Research On The Failure Mechanism And Process Improvement Of Integrated Circuits In Strong Shock Environment

The development of integrated circuits is changing with each passing day,and the integration level is getting higher and higher.As the core device inside the electronic system,the application environment is becoming more and more severe.In the face of the continuous modernization of weapons and equipment,the working environment faced by the integrated circuits in electromagnetic guns,electromagnetic pulse bombs and smart ammunition is extreme and complex.This makes the integrated circuit more susceptible to interference from the external strong impact environment,resulting in functional errors of the internal electronic system,and even damage to components.Therefore,it is of great significance to study the failure mechanism of integrated circuits under strong shock environment and to propose corresponding process improvement schemes.This paper takes the strong electromagnetic and strong mechanical shock environment in the electromagnetic gun bore as the specific research environment.In-depth research is carried out on the failure mechanism and process improvement of integrated circuits in this environment.The main research contents are as follows:(1)Based on the research on the launch principle and development status of the electromagnetic gun,the internal environment of the electromagnetic rail gun is selected as the research object of the strong impact environment.A mathematical model of the strong electromagnetic shock and strong mechanical shock environment in the rail gun bore is established.Through COMSOL finite element simulation,the railgun firing process is simulated.The spatial distribution law of the strong electromagnetic field in the bore and the dynamic response of the launch component are solved.Based on the theoretical model and simulation results,the stress distribution of the strong electromagnetic shock environment and the strong mechanical shock environment in the bore is analyzed.(2)The failure mode of integrated circuits under strong electromagnetic/mechanical shock stress is analyzed,and the failure mechanism is further studied.Establish a physical model of integrated circuit failure in strong electromagnetic shock environment and strong mechanical shock environment.The research results show that the strong electromagnetic shock stress is coupled into the integrated circuit through the metal interconnection system,causing the current density,electric field strength and temperature in the MOS structure to change drastically,resulting in device failure.Strong mechanical shock stress mainly acts on the integrated circuit packaging system.Mechanical stress exceeding the strength of the device results in failure of the interconnected system.The transient simulation of integrated circuit strong electromagnetic shock and the mechanical simulation of strong mechanical shock are established respectively.The characteristics of current density,electric field strength and temperature distribution in integrated circuit MOS structure under strong electromagnetic shock stress are studied.And the equivalent effect and equivalent strain of the integrated circuit under the multi-angle strong mechanical shock stress.Through the analysis of the simulation results,the further verification of the failure mechanism of the integrated circuit in the strong impact environment is realized.(3)In this paper,the reliability experiment of integrated circuit strong electromagnetic shock environment is designed.Equivalent injection experiments,irradiation experiments and strong electromagnetic shock environment simulation experiments were carried out for common MCU chips and military JQV300 respectively.The experimental results show that the integrated circuit will have internal soft failure under strong electromagnetic shock environment,and will fail completely with the enhancement of electromagnetic environment.Design the Macchett hammering experiment of strong mechanical shock of integrated circuit.It was found that the cracking,chipping or lead solder joints of the integrated circuit will appear in the environment of strong mechanical shock.Finally,according to the study of the failure mechanism of the integrated circuit in the strong impact environment,the improvement direction of the wire bonding process is determined,and the optimization scheme of the process is designed.On the basis of optimizing the integrated circuit wire bonding process,bonding materials and bonding methods.The effects of different process parameters on the quality of wire bonding were analyzed through strong impact wire bonding experiments.And the optimal parameter values of the main bonding parameters in the strong impact environment are determined.This paper aims to achieve the increase in integrated circuit reliability as much as possible.