Package Failure Understanding Through Crack Propagation Analysis

This paper discusses an in-depth failure analysis in which silicon die fracture surfaces are studied using a scanning electron microscope (SEM), and direction of crack propagation and failure mechanism are determined. The objective of this work was to establish a more systematic and reliable way of die crack root cause investigation. Several case studies were considered to demonstrate the identification of the breakage mechanism from analysis of fracture surface topographical information (e.g. Wallner lines) as well as crack branching patterns. Validation experiment was conducted using a 3-point bend test setup. From the results of the case studies, it has been demonstrated that a deeper analysis of the crack propagation as well as the location of the tensile stress area is very effective in finding the correct root cause.