Environmental friendly CSP

In this paper, the study on the relationship between green assembly material properties and failure mechanism of moisture sensitivity reliability are reported. It focuses on the JEDEC level 2 and 3 precondition conditions that are 85/spl deg/C, 60%RH for 168hrs and 30/spl deg/C, 60RH% for 192 hrs, respectively. Besides, the paper discusses the process parameters and relative material influences. For instance, package block warpage and compound moisture absorption effects. Cure kinetic and thermal resistances of the green compound were analyzed by differential scanning calorimetry (DSC) and thermo gravimetric analysis (TGA), respectively. On the surfaces of delamination of reliability test specimens, which are analysis by scanning electron microscope (SEM) and scanning acoustic tomograph (SAT). The remainder flux amount at melt range of lead free solder affects circularity of solder ball dramatically. Furthermore, block warpage and moisture sensitivity reliability results reveal some conflict between process and reliability request. The compound with higher filler content relatively with less resin ratio exhibits larger block warpage and lower moisture uptake, respectively. That conducts poor facility during process and good performances in reliability test.