Structural Design And Motion Control Research Of High Frequency Wire Bonding System

The integrated circuit industry is an important pillar of technological progress and economic development,yet chip packaging is a key link in the integrated circuit industry.As chips move towards higher levels of integration,the size of the chip package is becoming smaller and smaller.In order to achieve high efficiency and quality in packaging,wire bonding systems must be capable of high frequency reciprocation,high acceleration and high accuracy positioning,however these can lead to vibrations that inevitably affect the positioning time and positioning accuracy of the system.To address this problem,this thesis takes the wire bonding system as the object of research,starting from the mechanical structure design and motion control,in order to realize the system at high speed,high acceleration,high-frequency reciprocation with the ability to achieve high-precision positioning as the goal of the following research:Firstly,in order to make the wire bonding system have high acceleration and high speed motion capability,a new system structure was designed based on the system force and motion analysis.The wire bonding system uses a special rotating form,driven by an oscillating voice coil motor,which reduces the load on the system and helps to improve its response time.The key parameters for the motor selection were derived according to the high acceleration requirements,while a special structure was used to connect the motor rotor and motor load.The centre of gravity is positioned at the centre of rotation of the system,which helps to reduce the inertia of the system and stabilise the impact forces during the bonding movement.Secondly,in order to make the bonding system have the basic motion control ability,build the model of control system.Firstly,the mathematical model of the voice coil motor is established according to the principle and structure of the voice coil motor system,the frequency domain response of the voice coil motor system is analysed,and the accurate transfer function of the system is derived based on the least squares method of system identification.Secondly,a three-closed-loop feedback control system is established based on the transfer function,and a feed-forward compensation and fuzzy PID controller is designed to reduce the overshoot of the system.Finally,in order to improve the robustness and immunity of the system,it is proposed to combine fuzzy theory and neural network to design a fuzzy neural network controller,and the controller is proved to be effective through simulation.Then,in order to reduce the problem of excitation system residual vibration at the end of the high frequency point movement of the wire bonding system leading to long rectification time.Based on the typical motion trajectory method,an asymmetric S-curve velocity planning is proposed,which not only ensures the bonding system velocity but also reduces the positioning time and residual vibration of the system at the end of the system motion.Finally,a prototype of the high frequency wire bonding system was built and a control system was constructed.The ability of the wire bonding system to be precisely positioned at high speeds and accelerations was demonstrated by vibration tests,motion performance tests and impact force tests.