Research On ESD Protection Method Based On Slot Optimization And TVS Tube Parasitic Parameter Compensation

With the gradual complication of power electronic devices, ESD (Electro-static discharge) problems of electronic devices are becoming more serious, which has become a serious threat to electronic equipment and system. ESD has the characteristics of high potential, strong electric field and instant large current. The rise time of ESD current waveform can be less than 1 ns, so it will cause large current transient rate of change in a short time. Due to the diversity of the jamming mode and the limitations of crafts design of ESD, it is difficult for a single ESD protection method to solve the electrostatic problems of electronic equipment. In view of the above questions, this thesis carries out the research on electrostatic discharge protection methods based on apertures optimization and parasitic parameters of TVS tube compensation. The main work is as follows:1. Human body model and body metal model are introduced and the high frequency circuit model of the ESD generator is constructed, the parasitic parameters of the discharge circuit are extracted and three mathematical models of discharge current are studied, including four exponential function model, Gaussian function model and double exponential function model. In addition, the high frequency circuit model of the ESD generator is validated.2. The influence of apertures leakage is analyzed based on the theory of waveguide. Furthermore, the influence of apertures on electromagnetic shielding effectiveness and the interference mechanism of apertures grounding line are studied.The ideal enclosure shield model and the enclosure shield model with apertures are built based on Matlab/Simulink. Through the study on the simulation of the above circuit models, the optimization design method of apertures is put forward.3. The ESD protection mechanism of TVS tube is studied and the internal impedance of TVS tube is extracted based on the scattering parameter method.Through establishing the high frequency parasitic parameter model of TVS tube, the high frequency parasitic parameters of TVS tube are extracted. By studying the influence of high frequency parasitic parameters on the characteristics of TVS tube,the compensation method of parameter optimization of TVS tube is put forward, and the compensation method is verified by experiment.The results of theoretical analysis and experiments show that the ESD issues in complicated electrical equipment can be resolved by applying the methods proposed in this thesis. On the basis of the above research on electrostatic discharge protection methods, two engineering application of ESD immunity problems are solved, which includes intelligent meter and pelvic cavity instrument. This result proves the practicability and value of the ESD protection method studied in this paper.