Failure Analysis and Modeling of Blind Vias Crack in BGA-PCB Assemblies

Electronic products and devices including personal computers, servers and mobile phones are moving towards high performance and high integration to meet the demands of users. As the core components in electronic products and devices, the reliability and stability of printed circuit board assemblies (PCBAs) are urgently needed to be ensured. Inspired by these requirements, printed circuit board assemblies with ball grid arrays (BGAs), which have better electrical performance, are becoming the preferred choice for many electronic products and devices. Herein, the morphology and chemical composition of blind via cracks in BGA-PCBAs were mainly investigated by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) to determine their failure mechanism. Tthe temperature distribution, stress and strain at various power levels were analyzed by performing finite element simulations of typical BGA solder ball and blind via structures. Our findings indicated that the stresses concentrated at the connection between the blind via and the inner copper layer, which coincided with the failure site of the blind via. Meanwhile, the shear force would increase with the enhancement of chip power consumption and blind via temperature. Besides, this study provides critical insights for ensuring the reliability of BGA-PCBA, which will help manufacturers improve the fabricating methods of BGA-PCBs, thus greatly promoting the performance and stability of electronic products and devices.