Structure of the Thermal Interface connection made of sintered nano silver

Continuous miniaturization of semiconductor devices enables integration in packages on increasingly smaller surfaces. Increasing power and minimization of dimensions results in diametrical increase of thermal flux density. Current works are focused on high performance TIMs (Thermal Interface materials). The main role of such TIMs is efficient dissipation of heat from electronic device to the surface. Within the frame of the study thermal interconnections made of sintered nano silver pastes were evaluated in terms of the application as layers that effectively remove the heat from semiconductor structures. Structure of TIM interconnections between silicon die and ENIG (Electroless Nickel Immersion Gold) on copper/FR4 substrate was the object of the study. X-Ray CT analyses have shown that voids presence, contact surface and interconnection thickness strongly depends on nano-filled paste composition and technique of application. The results will be compared with results of further studies (i.e. electrical and thermo-mechanical measurements).