Research On Friction Analysis And Compensation For The High-Speed & High-Accuracy IC Packaging Platform

As ICs continue to be more sophisticated and minimum, the feature sizes keep shrinking, and the interval between inputs/outputs becomes more and more closer. The accuracy of micro-electronics packaging has become more higher than ever. Experimens results shows that nonlinear friction is one of the inherent nonlinearities which cause the stick-slip motion at extremely low velocity or at velocity reversal in high-speed and high-accuracy platform. The stick-slip motion would limit the precise position control and velocity tracking performance in IC packaging equipment. Now, although many well-rounded friction models describe presliding behaviors well, the compensation based on these models requires accurate velocity information, which is almost submerged by noise information at extremely low velocity or at velocity reversal. So these models are difficult to implement in practical engineering. To this problem, the thesis presents an expression of zero velocity interval on the basis of the characteristics of friction at velocity reversal, and proposes a simple and effective model of friction compensation which is not based on accurate velocity information but on the zero velocity interval. Simulation results show that the precise position control and velocity tracking performance can be improved effectively at extremely low velocity or at velocity reversal.