Study On The Electrothermal-mechanical Coupling Of Microwave Passive Structures Using Time-domain Differential Metho

With the continuous improvement of the integration of integrated circuits and the complexity of interconnection structures,the reliability problems of modern electronic devices are becoming increasingly prominent.Especially in the environment of high-power electromagnetic pulse,when the electric field or voltage exceeds the breakdown threshold of dielectric or interconnects,it can easily lead to electric breakdown,thermal breakdown and even deformation.Therefore,it is of great practical significance to use numerical methods to simulate the electro-thermo-mechanical characteristics of electronic devices.In this paper,firstly,the spectral-element time-domain method is used to simulate and analyze the electromagnetic-thermal coupling of nonlinear conductivity dielectric model.SETD has the characteristics of high precision and flexible modeling.Then,the electro-thermo-mechanical characteristics of multilayer interconnect model and microstrip filter are analyzed by using finite-difference time-domain method.FDTD has the advantages of high computational efficiency and wide application.The main work of this paper is divided into two parts:In the first part,the electromagnetic-thermal simulation analysis of nonlinear conductivity dielectric model under high power pulse is carried out based on the SETD method.Firstly,the basic theory of heat transfer is introduced,and the heat conduction equation based on the SETD method is established.Then the Maxwell equation is coupled with the heat conduction equation,and the nonlinear characteristics of dielectric materials under high-power microwave pulse radiation are introduced.The example is given to verify the accuracy of SETD method in analyzing this problem.Finally,the linear and nonlinear dielectric models filled in the dielectric waveguide are compared and simulated,and the transient electrothermal effect of the nonlinear conductivity dielectric model under different conditions is analyzed.In the second part,the electro-thermo-mechanical characteristics of multilayer interconnect structures under electrostatic pulses are studied based on the FDTD method.Firstly,a numerical algorithm for solving the dynamic equation by using the FDTD method is proposed,which is coupled with the heat conduction equation.Then,the interconnect structures of 90-nm and 65-nm are modeled.Considering the nonlinear characteristics of the thermal conductivity and conductivity of materials change with temperature,the transient thermal response and stress response of high-density interconnect structures with different processes under electrostatic pulse are studied.This provides a necessary research technical means for designing a reliable circuit system and the damage of devices caused by high power rate pulses,which is of great practical significance.