Creep Damage of BGA Solder Interconnects Subjected to Thermal Cycling and Isothermal Ageing

Solder joints of electronic components are the most critical part of any electronic device. Their untimely failure during the system's operation often culminates in catastrophic failure of the device. The determination of creep damage in electronic component solder joint is vital to the prediction of crack initiation and prevention of premature failure. This paper presents the creep damage in solder joints in a ball grid array (BGA) soldered on a printed circuit board (PCB) and subjected to thermal cycling as well as isothermal ageing. ANSYS 19.0 package is employed to model the isothermal ageing at -40, 25, 75 and 150°C temperatures for 45 days. Standard temperature cycle profile is used to simulate the effect of the coefficient of thermal expansion (CTE) mismatch on the bonded materials in the BGA component. The solders studied are lead-based eutectic solder alloy and lead-free SAC396, SAC387, and SAC305. Based on the results obtained for the stress, strain rate, deformation rate and strain energy of the solders, the research investigation advises on the most effective solder for achieving improvement in the thermo-mechanical reliability of solder joints in BGA soldered on PCB.