On the Elimination of Die Attach Defects Occurrence - Optimization of Silver Sinter Curing Profile Using Simultaneous Thermal Analyses

This study aims to utilize Simultaneous Thermal Analysis - Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA), along with respective differential curves to infer relative data points such as temperature and shape of peaks, duration and percentage of solvent outgassing to design and optimize curing profile with appropriate outgassing and sintering time and temperature, ramp up rate at shortest duration. Using different scan modes; isothermal and dynamic, five different curing profiles were derived and simulated to check thermal responses. The effectiveness of each profile was evaluated through curing of die-attached units and the presence of die bulging and channeling voids were assessed through five-point Bondline Thickness (BLT), SEM and SCAT. It was found out that gradual solvent outgassing at lower temperature and longer time, as well as choosing lower sintering temperature and ramp-up rate could prevent formation of these anomalies. It was also proven that unoptimized curing profile triggers the occurrence and recurrence of die bulging and channeling voids.