A Sensitivity Study of BGA Geometrical Parameters Based on Electro-thermal Fatigue Analysis

The efficient operation of electronic products depends primarily on the reliability of the interconnections, provided by tiny solder joints, throughout the life of the product, under real operating conditions. Over the years, the focus has been on the reliability of BGA (Ball Grid Array) components and their geometric and functional optimization. To this end, design optimization is set as an objective. To achieve this target, a sensitivity study of the mechanical response of the BGA component to the variation of the design variables: diameter and height was performed. The criterion of choice for the comparison of these parameters is the number of cycles to failure, resulting from a thermal fatigue study. To apply the fatigue law, a further investigation of the best alloy is conducted. Results showed that although Innolot has minimal plastic deformation, SAC (SnAgCu) is considered the best alloy in terms of reliability and functionality for the longest period. Furthermore, by examining the design variables when the BGA component is subjected to electrothermal cycling load, it is concluded that as the diameter and the height increases, the number of cycles to failure increases, and, thus, large solder joints are the most reliable. This thorough study can greatly help the electronics industry and researchers to decide on the best solder alloys for solder joints and to establish a good environment for the future determination of the optimal geometrical parameters for a BGA component.