Plastic Ball Grid Array Solder Joint Reliability Assessment Under Combined Cycling And Vibration Loading Conditions

Concurrent vibration and thermal environment is commonly encountered in the service life of electronic equipment, including those used in automotive, avionic, and military products. Though extensive research exists in literature for solder joint failures due to thermal cycling, limited research has been conducted on investigating solder joint failures due to a combination of vibration and thermal cycling.This dissertation takes the board level packages of plastic ball grid array as study object and investigates the reliabilities of typical electronic packages under combined thermal cycling and vibration loading conditions.Finite element analysis was conducted on PBGA assemblies under thermal cycling, vibration loading, and combined thermal cycling and vibration loading conditions. Finit element analysis results are compared with experimental test results. Both results showed much earlier PBGA solder joint failure under combined loading compared with either thermal cycling or vibration loading alone.It was found that traditional linear superposition can overpredict the solder joint fatigue life since it neglects the interaction of the vibration and thermal cycling loadings. An incremental damage superposition approach was applied to PBGA solder joint reliability assessment. This approach can model the nonlinear interactions between vibration loading and thermal cycling. It considers the temperature effect on vibration response and the effect caused by thermomechanical mean stress affects. This approach was validated though experiments and reflects the actual damage trends.Industry should benefit from this study on reliability prediction, qualification, and accelerated testing design.