Compliance, deformation and thermal fatigue behavior of multi-copper-column interconnects

In this paper, macro- and micro-modeling technique is implemented to correlate the compliance, deformation and thermal fatigue damage of composite interconnect structures that consist of copper columns and solder joint. Systematic simulation results reveal the dependence of solder joint fatigue life upon four geometric parameters such as column height, column radius, solder volume and substrate pad radius. A simple model has been developed to explain the dependence of plastic strain on the interconnect compliance. This work provides guidance for design of composite interconnect structure that is meant to enhance the solder joint reliability by incorporation of flexible strucutres.