Research Of The Joint Forming Control Method And System For Hot Bar Bonder

In hot bar bonder,the parameters of temperature and welding time are controlled with high precision,and it can achieve repeatable high quality production.It is widely used in electronic device connection.Traditional hot bar bonder equipment with pneumatic system causes solder crushing,wire scattering and overlapping.With the higher request to the connection reliability of electronic device in the electron industry,the problem of become prominent.It is significant to analyze the hot bar bonding process intensively and study the joint forming control method in order to improve the quality of welding joints.In this paper,temperature-force-disaplacement coordination control method has been studied combined with temperature control,high-precision electrode force control and displacement control.The control of solder melting and forming during the welding process has been realized,so as to effectively improve the quality of hot bar bonding.The solder joint forming control system of hot bar bonder was divided into power supply control system and servo motor control system according to the control object.This paper has designed a control system of hot bar bonder inverter based on dsPIC33FJ64GS610 and established the hardware circuit.According to the force control requirements of the hot bar bonder,the pressure feedback circuit and encoder feedback was designed to ensure the correctness and reliability of pressure and displacement detection,and indicate the relation between pressure and the displacement.As for the software design,the control program of controller was designed around dsPIC33FJ64GS610,and this arcticle forced on the design and research of temperature,pressure and displacement coordination control program.A fliendly human machine interface based on color touch screen realized the functions of parameter setting and real-time welding force display and force curve display.Then the experimental platform for bot bar bonder was built.The force control system of hot bar bonder was debugged,and experiment was carried out,and the temperature,pressure and displacement control program was adjusted according to the control effect.As the result shows,the control system was stable and reliable,and has acquired higher precision and rapider response.Its human-computer interface was humanized.The welding process was more controllable,and the solder joint forming were more beautiful,stable and reliable.