to obtain the wafer edge contour. It then places the wafer on the calibration stage 72 to obtain the placement angle deviation or center offset. The placement unit 8 then controls the wafer to pick it up and place it on the motion stage 2 for die bonding in the corrected position. During this process, a bottom-view camera 91, such as an infrared camera, is located above the automatic film changing assembly 52, the calibration stage 72, and the motion stage 2. When the wafer is below the bottom-view camera 91, the wafer's position data is obtained by acquiring images. Meanwhile, the bottom-view camera 91, located above the motion stage 2, captures images of the path island area, thereby obtaining the position deviation information of the path island area.

[0048] In one embodiment, the feeding unit 5 includes a blue film gripping assembly 51 and an automatic film changing assembly 52. ​​The blue film gripping assembly 51 includes a first gripper 511, a second gripper 512, a transfer table 513, and a waste tray 514. A material rack 515 for placing wafer carrier films is provided on one side of the first gripper 511. The first gripper 511 rotates on the frame 1 and moves vertically to grip the wafer carrier films in the material rack 515 to the transfer table 513. The waste tray 514 is located between the transfer table 513 and the automatic film changing assembly 52. ​​The second gripper 512 is horizontally movably mounted on the frame for gripping the wafer carrier films on the transfer table 513. The wafer carrier film above the automatic film changing assembly 52 is placed in the waste tray 514. The automatic film changing assembly 52 includes a first moving track 521, a second moving track, a cylinder 523, and several gripping members 524. The gripping members 524 are electrically connected to the cylinder 523. The cylinder 523 drives the gripping members 524 to move closer to or further away from each other in opposite directions to grip or release the wafer carrier film, so as to switch the wafer carrier film to be mounted without stopping the machine. The first moving track 521 and the second moving track 522 are located at the bottom of the cylinder 523 and are used to move the wafer carrier film to the wafer picking position or film changing position of the wafer picking unit 6.

[0049] In this embodiment, as Figure 4 As shown, the wafer rack 515 is used to store wafer carrier films (blue films), on which multiple wafers are placed. During operation, firstly, the first gripper 511 picks up the blue film from the wafer rack 515 using vacuum suction, i.e., the first gripper 511 has multiple vacuum suction holes. Next, the first gripper 511 rotates and places the blue film on the transfer table 513. The second gripper 512 then picks up the blue film from the transfer table 513. Then, the automatic film-changing assembly 52 moves to the blue film location via the first moving track 521 and the second moving track 522. Simultaneously, the cylinder 523 is driven to open the clamping member 524 to hold the blue film. After all the wafers on the blue film have been bonded, the first moving track 521 and the second moving track 522 move the blue film to the film-changing position. Then, the cylinder 523 opens the clamp, and the second gripper 512 picks up the remaining empty blue film and places it on the waste tray 514.

[0050] In one embodiment, when a deviation anomaly occurs in the main reference module, the control unit controls the corresponding module to take over as the new main reference module and reallocates the reference relationships of each path island region.

[0051] In this embodiment, a real-time status synchronization channel is established between the first placement module 3 and the second placement module 4. This channel synchronizes the current path island number, local reference matrix, real-time coordinates of the placement head, current compensation parameters, path execution queue, wafer pick-up status, and current placement cycle time. One of the first placement module 3 and the second placement module 4 operates as the master reference module, updating the local reference matrix corresponding to the path island region in real time; the other operates as the slave reference module, performing path-following placement based on the local reference matrix. When the control unit detects that the master reference module meets the following conditions: continuous deviation exceeding limits, visual calibration failure, abnormal placement head shutdown, wafer pick-up failure, or automatic film replacement timeout, it initiates the master-slave switching process.

[0052] In one specific embodiment, the reference update permission of the path island corresponding to the current master reference module is first suspended. Then, the local reference matrix corresponding to the current path island is sent to the slave reference module. Next, the slave reference module loads the current path execution queue. Then, the slave reference module is controlled to take over as the new master reference module. Then, the master-slave reference relationship corresponding to each path island area is re-established. Finally, the mounting operation of the frozen path island areas is restored.

[0053] Furthermore, during master-slave switching, non-abnormal path islands continue to perform placement actions, thereby reducing overall machine downtime. To ensure switching continuity, after each placement cycle, the master reference module updates the currently completed placement point number, local reference matrix version number, and coordinates of the next placement point to be placed to the shared memory in real time; when the slave reference module takes over, it reads the above information from the shared memory and continues execution from the breakpoint to avoid duplicate placement or omissions.

