Fracture Strength Characterization of the Die Active Side and Back Side for a Realistic Die Crack Assessment

Abstract

This paper discusses the characterization of an integrated circuit (IC) silicon die fracture strength to have a realistic die crack assessment. The evaluation was conducted using a 3-point bend test setup to measure the die strength of actual IC dies. Both the active side and the back side of the IC die were tested for 2 types of dies with different active side circuit layout. Results showed that the difference in the die active side circuit layout or structure has impact on die strength. It was also found that the active side was weaker than the back side. This implies that both the active side and the back side of an actual IC die must be subjected to fracture strength characterization to have an assessment that would be in a better agreement with real condition. Using only the strength of the back side would result in over-estimating the die strength. The common approach of using the fracture strength of the die back side to characterize the die strength is not realistic and can mislead the assessment of die crack or semiconductor package robustness.