Construction Analysis Of Domestic Flip Chip For Aerospace

With the development of our country’s aerospace electronic system towards multi-function,miniaturization and lightweight,flip chips packaging have been widely used in aerospace engineering,and become the key technology across the two fields of spacecraft platform technology and payload technology.Therefore,it is urgent to carry out construction analysis on flip chips,so as to clarify the relationship between chip structure,materials,process and failure mode,and failure mechanism,and determine whether the chip has failure risk and application reliability defects.However,the current construction analysis standards are mainly for conventional packaging chips,so it is impossible to evaluate flip chip comprehensively,which affects the reliability level of aerospace models.In this paper,flip chips are taken as the research objects.Systematic research is carried out on theoretical basis,technical methods,guiding specifications and so on.The specific structure of flip chip package is introduced.We focus on the difference between the flip chip packages and the conventional package,and establish a construction analysis process.The finite element model was used to carry out numerical simulation research on the external lead of flip chip BGA and CGA under the temperature cycle,and the stress distribution law of the external lead was more close to the edge,the greater the stress of the external lead.According to the result of numerical simulation,the temperature cycling Coffin-Manson fatigue model to predict the BGA and CGA encapsulation external lead can withstand temperature cycles,are around 1500 times.Mechanical vibration under the CGA external lead the welding column by outer deformation stress is the largest,column can withstand the mechanical vibration welding time of about 29 minutes.On this basis,the system scheme of construction analysis is designed,including the identification of construction analysis unit and failure mechanism elements,the selection and improvement of criteria for construction analysis elements.Based on the experimental scheme,the structure,materials,process conditions of flip chip packages and their relationship with chip failure mechanism were analyzed.We found that the corrosion risk existed in the domestic flip chip package and the quality of hole metallization alignment was poor.Through the research of this paper,a construction analysis guide is established,which provides a good technical support for the development and engineering application evaluation of domestic Flip chips.It has important guiding significance for the domestically controllable and reliable evaluation of aerospace flip chips.