[0054] In one embodiment, the wafer picking unit 6 is provided with a wafer picking rotating arm, and the placement unit 8 is provided with a placement rotating arm 81. The wafer picking rotating arm and the placement rotating arm 81 are each provided with a suction nozzle 611 for adsorbing wafers. Each suction nozzle 611 is connected to a vacuum tube 612. The wafer picking rotating arm is movably disposed between the automatic film changing assembly 52 and the calibration table 72, for adsorbing wafers on the wafer carrier film and placing them on the upward-viewing camera 71 and the calibration table 72 for calibration. The placement rotating arm 81 is movably disposed between the motion worktable 2 and the calibration table 72, for... The wafer on the calibration stage 72 is placed on the die bonding position on the motion stage 2; the placement unit 8 also includes a dispensing needle 82 and a glue tray 83. The dispensing needle 82 is movably disposed above the motion stage 2; the glue tray 83 is disposed on one side of the dispensing needle 82; the glue tray 83 contains silver paste; the dispensing needle 82 dips the silver paste from the glue tray 83 and dispenses it at the die bonding position to complete the die bonding; the placement rotating arm 81 and the dispensing needle 82 of the first placement module 3 and the second placement module 4 respectively perform differentiated placement angle compensation and dispensing position compensation for different path island areas.

[0055] In this embodiment, asFigure 5 As shown, the suction rod 611 on the wafer rotating arm picks up the wafer on the wafer carrier film on the automatic film changing assembly 52 and rotates it to place it above the upward-viewing camera 71 and the calibration stage 72 in sequence to complete the wafer calibration. The control unit generates wafer calibration parameters based on the detection results. Then, the mounting rotating arm 81 picks up the wafer on the calibration stage 72 and places it on the die bonding position on the motion worktable 2. Then, the dispensing needle 82 dips silver paste from the glue tray 83 and fixes it on the wafer / chip to fix the wafer on the PCB board.

[0056] Specifically, different path island regions correspond to different mounting compensation strategies. In one specific embodiment, high-density path islands employ a high-precision angle compensation mode, thermal drift path islands employ a thermal offset compensation mode, and ordinary mounting path islands employ a standard compensation mode. Then, the control unit, based on the local reference matrix corresponding to the path island, Different mounting angle compensation parameters are generated for each module. The mounting rotating arms 81 of the first mounting module 3 and the second mounting module 4 respectively call the corresponding angle compensation parameters to perform mounting. The dispensing needle 82 performs differentiated dispensing position compensation for different path islands to reduce mounting deviations caused by local thermal deformation.

[0057] Please refer to Figure 7 This invention provides a control method based on a high-precision PCB mounting equipment, comprising: S1: Establish the global mounting coordinate system for motion worktable 2; S2: Divide the PCB board into multiple path island regions; S3: Establish a local reference matrix for each path island region; S4: Set one of the first mounting module 3 and the second mounting module 4 as the main reference module; S5: The local reference matrix of the corresponding path island region is updated in real time by the main reference module; S6: Controls the path following placement from the reference module based on the corresponding local reference matrix; S7: When the pose deviation of any path island region exceeds the threshold, only the path queue of the corresponding path island region is frozen. S8: Reacquire the benchmark information of the island area along the path and reconstruct the local reference matrix; S9: During local reference matrix reconstruction, maintain continuous mounting of non-frozen path island regions; S10: After the local reference matrix is ​​updated, resume the mounting operation of the frozen path island area.

