The Investigation Of 2-DOF High-speed And High-precision Positioning System For IC Packaging

In order to develop a high speed and high precision positioning table for ICpackaging, this dissertation deals with the key issues relevant to mechanical design,dynamic modeling and control algorithm by means of dynamic design theory, finiteelement method and mechanical dynamics. As a result, a prototype machine of XYtable has been developed. The following creative works have been completed. Combining finite element method with the mechanical system dynamicsimulation method, a voice coil actuator direct-drive high speed and highprecision XY table patented has been developed. A new flexible decouplingmechanism is proposed to use in the table. So the driving element can bemounted on the base and the moving inertia has been reduced. Meanwhile, thetable is of conventional XY precision table kinematics decoupling characteristic. The finite element method is used in analyzing the static characteristics anddynamic characteristic of the XY table. The performance of the XY tablesubjected to different load has been studied and the natural frequency and modalshapes of the XY table have been obtained. Based on the results, the dynamicstructural design has been implemented. Considering the precision positioning table as lumped mass spring system, thedynamic model of X axial table and Y axial table has been developedrespectively. The analytic solution of displacement step responses anddisplacement impulse responses of the X axial table and Y axial table have beengiven by use of Laplace transform method. And the analytic solution of velocitystep responses and velocity impulse responses of the X axial table and Y axialtable have also been given. The dynamic model of the linear voice coil actuator is formulated, the transferfunction based on velocity PID controller of the voice coil actuator has beenpresented, and the parameters of the controller have been designed. The voicecoil actuator model together with the dynamic model of the mechanical systemallows the transfer function of the system as a whole to be developed. Thetransfer function based on displacement PID controller of the electromechanicalcoupling control system has been proposed. The above outcomes have been used for the development of a prototype machineof XY table. The XY table with high positioning accuracy and high dynamicperformance also can reach very high speed and acceleration. The prototypemachine has been checked and accepted by the expert committee of The NationalHigh Technology Research and Development Program of China (863 Program).