The Motion Control Research Of High-precision Positioning Platform For IC Packaging

Ultra precision X-Y 2-D motion platform is one of the key components in IC packaging equipment, while the traditional motion platform driven by the servo motor and ball screw is difficult to achieve the micron-grade location accuracy. The feeding way driven by linear motor directly cancelled transmission links, which can overcome the faults caused by the converting links,so it can improve the accuracy and efficiency of IC packaging equipment, but it will become more difficult to control for servo-system.The target of this paper is to develop the high-speed and high-acceleration positioning platform which driven by linear motor. And based on the 2-D high precision positioning platform, the control strategy and method be studied which can improve the velocity and precision of the platform. And the prototype of X-Y positioning precision platform be build.In this paper, the research achievements of IC packaging platform at home and abroad, including driving-model and sports organization form and dynamic modeling and control strategy are analyzed firstly. According to the proposed design index, choose needed hardware for IC packaging platform, and design its general structure of the control system. Discuss the characteristics and working principle of linear motor, and construct the mathematical drive model of linear motor, then let positioning platform of X axis be equivalent to the concentration of quality system, and establish its dynamic model. Finally the mechanical model of the system be established, which is a necessity for the design of controller. Based on mechanical model and PID control strategy, design the tri-loop controller with current loop, speed loop, position loop. In order to enhance the following characteristics of the platform, according to the principle of composite control, designed the controller with velocity feed-forward and acceleration feed-forward, and the results of controller simulation show that the controller can improve the precision of the system significantly.Finally, in order to get the optimal parameter, the parameter of actual system be set, based on the controller designed before. Using the optimal parameters in the system to test, the test shows that system has good performance with short setting time, high precision, fast dynamic response and big acceleration, which satisfied to the index.