[0058] In this embodiment, a global mounting coordinate system for the motion stage 2 is first established. That is, the control unit reads the PCB board mounting data and establishes the global mounting coordinate system for the PCB board. Next, the PCB board is divided into multiple path island regions; that is, the control unit automatically generates multiple path island regions based on mounting density, device package type, thermal deformation distribution, or mounting accuracy level. Then, a local reference matrix is ​​established for each path island region; wherein, The local reference matrix includes local coordinate offset parameters, rotation compensation parameters, thermal drift compensation parameters, and scaling compensation parameters. Next, one of the first mounting module 3 and the second mounting module 4 is designated as the master reference module. The master reference module is used to update the local reference matrix corresponding to the path island region in real time. Then, the slave reference module is controlled to perform path-following mounting based on the corresponding local reference matrix. Specifically, the slave reference module calls the local reference matrix of the corresponding path island to generate a local mounting path. Then, real-time pose deviation data of the path island region is acquired. Specifically, the vision detection unit 9 acquires the wafer center offset, mounting angle offset, and edge contour offset. When the pose deviation of any path island region exceeds a threshold, only the path queue of the corresponding path island region is frozen. Meanwhile, the non-frozen path islands continue to perform mounting actions. Next, multiple reference point information of the frozen path island regions is reacquired, and the local reference matrix is ​​reconstructed. In one specific embodiment, at least the first edge reference point, the second edge reference point, and the center reference point are acquired. During the local reference matrix reconstruction, the non-frozen path island regions continue mounting, and the frozen path island regions are prevented from participating in path scheduling. Finally, after the local reference matrix is ​​updated, the mounting operation of the frozen path island area is resumed, and the control unit adds the corresponding path island back to the global path scheduling queue.

[0059] Furthermore, when the master reference module malfunctions, the control unit takes over from the slave reference module to become the new master reference module and re-establishes the master-slave reference relationships for each path island. During the master-slave switchover, non-malfunctioning path islands continue to operate, thereby reducing overall machine downtime and improving continuous placement efficiency.

[0060] In one embodiment, such as Figure 8 As shown, the rack 1 is also equipped with a display screen to display the current status of the equipment (e.g., waiting for material loading), the coordinate information of the die bonding position (e.g., the left dispensing position XY, i.e., the dispensing position of the first mounting module), and the current working mode (fully automatic or die bonding only). In addition, the display screen can be electrically connected to the control unit and used to control the start, stop, or emergency stop of the equipment to deal with unexpected situations that occur during the operation of the equipment.

[0061] In summary, this invention enables continuous operation of the equipment in complex mounting environments through independent path island control, dynamic updating of the local reference matrix, and master-slave module collaborative control. It is applicable to applications such as BGA packaging, Mini LED mounting, Micro LED mounting, high-density wafer packaging, and high-precision semiconductor mounting.

[0062] It is worth mentioning that the mounting in this application is not limited to wafers, but can also be the mounting of chips on a PCB board.

[0063] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, apparatus, article, or method that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, apparatus, article, or method. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, apparatus, article, or method that includes that element.

[0064] The above are merely preferred embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A high-precision PCB mounting device, characterized in that, include: frame; A motion worktable, mounted on the frame, is used to support the PCB board, and the motion worktable has a global mounting coordinate system. A first mounting module and a second mounting module are respectively disposed on both sides of the motion worktable; Each of the mounting modules includes: The feeding unit is used to transport the wafer carrier film; The wafer picking unit is used to pick up wafers from the wafer carrier film. The calibration unit is used to acquire the positional deviation information of the wafer; The placement unit is used to place the chip onto the corresponding position on the PCB board; The vision inspection unit is used to acquire wafer pose data and position deviation information of the path island region; The control unit is used to divide the PCB board into multiple independent path island regions; A local reference matrix is ​​established for each of the aforementioned path island regions; Either the first mounting module or the second mounting module is set as the master reference module, and the other is set as the slave reference module; The main reference module is used to update the local reference matrix of the corresponding path island region in real time. The mounting path following is performed from the reference module based on the corresponding local reference matrix; When the pose deviation of any of the path island regions exceeds a preset threshold, the control unit freezes only the path queue of the corresponding path island region and re-establishes the local reference matrix of the path island region, while keeping the other path island regions continuously mounted.

2. The high-precision PCB mounting equipment according to claim 1, characterized in that, The local reference matrix includes local coordinate origin parameters, rotation compensation parameters, thermal drift compensation parameters, and mounting scaling parameters; The control unit dynamically updates the local reference matrix based on the regional reference point information obtained by the visual detection unit.

3. The high-precision PCB mounting equipment according to claim 1, characterized in that, After the control unit is frozen in the path island area, it controls the corresponding mounting module to enter the reference reconstruction mode. The reference reconstruction mode includes: Reacquire at least three reference points within the island region of the path, and regenerate the local reference matrix based on multiple reference points.

4. The high-precision PCB mounting equipment according to claim 1, characterized in that, During local reference matrix updates, the control unit controls the non-frozen path island regions to continue performing the mounting operation. And prevent the frozen path island region from participating in path scheduling.

