Experimental and numerical methods for evaluation of interface cracks in electronics systems

The ongoing development of highly integrated electronic packages leads to a steadily increasing number of material interfaces within a package. In combination with increasing harshness (vibration, humidity, temperature) of the system environment the reliability of such systems is often dominated by interface fracture. Therefore interface fracture mechanics is one of the main focuses of electronics reliability research. The authors present a combined simulative and experimental method for crack tip location determination and crack evaluation of interface specimens. The specimens are loaded in a testing apparatus which is an advancement of a mixed mode bending test. Based on crack length measurements and Finite Element Analysis critical energy release rates can be axtracted in a fast and inexpensive method. In addition the authors present a simulative approach to analyze the pumping and protrusion of copper-TSVs during thermal cycling. Cracking and delamination risks caused by the elevated temperature variation during BEoL ILD deposition are investigated with the help of fracture mechanics approaches.