The Thermal Dissipation Characteristics of The Novel System-In-Package Technology (ICE-SiP) for Mobile and 3D High-end Packages

As information technologies evolve with the 4th industry revolution, such as artificial intelligence and 5G mobile communication, much more computing power and data bandwidth are required for both mobile and server systems. However, one-dimensional thermal packaging solutions such as a heat spreader or high conductive materials are not sufficient to solve the heat dissipation problems for the system-in-packages. In this research, a novel thermal dissipation technology based on two-dimensional heat flow was studied for the 5G high thermal power system-in-package modems and high performance computing logics. By applying a high thermal conductive material such as silver paste to conventional epoxy mold compound structures and creating direct high thermal dissipation paths from a bottom logic die to the heat spreader, it can bypass memory die that is more sensitive to the temperature rise than the logic die. The thermal performance of this novel technology was demonstrated using actual 5G modem system-in-packages comprised of a modem and two LPDDR4x dice. In conclusion, two-dimensional heat dissipation technique using thermal chimney is effective to reduce thermal crosstalk between top memory and bottom logic dice. Consequently, the overall system thermal performance was able to be improved by reducing heat flow through top memory dice.