The Analysis Of Missile Borne Electronic Packaging Structure Under Thermal-Mechanical Coupling

With the rapid development of aerospace technology,working conditions of the electronic devices in missile becomes more complex.It is the key to ensure the overall stability and reliability of electronic products and improve the performance of electronic devices under harsh working conditions.The high acceleration screening test can expose the weak-points of the structure and acquire high reliability of the products.Therefore,it is essential to study dynamic characteristics and mechanism of heat transfer and variation responses of strain/stress in electronic devices and obtain the effect of test parameters on it.These research work can provide theoretical support and guidance to propose the scheme of the high acceleration screening test.In this paper,based on the theory of heat transfer and mechanics,the electronic devices in the cabin is regarded as the research subject and thermal characteristics of the electronic devices are studied,then effects of operating parameters on devices are obtained.The main research work is described as follows:(1)When carrying out the thermal-structure coupled analysis,Fourier law and thermal boundary condition are adopted and temperature distribution is gained.Then the temperature results couples with structure analysis and dynamic characteristics of stress/strain in the device is obtained,thus weak point of the electronic device is determined.Compared with the literature results,the effectiveness of the thermal-structure coupled method on thermal behavior of circuit board is demonstrated.A typical electronic packaging device is selected as the research object,and the results of simulation and comparison with the classical literature verify the rationality of its technical route analysis under the condition of heat-structure coupling.(2)The finite element analysis model of a electronic devices is established in Workbench to conduct thermal-structure coupled analysis.The model is verified by experimental data and transient responses of temperature and strain/stress are investigated.Besides,heat generating by chip is considered and studied in detail.(3)The temperature distribution and variation responses of strain/stress are investigated during temperature changing and effects of loading rate,dwell time and change range on thermal behavior of the device are obtained.The modeling results show the weak point of the structure and fatigue life of the device is calculated based on Coffin-Manson equation.(4)A finite model of certain cabin is built based on a sample and the thermal boundary condition is simplified by experimental data of surface temperature of the cabin.Then,on the basis of thermal-structure analysis,transient responses of temperature and train/stress are studied.The research results of this paper could provide guidance to propose the scheme of the high-acceleration screening test.