Relatively little is known about the performance of the doped Ball Grid Array (BGA) packages used in semiconductor industries, even though newer products are widely being introduced to the market. This work experimentally investigates the doping effects of the BGA packages with SAC 305 alloys, caused by the vibration loading. This experiment focuses on the vibration fatigue life of 15 mm CABGA packages with 208 perimeter solder balls on a 0.8 mm pitch. The test boards were built to withstand JEDEC JESD22-B103B standards of high stress test in vibrational shaker table to assess the solder joint performance. The test boards are built with three different reflow profiles and two different stencil thicknesses 8 mil (6 mil with overprint) and 4 mil to study the differences in doping effect of the new doped alloys. The WLCSP assembly was subjected to accelerated life test of severe random vibration per board. The reliability of the component is determined by the ability of the components to withstand vibration as a result of motion produced by field operations. The deleterious effect of the mechanical loading of BGA's on the characteristic fatigue lifetime is reported. The results show that the material characteristics has a direct impact on the total time to failure. The results show that the Time-ToFailure (TTF) of the solder joint decreases with doping. The effectiveness of this characteristics was demonstrated with promising results through vibration testing of different lead free low creep alloys. This paper concludes with discussion of the deterioration intensity aging has on SAC alloys and the change in reliability due to doping.
IntroductionA demand for using ball grid array (BGA) packages, with reduced substrate interconnect area, complexity, and cost of substrate assemblies, has significantly increased over the past few years. However, the failures in the BGA solder joints over vibration environments become a serious concern in electronic package industries. The reliability of these solder joints under vibrational study is considered vital to the success of BGA applications [1][2].Vibration study in electronic packages for solder joint characteristic life is still in early stages of development, in comparison to other established reliability tests like temperature cycling, drop test and thermal shock tests. The continuous reduction in the reliability of BGA package and solder ball dimensions is increasing the risk of solder joint failure under vibrational and mechanical loading. The present industry standards for vibrational testing are conducted mainly on pass or fail functional test criterion. This is a