Effect of Compressive Loading on the Interconnect Reliability Under Thermal Cycling

The ever increasing power density in modern semiconductor devices requires heat dissipation solution such as heat sink to remove the heat away from the device. A compressive loading was applied to reduce the interfacial thermal resistance between package and heat sink. In this study both numerical modeling and experimental approaches were employed to study the effect of compressive loading on the interconnect reliability, especially for high power density package, under thermal cycling loading conditions. The JEDEC standard thermal cycle tests were conducted and the resistance of the daisy chained circuits was in-situ measured to record the failure time. The failure analysis has been performed to indentify the failure modes of solder joint with and without the presence of compressive loading. A finite element based thermal fatigue life prediction model for SAC305 solder joint under compressive loading was also developed and validated with the experimental results.