QUICK ASSESSMENT METHODOLOGY FOR RELIABILITY OF SOLDER JOINTS IN BALL GRID ARRAY(BGA)ASSEMBLY——PART Ⅱ:RELIABILITY EXPERIMENT AND NUMERICAL SIMULATION

In the present study,a facility,i.e.,a mechanical deflection system(MDS),was established and applied to assess the long-term reliability of the solderjoints in plastic ball grid array (BGA) assembly.It was found that the MDS notonly quickly assesses the long-term reliability of solder joints within days,but canalso mimic similar failure mechanisms in accelerated thermal cycling (ATC) tests.Based on the MDS and ATC reliability experiments,the acceleration factors (AF)were obtained for different reliability testing conditions.Furthermore,by using thecreep constitutive relation and fatigue life model developed in part I,a numericalapproach was established for the purpose of virtual life prediction of solder joints.The simulation results were found to be in good agreement with the test results fromthe MDS.As a result,a new reliability assessment methodology was established as analternative to ATC for the evaluation of long-term reliability of plastic BGA assembly.