A Mesh Size Searching Method in WLP Reliability Prediction with Fixed Coffin-Manson Parameters

The reliability of wafer-level packaging (WLP) is critical in electronic packaging, and accelerated thermal cycling tests are widely used to evaluate it. However, these tests are time-consuming and costly. This study presents a finite element simulation approach to predict packaging lifetime, focusing on optimizing the critical mesh size for solder ball modeling. Using Chaboche parameters derived at three strain rates, the Coffin-Manson life prediction model parameters were fixed, and the optimal mesh size was determined. The methodology was validated with four test vehicles, achieving predicted lifetimes within 10% of experimental results. This approach ensures consistent and reliable predictions while reducing reliance on extensive experimental testing, making it a practical solution for enhancing WLP reliability assessment.