Market Application Background
Components on a PCB (such as electrolytic capacitors, through-hole cement resistors, chokes, etc.) are subject to mechanical stress and vibration during transmission and installation, which can lead to problems such as loosening of components, broken pins, or detachment.
Traditional connection methods such as welding, bolting, or riveting are insufficient to ensure a secure connection of components on a PCB. Therefore, a dispensing reinforcement process has been introduced. By applying adhesive to the bottom or side of the component, the adhesive fills the gaps between the component and the PCB surface, thereby stabilizing the bond, suppressing component movement, preventing pin breakage or detachment, avoiding short circuits and other abnormalities, ensuring normal equipment operation, and extending service life.
Limitations of traditional PCB component adhesive reinforcement solutions:
Currently, conventional manual and ordinary dispensing machines on the market cannot guarantee stable output during mass production, and cannot meet the needs of PCBs for rapid and precise dispensing reinforcement of components, resulting in unreliable output and quality.
Inaccurate control of the amount of adhesive applied manually can lead to poor reinforcement of components or inadequate heat dissipation.
Conventional dispensing machines suffer from poor operational flexibility and require frequent fixture changes when handling products of different specifications, impacting production efficiency. Furthermore, the varied shapes of components on PCBs make it difficult for conventional dispensing machines to adjust the dispensing posture of the modules to meet the dispensing needs of bottom and side rotation, resulting in poor reinforcement effects.
Positive motion technology solutions:
In response to market demand, Zhengdong has launched a PCB synchronous following vision dispensing solution based on a machine vision motion control all-in-one machine, realizing the integrated integration of vision and motion control.
It can be applied to the bonding and reinforcement of components on PCBs of different specifications. Through XYZ+R axis linkage and belt control, it achieves continuous, rotating dispensing operation. The built-in vision positioning function automatically identifies the position and orientation of PCB components on the conveyor belt and adjusts the working posture of the dispensing head in real time to ensure that the glue is evenly and accurately covered on the areas that need reinforcement.
The solution supports high-speed PSO, PWM, path planning, multi-axis synchronous following and other functions to ensure smooth dispensing trajectory, stable glue drop output and various dispensing processes. Users can quickly adjust dispensing parameters according to actual production needs, simplify the workflow, improve the production speed and product quality of the entire line and reduce production costs.
01. Application of Machine Vision Motion Control All-in-One Machine in PCB Follow-up Dispensing
Design of a synchronous visual dispensing solution for positive motion technology
20DI: Connects to origin, limit, and other sensors, as well as switch signals, encoders, etc.
20DO: High-speed output port for connecting to the hard trigger input of industrial cameras and dispensing valves;
EtherCAT interface: Connects to the EtherCAT bus driver to control the movement of the X, Y, Z, and R axes;
4-channel single-ended pulse output: connected to a pulse driver to control the conveyor belt;
RS232 communication interface: connected to the light source controller;
EtherNET interface: Gigabit Ethernet port, for connecting area scan cameras that support the Gigabit protocol to achieve visual positioning applications.
Motion control and machine vision implementation process
(1) Machine vision
The main function used is template matching. It visually identifies moving targets within the shooting range on the conveyor belt. This can be achieved through pre-set features such as shape, size, and mark points. Finally, the movement trajectory of the target is obtained, which facilitates the product's arrival at the processing area, where the dispensing head performs dispensing processing on each product individually.
(2) Motion control
By calculating and analyzing the encoder position, monitoring the product's running speed on the conveyor belt in real time, calculating coordinate offset, and dynamically adjusting the position of the dispensing head, the dispensing position can be determined even when the product moves.
The dispensing process is then precisely controlled via PSO and PWM functions. PSO controls the dispensing interval output cycle, while PWM adjusts the glue flow rate to ensure no glue accumulation at corners, guaranteeing uniform dispensing. Finally, through position synchronization and following, the system continuously adjusts the dispensing head position to synchronize with the real-time trajectory of the products on the conveyor belt. This maintains high-quality dispensing even with variations in production line speed.
Synchronous follow-up vision dispensing process
Core advantages of the solution
Visual positioning: The position and angle of PCB components on the production line are located in real time using a camera, and the machine can automatically correct the processing trajectory even when the components are placed arbitrarily.
Needle rotation: Through a four-axis interpolation motion control algorithm, the needle automatically tilts and rotates to match the appropriate dispensing angle, effectively avoiding interference from components on the PCB and ensuring a smooth dispensing process;
Intelligent glue discharge processing: No processing interruption is required. When no material is detected, the equipment automatically performs glue discharge. When material is available, normal operation resumes, ensuring continuous production and reducing downtime.
Precise weighing: By eliminating weighing points and simulating the glue dispensing process at specific points, the glue weight is accurately calculated, ensuring consistent glue dispensing for each product and improving product quality;
Matching production line speed: Automatically adjusts the belt speed according to the dispensing speed, enabling multi-position, high-degree-of-freedom dispensing operations and flexibly adapting to production rhythm;
Intelligent belt start/stop processing: The belt stops before the needle reaches the limit, and restarts only after processing is complete, preventing equipment collisions;
Belt angle correction: calibrates the belt placement angle deviation, automatically compensates for XYZ position, achieves synchronous following, and ensures accurate dispensing position.
Solution Hardware Configuration
02. VPLC7 Series Machine Vision and Motion Control Integrated Machine
This x86-based EtherCAT bus vision motion controller is cross-platform deployable, supports offline operation, and features rich built-in vision and motion control functions, significantly simplifying the configuration process. Its fast internal data exchange speed significantly reduces time and cost investment, improving project implementation efficiency.
The installation and disassembly process is convenient, the footprint is small, and it can be seamlessly integrated with other control unit components (such as servo drives, sensors, encoders, control valves, etc.) and MES systems. It provides an integrated machine vision + motion control solution with a real-time soft controller/soft PLC in an all-in-one open IPC form factor.
Optional 6-64 axis motion control (pulse + EtherCAT bus), with EtherCAT cycle time as fast as 250µs;
Supports multiple communication interfaces for easy integration into existing systems; equipped with MotionRT7, kernel-level interaction, and instruction calls are as fast as microseconds, supporting third-party vision software;
Multi-core parallel computing enables efficient processing of core tasks in automated equipment such as motion control and machine vision;
It features 20 onboard general-purpose inputs (10 of which are high-speed inputs) and 20 high-speed outputs;
It supports EtherCAT redundancy, solves single-point failure downtime, automatically diagnoses and continues to run, enhances system reliability, and simplifies maintenance.
03. Provides easy-to-use visual dispensing development and debugging software.
Positive Motion Technology continuously deepens and expands the application of the VPLC series vision motion control all-in-one machine in the dispensing industry, providing users with simple and easy-to-use vision dispensing development and debugging software.
The software combines rich vision and motion control functions, and can build vision dispensing project programs with only simple parameter settings, which can significantly shorten the project development cycle, reduce development costs, and meet the different process requirements of different products.
Suitable for various dispensing applications such as dot, line, potting, filling, underfill, encapsulation, and spraying.
Visual dispensing development and debugging software functions
Fully functional
It supports dispensing trajectory dot, line, circle, arc, continuous line segment, array, pre-opening and closing of dispensing, manual teaching, camera teaching, and dispensing process functions.
Machine vision correction
The product can be placed at any position and angle, and the vision system can automatically recognize and complete operations such as dispensing and spraying glue.
User-friendly interface with comprehensive functions
The debugging and programming operations are simple and convenient, and support teaching and jogging motion on visual images.
