Abstract
Molded underfill (MUF) is an essential component in ultra-thin flip chip packages to ensure their long-term reliability and mechanical integrity. However, the warpage evolution of package during the curing process of MUF has a critical effect on both the SMT yield and package reliability. Therefore, a thorough understanding of the MUF physical behavior under curing is essential. The present study therefore successfully establishes a novel process modeling approach based on finite element method to predict the final warpage of an ultra-thin flip chip scale package (fcCSP) in accordance with the chemical shrinkage and cure-dependent viscoelastic behavior of MUF. In describing the cure-dependent behavior of the MUF, the chemical shrinkage, curing kinetics and time-domain viscoelasticity are characterized by the pressure-volume-temperature (PVT) method, differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA), respectively. The predicted package warpage results are shown to be in good agreement with the experimental thermal Shadow Moire data. It is additionally shown that the accuracy of the warpage predictions is seriously degraded if the mechanical properties of MUF is modeled using a simple temperature-dependent elastic assumption.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: IEEE Transactions on Device and Materials Reliability
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
