Abstract
Warpage is a serious reliability issue in ultra-thin packages. Methods and approaches to address warpage and design initiatives aimed at minimizing it are still very preliminary considering the wafer level variations in the substrate material properties, metal line density distributions and process induced variations. In order to design for reliability of the ultra-thin package, it is first essential to have accurate time-efficient simulations that match closely with experimental values. This relies on the accuracy and precision of measurement of the material properties of the package. This study reviews the different experimental and modeling approaches to estimate the Young’s modulus and coefficient of thermal expansion (CTE) and compares the accuracy of warpage simulations using finite element analysis (FEA) by plugging in these different values for E and CTE from the different approaches with the experimental warpage measurements. The digital image correlation (DIC) is proposed as a useful technique to increase the resolution of material properties used as input to simulations and will be evaluated against more time-consuming methodologies.
•We compare different mathematical models and simulation methods for estimating material properties of electronic substrate.•Each method is evaluated by comparing the correlation of warpage simulations to experimental warpage measurement.•Digital image correlation (DIC) is proposed as a technique to increase spatial resolution of material property estimation.•The use of DIC allows for higher quality input to the warpage simulations.