| The electrical connectors are used in the electronic devices extensively to transmit electronic signals nowadays. In the information age,the reliability requirements of electric connector is becoming more and more important. So it’s necessary to do research on the failure phenomenon of electric connector. This paper takes USB3.0 electrical connector as the object,the electric heat coupling effect and contact failure mechanism are analyzed to improve the reliability of electrical connector.The main contents of this paper include:At first, the multi-physics coupling phenomena is analyzed to establish the incentive model of electromagnetic field and heat transfer model based onthe finite element method. In order to describes the influence of the electromagnetic field on the transient and steady-state temperature field, the nonlinear coupling method is taken to get relatively accurate mathematical model for the electro-thermal coupling phenomena. The electrical contact failure mechanism of electrical connector is analyzed based on the basic principle of electrical contact. The electro-thermal coupling law is used in analyzing the contact resistance variation and the temperature rise in the process of the electric contact failure.On the basis of the electro-thermal coupling effects, the changes of temperature lead to the thermal fatigue failure in solder joints is analyzed. According to the test standard of electrical connector, an accelerated simulation is designed to test the life of electrical connector. In accordance with the failure process, four-electrode method is used to test the change of electrical conductivity of solder joints. The resistance mathematical model in solder joints is established according to the electric contact theory and solder joint failure mechanism.In this paper a 3D structure model of USB3.0 electrical connector is established and simulated in software. Based on the Newton-Raphson iterative algorithm thermo electric, the distribution of temperature and electrical loss is calculated in software. The influence on the temperature field and the electrical loss is analyzed by changing the size of excitation current. The hot replacement cycle of electric connector is concluded by recording transient temperature changes.For solder fatigue failure material properties and its contact area changes in electrical connector, their simulations and analysis are respective. By comparing electrical loss and temperature changes in the process of failure of electrical connectors, the effect of solder material properties and contact area changes on electrical connectors is studied to analyze the change of the contact resistance. |
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