Stress-strain analysis and optimization of laminated solder joints under random vibration load based on Taguchi and grey correlation method

The formation and reliability of solder joints is the key to chip bonding technology, so the study of new types of solder joints is always a popular research topic in the field of electronic packaging. In this paper, a three-dimensional finite element analysis model is established for a new type of solder joints (laminated solder joints). Firstly, through the Taguchi method of experimental design, the effects of solder joints diameter, height, pitch and pad diameter on the stress-strain of the laminated solder joints under random vibration load are analyzed using the signal-to-noise ratio, and then the structural parameters of the solder joints are optimized by combining gray correlation analysis on the stress-strain of the laminated solder joints under random vibration load. The results show that the laminated solder joints are prone to stress concentrations at both ends of the solder joints and that the stress strain on the side of the contact surface with the PCB is greater than the stress strain on the side of the contact surface with the chip. Stress-strain clouds show that the stress-strain in the laminated solder joints gradually increases from the inside to the outside, with the highest stress-strain in the corners of the outer perimeter. The signal-to-noise analysis shows that the height of the weld joints has the greatest influence on the stress-strain of the laminated weld joints. 3.37% reduction in stress and 3.62% reduction in strain, the stress-strain values of the stacked solder joints were improved and the reliability of Taguchi and the grey correlation method was verified.