Investigating the temperature effect of reliability on integration IC 3D packaging under drop test

Abstract

Technological developments and increasing user demand have driven the evolution of electronic packaging from traditional single-chip packaging to multi-chip packaging, i.e., three-dimensional integrated circuit (3D-IC) packaging. The main advantages of 3D-IC packaging are its small size and lower signal delay. Thus, 3D-IC packaging has been broadly used in mobile electronic devices. Mobile electronic devices are prone to being dropped because of their portability. During drop impact, the temperature inside the packages becomes higher than ambient temperature especially for 3-D packaging, which would influence physical behavior of packaging. A simulation that uses the Input-G method was adopted to analyze the dynamic behavior of electronic packaging. Finite element (FE) model analysis that considers glass transition temperature (Tg) was performed to investigate the effect of temperature. The results showed that the reliability of electronic packaging with underfill might be worse than that without underfill when temperature loading is higher than Tg. This study focuses on drop reliability and considers the effect of Tg. An FE model was established based on a real 3D-IC integration package to predict the drop life by using CoffinManson semi-empirical equation. First, thermal stress analysis would be The drop analysis conducted after the thermal stress analysis indicates that the plastic strain of solder joint increased evidently when considering the effect of temperature during drop analysis and that a temperature higher than Tg has a more obvious influence on strain accumulation during thermal stress analysis than during drop impact analysis. Finally, the drop reliability of 3D-IC was predicted. For a structure without underfill, the drop life can be predicted reasonably, whereas it will be overestimated when the structure has underfill. These different findings may be due to the perfect bonding provided by the underfill during each drop in the simulation, which is unlike actual, real-world situations.