Simulation of micro-bump interconnections failure analysis for 2.5D IC packaging

This paper provides micro-bump fracture analysis in the context of a 2.5D IC package under reflow process. With the increasing demands for product functionality, the pitch size and diameter of micro-bumps have become smaller, as a means of achieving higher input/output counts in microelectronic packages. However, by decreasing micro-bump diameter, integrity of the microelectronic package is becoming compromised. The majority of research on the system in package (SiP) has focused on the Coefficient of Thermal Expansion (CTE) mismatch and heat junctions. The primary problems arising due to CTE mismatch and heat dissipation are failures or fatigues in 2.5D IC package, which can escalate to critical reliability issues. However, thermo-mechanical stress induced by temperature loading has a significant effect on material strength, causing, for example, interfacial cracking or micro-bump failure. Thus, 2.5D IC package modeling needs to be developed in order to identify factors that can mitigate micro-bump failure under reflow process. In this paper, we discuss the different insights pertaining to physics of thermo-mechanical loading for 2.5D IC package.