Reliability Modeling And Library Building Of RF Microsystem Interconnection

With the update and iteration of interconnection technology,RF electronic devices are developing rapidly towards high-performance,low-cost,high-integration and lowloss three-dimensional integrated(3D)microsystems,more advanced packaging and interconnection methods have been introduced,such as Ball Grid Array(BGA),Redistribution Layers(RDL),Through Silicon Via(TSV),etc.They can greatly reduce the package size,power consumption,device signal delay and the mismatch of RF transmission circuits.At the same time,due to the characteristics of miniaturization and high-density integration of RF microsystems,the heat per unit area of the structure is high,resulting in the interconnect structure in the package being subjected to greater thermal stress,which is easy to fail in complex working environments.Among them,the temperature and vibration environment have the most significant impact on the reliability life of the device.To this end,for different Fanout packaging models combined by BGA and RDL interconnect structures in RF microsystems,this thesis conducts reliability modeling and simulation research under the conditions of temperature shock and random vibration,the predicted life and reliability experimental results are compared and analyzed.In addition,it also builds model library and develops RF microsystem interconnect reliability design software.The specific work includes:(1)Taking the interconnection structure of the Fanout package model as the research object,the parametric modeling and solution are carried out in the finite element software.Under the conditions of temperature shock and random vibration load,the position of the dangerous solder ball is located at the outermost corner of the array through thermal stress analysis and modal analysis,and the fatigue life of the interconnection structure is predicted by Darveaux life model and Steinberg life model respectively.(2)the influence of the number,material and diameter of BGA solder ball arrays on the reliability of the Fanout model is studied.The simulation results show that the larger the diameter of BGAs,the longer the reliability life of the interconnect structure,The thermal fatigue resistance and vibration resistance of the lead-free solder SAC305 are better than those of the tin-lead solder Sn63Pb37,while the number of BGAs has different effects on the model under these two loading conditions;In addition,different power heat sources were applied to the silicon base inside the package by simulating the heat generation of the chip,and it was found that the thermal fatigue life of the BGA increased first and then decreased within a certain power range.(3)Based on the above temperature shock reliability analysis method,the thermal fatigue life prediction of a Fanout model that simulates the function of components was carried out,and studied the influence of the UBM diameter of the solder balls on the BGA life.The reliability simulation model is processed and manufactured,the failure mechanism research and reliability test are carried out,and the reliability data of the interconnection is obtained,which is compared and analyzed with the simulation data.The results show that both have the same trend in the BGA diameter range [150,300],which proves the accuracy of the model,but the accuracy needs to be improved.(4)Established an interconnect reliability simulation and modeling environment for RF microsystems,realized the modeling and simulation analysis of TSV,RDL and BGA interconnect structures and their combined packaging models;Multi-type models are created,and a reliability model library is formed in the software,and the configuration information is modified by parameterization to achieve the purpose of efficient simulation and analysis.The research results of this topic will help to improve the product life design.