Vibration Qualification of Area Array Packages

摘要

While much has been done to assess the integrity of area array interconnects which are subjected to a cyclic thermal loading, relatively little attention has been paid to those subjected to vibratory loading. This investigation involves finite element modeling to identify the role of package compliance in determining the loads in solder interconnects. Results are reported from vibration testing on two BGA packages having similar footprint but differing bending compliance which are mounted on printed wiring boards. The results suggest why there is a marked difference in the cycles to failure between the two designs. The results also suggest a criterion for qualifying packages for vibration use based upon the local curvature of the PWB. Slices are taken from each of the package types and high sensitivity moire interferometry is employed to assess the differences in internal loading for equal imposed curvature.