Fatigue life prediction for CBGA under random vibration loading by finite element method

In recent years, the reliability under vibration loading has become a very important problem of modern electronic devices. And existing researches have shown that the results of natural frequencies and modal shapes by FEA (Finite Element Analysis) fit that of modal test well. But it is challengeable to execute the vibration fatigue life analysis rapidly and accurately. In this paper, a predict method of fatigue life was used to calculate the random vibration life of CBGA, and the 1:1 finite model was built to obtain relevant data. And the results showed that the outmost corner solder balls were observed to have stress concentration along the interface by using the von Mises stress distributions of solder balls. So the outmost corner solder balls are the dangerous area and their random vibration life can be considered as whole device´s life. Through the methods, the random vibration life was obtained and the CBGA model showed a better performance under vibration loading.