Research On Torque Control Technology Of Downward Mechanism In Integrated Circuit Turret Test Handler

Turret test handler is a general kind of integrated circuit test handlers for final testing.It can complete the printing,image detection and electrical performance testing of the IC,then classification and packaging IC into the product according to the result of test.With the rapid development of Chin a's SIC packaging and testing industry,the large scale IC packaging enterprises improve the operation requirements of turret test handler,especially improve the operation standard of the stable contact force between the IC and the test reed when the downward mechanism is running at high speed.In this paper,the torque control technology of downward mechanism in turret is studied.In this paper,the basic structure of the permanent magnet synchronous motor and the mathematical models in each coordinate system are analyzed.Through the introduction and comparative analysis of several main control strategies of PMSM,the direct torque control strategy,which can meet the needs of enterprises,is selected and introduced in detail.Aiming at the inherent defect of excessive flux ripple and torque ripple when the traditional DTC system runs,the DTC based on Space Vector Pulse Width Modulation is adopted in the downward mechanism.Then use the Matlab/Simulink tool for simulation of the control system,the simulation results fully demonstrate the effectiveness of the SVM-DTC strategy and the feasibility of the strategy applied in the downward mechanism.Based on the analysis of simulation,it completes the design of the control system of turret downward mechanism and realizes downward motor torque control,when the control circuit which adopts the high performance digital signal processor TMS320F28335 as the core,combines with intelligent power module.By comparing current and voltage measurement results of the traditional DTC system and SVM-DTC system in the contrast experiment,confirmed the conclusion SVM-DTC better control strategy,the simulation results were consistent with earlier.This will be a base to study in the future for the turret downward mechanism.