Design Of A Linear Voice-coil Motor For Led Die Bonding Application

LED die bond machine belongs to an important part of packaging equipment in theprocess of the LED production. Its mission is to fix LED die isolated from the waferdisk by the arm system into the corresponding bearing material by glue. The kinematicaccuracy of vertical direction for the arm system is the key factor for the quality of diebonding, which affects the performance of the whole machine. The existing arm systemof the LED die bonder mostly used rotating servomotor to drive the Belt Transmissionand Cam Mechanism for implementing the motion of Z-axis, which has a bad kinematicaccuracy, complex mechanical structure and high manufacturing cost. Based on the anal-ysis of the structure of bond head system, the improvement scheme of the drive modewith VCM has been proposed and designed.Firstly, through the analysis of basic theory of electromagnetic field, the thesis usesfinite element method to do the simulation. To get the electromagnetic thrust, dynamicmodeling and calculation are carried out for the bond head system. The design index isproposed combining with technological requirements of die bond. The thesis introducesthe design process of the permanent magnet VCM concretely, including quantitative cal-culation, size optimization, material selection, volume calculation of permanent magnetand the design of voice coil etc. The model of VCM has been designed and simulated byusing Asoft Maxwell 12. Then, the prototype is designed. And the PI controller for thespeed loop and PID controller for position loop are chosen for the experiments researchand motor performance test.Secondly, through the mathematical modeling of the voice coil motor, the expres-sion of the electromagnetic force can be gotten. The constrained nonlinear optimizationalgorithm and the differential evolution algorithm for optimization iteration are taken tooptimize the key size of VCM.The thesis performs a lot of simulations and experiments to certify the effectivenessof the design proposal. It is shown that, through the mathematical modeling of the op-timized design of VCM, the production cost can be reduced and motor performance isgreatly improved.