5. The high-precision PCB mounting equipment according to claim 1, characterized in that, The control unit establishes a path island priority queue; When multiple path island regions exhibit abnormal deviations simultaneously, the reference matrix reconstruction is prioritized for the path island regions with higher mounting accuracy.

6. The high-precision PCB mounting equipment according to claim 2, characterized in that, The feeding unit includes a blue film gripping assembly and an automatic film changing assembly. The blue film gripping assembly includes a first gripper, a second gripper, a transfer table, and a waste tray. A material rack for placing wafer carrier films is provided on one side of the first gripper. The first gripper rotates on the frame and moves vertically to pick up the wafer carrier film in the rack and transfer it to the transfer station; The waste tray is located between the transfer station and the automatic film changing assembly; The second material claw is horizontally movable on the frame and is used to pick up the wafer carrier film on the transfer table and place it into the automatic film changing assembly or place the wafer carrier film above the automatic film changing assembly into the waste tray. The automatic film changing assembly includes a first moving track, a second moving track, a cylinder, and several clamping components. The clamping components are electrically connected to the cylinder. The cylinder drives the clamping components to move closer to or further away in opposite directions to clamp or release the wafer carrier film, so as to switch the wafer carrier film to be mounted without stopping the machine. The first and second moving tracks are located at the bottom of the cylinder and are used to move the wafer carrier film to the wafer picking position or film changing position of the wafer picking unit.

7. The high-precision PCB mounting equipment according to claim 6, characterized in that, The calibration unit includes an upward-viewing camera for acquiring the wafer edge contour and a calibration stage for acquiring the mounting angle deviation. The upward-facing camera and the calibration platform respectively correspond to the compensation updates for different path island regions; The visual inspection unit includes a downward-facing camera positioned above the automatic film changing assembly, the calibration stage, and the motion stage; wherein, the downward-facing camera positioned above the automatic film changing assembly and the calibration stage is used to acquire wafer pose data, and the downward-facing camera positioned above the motion stage is used to acquire positional deviation information of the path island region.

8. The high-precision PCB mounting equipment according to claim 1, characterized in that, When the main reference module experiences a deviation anomaly, the control unit controls the corresponding module to take over as the new main reference module and reallocates the reference relationships of each path island region.

9. The high-precision PCB mounting equipment according to claim 7, characterized in that, The wafer picking unit is equipped with a wafer picking rotating arm, and the placement unit is equipped with a placement rotating arm. The wafer picking rotating arm and the placement rotating arm are respectively equipped with a suction nozzle rod for adsorbing wafers. Each of the aforementioned nozzle rods is connected to a vacuum tube; The wafer picking rotating arm is movably disposed between the automatic film changing assembly and the calibration table, and is used to adsorb the wafer on the wafer carrier film and place it on the upward-viewing camera and the calibration table for calibration; The mounting rotating arm is movably disposed between the motion stage and the calibration stage, and is used to place the wafer on the calibration stage onto the die bonding position on the motion stage. The mounting unit also includes a dispensing needle and a glue tray, with the dispensing needle movably positioned above the moving worktable. The glue tray is located on one side of the dispensing needle; The adhesive tray contains silver paste; Silver paste is picked up from the adhesive tray using a dispensing needle and applied to the die bonding location to complete the die bonding process. The mounting rotating arms of the first mounting module and the second mounting module and the dispensing needle respectively perform differentiated angle compensation and dispensing position compensation for different path island areas.

10. A control method for a high-precision PCB mounting equipment according to any one of claims 1-9, characterized in that, include: S1: Establish the global mounting coordinate system for the motion worktable; S2: Divide the PCB board into multiple path island regions; S3: Establish a local reference matrix for each path island region; S4: Set one of the first mounting module and the second mounting module as the main reference module; S5: The local reference matrix of the corresponding path island region is updated in real time by the main reference module; S6: Controls the path following placement from the reference module based on the corresponding local reference matrix; S7: When the pose deviation of any path island region exceeds the threshold, only the path queue of the corresponding path island region is frozen. S8: Reacquire the benchmark information of the island area along the path and reconstruct the local reference matrix; S9: During local reference matrix reconstruction, maintain continuous mounting of non-frozen path island regions; S10: After the local reference matrix is ​​updated, resume the mounting operation of the frozen path island area.

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